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FIELD OF THE INVENTION
[0001] This invention relates generally to fabrication processes for microelectromechanical systems (MEMS) devices and more specifically to the manufacture of interferometric modulators.
BACKGROUND OF THE INVENTION
[0002] An interferometric modulator is a class of MEMS (micro-electromechanical systems) devices which have been described and documented in a variety of patents including U.S. Pat. Nos. 5,835,255, 5,986,796, 6,040,937, 6,055,090, and U.S. Pending patent application Ser. Nos. 09/966,843, 09/974,544, 10/082,397, 10/084,893, and 10/878,282, herein incorporated by reference. One of the key attributes of these devices is the fact that they are fabricated monolithically using semiconductor-like fabrication processes. Specifically, these devices are manufactured in a sequence of steps which combine film deposition, photolithography, and etching using a variety of techniques. More detail on these processes is described in patent application Ser. No. #10/074,562 filed on Feb. 12, 2002, and herein incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] [0003]FIG. 1 shows a block diagram of an integrated MEMS processing facility;
[0004] [0004]FIG. 2 shows a block diagram of a non-integrated MEMS processing facility;
[0005] [0005]FIG. 3 shows a block diagram of a MEMS device which can be fabricated using a precursor stack of the present invention; and
[0006] [0006]FIGS. 4A to 4 F show block diagrams of precursor stacks of the present invention, according to different embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0007] In the following detailed description of embodiments of the invention, numerous specific details are set forth such as examples of specific materials, machines, and methods in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that these specific details need not be employed to practice the present invention. In other instances, well known materials, machines, or methods have not been described in detail in order to avoid unnecessarily obscuring the present invention.
[0008] A common characteristic of processes for manufacturing MEMS devices is that they begin with the deposition of a stack of thin films which are crucial to the operation and subsequent fabrication of the device. These precursor films are useful in the fabrication of a broad variety of MEMs devices including interferometric modulators, and their deposition can occur as a part of a larger process to manufacture the MEMS device. In one embodiment of the present invention the films are deposited separately in a stand alone facility to form a precursor stack, which is then sent to multiple facilities which complete the processing. The primary benefit is that the stand alone facility can be optimized to produce these films or precursor stacks at very high throughputs that allow for economies of scale not possible in an integrated factory, i.e., one that does both the deposition and post-deposition processing. Furthermore, since the technology development of the precursor stack occurs at the stand alone facility, entities which desire to perform the subsequent processing steps are faced with a lower technological barrier to entry.
[0009] Patent application Ser. No. 10/074,562 herein incorporated by reference describes a prototypical fabrication sequence for building interferometric modulators. In general, interferometric modulator fabrication sequences and categories of sequences are notable for their simplicity and cost effectiveness. This is due in large part to the fact that all of the films are deposited using physical vapor deposition (PVD) techniques with sputtering being the preferred and least expensive of the approaches. Part of the simplicity derives from the fact that all interferometric modulator structures, and indeed many other planar MEMS structures are bound by the fact that they require a lower electrode, an insulating structure to prevent shorting, a sacrificial material, and an actuatable or movable structure. An insulating structure differs from a film in that it is not continuous in its form but by mechanical means is able to prevent electrical contact through its body. This fact presents an opportunity in that a subset of these films, a precursor stack comprising one or more of the lower electrode, insulating structure, the sacrificial layer, and optionally an actuatable structure may be manufactured separately and in advance of the actuatable structure or structures.
[0010] [0010]FIG. 1 of the drawings provides a block diagram of an integrated MEMS fabrication facility 102 . A precursor film deposition tool 100 , comprises a single or series of deposition tools which are configured to deposit these films using one or more deposition techniques, e.g., sputtering. The films are deposited on a suitable carrier substrate, which could be glass or plastic, for example, depending on the application, and subsequently transported to micro-machining loop 104 . Here, and as described in the aforementioned patent applications, a sequence of repeated steps, such as etching, patterning, and deposition, are performed and serve to define the actuatable structure of the MEMS device.
[0011] [0011]FIG. 2 of the drawings shows a non-integrated MEMS processing facility. Referring to FIG. 2, a pre-cursor facility 200 contains only a precursor film deposition tool 100 which is equivalent to that described in FIG. 1, hence the use of the same reference numeral. The facility 200 is capable of providing variations on both precursor film type and substrate size. After the deposition, the substrates are containerized and shipped as appropriate to one or more processing facilities indicated by reference numeral 202 . These facilities then perform the machining steps as required for the particular MEMS product that they are designed to produce.
[0012] [0012]FIG. 3 shows a schematic drawing of a simple MEMS device which can be fabricated using a precursor stack of the present invention. In this case an actuatable membrane 304 , is supported on posts 306 . Films 302 comprise materials which at a minimum provide a lower electrode and an insulating structure, though other functions, as will be discussed, may be incorporated. The entire assembly resides on a substrate 300 .
[0013] [0013]FIGS. 4A to 4 F of the drawings show block diagrams of precursor stacks in accordance with different embodiments of the invention. In FIGS. 4A to 4 F, the same reference numerals have been used to identify the same or similar features/components.
[0014] [0014]FIG. 4B shows a block diagram of a generalized precursor stack 400 A that includes conductor stack or structure 404 , an insulator layer 406 , and a sacrificial material layer 408 . All the films reside on a substrate 402 . The conductor stack 404 may comprise a single metal, a conductive oxide or polymer, a fluoride, a silicide or combinations of these materials. The exact composition of the conductive stack is determined by the requisite electrode properties of the MEMS device to be manufactured. The insulator 408 , can be any one or a combination of a variety of insulating materials which include but are not limited to oxides, polymers, fluorides, ceramics, and nitrides. The sacrificial material 408 , may include, for example, a single layer of materials such as silicon, molybdenum, or tungsten which are all etchable by XeF2, which is a process etch gas that has been described in prior patents. Other materials are possible subject to the compatibility of the etching medium to the materials and structures which must remain. Thicknesses vary according to the requisite behavior of the final device.
[0015] [0015]FIG. 4B shows a block diagram of a precursor stack 400 B designed for use in the fabrication of an interferometric modulator device. The stack 400 B includes a conductor stack 404 , the composition of which has been described above. Suitable metals for the conductor stack 404 in the present case include glossy metals such as Chromium, Tungsten, Molybdenum, or alloys thereof. The conductor stack 404 may have a thickness of up to 150 angstroms. Transparent conductors suitable for use in the conductor stack 404 include indium tin oxide (ITO), zinc oxide (ZnO), and titanium nitride (TiN). Typical thicknesses for the transparent conductors range from 100 to 800 angstroms. The conductor stack 404 resides on a transparent compensating oxide layer 410 , in one embodiment. The oxide layer 410 may be of a metallic oxide, such as zirconia (ZrO2) or hafnia (HfO2), which have a finite extinction coefficient within the visible range. The compensating oxide layer 410 is an optional film for all the designs discussed in this patent application. Typical thicknesses for the oxide layer 410 range from 100 to 800 angstroms. It should be noted that the positions of the conductor stack 404 and the compensating oxide layer 410 are interchangeable with only subtle changes in the optical behavior. This design, however, can be considered an embedded optical film design since the metal, which plays the primary optical function, resides on the side of insulator layer 406 , opposite that of the sacrificial layer 408 . The insulator layer 406 , may comprise a silicon dioxide film with a thickness ranging from 280 to 840 angstroms for good black states, although other thicknesses are useful for different interference modulator operational modes. Other oxides or combinations of oxides are possible as well. The sacrificial layer 408 may include a single layer of materials such as silicon, molybdenum, tungsten, for example, which are all etchable by XeF2, a process etch gas which has been described in prior patents. For the stack 400 B, the thickness of the layer 408 may vary from 1000, to 7000 angstroms.
[0016] [0016]FIG. 4C shows a block diagram of a precursor stack 400 C, in accordance with another embodiment. In this case, the conductor stack 404 does not perform any optical functions. Instead, a separate optical film 412 performs the optical function. The optical film 412 is separated from the conductor stack 404 by an insulator film or structure 414 . This design allows for high quality white states to be achieved when the actuatable membrane is driven. In this case the optical film 412 does not serve as a conductor. It is the transparent conductor stack 404 which functions as a conductor. An ancilliary insulator film or structure which is not shown in FIG. 4C but which is similar to the insulator layer 406 of FIG. 4B, may reside between the sacrificial layer 408 and the optical film 412 , in some embodiments. The thickness of the insulator film or structure may be less than 100 angstroms for this design.
[0017] [0017]FIG. 4D shows an embodiment 400 D of a precursor stack, known as a buried optical film design. In this case, an optical film 412 , resides over an optical compensation film 410 , which resides below an insulator film/structure 406 . A transparent conductor film or film stack 404 , follows and is capped by an additional oxide layer 416 , and a sacrificial film layer 408 . One advantage of the stack 400 D is that it allows for the effective optical distance between the optical film 412 and the mechanical film to be large while allowing the driving voltages to remain small. This is because the driving voltages are significantly determined by the distance between the conductor and the actuatable membrane.
[0018] [0018]FIG. 4E shows a precursor stack 400 E which includes a multi-layer etch stop stack 418 incorporated instead of a single layer sacrificial film. This 418 stack provides a convenient means for predefining the heights for multiple actuatable structures to be defined during subsequent micro-machining processes. In one embodiment, the stack 418 comprises at least two materials which can be etched using the same release etch, but can utilize alternative and different etch chemistries so that one material may act as an etch stop for the other. One example would be a combination of molybdenum and silicon that are both etchable in XeF2. However, a phosphoric based wet etchant may be used to etch molybdenum without attacking silicon, and a tetra-methyl-ammonium hydroxide (TMMA) which may be used to etch silicon without etching molybdenum. Many other combinations exist and can be identified and exploited by those skilled in the art. Further, it should be noted that the etch stop stack may be applied to any of the previously defined precursor stacks in place of the single sacrificial layer.
[0019] [0019]FIG. 4F of the drawings shows an embodiment 400 F of a precursor stack The precursor stack 400 F includes a mechanical structural material 420 . Using proper micro-machining techniques and sequences, a functioning MEM device may be fabricated using the precursor stack 400 F using only patterning and etching. Thus, during post-processing of the precursor stack 400 F no deposition is required. This means that a post-processing facility such as the facility 202 (see FIG. 2) does not require capital investment in deposition tools. The material 420 may comprise any number of materials, including but not limited to metals, polymers, oxides, and combinations thereof, whose stress can be controlled. | This invention provides a precursor film stack for use in the production of MEMS devices. The precursor film stack comprises a carrier substrate, a first layer formed on the carrier substrate, a second layer of an insulator material formed on the first layer, and a third layer of a sacrificial material formed on the second layer. | 1 |
BACKGROUND OF THE INVENTION
Preparation of plastic materials of high stability with electrically conductive properties has been a major goal of the plastic and electronics industry for some time. Such a plastic product would, for example, revolutionize the battery powered electric motor industry, such as in the automotive field, by making light weight batteries of high storage capacity available. In such batteries the lead plates would be replaced with a relatively light weight plastic material, making long range electric powered automobiles a reality.
Such light weight plastics with electrical conductive properties would also be beneficial in solar to electrical conversion equipment and provide equipment of far lighter weight. Such plastics would find a myriad of uses in many varying types of electrical equipment or in components thereof.
The production of isolatable films of poly(fluoroacetylene) or poly(difluoroacetylene) by the basic dehydrofluorination of poly(vinylidene fluoride) or poly(trifluoroethylene) containing polymers has not been reported in the literature.
A number of experimentors have proposed such dehydrofluorination but have failed to achieve such dehydrofluorinated polymers. For examples, in a brief report by McCarthy and Dias [Chem. & Eng. News. Sept. 5, 1983, p. 26 and Preprints of the Division of Polymeric Materials Science and Engineering, 49, 574 (1983)] the authors speculated that poly(vinylidene fluoride) would undergo dehydrofluorination when treated with aqueous caustic using a phase transfer catalyst. The authors isolated a polymer containing ketone groups after treatment with aqueous sulfuric acid.
In U.S. Pat. No. 2,857,366 that issued Oct. 21, 1956 to Middleton, monofluoroacetylene was prepared by thermal decomposition of monofluoromaleic anhydride and monofluoroacetylene polymers prepared therefrom. Such a process is expensive, dangerous, and is limited to monofluoroacetylene.
In Japanese Patent Jpn Kohai Tokkyo Koho JP No. 58 59,208 [83 59,208] April 3, 1983 by Mitsubishi Chemical Industries Co., Ltd. (Chem. Abstr. 99, 140600q 1983) poly(difluoroacetylene) was prepared by the polymerization of difluoroacetylene monomer in tetrahydrofuran solution at 0° C.
The process of the present invention merely removes HF from a wide variety of existing, commercially available, fluorine substituted polymers in a relatively inexpensive treatment with a basic solution. No catalyst is required for the process to proceed at commercial rates, although such catalysts might be economically beneficial for some conversions.
BRIEF SUMMARY OF THE INVENTION
The process of the invention is defined as a process for dehydrofluorinating a fluorine substituted polymer to provide a dehydrofluorinated polymeric composition which comprises treating a starting polymer selected from the group of starting polymers consisting essentially of a homopolymer of vinylidene fluoride monomeric units or trifluoroethylene monomeric units, copolymers or terpolymers containing a major portion of vinylidene fluoride monomeric units with at least one copolymerized monomeric unit selected from the group consisting essentially of hexafluoroproplene, trifluoroethylene, vinyl fluoride, vinyl chloride, chlorotrifluoroethylene, and mixtures of the homopolymer, copolymer, and terpolymer; with a basic solution for a sufficent period of time to remove HF from the polymer to provide a dehydrofluorinated polymer having at least 5 monomeric mol percent of the dehydrofluorinated unit ##STR1## wherein X is H or F and the dehydrofluorinated units form conjugated double bonds that impart electrical conductivity to articles prepared from the dehydrofluorinated polymer.
The starting polymers can be in film or powder form and the basic solution can contain alkali hydroxides or organic amines.
It is preferred that the basic treatment solution include at least one solvent selected from the group consisting essentially of water, dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, methanol, ethanol, and butanol.
It is preferred that the basic solution contain either sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, tetrabutylammonium hydroxide, or a tetrabutylammonium halide to provide a treatment pH within the range of about 10 to about 14.
Preferably, the starting polymer is treated to provide at least 40 monomeric mol percent of the dehydrofluorinated units.
Monomeric mol percent, with respect to the repeating dehydrofluorinated unit in (b), is the number of monomer units in the polymeric composition having a conjugated double bond divided by the total number of monomer units forming the particular polymer, times 100.
It is, of course, understood that other noninterfering monomeric units can be included or other polymers, such as polyacrylates, grafted onto the polymeric composition of the invention while remaining within the spirit and scope of applicant's invention.
Typically, the starting polymer is treated with the basic solution for a time period of at least about five minutes at a temperature within the range of about 20° C. to about 100° C.
The product or composition of this invention is defined as a fluorine substituted, conjugated carbon-to-carbon double bond containing polymeric composition that imparts electrical conductivity to structures made therefrom, consisting essentially of
(a) 0 to 95 monomeric mol percent of (i) vinylidene fluoride monomeric units or trifluoroethylene monomeric units, or (ii) a major portion of vinylidene fluoride monomeric units with at least one copolymerized monomeric unit selected from the group consisting essentially of hexafluoropropylene, trifluoroethylene, vinyl chloride, vinyl fluoride, chlorotrifluoroethylene, and tetrafluoroethylene monomeric units, and mixtures of (i) and (ii); and
(b) 100 to 5 monomeric mol percent of the unit ##STR2## wherein X is H or F and the monomeric units of (b) are arranged to form conjugated double bonds, with the proviso that when a homopolymer of (a)(i) is present, the mol percent in (b) is 95 to 5 and the mol percent in (a) is 5 to 95, to provide a polymeric composition that imparts electrical conductivity to articles prepared therefrom.
The preferred monomeric units in (a)(i) above are vinylidene fluoride or trifluoroethylene or both vinylidene fluoride and trifluoroethylene. It is preferred that the monomeric mol percent of the dehydrofluorinated unit in (a)(ii) above be at least 40. The product of the invention includes electrically conductive film and tubular structures, or other shapes, formed of the above polymeric compositions.
DETAILED DESCRIPTION OF THE INVENTION
The product of the invention is prepared by treating the appropriate commercially available, fluorine substituted polymer, in film or powder form, with a basic treatment solution (preferred pH of 10 to 14) that removes HF to such an extent that at least 5 monomeric mole percent of the treated polymer contains double bonds. The double bonds are conjugated, which means that at least 5 mole percent of the double bond containing units occur in pairs to provide a sequence of: single, double, single, double, single bonds. Other dehydrofluorinated units may occur, permissively, randomly throughout the polymer chain, but these units are not included in the threshold of 5%.
By way of illustration, equations I, II, and III below illustrate the process where full dehydrofluorination occurs. In I the starting polymer is poly(vinylidene fluoride) to provide poly(monofluoroacetylene) (PMFA); in II the starting polymer is poly(trifluoroethylene) to provide poly(difluoroacetylene) (PDFA); and in III the starting polymer is a copolymer of vinylidene fluoride and trifluoroethylene to provide poly(monofluoroacetylene, difluoroacetylene) copolymers. ##STR3##
It is thus apparent, that the X substituents forming the adjacent pairs of dehydrofluorinated units ##STR4## that form the conjugated double bonds, need not be the same. X can be H in one unit and F in the adjacent unit, or X could be the same in adjacent units. Moreover, the degree of dehydrofluorination can be such that from 5 to 100 monomeric mol percent of the polymer contains the dehydrofluorinated units that occur in pairs.
The polymeric composition of this invention may be prepared by the basic dehydrofluorination of poly(vinylidene fluoride) and poly(trifluoroethylene) and copolymers incorporating either or both of these polymers. The bases are derived either from alkali hydroxides or organic amines in aqueous or organic solvents at room temperatures (preferably 25° to 100° C. at pH of 10 to 14). The period of treatment is from about five minutes to 90 hours, or longer.
Preferred solvents for the basic solution are those selected from water, dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, methanol, ethanol or butanol.
Typical bases that can be included in the basic solution are: sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, and either quaternary ammonium compounds such as tetrabutylammonium hydroxide or tetrabutylammonium halides.
In some cases the addition of a surfactant aids the rate of reaction.
Optionally aliphatic, heterocyclic or aromatic amines such as triethylamine, pyridine, quinoline and salts derived from them, can be used as the basic producing agent.
The following examples illustrate the invention and are not to be taken as a limitation thereof.
EXAMPLE 1
To a mixture of 45 ml of 10% alcoholic potassium hydroxide (prepared from 10 g KOH and 90 g of ethanol) and 10 ml of dimethyl acetamide (DMAC) as solvent at 25° C. was added 0.005 g of a piece of commercially available poly(vinylidene fluoride) film (Kynar® 900 film, of about 0.003 in. thickness having about 2,400 monomer units, sold by Pennwalt Corporation under the Kynar trademark). After 90 hours at 25° C. the film turned brown and the solution was orange in color. The film was washed with water, dried and an infrared (IR) spectrum run on both the treated and untreated film. A comparison of the IR spectra show that significant amounts of poly(fluoroacetylene) was produced, as evidenced by the absorption bond at the 1595.7 wave number which is absent in the spectrum of the untreated poly(vinylidene fluoride) film.
EXAMPLE 2
12.8 of a commercially available powdered poly(vinylidene fluoride) homopolymer (Kynar® 901, sold by Pennwalt Corporation) was dissolved in 150 ml of DMAC and added to a solution of 11.2 KOH in 100 ml CH 3 OH, to provide a gel. The gel was washed with water and dried at 100° C. overnight to provide 9.5 g of product. The product was not soluble in DMAC, methyl isobutyl ketone (MIBK), or NaOH solution, and had a melting point in excess of 300° C. The IR spectra for the product showed an absorption band at about 1600 wave number [corresponding to poly(difluoroacetylene) units] which was absent with the starting polymer.
The C, H, and F analysis in weight percent was:
______________________________________ C H F______________________________________Starting Polymer 38.8 3.00 59.10Final Product 48.6 3.16 38.60______________________________________
which also shows significant elimination of HF to provide the conjugated double bonds in the product (monomeric mole percent about 100 would be equal to a polymer with 43% fluorine).
EXAMPLE 3
3.0 g of a commercially available poly(vinylidene fluoride) powder (sold under Kynar® trademark of Pennwalt Corporation) was dissolved in 100 ml DMAC and then the solution added to 21 g of 1,8-diazabicyclo[5,4,0]undec-7-ene. After 3 to 4 minutes the solution turned black. The next day the black solid was filtered, washed and dried at 110° C. to provide 2.6 g of product. The product did not show any melt flow behavior and exhibited an IR absorption at a wave number of about 1600, indicating the presence of poly(difluoroacetylene) units. The C, H, and F analysis in weight percent was:
______________________________________ C H F______________________________________Starting Polymer 38.8 3.00 59.10Final Product 39.8 3.44 54.20______________________________________
which indicates elimination of a substantial amount of HF to form the conjugated double bonds (approximately 30 mole % dehydrofluorination).
EXAMPLE 4
To a flask containing a solution of 4 g (0.1 mole) of sodium hydroxide in 20 ml of water and the mixture stirred magnetically at 70° C. for a few minutes. Then 1.0 g of poly(trifluoroethylene) film was added (softening point of 200°-202° C.). The flask was sealed with a stopper and the mixture stirred at 70° C. for five hours. The polymer turned dark brown and the solution was amber colored. The polymer film was rinsed with water and dried at room temperature for three days. In infrared spectrum of the film (attenuated total reflectance) shows that poly(difluoroacetylene) was produced as evidenced by absorption at the 1618.9 wave number which is absent in the control (before reaction) film.
EXAMPLE 5
This example illustrates severe over dehydrofluorination of the commercially available polyvinylidene fluoride powder of Example 2.
1.5 g of the Kynar® powder in 50 ml of DMAC was added to 10.7 g of 96% 1,8 diazabicyclo [5,4,0]undec-7-ene, then heated at reflux for 3 hours and allowed to remain at room temperature. The resulting polymer product obtained by filtration was then washed with water and dried.
The final product analysis of C, H, and F (weight %) was:
______________________________________ C H F______________________________________Starting Polymer 38.8 3.00 59.10Final Product 67.6 5.52 7.68______________________________________
which indicates severe over dehydrofluorination as the final F% is 7.68, whereas at 100 mol percent of the conjugated double bond containing monomeric unit, the %F should be about 43%.
EXAMPLE 6
To a stainless steel pressure vessel was added 1.0 g of poly(vinylidene fluoride) powder and 10 ml of triethylamine. The temperature was raised to 110°-155° C. (20-60 psig) and held there for 7 hours. The vessel was cooled, opened and the solid polymer washed with water. After drying at 110° C. the polymer had an analysis of C, H, and F as follows:
______________________________________ C H F______________________________________Starting Polymer 38.8 3.00 59.10Final Product 41.7 3.08 53.00______________________________________
This corresponds to about 37.5% dehydrofluorination.
EXAMPLE 7
To a flask containing the caustic solution described in Example 4 is added 1.0 g of poly(vinylidene fluoride/trifluoroethylene) copolymer (22.8% trifluoroethylene content) and reacted as in Example 4. The infrared spectrum of the dried film indicates that dehydrofluorination took place to a polyacetylene structure as indicated in the absorption at about 1609 wave number.
EXAMPLE 8
Other starting polymers, including copolymers and terpolymers containing a major portion of vinylidene fluoride monomeric units with at least one copolymerized monomeric unit selected from the group consisting essentially of hexafluoroproplene, trifluoroethylene, vinyl fluoride, vinyl chloride, chlorotrifluoroethylene, and mixtures of the copolymers, terpolymers, or homopolymers of vinylidene fluoride or trifluoroethylene, can be dehydrofluorinated by treating similarly as described in the preceding Examples 1-4 and 6-7, to provide the polymeric composition of the invention. The severity of the basic treatment, including the strength of the basic solution, time and temperature of exposure can be regulated to provide the degree of HF elimination desired to yield a polymer with up to 100 mole percent of conjugated double bond containing units. | Compositions of poly(fluoroacetylene) useful for providing electrically conductive properties to plastics by a method of dehydrofluorination of saturated fluoroethylene polymers. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] none
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to tools for the installation of wire. More particularly, it relates to devices for unrolling wire (e.g., barbed wire) in the field.
[0004] 2. Description of the Related Art
[0005] Wire, be it electrical wire or fence wire, is commonly supplied in the form of rolls which may be wound on a reel or drum. If the wire is of sufficient stiffness, it may hold the roll shape without being wound on a reel or drum. To avoid twisting the wire, it should be unwound from the reel or drum (as opposed to being spiraled off one end of the roll).
[0006] Most reels and drums have a central, axial opening through which a rod or shaft may be placed to allow the reel or drum to rotate freely. Perhaps the most simple wire dispenser is a dowel inserted through the center of the roll. Holding the dowel on either side of the roll while walking backwards allows the wire to pay out as the roll unwinds. Heavier rolls of wire may be unwound by two people, one on either side of the roll supporting the respective ends of a shaft inserted through the roll, reel or drum. Still heavier rolls may be carried on motorized vehicles—a common method being a shaft resting on the side walls of a pickup truck's bed.
[0007] Barbed wire is commonly manufactured in rolls 80 rods (1320 feet) in length, 70-90 lbs per roll depending on the gauge, number of strands, type and number of barbs. The rolls are typically wound on a wire frame having radial arms at either end for containing the roll (as shown in phantom in the drawing figures). Since it is both heavy and sharp, it is highly desirable to utilize a dispensing device of some sort when stringing barb wire.
[0008] One method of the prior art for the paying out of fencing wire and barbed wire is the wire spinner. An old plough disk can be used as a type of spinner by welding a piece of 25 mm water pipe into the centre of the disk with the disks edge resting on the ground. The reel of wire may be slipped onto the pipe and paying out the wire becomes a one person operation. However, if the spinner is stationary, the wire must be dragged across the ground. To move the spinner, a conveyance of some sort is required. An alternative to this is to slip the handle of a shovel through the eye of the reel and have two fencers then walk the barbed wire along the fence line having tied off one end.
[0009] Wire unrollers are available for mounting on the back of an All Terrain Vehicle (ATV). Such devices are said to permit one to quickly or slowly release a spool of wire when building fences. An adjustable drag brake prevents free wheeling. Hydraulically-powered wire winders are available for Cat. I, Cat. II or Cat. III tractor hitches. It is said that wire may be unwound from the device by putting the hydraulic control lever in the “float” position while the tractor is driven across the ground. The circulation of hydraulic fluid through the motor provides sufficient resistance to keep the reel from overspinning. However, such devices are relatively expensive and additional clearance along the fence line is needed to accommodate the vehicle. What is needed is a wire dispenser that can be loaded and operated by one person and is simple, reliable and easy to manufacture. The present invention solves this problem.
BRIEF SUMMARY OF THE INVENTION
[0010] A spool or roll of wire is held on a horizontal shaft or spindle mounted on a handcart. The shaft or spindle is offset from the wheel axle such that tipping the cart forward raises the spool off the ground and permits the wire to payout from the roll.
[0011] In one preferred embodiment, a portion of the frame of the handcart supporting the spindle is hinged to move between an open position and a closed position. In the open position, the frame can slide onto a roll of wire resting on the ground or other such surface. Once in position over the roll of wire, the frame may be closed thereby securing the roll of wire to the cart.
[0012] In an alternative embodiment, the horizontal shaft or spindle is removable. With the shaft removed, the cart may be positioned over a roll of wire resting on the ground. The shaft may then be inserted through the roll of wire and secured to the frame of the handcart.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0013] FIG. 1 is a perspective view of one embodiment of the invention.
[0014] FIG. 2 is an enlargement of latching mechanism employed in the embodiment of FIG. 1 .
[0015] FIG. 2 is an enlargement of the hinge mechanism employed in the embodiment of FIG. 1 .
[0016] FIG. 4 is a perspective view of the device illustrated in FIG. 1 in the open or loading position.
[0017] FIG. 5 is a rear view of the device shown in FIG. 1 in the open or loading position.
[0018] FIG. 6 is a perspective view showing the spindle and wheel assembly of the cart shown in FIG. 1 .
[0019] FIG. 7 is a perspective view of the wheel and spindle assembly of an alternative embodiment of the invention.
[0020] FIG. 8 is a partial cross-sectional view of the spindle-to-frame attachment used in the embodiment of FIG. 7 taken along line 8 - 8 in FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
[0021] The invention may be best understood by reference to the drawing figures wherein two preferred embodiments are illustrated.
[0022] The first preferred embodiment is shown in perspective in FIG. 1 . Carrier 10 may comprise a welded steel tubular frame to which handle 12 is attached. The frame may include a fixed portion 14 and a moveable or hinged portion 16 .
[0023] Carrier 10 has a transverse shaft or spindle 30 for holding a roll of wire 34 which may be barbed wire 32 for fencing. The wire is supplied on wire reel 36 which has a central, transverse opening through which shaft 30 may be passed. Other wire may be supplied on drums or spools which may also be used with the present invention.
[0024] Carrier 10 is also equipped with wheels 38 on axles 40 supported in axle brackets 42 . The wheels 38 are preferably aligned, one with the other, in a coaxial arrangement. The axis of aligned wheel axes 40 is offset from the axis of spindle 30 such that tipping carrier 10 forward on wheels 38 lifts spindle 30 , raising roll 34 and allowing wire 32 to payout from roll 34 as carrier 10 is moved across the ground, floor, or other such generally horizontal surface. Carrier 10 may be either pushed or pulled depending on which side of roll 34 it is desired to have wire 32 payout. Most commonly, carrier 10 will be pulled by the user and wire roll 34 will be mounted such that wire 32 pays out from the bottom of roll 34 .
[0025] Carrier 10 may be equipped with bushings 24 , 26 each having flange 28 which act to center roll 34 on shaft 30 and prevent roll 34 or reel 36 from contacting frame 14 or axle bracket 42 as it revolves on spindle 30 .
[0026] When the user desires to stop, he or she may move handle 12 to an approximately vertical position such that the bottom of roll 34 or reel 36 contacts the ground or floor. Carrier 10 is then in a stable position, resting on wheels 38 and wire roll 34 or reel 36 , as the case may be. Conversely, if it is desired to pull wire from roll 34 with cart 10 stationary, handle 12 may be lowered to the ground or floor, thereby raising spindle 30 and roll 34 such that the roll 34 may rotate freely on shaft 30 . In this configuration cart 10 is resting on wheels 38 and handle 12 .
[0027] The embodiment illustrated in FIG. 1 includes a hinged or moveable frame section 16 which facilitates loading and unloading wire roll 34 . Frame hinge 18 is shown in detail in FIG. 3 . Fixed frame section 14 and moveable frame section 16 are joined by frame hinge 18 which may comprise two opposing, spaced-apart plates. Bolt 50 having unthreaded portion 51 may be passed through aligned holes in the opposing plates and a hole proximate the end of moveable frame section 16 . Bolt 50 may be secured with nut 52 which may be a lock nut. Unthreaded portion 51 acts as a bearing surface for frame section 16 . Bolt 50 may be tightened to provide the desired amount of friction between frame member 16 and hinge 18 . It may be desired to have sufficient friction to hold frame member 16 in the open position when under the influence of its own weight.
[0028] FIGS. 4 and 5 show carrier 10 in the open or loading position (with the closed position shown in phantom in FIG. 4 ). Frame locking rod 22 is held out of the way by rod retainer 54 which, in the illustrated embodiment, comprises a U-shaped section welded to fixed frame section 14 . As shown in FIG. 5 , wire roll 34 is held on reel 36 having diameter D. Hinged frame member 16 is moved outward sufficiently to provide clearance C between flange 28 and the ground or floor on which reel 36 rests such that distance C is greater than diameter D. In this condition, cart 10 may be slid sideways such that spindle 30 is inserted through the center of roll 34 and/or a central aperture in reel 36 . Frame member 16 may then be moved to the closed position and locked in place by securing locking rod 22 in lock bracket 44 .
[0029] Moveable frame member 16 may be held in the closed position by frame locking rod 22 which pivots in hole 23 through fixed frame member 14 on one end and is releaseably secured by frame lock 20 on the opposing end. Frame lock 20 is shown in detail in FIG. 20 and may comprise lock bracket 44 having slot 45 arranged such that when locking rod 22 swings downward it enters slot 45 . The end of rod 22 may have a threaded portion to which backing nut 46 and wing nut 48 may be attached. Locking rod 22 may be secured by tightening lock bracket 44 between wing nut 48 and backing nut 46 . The alignment of frame member 16 with frame member 14 may be adjusted by moving backing nut 46 along the threaded portion of rod 22 .
[0030] As may be best seen in FIG. 6 , one end of spindle 30 may be secured in bushing 26 with spindle bolt 56 . Bushing 26 and spindle bolt 56 are on fixed frame member 14 . The opposing end of spindle 30 is in sliding engagement with bushing 24 on hinged frame member 16 . It will be appreciated by those skilled in the art that the central opening in bushing 24 must be large enough to accommodate spindle free end 58 as bushing 24 moves in an arc when frame section 16 pivots on bolt 50 in hinge 18 . To further assist in aligning spindle free end 58 with bushing 24 during the closing process, it may be advantageous to allow spindle 30 to pivot on spindle bolt 56 within the confines of bushing 26 .
[0031] An alternative embodiment of the invention is shown in FIGS. 7 and 8 . In this embodiment, frame 114 is fixed—i.e., unhinged—and may comprise cross member 115 for additional rigidity.
[0032] Referring to FIG. 7 , it may be seen that spindle shaft 130 is adapted for sliding engagement in spindle support brackets 164 which may comprise bushings 124 and 126 and flanges 128 . Each spindle bracket 164 may comprise hole 165 having an internal diameter slightly larger than the diameter of spindle 130 so as to permit spindle 130 to slide through hole 165 . Spindle 130 may include threaded stud 160 on each end. Washer 161 has an outside diameter larger than the diameter of hole 165 such that when nut 162 is screwed onto threaded stud 160 over washer 161 , spindle 130 is secured in spindle bracket 164 and prevented from sliding in the direction toward the center of the cart. The left side and right side of spindle 130 being similarly secured prevents spindle 130 from sliding in either direction and locks it within frame 114 .
[0033] The embodiment of FIGS. 7 and 8 may be used by removing one each of nut 162 and washer 161 and then sliding shaft 130 out of the frame. Cart 10 may then be rolled to or lifted over a roll of wire and positioned such that the axis of bushing 124 is in line with the axis of the wire roll. Shaft 130 may then be re-inserted, passing it from the outside of spindle bracket 164 through hole 165 and secured with nut 162 and washer 161 .
[0034] One disadvantage of the embodiment shown in FIGS. 7 and 8 is that tools may be required to tighten and/or loosen nut 162 . In yet other embodiments, nut 162 may be replaced with a knurled knob, wing nut, or similar fastening device that can be operated solely by hand.
[0035] In yet other embodiments, handle 12 may be replaced with a hitch to permit cart 10 to be pulled by a vehicle.
[0036] Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims. | A handcart for unrolling wire is disclosed. In a preferred embodiment, one leg of the handcart is hinged to permit a roll of wire to be loaded or unloaded onto a horizontal spindle on the cart without lifting the roll. The axles of the wheels of the cart are offset from the spindle such that tipping the cart lifts the roll of wire from the surface on which it is resting and permits the wire to payout from the roll as the cart is rolled across the ground. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. §119 of the filing date of International Application No. PCT/US2012/031956, filed Apr. 3, 2012. The entire disclosure of this prior application is incorporated herein by this reference.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates, in general, to equipment utilized in conjunction with operations performed in subterranean wells and, in particular, to a downhole circulating valve having a metal-to-metal seal in its non-circulating configuration and method for operating the downhole circulating valve between circulating and non-circulating configurations.
BACKGROUND OF THE INVENTION
[0003] Without limiting the scope of the present invention, its background will be described with reference to operations performed in a subterranean well that traverses a fluid-bearing subterranean formation, as an example. Subterranean wellbores are generally filled with fluids that extend from the lower end of the wellbore to the earth's surface. During drilling and completions operations, a weighted column of fluid is usually present adjacent to each of the fluid-bearing formations intersected by the wellbore, so that the column of fluid may exert hydrostatic pressure on the formations sufficient to prevent uncontrolled flow of fluid from the formations into the wellbore, which uncontrolled flow of fluid could result in a blowout.
[0004] In order to transport fluid, tools, instruments and the like within the wellbore, it is common practice to utilize a tubular string, such as drill pipe or production tubing, to which tools and instruments may be attached and within which fluid may be flowed and tools and instruments may be conveyed. When such a tubular string is disposed within the wellbore, the fluid column within the wellbore may be effectively divided into multiple portions. For example, a first fluid column may be contained in an annulus defined by the area separating the outside surface of the tubular string from the inside surface of the wellbore or casing string. At the same time, a second fluid column may be contained within the interior of the tubular string. In such a configuration, tools, instruments and the like may be transported within the wellbore attached to or within the tubular string without disturbing the relationship between the fluid column in the annulus and the fluid-bearing formations intersected by the wellbore.
[0005] After completing the well, it is typically desirable to remove the weighted column of fluid from both the interior of the tubular string, if present, and the annulus above the uppermost packer. This may be achieved through the use of a circulating valve disposed within in the tubular string, which has a primary purpose of selectively permitting fluid flow between the interior of the tubular string and the annulus. For example, when it is desired to remove the weighted column of fluid from the annulus, a lighter fluid may be pumped from the earth's surface down through the tubular string and radially outwardly from the tubular string through the circulating valve into the annulus and then back to the earth's surface up through the annulus. Typically, such tubing conveyed circulating valves have a sliding sleeve that may be longitudinally shifted between circulating and non-circulating positions using wireline or slickline techniques. In the non-circulating position, conventional circulating valves typically utilize resilient materials such as elastomers for sealing between movable metal parts to prevent fluid communication between the interior of the tubular string and the annulus.
[0006] It has been found, however, that resilient sealing materials may deteriorate due to the harsh chemical, physical and thermal environment downhole. When such deterioration occurs, the seals may fail to prevent fluid communication between the interior of the tubular string and the annulus when a conventional circulating valve is in its non-circulating configuration. Accordingly, a need has arisen for an improved circulating valve that is operable to selectively permit fluid flow between the interior of the tubular string and the annulus. In addition, a need has arisen for such an improved circulating valve that does not rely on resilient sealing materials to prevent fluid communication between the interior of the tubular string and the annulus when the circulating valve is in its non-circulating configuration.
SUMMARY OF THE INVENTION
[0007] The present invention disclosed herein comprises an improved circulating valve that is operable to selectively permit fluid flow between the interior of a tubular string and the annulus between the tubular string and the wellbore. In addition, the improved circulating valve of the present invention does not rely on resilient sealing materials to prevent fluid communication between the interior of the tubular string and the annulus when the circulating valve is in its non-circulating configuration but instead utilizes a metal-to-metal seal to provide a long lasting, high pressure seal.
[0008] In one aspect, the present invention is directed to a downhole circulating valve. The downhole circulating valve has a generally tubular outer housing having an axially extending internal passageway including an internal seat and at least one generally radially extending opening formed through the housing intersecting the internal seat. A valve element is rotatably disposed within the internal passageway. The valve element has an axially extending internal bore and a head portion disposed at least partially within the internal seat. The head portion includes at least one generally radially extending seal element. The valve element has a first position relative to the housing wherein the seal element is not aligned with the opening, thereby allowing fluid communication between the opening and the internal passageway. The valve element has a second position relative to the housing wherein the seal element is aligned with the opening and wherein the seal element forms a metal-to-metal seal with the internal seat, thereby preventing fluid communication between the opening and the internal passageway.
[0009] In one embodiment, the internal seat may have a spherical segment having a first radius. In this embodiment, the at least one generally radially extending opening may extend in the direction of the first radius. In some embodiments, an outer surface of the head portion may have a spherical segment having a second radius. In addition, the head portion may include at least one generally radially extending port that may extend in the direction of the second radius. The at least one generally radially extending seal element may also extend in the direction of the second radius. In certain embodiments, the first radius and the second radius may be sized to enable spherical mating of the at least one generally radially extending seal element and the internal seat. In such embodiments, the head portion may translate toward the internal seat when the valve element is operated from the first position to the second position to form the metal-to-metal seal. In one embodiment, the at least one generally radially extending seal element may include one or more seal rings each having a circular cross section.
[0010] In one embodiment, the housing may include a plurality of circumferentially distributed generally radially extending openings formed through the housing intersecting the internal seat. In this embodiment, the head portion may include a plurality of circumferentially distributed generally radially extending ports and a plurality of circumferentially distributed generally radially extending seal elements that are circumferentially offset from the ports such that in the first position, the ports are in fluid communication with the openings and, in the second position, each of the seal elements is aligned with one of the openings and forms a metal-to-metal seal with the internal seat.
[0011] In another aspect, the present invention is directed to a downhole circulating valve. The downhole circulating valve includes a generally tubular outer housing having an axially extending internal passageway including a spherical segment internal seat having a first radius and at least one generally radially extending opening formed through the housing intersecting the internal seat. A valve element is rotatably disposed within the internal passageway. The valve element has an axially extending internal bore and a head portion having an outer surface including a spherical segment with a second radius. The head portion is translatable relative to and disposed at least partially within the internal seat. The head portion includes at least one generally radially extending port and at least one generally radially extending seal element that is circumferentially offset from the port. The valve element has a first position relative to the housing wherein the port is in fluid communication with the opening and a second position relative to the housing wherein the seal element is aligned with the opening, wherein the seal element forms a metal-to-metal seal with the internal seat, wherein the first radius and the second radius are sized to enable spherical mating of the at least one generally radially extending seal element and the internal seat and wherein the head portion translates toward the internal seat when the valve element is operated from the first position to the second position.
[0012] In a further aspect, the present invention is directed to a downhole circulating system. The system includes a downhole power unit having an engagement assembly and a rotatable shaft. The system also includes a circulating valve having a generally tubular outer housing with an axially extending internal passageway including a profile, an internal seat and at least one generally radially extending opening formed through the housing intersecting the internal seat. A valve element is rotatably disposed within the internal passageway. The valve element has an axially extending internal bore with a profile and a head portion disposed at least partially within the internal seat. The head portion includes at least one generally radially extending seal element. A first portion of the engagement assembly is operably associated with the profile of the housing and a second portion of the engagement assembly is operably associated with the profile of the valve element such that when the downhole power unit is activated and the rotatable shaft is rotated, the valve element is rotatable between a first position relative to the housing wherein the seal element is not aligned with the opening and a second position relative to the housing wherein the seal element is aligned with the opening and wherein the seal element forms a metal-to-metal seal with the internal seat.
[0013] In an additional aspect, the present invention is directed to a method for operating a downhole circulating valve. The method includes providing a circulating valve having a generally tubular outer housing with an axially extending internal passageway including an internal seat and at least one generally radially extending opening formed through the housing intersecting the internal seat and a valve element rotatably disposed within the internal passageway, the valve element having an axially extending internal bore and a head portion disposed at least partially within the internal seat, the head portion including at least one seal element; running the circulating valve into a wellbore on a tubular string; running a rotating tool into the tubular string and engaging the circulating valve; and activating the rotating tool to rotate the valve element between a first position relative to the housing wherein the at least one seal element is not aligned with the at least one opening and a second position relative to the housing wherein the at least one seal element is aligned with the at least one opening and wherein the at least one seal element forms a metal-to-metal seal with the internal seat.
[0014] The method may also include running a downhole power unit having a rotatable shaft into the tubular string and engaging a profile of the housing and a profile of the valve element with the downhole power unit; activating an electric motor of the downhole power unit to impart rotary motion to the rotatable shaft; spherical mating the seal element and the internal seat by translating the head portion toward the internal seat and/or creating a metal-to-metal seal between at least one seal ring of the seal element and the internal seat.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
[0016] FIG. 1 is a schematic illustration of a well system operating a downhole circulating system according to an embodiment of the present invention;
[0017] FIGS. 2A-2E are cross sectional views of successive axial sections of a downhole circulating system according to an embodiment of the present invention;
[0018] FIG. 2F is a cross sectional view of the downhole circulating system of FIGS. 2A-2E taken along line 2 F- 2 F;
[0019] FIG. 3 is a cross sectional view of a downhole circulating valve according to an embodiment of the present invention in its circulating configuration;
[0020] FIG. 4 is a cross sectional view of a downhole circulating valve according to an embodiment of the present invention in its non-circulating configuration;
[0021] FIG. 5 is a side view of a head portion of a valve element of a downhole circulating valve according to an embodiment of the present invention;
[0022] FIG. 6 is a perspective view of a head portion of a valve element of a downhole circulating valve according to an embodiment of the present invention; and
[0023] FIG. 7 is an enlarged view of a metal-to-metal seal formed within a downhole circulating valve in its non-circulating configuration according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts, which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the present invention.
[0025] Referring initially to FIG. 1 , therein is depicted a well system including a downhole circulating system embodying principles of the present invention that is schematically illustrated and generally designated 10 . In the illustrated embodiment, a wellbore 12 extends through the various earth strata. Wellbore 12 has a substantially vertical section 14 , the upper portion of which has cemented therein a casing string 16 . Wellbore 12 also has a substantially horizontal section 18 that extends through a hydrocarbon bearing subterranean formation 20 . As illustrated, substantially horizontal section 18 of wellbore 12 is open hole.
[0026] Positioned within wellbore 12 and extending from the surface is a tubing string 22 . Tubing string 22 provides a conduit for formation fluids to travel from formation 20 to the surface and for injection fluids to travel from the surface to formation 20 . At its lower end, tubing string 22 is coupled to a completions string that has been installed in wellbore 12 and divides the completion interval into various production intervals adjacent to formation 20 . The completion string includes a plurality of sand control screens 24 , each of which is positioned between a pair of annular barriers depicted as packers 26 that provides a fluid seal between the completion string and wellbore 12 , thereby defining the production intervals. Tubing string 22 may include a variety of tools such as packer 28 that provides a seal between tubing string 22 and casing string 16 . An annulus 30 is defined between tubing string 22 and casing string 16 above packer 28 . As discussed above, during drilling and completions operations, a weighted column of fluid is usually present in the wellbore 12 to exert hydrostatic pressure on formation 20 sufficient to prevent uncontrolled flow of fluid from formation 20 into wellbore 12 . To enable production, however, the weighted column of fluid must be removed from wellbore 12 . In the illustrated embodiment, a circulating valve 32 is positioned within tubing string 22 above packer 28 and may be operated via a slickline or wireline deployed rotating tool depicted as downhole power unit 34 . Circulating valve 32 serves the primary purpose of selectively permitting fluid flow between the interior of tubing string 22 and annulus 30 .
[0027] For example, when it is desired to remove the weighted column of fluid from wellbore 12 , downhole power unit 34 may be deployed via wireline 36 to engage with circulating valve 32 . Typically, circulating valve 32 is initially run downhole in its non-circulating configuration to prevent fluid flow between the interior of tubing string 22 and annulus 30 . Once engaged, downhole power unit 34 may be activated to operate circulating valve 32 from its non-circulating configuration to its circulating configuration. Thereafter, a lighter fluid may be pumped from the earth's surface down through tubing string 22 and radially outwardly from tubing string 22 through circulating valve 32 into annulus 30 and then back to the earth's surface up through annulus 30 . After the weighted column of fluid is removed, downhole power unit 34 may be activated to operate circulating valve 32 from its circulating configuration to its non-circulating configuration. In the present invention, when circulating valve 32 is in its non-circulating configuration, one or more metal-to-metal seals prevent fluid communication between the interior of tubing string 22 and annulus 30 .
[0028] Even though FIG. 1 depicts the circulating valve of the present invention in a cased hole environment, it should be understood by those skilled in the art that the present invention is equally well suited for use in an open hole well. In addition, even though FIG. 1 depicts the circulating valve of the present invention in a vertical section of the wellbore, it should be understood by those skilled in the art that the present invention is equally well suited for use in wells having other directional configurations including horizontal wells, deviated wells, slanted wells, multilateral wells and the like. Accordingly, it should be understood by those skilled in the art that the use of directional terms such as above, below, upper, lower, upward, downward, left, right, uphole, downhole and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure, the uphole direction being toward the surface of the well and the downhole direction being toward the toe of the well.
[0029] Referring next to FIGS. 2A-2E , therein is depicted successive axial sections of a downhole circulating system embodying principles of the present invention that is representatively illustrated and generally designated 100 . System 100 includes a rotating tool depicted as downhole power unit 102 and a circulating valve 104 that may be deployed in a well system as part of the tubing string as described above. Downhole power unit 102 includes a housing assembly 106 that comprises suitably shaped and connected generally tubular housing members. An upper portion of housing assembly 106 includes an appropriate mechanism to facilitate coupling of housing 106 to a conveyance such as a wireline, slickline, electric line, coiled tubing, jointed tubing or the like.
[0030] In the illustrated embodiment, downhole power unit 102 includes a self-contained power source, eliminating the need for power to be supplied from an exterior source, such as a source at the surface, however, in other embodiments, power may be provided to downhole power unit 102 from the surface via a wired connection. A preferred power source comprises a battery assembly 108 which may include a plurality of batteries such as alkaline batteries, lithium batteries or the like. Downhole power unit 102 also has a force generating and transmitting assembly 110 that preferably includes a direct current electric motor and a gearbox. The electric motor may be of any suitable type. One example is a motor operating at 7500 revolutions per minute in unloaded condition, and operating at approximately 5000 rpm in a loaded condition, and having a horsepower rating of approximately 1/30th of a horsepower. In this implementation, the electric motor may be coupled through a gearbox, which provides approximately 5000:1 gear reduction to a sleeve assembly 112 , which is in turn coupled to a rotatable shaft 114 . Downhole power unit 102 may include a variety of sensors and controllers that are operable to activate and deactivate downhole power unit 102 including, but not limited to, a microcontroller, a pressure-sensitive switch, an accelerometer, a geophone or the like. Alternatively or additionally, downhole power unit 102 may be controlled from the surface via wired or wireless communications.
[0031] At its lower end, housing assembly 106 includes an engagement assembly 116 . In the illustrated embodiment, engagement assembly 116 includes a set of locating keys 118 , a set of anti-rotation keys 120 and a set of torque keys 122 . Preferably, anti-rotation keys 120 and torque keys 122 are rotatable relative to locating keys 118 . In addition, torque keys 122 are rotatable relative to anti-rotation keys 120 . Torque keys 122 are operably associated with rotatable shaft 114 such that when rotatable shaft 114 is rotated, torque keys 122 are rotated therewith.
[0032] Referring additionally now to FIGS. 3 and 4 , circulating valve 104 will now be described. Circulating valve 104 has a generally tubular outer housing 130 including, in the illustrated embodiment, an upper housing section 132 and a lower housing section 134 that are threadably coupled together. Housing 130 defines an axially extending internal passageway 136 . Upper housing section 132 includes a locating profile 138 . Upper housing section 132 also includes an internal seat depicted as a spherical segment internal seat 140 having a radius R 1 , as best seen in FIG. 3 . Upper housing section 132 further includes four generally radially extending openings 142 (only two such openings being visible in the figures) formed through upper housing section 132 intersecting internal seat 140 . Preferably, openings 142 radially extend through upper housing section 132 in the direction of radius R 1 . Even though upper housing section 132 has been described as having a particular number of openings 142 , other numbers of openings both greater than four and less than four including one opening could alternatively be formed through upper housing section 132 without departing from the principles of the present invention. Lower housing section 134 includes an anti-rotation profile depicted as plurality of circumferentially distributed slots 144 and a locating profile 146 .
[0033] Circulating valve 104 includes a valve element 148 . In the illustrated embodiment, valve element 148 includes a lower valve section 150 , an upper valve section 152 and a head portion 154 . Lower valve section 150 is threadably coupled to upper housing section 132 and is secured against rotation relative to upper housing section 132 by one or more set screws 156 . Upper valve section 152 is also threadably coupled to upper housing section 132 but is free to rotate relative to upper housing section 132 between two stopping points as described below. Upper valve section 152 includes a rotation profile depicted as plurality of circumferentially distributed slots 158 . Head portion 154 is threadably coupled to upper valve section 152 and is secured against rotation relative to upper valve section 152 by one or more set screws 160 . As such, upper valve section 152 and head portion 154 are operable to rotate together relative to upper housing section 132 . In addition, due to the threaded engagement between upper valve section 152 and upper housing section 132 , rotation of upper valve section 152 and head portion 154 relative to upper housing section 132 causes upper valve section 152 and head portion 154 to translate longitudinally relative to upper housing section 132 . The extent of downward longitudinally travels of upper valve section 152 and head portion 154 is limited by contact between an upper valve section 152 and lower valve section 150 . The extent of upward longitudinally travel of upper valve section 152 and head portion 154 is limited by contact between head portion 154 and internal seat 140 , as more fully described below.
[0034] Valve element 148 has an axially extending internal bore 162 . Head portion 154 has an outer surface including a spherical segment 164 with a radius R 2 , as best seen in FIG. 3 . Head portion 154 includes four generally radially extending ports 166 (only some of the ports being visible in the figures). Preferably, ports 166 radially extend through head portion 154 in the direction of radius R 2 . Even though head portion 154 has been described as having a particular number of ports 166 , other numbers of ports both greater than four and less than four including one port could alternatively be formed through head portion 154 without departing from the principles of the present invention. Also, even though head portion 154 has been described as having the same number of ports 166 as upper housing section 132 has openings 142 , this is not required by the present invention.
[0035] As best seen in FIGS. 5-7 , head portion 154 also includes four generally radially extending seal elements 168 (only some of the seal elements being visible in the figures). Preferably, seal elements 168 radially extend from head portion 154 in the direction of radius R 2 . Even though head portion 154 has been described as having a particular number of seal elements 168 , other numbers of seal elements both greater than four and less than four including one seal element could alternatively be formed on head portion 154 without departing from the principles of the present invention, however, the number of seal elements 168 should equal or exceed the number of openings 142 through upper housing section 132 . As illustrated, ports 166 and seal elements 168 are circumferentially distributed about head portion 154 at a uniform interval of 45 degrees with a port 166 positioned between each pair of seal elements 168 and a seal element 168 positioned between each pair of ports 166 .
[0036] In the illustrated embodiment, seal elements 168 include a pair of concentric seal rings 170 , 172 , each having a circular cross section. Preferably, seal rings 170 , 172 radially extend from head portion 154 in the direction of radius R 2 . As such, the outer surfaces of seal rings 170 , 172 lie in a spherical segment that has a radius that enables spherical mating between the outer surfaces of seal rings 170 , 172 and internal seat 140 when circulating valve 104 is in its non-circulating configuration.
[0037] In operation, downhole power unit 102 is adapted to cooperate with circulating valve 104 to enable and disable fluid circulation therethrough. Specifically, after circulating valve 104 has been run downhole as part of a tubing string and it is desired to circulate fluid between the interior of the tubing string and the annulus surrounding the tubing string, downhole power unit 102 is run downhole on a suitable conveyance such as a wireline. Upon reaching the desired depth downhole, downhole power unit 102 engages circulating valve 104 . Specifically, engagement assembly 116 interacts with circulating valve 104 . First, locating keys 118 engage locating profiles 146 of lower housing section 134 . At this point, anti-rotation keys 120 should be axially aligned with anti-rotation profile 144 and torque keys 122 should be axially aligned with rotation profile 158 . Slight rotation of rotatable shaft 114 may now be required to engage anti-rotation keys 120 with anti-rotation profile 144 and torque keys 122 with rotation profile 158 , as best seen in FIG. 2F . Thereafter, activation of downhole power unit 102 to rotate rotatable shaft 114 will cause upper valve section 152 and head portion 154 to rotate together relative to upper housing section 132 .
[0038] For example, to operate circulating valve 104 from the non-circulating configuration ( FIG. 4 ) to the circulating configuration ( FIG. 3 ), downhole power unit 102 is activated to rotate in a first direction which rotates upper valve section 152 and head portion 154 relative to upper housing section 132 such that seal elements 168 are rotationally and translationally shifted away from openings 142 and such that ports 166 are substantially aligned with openings 142 enabling fluid communication through circulating valve 104 . To operate circulating valve 104 from the circulating configuration ( FIG. 3 ) to the non-circulating configuration ( FIG. 4 ), downhole power unit 102 is activated to rotate in a second direction which rotates upper valve section 152 and head portion 154 relative to upper housing section 132 such that seal elements 168 are rotationally and translationally shifted toward openings 142 until the outer surfaces of seal rings 170 , 172 are spherically mated with internal seat 140 to create a metal-to-metal seal around each opening 142 that prevents fluid communication through circulating valve 104 . This process can be repeated as desired to operate circulating valve 104 between its circulating and non-circulating configurations. When desired, upward jarring will release downhole power unit 102 from circulating valve 104 and downhole power unit 102 can be retrieved to the surface.
[0039] While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments. | A downhole circulating valve includes a generally tubular outer housing having an axially extending internal passageway including an internal seat and at least one generally radially extending opening formed through the housing intersecting the internal seat. A valve element is rotatably disposed within the internal passageway. The valve element has an axially extending internal bore and a head portion disposed at least partially within the internal seat. The head portion includes at least one generally radially extending seal element. The valve element has a first position relative to the housing, wherein the seal element is not aligned with the opening, thereby allowing fluid communication between the opening and the internal passageway. The valve element has a second position relative to the housing, wherein the seal element is aligned with the opening and wherein the seal element forms a metal-to-metal seal with the internal seat, thereby preventing fluid communication between the opening and the internal passageway. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/674,356, filed on Jul. 22, 2012, and U.S. Provisional Patent Application Ser. No. 61/674,809, filed on Jul. 23, 2012 the entire disclosures of which are incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] This application relates generally to systems and methods for removing materials below the surface of the earth. More specifically, this application relates to systems and methods for removing subsurface materials without excavating the overburden using “open pit”, “floating dredge” or other conventional excavation methods.
BACKGROUND TECHNOLOGY
[0003] Core drilling allows sampling of subterranean materials from various depths to be obtained for many purposes. For example, drilling a core sample and testing the retrieved core helps determine what materials are present or are likely to be present in a given formation. For instance, a retrieved core sample can indicate the presence of petroleum, precious metals, sand, and other desirable materials. Accordingly, core samples can be used to determine the desirability of further exploration and/or mining in a given area.
[0004] In sonic core drilling processes, variable frequency vibration is created by an oscillator. The vibration is then mechanically transferred to the drill string of the core barrel and/or casing. The vibration is transmitted in an axial direction down through the drill string to an open-faced drill bit. As a result, the drill string may be rotated and/or mechanically pushed as it is vibrated into the subsurface formation.
[0005] Often, sonic core drilling processes are used to retrieve a sample of material from a desired depth below the surface of the earth. Although there are several ways to collect core samples, core barrel systems are often used for core sample retrieval. Core barrel systems include an outer tube with a coring drill bit secured to one end. The opposite end of the outer tube is often attached to a drill string that extends vertically to a sonic drill head that is often located above the surface of the earth. The core barrel systems also may include an inner polycarbonate tube located within the outer core barrel. As the drill bit cuts formations in the earth, the inner tube can be filled with a core sample. Once a desired amount of a core sample has been cut, the inner tube, core barrel, and core sample can be brought up through the drill string and retrieved at the surface.
[0006] The sonic drill head may include high-speed, rotating counterbalances that produce resonant energy waves and a corresponding high-speed vibration to be transmitted through the drill string to the core barrel. As a result, the sonic drill head can vertically vibrate the core barrel. In addition, the drill head can rotate and/or push the core barrel into the subsurface formation to obtain a core sample. Once the core sample is obtained, the core barrel (containing the core sample) is retrieved by removing the entire drill string out of the borehole that has been drilled. Once retracted to the surface, the core sample may then be removed from the core barrel.
[0007] In a sonic wireline drilling process, the core barrel and the casing are advanced together into the formation. The casing again has an open-faced drill bit and is advanced into the formation. However, the core barrel (inner tube) does not contain a drill bit or connect to a drill string. Instead, the core barrel mechanically latches inside of and at the bottom of the casing and advances into the formation along with the casing. When the core sample is obtained, a drill operator can retrieve the core barrel using a wireline system. Thereafter, the drill operator can remove the core sample from the core barrel at the surface, and then drop the core barrel back into the casing using the wire line system. As a result, the wireline system eliminates the time needed to trip the drill rods and drill string in and out of a borehole for retrieval of the core sample.
[0008] Conventionally, upon detecting the presence of subterranean desirable materials, such as precious metals, sand and the like, an open pit mine is dug. In open pit mining, a large pit is dug and the overburden material positioned over the desirable materials is removed and hauled to a different location. However, forming an open pit mine is very time-consuming and expensive. Often an extensive dewatering system is required. There is also a large carbon footprint as millions of tons of overburden material removed from the open pit are trucked away. Further, there can be large capital costs in excavation equipment and infrastructure such as roads in order to form the open pit. Moreover, in some instances the open pit can be refilled, increasing cost as the removed overburden material is returned to the pit.
[0009] Thus, there is a need in the art for systems and methods for removing desirable subsurface materials without the need to dig an open pit mine to remove the overburden waste material. The present invention fulfills these needs and provides further related advantages as described herein
[0010] The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced.
SUMMARY
[0011] The invention relates to systems and methods for removing a desired subsurface material. In one aspect, the systems and methods for removing a desired subsurface material comprise removing subsurface materials without excavating the overburden waste material other than that excavated when forming a conventional exploratory borehole.
[0012] The system for removing desired subsurface materials comprises a drilling system and a material removal system. In one aspect, the drilling system comprises a drill head assembly capable of rotating a drill string and transmitting oscillating forces to the drill string. In use, the drill head assembly can cause a drill bit attached to the drill string to form a borehole extending into a surface. The drill string can line the borehole forming an outer casing.
[0013] The material removal system comprises a sonic air lift tooling system (“S3RP”) and a discharge tank. In one aspect, the sonic air lift tooling system comprises an outer tube having an outer diameter and defining an inner volume. The outer tube annulus can be in fluid communication with a source of pressurized fluid, such as air, and the like.
[0014] The sonic air lift tooling system can further comprise an inner tube. In one aspect, the inner tube has an outer diameter sized so that that at least a portion of the inner tube can be positioned in the inner volume of the outer tube. In another aspect, the outer diameter of the inner tube can be sized so that an annular void is defined between the outer tube and the outer diameter of the inner tube. In a further aspect, a distal end of the inner tube can define at least one opening such that an interior conduit of the inner tube is in fluid communication with the annular void outside of the distal end of the inner tube. A proximal end of the inner tube can be in fluid communication with a discharge tank such that the interior conduit of the inner tube is in fluid communication with the discharge tank.
[0015] In use, the pressurized fluid, such as compressed air, and the like can be injected through the outlet tube inlet and into the annular void between the outer tube and the inner tube. The pressurized fluid can be urged towards the distal end of the inner tube. Upon reaching the distal end of the inner tube, in one aspect, the pressurized fluid can pass from the annular void through the opening to the interior conduit of the inner tube. Because the desired subsurface material can be a flowing material, such as, for example and without limitation, sand, the desired subsurface material can become entrained in the fluid in the interior conduit of the tube. In the interior conduit of the tube, the fluid and the desired subsurface material entrained therein can be “lifted” or otherwise urged to the discharge tank.
[0016] In other aspects, varying combinations of pressurized fluids and flow directions can be utilized. However, in each aspect, the desired material can be removed from below the surface using the same borehole that was formed during exploratory drilling without the need for additional overburden material removal.
[0017] For purposes of summarizing, some aspects, advantages and features of a few of the embodiments of the invention have been described in this summary. Some embodiments of the invention may include some or all of these summarized aspects, advantages and features. However, not necessarily all of (or any of) these summarized aspects, advantages or features will be embodied in any particular embodiment of the invention. Thus, none of these summarized aspects, advantages and features are essential. Some of these summarized aspects, advantages and features and other aspects, advantages and features may become more fully apparent from the following detailed description and the appended claims.
DETAILED DESCRIPTION OF THE DRAWINGS
[0018] The appended drawings contain figures of preferred embodiments to further clarify the above and other aspects, advantages and features. It will be appreciated that these drawings depict only preferred embodiments of the invention and are not intended to limit its scope. These preferred embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
[0019] FIG. 1 is an elevational view of a drilling system, according to one example.
[0020] FIG. 2A is a side elevational view of a sonic air lift tooling system of a system for sonic subsurface material removal, according to one aspect.
[0021] FIG. 2B is a cross-sectional view of the sonic air lift tooling system of FIG. 2A taken along line B-B of FIG. 2A .
[0022] FIG. 2C is a perspective view of the sonic air lift tooling system of FIG. 2A .
[0023] FIG. 3 is a schematic diagram illustrating a system and method for sonic subsurface material removal, according to one aspect.
[0024] FIG. 4 is schematic diagram illustrating a system and method for sonic subsurface material removal, according to one aspect.
[0025] FIG. 5 is an elevational view of an exemplary system and method for sonic subsurface material removal, according to one aspect.
[0026] FIG. 6 is an elevational view of a second exemplary system and method for sonic subsurface material removal, according to one aspect.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] The present invention can be understood more readily by reference to the following detailed description, examples, drawings, and claims, and their previous and following description. However, before the present devices, systems, and/or methods are disclosed and described, it is to be understood that this invention is not limited to the specific devices, systems, and/or methods disclosed unless otherwise specified, as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.
[0028] The following description of the invention is provided as an enabling teaching of the invention in its best, currently known embodiment. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects of the invention described herein, while still obtaining the beneficial results of the present invention. It will also be apparent that some of the desired benefits of the present invention can be obtained by selecting some of the features of the present invention without utilizing other features. Accordingly, those who work in the art will recognize that many modifications and adaptations to the present invention are possible and can even be desirable in certain circumstances and are a part of the present invention. Thus, the following description is provided as illustrative of the principles of the present invention and not in limitation thereof.
[0029] As used throughout, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a pipe” can include two or more such pipes unless the context indicates otherwise.
[0030] Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.
[0031] As used herein, the terms “optional” or “optionally” mean that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.
[0032] In one aspect, the system for sonic subsurface material removal can comprise a drilling system 100 and a material removal system 200 .
[0033] FIG. 1 illustrates a drilling system 100 for drilling into the surface 105 of the earth that comprises a drill head assembly 110 . The drill head assembly can be coupled to a mast 120 that in turn is coupled to a drill rig 130 . The drill head assembly 110 is configured to have a drill rod 140 coupled thereto to form a drill string 150 . As can be appreciated, any number of drill rods can be added so that the drill string is the desired length. In turn, the drill string 150 can be coupled to a drill bit 160 configured to interface with the material to be drilled, such as a formation 170 .
[0034] In at least one example, the drill head assembly 110 is configured to rotate the drill string 150 . In particular, the rotational rate of the drill string 150 can be varied as desired during the drilling process. Further, the drill head assembly 110 can be configured to translate relative to the mast 120 to apply an axial force to the drill head assembly 110 to urge the drill bit 160 into the formation 170 during a drilling process. The drill head assembly 110 can also generate oscillating forces that are transmitted to the drill rod 140 . These forces are then transmitted from the drill rod 140 through the drill string 150 to the drill bit 160 .
[0035] Upon insertion of a drill rod 140 into a borehole 180 , the drill rod can form an outer casing 190 . As a result, a drill operator can use the outer casing to maintain the borehole. Once an outer casing is in place, the drill operator can trip a core barrel and its corresponding drill string into the borehole through an interior volume 195 of the outer casing and advance the core barrel ahead of the casing to retrieve a core sample. In another aspect, in a wireline drilling processes, a drill operator can simultaneously advance the casing and the core barrel together through a formation. Using a wireline process, the drill operator can trip the inner core barrel in and out of the drill string to obtain core samples from the core barrel.
[0036] In one aspect, the material removal system 200 of the system for sonic subsurface material removal comprises at least one of a sonic air lift tooling system 210 , and a discharge tank 230 .
[0037] With reference to FIGS. 2A , 2 B and 2 C, the sonic air lift tooling system 210 can, in one aspect, comprise an outer tube 235 and an inner tube 240 . The outer tube can be sized such that at least a portion of the outer tube can be coupled to the outer casing 190 in the borehole. For example, at least a portion of the outer tube 235 can have an outer diameter 245 of about 4 inches, about 5 inches, about 6 inches, about 7 inches, about 8 inches, or greater than about 8 inches. In another aspect, a distal end 250 of the outer tube can be threaded to engage complementary threads on a portion of the outer casing. In a further aspect, an internal diameter of the outer tube 235 can be substantially the same as an internal diameter of the outer casing, and/or the external diameter of the outer tube can be substantially the same as the external diameter of the outer casing. In one aspect, a proximal end 255 of the outer tube 235 can be configured to couple to a discharge head 260 .
[0038] In another aspect, an outer tube inlet 265 can be defined in a portion of the outer tube 235 of the sonic air lift tooling system 210 . In this aspect, the outer tube inlet can be a boss configured to place an inner volume 270 of the outer tube in fluid communication with a source of pressurized fluid, such as air, and the like.
[0039] The inner tube 240 of the sonic air lift tooling system 210 can be sized such that at least a portion of the inner tube can be positioned in the inner volume 270 of the outer tube 235 . For example, at least a portion of the inner tube can have an outer diameter 275 of less than about 4 inches, about 4 inches, about 5 inches, about 6 inches, about 7 inches, or greater than about 7 inches. In one aspect, the outer diameter of the inner tube 240 can be sized so that, when the inner tube is positioned in the inner volume 270 of the outer tube 235 , an annular void 277 is defined between the outer tube and the inner tube 240 . In another aspect, a proximal end 280 of the inner tube can be configured to couple to the discharge head 260 such that an interior conduit 285 of the inner tube is in fluid communication with an inner conduit 290 of the discharge head.
[0040] A distal end 295 of the inner tube 240 can be open such that a fluid can enter or exit the interior conduit of the inner tube. In one aspect, the distal end of the inner tube can define a plurality of holes 300 . In this aspect, at least one hole of the plurality of holes can be angled from the center of the inner tube upwardly towards the outer diameter 275 of the inner tube 240 . That is, the longitudinal axis L H of the at least one hole can be at an acute angle relative to the longitudinal axis L I of the inner tube. For example, an angle formed between the longitudinal axis L I of the inner tube and the longitudinal axis L H of the at least one hole 300 can be about 10 degrees, about 20 degrees, about 30 degrees, about 40 degrees, about 45 degrees, about 50 degrees, about 60 degrees, about 70 degrees, about 80 degrees, or about 90 degrees. In still another aspect, each hole of the plurality of holes can have a hole diameter of less than 0.25 inches, about 0.25 inches, about 0.50 inches, about 0.75 inches, about 1.0 inches, or greater than about 1 inch.
[0041] A central portion 305 of the inner tube 240 can connect the distal end 295 of the inner tube to the proximal end 280 of the inner tube. As can be appreciated, the central portion can have a length configured so that the proximal end of the inner tube 240 is positioned above the surface 105 of the formation 170 and the distal end of the inner tube is positioned in the borehole 180 at a desired depth, described more fully below. For example, the central portion 305 of the inner tube can comprise a plurality of inner tube sections that can be coupled together at the surface to form an inner tube having the desired length.
[0042] In one aspect, the discharge head 260 can be sized and configured so that material removed from the borehole 180 through the sonic air lift tooling system 210 can be redirected to the discharge tank 230 . For example, material removed from the borehole can be urged through the interior conduit 285 of the inner tube, through the inner conduit 290 of the discharge head and to the discharge tank. In one aspect, at least a portion of the discharge head can have a diameter of about 3 inches, about 4 inches, about 5 inches, about 6 inches, about 7 inches, or greater than about 7 inches. It is contemplated that a variety of flanges, gaskets, fasteners, adapters and the like can be provided to couple portions of the sonic air lift tooling system and/or the discharge head together as necessary.
[0043] The discharge tank 230 , illustrated in FIGS. 5 and 6 , can be a tank configured to hold a liquid, such as water. In one aspect, the discharge tank can comprise a recirculation baffle plate 232 . The recirculation baffle plate can allow water to flow over the plate while restricting the flow of solids, such as a desired material 340 , from passing over the plate. Thus, the recirculation baffle plate 232 can at least partially separate the desired material from water or other fluid it can become mixed with. In another aspect, the discharge tank can further comprise a recirculation line 234 . In this aspect, the recirculation line can place the discharge tank in fluid communication with the outer tube inlet 265 of the sonic air lift tooling system 210 so that water from the discharge tank can be selectively directed to the inner volume 270 of the outer tube 235 . Optionally, the discharge tank can further comprise at least one of a cyclone 231 and a backhoe 233 , as known in the art, configured to further separate and/or remove the desired material from the fluid in the discharge tank. It is of course contemplated that the discharge tank 230 can further comprise at least one overflow drain, flow meter, valve and the like as necessary to process water discharged from and/or injected into the material removal system 200 .
[0044] Referring now to FIGS. 3 and 4 , in order to remove subsurface materials using sonic drilling techniques, a borehole 180 can be formed as in conventional sonic drilling. For example, a target drilling zone can be identified through obtaining sonic samples of geological formations 170 . In one aspect, the outer casing 190 and/or the core barrel can be advanced through any overburden material 335 and the desired material 340 until a lower layer 345 of the desired material is reached. As can be appreciated, sonic technology allows for the installation of the outer casing to the lower layer of the desired geological formation without the use of drilling fluids or disturbance to the target geological formation around the borehole (i.e., the area around the borehole can remain substantially intact until the mining process commences). Further, sonic drilling technology can accurately identify the bottom of the desired geological formation so that the outer casing 190 can be properly positioned.
[0045] Upon locating the lower layer 345 of the desired material 340 , a portion of the outer casing 190 can be retracted from the borehole 180 . In one aspect, the outer casing can be retracted from the borehole a predetermined distance, such 1 foot, 2 feet, 3 feet and the like. In another aspect, the outer casing 190 can be retracted from the borehole until a distal end 320 of the outer casing is positioned a predetermined distance from the lower layer 345 and/or an upper layer 350 of the desired material. For example, the distal end of the outer casing can be positioned just below the upper layer of the desired material. In still another aspect, the distal end 320 of the outer casing can be positioned at any location between the upper and lower layers of the desired material. If the desired material 340 is a flowing material, such as, for example and without limitation, quartz or sand containing ore, upon retraction of the outer casing 190 the predetermined distance, the desired material can at least partially flow into the open borehole 180 .
[0046] After the desired material has been located using the sonic drilling system 100 , at least a portion of the sonic drilling system can be removed and replaced with the material removal system 200 . Thus, at least a portion of the material removal system can be inserted into the same borehole 180 that was drilled to identify the location of the desired material 340 . ( FIG. 4 illustrates separate boreholes for clarity).
[0047] In one aspect, the outer tube 235 of the sonic air lift tooling system 210 can be coupled to an upper portion 355 of the outer casing 190 . After placing the distal end 320 of the outer casing in the predetermined position relative to the lower layer 345 and/or the upper layer 350 of the desired material 340 , the desired material can be removed from the borehole 180 using a plurality of removal methods, such as, for example and without limitation, a direct reverse lift method 420 , and a flooded reverse lift method 430 , illustrated in FIGS. 5-6 respectively.
[0048] As illustrated in FIG. 5 , the direct reverse lift method 420 comprises injecting a pressurized fluid, such as air, water and the like through the outer tube inlet 265 of the outer tube 235 . For example, a compressor 405 can urge pressurized air from above the surface 105 of the formation 170 through the annular void 277 defined between the outer tube/outer casing 190 and the inner tube 240 so that the pressurized fluid travels around the distal end 295 of the inner tube. Upon reaching the distal end of the inner tube, at least a portion of the pressurized fluid can pass through at least one hole 300 of the plurality of holes of the inner tube. As the distal end 320 of the outer casing 190 is typically below the water line 407 (i.e., at least portions of the borehole 180 and the interior conduit 285 of the inner tube 240 are filled with ground water), the pressurized fluid can bubble up through the ground water towards the surface. In one aspect, portions of the desired material 340 , such as for example and without limitation, sand, can become entrained in the pressurized fluid as it bubbles up through the interior conduit 285 of the inner tube and can be carried towards the surface 105 . Upon reaching the proximal end 280 of the inner tube, the portions of the desired material can be urged through the discharge head 260 to the discharge tank 230 for collection.
[0049] The flooded reverse lift method 430 comprises injecting a pressurized first fluid, such as air and the like through the outer tube inlet 265 of the outer tube 235 . For example, a compressor 405 can urge pressurized air from above the surface 105 of the formation 170 through the annular void 277 defined between the outer tube/outer casing 190 and the inner tube 240 . A second fluid, for example and without limitation, water, can also be injected into the outer casing so that the annular void defined between the inner tube and the outer casing is at least partially filled with a combination of the first and second fluids. In one aspect, water injected into the outer tube 235 can be water recycled from the discharge tank 230 . The pressurized first fluid can travel down the annular void towards the distal end 295 of the inner tube. Upon reaching the distal end of the inner tube, at least a portion of the first pressurized fluid can pass through at least one hole 300 of the plurality of holes of the inner tube. As the distal end of the inner tube 240 is below the water line 407 (i.e., at least portions of the borehole 180 and the interior conduit 285 of the inner tube can be filled with ground water and/or the second fluid), the pressurized first fluid can bubble up through the water in the inner tube towards the surface 105 . In one aspect, portions of the desired material 340 , such as for example and without limitation, sand, can become entrained in the first fluid as it bubbles up through the interior conduit 285 of the inner tube and can be carried towards the surface. Upon reaching the proximal end 280 of the inner tube, the portions of the desired material can be urged through the discharge head 260 to the discharge tank 230 for collection.
[0050] Regardless of the lifting method used, if at any time the desired material 340 is no longer being brought to the surface 105 at a desired rate, in one aspect, the distal end 320 of the outer casing 190 can be adjusted to a different predetermined from the lower layer 345 and/or an upper layer 350 of the desired material. For example, if a low level of desired material is being extracted from the borehole 180 , the outer casing can be lowered so that the distal end of the outer casing is adjusted to a different predetermined distance from the lower layer of the desired material 340 .
[0051] The methods and systems described above require no particular component or function. Thus, any described component or function—despite its advantages—is optional. Also, some or all of the described components and functions described above may be used in connection with any number of other suitable components and functions.
[0052] Although several embodiments of the invention have been disclosed in the foregoing specification, it is understood by those skilled in the art that many modifications and other embodiments of the invention will come to mind to which the invention pertains, having the benefit of the teaching presented in the foregoing description and associated drawings. It is thus understood that the invention is not limited to the specific embodiments disclosed hereinabove, and that many modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although specific terms are employed herein, as well as in the claims which follow, they are used only in a generic and descriptive sense, and not for the purposes of limiting the described invention, nor the claims which follow. | A system for removing desired subsurface materials. A drilling system has a sonic drill head assembly capable of rotating a drill string and transmitting oscillating forces to the drill string. A material removal system comprises an outer tube attachable to the drill string. An inner tube has an outer diameter sized so that that at least a portion of the inner tube is positionable in an inner volume of the outer tube with an annular void defined between the outer tube and the inner tube. A distal end of the inner tube defines at least one opening such that an interior conduit of the inner tube is in fluid communication with the annular void outside of the distal end of the inner tube. Pressurized fluid can be urged from the annular void through the opening to the interior conduit, entraining the desired subsurface materials therein for removal to a discharge tank. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of constraining by dynamic production data a fine geologic model representative of the distribution, in a heterogeneous reservoir, of a physical quantity characteristic of the subsoil structure, such as permeability or porosity.
2. Description of the Prior Art
The prior art to which reference is made hereafter is described in the following publications:
Wen, X.-H., et al.: “Upscaling hydraulic conductivities in heterogeneous media: An overview. Journal of Hydrology (183)”, ix-xxxii, 1996;
Renard, P.: “Modélisation des écoulements en milieux poreux hétérogénes: calcul des perméabilités équivalentes”. Thése, Ecole des Mines de Paris, Paris, 1999;
G. de Marsily: “De I'identification des systemes hydrologiques”. Thése, Université Paris 6, Paris, 1976;
Hu L.-Y. et al.: “Constraining a Reservoir Facies Model to Dynamic Data Using a Gradual Deformation Method”, VI European Conference on the Mathematics of Oil Recovery, Peebles, 1998;
Tarantola, A.: “Inverse Problem Theory: Method for Data Fitting and Model Parameter Estimation”. Elsevier, Amsterdam, 1987;
Anterion F. et al.: “Use of Parameter Gradients for Reservoir History Matching”, SPE 18433, Symposium on Reservoir Simulation of the Society of Petroleum Engineers, Houston, 1989;
Wen X.-H. et al.: “High Resolution Reservoir Models Integrating Multiple-Well Production Data”, SPE 38728, Annual Technical Conference and Exhibition of the Society of Petroleum Engineers, San Antonio, 1997;
Chu L. et al. : “Computation of Sensitivity Coefficients With Application to the Integration of Static and Well Test Pressure Data”, Eclipse International Forum, Milan, 1994.
Numerical simulations of flow models are widely used in the petroleum industry to develop a reservoir and to predict its dynamic behavior according to various production scenarios. The geostatistical models used to represent the geologic structure of the reservoir (permeability, porosity, etc.) require an identification of a large number of grid cells that can reach about ten millions.
To be able to carry out numerical flow simulations within reasonable computing times, common practice consists in constructing a rough simulation model by grouping together grids with different properties into macrogrids and by assigning to the macrogrids an equivalent property calculated from the local properties. This operation is referred to as upscaling.
The aim of constrained reservoir characterization is to determine the parameters of the simulation model so that the latter can reproduce the production data of the reservoir to be modelled. This parameter estimation stage is also referred to as production data fitting. The flow simulation model is thus compatible with all of the available static and dynamic data.
In common practice, the parameters of the simulation model are estimated by means of a series of trials and errors using the flow simulator.
The problem of production data fitting can also be formulated as a problem of minimizing an objective function measuring the difference between the production data observed in the field and the predictions provided by the flow simulator. Minimizing is then carried out using optimization or optimum control techniques.
A method of predicting, by means of an inversion technique, the evolution of the production of an underground reservoir, notably of a reservoir containing hydrocarbons, is for example described in U.S. Pat. No. 5,764,515 filed by the assignee.
As soon as the parameters of the simulation model are adjusted, this model can be used to simulate the present and future behavior of the reservoir. An evaluation of the in-situ reserves is thus available and a development scheme optimizing the production can be determined.
Constrained reservoir characterization thus involves multiple techniques, from geostatistical modeling to optimization problems. The introduction of the main techniques used within the scope of the “inversion and upscaling” coupling methodology is dealt with in the section hereafter.
Geostatistical Modelling
Geostatistics, in its probabilistic presentation, implies that a spatial variable such as the permeability, for example, can be interpreted as a particular realization of a random function, defined by its probability law at any point in space. The increasingly common use of geostatistics by oil companies leads to the construction of fine models that can reach a large number of grid cells, In fact, geostatistics allows estimation of petrophysical properties in space from local measurements. Strictly speaking, realization of the geostatistical model has to be carried out on the scale of the measurement support, and the model thus obtained can then reach several million grid cells. Numerical flow simulation on the scale of the geostatistical model is not conceivable with the power of current computers. In order to reduce the number of grids, the grids have to be grouped together, which requires computation of the equivalent properties of the new grids as a function of the properties of the small-scale grids. This operation is referred to as upscaling.
Upscaling
Computation of the equivalent permeability of heterogeneous porous media has been widely studied by the community of geologists, reservoir engineers and more generally of porous media physicists.
From a mathematical point of view, the process of upscaling each directional permeability can be represented by the vectorial operator F defined by:
F :R m→R M k→K (1)
k: the permeability on the scale of the geostatistical model (dimension R m ); K:the permeability on the scale of the flow simulation model (dimension R M ).
Wen et al. (1997) and Renard (1999), mentioned above, gave a review of the existing techniques from the prior art. Examples of known upscaling techniques are algebraic methods which involve simple analytical rules for plausible calculation of the equivalent permeabilities without solving a flow problem. The known method referred to as “power average” technique can be selected for example. The permeability K of block Ω is equal to a power average, also called average of order w , whose exponent w ranges between −1 and +1: K ( w ) = ( 1 mes ( Ω ) ∫ Ω k w Ω ) 1 / w ( 2 )
The problem of the equivalent permeability calculation thus comes down to the estimation of the exponent w allowing minimization of the error induced by upscaling (defined according to a certain criterion). For media with an isotropic log-normal distribution and a low correlation length, it is well-known that: w = 1 - 2 α ( 3 )
α being the dimension in space (α=1, 2 or 3).
There are also known numerical upscaling techniques wherein calculation of the equivalent permeability involves solving the pressure p and velocity v fields of a local or global flow problem: { - k μ ∇ p = v dans Ω div ( v ) = 0 dans Ω ( 4 )
μ denotes the viscosity of the flowing fluid.
Parameterization
The problem of geologic model updating by means of dynamic data is based on the solution of an inverse problem. This naturally poses the problem of the parameterization of the permeability field in order to allow minimization of the objective function which measures the difference (in the sense of the least squares) between the dynamic data observed in the field and the simulation results.
Parameterization of geostatistical models is a fundamental point which guarantees the success of the integration of the dynamic data into the geologic models. In fact, this integration is carried out according to an iterative procedure governed by the optimization process and disturbs an initial permeability field representative of the geostatistical model considered.
Ideally, the final permeability field must not only respect all the dynamic data taken into account in the objective function, but also must preserve the geostatistical coherence of the model (average, variogram, etc.). Observance of the dynamic data is controlled by the objective function whose value is an evaluation of the data fitting quality. Concerning the coherence of the geostatistical data, it is the parameterization of the permeability field that allows control thereof.
A known technique allowing this parameterization to be carried out is the pilot point method, which is based on the principle of the conditional geostatistical simulation applied to the Gaussian type models, described for example by de Marsily (1976) as mentioned above.
Another known technique allowing this parameterization to be carried out is the gradual deformation method. As described by Hu et al. (1998), as well as in French patents 2,780,798 and 2,795,841 and in French patent application EN-01/03,194 filed by the assignee, the gradual deformation method writes a new realization of the permeability field to be estimated, assumed to be of Gaussian type which is a linear combination of realizations independent of the random function modeling the permeability field. Permeability field k is therefore given by: k ( θ ) = ∑ i = 1 n θ i k i ( 5 )
(θ i ) 1≦i≦n : the coefficients of the linear combination, and
(k i ) 1≦i≦n : the independent realizations of the geostatistical model considered.
In order to preserve the geostatistical properties of the model, coefficients θ must meet the normality constraint as follows: ∑ i = 1 n θ i 2 = 1 ( 6 )
Coefficients θ are estimated so that the resulting permeability field k(θ) best reproduces the dynamic data.
Unlike the pilot point method, the gradual deformation method can be applied locally or globally. Strict observance of the geostatistical properties of the model is guaranteed by respecting the normality constraint (Equation 6) without introducing an a priori model in the objective function.
Objective Function
Updating a geologic model with dynamic data is based on the minimization of an objective function which measures the difference between the dynamic data observed in the field and the simulation results obtained for a set value of parameters θ.
Several formulations are possible to define an objective function. The formulation in the sense of the least squares is the most commonly used in the petroleum field. The objective function is thus expressed as follows: J 1 ( θ ) = 1 2 ( d obs - D ( θ ) ) T C d - 1 ( d obs - D ( θ ) ) ( 7 )
with:
d obs : the dynamic data observed in the field,
D(θ): the simulation results for the set value of parameters θ,
C d : the covariance matrix on the observations.
As described by Tarantola (1987), a formulation better suited to the solution of improperly expressed inverse problems adds a regularization term (a priori model) in the objective function: J 1 ( θ ) = 1 2 ( d obs - D ( θ ) ) T C d - 1 ( d obs - D ( θ ) ) + 1 2 ( θ - θ pri ) T C θ - 1 ( θ - θ pri ) ( 8 )
with:
θ pri : a priori estimation of parameters θ,
C θ : the covariance matrix on the parameters.
The latter formulation of the objective function has a probabilistic interpretation. In fact, in the context of a Bayesian inversion, the a priori model is given by a probability density function of any law.
For an a priori model of Gaussian law, of average θ pri and of covariance C θ , this probability density function is written as follows: f Θ ( θ ) ∝ exp { - 1 2 ( θ - θ pri ) T C θ - 1 ( θ - θ pri ) } ( 9 )
In the same context, the probability of obtaining observations d obs knowing the value of parameters θ, or likelihood function, can then be expressed in the following form: f D / Θ ( D = d obs / θ ) ∝ exp { - 1 2 ( d obs - D ( θ ) ) T C d - 1 ( d obs - D ( θ ) ) } ( 10 )
When the flow simulation operator D is linear in relation to parameters θ, the a posteriori probability density function still is of Gaussian law.
Minimization of objective function J 1 requires calculation of the derivatives of the simulation results in relation to the parameters to be estimated, i.e.: ∂ D ∂ θ ( θ ) ( 11 )
This calculation of the derivatives, essential for carrying out the minimization process under the best conditions, has been the subject of considerable work. A synthesis of the minimization process is given in the aforementioned article by Chu et al. (1994).
To date, two methods are essentially used in the petroleum industry: the numerical gradients and the gradients method. Considering its qualities in terms of numerical stability and rapidity, the gradients method has been selected for the calculation of the simulation result derivatives in relation to the parameterization of the fine geostatistical model.
The use of small letters refers to the fine geostatistical model and the use of capital letters refers to the rough simulation model. By way of example:
k denotes the permeability field on the scale of the geostatistical model, whereas K denotes the permeability field on the scale of the flow simulation model (after upscaling);
d denotes the simulation results obtained from the fine geostatistical model, whereas D denotes the simulation results obtained by means of the rough simulation model (after upscaling).
Calculation of the Derivatives—Gradients Method
The gradients method allows calculation of the derivatives of the results of a numerical flow simulation in relation to a certain number of parameters involved in the simulation model. By way of example, it is possible to calculate the derivatives of the main production results (pressure, saturation, flow rate, etc.) in relation to the petrophysical properties (permeability, porosity, etc.) assigned to zones of the reservoir.
The gradients method is based on the derivation of the defined equations of the flow model as described by Antérion et al. (1989) mentioned above. These defined equations have the form of a system of non-linear equations of the following type: { U 0 = U ini F ( θ , U n , U n + 1 ) = 0 ( 12 )
θ: the parameters to be estimated,
U ini : initialization of the unknowns to be simulated. This initialization is calculated from the initial conditions of the partial differential equation system modelling the flow,
U n : the simulation unknowns calculated at the time t n ,
U n+1 : the simulation unknowns calculated at the time t n+1 .
System ( 12 ) is non-linear and is generally solved by means of the Newton method based on successive linearizations of non-linear system ( 12 ) as follows: { U ( 0 ) = U n ∂ F ∂ U n + 1 ( θ , U n , U ( k ) ) ( U ( k + 1 ) - U ( k ) ) = - F ( θ , U n , U ( k ) ) ( 13 )
Calculation of the derivatives of the simulation results in relation to the parameterization θ is based on the direct derivation of system ( 12 ). A new linear system, whose unknowns are the derivatives ∂U n+1 /∂θ, results from this derivation. For each parameter θ i , this system is expressed in the following form: { ∂ U 0 ∂ θ i = ∂ U ini ∂ θ i ∂ F ∂ U n + 1 ( θ , U n , U n + 1 ) ∂ U n + 1 ∂ θ i + ∂ F ∂ U n ( θ , U n , U n + 1 ) ∂ U n ∂ θ i + ∂ F ∂ θ i ( θ , U n , U n + 1 ) = 0 ( 14 )
The matrix of the linear system is given by the term: [ ∂ F ∂ U n + 1 ( θ , U n , U n + 1 ) ] ( 15 )
It is the Newton matrix of system ( 13 ) at the final iteration. The second member of this linear system is given by the term: [ - ∂ F ∂ U n ( θ , U n , U n + 1 ) ∂ U n ∂ θ i - ∂ F ∂ θ i ( θ , U n , U n + 1 ) ] ( 16 )
The solution of this linear system (a second member per parameter) allows obtaining all the derivatives of the simulation unknowns U in relation to the desired parameterization.
By composite derivation, it is possible to express the derivatives of the main production results D in relation to the parameterization ∂ D ∂ θ = ∂ D ∂ U ∂ U ∂ θ ( 17 )
Optimization Techniques
The non-linear optimization algorithms allow calculation, according to an iterative process, of a value θ opt of parameters θ which minimizes (locally or globally) the objective function J 1 to be optimized.
The simulation results from the distribution k(θ opt ) must allow better dynamic data fitting than those obtained from the initial distribution k(θ (0) ). θ (0) denotes the value of the parameters θ used to initiate the optimization process.
The objective of the iteration (k+ 1 ) of such an optimization algorithm is to determine a new estimation of parameters θ according to the following principle:
θ (k+1) =θ (k) +t (k) s (k) (18)
Calculation of a direction: direction s (k) is the solution to a certain problem linearized at θ (k) . The formulation of this linearized problem is based on the simulation results and on their derivatives in relation to the parameterization considered. Let: D ( θ ( k ) ) and ∂ D ( θ ( k ) ) ∂ θ ( 19 )
Linear seeking: interval t (k) is calculated so as to meet the descent relation:
J 1 (θhu (k) +t (k) s (k) )< J 1 (θ (k) ) (20)
Various optimization methods are used in the petroleum industry. Examples thereof are the deepest descent method, the Fletcher-Powell method, the Levenberg-Marquardt method and the Gauss-Newton method, which are all well-known in the art.
Updating a geologic model by dynamic data is based on the combination of various methods and techniques that are discussed above. When the geostatistical model has a reasonable size, the inversion can be carried out directly thereon without using upscaling techniques. In this context, updating is carried according to the procedure illustrated in FIG. 2 .
However, when the size of the geostatistical model is too large to be used directly in the flow simulator, the use of an upscaling technique becomes mandatory. The goal of upscaling is to carry out the flow simulations on a simulation model of reduced size (referred to as rough model), thus allowing obtaining of the simulation results within a reasonable time limit. In common practice, data fitting is carried out on the rough simulation model and not on the geostatistical model. The general principle of this inversion is illustrated in FIG. 3 .
Unfortunately, upon convergence of the optimization process, only the simulation model is modified and it is very difficult to return to the underlying fine geostatistical model. In fact, during the inversion process, the coherence between the initial geologic model and the simulation model is not maintained. To overcome this problem, downscaling techniques have been worked out. The aim is to determine a geologic model compatible with the constrained simulation model.
These downscaling techniques are quite substantial from a numerical point of view, in particular when the geologic model is rather large in size. They do not always allow returning from the simulation scale to the geologic scale while respecting the geostatistical constraints. Furthermore, the major drawback of these techniques is that they do not guarantee that the fine geostatistical model obtained with the downscaling technique allows respecting the dynamic data (via a flow simulation on this fine model or on a simulation model after scaling).
The many publications dealing with the problem of large geologic model fitting, including notably the aforementioned publication by Wen et al. (1997), highlight the need for a new methodology for direct updating of the fine geologic model.
SUMMARY OF THE INVENTION
The method according to the invention allows updating, by the dynamic production data, a fine geologic model representative of the distribution in the reservoir of a physical quantity characteristic of the subsoil structure (the permeability or the porosity of the reservoir rocks for example).
The method provides reservoir engineers with a methodology allowing efficient updating of geologic models as dynamic data are acquired.
The method according to the invention allows direct updating, by dynamic data, of a geologic model discretized by of a fine grid pattern representative of the distribution, in an underground reservoir, of a physical quantity characteristic of the subsoil structure: the permeability (k), the porosity (Φ), etc. It comprises:
parameterization of the fine geologic model by a parameterization factor (θ) in order to obtain the distribution of the physical quantity in this geologic model
upscaling so as to determine the distribution of the physical quantity in a simulation model defined by a rough grid pattern;
solution, via the simulation model, of fluid flow equations to obtain simulated dynamic data ; and
determination of the analytical relations connecting variations of the simulated dynamic data and corresponding variations of parameterization factor (θ).
According to an implementation mode, the analytical relations connecting the variations of the simulated dynamic data and the corresponding variations of the parameterization factor of the fine geologic model are determined by combining the derivatives of the simulated dynamic data in relation to the parameterization factor on the scale of the simulation model and the derivatives of the parameterization factor of the simulation model in relation to the parameterization factor of the fine geologic model.
The simulation model is preferably first calibrated in order to reduce the error induced by upscaling, for example by carrying out the following operations:
an a priori fine geologic model representative of the model studied is selected (calibration model);
first simulation results compatible with this a priori model are directly determined;
a simulation model is determined by upscaling the fine geologic model;
second simulation results compatible with the simulation model formed, depending on upscaling parameters (c) and on simulation parameters (s), are directly determined;
calibration parameters (c, s) related to upscaling and simulation are adjusted so that the simulation results obtained from the a priori model and the simulation model are compatible.
The dynamic data are for example production data such as the pressure, the gas-oil ratio (GOR) or the fraction of water in oil.
According to an implementation mode, the parameterization parameter is selected by means of a gradual deformation or a pilot point technique.
According to an implementation mode, upscaling is carried out by means of an analytical method of a power average type or by means of a numerical method by solving a local or global flow problem.
In other words, the method according to the invention essentially includes two independent stages that can be used in an iterative process: a calibration stage and a fitting stage.
The goal of the calibration stage is to reduce the error induced by the upscaling procedure carried out to perform the flow simulation. Good calibration guarantees coherence between the fine geologic model (defined by a fine grid) and the simulation model in terms of flow. This is essential to allow reproduction of the fitting already obtained with the simulation model using the underlying fine geologic model or a rougher simulation model (modelled by a grid with larger grid cells) obtained after a new scaling operation. The calibration method of the invention is based on history matching techniques. The data to be fitted are no longer the dynamic data observed in the field, but the results of a reference simulation carried out on a given geologic model representative of the geostatistical model studied. Calibration is carried out using the simulation model obtained after scaling the reference geologic model.
The main objective of fitting is to constrain, by means of the dynamic data, directly the fine geologic model and not the simulation model. Direct parameterization of the fine geologic model is therefore performed. Upscaling is carried out on the geologic model after parameterization. Fitting involves, for example, calculation of the derivatives of the simulation results in relation to the parameterization on the scale of the fine geologic model. This allows a conventional optimization process to be used in order to directly update the fine geologic model.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the method according to the invention will be clear from reading the description hereafter of a non-limitative example, with reference to the accompanying drawings wherein:
FIG. 1 shows an upscaling domain,
FIG. 2 shows updating of the geostatistical model by direct inversion,
FIG. 3 shows updating of the simulation model after upscaling,
FIG. 4 shows the derivatives of the simulation results in relation to the parameterization of the geostatistical model,
FIG. 5 shows a general diagram of the fitting stage,
FIG. 6 shows a validation of the pressure gradient in relation to a gradual deformation parameter (production well),
FIG. 7 shows a validation of the pressure gradient in relation to a gradual deformation parameter (observation well),
FIG. 8 shows a general diagram of the calibration stage,
FIG. 9 shows a general diagram of the coupling methodology,
FIG. 10 shows a flow rate record,
FIG. 11 shows a reference geostatistical model,
FIGS. 12A to 12 E show a record of the observed bottomhole pressures,
FIG. 13 shows an initial geostatistical model,
FIGS. 14A to 14 E show a comparison between the calibration pressures and the simulation results before calibration,
FIGS. 15A to 15 E show a comparison between the calibration pressures and the simulation results after calibration,
FIG. 16 shows a constrained geostatistical model,
FIG. 17 shows a comparative table of the computing times which illustrates the significance of the method,
FIGS. 18A to 18 E show a comparison between the pressure data and the initial simulation results,
FIGS. 19A to 19 E show a comparison between the pressure data and the simulation results after fitting, and
FIGS. 20A to 20 C show bar graphs of the reference, initial and constrained geostatistical models respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The inversion and upscaling coupling method according to the invention comprises two independent stages which can be used in an iterative process: a fitting stage that can be advantageously completed by a prior calibration stage.
The objective of the fitting stage is to constrain, by the dynamic data directly, the fine geologic model and not the simulation model as was common practice to date. Direct parameterization of the geologic model is therefore carried out.
Upscaling is carried out on the geologic model after parameterization (FIG. 4 ). This fitting stage involves calculation of the derivatives of the simulation results in relation to the parameterization on the scale of the fine geologic model. This allows a conventional optimization process to be used in order to directly update the fine geologic model.
In order to highlight the key points of the method, the fitting stage is described. The calibration stage and the iterative procedure of the methodology is described thereafter.
1—Fitting Stage: Inversion & Upscalinq Coupling
In the method, upscaling is considered to be an integral part of the parameterization operation and not a preprocessing tool for the flow simulator, so that updating is performed directly on the fine geologic model and not on the rough simulation model.
1.1—Parameterization
The new parameterization is obtained by the composition of a conventional parameterization obtained with known techniques referred to as pilot point or gradual deformation techniques, already mentioned above, with an upscaling technique (FIG. 4 ): θ → Conventional parameterization k ( θ ) → Upscaling K ( θ ) ( 21 )
Direct updating of the geostatistical model by the dynamic production data requires computation of the derivatives of the simulation results in relation to the parameterization presented above. In order to be able to compute these derivatives, it is necessary first to compute the derivatives of the simulation model in relation to the parameterization (FIG. 4 ): θ → Conventional parameterization ∂ k ∂ θ ( θ ) → Upscaling ∂ K ∂ θ ( θ ) ( 22 )
These derivatives are obtained by means of a composite derivation technique (FIG. 4 ). For each parameter θ i , the following relation is used ∂ K l ∂ θ i ( θ ) = ∑ j ∂ K l ∂ k j ( θ ) ∂ k j ∂ θ i ( θ ) ( 23 )
1.2—Gradients method—Composite Derivation
Once all these derivatives have been calculated, it is possible to deduce the derivatives of the simulation results in relation to the parameterization from Equation 22: { ∂ U 0 ∂ θ i = ∂ U ini ∂ θ i ∂ F ∂ U n + 1 ( θ , U n , U n + 1 ) ∂ U n + 1 ∂ θ i + ∂ F ∂ U n ( θ , U n , U n + 1 ) ∂ U n ∂ θ i + ∂ F ∂ θ i ( θ , U n , U n + 1 ) = 0 ( 24 )
with: ∂ F l ∂ θ i ( θ , U n , U n + 1 ) = ∑ j ∂ F l ∂ K j ( θ , U n , U n + 1 ) ∂ K j ∂ θ i ( θ , U n , U n + 1 ) ( 25 )
The derivatives of the simulation results in relation to the parameterization is used by the inversion algorithm to compute an optimum parameter set θ opt allowing better fitting of the dynamic data than the initial parameter set θ (0) .
The general procedure of this fitting stage is illustrated in FIG. 5 .
1.3—Computer Implementation : Single-phase Context
All the algorithms allowing use of the methodology according to FIGS. 5 and 7 for the calibration and fitting stages have been developed within the framework of a generalized inversion loop.
In particular, in a single-phase context, the analytical calculation of the bottomhole pressure derivatives in relation to the parameterization of the geostatistical model has been developed and integrated, in a research version, in a flow simulator. The software essentially consists of two modules: a static module for preparation of the simulation model and a dynamic module for flow simulation.
1.3.1 Static Module
The parameterization of the fine geostatistical model and the upscaling process are carried out in this module. The module provides the rough simulation model K(θ) (Equation 21) as well as its derivatives in relation to the parameterization of the geostatistical model (Equation 22). A simple illustration of this module can be summarized as follows:
Parameterization by means of the gradual deformation method (a single parameter) of the geostatistical model amounts to:
k ( i )=sin(θ) k 1 ( i )+cos(θ) k 2 ( i ) (26)
Upscaling with the aforementioned power average method provides the permeability distribution of the simulation model: K ( I ) = ( 1 n i ∑ i = 1 n i k ( i ) w ) 1 / w ( 27 )
Composite derivation of Equation (27) gives the derivatives of the permeabilities of the simulation model in relation to the parameterization of the geostatistical model. These derivatives are given by: ∂ ∂ θ K ( I ) = ( K ( I ) 1 - w n i ∑ i = 1 n i k ( i ) w - 1 ∂ ∂ θ k ( i ) ) ( 28 )
Term ∂ ∂ θ k ( i )
results from the derivation of Equation (26): ∂ ∂ θ k ( i ) = - cos ( θ ) k 1 ( i ) + sin ( θ ) k 2 ( i ) ( 29 )
Let: ∂ ∂ θ K ( I ) = ( K ( I ) 1 - w n i ∑ i = 1 n i k ( i ) w - 1 ( - cos ( θ ) k 1 ( i ) + sin ( θ ) k 2 ( i ) ) ) ( 30 )
The results of Equations (27) and (30) are essential for an analytical computation of the bottomhole pressure gradients in relation to parameter θ. They are stored for the dynamic module.
1.3.2 Dynamic Module
In the case of a single-phase flow of a substantially compressible fluid, a defined equation which governs the evolution of the pressure in the reservoir is given by: c φ I v I P I ( n + 1 ) - P I ( n ) t ( n + 1 ) - t ( n ) - 1 μ ∑ υ ( I ) T I υ ( I ) ( P υ ( I ) ( n + 1 ) - P I ( n + 1 ) ) = ∑ J δ IJ Q J ( n + 1 ) ( 31 )
The transmissivity T Iν(I) between grid cell I and a neighboring grid cell ν(I) is given by: T Iiυ ( I ) = α 1 K ( I ) K ( υ ( I ) ) α 2 K ( I ) + α 3 K ( υ ( I ) ) ( 32 )
Coefficients α 1 , α 2 and α 3 are functions of the geometry of grid cells I and ν(I).
Applying the gradients method to Equation (31) (by deriving it in relation to θ) allows calculation of the bottomhole pressure derivatives in relation to this parameter: c φ I v I t ( n + 1 ) - t ( n ) ( ∂ P I ( n + 1 ) ∂ θ - ∂ P I ( n ) ∂ θ ) - ∑ υ ( I ) T I υ ( I ) μ ( ∂ P υ I ( n + 1 ) ∂ θ - ∂ P I ( n + 1 ) ∂ θ ) = ∑ υ I ∂ T I υ ( I ) ∂ θ ( P υ ( I ) ( n + 1 ) μ - P I ( n + 1 ) μ ) ( 33 )
Solution of Equation (33) requires, for each parameter θ, calculation of the corresponding second member. The results of the static module are used to calculate this second member: ∂ T I υ ( I ) ∂ θ = α 1 α 2 K ( I ) ∂ K ( υ ( I ) ) ∂ θ + α 1 α 2 K ( υ ( I ) ) ∂ K ( I ) ∂ θ [ α 2 K ( I ) + α 3 K ( υ ( I ) ) ] 2 ( 34 )
This calculation is completely explicated by using Equation (32) which allows calculation of the terms ∂ K ( υ ( I ) ) ∂ θ and ∂ K ( υ I ) ∂ θ .
1.4 Numerical Validation
Before using the bottomhole pressure derivatives in an inversion process, a validation of this computation has first been carried out. The simplest validation test is comparing the results obtained from the gradients method as developed herein with the results obtained by numerical gradients (centered differences).
The results (FIGS. 6 and 7) are given in a form of curves showing the evolution, during an interference test, of the derivatives of pressures in a production well and an observation well in relation to the gradual deformation parameter θ.
FIGS. 6 and 7 allow validation of the results of the derivatives that have been developed in the flow simulator used.
2.—Calibration Stage
The aim of this calibration stage is to reduce the error induced by upscaling during flow simulation. Good calibration guarantees coherence between the geologic model and the simulation model in terms of flow. This is essential to be able to reproduce the fitting already obtained with the simulation model by using the underlying fine geologic model or a simulation model obtained after a new scaling procedure.
The calibration method is based on history matching techniques. The data to be fitted are no longer the dynamic data observed in the field but the results of a reference simulation d ref carried out on a given geologic model k ref (called the reference model) representative of the studies geostatistical model.
Calibration is carried out using the simulation model obtained after scaling the reference geologic model. Within the context of the method, two types of calibration parameters are considered:
Calibration parameters relative to the upscaling process are denoted by c. In fact, for a given upscaling technique, the simulation model depends on the various options selected for applying the technique (boundary conditions, exponent of the power average, etc.). All of these numerical data constitute the calibration parameters denoted by c, relative to the upscaling procedure. The flow simulation model will of course be a function of these calibration parameters:
K ref ( c )= F ( k (θ (0) )) (35)
Calibration parameters relative to the flow simulation, are denote by s. In fact, it is conceivable to reduce the error induced by upscaling by modifying some of the parameters of the flow simulator. The goal of this modification is not to give a physical interpretation of the error induced by upscaling, but rather to minimize the consequences thereof by means of certain parameters controllable via the flow simulator.
In particular, upscaling generates a change in the numerical productivity index (IPN) of the wells. The productivity index being a function of the permeabilities: IPN = 2 π h k x k y μ ln ( r 0 rwe - s ) ( 36 )
In order to correct the modification of the numerical productivity index, it is possible, in certain cases, to artificially introduce a factor referred to as skin factor whose value is determined by calibration.
In a more general context, the calibration simulation results are therefore functions of calibration parameters c and s which the reservoir engineer considers necessary to calibrate:
D ( c,s ) (37)
After carrying out the reference simulation, it is possible to carry out the calibration parameters identification by minimizing the objective function as follows: J 2 ( c , s ) = 1 2 ( d ref - D ( c , s ) ) T C d - 1 ( d ref - D ( c , s ) ) ( 38 )
Parameters c opt and s opt resulting from this optimization are used in the fitting stage carried out after the calibration stage. The general procedure of this calibration stage is given in FIG. 8 .
As mentioned above, the goal of the calibration stage is to construct a simulation model as representative as possible of the underlying geologic model. Determination of an optimum upscaling formula (c) as well as an optimum flow simulation model (s) allows reduction of the simulation error induced by the upscaling process. The calibration stage is carried out on a given geostatistical model referred to as reference model k ref .
At the end of the fitting stage following the calibration stage, it is possible to carry out a confirmation simulation on part or all of the constrained geostatistical model so as to check the fitting quality. If the result is negative, the two calibration and fitting stages have to be repeated according to an iterative process until the convergence criteria are satisfied. The general procedure relative to this “inversion and upscaling” coupling methodology is given in FIG. 4 .
3.—Validation of the Method
A synthetic interference test has been constructed to validate the use of the methodology. This synthetic test comprises a reference geostatistical model of the permeability field, assumed to be representative of a real reservoir, and synthetic pressure data produced as a result of the flow simulation of this reference model.
During integration of the pressure data, the reference geostatistical model is assumed to be unknown. Application of the methodology presented in the previous section allows construction of a geostatistical model providing fitting of the pressure data and preserving the geostatistical properties of the reference model.
3.1—Description of the Validation Case
3.1.1 General Description
The validation case is a 3D reservoir whose horizontal extension is 4020 m×4020 m for a constant 50-m thickness having the following homogeneous petrophysical properties:
Porosity: ▭=0.3,
Horizontal anisotropy: ky/kx=1,
Vertical anisotropy: kz/kx=0.1,
Rock compressibility: c=0.0001 bar −1 ,
Viscosity: μ=1 cP.
The initial pressure of the reservoir is 200 bars (20 MPa) for an initial 10% water saturation. The compressibility of the water is 0.0000435 bar −1 , that of the oil is 0.000168 bar −1 . The total compressibility is 0.000255 bar −1 .
A 7.85-cm radius vertical producing well of zero skin factor is installed at the center of the reservoir. Its flow rate history consists of a 7-day period of 600-m 3 /day constant flow rate production, followed by a 35-day period of pressure buildup at zero flow rate (FIG. 10 ).
Four vertical observation wells perforated over all of the reservoir are arranged equidistant around the production well, perforated only over the first 30 meters of the reservoir.
3.1.2 Reference Geostatistical Model
The permeability of the reservoir is modelled by a random function of 300-mD average log-normal distribution and 300-mD standard deviation. This geostatistical model is completed by a spherical variogram with correlation lengths of 600 m, 300 m and 10 m along the principal anisotropy axes:
First axis: (1,1,0),
Second axis: (−1,1,0).
The third anisotropy axis is calculated so that the datum set formed by these three axes is orthonormal.
The geostatistical simulation grid is regular and consists of:
201 20-m grid cells along the x-axis,
201 20-m grid cells along the y-axis,
50 1-m grid cells alog the z-axis.
The total number of grid cells resulting from this defining is 2 020 050.
A reference geostatistical simulation of this model has been carried out in order to obtain the reference permeability field representative of the studies reservoir. This reference permeability field and the location of the wells are shown in FIG. 11 .
3.1.3 Reference Synthetic Data
A flow simulation is carried out for a 42-day period on the reference geostatistical model. The synthetic pressure history (FIG. 12) is defined from the results of this reference simulation by the production well bottomhole pressure, its derivative in relation to time and the bottomhole pressure of the four observation wells.
The disturbance emitted in the producing well reaches the observation wells with a delay of the order of 2 days. Only the period following this delay is taken into account for the observation wells. Concerning the production well, only the pressure buildup period and its derivative in relation to time are taken into account in the formulation of the objective function.
For the inversion stage, only the characterization of the permeabilities distribution is considered. The variogram of the reference model is assumed to be completely known (principal anisotropy directions and correlation lengths).
The permeabilities of the grid cells perforated by the five wells are also assumed to be known. These permeabilities are used for conditioning the fine geostatistical model upon each iteration of the inversion process.
3.2 Initial Geostatistical Model
The reference geostatistical model is now assumed to be unknown. Starting from a new realization (initial realization), a constrained model is determined to respect both the geostatistical properties of the reference model (in terms of average, standard deviation, variogram, etc.) and the pressure data (in terms of data fitting).
Simulation of an initial geostatistical model (FIG. 13 ), with a random seed, allows generation of an initial permeability field respecting the geostatistical properties of the reference model. However, this initial model does not allow the pressure data to be respected. In order to constrain the geostatistical model by the pressure data, the methodology presented in the previous section is applied to the initial realization.
3.3 Pressure Data Fitting
Integration of the pressure data in the initial geostatistical model has been carried out using:
the power average method for the upscaling stage;
the gradual deformation method for parameterization of the geostatistical model.
In order to best reproduce the bottomhole permeability values, integrated in the geostatistical model via a kriging stage, upscaling has not been carried out on the well grid cells (for each layer). The rough simulation model thus obtained consists of:
43 grid cells along the x-axis,
43 grid cells along the y-axis,
10 grid cells along the z-axis.
The total number of grid cells is thus 18 490, i.e. a reduction by more than 99% of the number of grid cells in relation to the geostatistical model. A reduction in the flow simulation time results from this reduction in the number of grid cells. Thus, the flow simulation on the geostatistical grid is of the order of 180 minutes against 3 minutes only on the rough grid (10-440 MHz SUN ULTRA station), that is a reduction of about 99%. A more global quantification of the (CPU time) gains provided by the methodology is presented in the next section.
As regards the gradual deformation method, a single deformation chain containing six realizations independent of the geostatistical model has been used.
3.3.1 Calibration Stage
During this calibration stage, reduction of the difference between the simulation results on the fine and on the rough grid for the initial geostatistical model (FIG. 13 ). The calibration parameters selected are:
skin factor s for producing well P 1 ;
exponent w of the upscaling formula.
In fact, there is a slight discrepancy between the results of the simulation carried out on the rough grid after upscaling using a harmonic mean (w=−1) and a zero skin factor in the producing well (the value of the physical skin factor) and those obtained on the fine grid (FIG. 14 ). This discrepancy corresponds to a value of 195 of the objective function.
During the calibration procedure, it has been possible to reduce this difference by modifying calibration parameters (s,w). Thus, by selecting an arithmetic mean for the upscaling stage (w=+1) and by introducing an artificial skin factor of −0.04, the simulation results for the rough grid after calibration are perfectly in accordance with those obtained for the fine grid (FIG. 15 ). The value of the objective function is then 10 after 5 iterations.
For this test case, the calibrated value of exponent w of the upscaling formula (w=+1) is a known result. However, this exponent was deliberately initialized at value −1 in order to validate the robustness of the calibration stage.
3.3.2 Fitting Stage
Once the calibration stage is completed, it is possible to carry out the integration of the pressure data in the initial geostatistical model. In fact, a discrepancy remains between the simulation results obtained for the rough grid, considering the calibration stage (w=+1, s=−0.004), and the pressure data (FIG. 17 ).
The objective function corresponding to this initial simulation is of the order of 112 . In order to reduce this objective function, a gradual deformation chain including six realizations independent of the geostatistical model has been constructed: k ( θ ) = ∑ i = 1 n θ i k i ( 39 )
The constrained geostatistical model (FIG. 16) has been obtained after 21 iterations with an objective function equal to 7.5.
This constrained geostatistical model allows very good fitting of the pressure data, as shown in FIG. 18 . Thus, the constrained geostatistical model allows respecting not only the pressure data, but also the geostatistical properties of the model. In particular, the experimental bar graphs corresponding to the reference, initial and constrained models are in accordance (FIG. 19 ).
3.3.3 Global Appraisal of the CPU Time Gains
In the test case presented in the previous section, about 10 CPU hours were necessary for data fitting. Updating of the geostatistical model without upscaling would have been much costlier in time since an a priori estimation of the CPU time required by such an approach is of the order of 378 hours. This CPU time is divided between the flow simulation and the computation of the gradients of the simulation results in relation to the various fitting and calibration parameters. A more detailed description of the CPU time distribution is given in Table 1.
It can thus be seen that the method according to the invention allows direct, coherent and fast updating of the geostatistical model. Direct parameterization of the fine geostatistical model, instead of that of the rough simulation model, and calculation of the simulation result gradients in relation to this paramerization have allowed direct updating of the geostatistical model in an iterative optimization process. Parameterization of the geostatistical model by the gradual deformation method allows to keep, during this iterative process, the global geostatistical properties of the model. The coherence of the constrained geostatistical model resulting from the iterative process is thus ensured. Coupling of the upscaling and inversion techniques allows considerable reduction of the CPU time required for integration of the pressure data in the geostatistical model.
The validation tests carried out in a single-phase context have shown the power of the proposed method for updating large geologic models by dynamic data.
The absolute permeability has been used here by way of example as the physical quantity characteristic of the subsoil structure. This is of course not limitative. The method according to the invention for integration of the dynamic data in large geologic models remains however applicable for other physical quantities, notably the porosity of the medium considered. | The invention is a method for direct updating, by dynamic production data, of a fine geologic model representative of the distribution, in a reservoir, of a physical quantity characteristic of the subsoil structure. The method couples inversion and upscaling techniques allowing optimization of petrophysical parameters of a rougher simulation model resulting from the fine geologic model. Direct parameterization of the fine geologic model is performed followed by upscaling only as a means of obtaining rapidly an approximation of simulation results and of derivatives thereof in relation to the parameterization of the fine geologic model. The model has applications for determination of a development scheme such as optimizing the production of a hydrocarbon reservoir. | 6 |
FIELD OF INVENTION
The present invention generally relates to beds, but more specifically relates to patient and convalescent beds for the care of persons who have restricted mobility and have limited abilities of movement. In particular, the present invention is directed to patient and convalescent beds which oscillate about a longitudinal axis.
BACKGROUND OF THE INVENTION
There has been a long felt need for improved patient care apparatus in the form of a convalescent bed which helps alleviate various physical and medical problems associated with persons who are confined to a bed for extended periods of time. The difficulties and secondary trauma resulting from such confinement are well documented. Many problems arise when a person's body is in a prone position and is un-moved for extended periods of time. For example, restricted movement of the body can cause blood to pool in lower portions; this pooling of blood can cause life threatening clots. Another significant secondary effect of such restricted movement is that the patient is subjected to a higher risk of pneumonia induced by stagnation of the bodily fluids. Other side effects, while less life threatening, are nonetheless unpleasant at best but potentially quite painful; these side effects include pressure sores (decubiti), other bed sores and kidney stones. Finally, it is not uncommon for persons who have prolonged periods of restricted movement to experience atrophied muscles.
In recognition of these problems, medical personal have long known that, when caring for bed ridden patients, it is necessary to turn the body of the patient periodically so that the weight thereof rests on different longitudinal sectors such as the right side, the left side and the back. The manual turning of a patient is, to say the least, cumbersome since often the patient may not be able to assist the turning operation, in any manner. In a hospital context, the to turn various patients can consume an inordinate amount of nursing care time and, where other emergencies often arise, the turning of a patient can often be delayed or overlooked. In a home care setting, the need to turn the convalescing person or patient from side to side requires almost the continuous presence of care personal which can place increased time pressures on family and friends or significant financial costs for in home medical care.
While there has been some development of mechanical apparatus to facilitate the manual turning of a patient in order to make this process less physically demanding or cumbersome on nursing personal, these turning apparatus commonly comprise articulated beds which have folding panels or sections. Of more interest to the scope of the present invention, however, are those bed constructions which pivot or oscillate about a longitudinal axis so as to shift the convalescing persons weight back and forth between his/her sides.
To this end, it may be helpful to recognize that the concept of a rocking bed, per se, was recognized many years ago in the form of rocking cradles for infants. These devices, however, were directed to mental calming an infant or a child for rest and inducement to sleep; these devices were not developed for purposes of eliminating potential physical trauma to a bed-ridden patient. Such mechanized cradle rocking structures have been taught at least as early as those devices such is shown in U.S. Pat. No. 459,555, issued 15 Sept. 1891, to Sutton and in U.S. Pat. No. 1,334,042 issued 16 Mar. 1920 to Lopatka. The patent to Sutton discloses a spring motor which oscillates a cradle bed along rockers which are supported on a main support frame to provide oscillatory movement for a child placed therein. The Lopatka patent discloses a hemispherical cradle which is spring driven for oscillatory motion to a main frame. In both of these disclosures, however, the structure provided is directed to a temporary rocking motion directed to relaxing a small child placed in the cradle as opposed to eliminating physical trauma as described above.
More germane to the scope of the present invention, though, are those rocking bed structures adapted to adjust the position of a patients body on the bed so as to shift the weight of the convalescing person to different portions of the body. One such example of a tilting bed is described in U.S. Pat. No. 3,013,281 to Steiner issued 19 Dec. 1961. In this patent, a cradle frame provides a rigid mattress support surface which is trough shaped in configuration. The cradle frame may reciprocally pivot about a longitudinal pivot axis. A gear is rigidly affixed to the axle of the cradle frame, and a hand crank drives a worm gear which drives the axle gear thus allowing a care person to manually rock the cradle frame from side to side and thereby shift the weight of the person supported thereon.
Another example of a prior art device is described in U.S. Pat. No. 3,737,924 issued 12 June 1973 to Davis. Here, a hemispherical cradle frame is pivotally journaled to a main frame by oppositely extending trunnions. A rocker arm assembly is interconnected to the cradle frame so that an electrical motor may drive a continuous chain that operates the rocker arm so as to oscillate the cradle frame between opposite angular orientations.
A further example of a prior art device showing an oscillatory patient bed is described in Australian Patent No. 210,469, lodged 5 Oct. 1955, by Cullis. In this Australian patent, a trough shaped bed supports a mattress as a lower flattened section longitudinally extending between a pair of upwardly extending side mattress sections on a wire under mattress. A reversible motor and drive chain assemblies provided, a limit switches are mounted on the underside of the trough shaped cradle to contact limit switches to reverse the direction of rotation of the cradle frame. In this manner, the cradle frame periodically cycles in a forward and reverse direction whereby the body of an invalid placed thereon will be rocked between his/her left and right sides.
Other examples of beds which may be rocked and locked into a desired angle of rotation are shown in U.S. Pat. No. 3,875,598 issued 8 Apr. 1975 to Foster et al and in German Patent No. 2,636,746 issued 30 Mar. 1978 to Malenski. In the Foster et al device, a cradle assembly is freely rotatable about a longitudinal axis, but a brake assembly is provided to lock the cradle against rotation and at a desired orientation. In the patent to Maleski, a trough shaped bed may be pivoted in an oscillatory manner by a motor which drives a worm gear which moves a geared carriage interconnecting the worm gear and the apex of the trough shaped cradle.
Despite the advances made by these various structures, there remains a need for improved bed structures which help eliminate the dangers and difficulties attendant persons who are confined to beds over extended periods of time and who are subjects of restricted movement.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a new and useful oscillatory bed which may be employed to help prevent or reduce the incidence of physical trauma accompanying convalescing patients.
Another object of the present invention is to provide an oscillatory bed that is simple and practical in construction yet which is attractive in appearance and which may be produced at an economical price so as to be affordable for a variety of applications, both in the medical care field and in the home care field.
A further object of the present invention is to provide a health care bed operative to shift the weight of a person's body onto different longitudinal sectors of the body through a controlled, motor driven drive assembly so as to eliminate a degree of attention necessary from health care personal.
Still a further object of the present invention is to provide an oscillatory bed which has a mattress support surface which is deformable under the weight of the body so as to provide a relatively flattened, horizontal support surface during oscillatory movement thereof.
According to the present invention, then, an oscillatory bed is adapted to support the body of a person during rest and convalescence. The bed oscillates periodically to shift the weight of the body between the left and right sides so that the body is supported along different longitudinal body sectors thereof. The oscillatory bed, in its broad form, includes a main support frame that is positionable on a support surface. A cradle frame is provided and is pivotally journaled to the main support frame for oscillatory movement about a longitudinal pivot axis. The cradle frame includes a pair of longitudinal side rails which are interconnected by a central cradle framework structure such that the side rails are parallel to one another. The side rails thus define a primary plane for the cradle frame. A support panel has one longitudinal side edge fastened to the cradle frame proximate the first side rail and has a second longitudinal side edge fastened to the cradle frame proximate the second side rail so that the support panel is suspended in an arcuate curvature between the first and second side edges thus forming a trough shaped bed member which has panel margins respectively adjacent the side edges and a central panel section extending between the first and second margins. This support panel is constructed as a deformable sheet of stiff yet resilient material. A drive assembly is provided in order to drive the cradle frame in oscillatory movement about a longitudinal pivot axis so that the cradle frame may oscillate between first and second angular orientations wherein the primary plane of the cradle frame is at first and second acute angles with respect to the horizontal. This oscillatory movement is operative to shift support of the body laterally along the support panel back and forth from the first panel margin, across the central panel section to the second panel margin. Accordingly, the weight of the person is reciprocally distributed on the right side of the body central portion of the body and the left side of the body over a cycle of operation. The deformable support panel may deform under the weight of the body placed thereon and, due to the attachment of its edges, the arcuate curvature of the support panel that underlies the body when it is supported will flatten. Naturally, a mattress may be provided to be supported on the support panel, and the person is laid on the mattress to cushion the body with respect to the support panel.
In its more detailed form, the present invention provides a cradle frame that is V-shaped and cross-sectioned including a longitudinal base member that defines a spine for the cradle frame. Pairs of first and second ribs are spaced from one another along the longitudinal base member, and these rib elements are thus organized in to a first set of rib elements and a second set of rib elements that respectively attach and interconnect the first and second side rails to the main support member. End braces may be secured to a head end and a foot end of the cradle frame, and these end braces rigidly mount oppositely extending trunnion shafts at the foot and head of the cradle frame. These trunnion shafts are then rotatably received and pillow blocks in the foot and head portions of the main frame. The main frame foot and head portions in turn, are interconnected by a central beam that underlies the cradle frame. Safety rails may extend upwardly and inwardly from the side rails, if desired, and safety straps may be provided to help secure a persons body in the trough shaped cradle frame.
In order to oscillatory drive the cradle frame, in the preferred embodiment, a motor assembly is mounted in the foot portion of the main frame assembly. Here, a drive wheel is mounted on the foot trunnion shaft and the drive motor assembly turns a drive gear so that a drive chain may mechanically link the drive wheel and the drive gear. An electric motor is provided which is both variable in speed and reversible, and this motor powers, through a gear reduction box, the drive gear. Adjustable limit stops in the form of contact switches are activated upon the turning of the drive wheel which carries contact posts so that, when a selected maximum angular rotation is achieved, a switch is contacted to automatically reverse the motor thus driving it to the opposite angular rotation wherein a switch again reverses the motor. A fail safe stop switch is provided should a selected angular rotation be exceeded, in either direction. As noted, the positioning of the contact posts with respect to the drive wheel may be varied to vary the maximum angular limit stop and, since the motor is variable speed, the period of oscillation may be selectively varied. A key activated on/off switch is provided so that the drive assembly may be key actuated to control operation of the oscillatory bed. The reduction gear assembly is self-locking so that, in a power failure condition, the bed automatically locks into the respective position it is in at the time of power failure. A clutch assembly can release the automatic lock so that the bed can manually be returned to the horizontal and can be otherwise manually positioned during power failures.
These and other objects of the present invention will become more readily appreciated and understood from a consideration of the following detailed description of the preferred embodiment when taken together with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the oscillatory bed assembly according to the preferred embodiment of the present invention;
FIG. 2 is a cross-sectional view taken about lines 2--2 of FIG. 1;
FIG. 3 is a side view in elevation, partially broken away of the oscillatory bed shown in FIG. 1;
FIG. 4 is an end view in elevation, partially broken away showing the foot portion of the main frame assembly and drive assembly according to the preferred embodiment of the present invention; and
FIGS. 5a-5c are diagrammatic views, in cross-section showing the angular oscillatory motion of the bed according to the preferred embodiment of the present invention over a cycle of angular movement thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is directed to an oscillatory bed which can be reciprocally driven through a cycle of operation at a selectively adjustable periodicity. As such, the present invention is particularly useful for patients who have restricted movement capabilities in order to reduce side effects resulting from a condition of extended periods of bed rest. In its broad form, the present invention includes a main frame that is positionable on a support surface, such as a support floor, a specially constructed cradle frame mounted rotatably journaled to the main frame and a specially constructed drive system for the cradle frame.
As is best seen in FIG. 1, oscillating bed 10 includes a main support frame 12 having a head frame portion 14 and a foot frame portion 16 which are rigidly connected to one another by means of a longitudinal steel channel beam 18. A cradle frame 20 is pivotally supported by main frame 12 and extends between head frame portion 14 and foot frame portion 16 above beam 18. Cradle frame 20 supports a mattress 22 which, along with pillow 24 can form a bed adapted to receive the body of a person. Adjustable restraining straps 26 and 28 are provided to help hold a person on bed 10.
The construction of cradle frame 20 according to the exemplary embodiment of the present invention may be seen with greater specificity in FIGS. 2 and 3. Here, it may be seen that cradle frame 20 includes first and second side rails 30 and 32 which are in the form of elongated tubular elements that are parallel to one another to define a cradle frame primary plane A. Side rails 30 and 32 are supported in spaced-apart relation to one another by a central cradle framework that includes a longitudinal base member 34, a plurality first rib elements 36 and a plurality of second rib elements 38. Preferably, base member 34 is formed of a heavy gauge square-shaped steel tube with rib elements 36 and 38 being welded at first ends thereof to base member 34 in perpendicular relation to one another. Thus, rib elements 36 form a first set of rib elements and rib elements 38 form a second set of rib elements. Each of rib elements 36 and 38 are preferably tubular steel having a common square cross-section as side rails 30 and 32. Second ends of rib elements 36 and 38 opposite their respective first ends are welded to side rails 30 and 32 respectively. Further, a first safety rail 40 is connected to first side rail 30 by means of tubular elements 41, and a second safety rail 42 is connected to second side rail 32 by means of tubular elements 43. In the preferred embodiment as shown in FIG. 2, mounting elements 41 and 43 are perpendicularly oriented with respect to their respective rib elements 36 and 38 so that safety rails 40 and 42 are spaced closer to one another than are first and second side rails 30 and 32. It may be appreciated, with reference to FIG. 2, then, that cradle frame 20 has a V-shaped cross-section.
Cradle frame 20 mounts a support panel 50 which defines a bed member operative to support mattress 22. Support panel 50 has a first longitudinal side edge 52 which is fastened to cradle frame 20 proximately to first side rail 30; preferably side edge 52 is connected to side rail 30. Similarly, support panel 50 has a second panel side edge 54 which is fastened to cradle frame 20 proximately to second side rail 40, and preferably directly to side rail 40. Support panel 50 has a foot end 53 and a head end 55 respectively at edges 60 and 62 of panel 50 and that are free spanning so that support panel 50 is therefore freely suspended in a downwardly depending arcuate curvature in V-shaped cradle frame 20 in order to form a trough shaped bed member. This trough shaped bed member has a central longitudinal panel section 56 that is flanked by a first longitudinal support panel margin 58 adjacent panel side edge 52 and a second longitudinal support panel margin 59 adjacent side edge 54. Support panel 50 is constructed of a deformable sheet of stiff, yet resilient metal, such as a medium gauge steel sheet with panel side edges 52 and 54 firmly secured proximate side rails 30 and 32, respectively. Since head end edge 55 and a foot end edge 53 are freely suspended, support panel 50 will readily deform as more thoroughly described below.
In order to further rigidify cradle frame 20, T-shaped end braces are provided on the opposite outermost pairs of rib elements 36 and 38. Thus, as is shown in FIGS. 2 and 3, a head end brace 64 includes a leg section 66 which extends from base member 34 upwardly to terminate in a cross-bar 68 that extends between an outermost end pair of rib elements 36, 38 proximate head frame portion 14. Similarly, a foot end brace 70 includes a leg section 72 which extends upwardly from base member 34 to a cross-bar section 72 which extends between an outermost end pair of rib elements 36, 38 proximate foot frame portion 16. Preferably, the various structural elements of cradle frame 20 are welded to one another with the exception that side edges 52 and 54 of support panel 50 is mounted by metal screws tapped into the respective side rails 30 and 40.
As noted above, cradle frame 20 is rotatably journaled for pivotal motion between head frame portion 14 and foot frame portion 16. To this end, as best shown in FIG. 3, foot frame portion includes a framework 80 of vertical and horizontal tubular members such as vertical members 81, transverse tubular members 82, and longitudinal members 83. This framework 80 is enclosed by panels 84, 85, 86, 87, 88 and 89. Similarly, foot frame portion 16 includes a framework 90 having vertical tubular members 91, horizontal transverse tubular members 92 and horizontal longitudinal members 93. Framework 90 is enclosed by top side and end panels 94, 95, 96, 97, 98 and 99. Head portion framework 80 supports a head pillow block 100 which rotatably receives a head trunnion shaft 102 which is secured to cross-bar section 68 of head end brace 64 by means of a collar 104. Similarly, foot framework 90 mounts a foot pillow block 110 which rotatably receives a foot trunnion shaft 112 which is secured to cross-bar section 74 of foot end brace 70 by means of collar 114. Thus, cradle frame 20 may pivot on trunnion shafts 102, 112 in pillow blocks 100, 110 to define a pivot axis B.
In order to drive cradle frame 20 for oscillatory motion, a drive assembly is provided with this drive assembly being best shown in FIGS. 3 and 4. Here, it may be seen that foot end framework 90 mounts a variable speed electric motor 120 that is driveably connected to a reduction gear box 122 that mounts a drive gear 124 through a clutch 123. Drive gear 124 is mechanically linked to a drive wheel 128 by means of a drive chain 126. Drive wheel 128 is attached to foot trunnion shaft 112 which is rotatably received in a mounting bracket 130 so that drive shaft 128 is positioned between bracket 130 and foot pillow block 110. Power to motor 120, which is a reversible, variable speed motor, having a power rating of one-fifteenth horsepower is supplied from a control box 140 that has a key actuated cut-off switch 142, variable control 144 and the associated electronics known in the art. Electric power to control box 140 is received through the traditional electric power cord 141. Key actuated cut-off switch 142 operates to activate and deactivate motor 120, and variable control 144 is a rheostat to vary the speed of motor 120 and thus the rotational speed of drive gear 124. This, correspondingly, varies the speed of drive wheel 128 and the period of oscillation of cradle frame 20. In order to reverse motor 120, a pair of limit switches 132 and 134 are provided on a lateral horizontal frame member 93' shown in FIG. 4. First and second limit posts 136 and 138 are respectively mounted in a selected one of a limit holes 137 and 139 and are oriented so as to contact, respectively, switches 132 and 134. Switches 132 and 134 are electrically connected by means of wires 150 and 152 to control box 140. Fail safe switches 133 provided to disable power to motor 120 through control box 140 in the event switches 132 and 134 fail and the selected maximum angular rotation set thereby is exceeded. Switch 133 can be dual position mercury switch or the like.
The operation of oscillating bed 10 can now be more fully appreciated, from a drive assembly standpoint. After initial activation of motor 120 by key actuated switch 142 and after the speed of motor 120 is set by variable control 144, drive wheel 128 first rotates, for example, counterclockwise in the direction of arrow R shown in FIG. 4. Rotation of drive wheel 128 causes cradle frame 20 to pivot in a counterclockwise direction until limit post 136 rotationally advances to contact limit switch 132. Post 136 activates switch 132 which causes a reversal of drive motor 120 at a maximum angular orientation for cradle, frame 20, and drive wheel 128 then begins to rotate in a clockwise direction. This motion continues until cradle frame primary plane A passes through the horizontal and is angularly rotated to a second maximum angular orientation occurring when limit post 138 contacts limit switch 134. Activation of switch 134 by post 138 again causes reversal of motor 120 and the cycle repeats. It should be appreciated that the selected mounting of post 136 in a selected hole 137 and a selected mounting of post 138 in a selected hole 139 allows for selective adjustment of the maximum angle of rotation of cradle frame 20.
Turning, then, to FIGS. 5a-5c, a cycle of motion of cradle frame 20 may be seen in diagrammatic form. As is shown in FIG. 5a, cradle frame 20 is in a medial position wherein primary cradle frame A is horizontal. Support panel 50 is symmetric about a reference plane C that is perpendicular to plane A and which contains pivot axis B. As drive wheel 128 rotates in a counterclockwise direction, cradle frame 20 moves to a maximum first angular orientation shown in FIG. 5b wherein it may be seen the support panel 50 is now asymmetric with respect to reference plane C due to its ability to deform. In this first maximum angular orientation, plane A is oriented at an acute angle θ with respect to the horizontal with this angle θ being defined as the limit set by the position of limit post 138 in holes 139. Here, person P is on the left side of the body. When drive motor 120 reverses, cradle frame 20 returns first through the medial position shown in FIG. 5a, with person P on his/her back, to a second maximum angle orientation shown in FIG. 5c wherein cradle plane A is at an acute angle φ with respect to the horizontal with the maximum angle φ being selectively adjusted by the positioning of post 136 in holes 137. In this second angular orientation, again it may be seen that support panel 50 is asymmetric with respect to reference plane C due to its deformability, and person P is supported on the right side of the body. Further, while it is usually desired for acute angles θ and φ to be equal in magnitude but opposite with respect to angular rotation, it is possible that different magnitudes for angles θ and φ be employed by the respective positioning of posts 136 and 138.
It can now be appreciated that, when a person P is placed on mattress 124 supported by support panel 50, the person will be rocked back and forth due to the cyclical motion of cradle frame 20. As a result of the deformability of support panel 50, it may be seen that the portion of the support panel which underlies the person during this motion will be flattened as the person is rolled from the right shoulder wherein the persons body is supported by margin 58, through the medial position wherein the persons body is supported by central section 56 to the right shoulder wherein the person is supported by margin 59. This motion has a period which has is preferably approximately thirty minutes but may be selectively varied by variable control 144. In the event of power failure, motor 120, and reduction gear box 122 are self locking so that cradle frame 20 will lock into the angular orientation corresponding to the angle of reference plane A with the horizontal at the time of power failure. Where it is desired to unlock cradle frame 20 during power failure, clutch 123 may be manually released to allow cradle frame 20 to pivot on trunnion shafts 102 and 112.
Accordingly, the present invention has been described with some degree of particularity directed to the preferred embodiment of the present invention. It should be appreciated, though, that the present invention is defined by the following claims construed in light of the prior art so that modifications or changes may be made to the preferred embodiment of the present invention without departing from the inventive concepts contained herein. | An oscillatory bed for a person operates to shift the person's weight in order to eliminate problems associated with convalescence. The bed has a main support frame which receives a cradle frame that is pivotally driven through a cycle about a pivot axis between opposite angular orientations. The cradle frame has side rails, and a support panel has longitudinal side edges fastened along the side rails so that it depends downwardly in an arcuate curvature therebetween. The support panel is constructed of a deformable sheet of stiff, resilient material so that the portion thereof that underlies the person during shifting remains somewhat flat as weight is shifted between the right and left sides of the body. The cradle frame is preferably mounted by trunnions, and a drive wheel is connected to one of the trunnions to be driven by a reversible motor though a gear box and, if desired, a clutch. Limit switches reverse the motor and back-up limit switches are used. The drive is key actuated and includes variable speed controls. | 0 |
FIELD OF THE INVENTION
The present invention relates generally to horizontal directional drill machines. It relates particularly to the stakedown assembly for a horizontal directional drill machine.
BACKGROUND OF THE INVENTION
A horizontal directional drill machine is commonly employed for installing pipes beneath the ground and generally parallel to the surface. These machines are used in many different applications and are available in a wide range of sizes. Typical applications where a horizontal directional drill machine might be used include the installation of fiber optic cables, electrical cables, gas lines, water systems, or sewer systems. Horizontal directional drill machines are commonly rated in terms of pull-back capacity. Some machines for smaller applications have as little as five thousand pounds of pull-back capacity. Other machines are available with a pull-back capacity of as much as one million pounds.
One alternative to a horizontal directional drill machine is the traditional trencher machine. A trencher machine simply digs a trench into the ground, and after (for example) pipe is laid down in the bottom of the trench, the trench is filled and the pipe is buried. The advantage of a horizontal directional drill machine over a trenching machine is that a pipe can be buried in the ground over long distances without digging a trench. Thus, a horizontal directional drill is particularly desirable when a trench would be difficult or too costly to dig. For example, a horizontal directional drill machine finds particularly advantageous application for installing pipes under roadways, where destruction of the road is expensive and inconvenient to travelers, or under a waterway like a river, where trenching would be impossible.
A unique aspect of a horizontal directional drill machine is the special drill head that is attached to the front end of a pipe to be laid. The drill head has an angled shape which allows the operator to change the direction of the pipe after it has entered the ground. Direction changes are achieved by stopping the pipe and drill head rotation and orienting the drill head at a desired angle. Then, by pushing on the drill pipe without rotating it, the drill head and attached pipe will veer in the desired direction. Thus, by effecting directional changes to pipe travel, a pipe might enter the ground at one angle, travel horizontally over a long distance, and exit the ground at another angle. This ability to change the direction of pipe travel also allows the operator to steer the pipe around underground obstacles like boulders.
In addition to pushing forces which must be applied to the pipe as it is inserted, it is often necessary to pull back on the pipe. This may be necessary when a direction change is not completely successful on the first attempt, or when an underground obstacle like a boulder is encountered. The machine then pulls the pipe and drill head back to permit a direction change.
The push and pull forces that a horizontal directional drill machine must apply to the drill pipe frequently exceed the weight of the machine itself. Therefore, a system is required to anchor the machine and resist these forces. The most common system for anchoring the drill machine comprises the use of stakes mounted on the machine body which are screwed into the ground. The stakes have flighting on their tips and are driven into the ground by applying simultaneous rotational and vertical driving forces to each stake. To drive and remove these stakes, a stakedown assembly is conventionally provided on the end of the drill machine where the drill head enters the ground.
A common stakedown assembly in the prior art includes a single drive head which is fixed in one position. This type of stakedown assembly provides a single location, predetermined by the manufacturer, at which a stake can be driven. Other stakedown assemblies, also in the prior art, have two drive heads so that two stakes can be installed into the ground for extra holding strength, or a single stake can be installed in either of the two available locations. Depending on the push-pull forces required and the texture of the ground material, however, a single stake may not be adequate to securely hold the machine in place. Several stakes may be required. The subsurface of the underlying ground may contain obstacles such as large rocks or previously buried pipes or lines which limit the locations where a stake may be installed. So, the two drive head assembly is frequently inadequate. Furthermore, the two drive head assembly is limited in the number of possible stake installation locations and suffers from the higher cost and added complexity associated with the use of dual components.
In a recently developed stakedown assembly, however, a single drive head can drive stakes into a variety of locations. This stakedown assembly is described and illustrated in Draney et al. U.S. patent application Ser. No. 09/495,136. This type of stakedown assembly reduces cost by requiring only a single drive head, but also provides added flexibility by allowing multiple stakes to be installed in varying locations. This added flexibility allows the stakes to be optimally placed to avoid underground obstacles and to gain maximum holding strength.
Because a variable position drive head assembly, as previously described, must be able to drive several different stakes, the stakes can not be rigidly attached to the drive shaft, but instead must be releasably connected to the drive shaft. It is therefore desirable to have a coupling that will allow quick and easy attachment and detachment of the stakes from the drive head.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a new and improved releasable coupler for coupling stakes and the drive shaft of a stake assembly drive motor.
It is another object to provide a coupler which facilitates simple and rapid coupling and decoupling from the stake.
According to the invention, the coupler includes an upper coupler member and a lower coupler member. The upper coupler member includes a cylindrical fitting having a cylindrical attachment pocket formed upwardly into its lower end. A pin is installed transversely through the socket and extends.
The lower coupler member comprises a cylindrical fitting having an outer diameter which is slightly smaller than the inner diameter of the socket, so as to permit a sliding fit between the two members.
The lower coupler fitting has a transverse, vertical slot that extends through, and longitudinally downward, from the top of the member. It has two circumferential horizontal slots which each extend around a portion of the circumference of the lower fitting coupler. The vertical slot intersects the horizontal slots at about the midpoint of the fitting.
The lower coupler fitting is fastened to a stake. Its fitting is slidably received upwardly into the upper fitting until the pin in the upper coupler fitting is seated in the bottom of the vertical slot. Then, the upper fitting is rotated on its axis in its driving direction and the fittings are interlocked.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
The invention, including its construction and method of operation, is illustrated more or less diagrammatically in the drawings, in which:
FIG. 1 is a side elevational view of a horizontal directional drill, showing the drill in its operating mode;
FIG. 2 is a perspective view of a stakedown assembly, with one stake installed into the ground and a second stake positioned under the drive head for installation; and
FIG. 3 is a perspective view of the coupling, in a disconnected position.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and particularly to FIG. 1, a horizontal directional drill machine is shown generally at 10 . The drill machine 10 includes a frame 12 supported by driven tracks 14 for moving the drill machine 10 from place to place.
The drill machine 10 includes a longitudinally elongated boom 16 pivotally mounted on the front end of the frame 12 , as at 17 . A conventional pipe drill assembly 18 is mounted on the boom 16 , extending coextensively therewith. The drill assembly 18 is designed to drill a series of pipe sections P 1 , P 2 , P 3 , et seq., into the ground, in sequence.
In the operating mode of the drill machine 10 , the boom 16 is pivoted upward away from the frame 12 so that pipe section P 1 extends from the drill assembly 18 and intersects the ground at an angle. A special drill head (not shown) is attached to the front end of the first drill pipe section P 1 . In order to drill the pipe section P 1 into the ground and make any desired directional changes in its path, a variety of push, pull, and rotational forces are applied to the pipe section P 1 by the drill assembly 18 . The manner in which the drill assembly 18 applies these forces to the drill pipe section P 1 are not described, but are well known to those skilled in the art.
As the first pipe section P 1 is drilled into the ground, new pipe sections P 2 , P 3 , et seq., are successively attached to the rear end of the preceding pipe sections. A cartridge 22 of pipe sections P 2 , P 3 , et seq. is provided on the boom 16 for storing these additional pipe sections, and a semi-automatic or fully automatic loader (not shown) may be provided for attaching them to the preceding pipe sections.
A stakedown assembly 24 is connected to the front end of the drill machine 10 . The stakedown assembly 24 is connected to the forward end of the boom 16 at a pivot connection 26 , which allows the stakedown assembly to be oriented level with the ground surface when the boom is tilted.
Turning now to FIG. 2, a stakedown assembly 24 is shown in greater detail. The stakedown assembly 24 includes a tower 27 mounted on a base plate 32 at a connection 31 which permits the tower 27 to rotate about its vertical axis. A drive head 28 is attached to the tower 27 through a sleeve 30 which permits longitudinal sliding along the tower 27 , and a cantilevered arm 29 on which the drive head 28 is mounted.
The lower end of a hydraulic cylinder 36 is pivotally attached to the tower 27 , while the upper end is pivotally attached to the arm 29 . Thus, the arm 29 and drive head 28 can be driven in a vertical direction by the hydraulic cylinder 36 .
The base plate 32 has a series of stake locator ports 34 extending vertically through it, for receiving stakes S when they are installed. These ports 34 are arranged in a semi-circular pattern at equal distances from the tower's 27 axis of rotation. The cantilevered arm 29 extends outwardly over the path of the ports 34 so that the drive head 28 can be positioned over any one of them as the tower 27 is rotated.
A drive motor 38 with a vertical output shaft 39 is mounted in the drive head 28 on the free end of the cantilevered arm 29 . By rotating the tower 27 , the output shaft 39 of the motor 38 can be positioned over any one of the guide ports 34 . The tower is rotated manually by the operator.
To operate the multiple position stakedown assembly 24 , the desired number of stakes S to be installed, and their placement, is first determined by testing soil conditions and locating any underground obstacles. The drive head 28 is rotated until its cantilevered arm 29 is over a desired guide port 34 , and then locked into position. The bottom end of a stake S is positioned in the desired guide hole 34 , and the top end of the stake S is attached to the drive shaft 39 of the motor 38 with a coupling 48 embodying features of the present invention.
Turning now to FIG. 3 and the present invention, the coupling 48 includes the lower coupler member 60 and an upper coupler member 50 . The lower coupler member 60 is mounted on the top end 42 of the stake 30 . The upper coupler member 50 is mounted on the lower end of the drive shaft 39 from the drive motor 38 .
The upper coupler member 50 comprises a cylindrical fitting 52 . The cylindrical fitting 52 has an attachment bore 53 formed coaxially in its upper end. A large diameter coupling socket 54 is formed coaxially in its lower end. A coupling pin 55 is mounted in the socket 54 , extending transversely through the fitting 52 .
The lower coupler member 60 comprises a cylindrical fitting 62 having a body 63 with an outer diameter slightly smaller than the inner diameter of the socket 54 , so as to provide a sliding fit between the two coupler members 50 , 60 . A coaxial clearance fore 64 is in the fitting body 63 provided with an inner diameter of immaterial size. A transverse, vertical slot 66 extends through the body 63 , downward from the top end 68 of the fitting body. Two circumferential, horizontal slots 69 extend around opposite sides of the fitting body 63 , at a location displaced from its top end, each extending through an arc of about 160°, i.e., about 80° to each side of the center line of the vertical slot 66 .
The coupling 48 is engaged by placing a stake S with an attached lower coupler member 60 directly below the upper coupler member 50 . The drive shaft 39 of the drive motor 38 is then rotated so that the pin 54 in the upper coupler member 50 is aligned with the vertical slot 66 of the lower coupler member 60 . Next, the drive head 28 is lowered, without drive shaft 39 rotation, so that the pin 55 slides into the slot 66 . When the pin 55 has been lowered sufficiently so that it is aligned with the horizontal slot 69 , the drive shaft 39 is rotated until opposite ends of the pin 55 contact the ends of the slot 69 . The stake 30 and the coupling 48 are then ready for the simultaneous rotational and vertical forces necessary to drive the stake 30 into the ground.
The driven stake S is then clamped to the base plate 32 . To this end, a cap 40 is installed on each of the stakes S. The cap 40 has an inner diameter clearance hole through its center which is large enough to provide a sliding fit between the cap 40 and the stake S, but is smaller than the lower coupler member 60 which is fixedly attached to the top end of the stake S. Because its outer diameter is larger than that of the guide ports 34 , the cap 40 is sandwiched between the base plate 32 and the lower coupler member 60 when the stake S is fully driven into the ground.
After disconnecting the first installed stake S from the drive shaft 39 , additional stakes S can be installed. To do so, the drive head 28 is rotated to a new position and the stake installation process is repeated.
While a preferred embodiment of the invention has been described, it should be understood that the invention is not so limited, and modifications may be made without departing from the invention. The scope of the invention is defined by the appended claims, and all devices that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein. | A coupling for quickly and easily attaching and detaching stakes from the drive head of a horizontal directional drill. The coupling includes an upper coupler member and a lower coupler member. The lower coupler member slides into the upper coupler member, and a pin in the upper coupler member rotates into opposed, horizontal slots in the lower coupler member. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to high speed tool steel produced by sintering powder for use in a cutting tool or a cold heading tool and exhibiting both excellent wear resistance and satisfactory toughness under a high speed operational condition in which hardness and wear resistance are required at high temperature and a method of producing the same.
2. Related Art
High speed tool steel for use in a cutting tool or a cold heading tool must exhibit superior wear resistance with high hardness and excellent toughness.
There have been disclosed a variety of methods of improving the toughness of high speed tool steel produced by melting; for example, there has been disclosed a method in which Nb and other elements are added to make crystal grains fine in size to improve toughness (as shown in Japanese Patent Laid-Open No. 58-73753 and Japanese Patent Laid-Open No. 58-117863). Another method has been disclosed in which Nb and rare earth element are added to provide MC-type carbides finely distributed uniformly which carbides are mainly composed of Nb, to thereby improve toughness (as disclosed in Japanese Patent Publication No. 61-896).
On the other hand, regarding the improvement of wear resistance, in a case of high speed tool steel produced by sintering powder, in which steel it is possible to uniformly distribute fine carbide grains and to make the crystal grains fine in size, it has been most usual to increase the amount of carbides. For example, in Japanese Patent Publication Nos. 57-2142 and 55-148747, W equivalent mainly made to be in a high level to thereby increase the amount of M 6 C-type carbides mainly composed of W and/or Mo, so that wear resistance is improved because of increased hardness.
Furthermore, in a high speed tool steel produced by sintering powder, it is proposed to add Nb for the purposes of making crystal grains fine in size and preventing grains from becoming coarse in size even when austenitizing temperature is high level as shown in Metall. Trans. 19A (1988) p. 1395 to 1401 and Japanese Patent Laid-Open No. 1-212736).
However, in the high speed tool steel produced by melting in Japanese Patent Laid-Open Nos. 58-73753 and 58-117863, the excessive addition of Nb causes the occurrence of crystallized coarse carbides of NbC essentially composed of Nb. Also coarse carbides are, at the time of the solidification, crystallized which are M 6 C-type carbides essentially composed of W and Mo. Therefore, the effect of improving toughness by making crystal grains fine is diminished, with the result that the toughness is undesirably deteriorated.
Furthermore, although in the high speed tool steel produced by sintering powder it has been effected to increase the quantity of carbides or to make the hardness of the tool high for improving wear resistance, toughness is undesirably deteriorated, causing a problem of a breakage or cracking of the tool.
In the high speed tool steel of the Japanese Patent Laid-Open No. 55-148747 produced by sintering powder to which Nb is added, Nb is only intended to form hard carbide by adding Nb in place of V.
In the high speed tool steel disclosed in Metall. Trans. 19A (1988) p. 1395 to 1401 and Japanese Patent Laid-Open No. 1-212736, the addition of Nb makes it possible to enhance the quenching temperature while preventing the coarsening of crystal grains. However, the inventors of the present invention have found that in that steel there is insufficient resistance to softening upon high temperature-tempering, such resistance is required at the high temperatures encountered in a severe use thereof. This is due to the low content of alloying elements, in particular, due to low level of W equivalent, and wear resistance is also insufficient due to the small amount of carbides.
Therefore, the above-shown conventional high speed tool steel cannot satisfy the tool usage condition required in recent years in which a higher speed operation is needed.
SUMMARY OF THE INVENTION
To this end, an object of the present invention is to obtain high speed tool steel with high toughness produced by sintering powder which steel is provided with not only remarkably improved resistance to softening on high temperature tempering so as to withstand the higher speed condition of the tool, but also higher density of carbides of 2 to 5 μm size so as to further increase wear resistance.
Recently, there has been a great desire of improving the hardness of tools as tools are used at very high speed. The inventors of the present invention studied the relationship between the service life of a tool and the material through actual experiments by using tools such as an end mill. As a result, the following results were obtained; that is, the characteristic of resistance to softening on softening is the most important factor to improve the life of the tool because the temperature of the tool is raised during its usage; and the wear resistance can be improved by adjusting the grain size of carbides.
The present invention was achieved depending upon the above-shown results and the following three technical discoveries:
(1) The resistance to softening on tempering can be improved satisfactorily by restricting the chemical composition so that W+2Mo, W/2Mo and C-Ceq are within specific ranges. That is, it is effective to increase the quantity of W+2Mo so as to disperse hard carbides and to increase the quantity of alloy elements which are in solid-solution in the matrix.
Furthermore, by increasing the quantity of W to make the ratio of W/2Mo be not less than 1, improved tempering hardness can be obtained. Therefore, further improved resistance to softening on tempering can be obtained in comparison to that realized by a material containing a large amount of Mo.
The content of C must be determined while taking the relationship with the amounts of elements which form the carbides into consideration, the above-described amounts being adjusted by C-Ceq. In order to obtain improved resistance to softening on tempering, C-Ceq must be restricted to maintain the quantity of C which is solid-solutioned in the matrix.
(2) In a case where the hardening temperature is raised for the purpose of placing many alloy elements into the matrix in solid solution, the crystal grains become coarse. The problem of the coarse crystal grains can be prevented by limit the Nb content to restrict the ratio of Nb/V, with the results that fine crystal grains can be obtained and that the deterioration in toughness is prevented. Similarly to V, Nb forms the MC-type carbides, however, Nb must be contained for the purpose of forming fine NbC size with 1 μm or less to effectively prevent the occurrence of coarse crystal grains. It is necessary to make the value of Nb/V be 0.5 or more by weight.
(3) An essential factor of the present invention is the discovery that the improvement in wear resistance can be achieved by raising the density of carbides having grain size of 2 to 5 μm. Medium grain carbides having grain size of 2 to 5 μm are effective to improve the wear resistance. Furthermore, the density of the above-described carbides must be 10000 pieces/mm 2 or higher. If the density is lower than the value, the tool can be worn excessively, causing the service life to be shortened. If the density of the medium size carbides having size of 2 to 5 μm exceeds 30000 pieces/mm 2 , the carbides commence gathering to one another, causing the toughness to be excessively deteriorated. Therefore, the density of the medium size carbides having grain size of 2 to 5 μm is determined to be 10000 to 30000 pieces/mm 2 .
Furthermore, it is found that the above-shown characteristics can be obtained for the first time when the tool steel has the following composition:
That is, according to an aspect of the present invention, there is provided a high speed tool steel produced by sintering powder, consisting essentially, by weight, of more than 1.5% but not more than 2.2% C, not more than 1.0% Si, not more than 0.6% Mn, 3.0 to 6.0% Cr, an amount of W and/or Mo in which the content of W+2Mo is in the range of 20 to 30% and in which the ratio of W/2Mo is not less than 1, not more than 5.0% V, 2.0 to 7.0% Nb, the ratio of Nb/V being not less than 0.5, and the balance Fe and incidental impurities, the value of C-Ceq, which Ceq is defined by 0.24+0.033×W+0.063×Mo+0.2×V+0.1×Nb, being in range of -0.20 to 0.05, the density of carbides having grain of 2 to 5 μm being in a range of 10,000 to 30,000 pieces/mm 2 .
According to another aspect of the present invention, there is provided a high speed tool steel produced by sintering powder, consisting essentially, by weight, of more than 1.5% but not more than 2.2% C, not more than 1.0% Si, not more than 0.6% Mn, 3.0 to 6.0% Cr, an amount of W and/or Mo in which the content of W+2Mo is in the range of 20 to 30% and in which the ratio of W/2Mo is not less than 1, not more than 5.0% V, 2.0 to 7.0% Nb, the ratio of Nb/V being not less than 0.5, not more than 15.0% preferably not less than 4.0% Co, and the balance Fe and incidental impurities, the value of C-Ceq, which Ceq is defined by 0.24+0.033×W+0.063×Mo+0.2×V+0.1×Nb, being in a range of -0.20 to 0.05, the density of carbides having size of 2 to 5 μm being in a range of 10,000 to 30,000 pieces/mm 2 .
If the quantity of Nb is too large in comparison to that of V, coarse NbC will easily be formed, causing the toughness to be deteriorated. Therefore, it is preferable that the following relationship be held: the ratio of Nb/V is not more than 2.
Furthermore, in order to improve the wear resistance, it is preferable that a relationship that the value of Nb+V is larger than 6 be held.
According to another aspect of the present invention, there is provided a method of producing high speed tool steel produced by sintering powder comprising the steps of: a step of sintering alloy powder to obtain a sintered material, the alloy powder consisting essentially, by weight, of more than 1.5% but not more than 2.2% C, not more than 1.0% Si, not more than 0.6% Mn, 3.0 to 6.0% Cr, an amount of W and/or Mo in which the content of W+2Mo is in the range of 20 to 30% and in which the ratio of W/2Mo is not less than 1, not more than 5.0% V, 2.0 to 7.0% Nb, the ratio of Nb/V being not less than 0.5, not more than 15.0% Co if required, and the balance Fe and incidental impurities, the value of C-Ceq, which Ceq is defined by 0.24+0.033×W+0.063×Mo+0.2×V+0.1×Nb, being in a range of - 0.20 to 0.05; and a step of performing a heating process at 1100° C. to 1200° C. before or during a hot working.
The essential characteristic of the present invention lies in that the density of carbides having grain size of 2 to 5 μm is 10000 to 30000 pieces/mm 2 in order to improve wear resistance while maintaining satisfactory hardness and resistance to softening on tempering. This density of carbides of the specific size cannot be realized simply by specifying the composition but it can be realized by performing the heat treatment such as soaking etc. during or before the hot working.
Fine carbides having size of 2 μm or less are dissolved if carbides are subjected to the heat treatment such as soaking etc., so that the density of the carbides having size of 2 to 5 μm can be raised due to the Ostward growth.
Although the wear resistance can be significantly improved by making the density of the medium size carbides having size of 2 to 5 μm to be 10000 pieces/mm 2 , the carbides commence gathering if it exceeds 30,000 pieces/mm 2 , causing the toughness to be deteriorated.
Then, the reason why the composition is made as disclosed above will now be explained.
C contributes to improve the wear resistance because it forms hard carbides in cooperation with Cr, W, Mo, V and Nb. Another effect can be obtained in that it is dissolved into the matrix at the time of austenitizing operation so that the secondary temper hardening is improved. However, if the quantity of C is too large, the quantity of C to be dissolved into the matrix is excessively enlarged, causing the toughness to be deteriorated. Therefore, the quantity of C must be determined while taking upon the relationship with the quantities of Cr, W, Mo, V and Nb into consideration. According to the present invention, the quantity of C is adjusted to a range of 1.5 to 2.2% while making the value of C-Ceq to be -0.20 to 0.50. By making this relation satisfied there is achieved one of the above-shown conditions required to obtain improved resistance to softening on high temperature tempering.
Although Si and Mn are added as deoxidizer, a problem of deterioration in toughness or the like occurs if they are added excessively. Therefore, the quantity of Si is made to be 1.0% or less and as well as that of Mn is made to be 0.6% or less.
Cr is added by a quantity of 3 to 6% in order to improve hardenability and secondary temper hardening characteristics. If it is smaller than 3%, the above-shown effect is reduced. If Cr is larger than 6%, the quantity of carbides of the M 23 C 6 type, the main component of which is Cr, increases excessively, causing the overall toughness to be reduced, and aggregation of carbides is accelerated at the time of tempering, causing the resistance to softening to deteiorated.
In order to realize improved wear resistance, which is one of the objects of the present invention, a large quantity of hard carbides must be dispersed and at the same time the hardness of the matrix must be improved.
The factors of the quantity of W and that of Mo are important factors according to the present invention. The quantity of W or that of W+2Mo is made to be 20 to 30%. If it is smaller than 20%, the above-shown effect is reduced. If W+2Mo exceeds 30%, gathered carbides increase rapidly, causing the alloy elements dissolved in the matrix to be increased excessively, with the result that toughness will be deteriorated very much. Therefore, the quantity of W or that of W+2Mo is made to be 20 to 30%. By limiting the ratio of W/2Mo to be 1 or more, another condition (the remaining one is the condition of C-Ceq) for remarkably improving the resistance to softening on tempering which is the object of the present invention can be met.
V is also able to improve the wear resistance. Although it is preferable to be contained as much as possible for the purpose of improving the wear resistance, coarse MC-type carbides are crystallized if the quantity thereof exceeds 5%, causing toughness and grindability of a tool to be deteriorated. Therefore, it is determined to be 5% or less.
Nb is one of the most important elements in the present invention. If Nb is made to be within a specific composition range, there are crystallized fine and hard carbides, the main component of which is Nb having size of 1 to 5 μm and which is effective to improve the wear resistance, the fine carbides having size of 1 μm or less.
The present inventors, found the facts that the fine NbC is able to prevent the growth of the crystal grains and that the limited range of its content can prevent coarse crystal grains from occurring even if the tempering temperature is raised. The fine NbC closely relates to the quantity of Nb and the ratio of Nb/V. Therefore, if the quantity of Nb and the ratio of Nb/V are small, the fine NbC is hardly crystallized. Thus, the quantity of Nb is adjusted so that the content of Nb is not less than 2% and the ratio of Nb/V is not less than 0.5. If the quantity of Nb exceeds 7%, excessively coarse NbC will be crystallized, causing toughness and grindability to be deteriorated, so that it is made to be 7% or less. Furthermore, if the quantity of Nb is too large in comparison to the quantity of V, the Nb carbides easily become coarse. Therefore, it is preferable that the ratio of Nb/V is made to be not more than 2.
Co is a very effective element to improve the resistance to softening on tempering which is the object of the present invention. It is dissolved into the matrix to delay the precipitation and the aggregation of carbides. As a result, the hardness and the strength at high temperature can be remarkably improved. Therefore, it performs a very important role when it is used in a case where a contact portion, at which a tool such as a cutting tool and an end mill comes in contact with a work, is heated considerably. However, if the content of Co exceeds 15.0%, the single Co-phase is crystallized in the solid-solutioned state, causing toughness to be deteriorated. Therefore, it is made to be not more than 15.0%.
In order to remarkably improve the resistance to softening on tempering by adding Co, it is preferable that Co be added by 4% or more.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B illustrate carbides contained in the structure of steel according to the present invention, where FIG. 1A is a metal structural photograph showing MC-type carbides and FIG. 1B is a metal structural photograph showing M 6 C-type carbides; and
FIGS. 2A and 2B illustrates contained in the structure of steel according to comparative example, where FIG. 2A is a metal structural photograph showing MC-type carbides and FIG. 2B is a metal structural photograph showing M 6 C-type carbides.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Table 1 shows the chemical compositions of three kinds of experimental materials produced by subjecting nitrogen gas-atomized powder to HIP (Hot Isostatic Pressing). Each material was subjected to soaking at temperature is a range of 1080° C. to 1190° C. after the HIP process had been completed. Then, each material was elongated by forming so as to be formed into a forged member about 16 mm square before it was annealed at 860° C. Then, the forged member was, for 15 minutes, austenitized at 1250° C. which was the highest temperature below which the occurrence of coarse crystal grains can be prevented. Then, hot bath hardening at 550° C. was performed. Tempering was then performed in such a manner that heating at 560° C. for one hour was carried out three times.
The density of the carbides having grain size of 2 to 5 μm was determined in such a manner that: the surface of vertical cross sections of each forged member was ground with diamond; M 6 C-type carbides were etched by Murakami reagent; electrolytic etching was performed by using 10% chromate solution to prepare specimens in which the MC-type carbides were etched; and the carbides of the specimens were determined by using an image analyzing device.
Furthermore, the hardness of the tempered specimens were measured, the crystal grain size (after hardening) shown by the intercept method and the hardness (hereinafter called "resistance to softening on tempering") shown after air-cooling which was effected after heating at 650° C. for one hour.
The results of the measurements are shown in Table 2.
TABLE 1__________________________________________________________________________Chemical composition (wt %)Sample W + W/No. C Si Mn Cr W Mo V Nb Co Fe 2Mo 2Mo ΔC* Nb/V__________________________________________________________________________1 1.86 0.35 0.38 3.98 14.21 6.13 3.01 2.44 -- Bal 26.5 1.16 -0.08 0.812 1.87 0.47 0.31 4.10 15.99 5.08 3.11 2.57 9.47 Bal 26.2 1.57 -0.10 0.833 1.90 0.26 0.32 4.01 14.10 6.03 3.02 2.48 9.41 Bal 26.2 1.17 -0.04 0.82__________________________________________________________________________ *ΔC is a value of deviation from the value of CCeq defined in the present invention.
TABLE 2__________________________________________________________________________ Density of carbides Resistance having Crystal to soften- grain size grain size Hard- ing on tem-Sample Specimen Soaking of 2-5 μm (intercept ness peringNo. No. condition (piece/mm.sup.2) method) (HRC) (HRC) Kind__________________________________________________________________________1 1a 1080° C. × 2 hr 7810 20.2 71.3 63.9 Comparative steel 1b 1120° C. × 4 hr 12020 19.4 70.8 63.4 Present invention 1c 1170° C. × 4 hr 18470 18.9 70.5 63.3 Present invention2 2a 1080° C. × 4 hr 5670 21.9 72.3 66.6 Comparative steel 2b 1120° C. × 4 hr 10080 20.5 71.9 66.4 Present invention 2c 1150° C. × 4 hr 13180 19.3 71.7 66.3 Present invention3 3a 1080° C. × 4 hr 6980 21.5 71.9 66.1 Comparative steel 3b 1120° C. × 4 hr 11160 20.2 71.3 65.8 Present invention 3c 1150° C. × 4 hr 14730 19.4 71.2 65.7 Present invention 3d 1170° C. × 4 hr 18210 19.0 71.0 65.5 Present invention 3e 1190° C. × 4 hr 22310 18.9 70.8 65.4 Present invention__________________________________________________________________________
Although the compositions of steel according to corresponding comparative examples 1a, 2a and 3a are alloys within the scope of the chemical composition of the present invention, they had small quantity of the carbides having the medium size of 2 to 5 μm because the soaking temperature was low. It can be understood from Table 2 that the quantity of the carbides having the medium size of 2 to 5 μm can be increased by raising the soaking temperature to a level higher than 1100° C.
By comparing the sample No. 1 containing no Co with Nos. 2 and 3 both containing Co, it can be understood that the containing of Co is appropriate in a tool in which a high temperature portion occurs by cutting or the like because the sample Nos. 2 and 3 containing Co show larger resistance to softening on tempering than that of the material containing no Co.
FIGS. 1 and 2 show photographs of carbide structures of typical specimens.
FIG. 1a is a photograph of specimen 1c according to the present invention and shown in Table 2, the specimen 1c being obtainable from polishing the surface with chrome oxide. Referring to the photograph, grains having clear contour are the MC-type carbides existing at a density of 4470 pieces/mm 2 . FIG. 1b is a photograph of specimen produced by selectively etching the same material with Murakami reagent. The density of the M 6 C-type carbides were 14000 pieces/mm 2 .
FIG. 2a is a photograph of a comparative specimen 1a shown in Table 2 and produced by polishing its surface by chrome oxide to emboss the MC-type carbides. The density of the MC-type carbides was 690 pieces/mm 2 . FIG. 2b is a photograph of a specimen similarly produced by selectively etching the same material with Murakami reagent. The density of the M 6 C-type carbides was 7120 pieces/mm 2 .
The toughness of each of these specimens was evaluated by a bending test performed in such a manner that an experimental specimen the size of which was 5 mm in diameter and 70 mm in length was made from the forged member before it was subjected to the heat treatments, that is, hardening and tempering; and the experimental specimens were bent at a span of 50 mm in length.
Furthermore, a point nose straight tool (8-15-6-6-20-15-0.5R, JIS) subjected to the similar heat treatments was subjected to a continuous cutting test performed by cutting steel SKD 61 (JIS) having 40 HRC under conditions shown in Table 3 so that the service life during the cutting operation was measured.
Furthermore, each of the specimens was subjected to the Ogoshi wear resistance test under conditions that the specimens are contacted with corresponding ring made of SCM415 (JIS) under the conditions of friction length of 400 m, final load of 6.8 kgf and friction speed of 3.5 m/S so that the quantity of specific wear was measured.
The results of the experiment are shown in Table 4.
It can be understood from Table 4 that, although the composition is the same, the specimens according to comparative examples 1a, 2a and 3a in each of which the density of the medium size carbides having size of 2 to 5 μm was low show unsatisfactory wear resistance in view of the excessively large quantity specific wear. Furthermore, the service life of the cutting tool during the cutting operation was unsatisfactory.
Furthermore, it can be understood that the specimens of the composition No. 2 and No. 3 each of which contains Co reveal excellent results in terms of the service life of the cutting tool and the quantity of specific wear in comparison to the specimen of the composition No. 1 which contains no Co.
TABLE 3______________________________________Work to be SKD61 (HRC40)machinedCutting 42 m/minspeedFeed 0.1 mm/revCut 1.0 mm Dry type______________________________________
TABLE 4__________________________________________________________________________ Service life of cutting tool Quantity Bending during cutting of speci-Sample Specimen strength operation fic wearNo. No. (kgf/mm.sup.2) (second) (×10.sup.-7) Kind__________________________________________________________________________1 1a 303 535 1.26 Comparative steel 1b 298 750 1.13 Steel according to the present invention 1c 295 820 1.08 Steel according to the present invention2 2a 287 870 1.03 Comparative steel 2b 301 1005 0.92 Steel according to the present invention 2c 292 1220 0.75 Steel according to the present invention3 3a 295 790 1.03 Comparative steel 3b 312 1010 0.94 Steel according to the present invention 3c 310 1100 0.81 Steel according to the present invention 3d 290 1230 0.72 Steel according to the present invention 3e 285 1280 0.68 Steel according to the present invention__________________________________________________________________________
EXAMPLE 2
Experimental materials, the compositions of which were as shown in Table 5, were produced by subjecting nitrogen gas-atomized powder to HIP (Hot Isostatic Pressing). Similarly to Example 1, each material was subjected to soaking at temperature in a range of 1080° C. to 1170° C. after the HIP process had been completed. Then, each material was elongated by forging so as to be formed into a forged member about 16 mm square before it was annealed at 860° C. Then, each of the forged member was austenitized at the highest temperature in which the crystal grains do not become coarse, that is, only specimen 11 was heated at 1210° C. for 15 minutes and other specimens were heated at 1250° C. for 15 minutes. Then, hot bath hardening at 550° C. was performed. Tempering was then performed in such a manner that heating at 560° C. for one hour was carried out three times.
TABLE 5__________________________________________________________________________Chemical composition (wt %)Sample W + W/No. C Si Mn Cr W Mo V Nb Co Fe 2Mo 2Mo ΔC Nb/V Kind__________________________________________________________________________4 1.61 0.87 0.18 4.12 20.13 -- 2.02 3.10 14.03 Bal 20.13 -- -0.01 1.53 Steel of the invention5 1.75 0.62 0.25 5.61 18.03 1.98 2.47 2.99 12.11 Bal 21.99 4.55 0.00 1.21 Steel of the invention6 1.94 0.32 0.31 3.48 15.82 3.96 3.45 3.38 8.03 Bal 23.74 1.99 -0.09 0.98 Steel of the invention7 2.00 0.13 0.32 2.34 18.14 4.01 3.72 3.41 6.13 Bal 26.16 2.26 - 0.18 0.92 Steel of the invention8 1.80 0.55 0.33 4.13 14.13 5.27 3.11 3.02 1.93 Bal 24.67 1.34 -0.16 0.97 Steel of the invention9 1.87 0.41 0.31 4.20 15.97 4.01 2.12 6.01 10.03 Bal 23.99 1.99 -0.17 2.83 Steel of the invention10 1.67 0.43 0.32 4.13 7.92 5.09 3.53 2.50 -- Bal 18.10 0.78 -0.11 0.71 Comparative steel11 2.01 0.51 0.42 3.52 10.05 7.01 5.02 -- -- Bal 24.07 0.72 -0.01 0 Comparative steel12 2.24 0.21 0.53 4.11 14.02 5.23 3.47 4.31 8.22 Bal 24.48 1.34 +0.08 1.24 Comparative steel13 1.60 0.39 0.32 4.03 14.11 4.13 3.02 3.12 -- Bal 22.37 1.71 -0.28 1.03 Comparative steel__________________________________________________________________________
Similarly to Example 1, the density of the carbides having grain size of 2 to 5 μm was determined in such a manner that: the surface of vertical cross sections of each forged member was ground with diamond; M 6 C-type carbides were etched by Murakami reagent; electrolytic etching was performed by using 10% chromate solution to prepare specimens in which the MC-type carbides were etched; and the carbides of the specimens were determined by using an image analyzing device.
Furthermore, the hardness of the tempered specimens, the crystal grain size (after hardening) realized by the intercept method and the hardness (resistance to loss of hardness on tempering) realized by air-cooling after heating at 650° C. for one hour were measured.
The results of the above-described measurements are shown in Table 6.
The toughness of each of the samples was evaluated by a bending test performed in such a manner that an experimental specimen the size of which was 5 mm in diameter and 70 mm in length was made from the forged member before it was subjected to the heat treatments, that is, hardening and tempering; and the experimental specimens were bent at a span of 50 mm in length.
Furthermore, a point nose straight tool (8-15-6-6-20-15-0.5R) subjected to the similar heat treatments was tested by continuously cutting steel SKD61 (JIS) made to have 40 HRC, under conditions shown in Table 3 so that the service life in the cutting operation was measured.
Furthermore, each of the specimens was subjected to the Ogoshi wear resistance test under conditions that it was contacted with the corresponding ring made of SCM415, with friction length of 400 m, with final load of 6.8 kgf and with friction speed of 3.5 m/S, the quantity of specific wear being measured.
The results of the above-described experiment are shown in Table 7.
TABLE 6__________________________________________________________________________ Density of ResistanceHeat carbides having Crystal to soften-treatment grain size of grain size Hard- ing onSamplecondi- 2-5 μm (intercept ness temperingNo. tion* (piece/mm.sup.2) method) (HRC) (HRC) Kind__________________________________________________________________________4 a 10020 17.1 70.2 66.1 Steel of the invention5 a 12110 18.9 71.1 66.7 Steel of the invention6 a 15320 19.0 71.4 66.8 Steel of the invention7 a 17030 20.1 71.8 67.1 Steel of the invention8 a 13200 20.0 69.8 63.5 Steel of the invention9 a 16100 20.3 71.7 66.7 Steel of the invention10 a 9320 16.1 67.9 60.1 Comparative steel11 b 14130 17.7 69.2 60.0 Comparative steel12 a 19010 20.5 72.1 65.7 Comparative steel13 a 12680 18.5 67.5 61.9 Comparative steel__________________________________________________________________________ a. After austenitizing treatment at 1250° C. for 15 minutes, test piece was cooled in a salt bath at 550° C. and tempered at 560° C. for one hour 3 times. b. After austenitizing treatment at 1210° C. for 15 minutes, the test piece was cooled in a salt bath at 550° C. and tempered at 560° C. for one hour 3 times.
a. After austenitizing treatment at 1250° C. for 15 minutes, test piece was cooled in a salt bath at 550° C. and tempered at 560° C. for one hour 3 times.
b. After austenitizing treatment at 1210° C. for 15 minutes, the test piece was cooled in a salt bath at 550° C. and tempered at 560° C. for one hour 3 times.
TABLE 7______________________________________ Service life of Quantity of Bending cutting tool in specificSample strength cutting operation wearNo. (kgf/mm.sup.2) (second) (×10.sup.-7)______________________________________4 342 980 1.025 323 1110 0.936 283 1300 0.877 265 1420 0.718 317 1280 0.919 223 1010 0.7010 340 395 1.3411 303 580 1.3012 180 990 0.8713 319 745 1.26______________________________________
Then, each of the specimens will now be explained in detail.
Each of specimen Nos. 4 to 9 of the present invention is steel containing Co so that it contains the medium grain carbides having grain size of 2 to 5 μm in a density range of 10000 pieces/mm 2 to 20000 pieces/mm 2 .
Each of specimens Nos. 6 to 8 of the present invention contains more than 6% (Nb+V) so that hard MC-type carbides are contained by a relatively large quantity. Therefore, it can be understood that they exhibit excellent service life of the cutting tool while revealing a reduced quantity of specific wear. Furthermore, since Co contained in specimen No. 8 is relatively small, its resistance to softening on tempering is deteriorated in comparison to specimen Nos. 6 and 7. Although specimen No. 9 of the present invention exhibits a satisfactory quantity of specific wear, the value of Nb/V undesirably exceeds 2, that is, the quantity of Nb is relatively large in comparison to the quantity of V, with the result that it contains a large quantity of relatively coarse NbC, causing its bending strength to be deteriorated in comparison to the other specimens. Therefore, it can be understood that it is preferable that the value of Nb/V be 2 or less.
It can be understood that the value of resistance to softening on tempering of specimen No. 10 is too small and thereby the service life of the cutting tool in the cutting operation is excessively shortened in comparison to the specimens according to the present invention because the addition amount of W and Mo in specimen No. 10 is small.
Since specimen No. 11 does not contain Nb, the quenching temperature cannot be raised in order to prevent the occurrence of coarse crystal grains. Therefore, it is impossible to cause alloy elements to be dissolved into the matrix with a sufficient quantity. As a result, satisfactory resistance to softening cannot be obtained. Therefore, the service life of the cutting tool in the cutting operation is very short in comparison to the specimens according to the present invention.
Specimen No. 12 is a specimen having ΔC calculated by C-Ceq which ΔC is a value deviated from the range of the present invention to,,the positive side. In this specimen, C is excessively dissolved into the matrix, so that the deflective strength is unsatisfactorily deteriorated.
Specimen No. 13 is a specimen having ΔC which is deviated from the range of the present invention in the negative side. Since ΔC is too small in this specimen, the hardness cannot be improved in comparison to the specimens of the present invention even if hardening and tempering are performed. Therefore, satisfactory service life of the cutting tool in the cutting operation cannot be realized and the quantity of specific wear cannot be reduced.
According to the present invention, the conventional problem in terms of the resistance to softening on tempering can be significantly improved. Therefore, the wear resistance at high temperature can significantly be improved. In addition, by adjusting the grain size of carbides, the wear resistance can be furthermore improved. Furthermore, since the obtainable toughness is satisfactory in comparison to the conventional material, the service life can be significantly improved under a high speed tool operational condition.
The present invention has been disclosed in its preferred form. The invention, however, is not limited thereto. The scope of the invention is to be determined by the appended claims and their equivalents. | A high speed tool steel produced by sintering powder, consisting essentially, by weight, of more than 1.5% but not more than 2.2% C, not more than 1.0% Si, not more than 0.6% Mn, 3.0 to 6.0% Cr, an amount of W and Mo in which the content of W+2Mo is in the range of 20 to 30% and in which the ratio of W/2Mo is not less than 1, not more than 5.0% V, 2.0 to 7.0% Nb, the ratio of Nb/V being not less than 0.5, and the balance Fe and incidental impurities, the value of C-Ceq, which Ceq is defined by 0.24+0.033×W+0.063×Mo+0.2×V+0.1×Nb, being in a range of -0.20 to 0.05, the density of carbides in the sintered steel having grain size of 2 to 5 μm being in a range of 10,000 to 30,000 pieces/mm 2 . | 2 |
CROSS REFERENCE TO RELATED APPLICATION
This is a continuation-in-part application of U.S. patent application Ser. No. 09/883,813 filed on Jun. 18, 2001, now U.S. Pat. No. 6,470,924.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a depression container that is capable of maintaining the internal pressure under a predetermined value, and more particularly to a depression container equipped with an air pump that can be activated when the internal pressure in the depression container is below a predetermined value.
2. Description of the Related Art
A typical depression container includes a one-way valve and a user may manually operate a hand air pump to draw air out of the container via the one-way valve. The internal pressure of the container is thus reduced to a relatively low valve (almost vacuum). This reduces the risk of the articles in the container from being wetted or contaminated by dust or bacteria, thereby lengthening the preserve time. It is, however, troublesome and labor-intensive for the user to reciprocatingly operate the hand air pump for many times. In addition, the user cannot know the exact internal pressure in the depression container. Furthermore, the depression container cannot provide an absolute sealing effect such that the internal pressure in the depression container may rise after a period of time and thus adversely affect preservation of the articles in the depression container.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a depression container that may automatically draw air out of the depression container after a cover is attached to enclose an open end of the depression container. The internal pressure of the depression container is reduced to a predetermined value.
It is another object of the present invention to provide a depression container that clearly shows the value of the internal pressure. The depression container also allows the user to reset the internal pressure desired for preserving articles.
It is a further object of the present invention to provide a depression container that may maintain the internal pressure thereof under a predetermined valve for a long time.
In accordance with a first aspect of the invention, a depression container comprises:
a vessel including a compartment with an open end;
a cover for enclosing the open end of the vessel and thus sealing the compartment;
an air pump for drawing air out of the compartment of the vessel; and
a pressure-activated switch for controlling on/off of the air pump;
the pressure-activated switch being capable of detecting an internal pressure in the compartment of the vessel, the air pump being turned on when the internal pressure is higher than a predetermined first pressure value, the air pump being turned off when the internal pressure is lower than a predetermined second pressure value that is smaller than the predetermined first pressure value;
the pressure-activated switch and the air pump being powered by an A.C. power source.
In accordance with a second aspect of the invention, a depression container comprises:
a vessel including a compartment with an open end;
a cover for enclosing the open end of the vessel and thus sealing the compartment;
an air pump for drawing air out of the compartment of the vessel; and
a pressure-activated switch for controlling on/off of the air pump;
the pressure-activated switch detecting a pressure difference resulting from a closing motion of the cover on the vessel and turning the air pump on to thereby draw air out of the compartment of the vessel, the air pump being turned off when an internal pressure in the compartment detected by the pressure-activated switch is lower than a predetermined pressure value;
the pressure-activated switch and the air pump being powered by an A.C. power source.
Thus, the air pump is activated by a pressure difference resulting from the closing motion of the cover, and the pump is deactivated after the internal pressure in the vessel is reduced to a first predetermined pressure value. When the internal pressure rises and exceeds a second predetermined pressure value higher than the first predetermined value, the pump is activated again until the internal pressure is reduced to the first predetermined pressure value. Thus, the articles in the vessel can be preserved for a long time by means of maintaining the internal pressure in the vessel under a predetermined low pressure suitable for preservation of articles.
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 a perspective view of a depression container in accordance with the present invention.
FIG. 2 is an exploded perspective view of the depression container in accordance with the present invention.
FIG. 3 is a sectional view of an upper portion of the depression container in accordance with the present invention.
FIG. 4 is a sectional view similar to FIG. 3, illustrating operation of the depression container upon closing of a cover.
FIG. 5 is a sectional view similar to FIG. 4, wherein the cover is moved to its fully closed position.
FIG. 6 is a perspective view illustrating a modified embodiment of the depression pump in accordance with the present invention.
FIG. 7 is an exploded perspective view illustrating a further modified embodiment of the depression pump in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 through 3, a depression container in accordance with the present invention generally includes a vessel 1 , a cover 20 , an air pump 2 , and a pressure-activated switch 3 .
The vessel 1 is cylindrical and includes a closed lower end and an open upper end and thus defines a compartment 11 for receiving articles to be preserved. The compartment 11 is enclosed and thus sealed by the cover 20 that is attached to the open upper end of the vessel 1 . The cover 20 includes a sealing plate 28 (FIG. 3 ), which also serves as a mounting plate. Namely, the sealing plate 28 seals the compartment 11 and provides a base on which the air pump 2 , and the pressure-activated switch 3 are mounted. In this embodiment, a space 21 is defined above the sealing plate 28 , and two parallel first walls 22 and two parallel second walls 23 are formed on top of the sealing plate 28 , best shown in FIG. 2 . Each first wall 22 includes, e.g., two slots 221 and each second wall 23 includes, e.g., two slots 231 . The sealing plate 28 further includes a first through-hole 25 and a second through-hole 26 that are communicated with the compartment 11 of the vessel 1 , which will be described in detail later.
The air pump 2 includes a casing 30 and an air duct 31 extending from a bottom side of the casing 30 . The casing 30 further includes two lateral sides each having, e.g., two engaging members 32 for engaging with the slots 221 of the associated wall 22 , thereby securely mounting the air pump 2 into the space 21 of the cover 20 . An airtight sleeve 33 is extended through the first through-hole 25 and the air duct 31 is mounted in the airtight sleeve 33 and thus located below the sealing plate 28 , best shown in FIG. 3 . Of course, an additional sealing plate 29 can be provided between the upper end face of the vessel 1 and the sealing plate 28 to assist in the sealing effect.
The pressure-activated switch 3 includes a casing 40 , a differential type pressure transducer 44 in the casing 40 , and a control chip 46 electrically connected to the air pump 2 through male and female connectors 104 and 106 . The pressure transducer 44 includes a sensor 48 that extends downward beyond the casing 40 . The casing 40 includes two lateral sides each having, e.g., two engaging members 41 for engaging with the slots 231 of the associated wall 23 , thereby mounting the pressure-activated switch 3 into the space 21 of the cover 20 . An airtight sleeve 42 is extended through the second through-hole 26 , and the sensor 48 is mounted in the airtight sleeve 42 and thus located below the sealing plate 28 , best shown in FIG. 3 .
A wire 100 is provided to connect the air pump 2 to an external A.C. power source (not shown), thereby powering the air pump 2 and the pressure-activated switch 3 . An adaptor 102 may be provided between the A.C. power source and the air pump 2 .
The pressure transducer 44 outputs a voltage in response a difference between a reference pressure (e.g., the atmosphere) and a detected internal pressure in the compartment 11 of the vessel. Namely, the output voltage of the pressure transducer 44 is in linear proportion to the pressure difference. In this embodiment, the output voltage is 3.3V if the detected internal pressure is equal to or above a first threshold pressure value (e.g., 1.15 atm); the output voltage is 1.2V if the detected internal pressure is equal to or below a second threshold pressure value (e.g., 0.1 atm); and the output voltage is 1.5V if the detected internal pressure is equal to or above a third threshold pressure value (e.g., 0.25 atm).
The control chip 46 has a set of controlling programs recorded therein and includes two logic control modes M 1 and M 2 switchable by a switch 45 . When switched to the control mode M 1 , the air pump 2 is activated when the output voltage of the pressure transducer 44 is higher than or equal to 3.3V and the air pump 2 is turned off when the output voltage of the pressure transducer 44 is lower than or equal to 1.2V. When switched to the control mode M 2 , the air pump 2 is activated when the output voltage of the pressure transducer 44 is higher than or equal to 1.5V and the air pump 2 is turned off when the output voltage of the pressure transducer 44 is lower than or equal to 1.2V.
In use, referring to FIG. 4, the switch 45 is firstly switched to the control mode M 1 , and the cover 20 is attached to and thus encloses the vessel 10 . During closing of the cover 20 (i.e., the cover 20 is moved downward relative to the vessel 10 ), the air inside compartment 11 of the vessel 1 is compressed and thus generates an instant pressure greater than 1.15 atm. The pressure transducer 44 of the pressure-activated switch 3 detects such a pressure and outputs a voltage higher than 3.3V. The air pump 2 is thus activated under the control of the control chip 46 , thereby drawing air out of the vessel 1 (e.g., vacuumizing the vessel 1 ). The pressure in the vessel 1 is accordingly reduced. When the air pressure in the vessel 1 is equal to or below 0.1 atm, the output voltage of the pressure transducer 44 is lower than 1.2V. The air pump 2 is thus turned off.
The switch 45 is switched to the control mode M 2 after depression. If the air pressure in the vessel 1 rises as a result of entrance of ambient air into the vessel 1 , the sensor 44 detects the air pressure and the air pump 2 is turned on when the air pressure in the vessel 1 is equal to or above 0.25 atm upon outputting an output voltage higher than 1.5V. When the air pressure inside the vessel 1 is equal to or lower than 0.1 atm, the pressure transducer 44 outputs a voltage lower than 1.2V to turn off the air pump 2 . Thus, the air pressure in the vessel 1 is kept at about 0.1 atm.
It is appreciated that the switch 45 and the control modes M 1 and M 2 can be simplified. For example, the control mode M 1 is OFF and the control mode M 2 is ON. More specifically, the pressure transducer 44 is turned on when in the control mode M 2 and is turned off when in the control mode M 1 . Thus, when in use, the user may attach the cover 20 to the vessel 1 and switch to the control mode M 2 after the cover 20 is in position. The air pump 2 is turned on when the air pressure in the vessel 1 is equal to or above 0.25 atm and the air pump 2 is turned off when the air pressure in the vessel 1 is equal to or lower than 0.1 atm.
In addition, referring to FIG. 6, the cover 20 may include a display 50 (e.g., a liquid crystal display) to display the air pressure in the vessel 1 . The cover 20 may further include an input device 52 for inputting the pressure value at which the articles in the vessel to be kept. Namely, the user may change the second threshold value (0.1 atm in the above embodiment) to any desired value. The input device 52 may also be used to input the name of the articles to be preserved in the vessel 1 .
FIG. 7 illustrates a modified embodiment of the depression container in accordance with the present invention. The depression container includes a vessel 5 , a cover 60 , an air pump 6 , and a pressure-activated switch 7 .
The vessel 5 is cylindrical and includes a closed lower end and an open upper end and thus defines a compartment 51 for receiving articles to be preserved. The compartment 51 is enclosed and thus sealed by the cover 60 that is attached to the open upper end of the vessel 5 . The cover 60 includes a sealing plate 68 , which also serves as a mounting plate. Namely, the sealing plate 68 seals the compartment 51 and provides a base on which the air pump 6 and the pressure-activated switch 7 are mounted. In this embodiment, a space 61 is defined above the sealing plate 68 , and a first cylindrical wall 63 and a second cylindrical wall 64 are formed on top of the sealing plate 68 . The sealing plate 68 further includes a first through-hole 65 surrounded by the first cylindrical wall 62 and a second through-hole 66 surrounded by the second cylindrical wall 64 . The through-holes 65 and 66 are communicated with the compartment 51 of the vessel 5 .
The air pump 6 includes a casing 70 and an air duct 71 extending from a bottom side of the casing 70 . An outer threading 72 is defined in an outer periphery of the casing 70 for engaging with an inner threading 631 of the first cylindrical wall 63 , thereby securely mounting the air pump 6 to the first cylindrical wall 63 . An airtight sleeve 74 is extended through the first through-hole 65 and the air duct 71 is mounted in the airtight sleeve 74 and thus located below the sealing plate 68 . Of course, an additional sealing plate 69 can be provided between the upper end face of the vessel 5 and the sealing plate 68 to assist in the sealing effect.
The pressure-activated switch 7 includes a casing 80 , a differential type pressure transducer 84 in the casing 80 , and a control chip 86 electrically connected to the air pump 6 . The pressure transducer 84 includes a sensor 88 that extends downward beyond the casing 80 . The casing 80 includes an outer threading 81 in an outer periphery thereof for engaging with an inner threading 641 of the second cylindrical wall 64 , thereby mounting the pressure-activated switch 7 into the space 61 of the cover 60 . An airtight sleeve 87 is extended through the second through-hole 66 , and the sensor 88 is mounted in the airtight sleeve 87 and thus located below the sealing plate 68 .
The sealing plate 68 further includes preserved passages allowing electrical connection between terminals 82 and 73 respectively on the pressure-activated switch 7 and the air pump 6 . A wire 100 is provided to connect the air pump 6 to an external A.C. power source (not shown), thereby powering the air pump 6 and the pressure-activated switch 7 . An adaptor 102 may be provided between the A.C. power source and the air pump 6 . Operation of the modified embodiment is identical to that of the first embodiment illustrated in FIGS. 1 through 5.
Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the invention as hereinafter claimed. | A depression container comprises a vessel including a compartment and a cover for enclosing and thus sealing the compartment. An air pump draws air out of the compartment and a pressure-activated switch controls on/off of the air pump. The pressure-activated switch detects an internal pressure in the compartment. The air pump is turned on when the internal pressure is higher than a predetermined first pressure value. The air pump is turned off when the internal pressure is lower than a predetermined second pressure value. In an alternative embodiment, the pressure-activated switch detects a pressure difference resulting from a closing motion of the cover on the vessel and turns the air pump on to thereby draw air out of the compartment of the vessel. The air pump is turned off when an internal pressure in the compartment detected by the pressure-activated switch is lower than a predetermined pressure value. | 5 |
TECHNICAL FIELD
The present invention pertains to a retroreflective sheeting that is adhered to an article body comprising a plasticized plastic such as a traffic cone to impart retroreflectiveness to the article.
BACKGROUND
In general, a retroreflective sheet such as an encapsulated lens type retroreflective sheet (see FIG. 3. hereinafter referred to as "encapsulated lens type sheet"), an enclosed lens type retroreflective sheet (see FIGS. 1 and 2. hereinafter referred to as "enclosed lens type sheet") and so on is adhered to a surface of an article comprising a plastic or a metal, and used.
Usually, an adhesive layer comprising an adhesive mass is separately provided on a back surface of the retroreflective sheet which is adhered to the surface of the article (opposite the surface on which the surface protective layer is present).
Some of the articles to which the retroreflective sheet is adhered contain a plasticized plastic. For example, a traffic cone is formed from a material containing plasticized polyvinyl chloride. However, when the conventional enclosed lens type sheet is adhered to the surface of the article containing the plasticized plastic, the following problems may arise:
That is, since a plasticizer migrates from the article to the adhesive layer and then to the spacing layer, the spacing layer is swelled. Thereby, a distance between the reflector and the glass microsphere is changed, and the retroreflective property (reflection luminance) decreases with time.
To prevent the decrease of reflection luminance, some improvements have been proposed.
One of examples of such improvements is an enclosed lens sheet comprising a resin layer contacting to a reflector, a barrier layer which is present below the resin layer to prevent the migration of a plasticizer, and an adhesive layer which is present below the barrier layer (see FIG. 2). This improved reflective sheet is disclosed in, for example, U.S. Pat. No. 4,377,988.
But, this improved reflective sheet still has the following drawbacks. A total thickness of the reflective sheet is increased by a thickness of the barrier, the sheet has less flexibility and is less stretched, so that it is difficult to adhere the sheet on an article having a curved surface, it is difficult to cut the reflective sheet in a desired size and form, and a production cost increases since a step for forming the barrier layer is added to the production process.
The above drawbacks of the improved enclosed lens type sheet can be avoided by the encapsulated lens type sheet. The encapsulated lens type sheet (see FIG. 3) has a reflector which contacts to the transparent microsphere, and therefore, the distance between the reflector and the transparent microsphere is hardly changed by the swell of the layer containing the resin such as the adhesive layer and the bonding layer. The encapsulated lens type sheets are disclosed in U.S. Pat. Nos. 4,025,159, 4,653,854, 5,066,098 and 5,069,964, and Japanese Patent KOKAI Nos. 2-93684 and 2-93685.
As shown in FIG. 3, in general, the capsule lens sheet has a retroreflective layer which comprises lens means made of plural transparent microspheres, a bonding layer having a support member in which the lens means is partly embedded and plural linking parts which are bonded to the protective layer so that spaces for encapsulating the transparent microspheres are formed between the protective layer and the support member and reflectors which are present with contacting the lens means; a surface protective film which is laminated on the retroreflective layer; and an adhesive layer for adhering the reflective sheet to an article. Usually, the reflective sheet has a releasing liner to protect the adhesive layer prior to the use. In general, an adhesive mass of the adhesive layer contains a pressure sensitive acrylic adhesive. Further, the bonding layer contains an acrylic resin, a polyurethane resin, a NBR resin, and the like.
When the reflective sheet comprising the adhesive layer which contains the pressure sensitive acrylic adhesive is adhered to the article comprising the plasticized plastic, its adhesion strength is deteriorated because of the migration of the plasticizer to the adhesive layer.
U.S. Pat. Nos. 4,763,985 and 4,533,592 disclose the use of a polyurethane resin as the adhesive layer. A resistance of the polyurethane adhesive to the plasticizer is higher than that of the pressure sensitive acrylic adhesive. The polyurethane adhesive has a softening point of 60° C. or lower.
While the reflective sheets have been improved in various ways in the prior arts, they have a multi-layer structure which essentially includes (1) a covering layer comprising a surface protective film, (2) a retroreflective layer which bonds the surface protective film and transparent microspheres, and has a retroreflective property, and (3) an adhesive layer which has a function to adhere the sheet to the adherent.
In these days, it is required to simplify the production process of the capsule lens sheet, that is, to eliminate any one of the layers, in view of the requirement for the reduction of production costs.
SUMMARY OF THE INVENTION
A first object of the present invention is to provide a retroreflective sheet which can be adhered to an article surface without the provision of a separate adhesive layer, and which can maintain a high reflection luminance and a high adhesion force for a long time when it is adhered to an article containing a plasticized plastic. The present invention intends to simplify the production process of the encapsulated lens type sheet and reduce the production cost.
A second object of the present invention is to provide an article having retroreflectiveness, wherein the reflective sheet is adhered to the article at a high adhesion force for a long time, the reflective sheet is hardly peeled off, and the high reflection luminance can be maintained for a long time.
To solve the above problems, the present invention provides a retroreflective sheet comprising a surface protective layer,
lens means made of plural transparent microspheres,
a bonding layer which comprises a support member in which said lens means is partly embedded and plural linking parts which are bonded to said protective layer so that spaces for encapsulating said transparent microspheres are formed between said protective layer and said support member,
and
reflectors which are present with contacting said lens means, wherein said bonding layer consists essentially of a single layer comprising a thermoplastic polyurethane resin having a softening point of 70° C. to 200° C., and a surface of said bonding layer opposite the surface to which said protective layer can be adhered to an adherent.
In addition, the present invention provides an article comprising an article body and the retroreflective sheet of the present invention which is adhered to the article body.
Components of the retroreflective sheet of the present invention will be explained further in detail. The structure of the retroreflective sheet of the present invention is shown in FIG. 4.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic cross sectional view of an enclosed lens type retroreflective sheet.
FIG. 2 shows a schematic cross sectional view of an enclosed lens type retroreflective sheet having a barrier layer.
FIG. 3 shows a schematic cross sectional view of a conventional encapsulated lens type retroreflective sheet.
FIG. 4 shows a schematic cross sectional view of an encapsulated lens type retroreflective sheet according to the present invention.
FIG. 4A shows a schematic cross sectional view of an article having retroreflectiveness including a retroreflective sheet according to the invention.
FIGS. 5, 6 and 7 show steps of the production process of the conventional encapsulated lens type retroreflective sheet.
FIGS. 8 and 9 show steps of the production process of the encapsulated lens type retroreflective sheet according to the present invention.
DETAILED DESCRIPTION
Bonding Layer
Referring to FIG. 4, the bonding layer comprises the support member in which the lens means is partly embedded and plural linking parts which are bonded to the protective layer 6 so that spaces 12 for encapsulating the transparent microspheres 2 are formed between the protective layer 6 and the support member. A surface of the bonding layer 13 opposite the surface to which the surface protective layer 6 is bonded can be adhered to the article surface 14, as shown in FIG. 4A. Then, the reflective sheet 15 of the present invention requires no separate adhesive layer.
The bonding layer of the present invention comprises a thermoplastic polyurethane resin having a softening point of 70° C. to 200° C.
Since the bonding layer comprises the thermoplastic polyurethane resin, it maintains a high adhesion force to the surface of the article containing the plasticized plastic for a long time. Accordingly, it is possible to eliminate a step for forming an adhesive layer from the production process of the reflective sheet, and it is not necessary to apply an adhesive on the article surface for adhering the reflective sheet to the article body.
When the softening point of the polyurethane resin of the bonding layer is too low, the following problems arise:
Since the polyurethane resin having the low softening point increases flowability of the bonding layer, the spaces for enclosing the lens members are collapsed by a winding pressure when the reflective sheet having such spaces is wound and stored in a roll form. As the result, the retroreflecting property is deteriorated. A conventionally used polyurethane base adhesive has in general a softening point of about 60° C. or lower, it cannot be used as the bonding layer of the present invention.
When the softening point of the polyurethane resin is too high, the reflective sheet cannot be adhered to the article surface at a sufficient adhesion force in the absence of the separate adhesion layer. The situation is the same when a resin of the bonding layer comprises a thermosetting resin, because the thermosetting resin is hardly softened by heating after it is heat cured, and a sufficient adhesion is not achieved. In such cases, the reflective sheet cannot be adhered to the article body at the sufficient adhesion force even if a primer, which will be explained below, is used.
When the resin of the bonding layer is the thermosetting resin, the softening point of the bonding layer is relatively high, the formation of the spaces tends to be difficult. For the above reasons, the softening point of the thermoplastic polyurethane resin is preferably from 80° to 180° C., more preferably from 100° to 150° C. The softening point herein used is a value measured by a ring and ball method.
When the adhesion force is expressed by a peeling strength of the reflective sheet at an angle of 180 degrees in relation to the article body, it is preferably at least 2 kg/25 mm, more preferably at least 3 kg/25 mm. When the adhesion force is less than 2 kg/25 mm, the reflective sheet may be peeled off when it is adhered to the article body and used outdoors. Herein, the peeling strength is measured according to JIS Z 0237 8.31.
The bonding layer "consisting essentially of a single layer" is intended to mean that there is no interlaminar interface between layers having different compositions in the bonding layer. The interlaminar interface may cause the peeling at the interlaminar interface, when the reflective sheet is adhered to the article containing the plasticized plastic. The bonding layer consisting essentially of a single layer includes a single layer that may be formed by coating or extruding a composition containing components of the bonding layer, or at least two layers formed from the same composition. The thickness of the bonding layer can be made relatively large by laminating at least two layers.
One of the preferred polyurethane resins is a polycarbonate polyurethane. The polycarbonate polyurethane has good adhesion forces to the surface protective layer, the lens members, and the article body, and is excellent in resistance to hydrolysis. Therefore, it will improve the practical durability of the reflective sheet which is used outdoors. When the article contains the plasticized plastic, the high adhesion force can be easily maintained for a long time.
The glass transition temperature of the polyurethane resin is preferably -10° C. or lower, more preferably -20° C. or lower. When the glass transition temperature is higher than -10° C., the adhesion force of the bonding layer to the surface protective layer, the lens members or the adherent tends to decrease.
Preferably, the polyurethane resin has a weight average molecular weight of 70,000 to 150,000.
A thickness of the bonding layer is preferably from 50 to 150 micrometers (μm.)
The surface of the bonding layer which can be adhered to the article body has indentations which correspond to net-form linking parts having a narrow width which are formed in the below explained production process. It is possible to make this surface flat to disappear indentations, whereby the adhesion force to the surface of the article body is increased.
Surface Protective Layer
As the surface protective layer, there may be used a single layer or a laminated film of one or more plastic films made of polyester resins, polyolefin resins, acrylic resins, polyurethane resins, polyvinyl chloride resins, fluororesins, ionomer resins, and so on.
A thickness of the surface protective layer is preferably from 10 to 200 μm, more preferably from 30 to 100 μm.
The surface protective layer may contain an additive such as an antioxidant, a UV light absorber, a colorant, etc.
Transparent Microspheres
As the transparent microspheres, glass beads or plastic beads having a desired refractive index may be used. A desired refractive index is usually from 1.4 to 2.7, preferably from 1.6 to 2.3.
When the refractive index is outside this range, the retroreflectiveness may be lost. That is, an amount of light which is retroreflected in the direction of the incident light is decreased, while an angle of observation of the reflected light is widened. Widening of the angle of observation to some extent may be used in a retroreflective sheet of a wide angle of observation type, which widens the angle of observation with maintaining the reflection luminance in an acceptable range. However, if the angle of observation is too large, the reflection luminance is decreased to a practically unpreferred level. Then, the more preferred refractive index is in the range between 1.9 and 2.1.
A diameter of the microsphere is usually from 10 to 860 μm, preferably from 20 to 150 μm, more preferably from 25 to 80 μm. When the diameter is too small, it is difficult to produce microspheres having a uniform diameter and a uniform refractive index, and the reflection luminance of the reflective sheet comprising such microspheres tends to decrease and the retroreflectiveness tends to deteriorate. When this diameter is too large, the thickness of the reflective sheet may increase, and the flexibility of the reflective sheet tends to decrease. The decrease of the flexibility of the reflective sheet causes peeling off of the reflective sheet when the sheet is adhered to the adherent.
Two or more kinds of the transparent microspheres having different refractive indexes may be used in combination, or two or more types of the transparent microspheres having different diameters may be used in combination.
When the transparent microspheres are colored by a colorant with maintaining the light transparency, reflected light has a different color from that of the incident light.
Reflector
As the reflector 3 shown in FIG. 4, a thin film having specular gloss, a reflective resin film containing a pearlescent pigment and the like can be used. The thin film may be formed by a thin film forming method such as vapor deposition from a metal such as aluminum, copper, silver, gold, zinc, etc. or a compound such as CeO 2 , Bi 2 O 3 , ZnS, TiO 2 , CaF 2 , Na 3 AIF 6 , SiO 2 , MgF 2 , etc. The reflective resin film may be formed by covering a paint comprising a resin and a pearlescent pigment (e.g. BiOCl 4 , PbCO 3 , guanine obtained from fish scales, etc.) on the lens element.
A thickness of the reflector is usually from 0.01 to 10 μm, preferably from 0.05 to 5 μm.
The pearlescent pigment may be added to the bonding layer to increase the reflection efficiency of the reflector.
Spaces for Encapsulating the Lens Members
The spaces for encapsulating the lens members are formed between the surface covering layer and the lens members with separating the surface covering layer and the lens members at a specific distance. With these spaces, the desired high reflection luminance is achieved. The formation of such spaces will be explained in connection with the production process.
Primer
In a preferred embodiment, the adhesion of the reflective sheet of the present invention to the adherent such as the article body is effected by applying a primer on the surface of the adherent, and adhering the surface of the bonding layer opposite the surface on which the surface protective layer is bonded, to the primer-applied surface.
As the primer, a solution containing a polymeric polyamine or the above described thermoplastic polyurethane is used. The primer improves the wettability between the adhering surface of the bonding layer and the surface of the adherent, and also dissolves the polyurethane resin on the adhering surface to impart an adhesion property thereto.
As a solvent to be contained in the solution, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, butyl carbitol, toluene, isopropyl alcohol, or their mixtures may be used.
A solvent itself which has a solubility parameter close to the polyurethane resin and a low evaporation rate such as butyl carbitol may be used as a primer containing no polymer.
The production process of the reflective sheet according to the present invention will be explained by making reference to FIGS. 8 and 9. For comparison, FIGS. 5, 6 and 7 show the production process of the conventional encapsulated lens type sheet having the conventional adhesive layer.
The production process of the encapsulated lens type sheet having the conventional adhesive layer comprises the following steps:
(1) On a carrier web, transparent microspheres 2 are partly embedded detachably to form a transparent microsphere layer which comprises the transparent microspheres as the lens means.
(2) On a surface of the exposed part of each microsphere 2, a mirror reflecting layer 3 is formed as a reflector by a thin film forming method.
(3) On the mirror reflecting layer 3, bonding layer 4 (shown as 13 in FIGS. 8 and 9) and a releasing film 5 are laminated.
(4) After the step (3), the carrier web 1 is removed to expose surfaces of microspheres 2 which are not covered by the mirror reflecting layer 3.
(5) On the surfaces of the microspheres 2 which are not covered by the mirror reflecting layer 3, the surface protective layer 6 is placed with leaving a predetermined gap.
(6) Then, on a releasing film 5, an embossing mold 7 having a net-form emboss pattern of thin lines 8 is pressed with heating to emboss the bonding layer 4 through the releasing film 5, whereby net-form linking parts having a narrow width, which bond the surface protective layer 6 partly to the bonding layer 4, are formed. At the same time, the combination of the linking parts and the surface protective layer 6 forms plural spaces 12.
(7) The releasing film 5 is removed to expose the other surface (to which an adhesive layer will be laminated) opposite the surface of the bonding layer 4 on which the surface protective layer 6 is bonded.
(8) On the other surface of the bonding layer, an adhesive layer having a releasing liner 11 is laminated.
In comparison with the production process of the capsule lens type having the conventional adhesive layer, the steps (7) and (8) can be eliminated in the production process of the encapsulated lens type sheet according to the present invention. That is, in the production process of the encapsulated lens type sheet according to the present invention, the releasing film 5 as such is used as the releasing liner to provide a final product.
Before the present invention, the releasing film 5 should be wasted as a used material from the production process, while the present invention provides an excellent production process from the view point of economy of resources.
Article Having Retroreflectiveness
An article 16 having retroreflectiveness according to the present invention comprises an article body 14 and the retroreflective sheet 15 of the present invention which is adhered to the article body 14, as shown in FIG. 4A. Since the retroreflective sheet has the above described structure, the sheet can be adhered to the article body with the high adhesion force for a long time, there is less possibility that the sheet is peeled off from the article body, and the high reflection luminance is maintained for a long time.
The article having retroreflectiveness according to the present invention has much better properties of maintaining the high adhesion force and high reflection luminance for a long time than the conventional encapsulated lens type sheet, when the article body contains the plasticized plastic, in particular, the plasticized polyvinyl chloride base resin.
Herein, the polyvinyl chloride base resin includes a homopolymer of vinyl chloride and vinyl chloride copolymers. Examples of the vinyl chloride copolymer are copolymers of vinyl chloride with at least one other copolymerizable monomer such as vinyl acetate, vinyl alcohol, vinyl acetal, maleic acid, styrene monomer, etc. Examples of the plasticizer to be contained in the polyvinyl chloride base resin are phthalate base plasticizers, polyester base plasticizers, adipate base plasticizers, fatty acid base plasticizers, trimellitate base plasticizers, epoxy base plasticizers, and so on. A content of the plasticizer is from 1 to 50 wt. % of the whole resin.
EXAMPLE 1
(1) Production of capsule lens type retroreflective sheet.
By the above steps (1) through (6), an encapsulated lens type sheet of the present invention was produced. The details of the materials used in this Example were as follows:
Transparent microspheres:
Glass beads having an average diameter of 65 μm.
Reflecting layer:
An aluminum layer formed, by vapor deposition, on the exposed surfaces of the transparent microspheres which were embedded in the carrier web to a depth of about 30% of the diameter, by vapor deposition.
Bonding layer:
A bonding layer having a thickness of about 50 μm was formed by coating a solution for a bonding layer prepared from the following components over the aluminum layer formed on the transparent microspheres, and drying the coated solution:
______________________________________Component Wt. Parts______________________________________Thermoplastic polyurethane 24.67(Polycarbonate polyurethanemanufactured by Nippon PolyurethaneCo., Ltd. Trade name: N-5199.Softening point of about 105° C.)Titanium dioxide 7.00(Taipeic manufactured by IshiharaIndustries, Ltd.)Antioxidant 0.48(Irganox manufactured by Ciba Geigy)Stearic acid 0.48Methyl ethyl ketone 49.49Cyclohexanone 17.88______________________________________
Releasing film:
A laminate film of a polyethylene layer having a thickness of 36 μm and a polyester layer having a thickness of 14 μm.
On the adhering surface of the bonding layer, this releasing film was laminated with facing the polyethylene layer to the bonding layer at 100° C. under 3 kg/cm 2 .
Surface protective layer:
An ethylene-acrylic acid copolymer film containing a UV light absorber with a thickness of about 75 μm (Primacor 3440 manufactured by Dow Chemical).
Space (air) layer
The laminate produced by the steps (1) through (5) was embossed between an embossing roll heated at 160° C. as a mold having the net-form emboss pattern of thin lines, and a rubber roll heated at 25° C.
(II) Adhesion of reflective sheet
A primer solution having the following composition was coated on a substrate made of a plasticized polyvinyl chloride (commercially sold soft vinyl chloride resin), and then the reflective sheet which had been produced was placed and pressed by a press roll:
______________________________________Component Wt. Parts______________________________________Thermoplastic polyurethane 10.00(The same as that used in the bondinglayer)Methyl ethyl ketone 58.50Toluene 18.00Isopropyl alcohol 13.50______________________________________
The substrate carrying the adhered reflective sheet was kept in an oven at 65° C. for one week to carry out an aging test.
After aging, the adhesion force (180 degree peeling strength) and retention of reflection luminance were measured.
With the reflective sheet of this Example, the adhesion strength by the 180 degree peeling test was 3.5 kg/25 mm, which was at the same level as the adhesion strength before aging.
The retention of reflection luminance was 98%. This result means that the reflective sheet of this Example does not lose the excellent property for maintaining the reflection luminance, which is one of the advantages of the encapsulated lens type sheet.
EXAMPLE 2
In the same manner as in Example 1 except that the thermoplastic polyurethane resin was changed to a thermoplastic polyurethane "N-5230" having the softening point of 130° C. (manufactured by Nippon Polyurethane), a reflective sheet was produced.
The reflective sheet of this Example had substantially the same test results as that of Example 1.
COMPARATIVE EXAMPLE 1
In the same manner as in Example 1 except that the thermoplastic polyurethane resin was changed to a thermoplastic polyurethane "N-2301" (manufactured by Nippon Polyurethane), and as a crosslinking agent, a polyisocyanate compound, Colonate L (manufactured by Nippon Polyurethane) was added to the resin composition for the bonding layer, a reflective sheet was produced.
The reflective sheet of this Comparative Example did not have sufficient adhesion force when it was adhered to the substrate, since the softening point of the cured bonding layer was 190° C.
COMPARATIVE EXAMPLE 2
In the same manner as in Example 1 except that the thermoplastic polyurethane resin was changed to a thermoplastic polyurethane "N-3113" having the softening point of 45° C. (manufactured by Nippon Polyurethane), a reflective sheet was produced.
Since the softening point of the bonding resin was too low, the bonding layer had large flowability, so that, when the sheet was wound and stored in the production process, the spaces (air layer) were collapsed by the winding pressure of the rolled sheet. As the result, a practically satisfactory encapsulated lens type sheet could not be produced.
COMPARATIVE EXAMPLE 3
The adhesion procedure and the aging test were repeated in the same manner as in Example 1 except that #3840 of 3M which is a conventional encapsulated lens type sheet was used as a reflective sheet, while no primer was used.
This reflective sheet had an adhesive layer comprising an acrylic pressure sensitive adhesive, on the adhering surface of the bonding layer.
In this Comparative Example, the retention of reflection luminance was 95%, while the adhesion force was very low and only 0.6 kg/25 mm.
COMPARATIVE EXAMPLE 4
The procedures of Comparative Example 3 were repeated using, as comparative samples, three enclosed lens type sheets. The comparative samples and results are as follows:
Sample/results
1) #580 of 3M (an adhesive layer comprising an acrylic pressure sensitive adhesive)/Adhesion force=0.7 kg/25 mm; Retention of reflection luminance=40%.
2) #FV-5000 of 3M (an adhesive layer comprising an acrylic pressure sensitive adhesive)/Adhesion force=1.6 kg/25 mm; Retention of reflection luminance=52%.
3) Reflective sheet manufactured by Unitica (an adhesive layer comprising a polyurethane base adhesive)/Adhesion force=2.5 kg/25 mm; Retention of reflection luminance=81%.
The sheets 1) and 2) had the low adhesion force, since they were adhered to the article body through the adhesion layer comprising the acrylic pressure sensitive adhesive.
The sheet 3) is an example of the reflective sheet using the adhesion layer comprising the polyurethane base adhesive. This sheet had a lower adhesion force than that of Example 1. This indicates that the encapsulated lens type sheet using the polyurethane base adhesive in the adhesion layer would have the same result. Since these sheets are the enclosed lens type sheet, they had the lower retention of reflection luminance than that of Example 1. | An encapsulated lens retroreflective sheeting that has a bonding layer that consists essentially of a thermoplastic polyurethane resin that has a softening point of 70° C. to 200° C. The bonding layer is sealed to a light transmissible surface protective layer by a multitude of bonds that form spaces between the protective layer and the bonding layer. Retroreflective elements are partially embedded in the bonding layer and interface with air in the spaces. An encapsulated lens retroreflective sheeting of this construction can be adhered to a highly plasticized plastic surface and maintain high adhesion force for an extended duration while at the same time maintaining good retroreflective performance. | 8 |
FIELD OF THE INVENTION
This invention relates to an image reproducing system such as, for example, a video tape recorder and, more particularly, to an image squeezing circuit for reproducing a small image or images overlapped with a large image on a display.
DESCRIPTION OF THE RELATED ART
There have been proposed various image reproducing systems such as video tape recorders, and an image reproducing system is provided with an image squeezing circuit so that an ordinary-sized image reproducible from one image signal is squeezed into a small-sized image for overlapping with another ordinary-sized image reproduced from another image signal on a display. The image reproducing system with the image squeezing circuit reproduces two different-sized images on the display, and the audience can enjoy two dramas concurrently proceeding on a single display. However, since a composite image signal carrying an image is produced through a quadrature two-phase modulation, the image squeezing can not be achieved simply through a decimating or thinning-out operation on the composite image signal. Two approaches are proposed for the image squeezing.
The first approach is described in "VIDEO TECHNICAL TOPICS", Television Technology 1986 July, pages 89 to 94, published by Electronic Technology Publishing Corporation According to the paper, a chrominance signal is demodulated for reproducing an original color signal, and the original color signal is decimated through a sampling operation with a relatively low sampling frequency. Then, the color signal is modulated into a chrominance signal again, and the chrominance signal thus decimated is used for reproducing a small-sized image.
The second approach is reported in "TOSHIBA DIGITAL Hi-Fi VIDEO A-900PCM", Television Technology 1987 January, pages 20 to 24. The second approach is characterized by changing a chrominance subcarrier signal in frequency. Namely, the chrominance subcarrier signal is decreased to a lower frequency than the ordinary frequency, and the reduction is equal to the proportion of the small-sized image to the ordinary-sized image. Finally, the reduced chrominance subcarrier signal is recovered to the ordinary frequency after a decimating operation. Of course, pieces of information indicative of the color phase are recovered after the decimating operation. For example, if the composite image signal is produced in accordance with the NTSC color system, the chrominance subcarrier signal is 3.58 MHz. When the small-sized image is assumed to be a half of the ordinary image, the chrominance subcarrier signal is decreased to 1.79 MHz.
The first approach is desirable for a television system, because the demodulated color signal is necessary so as to reproduce the image. However, if the first approach is applied to a video tape recorder system or an audio-visual amplifier system, the system requires a quadrature two-phase demodulator as well as a modulator. These circuits make the system arrangement complicated. Moreover, color mismatching tends to take place at the modulation and the demodulation.
On the other hand, the second approach encounters a difficulty in the preservation of the pieces of information indicative of the color phase, and, for this reason, the reduction ratio is inherently fixed to a single value. In other words, it is impossible to vary the reducing ratio.
SUMMARY OF THE INVENTION
It is therefore an important object of the present invention to provide an image squeezing circuit which is simple in circuit arrangement.
It is also an important object of the present invention to provide an image squeezing circuit with which it is relatively easy to vary the reducing ratio.
In accordance with the present invention, there is provided an image squeezing circuit operative to produce an output image carrying signal for reproducing a small-sized image on the basis of an input image carrying signal for being capable of reproducing an ordinary-sized image m times larger than the small-sized image, where m is an integer equal to or greater than two, comprising: (a) a separating section supplied with the input image carrying signal and operative to produce an analog luminance signal and an analog chrominance subcarrier signal; (b) a color subcarrier producing section supplied with the input image carrying signal and operative to produce a color subcarrier signal which is of a periodical signal; (c) a timing signal producing section operative to produce a first sampling clock signal an n times larger in frequency than the color subcarrier signal and appearing in every intervals of the color subcarrier signal where n is an integer equal to or greater than three, a second sampling signal n/m times larger in frequency than the color subcarrier signal and a high frequency periodical signal n times larger in frequency than the color subcarrier signal; (d) a first decimating section supplied with the analog chrominance subcarrier signal and responsive to the first sampling signal for producing a decimated digital chrominance signal, the decimated digital chrominance signal being delivered therefrom in response to the high frequency periodical signal; (e) a second decimating section supplied with the analog luminance signal and responsive to the second sampling signal for producing a decimated digital luminance signal, the decimated digital luminance signal being delivered therefrom in the presence of the high frequency periodical signal; and (f) an output section supplied with the decimated digital chrominance signal and the decimated digital luminance signal and operative to produce the output image carrying signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of an image squeezing circuit according to the present invention will be more clearly understood from the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a block diagram showing the arrangement of an image squeezing circuit according to the present invention;
FIG. 2 is a diagram showing the timing chart of the image squeezing circuit shown in FIG. 1;
FIG. 3 is a block diagram showing the arrangement of a part of another image squeezing circuit according to the present invention; and
FIG. 4 is a block diagram showing the arrangement of a part of still another image squeezing circuit according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First embodiment
Referring first to FIG. 1 and, concurrently, to FIG. 2 of the drawings, an image squeezing circuit according to the present invention is supplied with an input image carrying signal S1. In this instance, m and n are assumed to be three and four, respectively. The input image carrying signal S1 is transferred in parallel to a separating circuit 101 and a subcarrier producing circuit 102, and the separating circuit is operative to separate a luminance signal Y1 from a chrominance subcarrier signal D1. The subcarrier producing circuit 102 is provided for producing a color subcarrier signal F1 in synchronization with the color burst of the input image carrying signal S1, and the color subcarrier signal F1 is supplied in parallel to a frequency multiplier 103 and a mod-m counter circuit 104, and the frequency multiplier 103 produces a high frequency pulse signal F2 which is four times larger in frequency than the color subcarrier signal F1. In this instance, the mod-m counter circuit 104 is of the mod-3 counter, and is operative to produce a carry signal F3 the frequency of which is a third of that of the color subcarrier signal F1.
The high frequency pulse signal F2 is supplied to a gate circuit 105, and the gate circuit 105 is transparent to the high frequency pulse signal F2 in the presence of the carry signal F3 of a high voltage level. The high frequency pulse signal F2 passing through the gate circuit 105 serves as a first sampling clock signal F4. The high frequency pulse signal F2 is further supplied to a frequency demultiplier 106, and the frequency demultiplier 106 produces a second sampling clock signal F5 the frequency of which is a third of that of the high frequency pulse signal F2.
The luminance signal Y1 separated by the separating circuit 101 is supplied to an analog-to-digital converting circuit 211, and the analog-to-digital converting circuit 211 is responsive to the second sampling clock signal F5 for sampling the luminance signal Y1. Then, the discrete values of the luminance signal Y1 are converted into digital luminance signals Y2. Thus, the digital luminance signal Y2 is representative of the discrete values of the analog luminance signal Y1, and the discrete values are respectively indicated by Z1, Z2, . . . and Z23 in FIG. 2. The digital luminance signals Y2 are transferred from the analog-to-digital converting circuit 211 to a memory 212, and the second sampling clock signal F5 is supplied to a write-in controlling circuit 213 for producing a write-in timing signal WR1. The memory 212 memorizes the digital luminance signal Y2 in the presence of the write-in timing signal WR1, so that every third digital luminance signal Y2 is periodically memorized in the memory 212 and the other digital luminance signals are discarded. The digital luminance signals Y2 are thus decimated or thinned out, and are constituted by the digital luminance signals representative of the values Z2, Z5, . . . and Z23 in this instance. The digital luminance signals thus memorized are hereinunder referred to as decimated digital luminance signals Y3. The memory 212 is further associated with a read out controlling circuit 214, and the read out controlling circuit 214 is responsive to the high frequency pulse signal F2 for producing a read out timing signal RD1. The decimated digital luminance signals Y3 memorized in the memory 212 are successively read out from the memory 212 in the presence of the read out controlling signal RD1 as shown in FIG. 2, and the decimated digital luminance signal Y3 is supplied to a digital-to-analog converting circuit 215. The digital-to-analog converting circuit 215 changes the decimated digital luminance signal Y3 into an equivalent decimated analog luminance signal Y4 in response to the high frequency pulse signal F2, and the decimated analog luminance signal Y4 is supplied to a mixing circuit 107.
On the other hand, the chrominance subcarrier signal D1 separated by the separating circuit 101 is supplied to an analog-to-digital converting circuit 311, and the chrominance subcarrier signal D1 is sampled with the first sampling clock signal F4. Since the gate circuit 105 is gated by the carry signal F3, four component pulses of the high frequency pulse signals are periodically transferred so that the first sampling clock signal F4 is constituted by plural groups of pulses each consisting of four pulses. Assuming now C1, C2, . . . and C23 are representative of the discrete values of the analog chrominance subcarrier signal D1 sampled with the high frequency pulse signal F2, digital chrominance signals D2 are constituted by a plurality of digital signal groups at a certain interval each consisting of the four digital chrominance signals representative of, for example, C1, C2, C3 and C4. Thus, the analog chrominance subcarrier signal D1 is decimated upon the sampling operation by the analog-to-digital converting circuit 311, and the digital chrominance signals D2 are supplied to a memory 312. The memory 312 is associated with a write-in controlling circuit 313 and a read out controlling circuit 314, and the write-in controlling circuit 313 and the read out controlling circuit 314 are respectively responsive to the first sampling signal F4 and the high frequency pulse signal F2 for producing a write-in timing signal WR2 and a read out timing signal RD2, respectively. The digital chrominance signals D2 are memorized in the presence of the write-in controlling signal WR2, and the decimated digital chrominance signals are successively read out from the memory 312 in response to the read out controlling signal RD2. The decimated digital chrominance signals D3 thus successively read out are supplied to a digital-to-analog converting circuit 315. and are converted into a decimated analog chrominance subcarrier signal D4 which is transferred to the mixing circuit 107.
The mixing circuit 107 mixes the decimated analog luminance signal Y4 with the decimated analog chrominance subcarrier signal D4, and, accordingly, produces an output image carrying signal S2.
The circuit behavior of the image squeezing circuit shown in FIG. 1 is summarized as follows. If the input analog image carrying signal S1 is supplied to the separating circuit 101, the luminance signal Y1 is separated from the chrominance subcarrier signal D1. On the one hand, the analog luminance signal Y1 is successively converted into a series of the digital luminance signals Y2, while on the other hand, the analog chrominance subcarrier signal D1 is periodically converted into the digital chrominance signals. The series of the digital luminance signals Y2 are periodically written into the memory 212, while all of the digital chrominance signals D2 are written into the memory 312. In other words, the digital luminance signals Y2 are decimated upon memorization, while the analog chrominance subcarrier signal D1 is decimated upon sampling operation. Both the digital luminance signals Y2 and the digital chrominance signals D2 are read out from the respective memories 212 and 312 in synchronization with each other, and are mixed with each other for producing the output image carrying signal S2. In this instance, the digital luminance signals are decimated to a third, and the digital chrominance signal is also decimated to a third. Thus, the output image carrying signal S2 reproduces a small image squeezed to a third of the original image which is assumed to be reproduced with the input image carrying signal S1.
In the image squeezing circuit shown in FIG. 1, the frequency multiplier circuit 103 produces the high frequency pulse signal F2 which is four times as great in frequency as the color subcarrier signal F1, however, the high frequency pulse signal F2 may be a predetermined multiple n as great in frequency as the color subcarrier signal, and the predetermined multiple may be equal to or greater than three. Moreover, the counter is of the mod-3 counter, however, m may be equal to or greater than 2 depending upon the reduction ratio the image.
Now let us discuss the deviation between the decimated digital luminance signal Y3 and the decimated digital chrominance signal D3. As will be seen from the lowest two lines of FIG. 2, the suffixes of the decimated luminance signal Y3 are not identical with the suffixes of the corresponding decimated digital chrominance signal D3, and the mixing circuit 107 produces the output image carrying signal S2 on the basis of each combination of those decimated digital signals. However, in an actual application, the R-Y signal is in 0.5 MHz range, and the B-Y signal is also in 0.5 MHz range. On the other hand, the luminance signal has more than 3 MHz range. In this situation, the above-mentioned deviation is merely fallen into a variation of color of the order of a sixth in terms of the original color. Then, the deviation between the decimated digital luminance signal and the decimated digital chrominance signal is acceptable in so far as the reduction ratio ranges between about a half and about a quarter.
In the image squeezing circuit shown in FIG. 1, the separating circuit 101 and the subcarrier producing circuit 102 respectively form a separating section and a color subcarrier producing section, and the counter circuit 104, the frequency multiplier 103, the gate circuit 105 and the frequency demultiplier 106 as a whole constitute a timing signal producing section. The analog-to-digital converting circuit 311, the memory 312, the write-in controlling circuit 313, the read out controlling circuit 314 form in combination a first decimating section, and the analog-to-digital converting circuit 211, the memory 212, the write-in controlling circuit 213 and the read out controlling circuit 214 as a whole constitute a second decimating section. Finally, the digital-to-analog-converting circuits 215 and 315 and the mixing circuit 107 form in combination an output section.
Second embodiment
Turning to FIG. 3 of the drawings, an essential part of another image squeezing circuit embodying the present invention is illustrated. The image squeezing circuit shown in FIG. 3 is similar in arrangement to the image squeezing circuit shown in FIG. 1 with the exception of means for producing a high quality squeezed image. For this reason, component circuits are designated by the same reference numerals denoting the corresponding component circuits of the image squeezing circuit shown in FIG. 1. Moreover, the memories 212 and 312 are also associated with read out controlling circuits, digital-to-analog converting circuits and a mixing circuit in a similar manner to those shown in FIG. 1, however, these circuits are omitted from FIG. 3 for the sake of simplicity.
A low pass filter circuit 216 is coupled between the separating circuit 101 and the analog-to-digital converting circuit 211, so that noise components produced upon the separation are eliminated from the luminance signal Y1.
On the other hand, between the analog-to-digital converting circuit 311 and the memory 312 are coupled a series combination of a first adder 318, a first averaging circuit 319, a second adder 320 and a second averaging circuit 321 which is associated with a series combination of first and second shift registers 316 and 317. The first and second shift registers 316 and 317 are responsive to the high frequency pulse signal F2. The first shift register 316 introduces a delay in the transmission of the digital chrominance signal D2 by a time period tantamount to four pulses of the high frequency pulse signal F2, thereby producing a first delayed digital chrominance signal D5. The second shift register 317 further introduces a delay in the transmission of the first delayed digital chrominance signal D5 by a time period equivalent to the four pulses of the high frequency pulse signal F2, and produces a second delayed digital chrominance signal D6. Since the first adder 318 is coupled at the input nodes thereof to the analog-to-digital converting circuit 311 and the second shift register 317, the digital chrominance signal D2 is added to the second delayed digital chrominance signal D6. The first averaging circuit 319 is supplied with the sum from the first adder 318, and is operative to divide by two for taking an average. The second adder is coupled at the input nodes thereof to the first averaging circuit 319 and the first shift register 316, and the first delayed digital chrominance signal D5 is added to the average fed from the first averaging circuit 319. The sum fed from the second adder 320 is divided by two for taking an average. Thus, the three digital chrominance signals are averaged through the twice adding and dividing operations, and, for this reason, the reproduced image is natural in color without any rapid color change. Moreover, since each of the shift registers 316 and 317 introduces the time delay equivalent to four pulses, the three digital chrominance signals are identical with one another in phase in the signal groups each consisting of the fours digital chrominance signals successively sampled. For example, the digital chrominance signal labeled with C1 is added to the digital chrominance signal labeled with C9 at the first adder 318, and the sum is added to the digital chrominance signal labeled with C5 at the second adder 320. For this reason, no turbulence takes place in the phase information.
The digital chrominance signal D2 thus averaged is memorized in the memory 312 in response to the write-in controlling signal WR2 fed from the write-in controlling circuit 313, and the digital luminance signal Y2 is memorized into the memory 211 in response to the write-in controlling signal WR1 fed from the write-in controlling circuit 213. However, these write-in operations as well as the read out operations are similar to those of the image squeezing circuit shown in FIG. 1, and, for this reason, no further description is incorporated.
In the image squeezing circuit shown in FIG. 3, the shift registers 316 and 317, the adders 318 and 320, and the averaging circuits 319 and 321 are incorporated in the first decimating section.
Third embodiment
Turning to FIG. 4 of the drawings, a part of still another image squeezing circuit embodying the present invention is illustrated, and this image squeezing circuit aims at production of a high quality image similar to that shown in FIG. 3. However, the other parts are similar in arrangement to those of the image squeezing circuit shown in FIG. 1, and, for this reason, the component circuits are designated by the same reference numerals without any detailed description.
For producing a high quality image, between the memory 312 and the digital-to-analog converting circuit 315 is coupled a series combination of a first adder 403, a first averaging circuit 404, a polarity inverting circuit 405, a second adder 406 and a second averaging circuit 407 which is associated with a series combination of a first and second shift registers 401 and 402. Both of the first and second shift registers are supplied with the high frequency pulse signal F2 for shifting operations, and each of the first and second shift registers 401 and 402 introduces a delay into the transmission of the decimated digital chrominance signal D3 by a time period equivalent to two pulses of the high frequency pulse signals.
The circuit behavior is similar to that shown in FIG. 3 with the exception of the amount of the delay introduced by each shift register 401 or 402. When each of the shift registers 401 and 402 introduces the delay equivalent to two pulses, the second decimated digital chrominance signal added by the second adder 405 is different in phase from the first and third decimated digital chrominance signals by 180 degrees, and, for this reason, the polarity inverting circuit 405 is provided between the averaging circuit 404 and the second adder 406 for matching the phases.
Since the time delay introduced by each shift register 401 or 402 is shorter than the time delay introduced by each shift register 316 or 317, the bandwidth of the chrominance subcarrier signal responsible to the image squeezing circuit shown in FIG. 4 is wider than the bandwidth of the chrominance subcarrier signal responsible to the image squeezing circuit shown in FIG. 3. Comparing the chrominance signal written into the memory with the chrominance signal read out from the memory, the bandwidth at the reading out side is widened depending upon the reduction ratio of image. For example, if the reduction ratio is a half, the bandwidth is widened twice. Then, it is important not to excessively restrict the bandwidth.
In the image squeezing circuit shown in FIG. 4, the shift registers 401 and 402, the adders 403 and 406, the averaging circuits 404 and 407 and the polarity inverting circuit 405 are incorporated in the first decimating section.
Although particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention. | An image squeezing circuit produces an output image carrying signal for reproducing a small-sized image 1/m times larger than an ordinary-sized image (where m is an integer not less than two), and an input image carrying signal is separated for producing an analog chrominance subcarrier signal, an analog luminance signal and a color subcarrier signal, wherein the analog luminance signal is sampled with a sampling signal n/m times larger in frequency than the color subcarrier signal (where n is an integer not less than three) for producing a decimated digital luminance signal but the analog chrominance subcarrier signal is sampled with another sampling signal n times larger in frequency than the color subcarrier signal in every m pulse intervals of the color subcarrier signal for producing a decimated digital chrominance signal, the decimated digital luminance signal and the decimated digital chrominance signal being supplied to respective digital-to-analog converting circuits in response to a high frequency pulse signal n times larger in frequency than the color subcarrier signal for producing the output image carrying signal. | 7 |
This application is a division of application Ser. No. 682,699, filed on Apr. 9, 1991, U.S. Pat. No. 5,161,378; which is a division of application Ser. No. 570,169, filed on Aug. 17, 1990, abandoned; which is a division of application Ser. No. 478,726, filed on Feb. 12, 1990, U.S. Pat. No. 4,974,553; which is a division of application Ser. No. 277,714, filed on Nov. 30, 1988, abandoned.
FIELD OF THE INVENTION
The present invention relates to internal combustion engines and more particularly to rotary internal combustion engines where the engine block housing the cylinders is directly coupled to an output shaft and the engine block rotates about the axis of rotation of the output shaft.
BACKGROUND OF THE INVENTION
The conventional internal combustion engine is one where the cylinders, either in-line or in a V-block, for instance, have the cylinder connecting rods connected to a crank shaft and the crank shaft is rotatably driven by the combustion of the fuel mixture within the cylinders. The typical combustion cycle includes intake of an air-fuel mixture into the cylinder, compression of the air-fuel mixture by the piston, combustion which causes a rapid expansion of the gases within the cylinder to drive the piston and perform work, and the subsequent exhaust stroke evacuating the products of combustion. In a four stroke crank-type engine, the power or expansion stroke occurs once in each 720° of rotation of the crank shaft.
This conventional internal combustion engine also requires an intake and exhaust valve for each cylinder which must be timed to open and close in synchronization with the cycle of the pistons. The valves in a conventional internal combustion engine are poppet valves which have a stem and a mushroom shaped head with edges seating on the periphery of a valve opening and which ar opened and closed by synchronized cams. Because the seating faces of the exhaust valves in internal combustion engines are subjected to extremely high temperatures they tend to burn, oxidize or provide a source of pre-ignition. Pre-ignition is frequently a source of damaging engine knock. Accordingly, it is necessary to cool the valve, limit operating temperature and/or maintain a reducing atmosphere during combustion. In a conventional engine this is accomplished by using an excess of fuel, i.e. a rich mixture, over that necessary to support the combustion process. This excess fuel is utilized as a coolant for the exhaust valve as well as insuring that there is no free oxygen at the end of the combustion process, which could oxidize the valves. Because excess fuel is supplied to the cylinders, all the fuel is not completely combusted and unburned hydrocarbons from the uncombusted fuel are exhausted through the exhaust valves and the exhaust manifold system rather than contributing to the output power. Because of this, the exhaust gas from the internal combustion engine pollutes the atmosphere excessively.
The use of the crank shaft in a conventional internal combustion engine causes a kinematic limitation to the motion of the piston. That is, the translation of the reciprocating motion of the piston to rotary motion by means of a crank causes the piston to reciprocate up and down in the cylinder in the characteristic crank-slider motion, which is a higher order, non-sinusoidal motion. This characteristic crank-slider motion cannot be conveniently altered and is symmetric for each stroke, because it is fixed by the geometry of a crank/connecting rod assembly. The crank-slider motion of the piston in a conventional internal combustion engine is disadvantagous for several reasons, including: 1) crank-slider motion generates higher inertial stresses than does pure sinusoidal motion, 2) crank-slider motion results in increased time at or near top dead center ("TDC"), increasing the likelihood of pre-ignition, 3) increased dwell time results in increased heat loss to the engine both before and after firing, and 4) the torque arm just after firing is small, under utilizing the high gas pressures and 5) the torque arm near the end of the the stroke when pressure is low, i.e. near bottom dead center ("BDC") is too small for effective capture of the motive force in this gas. Furthermore, the crank-slider motion does not closely match the heat and pressure conditions as a function of time that are created in the combustion chamber during the operation of the engine.
In spark ignition engines the longer the time period that the air-fuel mixture is compressed the greater likelihood there is of pre-ignition. Because the upward rise of the piston in a conventional engine is relatively slow near TDC, the compressed air-fuel mixture is at or near its maximum compression during a relatively long period of time prior to top dead center. For this reason, relatively low compression ratios and/or high octane fuels are required to prevent pre-ignition.
Immediately after passing top dead center and beginning its downward expansion stroke, the piston in a crank-type engine is also moving relatively slowly. In both spark-ignition engines and compression-ignition (i.e. Diesel) engines, the relatively slow motion of the piston near top dead center causes excessive heat loss because of the relatively long length of time that the hot combustion gases are in contact with the head and cylinder walls. Finally, the crank-slider motion of the piston near the end of its stroke, that is near bottom dead center, where the pressures are the lowest, makes it difficult to effectively utilize the available motive force in the gases, due to the pressures involved coupled with the short effective arm of the crank at this position. Thus, in conventional engines, the exhaust valve begins to open a significant number of degrees before bottom dead center, resulting in a significant loss of available energy of the combusted gases.
Furthermore, in a crank-type engine, the intake stroke of the piston in a four stroke engine is inherently the same length as the expansion stroke. Because of the increase in temperature and pressure caused by combustion, at the bottom of the expansion stroke (even if the exhaust valve were not to be opened until bottom dead center), the combusted gases will still be at a higher pressure than ambient. Thus, significant loss in available motive force in the combusted gases occurs when the exhaust valve opens and exhausts the higher than ambient pressure gas to ambient pressure. Various mechanisms combined with the crank/connecting rod system have been proposed to try to capture more of this available work through more complete expansion, but have not proven successful due to their cost and mechanical complexity. For example, the Atkinson mechanism provides a crank/connecting rod system with a longer expansion stroke than intake stroke, but at greatly increased mechanical complexity.
Moreover, the octane quality of commercially available fuels, which affects the permissible compression ratio, varies considerably. Making provision for variable compression ratio in the cylinders would allow the maximum permissible compression ratio for a given fuel, and hence highest efficiency for a given fuel. However, efforts to make internal combustion engines with variable compression ratios have not proven very successful in practice due to mechanical complexity. Thus, conventional internal combustion engines have non-adjustable compression ratios and engine manufacturers must design compression ratios to accept the poorest available fuel. This compromise results in an engine having a lower compression ratio than the optimum, and hence a lower efficiency than the optimum for an average fuel. Gasoline manufacturers sell "super" octane gasoline, therefore conventional engines designed for poor fuel derive no benefit from using these costly "super" fuels.
In an attempt to alleviate some of the difficulties of the crank-type internal combustion engine, various rotary engine designs have been proposed where the engine block housing the cylinders and pistons of the engine is directly coupled to the output shaft of the engine and the entire block, with the assembly of cylinders and pistons, rotates along with the output shaft. In one such rotary engine proposal, U.S. Pat. No. 4,023,536, each piston has a roller which rolls against the interior surface of a cam to translate the reciprocating motion of the piston to rotary motion of the engine block rotor, instead of by means of a crank and connecting rod as in a crank-type engine.
Although the use of a cam overcomes the inherent kinematic limitations of a crank mechanism, these rotary designs have not been entirely successful. In such rotary engine designs the cam acts directly upon the roller which is directly connected to the piston. Since it is the tangential (i.e. side) component of force from the cam surface which causes rotation of the engine block, and hence the useful power output, these forces can only be transmitted to the engine block in these designs by means of side forces on the piston against the cylinder walls. These side forces and friction contribute to excessive wear on the piston and cylinder in these prior art designs.
Furthermore, because the entire engine block and pistons rotate in a rotary engine, centrifugal force tends to throw the piston outward against the cam. These centrifugal forces are very large in magnitude, tend to increase wear on the cam surface and cam roller in prior art rotary engine designs, thereby limiting engine speeds adversely.
In rotary engines, the engine block with the cylinders rotates within a housing. Because of this, cooling the cylinders has proven difficult in prior art designs, because delivering sufficient air or water to a rotating assembly of cylinders presents mechanical and sealing difficulties.
These and other problems have thus far prevented the the practical implementation of a rotary engine design.
OBJECTS OF THE INVENTION
Accordingly, it is an object of the present invention to provide an internal combustion engine utilizing a rotating engine block coupled directly to the output shaft of the engine which overcomes the foregoing disadvantages.
It is a further object of the present invention to provide a rotary internal combustion engine of increased efficiency and exhibiting lower unburned hydrocarbon and NO x emissions than conventional internal combustion engines.
Another object of the present invention is to provide a rotary internal combustion engine which avoids problems of excessive side wear on the pistons.
Still another object of the present invention is to provide a rotary internal combustion engine which avoids problems of the centrifugal forces acting on the pistons to cause excessive force and wear upon the cam track surface and cam follower, and to provide a force tending to return the piston to TDC.
Yet another object of the present invention is to provide a rotary internal combustion engine of the character described wherein increased efficiency is obtained from the power stroke of each of the cylinders because of a unique design of the stationary cam surface on which the connecting rods act.
A still further object of the present invention is to provide a rotary internal combustion engine which has a capability of developing a power stroke during more than 110° of rotation of the output shaft for each cylinder.
A further object of the present invention is to provide an internal combustion engine having a smooth power output and a low idle speed.
A still further object of the present invention is to provide a rotary internal combustion engine wherein provision can be made to vary the compression ratio within the cylinders during operation to optimize performance.
Still another object of the present invention is to provide an internal combustion engine having decreased emissions of hydrocarbon pollutants and oxides of nitrogen.
Yet another object of the present invention is to provide an rotary engine cooled by oil in a novel manner.
Yet another object of the present invention is to provide a rotary internal combustion engine wherein one or more of the pistons can be selectively locked or unlocked depending upon engine operating parameters to provide variable engine displacement and more efficient engine operation.
Still another object of the present invention is to provide an ideal power plant for a light propeller driven airplane.
SUMMARY OF THE INVENTION
In accordance with an embodiment of the present invention, a rotary internal combustion engine is provided which has a housing, a cam track internally disposed within the housing and adapted to receive a cam follower, and a rotatable engine block disposed within the housing and rotatable about a central axis. The block includes an axially extending output shaft and at least one radially arranged cylinder assembly on the block. Each cylinder assembly has a cylinder having a longitudinal axis extending generally radially outwardly from the rotational axis of the block and means defining an end wall on the cylinder. A piston member is disposed within the cylinder and is adapted to reciprocate within the cylinder. The piston includes a head end which together with said cylinder and its end wall defines a combustion chamber. Means permitting periodic introduction of air and fuel into the combustion chamber, means for causing combustion of a compressed mixture of air and fuel within the combustion chamber, and means permitting periodic exhaust of products of combustion of air and fuel from the combustion chamber are provided. The engine also includes means for imparting forces and motions of the piston within the cylinder to and from the cam track comprising linkage means and a cam follower operatively connected to the linkage means. The linkage means comprises a connecting rod having a first end portion pivotally connected to the piston member, a second end portion and a rocker arm. The rocker arm has a first end portion pivotally mounted to a mounting point fixed with respect to the block and offset with respect to the longitudinal axis of its associated cylinder, a second end portion pivotally connected to the second end portion of the connecting rod, and an arm portion connecting the first and second end portions of the rocker arm. The cam follower is adapted to ride along the cam track so that the cam follower forces and motions are transmitted to and from the piston, through the linkage means, to and from the cam track. The cam track includes at least a first segment and at least a second segment thereof. The first segment has a positive slope wherein the cam track segment has a generally increasing radial distance from the rotational axis of the engine block whereby as a piston moves outwardly in a cylinder on a power stroke while the cam follower is in radial register with the cam track segment, the reactive force of the respective cam follower through the linkage means against the cam track segment acts in a direction tending to impart rotation to the engine block in the direction of the positive slope of the cam track segment. The second segment has a negative slope wherein the cam track segment has a generally decreasing radial distance from the rotational axis of the engine block whereby as a cam follower rides along the negative slope of the cam track as said engine block rotates, the cam follower will cause a geometrically defined motion of the linkage means to compel a radially inward motion of the respective piston in its respective cylinder.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art upon reading the following description in conjunction with the figures, wherein:
FIG. 1 is a diagrammatic end view of a cutaway portion of a preferred embodiment of the rotary engine of the present invention, showing one complete cylinder assembly and portions of two other cylinder assemblies in their respective relative positions on the engine block;
FIG. 2 is a diagrammatic side view of the rotary engine depicted in FIG. 1, taken along the line 2--2 of FIG. 1, and a diagrammatic representation cf the oil cooling and lubricating system in accordance with a preferred embodiment of the present invention;
FIG. 2A is an end view of the static seal plate of the rotary valve of a preferred embodiment of the present invention;
FIG. 3 is a diagrammatic end view of another embodiment of the engine of the present invention, showing one embodiment of means for affecting the compression of the engine and a different embodiment of the linkage means;
FIG. 4 is a diagrammatic side view, partly in section, of the embodiment of the engine depicted in FIG. 3, taken along the line 4--4;
FIG. 5 is a diagrammatic sectional end view of still another embodiment of the present invention including a variation of the linkage means in accordance with the present invention, and showing means for selectively preventing pistons from reciprocating;
FIG. 6 is a diagrammatic sectional end view of a rotary engine in accordance with the present invention, showing another embodiment of the means for varying the compression ratio, including an adjustable cam track segment;
FIG. 6A is an enlarged sectional view taken along the line 6A--6A of FIG. 6, showing the construction of one embodiment of the adjustable cam track segment;
FIG. 7 is a graph of piston motions as functions of rotor angle in accordance with different embodiments of the present invention, and of piston motions in a crank-type engine for comparison purposes;
FIG. 8 is a table of the values of piston motion used to generate FIG. 7; and
FIG. 9 is a diagrammatic representation of a cam profile in accordance with a preferred embodiment of the present invention, with numbers on the periphery of the cam profile corresponding with the position numbers on the table of FIG. 8.
FIG. 10 is a side view of a multibank embodiment of the present invention, including two rotary engines connected together in series.
FIG. 11 is a partially cutaway view of a propeller driven light airplane including a two bank rotary engine in accordance with and embodiment of the present invention.
FIG. 12 is a graph of engine torque divided by cylinder pressure as a function of rotor angle for a rotary engine in accordance with the present invention having a simple harmonic motion, and a graph of engine torque divided by cylinder pressure for an equivalent conventional crank engine as a function of one half the crank angle.
FIG. 13 is a graph depicting piston acceleration for different cam profiles in an engine constructed in accordance with an embodiment of the present invention, with piston accelerations for a conventional crank shown for comparison.
DETAILED DESCRIPTION
With reference to the figures, and initially to FIGS. 3 and 4 thereof, a rotary internal combustion engine 10 accordance with one embodiment of the present invention is depicted. Engine 10 is a four stroke, spark ignition engine with a carburetor 11, intake pipe 12 leading to rotary valve assembly 189, and spark plug 115. A four stroke compression ignition (Diesel) cycle could also be employed, in which case carburetor 11 and spark plug 115 would be replaced with fuel injection directly into the cylinder. Two stroke spark ignition and compression ignition cycles could also be used.
Engine 10 includes a rotatable engine block 13 coupled to an output shaft 110 which extends axially from each end of the rotatable engine block 13 to provide a means of translating the rotation of the engine block 13 into useful work. Output shaft 110 is supported by inboard bearing 318 and outboard bearing 319 which extend axially from housing 14, which contains engine block 13 and permits its rotation. Bearing 318 and 319 are preferably conventional journal bearings, but other bearings such as ball or roller bearings could also be provided. Instead of an output shaft 110, other means such as a gear drive, chain drive, hydraulic drive, directly coupled electromagnetic generator or other means for capturing the useful work could also be provided. Furthermore, the engine in accordance with the present invention can also operate where the engine block 13 is held stationary, and the housing 14 allowed to rotate. In this case, the output shaft or other means would be connected to the housing 14.
Rotatable engine block 13 includes four radially arranged cylinder assemblies 30, which are preferably, though not necessarily, identical. Only one of these cylinder assemblies will be described in detail, and the same description would apply to the other three cylinder assemblies. It should be recognized, however, that the invention is not limited to four cylinder assemblies, or any particular number of cylinder assemblies.
Each of cylinder assemblies 30 includes a cylinder 31, within which a piston 21, preferably made of low inertia material such as aluminum, is reciprocally and slidably disposed. Piston 21 includes piston rings 91, preferably made of cast iron or steel.
Each cylinder assembly 30 includes an end wall at its radially inwardmost point, which is preferably a cylinder head 70, and a port opening 199. Each of pistons 21 include a crown or piston head 101. The space between piston head 101 and cylinder head 70, together with port opening 199, forms combustion chamber 71.
In order to introduce air and/or fuel into each of the combustion chambers 71, a rotary valve assembly 189 is included. This rotary valve assembly is best seen in FIGS. 2 2A, 3 and 4, and is preferably axially mounted at one end of output shaft 110. Port opening 199 in combustion chamber 71 functions as both an intake and exhaust port, and exposes the combustion chamber to the spark plug or diesel injection. This opening or port 199 extends through a rotating seal face 194, which is arranged to sealably face and rotate against a static seal plate 190 (not visible on FIG. 3). Static seal plate 190 is preferably mounted to housing 14 with output shaft 110 extending centrally through it. As shown in FIG. 2A, static seal plate 190 includes an intake port 196, and exhaust port 195 and a blanked-off portion containing no opening 197.
In operation, as engine block 13 rotates clockwise, port 199 will rotate into register with exhaust port 195 during the portion of the cycle wherein exhaust gases are to be discharged from combustion chamber 71. After the piston reaches the end of its exhaust stroke, the engine block 13 and opening 199 in rotating seal face 194 will rotate into register with intake port 196 and will remain in register with this intake port during the entire intake stroke. Following the intake stroke, as the engine block 13 continues to rotate, port 199 will move into register with blanked-off portion 197 of static seal plate 190 during the compression stroke. At the completion of the compression stroke, combustion will be initiated in the combustion chamber 71 by either compression-ignition, in a Diesel version, or initiation means of a spark through port 199 in a spark ignition version. As the engine block 13 continues to rotate, opening 199 will remain in register with blanked-off portion 197 of static seal plate 190 until the expansion stroke is substantially complete, at which point opening 199 rotates into register with exhaust port 195 to commence the cycle again.
As best seen in FIG. 2, the rear face 191 of static seal plate 190 is open to an oil conduit 309, which circulates oil adjacent rear face 191 and to oil return line 400. Gaskets 193 prevent leakage of this cooling oil out of the engine. Circulation of oil cools the static seal 190 directly, and the rotating seal face 194 of rotary valve assembly 189 indirectly by conduction. Instead of oil, water or other fluid could be used. Thus, the rotary valve assembly 189 can be kept at a temperature below that at which excessive oxidation would occur. Furthermore, the heated oil or fluid can be used to provide passenger comfort heat. Because the temperature of the valve is low, it is not necessary to use excessive fuel during combustion to prevent oxidation of the valves, as is the case with conventional poppet valves. This results in better fuel economy and lower emission of hydrocarbons and carbon monoxide, which otherwise result from rich fuel mixtures of prior art engines.
Furthermore, the engine of the present invention lends itself to greatly simplified ignition, and intake and exhaust manifolds. As shown in FIGS. 3 and 4, the engine has a "single point" intake 12 and a "single point" exhaust pipe 75, and a single spark plug, even though the engine has four cylinders. In a conventional four cylinder engine, complex and heavy intake and exhaust manifolds would be required, as well as four spark plugs and associated distributor and wiring. The "single point" intake is of especially great advantage in Diesel embodiments of the present invention. In a conventional engine, an injection pump is required for each cylinder. In small engines, this multipoint fuel injection system can cost as much as the rest of the engine. In the present invention, only a single injection pump would be required, regardless of the number of cylinders.
Returning now to FIG. 3, to transmit forces and motions to and from the piston into useful work (i.e. rotation of engine block 13 and shaft 110), a connecting rod 41 is pivotally connected at its upper end to piston 21 by means of wrist pin 81. At the opposite end of connecting rod 41, a cam follower 51 is rotatably mounted about an axle 55. In the embodiment shown, the cam follower is preferably a rotatable wheel to minimize wear and friction. However, a sliding cam follower, rather than a rolling cam follower, may also be employed.
Connecting rod 41 is linked by means of link arm or rocker arm 170 at a pivot 174 on the connecting rod 41 between axle 55 and pivot 81. The opposite end of rocker arm 170 is rockably pivoted about rocker arm pivot 173, which is mounted on mounting plate 175 which is affixed to and rotates with engine block 13. Pivot 173 is offset with respect to the centerline of cylinder 31 and causes the connecting rod 41 and cam follower 51 to move in a kinematically defined path as piston 21 reciprocates.
Cam follower 51 is adapted to follow and roll about the inside periphery of cam track 60 as engine block 13 rotates clockwise. Cam track 60 has a generally ellipsoid shape which is preferably generally anti-symmetrical across a 12:00/6:00 line. By "anti-symmetrical" is meant that if one were to cut the cam track at the 12:00/6:00 line, and turn one side of the cam track over about approximately the 9:00/3:00 line, the reversed, cam track would then be symmetrical across the 12:00/6:00 line. The reason for the anti-symmetry is the geometry of the connecting rod/linkage assembly with the rocker arm rocker pivot on each cylinder being positioned leading the centerline of its respective cylinder (i.e. more clockwise than cylinder centerline). Thus, anti-symmetry of cam track 60 causes pistons opposing one another to have the same radial position and reciprocal speed at a given rotor angle (but oppositely directed), resulting in less dynamic unbalance of the engine due to reciprocating masses.
The roughly 12:00 position of the track in FIG. 3 corresponds to top dead center of the compression stroke, the roughly 3:00 position corresponds to the bottom dead center of the expansion stroke, the roughly 6:00 position corresponds top dead center of the exhaust stroke, and the roughly 9:00 position corresponds to the bottom dead center of the intake stroke. Thus, a 360° rotation of engine block 13 corresponds to a complete four stroke cycle.
The cam track segment between the 12:00 top dead center angular position and the 3:00 bottom dead center angular position has a generally positive slope so that the radial distance between a point on cam track 60 and the center of rotation of engine block 13 generally, preferably continuously, increases between these angular positions of the engine block. Similarly, the cam track segment between the 3:00 bottom dead center angular position and the 6:00 top dead center position has a generally negative slope so that the radial distance between a point on cam track 60 and the center of rotation of engine block 13 generally, preferably continuously, decreases between these angular positions of the engine block.
As shown in FIGS. 1, 2 and 3, an inner cam track 65 is also preferably provided substantially parallel with outer cam track 60, and radially inwardly of cam follower 51. The purpose of inner cam track 65 to to ensure that cam follow 51 remains substantially adjacent to cam track 60, that is, that is does not go radially inward of cam track 60, particularly during intake and exhaust strokes when there is relatively little pressure in combustion chamber 71 acting on piston 21. Particularly in embodiments of the present invention where rocker arm extension 171 (and 171') and counterweight 172 (and 172') are used to counterbalance centrifugal forces in a manner to be further explained, at low engine speeds it is possible for centrifugal forces acting upon the piston/connecting rod/cam follower assembly to be insufficent to overcome friction during intake and exhaust strokes. Inner cam track 65 provides a means for applying a radially outward force on cam follower 51 to avoid this. Instead of an inner cam track, other means of ensuring that cam follower 51 remains substantially adjacent to cam track 60 may be provided, such as a spring to urge cam follower 51 outwardly aganist cam track 60, or a mechanical stop or bumper to prevent movement of the piston/connecting rod/linkage assembly beyond TDC.
As engine block 13 rotates, cam follower 51 traverses cam track 60. As the radial distance between a point on cam track 60 and the rotational axis of the engine block 13 increases and decreases, cam follower 51 moves radially inwardly and outwardly to transmit forces and motions to and from the cam track to from piston 21 by means of the connecting rod/rocker arm linkage assembly. Where the slope of cam 60 is positive (or negative), there is a tangential, or "side" component of force acting between cam follower 51 and cam track 60. It is this tangential component of force which, of course, causes rotation of engine block 13, and hence the power output of the engine. Correspondingly, the oppositely directed tangential force causes the piston to move radially inwardly during the exhaust and compressions strokes. Rocker arm 170 transmits a large proportion of the tangential component of force acting upon cam follower 51 by cam track 60 to mounting plate 175. In this way, forces imparted by the cam track 60 in a direction tending to rotate engine block 13 in either direction are not primarily transmitted by means of side forces acting upon the piston within its cylinder, as is the case with the prior art, but rather by means of the external linkage arrangement. Thus, side forces which would otherwise tend to prematurely cause wear on the piston are minimized. Furthermore, because the rocker pivot 173 is at a radially farther position than the average piston position, a greater lever arm is available for the transmission of torque.
The increased torque capability of the engine of the present invention as compared to an equivalently sized crankshaft-type engine is depicted diagrammatically in FIG. 12. The engines are equivalent in the sense of having the same piston area and stroke.
The absissa of the graph of FIG. 12 is the cam/rotor angle of an engine in accordance the present invention, having pure harmonic piston motion and one half the crank angle for a equivalent sized crankshaft-type engine. This is done because one revolution of the rotor of the present invention is equivalent to two for the crankshaft of a conventional engine. As can be seen from the graph, calculated torque per unit piston force is significantly higher for the engine of the present invention than for the equivalent conventional engine from 5° through 60° of rotor angle. Although the torque for the rotor of the present invention begins to drop sharply thereafter, dropping to less than the conventional engine, this is approximately the point at which the exhaust port or valves open, thus relieving the cylinder of pressure in any event. Thus, during substantially the entire period of rotation when useful work can be extracted from the gas (i.e. prior to opening the exhaust valve or port), the torque output of the present invention is substantially greater than that of a conventional engine, resulting in higher power output and efficiency.
Rocker arm 170 preferably includes an extension link 171 extending beyond pivot 173 and including counter-weight 172 at its extreme or free end. Extension link 171 and counter-weight 172 are weighted to substantially counterbalance centrifugal forces acting upon piston 21, connecting rod 41, cam follower 51 and link arm 170. These forces tend to throw piston 21 and these parts radially outwardly against the cam track surface 60, tending to increase wear on the cam track follower and cam track surface 60. Link extension 171 and counter-weight 172 are arranged so that link arm 171 and counter-weight 172 tend to move radially inwardly as piston 21 moves outwardly, thus tending to substantially counteract the centrifugal forces. However, preferably the weight of the counterweight is such that this does not completely offset the centrifugal forces, so that the piston and cam follower are urged into contact with the cam track surface. In this way, excessive wear due to centrifugal forces acting upon the cam track follower 51 and cam track 60 are minimized.
The arrangement of linkages with respect to connecting rod 41 as depicted in FIG. 3 is not the only arrangement that can be used to accomplish the purposes of the present invention. For example, in FIG. 1, another embodiment of the engine 10' is depicted. In this embodiment link 170 is connected to connecting rod 41 at the radially extreme end of connecting rod 41 by means of pivot 174" which is coaxial with axle 55 for cam follower 51. In another embodiment, engine 10" is depicted in FIG. 5. In this embodiment, cam follower 51 is connected to link arm 170' at the apex of a "V"-shaped bend in link arm 170', rather than being pivotally connected to connecting rod 41. In this embodiment, connecting rod 41 is relatively short, and the radially extreme end of connecting rod 41 is pivoted to link 170' by means of pivot 174'. Link 170' is pivotally mounted at pivot 173', which is in turn mounted to mounting plate 175. In this embodiment, extension link 171' and counter weight 172' are integral with one another.
Cam surface 60 is profiled so as to translate the reciprocating motion of piston 21 through the linkage assembly into rotary motion of engine block 13, and hence output shaft 110. Because the rotary engine of the present invention has no crank, the inherent kinematic limitations of the crank-slider motion of a piston with a crank arrangement are eliminated. Thus, the shape of cam surface 60 can be tailored to assume whatever profile best suits the heat and pressure characteristics of the combustion process and/or any other design parameters required.
One embodiment of a cam profile is depicted in FIG. 9. As depicted therein, the cam profile is a substantially anti-symmetrical ellipsoid. The profile of FIG. 9 has points 1-72 indicated about its periphery.
FIG. 8 is a tabulation of the relative piston radial reciprocal position as a function of rotor angle (Col. 2) for a cam follower 51 having a radius "r" of 1.5 inches (Col. 1). Each of the peripheral points 1-72 on FIG. 9 corresponds to a crank or rotor angle position as indicated in Col. 7 of FIG. 8, beginning at crank or rotor angle of 0° at position 1. Pure harmonic (i.e. sinusoidal) piston motion is tabulated in Col. 3, which is the piston motion generated by the cam profile of FIG. 9. A configuration where the expansion stroke continues during 110° of rotor rotation is tabulated in Col. 4. The calculated piston motion for a corresonding four stroke crank type engine are tabulated in Col. 5 for a true 720° cycle, and in Col. 6 for a two stroke crank type engine having a 360° cycle for comparison.
The pure or simple harmonic configuration is preferable in high-speed rotary engine designs, because it results in lower inertial stresses on the piston caused by reciprocation of the piston than crank-slider motion.
For even lower inertial stresses, a cam profile generating substantially constant piston reciprocating acceleration may be employed. In a constant acceleration configuation, the piston accelerates radially to a point at a substantially constant positive rate. At that point, the direction of acceleration reverses, and continues at a substantially constant but negative rate of acceleration. Calculated inertial stresses on a piston due to reciprocation for a constant acceleration configuration are depicted graphically in FIG. 13, along with calculated inertial stresses for simple harmonic and crank generation motions for comparison.
For applications where smooth power output and high efficiency is desired, the configuration having an expansion stroke of greater than 90°, preferably 110°, may be employed. The 110° also results makes possible a lower idle speed, because of the 20° overlap in power strokes for a four cylinder, four stroke design, thus resulting in lower fuel consumption in stop and go traffic where a significant amount of time is spent at idle.
Other cam profiles may be employed wherein the piston has a longer expansion stroke than intake stroke. This allows the high pressure combustion gases to expand to closer to ambient pressure before exhausting the gases, resulting in higher efficiency and lower heat rejection, and thereby less fuel consumption.
Another configuration is one where the piston moves very rapidly toward top dead center prior to the initiation of combustion to minimize the time for pre-ignition to occur. This allows higher compression ratios with lower quality fuels, resulting in higher efficiency and lower fuel costs.
Still another configuration is one where the piston moves very rapidly off top dead center following the initiation of combustion to minimize the time during which hot products of combustion are in contact with relatively cool cylinder walls, thus contributing to less heat loss and higher efficiency. The rapid expansion causes a rapid decrease in pressure and temperature, which decreases the garnering of pollutants, such as oxides of nitrogen, because there is less time at the high pressure and temperature at which oxides of nitrogen are formed.
The cam can also be configured to provide a full exhaust stroke to maximum TDC and a full intake stroke from maximum TDC to BDC irrespective of the compression ratio to yield better breathing and scavenging without valve overlap. Valve overlap (i.e., where both the exhaust and intake valves are open) can increase emissions.
These various cam profiles can be combined together in compromise profiles, and a myriad of other cam profiles can be adopted for other custom requirements.
Turning now to FIGS. 1 and 2, a preferred embodiment of the rotary engine of the present invention incorporating a novel oil cooling and lubricating system is depicted. In this system, a sump 300 containing oil is preferably positioned directly below housing 14. Oil from the sump 300 is withdrawn through suction line 301 into oil pump 302. This oil pump is driven by means of a gear set 315 driven by shaft 110. Oil pumped from oil pump 302 is pumped into discharge line 307A and through filter 305 to remove particulates. Oil after having passed through filter 305 is discharged into discharge line 306B and then through oil cooler 307, which may be either air or water cooled. Since oil pump 302 only operates when shaft 110 is rotating, the oil cooling and lubricating system preferably includes an electric oil pump 303 for shut down cooling and lubricating, and for lubricating prior to start up of the engine. Electric oil pump 303 also takes intake from sump 300 through an intake line 301 and discharges through a check valve 304 into discharge line 307A, then through filter 305 and oil cooler 307 in the same manner as for oil pumped from oil pump 302.
Instead of (or in addition to) positioning oil cooler 307 on discharge line 306B, an oil cooler 307' can be included on the oil return line 400 just up stream of the sump 300 to cool the oil just before the oil enters oil sump 300.
Oil, after having been cooled by means of oil cooler 307, passes into a stationary line 307C and into rotating oil inlet 308 to the engine rotor. Because inlet 308 rotates with respect to oil discharge line 307C, a rotating oil seal 310 is included to prevent leakage of oil.
A side stream of oil is taken from discharge line 307C and into line 309 to cool the rear face 191 of static seal plate 190 in the manner previously described. Oil from passageway 309 passes adjacent rear face 191 to cool the static seal plate and is discharged into oil return line 400.
Oil from passageway 308 passes into the head end 311 of cooling jacket 320. Head end 311 includes a plurality of generally radially inwardly oriented walls or fins 313, which are substantially parallel to one another. Walls or fins 313 are spaced apart from one another to form troughs 312 between fins 313. As the cylinder block 13 rotates, centrifugal force acting upon the oil will tend to cause the oil to be retained within troughs 312. The rotation of the engine block will also cause a centrifugal force field to be placed upon oil contained within each of the troughs 312 thereby tending to increase the natural convective forces acting upon oil within each trough, because oil within each trough tends to be heated at the radially inward "bottom" of the trough and tend to "rise" away from the rotational center to be replaced by cooler oil. By "natural convective force" is meant the tendency of hot, less dense, fluid to rise above and be displaced by cooler, more dense, fluid under gravitational or other acceleration forces due to the difference in their densities, as distinguished from convection due to pumping the fluid by mechanical means past the surface to be cooled. In the present invention, centripital acceleration caused by rotation of the engine block substitutes for gravitational acceleration in the "natural" convention. Thus, cooler oil will tend to be forced into the bottom of each trough 312 while hotter oil will tend to be displaced over the tops of walls 313 and radially outwardly. After passing through the head end 311 of the oil cooling jacket oil exits at 314, and into the oil jacket 320 around the cylinder 31.
This heated oil will continue to pass through oil cooling jacket 320 adjacent cylinder 31 to cool the cylinder until the oil reaches an oil hole 321. Oil hole 321 is oriented so as to spray the discharge oil onto the cam follower 51 to cool and lubricate the cam follower. Oil return lines 400 are included on the bottom of housing 14 to allow the spent oil to return to oil sump 300.
In addition to passing into oil cooling jacket 320, a side stream of oil from rotor inlet 308 passes into a lubricating line 317, and hence through inboard rotor bearing 318 and then into oil cooling jacket 320, and a side stream passes to outboard rotor bearing 319, then to the driving gear set 315 for oil pump 302, and then to oil return line 400 to be returned to pump 300 to cool and lubricate these parts.
Because engine block 13 is rotating, centrifugal forces acting on the oil contained within oil cooling jacket 320 will tend to force the oil radially outwardly. Because of this, a smaller oil pump 302 then would be necessary in a conventional engine its required, resulting in greater net power output from shaft 110. In addition, because oil is used for cooling, as well as for lubricating, no water jacket around the cylinders is required. Furthermore, the engine block also transfers heat to the housing indirectly by heating the air within the housing, which in turn transfers its heat to the housing. This indirect cooling is assisted by rotation of the engine block within the housing, which causes movement and mixing of the air in the housing.
The inner surface of piston head 101 and wrist pin 81 are cooled and lubricated by means of oil thrown off the surface of cam follower 51 as it rotates. Finally, another oil spray hole 322 is provided on the outside of oil cooling jacket 320 directed to the pivot 173 of rocker arm 170 to provide lubrication of this pivot. In this manner, a very simple and reliable oil cooling and lubricating system which eliminates the need to use direct air or water cooling of the cylinders is provided. In addition to simplifying the construction, the use of oil cooling in accordance with the present invention allows the engine to run hotter, resulting in higher efficiency.
In order to make most effective use of available fuels, the engine in accordance with the present invention preferably includes means for varying the compression ratio in each cylinder assembly 30 while the engine is operating. In accordance with one embodiment of the present invention, depicted in FIGS. 6 and 6A as engine 10"', compression can be varied while the engine is operating by means of a compression control system 120. Compression control system 120 includes a knock sensor 125, which is preferably a piezoelectric crystal. Knock sensor 25 detects the commencement of engine knock in the cylinder assemblies 30. Signals from knock sensor 125 are fed into an amplifier and control unit 130. Amplifier and control unit 130 control the power input to a servomotor 135 to cause the servomotor to rotate in one direction, tending to decrease compression when engine knock is detected, and to rotate in the opposite direction to increase compression when engine knock is not detected.
Servomotor 135 has an output gear 140 which drives a reduction gear 145. Reduction gear 145 in turn drives a ramp drive worm gear 150. Worm gear 150, in turn, rotates ramp drive threads 155, causing drive element 153 to rotate axially thereby rotating acme threads 156 in and out. This causes ramp drive rod 158 to either extend or retract, depending on the rotational direction of servomotor 135. Ramp drive rod 158 is connected to a movable cam track segment 159, which is positioned in an opening 157 in cam track 60. Of course, other means of moving the cam track segment 159, such as a hydraulic cylinder can be used, and there is no intention of limiting the invention to the exemplary embodiment shown.
Movable cam track segment 159 is comprised of a leading ramp 161 (and 161') and a trailing ram 162 interdigitatably connected to one another by means of center joint pivot 166 having pivot head 167 and 167'. Center joint pivot 166 is suitably connected to trailing edge 162, and extends through a slot 165 (and 165') in leading ramp 161. Trailing ramp 162 is pivotably mounted by means of pivot 164, and leading ramp 161 is pivotably mounted about pivot 163. As ramp drive rod 158 moves in and out in response to the motion of servomotor 135, leading ramp 161 and trailing ramp 162 will be pivotably moved in response thereto from radially further positions to radially closer positions. Accordingly, as cam follower 151 rotates about cam track 60, when it reaches leading ramp 161, it will be compelled to ride along leading ramp 161 until it reaches trailing ramp 162 and will ride along trailing ramp 162 until it reaches the continuation of cam track 60. Thus, the path of cam follower 51 can be altered by moving leading ramp 161 and trailing ramp 162 radially inwardly or outwardly, either manually or automatically depending upon engine load or other engine parameters. For example, engine parameters such as engine temperature, exhaust temperature, intake air temperature, engine speed could be fed into a suitably programmed microprocessor to effect the control function. Thus, the highest compression possible, without engine knock, that is possible for a given fuel and engine load can be accomplished, resulting in increased engine efficiency. Furthermore, the compression can be reduced prior to starting the engine and kept low until just after the engine starts to decrease the power required to crank the engine. Also, the compression can be lowered, manually or automatically, at idle. This reduces torque variation and thereby reduces the stable idle speed and fuel consumption at idle.
The compression ratio in the engine of the present invention can be varied as much as desired, but a particularly desirable range is from a low of 7:1 to 17:1. This range allows use of a wide variety of fuels in a spark ignition engine previously believed to be impossible. For example, it is believed that even jet fuel can be carbureted and used successfully in an engine of the present invention, when the compression is lowered to about 7:1. When higher octane fuel is available, the compression ratio can be raised to allow higher efficiency commensurate with the quality of the fuel.
An alternate embodiment of the rotary engine of the present invention having means for varying the compression ratio during operation is depicted in FIGS. 3 and 4. As depicted therein, the rotary engine 10 includes driving gear 200 which is mounted to output shaft 110. Driving gear 200 drives a first idler gear 201, which, in turn, drives a second idler gear 202. Idler gear 202 drives a driven gear 203 which is connected to a compressor cam 204. Thus, as the rotatable engine block 13 rotates, compressor cam 204 will be rotated a corresponding number of degrees by gears 200, 201, 202 and 203.
Compressor cam 204 includes four lobes, each having a peak 206 and a notch 205 on the trailing side of the cam. As cam 204 rotates, it acts upon a driven roller 207 which is mounted to a movable cam track segment 209 by means of roller axle 208. Movable cam track segment 209 is pivotably attached by means of pivot 210 to housing 14.
In operation, movable cam track segment 209 is in the radially outward position, i.e. with its leading edge substantially flush with the remainder of cam track surface 60. As engine block 13 rotates into position, and cam follower 51 rotates sufficiently so that it is entirely upon the leading portion of the movable cam track segment 209, cam compressor 204 rotates correspondingly to a position where peak 206 acts upon driven roller 207 to cause movable cam track segment 209 to pivot radially inwardly, thereby driving cam follower 51 and hence piston 21 into a position of higher compression. This compression is effected relatively quickly because of the cam action of cam compressor 204. Because pre-ignition is time-dependent, that is the faster the compression the less likely pre-ignition is to occur with the same compression ratio, the rapid compression imparted by cam 204 minimizes the propensity for pre-ignition even at high compression ratios. Therefore, much higher compression ratios, in the range of 18:1, can be used resulting in higher efficiency then is possible in engines of the prior art with relatively slow compression. In this embodiment, inner cam track 65 has an indentation 66 near 12:00 top dead center. Indentation permits movable cam track segment 209 to move cam follower 51 radially inwardly without interference with inner cam track 65 at that point. Because the region around 12:00 top dead center is always under relatively high pressure (due to compression and combustion) cam follower 51 will always be firmly held against outer cam track 60 at this position, irrespective of the lack of an inner cam track at this position.
As cam 204 continues to rotate, driven roller 207 will fall into notch 205 causing the cam track segment 209 to rapidly return to a relatively flush position with the remainder of cam track 60. This quickly reduces pressure and temperature of the combustion gases, resulting in higher efficiency and lower emission of nitrous oxides. Thus, as cam follower 51 continues past the cam track segment 209, when it reaches cam track 60, movable cam track segment 209 will be relatively flush with cam track 60 to allow the cam track roller 51 to continue unimpeded, and ready for another cycle with the next piston assembly.
Turning now to FIG. 5, an embodiment of the present invention utilizing a device for selectively locking a particular piston and linkage assembly so that it does not reciprocate as the engine block 13 rotates is depicted. This locking device includes a plunger lock 801 fixedly mounted to cylinder 31. Plunger lock is preferably a solenoid but could be a hydraulic cylinder. Plunger lock 801 includes a centrally disposed plunger pin 802. Rocker arm 170 includes a mating hole 803 which is adapted to receive plunger pin 802. When rocker arm 170 is in the appropriate position, i.e. with the piston substantially at the top dead center of its stroke, plunger lock 801 can be selectively energized to drive plunger pin 802 into mating hole 803. Once engaged in mating hole 803, rocker arm 170 will be locked and piston 21 will not be able to reciprocate as engine block 13 rotates. Of course, in this embodiment, inner cam track 65 would not be used because it would interfere with the motion of cam follower 51. Furthermore, this structure enables the engine of the present invention to continue to run even if one or more pistons seize. By selectively disengaging pistons from reciprocating, only the number of pistons necessary to supply the required load will be operating, which results in higher efficiency.
Plunger lock 801 can be operated manually, or automatically in response to engine load or other engine parameters. When operated automatically, an engine sensor 804 is provided responsive to engine parameters, such as engine speed and throttle position. When engine load is low, control means 805 can actuate plunger lock 801 at the point in the rotation of engine block 13 where mating hole 803 is aligned with plunger pin 802. When engine load increases to the point that additional cylinders are required, control means 805 disengages plunger pin from mating hole 803 at the same, approximately top dead center, position of the piston.
An engine in accordance with the present invention is an ideal power plant for propeller driven light airplanes. In light airplanes, the propeller speed generally does not exceed about 2500 revolutions per minute ("rpm"). Because 2500 rpm is a relatively low speed for conventional crank type engines, reduction gearing between the engine and the propeller is frequently necessary so that the engine can run at a higher, more efficient speed. In a rotary engine in accordance with the present invention, the shaft speed is one half that of a crank-type engine having the same displacement and number of cylinders. That is, a power stroke occurs for each cylinder of the rotary engine in accordance with a prefered four-stroke embodiment of the present invention once every shaft revolution, whereas in a crank-type four stroke engine, a power stroke occurs every other revolution. Thus, the rotary engine of the present invention rotates slowly enough to be directly coupled to a light airplane propeller without reduction gearing, while having the high efficiency of an "effective" speed (compared to an equivalent crank-type engine) of twice its actual shaft speed.
Reference is now made to FIG. 10 showing an alternate embodiment of the present invention wherein two similar engines 10A and 10B are provided on the same drive shaft 901. In this construction each of the engine blocks 13 associated with the respective engine is coupled to drive shaft 901 by free wheeling bearings in a hydraulically actuated clutch assembly 902. The engine block 13 of engine 10A and its output shaft 903 are hollow to permit output shaft 904 of engine 10B to pass therethrough to connect with hydraulic clutch 902. Hydraulic clutch 902 is operable to selectively couple either or both of output shafts 903 and 904 to the drive shaft 901. When both engines are coupled, the output shafts of the engines preferably rotate in the same direction at the sam speed.
Engine 10B may also include an input shaft 905 and another hydraulic clutch 906. Input shaft 905 can lead from another engine and be connected to engines 10A and 10B by hydraulic clutch 906. Thus, as many engines as desired can be banked together in series in this manner, the output shaft of one engine extending through a hollow rotor and output shaft of the next engine in the series. Thus, if some of the engines were operating and the others were not, the other engines could remain idle on the output shaft without creating a drag to the operation of the other engines.
The banked engine concept shown in FIG. 10 may be utilized where the expected load to be driven will vary and at times two engines may be needed while at other times only one engine will be sufficient to provide the power output requirement necessary. Hence, during periods of high torque load demand both engines would be engaged on the drive shaft and, after high torque load demands have subsided, one of the engines can be stopped, the hydraulic clutch disengaged and that engine remain stationary and idle while other engine powers the output shaft.
To do so, clutch 902 can be disengaged engaged so that engine 10B is actuated only in high torque load demand situations. After a period of engine use, clutch 902 is placed in a state so that engine 10B operates continuously while engine 10A operates only intermittently. In this way engine wear is shared by the plurality of engines in the bank. Thus, after a period of continuous use, a particular engine is relegated to standby use while another engine, which previously has operated only intermittently, is relegated to continuous operation.
Where the banked engine concept of the present invention is used for automobile power plants the switching of the engine can be accomplished after fifty thousand miles of operation and in essence a relatively new engine will assume the major burden of power output requirement while the engine which has functioned continuously for the fifty thousand miles is relegated to intermittent duty.
Engines in accordance with the present invention, and particularly multibanked engines, are particularly well suited for driving light airplane propellers, because the "extra" engine provides an additional margin of safety in case of failure of one of the engines. FIG. 11 depicts a light propeller driven airplane 907 including a two bank embodiment of the present invention. The airplane includes a fuselage 908 and a propeller 909 driven by propeller drive shaft 901 extending from two similar rotary engines 10A and 10B connectable together in series. The intake line 911 and exhaust line 912 to and from the static valve plates are conveniently positioned between the two engines 10A and 10B, respectively. Each of engines 10A and 10B can be selectively coupled or decoupled from the propeller drive shaft 901 by means of hydraulic clutch 902. In this manner, the safety and power of two independent engines can be provided, while retaining the simplicity and cost savings of a single propeller design.
Although the invention has been described in accordance with preferred embodiments, it will be seen by those skilled in the art that many modifications can be made within the spirit and scope of the present invention, and no intention is made to limit the scope of the present invention to any of these embodiments. Rather, the scope of the present invention is to be measured by the appended claims. | A rotary internal combustion engine wherein the cylinders making up the engine block are radially disposed in a common plane and rotate with the output shaft. The engine block rotates within a surrounding cam surface and the pistons in each cylinder move radially in and out in a motion geometrically defined by connecting rods, a rocker arm pivoted at a point fixed with respect to the rotating engine block and a cam follower which rides on the cam surface. The rocker arm preferably is counterbalanced to reduce centrifugal forces on the cam surface. The cam surface is contoured to produce the motion to the pistons by means of the linkage as the engine block rotates. The engine block includes a rotary valve port associated with each cylinder. The engine block rotates into cooperating relationship with stationary inlet and exhaust ports in the engine housing to provide intake and exhaust cycles. The power stroke for each cylinder is radially outward and the piston drive linkage and cam slope are arranged to convert the radial forces into shaft torque. The engine has means for varying the compression during operation. A novel oil cooling system with centrifugally assisted circulation is also provided. The rotary engines can be selectively connected in series to form a multibank engine. The rotary engine of the present invention is ideal for powering light airplanes. | 5 |
RELATED APPLICATION
This application is related to Provisional Application Ser. No. 60/526,440 filed Dec. 2, 2003.
FIELD OF THE INVENTION
The present invention relates to a method and composition for controlling odors emanating from organic waste produced by metabolic processes, including human and animal waste, as well as industrial wastes, effluents, sewage, and the like.
BACKGROUND OF THE INVENTION
The biogenic production of volatile compounds which cause objectionable odors is one of the problems associated with the collection and treatment of various waste materials. Domestic sewage is the largest source of such odorous compounds. Various reduced sulfur-containing compounds are common, with hydrogen sulfide being the most objectionable odor-causing compound in such wastes. Because of the magnitude of domestic sewage that is collected and treated and the prominence of the associated odorous sulfidic compounds, the present invention is particularly directed, but not limited to the control of hydrogen sulfide and other sulfide odors in municipal or industrial waste. As used herein, the term “sulfidic compounds” also includes hydrogen sulfide (H 2 S), mercaptans (RSH), and other related odoriferous sulfidic compounds.
The mixed biological population common to municipal or industrial waste utilizes the compounds found in the waste as a source of nutrient. In this process, oxygen is the preferred terminal electron acceptor, and the nutrient, commonly an organic compound, is oxidized. In highly nutrient loaded systems such as municipal sewage, bacterial action can result in a rapid consumption of oxygen in the water. In the absence of oxygen, bacteria require an alternate terminal electron acceptor.
In general, bacteria will utilize the terminal electron acceptor that provides them with the greatest amount of energy. Thus, there is a preferred selection order of a terminal electron acceptor by bacteria. This order is shown below.
O 2 >NO 3 − >Fe>SO 4 −2 >CO 3 −2
As nitrate is not typically found in natural waters, the sulfate ion (SO 4 −2 ) is generally the preferred alternate. In the absence of oxygen, unless nitrate is added supplementally, those bacteria which can utilize sulfate as a terminal electron acceptor in their respiration process will predominate. The most well-characterized bacteria of this type is Desulfovibrio desulfuricans , and is most commonly referred to as sulfate-reducing bacteria, SRB. SRB are known to metabolize sulfate ion with organic matter to form H 2 S as shown in the following equation.
SO 4 −2 + organic matter+SRB→H 2 S+CO 2 +H 2 O
H 2 S, responsible for the characteristic odor from rotten eggs, is toxic in low concentrations. Citizen complaints are often the driving force behind efforts to control odor. Such odors are generally regarded as a public nuisance and a health hazard.
Although H 2 S is a gas, H 2 S in water can dissociate with increasing pH as shown in the following equations. Thus at a given pH, the relative amount of dissolved H 2 S species can be predicted. The sulfide ion, S −2 , and bisulfide ion, HS − , being ionic, are constrained to remain in the aqueous phase.
H 2 S+OH − →HS − +H 2 O
HS—+OH − →S −2 +H 2 O
(H 2 S—gas phase & aqueous phase, HS − & S −2 aqueous phase)
Description of Figure
The figure herein shows the relationship between these species, the evolution of the gas from aqueous solution being a function of pH. At the pH typically found in sewer systems, a significant percent of the H 2 S formed evolves from solution. The gas can redissolve on the crown of the sewer line, and the presence of Thiobacillus bacteria and others, metabolize the H 2 S, producing sulfuric acid, H 2 SO 4 . This can and has resulted in sewer line collapse and results in a significant cost in terms of their repair and replacement.
H 2 S is also corrosive towards steel and concrete. H 2 S is a gas, with the evolution of the gas from aqueous solution being a function of pH. At pHs often found in sewer systems, a significant percent of the H 2 S formed evolves from solution. The gas can redissolve on the crown of the sewer line, and the presence of Thiobacillus bacteria and others, metabolize the H 2 S, producing sulfuric acid, H 2 SO 4 . This can and has resulted in sewer line collapse and results in a significant cost in terms of their repair and replacement.
Various compounds, including hypochlorite (sodium or calcium), potassium permanganate, sodium nitrate, ferrous and ferric salts, hydrogen peroxide, chlorine, chlorine dioxide, and sodium chlorite have been widely used for the control of odor in wastes, and sewage waste in particular.
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Heukelekian, H., “Effect of the Addition of Sodium Nitrate to Sewage on Hydrogen Sulfide Production and BOD Reduction,” Sewage Works Journal 15(2), 225(1943).
Heukelekian, H., “Some Bacteriological Aspects of Hydrogen Sulfide Production from Sewage,” Sewage Works Journal, 20(3), 490(1948).
Hobson, J., and Yang, G., “The Ability of Selected Chemicals for Suppressing Odour Development in Rising Mains,” Water Science and Technology 41(6), 165(2000).
Jefferson, B., Hurst, A., Stuetz, R., and Parsons, S., “A Comparison of Chemical Methods for the Control of Odours in Wastewater,” Trans IChemE, 80(b) 93(March 2002).
Jenneman, et al., “Effect of Nitrate on Biogenic Sulfide Production, 51 Appl Env. Micro, 1205(1986).
Lang, M, “Chemical Control of Water Quality in a Tidal Basin,” Journal WPCF, 38, 1410(1966).
Lawrance, W., “The Addition of Sodium Nitrate to the Androscoggin River,” Sew and Ind Wastes, 22, 820(1950).
Londry, K., and Suflita, J., “Use of Nitrate to Control Sulfide Generation by Sulfate Reducing Bacteria Associated with Oily Waste,” Journal of Industrial Microbiology and Biotechnology, 22, 582(1999).
Lorgan, G. P., et al., “Nitrate Addition for the Control of Odor Emissions from Organically Overloaded, Super Rate Trickling Filters”, 33rd Ann. Purdue Ind. Waste Conf., West Lafayette, Ind., (1978).
McKinney, R., “The Role of Chemically Combined Oxygen in Biological Systems,” Journal of the Sanitary Engineering Division, ASCE, (paper 1053), August, 1956).
Montgomery, A., McInerney, M., and Sublette, K., “Microbial Control of the Production of Hydrogen Sulfide by Sulfate-Reducing Bacteria,” Biotechnology and Bioengineering, 35, 533(1990).
Moss, W., Schade, R., Sebesta, S., Scheutzow, K., Beck, P., and Gerson, D., “Full-scale Use of Physical/Chemical Treatment of Domestic Wastewater at Rocky River, Ohio,” Journal WPCF, 2249(November 1977).
Myhr, S., Lillebo, B., Sunde, E., Beeder, J., and Torsvik, T., “Inhibition of Microbial H 2 S Production in an Oil Reservoir Model Column by Nitrate Injection,” Applied Microbiology Biotechnology, 58, 400(2002).
Nemati, M., Jenneman, G., and Voordouw, G., “Mechanistic Study of Microbial Control of Hydrogen Sulfide Production in Oil Reservoirs,” Biotechnology and Bioengineering, 74(5), 424(Sep. 5, 2001).
Okabe, S., Santegoeds, C., and DeBeer, D., “Effect of Nitrite and Nitrate on In Situ Sulfide Production in an Activated Sludge Immobilized Agar Gel Film as Determined by Use of Microelectrodes,” Biotechnology and Bioengineering, 81(5), 570(Mar. 5, 2003).
Painter, H. A., “A Review of Literature on Inorganic Nitrogen Metabolism in Microorganisms”, Water Research, 4(6), 393(1970).
Poduska, R., and Anderson, B., “Successful Storage Lagoon Odor Control,” Journal WPCF, 53(3), 299(March, 1981).
Poduska, R. A., “Operation, Control, and Dynamic Modeling of the Tennessee Eastman Company Industrial Wastewater Treatment System”, 34th Ann. Purdue Indust. Waste Conf., Lafayette, Md. (1970).
Pollack, D., and Marano, V., “Award Winnihg Utility District Eliminates Chlorine and Extends Life of Costly Carbon Scrubber with Bioxide,” The Bulletin, 12(Spring, 1993).
Pomeroy, Johnston and Bailey, “Process Design Manual For Sulfide Control in Sanitary Sewage Systems”, October 1974.
Pomeroy, R., and Bowlus, F., “Progress Report on Sulfide Control Research,” Sewage Works Journal, 18(4), 597(July, 1946).
Pomeroy, R. D., “Controlling Sewage Plant Odors”, Consulting Eng., Feb. 101 (1963).
Pomeroy, R. D., et al., “Feasibility Study on In-Sewer Treatment Methods”, Municipal, Environmental Research Lab. Chapter 6, “Chemical Treatment”, 77 (1977).
Pomeroy, R. D., et al., “Sulfide Occurrence and Control in Sewage Collection Systems”, U.S. Environmental Protection Agency, EPA 600/X-85-052, Cincinnati, Ohio (1985).
Postgate, J. “The Sulfate Reducing Bacteria,” Cambridge University Press, Second Edition, 1984.
Prakasam, T. B. S., et al., “Microbial Dentrification of a Wastewater Containing High Concentrations of Oxidized Nitrogen”, Proceedings of the 31st Industrial Waste Conference, May 4-6, 1976, Purdue University.
Price, E. C., et al., “Sewage Treatment Plants Combat Odor Pollution Problems”, Water and Sew. Works, 125(10), 64(1978).
Reid, G. W., et al., “Sewer Odor Studies”, Sew. and Ind. Wastes, 28, 991 (1956).
Reinsel, M., Sears, J., Stewart, P., and McInerney, M., “Control of Microbial Souring by Nitrate, Nitrite, or Glutaraldehyde Injection in a Sandstone Column,” Journal of Industrial Microbiology, 17, 128(1996).
Ryan, W. A., “Experiences with Sodium Nitrate Treatment of Cannery Wastes”, Sew. Works Jour., 17, 1227 (1945).
Ripl, W., Biochemical Oxidation of Polluted Lake Sediment with Nitrate—A New Lake Restoration Method,”, Ambio v 5 n 3 1976 p 132-135
Salle, A., “Fundamental Principles of Bacteriology,” Sixth Edition, McGraw-Hill Book Company, New York, 1967.
Sanborn, N., “Use of Sodium Nitrate in Waste Treatment,” Canning Trade, March, 1941.
Sanborn, N. H., “Nitrate Treatment of Cannery Waste”, The Fruit Products Journal and American Vinegar Industry, 207(1941).
Santry, I., “Hydrogen Sulfide Odor Control Measures,” Journal WPCF, 38(3), 459 (March, 1966).
Santry, I. W., Jr., “Hydrogen Sulfide in Sewers”, Jour. Water Poll. Control Fed., 35, 1580 (1963).
Standard Methods for the Examination of Water and Wastewater, 14th Ed., Amer. Pub. Health Assn., Wash. D.C., 499-509 1976.
Steel, Ernest W., “Water Supply and Sewerage”, Chapter 27, pp. 600-601 (4th Ed. 1960).
Sturman, P., Goeres, D., and Winters, M., “Control of Hydrogen Sulfide in Oil and Gas Wells with Nitrite Injection,” Paper SPE 56772, SPE Tech Conference and Exhibition, Houston, Tex., Oct. 3-6, 1999.
Sublette, K., and Sylvester, D., “Oxidation of Hydrogen Sulfide by Thiobacillus denitrificans : Desulfurization of Natural Gas,” Biotechnology and Bioengineering, 29, 249(1987). Thistlethwayte, D. K. B., “The Control Of Sulfides In Sewerage Systems”, Ann Arbor Science Publishers Inc., Chapter 13, “Corrective Measures For Existing Systems”, 159 (1972).
Wanner, O., and Gujer, W., “Competition in Biofilms,” Water Science and Technology, 17, 27(1984).
Willenbring et al., “Calcium Nitrate” (incomplete title), October 1988 or earlier. “Biochemical Oxidation of Polluted Lake Sediment with Nitrate—A New Lake Restoration Method”, 1976.
Zhang, T., “Feasibility of Using Sulfur:Limestone Pond Reactors to Treat Nitrate-Contaminated Surface Water and Wastewater,” submitted for publication in Journal of Environmental Engineering (ASCE).—received Jun. 23, 2000.
REFERENCES DESCRIBING BACKGROUND OF THE INVENTION
Basic Research On Sulfide Occurrence and Control In Sewage Collection Systems, National Technical Information Service, a-5 (Feb. 28, 1969).
Beardsley, C. W., et al., “Removal of Sewer Odors By Scrubbing With Alkaline Solutions”, Sewage and Industrial Wastes, vol. 30, 220 (1958).
Bryan, A. C., “Experiences With Odor Control at Houston, Tex.”, Sew. & Ind. Wastes, 28, 1512 (1956).
Carpenter, W. T., “Sodium Nitrate Used to Control Nuisance”, Water Works and Sew., 79, 175 (1932).
Directo et al., “Pilot plant study of physical-chemical treatment”, Journal Water Pollution Control Federation, 49(1),: 2,081-2,098; October 1977.
Eliassen, R., et al., “The Effect of Chlorinated Hydrocarbons on Hydrogen Sulfide Production”, Sew. Works Jour., 21, 457 (1949).
Fales, A. L., “Treatment of Industrial Wastes from Paper Mills and Tannery on Neponset River”, Jour. Ind. Eng. Chem., 21, 216 (1929).
Heukelekian, H., “Effect of the Addition of Sodium Nitrate to Sewage on Hydrogen Sulfide Production and B.O.D. Reduction”, Sewage Works Journal 15(2):255-261 (1943).
Heukelekian, H., “Some Bacteriological Aspects of Hydrogen Sulfide Production from Sewage”, Sew. Works Jour., 20,490 (1948).
Lang, M., “Chemical Control Of Water Quality In A Tidal Basin”, Journal WPCF, 1414-1416 (1966).
Lawrance, W. A., “The Addition of Sodium Nitrate to the Androscoggin River”, Sew. and Ind. Wastes, 22, 820 (1950).
Lorgan, G. P., et al., “Nitrate Addition for the Control of Odor Emissions from Organically Overloaded, Super Rate Trickling Filters”, 33rd Ann. Purdue Ind. Waste Conf., West Lafayette, Ind., (1978).
McKinney, R. E., “The Role of Chemically Combined Oxygen in Biological Systems”, Jour. San. Eng. Div., Proc. Amer. Soc. Civil Engr., 82 SA4, 1053 (1956).
Methods For Chemical Analysis of Water and Wastes, U.S. Environmental Protection Agency, (1974).
Painter, H. A., “A Review of Literature on Inorganic Nitrogen Metabolism in Microorganisms”, Water Research, The Journal of the International Association on Water Pollution Research, vol. 4, No. 6, (1970).
Poduska et al., “Successful storage lagoon odor control”, Journal Water Pollution Control Federation, 53(3): 299,310; March 1981.
Poduska, R. A., “Operation, Control, and Dynamic Modeling of the Tennessee Eastman Company Industrial Wastewater Treatment System”, 34th Ann. Purdue Indust. Waste Conf., Lafayette, Md. (1970).
Pomeroy, Johnston and Bailey, “Process Design Manual For Sulfide Control in Sanitary Sewage Systems”, October 1974.
Pomeroy, R. D., et al., “Feasibility Study on In-Sewer Treatment Methods”, Municipal, Environmental Research Lab. Chapter 6, “Chemical Treatment”, 77 (1977).
Pomeroy, R. D., et al., “Sulfide Occurrence and Control in Sewage Collection Systems”, U.S. Environmental Protection Agency, EPA 600/X-85-052, Cincinnati, Ohio (1985).
Pomery, R. D., “Controlling Sewage Plant Odors”, Consulting Eng., Feb. 101 (1963).
Prakasam, T. B. S., et al., “Microbial Dentrification of a Wastewater Containing High Concentrations of Oxidized Nitrogen”, Proceedings of the 31 st Industrial Waste Conference, May 4-6, 1976, Purdue University.
Price, E. C., et al., “Sewage Treatment Plants Combat Odor Pollution Problems”, Water and Sew. Works, 125, 10, 64 (1978).
R. R. Dague, “Fundamentals of Odor Control”, Journal Water Pollution Control Federation, 44(4): 583-594: April 1972.
Reid, G. W., et al., “Sewer Odor Studies”, Sew. and Ind. Wastes, 28, 991 (1956).
Ryan, W. A., “Experiences with Sodium Nitrate Treatment of Cannery Wastes”, Sew. Works Jour., 17, 1227 (1945).
Sanborn, N. H., “Nitrate Treatment of Cannery Waste”, The Fruit Products Journal and American Vinegar Industry, (1941).
Santry, I. W., Jr., “Hydrogen Sulfide in Sewers”, Jour. Water Poll. Control Fed., 35, 1580 (1963).
Santry, I. W., Jr., “Hydrogen Sulfide Odor Control Measures”, Jour. Water Poll. Control Fed., 38 459 (1966).
Standard Methods for the Examination of Water and Wastewater, 14th Ed., Amer. Pub. Health Assn., Wash. D.C., 499-509 1976.
Steel, Ernest W., “Water Supply and Sewerage”, Chapter 27, pp. 600-601 (4th Ed. 1960).
Thistlethwayte, D. K. B., “The Control Of Sulfides In Sewerage Systems”, Ann Arbor Science Publishers Inc., Chapter 13, “Corrective Measures For Existing Systems”, 159 (1972).
Willenbring et al., “Calcium Nitrate” (incomplete title), October 1988 or earlier. “Biochemical Oxidation of Polluted Lake Sediment with Nitrate—A new Lake Restoration Method”, 1976.
William H. Moss et al., “Full-scale use of physical/chemical treatment of domestic wastewater at Rocky River, Ohio”, Journal Water Pollution Control Federation, 49(11): 2.249-2,254; November 1977.
Sodium chlorite has been used alone for odor control. Several references to such use follow:
“Control of Odors from Sewage Sludge,” Gas, Wasser, Abwasser, Vol. 65, pp. 410-413 (1985) in Chemical Abstracts 104:10062 (German); “Polyelectrolyte Conditioning of Sheffield Sewage Sludge,” Water Science Technology, Vol. 16, pp. 473-486 (1984) in Chemical Abstracts 102:100249; “Slime and Odor Elimination in Process Water of the Paper Industry,” Papier, Vol. 29, pp. 43-51 (1975) in Chemical Abstracts 85:82749 (German); and “Deodorization of Sludge for Dewatering by Controlled Adding Chlorite,” Japanese Patent Publ. No. 06320195 (1994).
It is also known that nitrates added to sewage effect reduction in BOD and even suppress the formation of hydrogen sulfide gas via bacterial action.
U.S. Pat. No. 3,300,404 for example, cites the use of about 500 ppm of nitrate to prevent odor emanation from a lagoon.
U.S. Pat. No. 4,911,843 cites the use of cite the use of nitrate to remove existing sulfide. A dosage of 2.4 parts nitrate-oxygen per part of existing dissolved H 2 S is required.
U.S. Pat. Nos. RE36,651 and RE37,181E cite the use of nitrate to remove existing sulfide. A dosage of 2.4 parts nitrate-oxygen per part of existing dissolved H 2 S is required.
Even nitrite has been used to control sulfate reducing bacteria and associated odors:
U.S. Pat. No. 4,681,687 cites the use of sodium nitrite to control SRB and H 2 S in flue gas desulfurization sludge.
In addition, the use of some sulfide reactive chemicals in combination with nitrates is known:
For example, U.S. Pat. No. 3,966,450 cites the use of 5-500 mg/L of hydrogen peroxide and the addition of nitric acid to maintain a pH of 3.5-5.5 to enhance the nutrient value of the waste.
U.S. Pat. No. 4,108,771 cites the use of chlorate and nitrate coupled with an iron salt in pH<5 to control odors in a waste stream.
U.S. Pat. No. 4,446,031 cites the use of an aqueous solution of ferric sulfate and ferric nitrate in a ratio of from 1:0.5 to 1:3 to control odors in rising sewer mains. Optionally the composition may contain nitric acid.
U.S. Pat. No. 5,114,587 cites the use of nitrate in conjunction with oxygen, air, or iron salt, the dosage controlled by ORP, to reduce the concentration of soluble organic matter.
U.S. Pat. No. 5,200,092 cites the use of about 0.5 to about 10 weight percent potassium permanganate with about 0.5 to about 42 weight percent sodium nitrate for odor control.
Feedrate of the product is such that the permanganate: sulfide ratio is maintained in the range of from about 2:1 to about 6:1.
U.S. Pat. No. 5,405,531 cites the use of nitrite and nitrate and/or molybdate for removal of H 2 S in an aqueous system.
U.S. Pat. No. 5,984,993 cites the use of a synergistic blend of 22.5 weight percent chlorite salt and 10 weight percent sodium nitrate for controlling odors.
A combination of nitrate and microorganisms is taught in the following patent:
U.S. Pat. No. 6,059,973 teaches an emulsion of nitrate and microorganisms of the Bacillus type for odor control in sewers.
Other compounds reactive with sulfide are known:
U.S. Pat. No. 3,959,130 cites the use of pH adjustment to a value over 7.0 and bringing the stream into contact with an ash product to control cyanide and hydrogen sulfide.
U.S. Pat. No. 4,501,668 cites the use of polycondensation products produced by the condensation of acrolein and formaldehyde to consume hydrogen sulfide in aqueous systems, such as waste water clarification plants.
The use of compounds to elevate pH to convert sulfide species to ionic species which remains in solution and minimizes H 2 S gas evolution is taught in the following patents:
U.S. Pat. No. 3,959,130, describes the use of fly ash to elevate the pH of a waste stream containing cyanide and possibly H 2 S to above 8.0.
U.S. Pat. No. 5,833,864, cites the use of magnesium oxide or magnesium hydroxide to elevate the pH to the range of 7.5-9.5, thus minimizing the amount of sulfide in the form of gaseous H 2 S.
The use of compounds to elevate pH to convert sulfide species to ionic species which remains in solution and minimizes H 2 S gas evolution is taught in the following patents:
U.S. Pat. No. 3,959,130, describes the use of fly ash to elevate the pH of a waste stream containing cyanide and possibly H 2 S to above 8.0.
U.S. Pat. No. 5,833,864, cites the use of magnesium oxide or magnesium hydroxide to elevate the pH to the range of 7.5-9.5, thus minimizing the amount of sulfide in the form of gaseous H x S.
Some of the treatments using specific chemicals have advantages in certain applications. However, they also suffer from various drawbacks, some of which are listed below. The chemicals are separated by their rate of reaction with sulfide or H 2 S.
Reacts rapidly with H 2 S or sulfide
Hypochlorite
Can degrade during storage.
Reacts with ammonia for additional consumption.
Generates chlorine odor with over-doses.
Has no long-term effect.
Corrosive to feed equipment
Potassium Permanganate
Powder is labor intensive to add.
Causes discoloration with over-doses.
Results in precipitation of manganese.
Iron Salts
Are ineffective for non-sulfide odors.
Cause build-up of solids.
Impure products can contain heavy metals.
Can be toxic to microorganisms.
Deplete dissolved oxygen and alkalinity.
Corrosive to feed equipment.
Chlorine Dioxide
Requires a generator, multiple precursors.
Generates chlorine-type odor with over-doses.
Is not long lasting.
Sodium Chlorite
Can be costly in high doses.
Rapid reaction with H 2 S or sulfide requiring a catalyst
Hydrogen Peroxide
Slow reacting without catalyst
Requires catalysis for non-sulfide odors.
Causes foaming.
Is not long lasting.
Does not react directly with H 2 S or sulfide
Nitrates
Have no immediate or short term effect.
Produce nitrogen by-products which can present treatment problems.
Reacts indirectly by promoting the growth of sulfide-oxidizing bacteria
Require the presence of nitrate-reducing, sulfide oxidizing bacteria
to work.
Magnesium oxide, Magnesium hydroxide, Calcium oxide, Calcium
hydroxide
Sparingly soluble
At high concentrations must be fed as a slurry
Can result in precipitation and plugging of pumps, lines
In view of the disadvantages cited above, there is a need in the art for a method and composition for abating odor in waste materials that is cost effective, has the capability of consuming aqueous sulfide or H 2 S immediately, adjusts the pH into a range where H 2 S form is very low and provides long term control of biogenic sulfide production. Accordingly, it is an object of the present invention to address this need in the art. This and other objects of the present invention will become more apparent in light of the following summary and detailed description of the invention.
SUMMARY OF THE INVENTION
This invention relates to a method and composition for the elimination or reduction of sulfidic odors in sewer systems, municipal waste treatment plants and in other industrial waste applications. The composition comprises a synergistic combination of a rapid sulfide-consuming chemical, which is selected from the group comprising an iron salt, a hypochlorite, a permanganate, a persulfate, a perborate, a periodate, a percarbonate, a chlorite, a nitrite, a chlorate, a perchlorate, a peroxide and mixtures thereof and a nitrate salt from the group comprising an ammonium, alkali alkaline metal, or metal nitrate. The method according to the present invention comprises the step of contacting the waste products or their surrounding airspace with the composition.
Existing sulfides are consumed immediately by the sulfide-consuming chemical. The pH-elevating compound adjusts the pH into a range of 7.5-8.5, where the form of sulfide soluble only in aqueous solution is promoted. In addition, adjustment of the pH into this range promote growth of sulfide-oxidizing, nitrate-reducing bacteria, which grow best in this pH range. The nitrate then inhibits the biogenic production of H 2 S downstream by both promoting the growth of various sulfide-oxidizing bacteria and inhibiting the growth of anaerobic sulfate reducing bacteria by elevating the oxidation reduction potential into a range which do not provide an environment conducive to their growth. In systems where no sulfide-oxidizing bacteria exist, such bacteria or their enzymes may be incorporated into the formulation. Malodorous compounds can be destroyed and prevented easily, rapidly, at a reasonable cost and continue to be controlled with the composition according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The composition for controlling odor from waste products according to the present invention comprises a combination of a rapid-acting sulfide-consuming material and a longer acting material which prevents biogenic sulfide production. For water streams which do not contain sufficient sulfide-oxidizing bacteria, such bacteria are incorporated into the formulation. The rapid-acting sulfide consuming material is selected from the group which includes an iron salt, or a hypochlorite, a permanganate, a persulfate, a perborate, a periodate, a percarbonate, a chlorite, a nitrite, a chlorate, a perchlorate and a peroxide of ammonium, metal or alkali metal and mixtures thereof. The longer acting chemical which prevents the formation of biogenic sulfide is an ammonium, alkali, alkaline metal, or metal nitrate. As used herein, the term “controlling odor” means reducing and/or eliminating odor that is offensive to humans. Such odors are usually caused by volatile sulfides and other volatile odorous substances.
Exemplary of a bacterial microorganism useful for the herein disclosed invention is Thiobacillus denitrificans which has the ability to oxidize a variety of reduced sulfur compounds, including H 2 S (sulfide), S (elemental sulfur), S 2 O 2 −2 (thionite ion), S 4 O 6 −2 (dithionite ion), and SO 3 −2 (sulfite ion). The microorganism can function either aerobically or anaerobically with nitrate.
The waste products treatable with the present invention include, but are not limited to organic waste produced by metabolic processes, including human and animal waste, as well as industrial wastes, effluents, sewage, and the like. The preferred aqueous composition includes sodium chlorite at a weight percent of 0.01-0.39%, and sodium nitrate which may range in concentration from 40-80% weight percent, and water at 19.6-59.99 wt %. The preferred dry composition includes sodium chlorite at concentrations of 1-65%, sodium nitrate at 6-90%, magnesium hydroxide or magnesium oxide at 30-95%, a dry bacterial consortium containing mostly Thiobacillus denitrificans at concentrations of 0.001-2% by weight, and a blend of dry enzymes including mostly sulfide dehydrogenase at concentrations of 0.001-2% by weight.
The aqueous solution or the dry composition according to the invention can be employed to destroy and prevent the malodorous characteristics of odor causing compounds such as sulfides found in sewage and other waste products. The solution can be pumped into the material to be treated (liquid, sludge, or solid) or sprayed onto the surface or into the airspace surrounding the material. The dry material can be mixed into a slurry or solution at the point of application and applied in a similar manner.
A solution of sodium chlorite and sodium nitrate according to the invention can be employed to destroy and prevent the malodorous characteristics of odor causing compounds such as sulfides found in sewage and other waste products. The solution can be pumped into the material to be treated (liquid, sludge, or solid) or sprayed onto the surface or into the airspace surrounding the material.
Sodium chlorite is relatively non-reactive with the vast majority of compounds found in sewage. It will react rapidly with sulfide. Thus, the vast majority of the chlorite added to the sewage will consume sulfide, which allows such low levels to be used. The sodium chlorite provides rapid control of low levels of sulfides commonly found at upstream points early in the sewer line distribution system. The treatment concentration is directly dependent upon the amount of odor causing compounds with chlorite demand that are present in the waste.
The sodium nitrate prevents sulfate reducing bacteria from producing H 2 S. The arrest of H 2 S production using nitrate alone is not immediate, can take from 10-24 hours, and will remain until no nitrate is present. The concentration of nitrate salt present in the treatment solution may vary depending upon the amount of residual control of malodorous compounds that is required. Nitrate is less costly than chlorite and thus lowers the cost per pound of the treatment solution. Using a combination of nitrate plus chlorite treatment of sulfide odors also has an unexpected beneficial effect. It is expected that the treatment combination is capable of controlling sulfide odors much more effectively than the sum of the control when using either nitrate or chlorite alone.
As the nitrate requires the presence of nitrate-reducing, sulfide-oxidizing bacteria for it to be effective at consuming sulfide, in systems where no such bacteria reside, such nitrate-reducing, sulfide-oxidizing bacteria or their enzymes may be incorporated into the formulation.
The pH-elevating salt results in an increase in the pH of the waste to be treated, causing the H 2 S to revert to a soluble form of bisulfide ion, HS − , or sulfide ion, S −2 . Controlling the pH of the waste in a range of above 7.5 has also been shown to promote the growth and metabolism of sulfide-oxidizing nitrate-reducing bacteria.
In another embodiment, it is desirable for one of the nitrates to be aluminum nitrate, as use of aluminum salts is known to be effective for phosphorous removal, which is a common problem in municipal wastewater treatment plants. Employment of aluminum nitrate as one of the nitrate salts in the above mentioned formulation can have additional positive benefits which include both rapid consumption of sulfide by the Al +3 ion and also promote the removal of phosphorous downstream in the wastewater treatment plant.
It is to be pointed out that U.S. Pat. No. 6,059,973 discloses a mixture of chlorite salt and nitrate salt, the ratios of the patent are different than those claimed herein. Note that the effective range of the herein disclosed invention employs more nitrate than chlorite.
Bacterial consortia is defined as meaning a group of bacteria as found in nature. That is in nature, bacteria do not exist independently of other bacteria. There is always a community required to survive. It is not always feasible nor possible to single out a bacterial strain of the mix. In the a consortia or community of this invention, the predominant bacteria is one like Thiobacillus denitrificans (although others are known), which has the ability to oxidize sulfide while using nitrate as the terminal electron acceptor.
In the processes of this invention, the aluminum ion also can react with sulfide in a 3:1 molar ratio and tie up the sulfide and prevent it from off-gassing to cause odor problems. So the aluminum has a double benefit. Tying up the sulfide short term and then precipitating with the phosphate later in the waste treatment plant.
In greater detail the herein disclosed invention is directed to a composition useful for reducing sulfidic odors comprising effective amounts of a sulfide consuming chemical and a nitrate compound. Effective amounts are those amounts herein disclosed. The sulfide consuming chemical may be a chlorite salt and the nitrate compound may be a nitrate salt, with the amount of nitrate compound being in excess of the sulfide consuming chemical. More specifically the chlorite salt is sodium chlorite present in an amount of 0.01-0.39% and the nitrate compound is sodium nitrate and is present in an amount of 40-80%.
The invention also involves a process for removing dissolved hydrogen sulfide and odoriferous reduced sulfur compounds found in waste systems comprising the step of adding to the waste system an aqueous composition comprising a combination of a sulfide consuming chemical, a nitrate salt, and bacterial consortia in a wt ratio comprising 2-10 parts sulfide consuming chemical, 40-80 parts of nitrate salt, 0.01-1 part bacteria or bacterial enzyme, and 9-57.99 parts water. The sulfide consuming chemical may be selected from the group comprising alkali metal salts of hypochlorite, chlorite, nitrite, peroxide, percarbonate, perborate, or ferrous or ferric iron salts, peroxy monosulfuric acid, chlorine, hydrogen peroxide, chlorine dioxide and mixtures thereof. The preferred alkali metal chlorite is selected from the group comprising sodium chlorite, calcium chlorite, potassium chlorite and mixtures thereof, and the most preferred alkali metal chlorite is sodium chlorite. The nitrate salt is selected from the group comprising sodium nitrate, calcium nitrate, potassium nitrate, ammonium nitrate, aluminum nitrate and mixtures thereof. A mixture of ammonium nitrate and other nitrate salts may be employed to achieve a desired crystallization temperature. In a specific embodiment an aluminum nitrate is one of the nitrate salts in the blend and is fed so that the aluminum has the benefit of reducing phosphate in the downstream wastewater plant. In the process the bacterial consortia are comprised of a mixture of nitrate reducing and sulfide-oxidizing bacteria, or enzymes produced by nitrate-reducing, sulfide-oxidizing bacteria. The preferred bacteria is Thiobacillus denitrificans , and the preferred enzyme is sulfide dehydrogenase. In the process the aqueous composition may be in the for n of an aqueous solution and the composition may be added to provide sulfide consuming chemical in the ratio of 2-10 parts sulfide-consuming chemical per part sulfide to accomplish removal of sulfide. Further, the composition may be added to provide nitrate ion in the ratio of 10-30 parts nitrate ion per one part sulfide ion by weight. In a most specific process for removing dissolved odoriferous sulfidic compounds including all odoriferous reduced sulfur compounds found in wastewater including dissolved hydrogen sulfide comprises the steps of adding to the waste either as a dry solid or an aqueous composition comprising a combination of a sulfide consuming chemical, a nitrate salt, a salt for pH elevation, a bacterial consortia and enzyme blend added in such a manner that the applied dosage ratio comprises 1-10 parts by weight of sulfide consuming chemical, 10-30 parts by weight of nitrate salt, 10-100 parts by weight of a pH-elevating salt, 0.0001-1 parts by weight of a bacterial consortia, and 0.0001-1 parts by weight of a blend of bacterial enzymes per million parts by weight of water.
As used herein the sulfide consuming chemical is selected from the group comprising alkali metal salts of hypochlorite, chlorite, nitrite, peroxide, percarbonate, permanganate, perborate, ferrous or ferric iron salts, peroxy monosulfuric acid, chlorine, hydrogen peroxide, oxygen, air, chlorine dioxide and mixtures thereof.
In the process an aluminum nitrate is one of the nitrates in the blend and is fed so that the aluminum has the benefits of both consuming sulfide and reducing phosphate in the downstream wastewater plant. In the process a pH elevating salt is selected from the group comprising metal or alkali metal salts of carbonate ion or hydroxide ion or of metal or alkali metal oxides which react with water to form hydroxide ion, and metal or alkali. The preferred metal salts are selected from the group comprising magnesium hydroxide, calcium hydroxide, magnesium oxide, and calcium oxide and mixtures thereof.
The bacterial consortia are comprised of a mixture of nitrate reducing and sulfide-oxidizing bacteria and may include Thiobacillus denitrificans , a nitrate-reducing, sulfide-oxidizing bacteria.
An enzyme blend may be comprised of enzymes produced by nitrate-reducing, sulfide-oxidizing bacteria and more specifically the enzyme blend is comprised of sulfide dehydrogenase.
The composition is provided with sulfide consuming chemical in the weight ratio of 1-parts by weight of sulfide consuming chemical per part by weight of sulfide to accomplish removal of sulfide.
Further, the composition is added to provide nitrate ion in the weight ratio of 10-30 parts nitrate ion per million parts by weight of water to prevent biogenic generation of sulfide and the composition is added to provide pH-elevating salt in the weight ratio of 10-100 parts pH-elevating salt by weight per million parts by weight of waste.
The sulfide consuming chemical in the weight ratio of 1-10 parts by weight of sulfide consuming chemical per part by weight of sulfide is added to accomplish removal of sulfide.
The composition is added to provide nitrate ion in the weight ratio of 10-30 parts nitrate ion per million parts by weight of water to prevent biogenic generation of sulfide. The process involves a composition being added to provide pH-elevating salt in the weight ratio of 10-100 parts pH-elevating salt by weight per million parts by weight of waste.
Obviously, many modifications may be made without departing from the basic spirit of the present invention. Accordingly, it will be appreciated by those skilled in the art that within the scope of the appended claims, the invention may be practiced other than has been specifically described herein. | A synergistic composition is provided for controlling odor from waste products. The composition comprises a combination of nitrate salt, sulfide-consuming compound, pH-elevating compound, sulfide-oxidizing, nitrate-reducing bacteria, and sulfide-oxidizing enzyme. The method includes adding a sufficient amount of the composition to a waste stream to provide sufficient sulfide-consuming compound to effect immediate removal of sulfide. The composition incorporates a pH elevating compound, which both decreases the amount of gaseous H 2 S and puts the aqueous phase into a pH range where naturally occurring bacteria can more easily metabolize the sulfide. The composition also includes one or more nitrate salts which will accomplish longer term prevention of odors. Specific bacteria are incorporated into the formulation to insure that the nitrate has the right type and amount of bacteria present to prevent formation of and/or consume sulfide. Specific enzymes are incorporated into the formulation to promote oxidation of sulfide. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not Applicable.
TECHNICAL FIELD
[0004] This invention is directed to methods of clarifying industrial wastewater, specifically industrial laundry wastewater that includes wastewater from light to heavy product mix industrial laundry plants utilizing both full and split streams as defined by a client-user.
BACKGROUND OF THE INVENTION
[0005] In the laundry wastewater treatment field of solids/liquid separation, suspended and emulsified solids are removed from water by a variety of processes, including sedimentation, straining, flotation, filtration, coagulation, flocculation, and emulsion breaking among others. Additionally, after solids are removed from the wastewater they must often be dewatered. Liquids treated for solids removal often have as little as several parts per million (ppm) of suspended solids or dispensed oils, or may contain several thousand ppm of suspended solids or oils. Solids being generated as sludge may contain anywhere from 0.1 to 6 weight percent solids prior to dewatering, and from 20 to 50 weight percent solids material after dewatering by a plate and frame press. Solids/liquid separation processes are designed to remove solids from liquids and the more solids generated in the process, the more costly its disposal.
[0006] While strictly mechanical means have been used to effect solids/liquid separation, the modern methods often rely on mechanical separation techniques that are augmented by synthetic and natural polymeric materials to accelerate the rate at which solids can be removed from water. These processes include the treatment of wastewater with cationic organic and inorganic coagulants that coagulate suspended particulates to form larger particles that then may be brought together by an anionic flocculent to create particles large enough to be removed from the waste stream by mechanical means, i.e., flotation or clarification, and make the effluent suitable for industrial reuse or disposal in compliance with local permit discharge requirements.
[0007] In the industrial laundry industry, the chemical treatment of wastewater to a typical municipal standard of 100 ppm of oil and grease (EPA method 1664) prior to the introduction of this invention has been: the hydraulic equalization of untreated wastewater followed by the metered flow of the wastewater through a pipe or tanks to provide for retention time for the injection of a variety of chemicals including combinations and individually, both organic and inorganic coagulants and aids, followed by an organic component flocculent to produce coagulation and flocculation. These inorganic components used for coagulation or coagulation aids, typically have simple hydration factors of approximately 6-12 water molecules and may also be used in conjunction with a separate component, i.e. perlite or diatomaceous earth or bentonite clay, to act as a “body builder” to produce sludge so that in down stream processes it may be dewatered. A variety of organic and inorganic coagulants and aids exist throughout the marketplace. Historical data has shown that used in correct combination these chemistries can produce suitable effluent with sludge generation of approximately 1.1 to 2.5% of influent flow, whereas by use of this invention sludge production is reduced to approximately 0.25 to 1.0% of influent flow.
[0008] Chemical treatment generally refers to the removal of nonsettleable material by coagulation and flocculation. Chemical treatment for wastewater clarification is typically employed when colloidal and microemulsified solids need to be removed so that the total petroleum hydrocarbons (TPH), fat, oil and grease (FOG), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and other contaminants being discharged to a receiving stream need to be minimized. Typically, such treatment comprises using a cationic coagulant with one or more inorganic components, injected in combination or individually, followed by an anionic flocculent. Coagulation is the process of destabilization of the colloid waste particle by causing the coagulant (at 50-1000 ppm) to absorb by means of charge neutralization to form microfloc and impart residual cationic surface charge of the coagulated particles. The second step is to introduce a coagulant aid, i.e., ferric chloride, aluminum sulfate, ferrous sulfate, calcium chloride, polyaluminum chloride, typically at a rate of 75-700 ppm depending on the species, to increase the ability to form a more highly cationic surface that will cause the further adsorption of the coagulated particles onto the surface of an additional chemical, usually bentonite clay, at 200-900 ppm through a “sponge” effect. Flocculation occurs when the highly charged anionic flocculent bridges the previously formed cationic particles. Once neutralized, particles no longer repel each other and can come together to form larger agglomerated solids or sludge, which may then be removed from the water. The third step that is occasionally taken is the addition of sludge thickeners that assist in allowing the sludge to dewater, i.e. perlite, bentonite clay, diatomaceous earth and others. This invention is specifically directed to eliminating the second and/or third steps, i.e., the addition of coagulant aids and or sludge thickeners and a resultant reduction of the formation of sludge by up to 80% compared to previous historically used methods.
[0009] Clarification chemicals are typically utilized in conjunction with mechanical clarifiers including dissolved air flotation systems (DAFs), induced air flotation systems (IAFs), and settlers for the removal of solids from the treated water. The clarification chemicals coagulate and/or flocculate the suspended solids into larger particles, which can then be removed from the water by gravitational settling, flotation, or other mechanical means.
[0010] Processes for the preparation of high molecular weight cationic dispersion polymer flocculents are described in U.S. Pat. Nos. 5,006,590 and 4,929,655. High molecular weight, high active polymer cationic solution polymers for water clarification, dewatering and retention and drainage are disclosed in U.S. Pat. No. 6,171,505.
BRIEF SUMMARY OF THE INVENTION
[0011] The invention is directed to methods of clarifying industrial wastewater, specifically industrial laundry wastewater, to produce a compliant effluent and a reduction of sludge of between 30%-80%, using a two part system of a pDADMAC/ACH blended coagulant followed by a poly(acrylamide-co-acrylate) flocculent. Furthermore, the sludge produced using this invention will dewater in a typical plate and frame press without the use of any other organic or inorganic compounds added to the waste stream or sludge.
[0012] This invention pertains to the use of a cationic aqueous solution containing a mostly equal blend of a 50% ratio of approximately a 2-35% concentration of solids by weight of polydiallydimethylammonium chloride (pDADMAC) organic polymer and a combination of epichlorohydrin-quaternaryammonium species where pDADMAC is the major constituent, together with approximately 540% concentration of solids by weight of aluminum chlorohydrate (also known by other names i.e. ACH, also known as partially neutralized polyaluminum chloride) an inorganic compound utilized as a coagulant (along with a combination of other chloride species where ACH is the major constituent) in the chemical demulisification of laundry wastewater to produce catatonic charged particles.
[0013] The wastewater is cleaned using a medium to high molecular weight medium to very highly charged cationic solution coagulant (polymer) premixed with an inorganic aluminum species as one product, followed by a high to very high molecular weight anionic flocculent, I.e., poly(acrylamide-co-acrylate), (also known herein as sodium acrylate flocculent) with a 35% charge or higher (preferably 50% or higher), added in solution to produce particulate of sufficient size to be removed by physical means without the use of secondary, tertiary, or quaternary coagulation or flocculation aids. The wastewaters, to which this invention is directed, may be produced by the industrial cleaning of products including but not limited to: uniforms, shop towels, ink towels, mats, rugs, bar mops, aprons, coveralls and coats, used to protect personnel from manufacturing or commercial wastes.
[0014] The creation of the wastewater stream can be through the use of all available commercial equipment that is used for washing the various products. These streams must then be collected in such a way as to promote the batch collection or intermittent or continuous flow of the stream. This collection of wastewater then may be further treated by batch or flow proportion as to allow for the injection and mixing of treatment chemicals by primary coagulation and flocculation only. This invention cleans the wastewater and reduces the sludge generation by as much as 80% from traditional methods of industrial laundry wastewater treatment, resulting in the elimination of additional in-stream and downstream additives. Furthermore, at the proper doses, this invention allows the sludge to be dewatered in a typical plate and frame press or other equipment used for the dewatering of sludge.
[0015] The specific invention herein relates to the wastewater batch, or the in-stream use of the coagulant polymer compound containing pDADMAC coagulant and ACH injected into the wastewater stream in a diluted or an undiluted form, at any point prior to the sodium acrylate acrylamide flocculent injection with at least a two (2) second interval between the injections. The coagulant must be injected in the correct empirical quantity and given sufficient predetermined time to begin and complete the coagulation of the waste particles and the flocculent must be injected in the correct empirical quantity and given sufficient time to begin and complete the flocculation of the coagulated particles prior to dewatering. The coagulant and flocculent must be injected in sufficient quantity to create the conditions in the sludge that allow for the dewatering of the sludge generated by this process. These injection or dosing ratios are critical to the overall performance of the invention.
[0016] The dry anionic flocculent is made into any solution strength commonly between 0.05-0.5%, 0.2% being preferred, and injected post coagulant by at least a two (2) second interval and in sufficient empirical quantities as to cause coagulated wastewater to form flocculated waste particles of sufficient size to settle in clarification or rise by flotation, as by dissolved/induced air or other means.
[0017] The combination of the coagulant and the flocculent in the waste-stream produces a sludge volume 30-80% less than with those previous laundry wastewater treatments which utilize additional treatment chemicals or aids. The process testing of this invention has shown these reductions to be typical of the specific application of the invention disclosed herein.
[0018] The flocculents of this invention must be of sufficient charge density, molecular weight and added in sufficient quantities, as to aid in all dewatering mechanisms, typically being a plate and frame press often found in typical plants.
BRIEF DESCRIPTION OF THE DRAWING
[0019] The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing, which illustrates schematically an industrial laundry wastewater treatment system embodying features of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In accordance with the present invention, methods are provided for removing contaminants from an aqueous solution.
[0021] Methods are provided for removing: surfactants, phenolics, total petroleum hydrocarbons, fats oil and grease, TSS contributors, BOD contributors, COD contributors, and TOC contributors from an aqueous solution. The surfactants, phenolics, total petroleum hydrocarbons, fats, oil and grease (FOG), TSS contributors, BOD contributors, COD contributors, and TOC contributors from an aqueous solution are removed by adsorption onto a carrier precipitate which is formed in situ within the aqueous solution. In each of the embodiments of the invention the preferred method involves rapidly forming the precipitate.
[0022] The method of the invention can be used to remove the following contaminants from the laundry wastewater stream: TSS contributors, BOD contributors, COD contributors, TOC contributors, and/or fats, oil and grease (FOG). The invention will now be described first with respect to FOG, TSS contributors, BOD contributors. COD contributors, and TOC contributors. Unless otherwise stated, all process and apparatus parameters disclosed for FOG removal are equally effective for the removal of the other contaminants as well. Likewise, unless otherwise stated, all process and apparatus parameters disclosed for the removal of the other non-volatile contaminants are equally effective for heavy metal removal as well.
[0023] “Coprecipitation” as used with respect to the invention described herein refers to the chemical phenomenon where, within an aqueous solution containing a cationic carrier precipitate precursor, an anionic carrier precipitate precursor, and one or more coprecipitant precursors, the cationic and anionic carrier precipitate precursors are caused to chemically react and precipitate out of the aqueous solution as carrier precipitate particles; and, as the carrier precipitate particles are formed, coprecipitant precursors are removed from the aqueous solution by adsorption onto the surface of the carrier precipitate particle and/or by occlusion within the interior of the carrier precipitate particle.
[0024] The coprecipitant reaction is very rapid. Typically, more than 85 weight percent, and usually more than ninety-nine (99) weight percent, of the oil and grease are removed from the waste solution within about one minute after the formation of the agglomerated particle.
[0025] Finally, the methods of the invention are superior to conventional precipitation methods in that these methods also produce less precipitate sludge. The lower sludge production stems, in part, from the removal of separately or blended inorganic components including but not limited to: ferric chloride, ferrous sulfate, polyaluminum chloride, bentonite clay, perlite, diatomaceous earth, aluminum chloride (except for the blend of 20% pDADMAC and 20% aluminum chlorohydrate used in accord with this invention).
[0026] The aqueous polymeric coagulant pDADMAC is made by several manufacturers and of pre-described weight percent of solids combined with the pre-described aqueous polyaluminum chloride. The first chemical of the invention is mixed in controlled conditions with water to produce a cationic blend polymer and then injected into the waste stream in empirical quantities of 50-700 parts per million (ppm), depending primarily on stream flow rate or strength to cause the coagulation of negatively charged waste particles.
[0027] The resulting coagulated particles then have sufficient mass and residual cationic charge to react with the subsequent addition of the pre-described, wetted, water dispersed dry anionic flocculent to create an agglomerated particle of sufficient size for removal by mechanical means. The flocculent is injected into the waste stream after a predetermined time to permit the cationic blend to substantially complete the coagulation of the particles by at least two (2) seconds after the injection of the coagulant blend in empirical quantities of 5-50 ppm. This dose of flocculent is critical to not only the flocculation of the coagulated particles but to the later dewatering of the sludge. If either insufficient or excessive flocculent is injected into the wastewater stream, the sludge will not appropriately dewater.
[0028] The time interval for the coagulant to sufficiently absorb the waste particles prior to injection of the flocculent must be no less than two (2) seconds and no longer than ten (10) minutes. Sufficient passive or active mechanical action must take place between the wastewater and the coagulant as to allow the intimate commingling of the waste particles with the coagulant prior to addition of the flocculent.
[0029] The dry anionic flocculent must be of a molecular weight as termed in the industry as “very high” and of a charge density of no less than thirty-five percent (35%) but usually around fifty percent (50%). Again depending on wastewater stream strength the preferred range of 7-30 ppm of flocculent is needed to flocculate the coagulated particles to a level where the additional use of other coagulant aids and/or dewatering aids is not necessary.
[0030] Using this invention, typical sludge generation is reduced 30-80% which equates to 0.2 to 0.6% of sludge being produced of the influent flow and after typical dewatering using a plate and frame press the sludge is reduced another 50%. This compares to other typical treatments utilizing the above described three part systems or others generating 0.8 to 2.5% of the influent flow as sludge. Dewatering characteristics of the sludge in other prior art systems vary from system to system and do cause an additional “body feed” to the sludge in order to achieve dewaterability.
[0031] The following examples, are set forth to illustrate this invention and render same more understandable but are not intended to limit the scope of the herein disclosed and claimed invention.
EXAMPLE ONE
[0032] Laundry plant #1 with a daily average water usage of 110,000 gallons per day with 50% of the input product being shop towels, mats, ink wipers and other heavy soils was producing 1.1% of their daily wastewater as liquid sludge. The prior existing program being used for industrial pretreatment was a poly(diallydimethylammonium chloride) solution with a dose rate of 200-500 ppm coupled with the use of a six percent bentonite clay fed at the rate of 600 ppm, residence time for each chemical was 15-20 seconds at 125 gpm flow. This created coagulated particles that were then flocculated with a 0.2% polyacrylate flocculent at 6-8 ppm to produce particles able to be floated through mechanical means. The plate and frame press produced dewatered sludge cakes amounting to 135 cubic feet per day.
[0033] The method of this invention was used to replace the then existing program with a dose rate of 200400 ppm of coagulant using a mix time of approximately 20 seconds, and the application of the flocculent at 20-30 ppm using a mix time of approximately 40 seconds, resulting in floc that was floated through mechanical means. The amount of sludge produced was 0.3% of the influent flow thereby resulting in a dewatered sludge reduction of 66%. Since the application of this invention to plant #1, all required effluent parameters have been compliant with EPA requirements.
[0034] The effect on the plate and frame dewatering press was a reduction in the final amount of dewatered sludge to 45 cubic feet per day, thus reducing disposal costs of the sludge, as well as substantial savings in treatment chemicals and other additives used in the prior program.
EXAMPLE TWO
[0035] A newly installed dissolved air flotation wastewater system at Plant #2 began utilization of the methods of this invention for chemical treatment of the wastewater at start-up. The volume of water produced by the facility was approximately 70,000 gallons per day and the product mix comprised mostly of heavily grease-laden linen from the food industry. The methods of the invention were applied at 300-600 ppm using a mix time of approximately 15 seconds of coagulant and 25-45 ppm of flocculent using a mix time of approximately 30 seconds, resulting in floc able to be floated through mechanical means, with a resulting sludge production of 0.3% of the influent flow. Since the application of the invention, all required effluent parameters have been compliant with EPA requirements.
[0036] Treatment in accord with this invention resulted in an influent reduction of 421 ppm of biochemical oxygen demand (BOD) to <5.3 ppm (method EPA 405.1), and 360 ppm to <5.0 ppm oil and grease (method EPA 1664).
[0037] The effect on the plate and frame dewatering press was to produce only 25 cubic feet of dewatered sludge per day.
[0038] These examples one and two exemplify the consistent results achievable by this invention. While the dewatered sludge from Plant #2 could have been expected to amount to about 28.6 cubic feet, if the wastewater from the two plants were the same. Also, the newer equipment and other noted differences in the dosage and differing effluents will cause various results while being considered consistent in accord with this invention.
EXAMPLE THREE
[0039] An industrial laundry with an average flow of 80,000 gallons per day treated the wastewater with a pDADMAC coagulant coupled with an aluminum salt (200400 ppm) injected prior to the transfer pump and bentonite clay (600-900 ppm) injected 15 seconds later and sodium acrylate flocculent (7 ppm) 15 seconds down stream. Water was non compliant with a reading of eight (8) on a standard turbidity wedge. Sludge production for the facility was 1100 gallons per day. Filter cakes were not forming inside of the press which necessitated hauling away the liquid sludge.
[0040] After replacement of the above-described program in accord with this invention at 250 ppm of coagulant being injected prior to the transfer pump and 30 ppm of flocculent being injected at the former clay injection point, sludge was reduced to 350 gallons per day. The plant became compliant with 35+ on a standard turbidity wedge. This new process formed sludge cakes by the press amounting to 7 cubic feet per day, and substantial savings in disposal costs were achieved.
[0041] Presented in Table 1 are the results of Total Contained Leaching Process (TCLP) data used for determining the long-term hazardous effects of dewatered sludge. The TCLP approximates under laboratory conditions what the sludge will discharge during decomposition into the surrounding environment as known hazardous components. Table 1 is the qualitative analysis of those hazardous components taken from sludge cake utilizing a prior method including bentonite clay (year 2002) and those utilizing the method in accord with this invention (year 2003).
TABLE 1 TCLP 2002 TCLP 2003 Before Invention After Invention ANALYTE RESULT UNITS RESULT UNITS METHOD BENZENE <0.001 ppm <0.01 ppm 8260 CARBON TETRACHLORIDE <0.001 ppm <0.01 ppm 8260 CHLOROBENZENE <0.001 ppm <0.01 ppm 8260 CHLOROFORM <0.005 ppm <0.01 ppm 8260 DICHLOROBENZENE, 1,4- <0.005 ppm 0.016 ppm 8260 DICHLOROETHANE, 1,2- <0.005 ppm <0.01 ppm 8260 DICHLOROETHYLENE, 1,1- <0.005 ppm <0.01 ppm 8260 METHYL ETHYL KETONE <0.019 ppm <0.01 ppm 8260 TETRACHLOROETHYLENE <0.017 ppm <0.113 ppm 8260 TRICHLOROETHYLENE <0.005 ppm <0.01 ppm 8260 VINYL CHLORIDE <0.002 ppm <0.001 ppm 8260 CRESOL, M&P <0.1 ppm <0.05 ppm 8270 CRESOL, 0- <0.15 ppm <0.1 ppm 8270 DINITROTOLUENE, 2,4- <0.01 ppm <0.05 ppm 8270 HEXACHLOROBENZENE <0.01 ppm <0.05 ppm 8270 HEXACHLOROBUTADIENE <0.005 ppm <0.05 ppm 8270 HEXACHLOROETHANE <0.005 ppm <0.05 ppm 8270 NITROBENZENE <0.05 ppm <0.05 ppm 8270 PENTACHLOROPHENOL <0.05 ppm <0.05 ppm 8270 PYRIDINE <0.1 ppm <0.1 ppm 8270 TRICHLOROPHENOL, 2,3,5- <0.05 ppm <0.05 ppm 8270 TRICHLOROPHENOL, 2,4,6- <0.05 ppm <0.05 ppm 8270 CHLORDANE <0.01 ppm <0.01 ppm 8270i ENDRIN <0.01 ppm <0.01 ppm 8270i HEPTACHLOR <0.01 ppm <0.008 ppm 8270i HEPTACHLOR EPOXIDE (BETA) <0.008 ppm <0.008 ppm 8270i LINDANE <0.01 ppm <0.01 ppm 8270i METHOXYCHLOR <0.05 ppm <0.01 ppm 8270i TOXAPHENE <0.1 ppm <0.01 ppm 8270i 2,4 D <0.002 ppm <0.02 ppm 8151 2,3,5-TP SILVEX <0.002 ppm <0.02 ppm 8151 ARSENIC, As <0.01 ppm <0.001 ppm 7060 BARIUM, Ba 0.478 ppm <0.1 ppm 7080 CADMIUM, Cd <0.01 ppm <0.01 ppm 7130 LEAD, Pb 0.051 ppm <0.1 ppm 7421 CHROMIUM, Cr 0.049 ppm <0.01 ppm 7190 MERCURY, Hg <0.001 ppm <0.02 ppm 7470 SELENIUM, Se <0.02 ppm <0.02 ppm 7740 SILVER, Ag <0.005 ppm <0.05 ppm 7760 METALS, DIGESTION FOR 1 ea sample 1 ea sample 3030 D SOLIDS 100 percent 100 percent 1311 CORROSIVITY Ph >12.5 or <2 5.1 units 5.9 units 9040 IGNITABILITY >140 .F >140 .F 1010 TOTAL RELEASABLE CYANIDE <0.01 mg/kg <0.009 ppm 9010 TOTAL RELEASABLE SULFIDE <0.5 mg/kg <0.5 ppm 9030 REACTIVITY =0 Negative =0 Negative Exam TCLP SEMI/NON-VOLATILES EXTRACT 1 ea 1 ea 1311 TCLP VOLATILES EXTRACT 1 ea 1 ea 1311
[0042] It can be extrapolated from the above two sets of data that neither TCLP has components in sufficient quantities as to categorize the sludge as hazardous under most current regulations for the disposal of sludge.
EXAMPLE FOUR
[0043] An industrial laundry whose wash mix is a majority of heavy soil products treated their wastewater with separately fed injections of 20% solids by weight pDADMAC (200-500 ppm) followed approximately 20 seconds later by a second injection of polyaluminum chloride (400-800) and in approximately 10 seconds an injection of sodium acrylate flocculent to produce EPA and municipal non-compliant effluent (eight on a standard turbidity wedge) and approximately 2200 gallons of sludge with a daily flow of 120,000 gallons of wastewater per day. In order for the facility to dewater the sludge by plate and frame press method, 350 pounds of diatomaceous earth was added as a body feed to produce a sludge cake.
[0044] After elimination of the previous treatment program and introduction of the methods in accord with this invention, the plant became compliant (35+on a standard turbidity wedge) and the amount of sludge produced was approximately 600 gallons per day. The body feed of Kenite (perlite), needed to produce sludge cake, was eliminated. The coagulant injected at the intake side of the transfer pump was at 150-300 ppm and the flocculent was injected approximately 20 seconds later at 35 ppm. Effluent testing done by a local laboratory showed total petroleum hydrocarbons to be 4 mg/l, which was well within EPA and municipal limits.
EXAMPLE FIVE
[0045] This plant was an industrial laundry with an average daily flow of 70,000 gallons and a mixed product load requiring treatment of the wastewater to meet local limits. An epi-quanternary amine coagulant was being injected prior to the wastewater transfer pump at 500 ppm with an injection of technical grade ferric chloride at 250 ppm into a chemical reaction tank with two minutes detention time at 75 gallons per minute. Then it was gravity fed to a second tank and a sodium acrylate emulsion polymer was fed at 10 ppm. The sludge produced daily was approximately one percent (1%) of the daily flow (700 gallons) and was being hauled for disposal as a liquid.
[0046] After removal of the above process and incorporating the process in accord with this invention with the coagulant injection point being at the first tank at 400 ppm and the flocculent fed at 25 ppm into the second tank, the effluent quality was clear at 35 on a standard turbidity wedge. Sludge was reduced to 0.5% (350 gallons) of the influent and was hauled for disposal as a liquid because this plant had no plate and frame press.
EXAMPLE SIX
[0047] This plant was an industrial laundry out of compliance on all parameters. At 70,000 gallons per day the facility was producing 1100 gallons of sludge and needed to add as much as 600 pounds of bentonite clay for treatment and as a body feed for sludge dewatering. The treatment scheme utilized at the time was an epi-amine/DADMAC (400-600 ppm) combination coagulant followed by bentonite clay injection (600-1200 ppm) and sodium acrylate flocculent (7-10 ppm).
[0048] As shown on Table Two, once the prior process was abandoned and the process in accord with this invention was introduced, the plant became compliant with local standards. Injection of the coagulant was made prior to the intake side of the wastewater transfer pump with a five second interval for the injection of the flocculent. Sludge was reduced to 300-350 gallons per day with 25 cubic feet of sludge being produced after plate and frame dewatering.
TABLE TWO PARAMETER LIMIT Before Invention After Invention BIOCHEMICAL 300 mg/L 1110 mg/L 120 mg/L OXYGEN DEMAND OIL & GREASE 100 mg/L 187 mg/L 5.2 mg/L (TOTAL pH Acidic <5.5 7.58 9.33 pH Basic >11.5 7.58 9.33 TOTAL SUSPENDED 300 mg/L 1555 mg/L 26 mg/L SOLIDS
[0049] It is to be noted that under extremely limited conditions, a plant may introduce a small amount of bentonite clay, for example, into the waste stream at approximately two to six seconds after the addition of the coagulant and before the addition of the flocculent, in the herein disclosed method, as a sludge conditioner. Though this is not necessary with this invention, when the waste stream is extremely heavy in oil and grease components (over 1000 ppm), the clay will assist in the dewatering of the sludge. The addition of the clay to be added should be in a much smaller quantity (less than 200 ppm) than used in the prior art methods, i.e., without the use of the present invention. The clay is used for conditioning the sludge only, and not for achieving effluent quality standards, which are attained without clay addition.
[0050] While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention. | Methods are described for removing contaminates from aqueous industrial wastewater process streams, specifically industrial laundries to yield a less contaminated aqueous effluent for discharge to a sewer and reduce the sludge generated therefrom. A premixed medium/high molecular weight and medium/high charged cationic coagulant solution polymer and an inorganic aluminum species is injected into the wastewater, and after at least a two second delay, a high molecular weight highly charged anionic flocculent polymer solution is injected into the wastewater which reduces sludge generation, while maintaining or exceeding effluent quality. Also, no coagulant, flocculent or sludge aids are needed to attain the results and the sludge can be dewatered in a plate and frame press. | 2 |
FIELD OF THE INVENTION
[0001] This application relates to the field of equipment used in drilling large foundation holes for buildings and bridges and more specifically to a unique telescopic drilling bucket mechanism. The current invention provides a drilling bucket assembly along with a unique drill head apparatus that improves the operation by which a drilling operator can remove dirt from a drilling device. With the combination of a drilling head and bucket, the unit can be raised to the surface where the bucket portion is moved up or down from the drill head to empty the excavated material.
BACKGROUND OF THE INVENTION
[0002] Foundation chilling has evolved over time and continues to be an essential operation for all construction of bridges, buildings and skyscrapers. Without proper holes for the drilled foundation piles, a budding or bridge could be destroyed in the event of an earthquake. In an effort to improve the production and quality of drilled foundations, there has been a sizable investment, and significant advancement, in the equipment and tools of the trade.
[0003] Some of the most common tools used by foundation drillers are the separate digging, and cleanout buckets. Digging buckets are used to dig through hard layers of dirt and rock and are known for their ability to keep holes true and straight as possible. Drilling buckets are often used to manage water in the hole when drilling fluid is necessary to keep the holes from caving in. Axially separating drill buckets keep the drill fluids clean by containing the loose soils and preventing them from mixing with or contaminating drill fluids. Augers are used for digging large holes but have no efficient means of moving the material to the surface. Cleanout buckets are used to clean the bottom of the holes during the digging process to remove any loose rocks and soil to ensure a clean solid bottom surface for a foundation.
[0004] In executing pile foundations in construction work, a unique method of drilling earth is proposed in this application. In this method a rotatable bucket is used for excavating a straight pile bore and also moving the excavated soil from the bore hole to the surface. The Axially separating drill bucket assembly is attached to the lowermost position of a Kelly bar, a conventional part of the drilling rig, and suspended to perform the drilling operation. When the bucket is rotated, the soil excavated by a unique drill head is moved into the drill bucket. The drill bucket filled with the excavated soil is then raised by the drilling rig and the soil in the bucket is removed when an actuator member comes in contact with the stationary sombrero, a conventional part of the drilling rig, and the drill bucket is either raised above the drill head or the drill head pushed down from the drill bucket. Several methods can be used to accomplish this similar process, some being a scissor action mechanical method, a hydraulic actuated method, a direct downward pressure method and a method where a latch is actuated by a rod coming against the sombrero to release the drill head to translate down a telescoping shaft to remove the material by the means of rapidly spinning the device.
[0005] Numerous innovations for drills used for drilling foundation piles have been provided in the prior art that are described as follows. Even though these innovations may be suitable for the specific individual purposes to which they address, they differ from the present design as hereinafter contrasted. The following is a summary of those prior art patents most relevant to this application at hand, as well as a description outlining the difference between the features of the Axially separating drill bucket and the prior art.
[0006] U.S. Pat. No. 5,234,062 of Hachiro Inoue describes an automatic evacuation drilling bucket comprising a follower formed with a working space for receiving a blade member which is capable of coming in contact with an osculating arm, the working space having upper, lower, transition and receiving compartments. If the blade member is located in the upper and lower compartments, the blade member is engaged with the follower when a drive shaft member is rotated in the normal and reverse directions. If the blade member is urged to move into the receiving compartment through the transition compartment, the blade member comes in contact with the osculating arm when the drive shaft member is rotated in the reverse direction.
[0007] This patent describes an automatic evacuation drilling bucket that operates with a fixed drill bucket that has a hinged member at the bottom for the removal of the excavated material. If the material sticks to the side of the drill bucket it must be jarred to remove it and that often damages the equipment involved. It does not have the capability of digging the hole, cleaning the hole out, moving the material to the surface, separating the drill bucket from the drill head and pushing the material out in one operation.
[0008] U.S. Pat. No. 4,971,163 of Akira Ohashi et al. describes a drilling bucket apparatus for expanding a bore-hole bottom for a cast-in-place pile. Drill bits are pivotally suspended from the upper portion of a drill pipe, which is a main frame of the apparatus, and are expanded and retracted radially by means of hydraulic cylinders. A bucket is attached to the lower end of the drill pipe and scrapers are installed on the side of the bucket. The scrapers are arranged to open and close sideward, following the movement of the drill bits. During drilling work, the apparatus is suspended from a Kelly bar of a drilling machine. When the apparatus is rotated and the drill bits are expanded, the whole expanded shape of a bore-hole bottom is drilled simultaneously and cuttings are scraped into the bucket by means of the drill bits and the scrapers. Further, a bottom lid of the bucket can be released by operating a hydraulically-actuated opening lever, whereby, cuttings are discharged automatically.
[0009] This patent describes a drilling bucket apparatus for expanding a bore-hole bottom for a cast-in-place pile. It does not have the capability of digging the hole, cleaning the hole out, moving the material to the surface, separating the drill bucket from the drill head and pushing, the material out in one operation.
[0010] U.S. Pat. No. 4,604,818 of Hachiro Inoue describes an under reaming pile bore excavating bucket and the method of excavating an under reamed part of a pile bore, and more particularly to an excavating bucket such that an under reamed part of a pile bore can be excavated and further the excavated soil can be moved into the bucket body for easy removal of soil. The bucket includes, in particular, a plurality of slidable wing bits housed within a bucket and moved downward and extended outward along guide rails at the bottom of an already excavated straight pile bore.
[0011] This patent describes an under reaming pile bore excavating bucket and the method of excavating an under reamed part of a pile bore. The bucket includes, in particular, a plurality of slidable wing hits housed within a bucket and moved downward and extended outward along guide rails at the bottom of an already excavated straight pile bore. It does not have the capability of digging the hole, cleaning the hole out, moving the material to the surface, separating the drill bucket from the drill head and pushing the material out in one operation.
[0012] U.S. Pat. No. 2,126,124 of Frank S. McCutcheon describes an excavating bucket that may be used for circular shafts and wells, and that may be completely operated and controlled with only one cable. A further object of my invention is to provide an excavating bucket to be used in confined quarters where the space of operation is limited. Still further objects of this invention are to provide an excavating bucket that is positive in its action, which conforms to the shape of the excavation, that allows water to run from the excavated material in the bucket and that has few moving parts. A still further object of my invention is to provide an excavating bucket that is economical in manufacture, durable and efficient in use.
[0013] This patent describes an excavating bucket that may be used for circular shafts and wells, It does not have the capability of digging the hole, cleaning the hole out, moving the material to the surface, separating the drill bucket from the drill head and pushing the material out in one operation.
[0014] Patent Application Publication No. US 2004/0168831 A1 of Satoshi Nozaki et al. describes locking elements that are provided at an inner member connected to a Kelly bar, and a locking element bearing plate provided at an outer member. The outer member includes a cylindrical bucket and a grab bucket housed inside the cylindrical bucket. When an excavating tool is in its most contracted state, the inner member is rotated forward to lock the locking elements at the locking element bearing plate, thereby disallowing relative vertical movement of the inner member and the outer member. As the excavating tool is rotated by applying a force to the Kelly bar along the lifting direction in this state, an excavating operation can be executed while applying a load smaller than the load of the excavating tool. As a result, it becomes possible to execute an excavating operation with a large excavating tool in conjunction with an earth drill having a small drive force. Projections provided at the outer circumference of the inner member are fitted at guide rails extending along the longitudinal direction and provided at the inner circumference of the second member so as to be allowed to move up/down freely. Thus, the grab bucket having an underground obstacle grabbed therein can be rotated to remove the underground obstacle.
[0015] This patent describes a device where the outer member includes a cylindrical bucket and a grab bucket housed inside the cylindrical bucket. When an excavating tool is in its most contracted state, the inner member is rotated forward to lock the locking elements at the locking element bearing plate, thereby disallowing relative vertical movement of the inner member and the outer member. It does not have the capability of digging the hole, cleaning the hole out, moving the material to the surface, separating the drill bucket from the drill head and pushing the material out in one operation.
[0016] None of these previous efforts, however, provides the benefits attendant with the Axially separating drill bucket. The present design achieves its intended purposes, objects and advantages over the prior art devices through a new, useful and unobvious combination of method steps and component elements, with the use of a minimum number of functioning parts, at a reasonable cost to manufacture, and by employing readily available materials.
[0017] In this respect, before explaining at least one embodiment of this application in detail it is to be understood that the design is not limited in its application to the details of construction and to the arrangement of the components set forth in the following description or illustrated in the drawings. The Axially separating drill bucket is capable of other embodiments and of being practiced and carried out in various ways. In addition, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
SUMMARY OF THE INVENTION
[0018] The principal advantage of the Axially separating drill bucket is that it eliminates the stress and shock loads incurred on the machinery's hydraulic equipment when attempting to remove material from existing drill buckets.
[0019] Another advantage of the Axially separating drill bucket is that it both drills the hole and removes the material in a single operation.
[0020] Another advantage of the Axially separating drill bucket is that in different designs the bucket can be raised above the drill head or the drill head can be lowered below the bucket to remove the excavated material.
[0021] Another advantage is Axially separating drill buckets keep the drill fluids clean by containing the loose soils and preventing them from mixing with or contaminating drill fluids.
[0022] Another advantage of the Axially separating drill bucket is that the unique drill head has the capability to be rotated in one direction to drill the hole with the material entering the drill bucket and rotating in the opposite direction to close off the opening to the internal cavity to retain the material to be lifted to the surface.
[0023] Another advantage of the Axially separating drill bucket is that several methods can be used to either raise the bucket or lower the drill head.
[0024] Another advantage of the Axially separating drill bucket is that when lifted above the surface an actuator member can come in contact with the sombrero of the drill rig to activate the release mechanism.
[0025] Another advantage of the Axially separating drill bucket is the material does not rely on gravity to fall out of the bucket.
[0026] Another advantage of the Axially separating drill bucket is the material can be pushed out and spread out evenly by the accelerated spinning motion.
[0027] Another advantage of the Axially separating drill bucket is the material cannot stick in the bucket.
[0028] Another advantage of the Axially separating drill bucket is if water is in the hole when drilling, there is an internal cavity to allow the water to pass through the Drill Bucket.
[0029] Another advantage is the time saved by only using a single operation rather than lowering a drill unit and an excavating unit separately.
[0030] Another advantage is to provide an Axially separating drill bucket assembly that reduces costly repairs.
[0031] Another advantage is to provide a simple device with few moving parts.
[0032] Another advantage is to provide spring loaded latching mechanism to release and re-latch the drill head from the drill bucket.
[0033] Another advantage is having the angled section on the spring loaded push rod to activate the spring loaded latching mechanism.
[0034] Another advantage is having the spring loaded push rod pressed down by the sombrero against the pusher plate to move the material within the drill bucket out.
[0035] Another advantage is having the telescoping capability between the outer tubular telescoping drill stem with a latching catch and the inner tubular drill stem.
[0036] Another advantage is using square heavy all tubing for the outer tubular telescoping dull stem and the inner tubular drill stem to minimize the torsional stresses on the drill stem when the Axially separating drill bucket is rotated.
[0037] Another advantage is using a sealed hydraulic or pneumatic cylinder with a limited bypass within the square drill stem to cushion lowering of the drill head.
[0038] Another advantage is the addition of the centering tip on the dill head.
[0039] Another advantage is the addition of digging teeth on the outer perimeter of the drill tip plate to create a cleaner clearance hole.
[0040] Another advantage is using a nylon strap or limiting device within the square drill stem to cushion abrupt stopping of the drill head when the material is released.
[0041] Another advantage is using a hydraulic cylinder with a manual fluid flow control valve to cushion lowering of the drill head.
[0042] Another advantage is using a hydraulic cylinder along with a second hydraulic cylinder and a pilot operated check valve to control and cushion the lowering and latching of the drill head.
[0043] Another advantage will be the addition of the bowtie configuration of the drill tip plate along with the two orifices in the drill head plate creating the ability to fill the drill bucket faster.
[0044] These together with other advantages of the Axially separating drill bucket along with the various features of novelty, which characterize the design, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. In this respect, before explaining at least one of the embodiments of the Axially separating drill bucket in detail it is to be understood that the design is not limited in its application to the details of construction and to the composition set forth in the following description or illustrated in the drawings
[0045] The Axially separating drill bucket is controlled by the means of heavy equipment, commonly called the drill rig, with a drill boom that rotatably activates a conventional Kelly bar attached to the device. A unit called the sombrero is a fixed pan of the drill boom that the Kelly bar passes through extending to a box section of the Axially separating drill bucket assembly. The Kelly bar attaches to the box section by a variety of connection means but most often by the means of a square section inserted in a square orifice with a locking retainer. The box section is permanently attached to the drill stem that can be either a round or square cross section and extends through the drill bucket to be connected to the drill head. The drill bucket consists of a heavy walled steel tubular member open at one end and closed at the other h the means of a heavy steel cap plate welded in place. In the center of the cap plate on the preferred embodiment is an orifice where the drill stem passes through and the drill bucket translates up and down.
[0046] A long vertical key section is part of the drill stem that engages in a key slot in the steel cap plate keeping the drill bucket from rotating when the Axially separating drill bucket assembly is turning A pusher plate can be permanently attached to the drill stem in order to push the material out of the drill bucket central cavity when drill bucket is raised.
[0047] In the preferred embodiment the drill bucket will be raised by a single external scissor action mechanism on the outside of the drill bucket above the steel cap plate. The actuator member translates through an elongated slot of the box section to pivotally attach to the first scissor section that rotates about a pivot attached to the drill stem. At the distal end of the first scissor section is a pivoting link attached to a pivot lug fixed to the upper surface of the steel cap plate. A second similar external scissor action mechanism can be added on the other side of the drill stem to equalize the forces required to raise the drill bucket. When the Axially separating drill bucket is raised above the surface the actuator member makes contact with the stationary sombrero exerting a downward force raising the drill bucket. The elongated slot in the box section keeps the mechanism from being clogged when in operation.
[0048] In the first alternate embodiment of the Axially separating drill bucket where the drill bucket will be raised by a single internal scissor action mechanism within the drill bucket. In this process the actuator member translates through an elongated slot of the box section and an elongated slot in the steel cap plate to pivotally attach to the first scissor section that rotates about a pivot point on the drill stem. At the distal end of the first scissor section the second scissor section is pivotally attached with its distal end pivotally attached to a pivot lug fixed to the under surface of the steel cap plate. When the Axially separating drill bucket is raised, the actuator member makes contact with the stationary sombrero exerting a downward force raising the drill bucket. The elongated slots in both the box section and the steel cap plate keep the mechanism from being clogged when in operation. A second similar scissor action mechanism within the drill bucket can be added on the other side of the drill stem to equalize the forces required to raise the drill bucket.
[0049] The drill head consists of a drill head plate that is permanently attached to the distal end of the drill stem. There may be several drill bucket alignment features with the first, being a beveled edge to the drill bucket mating with a beveled edge on the drill head plate. Another alignment feature will be a number of alignment tabs welded around the circumference of the drill head plate with anti-rotation stop blocks attached to the inner surface of the drill bucket to resist any twisting between the drill bucket and the drill head plate. Another alignment feature will be an extension of intermittent side segments of the lower surface of the drill bucket mating with cutouts in the drill head plate. The drill tip plate has polarity of digging teeth and a central rod extending into as mating hole in the drill stem. A circumferential groove on the central rod aligns with a slot in the drill stem where a drill tip plate retainer allows the drill tip plate to rotate and be easily removed if necessary.
[0050] In the digging operation the drill tip plate with cutting teeth pivots against a stop plate welded on the drill head plate so that when rotating the Axially separating drill bucket the opening in the drill head plate is exposed with the material going into the drill bucket cavity. By reversing the rotation, the drill tip plate is forced in the opposite direction against a second stop plate closing the opening in the drill head plate so that the device can be raised to the surface without releasing the excavated material. The limiting stops, on the bottom surface of the drill head plate, act to keep the drill tip plate from making a full rotation in either direction.
[0051] A steel angle bar can be welded to the length of the inner surface of the drill bucket with an orifice in the steel cap plate and the drill head plate creating a separate cavity where water that might accumulate at the bottom of the hole could travel up through the Axially separating drill bucket. This is an option that can be incorporated into any of the embodiments of this application.
[0052] In the second alternate embodiment of the Axially separating drill bucket assembly, the process is to raise the drill bucket by the means of using a large capacity hydraulic cylinder attached to the box section with an actuator member extending up to make contact with the sombrero when the Axially separating drill bucket is raised above the surface. This contact forces the hydraulic fluid into a smaller and longer hydraulic cylinder attached to a lug on the upper surface of the steel cap plate raising the drill bucket away from the drill head plate. Additionally, a second smaller and longer hydraulic cylinder connected to the same large capacity hydraulic cylinder, would be attached to a second lug. on the other side of the drill stem on the upper surface of the steel cap plate to equalize the forces required to raise the drill bucket.
[0053] A third alternate embodiment of the Axially separating drill bucket assembly w use the large capacity hydraulic cylinder with actuator member extending up to make contact with the sombrero when the Axially separating drill bucket assembly is raised above the surface. This contact forces the hydraulic fluid into a second set of smaller and longer hydraulic cylinders attached to a lug on the under surface of the steel cap plate raising the drill bucket away from the drill head plate.
[0054] A forth alternate embodiment of the Axially separating drill bucket assembly will use the large capacity hydraulic cylinder attached to the box section that is permanently attached to the drill stem with the actuator member extending up to make contact with the sombrero when the Axially separating drill bucket assembly is raised above the surface. The drill bucket will be welded permanently to the drill stem and hydraulic fluid forced into one or more smaller and longer hydraulic cylinders attached to a lug on the under surface of the steel cap plate. This action lowers the drill bead plate by the means of a telescoping stem inner member that is an integral part of the drill head plate.
[0055] A fifth alternate embodiment of the Axially separating drill bucket assembly will have the actuating rod spring loaded against the top surface of the drill bucket. The drill bucket and drill stem are welded together with a telescoping stem inner member part of the drill head plate. The actuating rod is welded to the steel drill head plate so that when it comes in contact with the sombrero on the surface the spring is compressed and the drill head plate is lowered away from the drill bucket.
[0056] The sixth alternate embodiment of the Axially separating drill bucket assembly will have a spring loaded latching mechanism holding the drill head up against the drill bucket with an actuator member extending up through the steel cap plate. The box section is permanently attached to the steel cap plate with the Kelly bar held in place by the means of the locking retainer. When the Axially separating drill bucket assembly is raised the actuator member makes contact with the Sombrero releasing the telescoping drill stem extension to lower by the means of gravity until it hits the stop on the lower inner surface of the drill bucket.
[0057] Another embodiment of the Axially separating drill bucket assembly will have a spring loaded latching mechanism incorporating a spring loaded push rod and a central hydraulic cylinder. The spring loaded push rod translates downward through the tubular guide with the angled lower section that activates the spring loaded latching mechanism when pressure is applied by the sombrero as the Axially separating drill bucket assembly is raised. An enlarged tubular guide section of the tubular guide limits the downward travel when pushed downward by the sombrero. The spring loaded push rod translates further downward pressing the pusher plate down to assist in emptying the drill bucket A hydraulic cylinder is housed within the outer tubular square drill stem and the inner tubular square drill stem anchored at the top by the means of the cross pin in the inner tubular drill stem and at the bottom in the outer tubular drill stem by the means of the cross pin. The drill head is at the lower end of the drill bucket.
[0058] Another embodiment of the Axially separating drill bucket assembly will have the spring loaded latching mechanism with a nylon strap replacing the hydraulic cylinder to lower the drill head to a cushioned lower position. The strap will be held by the means of the cross pin in the inner tubular drill stem and at the bottom in the outer tubular drill stem by the means a second cross pin.
[0059] Another embodiment of the Axially separating drill bucket assembly with the spring loaded latching mechanism will have the hydraulic cylinder where the fluid flow is controlled through the hydraulic lines to the manual hydraulic fluid flow control valve attached to the exterior of the drill bucket or within the cab of the drill rig to control the descent of the drill head.
[0060] Another embodiment of the Axially separating drill bucket assembly having the drill head released by the means of the sombrero pressing down on the activation rod of a second hydraulic cylinder to open pilot operated check valve to release and control descent of the drill head through the hydraulic cylinder.
[0061] The Axially separating drill bucket assembly will have an interlocking system between the drill head plate and the drill bucket where the segments of the drill bucket interlock with the cavities in the drill head plate to create a rigid structure. In this embodiment the drill head plate has two orifices into the central cavity of the drill bucket constructed in a bow tie shape with the digging teeth on either side Digging teeth can additionally be added around the perimeter of the drill tip plate. Two stop blocks are welded on the drill head plate to limit the rotation of the drill tip plate to a point of opening or covering the two orifices and trapping the material within the drill bucket central cavity. A replaceable centering tip, with digging teeth, is located on the drill tip plate.
[0062] The foregoing has outlined rather broadly the more pertinent and important features of the present Axially Separating Drill Bucket in order that the detailed description of the application that follows may be better understood so that the present contribution to the art may be more fully appreciated. Additional features of the design will be described hereinafter which form the subject of the claims of this disclosure. It should be appreciated by those skilled in the art that the conception and the disclosed specific embodiment may be readily utilized as a basis for modifying or designing other structures and methods for carrying out the same purposes of the present design. It should also be realized by those skilled in the art that such equivalent constructions and methods do not depart from the spirit and scope of this application as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0063] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the Axially Separating Drill Bucket and together with the description, serve to explain the principles of this application.
[0064] FIG. 1 depicts a perspective drawing of the Axially Separating Drill Bucket being lowered into a hole by the means of a drill rig.
[0065] FIG. 2 depicts a cross sectional view of the preferred embodiment of the Axially Separating Drill Bucket with a single external scissor action movement having the drill head in upper position.
[0066] FIG. 3 depicts an exploded view of the retainer in the drill stem securing the drill tip plate into position.
[0067] FIG. 4 depicts a perspective view of the preferred embodiment of the Axially Separating Drill Bucket with a double external scissor action movement having the drill head in upper position.
[0068] FIG. 5 depicts a cross sectional view of the first alternate embodiment of the Axially Separating Drill Bucket with a single internal scissor action movement having the drill head in the upper position.
[0069] FIG. 6 depicts a bottom view of the Axially Separating Drill Bucket with the drill tip plate rotated closing the opening in the drill head plate.
[0070] FIG. 7 depicts a cross sectional view of the first alternate embodiment of the Axially Separating Drill Bucket with the single internal scissor action movement having the drill head in the partially extended position.
[0071] FIG. 8 depicts a bottom view of the Axially Separating Drill Bucket with the drill tip plate rotated exposing the opening in the drill head plate.
[0072] FIG. 9 depicts a cross sectional view of the first alternate embodiment of the Axially Separating Drill Bucket with the single internal scissor action movement having the drill head in the fully extended position.
[0073] FIG. 10 depicts a perspective view of the first alternate embodiment of the Axially Separating Drill Bucket with a double internal scissor action movement having the drill head in upper position.
[0074] FIG. 11 depicts a cross sectional view of the second alternate embodiment of the Axially Separating Drill Bucket using a hydraulic method using a large capacity hydraulic cylinder connected to a smaller longer hydraulic cylinder to raise the drill bucket from the drill head.
[0075] FIG. 12 depicts a perspective view of the second alternate embodiment of the Axially Separating Drill Bucket using a hydraulic method using a large capacity hydraulic cylinder connected to two smaller longer hydraulic cylinders to raise the drill bucket from the drill head.
[0076] FIG. 13 depicts the third alternate embodiment of the Axially Separating Drill Bucket using a hydraulic method using a large capacity hydraulic cylinder connected to two smaller longer hydraulic cylinders to raise the drill bucket from the drill head.
[0077] FIG. 14 depicts a cross sectional view of the forth alternate embodiment of the Axially Separating Drill Bucket having the drill bucket connected to the telescoping drill stem using a hydraulic method with a large hydraulic cylinder connected to two smaller longer hydraulic cylinders to lower the drill head using a telescoping drill stem.
[0078] FIG. 15 depicts a cross sectional view of the fifth alternate embodiment of the Axially Separating Drill Bucket having the drill bucket connected to the telescoping drill stem and the spring loaded actuator member connected to the drill head. When the bucket is raised to the surface and the actuator comes in contact with the sombrero and the drill head is pushed down.
[0079] FIG. 16 depicts a cross sectional view of the sixth alternate embodiment of the Axially Separating Drill Bucket assembly having a spring loaded latching mechanism holding the drill head up against the drill bucket
[0080] FIG. 17 depicts top view of the Axially Separating Drill bucket.
[0081] FIG. 18 depicts a cross sectional view of the sixth alternate embodiment of the Axially Separating Drill Bucket assembly having a spring loaded latching mechanism released with the drill head in the lowered position.
[0082] FIG. 19 depicts a perspective view of the sixth alternate embodiment of the Axially Separating Drill Bucket assembly having a spring loaded latching mechanism holding the drill head up against the drill bucket incorporating a flapper door open over the opening in the drill head plate with the water transfer channel exposed.
[0083] FIG. 20 depicts a perspective view of the sixth alternate embodiment of the Axially Separating Drill Bucket assembly having a spring loaded latching mechanism released and the drill bead in the lowered position incorporating a flapper closed over the opening in the drill head plate with the water transfer channel exposed.
[0084] FIG. 21A depicts a cross section side view of another embodiment of the Axially Separating Drill Bucket assembly having a spring loaded latching mechanism incorporating a push rod and a central hydraulic cylinder.
[0085] FIG. 21B depicts a top plan view of the spring loaded push rod and the guide stop section, in relation to he tubular guide.
[0086] FIG. 21C depicts an enlarged cross section of the spring loaded latching mechanism.
[0087] FIG. 21D depicts an enlarged cross section of the drill head end of the Axially Separating Drill Bucket assembly with the mounting end of the hydraulic cylinder.
[0088] FIG. 22A depicts an end view of the spring loaded latching mechanism.
[0089] FIG. 22B depicts an exploded end view of the spring loaded latching mechanism.
[0090] FIG. 23A depicts a cross section side view of the Axially Separating Drill Bucket assembly having the spring loaded latching mechanism released by the means of the angled lower section of the spring loaded push rod.
[0091] FIG. 23B depicts an enlarged cross section of the spring loaded latching mechanism released by the means of the tapered section of the push rod.
[0092] FIG. 24 depicts a cross section side view of another embodiment of the Axially Separating Drill Bucket assembly having the spring loaded latching mechanism with a nylon strap replacing the hydraulic cylinder.
[0093] FIG. 25 depicts a cross section side view of the another embodiment of the Axially Separating Drill Bucket assembly having the spring loaded latching mechanism and the external flow control valve for a hydraulic cylinder.
[0094] FIG. 26 depicts a cross section of the tipper and lower telescoping drill stems illustrating the location of the channel adjacent to the hydraulic cylinder for the hydraulic lines to the external flow control valve for the hydraulic cylinder.
[0095] FIG. 27 depicts a cross section of the upper and lower telescoping drill stems and hydraulic cylinder illustrating reduced size piston allowing the restricted flow of the hydraulic fluid when the drill head is released.
[0096] FIG. 28 depicts a cross section side view of another embodiment of the Axially Separating Drill Bucket assembly having the drill head released by the means of the sombrero pressing down on the activation rod of a second hydraulic cylinder to activate a pilot operated check valve to release and control descent of the drill head.
[0097] FIG. 29 depicts a Perspective view of the drill head end of the Axially Separating Drill Bucket assembly illustrating the interlocking system between the drill head and the drill bucket, the dual cavity opening into the drill bucket in the drill head plate and the bow tie shape of the drill tip plate with the centering tip exploded away.
[0098] For a fuller understanding of the nature and advantages of the Axially Separating Drill Bucket, reference should be had to the following detailed description taken in conjunction with the accompanying drawings which are incorporated in and form a part of this specification, illustrate embodiments of the design and together with the description, serve to explain the principles of this application.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0099] Referring now to the drawings, wherein similar parts of the Axially Separating Drill Bucket 10 are identified by like reference numerals, there is seen in FIG. 1 a perspective drawing of the Axially separating drill bucket 10 being lowered into a hole 12 by the means of a drill rig 14 with the Kelly bar 16 extending through the stationary sombrero 18 below the rotational drive mechanism 20 .
[0100] FIG. 2 depicts a cross sectional view of the preferred embodiment of the Axially Separating Drill Bucket 10 A with a single external scissor action movement 22 on the outside of the drill bucket above the steel cap plate 24 where the actuator member 26 translates through an elongated slot 28 of the box section 30 to pivotally attach to the first scissor section 32 that rotates about a pivot 34 attached to the drill stem 36 . At the distal end of the first scissor section 32 is a pivoting link 38 attached to a pivot lug 40 fixed to the upper surface of the steel cap plate 24 . When the Axially Separating Drill Bucket 10 A is raised above the surface the actuator member 26 makes contact with the stationary sombrero 18 exerting a downward force raising the drill bucket 48 . The elongated slot 50 in the box section 30 keeps the mechanism from being clogged when in operation. A long vertical key 52 is part of the drill stem 36 that engages in a key slot 46 in the steel cap plate 24 securing the drill bucket 48 to the drill stem 36 when the Axially Separating Drill Bucket 10 A is rotated. A pusher plate 54 can be permanently attached to the drill stem 36 in order to push the material out of the drill bucket central cavity 56 when drill bucket 48 is raised.
[0101] At the lower distal end of the drill stem 36 is the drill head 60 consisting of a drill head plate 62 that is permanently attached to the distal end of the drill stem 36 . A drill tip plate 64 located below the drill head plate 62 has polarity of digging teeth 66 and a central rod 68 extending into a mating hole 70 in the drill stem 36 . A circumferential groove 72 in the central rod 48 aligns with a slot 74 in the drill stem 36 where a drill tip plate retainer 76 allows the drill tip plate 64 to rotate and be easily removed if necessary An opening 78 ahead of the digging teeth 66 of the drill tip plate 64 allows the excavated material to enter the drill bucket central cavity 56 .
[0102] FIG. 3 depicts an exploded view of the drill tip plate retainer 76 in the drill stem 36 securing the drill tip plate 64 into position.
[0103] FIG. 4 depicts a perspective view of the preferred embodiment of the Axially Separating Drill Bucket 10 A with a second external scissor action movement 82 having the drill head 60 in upper position. The rotational drive mechanism 84 is located above the sombrero 18 with the Kelly bar 16 having a square distal end 86 that will mate with the square orifice 88 in the box section 30 using the locking pin 90 to secure it in place. A steel angle bar 92 welded to the length of the inner surface of the drill bucket 48 with an upper orifice 94 in the steel cap plate 24 and a lower orifice 96 in the drill head plate 62 creates a separate water transfer channel 98 where water 100 might accumulate at the bottom of the hole 12 that can travel up through the Axially separating drill bucket 10 A assembly during the drilling operation. This is an option that can be incorporated into any of the embodiments of this application.
[0104] FIG. 5 depicts a cross sectional view of the first alternate embodiment of the Axially Separating Drill Bucket 1013 where the drill bucket 48 will be raised by a single internal scissor action mechanism 104 within the drill bucket 48 . In this action an actuator member 26 translates through an elongated slot 50 of the box section 30 and an elongated slot 106 in the steel cap plate 24 to pivotally attach to the first scissor section 108 that rotates about a pivot 110 attached to the drill stem 36 . At the distal end 112 of the first scissor section 108 the second scissor section 114 is pivotally attached with its distal end pivotally attached to a pivot lug 116 fixed to the under surface of the steel cap plate 24 . When the Axially separating drill bucket 108 is raised the actuator member 26 makes contact with the stationary sombrero 18 exerting a downward force raising the drill bucket 48 . The elongated slots 50 and 106 in both the box section 30 and the steel cap plate 24 keep the mechanism from being clogged when in operation. There may be several drill bucket 48 alignment features with the first, being a beveled edge 120 to the drill bucket 48 mating with a beveled edge 122 on the drill head plate 62 . Another alignment feature will be a number of alignment tabs 124 welded around the circumference of the drill head plate 62 with anti-rotation stop blocks 126 attached to the inner surface of the drill bucket 48 to resist any twisting between the drill bucket 48 and the drill head plate 62 .
[0105] FIG. 6 depicts a bottom view of the Axially Separating Drill Bucket 10 B with the drill tip plate 64 rotated closing the opening 78 in the drill head plate 62 . The two rotational stops 128 are welded to the bottom surface of the drill head plate 62 .
[0106] FIG. 7 depicts a cross sectional view of the first alternate embodiment of the Axially Separating Drill Bucket 10 B with the single internal scissor action movement 104 having the drill head 60 in the partially extended position. Another optional alignment feature illustrated will be an extension of intermittent side segments 130 of the lower surface of the drill bucket 48 mating with cutouts in the drill head plate 62 .
[0107] FIG. 8 depicts a bottom view of the Axially Separating Drill Bucket TUB with the drill tip plate 64 rotated exposing the opening 78 in the drill head plate 62 with the two rotational stops 128 welded to the bottom surface of the drill head plate 62 .
[0108] FIG. 9 depicts a cross sectional view of the first alternate embodiment of the Axially Separating Drill Bucket 10 B with the single internal scissor action movement 104 having the drill head 60 in the full extended position. The arrows 132 indicate the direction that the excavated material would be pushed out by the pusher plate 54 .
[0109] FIG. 10 depicts a perspective view of the first alternate embodiment of the Axially Separating Drill Bucket 108 with a second similar scissor action movement 104 within the drill bucket 48 that can be added on the other side of the drill stem 36 to equalize the farces required to raise the drill bucket 48 .
[0110] FIG. 11 depicts a cross sectional view of the second alternate embodiment of the Axially Separating Drill Bucket 10 C using a hydraulic method with a large capacity hydraulic cylinder 136 connected to a single smaller longer hydraulic cylinder 138 to raise the drill bucket 48 from the drill head 60 . The large capacity hydraulic cylinder 136 attached to the box section 30 with an actuator member 26 extending up to make contact with the sombrero 18 when the Axially Separating Drill Bucket IOC is raised above the surface. This contact forces the hydraulic fluid into a smaller and longer hydraulic cylinder 138 attached to a lug 40 on the upper surface of the steel cap plate 24 raising the drill bucket 48 away from the drill head 60 .
[0111] FIG. 12 depicts a perspective view of the second alternate embodiment of the Axially Separating Drill Bucket 10 C using a hydraulic method with a large capacity hydraulic cylinder 136 connected to two smaller longer hydraulic cylinders 138 to raise the drill bucket 48 from the drill head 60 to equalize the forces required to raise the drill bucket 48 .
[0112] FIG. 13 depicts cross sectional view of the third alternate embodiment of the Axially Separating Drill Bucket 10 D using a hydraulic method with a large capacity hydraulic cylinder 136 connected to two smaller longer hydraulic cylinders 138 to raise the drill bucket 48 from the drill head 60 .
[0113] FIG. 14 depicts a cross sectional view of the forth alternate embodiment of the Axially Separating Drill Bucket IDE having the drill bucket 48 permanently attached to the drill stem 36 using a hydraulic method with a large hydraulic cylinder 136 connected to two smaller longer hydraulic cylinders 138 to lower the drill head 60 using a telescoping drill stem 140 attached to the drill head 60 .
[0114] FIG. 15 depicts a cross sectional view of the fifth alternate embodiment of the Axially Separating Drill Bucket 10 F having the drill bucket 48 connected to the telescoping drill stem 140 and the spring loaded actuator member 142 connected to the drill head 60 . When the drill bucket 48 is raised to the surface and the actuator comes in contact with the sombrero 18 the drill head 60 is pushed down.
[0115] FIG. 16 depicts a cross sectional view of the sixth alternate embodiment of the Axially Separating Drill Bucket 10 G having a spring loaded latching mechanism 148 holding the drill head 60 up against the drill bucket 48 . The spring loaded latching mechanism 148 operates by the means of the spring loaded actuator member 152 attached to the connector link 150 and the pivotal latch 154 . The pivotal latch 154 is illustrated making contact with the latch catch 156 that is an integral part of the drill stem 36 . A latch stop 158 is fixed to the lower rim of the drill bucket 48 . In this embodiment the box section 160 is permanently attached to the steel cap plate 162 .
[0116] FIG. 17 depicts top view of the Axially Separating Drill Bucket 10 G where the box section 160 is permanently attached to the steel cap plate 162 exposing the upper orifice 94 of the water transfer channel 98 and the end of the spring loaded actuator member 152 .
[0117] FIG. 18 depicts a cross sectional view of the sixth alternate embodiment of the Axially Separating Drill Bucket JOG having a spring loaded latching mechanism 148 released with the drill head 60 in the lowered position.
[0118] FIG. 19 depicts a perspective view of the sixth alternate embodiment of the Axially Separating Drill Bucket 10 G having a spring loaded latching mechanism 148 holding the drill head 60 up against the drill bucket 48 incorporating a flapper door 166 open over the opening 78 in the drill head plate 62 with the water transfer channel 98 exposed.
[0119] FIG. 20 depicts a perspective view of the sixth alternate embodiment of the Axially Separating Drill Bucket 10 G having a spring loaded latching mechanism 148 released and the drill head 60 in the lowered position incorporating a flapper door 166 closed over the opening 78 in the drill head plate 62 with the water transfer channel 98 exposed.
[0120] FIG. 21A depicts a cross section side view of another embodiment of the Axially Separating Drill Bucket assembly 200 having a spring loaded latching mechanism 204 incorporating a spring loaded push rod 206 and a central hydraulic cylinder 214 . The spring loaded push rod 206 translates downward through the tubular guide 210 with the angled lower section 212 that activates the spring loaded latching mechanism 204 when pressure is applied by the sombrero 18 as the Axially separating drill bucket assembly 200 is raised. A guide stop section 213 of the tubular guide 210 limits the downward travel when pushed downward by the sombrero 18 . The spring loaded push rod 206 translates further downward pressing the pusher plate 54 down to assist in emptying the drill bucket 48 . A hydraulic cylinder 214 is housed within the outer tubular square drill stem 216 and the inner tubular square drill stem 218 anchored at the top by the means of the cross pin 220 in the inner tubular drill stem 218 and at the bottom in the outer tubular drill stem 216 by the means of the cross pin 222 . The drill head 60 is at the lower end of the drill bucket 48 .
[0121] FIG. 21B depicts a top plan view of the spring loaded push rod 206 and the guide stop section 213 in relation to the tubular guide 210 .
[0122] FIG. 21C depicts an enlarged cross section of the spring loaded latching mechanism 204 where more clearly depicted is the lower end of the spring loaded push rod 206 and the angled lower section 212 of the tubular guide 210 . The angled lower section 212 is against the actuating roller 224 between the two links 226 and 228 which are pivotally attached to the upper end on the latching mechanism 230 . The support roller 232 maintains the location of the actuating roller 224 before the spring loaded push rod 206 is moved downward. The latching mechanism 230 pivots about the pivot pin 234 to release the catch 236 on the outer tubular square drill stem 216 to lower the drill head 60 . The latching mechanism 230 is held against the catch 236 on the outer surface of the outer tubular square drill stem 216 by the means of the spring 238 in the spring housing 240 . The spring 238 tension can he adjusted by the adjustment screw 242 .
[0123] FIG. 21D depicts an enlarged cross section of the drill head 60 of the Axially Separating Drill Bucket assembly 200 with the mounting end of the hydraulic cylinder 214 connected to the outer tubular square drill stem 216 and the drill head plate 62 by the means of the cross pin 222 . A replaceable centering tip 244 with digging teeth 66 is attached to the drill tip plate 64 .
[0124] FIG. 22A depicts an end view of the spring loaded latching mechanism 204 illustrating the two links 226 and 228 , the actuating roller 224 , the support roller 232 , and the spring housing 240 and spring 238 .
[0125] FIG. 22B depicts an exploded end view of the spring loaded late ling mechanism 204 with the spring housing 240 moved down for maintenance.
[0126] FIG. 23A depicts a cross section side view of the Axially Separating Drill Bucket assembly 200 having the spring loaded latching mechanism 204 released by the means of the angled lower section 212 of the push rod 206 being moved down by the sombrero 18 releasing the latching mechanism 230 while pushing the spring loaded push rod 206 on down against the material pusher plate 54 along with the controlled downward movement of the drill head 60 by the means of the central hydraulic cylinder 214 . The drill head 60 is shown lowered from the drill bucket 48 illustrating the interlocking lower edge 246 of the drill bucket 48 interconnecting with the edge of the drill head plate 62 serving to secure the two parts together until the drill head 60 is lowered. The arrows 248 indicate the movement of the material within the drill bucket 48 and arrows 250 indicate downward pressure to remove the material in the drill bucket 48 .
[0127] FIG. 23B depicts an enlarged cross section of the spring loaded latching mechanism 204 released by the means of the angled lower section 212 of the push rod 206 has been rotated back away from the catch 236 on the outer tubular square drill stem 216 and compressing the spring 238 .
[0128] FIG. 24 depicts a cross section side view of another embodiment of the Axially Separating Drill Bucket assembly 200 having the spring loaded latching mechanism 204 with a nylon strap 252 replacing the hydraulic cylinder 214 to lower the drill head 60 to a cushioned lower position. The strap will be held by the means of the cross pin 220 in the inner tubular drill stem 218 and at the bottom in the outer tubular drill stem 216 by the means of the cross pin 222 . It must be understood that any form of elastic, spring, chain or limiting mechanism could function for this purpose and still remain within the scope of this application.
[0129] FIG. 25 depicts a cross section side view of another embodiment of the Axially Separating Drill Bucket assembly 200 having the spring loaded latching mechanism 204 . The flow within the hydraulic cylinder 214 is controlled through the hydraulic lines 258 to the manual hydraulic fluid flow control valve 254 attached to the exterior of the drill bucket 48 or remotely within the cab of the drill rig 14 will control the decent of the drill head 60 .
[0130] FIG. 26 depicts a cross section of the inner tubular drill stem 218 and outer tubular telescoping drill stem 216 illustrating the location of the drill stem channel 256 adjacent to the hydraulic cylinder 214 for the hydraulic lines 258 to extend to the manual hydraulic fluid flow control valve 254 to release and control decent through the hydraulic cylinder 214 of the drill head 60 .
[0131] FIG. 27 depicts a cross section of the inner tubular drill stem 218 and outer tubular telescoping drill stern 216 and hydraulic cylinder 214 illustrating the reduced diameter of the cylinder piston 262 allowing a restricted flow of the hydraulic fluid through the edge cavity 264 when the drill head 60 is released by the spring loaded latching mechanism 204 slowing and cushioning the decent of the drill head 60 . With this system a sealed hydraulic cylinder 214 can be used effectively with no hoses. It is important to be noted that a full sized piston with an orifice or by-pass could also be used to control fluid flow internally without hoses.
[0132] FIG. 28 depicts a cross section side view of another embodiment of the Axially Separating Drill Bucket assembly 200 having the drill head 60 released by the means of the sombrero 18 pressing down on the activation rod 266 of a second hydraulic cylinder 268 to open pilot operated check valve 270 to release and control decent of the drill head 60 through the hydraulic cylinder 214 .
[0133] FIG. 29 depicts a Perspective view of the drill head 60 end of the Axially Separating Drill Bucket assembly 200 illustrating the interlocking system between the drill head plate 62 and the drill bucket 48 where the segments 272 interlock with the cavities 274 in the drill head plate 62 to create a rigid structure. In this embodiment the drill head plate 62 has two orifices 276 into the central cavity 56 of the drill bucket 48 . The drill tip plate 64 is constructed in a how tie shape with the digging teeth 66 on either side. Digging teeth 66 can additionally be added around the perimeter of the drill tip plate 64 . Two stop blocks 278 are welded on the drill head plate 62 to limit the rotation of the drill tip plate 64 to a point of opening or covering the two orifices 276 and trapping the material within the drill bucket central cavity 56 . The replaceable centering tip 244 with digging teeth 66 is shown exploded away from the drill tip plate 64 where a locking pin 280 and nut 282 will secure it in place.
[0134] The unique feature of this application is when the Axially Separating Drill Bucket assembly 200 is rotating in a clockwise direction in the digging operation, indicated by the arrow 284 , the drill tip plate 64 is held against the two stop blocks 278 opening the two orifices 276 into the drill bucket central cavity 56 . After the digging the Axially separating drill bucket assembly 200 is rotating in the counter clockwise direction moving the drill tip plate 64 to closes off the two openings 276 to the drill bucket central cavity 56 . To remove the material, the Axially separating drill bucket assembly 200 is raised up till the pushrod presses against the sombrero releasing the latch mechanism and the drill head 60 is lowered and rotated spreading the material out to the sides. When the drill bucket 60 is emptied it is lowered down away from the sombrero and pushed against the ground to automatically latch the assembly closed again. This operation can be completed by one person in the drill rig 14 with just the Axially separating drill bucket assembly 200 .
[0135] The Axially Separating Drill Bucket 10 , and the Axially Separating Drill Bucket assembly 200 , shown in the drawings and described in detail herein disclose arrangements of elements of particular construction and configuration for illustrating preferred and alternate embodiments of structure and method of operation of the present application. It is to be understood, however, that elements of different construction and configuration and other arrangements thereof, other than those illustrated and described may be employed for providing an Axially Separating Drill Bucket 10 , and the Axially Separating Drill. Bucket assembly 200 , in accordance with the spirit of this disclosure, and such changes, alternations and modifications as would occur to those skilled in the art are considered to be within the scope of this design as broadly defined in the appended claims of this application.
[0136] Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. | There is provided an Axially separating drill bucket for drilling large holes in the earth by which a drilling operator can perform the drilling operation with the Axially Separating Drill Bucket, incorporating a spring loaded latching mechanism and a hydraulic cylinder within a drill head casing, and remove the excavated material in one operation. The unit can be raised to the surface where the bucket portion is moved up or down from the drill head to empty the excavated material. A spring loaded latching mechanism is disclosed having a pushrod which activates the latch by making contact with an external force. A centrally located hydraulic cylinder power assists the drill head to be raised and lowered to remove the material collected within the drill bucket. | 4 |
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to a method of making a pipe fitting and, more particularly, to a fitting having three or more legs arranged in any desired shape. It constitutes an improvement on U.S. Pat. No. 3,961,513 granted June 8, 1976.
Fittings of the type contemplated by the invention are used in a wide variety of fluid-conducting installations and, when the legs are curved, provide an extremely advantageous return bend connection for equipment using coils (either for heating or cooling).
Inasmuch as fittings (and the coils or other tubing to which they are attached) are of relatively small size -- generally ranging in outside diameters from 3/8 inches to 1/2 inches, with diameter to wall thickness ratios of about 5 to 30 -- it is important that the interior walls of the fittings be relatively smooth with the tubes having a fairly uniform inside diameter so as not to restrict fluid flow. Additionally, because these fittings are integrated into coil equipment and the like, as by brazing or other heat employing uniting operations, it is important that the fitting have high structural integrity so as to resist deformation which could result in resistance to fluid flow -- or even premature rupture, resulting in extensive and expensive repair.
The invention herein is specifically directed to the making of a pipe fitting having three or more legs arranged in any desired manner from an elongated tube wherein the legs have a length to diameter ratio of more than 3 and where the ratio of diameter to wall thickness of the fitting is in the range of about 5 to 30. It will be appreciated that the provision of such a fitting requires extensive shifting of metal and the invention in the above identified patent sought to achieve this through the provision of a thicker wall adjacent the closed end of the starting tube or capsule. Although the invention of the above identified patent provides fittings characterized by a high degree of integrity, it has not provided fittings wherein the wall thickness is substantially uniform throughout the various branches of the fitting, i.e., less than about 10% variation. In fact, in some instances, the variation in wall thickness in products made according to the above identified patent ranges as high as 200%. Although the thicknesses per se are relatively small -- of the order of 0.018-0.035 inches, the substantial variation does impede fluid flow and further makes difficult the union of the fitting into a piping system -- it is difficult to braze different thickness walls together because the thicker wall element takes longer to heat and provides a "heat sink" effect.
The problems of the prior art have been solved through the employment of a constant volume filler material during the deformation of the elongated tube and maintaining the filler material at constant volume throughout the deformation. Additionally, I have found it advantageous to position the leg-forming cavities intermediate the length of the tube particularly where the fitting has fairly long legs to avoid shear planes, flow faults, or buildup. With the constant volume filler material, metal from both ends of the tube flows or feeds into the legs -- thereby achieving a process akin to extrusion as contrasted to the "bulging" characteristic of the prior art procedures -- as in U.S. Pat. No. 3,681,960.
Other objects and advantages of the invention may be seen in details of the ensuing specification.
DETAILED DESCRIPTION
The invention is described in conjunction with the accompanying drawing, in which
FIG. 1 is a fragmentary, partially schematic elevational view, partially in section, of apparatus employed in the practice of the invention;
FIG. 2 is a sectional view taken on the line 2--2 of FIG. 1 with the apparatus removed illustrating a fitting produced according to the practice of the invention wherein two of the legs are curved;
FIG. 3 is a perspective view of a tripod fitting made in accordance with the invention; and
FIG. 4 is a perspective view illustrating a fitting produced according to the practice of the invention wherein two of the legs are curved differently through substitution of different dies from those seen in the apparatus of FIG. 1.
In the illustration given and with reference first to FIG. 1, the numeral 20 generally designates apparatus employed in the practice of the invention. The apparatus 20 includes a platform and framework (not shown) used to provide a mounting for an upper die 21, a lower die 22 and an insert die 23 as well as cylinder means (not shown) which are employed for raising and lowering the upper die 21 and camming means (not shown) used to provide a means for laterally moving the insert die 23. The upper die 21, the lower die 22, and the insert die 23 are equipped with grooves and recesses as at 24, 25 and 26, respectively, so as to receive a tube 27 (shown in phantom) to be deformed in a single step. With reference to the illustration of FIG. 1, the tube 27 is also illustrated in a fully deformed state which corresponds generally to the showing in FIGS. 2 and 3 designated by the numeral 28.
The apparatus 20 includes a pair of operably associated rams 29 and 30 which are mounted for movement toward and away from each other (as indicated by the arrows applied thereto) and which serve to deform the tube 27 into curved cavities such as 31 (only one of the cavities being shown). A knock-out 32 is provided in at least one of the curved cavities such as 31 for removing the completed fitting 28 from the grooves or recesses 24, 25 and 26 after the curved legs 33 and 34 and the straight leg 35 of the fitting 28 have been formed. In some instances, the development of the curved legs 33 and 34 may be restrained to equal development through the use of suitable pistons mounted in both of the curved cavities such as 31.
In the practice of the invention, a tube 27 is initially installed within the bore developed by the recesses 24 and 25. As detailed in the above-mentioned U.S. Pat. No. 3,961,513, the tube 27 may itself be provided from a solid blank or plug of malleable metal by cold working the same. Normally, these fittings are constructed of aluminum or copper as being suitable advantageous malleable metals. In any event, the tube 27 is characterized by having a closed end 36 and an open end 37.
Next, the tube 27 is substantially filled with a constant volume filler material. Excellent results have been obtained whether the material is solid or liquid at room temperatures, and if solid, a form of Woods metal is advantageous for this purpose -- containing lead, tin and bismuth. Thereafter, the filled tube 27 is installed in the deformation apparatus 20 such as is schematically illustrated in phantom in FIG. 1.
The apparatus 20 shown in FIG. 1 is illustrated in the mode it employs when fashioning a fitting particularly wherein the legs have a substantial length, i.e., length to diameter ratio of 3 or more. The rams 29 and 30 are positioned so that the curved cavities such as 31 are located intermediate the length of the tube. The rams 29 and 30 then exert force on the tube 27 from both ends resulting in a deformation essentially like extrusion to develop the legs 33, 34 and 35 (as shown in FIG. 2). After the final configuration of FIG. 2 is reached, the fitting 28 is removed from the deforming apparatus 20 and the closed ends 38 and 39 of the curved legs 33 and 34, respectively, and transversely severed to provide the fitting 28 with three clear, open branches -- as seen in FIG. 3.
As seen in FIG. 3, the legs 33 and 34 are cylindrical or tubular in shape but unlike the tripod fittings made in accordance with the prior art, viz., U.S. Pat. No. 3,961,513, the axis of each of the legs 33 and 34 does not lie in a single plane. Rather the axis follows a curved path consisting of a straight portion 40 adjacent the open end 38' or 39' as the case may be. Thereafter, in proceeding toward the junction 41 (as shown in FIG. 2) the axis curves as at 42 but is still essentially in the same plane as that containing the axis portion 40. Still further, the axis in approaching the junction 41 curves inwardly as at 43 in the sense of approaching the other curved leg. Thus, I have provided a fitting made in but one step but which provides three open-ended legs arranged in a triangle, i.e., a tripod.
I prefer to employ the liquid filler material in the practice of the invention although it is possible to use other materials such as solids as the constant volume filler material. Solids have the advantage of requiring a less complicated apparatus since valving, flow passages, etc. are not necessary but liquids have the advantage of eliminating the step of melting the filler material to provide clear, open branches within the fitting. When liquid filler material is employed, the valving (not shown) is arranged to maintain the filler material at constant volume through a flow passage 44 in the ram 29 which can purge air through a vent 45 in the upper die 21.
As indicated previously, the fitting 28 may be developed in th apparatus 20 of FIG. 1 with the legs 33 and 34 curved incident to deformation in the curved cavities such as 31 as illustrated by the showing in FIGS. 2 and 3. The cavities can also be curved differently (as having the axes coplanar) to form a fitting 128 as seen in FIG. 4, or they can be arranged in any other desired shape. With the fitting 128, the curved legs are designated 133 and 134 and the remaining leg or straight portion, which is designated 135, can be arched or curved in a conventional fashion to convert the configuration into a tripod fitting. Even though the extra bending step is required, there is still available the substantial benefits of the invention relative to achieving uniform wall thickness.
While in the foregoing specification a detailed description of the invention has been set down for the purpose of explanation, many variations in the details hereingiven may be made by those skilled in the art without departing from the spirit and scope of the invention. | A method of making a pipe fitting havin three or more legs arranged in any desired shape by deforming a malleable metal tube substantially filled with a constant volume filler material in a single step without the need for secondary bending while maintaining the filler material at constant volume to provide a fitting wherein the variation in wall thickness is less than about 10%. | 8 |
This application is a divisional of U.S. application Ser. No. 10/145,206 filed May 13, 2002, now U.S. Pat. No. 7,259,137, related to U.S. provisional application No. 60/290,196, filed May 11, 2001, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
After years of study in necrosis of tumors, tumor necrosis factors (TNFs) α and β were finally cloned in 1984. The ensuing years witnessed the emergence of a superfamily of TNF cytokines, including fas ligand (FasL), CD27 ligand (CD27L), CD30 ligand (CD30L), CD40 ligand (CD40L), TNF-related apoptosis-inducing ligand (TRAIL, also designated AGP-1), osteoprotegerin binding protein (OPG-BP or OPG ligand), 4-1BB ligand, LIGHT, APRIL, and TALL-1. Smith et al. (1994), Cell 76: 959-962; Lacey et al. (1998), Cell 93: 165-176; Chichepotiche et al. (1997), J. Biol. Chem. 272: 32401-32410; Mauri et al. (1998), Immunity 8: 21-30; Hahne et al. (1998), J. Exp. Med. 188: 1185-90; Shu et al. (1999), J. Leukocyte Biology 65: 680-3. This family is unified by its structure, particularly at the C-terminus. In addition, most members known to date are expressed in immune compartments, although some members are also expressed in other tissues or organs, as well. Smith et al. (1994), Cell 76: 959-62. All ligand members, with the exception of LT-α, are type II transmembrane proteins, characterized by a conserved 150 amino acid region within C-terminal extracellular domain. Though restricted to only 20-25% identity, the conserved 150 amino acid domain folds into a characteristic β-pleated sheet sandwich and trimerizes. This conserved region can be proteolytically released, thus generating a soluble functional form. Banner et al. (1993), Cell 73: 431-445.
Many members within this ligand family are expressed in lymphoid enriched tissues and play important roles in the immune system development and modulation. Smith et al. (1994). For example, TNFα is mainly synthesized by macrophages and is an important mediator for inflammatory responses and immune defenses. Tracey & Cerami (1994), Ann. Rev. Med. 45: 491-503. Fas-L, predominantly expressed in activated T cell, modulates TCR-mediated apoptosis of thymocytes. Nagata, S. & Suda, T. (1995) Immunology Today 16:39-43; Castrim et al. (1996), Immunity 5: 617-27. CD40L, also expressed by activated T cells, provides an essential signal for B cell survival, proliferation and immunoglobulin isotype switching. Noelle (1996), Immunity 4:415-9.
The cognate receptors for most of the TNF ligand family members have been identified. These receptors share characteristic multiple cysteine-rich repeats within their extracellular domains, and do not possess catalytic motifs within cytoplasmic regions. Smith et al. (1994). The receptors signal through direct interactions with death domain proteins (e.g. TRADD, FADD, and RIP) or with the TRAF proteins (e.g. TRAF2, TRAF3, TRAF5, and TRAF6), triggering divergent and overlapping signaling pathways, e.g. apoptosis, NF-κB activation, or JNK activation. Wallach et al. (1999), Annual Review of Immunology 17: 331-67. These signaling events lead to cell death, proliferation, activation or differentiation. The expression profile of each receptor member varies. For example, TNFR1 is expressed on a broad spectrum of tissues and cells, whereas the cell surface receptor of OPGL is mainly restricted to the osteoclasts. Hsu et al. (1999) Proc. Natl. Acad. Sci. USA 96: 3540-5.
A number of research groups have recently identified TNF family ligands with the same or substantially similar sequence. The ligand has been variously named neutrokine α (WO 98/18921, published May 7, 1998), 63954 (WO 98/27114, published Jun. 25, 1998), TL5 (EP 869 180, published Oct. 7, 1998), NTN-2 (WO 98/55620 and WO 98/55621, published Dec. 10, 1998), TNRL1-alpha (WO 9911791, published Mar. 11, 1999), kay ligand (WO99/12964, published Mar. 18, 1999), and AGP-3 (U.S. Prov. App. Nos. 60/119,906, filed Feb. 12, 1999 and 60/166,271, filed Nov. 18, 1999, respectively); and TALL-1 (WO 00/68378, published Nov. 16, 2000). Each of these references is hereby incorporated by reference. Hereinafter, the ligands reported therein are collectively referred to as TALL-1.
TALL-1 is a member of the TNF ligand superfamily that is functionally involved in B cell survival and proliferation. Transgenic mice overexpressing TALL-1 had severe B cell hyperplasia and lupus-like autoimmune disease. Khare et al. (2000) PNAS 97(7):3370-3375). Both TACI and BCMA serve as cell surface receptors for TALL-1. Gross et al. (2000), Nature 404: 995-999; Ware (2000), J. Exp. Med. 192(11): F35-F37; Ware (2000), Nature 404: 949-950; Xia et al. (2000), J. Exp. Med. 192(1):137-143; Yu et al. (2000), Nature Immunology 1(3):252-256; Marsters et al. (2000), Current Biology 10:785-788; Hatzoglou et al. (2000) J. of Immunology 165:1322-1330; Shu et al. (2000) PNAS 97(16):9156-9161; Thompson et al. (2000) J. Exp. Med. 192(1):129-135; Mukhopadhyay et al. (1999) J. Biol. Chem. 274(23): 15978-81; Shu et al. (1999) J. Leukocyte Biol. 65:680-683; Gruss et al. (1995) Blood 85(12): 3378-3404; Smith et al. (1994), Cell 76: 959-962; U.S. Pat. No. 5,969,102, issued Oct. 19, 1999; WO 00/67034, published Nov. 9, 2000; WO 00/40716, published Jul. 13, 2000; WO 99/35170, published Jul. 15, 1999. Both receptors are expressed on B cells and signal through interaction with TRAF proteins. In addition, both TACI and BCMA also bind to another TNF ligand family member, APRIL. Yu et al. (2000), Nature Immunology 1(3):252-256. APRIL has also been demonstrated to induce B cell proliferation.
To date, no recombinant or modified proteins employing peptide modulators of TALL-1 have been disclosed. Recombinant and modified proteins are an emerging class of therapeutic agents. Useful modifications of protein therapeutic agents include combination with the “Fc” domain of an antibody and linkage to polymers such as polyethylene glycol (PEG) and dextran. Such modifications are discussed in detail in a patent application entitled, “Modified Peptides as Therapeutic Agents,” published WO 00/24782, which is hereby incorporated by reference in its entirety.
A much different approach to development of therapeutic agents is peptide library screening. The interaction of a protein ligand with its receptor often takes place at a relatively large interface. However, as demonstrated for human growth hormone and its receptor, only a few key residues at the interface contribute to most of the binding energy. Clackson et al. (1995), Science 267: 383-6. The bulk of the protein ligand merely displays the binding epitopes in the right topology or serves functions unrelated to binding. Thus, molecules of only “peptide” length (2 to 40 amino acids) can bind to the receptor protein of a given large protein ligand. Such peptides may mimic the bioactivity of the large protein ligand (“peptide agonists”) or, through competitive binding, inhibit the bioactivity of the large protein ligand (“peptide antagonists”).
Phage display peptide libraries have emerged as a powerful method in identifying such peptide agonists and antagonists. See, for example, Scott et al. (1990), Science 249: 386; Devlin et al. (1990), Science 249: 404; U.S. Pat. No. 5,223,409, issued Jun. 29, 1993; U.S. Pat. No. 5,733,731, issued Mar. 31, 1998; U.S. Pat. No. 5,498,530, issued Mar. 12, 1996; U.S. Pat. No. 5,432,018, issued Jul. 11, 1995; U.S. Pat. No. 5,338,665, issued Aug. 16, 1994; U.S. Pat. No. 5,922,545, issued Jul. 13, 1999; WO 96/40987, published Dec. 19, 1996; and WO 98/15833, published Apr. 16, 1998 (each of which is incorporated by reference in its entirety). In such libraries, random peptide sequences are displayed by fusion with coat proteins of filamentous phage. Typically, the displayed peptides are affinity-eluted against an immobilized target protein. The retained phages may be enriched by successive rounds of affinity purification and repropagation. The best binding peptides may be sequenced to identify key residues within one or more structurally related families of peptides. See, e.g., Cwirla et al. (1997), Science 276: 1696-9, in which two distinct families were identified. The peptide sequences may also suggest which residues may be safely replaced by alanine scanning or by mutagenesis at the DNA level. Mutagenesis libraries may be created and screened to further optimize the sequence of the best binders. Lowman (1997), Ann. Rev. Biophys. Biomol. Struct. 26: 401-24.
Structural analysis of protein-protein interaction may also be used to suggest peptides that mimic the binding activity of large protein ligands. In such an analysis, the crystal structure may suggest the identity and relative orientation of critical residues of the large protein ligand, from which a peptide may be designed. See, e.g., Takasaki et al. (1997), Nature Biotech. 15: 1266-70. These analytical methods may also be used to investigate the interaction between a receptor protein and peptides selected by phage display, which may suggest further modification of the peptides to increase binding affinity.
Other methods compete with phage display in peptide research. A peptide library can be fused to the carboxyl terminus of the lac repressor and expressed in E. coli . Another E. coli -based method allows display on the cell's outer membrane by fusion with a peptidoglycan-associated lipoprotein (PAL). Hereinafter, these and related methods are collectively referred to as “ E. coli display.” In another method, translation of random RNA is halted prior to ribosome release, resulting in a library of polypeptides with their associated RNA still attached. Hereinafter, this and related methods are collectively referred to as “ribosome display.” Other methods employ peptides linked to RNA; for example, PROfusion technology, Phylos, Inc. See, for example, Roberts & Szostak (1997), Proc. Natl. Acad. Sci. USA, 94: 12297-303. Hereinafter, this and related methods are collectively referred to as “RNA-peptide screening.” Chemically derived peptide libraries have been developed in which peptides are immobilized on stable, non-biological materials, such as polyethylene rods or solvent-permeable resins. Another chemically derived peptide library uses photolithography to scan peptides immobilized on glass slides. Hereinafter, these and related methods are collectively referred to as “chemical-peptide screening.” Chemical-peptide screening may be advantageous in that it allows use of D-amino acids and other unnatural analogues, as well as non-peptide elements. Both biological and chemical methods are reviewed in Wells & Lowman (1992), Curr. Opin. Biotechnol. 3: 355-62. Conceptually, one may discover peptide mimetics of any protein using phage display, RNA-peptide screening, and the other methods mentioned above.
SUMMARY OF THE INVENTION
The present invention concerns therapeutic agents that modulate the activity of TALL-1. In accordance with the present invention, modulators of TALL-1 may comprise an amino acid sequence Dz 2 Lz 4 (SEQ ID NO: 108) wherein z 2 is an amino acid residue and z 4 is threonyl or isoleucyl. Such modulators of TALL-1 comprise molecules of the following formulae:
I(a) a 1 a 2 a 3 CDa 6 La 8 a 9 a 10 Ca 12 a 13 a 14 (SEQ. ID. NO:100)
wherein:
a 1 , a 2 , a 3 are each independently absent or amino acid residues; a 6 is an amino acid residue; a 9 is a basic or hydrophobic residue; a 8 is threonyl or isoleucyl; a 12 is a neutral hydrophobic residue; and a 13 and a 14 are each independently absent or amino acid residues.
(SEQ. ID. NO:104) I(b) b 1 b 2 b 3 Cb 5 b 6 Db 8 Lb 10 b 11 b 12 b 13 b 14 Cb 16 b 17 b 18
wherein:
b 1 and b 2 are each independently absent or amino acid residues; b 3 is an acidic or amide residue; b 5 is an amino acid residue; b 6 is an aromatic residue; b 8 is an amino acid residue; b 10 is T or I; b 11 is a basic residue; b 12 and b 13 are each independently amino acid residues; b 14 is a neutral hydrophobic residue; and b 16 , b 17 , and b 18 are each independently absent or amino acid residues.
(SEQ. ID. NO:105) I(c) c 1 c 2 c 3 Cc 5 Dc 7 Lc 9 c 10 c 11 c 12 c 13 c 14 Cc 16 c 17 c 18
wherein:
c 1 , c 2 , and c 3 are each independently absent or amino acid residues; c 5 is an amino acid residue; c 7 is an amino acid residue; c 9 is T or I; c 10 is a basic residue; c 11 and c 12 are each independently amino acid residues; c 13 is a neutral hydrophobic residue; c 14 is an amino acid residue; c 16 is an amino acid residue; c 17 is a neutral hydrophobic residue; and c 18 is an amino acid residue or is absent.
(SEQ. ID. NO:106) I(d) d 1 d 2 d 3 Cd 5 d 6 d 7 WDd 10 Ld 12 d 13 d 14 Cd 15 d 16 d 17
wherein:
d 1 , d 2 , and d 3 are each independently absent or amino acid residues; d 5 , d 6 , and d 7 are each independently amino acid residues; d 10 is an amino acid residue; d 13 is T or I; d 14 is an amino acid residue; and d 16 , d 17 and d 18 are each independently absent or amino acid residues.
(SEQ. ID. NO:107) (I)e e 1 e 2 e 3 Ce 5 e 6 e 7 De 9 Le 11 Ke 13 Ce 15 e 16 e 17 e 18
wherein:
e 1 , e 2 , and e 3 are each independently absent or amino acid residues; e 5 , e 6 , e 7 , e 9 , and e 13 are each independently amino acid residues; e 11 is T or I; and e 15 , e 16 , and e 17 are each independently absent or amino acid residues.
I(f) f 1 f 2 f 3 Kf 5 Df 7 Lf 9 f 10 Qf 12 f 13 f 14 (SEQ. ID NO:109)
wherein:
f 1 , f 2 , and f 3 are absent or are amino acid residues (with one of f 1 , f 2 , and f 3 preferred to be C when one of f 12 , f 13 , and f 14 is C); f 5 is W, Y, or F (W preferred); f 7 is an amino acid residue (L preferred); f 9 is T or I (T preferred);
f 10 is K, R, or H (K preferred);
f 12 is C, a neutral hydrophobic residue, or a basic residue (W, C, or R preferred); f 13 is C, a neutral hydrophobic residue or is absent (V preferred); and f 14 is any amino acid residue or is absent; provided that only one of f 1 , f 2 , and f 3 may be C, and only one of f 12 , f 13 , and f 14 may be C.
Compounds of formulae I(a) through I(f) above incorporate Dz 2 Lz 4 , as well as SEQ ID NO: 63 hereinafter. The sequence of I(f) was derived as a consensus sequence as described in Example 1 hereinbelow. Of compounds within formula I(f), those within the formula
I(f′) f 1 f 2 f 3 KWDf 7 Lf 9 KQf 12 f 13 f 14 (SEQ ID NO:125)
are preferred. Compounds falling within formula I(f′) include SEQ ID NOS: 32, 58, 60, 62, 63, 66, 67, 69, 70, 114, 115, 122, 123, 124, 147-150, 152-177, 179, 180, 187.
Also in accordance with the present invention are compounds having the consensus motif:
PFPWE (SEQ ID NO:110)
which also bind TALL-1.
Further in accordance with the present invention are compounds of the formulae:
I(g)
g 1 g 2 g 3 Cg 5 PFg 8 Wg 10 Cg 11 g 12 g 13
(SEQ. ID. NO. 101)
wherein:
g 1 , g 2 and g 3 are each independently absent or amino acid residues; g 5 is a neutral hydrophobic residue; g 8 is a neutral hydrophobic residue; g 10 is an acidic residue;
I(h)
h 1 h 2 h 3 CWh 6 h 7 WGh 10 Ch 12 h 13 h 14
(SEQ. ID. NO:102)
wherein:
h 1 , h 2 , and h 3 are each independently absent or amino acid residues; h 6 is a hydrophobic residue; h 7 is a hydrophobic residue; h 10 is an acidic or polar hydrophobic residue; and h 12 , h 13 , and h 14 are each independently absent or amino acid residues.
(SEQ. ID. NO: 103) I(i) i 1 i 2 i 3 Ci 5 i 6 i 7 i 8 i 9 i 10 Ci 12 i 13 i 14
wherein:
i 1 is absent or is an amino acid residue; i 2 is a neutral hydrophobic residue; i 3 is an amino acid residue; i 5 , i 6 , i 7 , and i 8 are each independently amino acid residues; i 9 is an acidic residue; i 10 is an amino acid residue; i 12 and i 13 are each independently amino acid residues; and i 14 is a neutral hydrophobic residue.
The compounds defined by formulae I(g) through I(i) also bind TALL-1.
Further in accordance with present invention, modulators of TALL-1 comprise:
a) a TALL-1 modulating domain (e.g., an amino acid sequence of Formulae I(a) through I(i)), preferably the amino acid sequence Dz 2 Lz 4 , or sequences derived therefrom by phage display, RNA-peptide screening, or the other techniques mentioned above; and b) a vehicle, such as a polymer (e.g., PEG or dextran) or an Fc domain, which is preferred;
wherein the vehicle is covalently attached to the TALL-1 modulating domain. The vehicle and the TALL-1 modulating domain may be linked through the N- or C-terminus of the TALL-1 modulating domain, as described further below. The preferred vehicle is an Fc domain, and the preferred Fc domain is an IgG Fc domain. Such Fc-linked peptides are referred to herein as “peptibodies.” Preferred TALL-1 modulating domains comprise the amino acid sequences described hereinafter in Tables 1 and 2. Other TALL-1 modulating domains can be generated by phage display, RNA-peptide screening and the other techniques mentioned herein.
Further in accordance with the present invention is a process for making TALL-1 modulators, which comprises:
a. selecting at least one peptide that binds to TALL-1; and
b. covalently linking said peptide to a vehicle.
The preferred vehicle is an Fc domain. Step (a) is preferably carried out by selection from the peptide sequences in Table 2 hereinafter or from phage display, RNA-peptide screening, or the other techniques mentioned herein.
The compounds of this invention may be prepared by standard synthetic methods, recombinant DNA techniques, or any other methods of preparing peptides and fusion proteins. Compounds of this invention that encompass non-peptide portions may be synthesized by standard organic chemistry reactions, in addition to standard peptide chemistry reactions when applicable.
The primary use contemplated for the compounds of this invention is as therapeutic or prophylactic agents. The vehicle-linked peptide may have activity comparable to—or even greater than—the natural ligand mimicked by the peptide.
The compounds of this invention may be used for therapeutic or prophylactic purposes by formulating them with appropriate pharmaceutical carrier materials and administering an effective amount to a patient, such as a human (or other mammal) in need thereof. Other related aspects are also included in the instant invention.
Numerous additional aspects and advantages of the present invention will become apparent upon consideration of the figures and detailed description of the invention.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows exemplary Fc dimers that may be derived from an IgG1 antibody. “Fc” in the figure represents any of the Fc variants within the meaning of “Fc domain” herein. “X 1 ” and “X 2 ” represent peptides or linker-peptide combinations as defined hereinafter. The specific dimers are as follows:
A, D: Single disulfide-bonded dimers. IgG1 antibodies typically have two disulfide bonds at the hinge region of the antibody. The Fc domain in FIGS. 1A and 1D may be formed by truncation between the two disulfide bond sites or by substitution of a cysteinyl residue with an unreactive residue (e.g., alanyl). In FIG. 1A , the Fc domain is linked at the amino terminus of the peptides; in 1 D, at the carboxyl terminus.
B, E: Doubly disulfide-bonded dimers. This Fc domain may be formed by truncation of the parent antibody to retain both cysteinyl residues in the Fc domain chains or by expression from a construct including a sequence encoding such an Fc domain. In FIG. 1B , the Fc domain is linked at the amino terminus of the peptides; in 1 E, at the carboxyl terminus.
C, F: Noncovalent dimers. This Fc domain may be formed by elimination of the cysteinyl residues by either truncation or substitution. One may desire to eliminate the cysteinyl residues to avoid impurities formed by reaction of the cysteinyl residue with cysteinyl residues of other proteins present in the host cell. The noncovalent bonding of the Fc domains is sufficient to hold together the dimer.
Other dimers may be formed by using Fc domains derived from different types of antibodies (e.g., IgG2, IgM).
FIG. 2 shows the structure of preferred compounds of the invention that feature tandem repeats of the pharmacologically active peptide. FIG. 2A shows a single chain molecule and may also represent the DNA construct for the molecule. FIG. 2B shows a dimer in which the linker-peptide portion is present on only one chain of the dimer. FIG. 2C shows a dimer having the peptide portion on both chains. The dimer of FIG. 2C will form spontaneously in certain host cells upon expression of a DNA construct encoding the single chain shown in FIG. 3A . In other host cells, the cells could be placed in conditions favoring formation of dimers or the dimers can be formed in vitro.
FIG. 3 shows exemplary nucleic acid and amino acid sequences (SEQ ID NOS:1 and 2, respectively) of human IgG1 Fc that may be used in this invention.
FIGS. 4A through 4F show the nucleotide and amino acid sequences (SEQ ID NOS:3-27) S of NdeI to SalI fragments encoding peptide and linker.
FIGS. 5A through 5M show the nucleotide sequence (SEQ ID NO: 28) of pAMG21-RANK-Fc vector, which was used to construct Fc-linked molecules of the present invention. These figures identify a number of features of the nucleic acid, including:
promoter regions PcopB, PrepA, RNAI, APHII, luxPR, and luxPL; mRNA for APHII, luxR; coding sequences and amino acid sequences for the proteins copB protein, copT, repAI, repA4, APHII, luxR, RANK, and Fc; binding sites for the proteins copB, CRP; hairpins T1, T2, T7, and toop; operator site for lux protein; enzyme restriction sites for Pfll108 I, Bgl II, Sca I, Bmn I, Drd II, Dra III, Bst BI, Ace III, Afl II, PFlM I, Bgl I, Sfi I, BstE II, BspLull I, Nsp V, Bpl I, Eag I, Bcg I, Nsi I, Bsa I, P spl406 I, Aat II, Bsm I, Nru I, Nde I, ApaL I, Acc65 I, Kpn I, Sal I, Acc I, BspE I, Ahd I, BspH I, Econ I, BsrG I, Bma I, Sma I, SexA I, BamH I, and Blp I.
FIGS. 6A and 6B show the DNA sequence (SEQ ID NO: 97) inserted into pCFM1656 between the unique Aat II (position #4364 in pCFM1656) and Sac II (position #4585 in pCFM1656) restriction sites to form expression plasmid pAMG21 (ATCC accession no. 98113).
FIG. 7 shows that the TALL-1 peptibody (SEQ ID NO: 70) inhibits TALL-1-mediated B cell proliferation. Purified B cells (10 5 ) from B6 mice were cultured in triplicates in 96-well plated with the indicated amounts of TALL-1 consensus peptibody in the presence of 10 ng/ml TALL-1 plus 2 μg/ml anti-IgM antibody. Proliferation was measured by radioactive [ 3 H]thymidine uptake in the last 18 h of pulse. Data shown represent mean±SD triplicate wells.
FIG. 8 shows that a TALL-1 N-terminal tandem dimer peptibodies (SEQ ID NO: 123, 124 in Table 5B hereinafter) are preferable for inhibition of TALL-1-mediated B cell proliferation. Purified B cells (10 5 ) from B6 mice were cultured in triplicates in 96-well plated with the indicated amounts of TALL-1 12-3 peptibody and TALL-1 consensus peptibody (SEQ ID NOS: 115 and 122 of Table 5B) or the related dimer peptibodies (SEQ ID NOS: 123, 124) in the presence of 10 ng/ml TALL-1 plus 2 μg/ml anti-IgM antibody. Proliferation was measured by radioactive [ 3 H]thymidine uptake in the last 18 h of pulse. Data shown represent mean±SD triplicate wells.
FIG. 9 . AGP3 peptibody binds to AGP3 with high affinity. Dissociation equilibrium constant (K D ) was obtained from nonlinear regression of the competition curves using a dual-curve one-site homogeneous binding model (KinEx™ software). K D is about 4 pM for AGP3 peptibody binding with human AGP3 (SEQ ID NO: 123).
FIGS. 10A and 10B . AGP3 peptibody blocks both human and murine AGP3 in the Biacore competition assay. Soluble human TACI protein was immobilized to B1 chip. 1 nM of recombinant human AGP3 protein (upper panel) or 5 nM of recombinant murine AGP3 protein (lower panel) was incubated with indicated amount of AGP3 peptibody before injected over the surface of receptor. Relative human AGP3 and murine AGP3 (binding response was shown (SEQ ID NO: 123).
FIGS. 11A and 11B . AGP3 peptibody blocked AGP3 binding to all three receptors TACI, BCMA and BAFFR in Biacore competition assay. Recombinant soluble receptor TACI, BCMA and BAFFR proteins were immobilized to CM5 chip. 1 nM of recombinant human AGP3 (upper panel) were incubated with indicated amount of AGP3 peptibody before injected over each receptor surface. Relative binding of AGP3 was measured. Similarly, 1 nM of recombinant APRIL protein was incubated with indicated amount of AGP3 peptibody before injected over each receptor surface. AGP3 peptibody didn't inhibit APRIL binding to all three receptors (SEQ ID NO: 123).
FIGS. 12A and 12B . AGP3 peptibody inhibits mouse serum immunoglobulin level increase induced by human AGP3 challenge. Balb/c mice received 7 daily intraperitoneal injections of 1 mg/Kg human AGP3 protein along with saline, human Fc, or AGP3 peptibody at indicated doses, and were bled on day 8. Serum total IgM and IgA level were measured by ELISA (SEQ ID NO: 123).
FIG. 13 . AGP3 peptibody treatment reduced arthritis severity in the mouse CIA model. Eight to 12 weeks old DBA/1 male mice were immunized with bovine collagen type II (bCII) emulsified in complete freunds adjuvant intradermally at the base of tail, and were boosted 3 weeks after the initial immunization with bCII emulsified in incomplete freunds adjuvant. Treatment with indicated dosage of AGP3 peptibody was begun from the day of booster immunization for 4 weeks. As described before (Khare et al., J. Immunol. 155: 3653-9, 1995), all four paws were individually scored from 0-3 for arthritis severity (SEQ ID NO: 123).
FIG. 14 . AGP3 peptibody treatment inhibited anti-collagen antibody generation in the mouse CIA model. Serum samples were taken one week after final treatment (day 35) as described above. Serum anti-collagen II antibody level was determined by ELISA analysis (SEQ ID NO: 123).
FIGS. 15A and 15B . AGP3 peptibody treatment delayed proteinuria onset and improved survival in NZB/NZW lupus mice. Five-month-old lupus prone NZBx NZBWF1 mice were treated i.p. 3×/week for 8 weeks with PBS or indicated doses of AGP3 peptibody (SEQ ID NO: 123) or human Fc proteins. Protein in the urine was evaluated monthly throughout the life of the experiment with Albustix reagent strips (Bayer AG).
FIGS. 16A and 16B show the nucleic acid and amino acid sequences of a preferred TALL-1-binding peptibody (SEQ ID NOS: 189 and 123)
DETAILED DESCRIPTION OF THE INVENTION
Definition of Terms
The terms used throughout this specification are defined as follows, unless otherwise limited in specific instances.
GENERAL DEFINITIONS
The term “comprising” means that a compound may include additional amino acids on either or both of the N- or C-termini of the given sequence. Of course, these additional amino acids should not significantly interfere with the activity of the compound.
Additionally, physiologically acceptable salts of the compounds of this invention are also encompassed herein. The term “physiologically acceptable salts” refers to any salts that are known or later discovered to be pharmaceutically acceptable. Some specific examples are: acetate; trifluoroacetate; hydrohalides, such as hydrochloride and hydrobromide; sulfate; citrate; tartrate; glycolate; and oxalate.
Amino Acids
The term “acidic residue” refers to amino acid residues in D- or L-form having sidechains comprising acidic groups. Exemplary acidic residues include D and E.
The term “amide residue” refers to amino acids in D- or L-form having sidechains comprising amide derivatives of acidic groups. Exemplary residues include N and Q.
The term “aromatic residue” refers to amino acid residues in D- or L-form having sidechains comprising aromatic groups. Exemplary aromatic residues include F, Y, and W.
The term “basic residue” refers to amino acid residues in D- or L-form having sidechains comprising basic groups. Exemplary basic residues include H, K, and R.
The term “hydrophilic residue” refers to amino acid residues in D- or L-form having sidechains comprising polar groups. Exemplary hydrophilic residues include C, S, T, N, and Q.
The term “nonfunctional residue” refers to amino acid residues in D- or L-form having sidechains that lack acidic, basic, or aromatic groups. Exemplary nonfunctional amino acid residues include M, G, A, V, I, L and norleucine (Nle).
The term “neutral hydrophobic residue” refers to amino acid residues in D- or L-form having sidechains that lack basic, acidic, or polar groups. Exemplary neutral hydrophobic amino acid residues include A, V, L, I, P, W, M, and F.
The term “polar hydrophobic residue” refers to amino acid residues in D- or L-form having sidechains comprising polar groups. Exemplary polar hydrophobic amino acid residues include T, G, S, Y, C, Q, and N.
The term “hydrophobic residue” refers to amino acid residues in D- or L-form having sidechains that lack basic or acidic groups. Exemplary hydrophobic amino acid residues include A, V, L, I, P, W, M, F, T, G, S, Y, C, Q, and N.
Peptides
The term “peptide” refers to molecules of 1 to 40 amino acids, with molecules of 5 to 20 amino acids preferred. Exemplary peptides may comprise the TALL-1 modulating domain of a naturally occurring molecule or comprise randomized sequences.
The term “randomized” as used to refer to peptide sequences refers to fully random sequences (e.g., selected by phage display methods or RNA-peptide screening) and sequences in which one or more residues of a naturally occurring molecule is replaced by an amino acid residue not appearing in that position in the naturally occurring molecule. Exemplary methods for identifying peptide sequences include phage display, E. coli display, ribosome display, RNA-peptide screening, chemical screening, and the like.
The term “TALL-1 modulating domain” refers to any amino acid sequence that binds to the TALL-1 and comprises naturally occurring sequences or randomized sequences. Exemplary TALL-1 modulating domains can be identified or derived by phage display or other methods mentioned herein.
The term “TALL-1 antagonist” refers to a molecule that binds to the TALL-1 and increases or decreases one or more assay parameters opposite from the effect on those parameters by full length native TALL-1. Such activity can be determined, for example, by such assays as described in the subsection entitled “Biological activity of AGP-3” in the Materials & Methods section of the patent application entitled, “TNF-RELATED PROTEINS”, WO 00/47740, published Aug. 17, 2000.
Vehicles and Peptibodies
The term “vehicle” refers to a molecule that prevents degradation and/or increases half-life, reduces toxicity, reduces immunogenicity, or increases biological activity of a therapeutic protein. Exemplary vehicles include an Fc domain (which is preferred) as well as a linear polymer (e.g., polyethylene glycol (PEG), polylysine, dextran, etc.); a branched-chain polymer (see, for example, U.S. Pat. No. 4,289,872 to Denkenwalter et al., issued Sep. 15, 1981; U.S. Pat. No. 5,229,490 to Tam, issued Jul. 20, 1993; WO 93/21259 by Frechet et al., published 28 Oct. 1993); a lipid; a cholesterol group (such as a steroid); a carbohydrate or oligosaccharide (e.g., dextran); any natural or synthetic protein, polypeptide or peptide that binds to a salvage receptor; albumin, including human serum albumin (HSA), leucine zipper domain, and other such proteins and protein fragments. Vehicles are further described hereinafter.
The term “native Fc” refers to molecule or sequence comprising the sequence of a non-antigen-binding fragment resulting from digestion of whole antibody, whether in monomeric or multimeric form. The original immunoglobulin source of the native Fc is preferably of human origin and may be any of the immunoglobulins, although IgG1 and IgG2 are preferred. Native Fc's are made up of monomeric polypeptides that may be linked into dimeric or multimeric forms by covalent (i.e., disulfide bonds) and non-covalent association. The number of intermolecular disulfide bonds between monomeric subunits of native Fc molecules ranges from 1 to 4 depending on class (e.g., IgG, IgA, IgE) or subclass (e.g., IgG1, IgG2, IgG3, IgA1, IgGA2). One example of a native Fc is a disulfide-bonded dimer resulting from papain digestion of an IgG (see Ellison et al. (1982), Nucleic Acids Res. 10: 4071-9). The term “native Fc” as used herein is generic to the monomeric, dimeric, and multimeric forms.
The term “Fc variant” refers to a molecule or sequence that is modified from a native Fc but still comprises a binding site for the salvage receptor, FcRn. International applications WO 97/34631 (published 25 Sep. 1997) and WO 96/32478 describe exemplary Fc variants, as well as interaction with the salvage receptor, and are hereby incorporated by reference in their entirety. Thus, the term “Fc variant” comprises a molecule or sequence that is humanized from a non-human native Fc. Furthermore, a native Fc comprises sites that may be removed because they provide structural features or biological activity that are not required for the fusion molecules of the present invention. Thus, the term “Fc variant” comprises a molecule or sequence that lacks one or more native Fc sites or residues that affect or are involved in (1) disulfide bond formation, (2) incompatibility with a selected host cell (3) N-terminal heterogeneity upon expression in a selected host cell, (4) glycosylation, (5) interaction with complement, (6) binding to an Fc receptor other than a salvage receptor, or (7) antibody-dependent cellular cytotoxicity (ADCC). Fc variants are described in further detail hereinafter.
The term “Fc domain” encompasses native Fc and Fc variant molecules and sequences as defined above. As with Fc variants and native Fc's, the term “Fc domain” includes molecules in monomeric or multimeric form, whether digested from whole antibody or produced by other means.
The term “multimer” as applied to Fc domains or molecules comprising Fc domains refers to molecules having two or more polypeptide chains associated covalently, noncovalently, or by both covalent and non-covalent interactions. IgG molecules typically form dimers; IgM, pentamers; IgD, dimers; and IgA, monomers, dimers, trimers, or tetramers. Multimers may be formed by exploiting the sequence and resulting activity of the native Ig source of the Fc or by derivatizing (as defined below) such a native Fc.
The term “dimer” as applied to Fc domains or molecules comprising Fc domains refers to molecules having two polypeptide chains associated covalently or non-covalently. Thus, exemplary dimers within the scope of this invention are as shown in FIG. 1 .
The terms “derivatizing” and “derivative” or “derivatized” comprise processes and resulting compounds respectively in which (1) the compound has a cyclic portion; for example, cross-linking between cysteinyl residues within the compound; (2) the compound is cross-linked or has a cross-linking site; for example, the compound has a cysteinyl residue and thus forms cross-linked dimers in culture or in vivo; (3) one or more peptidyl linkage is replaced by a non-peptidyl linkage; (4) the N-terminus is replaced by —NRR 1 , NRC(O)R 1 , —NRC(O)OR 1 , —NRS(O) 2 R 1 , —NHC(O)NHR, a succinimide group, or substituted or unsubstituted benzyloxycarbonyl-NH—, wherein R and R 1 and the ring substituents are as defined hereinafter; (5) the C-terminus is replaced by —C(O)R 2 or —NR 3 R 4 wherein R 2 , R 3 and R 4 are as defined hereinafter; and (6) compounds in which individual amino acid moieties are modified through treatment with agents capable of reacting with selected side chains or terminal residues. Derivatives are further described hereinafter.
The terms “peptibody” and “peptibodies” refer to molecules comprising an Fc domain and at least one peptide. Such peptibodies may be multimers or dimers or fragments thereof, and they may be derivatized. In the present invention, the molecules of formulae II through VI hereinafter are peptibodies when V 1 is an Fc domain.
Structure of Compounds
In General. The present inventors identified sequences capable of binding to and modulating the biological activity of TALL-1. These sequences can be modified through the techniques mentioned above by which one or more amino acids may be changed while maintaining or even improving the binding affinity of the peptide.
In the compositions of matter prepared in accordance with this invention, the peptide(s) may be attached to the vehicle through the peptide's N-terminus or C-terminus. Any of these peptides may be linked in tandem (i.e., sequentially), with or without linkers. Thus, the vehicle-peptide molecules of this invention may be described by the following formula:
(X 1 ) a —V 1 —(X 2 ) b II
wherein:
V 1 is a vehicle (preferably an Fc domain);
X 1 and X 2 are each independently selected from -(L 1 ) c -P 1 , -(L 1 ) c -P 1 -(L 2 ) d -P 2 , -(L 1 ) c -P 1 -(L 2 ) d -P 2 -(L 3 ) e -P 3 , and -(L 1 ) c -P 1 -(L 2 ) d -P 2 -(L 3 ) e -P 3 -(L 4 ) f -P 4
P 1 , P 2 , P 3 , and P 4 are each independently sequences of TALL-1 modulating domains, such as those of Formulae I(a) through I(i);
L 1 , L 2 , L 3 , and L 4 are each independently linkers; and
a, b, c, d, e, and f are each independently 0 or 1, provided that at least one of a and b is 1.
Thus, compound II comprises preferred compounds of the formulae
X 1 —V 1 III
and multimers thereof wherein V 1 is an Fc domain and is attached at the C-terminus of A 1 ;
V 1 —X 2 IV
and multimers thereof wherein V 1 is an Fc domain and is attached at the N-terminus of A 2 ;
V 1 -(L 1 ) c -P 1 V
and multimers thereof wherein V 1 is an Fc domain and is attached at the N-terminus of -(L 1 ) c -P 1 ; and
V 1 -(L 1 ) c -P 1 -(L 2 ) d -P 2 VI
and multimers thereof wherein V 1 is an Fc domain and is attached at the N-terminus of -L 1 -P 1 -L 2 -P 2 .
Peptides. The peptides of this invention are useful as TALL-1 modulating peptides or as TALL-1 modulating domains in the molecules of formulae II through VI. Molecules of this invention comprising these peptide sequences may be prepared by methods known in the art.
Preferred peptide sequences are those of the foregoing formulae I(a) having the substituents identified below.
TABLE 1
Preferred peptide substituents
Formula I(a)
a 8 is T;
a 9 is a basic residue (K most preferred); and
a 12 is a neutral hydrophobic residue (F most
preferred).
Formula I(b)
b 3 is D, Q, or E;
b 6 is W or Y;
b 10 is T;
b 11 is K or R; and
b 14 is V or L.
Formula I(c)
c 9 is T;
c 10 is K or R;
c 13 is a I, L, or V; and
c 17 is A or L.
Formula I(d)
d 13 is T.
Formula I(e)
e 11 is T.
Formula I(f)
f 6 is T;
f 7 is K; and
f 10 is V.
Formula I(g)
g 5 is W;
g 8 is P;
g 10 is E; and
g 13 is a basic residue.
Formula I(h)
h 1 is G;
h 6 is A;
h 7 is a neutral hydrophobic residue; and
h 10 is an acidic residue.
Formula I(i)
i 2 is W; and
i 14 is W.
Preferred peptide sequences appear in Table 2 below.
TABLE 2
Preferred TALL-1 modulating domains
Sequence
SEQ ID NO:
PGTCFPFPWECTHA
29
WGACWPFPWECFKE
30
VPFCDLLTKHCFEA
31
GSRCKYKWDVLTKQCFHH
32
LPGCKWDLLIKQWVCDPL
33
SADCYFDILTKSDVCTSS
34
SDDCMYDQLTRMFICSNL
35
DLNCKYDELTYKEWCQFN
36
FHDCKYDLLTRQMVCHGL
37
RNHCFWDHLLKQDICPSP
38
ANQCWWDSLTKKNVCEFF
39
YKGRQMWDILTRSWVVSL
126
QDVGLWWDILTRAWMPNI
127
QNAQRVWDLLIRTWVYPQ
128
GWNEAWWDELTKIWVLEQ
129
RITCDTWDSLIKKCVPQS
130
GAIMQFWDSLTKTWLRQS
131
WLHSGWWDPLTKHWLQKV
132
SEWFFWFDPLTRAQLKFR
133
GVWFWWFDPLTKQWTQAG
134
MQCKGYYDILTKWCVTNG
135
LWSKEVWDILTKSWVSQA
136
KAAGWWFDWLTKVWVPAP
137
AYQTWFWDSLTRLWLSTT
138
SGQHFWWDLLTRSWTPST
139
LGVGQKWDPLTKQWVSRG
140
VGKMCQWDPLIKRTVCVG
141
CRQGAKFDLLTKQCLLGR
142
GQAIRHWDVLTKQWVDSQ
143
RGPCGSWDLLTKHCLDSQ
144
WQWKQQWDLLTKQMVWVG
145
PITICRKDLLTKQVVCLD
146
KTCNGKWDLLTKQCLQQA
147
KCLKGKWDLLTKQCVTEV
148
RCWNGKWDLLTKQCIHPW
149
NRDMRKWDPLIKQWIVRP
150
QAAAATWDLLTKQWLVPP
151
PEGGPKWDPLTKQFLPPV
152
QTPQKKWDLLTKQWFTRN
153
IGSPCKWDLLTKQMICQT
154
CTAAGKWDLLTKQCIQEK
155
VSQCMKWDLLTKQCLQGW
156
VWGTWKWDLLTKQYLPPQ
157
GWWEMKWDLLTKQWYRPQ
158
TAQVSKWDLLTKQWLPLA
159
QLWGTKWDLLTKQYIQIM
160
WATSQKWDLLTKQWVQNM
161
QRQCAKWDLLTKQCVLFY
162
KTTDCKWDLLTKQRICQV
163
LLCQGKWDLLTKQCLKLR
164
LMWFWKWDLLTKQLVPTF
165
QTWAWKWDLLTKQWIGPM
166
NKELLKWDLLTKQCRGRS
167
GQKDLKWDLLTKQYVRQS
168
PKPCQKWDLLTKQCLGSV
169
GQIGWKWDLLTKQWIQTR
170
VWLDWKWDLLTKQWIHPQ
171
QEWEYKWDLLTKQWGWLR
172
HWDSWKWDLLTKQWVVQA
173
TRPLQKWDLLTKQWLRVG
174
SDQWQKWDLLTKQWFWDV
175
QQTFMKWDLLTKQWIRRH
176
QGECRKWDLLTKQCFPGQ
177
GQMGWRWDPLIKMCLGPS
178
QLDGCKWDLLTKQKVCIP
179
HGYWQKWDLLTKQWVSSE
180
HQGQCGWDLLTRIYLPCH
181
LHKACKWDLLTKQCWPMQ
182
GPPGSVWDLLTKIWIQTG
183
ITQDWRFDTLTRLWLPLR
184
QGGFAAWDVLTKMWTTVP
185
GHGTPWWDALTRIWILGV
186
VWPWQKWDLLTKQFVFQD
187
WQWSWKWDLLTRQYISSS
188
NQTLWKWDLLTKQFITYM
60
PVYQGWWDTLTKLYIWDG
61
WLDGGWRDPLIKRSVQLG
62
GHQQFKWDLLTKQWVQSN
63
QRVGQFWDVLTKMFITGS
64
QAQGWSYDALIKTWIRWP
65
GWMHWKWDPLTKQALPWM
66
GHPTYKWDLLTKQWILQM
67
WNNWSLWDPLTKLWLQQN
68
WQWGWKWDLLTKQWVQQQ
69
GQMGWRWDPLTKMWLGTS
70
It is noted that the known receptors for TALL-1 bear some sequence homology with preferred peptides:
12-3
LPGCK WDLL I K QWVCDP L
BAFFR
MRRGPRSLRGRDAPVPTPCVPTEC YDLL V R KCVDCR L L
TACI
TICNHQSQRTCAAFCRSLSCRKEQGKF YD H L L R DCISCASI
BCMA
FVSPSQEIRGRFRRMLQMAGQCSQNEY FD S L L H ACIPCQ L RC
(SEQ ID NOS: 33, 195, 196, and 197, respectively).
Any peptide containing a cysteinyl residue may be cross-linked with another Cys-containing peptide, either or both of which may be linked to a vehicle. Any peptide having more than one Cys residue may form an intrapeptide disulfide bond, as well. Any of these peptides may be derivatized as described hereinafter.
Additional useful peptide sequences may result from conservative and/or non-conservative modifications of the amino acid sequences of the sequences in Table 2.
Conservative modifications will produce peptides having functional and chemical characteristics similar to those of the peptide from which such modifications are made. In contrast, substantial modifications in the functional and/or chemical characteristics of the peptides may be accomplished by selecting substitutions in the amino acid sequence that differ significantly in their effect on maintaining (a) the structure of the molecular backbone in the area of the substitution, for example, as a sheet or helical conformation, (b) the charge or hydrophobicity of the molecule at the target site, or (c) the size of the molecule.
For example, a “conservative amino acid substitution” may involve a substitution of a native amino acid residue with a normative residue such that there is little or no effect on the polarity or charge of the amino acid residue at that position. Furthermore, any native residue in the polypeptide may also be substituted with alanine, as has been previously described for “alanine scanning mutagenesis” (see for example, MacLennan et al., 1998 , Acta Physiol. Scand. Suppl. 643:55-67; Sasaki et al., 1998 , Adv. Biophys. 35:1-24, which discuss alanine scanning mutagenesis).
Desired amino acid substitutions (whether conservative or non-conservative) can be determined by those skilled in the art at the time such substitutions are desired. For example, amino acid substitutions can be used to identify important residues of the peptide sequence, or to increase or decrease the affinity of the peptide or vehicle-peptide molecules (see preceding formulae) described herein. Exemplary amino acid substitutions are set forth in Table 3.
TABLE 3
Amino Acid Substitutions
Original
Exemplary
Preferred
Residues
Substitutions
Substitutions
Ala (A)
Val, Leu, Ile
Val
Arg (R)
Lys, Gln, Asn
Lys
Asn (N)
Gln
Gln
Asp (D)
Glu
Glu
Cys (C)
Ser, Ala
Ser
Gln (Q)
Asn
Asn
Glu (E)
Asp
Asp
Gly (G)
Pro, Ala
Ala
His (H)
Asn, Gln, Lys, Arg
Arg
Ile (I)
Leu, Val, Met, Ala,
Leu
Phe, Norleucine
Leu (L)
Norleucine, Ile, Val,
Ile
Met, Ala, Phe
Lys (K)
Arg, 1,4 Diamino-
Arg
butyric Acid, Gln, Asn
Met (M)
Leu, Phe, Ile
Leu
Phe (F)
Leu, Val, Ile, Ala, Tyr
Leu
Pro (P)
Ala
Gly
Ser (S)
Thr, Ala, Cys
Thr
Thr (T)
Ser
Ser
Trp (W)
Tyr, Phe
Tyr
Tyr (Y)
Trp, Phe, Thr, Ser
Phe
Val (V)
Ile, Met, Leu, Phe,
Leu
Ala, Norleucine
In certain embodiments, conservative amino acid substitutions also encompass non-naturally occurring amino acid residues which are typically incorporated by chemical peptide synthesis rather than by synthesis in biological systems.
As noted in the foregoing section “Definition of Terms,” naturally occurring residues may be divided into classes based on common sidechain properties that may be useful for modifications of sequence. For example, non-conservative substitutions may involve the exchange of a member of one of these classes for a member from another class. Such substituted residues may be introduced into regions of the peptide that are homologous with non-human orthologs, or into the non-homologous regions of the molecule. In addition, one may also make modifications using P or G for the purpose of influencing chain orientation.
In making such modifications, the hydropathic index of amino acids may be considered. Each amino acid has been assigned a hydropathic index on the basis of their hydrophobicity and charge characteristics, these are: isoleucine (+4.5); valine (+4.2); leucine (+3.8); phenylalanine (+2.8); cysteine/cystine (+2.5); methionine (+1.9); alanine (+1.8); glycine (−0.4); threonine (−0.7); serine (−0.8); tryptophan (−0.9); tyrosine (−1.3); proline (−1.6); histidine (−3.2); glutamate (−3.5); glutamine (−3.5); aspartate (−3.5); asparagine (−3.5); lysine (−3.9); and arginine (−4.5).
The importance of the hydropathic amino acid index in conferring interactive biological function on a protein is understood in the art. Kyte et al., J. Mol. Biol., 157: 105-131 (1982). It is known that certain amino acids may be substituted for other amino acids having a similar hydropathic index or score and still retain a similar biological activity. In making changes based upon the hydropathic index, the substitution of amino acids whose hydropathic indices are within ±2 is preferred, those which are within ±1 are particularly preferred, and those within ±0.5 are even more particularly preferred.
It is also understood in the art that the substitution of like amino acids can be made effectively on the basis of hydrophilicity. The greatest local average hydrophilicity of a protein, as governed by the hydrophilicity of its adjacent amino acids, correlates with its immunogenicity and antigenicity, i.e., with a biological property of the protein.
The following hydrophilicity values have been assigned to amino acid residues: arginine (+3.0); lysine (+3.0); aspartate (+3.0±1); glutamate (+3.0±1); serine (+0.3); asparagine (+0.2); glutamine (+0.2); glycine (0); threonine (−0.4); proline (−0.5±1); alanine (−0.5); histidine (−0.5); cysteine (−1.0); methionine (−1.3); valine (−1.5); leucine (−1.8); isoleucine (−1.8); tyrosine (−2.3); phenylalanine (−2.5); tryptophan (−3.4). In making changes based upon similar hydrophilicity values, the substitution of amino acids whose hydrophilicity values are within ±2 is preferred, those which are within ±1 are particularly preferred, and those within ±0.5 are even more particularly preferred. One may also identify epitopes from primary amino acid sequences on the basis of hydrophilicity. These regions are also referred to as “epitopic core regions.”
A skilled artisan will be able to determine suitable variants of the polypeptide as set forth in the foregoing sequences using well known techniques. For identifying suitable areas of the molecule that may be changed without destroying activity, one skilled in the art may target areas not believed to be important for activity. For example, when similar polypeptides with similar activities from the same species or from other species are known, one skilled in the art may compare the amino acid sequence of a peptide to similar peptides. With such a comparison, one can identify residues and portions of the molecules that are conserved among similar polypeptides. It will be appreciated that changes in areas of a peptide that are not conserved relative to such similar peptides would be less likely to adversely affect the biological activity and/or structure of the peptide. One skilled in the art would also know that, even in relatively conserved regions, one may substitute chemically similar amino acids for the naturally occurring residues while retaining activity (conservative amino acid residue substitutions). Therefore, even areas that may be important for biological activity or for structure may be subject to conservative amino acid substitutions without destroying the biological activity or without adversely affecting the peptide structure.
Additionally, one skilled in the art can review structure-function studies identifying residues in similar peptides that are important for activity or structure. In view of such a comparison, one can predict the importance of amino acid residues in a peptide that correspond to amino acid residues that are important for activity or structure in similar peptides. One skilled in the art may opt for chemically similar amino acid substitutions for such predicted important amino acid residues of the peptides.
One skilled in the art can also analyze the three-dimensional structure and amino acid sequence in relation to that structure in similar polypeptides. In view of that information, one skilled in the art may predict the alignment of amino acid residues of a peptide with respect to its three dimensional structure. One skilled in the art may choose not to make radical changes to amino acid residues predicted to be on the surface of the protein, since such residues may be involved in important interactions with other molecules. Moreover, one skilled in the art may generate test variants containing a single amino acid substitution at each desired amino acid residue. The variants can then be screened using activity assays know to those skilled in the art. Such data could be used to gather information about suitable variants. For example, if one discovered that a change to a particular amino acid residue resulted in destroyed, undesirably reduced, or unsuitable activity, variants with such a change would be avoided. In other words, based on information gathered from such routine experiments, one skilled in the art can readily determine the amino acids where further substitutions should be avoided either alone or in combination with other mutations.
A number of scientific publications have been devoted to the prediction of secondary structure. See Moult J., Curr. Op. in Biotech., 7(4): 422-427 (1996), Chou et al., Biochemistry 13(2): 222-245 (1974); Chou et al., Biochemistry, 113(2): 211-222 (1974); Chou et al., Adv. Enzymol. Relat. Areas Mol. Biol., 47:45-148 (1978); Chou et al., Ann. Rev. Biochem., 47: 251-276 and Chou et al., Biophys. J., 26: 367-384 (1979). Moreover, computer programs are currently available to assist with predicting secondary structure. One method of predicting secondary structure is based upon homology modeling. For example, two polypeptides or proteins which have a sequence identity of greater than 30%, or similarity greater than 40% often have similar structural topologies. The recent growth of the protein structural data base (PDB) has provided enhanced predictability of secondary structure, including the potential number of folds within a polypeptide's or protein's structure. See Holm et al., Nucl. Acid. Res., 27(1): 244-247 (1999). It has been suggested (Brenner et al., Curr. Op. Struct. Biol., 7(3): 369-376 (1997)) that there are a limited number of folds in a given polypeptide or protein and that once a critical number of structures have been resolved, structural prediction will gain dramatically in accuracy.
Additional methods of predicting secondary structure include “threading” (Jones, D., Curr. Opin. Struct. Biol., 7(3): 377-87 (1997); Sippl et al., Structure, 4(1): 15-9 (1996)), “profile analysis” (Bowie et al., Science, 253: 164-170 (1991); Gribskov et al., Meth. Enzym., 183: 146-159 (1990); Gribskov et al., Proc. Nat. Acad. Sci., 84(13): 4355-8 (1987)), and “evolutionary linkage” (See Home, supra, and Brenner, supra).
Vehicles. This invention requires the presence of at least one vehicle (V 1 ) attached to a peptide through the N-terminus, C-terminus or a sidechain of one of the amino acid residues. Multiple vehicles may also be used; e.g., Fc's at each terminus or an Fc at a terminus and a PEG group at the other terminus or a sidechain. Exemplary vehicles include:
an Fc domain; other proteins, polypeptides, or peptides capable of binding to a salvage receptor; human serum albumin (HSA); a leucine zipper (LZ) domain; polyethylene glycol (PEG), including 5 kD, 20 kD, and 30 kD PEG, as well as other polymers; dextran;
and other molecules known in the art to provide extended half-life and/or protection from proteolytic degradation or clearance.
An Fc domain is the preferred vehicle. The Fc domain may be fused to the N or C termini of the peptides or at both the N and C termini. Fusion to the N terminus is preferred.
As noted above, Fc variants are suitable vehicles within the scope of this invention. A native Fc may be extensively modified to form an Fc variant in accordance with this invention, provided binding to the salvage receptor is maintained; see, for example WO 97/34631 and WO 96/32478. In such Fc variants, one may remove one or more sites of a native Fc that provide structural features or functional activity not required by the fusion molecules of this invention. One may remove these sites by, for example, substituting or deleting residues, inserting residues into the site, or truncating portions containing the site. The inserted or substituted residues may also be altered amino acids, such as peptidomimetics or D-amino acids. Fc variants may be desirable for a number of reasons, several of which are described below. Exemplary Fc variants include molecules and sequences in which:
1. Sites involved in disulfide bond formation are removed. Such removal may avoid reaction with other cysteine-containing proteins present in the host cell used to produce the molecules of the invention. For this purpose, the cysteine-containing segment at the N-terminus may be truncated or cysteine residues may be deleted or substituted with other amino acids (e.g., alanyl, seryl). In particular, one may truncate the N-terminal 20-amino acid segment of SEQ ID NO: 2 or delete or substitute the cysteine residues at positions 7 and 10 of SEQ ID NO: 2. Even when cysteine residues are removed, the single chain Fc domains can still form a dimeric Fc domain that is held together non-covalently. 2. A native Fc is modified to make it more compatible with a selected host cell. For example, one may remove the PA sequence near the N-terminus of a typical native Fc, which may be recognized by a digestive enzyme in E. coli such as proline iminopeptidase. One may also add an N-terminal methionine residue, especially when the molecule is expressed recombinantly in a bacterial cell such as E. coli . The Fc domain of SEQ ID NO: 2 is one such Fc variant. 3. A portion of the N-terminus of a native Fc is removed to prevent N-terminal heterogeneity when expressed in a selected host cell. For this purpose, one may delete any of the first 20 amino acid residues at the N-terminus, particularly those at positions 1, 2, 3, 4 and 5. 4. One or more glycosylation sites are removed. Residues that are typically glycosylated (e.g., asparagine) may confer cytolytic response. Such residues may be deleted or substituted with unglycosylated residues (e.g., alanine). 5. Sites involved in interaction with complement, such as the C1q binding site, are removed. For example, one may delete or substitute the EKK sequence of human IgG1. Complement recruitment may not be advantageous for the molecules of this invention and so may be avoided with such an Fc variant. 6. Sites are removed that affect binding to Fc receptors other than a salvage receptor. A native Fc may have sites for interaction with certain white blood cells that are not required for the fusion molecules of the present invention and so may be removed. 7. The ADCC site is removed. ADCC sites are known in the art; see, for example, Molec. Immunol. 29 (5): 633-9 (1992) with regard to ADCC sites in IgG1. These sites, as well, are not required for the fusion molecules of the present invention and so may be removed. 8. When the native Fc is derived from a non-human antibody, the native Fc may be humanized. Typically, to humanize a native Fc, one will substitute selected residues in the non-human native Fc with residues that are normally found in human native Fc. Techniques for antibody humanization are well known in the art.
Preferred Fc variants include the following. In SEQ ID NO: 2 ( FIG. 3 ), the leucine at position 15 may be substituted with glutamate; the glutamate at position 99, with alanine; and the lysines at positions 101 and 103, with alanines. In addition, one or more tyrosine residues can be replaced by phenyalanine residues.
An alternative vehicle would be a protein, polypeptide, peptide, antibody, antibody fragment, or small molecule (e.g., a peptidomimetic compound) capable of binding to a salvage receptor. For example, one could use as a vehicle a polypeptide as described in U.S. Pat. No. 5,739,277, issued Apr. 14, 1998 to Presta et al. Peptides could also be selected by phage display or RNA-peptide screening for binding to the FcRn salvage receptor. Such salvage receptor-binding compounds are also included within the meaning of “vehicle” and are within the scope of this invention. Such vehicles should be selected for increased half-life (e.g., by avoiding sequences recognized by proteases) and decreased immunogenicity (e.g., by favoring non-immunogenic sequences, as discovered in antibody humanization).
As noted above, polymer vehicles may also be used for V 1 . Various means for attaching chemical moieties useful as vehicles are currently available, see, e.g., Patent Cooperation Treaty (“PCT”) International Publication No. WO 96/11953, entitled “N-Terminally Chemically Modified Protein Compositions and Methods,” herein incorporated by reference in its entirety. This PCT publication discloses, among other things, the selective attachment of water soluble polymers to the N-terminus of proteins.
A preferred polymer vehicle is polyethylene glycol (PEG). The PEG group may be of any convenient molecular weight and may be linear or branched. The average molecular weight of the PEG will preferably range from about 2 kiloDalton (“kD”) to about 100 kD, more preferably from about 5 kD to about 50 kD, most preferably from about 5 kD to about 10 kD. The PEG groups will generally be attached to the compounds of the invention via acylation or reductive alkylation through a reactive group on the PEG moiety (e.g., an aldehyde, amino, thiol, or ester group) to a reactive group on the inventive compound (e.g., an aldehyde, amino, or ester group).
A useful strategy for the PEGylation of synthetic peptides consists of combining, through forming a conjugate linkage in solution, a peptide and a PEG moiety, each bearing a special functionality that is mutually reactive toward the other. The peptides can be easily prepared with conventional solid phase synthesis. The peptides are “preactivated” with an appropriate functional group at a specific site. The precursors are purified and fully characterized prior to reacting with the PEG moiety. Ligation of the peptide with PEG usually takes place in aqueous phase and can be easily monitored by reverse phase analytical HPLC. The PEGylated peptides can be easily purified by preparative HPLC and characterized by analytical HPLC, amino acid analysis and laser desorption mass spectrometry.
Polysaccharide polymers are another type of water soluble polymer which may be used for protein modification. Dextrans are polysaccharide polymers comprised of individual subunits of glucose predominantly linked by α1-6 linkages. The dextran itself is available in many molecular weight ranges, and is readily available in molecular weights from about 1 kD to about 70 kD. Dextran is a suitable water soluble polymer for use in the present invention as a vehicle by itself or in combination with another vehicle (e.g., Fc). See, for example, WO 96/11953 and WO 96/05309. The use of dextran conjugated to therapeutic or diagnostic immunoglobulins has been reported; see, for example, European Patent Publication No. 0 315 456, which is hereby incorporated by reference in its entirety. Dextran of about 1 kD to about 20 kD is preferred when dextran is used as a vehicle in accordance with the present invention.
Linkers. Any “linker” group is optional. When present, its chemical structure is not critical, since it serves primarily as a spacer. The linker is preferably made up of amino acids linked together by peptide bonds. Thus, in preferred embodiments, the linker is made up of from 1 to 30 amino acids linked by peptide bonds, wherein the amino acids are selected from the 20 naturally occurring amino acids. Some of these amino acids may be glycosylated, as is well understood by those in the art. In a more preferred embodiment, the 1 to 20 amino acids are selected from glycine, alanine, proline, asparagine, glutamine, and lysine. Even more preferably, a linker is made up of a majority of amino acids that are sterically unhindered, such as glycine and alanine. Thus, preferred linkers are polyglycines (particularly (Gly) 4 , (Gly) 5 ), poly(Gly-Ala), and polyalanines. Other specific examples of linkers are:
(Gly) 3 Lys(Gly) 4 ; (SEQ ID NO:40) (Gly) 3 AsnGlySer(Gly) 2 ; (SEQ ID NO:41) (Gly) 3 Cys(Gly) 4 ; (SEQ ID NO:42) and GlyProAsnGlyGly. (SEQ ID NO:43)
To explain the above nomenclature, for example, (Gly) 3 Lys(Gly) 4 means Gly-Gly-Gly-Lys-Gly-Gly-Gly-Gly (SEQ ID NO: 40). Combinations of Gly and Ala are also preferred. The linkers shown here are exemplary; linkers within the scope of this invention may be much longer and may include other residues.
Preferred linkers are amino acid linkers comprising greater than 5 amino acids, with suitable linkers having up to about 500 amino acids selected from glycine, alanine, proline, asparagine, glutamine, lysine, threonine, serine or aspartate. Linkers of about 20 to 50 amino acids are most preferred. One group of preferred linkers are those of the formulae
(SEQ ID NO:193) GSGSATGGSGSTASSGSGSATx 1 x 2 and (SEQ ID NO:194) GSGSATGGSGSTASSGSGSATx 1 x 2 GSGSATGGSGSTASSGSGSATx 3 x 4
wherein x 1 and x 3 are each independently basic or hydrophobic residues and x 2 and x 4 are each independently hydrophobic residues. Specific preferred linkers are:
(SEQ ID NO:59)
GSGSATGGSGSTASSGSGSATHM
(SEQ ID NO:190)
GSGSATGGSGSTASSGSGSATGM
(SEQ ID NO:191)
GSGSATGGSGSTASSGSGSATGS,
and
(SEQ ID NO:192)
GSGSATGGSGSTASSGSGSATHMGSGSATGGSGSTASSGSGSATHM.
Non-peptide linkers are also possible. For example, alkyl linkers such as —NH—(CH 2 ) s —C(O)—, wherein s=2-20 could be used. These alkyl linkers may further be substituted by any non-sterically hindering group such as lower alkyl (e.g., C 1 -C 6 ) lower acyl, halogen (e.g., Cl, Br), CN, NH 2 , phenyl, etc. An exemplary non-peptide linker is a PEG linker,
wherein n is such that the linker has a molecular weight of 100 to 5000 kD, preferably 100 to 500 kD. The peptide linkers may be altered to form derivatives in the same manner as described above.
Derivatives. The inventors also contemplate derivatizing the peptide and/or vehicle portion of the compounds. Such derivatives may improve the solubility, absorption, biological half life, and the like of the compounds. The moieties may alternatively eliminate or attenuate any undesirable side-effect of the compounds and the like. Exemplary derivatives include compounds in which:
1. The compound or some portion thereof is cyclic. For example, the peptide portion may be modified to contain two or more Cys residues (e.g., in the linker), which could cyclize by disulfide bond formation. 2. The compound is cross-linked or is rendered capable of cross-linking between molecules. For example, the peptide portion may be modified to contain one Cys residue and thereby be able to form an intermolecular disulfide bond with a like molecule. The compound may also be cross-linked through its C-terminus, as in the molecule shown below.
In Formula VIII, each “V 1 ” may represent typically one strand of the Fc domain.
3. One or more peptidyl [—C(O)NR—] linkages (bonds) is replaced by a non-peptidyl linkage. Exemplary non-peptidyl linkages are —CH 2 -carbamate [—CH 2 —OC(O)NR—], phosphonate, —CH 2 -sulfonamide [—CH 2 —S(O) 2 NR—], urea [—NHC(O)NH—], —CH 2 -secondary amine, and alkylated peptide [—C(O)NR 6 — wherein R 6 is lower alkyl].
4. The N-terminus is derivatized. Typically, the N-terminus may be acylated or modified to a substituted amine. Exemplary N-terminal derivative groups include —NRR 1 (other than —NH 2 ), —NRC(O)R 1 , —NRC(O)OR 1 , —NRS(O) 2 R 1 , —NHC(O)NHR 1 , succinimide, or benzyloxycarbonyl-NH— (CBZ-NH—), wherein R and R 1 are each independently hydrogen or lower alkyl and wherein the phenyl ring may be substituted with 1 to 3 substituents selected from the group consisting of C 1 -C 4 alkyl, C 1 -C 4 alkoxy, chloro, and bromo.
5. The free C-terminus is derivatized. Typically, the C-terminus is esterified or amidated. Exemplary C-terminal derivative groups include, for example, —C(O)R 2 wherein R 2 is lower alkoxy or —NR 3 R 4 wherein R 3 and R 4 are independently hydrogen or C 1 -C 8 alkyl (preferably C 1 -C 4 alkyl).
6. A disulfide bond is replaced with another, preferably more stable, cross-linking moiety (e.g., an alkylene). See, e.g., Bhatnagar et al. (1996), J. Med. Chem. 39: 3814-9; Alberts et al. (1993) Thirteenth Am. Pep. Symp., 357-9.
7. One or more individual amino acid residues is modified. Various derivatizing agents are known to react specifically with selected sidechains or terminal residues, as described in detail below.
Lysinyl residues and amino terminal residues may be reacted with succinic or other carboxylic acid anhydrides, which reverse the charge of the lysinyl residues. Other suitable reagents for derivatizing alpha-amino-containing residues include imidoesters such as methyl picolinimidate; pyridoxal phosphate; pyridoxal; chloroborohydride; trinitrobenzenesulfonic acid; O-methylisourea; 2,4 pentanedione; and transaminase-catalyzed reaction with glyoxylate.
Arginyl residues may be modified by reaction with any one or combination of several conventional reagents, including phenylglyoxal, 2,3-butanedione, 1,2-cyclohexanedione, and ninhydrin. Derivatization of arginyl residues requires that the reaction be performed in alkaline conditions because of the high pKa of the guanidine functional group. Furthermore, these reagents may react with the groups of lysine as well as the arginine epsilon-amino group.
Specific modification of tyrosyl residues has been studied extensively, with particular interest in introducing spectral labels into tyrosyl residues by reaction with aromatic diazonium compounds or tetranitromethane. Most commonly, N-acetylimidizole and tetranitromethane are used to form O-acetyl tyrosyl species and 3-nitro derivatives, respectively.
Carboxyl sidechain groups (aspartyl or glutamyl) may be selectively modified by reaction with carbodiimides (R′—N═C═N—R′) such as 1-cyclohexyl-3-(2-morpholinyl-(4-ethyl) carbodiimide or 1-ethyl-3-(4-azonia-4,4-dimethylpentyl) carbodiimide. Furthermore, aspartyl and glutamyl residues may be converted to asparaginyl and glutaminyl residues by reaction with ammonium ions.
Glutaminyl and asparaginyl residues may be deamidated to the corresponding glutamyl and aspartyl residues. Alternatively, these residues are deamidated under mildly acidic conditions. Either form of these residues falls within the scope of this invention.
Cysteinyl residues can be replaced by amino acid residues or other moieties either to eliminate disulfide bonding or, conversely, to stabilize cross-linking. See, e.g., Bhatnagar et al. (1996), J. Med. Chem. 39: 3814-9.
Derivatization with bifunctional agents is useful for cross-linking the peptides or their functional derivatives to a water-insoluble support matrix or to other macromolecular vehicles. Commonly used cross-linking agents include, e.g., 1,1-bis(diazoacetyl)-2-phenylethane, glutaraldehyde, N-hydroxysuccinimide esters, for example, esters with 4-azidosalicylic acid, homobifunctional imidoesters, including disuccinimidyl esters such as 3,3′-dithiobis(succinimidylpropionate), and bifunctional maleimides such as bis-N-maleimido-1,8-octane. Derivatizing agents such as methyl-3-[(p-azidophenyl)dithio]propioimidate yield photoactivatable intermediates that are capable of forming cross-links in the presence of light. Alternatively, reactive water-insoluble matrices such as cyanogen bromide-activated carbohydrates and the reactive substrates described in U.S. Pat. Nos. 3,969,287; 3,691,016; 4,195,128; 4,247,642; 4,229,537; and 4,330,440 are employed for protein immobilization.
Carbohydrate (oligosaccharide) groups may conveniently be attached to sites that are known to be glycosylation sites in proteins. Generally, O-linked oligosaccharides are attached to serine (Ser) or threonine (Thr) residues while N-linked oligosaccharides are attached to asparagine (Asn) residues when they are part of the sequence Asn-X-Ser/Thr, where X can be any amino acid except proline. X is preferably one of the 19 naturally occurring amino acids other than proline. The structures of N-linked and O-linked oligosaccharides and the sugar residues found in each type are different. One type of sugar that is commonly found on both is N-acetylneuraminic acid (referred to as sialic acid). Sialic acid is usually the terminal residue of both N-linked and O-linked oligosaccharides and, by virtue of its negative charge, may confer acidic properties to the glycosylated compound. Such site(s) may be incorporated in the linker of the compounds of this invention and are preferably glycosylated by a cell during recombinant production of the polypeptide compounds (e.g., in mammalian cells such as CHO, BHK, COS). However, such sites may further be glycosylated by synthetic or semi-synthetic procedures known in the art.
Other possible modifications include hydroxylation of proline and lysine, phosphorylation of hydroxyl groups of seryl or threonyl residues, oxidation of the sulfur atom in Cys, methylation of the alpha-amino groups of lysine, arginine, and histidine side chains. Creighton, Proteins: Structure and Molecule Properties (W. H. Freeman & Co., San Francisco), pp. 79-86 (1983).
Compounds of the present invention may be changed at the DNA level, as well. The DNA sequence of any portion of the compound may be changed to codons more compatible with the chosen host cell. For E. coli which is the preferred host cell, optimized codons are known in the art. Codons may be substituted to eliminate restriction sites or to include silent restriction sites, which may aid in processing of the DNA in the selected host cell. The vehicle, linker and peptide DNA sequences may be modified to include any of the foregoing sequence changes.
Methods of Making
The compounds of this invention largely may be made in transformed host cells using recombinant DNA techniques. To do so, a recombinant DNA molecule coding for the peptide is prepared. Methods of preparing such DNA molecules are well known in the art. For instance, sequences coding for the peptides could be excised from DNA using suitable restriction enzymes. Alternatively, the DNA molecule could be synthesized using chemical synthesis techniques, such as the phosphoramidate method. Also, a combination of these techniques could be used.
The invention also includes a vector capable of expressing the peptides in an appropriate host. The vector comprises the DNA molecule that codes for the peptides operatively linked to appropriate expression control sequences. Methods of effecting this operative linking, either before or after the DNA molecule is inserted into the vector, are well known. Expression control sequences include promoters, activators, enhancers, operators, ribosomal binding sites, start signals, stop signals, cap signals, polyadenylation signals, and other signals involved with the control of transcription or translation.
The resulting vector having the DNA molecule thereon is used to transform an appropriate host. This transformation may be performed using methods well known in the art.
Any of a large number of available and well-known host cells may be used in the practice of this invention. The selection of a particular host is dependent upon a number of factors recognized by the art. These include, for example, compatibility with the chosen expression vector, toxicity of the peptides encoded by the DNA molecule, rate of transformation, ease of recovery of the peptides, expression characteristics, bio-safety and costs. A balance of these factors must be struck with the understanding that not all hosts may be equally effective for the expression of a particular DNA sequence. Within these general guidelines, useful microbial hosts include bacteria (such as E. coli sp.), yeast (such as Saccharomyces sp.) and other fungi, insects, plants, mammalian (including human) cells in culture, or other hosts known in the art.
Next, the transformed host is cultured and purified. Host cells may be cultured under conventional fermentation conditions so that the desired compounds are expressed. Such fermentation conditions are well known in the art. Finally, the peptides are purified from culture by methods well known in the art.
The compounds may also be made by synthetic methods. For example, solid phase synthesis techniques may be used. Suitable techniques are well known in the art, and include those described in Merrifield (1973), Chem. Polypeptides , pp. 335-61 (Katsoyannis and Panayotis eds.); Merrifield (1963), J. Am. Chem. Soc. 85: 2149; Davis et al. (1985), Biochem. Intl. 10: 394-414; Stewart and Young (1969), Solid Phase Peptide Synthesis ; U.S. Pat. No. 3,941,763; Finn et al. (1976), The Proteins (3rd ed.) 2: 105-253; and Erickson et al. (1976), The Proteins (3rd ed.) 2: 257-527. Solid phase synthesis is the preferred technique of making individual peptides since it is the most cost-effective method of making small peptides.
Compounds that contain derivatized peptides or which contain non-peptide groups may be synthesized by well-known organic chemistry techniques.
Uses of the Compounds
Compounds of this invention may be particularly useful in treatment of B-cell mediated autoimmune diseases. In particular, the compounds of this invention may be useful in treating, preventing, ameliorating, diagnosing or prognosing lupus, including systemic lupus erythematosus (SLE), and lupus-associated diseases and conditions. Other preferred indications include B-cell mediated cancers, including B-cell lymphoma.
The compounds of this invention can also be used to treat inflammatory conditions of the joints. Inflammatory conditions of a joint are chronic joint diseases that afflict and disable, to varying degrees, millions of people worldwide. Rheumatoid arthritis is a disease of articular joints in which the cartilage and bone are slowly eroded away by a proliferative, invasive connective tissue called pannus, which is derived from the synovial membrane. The disease may involve peri-articular structures such as bursae, tendon sheaths and tendons as well as extra-articular tissues such as the subcutis, cardiovascular system, lungs, spleen, lymph nodes, skeletal muscles, nervous system (central and peripheral) and eyes (Silberberg (1985), Anderson's Pathology, Kissane (ed.), II:1828). Osteoarthritis is a common joint disease characterized by degenerative changes in articular cartilage and reactive proliferation of bone and cartilage around the joint. Osteoarthritis is a cell-mediated active process that may result from the inappropriate response of chondrocytes to catabolic and anabolic stimuli. Changes in some matrix molecules of articular cartilage reportedly occur in early osteoarthritis (Thonar et al. (1993), Rheumatic disease clinics of North America, Moskowitz (ed.), 19:635-657 and Shinmei et al. (1992), Arthritis Rheum., 35:1304-1308). TALL-1, TALL-1R and modulators thereof are believed to be useful in the treatment of these and related conditions.
Compounds of this invention may also be useful in treatment of a number of additional diseases and disorders, including:
acute pancreatitis; ALS; Alzheimer's disease; asthma; atherosclerosis; autoimmune hemolytic anemia; cancer, particularly cancers related to B cells; cachexia/anorexia; chronic fatigue syndrome; cirrhosis (e.g., primary biliary cirrhosis); diabetes (e.g., insulin diabetes); fever; glomerulonephritis, including IgA glomerulonephritis and primary glomerulonephritis; Goodpasture's syndrome; Guillain-Barre syndrome; graft versus host disease; Hashimoto's thyroiditis; hemorrhagic shock; hyperalgesia; inflammatory bowel disease; inflammatory conditions of a joint, including osteoarthritis, psoriatic arthritis and rheumatoid arthritis; inflammatory conditions resulting from strain, sprain, cartilage damage, trauma, orthopedic surgery, infection or other disease processes; insulin-dependent diabetes mellitus; ischemic injury, including cerebral ischemia (e.g., brain injury as a result of trauma, epilepsy, hemorrhage or stroke, each of which may lead to neurodegeneration); learning impairment; lung diseases (e.g., ARDS); multiple myeloma; multiple sclerosis; Myasthenia gravis; myelogenous (e.g., AML and CML) and other leukemias; myopathies (e.g., muscle protein metabolism, esp. in sepsis); neurotoxicity (e.g., as induced by HIV); osteoporosis; pain; Parkinson's disease; Pemphigus; polymyositis/dermatomyositis; pulmonary inflammation, including autoimmune pulmonary inflammation; pre-term labor; psoriasis; Reiter's disease; reperfusion injury; septic shock; side effects from radiation therapy; Sjogren's syndrome; sleep disturbance; temporal mandibular joint disease; thrombocytopenia, including idiopathic thrombocytopenia and autoimmune neonatal thrombocytopenia; tumor metastasis; uveitis; and vasculitis.
Compounds of this invention may be administered alone or in combination with a therapeutically effective amount of other drugs, including analgesic agents, disease-modifying anti-rheumatic drugs (DMARDs), non-steroidal anti-inflammatory drugs (NSAIDs), and any immune and/or inflammatory modulators. Thus, compounds of this invention may be administered with:
Modulators of other members of the TNF/TNF receptor family, including TNF antagonists, such as etanercept (Enbrel™), sTNF-RI, onercept, D2E7, and Remicade™. Nerve growth factor (NGF) modulators. IL-1 inhibitors, including IL-1ra molecules such as anakinra and more recently discovered IL-1ra-like molecules such as IL-1Hy1 and IL-1Hy2; IL-1 “trap” molecules as described in U.S. Pat. No. 5,844,099, issued Dec. 1, 1998; IL-1 antibodies; solubilized IL-1 receptor, and the like. IL-6 inhibitors (e.g., antibodies to IL-6). IL-8 inhibitors (e.g., antibodies to IL-8). IL-18 inhibitors (e.g., IL-18 binding protein, solubilized IL-18 receptor, or IL-18 antibodies). Interleukin-1 converting enzyme (ICE) modulators. insulin-like growth factors (IGF-1, IGF-2) and modulators thereof. Transforming growth factor-β (TGF-β), TGF-β family members, and TGF-β modulators. Fibroblast growth factors FGF-1 to FGF-10, and FGF modulators. Osteoprotegerin (OPG), OPG analogues, osteoprotective agents, and antibodies to OPG-ligand (OPG-L). bone anabolic agents, such as parathyroid hormone (PTH), PTH fragments, and molecules incorporating PTH fragments (e.g., PTH (1-34)-Fc). PAF antagonists. Keratinocyte growth factor (KGF), KGF-related molecules (e.g., KGF-2), and KGF modulators. COX-2 inhibitors, such as Celebrex™ and Vioxx™. Prostaglandin analogs (e.g., E series prostaglandins). Matrix metalloproteinase (MMP) modulators. Nitric oxide synthase (NOS) modulators, including modulators of inducible NOS. Modulators of glucocorticoid receptor. Modulators of glutamate receptor. Modulators of lipopolysaccharide (LPS) levels. Anti-cancer agents, including inhibitors of oncogenes (e.g., fos, jun) and interferons. Noradrenaline and modulators and mimetics thereof.
Pharmaceutical Compositions
In General. The present invention also provides methods of using pharmaceutical compositions of the inventive compounds. Such pharmaceutical compositions may be for administration for injection, or for oral, pulmonary, nasal, transdermal or other forms of administration. In general, the invention encompasses pharmaceutical compositions comprising effective amounts of a compound of the invention together with pharmaceutically acceptable diluents, preservatives, solubilizers, emulsifiers, adjuvants and/or carriers. Such compositions include diluents of various buffer content (e.g., Tris-HCl, acetate, phosphate), pH and ionic strength; additives such as detergents and solubilizing agents (e.g., Tween 80, Polysorbate 80), anti-oxidants (e.g., ascorbic acid, sodium metabisulfite), preservatives (e.g., Thimersol, benzyl alcohol) and bulking substances (e.g., lactose, mannitol); incorporation of the material into particulate preparations of polymeric compounds such as polylactic acid, polyglycolic acid, etc. or into liposomes. Hyaluronic acid may also be used, and this may have the effect of promoting sustained duration in the circulation. Such compositions may influence the physical state, stability, rate of in vivo release, and rate of in vivo clearance of the present proteins and derivatives. See, e.g., Remington's Pharmaceutical Sciences, 18th Ed. (1990, Mack Publishing Co., Easton, Pa. 18042) pages 1435-1712 which are herein incorporated by reference in their entirety. The compositions may be prepared in liquid form, or may be in dried powder, such as lyophilized form. Implantable sustained release formulations are also contemplated, as are transdermal formulations.
Oral dosage forms. Contemplated for use herein are oral solid dosage forms, which are described generally in Chapter 89 of Remington's Pharmaceutical Sciences (1990), 18th Ed., Mack Publishing Co. Easton Pa. 18042, which is herein incorporated by reference in its entirety. Solid dosage forms include tablets, capsules, pills, troches or lozenges, cachets or pellets. Also, liposomal or proteinoid encapsulation may be used to formulate the present compositions (as, for example, proteinoid microspheres reported in U.S. Pat. No. 4,925,673). Liposomal encapsulation may be used and the liposomes may be derivatized with various polymers (e.g., U.S. Pat. No. 5,013,556). A description of possible solid dosage forms for the therapeutic is given in Chapter 10 of Marshall, K., Modern Pharmaceutics (1979), edited by G. S. Banker and C. T. Rhodes, herein incorporated by reference in its entirety. In general, the formulation will include the inventive compound, and inert ingredients which allow for protection against the stomach environment, and release of the biologically active material in the intestine.
Also specifically contemplated are oral dosage forms of the above inventive compounds. If necessary, the compounds may be chemically modified so that oral delivery is efficacious. Generally, the chemical modification contemplated is the attachment of at least one moiety to the compound molecule itself, where said moiety permits (a) inhibition of proteolysis; and (b) uptake into the blood stream from the stomach or intestine. Also desired is the increase in overall stability of the compound and increase in circulation time in the body. Moieties useful as covalently attached vehicles in this invention may also be used for this purpose. Examples of such moieties include: PEG, copolymers of ethylene glycol and propylene glycol, carboxymethyl cellulose, dextran, polyvinyl alcohol, polyvinyl pyrrolidone and polyproline. See, for example, Abuchowski and Davis, Soluble Polymer - Enzyme Adducts, Enzymes as Drugs (1981), Hocenberg and Roberts, eds., Wiley-Interscience, New York, N.Y., pp. 367-83; Newmark, et al. (1982), J. Appl. Biochem. 4:185-9. Other polymers that could be used are poly-1,3-dioxolane and poly-1,3,6-tioxocane. Preferred for pharmaceutical usage, as indicated above, are PEG moieties.
For oral delivery dosage forms, it is also possible to use a salt of a modified aliphatic amino acid, such as sodium N-(8-[2-hydroxybenzoyl]amino) caprylate (SNAC), as a carrier to enhance absorption of the therapeutic compounds of this invention. The clinical efficacy of a heparin formulation using SNAC has been demonstrated in a Phase II trial conducted by Emisphere Technologies. See U.S. Pat. No. 5,792,451, “Oral drug delivery composition and methods”.
The compounds of this invention can be included in the formulation as fine multiparticulates in the form of granules or pellets of particle size about 1 mm. The formulation of the material for capsule administration could also be as a powder, lightly compressed plugs or even as tablets. The therapeutic could be prepared by compression.
Colorants and flavoring agents may all be included. For example, the protein (or derivative) may be formulated (such as by liposome or microsphere encapsulation) and then further contained within an edible product, such as a refrigerated beverage containing colorants and flavoring agents.
One may dilute or increase the volume of the compound of the invention with an inert material. These diluents could include carbohydrates, especially mannitol, α-lactose, anhydrous lactose, cellulose, sucrose, modified dextrans and starch. Certain inorganic salts may also be used as fillers including calcium triphosphate, magnesium carbonate and sodium chloride. Some commercially available diluents are Fast-Flo, Emdex, STA-Rx 1500, Emcompress and Avicell.
Disintegrants may be included in the formulation of the therapeutic into a solid dosage form. Materials used as disintegrants include but are not limited to starch including the commercial disintegrant based on starch, Explotab. Sodium starch glycolate, Amberlite, sodium carboxymethylcellulose, ultramylopectin, sodium alginate, gelatin, orange peel, acid carboxymethyl cellulose, natural sponge and bentonite may all be used. Another form of the disintegrants are the insoluble cationic exchange resins. Powdered gums may be used as disintegrants and as binders and these can include powdered gums such as agar, Karaya or tragacanth. Alginic acid and its sodium salt are also useful as disintegrants.
Binders may be used to hold the therapeutic agent together to form a hard tablet and include materials from natural products such as acacia, tragacanth, starch and gelatin. Others include methyl cellulose (MC), ethyl cellulose (EC) and carboxymethyl cellulose (CMC). Polyvinyl pyrrolidone (PVP) and hydroxypropylmethyl cellulose (HPMC) could both be used in alcoholic solutions to granulate the therapeutic.
An antifrictional agent may be included in the formulation of the therapeutic to prevent sticking during the formulation process. Lubricants may be used as a layer between the therapeutic and the die wall, and these can include but are not limited to; stearic acid including its magnesium and calcium salts, polytetrafluoroethylene (PTFE), liquid paraffin, vegetable oils and waxes. Soluble lubricants may also be used such as sodium lauryl sulfate, magnesium lauryl sulfate, polyethylene glycol of various molecular weights, Carbowax 4000 and 6000.
Glidants that might improve the flow properties of the drug during formulation and to aid rearrangement during compression might be added. The glidants may include starch, talc, pyrogenic silica and hydrated silicoaluminate.
To aid dissolution of the compound of this invention into the aqueous environment a surfactant might be added as a wetting agent. Surfactants may include anionic detergents such as sodium lauryl sulfate, dioctyl sodium sulfosuccinate and dioctyl sodium sulfonate. Cationic detergents might be used and could include benzalkonium chloride or benzethonium chloride. The list of potential nonionic detergents that could be included in the formulation as surfactants are lauromacrogol 400, polyoxyl 40 stearate, polyoxyethylene hydrogenated castor oil 10, 50 and 60, glycerol monostearate, polysorbate 40, 60, 65 and 80, sucrose fatty acid ester, methyl cellulose and carboxymethyl cellulose. These surfactants could be present in the formulation of the protein or derivative either alone or as a mixture in different ratios.
Additives may also be included in the formulation to enhance uptake of the compound. Additives potentially having this property are for instance the fatty acids oleic acid, linoleic acid and linolenic acid.
Controlled release formulation may be desirable. The compound of this invention could be incorporated into an inert matrix which permits release by either diffusion or leaching mechanisms; e.g., gums. Slowly degenerating matrices may also be incorporated into the formulation, e.g., alginates, polysaccharides. Another form of a controlled release of the compounds of this invention is by a method based on the Oros therapeutic system (Alza Corp.), i.e., the drug is enclosed in a semipermeable membrane which allows water to enter and push drug out through a single small opening due to osmotic effects. Some enteric coatings also have a delayed release effect.
Other coatings may be used for the formulation. These include a variety of sugars which could be applied in a coating pan. The therapeutic agent could also be given in a film coated tablet and the materials used in this instance are divided into 2 groups. The first are the nonenteric materials and include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, methylhydroxy-ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl-methyl cellulose, sodium carboxy-methyl cellulose, providone and the polyethylene glycols. The second group consists of the enteric materials that are commonly esters of phthalic acid.
A mix of materials might be used to provide the optimum film coating. Film coating may be carried out in a pan coater or in a fluidized bed or by compression coating.
Pulmonary delivery forms. Also contemplated herein is pulmonary delivery of the present protein (or derivatives thereof). The protein (or derivative) is delivered to the lungs of a mammal while inhaling and traverses across the lung epithelial lining to the blood stream. (Other reports of this include Adjei et al., Pharma. Res . (1990) 7: 565-9; Adjei et al. (1990), Internatl. J. Pharmaceutics 63: 135-44 (leuprolide acetate); Braquet et al. (1989), J. Cardiovasc. Pharmacol. 13 (suppl. 5): s. 143-146 (endothelin-1); Hubbard et al. (1989), Annals Int. Med. 3: 206-12 (α1-antitrypsin); Smith et al. (1989), J. Clin. Invest. 84: 1145-6 (α1-proteinase); Oswein et al. (March 1990), “Aerosolization of Proteins”, Proc. Symp. Resp. Drug Delivery II , Keystone, Colo. (recombinant human growth hormone); Debs et al. (1988), J. Immunol. 140: 3482-8 (interferon-γ and tumor necrosis factor α) and Platz et al., U.S. Pat. No. 5,284,656 (granulocyte colony stimulating factor).
Contemplated for use in the practice of this invention are a wide range of mechanical devices designed for pulmonary delivery of therapeutic products, including but not limited to nebulizers, metered dose inhalers, and powder inhalers, all of which are familiar to those skilled in the art. Some specific examples of commercially available devices suitable for the practice of this invention are the Ultravent nebulizer, manufactured by Mallinckrodt, Inc., St. Louis, Mo.; the Acorn II nebulizer, manufactured by Marquest Medical Products, Englewood, Colo.; the Ventolin metered dose inhaler, manufactured by Glaxo Inc., Research Triangle Park, N.C.; and the Spinhaler powder inhaler, manufactured by Fisons Corp., Bedford, Mass.
All such devices require the use of formulations suitable for the dispensing of the inventive compound. Typically, each formulation is specific to the type of device employed and may involve the use of an appropriate propellant material, in addition to diluents, adjuvants and/or carriers useful in therapy.
The inventive compound should most advantageously be prepared in particulate form with an average particle size of less than 10 μm (or microns), most preferably 0.5 to 5 μm, for most effective delivery to the distal lung.
Pharmaceutically acceptable carriers include carbohydrates such as trehalose, mannitol, xylitol, sucrose, lactose, and sorbitol. Other ingredients for use in formulations may include DPPC, DOPE, DSPC and DOPC. Natural or synthetic surfactants may be used. PEG may be used (even apart from its use in derivatizing the protein or analog). Dextrans, such as cyclodextran, may be used. Bile salts and other related enhancers may be used. Cellulose and cellulose derivatives may be used. Amino acids may be used, such as use in a buffer formulation.
Also, the use of liposomes, microcapsules or microspheres, inclusion complexes, or other types of carriers is contemplated.
Formulations suitable for use with a nebulizer, either jet or ultrasonic, will typically comprise the inventive compound dissolved in water at a concentration of about 0.1 to 25 mg of biologically active protein per mL of solution. The formulation may also include a buffer and a simple sugar (e.g., for protein stabilization and regulation of osmotic pressure). The nebulizer formulation may also contain a surfactant, to reduce or prevent surface induced aggregation of the protein caused by atomization of the solution in forming the aerosol.
Formulations for use with a metered-dose inhaler device will generally comprise a finely divided powder containing the inventive compound suspended in a propellant with the aid of a surfactant. The propellant may be any conventional material employed for this purpose, such as a chlorofluorocarbon, a hydrochlorofluorocarbon, a hydrofluorocarbon, or a hydrocarbon, including trichlorofluoromethane, dichlorodifluoromethane, dichlorotetrafluoroethanol, and 1,1,1,2-tetrafluoroethane, or combinations thereof. Suitable surfactants include sorbitan trioleate and soya lecithin. Oleic acid may also be useful as a surfactant.
Formulations for dispensing from a powder inhaler device will comprise a finely divided dry powder containing the inventive compound and may also include a bulking agent, such as lactose, sorbitol, sucrose, mannitol, trehalose, or xylitol in amounts which facilitate dispersal of the powder from the device, e.g., 50 to 90% by weight of the formulation.
Nasal delivery forms. Nasal delivery of the inventive compound is also contemplated. Nasal delivery allows the passage of the protein to the blood stream directly after administering the therapeutic product to the nose, without the necessity for deposition of the product in the lung. Formulations for nasal delivery include those with dextran or cyclodextran. Delivery via transport across other mucous membranes is also contemplated.
Dosages. The dosage regimen involved in a method for treating the above-described conditions will be determined by the attending physician, considering various factors which modify the action of drugs, e.g. the age, condition, body weight, sex and diet of the patient, the severity of any infection, time of administration and other clinical factors. Generally, the daily regimen should be in the range of 0.1-1000 micrograms of the inventive compound per kilogram of body weight, preferably 0.1-150 micrograms per kilogram.
Specific Preferred Embodiments
The inventors have determined preferred structures for the preferred peptides listed in Table 4 below. The symbol “Λ” may be any of the linkers described herein or may simply represent a normal peptide bond (i.e., so that no linker is present). Tandem repeats and linkers are shown separated by dashes for clarity.
TABLE 4 Preferred embodiments SEQ ID Sequence/structure NO: LPGCKWDLLIKQWVCDPL-Λ-V 1 44 V 1 -Λ-LPGCKWDLLIKQWVCDPL 45 LPGCKWDLLIKQWVCDPL-Λ-LPGCKWDLLIKQWVCDPL-Λ-V 1 46 V 1 -Λ-LPGCKWDLLIKQWVCDPL-Λ-LPGCKWDLLIKQWVCDPL 47 SADCYFDILTKSDVCTSS-Λ-V 1 48 V 1 -Λ-SADCYFDILTKSDVCTSS 49 SADCYFDILTKSDVTSS-Λ-SADCYFDILTKSDVTSS-Λ-V 1 50 V 1 -Λ-SADCYFDILTKSDVTSS-Λ-SADCYFDILTKSDVTSS 51 FHDCKWDLLTKQWVCHGL-Λ-V 1 52 V 1 -Λ-FHDCKWDLLTKQWVCHGL 53 FHDCKWDLLTKQWVCHGL-Λ-FHDCKWDLLTKQWVCHGL-Λ-V 1 54 V 1 -Λ-FHDCKWDLLTKQWVCHGL-Λ-FHDCKWDLLTKQWVCHGL 55
“V 1 ” is an Fc domain as defined previously herein. In addition to those listed in Table 4, the inventors further contemplate heterodimers in which each strand of an Fc dimer is linked to a different peptide sequence; for example, wherein each Fc is linked to a different sequence selected from Table 2.
All of the compounds of this invention can be prepared by methods described in PCT appl. no. WO 99/25044.
The invention will now be further described by the following working examples, which are illustrative rather than limiting.
EXAMPLE 1
Peptides
Peptide Phage Display
1. Magnetic Bead Preparation
A. Fc-TALL-1 Immobilization on Magnetic Beads
The recombinant Fc-TALL-1 protein was immobilized on the Protein A Dynabeads (Dynal) at a concentration of 8 μg of Fc-TALL-1 per 100 μl of the bead stock from the manufacturer. By drawing the beads to one side of a tube using a magnet and pipetting away the liquid, the beads were washed twice with the phosphate buffer saline (PBS) and resuspended in PBS. The Fc-TALL-1 protein was added to the washed beads at the above concentration and incubated with rotation for 1 hour at room temperature. The Fc-TALL-1 coated beads were then blocked by adding bovine serum albumin (BSA) to 1% final concentration and incubating overnight at 4° C. with rotation. The resulting Fc-TALL-1 coated beads were then washed twice with PBST (PBS with 0.05% Tween-20) before being subjected to the selection procedures.
B. Negative Selection Bead Preparation
Additional beads were also prepared for negative selections. For each panning condition, 250 μl of the bead stock from the manufacturer was subjected to the above procedure (section 1A) except that the incubation step with Fc-TALL-1 was omitted. In the last washing step, the beads were divided into five 50 μl aliquots.
2. Selection of TALL-1 Binding Phase
A. Overall Strategy
Two filamentous phage libraries, TN8-IX (5×10 9 independent transformants) and TN12-I (1.4×10 9 independent transformants) (Dyax Corp.), were used to select for TALL-1 binding phage. Each library was subjected to either pH 2 elution or ‘bead elution’ (section 2E). Therefore, four different panning conditions were carried out for the TALL-1 project (TN8-IX using the pH2 elution method, TN8-IX using the bead elution method, TN12-I the using pH2 elution method, and TN12-I using the bead elution method). Three rounds of selection were performed for each condition.
B. Negative Selection
For each panning condition, about 100 random library equivalent (5×10 11 pfu for TN8-IX and 1.4×10 11 pfu for TN12-I) was aliquoted from the library stock and diluted to 300 μl with PBST. After the last washing liquid was drawn out from the first 50 μl aliquot of the beads prepared for negative selections (section 1B), the 300 μl diluted library stock was added to the beads. The resulting mixture was incubated for 10 minutes at room temperature with rotation. The phage supernatant was drawn out using the magnet and added to the second 50 μl aliquot for another negative selection step. In this way, five negative selection steps were performed.
C. Selection Using the Fc-TALL-1 Protein Coated Beads
The phage supernatant after the last negative selection step (section 1B) was added to the Fc-TALL-1 coated beads after the last washing step (section 1A). This mixture was incubated with rotation for two hours at room temperature, allowing specific phage to bind to the target protein. After the supernatant is discarded, the beads were washed seven times with PBST.
D. pH2 Elution of Bound Phage
After the last washing step (section 2C), the bound phages were eluted from the magnetic beads by adding 200 μl of CBST (50 mM sodium citrate, 150 mM sodium chloride, 0.05% Tween-20, pH2). After 5 minute incubation at room temperature, the liquid containing the eluted phage were drawn out and transferred to another tube. The elution step was repeated again by adding 200 μl of CBST and incubating for 5 minutes. The liquids from two elution steps were added together, and 100 μl of 2 M Tris solution (pH 8) was added to neutralize the pH. 500 μl of Min A Salts solution (60 mM K 2 HPO 4 , 33 mM KH 2 PO 4 , 7.6 mM (NH 4 )SO 4 , and 1.7 mM sodium citrate) was added to make the final volume to 1 ml.
E. ‘Bead Elution’
After the final washing liquid was drawn out (section 2C), 1 ml of Min A salts solution was added to the beads. This bead mixture was added directly to a concentrated bacteria sample for infection (section 3A and 3B).
3. Amplification
A. Preparation of Plating Cells
Fresh E. Coli . (XL-1 Blue MRF′) culture was grown to OD 600 =0.5 in LB media containing 12.5 μg/ml tetracycline. For each panning condition, 20 ml of this culture was chilled on ice and centrifuged. The bacteria pellet was resuspended in 1 ml of the Min A Salts solution.
B. Transduction
Each mixture from different elution methods (section 2D and 2E) was added to a concentrated bacteria sample (section 3A) and incubated at 37° C. for 15 minutes. 2 ml of NZCYM media (2XNZCYM, 50 μg/ml ampicillin) was added to each mixture and incubated at room temperature for 15 minutes. The resulting 4 ml solution was plated on a large NZCYM agar plate containing 50 μg/ml ampicillin and incubated overnight at 37° C.
C. Phage Harvesting
Each of the bacteria/phage mixture that was grown overnight on a large NZCYM agar plate (section 3B) was scraped off in 35 ml of LB media, and the agar plate was further rinsed with additional 35 ml of LB media. The resulting bacteria/phage mixture in LB media was centrifuged to pellet the bacteria away. 50 ml the of the phage supernatant was transferred to a fresh tube, and 12.5 ml of PEG solution (20% PEG8000, 3.5M ammonium acetate) was added and incubated on ice for 2 hours to precipitate phages. Precipitated phages were centrifuged down and resuspended in 6 ml of the phage resuspension buffer (250 mM NaCl, 100 mM Tris pH8, 1 mM EDTA). This phage solution was further purified by centrifuging away the remaining bacteria and precipitating the phage for the second time by adding 1.5 ml of the PEG solution. After a centrifugation step, the phage pellet was resuspended in 400 μl of PBS. This solution was subjected to a final centrifugation to rid of remaining bacteria debris. The resulting phage preparation was titered by a standard plaque formation assay (Molecular Cloning, Maniatis et al 3 rd Edition).
4. Two More Rounds of Selection and Amplification.
In the second round, the amplified phage (10 10 pfu) from the first round (section 3C) was used as the input phage to perform the selection and amplification steps (sections 2 and 3). The amplified phage (10 10 pfu) from the 2 nd round in turn was used as the input phage to perform 3 rd round of selection and amplification (sections 2 and 3). After the elution steps (sections 2D and 2E) of the 3 rd round, a small fraction of the eluted phage was plated out as in the plaque formation assay (section 3C). Individual plaques were picked and placed into 96 well microtiter plates containing 100 μl of TE buffer in each well. These master plates were incubated in a 37° C. incubator for 1 hour to allow phages to elute into the TE buffer.
5. Clonal Analysis (Phage ELISA and Sequencing)
The phage clones were analyzed by phage ELISA and sequencing methods. The sequences were ranked based on the combined results from these two assays.
A. Phage ELISA
An XL-1 Blue MRF′ culture was grown until OD 600 reaches 0.5. 30 μl of this culture was aliquoted into each well of a 96 well microtiter plate. 10 μl of eluted phage (section 4) was added to each well and allowed to infect bacteria for 15 min at room temperature. 130 μl of LB media containing 12.5 μg/ml of tetracycline and 50 μg/ml of ampicillin was added to each well. The microtiter plate was then incubated overnight at 37° C. The recombinant TALL-1 protein (1 μg/ml in PBS) was allowed to coat onto the 96-well Maxisorp plates (NUNC) overnight and 4° C. As a control, the recombinant Fc-Trail protein was coated onto a separate Maxisorp plate at the same molar concentration as the TALL-1 protein.
On the following day, liquids in the protein coated Maxisorp plates were discarded, and each well was blocked with 300 μl of 2% BSA solution at 37° C. for one hour. The BSA solution was discarded, and the wells were washed three times with the PBST solution. After the last washing step, 50 μl of PBST was added to each well of the protein coated Maxisorp plates. Each of the 50 μl overnight cultures in the 96 well microtiter plate was transferred to the corresponding wells of the TALL-1 coated plates as well as the control Fc-Trail coated plates. The 100 μl mixtures in the two kinds of plates were incubated for 1 hour at room temperature. The liquid was discarded from the Maxisorp plates, and the wells were washed five times with PBST. The HRP-conjugated anti-M13 antibody (Pharmacia) was diluted to 1:7,500, and 100 μl of the diluted solution was added to each well of the Maxisorp plates for 1 hour incubation at room temperature. The liquid was again discarded and the wells were washed seven times with PBST. 100 μl of tetramethylbenzidine (TMB) substrate (Sigma) was added to each well for the color reaction to develop, and the reaction was stopped with 50 μl of the 5 N H 2 SO 4 solution. The OD 450 was read on a plate reader (Molecular Devices).
B. Sequencing of the Phage Clones.
For each phage clone, the sequencing template was prepared by a PCR method. The following oligonucleotide pair was used to amplify about 500
nucleotide fragment: primer #1 (5′-CGGCGCAACTATCGGTATCAAGCTG-3′) (SEQ ID NO:56) and primer #2 (5′-CATGTACCGTAACACTGAGTTTCGTC-3′). (SEQ ID NO:57)
The following mixture was prepared for each clone.
Reagents
volume (μL)/tube
dH 2 O
26.25
50% glycerol
10
10B PCR Buffer (w/o MgCl 2 )
5
25 mM MgCl 2
4
10 mM dNTP mix
1
100 μM primer 1
0.25
100 μM primer 2
0.25
Taq polymerase
0.25
Phage in TE (section 4)
3
Final reaction volume
50
The thermocycler (GeneAmp PCR System 9700, Applied Biosystems) was used to run the following program: 94° C. for 5 min; [94° C. for 30 sec, 55° C. for 30 sec, 72° C. for 45 sec.]×30 cycles; 72° C. for 7 min; cool to 4° C. The PCR product was checked by running 5 μl of each PCR reaction on a 1% agarose gel. The PCR product in the remaining 45 μl from each reaction was cleaned up using the QIAquick Multiwell PCR Purification kit (Qiagen), following the manufacturer's protocol. The resulting product was then sequenced using the ABI 377 Sequencer (Perkin-Elmer) following the manufacturer recommended protocol.
6. Sequence Ranking and Consensus Sequence Determination
A. Sequence Ranking
The peptide sequences that were translated from variable nucleotide sequences (section 5B) were correlated to ELISA data. The clones that showed high OD 450 in the TALL-1 coated wells and low OD 450 in the Fc-Trail coated wells were considered more important. The sequences that occur multiple times were also considered important. Candidate sequences were chosen based on these criteria for further analysis as peptides or peptibodies. Five and nine candidate peptide sequences were selected from the TN8-IX and TN12-I libraries, respectively.
B. Consensus Sequence Determination
The majority of sequences selected from the TN12-I library contained a very conserved DBL motif. This motif was also observed in sequences selected from the TN8-IB library as well. Another motif, PFPWE (SEQ ID NO: 110) was also observed in sequences obtained from the TN8-IB library.
A consensus peptide, FHDC KWDLLTKOWV CHGL (SEQ ID NO: 58), was designed based on the DBL motif. Since peptides derived from the TN12-I library were the most active ones, the top 26 peptide sequences based on the above ranking criteria (section 5A) were aligned by the DBL motif The underlined “core amino acid sequence” was obtained by determining the amino acid that occur the most in each position. The two cysteines adjacent to the core sequences were fixed amino acids in the TN12-I library. The rest of the amino acid sequence in the consensus peptide is taken from one of the candidate peptides, TALL-1-12-10 (Table 2, SEQ ID NO: 37). The peptide and peptibody that was derived from this consensus sequence were most active in the B cell proliferation assay.
EXAMPLE 2
Peptibodies
A set of 12 TALL-1 inhibitory peptibodies (Table 5) was constructed in which a monomer of each peptide was fused in-frame to the Fc region of human IgG1. Each TALL-1 inhibitory peptibody was constructed by annealing the pairs of oligonucleotides shown in Table 6 to generate a duplex encoding the peptide and a linker comprised of 5 glycine residues and one valine residue as an Nde I to Sal I fragment. These duplex molecules were ligated into a vector (pAMG21-RANK-Fc, described herein) containing the human Fc gene, also digested with Nde I and Sal I. The resulting ligation mixtures were transformed by electroporation into E. coli strain 2596 cells (GM221, described herein). Clones were screened for the ability to produce the recombinant protein product and to possess the gene fusion having the correct nucleotide sequence. A single such clone was selected for each of the peptibodies. The nucleotide and amino acid sequences of the fusion proteins are shown in FIG. 4A through 4F .
TABLE 5
Peptide sequences and oligonucleotides used to generate
TALL-1 inhibitory peptibodies.
Peptibody
Sense
Antisense
SEQ ID
oligo-
oligo-
Peptibody
NO
Peptide Sequence
nucleotide
nucleotide
TALL-1-8-1-a
29
PGTCFPFPWECTHA
2517-24
2517-25
TALL-1-8-2-a
30
WGACWPFPWECFKE
2517-26
2517-27
TALL-1-8-4-a
31
VPFCDLLTKHCFEA
2517-28
2517-29
TALL-1-12-4-a
32
GSRCKYKWDVLTKQCFHH
2517-30
2517-31
TALL-1-12-3-a
33
LPGCKWDLLIKQWVCDPL
2517-32
2517-33
TALL-1-12-5-a
34
SADCYFDILTKSDVCTSS
2517-34
2517-35
TALL-1-12-8-a
35
SDDCMYDQLTRMFICSNL
2517-36
2517-37
TALL-1-12-9-a
36
DLNCKYDELTYKEWCQFN
2521-92
2521-93
TALL-1-12-10-a
37
FHDCKYDLLTRQMVCHGL
2521-94
2521-95
TALL-1-12-11-a
38
RNHCFWDHLLKQDICPSP
2521-96
2521-97
TALL-1-12-14-a
39
ANQCWWDSLTKKNVCEFF
2521-98
2521-99
TALL-1-
58
FHDCKWDLLTKQWVCHGL
2551-48
2551-49
consensus
TABLE 5B
TALL-1 inhibitory peptibodies.
Peptibody
SEQ ID
Peptibody
NO
Peptide Sequence
TALL-1-8-
111
MPGTCFPFPW
ECTHAGGGGG
VDKTHTCPPC
PAPELLGGPS
1-a
VFLFPPKPKD
TLMISRTPEV
TCVVVDVSHE
DPEVKFNWYV
DGVEVHNAKT
KPREEQYNST
YRVVSVLTVL
HQDWLNGKEY
KCKVSNKALP
APIEKTISKA
KGQPREPQVY
TLPPSRDELT
KNQVSLTCLV
KGFYPSDIAV
EWESNGQPEN
NYKTTPPVLD
SDGSFFLYSK
LTVDKSRWQQ
GNVFSCSVMH
EALHNHYTQK
SLSLSPGK
TALL-1-8-
112
MWGACWPFPW
ECFKEGGGGG
VDKTHTCPPC
PAPELLGGPS
2-a
VFLFPPKPKD
TLMISRTPEV
TCVVVDVSHE
DPEVKFNWYV
DGVEVHNAKT
KPREEQYNST
YRVVSVLTVL
HQDWLNGKEY
KCKVSNKALP
APIEKTISKA
KGQPREPQVY
TLPPSRDELT
KNQVSLTCLV
KGFYPSDIAV
EWESNGQPEN
NYKTTPPVLD
SDGSFFLYSK
LTVDKSRWQQ
GNVFSCSVMH
EALHNHYTQK
SLSLSPGK
TALL-1-8-
113
MVPFCDLLTK
HCFEAGGGGG
VDKTHTCPPC
PAPELLGGPS
4-a
VFLFPPKPKD
TLMISRTPEV
TCVVVDVSHE
DPEVKFNWYV
DGVEVHNAKT
KPREEQYNST
YRVVSVLTVL
HQDWLNGKEY
KCKVSNKALP
APIEKTISKA
KGQPREPQVY
TLPPSRDELT
KNQVSLTCLV
KGFYPSDIAV
EWESNGQPEN
NYKTTPPVLD
SDGSFFLYSK
LTVDKSRWQQ
GNVFSCSVMH
EALHNHYTQK
SLSLSPGK
TALL-1-12-
114
MGSRCKYKWD
VLTKQCFHHG
GGGGVDKTHT
CPPCPAPELL
4-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
115
MLPGCKWDLL
IKQWVCDPLG
GGGGVDKTHT
CPPCPAPELL
3-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
116
MSADCYFDIL
TKSDVCTSSG
GGGG VDKTHT
CPPCPAPELL
5-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
117
MSDDCMYDQL
TRMFICSNLG
GGGGVDKTHT
CPPCPAPELL
8-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
118
MDLNCKYDEL
TYKEWCQFNG
GGGGVDKTHT
CPPCPAPELL
9-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
119
MFHDCKYDLL
TRQMVCHGLG
GGGGVDKTHT
CPPCPAPELL
10-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
120
MRNHCFWDHL
LKQDICPSPG
GGGGVDKTHT
CPPCPAPELL
11-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-12-
121
MANQCWWDSL
TKKNVCEFFG
GGGGVDKTHT
CPPCPAPELL
14-a
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1-
122
MFHDCKWDLL
TKQWVCHGLG
GGGGVDKTHT
CPPCPAPELL
consensus
GGPSVFLFPP
KPKDTLMISR
TPEVTCVVVD
VSHEDPEVKF
NWYVDGVEVH
NAKTKPREEQ
YNSTYRVVSV
LTVLHQDWLN
GKEYKCKVSN
KALPAPIEKT
ISKAKGQPRE
PQVYTLPPSR
DELTKNQVSL
TCLVKGFYPS
DIAVEWESNG
QPENNYKTTP
PVLDSDGSFF
LYSKLTVDKS
RWQQGNVFSC
SVMHEALHNH
YTQKSLSLSP
GK
TALL-1 12-
123
MLPGCKWDLL
IKQWVCDPLG
SGSATGGSGS
TASSGSGSAT
3 tandem
HMLPGCKWDL
LIKQWVCDPL
GGGGGVDKTH
TCPPCPAPEL
dimer
LGGPSVFLFP
PKPKDTLMIS
RTPEVTCVVV
DVSHEDPEVK
FNWYVDGVEV
HNAKTKPREE
QYNSTYRVVS
VLTVLHQDWL
NGKEYKCKVS
NKALPAPIEK
TISKAKGQPR
EPQVYTLPPS
RDELTKNQVS
LTCLVKGFYP
SDIAVEWESN
GQPENNYKTT
PPVLDSDGSF
FLYSKLTVDK
SRWQQGNVFS
CSVMHEALHN
HYTQKSLSLS
PGK
TALL-1
124
MFHDCKWDLL
TKQWVCHGLG
SGSATGGSGS
TASSGSGSAT
consensus
HMFHDCKWDL
LTKQWVCHGL
GGGGGVDKTH
TCPPCPAPEL
tandem
LGGPSVFLFP
PKPKDTLMIS
RTPEVTCVVV
DVSHEDPEVK
dimer
FNWYVDGVEV
HNAKTKPREE
QYNSTYRVVS
VLTVLHQDWL
NGKEYKCKVS
NKALPAPIEK
TISKAKGQPR
EPQVYTLPPS
RDELTKNQVS
LTCLVKGFYP
SDIAVEWESN
GQPENNYKTT
PPVLDSDGSF
FLYSKLTVDK
SRWQQGNVFS
CSVMHEALHN
HYTQKSLSLS
PGK
TABLE 6 Sequences of oligonucleotides used in peptibody construction. Oligo- nucleotide SEQ ID ID number NO Sequence 2517-24 71 TAT GCC GGG TAC TTG TTT CCC GTT CCC GTG GGA ATG CAC TCA CGC TGG TGG AGG CGG TGG GG 2517-25 72 TCG ACC CCA CCG CCT CCT GGA GCG TGA GTG CAT TCC CAC GGG AAG CCG AAA CAA GTA CCC GGC A 2517-26 73 TAT GTG GGG TGC TTG TTG GCC GTT CCC GTG GGA ATG TTT CAA AGA AGG TGG AGG CGG TGG GG 2517-27 74 TCG ACC CCA CCG CCT CCA CCT TCT TTG AAA CAT TCC CACGGG AAC GGC CAA CAAGCA CCC CAC A 2517-28 75 TAT GGT TCC GTT CTG TGA CCT GCT GAC TAA ACA CTG TTT CGA AGC TGG TGG AGG CGG TGG GG 2517-29 76 TCG ACC CCA CCG CCT CCA CCA GCT TCG AAA CAG TGT TTA GTC AGC AGG TCA CAGAAC GGA ACC A 2517-30 77 TAT GGG TTC TCG TTG TAA ATA CAA ATG GGA CGT TCT GAC TAA ACA GTG TTT CCA CCA CGG TGG AGG CGG TGG GG 2517-31 78 TCG ACC CCA CCG CCT CCA CCG TGG TGG AAA CAC TGT TTA GTC AGA ACG TCC CAT TTG TAT TTA CAA CGA GAA CCC A 2517-32 79 TAT GCT GCC GGG TTG TAA ATG GGA CCT GCT GAT CAA ACA GTG GGT TTG TGA CCC GCT GGG TGG AGG CGG TGG GG 2517-33 80 TCG ACC CCA CCG CCT CCA CCC AGC GGG TCA CAA ACG CAC TGT TTG ATC AGC AGG TCC CAT TTA CAA CCC GGC AGC A 2517-34 81 TAT GTC TGC TGA CTG TTA CTT CGA CAT CCT GAC TAA ATC TGA CGT TTG TAC TTC TTC TGG TGG AGG CGG TGG GG 2517-35 82 TCG ACC CCA CCG CCT CCA CCA GAA GAA GTA CAA ACG TCA GAT TTA GTC AGG ATG TCG AAG TAA CAG TCA GCA GAC A 2517-36 83 TAT GTC TGA CGA CTG TAT GTA CGA CCA GCT GAC TCG TAT GTT CAT CTG TTC TAA CCT GGG TGG AGG CGG TGG GG 2517-37 84 TCG ACC CCA CCG CCT CCA CCC AGG TTA GAA CAG ATG AAC ATA CGA GTC AGC TGG TCG TAC ATA CAG TCG TCA GAC A 2521-92 85 TAT GGA CCT GAA CTG TAA ATA CGA CGA ACT GAC TTA CAA AGA ATG GTG TCA GTT CAA CGG TGG AGG CGG TGG GG 25221-93 86 TCG ACC CCA CCG CCT CCA CCG TTG AAC TGA CAC CAT TCT TTG TAA GTC AGTTCG TCG TAT TTA CAG TTC AGG TCC A 2521-94 87 TAT GTT CCA CGA CTG TAA ATA CGA CCT GCT GAC TCG TCA GAT GGT TTG TCA CGG TCT GGG TGG AGG CGG TGG GG 2521-95 88 TCG ACC CCA CCG CCT CCA CCC AGA CCG TGA CAA ACC ATC TGA CGA GTC AGC AGG TCG TAT TTA CAG TCG TGG AAC A 2521-96 89 TAT GCG TAA CCA CTG TTT CTG GGA CCA CCT GCT GAA ACA GGA CAT CTG TCC GTC TCC GGG TGG AGG CGG TGG GG 2521-97 90 TCG ACC CCA CCG CCT CCA CCC GGA GAC GGA CAG ATG TCC TGT TTC AGC AGG TGG TCC CAG AAA CAG TGG TTA CGC A 2521-98 91 TAT GGC TAA CCA GTG TTG GTG GGA CTC TCT GCT GAA AAA AAA CGT TTG TGA ATT CTT CGG TGG AGG CGG TGG GG 2521-99 92 TCG ACC CCA CCG CCT CCA CCG AAG AAT TCA CAA ACG TTT TTT TTC AGC AGA GAG TCC CAC CAA CAC TGG TTA GCC A 2551-48 93 TAT GTT CCA CGA CTG CAA ATG GGA CCT GCT GAC CAA ACA GTG GGT TTG CCA CGG TCT GGG TGG AGG CGG TGG GG 2551-49 94 TCG ACC CCA CCG CCT CCA CCC AGA CCG TGG CAA ACC CAC TGT TTG GTC AGC AGG TCC CAT TTG CAG TCG TGG AAC A
pAMG21-RANK-Fc Vector
pAMG21. The expression plasmid pAMG21 (ATCC accession no. 98113) can be derived from the Amgen expression vector pCFM1656 (ATCC #69576) which in turn be derived from the Amgen expression vector system described in U.S. Pat. No. 4,710,473. The pCFM1656 plasmid can be derived from the described pCFM836 plasmid (U.S. Pat. No. 4,710,473) by:
destroying the two endogenous NdeI restriction sites by end filling with T4 polymerase enzyme followed by blunt end ligation; replacing the DNA sequence between the unique Aat II and Cla I restriction sites containing the synthetic P L promoter with a similar fragment obtained from pCFM636 (U.S. Pat. No. 4,710,473) containing the P L promoter (see SEQ ID NO: 95 below); and substituting the small DNA sequence between the unique Cla I and Kpn I restriction sites with the oligonucleotide having the sequence of SEQ ID NO: 96.
SEQ ID NO:95:
Aat II
5′ CTAATTCCGCTCTCACCTACCAAACAATGCCCCCCTGCAAAAAATAAATTCATAT-
3′ TGCAGATTAAGGCGAGAGTGGATGGTTTGTTACGGGGGGACGTTTTTTATTTAAGTATA-
-AAAAAACATAGAGATAACCATCTGGGGTGATAAATTATCTCTGGCGGTGTTGACATAAA-
-TTTTTTGTATGTGTATTGGTAGACGGCACTATTTAATAGAGACCGCCACAACTGTATTT-
-TACCACTGGCGGTGATACTGAGCACAT 3′
-ATGGTGACCGCCACTATGACTCGTGTAGC 5′
ClaI
SEQ ID NO:96:
5′ CGATTTGATTCTAGAAGGAGGAATAACATATGGTTAACGCGTTGGAATTCGGTAC 3′
3′ TAAACTAAGATCTTCCTCCTTATTGTATACCAATTGCGCAACCTTAAGC 5′
Cla I Kpn I
The expression plasmid pAMG21 can then be derived from pCFM1656 by making a series of site-directed base changes by PCR overlapping oligonucleotide mutagenesis and DNA sequence substitutions. Starting with the Bgl II site (plasmid bp # 180) immediately 5′ to the plasmid replication promoter P copB and proceeding toward the plasmid replication genes, the base pair changes are as shown in Table 7 below.
TABLE 7
Base pair changes resulting in pAMG21
pAMG21 bp #
bp in pCFM1656
bp changed to in pAMG21
# 204
T/A
C/G
# 428
A/T
G/C
# 509
G/C
A/T
# 617
—
insert two G/C bp
# 679
G/C
T/A
# 980
T/A
C/G
# 994
G/C
A/T
# 1004
A/T
C/G
# 1007
C/G
T/A
# 1028
A/T
T/A
# 1047
C/G
T/A
# 1178
G/C
T/A
# 1466
G/C
T/A
# 2028
G/C
bp deletion
# 2187
C/G
T/A
# 2480
A/T
T/A
# 2499-2502
AGTG
GTCA
TCAC
CAGT
# 2642
TCCGAGC
7 bp deletion
AGGCTCG
# 3435
G/C
A/T
# 3446
G/C
A/T
# 3643
A/T
T/A
The DNA sequence between the unique Aat II (position #4364 in pCFM1656) and Sac II (position #4585 in pCFM1656) restriction sites is substituted with the DNA sequence below (SEQ ID NO: 97).
[ AatII sticky end] 5′ GCGTAACGTATGCATGGTCTCC-
(position #4358 in pAMG21) 3′ TGCACGCATTGCATACGTACCAGAGG-
-CCATGCGAGAGTAGGGAACTGCCAGGCATCAAATAAAACGAAAGGCTCAGTCGAAAGACT-
-GGTACGCTCTCATCCCTTGACGGTCCGTAGTTTATTTTGCTTTCCGAGTCAGCTTTCTGA-
-GGGCCTTTCGTTTTATCTGTTGTTTGTCGGTGAACGCTCTCCTGAGTAGGACAAATCCGC-
-CCCGGAAAGCAAAATAGACAACAAACAGCCACTTGCGAGAGGACTCATCCTGTTTAGGCG-
-CGGGAGCGGATTTGAACGTTGCGAAGCAACGGCCCGGAGGGTGGCGGGCAGGACGCCCGC-
-GCCCTCGCCTAAACTTGCAACGCTTCGTTGCCGGGCCTCCCACCGCCCGTCCTGCGGGCG-
-CATAAACTGCCAGGCATCAAATTAAGCAGAAGGCCATCCTGACGGATGGCCTTTTTGCGT-
-GTATTTGACGGTCCGTAGTTTAATTCGTCTTCCGGTAGGACTGCCTACCGGAAAAACGCA-
AatII
-TTCTACAAACTCTTTTGTTTATTTTTCTAAATACATTCAAATATGGACGTCGTACTTAAC-
-AAGATGTTTGAGAAAACAAATAAAAAGATTTATGTAAGTTTATACCTGCAGCATGAATTG-
-TTTTAAAGTATGGGCAATCAATTGCTCCTGTTAAAATTGCTTTAGAAATACTTTGGCAGC-
-AAAATTTCATACCCGTTAGTTAACGAGGACAATTTTAACGAAATCTTTATGAAACCGTCG-
-GGTTTGTTGTATTGAGTTTCATTTGCGCATTGGTTAAATGGAAAGTGACCGTGGGCTTAC-
-CCAAACAACATAACTCAAAGTAAACGCGTAACCAATTTACCTTTCACTGGCACGCGAATG-
-TACAGCCTAATATTTTTGAAATATCCCAAGAGCTTTTTCCTTCGCATGCCCACGCTAAAC-
-ATGTCGGATTATAAAAACTTTATAGGGTTCTCGAAAAAGGAAGCGTACGGGTGCGATTTG-
-ATTCTTTTTCTCTTTTGGTTAAATCGTTGTTTGATTTATTATTTGCTATATTTATTTTTC-
-TAAGAAAAAGAGAAAACCAATTTAGCAACAAACTAAATAATAAACGATATAAATAAAAAG-
-GATAATTATCAACTAGAGAAGGAACAATTAATGGTATGTTCATACACGCATGTAAAAATA-
-CTATTAATAGTTGATCTCTTCCTTGTTAATTACCATACAAGTATGTGCGTACATTTTTAT-
-AACTATCTATATAGTTGTCTTTCTCTGAATGTGCAAAACTAAGCATTCCGAAGCCATTAT-
-TTGATAGATATATCAACAGAAAGAGACTTACACGTTTTGATTCGTAAGGCTTCGGTAATA-
-TAGCAGTATGAATAGGGAAACTAAACCCAGTGATAAGACCTGATGATTTCGCTTCTTTAA-
-ATCGTCATACTTATGCCTTTGATTTGGGTCACTATTCTGGACTACTAAAGCGAAGAAATT-
-TTACATTTGGAGATTTTTTATTTACAGCATTGTTTTCAAATATATTCCAATTAATCGGTG-
-AATGTAAACCTCTAAAAAATAAATGTCGTAACAAAAGTTTATATAAGGTTAATTAGCCAC-
-AATGATTGGAGTTAGAATAATCTACTATAGGATCATATTTTATTAAATTAGCGTCATCAT-
-TTACTAACCTCAATCTTATTAGATGATATCCTAGTATAAAATAATTTAATCGCAGTAGTA-
-AATATTGCCTCCATTTTTTAGGGTAATTATCCAGAATTGAAATATCAGATTTAACCATAG-
-TTATAACGGAGGTAAAAAATCCCATTAATAGGTCTTAACTTTATAGTCTAAATTGGTATC-
-AATGAGGATAAATGATCGCGAGTAAATAATATTCACAATGTACCATTTTAGTCATATCAG-
-TTACTCCTATTTACTAGCGCTCATTTATTATAAGTGTTACATGGTAAAATCAGTATAGTC-
-ATAAGCATTGATTAATATCATTATTGCTTCTACAGGCTTTAATTTTATTAATTATTCTGT-
-TATTCGTAACTAATTATAGTAATAACGAAGATGTCCGAAATTAAAATAATTAATAAGACA-
-AAGTGTCGTCGGCATTTATGTCTTTCATACCCATCTCTTTATCCTTACCTATTGTTTGTC-
-TTCACAGCAGCCGTAAATACAGAAAGTATGGGTAGAGAAATAGCAATGGATAACAAACAG-
-GCAAGTTTTGCGTGTTATATATCATTAAAACGGTAATAGATTGACATTTGATTCTAATAA-
-CGTTCAAAACGCACAATATATAGTAATTTTGCCATTATCTAACTGTAAACTAAGATTATT-
-ATTGGATTTTTGTCACACTATTATATCGCTTGAAATACAATTGTTTAACATAAGTACCTG-
-TAACCTAAAAACAGTGTGATAATATAGCGAACTTTATGTTAACAAATTGTATTCATGGAC-
-TAGGATCGTACAGGTTTACGCAAGAAAATGGTTTGTTATAGTCGATTAATCGATTTGATT-
-ATCCTAGCATGTCCAAATGCGTTCTTTTACCAAACAATATCAGCTAATTAGCTAAACTAA-
-CTAGATTTGTTTTAACTAATTAAAGGAGGAATAACATATGGTTAACGCGTTGGAATTCGA-
-GATCTAAACAAAATTGATTAATTTCCTCCTTATTCTATACCAATTGCGCAACCTTAAGCT-
SacII
-GCTCACTAGTGTCGACCTGCAGGGTACCATGGAAGCTTACTCGAGGATCCGCGGAAAGAA-
-CGAGTGATCACAGCTGGACGTCCCATGGTACCTTCGAATGAGCTCCTAGGCGCCTTTCTT-
-GAAGAAGAAGAAGAAAGCCCGAAAGGAAGCTGAGTTGGCTGCTGCCACCGCTCAGCAATA-
-CTTCTTCTTCTTCTTTCCGGCTTTCCTTCGACTCAACCGACGACGGTGGCGACTCGTTAT-
-ACTAGCATAACCCCTTGGGGCCTCTAAACGGGTCTTGAGGGGTTTTTTGCTGAAAGGAGG-
-TGATCGTATTGGGGAACCCCGGAGATTTGCCCAGAACTCCCCAAAAAACGACTTTCCTCC-
-AACCGCTCTTCACGCTCTTCACGC 3′ [ SacII sticky end]
-TTGGCGAGAAGTGCGAGAAGTG 5′ (position #5904 in pAMG21)
During the ligation of the sticky ends of this substitution DNA sequence, the outside Aat II and Sac II sites are destroyed. There are unique Aat II and Sac II sites in the substituted DNA.
A gene encoding human RANK fused to the N-terminus of Fc was ligated into pAMG21 as an Nde I to Bam HI fragment to generate Amgen Strain #4125. This construct was modified to insert a valine codon at the junction of RANK and Fc. The adjacent valine and aspartate codons create a unique Sal I site. This allows for the fusion of peptides at the N-terminus of Fc3 between the unique Nde I and Sal I sites. The RANK sequence is deleted upon insertion of a new Nde I- Sal I fragment. The sequence of the vector is given in FIG. 5A through 5M .
GM221 (Amgen #2596). The Amgen host strain #2596 is an E. coli K-12 strain derived from Amgen strain #393, which is a derivative of E. coli W1485, obtained from the E. coli Genetic Stock Center, Yale University, New Haven, Conn. (CGSC strain 6159). It has been modified to contain both the temperature sensitive lambda repressor cI857s7 in the early ebg region and the lacI Q repressor in the late ebg region (68 minutes). The presence of these two repressor genes allows the use of this host with a variety of expression systems, however both of these repressors are irrelevant to the expression from luxP R . The untransformed host has no antibiotic resistances.
The ribosome binding site of the cI857s7 gene has been modified to include an enhanced RBS. It has been inserted into the ebg operon between nucleotide position 1170 and 1411 as numbered in Genbank accession number M64441Gb_Ba with deletion of the intervening ebg sequence. The sequence of the insert is shown below with lower case letters representing the ebg sequences flanking the insert shown below (SEQ ID NO: 98):
ttattttcgtGCGGCCGCACCATTATCACCGCCAGAGGTAAACTAGTCAA
CACGCACGGTGTTAGATATTTATCCCTTGCGGTGATAGATTGAGCACATC
GATTTGATTCTAGAAGGAGGGATAATATATGAGCACAAAAAAGAAACCAT
TAACACAAGAGCAGCTTGAGGACGCACGTCGCCTTAAAGCAATTTATGAA
AAAAAGAAAAATGAACTTGGCTTATCCCAGGAATCTGTCGCAGACAAGAT
GGGGATGGGGCAGTCAGGCGTTGGTGCTTTATTTAATGGCATCAATGCAT
TAAATGCTTATAACGCCGCATTGCTTACAAAAATTCTCAAAGTTAGCGTT
GAAGAATTTAGCCCTTCAATCGCCAGAGAATCTACGAGATGTATGAAGCG
GTTAGTATGCAGCCGTCACTTAGAAGTGAGTATGAGTACCCTGTTTTTTC
TCATGTTCAGGCAGGGATGTTCTCACCTAAGCTTAGAACCTTTACCAAAG
GTGATGCGGAGAGATGGGTAAGCACAACCAAAAAAGCCAGTGATTCTGCA
TTCTGGCTTGAGGTTGAAGGTAATTCCATGACCGCACCAACAGGCTCCAA
GCCAAGCTTTCCTGACGGAATGTTAATTCTCGTTGACCCTGAGCAGGCTG
TTGAGCCAGGTGATTTCTGCATAGCCAGACTTGGGGGTGATGAGTTTACC
TTCAAGAAACTGATCAGGGATAGCGGTCAGGTGTTTTTACAACCACTAAA
CCCACAGTACCCAATGATCCCATGCAATGAGAGTTGTTCCGTTGTGGGGA
AAGTTATCGCTAGTCAGTGGCCTGAAGAGACGTTTGGCTGATAGACTAGT
GGATCCACTAGTgtttctgccc
The construct was delivered to the chromosome using a recombinant phage called MMebg-cI857s7 enhanced RBS #4 into F′tet/393. After recombination and resolution only the chromosomal insert described above remains in the cell. It was renamed F′tet/GM101. F′tet/GM101 was then modified by the delivery of a lacI Q construct into the ebg operon between nucleotide position 2493 and 2937 as numbered in the Genbank accession number M64441Gb_Ba with the deletion of the intervening ebg sequence. The sequence of the insert is shown below with the lower case letters representing the ebg sequences flanking the insert (SEQ ID NO: 99) shown below:
ggcggaaaccGACGTCGATCGAATGGTGCAAAACCTTTCGCGGTATGGCA
TGATAGCGCCCGGAAGAGAGTCAATTCAGGGTGGTGAATGTGAAACCAGT
AACGTTATACGATGTCGCAGAGTATGCCGGTGTCTCTTATCAGACCGTTT
CCCGCGTGGTGAACCAGGCCAGCCACGTTTCTGCGAAAACGCGGGAAAAA
GTCGAAGCGGCGATGGCGGAGCTGAATTACATTCCCAACCGCGTGGCAGA
ACAACTGGCGGGCAAACAGTCGCTCGTGATTGGCGTTGCCACCTCCAGTC
TGGCCCTGCACGCGCCGTCGCAAATTGTCGCGGCGATTAAATCTCGCGCC
GATCAACTGGGTGCCAGCGTGGTGGTGTCGATGGTAGAACGAAGCGGCGT
CGAAGCCTGTAAAGCGGCGGTGCACAATCTTCTCGCGCAACGCGTCAGTG
GGGCTGATCATTAACTATCCGCTGGATGACCAGGATGCCATTGCTGTGGA
AGCTGCCTGCAGTAATGTTCCGGCGTTATTTCTTGATGTCTGTGACCAGA
CACGCATCAACAGTATTATTTTCTCCCATGAAGACGGTACGCGACTGGGC
GTGGAGCATCTGGTCGCATTGGGTCAGCAGCAAATCGCGCTGTTAGCGGG
CCCATTAAGTTCTGTCTCGGCGCGTCTGCGTCTGGCTGGCTGGCATAAAT
ATCTCACTCGCAATCAAATTCAGCCGATAGCGGAACGGGAAGGCGACTGG
AGTGGCATGTCCGGTTTTCAACAAACCATGCAAATGCTGAATGAGGGCAT
CGTTCCCACTGCGATGCTGGTTGCCAACGATCAGATGGCGCTGGGCGCAA
TGCGCGCCATTACCGAGTCCGGGCTGCGCGTTGGTGCGGATATCTCGGTA
GTGGGATACGACGATACCGAAGACAGCTCATGTTATATGCCGCCGTTAAG
CACCATCAAACAGGATTTCGCCTGCTGGGGCAAACCAGCGTGGACCGCTT
GCTGCAACTCTCTCAGGGCCAGGGGGTGAAGGGCAATCAGCTGTTGCCCG
TCTCACTGGTGAAAAGAAAAACCACCCTGGCGCCCAATACGCAAACCGCG
TCTCCCCGCGCGTTGGCCGATTCATTAATGCAGCTGGCACGACAGGTTTC
CGGACTGGAAAGCGGACAGTAAGGTACCATAGGATGCaggcacagga
The construct was delivered to the chromosome using a recombinant phage called AGebg-LacIQ#5 into F′tet/GM101. After recombination and resolution only the chromosomal insert described above remains in the cell. It was renamed F′tet/GM221. The F′tet episome was cured from the strain using acridine orange at a concentration of 25 μg/ml in LB. The cured strain was identified as tetracyline sensitive and was stored as GM221.
Expression in E. coli . Cultures of each of the pAMG21-Fc-fusion constructs in E. coli GM221 were grown at 37° C. in Luria Broth medium. Induction of gene product expression from the luxPR promoter was achieved following the addition of the synthetic autoinducer N-(3-oxohexanoyl)-DL-homoserine lactone to the culture media to a final concentration of 20 ng/ml. Cultures were incubated at 37° C. for a further 3 hours. After 3 hours, the bacterial cultures were examined by microscopy for the presence of inclusion bodies and were then collected by centrifugation. Refractile inclusion bodies were observed in induced cultures indicating that the Fc-fusions were most likely produced in the insoluble fraction in E. coli . Cell pellets were lysed directly by resuspension in Laemmli sample buffer containing 10% β-mercaptoethanol and were analyzed by SDS-PAGE. In each case, an intense Coomassie-stained band of the appropriate molecular weight was observed on an SDS-PAGE gel.
EXAMPLE 3
TALL-1 Peptibody Inhibits TALL-1 Mediated B Cell Proliferation
Mouse B lymphocytes were isolated from C57BL/6 spleens by negative selection. (MACS CD43 (Ly-48) Microbeads, Miltenyi Biotech, Auburn, Calif.). Purified (10 5 ) B cells were cultured in MEM, 10% heat inactivated FCS, 5×10 −5 M 2-mercaptoethanol, 100 U/ml penicillin, 100 μg/ml streptomycin) in triplicate in 96-well flat bottom tissue culture plates with 10 ng/ml TALL-1 protein and 2 μg/ml of Goat F(ab′) 2 anti-mouse IgM (Jackson ImmunoResearch Laboratory, West Grove, Pa.) with the indicated amount of recombinant TALL-1 peptibody for a period of 4 days at 37° C., 5% CO 2 . Proliferation was measured by the uptake of radioactive 3 [H] thymidine after an 18-hour incubation period.
EXAMPLE 4
TALL-1 Peptibody Blocks TALL-1 Binding to its Receptors
Reacti-Gel 6x (Pierce) were pre-coated with human AGP3 (also known as TALL-1, Khare et al., Proc. Natl. Acad. Sci. 97:3370-3375, 2000) and blocked with BSA. 100 pM and 40 pM of AGP3 peptibody samples were incubated with indicated various concentrations of human AGP3 at room temperature for 8 hours before run through the human AGP3-coated beads. The amount of the bead-bound peptibody was quantified by fluorescent (Cy5) labeled goat anti-human-Fc antibody (Jackson Immuno Research). The binding signal is proportional to the concentration of free peptibody at binding equilibrium. Dissociation equilibrium constant (K D ) was obtained from nonlinear regression of the competition curves using a dual-curve one-site homogeneous binding model (KinEx™ software). K D is about 4 pM for AGP3 peptibody (SEQ ID NO: 123) binding with human AGP3 ( FIG. 9 ).
To determine if this AGP3 peptibody can neutralize murine AGP3 binding as well as human AGP3, a BIAcore neutralizing assay was utilized. All experiments were performed on a BIAcore 3000 at room temperature. Human TACI-Fc protein (Xia et al, J. Exp. Med. 192, 137-144, 2000) was immobilized to a B1 chip using 10 mM Acetate pH 4.0 to a level of 2900RU. A blank flow cell was used as a background control. Using a running buffer of PBS (without calcium or magnesium) containing 0.005% P20, 1 nM recombinant human AGP3 (in running buffer plus, 0.1 mg/ml BSA) was incubated without and with indicated various amount of AGP3 peptibody (x axis) before injected over the surface of the receptor. Regeneration was performed using 8 mM glycine pH 1.5 for 1 minute, 25 mM 3-[cyclohexylamino]-1-propanesulfonic acid (CAPS) pH 10.5, 1 M NaCl for 1 minute. For determination of murine AGP3 binding, human his-tagged TACI was immobilized to 1000 RU in the above buffer. 5 nM recombinant murine AGP3 (in running buffer plus, 0.1 mg/ml BSA) was incubated without and with the various amounts indicated in FIG. 11 of AGP3 peptibody (x axis) before injected over the surface of the receptor. Regeneration was performed with 10 mM HCl pH2, twice for 30 seconds. Relative binding of both human and murine AGP3 at presence vs absence of AGP3 peptibody (SEQ ID NO: 123) was measured (y axis). Relative binding response was determined as (RU-RU blank/RUo-RU blank). The AGP3 peptibody (SEQ ID NO: 123) inhibited both human and murine AGP3 binding to its receptor TACI ( FIGS. 10A and 10B ). To examine if this AGP3 peptibody blocks AGP3 binding to all three receptors (TACI, BCMA and BAFFR), recombinant soluble receptor TACI, BCMA and BAFFR proteins were immobilized to CM5 chip. Using 10 mM acetate, pH4, human TACI-Fc was immobilized to 6300 RU, human BCMA-Fc to 5000 RU, and BAFFR-Fc to 6000 RU. 1 nM of recombinant human AGP3 (in running buffer containing 0.1 mg/ml BSA and 0.1 mg/ml Heparin) or 1 nM recombinant APRIL protein (Yu, et al., Nat. Immunol., 1:252-256, 2000) were incubated with indicated amount of AGP3 peptibody before injection over each receptor surface. Regeneration for the AGP3 experiment was done with 8 mM glycine, pH 1.5, for 1 minute, followed by 25 mM CAPS, pH 10.5, 1M NaCl for 1 minute. Regeneration for the APRIL experiment was performed with 8 mM glycine, pH 2, for one minute, followed by 25 mM CAPS, pH 10.5, 1 M NaCl for one minute. Relative binding of AGP3 or APRIL was measured. AGP3 peptibody (SEQ ID NO: 123) blocked AGP3 binding to all three receptors ( FIG. 11A ). AGP3 peptibody didn't affect APRIL binding to the receptors ( FIG. 11B ).
EXAMPLE 5
AGP3 Peptibody Blocks AGP3 Mediated B Cell Proliferation
Mouse B lymphocytes were isolated from C57BL/6 spleens by negative selection. (MACS CD43 (Ly-48) Microbeads, Miltenyi Biotech, Auburn, Calif.). Purified (10 5 ) B cells were cultured in minimal essential medium (MEM), 10% heat inactivated fetal calf serum (FCS), 5×10 −5 M 2-mercaptoethanol, 100 U/ml penicillin, 100 μg/ml streptomycin) in triplicate in 96-well flat bottom tissue culture plates with 10 ng/ml AGP3 (TALL-1) protein and 2 μg/ml of Goat F(ab′) 2 anti-mouse IgM (Jackson ImmunoResearch Laboratory, West Grove, Pa.) with the indicated amount of recombinant AGP3 peptibody (SEQ ID NO: 123) for a period of 4 days at 37° C., 5% CO 2 . Proliferation was measured by the uptake of radioactive 3 [H] thymidine after an 18-hour incubation period.
EXAMPLE 6
AGP3 Peptibody on AGP3-Stimulated Ig Production in Mice
Mice (Balb/c females of 9-14 weeks of age and 19-21 g of weight) were purchased from Charles River Laboratories, Wilmington, Mass. Mice (n=10) were treated i.p. with 1 mg/Kg of human AGP3 once a day for five consecutive days followed by 5 mg/Kg or 0.5 mg/Kg of AGP3 peptibody (SEQ ID NO: 123) or by saline or by 5 mg/Kg of human Fc. Other mice were left untreated. Mice were sacrificed on the sixth day to measure serum IgM and IgA, which were measured by ELISA. Briefly, plates were coated with capture antibodies specific for IgM or IgA (Southern Biotechnology Associates, Birmingham, Ala.), blocked, and added with dilutions of standard (IgM from Calbiochem, San Diego, Calif. and IgA from Southern Biotechnology Associates) or test samples. Captured Ig were revealed using biotinylated antibodies specific for IgM or IgA (Southern Biotechnology Associates), neutravidin-conjugated peroxidase (Pierce, Rockford, Ill.), and tetramethylbenzidine (TMB) microwell peroxidase substrate (KPL, Gaithersburg, Md.). Optical densities were quantitated in a Thermomax ELISA reader (Molecular Devices, Menlo Park, Calif.).
Human AGP3-stimulated increase in serum levels of IgM and IgA was blocked by 5 mg/Kg of the anti-AGP3 peptibody (SEQ ID NO: 123) and not by 0.5 mg/Kg ( FIGS. 12A and 12B ).
EXAMPLE 7
AGP3 Peptibody Reduced Spleen B Cell Number in Mice
Mice (as above, n=7) were treated i.p. for seven consecutive days with 5 mg/Kg or 1.5 mg/Kg or 0.5 mg/Kg of AGP3 peptibody (SEQ ID NO: 123) or with saline or with 5 mg/Kg of human Fc. Mice were sacrificed on the eighth day to count spleen B cell number. Spleens were collected in saline and gently disrupted by manual homogenization to yield a cell suspension. The total cell number was obtained with a H1E counter (Technicon, Tarrytown, N.Y.). Percentages of B cells were derived by immunofluorescence double staining and flow cytometry using fluorescein isothiocyanate (FITC)-conjugated and phycoerythrin (PE)-conjugated Ab against CD3 and B220, respectively (PharMingen, San Diego, Calif.) and a FACScan analyser (Becton and Dickinson, Mountain View, Calif.). B cells were identified for being CD3-B220+. At all doses, the AGP3 peptibody (SEQ ID NO: 123) decreased spleen B cell number in a dose-response fashion ( FIGS. 12A and 12B ) (SEQ ID NO: 123).
TABLE 8
AGP3 Pb Reduces B Cell Number in Normal Mice
spleen B cell
n = 7
dose (1/day × 7)
(1 × 10e6)
SD
t test
saline
51.3
9.6
Fc
5 mg/Kg
45.5
7.1
Peptibody
5 mg/Kg
20.1
3.8
1.37856E−05
1.5 mg/Kg
22.6
6.9
5.10194E−05
0.5 mg/Kg
25.8
3.6
0.000111409
EXAMPLE 8
AGP3 Peptibody Reduced Arthritis Severity in Mouse CIA Model
Eight to 12 week old DBA/1 mice (obtained from Jackson Laboratories, Bar Harbor, Me.) were immunized with bovine collagen type II (bCII) (purchased from University of Utah), emulsified in complete Freunds adjuvant (Difco) intradermally at the base of tail. Each injection was 100 μl containing 100 μg of bCII. Mice were boosted 3 weeks after the initial immunization with bCII emulsified in incomplete Freunds adjuvant. Treatment was begun from the day of booster immunization for 4 weeks. Mice were examined for the development of arthritis. As described before (Khare et al., J. Immunol. 155: 3653-9, 1995), all four paws were individually scored from 0-3. Therefore arthritis severity could vary from 0 to 12 for each animal. AGP3 (SEQ ID NO: 123) peptibody treatment significantly reduced the severity of arthritic scores ( FIG. 13 ).
Serum samples were taken one week after final treatment (day 35) for the analysis of anti-collagen antibody level. High binding ELISA plates (Immulon, Nunc) were coated with 50 μl of 4 μg/ml solution of bovine CII in carbonate buffer and plated were kept in cold overnight in the refrigerator. Plates were washed three times with cold water. 75 μl of blocking solution made up of PBS/0.05% tween 20/1% BSA was used to block non-specific binding for an hour. Samples were diluted (in blocking buffer) in dilution plates at 1:25, 1:100, 1:400, and 1:1600 and 25 μl of these samples were added to each well of the ELISA plate for a final dilution of 100, 400, 1600, and 6400 with a final volume of 100 μl/well. After incubation at room temperature for 3 hours, plates were washed three times again. 100 μl of secondary antibody diluted in blocking buffer (rat anti-mouse IgM, IgG2a, IgG2b, IgG1, IgG3-HRP) was added to each well and plates were incubated for at least 2 hours. Plates were washed four times. 100 μl of TMB solution (Sigma) was added to each well and the reaction was stopped using 50 μl of 25% sulfuric acid. Plates were read using an ELISA plate reader at 450 nm. OD was compared with a standard pool representing units/ml. AGP3 peptibody (SEQ ID NO: 123) treatment reduced serum anti-collagen II IgG1, IgG3, IgG2a, and IgG2b levels compared to PBS or Fc control treatment groups ( FIG. 14 ).
EXAMPLE 9
Treatment of AGP3 Peptibody in NZB/NZW Lupus Mice
Five month old lupus prone NZBx NZBWF1 mice were treated i.p. 3×/week for 8 weeks with PBS or indicated doses of AGP3 peptibody or human Fc proteins. Prior to the treatment, animals were pre-screened for protein in the urine with Albustix reagents strips (Bayer AG). Mice having greater than 100 mg/dl of protein in the urine were not included in the study. Protein in the urine was evaluated monthly throughout the life of the experiment. AGP3 peptibody (SEQ ID NO: 123) treatment led to delay of proteinuria onset and improved survival ( FIGS. 15A and 15B ).
AGP3 peptibody treatment reduced B cell number in mice. Balb/c mice received 7 daily intraperitoneal injections of indicated amount of AGP3 peptibody (SEQ ID NO: 123) or human Fc protein. On day 8, spleens were collected, and subject to FACS analysis for B220+B cells as set for in Table 8.
TABLE 8
AGP3 Pb Reduces B Cell Number in Normal Mice
Spleen B cell
n = 7
dose (1/day × 7)
(1 × 10e6)
SD
t test
saline
51.3
9.6
Fc
5 mg/Kg
45.5
7.1
Peptibody
5 mg/Kg
20.1
3.8
1.37856E−05
1.5 mg/Kg
22.6
6.9
5.10194E−05
0.5 mg/Kg
25.8
3.6
0.000111409
The invention now being fully described, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto, without departing from the spirit and scope of the invention as set forth herein. | The present invention concerns therapeutic agents that modulate the activity of TALL-1. In accordance with the present invention, modulators of TALL-1 may comprise an amino acid sequence Dz 2 Lz 4 wherein z 2 is an amino acid residue and z 4 is threonyl or isoleucyl. Exemplary molecules comprise a sequence of the formulae
(SEQ. ID. NO:100) a 1 a 2 a 3 CDa 6 La 8 a 9 a 10 Ca 12 a 13 a 14 , (SEQ. ID. NO:104) b 1 b 2 b 3 Cb 5 b 6 Db 8 Lb 10 b 11 b 12 b 13 b 14 Cb 16 b 17 b 18 (SEQ. ID. NO:105) c 1 c 2 c 3 Cc 5 Dc 7 Lc 9 c 10 c 11 c 12 c 13 c 14 Cc 16 c 17 c 18 (SEQ. ID. NO:106) d 1 d 2 d 3 Cd 5 d 6 d 7 WDd 10 Ld 13 d 14 d 15 Cd 16 d 17 d 18 (SEQ. ID. NO:107) e 1 e 2 e 3 Ce 5 e 6 e 7 De 9 Le 11 Ke 13 Ce 15 e 16 e 17 e 18 (SEQ. ID NO:109) f 1 f 2 f 3 Kf 5 Df 7 Lf 9 f 10 Qf 12 f 13 f 14
wherein the substituents are as defined in the specification. The invention further comprises compositions of matter of the formula
(X 1 ) a —V 1 —(X 2 ) b
wherein V 1 is a vehicle that is covalently attached to one or more of the above TALL-1 modulating compositions of matter. The vehicle and the TALL-1 modulating composition of matter may be linked through the N- or C-terminus of the TALL-1 modulating portion. The preferred vehicle is an Fc domain, and the preferred Fc domain is an IgG Fc domain. | 2 |
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Applications No. 60/515,373, filed Oct. 29, 2003.
FIELD OF THE INVENTION
[0002] The invention relates to the use of carrier fiber for the assembly of autologous tissue structures for implantation in a patient's body, and more particularly to a process and machine for making two and three dimensional implantable structures of carrier fiber and autologous tissue.
BACKGROUND OF INVENTION
[0003] The development of tissue engineered structures for surgical implantation has involved the assembly of various materials types. The common theme in this work has been the use of Glutaraldehyde fixed materials from bovine or porcine sources. The use of autologous cultured cells grown on scaffolds has been attempted with very limited success. The manufacturers manipulate this fixed tissue to form heart valves and other implantable grafts. Surgical techniques of cutting and stitching of sheets of fixed tissue material are now common. Fixed tissue structures of the animal or donor source such as a heart valve are used without modification of their shape.
[0004] The fields of plastic surgery and heart by-pass coronary surgery have used autologous tissue as a source for surgical procedures. In these cases, the autologous tissue is again manipulated using surgical methods. The saphonis vein is used for bypass because a vessel is required. In all this work on autologous tissue, if a three dimensional shape is required it must be harvested from the body or fabricated from fixed tissue or synthetic materials such as polyester.
SUMMARY OF THE INVENTION
[0005] In this invention, carrier fiber is used to facilitate the assembly of two and three dimensional structures with autologous tissue. Autologous tissue is harvested from the donor and assembled into complex forms rapidly. The tissue is kept live and viable during extracorporeal assembly and is replaced in the donors body. The use of carrier fiber facilitates this rapid assembly of the two and three dimensional structures. The autologous tissue is modified into thin long sections and is integrated with the carrier fiber. Carrier fiber of various types are used to facilitate the assembly process. The use of twisting, spinning, weaving, knitting, and braiding assembly processes to integrate the carrier fiber and the autologous tissue strips is made practical for assembly into structures by using long pre-threaded carrier yarn leaders for machine set up, in order to draw the autologous tissue into the assembly process when ready. In this way, the limited quantity of autologous tissue is not wasted in the set up and thread-up of the assembly equipment. The finished autologous structures allow for complete healing in the patients body. The carrier fiber of the tissue/fiber composite structure is either bio-absorbed or forms a bio-compatible substructure for the patient's native tissue as healing progresses.
[0006] It is therefore an objective of the invention to provide a process by which autologous or other tissue that has been harvested or otherwise produced, can be processed, and assembled into two and three dimensional structures suitable for medical implantation as a tissue-based scaffold to support the growth or regrowth of native tissue.
[0007] It is a further objective to provide a machine by which such a process may be conducted.
BRIEF DESCRIPTION OF THE FIGURES
[0008] FIG. 1 is a simplified flow chart of a preferred embodiment of the invention.
[0009] FIG. 2 is a diagrammatic illustration of a ply twisting operation for integrating tissue yarn with a carrier fiber.
[0010] FIG. 3 is a diagrammatic illustration of a braiding operation for integrating tissue yarn with a carrier fiber.
[0011] FIG. 4 is a diagrammatic illustration of weaving a fabric tube with tissue yarn in the fill and carrier fiber in the warp.
DESCRIPTION OF PREFERRED EMBODIMENT
[0012] The invention is susceptible of many embodiments. What is explained here are preferred embodiments and best mode for practicing the invention, and should be construed as illustrative and not limiting of the invention.
[0013] While preferred embodiments presume the tissue to be autologous tissue being used for assembly into useful fiber/tissue structures for surgical implantation in the donor's own body; the description and claims extend to the use of any living or synthetic tissue or tissue precursor in the process of the invention, whether naturally occurring or cultivated in an alternate fashion, whether harvested from the recipient or from another natural or cultivated source.
Selection of Carrier Fiber
[0014] The preferred carrier fiber or yarn (CF) system is of small denier in the 10 to 300 range. In many situations, it is desirable for the carrier fiber to be absorbable in the body. Poly Glycolic Acid (PGA) and Poly Lactic Acid (PLA fibers has been used extensively in suture yarns and have well known bio-absorption characteristics. The PGA/LGA fiber also have tensile and modulus characteristics that are biocompatible based on its experience base from use in surgical sutures.
[0015] In addition to the use of bio-absorbable fiber, the use of fixed animal fiber is also an option. Also materials such as those based on various collagen types have application to the invention. The relative value of carrier fiber types is dependent on the interaction with healing mechanisms in the body. In addition to the type of stresses, the time frame for healing will suggest the optimum carrier fiber type for use in a structure. In some case the use of synthetic fibers like polyester may be indicated.
Autologous Tissue Processing
[0016] The harvesting of Autologous Tissue (AT) and manufacturing of AT yarn or tape (ATY) is surgical in nature. Pericardium or other appropriate membranes are removed from the patient's body and mounted on a frame. In a preferred method, a spiral ruled cutter and press form a narrow tape from the harvested membrane. For the manufacture of small vessels, the ATY has to be small, preferably 0.005-0.025 inches in width. Other larger structures may be able to use ATY as large as 0.1 inches in width. The appropriate autologous membranes may not have a thickness compatible with these dimensions and can be skived, planed, slit or microtomed to meet a desired dimension. This process also offers the surgeon the control options for the type of tissue to be used to form the ATY. In most cases the membrane and tissues that can be harvested have a multi-layer structure. It may be desirable to use only some of these layers and not use others in the formation of ATY. Other cutting or fiber formation methods such a straight-line slitting, laser cutting, water jet cutting, or helical slitting are all candidate methods for formation of ATY. The ATY need not be monofilament in nature; it can be multifilament or it can be multifilament with twist as in a staple fiber formation, which will be readily understood by those in the textile arts.
[0017] Yarn sizes and vessel wall thickness must be related. For very small structures, such as 1 or 2 mm diameter veins, the wall thickness must be equally thin. In this case the available autologous tissue membrane may require not only thin sectioning into tapes or strips but also reduction in thickness. This processing can be done both before and after the initial sectioning has been done and can include both mechanical rolling or drawing and cutting or skiving techniques. The imperfections in the ATY in very thin sections result in higher breakage and reduce the average length of undivided material. However with the use of fine CF these shorter ATY sections are supported and carried through the assembly process.
Equipment Setup
[0018] The use of carrier fibers allows the fabrication equipment to be setup and all the elements to be threaded and ready for the surgical session. The use of live autologous tissue requires that the assembly process be rapid and reliable. The threading of the equipment with ATY would not only consume time during the procedure but would also require large amount of ATY for threading and start up. The use of carrier yarn leaders allows all the thread up and tension control devices to be initialized with the bare carrier yarn CF leaders, and the ATY used almost exclusively for the formation of the finished structure. In addition to speed and utilization advantages, the carrier fiber provides an improved cover factor in the ATY fabric and helps reduce the porosity of the structure. The term “cover” or “cover factor” and various other terms and phrases of the textile arts used through this specification are defined and/or clarified by reference to other Charles A. Howland patents including U.S. Pat. No. 5,564,264; U.S. Pat. No. 5,837,623; and U.S. Pat. No. 5,976,996, and also to such industry references as the Dictionary of Fiber and Textile Technology, copyright 1999 KoSa, ISBN 0-9670071-0-0.
Autologous Tissue and Healing
[0019] The use of ATY fabrics and structures allows the healing process in the body to take over and remake the structure. During this healing process the carrier fiber fills in as a tension bearing threadline or matrix, for defects in the ATY and the assembly process. There will be splices, terminations and incomplete coverage of the ATY portion of the structural fabric initially. Before the healing process has corrected these small imperfections, the carrier fiber provides both redundant structure and improved surface area coverage.
[0020] Integration of CF to ATY with the carrier yarns is the first step in the assembly process. Ply twisting, hitch loops, serving, wrapping or braiding, terms understood in the textile arts, are all useful in integrating the ATY with the CF. Each method is outlined below. Referring to FIG. 2 , in the ply twisting case, a preferred approach makes use of short lengths to be processed, and feeds the ATY 201 from a fixed position, with the bobbin of CF 202 moving around the ATY material. In some cases, a rotating hollow clamp 203 is used to guide the continuous CF and the free end of the ATY. The clamp turns and provides the ply twist for the CF/ATY pair 204 .
[0021] The use of multiple CF yarns is useful to help support thin or fragile ATY. After twisting, the free ends of the ATY are released from the rotating and fixed clamp. They are then knotted or coated to prevent untwisting. The integrated section of ATY and CF is then be advanced into the assembly section of the apparatus. It is preferred to use a balanced twist (s versus z) in the CF singles yarn to prevent liveliness or torque in the ply structure. A ply twist between 1 and 30 turns per inch is typical to integrate CF with ATY. Twisting has the advantage that the process is simple and a hundred or more clamp-type twisting units take up little space, facilitating the parallel integration of the CF and ATY. The multi-up assembly process, well understood to those skilled in the textile arts, is also desirable as it avoids the requirement to move integrated thread lines from the CF/ATY integration step to the assembly step. In the case of weaving or other assembly modes where multiple ends are required, this parallel process can save time in the procedure.
[0022] A second configuration of CF integrated with ATY is where the CF forms a clove hitch over the free end of the ATY. Additional hitch or loop fastening of CF to ATY is used along the ATY length to integrate the two yarns, the fastening points being spaced as often as necessary to provide adequate thread line behavior.
[0023] A serving or winding configuration uses a hollow bobbin and feeds the ATY through the hollow core. In general a CF yarn is paired with the ATY in the core feed to support the ATY and reduce the lengths required. In this process the wrap count of the CF is selected to meet the required thread line behavior. The number of CF wraps per inch should not be excessive as a very high CF cover would reduce the available surface area of the ATY and hence the healing performance of the integrated finished CF/ATY fiber.
[0024] Referring to FIG. 3 , in the braiding process and configuration, the CF 302 is set up on the three bobbins 303 the braiding unit 300 and ATY 301 is feed as a core to the braid at braid point 304 . This method provides very low ATY tension in the integration process and is useful for handling very short sections of ATY. The braiding process is desirable when integrating CF and ATY for knitting as the braiding process can be run in parallel with the knitting or weaving filling insertion of the structure. The braiding complexity makes it less attractive for use as a warp component of assembly where more thread lines are required. Core braid insertion for CF/ATY can be readily automated.
[0025] Assembly of useful tissue fabrics and structures using the integrated CF/ATY may be accomplished in several ways; as described in the following examples.
EXAMPLE #1
Weaving of Tubular ATY/CF Structures Oriented in the Fill Direction
[0026] The first example of an ATY/CF scaffold or structure and process of the invention is of weaving ATY/CF fabric tubes oriented in the fill direction. For this example, cylindrical tubes are fabricated to various lengths and diameters. The use of a weaving process is preferred because it allows separate selection of the thread line density and type in the axial and circumferential directions. Narrow width weaving equipment of a few inches is preferred. Needle or rapier insertion are best for the filling insertion mechanism. Referring to FIG. 4 , the major modification of the heddle/reed insertion section 400 is the use of an aqueous saline bath 404 to preserve the viability of live tissue. Tissue yarn ATY 401 is used in filling, and carrier fiber CF 402 is used in warp. The weave design uses the filling oriented tube method. The key advantage of this system over warp oriented tubes is the ease with which the tube diameter can be modified by simply changing the number of filling insertions in the double layer section. Tube diameter variation is necessary to match the donor's native vessels and is not known with precision except at the time of performing the associated medical procedure.
[0027] For this set up, the preferred warp feed would be from a single end creel for the CF warp. As described, the clamp-type twisting or knotting integration methods are preferred as inline or parallel parts of the creel thread lines. This process creates a set of ATY/CF warp yarns. The normally very limited amount of ATY requires that the ATY/CF yarns each have a length close to the total length required for the structure being formed. The rest of the threaded length for the assembly equipment can be provided by the CF only, as an ATY/CF yarn leader. After the required number of CF/ATY thread lines have been integrated, the integrated sections are moved into the assembly zone in the fabric forming equipment. In the example of weaving equipment, this would move the CF/ATY yarns into the fell zone and just at the location for next insertion to fall on integrated CF/ATY sections. In the case of knitting or braiding equipment, a similar advance into the assembly zone starts the next part of those processes.
[0028] In the case of woven structures, the filling direction yarns can be different than the warp yarns. In some cases, the CF yarn need only be used in one of the machine directions. In the general case, there are integrated CF/ATY lines or yarns in both directions. This provides additional options for configuring the effective cover of the ATY related healing and face-side related symmetry and asymmetry options for medically healing and tissue presentation, the means for achieving which will be understood by those in the textile arts.
[0029] In the case of the warp yarn, there are a number of options for integration. The ATY can be knotted, served with a second CF tread line, twisted into a ply with the CF or braided into an integrated unit. In the case of the filling yarn, the degree of mechanical abrasion in weaving is very low and the required filling feed tension is also very low. This allows for using a very limited degree of integration or amount of CF to ATY, and even the use of no CF material and only ATY, in the filling direction when desirable.
[0030] In the example of a CF/ATY fabric tube or vessel assembly with weaving, the selected filling type, CF, ATY, or CF/ATY, is inserted into a warp pattern that links all the warp fiber units. The optimal weave pattern in this Closed Tape Zone (CTZ) is a tight plain weave with weave cover in the range of 50-80%. The number of insertions will depend on the width of the CTZ and the inter-fiber friction of the total system. In the preferred case, small CF material is woven to create a tight CTZ to prevent any structural problems such as the loss of crossing points after removal for use on the assembly fixture. As with a fringe or any fabric edge, the CTZ may be terminated with knots to further prevent loss of crossing points.
[0031] After the completion of the CTZ, the tube section (TS) of the assembly is formed. In this step of the assembly process the warp fiber is controlled with the hettles to create two sheets in the formation zone. Typically half the warp fiber is formed into an upper sheet and the other half is formed into the lower sheet. The TS formation continues until the required tube diameter is formed. The actual resulting TS diameter can be tested with a mandrel by slacking off the warp tension at this point in the process. When the TS is long enough then the second CTZ can be formed and this allows for a closed tube.
[0032] At this point the formed tube can be removed from the assembly unit and the CTZ and ends can be finished as required to prepare the ATY/CF structure or scaffold for insertion into the patient's body.
EXAMPLE #2
Weaving of Tubular ATY/CF Structures Oriented in the Warp Direction
[0033] The second example of an ATY/CF scaffold or structure and process according to the invention is the weaving of a warp oriented tube. In this example, shuttle type weaving is preferred and the formation is of a two-ply fabric with woven selvedges. This follows the techniques for fly shuttle weaving, which are well understood in the textile arts. The filling yarn must be wound on a shuttle bobbin and the shuttle moves for each filling insertion. In this method the tube diameter must be pre-defined as the warp end-count and the reed size in use will define the tube circumference. The key advantage of this method is the elimination of the CTZ (closed tape zone) at the two edges of the tube. With fly shuttle weaving, woven selvedges avoid the requirement of a CTZ. With these exceptions to the first example fill direction tube process, all the other weaving related process specifications apply. Combined and/or bifurcated structures based on this and the other assembly techniques described herein are also possible.
EXAMPLE #3
Braiding of ATY/CF Structures
[0034] The third example of an ATY/CF scaffold or structure and process according to the invention is of braiding methods and braided structures useful for the assembly of small vessel scaffolds. The CF is integrated with the ATY as described and is wound on bobbins. The section of integrated CF/ATY is moved forward into the braiding zone and the structure is fabricated using the required number of braided ends for the tube size required. The method may be preferred for the elasticity intrinsic to the braid and rapid change in tube diameter, mirroring the recipient's vessel variation. It should be noted that fiber orientation in such structures is limited and cover in larger vessel sizes requires very complicated equipment.
EXAMPLE #4
Knitting of ATY/CF Structures
[0035] The fourth example of an ATY/CF scaffold or structure and assembly process according to the invention is of knitting methods and knitted structures. The use of circular knitting and other complex knitting methods known in the textile arts are used for larger tubular and bifurcated structures. As the gage of the knitting machines is limited, the fineness of knitted structures is less appropriate in small structures. However the knitting process has the advantage of only requiring a few yarn ends for processing. The integration of the ATY and the CF can be accomplished in-line with the knitting process. The use of knit structures is desirable when very compliant structures are required. However cover and porosity characteristics in knitted structures are not ideal for liquid tight requirements and such ATY/CF scaffolds or structures may require post processing to address these issues.
Environmental Conditions in the Assembly Process
[0036] The integration and assembly process is accomplished at low temperature and under saline spray or saline immersion. The time required for CF/ATY formation, integration, assembly and post processing defines the environmental requirements. The longer the process time needed, the lower the temperatures required, the more critical the saline formulations are to maintaining the viability of the ATY tissue.
Crossing Point Design
[0037] At the level of fabric design, the options for the integration of the CF and ATY materials are numerous. A key criteria in this step or design is keeping the cover factor and available surface areas of ATY in a ratio that facilitates complete healing. In some cases the ATY materials will need to be nearly continuous on the surface of the structure. This is accomplished in one way by having much smaller carrier fibers relative to the size of the ATY material. A preferred pattern in this case would cross the CF on the ATY with respect to machine directions and pack the ATY in the pattern to provide optimal cover. In other situations where healing mechanisms allow for incomplete ATY coverage, CF can be used to complete the surface of the structure. Patterns where only some of the fibers contain ATY in either or both directions are within the scope of the invention. It is expected that symmetrical face patterns will be used in some applications. However in cases where the inside and outside of a vessel have differential healing characteristics, the ratio of ATY and CF can be asymmetrical as in twill or sateen designs. Those skilled in the textile arts will readily understand such variations.
Post Processing and Re-introduction
[0038] When there is excessive porosity in the assembled part, this may be addressed either by mechanical compaction of the surface as with calendering or by coating with various surgical dips. As in the case of synthetic grafts, the use of albumin or blood is useful in closing any fine porosity in a newly assembled structure.
[0039] In many situations, the use of CF, ATY, or CF/ATY fibers in the terminations of the structure can be used as the suture for the emplacement of the structure in the patient's body. This method avoids the need to penetrate the assembled structure with a separate suture. As the assembled structure is manufactured to fit the reassembly site in the donor, the suturing is made in a preferred geometry to accommodate the planned placement. This preserves the integrity of the structure and promotes rapid healing.
[0040] Referring now to FIG. 1 , the six fundamental steps of the invention are illustrated. At step 1 , autologous tissue AT, or any tissue, is harvested from its source in a non-destructive manner. At step 2 , the tissue is processed by any of the means described above into an ATY or autologous tissue yarn format suitable for the process that follows. At step 3 , as described above, a medically suitable carrier fiber CF is integrated with the ATY to form a workable composite yarn of CF and ATY. As illustrated in FIG. 1 , preferred embodiments use a saline spray, and low temperature environment, to promote the longevity of the tissue material during this and subsequent steps. At step 4 , again as aptly described above, CF/ATY yarn, and optionally unintegrated CF and ATY, are assembled into a tissue and fiber fabric structure of the desired geometry and balance of physical properties of the tissue and fiber, suitable for a specific medical implantation requirement.
[0041] The integration and assembly steps of the process of FIG. 1 draw heavily on the art, practice, and machines of the textile industry in novel and heretofore unobvious ways to advance this aspect of the medical arts. The invention extends further to the use of carrier fiber leaders for machine set up to conserve tissue and accelerate the process, then for drawing of the tissue into the integrating step and of the carrier fiber and tissue composite into the assembly process. As shown, a saline spray and other efforts may be used to maintain the viability of the tissue during integration and assembly steps until the step 5 implantation is accomplished. In healing step 6 , new tissue NT builds on the AT tissue, gradually replacing the carrier fiber CF and fleshing out the full form of the structure as the CF is slowly absorbed.
[0042] The invention has many possible embodiments and variations. For example, there is a process for repair of a tissue-based body structure in a patient using the steps: harvesting autologous tissue from a donor; processing the autologous tissue into autologous tissue yarn; integrating the autologous tissue yarn with a carrier fiber into a fiber/tissue composite yarn; using a leader of carrier fiber for drawing the composite yarn into an assembly process; assembling by the assembly process a fiber and autologous tissue body structure; and implanting the structure in the patient.
[0043] The processing step may include reducing the autologous tissue into strips of 0.005 to 0.1 inches in width. The integrating step may use at least one technique from among the group of techniques consisting of ply twisting, hitch loops, serving, wrapping, braiding, and entanglement. The assembly process may include any of: weaving a tubular tissue and fiber structure oriented in the fill direction; weaving a tubular tissue and fiber structure oriented in the warp direction; braiding a tissue and fiber structure; knitting a tissue and fiber structure; or other manual or machine construction of structures by use of yarns and fibers.
[0044] The integrating step and/or the assembling steps may include applying lower than ambient temperature and a saline solution to the autologous tissue. The assembly process may include weaving a tissue and fiber fabric on a machine where the autologous tissue yarn is run in one machine direction and the carrier fiber is run in the other machine direction. The assembly process may include compacting the walls of the structure and/or coating the structure for reducing porosity.
[0045] The assembly process may include terminating the fabrication of the structure leaving extended lengths of yarn suitable for suturing the structure into place, where the yarns are any or all of carrier fiber, tissue yarn, or the composite fiber/tissue yarn.
[0046] Another example of the invention is a produce of the process, a structure formed by the process. The structure may incorporate a fabric constructed of autologous tissue yarn and carrier fiber and containing crossing points formed by any of weaving, knitting, braiding or entanglement techniques, or other techniques.
[0047] As another example of the invention, there is a process for making a tissue-based body structure consisting of the basic steps: processing body tissue into tissue yarn; integrating the tissue yarn with a carrier fiber into a fiber/tissue composite yarn; using a leader of the carrier fiber for drawing the composite yarn into an assembly process; and assembling by the assembly process a fiber and tissue structure. This example may employ the other variations and options described above, as well as products of the process of this example and its variations.
[0048] Yet another example of the invention is simply a structure made from a fabric consisting of autologous tissue yarn and carrier fiber, where the tissue yarn consists of strips of tissue between 0.005 and 0.1 inches in width. And a further simple example is a structure made from a fabric consisting of a composite yarn consisting of comprising autologous tissue yarn and carrier fiber, again where the autologous tissue yarn consists of strips of autologous tissue between 0.005 and 0.1 inches in width.
[0049] Other and various examples and variations of the invention will be evident from the abstract, description, figures, and following claims. | Methods and structures are disclosed where carrier fiber is used to enable the assembly of two and three dimensional structures of autologous tissue. Tissue is harvested from the donor, integrated with a carrier fiber, and assembled into complex forms rapidly. The structures can be tailored to the requirements of a specific medical procedure. The tissue is kept live and viable during extracorporeal assembly and the finished structure is emplaced in the donor's body. The use of a carrier fiber leader for pre-threading integration and assembly machines facilitates machine set up, drawing of the tissue into the process, and rapid integration and assembly of the multi-dimensional structures. Assembly can include providing tissue and fiber leaders extending from the structure for attaching the structure in place. The carrier fiber either is bio-absorbed as new tissue forms, or forms a bio-compatible substructure for the patient's native tissue. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to recording media recorded with a program for detecting database operation timing such as timing of performing page relocation in a database or timing of performing the capacity expansion of the database, methods of detecting database operation timing, and apparatuses for detecting database operation timing, and more particularly to a recording medium recorded with a program for detecting database operation timing, a method of detecting database operation timing, and an apparatus for detecting database operation timing which program, method, and apparatus detect timing of performing page relocation in a database or timing of performing the capacity expansion of the database.
A network structure database employs prime pages and overflow pages, which are used when the prime pages have no space, so as to enable a high-speed access thereto.
Once on-line operations start, such a database requires page (record) relocation since record addition, deletion, or update creates fragmentary spaces in the prime and overflow pages. Further, if the database seems to run out of its capacity, the capacity of the database has to be expanded.
Timing of performing the page relocation in or the capacity expansion of such a database should be detected accurately with a minimum influence on the on-line operations.
2. Description of the Related Art
Conventionally, a system administrator has judged the necessity of page relocation in or the capacity expansion of a database based on the analysis results of a job executed to recognize the storage condition of data in the database, that is, based on analysis results as to whether the number of regions that are not reusable due to fragmentation is large or small.
Then, if the system administrator determines, based on the analysis results, that the number of reusable regions is so large that the database requires page relocation, the system administrator performs the page relocation during a jog execution by activating a program configured in accordance with an invention disclosed in Japanese Laid-Open Patent Application No. 6-110743.
Further, if the system administrator determines, based on the analysis results, that such page relocation does not allow the database to store further data, the system administrator activates a program for implementing the capacity expansion of the database so as to expand the capacity of the database.
Thus, according to a conventional method, the system administrator judges the necessity of page relocation in or the capacity expansion of the database by executing the job for recognizing the data storage condition of the database. This job is executed at a timing when the on-line operations are stopped.
The job executed at this timing is input to and output from the entire database so as to recognize the data storage condition of the database.
According to such a conventional method, however, the on-line operations should be stopped in order to judge the necessity of the page relocation in or the capacity expansion of the database, thus causing a problem that a request for an on-line operation hour extension cannot be answered. Especially, this is a problem in 24-hour continuous on-line operations.
Further, according to the conventional method, the system administrator, based on her/his experience, judges the necessity of the page relocation in or the capacity expansion of the database, referring to the analysis results of the above-described job.
However, this does not mean that the page relocation in or the capacity expansion of the database is always performed at an appropriate timing.
Therefore, in the worst case, the conventional method causes the shortage of the capacity of the database so that an on-line program is prevented from storing records to end abnormally.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide a recording medium recorded with a program for detecting database operation timing, a method of detecting database operation timing, and an apparatus for detecting database operation timing in which the above-described disadvantage is eliminated.
A more specific object of the present invention is to provide a recording medium recorded with a program for detecting database operation timing, a method of detecting database operation timing, and an apparatus for detecting database operation timing which program, method, and apparatus accurately detect timing of performing page relocation in a database or timing of performing the capacity expansion of the database with a minimum influence on on-line operations.
The above objects of the present invention are achieved by a recording medium including a program causing a computer to execute the steps of (a) predicting a data storage condition of a database from a record operation, (b) computing a number of relocatable areas and a number of areas in an expansion direction based on the data storage condition predicted in the step (a), and (c) detecting operation timing with respect to the database based on the numbers computed in the step (b).
The above objects of the present invention are also achieved by a recording medium including a program causing a computer to execute the steps of (a) determining whether a new overflow area is generated by a record operation, (b) determining whether fragmentation is generated in a prime area or overflow areas including the new overflow area linked thereto by the record operation if it is determined in the step (a) that the new overflow area is generated, (c) computing a number of relocatable areas and a number of areas in an expansion direction based on a result of the step (b), and (d) detecting operation timing with respect to the database based on the numbers computed in the step (c).
The above objects of the present invention are also achieved by a method of detecting database operation timing which method includes the steps of (a) determining whether a new overflow area is generated by a record operation, (b) determining whether fragmentation is generated in a prime area or overflow areas including the new overflow area linked thereto by the record operation if it is determined in the step (a) that the new overflow area is generated, (c) computing a number of relocatable areas and a number of areas in an expansion direction based on a result of the step (b), and (d) detecting operation timing with respect to the database based on the numbers computed in the step (c).
The above objects of the present invention are further achieved by an apparatus for detecting database operation timing which apparatus includes a first determination part for determining whether a new overflow area is generated by a record operation, a second determination part for determining whether fragmentation is generated in a prime area or overflow areas including the new overflow area linked thereto by the record operation if it is determined by the first determination part that the new overflow area is generated, a computation part for computing a number of relocatable areas and a number of areas in an expansion direction based on a determination result of said second determination part, and a detection part for detecting operation timing with respect to the database based on the numbers computed by the computation part.
According to the above-described recording media, method, and apparatus, the necessity of page relocation in or the capacity expansion of the database can be judged without executing a job for recognizing the data storage condition of the database. Therefore, on-line operations are prevented from a stoppage, thus minimizing influence thereon.
Further, the necessity of page relocation in or the capacity expansion of the database can be judged without depending on a system administrator, thus preventing unnecessary page relocation in the database or an unnecessary capacity expansion thereof from being performed.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings, in which:
FIG. 1 is a diagram showing a structure of a computer system according to the present invention;
FIG. 2 is a diagram showing a program structure of a DB management mechanism shown in FIG.
FIG. 3 is a diagram for illustrating an NDB shown in FIGS. 1 and 2 ;
FIG. 4 is a diagram showing embodiments of a prime area and an overflow area of the NDB;
FIG. 5 is a diagram for illustrating an operation of an overflow management page shown in FIG. 4 ;
FIG. 6 is a diagram showing an embodiment of prediction management information of each prime page shown in FIGS. 4 and 5 ;
FIG. 7 is a diagram for illustrating an overflow page management operation performed by an overflow management page shown in FIGS. 4 and 5 ;
FIGS. 8A and 8B are flowcharts of an operation performed by a database access program shown in FIGS. 2 and 3 ;
FIGS. 9 and 10 are flowcharts of an operation performed by an overflow prediction management program shown in FIG. 2 ;
FIG. 11 is a diagram showing cases to which a record operation corresponds in step S 5 of FIG. 9 ;
FIG. 12 is a diagram for illustrating a prediction management update operation performed in step 6 of FIG. 9 ;
FIG. 13 is a diagram for illustrating a method of determining timings to perform page relocation in the NDB and an expansion thereof in steps 7 through 14 in FIGS. 9 and 10 ;
FIG. 14 is a diagram for illustrating the page relocation in and the expansion of the NDB; and
FIGS. 15A through 17B are diagrams for illustrating an operation of a system of FIG. 14 according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A description will now be given, with reference to the accompanying drawings, of an embodiment of the present invention.
FIG. 1 is a diagram showing a structure of a computer system according to the present invention. As shown in FIG. 1 , the computer system includes an operating system (OS) 1 , an application program 2 , a terminal 3 , a network structure database (NDB) 4 , an expansion NDB 5 capacity-expanded from the NDB 4 , a terminal control mechanism 6 operating under the OS 1 to control the terminal 3 , a database (DB) management mechanism 7 operating under the OS 1 to manage the NDB 4 and the expansion NDB 5 , and a transaction control mechanism 8 for controlling transactions.
FIG. 2 is a diagram showing a program structure of the DB management mechanism 7 .
As shown in FIG. 2 , the DB management mechanism 7 includes an overflow prediction management program 11 provided to realize the present invention as well as a conventionally provided database access program 10 .
As will be described later, the overflow prediction management program 11 updates prediction management information 400 recorded in prime pages, performs an addition operation of an overflow page, and posts an instruction for page relocation in the NDB 4 or the expansion NDB 5 , and an instruction for the generation of the expansion NDB. The overflow prediction management program 11 can be stored in an appropriate recording medium such as a computer-readable semiconductor memory.
FIG. 3 is a diagram for illustrating the NDB 4 .
The NDB 4 is accessed by the record, and, as shown in FIG. 3 , employs two types of pages (input/output units) of the prime pages loaded into a prime area 40 and overflow pages loaded into an overflow area 41 . The NDB 4 uses the prime pages prior to the overflow pages. If there is no space in the prime pages, the NDB 4 uses the overflow pages. If there is no space in the overflow pages, the NDB 4 allocates the next overflow page from the overflow area 41 . Thereby, the NDB 4 enables a high-speed access thereto.
If the NDB 4 is filled to its capacity, overflow pages loaded into an overflow area 50 of the expansion NDB 5 are used.
FIG. 4 is a diagram showing embodiments of the prime area 40 and the overflow area 41 of the NDB 4 .
The overflow area 50 of the expansion NDB 5 has the same structure as the overflow area 41 of the NDB 4 .
As shown in FIG. 4 , each prime page loaded into the prime area 40 has the two-bit prediction management information 400 . On the other hand, an overflow management page 410 is provided in the overflow area 41 to manage the numbers of expansion pages (pages in an expansion direction) and relocation (relocatable) pages.
FIG. 5 is a diagram for illustrating an operation of the overflow management page 410 .
In addition to the management of the numbers of expansion pages and relocation pages, the overflow management page 410 identifies an overflow page in use by using a link as shown in FIG. 5 .
A record to be stored in a prime page identifies overflow pages linked to the prime page by using a pointer, which is not shown in FIG. 5 .
FIG. 6 is a diagram showing an embodiment of the prediction management information 400 of each prime page.
As shown in FIG. 6 , the prediction management information 400 is formed of two bits, and manages a value “00” in an initial state, a value “10” if a prime page having the prediction management information 400 and overflow pages linked to the prime page are relocatable, and a value “11” if the prime page and the overflow pages linked thereto are in the expansion direction.
That is, the values “10” and “11” of the prediction management information 400 indicate, respectively, that a page set of the prime page and the overflow pages linked thereto has fragmentation and thus is relocatable, and that the page set has no fragmentation and thus is in the expansion direction.
FIG. 7 is a diagram for illustrating an overflow page management operation.
For instance, as shown in FIG. 7 , if the prediction management information 400 of a prime page i is recorded with the value “10”, it is indicated that a page set of the prime page i and overflow pages linked thereto has fragmentation, and thus is relocatable. If the prediction management information 400 of a prime page p is recorded with the value “11”, it is indicated that a page set of the prime page p and overflow pages linked thereto has no fragmentation, and thus is in the expansion direction.
The number of expansion pages managed by the overflow management page 410 is the total number of the overflow pages of the page set in the expansion direction. In FIG. 7 , the overflow management page 410 manages the number “4” as the number of expansion pages.
On the other hand, the number of relocation pages managed by the overflow management page 410 is the total number of the overflow pages of the relocatable page set. In FIG. 7 , the overflow management page 410 manages the number “3” as the number of relocation pages.
If fragmentation is generated in the page set in the expansion direction, the page set becomes relocatable. In this case, the prediction management information 400 has the value “11” updated to the value “10” as shown in FIG. 6 .
If the fragmentation disappears in the relocatable page set, the page set is to be in the expansion direction. However, this seldom happens and is quite exceptional. Therefore, the page set in which fragmentation is once generated is considered as relocatable even if a new overflow page is added to the page set after the generation of the fragmentation. Consequently, as shown in FIG. 6 , once the prediction management information 400 is set to the value “10”, the value “10” is never updated to the value “11”.
FIGS. 8A and 8B are flowcharts of an operation performed by the database access program 10 , and FIGS. 9 and 10 are flowcharts of an operation performed by the overflow prediction management program 11 .
Next, a description will be given of the present invention in accordance with these flowcharts.
First, a description will be given of the operation performed by the database access program 10 .
As shown in FIG. 8A , the database access program 10 performs an initialization operation to reserve a work area when a transaction starts.
On the other hand, when the transaction ends, as shown in FIG. 8B , the database access program 10 first determines in step S 1 whether or not the prediction management information 400 of a prime page is updated and/or the number of expansion pages and/or the number of relocation pages managed by the overflow management page 410 are/is updated by a record operation in the transaction.
If it is determined in step S 1 that such a prediction management update operation, which is performed by the overflow prediction management program 11 as will be described later, is not performed, the operation proceeds to step S 2 . In step S 2 , the prime page and the overflow pages read in response to the issuance of the macro instruction for the record operation are written to the NDB 4 in a direct access storage device (DASD), and then the operation ends.
On the other hand, if it is determined in step S 1 that a prediction management update operation is performed, the operation proceeds to step S 3 . In step S 3 , the updated prediction management information 400 of the prime page is written to the NDB 4 in the DASD, and in step S 4 , the updated number of expansion pages and/or the updated number of relocation pages managed by the overflow management page 410 are/is written to the NDB 4 in the DASD.
Next, in step S 5 , the rest of the prime page and the overflow pages are written to the NDB 4 in the DASD, and then the operation ends.
Thus, when the transaction ends, the database access program 10 writes to the NDB 4 in the DASD the prime page and overflow pages read in response to the issuance of the macro instruction for the record operation, and the overflow management page 410 . Thereafter, the database access program 10 terminates the operation.
Next, a description will be given of the operation performed by the overflow prediction management program 11 .
If the database access program 10 issues a macro instruction for a record operation in response to a request from the application program 2 in a transaction, the overflow prediction management program 11 first determines in step S 1 whether the issued macro instruction is of an update type as shown in FIG. 9 .
If it is determined in step S 1 that the issued macro instruction is not of an update type, that is, if it is determined that the issued macro instruction is for a record retrieval, it is determined that a below-described prediction management is unnecessary, the operation ends without performing further steps.
On the other hand, if it is determined in step S 1 that the issued macro instruction is of an update type, such as a record addition, deletion, or update, the operation proceeds to step S 2 . In step S 2 , a predicted size of a record (a record length) processed by the macro instruction is obtained from the database access program 10 .
Next, in step S 3 , it is determined whether the database access program 10 performs the record operation on an overflow page in response to the issuance of the macro instruction. If it is determined in step S 3 that the record operation is not performed on the overflow page, that is, if it is determined that the record operation is performed on a prime page, it is determined that a below-described prediction management is unnecessary, and the operation ends without performing further steps. This is because, at this stage, no relocatable or capacity expansion state is generated, that is, no page set is relocatable or in the expansion direction.
On the other hand, if it is determined in step S 3 that the database access program 10 performs the record operation on the overflow page, the operation proceeds to step S 4 . In step S 4 , it is determined whether the database access program 10 allocates a new overflow page during the transaction in process. If it is determined in step S 4 that a new overflow page is not allocated in the transaction, it is determined that a below-described prediction management is unnecessary, and the operation ends without performing further steps. This is because, at this stage, no relocatable or capacity expansion state is generated.
On the other hand, if it is determined in step S 4 that a new overflow page is allocated in the transaction, the operation proceeds to step S 5 . In step S 5 , it is determined which case the record operation performed by the database access program 10 this time corresponds to based on record operation types and predicted sizes of records (record lengths) of last time and this time.
FIG. 11 is a diagram showing cases to which the record operation corresponds. For convenience of description, a description will be given of typical six cases.
If a record length deleted by the last operation is equal to that added by this operation, it is determined that this operation corresponds to CASE 1 having a future prediction of NO CHANGE.
If a record length deleted by the last operation is longer than that added by this operation, it is determined that this operation corresponds to CASE 2 having a future prediction of EXPANSION DIRECTION.
If a record length deleted by the last operation is shorter than that added by this operation, it is determined that this operation corresponds to CASE 3 having a future prediction of RELOCATABLE indicating generation of fragmentation.
If a record length updated by the last operation is equal to that updated by this operation, it is determined that this operation corresponds to CASE 4 having the future prediction of NO CHANGE.
If a record length updated by the last operation is longer than that updated by this operation, it is determined that this operation corresponds to CASE 5 having the future prediction of EXPANSION DIRECTION.
If a record length updated by the last operation is shorter than that updated by this operation, it is determined that this operation corresponds to CASE 6 having the future prediction of RELOCATABLE indicating generation of fragmentation.
Next, in FIG. 9 , after it is determined in step S 5 which case the record operation performed by the database access program 10 this time corresponds to, in step S 6 , a prediction management update operation is performed to update the prediction management information 400 of the prime page and/or the number of expansion pages and/or the number of relocation pages managed by the overflow management page 410 based on the case to which the record operation corresponds.
FIG. 12 is a diagram for illustrating the prediction management update operation.
For instance, if the record operation performed by the database access program 10 corresponds to CASE 1 or 4 , the value of the prediction management information 400 of the prime page is not updated as shown in FIG. 12 .
In this case, if the value of the prediction management information 400 indicates “10 (RELOCATABLE)”, the number of relocation pages managed by the overflow management page 410 is incremented by one, and if the value of the prediction management information 400 indicates “11 (EXPANSION DIRECTION)”, the number of expansion pages managed by the overflow management page 410 is incremented by one.
In the case where the record operation performed by the database access program 10 corresponds to CASE 2 or 5 , as shown in FIG. 12 , the value of the prediction management information 400 is updated to “11 (EXPANSION DIRECTION)” if the value indicates “00 (INITIAL STATE)”, but is not updated for the reason previously described with reference to FIG. 6 if the value indicates “10 (RELOCATABLE)”. The value is not updated either if the value indicates “11 (EXPANSION DIRECTION)”, for there is no change in the future prediction.
At this point, if the value of the prediction management information 400 is updated from “00 (INITIAL STATE)” to “11 (EXPANSION DIRECTION)”, a value “1” is entered in the number of expansion pages managed by the overflow management page 410 . In the case where the value is not updated, the number of relocation pages managed by the overflow management page 410 is incremented by one if the value indicates “10 (RELOCATABLE)”, and the number of expansion pages is incremented by one if the value indicates “11 (EXPANSION DIRECTION)”.
In the case where the record operation performed by the database access program 10 corresponds to CASE 3 or 6 , as shown in FIG. 12 , the value of the prediction management information 400 of the prime page is updated to “10 (RELOCATABLE)” if the value indicates “00 (INITIAL STATE)” or “11 (EXPANSION DIRECTION)”, is not updated if the value indicates “10 (RELOCATABLE)”, for there is no change in the future prediction.
At this point, if the value is updated from “00 (INITIAL STATE)” to “10 (RELOCATABLE)”, a value “1” is entered in the number of relocation pages managed by the overflow management page 410 . If the value is not updated, the number of relocation pages is incremented by one. If the value is updated from “11 (EXPANSION DIRECTION)” to “10 (RELOCATABLE)”, the number of all the overflow pages linked to the prime page is entered in the number of relocation pages, and the number of expansion pages is reset to an initial value “0”.
Thus, in step S 6 , the prediction management update operation is performed so that the overflow management page 410 manages the numbers of expansion and relocation pages as described above in FIG. 7 .
Next, in step S 7 , based on the total number of overflow pages (TN) loaded into the overflow area 41 , which number is entered in the overflow management page 410 , and the numbers of expansion and relocation pages (NE and NR) managed by the overflow management page 410 , the rate of use of overflow pages (RU) is given by the following equation
RU =( NE+NR )/ TN,
and the ratio of relocatable overflow pages (RR) and the ratio of overflow pages in the expansion direction (RE) are given by the following equations
RR=NR/TN
RE=NE/TN
Next, as shown in FIG. 10 , it is determined in step S 8 whether the rate of use of overflow pages is higher than 90%. If it is determined in step S 8 that the rate of use of overflow pages is higher than 90%, the operation proceeds to step S 9 . In step S 9 , an instruction is issued to expand the NDB 4 , and then the operation ends.
That is, if the rate of use of overflow pages is higher than 90%, the NDB 4 is almost filled to its capacity. Therefore, the instruction is issued to expand the NDB 4 irrespective of the ratio of relocatable overflow pages or overflow pages in the expansion direction.
On the other hand, if it is determined in step S 8 that the rate of use of overflow pages does not exceed 90%, the operation proceeds to step S 10 to determine whether the rate of use is higher than 70% and lower than or equal to 90%, whether the rate of use is higher than 50% and lower than or equal to 70%, and whether the rate of use is lower than or equal to 50%.
If it is determined in step S 10 that the rate of use is lower than or equal to 50%, the operation ends without providing an instruction to expand the NDB 4 or perform page relocation therein.
That is, if the rate of use is lower than or equal to 50%, the NDB 4 has sufficient space in its capacity. Therefore, no instruction is issued to expand the NDB 4 or perform page relocation therein.
On the other hand, if it is determined in step S 10 that the rate of use is higher than 70% and lower than or equal to 90%, the operation proceeds to step S 11 to determine whether the ratio of overflow pages in the expansion direction (RE) is higher than 80%. If it is determined in step S 11 that the RE is higher than 80%, the operation proceeds to step S 12 to issue an instruction to expand the NDB 4 , and then the operation ends.
That is, if the rate of use is higher than 70% and lower than or equal to 90% and the RE is higher than 80%, the NDB 4 is almost filled to its capacity. Therefore, the instruction is issued to expand the NDB 4 .
On the other hand, if it is determined in step S 11 that the RE is lower than or equal to 80%, or if it is determined in step S 10 that the rate of use is higher than 50% and lower than or equal to 70%, the operation proceeds to step S 13 to determine whether the ratio of relocatable overflow pages (RR) is higher than 30%.
If it is determined in step S 13 that the RR is higher than 30%, the operation proceeds to step S 14 to issue an instruction to perform page relocation in the NDB 4 , and then the operation ends. On the other hand, if it is determined in step S 13 that the RR is lower than or equal to 30%, the operation ends without providing an instruction to perform page relocation in the NDB 4 .
That is, if the rate of use is higher than 50% and lower than or equal to 70% and the RR is higher than 30%, it is desirable to lower the rate of use by page relocation in the NDB 4 . Therefore, the instruction is issued to perform page relocation in the NDB 4 .
If the rate of use is higher than 50% and lower than or equal to 70%, the RE is lower than or equal to 80% so that the expansion of the NDB 4 is not necessary, and the RR is higher than 30%, it is desirable to lower the rate of use by page relocation in the NDB 4 . Therefore, the instruction is issued to perform page relocation in the NDB 4 .
Thus, the overflow prediction management program 11 predicts the data storage condition of the NDB 4 from a record operation performed in a transaction so as to compute the rate of use of overflow pages, the ratio of relocatable overflow pages, and the ratio of overflow pages in the expansion direction, based on which the overflow prediction management program 11 issues an instruction to expand the NDB 4 or perform page relocation therein in accordance with, for instance, a determination method as shown in FIG. 13 .
In the above-described steps, steps S 1 through S 4 form a first determination step, step 5 forms a second determination step, step 6 forms a computation step, and steps 7 through 14 form a detection step of a method of detecting database operation timing.
Further, in the above-described steps, steps S 1 through S 4 form a first determination part, step 5 forms a second determination part, step 6 forms a computation part, and steps 7 through 14 form a detection part of an apparatus for detecting database operation timing.
FIG. 14 is a diagram for illustrating page relocation in and the expansion of the NDB 4 .
In response to the instruction to perform page relocation in the NDB 4 issued by the overflow prediction management program 11 , a relocation program 100 , for instance, is activated as shown in FIG. 14 so as to perform page relocation in the NDB 4 . At this point, it is desirable that the object of page relocation should not be limited to the relocatable overflow pages, but include all the overflow pages and all the prime pages,
On the other hand, in response to the instruction to expand the NDB 4 issued by the overflow prediction management program 11 , a DB expansion program 200 , for instance, is activated as shown in FIG. 14 so that the expansion NDB 5 is generated to expand from the NDB 4 .
According to a system shown in FIG. 14 , the relocation program 100 or the DB expansion program 200 is activated in response to the instruction issued by the overflow prediction management program 11 so as to automatically perform page relocation in the NDB 4 or the expansion thereof. On the other hand, in some cases, a message to instruct page relocation in the NDB 4 or the expansion thereof is output on the display screen of the terminal 3 shown in FIG. 1 .
Next, a description will be given, with reference to FIGS. 15A through 17B , of an operation of the system of the above-described structure.
If the database access program 10 , during the execution of a transaction, receives an addition request of a record B of a record length of 400 after deleting a record A of a record length of 400 stored in a prime page as shown in FIG. 15A , the database access program 10 store the record B in the prime page having a space of the record length of 400 as shown in FIG. 15 B.
Thereafter, if the database access program 10 receives an addition request of a record C of a record length of 500 , the database access program 10 allocates a new overflow page to store the record C therein since the prime page is full as shown in FIG. 15 C.
The overflow prediction management program 11 determines the case of this record operation (the case of a series of additions) in this transaction so as to determine that the NDB 4 is in the expansion direction. Then, as shown in FIG. 16A , the overflow prediction management program 11 sets the value of the prediction management information 400 of the prime page to “11 (EXPANSION DIRECTION)”, and increment the number of expansion pages managed by the overflow management page 410 by one to set the number of expansion pages to “1”. Thereafter, at the end of the transaction, the overflow prediction management program 11 writes the updated value of the prediction management information 400 and the updated number of expansion pages to the NDB 4 in the DASD.
Next, the database access program 10 fills the allocated overflow page by executing several transactions as shown in FIG. 16 B.
Thereafter, if the database access program 10 , while executing a transaction following the preceding transactions, receives an addition request of a record E of a record length of 500 after deleting a record D of a record length of 400 as shown in FIG. 16C , the database access program 10 allocates a new overflow page to store the record E therein since the allocated overflow page is full as shown in FIG. 17 A.
The overflow prediction management program 11 determines the case of this record operation (the case of adding a record of a record length longer than a space produced by deleting a record) in this transaction so as to determine that the NDB 4 is in condition to have page relocation. Then, as shown in FIG. 17B , the overflow prediction management program 11 sets the value of the prediction management information 400 of the prime page to “10 (RELOCATABLE)”, and sets the numbers of expansion and relocation pages managed by the overflow management page 410 to “0” and “2”, respectively. Thereafter, at the end of the transaction, the overflow prediction management program 11 writes the updated value of the prediction management information 400 and the updated numbers of expansion and relocation pages to the NDB 4 in the DASD.
Thus, the overflow prediction management program 11 detects the numbers of expansion and relocation pages indicating the data storage condition of the NDB 4 from record operations in transactions.
As previously described in FIGS. 9 and 10 , the overflow prediction management program 11 issues an instruction to perform page relocation in the NDB 4 or the expansion thereof based on the predicted data storage condition of the NDB 4 .
The present invention is not limited to the specifically disclosed embodiment, but variations and modifications may be made without departing from the scope of the present invention.
The present application is based on Japanese priority application No. 2000-288116 filed on Sep. 22, 2000, the entire contents of which are hereby incorporated by reference. | A recording medium includes a program causing a computer to execute the steps of (a) predicting a data storage condition of a database from a record operation, (b) computing a number of relocatable areas and a number of areas in an expansion direction based on the data storage condition predicted in step (a), and (c) detecting operation timing with respect to the database based on the numbers computed in step (b). | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 09/900,585, filed on Jul. 6, 2001, which is a continuation of U.S. patent application Ser. No. 09/106,585, filed on Jun. 29, 1998, which is a continuation-in-part of U.S. Design Application Ser. No. 29/089,942, entitled Hand-held Messaging Device with Keyboard, filed on Jun. 26, 1998 and assigned to the assignee of the present invention.
BACKGROUND OF THE INVENTION
[0002] The present invention is directed toward the field of small, hand-held electronic devices such as personal data assistants (PDA's), personal information managers (PIM's), two-way pagers and the like. In particular, the system and method of the present invention provide the user of the hand-held device with the ability to input data with a minimal amount of key strokes and optimized for use substantially with the thumbs.
[0003] In a two-way paging system that provides two-way, full text messaging, there is a need to permit the user to initiate messages and to respond to messages in a timely fashion and with text entirely created by the user. In order to keep the form factor of the two-way pager small enough to be worn on the body of the user, such as with a belt clip, the input device needs to be small, have a minimal number of keys and optimized for use with a minimal number of key strokes. Prior art systems have attempted to address these needs by incorporating virtual keyboards or pen-based input systems for user inputs to the device, but such systems require the user to input data in an unfamiliar manner. Additionally, in a small hand-held messaging device, such as a two-way pager. these systems prove awkward to use.
[0004] In order to provide a hand-held electronic device that permits a user the opportunity to enter data into an address book, a calendar, a task list, an email message or a similar text file that requires user-generated data, the instant invention is directed to an input device that is oriented to be used substantially through use of the thumbs. This is accomplished first by providing a keyboard with a minimal number of keys, but with the keys representing the alphabet generally placed in the same order as they would appear on a standard keyboard, such as in a standard QWERTY or a DVORAK keyboard layout. The use of a keyboard layout that is familiar to the user enables the user to immediately use the device without having to hunt for the keys he or she wishes to use.
[0005] Although the layout is similar to a standard keyboard, the keys are placed at an orientation and in a particular shape that attempts to maximize the surface area of the thumb hitting the key and to provide the user with a comfortable position of the hands for data input. Also, the orientation encourages input by the thumbs, which the inventors of the instant invention have discovered to be faster and more accurate in small hand-held electronic devices than touch-typing or “hunting and pecking” typing.
[0006] An additional feature of the invention is thus use of an additional input means for control of functions that might otherwise be controlled by a keyboard that included function keys. To encourage data entry using thumbs and again to minimize the number of keys on the keyboard, the instant invention also includes a thumb-wheel for control of menus for section of forms and functions relevant to data input. The thumb-wheel is positioned in close proximity to the keyboard to enable the easily transition from thumb-based typing to thumb control of forms and functions.
[0007] In addition to hardware features that encourage optimal data entry through the use of thumbs, there are several software features that are designed to minimize keystrokes and aid in entry of data.
[0008] The features of this invention, both individually and collectively, have not, to the knowledge of the inventors, been applied to a small hand-held electronic device that requires user-generated data entry. To permit efficient operation of such devices while keeping the form factor of the device small enough to be worn on the body, there is a general need for a hand-held electronic device that can fit in the palm of the hand and that can be operated substantially with the thumbs.
[0009] There is a further need for a keyboard for a palm-size data entry device with keys placed at an angle to optimize operation of the keyboard by the use of the thumbs.
[0010] There remains another need for a keyboard with keys that are shaped and sized to maximize contact with the thumbs while minimizing the keyboard area required for such keys.
[0011] There also remains a need for an auxiliary input device that is to be operated by the thumb for data inputs forms and function control and that, in conjunction with the keyboard, encourages and permits data entry and management through input performed substantially by the thumbs.
[0012] There remains still another need for a software-implemented user interface system that is designed, at least in part, to support and encourage data entry through use of the thumbs.
SUMMARY
[0013] The present invention overcomes the problems noted above and satisfies the needs in this field for a hand-held electronic device with a keyboard optimized for use with the thumbs. In the preferred embodiment of the present invention, the hand-held electronic device is a two-way paging device that permits full-text, two-way messaging such as email messaging and that includes standard PDA or PIM features such as an address book, an electronic calendar, a task list and other text-based features. These features require user input of text strings that can be lengthy and that cannot be reduced to pre-determined or “canned” strings. Thus, for such a device, the efficient entry of data in a device meant to fit into the palm of one's hand requires that two goals are achieved. First, the data entry must be relatively easy from a user perspective. This means that the user must be somewhat familiar with analogous forms of data entry and not have to be trained to use the data entry for the hand-held device. Second, the form factor does not permit a large number of keys or keys that are very large. Thus efficient use of the keyboard space is required and functions that might be able to be performed by a standard keyboard are off-loaded to an auxiliary input device or are performed, through a minimal number of keystrokes that encourage the use of thumb-based data entry.
[0014] To accomplish these goals. the invention first optimizes the placement of the keys on the device keyboard. In order to work within the limited space available for the keyboard, it was determined that it was preferable to use keys that were oval or oblong and that were placed at angles designed to facilitate use by thumb typing. An angle for the keys on the right side of the keyboard and a complementary angle for the keys on the left side of the keyboard are chosen based upon observation of the angle at which a user will orient his or her thumbs while thumb-typing.
[0015] The invention also minimizes the number of keys available for data input. In the preferred embodiment, only keys for the 26 letters of the English alphabet are available as well as a backspace key, a line feed key, an “alt” key, a “cap” key and a space bar. The alt key enables the user in conjunction the other keys to input numbers and symbols to perform certain functions. The placement of the keys is designed to enhance the user experience while typing with the thumbs by meeting two seemingly opposite goals—minimizing the keyboard footprint while maximizing the likelihood that proper keys will be struck by the thumb-typing user.
[0016] The invention also provides additional incentive for the user to use thumb input by providing an input device adjacent to the keyboard, but integral to the overall hand-held device. Although other devices can be used in an auxiliary fashion, the preferred device is a thumbwheel that registers movement of the wheel by measuring the number of indents traversed while rolling the wheel and that also registers as an input the depression or “clicking” of the wheel, which is performed by pressing the wheel toward the back of the pager. This clicking of the wheel is similar to the clicking of a mouse associated with a PC or any other input device that registers the depression of a button. The thumbwheel in the preferred embodiment is placed vertically on the two-way paging device so that the user can easily move his or her thumb from the thumbwheel to the keyboard and back for performing functions and retrieving data forms, such as an e-mail template or address book entry template. for data entry.
[0017] Additionally, various software techniques can be implemented to enhance the thumbtyping use's experience in using the device of the instant invention. In the preferred embodiment, for example, the user can change the capitalization of a particular letter simply by keeping a key depressed for a particular length of time without an intermittent release being detected by the keyboard controller.
[0018] The primary advantage of the present invention is that it enables efficient and user-friendly data entry into a palm-sized electronic device by maximizing the potential for user data entry through thumb typing.
[0019] These are just a few of the many advantages of the present invention, as described in more detail below. As will be appreciated, the invention is capable of other and different embodiments and its several details are capable of modifications in various respects, all without departing from the spirit of the invention. Accordingly, the drawings and description of the preferred embodiment set forth below are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention satisfies the needs noted above as will become apparent from the following description when read in conjunction with the accompanying drawings wherein:
[0021] [0021]FIG. 1 is a block diagram of a two-way, full-text, messaging device incorporating a keyboard and an auxiliary data entry device.
[0022] [0022]FIG. 2 is a frontal view of the hand-held device showing the shape and placement of the keys on the keyboard and the auxiliary input device.
[0023] [0023]FIG. 3 is a diagram of showing the shape. size and placement of the keys on the keyboard.
[0024] [0024]FIG. 4 is a diagram of the control circuitry for the thumbwheel.
DETAILED DESCRIPTION
[0025] Referring now to the drawings, FIG. 1 is a block diagram of the major subsystems and elements comprising a palm-sized, mobile, two-way messaging device that preferably incorporates the invention. In its broadest terms, the messaging device includes a transmitter/receiver subsystem 100 connected to a DSP 200 for digital signal processing of the incoming and outgoing data transmissions, power supply and management subsystem 300 , which supplies and manages power to the overall messaging device components, microprocessor 400 , which is preferably an X86 architecture processor, that controls the operation of the messaging device, display 500 , which is preferably a full graphic LCD, FLASH memory 600 , RAM 700 , serial output and port 800 , keyboard 900 , thumbwheel 1000 and thumbwheel control logic 1010 . In its intended use, a message comes via a wireless data network, such as the Mobitex network, into subsystem 100 , where it is demodulated via DSP 200 and decoded and presented to microprocessor 300 for display on display 500 . To access the display of the message, the user may choose from functions listed under a menu presented as a result of user interaction with thumbwheel 1000 . If the message is an email message, the user may chose to respond to the email by selecting “Reply” from a menu presented on the display through interaction via thumbwheel 1000 or via menu selection from keyboard 900 . In typing the reply, the user can use keyboard 900 to type full text message replies, or insert pre-determined or “canned” response by using either a particular keystroke pattern or through pulling down pre-determined text strings from a menu of items presented on display 500 through the use of thumbwheel 1000 . When the reply to the message is composed. the user can initiate the sending of the message preferably by interaction through thumbwheel 1000 , or alternatively, with less efficiency, through a combination of keyboard 900 keystrokes. When the microprocessor 300 receives an indication that the message is to be sent, it processes the message for transport and, by directing and communicating with transmitter/receiver subsystem 100 , enables the reply message to be sent via the wireless communications data network to the intended recipient. Similar interaction through I/O devices keyboard 900 and thumbwheel 1000 can be used to initiate full-text messages or to forward messages to another party. Also, the keyboard 900 and thumbwheel 1000 can be used to permit data entry to an address book resident on the messaging device, or an electronic calendar or log book, or any other function on the messaging device requiring data entry. Preferably, the thumbwheel is a thumbwheel with a push button SPST with quadrature signal outputs, such as that manufactured by Matsushita Electronic Components Co. Ltd. as part number EVQWK2001.
[0026] [0026]FIG. 2 is a front view of messaging device 10 that incorporates the invention. Shown in FIG. 2 are a plurality of letter keys 901 , and specialized keys 902 , 903 , 904 and 905 and space bar 906 . Also shown is thumbwheel 1000 in its vertical orientation and in association with display 500 and keyboard 900 . In the preferred embodiment, 902 is the alt key, 903 is the cap key. 904 is the line feed key and 905 is the backspace key.
[0027] [0027]FIG. 3 is a view of a subset of the letter keys 901 , showing the dimensions and relative position of the keys. Shown also is the point 950 that marks the center of keyboard 900 , key dimensions 970 , 971 , 972 and 973 , as well as angle 960 and the rho value 965 , representing curvature of a letter key 901 . In investigating optimal key placement on the keyboard, it was determined that the keys should be placed at an angle 960 relative to vertical that facilitated easy typing using thumbs. That angle is preferably positive 40 degrees relative to vertical for keys on the right side of the keyboard (where 950 is the center of the keyboard) and negative 40 degrees for the keys on the left side of the keyboard, although complementary angles ranging from 20 degrees to 70 degrees could also be used to accomplish the goal, albeit less optimally, of facilitating thumb typing. Also as shown on FIGS. 2 and 3, the keys are dispersed across keyboard 900 evenly so that there is sufficient space between the keys to decrease the opportunity for multiple keys being depressed while thumb typing. Additionally, the keys are sized appropriate given the footprint of the messaging device and the keyboard 900 . In its preferred embodiment, the messaging device 10 measures across its face 64 mm by 89 mm, which does not leave much room for keyboard 900 and display 500 . In the preferred embodiment, keyboard 900 occupies over half of the face of the messaging device 10 .
[0028] The key shape and dimensions are also key components of the invention. In order to maximize the surface area of the key that a thumb would hit, the keys are preferably oval, and have a rho 965 defining the curvature of the key of 0.4 14, although values may range higher or lower. Other rho values will lead to an acceptable, but not as optimal or aesthetically pleasing shape of keys 901 . As to the key dimensions, the width 970 of the key 901 is 4.8 millimeters ( 971 representing the radius of half that value, 2.4 mm) and the length (or height) 972 of the key 901 is 7 millimeters millimeters ( 973 representing the radius of half that value, 3.5 mm).
[0029] Turning to one of the software features that aids in the device 10 being optimally used for thumb typing is a capitalization feature implemented via software. If a user depresses a key 901 , the operating system detects a key down event. If the key is released after a period of time, the operating system detects a key up event. If upon a key down event, a period of time elapses before a key up event is detected, the operating system determines that a key repeat event has occurred representing a situation where a user has continued to depress a key without releasing it. A key repeat event is then treated by application software residing in either FLASH 600 or RAM 700 as an event that requires the capitalization of the key previously depressed. This feature disables a key repeat feature and substitutes instead a capitalization feature based upon a key repeat. The timing of the key scanning to determine whether a key has been released can be set to permit a slower keyboard response or a faster keyboard response, depending upon user experience or preferences. Although the capitalization function preferably works only to change the state of a letter to a capital, it alternatively could operate to change a capital letter to a lower case letter. The actual display is changed by the application program substituting the value of the capital letter in the register that holds the value of the letter to be displayed. As alternatively implemented, the continued depressing without release of a letter key could result in a key oscillating between upper case and lower case, depending on the length of time the key is depressed.
[0030] [0030]FIG. 4 is the logic circuitry 1010 associated with thumbwheel 1000 . Thumbwheel 1000 outputs quadrature signals phase A 1021 and phase B 1022 , which are processed by D flip-flops 1031 and 1032 to present signals 1041 W_UP and 1042 W_DN to microprocessor 300 . Signals 1041 and 1042 represent, respectively, a user rolling the thumbwheel up and rolling the thumbwheel down.
[0031] Having described in detail the preferred embodiments of the present invention, including the preferred methods of operation, it is to be understood that this operation could be carried out with different elements and steps. This preferred embodiment is presented only by way of example and is not meant to limit the scope of the present invention which is defined by the following claims. | A hand-held electronic device with a keyboard optimized for use with the thumbs is disclosed. In order to operate within the limited space available on a hand-held electronic device, the present invention optimizes the placement and shape of the keys, preferably using keys that are oval or oblong in shape, and that are placed at angles designed to facilitate thumb-typing. | 7 |
FIELD OF THE INVENTION
[0001] The invention relates generally to structural components and related methods, and more specifically to a nestable spherical hollow body that is convenient to use and assemble at least for structural support and/or creating internal cavities in concrete or similar applications.
BACKGROUND OF THE INVENTION
[0002] Many concrete or similar structural components conventionally are relatively thick and heavy, compared to their weight bearing capacity. The formation of voids within concrete can improve the economics, performance, and versatility of the concrete and its implementation.
[0003] Prestressed, prefabricated concrete elements with extended cross sections and internal hollow cylindrical cavities have been used to reduce the weight “problems”, but they typically only span in a “single” direction. In other words, they are typically relatively long and narrow concrete beams with one or more web elements extending significantly below the concrete “deck.” Alternative approaches have included placing lightweight balls within the concrete as it is poured (for example, see DE 2,116,479) or similarly positioning hollow spheres within a mesh assembly in the concrete (for example, see U.S. Pat. No. 5,396,747, issued to Breuning in 1995).
[0004] A system using embedded blow-molded plastic balls is described at the website of BubbleDeck North America Ltd. BubbleDeck currently produces a pre-fabricated solid concrete slab structure having plastic balls embedded in concrete, to reduce the slab's weight. According to BubbleDeck, the pre-fabricated concrete slab can reduce construction material weight by up to fifty percent (50%). The BubbleDeck plastic balls are hollow, spherical shapes (similar to ping pong balls), and are of a solid fixed single piece construction. That single piece hollow body construction apparently has a generally uniform wall thickness sufficient to withstand the stress imposed by the surrounding concrete material, but that solid fixed single piece construction limits at least the shipping and handling characteristics of the inserts (balls) prior to use, and can also affect the stress handling capacity of the plastic balls.
[0005] Thus, the weight advantages of systems such as the BubbleDeck balls are compromised by certain disadvantages inherent in their design. Among other things, because they are blow-molded spheres, they are cannot be efficiently stored or transported prior to their use on a jobsite.
SUMMARY OF THE INVENTION
[0006] The invention is directed to a nestable hollow body that, among other things, is useful for at least structural support and/or creating internal cavities for an improved strength-to-weight ratio in a variety of concrete or other structures. Rather than a series of loose components separate from each other (see, for example, FIGS. 3-5 of the aforementioned '747 patent), the present invention preferably provides a single connected element whose parts can be easily moved (via hinges or otherwise) from an “open” or nestable position into a “closed” or assembled position. The invention provides for, among other things, nestabilty in a hollow body, and provides for space saving and efficient methods of manufacturing, handling, storing, transporting, and/or assembling the hollow bodies. The invention further facilitates additional structural support within the hollow body itself, to increase the load bearing capacity of the hollow body when subjected to external forces such as those commonly imposed on it by concrete or when otherwise used for its intended purposes.
[0007] In one embodiment, the device is preferably a multi-section hollow body having: (1) a structural support network disposed within or formed in its interior; (2) a hinge mechanism to keep the sections connected to each other prior to assembly and to permit repositioning (or “closing”) of the sections into a final desired configuration prior to their use; and (3) at least one latch mechanism to help hold the sections in that final desired configuration prior to their use. For embodiments having two sections formed of plastic via injection molding, an integral hinge preferably permits a top or first section of the hollow body and a bottom or second section of the hollow body to be (1) fabricated in an opened or an extended state (which permits stacking or nesting of a plurality of hollow bodies on top of each other prior to their eventual use), and then (2) moved to a closed or an assembled state to permit use of the hollow body for its intended purposes.
[0008] Methods of fabrication, transportation, and use related to the aforementioned apparatus are also described herein. Among other things, such methods improve the efficiency of storage and transport and assembly of the void-making devices prior to their use in a concrete or similar construction application.
[0009] Certain objects and advantages have been and are further described herein. Persons of ordinary skill in the art will understand that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
[0010] These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view showing a multi-portion hollow body in a closed or assembled state, in accordance with one embodiment of the present invention.
[0012] FIG. 2 is similar to FIG. 1 , but shows the hollow body in a slightly open position.
[0013] FIG. 3 is a perspective view looking down into the interior of the body of FIG. 2 after it has been further opened, and illustrates an embodiment of a structural support network disposed within each of the sections of the body.
[0014] FIG. 4( a ) is a side perspective view of a plurality of the bodies of FIG. 3 , inverted and stacked and nested with each other.
[0015] FIG. 4( b ) is a sectional view of the stacked and nested bodies of FIG. 4( a ), with the section being taken along the widest portion of the bodies and generally parallel to the plane of the paper on which FIG. 4( a ) is shown.
[0016] FIG. 5 is similar to FIG. 3 , but shows a close-up view of the central interconnecting portion of the body, illustrating one embodiment of a hinge that can be used in the hollow body of FIG. 1 .
[0017] FIG. 6 is similar to FIG. 2 , but shows a close-up view of one embodiment of a latch mechanism that can be used in the hollow body of FIG. 1 .
[0018] FIG. 7( a ) is similar to FIG. 6 , but shows the latch mechanism in a closed or secured position, such as the position shown in FIG. 1 . FIG. 7( b ) is similar to FIG. 7( a ), but shows a partially sectional perspective view of the latch mechanism, with the section taken in a generally vertical plane through FIG. 7( a ).
DETAILED DESCRIPTION
[0019] Embodiments of the present invention will now be described with references to the accompanying Figures, wherein like reference numerals refer to like elements throughout. The terminology used in the description presented herein is not intended to be interpreted in any limited or restrictive manner, simply because it is being utilized in conjunction with a detailed description of certain embodiments of the invention. Furthermore, various embodiments of the invention (whether or not specifically described herein) may include novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the invention herein described.
[0020] Persons of ordinary skill in the art will understand that the invention can be practiced using any of a wide variety of suitable processes and materials. By way of example and not by way of limitation, fabrication processes include die cast, investment casting, sheet metal stamping, single/twin sheet thermo-form, blow-molding, rotational molding, injection molding, gas assist, water assist, web molding, structural foam molding, and many other existing and new processes that may come into being. Materials are not limited in anyway and could extend from metals to resins of all types. A preferred material is plastic, and a preferred method of fabrication is by injection molding.
[0021] The device described herein may generally be used for at least structural support and/or creating internal cavities for improved strength-to-weight ratio in a variety of structures. In this regard, the structural hollow bodies described herein are typically intended to be embedded in concrete or some other material for the purpose of eliminating the concrete or some other material that has weight but no carrying effect. Persons of ordinary skill in the art will understand that although the aforementioned application may be a preferred use, the structural hollow bodies described herein may be used in any number of other applications.
[0022] As shown in FIGS. 1-4 , in one embodiment, the device is preferably a hollow body 5 having: (1) a top/first section 10 and a bottom/second section 15 of substantially the same size and shape; (2) a structural support network 20 disposed within the hollow body 5 to increase the load bearing capacity of the hollow body 5 when subjected to external forces; (3) at least one latch mechanism 25 positioned along the periphery 40 of the hollow body 5 ; and (4) a corresponding hinge 30 positioned along the periphery 40 of the hollow body 5 so as to permit repositioning of the top section 10 of the hollow body 5 and the bottom section 15 of the hollow body 5 from an opened state, to permit nesting of a plurality of such hollow bodies 5 on top of each other, to a closed state to permit use of the hollow body 5 for its intended purposes. Persons of ordinary skill in the art will understand that the orientation of “top” or “bottom” used herein is for convenience only, and that the specific orientation of the body within a particular application can be any direction.
[0023] The geometric shape of the device 5 described herein is preferably spherical, having a top section 10 and a bottom section 15 of substantially the same size and shape (i.e., half spheres). However, persons of ordinary skill in the art will understand that as long as the general attributes and principles of the device (hollow body) 5 as described herein are utilized, the device 5 can be of virtually any size and shape. Such shapes may include a square, triangle, hexagon, geodesic dome/sphere, or other shape. In addition, the wall thickness of the hollow body 5 and/or structural support network 20 may vary and will typically depend on the device's intended use or application.
[0024] As shown in FIG. 5 , the preferred hinge 30 (connecting the top section to the bottom section) is formed as part of an area of reduced thickness of plastic 35 along the periphery 40 between the top section 10 and the bottom section 15 of the hollow body 5 . For injection molded embodiments, the hinge can be a “living hinge” formed of the same plastic as the rest of the body.
[0025] When used for their intended purposes (i.e., for structural support and/or creating internal cavities for improved strength-to-weight ratio in a variety of structures), the hollow bodies 5 preferably are in a closed or assembled state, as shown in FIG. 1 . No further repositioning of the top section 10 of the hollow body 5 relative to the bottom section 15 of the hollow body 5 is needed. While other more durable hinge types may be utilized, the hinge 30 is intended for a single use application so its durability is relatively less important than its lightweight and cost effective production.
[0026] As shown in FIG. 4 , the hinge 30 permits the hollow bodies 5 to be shipped or transported from the manufacturer to an end user in an opened or an extended state to facilitate efficient stacking and/or nesting of a plurality of such hollow bodies 5 on top of each other, thereby increasing the number of hollow bodies 5 capable of being contained in a given space (as compared to the number of assembled hollow bodies (or fixed, single piece ping-pong ball type bodies) capable of being contained in the same space).
[0027] As shown in FIGS. 2 and 3 , the hollow body 5 preferably includes at least one latch mechanism 25 , and preferably includes a plurality of such latch mechanisms 25 . The latch mechanism 25 preferably includes an enlarged head or male portion 45 formed on the periphery 40 and protruding from a first recessed portion 50 formed on one of the top section 10 or a bottom section 15 of the hollow body 5 , and a correspondingly shaped cavity or female portion 55 formed on the periphery 40 as part of a second recessed portion 60 on the other one of the top section 10 or the bottom section 15 of the hollow body 5 for receiving or mating with the head 45 to join, close, or seal the top and bottom sections 10 , 15 along the peripheral 40 (mating area between the top section 10 and bottom section 15 of the hollow body) when the hollow body 5 is in the closed or assembled state.
[0028] As shown in FIGS. 7( a )-( b ), the head 45 preferably is constructed with an enlarged protrusion 65 such that, as the head 45 makes initial contact with the cavity 55 , the head 45 moves in a direction away from the periphery 40 of the hollow body 5 so as to be received into the cavity 55 . After the head 45 is completely received into the cavity 55 , material memory (and/or compressive hoop stress) causes the head 45 to move back out into its original position, securing the protruding portion 65 of the head 45 firmly against a lip 70 of the cavity 55 , and securing the top section 10 of the hollow body 5 to the bottom section 15 of the hollow body 5 along the peripheral edges 40 .
[0029] Similar to the hinge 30 , the latch 25 is intended for a single use application. In this regard, once secured in the closed or assembled state the hollow body 5 is ready for its intended use. No further repositioning of the top section 10 of the hollow body 5 relative to the bottom section 15 of the hollow body 5 is needed. A plurality of latch mechanisms 25 are preferably provided and used, to increase the integrity of the hollow body 5 in its closed or “sealed” state (i.e., to maximize accurate engagement and minimize the risk of collapse or deformation of the hollow body 5 due to external stress resulting in partial or total separation of the top section 10 from the bottom section 15 , or other “failure” of the body's void-making purpose in certain applications).
[0030] In certain applications such as forming voids in concrete, it is unlikely that the assembled ball or body will ever need to be “opened.” Accordingly, securing the top section 10 of the hollow body 5 to the bottom section 15 of the hollow body 5 is of primary importance, and the ability to “unsecure” or open the latch mechanism(s) 25 is moot, undesirable, and/or irrelevant.
[0031] Persons of ordinary skill in the art will understand that any suitable latch may be utilized within the scope of the invention. In this regard, and by way of example, even if just a single latch element 25 is provided on the hollow body, the sealing or further securing of the top section 10 of the hollow body 5 to the bottom section 15 of the hollow body 5 along the periphery 40 may be further aided or facilitated in any number of ways, including the use of a mating tongue and groove structure and/or gasket member along the periphery 40 , for example.
[0032] As best shown in FIG. 1 , the hinge 30 and latch(es) 25 preferably are constructed such that in the closed or assembled state the hinge 30 and latch(es) 25 do not protrude beyond the designated outside diameter of the hollow body 5 . In this regard, as indicated above, each of the hinge 30 and latch(es) 25 are formed on a recessed portion 50 , 60 of the top section 10 of the hollow body 5 and the bottom section 15 of the hollow body 5 . Accordingly, as shown in FIG. 7( a ), each recessed portion 50 , 60 is sloped (as indicated by reference “s”) such that the hinge 30 and latch(es) 25 formed on the periphery 40 as part of each recess 50 , 60 are inset a distance (as indicated by reference “i”) from the perimeter 40 of the hollow body 5 . Among other things, such an inset “i” configuration of the hinge 30 and latch(es) 25 provides a generally smooth outer periphery 40 or profile of the hollow body 4 for purposes of efficient and stable stacking or nesting of a plurality of such hollow bodies 5 on top of each other in the opened or extended state as shown in FIGS. 4( a )-( b ).
[0033] As shown in FIG. 3 , each of the top section 10 and the bottom section 15 of the hollow body 5 preferably includes a structural support network 20 (or web or rib(s)) formed on or disposed in or operatively affixed to the body section or sections. Among other things, the structural support network 20 can increase the load bearing capacity of the hollow body 5 when subjected to the external forces commonly imposed on it, when used for at least structural support and/or to create internal cavities in a variety of structures. The structural support network 20 disposed within the hollow body 5 may be considered as somewhat of a compromise between a hollow body 5 without such a structural support 20 and a completely solid hollow body. In this regard, the structural support network 20 permits a greater load bearing capacity than a hollow body 5 without such a structural support network 20 , but at a reduced weight when compared to a completely solid body.
[0034] In one embodiment, the reinforcing ribs or structural support network 20 includes a concentric ring 75 positioned generally near a central or bottom portion 80 of each of the top section 10 and the bottom section 15 of the hollow body 5 . In other words, in this embodiment, the concentric ring 75 is distal from the periphery opening 40 of the hollow body 5 . Preferably, a plurality of equally spaced (or other pattern of) support arms 85 radiate outward from the concentric ring 75 toward the periphery 40 of each of the top section 10 and the bottom section 15 to add structural stability to the hollow body sidewall.
[0035] Persons of ordinary skill in the art will understand that the invention can be practiced in other embodiments without any such ribs or webbing, or with any of a wide variety of patterns, shapes, and sizes of ribs or similar support network. Similarly, persons of ordinary skill in the art will understand that, among other things, the diameter, depth, and/or thickness of the concentric ring 75 as well as the number, spacing, and length of each support arm 85 may vary depending on the hollow body's intended purpose or application. For example, a hollow body structural support network 20 (a concentric ring 75 and one or more of the associated support arms 85 ) intended to withstand the force imposed on a hollow body 5 buried or encased in concrete may be constructed considerably thicker and/or larger in some aspect as compared to a hollow body structural support network 20 that is intended to be buried or encased in some lighter material.
[0036] The apparatus and methods of the present invention have been described with some particularity, but the specific designs, constructions and steps disclosed are not to be taken as delimiting of the invention. Obvious modifications will make themselves apparent to those of ordinary skill in the art, all of which will not depart from the essence of the invention and all such changes and modifications are intended to be encompassed within the appended claims, to the extent permitted by any prior art and applicable law. | A multi-piece interconnected body for use in at least structural support and/or in creating internal cavities for an improved strength-to-weight ratio in a variety of structures is nestable prior to its assembly and use. When assembled, the device preferably forms a generally spherical and hollow body, with (1) one or more ribs or similar structural support network associated with and/or integrally formed in the body; (2) at least one latch mechanism to help hold the pieces in a desired assembled relationship with each other; and (3) a hinge or other interconnecting element that facilitates nesting and/or stacking of a plurality of the bodies with each other prior to assembly, association of the multiple parts of each body with each other prior to assembly, and ready repositioning of those parts into a desired assembled position. | 4 |
FIELD OF THE INVENTION
This invention relates to a device for attachment to motor vehicle safety seat belts. More specifically this invention relates to a device for relieving the tension of the seat belt on the user.
BACKGROUND AND DISCUSSION OF THE PRIOR ART
In connection with the safety seat belts known today, one end of the belt is permanently retained by a spring-loaded roller in a wound and strained position in a way such that with slow pullout motions of the seat belt, the seat belt is fastened and the occupant is held by the belt against the force of the spring. When a sudden motion occurs, that is by high accelerations, the seat belt is blocked by the spring due to the mass moment of inertia as it may occur, for example, when the vehicle is suddenly retarded due to contact with an obstacle or another vehicle and the belt is retained at its two ends, permitting the spring to perform the retaining function it is expected to perform.
Normally, the seat belts are currently fitted by the automobile manufacturers and mounted in different ways. The use of said belts, which are permanently under spring tension, is considered an inconvenience in many cases particularly because the belt is placed across the torso or upper part of the chest, thus causing many drivers to have a feeling of being constricted in an unpleasant way.
The prior art sought an additional attachment for motor vehicles which attachment made it possible to loosen the initial stress exerted on the belt by the spring, so that the user is not constricted by the belt pressure.
Typical prior art devices are disclosed in U.S. Pat. No. 4,297,467 granted Oct. 13, 1981 to Frantom and U.S. Pat. No. 4,484,766 granted Nov. 27, 1984 to Buchmeier. Those devices required the manufacture, assembly and mounting of several specially machined interfitting metal members. This was a costly solution to the problem of seat belt strain relief, and which engendered unwieldy installation, and provided the undesirable addition of metal frame members mounted on the inside of the automobile adjacent the driver and passengers.
Now there is provided by the present invention a readily retrofitted and universally adaptable seat belt tension relief device which eliminates the aforesaid prior art problems associated with specially machined interfitting metal members. SUMMARY OF THE INVENTION
A seat belt tension relief device is formed with an adjustable length elastic member which at one end is pivotally mounted adjacent the door frame while at the other end is formed with a flexible adjustable member which encompasses the seat belt at the portion of the user's torso. The device is substantially of flexible material construction. When not in use the device is readily removed or stowed.
In use, the device portion which encompasses the seat belt readily disengages from the seat belt under high accelerations so that the seat belt holds in its intended fashion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the invention in actual use, with the stowed disposition being shown in phantom line.
FIG. 2 is an enlarged fragmentary sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is a plan view of the pivotal mounting member;
FIG. 4 is a side elevational view of the pivotal mounting member of FIG. 3.
FIG. 5 is a plan partial fragmentary view of another embodiment of the invention;
FIG. 6 is a sectional side view of the embodiment of FIG. 5; and
FIG. 7 is a sectional partial fragmentary view of the embodiment of FIG. 5, in actual use wedged between the door frame and auto frame.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the FIGURES there is shown the seat belt tension relief device of the present invention generally referred to as 10. Device 10 comprises an elastic member or belt 11 being formed as an elongated loop 12. Ends 13 and 14 of belt 11 are respectively, fixedly mounted and adjustably mounted, to conventional adjustable belt buckle 15 for adjusting the length of the belt 11 and in turn loop 12.
Door mount assembly 16 is formed of a rigid metal rectilinear link element 17, a post 18 rotatably holding link leg 39 of element 17, at 19, and a pivot 20 formed with post 18. Pivot 20 is of well known construction and is mounted in base mounting member 21 for the free rotation of the pivot 20, and in turn, post 18 and element 17. Pivot 20 may be of ball joint construction. Base member 21 is affixedly attached to a compressible plastic mount member 22 by adhesive or other suitable means. Members 21 and 22 are affixed above the door frame by suitable means well known in the art including permanent adhesives and other well known means.
Belt 11 engages element 17 at belt portion 23 for purposes hereinafter appearing. Rectilinear metal link or loop 24 engages belt 11 at opposite portion 25. A band of flexible material or fabric 26 is affixedly covered with Velcro strip 27 and pad 28 on opposite band faces 29 and 30, respectively. Velcro strip 27 and Velcro pad 28 interengage at portion 31. Velcro strip 27 is formed of the multiple plastic looped Velcro elements and the pad 28 is formed of tufted Velcro material. Portion 32 is impregnated with stiffening adhesive or resin impregnated in a portion of the band so as to form a semi-flexible leg 33 of othewise flexible triangular loop 34.
A tufted Velcro pad 35 is adhesively mounted above the inside door frame for purposes hereinafter appearing.
A conventional spring-loaded seat belt 36 is shown with torso engaging portion 37.
In operation, the user wears seat belt 36, and pulls band 26 around belt portion 37 and engages pad 28 with strip 27 to form the triangular loop or alternatively pulls the seat belt 36 through the pre-formed triangular loop 34. The elastic member 11 holds the seat belt and elastically pulls belt portion 37 away from the user's torso thereby providing the desired relief. Buckle 15 may be adjusted to provide the desired degree of relief of belt portion 37 away from the torso of the wearer. When the user is exiting from the car, seat belt 36 is released and passed through triangular loop 34 or loop 34 is opened. Strip 27 is then attached to pad 35 so that the device is stowed away directly above and parallel to the door frame (see phantom line of FIG. 1).
It is understood that mounting pad 35 and base mounting member 21 may be mounted to the inside of the car above, adjacent or on the door frame by one of several well known means. It is also within the contemplation of the invention to provide non-permanent mounting means such as with magnetic members, and the like.
Under high acceleration, the seat belt pulls towards the user, and this force is sufficient to overcome the Velcro holding force of the triangular loop so as to disengage the Velcro pads and "knock down" the triangular loop, thus permitting the seat belt to hold the user in its intended manner.
Referring now to FIGS. 5-7 there is shown alternate embodiment generally referred to as 50. Device 50 is formed of a thin normally flat flexible card 51 formed with a top flexible magnetic portion 52 and a coextensive flat flexible plastic portion 53 integrally bonded therewith. Portion 53 tapers at 54 to form a v-shaped cylindrical plate extension portion 55. Portion 55 is formed with through hole 56. Metal ring 57 slidably moves in hole 56. A swivel member 58 of conventional construction is formed with oppositely disposed loops 59 and 60. Loop 59 is engaged by ring 57, while loop 60 is engaged by end 61 of cylindrical, flexible, and elastically retractably extensible member or cord 62. End 61 is permanently held by stitching 65. Cord 62 may be adjustably looped as at 63 through and with adjustment retaining member 64 of well known construction, to adjust the length of cord 62.
End 62' of cord 62 is stitched at 66 to side 67 of flat flexible fabric piece 68. Fabric piece 68 is of similar size and shape to fabric piece 26 heretofore described. Opposed interengaging Velcro pads 69 and 70 are affixedly mounted to sides 71 and 72 of fabric piece 68, so that when pads 69 and 70 are engaged a triangular loop 73 is formed. A stiff cardboard plate 75 is adhesively secured at 76 to portion 77 of fabric piece 68 to ensure the integrity of the triangular loop 73 with the Velcro pads 69 and 70 interengaged.
A seat belt (not shown in FIGS. 5-7) passes through and resides in triangular loop 73 in a manner similar to that heretofore discussed in relation to the first described embodiment.
In use, flexible card 51 is placed with magnetic face 52 upwardly against the underside of automobile frame 80 at the door portion. Card is magnetically held in place with the door 81 open. The door 81 and specifically top door frame 82 is closed so as to wedge flexible card 51 between the automobile frame 80 and the door frame 82. The device is then used in a manner similar to that previously described.
The device 50 is disengaged by opening the triangular loop 73 and then opening the car door while holding card 51.
In this manner of construction device 50 may be readily used and removed without providing permanently mounted elements in the automobile.
It is to be understood that variations and modifications of the present invention may be made without departing from the scope thereof. It is also to be understood that the present invention is not to be limited by the specific embodiments disclosed herein but only in accordance with the appended claims when read in light of the foregoing specification. | A seat belt tension relief device is formed with an elastic self-retracting member which at one end is pivotally mounted adjacent the door frame while at the other end adjustably engages the torso engaging portion of the seat belt. The length of the elastic self-retracting member, as well as the strap engaging end portion, are readily adjustable to the comfort of the user. When not in use the device is adjustably mounted parallel to and along the door frame. The device is designed to be economically retrofitted in automobiles with spring-loaded seat belts. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for cooling high-temperature particles and more particularly an apparatus for air-cooling high-temperature clinker in a cement burning process or for cooling high-temperature particles in a process of burning or sintering steel, lime stone or alumina.
Japanese Patent Application Nos. 2226/1983 (laid open under No. 128243/1984) and 2227/1983 (laid open under No. 128244/1984) disclose a cooling apparatus which can overcome the problems encountered in conventional grate type coolers for air-cooling high-temperature cement clinker. The above-mentioned cooling apparatus will be described with reference to FIGS. 8 and 9. First referring to FIG. 8, reference numeral 31 designates a first cooling zone in which high-temperature particles such as cement clinker is air-quenched; 32, a second cooling zone which is disposed below the first cooling zone 31 to gradually cool the cement clinker which has been quenched in the first cooling zone 31; and 33, a rotary kiln for burning cement.
The first cooling zone 31 comprises a vertical guide tube 34 which is disposed at the inlet and is adapted to temporarily hold high-temperature cement clinker and to prevent the cement clinker from being rapidly spread in the radially outward direction; a conical or pyramidal body 35 which has a large number of air distributing holes, is disposed coaxially with the guide tube 34, spaced apart therefrom by a predetermined distance and has a very gentle inclination angle smaller than an angle of repose; a motion acceleration device 36 which is vertically movable between the top of the conical or pyramidal body 35 and the guide tube 34, thereby accelerating the movement of cement clinker along the outer surface of the body 35 in the radially outward direction; and an air-cooling device 37 which supports the vertical guide tube 34 and is adapted to cool the outer surface thereof.
The second cooling zone 32 comprises a packed moving bed type cooling device 38 in which rapidly cooled cement clinker is packed into layers which move downward.
Still referring to FIG. 8, reference numeral 39 designates a control rod for controlling the downward movement of cement clinker; 40, a scraper ring; 41, a discharge scraper; 42, a turntable; 43, a conveyor for discharging the cooled cement clinker out of the system; 44, a main air supply line for supplying the air for cooling the high-temperature (or first cooling) zone; 45, a blower; 46, an air supply line for supplying the air for cooling the low-temperature (or second cooling) zone; 47, a blower; 48, an air compressor; 49, a directional control valve; 50, an air supply line for supplying the air to activate the motion acceleration device; 51, an auxiliary air supply line for supplying the air to cool the high-temperature zone; 52, an air discharge line for discharging air from the motion acceleration device; 53, a valve; and 54, an air supply line for supplying the combustion air to a calcination furnace.
Next referring to FIG. 9, the relationship among the vertical guide tube 34, the conical or pyramidal body 35 and the motion acceleration device 36 and the construction of the motion acceleration device 36 will be described. The motion acceleration device 36 is in the form of a piston whose upper end terminates into a cone with a large number of holes and is mounted on a stationary member 55 disposed below the guide tube 34 in coaxial relationship with the axis 56 of the guide tube 34 for vertical movement. The motion acceleration device 36 comprises a hollow conical head 57 with a bottom, an outer tube 58 and an inner tube 59 which are formed integral with the head 57. A high pressure chamber 60 is defined between the outer and inner tubes 58 and 59. The stationary member 55 comprises an inner tube 61 and an outer tube 62. A lower end portion of the inner tube 59 is inserted into the inner tube 61 while a lower portion of the outer tube 58 is air-tightly fitted over the outer tube 62. The motion acceleration device 36 is vertically slidable relative to the stationary member 55. The stationary member 55 has an air inlet 63 communicated with the air supply line 50, an air inlet 64 communicated with the auxiliary air supply line 51 and an air outlet communicated with the air discharge line 52.
With the cooling apparatus of the type described above, cement clinker 67 which is burned in the rotary kiln 33 to a high temperature of about 1350° C. is fed into the vertical guide tube 34 as indicated by a broken-line arrow 68, temporarily remains therein and then discharged over the conical or pyramidal body 35. Due to the slope of the conical or pyramidal body 35, the pressure of the air flowing upwards through the air distributing holes as indicated by the arrows 71 and the vertical movement of the motion acceleration device, cement clinker is distributed radially outwardly. Since cement clinker is forced to flow along the outer surface of the conical or pyramidal body 35 radially outwardly in the first cooling zone 31, it is rapidly and uniformly cooled to about 950° C. by the air flowing upwardly as indicated by the arrows 71. Cement clinker thus rapidly cooled is then fed into the packed moving bed type cooling device 38 which constitutes the second cooling zone 32 and is gradually cooled by the air supplied through the cooling air supply line 46. Cement clinker thus cooled is discharged by the conveyor 43 out of the system.
The air from the main air supply lines 44 is at room temperature and flows in the directions indicated by the arrows 69, 70, 71 and 72 so that the air is heated to about 1050° C. and is used as the combustion air in the rotary kiln 33. The air at room temperature from the cooling air supply line 46 passes through the packed moving bed type cooling device 38 and is heated to about 800° C. and flows into the air supply line 54 for supplying the combustion air into the calcination furnace.
The compressed air from the air compressor 48 is switched by the directional control valve 49 to flow into the air supply line 50 for supplying the air for activating the motion acceleration device or into the auxiliary air supply line 51 for supplying the cooling air to the high temperature zone. More particularly, as best shown in FIG. 9, the compressed air supplied through the auxiliary cooling air supply line 51 flows through the air inlet 64, the inner tube 61 and the inner tube 59 into the hollow space in the conical head 57. The air is discharged upwardly from the conical head 57 into the vertical guide tube 34, thereby mixing and cooling cement clinker remaining therein. When the compressed air is forced to flow through the air supply line 50 for supplying the air to activate the motion acceleration device, the valve 53 is closed. Then the compressed air from the line 50 flows into the air inlet 63 and through the space defined between the inner and outer tubes 61 and 62 to the high pressure chamber 60 where the compressed air is blocked. As a result, the motion acceleration device 36 is forced to move upwardly relative to the stationary member 55. On the other hand, when the supply of the compressed air to the line 50 is interrupted while the valve 53 is opened, the compressed air in the high pressure chamber 60 is discharged through the air discharged line 52 so that the motion acceleration device 36 is caused to move downwardly by its own weight relative to the stationary member 55. Thus, when the valve 53 is closed to introduce the compressed air through the line 50 into the high pressure chamber 60 and when the supply of the compressed air to the line 50 is interrupted while the valve 53 is opened, thereby discharging the compressed air from the high pressure chamber 60, the motion acceleration device 36 is forced to vertically move relative to the stationary member 55. In this case, a slight vertical stroke is sufficient enough to accelerate the movement of cement clinker along the outer surface of the conical or pyramidal body 35 so that the motion acceleration device vertically reciprocates a stroke indicated by 57 and 57a. However, when a large lump of cement clinker is fed into the vertical guide tube 34, the motion acceleration device is caused to move down to the position indicated by 57b so that the large lump drops not through the conical or pyramidal body 35 but directly downwardly and is discharged out of the cooling apparatus through a discharge port (not shown) later at a suitable time.
With the apparatus for cooling high-temperature particles of the type described above, the stability of the moving layer of high-temperature particles along the outer surface of the conical or pyramidal body is adversely affected due to the fluctuations in flow rate and pressure of the mixing and cooling air flowing through the motion acceleration device, the disturbances in mixing action in the high-temperature particle layer, the changes in pressure distribution between the high-temperature particle layers both caused by the vertical movement of the motion acceleration device, the variation in particle size distribution of the high-temperature particles fed from the rotary kiln, the response of the change in pressure distribution between the layers caused by the drop impact pressure, and the other variables of high-temperature particles in the vertical guide tube. For instance, high-temperature particles are abnormally forced to flow from the vertical guide tube to the conical or pyramidal body. As a result, the whole burning process including a step in the cooling apparatus is adversely affected.
Furthermore with the cooling apparatus of the type described above, in order to remove large and medium lumps in high-temperature particles, the motion acceleration device is forced to move to the lower dead point. Then the large and medium lumps are caused to drop together with the high-temperature particles remaining in the vertical guide tube and are removed out of the cooling apparatus later at a suitable time.
However, when large and medium lumps frequently admix in the high-temperature particles, they cannot be removed because of the insufficient capacity of the lower storage zone and because of a time required for naturally cooling the large and medium lumps dropped together with the high-temperature particles, resulting in shutdown of the rotary kiln and the cooling apparatus.
The present invention was made to overcome the above and other problems encountered in the cooling apparatus of the type described above.
A primary object of the present invention is, therefore, to provide an apparatus for cooling high-temperature particles in which variable factors in the vertical guide tube will not adversely affect the stability of the moving layer of high-temperature particles along the surface of the conical or pyramidal body.
A further object of the present invention is to provide an apparatus for cooling high-temperature particles in which high-temperature large and medium lumps mixed in the high-temperature particles from the rotary kiln can be crushed while their temperatures are still high, whereby the performacne of the cooling apparatus can be improved and enhanced.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of some preferred embodiments thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view of a first embodiment of the present invention;
FIG. 2 is a vertical sectional view of a second embodiment of the present invention;
FIG. 3 is a vertical sectional view of a third embodiment of the present invention;
FIG. 4 is a vertical sectional view of a fourth embodiment of the present invention;
FIG. 5 is a vertical sectional view of a fifth embodiment of the present invention;
FIG. 6 is a sectional view taken along the line VI--VI of FIG. 5;
FIG. 7 is a vertical sectional view of a sixth embodiment of the present invention;
FIG. 8 is a view used to explain a cooling apparatus; and
FIG. 9 is a fragmentary view, on enlarged scale, thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a first embodiment of the present invention which is substantially similar in construction to the cooling apparatus described above with reference to FIGS. 8 and 9. In FIG. 1, reference numeral 1 designates a vertical guide tube for temporarily holding high-temperature particles such as high-temperature cement clinker discharged from a rotary kiln (not shown) and also for preventing the rapid spread of the high temperature particles in the radially outward directions; 2, an axis of the vertical guide tube 1; 3, a vertical outer tube which is disposed space below the vertical guide tube 1 in coaxial relationship therewith and defines together with the vertical guide tube 1 a double wall guide tube; 4, refractory brick or castable lining over the inner surfaces of the vertical guide tube 1 and outer tube 3; 5, a conical or pyramidal body which is disposed space below the outer tube 3 such that its imaginary vertex coincides with the axis 2 of the guide tube 1 and whose inclination angle is smaller than an angle of repose; 6, air holes formed through the conical or pyramidal body 5; 7, a motion acceleration device which extends from the top of the conical or pyramidal body 5 into the guide tube 1 and which is vertically movable so that the distribution in the radially outward directions of the particles along the outer surface of conical or pyramidal body 5 is accelerated, the top portion of the motion acceleration device 7 being in the form of a cone while the remaining portion is in the form of a cylinder; 8, air holes formed through the conical head and upper cylindrical wall portion of the motion acceleration device 7; 9, high-temperature particles; 10, an annular opening defined between the lower circular end of the guide tube 1 and the upper circular end of the outer tube 3; 11, a free surface of a high-temperature particle layer formed in the annular opening 10; 12, a gap for controlling the thickness of a layer formed between the lower end of the outer tube 3 and the conical or pyramidal body 5; 13, arrows indicating the directions of the air flowing through the motion acceleration device 7 into the guide tube 1, thereby mixing and cooling the high-temperature particles remaining therein; 14, arrows indicating the direction of the flows of the air for cooling the high-temperature particles 9 on the conical or pyramidal body 5; and h, a vertical stroke of the motion acceleration device 7 in the case of the normal operation thereof.
The inner surface of the outer tube 3 is composed by three conical surfaces concentric with the axis 2 of the guide tube 1 and having respective generating lines, i.e., a line segment AB which is inclined downwardly toward the axis 2, a line segment BC whose upper end is merged to a lower end of the line segment AB and which is located away from the axis 2 in the downward direction and a line segment CD whose upper end is merged to a lower end of the line segment BC and which is inclined downwardly toward the axis 2; thus the inner surface of the outer tube has a zigzag cross section. Both the angle α of inclination of the line segment AB and the angle β of inclination of the line segment BC are sufficiently larger than an angle of repose and the line segments CD and BC are substantially perpendicular relative to each other. The position of the upper end A of the outer tube 3 is slightly higher than the position of the lower end K of the guide tube 1 to thereby prevent the overflow of the high-temperature particles 9 through the annular opening 10 and to ensure the stable formation of the free surface 11 of the high temperature particles 9. Since the angle α of inclination is greater than the angle of repose, the high-temperature particles 9 in the vicinity of the free surface 11 at the annular opening 10 smoothly flow down along the conical wall surface generated by the line segment AB. Since the angle β of inclination is greater than the angle of repose, the high-temperature particles 9 are forced against the conical wall surface generated by the line segment BC. In addition, the conical wall surface generated by the line segment CD which is substantially perpendicular to the line segment BC serves to prevent the displacement of high-temperature particles 9. As a result, a tarrying zone 15 in which the high-temperature particles 9 remain is defined. The high-temperature particles 9 are displaced along the boundary surface generated by revolution of an arc BD about the axis 2. The gap 12 for controlling the thickness of the moving layer of high temperature particles along the outer surface of the conical or pyramidal body 5 is defined by a conical surface generated by revolution of a line segment EF about the axis 2 where E is the lower end of the outer tube 3 and the point F is on the inclined surface of the conical or pyramidal body 5 at which the line segment EF is perpendicular to the inclined surface of the conical or pyramidal body 5. The conical or pyramidal body 5 inside the layer thickness control gap 12 is formed with a cylindrical recess whose axis coincides with the axis 2. The air for mixing and cooling the high-temperature particles 9 remaining in the guide tube 1 is forced to flow through the gap 19 defined between the bottom 18 of the cylindrical recess and the motion acceleration device 7 and through the motion acceleration device 7 itself. The cylindrical wall 17 and the bottom 18 of the cylindrical recess are not formed with any air hole. Thus, a tarrying zone where the high-temperature particles stay is defined as indicated by the reference numeral 16. Therefore, the high-temperature particles 9 are displaced along the boundary surface generated by revolution of an arc GH about the axis 2. The angle α of inclination at the point G of the arc GH is substantially equal to the angle of repose.
Two surfaces of revolution generated by revolution of the arcs BD and GH, respectively, about the axis 2 define a passage of high-temperature particles 9 which converges gradually from and below the annular opening 10 toward the layer thickness control gap 12 on the conical surface. Therefore, the high-temperature particles 9 passing through this passage are applied with a suitable pressure. Furthermore, the free surface 11 itself of the high-temperature particles 9 in the annular opening 10 prevents disturbances by the various variable factors. As a result, various factors which disturb the stability of the moving layer of high-temperature particles formed on the conical or pyramidal body 5 can be substantially eliminated.
The advantage of forming the boundary surfaces of the passage by the arcs BD and GH in the layer of the high-temperature particles resides in the fact that in response to the displacement of the moving layer of high-temperature particles along the outer surface of the conical or pyramidal body 5, the high-temperature particles 9 are supplied through the layer thickness control gap 12 smoothly and at a predetermined flow rate. Therefore, no clogging occurs and the wear of the surfaces of the structual parts can be avoided.
The protective cooling air is forced to flow through the guide tube 1 and the outer tube 3 and a supporting member (indicated by the reference number 23 in FIG. 5). The outer surfaces of the guide tube 1, the outer tube 3 and the supporting member 23 are lined with refractory brick or castable 4 so as to protect the outer surfaces from high temperature heat.
FIG. 2 shows a second embodiment of the present invention. In the first embodiment shown in FIG. 1, the arc BD defines the tarrying zone 15; but in the second embodiment as shown in FIG. 2, the boundary surface generated by the arc BD is a part of the inner wall surface of the outer tube 3. Except this, the second embodiment is substantially similar in construction to the first embodiment.
FIG. 3 shows a third embodiment of the present invention. While in the first embodiment described above with reference to FIG. 1, the tarrying zone 16 is defined by the arc GH, the surface generated by the arc GH in the third embodiment constitutes a part of the conical or pyramidal body 5. Except this, the third embodiment is substantially similar in construction to the first embodiment.
FIG. 4 shows a fourth embodiment of the present invention in which the inner wall of the outer tube 3 is substantially similar to that in the second embodiment described above with reference to FIG. 2 and the upper central portion of the conical or pyramidal body 5 is substantially similar to that in the third embodiment described above with reference to FIG. 3. Except these two features, the fourth embodiment is substantially similar in construction to the first embodiment described above with reference to FIG. 1.
FIGS. 5 and 6 show a fifth embodiment of the present invention in which high-temperature large- or medium-sized lumps 21 can be crushed. Reference numeral 20 designates a projection of refractory brick or castable 4 lined over the inner wall surface of the guide tube 1. The projections 20 extend radially inwardly toward the axis 2 as best shown in FIG. 6. The spacing between the adjacent projections 20 and the spacing between the projections 20 and the motion acceleration device 7 are smaller than a permissible particle size and than the thickness of the moving layer of the high-temperature particles 9 along the outer surface of the conical or pyramidal body 5. Reference numeral 22 designates an arrow indicating the direction of the flow of the cooling air for protecting the guide tube 1 and the guide tube supporting member 23 from high temperature; and 24, arrows indicating the directions of the flows of the compressed air for activating the motion acceleration device 7.
With the apparatus for cooling high-temperature particles of the type described above with reference to FIGS. 5 and 6, the cross sectional areas of the high-temperature particle passages in the guide tube 1 are smaller than a permissible particle size because a plurality of projections 20 are provided as descrbied above. Therefore, the high-temperature particles 9 whose particle sizes are smaller than a predetermined permissible particle size smoothly move downward through the guide tube 1, but a large-sized or medium-sized lump whose size is larger than a predetermined permissible particle size is prevented by the projections 20 from being dropped so that it temporarily stays in the guide tube 1. In this case, as the motion acceleration device 7 vertically reciprocates, the upper leading end thereof strikes the lump 21, thereby breaking it into small-sized particles. This can be accomplished easily because the large-sized or medium-sized lumps 21 which have been just discharged out of the rotary kiln and have not been cooled yet are very fragile. In other words, when the large- or medium-sized lump 21 is cooled, its strength is remarkably increased so that it requires a great force to break it into smaller particles. It follows, therefore, that it is advantageous to break the lump 21 into smaller particles while it is still hot as described above. The crushed particles whose sizes are smaller than a predetermined particle size move down through the guide tube 1 onto the conical or pyramidal body 5 where the crushed particles are cooled by the air.
FIG. 7 shows a sixth embodiment of the present invention in which the motion acceleration device 7 comprises an inner tube 25 and an outer tube 26. The vertical stroke H of the motion acceleration device 7 in the sixth embodiment shown in FIG. 7 is longer than the stroke h of the motion acceleration device 7 of the type shown in FIG. 5 so that large-sized and medium-sized lumps are more easily broken into smaller particles.
Same reference numerals are used to designate similar parts throughout FIGS. 1-7.
In the apparatus for cooling high-temperature particles in accordance with the present invention, the guide tube and the outer tube which is interposed between the guide tube and the conical or pyramidal body coaxially of the guide tube constitute a double-guide-tube system. The free surface of the high-temperature particle layer is formed in the annular opening defined between the guide tube and the outer tube. Therefore, part of the air which flows through the motion acceleration device to mix and cool the high-temperature particles remaining in the guide tube is prevented from being directed toward the moving high-temperature particle layer along the outer surface of the conical or pyramidal body, but is directed toward the annular opening. In addition, the upper end of the outer tube is slightly higher than the lower end of the guide tube so that influence of the decrease in angle of repose of the high-temperature particles due to the air flow for mixing and cooling the high-temperature particles in the guide tube is prevented and consequently the free surface can be maintained in a stable manner. Moreover, the passage for the high-temperature particles defined in the outer tube is gradually converged toward the layer thickness control gap defined between the lower end of the outer tube and the conical or pyramidal dody so that the high-temperature particles are applied with an optimum pressure as they move toward the layer thickness control gap. As a result, various factors which disturbe the stability of the high-temperature particle layer formed over the conical or pyramidal dody can be substantially eliminated because the free surface of the high-temperature particles in the annular opening exhibits the stabilizing effect and the high-temperature particles which move through the passage defined in the outer tube are applied with an optimum pressure. Furthermore, the guide tube has a plurality of radially inwardly extended projections and the spacing between the adjacent projections and the spacing between the projections and the motion acceleration device are smaller than a predetermined permissible particle size so that the cross sectional areas of the high-temperature particle passages defined in the guide tube are smaller than a predetermined permissible particle size. Therefore, the high-temperature particles whose sizes are smaller than a predetermined permissible particle size are permitted to freely drop through the guide tube, but high-temprature large-sized or medium-sized lumps whose sizes are greater than a predetermined permissible particle size temporarily stay on the projections in the guide tube and then are broken into smaller particles when the upper end of the motion acceleration device, which is vertically reciprocable, strikes the large-sized or medium-sized lump trapped by the projections while it is still hot. As a consequence, the breakers or the like which are indispensable in the above-described conventional grate type cooler can be eliminated. In addition, the performance of the cooling apparatus of the type described in Japanese Patent Application Nos. 2226/1983 and 2227/1983 can be remarkably improved and positively ensured. | An apparatus for cooling high-temperature particles in which various factors which adversely disturb the stability of the moving layer of high-temperature particles can be substantially eliminated and large-sized and medium-sized lumps contained in the high-temperature particles are forcibly broken into smaller particles for prevention of shutdown of a clinker burning process or the like. | 5 |
BACKGROUND OF THE INVENTION
A process for preparing m-phenylene isophthalamide fiber involves spinning the solution of the polymer, as prepared, including dimethylacetamide and by-product calcium chloride and contacting the extruded filaments with a hot inert gas such as nitrogen to partially remove solvent. A cold aqueous solution is used to quench and coagulate the filaments. Finally, the filaments are wash-drawn and collected. Satisfactory results have been achieved by this process, however, attempts to increase throughput in the quench-coagulation step has often resulted in nonuniformities as shown by opaque white streaks in the otherwise translucent filaments and by variations in tensile strength among the filaments. Also, fusion between filaments may occur as well because of slow, non-uniform cooling of some filaments. The present invention has applicability to processes wherein the freshly extruded solvent-containing filaments first contact an inert gas or fluid before quench-coagulation with an aqueous solution as well as to wet-spinnning processes wherein the solvent-containing filaments are spun directly into an aqueous quench-coagulation solution.
DRAWINGS
FIG. 1 depicts a fiber manufacturing process under consideration in this invention. In Step 1, the polymer solution is extruded into filaments. In Step 2, the filaments are optionally contacted with a flow of hot inert gas to drive off part of the solvent. In Step 3, the filaments are contacted with a liquid which quenches and coagulates the filaments. In Step 4, the filaments are wash-drawn and in Step 5 the filaments are collected.
FIG. 2 is a schematic side view of the chamber in which quench-coagulation takes place.
SUMMARY OF THE INVENTION
The present invention provides an improved process for preparing fiber from a polymer solution which includes the steps of:
a) extruding the solution from a spinneret to form a plurality of filaments;
b) optionally passing the extruded filaments through an inert gas;
c) treating the filaments with an aqueous liquid coagulant to quench and coagulate the filaments;
d) washing and drawing the filaments; and
e) collecting the filaments; the improvement comprising, quench coagulating the filaments more uniformly and more rapidly in step c) by passing the filaments between substantially parallel opposing walls of a chamber containing the aqueous liquid coagulant, the said opposing walls comprising the faces of ultrasonic transducers, and driving the transducers, in phase, at a frequency of from 5 to 100 kHz to cause pressure fluctuations in the liquid coagulant, the spacing between the said opposing walls being less than one-half the wavelength of sound generated by the transducers in the liquid coagulant.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described below with reference to a process for preparing m-phenylene isophthalamide (MPDI) fiber. However, the invention can be applied to other processes such as the spinning process described in the Blades patent U.S. Pat. No. 3,767,756 for making poly(p-phenylene terephthalamide) fiber wherein the solvent-containing filaments leaving the spinneret are first passed through an air gap and then through aqueous liquid coagulant or a spinning process wherein the solvent-containing filaments leaving the spinneret are passed directly into and through an aqueous liquid coagulant. The process is particularly effective in the production of aromatic polyamide fiber, preferably aramid fiber where a salt is present in the spin dope. Conventional quench coagulation is adversely affected by the presence of salts in the spin dope, as will be understood to those skilled in the art.
As-prepared MPDI polymer solution conventionally contains dimethyl acetamide (DMAc) or other solvent and calcium chloride or other salt in addition to the polymer itself. The solvent may constitute as much as about 80% of the solution. In the process for preparing fiber from the polymer, this solution or spin dope is spun or extruded through a spinneret to form a plurality of filamentary streams, and a flow of hot inert gas such as nitrogen at a temperature of about 450° C. is passed in contact with the spun filaments. The solvent content of the filaments is thereby reduced. In the next step of the process, the hot filaments are contacted with an aqueous liquid, generally cold water, below 5° C., which quenches and coagulates the filaments. It is this step which is the focus of the present invention. Streaks are the result of improper quenching, that is, the quench liquid is not uniformly distributed around the filaments when they contact the quench liquid. Uniform quenching produces a uniform, polymer-rich skin structure on the surface of the fiber. Improper quenching allows water to penetrate the skin structure and create voids in the surface.
To achieve the improvement of the present process, the filaments are quench-coagulated in a special manner. The filaments, after treatment with the hot inert gas, are passed through a chamber having opposing walls comprising radiating ultrasonic transducer faces. The filaments in bundles of 15,000 denier or greater may traverse the length of the chamber at speeds of 200 to 250 yards per min. or even faster. Cold liquid is fed into the chamber generally at a rate of 80 to 120 gallons per hour, to quench and coagulate the filaments. The procedure can be performed as depicted in FIG. 2 showing a schematic side view of the chamber 1, having opposing walls 2. Aqueous liquid coagulant 3 enters through ports 4 to maintain a desired level in the chamber. Filaments 5 enter the chamber, are centered and flattened into a ribbon by guide 6 and pass through the chamber in contact with coagulant liquid 3. The opposing faces 2 of ultrasonic transducers 8 are driven, in phase, at a frequency of from 5-100 kilohertz kHz. By "in phase" is meant that the two opposing transducer faces move towards and away from each other in synchronism. Magnetostrictive or piezoelectric devices may be employed as the transducers. Preferably, a frequency of from 20 to 70 kHz is employed. Vibra-Bar transducers (Crest Ultrasonics, Trenton, N.J.) at 40 or 65 kHz are suitable for this purpose. The distance between the two opposing walls of the chamber which are constituted by the radiating transducer faces should be less than one-half the wavelength of the sound generated by the transducers in the liquid coagulant. Generally, 1 inch or less is suitable, the specific distance limit being readily determined by the frequency at which the transducers are driven and the coagulant fluid employed, as is well-understood by the art. For example, at a frequency of 40 kHz with water as coagulant at 4° C. the faces are about 3/4 inch apart or less.
The transducers used in this invention are driven at a total average power level of 36 to 250 watts to provide average power densities of approximately 1 to 7 watts per square inch of radiating area and 4 to 28 watts per cubic inch of liquid in the quench chamber. When compared to conventional ultrasonic cleaning baths, the maximum area power density of this invention is 2 to 3 times higher, while the maximum volume power density is 100 to 600 times higher.
The intense sound field generated by the transducers is characterized by pressure fluctuations in the quench liquid that are most intense in the plane centered between the radiating transducer faces, which is congruent with the path of the ribbon of filaments. The pressure fluctuations produce several beneficial effects that improve the uniformity and speed of filament quenching or coagulation. On a macroscopic scale, the quench liquid is driven into and out of the filament ribbon to improve the uniformity of the liquid contact with all of the filaments, particularly those not in the surface layer of the ribbon. On a microscopic scale, localized, high-velocity liquid eddies and currents penetrate the filament boundary layers to continually carry fresh quench liquid to the filament surfaces. Also, cavitation bubbles form and collapse as the sound pressure field alternates below and above the ambient pressure, creating extremely localized shock waves. These microscopic phenomena combine to increase thermal diffusion and mass transfer rates, thereby increasing the speed of the quench-coagulation process.
The treated fiber bundle and entrained liquid exits the chamber through port 7. The quenched-coagulated MPD-I filaments are normally subjected to a wash-draw where the filaments are washed and drawn and then collected before or after drying.
The following example of the invention is not intended as limiting.
EXAMPLES
The fibers or filaments of these examples were prepared from aromatic polymers such as are disclosed in U.S. Pat. No. 3,063,966 to Kwolek, Morgan, and Sorenson; 3,094,511 to Hill, Kwolek and Sweeny; and 3,287,324 to Sweeny, for example. Filaments were prepared from a filtered solution consisting of 19.2%, based on the weight of the solution, of poly(meta-phenylene isophthalamide) in N,N-dimethylacetamide (DMAc) that contains 45% calcium chloride based on the weight of the polymer. The polymer had an inherent viscosity of 1.57 as measured on a 0.55 solution in DMAc/4% LiCl at 25 degrees C. The spinning solution was heated to 120-145 degrees C and extruded through a 3600-hole spinneret, each hole 0.006 inch (150 microns) in diameter and 0.012 inch (300 microns) long, into heated spinning cells containing an inert gas. For each of the following examples, the speed of the just-spun filaments was in excess of 200 ypm.
EXAMPLE 1 (CONTROL)
This example illustrates a prior art process, which is disclosed in U.S. Pat. No. 3,493,422 to Berry; this reference discloses an apparatus and process for efficient heat and/or mass transfer by sequentially contacting a moving shaped structure through a stripping liquid. The filaments, as spun above, (each filament being about 12 dpf as spun), were formed into a flat ribbon of filaments at the top of the quench zone and then brought in contact with a cold, approximately 4° C., aqueous solution containing 4-12% DMAc and flowing essentially co-current with the filament ribbon in a serpentine manner as dictated by the shape of the quenching apparatus. Filaments made by this process had visible streaks, the quantity of which was proportional to the speed of the filament ribbon.
EXAMPLE 2
This example illustrates the invention of this application. The filaments, as spun above (each filament being about 12 dpf as spun), were formed into a flat ribbon at the top of the quench zone and then entered a straight rectangular quench chamber approximately 1 in. by 3 in. in cross-section and 6 in. long, said chamber containing a cold, approximately 4 degrees C, aqueous solution containing 4-12% DMAc and flowing co-current with the filament ribbon. The radiating faces of two piezoelectric transducers constituted the opposing wider walls of the chamber as illustrated in FIG. 2. The width of the ribbon passed between the two opposing transducer faces which were vibrated in phase (moving towards and away from each other in synchronism) at a sonic frequency of 40 kHz, generating intense pressure fluctuations in the liquid in the sonic field zone. The two transducers were driven at a total average power level of 250 watts to provide average power densities of approximately 7 watts per square inch of radiating surface area and 28 watts per cubic inch of liquid in the quench zone. Essentially none of the filaments made by this process had visible streaks; and filament quality was not as sensitive to the speed of the filament ribbon. | More uniform and more rapid quenching and coagulation of filaments is achieved by contacting the filaments in a chamber with coagulating liquid and generating pressure fluctuations in the liquid at high frequency sonic or ultrasonic frequencies. | 3 |
FIELD OF THE INVENTION
The present invention pertains to a burner of a vehicle heater and in particular to a burner where liquid fuel is evaporated by a porous lining in a combustion chamber and a glow plug ignites the fuel.
BACKGROUND OF THE INVENTION
The ignition of the fuel in a combustion chamber causes very harsh and adverse conditions which can cause a glow plug to deteriorate. Also byproducts of combustion can accumulate on a glow plug causing fouling and blocking the glow plug from igniting the fuel. In the combustion chamber conditions progress from being almost completely full of liquid fuel, to varying fuel air mixtures, to partial combustion, to full combustion and then to full exhaust. The position of the glow plug is therefore of very great significance for ignition in such burners to avoid deterioration and fouling of the glow plug and still ignite the fuel or fuel-air mixture. The position of the glow plug is also of very great significance for an optimal ignition process in such burners. Previously the glow plug was arranged in a socket projecting radially away from the circumferential wall of the combustion chamber, or it was positioned behind the bottom of the combustion chamber.
SUMMARY AND OBJECTS OF THE INVENTION
The basic object of the present invention is to design the burner with regard to the arrangement of the glow plug such that favorable conditions will be achieved for the ignition, and the glow plug is accommodated in an especially space-saving manner.
To accomplish this object, the burner is characterized according to the present invention in that
e) the glow plug is arranged such that it has a plug longitudinal axis located essentially in a tangential plane of the circumferential wall of the combustion chamber.
A large part of the glow area of the glow plug is brought into the favorable vicinity of the interior space of the combustion chamber due to the arrangement of the glow plug. At the same time, especially little space is needed in the environment of the combustion chamber.
The location and the arrangement of the glow plug can also be expressed such that its plug longitudinal axis extends essentially in the tangential direction in relation to the circumferential wall of the combustion chamber, and this should not mean that the longitudinal axis of the glow plug absolutely has to lie in a plane which extends at right angles to the longitudinal axis of the combustion chamber. The longitudinal axis of the glow plug may assume any position in a tangential plane of the circumferential wall of the combustion chamber, and it may even extend in parallel to the longitudinal axis of the combustion chamber in the limiting case, which is even a favorable one. The mounting plane in which the longitudinal axis of the glow plug is located may be shifted somewhat to the inside of the combustion chamber or away from the interior of the combustion chamber in relation to the plane which is mathematically the tangential plane of the circumferential wall of the combustion chamber, as will be shown in the exemplary embodiments described below. The glow area of the glow plug is preferably arranged in an outer side chamber of the combustion chamber, and the side chamber is in connection with the combustion chamber via an opening. The glow plug is thus protected from adverse effects caused by the conditions prevailing in the combustion chamber, especially in terms of exposure to flame and dirt accumulation.
The opening preferably passes through the lining of the combustion chamber, and it is especially favorable for the lining to have a surface area facing the side chamber next to the opening or around the opening. These measures ensure the best conditions for the evaporation of fuel in the immediate vicinity of the glow plug and the formation of a ready-to-ignite fuel-air mixture there.
As an alternative, it is preferable to arrange the glow area of the glow plug in a recessed space of the lining, which is in connection with the combustion chamber via an opening. This also ensures favorable conditions for ignition, on the one hand, and sealing of the glow plug against adverse effects of the conditions prevailing in the combustion chamber.
In a preferred variant of the present invention, the lining, which is designed as a mounted part manufactured as a whole, has a circumferential area and a bottom area. This designing as a mounted part manufactured as a whole, makes possible an especially efficient manufacture and leads to optimal distribution of the fuel being supplied in the lining. Metal netting, metal fabric, sintered metal bodies, and porous ceramic materials are especially suitable materials for the lining or the mounted part. In the case of manufacture from metal netting, metal fabric or the like, it is possible to use especially a disk-shaped blank as the raw material, which is then drawn or compressed to the shape of, e.g., a cup. The lining may also be made from a cut piece. Any openings that may be necessary may be prepared without any problems by, e.g., punching.
At least one intake opening for combustion air is preferably provided in a wall, which is adjacent to the rear side of the lining facing away from the combustion chamber. The combustion air flowing through this intake opening, or intake openings, subsequently passes through the lining and promotes the removal of fuel vapors from the lining into the combustion chamber. The combustion air flowing in there enters the combustion chamber in a finely dispersed form, as desired. Only part of the entire amount of combustion air usually flows into the combustion chamber by this route.
The means for supplying fuel preferably has a fuel supply channel opening to the lining, and this outlet opening should preferably be located at a rather short distance from the point at which the glow area of the glow plug is close to the lining. An especially high degree of saturation of the lining with fuel will thus be attained precisely in the area of the lining which is close to the glow area of the glow plug.
The outlet opening may favorably be located essentially in the same plane of the combustion chamber as the glow plug, and the angular distance between the outlet opening and the point at which the glow area of the glow plug is close to the lining is less than 90° and preferably less than 60°.
To create the best possible conditions for supplying the combustion air, an air supply pre-chamber of the combustion chamber may be provided.
One or more combustion air supply tubes, which open into the air supply pre-chamber, are preferably provided. It is especially favorable for this supply tube or these supply tubes to extend tangentially to a circumferential wall of the air supply pre-chamber.
As an alternative, an essentially axially extending combustion air supply tube, which opens into the air supply pre-chamber, may be provided, and a distributor for generating a swirl component of the air being supplied is preferably provided at the passage between the pre-chamber and the combustion chamber.
The purpose of the described types of supplying combustion air by means of an air supply pre-chamber is to allow combustion air to flow into the combustion chamber with a swirl, which is favorable for complete combustion and for reliable burner operation over a large output range. If a plurality of tangentially arranged combustion air supply tubes are provided, these preferably open, circumferentially distributed, into the pre-chamber.
According to another preferred measure, an essentially tubular combustion chamber insert, which extends farther beyond the site of arrangement of the glow plug in the downstream direction, is provided, and openings for the discharge of combustion air into the space between the combustion chamber insert and the circumferential wall of the combustion chamber are provided in the combustion chamber insert.
A sheathed element glow plug, which is sometimes also called a rod plug, is preferably provided as the glow plug. Unlike conventional glow plugs, sheathed element glow plugs have a sheathed spiral filament. The essentially cylindrical glow plug, which is rounded at its ends, consists of a ceramic or metallic material. The sheathed element glow plug reaches high temperatures very rapidly, and it is less sensitive. In addition, the power consumption per ignition process is lower.
The burner according to the present invention is intended for use in vehicle heaters, especially vehicle heaters for installation in passenger cars, trucks, ships, campers, trailer-type recreational vehicles, bulldozers, etc. If the vehicle heaters are installed in motor vehicles driven by internal combustion engines, the heater may be connected to the liquid circuit, which is usually provided for cooling the internal combustion engine and for heating the interior of the vehicle. The vehicle heater may be, in general, either a so-called water heater, which releases the heat generated to a liquid circuit, or a so-called air heater, which releases the heat generated directly as a warm air flow. Gasoline or diesel fuel may be primarily used as the fuel.
The burner according to the present invention may also be used as a heat generator for the thermal regeneration of particle filters, especially in the exhaust pipes of diesel engines.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a horizontal longitudinal section along I--I in FIG. 2 of the burner area of a vehicle heater,
FIG. 2 is a cross section along II--II in FIG. 1 of the area of the burner where the glow plug is positioned,
FIG. 3 is a longitudinal section of a partial area of a modified embodiment of the burner, and
FIG. 4 is a cross section analogous to FIG. 2 of a partial area of a modified embodiment of the burner.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and in particular to FIG. 1, a burner area of a vehicle heater has as its most essential components, a combustion chamber with a glow plug 4 and with a fuel supply means 6, which will be described below, as well as a combustion air blower 8. The housing of the heater is not shown for clarity's sake. In addition, the heater according to FIG. 1 has, joining the combustion chamber 2 on the right, a heat exchanger for transferring heat from the hot combustion gases to a liquid or air.
The combustion air blower 8 comprises an electric motor 10 and a blower impeller 12, which is shown schematically in FIG. 1. Side-channel blowers, which have a stationary channel and a blower impeller rotating at a short distance therefrom, are frequently used in practice.
The combustion chamber 2 is essentially cylindrical in the exemplary embodiment shown. An air supply pre-chamber 14 is arranged in front of the combustion chamber 2 in the left-hand part of FIG. 1. The air supply pre-chamber 14 has the shape of a cylinder with an axial length considerably shorter than the diameter. Beginning from the pre-chamber 14, a tubular combustion chamber insert 16 extends into the combustion chamber 2. The combustion chamber insert 16 is open toward the pre-chamber 14 in the left-hand part of FIG. 1, and it is also open toward the combustion chamber 2 in the right-hand part of FIG. 1. A circular disk-shaped flow-guiding plate 18 is arranged in front of the opening toward the combustion chamber. The circular disk-shaped flow-guiding plate 18 is bent out of its plane and deflects the flow discharged from the insert 16 radially to outward.
An annular partition or end wall 22 extends at right angles to the longitudinal axis 24 of the burner and is located between the insert 16 and the circumferential wall 20 of the combustion chamber 2. A porous lining 24 is arranged on the combustion chamber side joining the partition or end wall 22. The porous lining 24 is as a whole pot-shaped or cup-shaped, and has both a bottom area 26 and a circumferential area 28. The bottom area 26 has such a large central opening that it just fits around the insert 16. The end face of the bottom area 26, which is the left end face of FIG. 1, is in contact with the partition 22. The outer circumferential surface of the circumferential area 28 is in contact with the inner circumference of the combustion chamber 2. The lining 24 is shorter in the axial direction than the insert 16.
The porous lining 24 preferably consists of metal netting, metal braiding, porous sintered metal or porous ceramic material. The lining 24 is a mounted part manufactured as a whole in the exemplary embodiment shown.
A tangential or peripheral glow plug socket or plug chamber 30, which extends vertically in the exemplary embodiment shown, is attached laterally to the outer circumference of the circumferential wall 20 of the combustion chamber 2. The socket 30 has a square cross section in the exemplary embodiment shown, but it could also have, e.g., a circular or round cross section. The glow plug 4, designed as a sheathed element glow plug here, is screwed into the socket 30. As shown in FIG. 2, the glow plug 4 has a glow area 32. The plug longitudinal axis of the glow plug extends in a tangential direction with respect to the circumferential wall 20 of the combustion chamber, as it is clearly recognizable from FIG. 2. At the point at which the socket 30 passes over into the circumferential wall 20, the circumferential wall 20 is perforated. The lining 24 also has an opening at this point, but this opening is somewhat smaller than the perforation of the circumferential wall 20. A plug opening 34 is thus formed as a passage between the interior space of the socket 30 and the interior space of the combustion chamber 2.
A first part of the combustion air delivered by the blower 8, enters the pre-chamber 14 via two tubes 36. As is shown especially clearly in FIG. 2, the two tubes 36 extend tangentially to the circumferential wall of the pre-chamber 14 and open at diametrically opposed points. An air flow with a pronounced swirl component is generated in the pre-chamber 14 as a result. The combustion air flows from the pre-chamber 14 into the insert 16. From the insert 16 the combustion air is discharged into the space between the insert 16 and the circumferential wall 20 of the combustion chamber 2 through radial insert openings 38. The combustion air is also partly discharged out of the right-hand end of the insert 16.
Another part of the combustion air flows into the combustion chamber 2 through radial openings which are provided downstream of the insert 16 in the circumferential wall 20 of the combustion chamber 2. Moreover, additional openings for the flow of combustion air are also shown in the drawing, which are preferably present but do not have to be. On the one hand, there are end wall openings 42 in the partition 22. Through these end wall openings 42, relatively small amounts of combustion air can flow into the bottom area 26 of the lining 24, and, finely dispersed, these amounts of combustion air can pass over into the combustion chamber 2. The lining 24 has no larger openings at these points aside from its porosity. On the other hand, there are openings 44 in the circumferential wall 20 of the combustion chamber 2 at points which are reached by the lining 24 with its circumferential area 28, and these openings 44 pass through the lining 24. An inlet opening 46 for a small amount of air into the socket 30 is also present.
A flame diaphragm 48, which has a large central opening 50, is located at the right-hand end of the combustion chamber 2 in FIG. 1. The flame diaphragm 48 is joined, to the right in FIG. 1, by a flame tube 52, in which the combustion of the fuel takes place completely.
As can be recognized from FIG. 2, fuel can be supplied to the lining 24 by means of a fuel supply channel, which is embodied by a fuel line 6, and passes through the circumferential wall 20 of the combustion chamber 2. The point at which the line 6 opens is located in the same cross section plane as the glow area 32 of the glow plug 4, and it is located at an angular distance of 45° from the central axis of the above-described plug opening 34.
When the glow plug 4 is switched on to ignite the burner, fuel evaporates from the lining 24 into the interior of the combustion chamber 2 as well as into the interior of the socket 30, this evaporation being promoted by the heating originating from the glow area 32 of the glow plug 4. A surface area 54 of the lining 24 facing the interior of the socket 30 being additionally beneficial to evaporation. After an ignitable fuel-air mixture has formed, this mixture is ignited in the glow area 32 of the glow plug 4. The ignition propagates through the plug opening 34 into the interior of the combustion chamber 2.
The wall of the socket 30 may, but does not have to, be provided with a porous lining on its inside. However, since the glow area 32 of the glow plug 4 is arranged at a closely spaced location from the lining 24 in the area of the plug opening 34, such a lining of the socket 30 is in many cases unnecessary.
It should be pointed out that more than two combustion air supply tubes 36 may also be provided instead of the two combustion air supply tubes shown in the drawing, or that it is also possible to use only one supply tube 36, which would have a correspondingly increased diameter in this case.
FIG. 3 shows a modification of the combustion air supply. The combustion air no longer flows into the pre-chamber 14 through tangential tubes, but through an axially extending, central tube 56. A distributor 58 for generating a swirled flow is arranged in front of the inlet opening of the insert 16. The distributor 58 comprises a plate 60 placed in front of the inlet opening of the insert 16 and flow-deflecting surfaces 62. The flow-deflecting surfaces 62 are distributed over the circumference of plate 60 and are arranged between the plate 60 and the partition 22. The deflecting surfaces 62 are placed obliquely in relation to the radial direction such that the desired swirl is generated.
FIG. 4 shows a modified embodiment, in which the glow area 32 of the glow plug 4 is no longer accommodated in a socket 30 arranged outside the circumferential wall 20 of the combustion chamber 2, but in a recess 64 of the lining 24 surrounding the glow area 32 on all sides. Analogously to the above-described exemplary embodiment, an air supply opening 46 to the interior of the recess 64 and a plug opening 34, through which the ignition can propagate into the inside of the combustion chamber 2, can also be recognized. The recess has an approximately cylindrical shape in the exemplary embodiment shown.
The glow plug 4 is also arranged in the exemplary embodiment last described such that its plug longitudinal axis extends in the tangential direction in relation to the adjacent circumferential wall 20 of the combustion chamber. Consequently, the term "tangential direction" does not mean that the glow plug 4 forms a tangent to the circumferential wall 20 in the mathematical sense.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A burner for a vehicle heating device having a fan or blower for supplying combustion air. A combustion chamber 2 has an inner surface which is provided with a porous lining. A fuel supply line is provided for supplying fuel to the lining. A glow plug ignites the fuel evaporated from the lining. A longitudinal axis of the glow plug has a longitudinal axis which is substantially parallel to a tangential plane of the circumferential wall of the combustion chamber. | 5 |
FIELD OF THE INVENTION
This invention relates generally to nonvolatile semiconductor memory devices and materials used in their fabrication. In particular, this invention is directed to a nonvolatile Electrically Erasable Programmable Read Only Memory (EEPROM).
BACKGROUND OF THE INVENTION
In the computer industry, memory devices and methods for the storage of information have long been of critical importance. Accordingly, the improvement of semiconductor technology, and the memory elements thereby produced, is of significant value.
The term EEPROM is used for memory elements which have the ability to be erased and rewritten after fabrication. These memory cells are generally based on MOS technology and utilize a floating gate structure. In such memory cells, an electrical charge is transferred or written onto the electrically isolated floating gate thus controlling the threshold voltage of the device. A read operation differentiates between the impedance presented by a charged gate and an uncharged gate. Thus, a charged gate may be used to represent one (binary) state of the cell, an uncharged gate the other. To reverse the state of the cell, the charge is transferred off the floating gate or erased.
Typically, an EEPROM is comprised of multiple memory cells in an array or matrix-type structure, i.e. it is fabricated as a multiplicity of parallel bit or column lines which are generally perpendicular to a multiplicity of parallel word or row lines. In such an array, a single memory cell may be identified by the intersection of a specified column line with a specified row line. That cell may be programmed or erased by applying appropriate voltages to a particular column and a particular row line. EEPROMs in which erasure may be performed over the entire array or matrix of cells are referred to as flash EEPROMs. Bulk erases of this nature have an advantage in that it permits smaller cell size.
Numerous solutions have been proposed to facilitate the programming (or writing) and erasing of floating gates.
Some solutions focus on the structure or design of the memory cell. For example, one such design uses a single control gate separated from the floating gate by an insulating layer. Writing is accomplished by biasing the control gate sufficiently positive that the electron flow is induced from the floating gate to the control gate. The floating gate accordingly accumulates positive charge. To erase, the control gate is ramped negative so that the floating gate accumulates negative charge. (This approach is discussed in Lee, A New approach for the Floating Gate MOS Nonvolatile Memory, Applied Physics Letters, Vol. 31, No. 7, October 1977, pp. 475-476.)
Another common design uses both a programming gate and an erase gate. In cells based on this type of design, the floating gate is programmed by inducing electron flow from the programming gate to the control gate and erased by inducing electron flow from the floating gate to the erasure gate. (This design is exemplified in U.S. Pat. No. 4,314,265.)
Other solutions focus on the methods of writing or erasing the floating gate. The charge transfer mechanisms most frequently used for these purposes are hot electron injection (typically from avalanche breakdown although hot electron injection may also result from channel hot electrons) or Fowler-Nordheim tunneling.
HOT-ELECTRON INJECTION
A typical method of using the hot electron injection to perform a data write operation requires that a voltage be applied to a drain region of the memory cell and the control gate. The applied voltage causes elections in the channel region located under the floating gate to be injected into the floating gate. The hot electrons will be set at a predetermined potential by the high voltage applied to the control gate. The injection of electrons in the floating gate will increase the threshold voltage in the channel region. To erase, a high voltage is applied to the erase gate resulting in electrons from the floating gate being discharged into the erase gate.
There are certain drawbacks to this method of charge transfer. While relatively low voltage is required to program a memory cell by hot electron injection, an additional power supply may be required because of high current requirements. Further, using hot injection for erasure can damage the insulator layer, resulting in cell degradation and failure. A practical effect of this condition is that the total number of writes and erase which may be carried out is limited. To put it another way, high current densities have a significant negative impact on the useful lifetime of the device.
Tunneling is an alternate method to transfer charge to a floating gate from a programming gate and from the floating gate to an erasing gate. (See, for example, U.S. Pat. No. 4,099,196, Simko, Triple Layer Polysilicon Cell.)
Tunneling requires higher voltage than injection, but has very low current requirements. The advantage of using lower current to erase a floating gate is that such process causes less damage to the tunnel window and has a corresponding positive effect on memory cell durability and reliability. However, the higher voltages required by tunnel erasing lead to source junction field plate breakdown and the generation of hot holes.
The higher voltages used in tunneling can also cause problems to occur outside of the individual memory cell. For example, in the memory cell arrays used by flash EEPROMS, the high voltage use to write to one cell can cause another cell to be written to in error. This situation is generally referred to as erroneous data writes. This problem occurs under the following conditions. When a high voltage is applied to both the control gate and the drain to write to a specific memory cell, the voltage in the control gate may result in the floating gate of other memory cells sharing that same control gate being pulled to a high potential level. One consequence is that an electric field will be established between the floating gate and the erase gate of these other cells. Leak currents will flow between surfaces with irregularities or asperities: generally the flow from the surface with the smaller asperity to the larger asperity is larger than the leak flow in the other direction. Thus, if the asperity on the upper surface of the erase gate is larger than the lower surface of the floating gate, electrons may be travel through the insulating layer between the erase gate and the floating gate and be injected into the floating gate. The net effect is an erroneous data write.
An analogous problem occurs during an erase cycle. That is, high voltage can also cause erroneous data erasures. Clearly, reducing the probability of erroneous data writes and erases is of significant concern in the fabrication of memory cells.
Another difficulty which occurs when tunneling is used as the charge transfer mechanism is determining the optimal composition and thickness of the tunneling dielectric (that is, the layer of dielectric material used to separate the floating gate from the programming and erase gate). If the tunneling layer is relatively thick (e.g. 100 nm), higher currents are required during writing since only a small fraction of the programming current has sufficient energy to reach the floating gate through the intervening insulator. Very thin (5-20 nm) layers reduce the current required, but fabrication of such thin semiconductors can present problems in production.
In U.S. Pat. No. 4,099,196, enhanced tunneling is used to permit relatively conventional programming voltages to successfully operate with relatively thick oxides. However, even these conventional levels of current are known to degrade the insulating materials and so limit the life of the EEPROM by limiting the total number of write/erase operations that may be performed.
It is known in the art that a tunneling enhancement can be observed if a silicon-rich oxide deposited on an silicon substrate. (See, for example, D. J. DiMaria and D. W. Dong, Applied Physics Letter, 37, 61 (1980).) However, because of the non-stoichiometric nature of the silicon-rich oxide, it is difficult to control the silicon/oxide interface, leading to a fairly large leakage current (about 3×10 -10 A). Thus, this material has significant disadvantages when used in a memory cell.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide device structures and dielectric materials which enable an EEPROM to operate at relatively low voltages avoiding problems such as unwanted generation of hot holes, erroneous data writes and erroneous data erasures.
It is a further object to provide a device structure and dielectric material which increases the number of operations that may be performed, thus lengthening the EEPROMs useful life.
It is a further object to provide a dielectric material whose dielectric constant can be controlled so that it may be scaled to accommodate the electrical properties of various devices.
Other objects and advantages of the present invention will be apparent to those skilled in the relevant art in view of the following description of the invention, the appended claims and the accompanying drawings.
In achieving the above mentioned and other objects, advantages and features of the present invention, a flash EEPROM is produced comprising multiple MOS cells. In each cell, programming and erasing are performed through tunneling from the write gate to the floating gate and by tunneling from the floating gate to the erase gate, respectively. The tunneling layer employed is a multilayered structured (MLS) oxide, where thin oxide and thin polycrystalline silicon form alternating layers. This layering is asymmetric: that is, either the uppermost or bottommost layer is thicker than the other layers. As a result of this structure, the oxide exhibits directionality, that is, the tunneling is easier in one direction than the reverse direction. In addition, the MLS oxide significantly enhances the tunneling phenomena (tunneling current can be observed at as low as 4.7 V). Finally, by varying the thickness and number of the layers, the MLS oxide can be fabricated having different dielectric constants. The directionality, coupled with the separate write and erase gates, gives the new flash EEPROM cell a number of advantages: it is low-voltage operable, it is highly resistant to disturbance and has an easily scalable structure (that is, it can be made to operate at any given voltage within a specified scale).
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cut-away top view of a portion of a flash EEPROM comprised of an array of twelve memory cells. Typically, in an EEPROM, all the cells in a given memory array are fabricated at one time and, accordingly, have similar structure. As a result, an array of any column and row size may be described by reference to the twelve cells shown in FIG. 1.
FIG. 2 shows a cross-sectional view of the flash EEPROM along the line A--A of FIG. 1.
FIG. 3 shows a cross-sectional view of the flash EEPROM along the line B--B of FIG. 1.
FIG. 4 shows a cross-sectional view of two examples the multilayered directional dielectric. FIG. 4A shows a cross-sectional view along the line C--C of FIG. 2 of the first directional dielectric in which tunneling movement is enhanced from the bottom of the structure to its top. FIG. 4B shows a cross-sectional view along the line D--D of FIG. 2 of the second directional dielectric in which tunneling is enhanced from the top of the structure to the bottom.
FIG. 5 shows a cross-sectional view of the flash EEPROM along the line B--B of FIG. 1 during fabrication. This figure shows the formation of the split gate.
FIG. 6 shows a cross-sectional view of the flash EEPROM along the line A--A of FIG. 1 during fabrication, after the completion of the control gate.
FIG. 7 is a graph showing the relationship between the effective dielectric constant and the number of polycrystalline silicon layers of the dielectric material.
FIG. 8 is a graph showing the relationship between the threshold voltage of Fowler-Nordheim tunneling and the number of polycrystalline silicon layers of the dielectric material. The relationship is shown for two different thickness (3 and 15 nm) of the first layer of the dielectric material.
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of an EEPROM device according to this invention willbe described referring to FIGS. 1 and 2.
FIG. 1 shows the top view of one embodiment of the EEPROM in which the memory cells are arranged in a 3 by 4 array. Each cell consists of an erase gate 10 which is substantially parallel to a control gate 12, connected to a floating gate 14 through a first tunneling layer comprised of a multilayered structure tunneling (MLS) oxide 16. FIG. 4A shows a detailed cross section of the first directional dielectric 16. It will be observed that, for the first directional dielectric 16a, the oxide on the lowest layer 16b is thinner than the oxide on the uppermost layer 16c. Theeffect of this structure is to make tunneling from the lowest layer to the uppermost layer easier than in the reverse direction.
Returning to FIG. 1, the erase gate 10, in an erase operation, is biased toa positive voltage greater than the tunneling threshold of the first directional dielectric 16. Since any given erase gate 10a is substantiallyparallel to its related control gate 12a and is shared by two rows of floating gates 14a-f, all the cells connected to the selected gate 10a will be erased, resulting in a sector erase.
Sources 18 and drains 20 are as indicated. As a specific example, the substrate (5) could be p-type silicon in which Recessed Oxide (ROX) or Shallow Trench Isolation (STI) regions are formed using typical techniques. N-type sources 18 and drains 20 could then be formed in these regions using standard ion-implantation techniques. As is clear from FIG. 1, the sources 18 and drains 20 are shared with, and substantially perpendicular to, the control gates 12, eliminating the requirement of separate contacts for each cell.
The program or write gate 22 is parallel to the source 18 and drain 20 and is perpendicular to the control gate 12. To program a specific cell 26, the selected control gate 12 is raised from ground to positive voltage, capacitively coupling the voltage of the floating gate 14 to a positive value. The selected write gate 22 is lowered from ground to a negative value such that the difference between the selected write gate 22 and floating gate 14 is above the tunneling threshold voltage of the second directional multilayered directional dielectric 24. This second oxide 24 is positioned between the write gate 22 to the control gate 12.
FIG. 4B shows a detailed cross section of the second directional dielectric24a. It will be observed that, for the second directional dielectric 24a, the oxide on the lowest layer 24b is thicker than the oxide on the uppermost layer 24c. This makes tunneling from uppermost layer to the lowest layer easier than in the reverse direction.
Returning to FIG. 1, writing occurs only at the cell 26 at the cross point of the selected control gate 12 and the selected write gate 22.
It should be noted that for improved performance, the selected floating gate 14 is positively biased to one half of the tunneling threshold voltage of the first directional dielectric 16 and the selected write gate22 is slightly more negative than one half of the tunneling threshold voltage of the second directional dielectric 24.
FIG. 2 shows a cross-section of a memory cell of the EEPROM along lines A--A of FIG. 1. Note that three insulating layers are shown. The first insulating layer 8 separates the substrate from the floating gate. The second insulating layer 30 separates the control gate 12 from the floatinggate 14, the erase gate 10, and the first directional dielectric 16. The third insulating layer 32 separates the control gate 12 from the floating gate 14, the write gate 22, and the second directional dielectric 24. FIG.3 shows a cross-section of the cell along the lines B--B of FIG. 1. The split gate region 34 connects the control gate 12 and the floating gate 14in series. The connection of the enhance-mode control gate 12 in series with the floating gate 14 removes any potential problem due to over-erase.
METHOD OF MANUFACTURE
The following description is for a method of manufacturing the previously described memory cells. Referring to FIG. 5, as an initial step, recessed isolation regions (ROX or STI) 42a and b are grown on a semiconductor substrate 5 using typical techniques, thus defining sources, drains and gate regions. A thin gate oxide 8 is then grown on the upper surface of the substrate 5a forming a first insulating layer. Polycrystalline siliconis deposited over this oxide. The result is etched using a photomask in a typical photolithographic process to form a floating gate 14. A thin thermal oxide 44 is grown over the floating gate 14.
Two sidewall spacers are formed on two opposite sides 14h and i of the floating gate 14. One of these spacers is removed by etching, using a photomask with a typical photolithographic process. This leaves a single sidewall spacer 46 as shown in FIG. 5.
Referring to FIG. 6, an ion-implantation technique is used to form a source18 and drain 20 in the substrate 5. Multiple layers of thin oxide and thin polycrystalline silicon are deposited sequentially to form a first directional dielectric 16. As has been previously noted, a detailed depiction of the cross-section of the first directional dielectric 16 is shown in FIG. 4. Next, polysilicon is deposited on the first directional dielectric 16. Using a photomask and standard photolithographic techniques, the polysilicon and the first directional dielectric 16 are etched to form a structure which consists of an erase gate 10 on top of the first directional dielectric 16. This structure partially overlaps thefloating gate 14. The configuration is shown in FIG. 6.
Continuing to refer to FIG. 6, a second insulating layer 30 of silicon dioxide is grown across the upper surface of the structure. The silicon dioxide will oxide the portion 16g of first directional dielectric uncovered by the formation of the erase gate 10. The insulating layer is etched, using a photomask and standard photolithographic techniques, to form a structure which totally overlaps the erase gate 10 and first directional dielectric 16 and partially overlaps the floating gate 14.
A polysilicon layer is deposited over the layer of silicon dioxide and etched using a photomask and standard photolithographic techniques to forma control gate 12. The etching is performed so as to expose portion 30a of the first insulating layer and 14c of the floating gate 14. It will be noted that the control gate 12 is totally insulated from the floating gate14 by the first insulating layer 30. The resulting configuration is as shown in FIG. 6.
Referring to FIG. 2, a third insulating layer 40 is deposited over the upper surface of the structure. This layer 40 is etched using standard photolithographic techniques so that a portion 14j of the surface of the floating gate and a portion 18d of the surface of the source is exposed.
The second directional dielectric 42 is deposited over the third insulatinglayer 40, the exposed portion 14j of the floating gate and the exposed portion 18d of the ROX. A final polysilicon layer is deposited. It is etched using standard photolithographic techniques to form a write gate 14.
Metal lines are finished using standard CMOS processes.
CHARACTERISTICS OF THE TUNNELING OXIDE
The novel characteristics of the tunneling layers, and the enhancement theyprovide to the operation of the EEPROM, will now be reviewed. As has been noted, FIGS. 4A and B represent cross-sections of the first 16 and second 24 directional dielectric. As can be seen, the tunneling layers are composed of alternating layers of two different materials with two different dielectric constants.
The following discussion presumes that SiO 2 and undoped polycrystalline silicon are the two materials used. However, it is known to those skilled in the art that other pairs of materials have similar relationships between their electrical characteristics.
The first directional dielectric is formed by creating alternating layers of SiO 2 and undoped polycrystalline silicon. First, 3 nm of SiO 2 was deposited on a silicon substrate by low pressure chemical vapor deposition. Following this, a 2.5 nm thick layer of polycrystalline silicon and a 5 nm thick layer of SiO 2 were sequentially deposited bylow pressure chemical vapor deposition at a temperature of 700° C. It will be clear to those skilled in the art that the process of depositing the layers could be carried out by other means such as pulsed PECVD in an ECR plasma reactor at lower temperatures, such as 300° C.
Experiments have shown that the effective dielectric constant of the directional dielectric increases with the number of polycrystalline silicon layers. For example, while the effective dielectric constant of SiO 2 is 3.9, the constant for SiO 2 and three alternating layers of polycrystalline silicon is 8.4. (FIG. 7 shows the relationship between the dielectric constant and the number of polycrystalline silicon layers in graphic form.) From the results of these experiments, it is projected that as the number of polycrystalline silicon layers increases further, the effective dielectric constant may level off to a value somewhat below the dielectric constant of silicon (11.9).
The actual effective dielectric constant of the multilayered directional dielectric will also depend on the composite materials used. As a result, one can create a directional dielectric of any desired dielectric constantby varying materials and number of layers. For dielectric constants lower than 3.9, polycrystalline silicon should be replaced with a material with a low dielectric constant such as polymeric insulators (with dielectric constants of 1.45) or other inorganic materials of low polarizability. Fora structure with a dielectric constant higher than 10, polycrystalline silicon may be replaced with a material with a high dielectric constant such as Ta 2 O 2 .
Another advantage to the multilayered directional dielectric of this invention is the variation of the threshold voltage to Fowler-Nordheim tunneling which results from a) varying the thicknesses of the SiO 2 layer closest to the silicon substrate, and b) increasing the number of polycrystalline silicon layers. FIG. 8 shows the results of two experiments one in which the first layer oxide was 3 nm, the second in which the first layer oxide was 15 nm. As can be seen from the graph, the threshold voltage of Fowler-Nordheim tunneling decreases as the number of polycrystalline silicon layers are increased. Additionally, the threshold voltage is very sensitive to the thickness of the fist SiO 2 layer.
It should be noted that the present invention corrects the previously notedproblem of leakage which accompanies a silicon-rich oxide deposited on a silicon substrate. By inserting a stoichiometric SiO 2 layer, the present invention controls the silicon/oxide interface as well as the tunneling enhancement. Specifically, the leakage current in the multilayered directional dielectric was about 10 -11 A with the 3 nm thick first-layer oxide and about 10 -12 A with the 15 nm thick oxide.
The directional dielectric disclosed above provide several significant benefits for semiconductor technology. First, since the dielectric constant can be controlled by varying the number of layers of polycrystalline silicon used, the resulting dielectric material can be tailored to the electrical characteristics of a specific semiconductor. Further, the Fowler-Nordheim tunneling enhancement exhibited by the material permits tunneling type charge transfer to occur at lower voltages, thus avoiding the problems, such as erroneous data write and erroneous data erase, which are caused by high voltages. Finally, the directionality of the material helps control the problem of leakage which had occurred in prior art.
Use of the directional dielectric together with the EEPROM structure discussed above results in an improved EEPROM which can operate at lower voltages and thus has a longer useful life.
It will be recognized by those skilled in the art that a) some of the abovefeatures and structures may be used without other features and structures and b) modifications (structural, operational and otherwise) may be made to the above description without departing from the spirit of the invention. For example, other equivalent techniques may be used to form the source and drain regions and other placement of the gates is possible.It will also be recognized that the directional dielectric has other applications in the field of semiconductor technology as well as in other industries. | A flash EEPROM is produced comprising multiple MOS cells. In each cell, programming and erasing are performed through tunneling from the write gate to the floating gate and by tunneling from the floating gate to the erase gate, respectively. The directional dielectric employed is a multilayered structured (MLS) oxide, where thin oxide and thin polycrystalline silicon form alternating layers. The layering is asymmetric: that is, either the uppermost or bottommost layer is thicker than the other layers. As a result of this structure, the oxide exhibits directionality, that is, the tunneling is easier in one direction than the reverse direction, and significantly enhances the tunneling phenomena (tunneling current can be observed at as low as 4.7 V). In addition, the MLS oxide can be fabricated having different dielectric constants. The directionality, coupled with the separate write and erase gates, gives the new flash EEPROM cell a number of advantages: it is low-voltage operable, it is highly resistant to disturbance and has an easily scalable structure (that is, it can be made to operate at any given voltage within a specified scale). | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of priority under 35 USC §119 e) based on U.S. provisional patent application Ser. No. 61/251,959 filed on Oct. 15, 2009 by T. Awad et al. The contents of the aforementioned document are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of processors, and, more specifically, to a method and apparatus for use in encoding logical expressions to generate machine-readable instructions for execution by a processor as well as a processor for executing the machine-readable instructions.
BACKGROUND
[0003] A compiler is a computer program that translates a program written in a high-level language into another language, usually machine readable code that a CPU can execute. Typically, a programmer writes language statements in a high-level language one line at a time using an editor. The appropriate language compiler is then invoked in order to process the program. When executing (running), the compiler first parses (or analyzes) the language statements syntactically one after the other and then, in one or more successive stages or “passes”, builds the output code.
[0004] Much general-purpose code is control intensive code, with branches and logical expressions. Executing instructions in order to evaluate logical expressions is costly in terms of processor resources and computing time. The costs escalate with the level of complexity of the logical expression. Various approaches have been proposed so that the resulting encoded logical expressions can be more efficiently executed.
[0005] One of the approaches proposed is sometimes referred to as predicated execution of instructions. Predicated execution is conditional execution of instructions based upon a Boolean value called a predicate. Superscalar processors have used predicated execution to exploit instruction-level parallelism (ILP) in control code.
[0006] Predicated execution allows generally efficient encoding of logical expressions. Take for example the following logical expression:
[0000] X =(((( A== 1)|( B== 2))&( C== 3))|( D== 4));
[0007] This expression may be encoded as follows using a predicated execution approach:
[0000]
CMPEQ
P1, 1, A
[!P]
CMPEQ
P1, 2, B
[P1]
CMPEQ
P1, 3, C
[!P1]
CMPEQ
P1, 4, D
MOV
X, P1
[0008] Compare the above to using bitwise AND/OR instructions, which require more instructions and an additional general-purpose register.
[0000]
CMPEQ
R, 1, A
CMPEQ
T, 2, B
OR
R, T
CMPEQ
T, 3, C
AND
R, T
CMPEQ
T, 4, D
OR
R, T
[0009] A deficiency with the use of predicated execution is that it requires significant extensions to the instruction-set and micro-architecture of a processor making use of such an approach. In any practical implementation of a processor there are a limited number of predicate flags that can be implemented limiting the size or depth of the logical expression that can be evaluated with this method. When a logical expression in the code exceeds this size, the compiler used to generate machine code based on this approach has to breakdown the logical expression into pieces to operate with a limited number of predicate flags that are supported by the processor.
[0010] In light of the above, it appears that there is a need in the industry for providing a method and associated apparatus for evaluating a logical expression that alleviate at least in part the deficiencies of the prior art.
SUMMARY
[0011] In accordance with a broad aspect, the invention provides a method and apparatus for use in evaluating a logical expression using a general-purpose register and an extended set of instruction.
[0012] In accordance with a specific example of implementation, instructions that perform Boolean operations, such as for examples compares or bitwise tests, are extended using an apparatus and/or an extended instruction set to provide functionality for updating a specified general-purpose register the value of which is dependent in part upon the result of a Boolean operation.
[0013] In accordance with a first aspect, the invention provides a processor suitable for executing machine instructions. The processor comprises an input for receiving a machine instruction, the received machine instruction defining a first operand, a second operand, a third operand and a function to be applied to the first operand, the second operand and third operand. The processor also comprises a logic module for applying the function to the first operand and second operand to obtain an initial Boolean result and for applying the function to the initial Boolean result and the third operand to derive an updated result. The logic module is also configured for modifying the third operand so that its value corresponds to the updated result.
[0014] In accordance with a specific implementation, the processor comprises memory devices in communication with the logic module for storing the first operand, the second operand and the third operand. The memory devices may include, for example, respective registers for storing the first operand, the second operand and the third operand. In a specific implementation, modifying the third operand to correspond to the updated result includes storing the updated result in the register storing the third operand.
[0015] In a specific implementation, the function when applied to the initial Boolean result and the third operand is such that the updated result corresponds to one of the initial Boolean result, the third operand and a modified version of the third operand. More particularly, when the function conveys a first function type, the logic module is configured for processing the initial Boolean result to derive the updated result by setting the updated result to correspond to the initial Boolean result. When the function conveys a second function type, the logic module is configured for processing the third operand to set the updated result to correspond to a selected one of the initial Boolean result and the third operand. When the function conveys a third function type, the logic module is configured for processing the third operand to set the updated result to correspond to a selected one of the initial Boolean result and a modified version of the third operand.
[0016] In a specific example of implementation, the function defined by the machine instruction includes an operation and an operation modifier. In this specific implementation, the logic module is configured for applying the operation to the first operand and second operand to obtain the initial Boolean result and for applying the operation modifier to the initial Boolean result and the third operand to derive the updated result. In a non-limiting example, the logic module may include a first logic module and a second logic module. The first logic module is for applying the operation to the first operand and second operand to obtain the initial Boolean result. The second logic module, which is in communication with the first logic module, is configured for applying the operation modifier to the initial Boolean result and to the third operand to derive the updated result and for modifying the third operand to correspond to the updated result.
[0017] In accordance with a second aspect, the invention provides a processor suitable for executing machine instructions. The processor comprises an input for receiving a machine instruction, the received machine instruction defining a first operand, a second operand, a third operand and a function to be applied to the first operand, the second operand and third operand. The processor also comprises a logic module for applying the function to the third operand to derive a preliminary result indicator. In dependence of the derived preliminary result indicator, the logic module is configured for selectively applying the function to the first operand and second operand to update the derived preliminary result indicator. The logic module is also configured for storing the derived preliminary result indicator in a memory associated with the third operand.
[0018] In accordance with a specific implementation, the processor comprises memory devices in communication with the logic module for storing the first operand, the second operand and the third operand. The memory devices may include, for example, respective registers for storing the first operand, the second operand and the third operand.
[0019] In a specific implementation, the function when applied is such that the result corresponds to one of a Boolean result obtained by applying the function to the first operand and second operand, the third operand and a modified version of the third operand. More specifically, when the function conveys a first function type, the logic module is configured for updating the preliminary result indicator by setting the derived preliminary result indicator to correspond to a Boolean result obtained by applying the function to the first operand and second operand. When the function conveys a second function type, the logic module is configured for updating the preliminary result indicator to a selected one of the third operand and the Boolean result obtained by applying the function to the first operand and second operand. When the function conveys a third function type, the logic module is configured for updating the preliminary result indicator to a selected one of a modified version of the third operand and the Boolean result obtained by applying the function to the first operand and second operand.
[0020] In a specific example of implementation, the function defined by the machine instruction includes an operation and an operation modifier. In this specific implementation, the logic module is configured for applying the operation modifier to the third operand to derive the preliminary result indicator and for applying the operation to the first operand and the second operand to derive a Boolean result. The logic module is also configured for conditionally using the Boolean result to update the preliminary result indicator.
[0021] In a specific implementation, the operation modifier is selected from a set of available operation modifiers including at least a first modifier type, a second modifier type and a third modifier type. When the operation modifier conveys a first modifier type, the logic module is configured for updating the preliminary result indicator by setting the derived preliminary result indicator to correspond to the Boolean result. When the operation modifier conveys a second modifier type, the logic module is configured for performing an update of the preliminary result indicator when the preliminary result indicator conveys a pre-determined value, the update of the preliminary result indicator including setting the derived preliminary result indicator to correspond to the Boolean result. When the operation modifier conveys a third modifier type, the logic module is configured for performing an update of the preliminary result indicator so that:
when the preliminary result indicator conveys the pre-determined value, the derived preliminary result indicator is set to correspond to the Boolean result; and when the preliminary result indicator is different from the pre-determined value, the preliminary result indicator is modified.
[0024] In a non-limiting example, the logic module may include a first logic module and a second logic module. The first logic module applies the operation modifier to the third operand to derive the preliminary result indicator. The second logic module applies the operation to the first operand and second operand to obtain the Boolean result and in dependence of the derived preliminary result indicator, selectively updates the derived preliminary result indicator based on the Boolean result. The second logic module also stores the derived preliminary result indicator in a memory associated with the third operand.
[0025] In accordance with another aspect, the invention provides process implemented by a processor having a logic module. The process comprises receiving a machine instruction, the received machine instruction defining a first operand, a second operand, a third operand and a function to be applied to the first operand, the second operand and third operand. The process also comprises using the logic module of the processor to apply the function to the first operand and second operand to obtain an initial Boolean result and using the logic module of the processor to apply the function to the initial Boolean result and the third operand to derive an updated result. The process also comprises storing the updated result in a memory unit associated with the third operand so that the third operand is modified to correspond to the updated result.
[0026] In accordance with a specific example of implementation, when the function conveys a first function type, the logic module is used for processing the initial Boolean result to derive the updated result by setting the updated result to correspond to the initial Boolean result. When the function conveys a second function type, the logic module is used for processing the third operand to set the updated result to correspond to a selected one of the initial Boolean result and the third operand. When the function conveys a third function type, the logic module is used for processing the third operand to set the updated result to correspond to a selected one of the initial Boolean result and a modified version of the third operand.
[0027] In accordance with another aspect, the invention provides a process implemented by a processor having a logic module. The process comprises receiving a machine instruction, the received machine instruction defining a first operand, a second operand, a third operand and a function to be applied to the first operand, the second operand and third operand. The process also comprises using the logic module to apply the function to the third operand to derive a preliminary result indicator and, in dependence of the derived preliminary result indicator, using the logic module to selectively apply the function to the first operand and second operand to update the derived preliminary result indicator. The process also comprises storing the derived preliminary result indicator in a memory associated with the third operand.
[0028] In accordance with a specific example of implementation, when the function conveys a first function type, the logic module is used for updating the preliminary result indicator by setting the derived preliminary result indicator to correspond to a Boolean result obtained by applying the function to the first operand and the second operand. When the function conveys a second function type, the logic module is used for updating the preliminary result indicator to a selected one of the third operand and the Boolean result obtained by applying the function to the first operand and second operand. When the function conveys a third function type, the logic module is used for updating the preliminary result indicator to a selected one of a modified version of the third operand and the Boolean result obtained by applying the function to the first operand and second operand.
[0029] In accordance with another aspect, the invention provides a computer readable storage medium storing a set of computer-readable instructions. The computer-readable instructions are configured to be executed by a processor having a logic module suitable for executing at least some of the computer-readable instructions in the set. The set of computer-readable instructions includes a machine instruction defining a first operand, a second operand, a third operand and a function to be applied to the first operand, the second operand and third operand. When executed by the logic module of the processor, the machine instruction causes the logic module to:
apply the function to the first operand and second operand to obtain an initial Boolean result; apply the function to the initial Boolean result and the third operand to derive an updated result; and store the updated result in a memory of the processor associated with the third operand.
[0033] In a specific implementation, the function when applied to the initial Boolean result and the third operand is such that the updated result corresponds to one of the initial Boolean result, the third operand and a modified version of the third operand. More particularly, in accordance with a specific example of implementation, when the function conveys a first function type, the logic module when executing the machine instruction is caused to process the initial Boolean result to derive the updated result by setting the updated result to correspond to the initial Boolean result. When the function conveys a second function type, the logic module when executing the machine instruction is caused to process the third operand to set the updated result to correspond to a selected one of the initial Boolean result and the third operand. When the function conveys a third function type, the logic module when executing the machine instruction is caused to process the third operand to set the updated result to correspond to a selected one of the initial Boolean result and a modified version of the third operand.
[0034] In accordance with another aspect, the invention provides a computer readable storage medium storing a set of computer-readable instructions. The computer-readable instructions are configured to be executed by a processor having a logic module suitable for executing at least some of the computer-readable instructions in the set. The set of computer-readable instructions includes a machine instruction defining a first operand, a second operand, a third operand and a function to be applied to the first operand, the second operand and third operand. When executed by the logic module, the machine instruction causes the logic module to:
apply the function to the third operand to derive a preliminary result indicator; in dependence of the derived preliminary result indicator, selectively apply the function to the first operand and second operand to update the derived preliminary result indicator; and store the derived preliminary result indicator in a memory of the processor associated with the third operand.
[0038] In accordance with a specific example of implementation, when the function conveys a first function type, the logic module when executing the machine instruction is caused to update the preliminary result indicator by setting the derived preliminary result indicator to correspond to a Boolean result obtained by applying the function to the first operand and second operand. When the function conveys a second function type, the logic module when executing the machine instruction is caused to update the preliminary result indicator to correspond to a selected one of the third operand and the Boolean result obtained by applying the function to the first operand and second operand. When the function conveys a third function type, the logic module when executing the machine instruction is caused to update the preliminary result indicator to a selected one of a modified version of the third operand and the Boolean result obtained by applying the function to the first operand and second operand.
[0039] In accordance with another aspect, the invention provides a computer program product storing a program element suitable to be executed by a computing apparatus for implementing a process for parsing a logical expression to create a set of computer-readable instructions. The set of computer-readable instructions is suitable for causing a processor to evaluate a Boolean result associated with the logical expression, the logical expression being comprised of a plurality of sub-expressions. The program element when executed by the computing apparatus is configured for processing the sub-expressions in the plurality of sub-expressions to generate the set of computer-readable instructions, the processed sub-expressions being associated with respective nesting levels relative to the logical expression being evaluated. At least one computer readable instruction associated with a sub-expression of the plurality of sub-expressions defines a first operand, a second operand, a third operand and a function to be applied to the first operand, the second operand and third operand. The function defined in the at least one computer readable instruction is such that, when executed by the processor, the third operand is caused to convey information related to a combination of:
an intermediate result of the logical expression being evaluated; and a level of nesting associated with a sub-expression with which the at least one computer readable instruction is associated.
[0042] The set of generated computer-readable instructions is then stored on a memory device.
[0043] In accordance with a specific example of implementation, the logical expression processed by the program element is a normalized logical expression in which Boolean operators selected from a set of available Boolean operators are used. In a first specific example, the set of available Boolean operators consists of OR and NOT operators. In a second specific example, the set of available Boolean operators consists of AND and NOT operators.
[0044] In accordance with an alternative example of implementation, the program element, when executed by the computing apparatus, is configured for processing the logical expression to derive a normalized logical expression, the normalized logical expression including Boolean operators selected from a set of available Boolean operators, and for generating the set of computer-readable instructions based on sub-expressions in the normalized logical expression.
[0045] In accordance with another aspect, the invention provides a computer program product storing a program element suitable to be executed by a computing apparatus for implementing a process for parsing a logical expression to create a set of computer-readable instructions. The set of computer-readable instructions is suitable for causing a processor to evaluate a Boolean result associated with the logical expression, the logical expression being comprised of a plurality of sub-expressions, each sub-expression being associated with a respective nesting level relative to the logical expression being evaluated. The process implemented by the program element when executed by the computing apparatus comprises processing a sub-expression of the plurality of sub-expressions to generate a computer readable instruction. The computer readable instruction defines a function to cause information to be stored in a memory associated with a processor executing the computer readable instruction. The information cause information to be stored in the memory is related to a combination of:
a preliminary result of the logical expression being evaluated; and a level of nesting associated with the sub-expression processed to generated the least one computer readable instruction.
[0048] In accordance with another aspect, the invention provides a computer program product storing a program element suitable to be executed by a computing apparatus for implementing a process for parsing a logical expression to create a set of computer-readable instructions, the set of computer-readable instructions being suitable for causing a processor to evaluate a Boolean result associated with the logical expression. The process implemented by the program element when executed by the computing apparatus comprises processing the logical expression to generate at least one computer readable instruction defining a first operand, a second operand, a third operand and a function to be applied to the first operand, the second operand and third operand. When executed by the processor, the machine instruction causes the processor to apply the function to the first operand and second operand to obtain an initial Boolean result and to apply the function to the initial Boolean result and the third operand to derive an updated result. The machine instruction also causes the processor to store the updated result in a memory of the processor associated with the third operand.
[0049] In accordance with a specific example of implementation, the third operand conveys information being related to a combination of a preliminary result of the logical expression being evaluated and a level of nesting associated with the sub-expression processed to generated the least one computer readable instruction.
[0050] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] A detailed description of examples of implementation of the present invention is provided herein below with reference to the following drawings, in which:
[0052] FIG. 1A is block diagrams of an apparatus for use in a processor suitable for executing machine instructions in accordance with a first specific example of implementation of the invention;
[0053] FIG. 1B is block diagrams of an apparatus for use in a processor suitable for executing machine instructions in accordance with a second specific example of implementation of the invention. This block diagram show an apparatus 210 coupled to the output of a Boolean operation 20 . The inputs to the apparatus 210 are the single bit result from the Boolean operation, the third operand 230 and the operation modifier 220 . The apparatus 210 produces result 240 . The result may be stored in the same register as the third operand 230 .
[0054] FIG. 1C is block diagrams of an apparatus for use in a processor suitable for executing machine instructions in accordance with a third specific example of implementation of the invention;
[0055] FIG. 2 shows a 32-bit register for holding an operand conveying information in accordance with a specific example of implementation of the invention. The operand has an N-bit nesting count supporting a maximum nesting level of 2 N-1 ;
[0056] FIGS. 3A and 3B are flow diagram showing processes for executing an instruction in accordance with specific examples of implementation of the invention;
[0057] FIG. 4 shows a computer program product and processor for parsing a logical expression to create a set of computer-readable instructions in accordance with a specific example of implementation of the invention;
[0058] FIG. 5 shows a computer program product and an associated processor for the execution of the computer program product including a set of computer-readable instructions in accordance with a specific example of implementation of the invention;
[0059] FIG. 6 is a block diagram of a circuit including a processor having a logic unit for applying an instruction in accordance with a specific example of implementation of the invention.
[0060] In the drawings, embodiments of the invention are illustrated by way of example. It is to be expressly understood that the description and drawings are only for purposes of illustration and as an aid to understanding, and are not intended to be a definition of the limits of the invention.
DETAILED DESCRIPTION
[0061] A typical implementation of assembly level conditional instructions in a processor compare either two (2) registers or a single register against an immediate value or state to produce a one bit result (true or false) that is place in a result register. For example an expression:
[0000] CMPNE r3,r1,r2
[0000] would set r3 to “1” (true) if r1 were not equal to r2 and “0” if r1 equaled r2.
[0062] In accordance with a specific example, proposed new instructions are provided in which the logical evaluation would manipulate an N-bit nesting count (ncnt) to update it by each instruction composing the terms of the logical expression. The ncnt provides an indication of whether or not the result of the logical expression is determinate and, optionally, provides an indication of the nesting level of the instruction within the overall logical expression that is being evaluated.
[0063] FIG. 2 of the drawings shows a 32-bit register for holding an operand for storing the N-bit nesting count (ncnt). The operand has an N-bit nesting count supporting a maximum nesting level of 2 N-1 . The register for storing ncnt may be a general purpose register in a processor or, alternatively, may be a dedicated register for use in storing ncnt. As a further optimization, the sign bit (S) of the register for storing ncnt can optionally be set to one when the nesting count is not zero. It is zero otherwise. This enables a single bit evaluation of the state of the conditional expression evaluation to always be available. This would allow, for example, conditional jumps based on the state of the sign bit.
[0064] In the exemplary embodiment described here, the logical expression being evaluated is expressed using only combinations of OR operands and NOT operands. “ncnt” is defined so that:
if the ncnt is zero, the result of the sub-expression currently being evaluated within the overall logical expression is not determinate and further terms are needed to evaluate the result of the current sub-expression; if the ncnt is non-zero, the result of the sub-expression currently being evaluated within the overall logical expression is determinate and subsequent terms of the sub-expression have no effect on the final result of the sub-expression.
[0067] In a first specific example of implementation, three types of operation manipulations (modifiers) are used to implement a logical evaluation process using the N-bit nesting count (ncnt):
start (.S), continue (.C) pop (.P)
[0071] For example the CMPNE (compare-not-equal) operation would be modified using the above modifiers and denoted by adding the .S, .C or .P to the instruction. For example CMPNE.P would indicate the pop modifier should be applied to the operation.
[0072] It will be observed that each distinct combination of an operation (example CMPNE) and operation modifier (example .S, .C or .P) defines a new function.
[0073] The specific operation modifiers in accordance with a specific example are defined as follows:
Start (.S)
[0000]
The ncnt is set to the result of the Boolean operation. If the result is true, ncnt is set to one. Otherwise, it is set to zero. This update type is used to initialize the logical expression operand at the start of an expression evaluation.
Continue (.C)
[0000]
If ncnt is zero, it is set to the result of the Boolean operation. Otherwise, it remains unchanged. This update type is used to continue the expression evaluation at the same nesting level.
Pop (.P)
[0000]
If ncnt is zero, it is set to the result of the Boolean operation. Otherwise, it is decremented by one. This update type is used to terminate the expression evaluation at the current level and resume at a lower nesting level.
[0077] FIGS. 1A , 1 B and 1 C of the drawings depict embodiments of processors for executing machine instructions including the new instructions described above.
[0078] More specifically, with reference to FIG. 1A , there is shown a processor 180 suitable for executing machine instructions. The processor 180 includes inputs for receiving a machine instruction, the received machine instruction defining a first operand 22 , a second operand 24 , a third operand 230 and a function 274 to be applied to the first operand 22 , the second operand 24 and third operand 230 by a logic module 270 to derive a result 240 . The result 240 is used to modify a memory unit (not shown in FIG. 1A ) associated with the third operand 230 . In this example the third operand is used to store “ncnt” defined above.
[0079] In accordance with a first approach, logic module 270 is configured to apply the function 274 to the first operand and second operand to obtain an initial Boolean result. When the function 274 conveys a first function type, the logic module 270 is configured for processing the initial Boolean result to derive the result 240 by setting the result 240 to correspond to the initial Boolean result. In a non-limiting example, the first function type is a function as modified by the (.S) extension as described above. When the function 274 conveys a second function type, the logic module 270 is configured for processing the third operand 230 to set the result 240 to correspond to a selected one of the initial Boolean result and the third operand 230 . In a non-limiting example, the first function type is a function as modified by the (.C) extension as described above. When the function conveys a third function type, the logic module is configured for processing the third operand 230 to set the result 240 to correspond to a selected one of the initial Boolean result and a modified version of the third operand. In the embodiment described the modified version of the third operand corresponds to the third operand 230 decremented by one (1). In a non-limiting example, the first function type is a function as modified by the (.P) extension as described above.
[0080] FIG. 1B depicts a specific example of a processor 180 ′, analogous to processor 180 of FIG. 1A , including an implementation of the logic module 270 for FIG. 1A in accordance with the first approach described above, identified as logic module 270 ′ in FIG. 1B for the purpose of clarity. In accordance with this first specific example, the function 274 includes an operation 26 and an operation modifier 220 . The logic module 270 ′ is configured for applying the operation 26 to the first operand 22 and second operand 24 to obtain the initial Boolean result and for applying the operation modifier 220 to the initial Boolean result and the third operand 230 to derive the result 240 . In the embodiment depicted first logic module 20 applies the operation 26 to the first operand and second operand to obtain the initial Boolean result and second logic module 210 applies the operation modifier to the initial Boolean result and the third operand 230 to derive the result 240 .
[0081] The operation modifier is selected from a set of available operation modifier type, in this non-limiting example the start (.S) modifier type, continue (.C) modifier type and pop (.P) modifier type.
[0082] The first logic module 20 may be implemented in accordance with conventional boolean (logic) modules which are well known in the art and will not be described further here.
[0083] The second logic module 210 is configured for generating the result 240 in dependence on the operation modifier. In particular, when the operation modifier 220 conveys the start (.S) modifier type, the second logic module 20 is configured for processing the initial Boolean result to derive the updated result by setting the result to correspond to the initial Boolean result. When the operation modifier conveys the continue (.C) modifier type, the second logic module 20 is configured for processing the third operand 230 to set the result 240 to correspond to a selected one of the initial Boolean result and the third operand 230 . When the operation modifier 220 conveys the pop (.P) modifier type, the logic module 210 is configured for processing the third operand 230 to set the result 240 to correspond to a selected one of the initial Boolean result and a modified version of the third operand 230 . The modified version in this case corresponds to the third operand 230 being decremented by one (1).
[0084] FIG. 3A is a flow diagram depicting a process implemented by processor 180 ′ depicted in FIG. 1B . At step 500 a machine instruction is received by the processor 180 ′. The machine instruction defines a first operand, a second operand, a third operand and a function to be applied to the first operand, the second operand and third operand. At step 502 , the function is applied by the first logic module 20 (shown in FIG. 1B ) to the first operand and second operand to obtain an initial Boolean result. At step 504 , the function is applied to the initial Boolean result and the third operand to derive an updated result. At step 506 , the updated result is stored in a memory unit associated with the third operand so that the third operand is modified to correspond to the updated result.
[0085] Returning now to FIG. 1A , in accordance with a second approach, logic module 270 is configured to apply the function 274 to the third operand 230 to derive a preliminary result indicator. In dependence of the derived preliminary result indicator, logic module 270 is configured to selectively applying the function 274 to the first operand 22 and second operand 24 to update the derived preliminary result indicator and obtain the result 240 .
[0086] FIG. 1C depicts a specific example of a processor 180 ″, analogous to processor 180 of FIG. 1A , including an implementation of the logic module 270 for FIG. 1A in accordance with the second approach described above, identified as logic module 270 ″ in FIG. 1C for the purpose of clarity. In accordance with this second specific example, the function 274 includes an operation 26 and an operation modifier 220 . The logic module 270 ″ is configured for applying the operation modifier 220 to the third operand 230 to derive a preliminary result indicator. The logic module 270 ″ is also configured for, in dependence of the derived preliminary result indicator, selectively applying the operation 26 to the first operand 22 and second operand 24 to update the derived preliminary result indicator and derive the result 240 .
[0087] In the embodiment depicted, first logic module 20 ′ applies the operation 26 to the first operand 22 and second operand 24 to obtain an initial Boolean result, second logic module 310 applies the operation modifier to the third operand 230 to derive the preliminary result indicator. A third logic module 360 , referred to as the updating module 360 , processes the preliminary result indicator and the initial Boolean result to derive the result 240 .
[0088] The operation modifier 220 is selected from a set of available operation modifier type, in this example the start (.S) modifier type, the continue (.C) modifier type and the pop (.P) modifier type.
[0089] The first logic module 20 may be implemented in accordance with conventional Boolean (logic) modules which are well known in the art and which as such will not be described further here.
[0090] The second logic module 310 and the updating module 360 are configured for generating the result in according with the operation modifier. In particular, when the operation modifier 220 conveys the start (.S) modifier type, the second logic module 310 and the updating module 360 are configured for deriving a result 340 that corresponds to the initial Boolean result. When the operation modifier conveys continue (.C) modifier type, the second logic module 310 and the updating module 360 are configured for deriving a result 340 that corresponds to the initial Boolean result when the third operand 230 conveys a pre-determined value, and for the deriving a result 340 that corresponds to the third operand 230 otherwise. In a specific implementation the pre-determined value is “0”. When the operation modifier conveys the pop (.P) modifier type, the second logic module 310 and the updating module 360 are configured for deriving a result 340 that corresponds to;
the initial Boolean result when the third operand 230 conveys a pre-determined value. In a specific implementation the pre-determined value is “0”; a modified version of the third operand 230 otherwise. The modified version in this case corresponds to third operand 230 decremented by one (1).
[0093] FIG. 3B is a flow diagram depicting a process implemented by processor 180 ″ depicted in FIG. 1C . At step 550 a machine instruction is received by the processor 180 ″. The machine instruction defines a first operand, a second operand, a third operand and a function to be applied to the first operand, the second operand and third operand. At step 552 , the function is applied to the third operand to derive a preliminary result indicator. At step 554 , in dependence of the derived preliminary result indicator, the function is selectively applied to the first operand and the second operand to update the derived preliminary result indicator. At step 556 , the derived preliminary result indicator is stored in a memory unit associated with the third operand so that the third operand is modified to correspond to the derived preliminary result indicator.
[0094] It is to be appreciated by the person skilled in the art that the functionality of the logic units 270 270 ′ and 270 ″ described with reference to FIGS. 1A , 1 B and 1 C may be implemented using any suitable hardware components and many possible implementations will become readily apparent to the person skilled in the art in light of the present description. The specific combination of hardware elements and configuration used in practical implementations for achieving the above described functionality is not critical to the invention and therefore will not be described in detail here.
Method for Generating Computer-Readable Code
[0095] To use the above described processors to evaluate a logical expression, a generalized method is introduced here for generating a set of computer-readable instructions which makes use of the new instructions described above.
[0096] In particular, a process for parsing a logical expression to generate a set of computer-readable instructions being suitable for causing a processor to evaluate a Boolean result associated with the logical expression. The generated set of computer-readable instructions make use of the augmented instruction set described above in order to makes use of a register for storing information (in this example ncnt) related to a combination of:
a preliminary result of the logical expression being evaluated; and a level of nesting associated with the sub-expression processed to generated the least one computer readable instruction.
[0099] Generally speaking, the logical expression is comprised of a plurality of sub-expressions, each sub-expression being associated with a respective nesting level relative to the logical expression being evaluated. The process comprises processing the sub-expressions of the plurality of sub-expressions to generate computer readable instructions.
[0100] For the purpose of the present description, a logical expression that is expressed using either only OR and NOT logical operators or only AND and NOT logical operators is referred to as a “normalized” logical expression.
[0101] In the present description a basic method configured to be applied to a logical expression that has been reduced to be expressed using only OR and NOT logical operators will be described. It will become readily apparent to the person skilled in the art on how to apply a modified alternative version of the method described here to a logical expression that has been reduced to be expressed using only AND and NOT logical operators and as such this alternative version of the method will not be described in detail here.
[0102] If the logical expression to be evaluated is not a normalized logical expression, it can ne normalized so that it is expressed using only OR and NOT logical operators through the use of well known De Morgan's Law of logical equivalence. For example the expression:
[0000] result=( A B ) ( C 0)
[0000] can be converted to:
[0000] result= ( A B ) ( C D )
[0000] In another example, the expression:
[0000] result= A ((( B C ) D ) E )
[0000] can be converted to:
[0000] result= A ( ( ( B C ) D ) E )
[0103] In accordance with an example of implementation of the invention, the expression can then be parsed left to right in the following manner:
1. Initialize ncnt to zero once at the beginning of parsing an expression 2. For each entry into a sub-expression (“(”) if ncnt is greater than 0 increment ncnt by 1. Note that entering the first sub-expression after initialization ncnt will never be greater than 0. 3. For each conditional evaluation in a sub-expression, if ncnt equals zero, ncnt is set to the one bit result of the conditional evaluation (ncnt value would become 1 or 0). 4. For each exit of a sub-expression (“)”) if ncnt is greater than 1 decrement ncnt by 1. 5. For each evaluated sub-expression (after performing exit step above) if ncnt is less than or equal to one, ncnt is set to the one bit result of the conditional evaluation of the sub-expression
[0109] Using the operation modifiers described above, we note that:
Start (.S) is the combination of steps 1, 2, and 3 Continue (.C) is step 3 Pop (.P) is the combination of steps 4 and 5.
[0113] For the purpose of illustration we will apply the described parsing approach to two example logical expressions using the following notation:
A, B, C, D: boolean variables with a value of 0 or 1 result: register ncnt: general purpose register used for N-Bit nesting count : not : and : or condition expression (if condition is true then do expression, otherwise do nothing)
FIRST EXAMPLE
[0121] Applying the above approach to the example expression (the sub-expressions marked in bold is the one being parsed):
[0000]
result = ( A B) ( C D)
ncnt = 0
(1) Initialize ncnt register
ncnt > 0 ncnt := ncnt + 1
(2) Parse open parentheses (“(”)
( A B) ( C D)
note: will always be “0” after initialization
ncnt = 0 ncnt := A
(3) Evaluate condition in sub-expression
( A B) ( C D)
ncnt = 0 ncnt := B
(3) Evaluate condition in sub-expression
( A B ) ( C D)
ncnt > 1 ncnt := ncnt − 1
(4) Parse close parentheses
( A B) ( C D)
ncnt ≦ 1 ncnt := ncnt
(5) Evaluate condition of sub-expression
( A B) ( C D)
ncnt > 0 ncnt := ncnt + 1
(2) Parse open parentheses (“(”)
( A B) ( C D)
ncnt = 0 ncnt := C
(3) Evaluate condition in sub-expression
( A B) ( C D)
ncnt = 0 ncnt := D
(3) Evaluate condition in sub-expression
( A B) ( C D )
ncnt > 1 ncnt := ncnt − 1
(4) Parse close parentheses
( A B) ( C D)
ncnt ≦ 1 ncnt := ncnt
(5) Evaluate condition of sub-expression
( A B) ( C D)
[0122] The above listing can be simplified in the following manner
[0000]
[
ncnt
:=
0
ncnt
>
0
⇒
ncnt
:=
ncnt
+
1
ncnt
=
0
⇒
ncnt
:=
A
]
(
combined
)
(
removed
because
ncnt
always
0
at
beginning
of
evaluation
)
(
combined
)
ncnt
:=
A
[
ncnt
=
0
⇒
ncnt
:=
B
ncnt
>
1
⇒
ncnt
:=
ncnt
-
1
ncnt
≤
1
⇒
ncnt
:=
ncnt
]
(
combined
)
(
combined
)
(
combined
)
ncnt
=
0
⇒
ncnt
:=
B
ncnt
>
0
⇒
ncnt
:=
ncnt
-
1
ncnt
>
0
⇒
ncnt
:=
ncnt
+
1
ncnt
=
0
⇒
ncnt
:=
C
[
ncnt
=
0
⇒
ncnt
:=
D
ncnt
>
1
⇒
ncnt
:=
ncnt
-
1
ncnt
≤
1
⇒
ncnt
:=
ncnt
]
(
combined
)
(
combined
)
(
combined
)
ncnt
=
0
⇒
ncnt
:=
D
ncnt
>
0
⇒
ncnt
:=
ncnt
-
1
[0123] The above operations can be expressed in assembly language for execution by a processor. In order to illustrate this, consider the following conventions:
s0 “first operand”, a source of an operand for an instruction, may be either a register or an immediate value s1 “second operand”, a source of an operand for an instruction, may be either a register or an immediate value ds2 “third operand”, the destination register of an instruction and optionally a source register of an instruction
[0000]
CMPNE
ds2, s1, s0
Compare Not Equal
if s1 is not equal to s2, ds2 is set to 1 otherwise 0
CMPEQ
ds2, s1, s0
Compare Equal
if s1 is equal to s2, ds2 is set to 1 otherwise 0
CADDNZ
ds2, s1, s0
Conditional Add Not Zero
if s0 is not equal to zero,
ds2 is set to s0 plus s1 otherwise 0
[0127] By applying the proposed modifiers and converting to assembly language this becomes:
[0000]
CMPNE.S
ncnt, 1, A
ncnt = 0
ncnt > 0 ncnt := ncnt + 1
ncnt = 0 ncnt := A
CMPEQ.P
ncnt, 1, B
ncnt = 0 ncnt := B
ncnt > 1 ncnt := ncnt − 1
ncnt ≦ 1 ncnt := ncnt
CADDNZ
ncnt, 1, ncnt
ncnt > 0 ncnt := ncnt + 1
CMPNE.C
ncnt, 1, C
ncnt = 0 ncnt := C
CMPEQ.P
ncnt, 1, D
ncnt = 0 ncnt := D
ncnt > 1 ncnt := ncnt − 1
ncnt ≦ 1 ncnt := ncnt
[0128] After the last instruction ncnt contains the one bit result of the original expression.
SECOND EXAMPLE
[0129] Applying the above process to the following second expression (the sub-expressions marked in bold is the one being parsed):
[0000] result= A ( ( ( B C ) D ) E )
[0000] we get the following:
[0000]
ncnt = 0
(1) Initialize ncnt register
ncnt = 0 ncnt := A
(3) Evaluate condition in sub-expression
A ( ( ( B C) D) E)
ncnt > 0 ncnt := ncnt + 1
(2) Parse open parentheses (“)”)
A ( ( ( B C) D) E)
ncnt > 0 ncnt := ncnt + 1
(2) Parse open parentheses (“)”)
A ( ( ( B C) D) E)
ncnt > 0 ncnt := ncnt + 1
(2) Parse open parentheses (“)”)
A ( ( ( B C) D) E)
ncnt = 0 ncnt := B
(3) Evaluate condition in sub-expression
A ( ( ( B C) D) E)
ncnt = 0 ncnt := C
(3) Evaluate condition in sub-expression
A ( ( ( B C ) D) E)
ncnt >1 ncnt := ncnt − 1
(4) Parse close parentheses (“)”)
A ( ( ( B C) D) E)
ncnt ≦ 1 ncnt := ncnt
(5) Evaluate condition of sub-expression
A ( ( ( B C) D) E)
ncnt = 0 ncnt := D
(3) Evaluate condition in sub-expression
A ( ( ( B C) D ) E)
ncnt >1 ncnt := ncnt − 1
(4) Parse close parentheses (“)”)
A ( ( ( B C) D) E)
ncnt ≦ 1 ncnt := ncnt
(5) Evaluate condition of sub-expression
A ( ( ( B C) D) E)
ncnt = 0 ncnt := E
(3) Evaluate condition in sub-expression
A ( ( ( B C) D) E )
ncnt >1 ncnt := ncnt − 1
(4) Parse close parentheses (“)”)
A ( ( ( B C) D) E)
ncnt ≦ 1 ncnt := ncnt
(5) Evaluate condition of sub-expression
A ( ( ( B C) D) E)
[0130] The above can be simplified in the following manner
[0000]
[
ncnt
:=
0
ncnt
=
0
⇒
ncnt
:=
A
]
(
combined
)
(
combined
)
ncnt
:=
A
[
ncnt
>
0
⇒
ncnt
:=
ncnt
+
1
ncnt
>
0
⇒
ncnt
:=
ncnt
+
1
ncnt
>
0
⇒
ncnt
:=
ncnt
+
1
]
(
combined
)
(
combined
)
(
combined
)
ncnt
>
0
⇒
ncnt
:=
ncnt
+
3
ncnt
=
0
⇒
ncnt
:=
B
[
ncnt
=
0
⇒
ncnt
:=
C
ncnt
>
1
⇒
ncnt
:=
ncnt
-
1
ncnt
≤
1
⇒
ncnt
:=
ncnt
]
(
combined
)
(
combined
)
(
combined
)
ncnt
=
0
⇒
ncnt
:=
C
ncnt
>
0
⇒
ncnt
:=
ncnt
-
1
[
ncnt
=
0
⇒
ncnt
:=
D
ncnt
>
1
⇒
ncnt
:=
ncnt
-
1
ncnt
≤
1
⇒
ncnt
:=
ncnt
]
(
combined
)
(
combined
)
(
combined
)
ncnt
=
0
⇒
ncnt
:=
D
ncnt
>
0
⇒
ncnt
:=
ncnt
-
1
[
ncnt
=
0
⇒
ncnt
:=
E
ncnt
>
1
⇒
ncnt
:=
ncnt
-
1
ncnt
≤
1
⇒
ncnt
:=
ncnt
]
(
combined
)
(
combined
)
(
combined
)
ncnt
=
0
⇒
ncnt
:=
E
ncnt
>
0
⇒
ncnt
:=
ncnt
-
1
[0131] By applying the proposed modifiers and converting to assembly this becomes:
[0000]
CMPEQ.S
ncnt, 1, A
ncnt = 0
ncnt = 0 ncnt := A
CADDNZ
ncnt, 3, ncnt
ncnt > 0 ncnt := ncnt + 1
ncnt > 0 ncnt := ncnt + 1
ncnt > 0 ncnt := ncnt + 1
CMPNEQ.C
ncnt, 1, B
ncnt = 0 ncnt := B
CMPEQ.P
ncnt, 1, C
ncnt = 0 ncnt := C
ncnt > 1 ncnt := ncnt − 1
ncnt ≦ 1 ncnt : ncnt
CMPNE.P
ncnt, 1, D
ncnt = 0 ncnt := D
ncnt > 1 ncnt := ncnt − 1
ncnt ≦ 1 ncnt := ncnt
CMPEQ.P
ncnt, 1, E
ncnt = 0 ncnt := E
ncnt > 1 ncnt := ncnt − 1
ncnt ≦ 1 ncnt := ncnt
[0132] After the last instruction executes, ncnt contains the one bit result of the original expression.
[0133] The parsing approach for parsing a logical expression described above may be implemented by a computer program, for example as part of a compiler, and used for parsing a logical expression to create a set of computer-readable instructions to evaluate the result of the logical expression. FIG. 4 of the drawings depicts a computer readable storage medium 650 storing a program element 658 suitable to be executed by a computing apparatus, depicted as processor 652 . The program element 658 when executing on the processor 658 implements the process of the type described above for parsing a logical expression, such as logical expression 654 stored on a memory 660 , to create a set of computer-readable instructions 656 for evaluating the result of the logical expression. The derived set of computer-readable instructions 656 is then stored in a memory 662 for use by a processor having a logic unit of the type described earlier, for example, in connection with any one of FIGS. 1A , 1 B and 1 C.
[0134] FIG. 5 shows a computer readable storage medium 610 storing a program element 620 including a set of computer-readable instructions generated according to the process described above. FIG. 5 also depicts a processor 600 suitable for executing the program element 620 . In a non-limiting example the processor 600 may include an apparatus of the type described in FIG. 1A , 1 B or 1 C.
[0135] Although the specific example of implementation described has described a method applied to a logical expression that has been reduced to be expressed using only OR and NOT logical operators, alternative implementations of the parsing method can also be applied to a logical expression that has been reduced to be expressed using only AND and NOT. This type of conversion and can be achieved for any expression through the use of well known De Morgan's Law of logical equivalence. A slightly modified approach to the one described above for parsing the Boolean expression would be applied. Such a modified approach will be readily apparent to the person skilled in the art in light of the present description and will hence not be described in further detail here.
Processing Circuit 750 (FIG. 6)
[0136] FIG. 6 is a block diagram of a circuit 750 having a logic unit (ALU) 700 for applying an instruction in accordance with the above described functionality. For example the functionality of the apparatus described with reference to FIG. 1A , 1 B or 1 C may be integrated as part of logic unit 700 . As depicted, the circuit 750 includes and instruction memory 758 for storing a set of machine readable instruction including instructions of the types described in the present application. The circuit 750 also includes first circuitry 756 for fetching a next instruction to be executed from the instruction memory 758 and second circuitry 754 for decoding an instruction fetched from the instruction memory 758 into a format that is suitable to be processed by the ALU 700 . The circuit 750 also includes a data memory 752 . In accordance with an example of implementation of the invention, the instruction fetched from memory 758 defines a first operand (S0), a second operand (S1), a third operand (DS2) and a function to be applied to the first operand, the second operand and third operand. The values for the first operand (S0), the second operand (S1) and the third operand (DS2) are provided to the ALU 700 through Registers 702 .
[0137] The values may be already present in the Registers 702 and/or may be part of the instruction fetched from memory 758 and loaded into the Registers 702 . The function defined by the instruction fetched from memory 758 is provided to the ALU 700 at 780 . The ALU 700 is configured to apply the function 780 to the first operand (S0), second operand (S1) and third operand (S2) to obtain a result 782 . The result 782 is released at the output of the ALU 700 and can be stored in a register in the Registers 702 corresponding to the third operand (S2). In a specific example, the ALU 700 is configured to apply the function to the first operand (S0) and second operand (S1) to derive an initial Boolean result. The ALU 700 also applies the function to the initial Boolean result and the third operand to derive an updated result, corresponding to ncnt, which is released at the output of the ALU 700 .
[0138] It is to be appreciated that the circuit 700 is an exemplary circuit and has been provided for the purpose of illustration only. Practical implementation of processors making use of the invention may differ from the example shown without detracting from the spirit of the invention.
[0139] It is to be appreciated that many suitable components for implementing a practical processor having the above described functionality are possible and will become readily apparent to the person skilled in the art in light of the present description. The specific combination of hardware elements used in practical implementations is not critical to the invention and therefore will not be described in detail here.
[0140] In addition, although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, variations and refinements are possible. Therefore, the scope of the invention should be limited only by the appended claims and their equivalents. | A method and associated processor suitable for executing machine instructions for evaluating a logical expression are provided. The approach suggested makes use of a memory and an extended set of instructions. The memory, which can be embodied in a general purpose register for example, is for storing information related to an intermediate results obtained in evaluating the logical expression as well as a nesting level of sub-expressions in the logical expression being evaluated. The extended set of instruction allows for initializing and updating the information in that memory. A processor for executing the extended set of instruction is also provided along with a process for generating machine code making use of this extended set of instructions for evaluating a logical expression. | 6 |
FIELD OF THE INVENTION
The present invention relates to central processing units of data processing systems. More particularly, the invention relates to microbranching within sets of microinstructions for use within a central processing unit of a data processing system and the hardware for performing microbranching.
BACKGROUND OF THE INVENTION
The concept of microbranching, that is, branching within the microcode level of microinstructions in a central processing unit of data processing systems is well known in the art. It is known to perform microbranching upon selected results of selected test conditions in the central processing units of data processing systems. Within data processing systems which employ pipelined architectures, it is known to perform microbranching as the result of tests which are performed during the execution of different ranks of the microcode field for a single microinstruction. Some prior art systems have the capability to only do "fast" branches, that is, to branch on the result of test conditions which are sensed during the execution of the rank one microcode bit field in any given microinstruction. Other systems have had the capability to branch only in a "slow" manner, that is, upon the results of test conditions which occur during execution of the rank two microcode for any given microinstruction. Some of the systems known in the prior art which are capable of performing microbranching have the capability to inhibit lines of microcode which enter the pipeline after the line of microcode which causes the branch to occur. The necessity to inhibit the execution of such later lines of microcode is dependent on the function that the microcode performs and whether it is compatible with the branch which is taken by the CPU under the direction of the microcode as the result of the test conditions.
While these prior art microbranching architecture schemes have provided flexibility to system designers and have made possible the design of systems which are capable of making more decisions and thus functioning on higher levels of abstraction, there is still room for improvement in the design and execution of such system hardware.
For example, systems which are not capable of performing both fast and slow branches are not as flexible as systems which are so designed. Such systems do not generally have the capability of performing more than one test at any one particular time or even the capability of performing more than one test during the execution of any one microinstruction. Some such systems have the capability of only performing fast microbranches and some systems only perform slow microbranches. The systems which are capable of only performing fast microbranches cannot branch on conditions generated by the rank two execution of the current microinstruction. The obvious reason for this shortcoming is that the condition which invokes the decision to branch occurs during a later period in time than is capable of being sensed by the branching hardware.
On the other hand, systems which only perform slow branches must always wait an extra clock cycle for the conditions which invoke the branch to occur under the direction of rank two microcode and thus lose a clock cycle before execution of microcode at the branch target can begin.
Another drawback of the prior art systems which are capable of performing slow microcode branching is that they lack the flexibility to selectively inhibit either one or both lines of microcode which enter the pipeline before the branch decision is made. Likewise, prior art systems which are capable of performing fast microbranching typically lack the flexibility to selectively inhibit either one or both of the current or next lines of microcode which enter the pipeline before the branch decision can be made.
Furthermore, prior art systems which allow lines of microcode to execute after the decision to microbranch as the result of a test condition has been made generally do not have the capability of calling a subroutine and then returning to any other line of microcode other than the line of microcode which followed the line of microcode which invoked the branch.
Another drawback of currently employed microbranching hardware is that the hardware employed by the prior art for performing both fast and slow microbranching cannot be checked against one another without the need to employ additional checking hardware.
Finally, a return address stack is commonly employed by systems which perform any type of microbranching. This return address stack is used as a vector by the system to point to an address to which the processor should return to resume executing the microcode it was executing prior to the branch being taken. Prior art return address architectures known to the inventors of the present invention share the common architectural feature that the loading of the return address is not decoupled from the rotation of the stack. This tends to reduce flexibility or increase the hardware cost of prior CPU's.
Therefore, it is an object of the present invention to provide an architecture for use in central processing units for performing microbranching which is capable of performing both fast and slow microbranching.
It is a further object of the present invention to provide a microbranching architecture which is capable of performing more than one test during the execution of any single microinstruction.
It is a further object of the present invention to provide a microbranching architecture which is capable of inhibiting either or both of the lines of microcode which enter the pipeline during a slow microcode branch.
It is yet another object of the present invention to provide a microbranching architecture which is capable of inhibiting either or both of the current and the following line microcode which enter the pipeline during a fast microbranch.
Yet another object of the present invention is to provide a microbranching architecture which allows lines of microcode in the pipeline to be executed and has the capability of calling a subroutine and then executing any line microcode in the control store upon returning from the subroutine.
A further object of the present invention is to provide for a microbranching architecture capable of performing both fast and slow microcode jumps and having the further capability of allowing the operations of both the fast and slow microcode jumping hardware to be checked against one another.
It is also an object of the present invention to provide a return address stack for use in performing microbranching in which the return address loading is decoupled from the rotating of the stack.
These and other objects of the present invention will become apparent to those of ordinary skill in the art from an examination of the specification, accompanying drawings, and appended claims.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
An architecture for use in a CPU for performing microbranching can selectively elect to execute either the next line of microcode in a control store or a line of microcode pointed to by a vector which is supplied in response to the positive result of a test that occurs during the execution of the rank one portion of the microcode for the current microinstruction or to a vector supplied as the result of the execution of the rank two portion of the microcode of the current microinstruction. If both conditions are met, i.e., both the test performed during the rank one microcode execution and rank two microcode execution prove true, the branch address pointed to by the result of the rank two microcode portion of the execution is chosen in priority over the other one.
If a microbranch is selected, either none, one or all of the instructions which have entered the pipeline since the instruction which caused the microbranch can be optionally inhibited.
In addition, an extra block of hardware logic enables the system to proceed as if the decision to not take the microbranch was correctly made and proceed to load the pipeline upon that assumption but to recover from the error if that assumption was incorrect and substitute a vector to the microbranch address at a later time. During the time in which this address is fetched and loaded, pause circuitry halts other system clocks.
When a decision to take a microcode call is made, a return address is placed on a return address stack. This return address is not limited to the address which was pending when the microbranch was taken, but may be any address in control store. The loading of a return address onto the stack is decoupled from the rotating of the stack.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the dual speed microbranching hardware in a preferred embodiment of the present invention.
FIG. 2 is a block and logic level diagram of the hardware for optionally inhibiting operations in the pipeline after a microbranch has been taken.
FIG. 3 is a logic level diagram of the hardware for revectoring to a correct address after an incorrect assumption on microbranching has been made, including hardware for pausing system clocks when the revectoring is performed.
FIG. 4 is a block diagram of a preferred embodiment of a return address stack according to the present invention.
FIG. 5 is a block diagram of hardware for implementing the decision to microbranch which may select from a plurality of available test conditions.
DETAILED DESCRIPTION OF THE INVENTION
Microbranching is the ability of a machine which is executing microcode to inhibit the sequential execution of the next line of microcode in favor of executing a series of instructions which are pointed to by a vector in response to the true result of a test condition. The present invention is particularly useful in conjunction with central processing unit hardware like that described in copending application Ser. Nos. 537,038, 537,429 and 537,877 filed Sept. 29, 1983, which are expressly incorporated herein by reference.
Microinstructions are typically accessed from a control store by placing the address of the desired microinstruction on a control store address bus. Referring first to FIG. 1, in the present invention, addresses for lines of microcode are presented on control store bus 10, which may be as wide as necessary to accommodate the number of address bits in a system. Control store bus 10 is driven by control store address bus 4:1 multiplexer 12. Multiplexer 12 selects from among three data sources: control store address register 14, via line 16; fast microbranch register 18 via line 20; and slow microbranch register 22 via line 24.
During sequential microinstruction operation, i.e., when microbranching not taking place, control store bus 10 is fed back via line 26, incremented in incrementing circuit 28 and fed back into control store address register 14 after the next clock cycle from the system clock. Thus, during normal operation control store address bus 10 contains the address one greater than the previous address on address bus 10. This address is held in control store address register 14, and connected to multiplexer 12 via line 16.
When, however, microbranching is desired, multiplexer 12 selects a vector address from either fast microbranch 18 or slow microbranch register 22. It does so according to the states of slow test met (SMET) flip-flop 30 and fast test met (FMET) flip-flop 32 which drive the select input A and B of multiplexer 12 via lines 34 and 36 respectively. As can be seen from FIG. 1, control store address register 14, fast microbranch register 18, slow microbranch register 22, FMET flip-flop 30 and fast FMET flip-flop 32 are all driven from the system clock via line 38.
SMET flip-flop 30 and FMET flip-flop 32 are driven as a result of one of numerous test conditions 40 which are supplied via multiple lines 42 to slow test selector 44 which drives SMET flip-flop 30 via line 46 and fast test selector 48 which drives FMET flip-flop 32 via line 50. This will be explained more fully with respect to FIG. 5. Both slow test selector 44 and fast test selector 48 select from among the various test conditions 40 presented on their multiple lines 42 in accordance with the contents of encoded microcode fields. Slow test selector 44 uses a microcode field from the rank 2 portion of the microcode to select which one of test conditions 40 it will test. Fast test selector 48 uses a microcode field in the rank one microcode to select which one of test conditions 40 it will act upon.
By use of the hardware of the present condition, a guess can be made with respect to the outcome of either one of the slow or fast tests, i.e., tests made on conditions during the rank one microcode field or those made during the enablement of the rank two microcode field so that a preliminary microbranch decision may be made prior to actual results of that test being available. While this hardware feature obviously speeds up system performance, guesses are prone to be wrong and if an incorrect guess is made the system clocks can be paused while the correct vector is supplied to control store address bus 10. This feature is implemented by pause logic 56. Pause logic 56 overrides the decision made by the guess to slow test selector unit 44 via line 58 and to fast test selector unit 48 via line 60. An additional signal supplied on line 62 inhibits the clocking of selected registers until the substitution of the correct vector has been made. The operation of pause logic 56 will be more fully explained with respect to FIG. 3.
The selection of vectors for both fast microbranch register 18 and slow microbranch register 22 are made by multiplexers. Specifically, multiplexer 64 supplies a vector to fast microbranch register 18 via line 66 and multiplexer 68 supplies a vector to slow microbranch register 22 via line 70. Multiplexer 64 and multiplexer 68 have several sources. Multiplexer 64 and multiplexer 68 may obtain a vector from the return address stack 72 via line 74. Multiplexer 64 may additionally obtain a vector from a portion of the rank one microcode field obtained at the output of the horizontal control store 76 via line 78. Thus, it can be seen that the vector supplied to fast microbranch register 18 may be specified by a portion of the rank one microcode while another portion of that same microcode specifies which test condition may cause this vector to be selected.
Multiplexer 68 may be supplied with a vector from a portion of the rank two microcode from the output of rank two register 80 via line 82. Thus, a portion of the rank two microcode field may specify the vector to which the system will branch as a result of a particular test which is also specified by another portion of that rank of microcode.
Using the hardware of the present invention, a decision may be made to inhibit either one or both or neither of the two following lines of microcode which will enter the pipeline between the time a slow branch instruction is executed and the branch target line is executed. Likewise, a decision may be made whether to inhibit the operation of a current line of code, the next line of code, or neither when a fast microcode branch is taken. The hardware responsible for implementing this function is NOP generator 84 which generates signals NOP1 and NOP2 via lines 86 and 88, respectively. NOP generator 84 makes its decision based on the conditions of the outputs of slow test met flip-flop 30, fast test met flip-flop 32, a bit field of the rank two microcode from rank two register 80 via line 90, and a bit field of the rank three microcode from rank three register 92 via line 94.
The determination of which vectors are to be selected by multiplexers 64 and 68 is controlled by fields in the rank one and rank two microcode, respectively.
As is apparent from FIG. 1, a clock pulse on line 38 places the contents of either the fast microbranch register 18, slow microbranch register 22 or control store address register 14 through multiplexer 12 and on to control store bus 10. It will be apparent that the contents of control store address bus 10 will be clocked into rank one address (R1ADR) register 96 following the next clock pulse. It is this same clock pulse which is used to register the contents of control store which are accessed by this signal. Thus, at any given time the contents of R1ADR 96 will be the vector pointing to the microcode residing in rank 1 register for execution. The contents of R1ADR 96 are therefore a vector to the nominal return address after a microcode branch has been executed.
The contents of R1ADR 96 are made available to return address stack (RAS) 72 via multiplexer 98. Since the input to return address 72 is via multiplexer 98, a vector other than the original vector appearing in R1 address register 96 may be placed in the return address stack. Multiplexer 98 is shown having another input from the SK bus 100 shown in FIG. 1 of copending application Ser. No. 537,877, filed Sept. 29, 1983.
One of the ways in which the enhanced microbranching capabilities of the present invention is realized is by allowing a means for vectoring to microcode based on a macroinstruction to be executed. For this purpose, multiplexer 68 which accesses slow microcode branch register 22 may also be sourced by the entry point table which holds a vector to the macroinstruction about to be executed. Therefore, the branching capability of the present invention encompasses vectoring microcode based on this instruction.
The hardware of a preferred embodiment of the present invention possesses the capability to optionally inhibit lines of code which enter the pipeline between the time the branching instruction enters the pipeline and the time that the decision to branch is made. These options may be coded in microcode, since it is not always desired to inhibit any of these instructions.
Referring now to FIG. 2, a block diagram of the hardware used to optionally inhibit lines of code, the inhibiting mechanism is described. Two bit fields in the microcode performing the branch, early no-operation bit field (ENOP) 102 and late no-operation bit field (LNOP) 104, may be selectively set to inhibit lines of microcode. If a fast branch is being taken the ENOP field 102 inhibits the rank two operation of the current line; if it is a slow branch, ENOP 102 inhibits the rank two operation of the next line of code. The LNOP field, if a fast microbranch is taken, inhibits the next line of microcode in the pipeline and if a slow branch is taken, inhibits the rank two operation of the line of microcode one level further in the pipeline.
Microcode bits 102 and 104, along with the other microcode fields, are passed on successive clock cycles through rank two register 80 and rank three register 92. When these two bits are in the rank two position in the pipeline, they work in the conjunction with FMET flip-flop 32 to determine which, if any, lines of microcode to inhibit. When these bits are in the rank three stage of the pipeline, they work in conjunction with SMET flip-flop 30 to determine which, if any, lines of code to inhibit.
Since, in the preferred embodiment shown in FIG. 2, the decision making hardware is AND gate based, it will be obvious that if neither fast test met flip-flop 32 nor slow test met flip-flop 30 is set (i.e., holds a logic one) no lines of code will be inhibited since no branching has been selected. However, if either one or both of these flip-flops has been set, the decision to inhibit microcode lines rests entirely with the ENOP 102 and LNOP 104 portions of the microcode. If neither of these bits is a logic one, then no lines of microcode are inhibited. However, if one or both of these lines is a logic one, the inhibition hardware performs as follows.
In the case of a fast branch, assume that fast test MET flip-flop 32 has been set. Thus, on one of the inputs of both AND gates 106 and 108 a one will appear. If LNOP bit 104 has been set then AND gate 106 will present a one at its output. This represents the signal to inhibit the next line of microcode. If the ENOP bit 102 has been set AND gate 108 presents a one at its output. This is the signal to inhibit the current line of microcode. Regardless of the state of SMET flip-flop 30 the presence of a logic one at the output of AND gate 106 will cause a logic one to appear at the output of OR gate of 110 and hence, the NOP1 signal 112 will be a logic one. NOP1 signal 112 is used to inhibit operations taken as a result of rank one microcode options. The output of OR gate 110 is also presented to the D input of flip-flop 114. Flip-flop 114 provides a delay of one clock cycle before presenting the logic one at the output of gate 110 to the input of OR gate 116, and thus, to the NOP 2 output 118. The NOP2 output 118 is used to inhibit all of the rank two operations of the microcode.
When slow test met flip-flop 30 has presented a logic one at its output, this logic one is presented to AND gate 120 and 122. The presence of a one in the ENOP bit 102 position in the rank three register will enable AND gate 122. The output of AND gate 122 is the next microinstruction inhibit signal which is presented to OR gate 116 which asserts NOP2 118. If the LNOP bit 104 position in the rank three register has been set it will act through AND gate 120 to place a one at the output of OR gate 110, asserting NOP1 output 112. This one bit will progate through flip-flop 114 one clock pulse later and present itself at the output NOP2 via OR gate 116.
In a preferred embodiment of the present invention, guesses can be made with regard to test results which are not yet available and microbranching decisions made as a result of those guesses. Guesses being what they are, there are instances in which a guess has been made which turns out to be incorrect. The hardware of the present invention via pause logic block 56 of FIG. 1, allows the correct values to be placed in the SMET flip-flop and the FMET flip-flop 30 and 32, respectively, which then allows the correct choice of address to be placed on control store address bus via 4:1 multiplexer 12, and the correct values for NOP1 and NOP2 to be placed on lines 86 and 88.
Referring to FIG. 3, the hardware for vectoring to the correct address during a pause is now described.
As an example of an incorrect guess which could be made, reference is made to a cache which is used to hold instructions or data. In any cache, if the requested data or code is not present, a signal will be generated indicating a cache "miss".
Cache and cache "miss" hardware are well known in the art, and are beyond the scope of the present invention. Assume for purposes of the present disclosure that the cache miss signal is a logical one appearing on line 200. This logical one is passed through AND gate 202 only if a microcode field has indicated that the guess was going to be made. The microcode field which indicates whether this guess was made for a slow or fast mode is decoded to generate signals which appear on lines 204 and 206 respectively. A logical one on one of these lines indicates that a guess was made. Either logical one will enable the second input to AND gate 202 via OR gate 208. The output of AND gate 202 drives the D input of flip-flop 210 and AND gates 212 and 214. The fact that a guess was made, indicated by a one on either line 204 or 206 when ANDed with the output from gate 202 produces a signal which indicates a fast or slow test operation currently in progress should be overridden in order to correct the current value if FMET or SMET flip-flop 30 or 32. AND gates 212 and 214 use this signal to determine whether SMET 30 or FMET 32 is to be corrected.
Referring momentarily to FIG. 1, these override signals are placed on lines 58 and 60, respectively. The purpose of flip-flop 210 in FIG. 3 is to allow the clock cycle currently under execution to be completed before any subsequent clock pauses occur in order to avoid locking up the CPU. In the case of an incorrect guess, of course, an incorrect vector appears on control store address lines 10 for one clock cycle while the correct choice is loaded through multiplexer 12 to control storage address bus 10. The clocks to all registers except SMET 30, FMET 32 and flip-flop 210 are inhibited for one cycle. This occurs, as shown in FIG. 3, by connecting the signal from invertor 216 to AND gate 218, to produce the inhibit signal.
Referring now to FIG. 4, a preferred embodiment of the return address stack is shown. The return address stack may be configured of multiplexers and registers. The multiplexers act to couple the registers into a pass-through, recirculate, or feedback arrangement. Although those skilled in th art well know that any number of stages can be used, the embodiment of FIG. 4 as shown has N stages.
Referring first to MUX0 220 it can be seen that MUX0 220 may either load RAS0 222 from MUX 98 via line 224, receive the contests of return address stack register RASN 226 via line 228, recirculate the contents from its own RAS0 222 via line 230, or receive the contents of RAS1 232 via line 234. Similarly, MUX 1 236 may load RAS1 232 from from MUX 98 via line 238, may receive the contents of RAS0 222 via line 240, may recirculate the contents of RAS1 232 via line 242, or may receive the contents of RAS2 244 via line 246.
MUX0 220 and MUX1 236 are the only multiplexers which may be loaded from MUX 98. All other multiplexers in the system may only take the contents of the immediately preceeding register, recirculate the contents of its accompanying register, or receive the contents of the next register in line. In this manner, data may be passed down the stack, up the stack or stand still.
Multiplexer control is made via a select logic unit 270 which places a signal on lines 272. This signal controls all of the multiplexers in the return address stack and determines the flow pattern in the registers. Select logic unit 270 is driven by the signals NOP1 and NOP2 (generated as disclosed with respect to FIG. 2) and by the outputs from the SMET and FMET flip-flops 32 and 30 (from FIG. 1). In addition, a field from the rank two portion of microcode is presented to select logic unit 270 via line 274.
The operation of the stack is as follows. Normally, select logic unit 270 causes the stack registers to recirculate. When a subroutine call is taken, a return address is placed on the stack at either RAS0 or RAS1 depending on whether a fast or slow call has been taken. Select logic unit 270 conditions the stack multiplexers to push the contents of all stack registers forward. Microcode determines whether the contents of R1ADR register 96 or the SK bus 100 are placed on the stack.
If a slow subroutine call has been taken, a microcode field 274 causes MUX0 to load RAS0 when the instruction which made the call is in rank two of execution. On the next clock pulse the stack is pushed only if SMET flip-flop has been set.
Similarly, if a fast call has been taken, MUX1 is caused to load RAS1 when the instruction which made the call is in rank two of execution. Unlike ths slow call, however, neither loading nor pushing take place unless FMET flip-flop 37 has been set.
From FIG. 4 it can be seen that the load and push operations are decoupled from one another. Hardware which would normally have to provide copies of the return address until the branching decision had been resolved is not necessary by use of this stack.
The popping of the stack, or returning from subroutine calls, operates as follows.
In a slow return, microcode field 274 in conjunction with SMET flip-flop 30, through select logic unit 270 conditions the stack multiplexers to pass register contents up the stack (known as popping). This occurs when the instruction specifying the return is in rank three of its execution and SMET is set. The output of RAS1 232 is supplied to multiplexer 64 on the clock pulse prior to popping the stack.
Similarly, a fast return pops the stack when the instruction specifying the return is in rank two of execution and FMET is set. It should be noted that, due to pipelining, there are cases in which a conflict between pushing and popping could occur. In these cases, neither occurs. However, loading does occur.
If the signal NOP2 occurs at the input of select logic unit 270 during the rank two execution of either a fast or slow call or return, no loading, pushing, or popping occurs.
An alternative design for the stack is to employ a dual ported register file with decoupled pointers for storing data into the stack and reading data out of the stack.
Referring now to FIG. 5, a block level diagram of the test select logic for fast and slow test selection, the operation of those modules will now be described. As shown in FIG. 3, numerous test conditions shown diagramatically at 40 are presented to the inputs of multiplexer 302. The selection of which input to pass through multiplexer 302 is made by a microcode field in the rank one level of the microcode shown at 304. The output of multiplexer 302 on line 306 is placed in one input of 2:1 override multiplexer 308. The other input to 2:1 multiplexer 308 is from a field in the part of the microcode which determines whether the test MET condition is either positive true or negative true. The multiplexer is driven by override input 58 or 60 depending on whether this unit represents the slow selector or the fast selector. The output of multiplexer 308 is test MET line 46 or 50 depending on which module is being discussed. Thus it can be seen by those skilled in the art that any one of a number of test conditions may be used to set either SMET or FMET flip-flops 30 or 32, respectively. The selection of the condition is completely under the control of microcode. The presence of an override condition is the result of the selection of a test condition made by a previous line of microcode. | Hardware for performing microcode branching in a pipeline central processing unit allows for two different speeds of branches which can be used by microcode and includes flexibility to optionally inhibit lines of microcode which are in the pipeline when a branch has been sensed. A default branch path can be taken for a test result not yet available and can be replaced with a correct branch target during a clock pause if the test result is false. A return address stack is provided with decoupling loading and pushing to accommodate the two branching speeds. The microcode can specify loading the return address stack with a literal or register value to allow vectored branching and return to a desired line after a delayed call. | 6 |
FIELD OF THE INVENTION
This invention relates generally to insulated casings for hot fluid transfer and more particularly to a new and improved insulated casing assembly for oil well steam injection or above ground steam transport which greatly reduces heat transfer between the fluid and the casing components, provides increased structural integrity and reliability, and permits the outer sections of plural casings to be repeatedly and rigidly coupled together, using standard oil field equipment without fluid leakage while the inner sections of the casings absorb the lengthwise expansion/contraction loads in response to the temperature changes of the fluid which they carry with minimal relative motions.
DESCRIPTION OF THE PRIOR ART
Casing assemblies utilized to transfer fluids downhole must be constructed so as to be structurally rigid and leakproof while being capable of cyclic response to temperature changes of the fluid flowing through them. This is particularly true when the casing assembly is used to inject very high temperature steam into an oil well. The purpose of steam injection is to lower the viscosity of heavy crude oil so that it can be pumped or forced to the surface and thus extend recovery. The casing assemblies which are used in such a manner, however, are subject to several potentially destructive forces. Very high static internal and external pressure forces are exerted on the casing walls and the couplings when the assemblies are inserted deep into the ground. Each casing is subjected to the axially directed force of the weight of the other casings suspended below it in the casing string. The corrosive effects, the erosive effects, and the pressure forces caused by the steam itself on the internal components of the casing as well as the differential thermal expansion of such components caused by the high temperature of the steam and contamination by downhole fluids can cause structural failure of the casing assembly. Insulated assemblies currently used for transporting fluids of less extreme temperatures cannot be readily adapted for oil well steam injection purposes because of the severe conditions encountered downhole in the well. Conventionally insulated flowtubes leave the insulation susceptible to contamination by downhole fluids causing loss of insulating properties and potential failure of the permanent well casing due to overstressing. Another prior art approach encases the majority of the insulation in a sealed metal jacketing but leaves the joint area completely uninsulated to allow for joint makeup tooling. This uninsulated portion allows high heat transfer locally to the permanent well casing thus producing potential failure stresses in that casing. Another prior art approach encases the entire length with conventional insulation of moderate K-factor but fastens the inner and outer tubular with a high conductivity coupling resulting in excessive heat loss and high temperatures at the outer tubular threads. Early systems have no provision for accommodating thermal expansion of the flowtube which may amount to more than 10 feet in moderate depth wells and present very difficult sealing problems for the bottom hole packer. A previous system accommodated thermal expansion by means of a thin flexible bellows which also sealed the inner to outer pipe insulation annulus (see U.S. Pat. No. 4,130,301). The necessity for flexibility in the sealing bellows makes it susceptible to physical damage. The accommodation of pipe elongation without a corresponding insulation elongation produces thermal insulation gaps. Elongation of the pipes also produces a variable length coupling cavity which dictates the use of compressible cavity insulation and exposure of the coupling to live steam pressures and temperatures.
A primary objective of the present invention is therefore to provide a new and improved insulating casing assembly for transferring fluids in which elongation due to temperature changes of an inner fluid-carrying section of each casing is restrained by the rigid outer casing. Loads induced in the inner section due to temperature changes are transferred to the outer casing with negligible change in length through an elongated thrust ring which minimizes heat losses through the structural connection.
Another object of the present invention is to provide an insulated casing assembly in which insulation separating the fluid-carrying portion of each casing from the rigid portions is isolated and thus protected from the fluid.
Another object of the present invention is to minimize heat transfer by conduction from the inner pipe to the outer casing through the thrust ring at the coupling area.
Another object of the present invention is to provide a fixed coupling cavity volume which does not vary significantly with temperature or pressure change so that a rigid insulation, capable of withstanding the high temperature and pressure from live steam can be used in the coupling cavity area.
Another objective of the present invention is to provide a primary steam seal on the inner pipe which would effectively prevent egress of the live steam into the coupling cavity and would thus prevent contact of the steam with the casing coupling and coupling cavity insulation.
Another object of the present invention is to provide an insulated casing assembly in which couplings used to join adjacent casings provide a secondary seal which is normally protected from the high temperature fluid by the primary seal ring on the inner pipe assembly.
Another object of the present invention is to provide an insulated casing assembly which insulates along its entire length thus avoiding high heat losses at the coupling area.
Another object of the present invention is to provide an insulated casing with a substantially lower overall thermal conductivity than presently available.
Another object of the present invention is to provide an insulated casing assembly with threaded sections which can be easily repaired without violation of the sealed insulation annulus.
Still another object of the present invention is to provide an insulated casing assembly capable of withstanding radial and longitudinal static and dynamic shipping handling and installation forces without casing assembly failure.
SUMMARY OF THE INVENTION
The present invention, in accordance with one embodiment thereof, comprises an insulated casing assembly including a plurality of insulated casings which, when coupled or strung together, permit fluids of high temperatures and pressures to flow therethrough with low heat loss and without leakage. Each casing comprises radially spaced outer and inner tubular sections defining an annular space therebetween. The annular space is filled with thermal insulating material, preferably a high efficiency multilayered or microsphere insulation, and a filling point in the outer tubular section permits the annular space to be evacuated of air and back-filled with a low conductivity gas to envelop the insulation and thus improve the insulating characteristics of the casing. A fluidtight load bearing thrust ring at each end of the casing, seals the outer and inner tubular sections and transfers the thermal expansion/contraction loads from the inner tubular to the outer tubular section while also protecting the insulation within the annular space from the fluid. Each of the thrust rings is joined to the outer tubular section at a region spaced inwardly from the respective end of the section. Thereby, when two casings are joined, a sealing ring can be fitted over spaced opposing ends of adjacent inner tubular sections to prevent fluid escape into the coupling cavity and to prevent steam migration through the coupling insulation. Additionally, an insulated filler ring is fitted into the coupling cavity to inhibit heat transfer from the inner pipe to the outer casing coupling. A threaded coupling is screwed onto the ends of adjacent casings to rigidly maintain them in a longitudinally coaxial relationship.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a fragmented cross-sectional view of an insulated casing according to the present invention.
FIG. 2A is a cross-sectional view of an insulated casing incorporating multi-layered insulation within the annular space, taken along lines 2--2 of FIG. 1.
FIG. 2B is a cross-section view of an insulated casing incorporating microsphere insulation within the annular space, taken along lines 2--2 of FIG. 1.
FIG. 3 is a fragmentary cross-sectional view of the insulated casing assembly including two casings and coupling means according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown insulated casing 10. Casing 10 can be joined to other insulated casings, in a manner to be described hereinafter, to establish a conduit for transporting fluids, particularly high temperature fluids over long distances with low heat loss and without leakage.
The outer wall of casing 10 is formed by outer tubular section 12. The inner wall of the casing, which forms a flowtube through which fluids flow, is formed by inner tubular section 14. The inner and outer tubular sections are concentric and the radial spacing of the inner and outer section walls is such as to provide annular space 16 therebetween.
The specific material from which the tubular sections are made, as well as its grade and thickness, will vary with the conditions to which the casing is subjected. Several factors must be considered. The tubular sections should be constructed of a material which provides adequate structural support for the casing. When a primary use for the casing is to inject high pressure steam deep into the earth, the material must also be capable of withstanding the effects of excessive pressure, temperature, and corrosion. Further, if the tubular sections undergo welding during manufacturing, a material with a suitable weldability must be selected. Steel alloys of various types are examples of materials suitable for use in forming the tubular sections 12 and 14.
The region in annular space 16 at each end of casing 10 constitutes coupling cavity 18. Within cavity 18 is located fluid-tight thrust ring 20. The purpose of thrust rings 20 is to seal the corresponding ends of the tubular sections while transferring the thermal expansion and contraction induced loads from inner tubular section 14 to outer tubular section 12. The sealing prevents any fluid which enters coupling cavity 18 from entering annular space 16 and prevents back fill gas contained in the annulus from escaping and thereby adversely affecting insulation value of the material therein. To accomplish this, one end of thrust ring 20 is sealingly connected to the inner surface of outer tubular section 12 at a point substantially spaced axially inwardly from the end of section 12 and the other end is similarly connected to the outer surface of inner tubular section 14 near its end.
Thrust ring 20 can be made of any material which is sufficient to withstand the stresses induced by the thermal loading and steam pressure coupled with the downhole corrosive environment. Another consideration for the choice of thrust ring material is that when the casing is used to convey high temperature fluids, particularly steam under pressure, the thrust ring must be able to function properly for numerous thermal cycles despite the adverse effects of such temperature, pressure, load cycles, and corrosion factors.
An example of a suitable thrust ring material when the casings are used for injection of high temperature steam into wells is a corrosion resistant steel such as AISI type 316. For lower temperature conditioned steam, an alloy such as 4130 steel may be satisfactorily substituted.
The shape of the thrust ring should be such as to minimize heat transfer between the hot inner pipe and the cooler outer pipe. As such, the cross-sectional area of the thrust ring should be as small as feasible whilst the length of the ring should be adequate to provide a long thermal path, maximizing the temperature drop along its length.
Thrust rings 20 are connected to the corresponding ends of tubular sections 12 and 14 by means appropriate to the materials of which thrust ring 20 and tubular sections 12 and 14 are made. More specifically, when the thrust ring and tubular sections are made of AISI 4130 steel and API 5A N-80 grade tubing, respectively, connection may be made, for example, by welding the respective ends of the thrust ring to the tubing, by the use of a high strength corrosion resistance filler wire such as G.E. B50A678-B3 chrome-moly steel alloy. Welding of both thrust rings to the inner tubular and of one thrust ring to the outer tubular can be accomplished in a normal shop environment; however, the final closeout weld of the second thrust ring must be made while the inner tubular is elongated to a dimension equivalent to approximately half the nominal expansion which would be expected for an unrestrained inner tubular at maximum operating temperature. This pre-tensioning operation is required to prevent overstressing (in compression) the inner tubular during normal steam startup operation and can be accomplished by performing the final closeout weld while the temperature difference between the inner and outer pipe is approximately half the nominal operational temperature difference or by mechanically stretching the inner tubular. To facilitate making the weld between the second thrust ring 20 and outer tube 12, the threaded end section 15 is not attached until after this weld is made.
The thrust rings can also be connected to the inner and/or outer tubulars by threading the ring and the tubulars. A seal weld to prevent thread leakage is recommended at the steam end of the threads.
The thrust rings are designed to carry the nominal operational thrust loads at worst case temperature differentials with minimal yielding of creep of the material. The thrust ring overlaps the butt weld area of the outer tubular providing an effective backing ring which produces an excellent three-way weld. Repair or replacement of threaded section 15 may be accomplished by cutting the outer tubular at the three-way weld and adding a new threaded section without violating the insulation cavity.
Centralizers 21, which preferably have a plurality of holes therethrough to minimize transfer of heat from inner tubular 14 to outer tubular 12, are spaced at intervals along the length of the inner tubular and are used to help maintain the desired spacing between the inner and outer tubulars.
The remainder of the annular space 16 is filled with a thermal insulating material 22. The appropriate insulating material utilized is determined by the use, by the available annular volume, and particularly by the extremes of temperature, to which the casing assembly is to be subjected. For example, when the casing assembly is to be used to inject steam into a well with a limited cross section, a high efficiency multilayered or multicellular insulation is appropriate.
One type of multilayered insulation which is suitable is shown in FIG. 2A and comprises layers of reflective aluminum radiation shields 24 separated by a low conductivity, loose weave, random-oriented, long-fiber fiberglass spacer material 26. FIG. 2B shows a typical multicellular insulation 28 in a low conductivity gas or vacuum environment. However, as was indicated above, any other insulating material can be utilized which possesses the proper thermal insulating qualities required by the use to be made of the casing assembly. The multilayered insulation used can be manufactured in the shape of a tube and inserted into the annular space 16. Alternatively, it can be manufactured into a flat blanket and wrapped around the inner tubular section, overlapping itself sufficiently to negate gap heat loss. Multicellular insulation can be poured and packed in the annulus by conventional methods, or can be fabricated by the use of a binding agent into cylindrical tubes or segments thereof to facilitate assembly procedures.
As an additional insulation measure in the casing 10, a partial vacuum can be effected in the annular space 16 through a filling point 30, FIG. 1, after the insulation is placed therein, and then the annular space is back-filled through the same filling point 30 with a low conductivity gas, selected from the group consisting of argon, krypton, xenon, and combinations thereof. After the back-filling is complete, annular space 16 is hermetically sealed at filling point 30. The gas envelops the insulation within annular space 16 and thereby improves its insulating efficiency.
FIG. 3 shows insulated casings 10A and 10B connected together in such a manner that fluid flowing through the inner tubular section of one casing can continue to flow into the inner tubular section of the adjacent casing without leakage. When casings 10A and 10B are properly joined, the ends of the inner tubulars compress seal ring 32 and form a pressure seal which prevents fluid flowing in the inner tubular from entering the coupling cavity. The sealing ring is recessed into the inner tubular inside diameter sufficiently to allow down hole tools to pass unobstructed. The ring is made of an appropriate alloy which can be one of several corrosion resistant materials such as 17-4PH stainless steel or similar. The ring may be sized to seal by compression/crushing between the ends of the inner pipe or by pressure against the inside lip of the inner pipe. When sealing is effected by pressure against the inside lip, the lip must be protected from corrosion and/or oxidation in the elevated temperature environment by an appropriate plating or coating over the exposed steel alloy. A plating such as electrodeposited nickel over hard copper has been successfully used for this application, however a welded overlay of corrosion resistant alloy is equally suitable.
Filler insulation 34A and 34B is fitted over the thrust rings 20A and 20B to minimize heat loss through the coupling cavity area from the thrust rings to the coupling. The filler insulation may be cast in place during assembly with material such as "Fiberfrax LDS moldable" by the Carborundum Company or may be inserted at installation using "Fiberfrax T-30" insulation tubes or similar materials offered by others.
The gap between the coupling cavity insulation 34A and 34B which is left vacant is filled with gap insulation 36. The gap insulation, like the coupling cavity insulation, may be cast in place, using Fiberfrax LDS during manufacture of the casing or it may be field installed using Fiberfrax T-30 tube insulation or Fiberfrax Vaccucast pre-molded insulation. The purpose of gap insulation 36 is to provide a thermal barrier between the inner portion of the tubing and coupling 38. Since seal ring 32 effectively prevents leakage into the gap, the insulation in the gap and the coupling cavities operates at near atmospheric pressure resulting in maximum thermal efficiency for the insulation.
Adjacent casings 10A and 10B are connected by suitable couplings 38 which join by fixed position rather than by torque. Couplings with standard API buttress threads may be satisfactorily used for this application. Once satisfactorily jointed in the proper fixed, longitudinally coaxial, end-to-end relationship, the relative position of the weldments and seal rings remain unchanged during operation.
Two casings, each containing an outer tubular 12, and inner tubular 14, thrust rings 20, centralizers 21, and insulating material 22, 34 and 36 are joined to comprise a completed insulated casing assembly as follows. Thread coupling 38 is screwed onto the threads on the end of outer tubular 12 of a first casing. Seal ring 32 is slipped onto the inner tubular section of the first casing. The second casing is then stabbed into the coupling 38 and the coupling is screwed tightly onto the outer tubular section of the second casing. As a result, the two casings are maintained in a fixed, longitudinally coaxial relationship. In this arrangement, the sealing ring 32 provides a pressure seal between the inner tubulars 14.
It is to be understood that this invention is not limited to the particular embodiment disclosed, and it is intended to cover all modifications coming within the true spirit and scope of this invention as claimed. | An insulated casing assembly for use in injecting steam into wells or transmitting steam from the generating source to the wellhead is disclosed. A plurality of interconnected casings are used, each casing have outer and inner tubular sections and an annular spacing between the two sections containing either multilayered thermal insulation or glass microspheres, enveloped in a low conductivity gas. Rigid thrust rings connect and prevent relative movement between the corresponding ends of the two sections. A pressure sealing ring disposed between adjacent inner tubular sections prevents ingress of steam into the coupling cavity. An insulation assembly between adjacent casings includes coupling cavity insulation fitted tightly over the thrust rings and a gap insulating ring disposed between adjacent outer tubular sections. A threaded coupling screwed onto threaded ends of outer tubular sections of adjacent casings joins them. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a safety gate, and more particularly to a safety gate capable of locking a distance between two sides of the safety gate for the purpose of repeated mountings.
2. Description of the Related Art
Safety gates serve to block young children or pets at the top of stairs for a fall protection or at the entrance to a room, such as kitchen or living room, to limit the infants or pets to stay in the room or from accessing the room.
A conventional safety gate substantially comprises two movable frames and a fixing element. After the two movable frames are adjusted to abut against two opposite sides of an entrance, the fixing element is used to keep the movable frames at the relative distance so that the safety gate can be tightly mounted on the sides of the entrance in completion of the mounting process.
A successful mounting of the conventional safety gate relies on simultaneous and tight contact of the edges of the movable frames with the door frame and the locking of the fixing element at the same time to prevent the safety gate from easily toppling and falling, but it is rather difficult for only one person to independently mount the conventional safety gate.
In addition, a stretcher element is further provided to slightly stretch the two movable frames outwardly to abut against two sides of an entrance. Therefore, when the relative distance between the two movable frames is adjusted, contact tightness between two sides of the entrance and the two movable frames may not be critical as the stretcher element makes the mounting of such safety gate easier and more secure.
However, the fixing elements and the stretcher elements of the conventional safety gates are designed and manufactured in combination, or in other words, they can only be operated at the same time. When the safety gate is dismounted and the stretcher element is released, the two movable frames are unattached to the sides of the entrance, and the relative distance between the movable frames for mounting is easily altered after the safety gate is dismounted. As a result, the relative distance between the movable frames needs to be repeatedly adjusted even though the safety gate is mounted at a same place again. Such readjustment over and over again causes inconvenience in use and the conventional safety gates need to be further improved.
SUMMARY OF THE INVENTION
An objective of the present invention is to provide a safety gate capable of locking a distance between two sides of the safety gate for the purpose of repeated mountings.
To achieve the foregoing objective, the safety gate has a first frame assembly, a second frame assembly, a shaft fixing assembly and a stretcher assembly.
The first frame assembly has a first frame, a first shaft rack and a first shaft. The first shaft rack is mounted on one side edge of the first frame in a transverse direction. The first shaft is securely mounted on the first shaft rack.
The second frame assembly is adjacent to the other side edge of the first frame in the transverse direction and has a second frame, a second shaft rack and a second shaft. The second frame is mounted between the first frame and the first shaft. The second shaft rack is mounted on a side edge of the second frame adjacent to the first shaft rack in the transverse direction, and has a rack abutting surface formed on the second shaft rack and faces the first shaft rack. The second shaft is securely mounted on the second shaft rack and is transversely slidable when combined with the first shaft.
The shaft fixing assembly is mounted around the first shaft and has a clamping sleeve, a compression arm and a stretcher assembly. The clamping sleeve is mounted around the first shaft and has two open sides, an open top, a chamber, two pressing walls, two pressing protrusions, two positioning grooves, two first pivot holes and two second pivot holes. The chamber is defined in the clamping sleeve and communicates with the open sides and the open top. A section of the chamber along a longitudinal direction perpendicular to the transverse direction corresponds to that of the first shaft along the longitudinal direction. The pressing walls are respectively formed on and protrude upwardly from two top portions of the clamping sleeve. The pressing protrusions are respectively formed on and protruding outwardly from peripheries of the two pressing walls. The positioning grooves are respectively formed in the peripheries of the two pressing walls. Each first pivot hole is formed through one end of one of the pressing walls facing the first shaft rack and aligning with the other first pivot hole. Each second pivot hole is formed through the other end of one of the pressing walls away from the first shaft rack and aligns with the other second pivot hole.
The compression arm is mounted above the clamping sleeve and has an open side, an open bottom, two inner walls, a chamber, two walls and two positioning ribs. The inner walls are opposite to each other. The chamber is defined in the compression arm and communicates with the open side and the open bottom. The walls sandwich the chamber and are respectively mounted on the peripheries of the pressing walls when the compression arm is pivoted downwardly to rest on the pressing walls. The positioning ribs are respectively formed on and protrude from the two inner walls of the compression arm and respectively align with the positioning grooves. One end of the compression arm is pivotally connected to the first pivot holes of the pressing walls.
The stretcher assembly is mounted around the first shaft, the clamping sleeve and the compression arm, is pivotally connected to the second pivot holes of the clamping sleeve and has a top surface and two sidewalls. The top surface has a top hole formed through one end of the top surface opposite to the first shaft rack. Each sidewall has a first abutting edge, a second abutting edge and a pivot hole. The first abutting edge is intersected by the top surface of the stretcher assembly and the sidewall. The second abutting edge is connected with the first abutting edge and is opposite to the first shaft rack. The pivot hole is formed through the sidewall to align with the pivot hole of the other sidewall, and is pivotally connected to the second pivot holes of the clamping sleeve. A distance from the pivot hole to the first abutting edge is smaller than a distance from the pivot hole to the second abutting edge.
The shaft fixing assembly serves to fix a relative distance between the first frame and the second frame. The stretcher assembly and the second shaft rack are used to further stretch out the first frame and the second frame so that the safety gate tightly abuts against two walls of a mounting premise and does not topple. When the safety gate is not in use, the safety gate can be loosened easily from the walls after the stretcher assembly is released and the safety gate can be then moved to elsewhere for storing. Without the readjustment of the shaft fixing assembly, the same relative distance between the first frame and the second frame can be repeatedly applied to subsequent mountings. Accordingly, the safety gate can be mounted easily and conveniently.
Other objectives, 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 a perspective view of a safety gate in accordance with the present invention;
FIG. 2 is a first enlarged exploded perspective view of the safety gate in FIG. 1 ;
FIG. 3 is a second enlarged exploded perspective view of the safety gate in FIG. 1 ;
FIG. 4 is a third enlarged exploded perspective view of the safety gate in FIG. 1 ;
FIG. 5 is an enlarged side view in partial section of the safety gate in FIG. 1 ;
FIG. 6 is an operational front view of the safety gate in FIG. 1 ;
FIG. 7 is a first enlarged operational front view of the safety gate in FIG. 6 ;
FIG. 8 is a second enlarged operational front view of the safety gate in FIG. 6 ; and
FIG. 9 is a third enlarged operational front view of the safety gate in FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1 and 2 , a safety gate in accordance with the present invention has a first frame assembly 10 , a second frame assembly 20 , a shaft fixing assembly 40 , a stretcher assembly 61 , an anti-pinch assembly 70 and multiple contact pads 80 .
With reference to FIGS. 1 to 5 , the first frame assembly 10 has a first frame 11 , a first shaft rack 12 and a first shaft 13 . The first shaft rack 12 is mounted on one side edge of the first frame 11 in a transverse direction. The first shaft 13 is securely mounted on the first shaft rack 12 and has a non-circular section.
The second frame assembly 20 is adjacent to the other side edge of the first frame 11 in the transverse direction and has a second frame 21 , a second shaft rack 22 and a second shaft 23 . The second frame 21 is mounted between the first frame 11 and the first shaft 13 . A slider is mounted on each of the top edges and the bottom edges of the first frame 11 and second frame 21 so that the first frame 11 and the second frame 21 can be smoothly slidable relative to each other and a length between outer edges of the first frame assembly 10 and the second frame assembly 20 of the safety gate in the transverse direction can be telescopic. The second shaft rack 22 is mounted on a side edge of the second frame 21 adjacent to the first shaft rack 12 in the transverse direction, and has a rack abutting surface 221 formed thereon and facing the first shaft rack 12 . The second shaft 23 is securely mounted on the second shaft rack 22 and is transversely slidable when combined with the first shaft 13 . In the present embodiment, the second shaft 23 is hollow and tubular and has an opening formed through one end of the second shaft 23 facing the second shaft rack 22 . The second shaft 23 is unrotatably mounted around the first shaft 13 .
The shaft fixing assembly 40 is mounted around the first shaft 13 and may be securely mounted on the first shaft 13 that has a non-circular section. The shaft fixing assembly 40 has a clamping sleeve 41 and a compression arm 42 . The clamping sleeve 41 has two open sides, an open top, a chamber, two pressing walls 411 , two pressing protrusions 412 , two positioning grooves 413 , two first pivot holes 414 and two second pivot holes 415 . The chamber is defined in the clamping sleeve 41 and communicates with the open sides and the open top. A cross section of the chamber along a longitudinal direction that is perpendicular to the transverse direction corresponds to that of the first shaft 13 along the longitudinal direction. The two pressing walls 411 are respectively formed on and protrude upwardly from two top portions of the clamping sleeve 41 . The two pressing protrusions 412 are respectively formed on and protrude outwardly from peripheries of the two pressing walls 411 . The two positioning grooves 413 are respectively formed in the peripheries of the two pressing walls 411 . Each first pivot hole 414 is formed through one end of one of the pressing walls 411 facing the first shaft rack 12 and aligns with the other first pivot hole 414 . One end of the compression arm 42 is pivotally connected to the first pivot holes 414 of the pressing walls 411 and is located above the clamping sleeve 41 . The second pivot holes 415 are respectively formed through two rear top edges of the clamping sleeve 41 beside the open top and align with each other. The compression arm 42 has an open side, an open bottom and a chamber defined in the compression arm 42 and communicating with the open side and the open bottom. Two walls of the compression arm 42 between which the chamber is defined are respectively mounted on the peripheries of the pressing walls 411 when the compression arm 42 is pivoted downwardly to rest on the pressing walls 411 . The compression arm 42 has two positioning ribs 421 respectively formed on and protruding from two opposite inner walls of the compression arm 42 and respectively aligning with the positioning grooves 413 .
The stretcher assembly 61 is mounted around the first shaft 13 , the clamping sleeve 41 and the compression arm 42 , and is pivotally connected to the second pivot holes 415 of the clamping sleeve 41 . The stretcher assembly 61 has a top surface 611 , two sidewalls 612 , a plate insert slot 621 , a spring channel 622 and a locating hole 623 . The top surface 611 has a top hole 613 formed through one end of the top surface 611 opposite to the first shaft rack 12 . Each sidewall 612 has a first abutting edge 614 , a second abutting edge 615 , a tooth 616 and a pivot hole 617 . The first abutting edge 614 is intersected by the top surface 611 and the sidewall 612 . The second abutting edge 615 is connected with the first abutting edge 614 and is opposite to the first shaft rack 12 . The tooth 616 is formed on and protrudes from a portion of an inner wall of the sidewall 612 adjacent to the first pivot holes 414 . The two pivot holes 617 are respectively formed through the sidewalls 612 , align with each other, and are pivotally and respectively connected to the second pivot holes 415 of the clamping sleeve 41 . A distance from the pivot hole 617 to the first abutting edge 614 is smaller than that from the pivot hole 617 to the second abutting edge 615 . The plate insert slot 621 is formed in and recessed from an end edge of the top surface 611 opposite to the first shaft rack 12 and communicates with the top hole 613 . The spring channel 622 has a circular cross section and is formed in a top inner wall and a bottom inner wall of the plate insert slot 621 . The locating hole 623 is downwardly formed through an inner wall of the spring channel 622 and is elongated.
The anti-pinch assembly 70 is mounted in the stretcher assembly 61 and has a spring 71 and an anti-pinch plate 72 . The spring 71 is mounted in the spring channel 622 , and one end of the spring 71 abuts against an inner wall of the plate insert slot 621 facing the second shaft rack 22 . The anti-pinch plate 72 is mounted in the plate insert slot 621 , has a pin 721 and a locating piece 722 , and one end of the anti-pinch plate 72 opposite to the first shaft rack 12 is located within the top hole 613 . The pin 721 is formed on and transversely protrudes from one end of the anti-pinch plate 72 facing the first shaft rack 12 , and is mounted in the other end of the spring 71 . The locating piece 722 is formed on and protrudes from a bottom of the anti-pinch plate 72 and is mounted within and limited to move within the locating hole 623 .
With reference to FIG. 1 , the contact pads 80 are respectively mounted on the side edge of the first frame 11 on which the first shaft rack 12 is mounted and on the side edge of the second frame 21 away from the second shaft rack 22 .
With reference to FIGS. 2 and 6 to 9 , when the safety gate is in use, the compression arm 42 and the stretcher assembly 61 stay upright relative to the clamping sleeve 41 . The first frame 11 and the second frame 21 are pulled to move and depart from each other transversely so as to slightly contact the walls as shown in FIG. 6 .
The shaft fixing assembly 40 and the stretcher assembly 61 are then moved and the first abutting edge 614 of the stretcher assembly 61 abuts against the rack abutting surface 221 of the second shaft rack 22 as shown in FIG. 7 .
The compression arm 42 is pivoted downwardly to cover the pressing walls 411 of the clamping sleeve 41 until the positioning rib 421 of the compression arm 42 engages the positioning groove 413 of the clamping sleeve 41 and the two sidewalls of the compression arm 42 hold and tightly squeeze the pressing protrusions 412 and the pressing walls 411 . Accordingly, the shaft fixing assembly 40 and the first shaft 13 can be mutually fixed in the transverse direction as shown in FIG. 8 . The mutual engagement between the positioning ribs 421 and the positioning grooves 413 holds the compression arm 42 on the clamping sleeve 41 in place.
The stretcher assembly 61 is pivoted downwardly to cover the compression arm 42 until the second abutting edges 615 of the stretcher assembly 61 fully abut against the rack abutting surface 221 of the second shaft rack 22 as shown in FIG. 9 and the teeth 616 are located under the first shaft 13 so that the first shaft 13 can be held and positioned by the teeth 616 .
As the distance between the pivot hole 617 and the first abutting edge 614 is smaller than the distance between the pivot hole 617 and the second abutting edge 615 , such difference in distance allows the stretcher assembly 61 to push the second shaft rack 22 and the second frame 21 away from the first shaft rack until the contact pads 80 of the second frame assembly 20 tightly abut against one of the walls. Meanwhile, as the stretcher assembly 61 is mounted on the shaft fixing assembly 40 and the shaft fixing assembly 40 is fixed on the first shaft 13 , the reaction force exerted on the stretcher assembly 61 drives the first shaft 13 and the first shaft rack 12 to move away from the second shaft rack 22 . Hence, the first frame assembly 10 is pushed to move away from the second frame assembly 20 until the contact pads 80 of the first frame assembly 20 tightly abut against the other wall to complete the mounting of the safety gate.
When the safety gate is not in use, the stretcher assembly 61 is pivoted upwardly so that the first abutting edge 614 abuts against the rack abutting surface 221 of the second shaft rack 22 . As the distance between the pivot hole 617 and the first abutting edge 614 is smaller than the distance between the pivot hole 617 and the second abutting edge 615 , the first frame assembly 10 and the second frame assembly 20 do not tightly and respectively abut against the walls, and the safety gate can be removed from the walls and stored elsewhere. When the safety gate is mounted on the same walls again, the first abutting edge 614 of the stretcher assembly 61 only has to abut against the rack abutting surface 221 prior to the mounting process. Then, the stretcher assembly 61 is pivoted downwardly and the contact pads 80 of the first frame assembly 10 and the second frame assembly 20 tightly and respectively abut the walls. As long as the clamping sleeve 41 is not loosened from the first shaft 13 , the safety gate with the same relative distance between the first frame assembly 10 and the second frame assembly 20 can be repeatedly used at an identical mounting premise without requiring the readjustment of the relative distance between the first frame assembly 10 and the second frame assembly 20 at all.
When the second abutting edge 615 of the stretcher assembly 61 abuts against the rack abutting surface 221 of the second shaft rack 22 , the top hole 613 faces up and is exposed and the anti-pinch plate 72 of the anti-pinch assembly 70 is located within the top hole 613 to prevent children from inserting their fingers into the top hole 613 and getting injured. When the first abutting edge 614 of the stretcher assembly 61 abuts against the rack abutting surface 221 , the anti-pinch plate 72 gradually compresses the spring 71 for being propped by the first shaft 13 and empties out the top hole 613 so that the top hole 613 is available to receive the first shaft 13 and the stretcher assembly 61 can be pivoted as intended without being blocked by the first shaft 13 .
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. 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. | A safety gate has two frame assemblies, a shaft fixing assembly and a stretcher assembly. A relative distance between the two frame assemblies is fixed by the shaft fixing assembly first. The stretcher assembly further pushes the two frame assemblies outwardly so that the two frame assemblies tightly abut against two walls of a mounting premise and can be held on the walls securely. When the safety gate is not in use, the stretcher assembly is released to loosen the safety gate from the walls and the stretcher assembly can be moved to elsewhere. As the safety gate can be repeatedly mounted without having to readjust the relative distance between the two frame assemblies with the shaft fixing assembly, the operation of the safety gate is easy and convenient. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is based on, and claims priority from, Korean Application Serial Number 10-2008-0055112, filed on Jun. 12, 2008, the disclosure of which is hereby incorporated by reference herein in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a power train of a hybrid vehicle, particularly a power train of a hybrid vehicle that uses an internal combustion engine and a motor generator driven by electricity as a power source providing a driving force to driving wheels.
BACKGROUND ART
[0003] Hybrid vehicles using an engine and a motor generator reduce the fuel consumption on the basis of a technology that uses, as a driving force, power from a motor generator having relatively good low-velocity torque characteristics at a low velocity and uses power from an engine having relatively good high-velocity torque characteristics at a high velocity. Further, as the hybrid vehicles do not generate exhaust gas while being driven by only the motor generator, it is environment-friendly. Techniques for reducing fuel consumption with a simpler configuration have been proposed.
[0004] The above information disclosed in this Background ART section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
SUMMARY
[0005] Embodiments of the present invention provide a power train of a hybrid vehicle having simple configuration, high power performance, and reduced weight and fuel consumption, while being easily equipped in the vehicle.
[0006] A power train of a hybrid vehicle according to the invention includes a first planetary gear set, a second planetary gear set, a first brake, a second brake, and a clutch. The first planetary gear includes three elements where a first motor generator and an output shaft are separately connected. The second planetary gear includes three elements where an engine, a second motor generator, and the output shaft are separately connected. The first brake is provided to fix the element of the first planetary gear set other than the elements connected with the first motor generator and the output shaft. The second brake is provided to fix the element of the second planetary gear set connected with the second motor generator. The clutch is rotatably engaged with the element of the first planetary gear set connected with the first brake and the element of the second planetary gear set connected with the second brake.
[0007] The first planetary gear set is a single-pinion type planetary gear set including a first sun gear connected with the first motor generator, a first carrier connected with the output shaft, and a first ring gear connected with the first brake. The second planetary gear set is a single-pinion type planetary gear set including a second sun gear connected with the second motor generator, a second carrier connected with the engine, and a second ring gear connected with the output shaft.
[0008] The first planetary gear set and the second planetary gear set are coaxially arranged in parallel, the first motor generator is connected with the first planetary gear set, the output shaft is connected with the second ring gear through the first carrier, the engine is connected with the second carrier through between the first planetary gear set and the second planetary gear set, and the second motor generator is connected with the second planetary gear set.
[0009] The first planetary gear set, in a lever analysis diagram, is arranged on a first straight line in the order of an element connected with the first motor generator, an element connected with the output shaft, and an element connected with the second planetary gear set through the clutch. Further, the second planetary gear set, in the lever analysis, is arranged on a second straight line, which crosses the first straight line at at least one point, in the order of an element connected with the first planetary gear set through the clutch, an element connected with the engine, and an element connected with the output shaft, in which as the clutch is engaged, the first straight line and the second straight line make a single straight line.
[0010] The power train of a hybrid vehicle according to the invention has a simple configuration, high power performance, and reduced weight and fuel consumption, while being easily equipped in the vehicle. In particular, a significant amount of fuel consumption can be reduced when a vehicle is traveling at a high speed for a long time.
[0011] It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles.
[0012] The above and other features of the invention are discussed infra.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For better understanding of the nature and objects of the present invention, reference should be made to the following detailed description with the accompanying drawings, in which:
[0014] FIG. 1 is a view illustrating an example of the configuration of a power train of a hybrid vehicle according to the invention;
[0015] FIG. 2 shows a power flow diagram and a lever analysis diagram illustrating that the power train of FIG. 1 achieves an electric vehicle mode;
[0016] FIG. 3 shows a power flow diagram and a lever analysis diagram illustrating that the power train of FIG. 1 achieves a first hybrid mode;
[0017] FIG. 4 shows a power flow diagram and a lever analysis diagram illustrating that the power train of FIG. 1 achieves a second hybrid mode; and
[0018] FIG. 5 shows a power flow diagram and a lever analysis diagram illustrating that the power train of FIG. 1 achieves an engine mode.
DETAILED DESCRIPTION
[0019] Embodiments of the invention are described hereafter in detail with reference to the accompanying drawings, but theses embodiments are just examples and can be achieved in various modifications by those skilled in the art. Therefore, the present invention is not limited to the embodiments.
[0020] Referring to FIG. 1 , a power train of a hybrid vehicle according to an embodiment of the invention includes: a first planetary gear set 5 including three elements where a first motor generator 1 and an output shaft 3 are separately connected; a second planetary gear set 11 including three elements where an engine 7 , a second motor generator 9 , and output shaft 3 are separately connected; a first brake 13 that is provided to fix the element of first planetary gear set 5 other than the elements connected with the first motor generator 1 and the output shaft 3 ; a second brake 15 that is provided to fix the element of the second planetary gear set 11 connected with the second motor generator 9 ; and a clutch 17 that can be rotatably engaged with the element of the first planetary gear set 5 connected with the first brake 13 and the element of the second planetary gear set 11 connected with the second brake 15 .
[0021] That is, the power train includes the two planetary gear sets 5 , 11 , one clutch 17 , and two brakes 13 , 15 such that it can transmit/receive power to/from the two motor generators 1 , 9 , and receive power from the engine 7 and outputs shifted power through the output shaft 3 .
[0022] In this embodiment, the first planetary gear set 5 is a single-pinion type planetary gear set, in which a first sun gear is connected with the first motor generator 1 , a first carrier is connected with output shaft 3 , and a first ring gear is connected with the first brake 13 .
[0023] The second planetary gear set 11 is also a single-pinion type planetary gear set, in which a second sun gear is connected with the second motor generator 9 , a second carrier is connected with the engine 7 , and a second ring gear is connected with the output shaft 3 .
[0024] The first planetary gear set 5 and the second planetary gear set 11 are coaxially arranged in parallel, the first motor generator 1 is connected with the first planetary gear set 5 , the output shaft 3 is connected with the second ring gear through the first carrier, the engine 7 is connected with the second carrier through between the first planetary gear set 5 and the second planetary gear set 11 , and the second motor generator 9 is connected with the second planetary gear set 11 .
[0025] That is, the first carrier is directly connected with the second ring gear and also rotatably connected with output shaft 3 . Further, the first brake 13 and the clutch 17 are connected with the first ring gear and the second brake 15 and the clutch 17 are connected with the second sun gear. Accordingly, when the clutch 17 is not engaged, the first ring gear and the second sun gear are fixed by the operations of the first brake 13 and the second brake 15 , respectively. On the other hand, when the clutch 17 is engaged, as either the first brake 13 or the second brake 15 operates, both of the first ring gear and the second sun gear are fixed.
[0026] Further, the second motor generator 9 is directly connected with the second sun gear, such that the second motor generator 9 is fixed with the second sun gear by the operation of second brake 15 , and operates with the first ring gear when the clutch 17 is actuated.
[0027] As shown in the lever analysis diagrams of FIGS. 2 to 5 , the first planetary gear set 5 is arranged on a first straight line 19 in the order of an element connected with the first motor generator 1 , an element connected with the output shaft 3 , and an element connected with the second planetary gear set 11 through the clutch 17 .
[0028] The second planetary gear set 11 is arranged on a second straight line 21 , which crosses the first straight line 19 at one or more points, in the order of an element connected with the first planetary gear set 5 through the clutch 17 , an element connected with the engine 7 , and an element connected with the output shaft 3 through the first planetary gear set 11 , in which as the clutch 17 is engaged, the first straight line 19 and the second straight line 21 make a single straight line.
[0029] That is, the first sun gear, the first carrier, and the first ring gear are sequentially arranged on first straight line 19 , and the second sun gear, the second carrier, and the second ring gear are sequentially arranged on second straight line 21 . Accordingly, an end of the second straight line 21 always crosses the first straight line 19 at the point where the second ring gear is connected with output shaft 3 together with the first carrier.
[0030] When the clutch 17 is engaged, the second straight line 21 overlaps the first straight line 19 such that the second sun gear and the first ring gear make a point, resulting that the second carrier connected with the engine 7 on the second straight line 21 is positioned between the first ring gear and the first carrier on the first straight line 19 .
[0031] The operation in each mode of the power train of a hybrid vehicle according to an embodiment of the invention is described hereafter with reference to the lever analysis diagrams of FIGS. 2 to 5 , which shows arrangement of the elements of the planetary gear sets and relative gear ratios of the elements as well.
[0032] FIG. 2 illustrates an electric vehicle mode in which the vehicle is driven by at least one motor generator without operating an engine.
[0033] In this mode, the first brake 13 is engaged while the clutch 17 and the second brake 15 are disengaged. Torque generated by the first motor generator 1 is supplied through the first sun gear, reduced according to a gear ratio of the first planetary gear set 5 , and then outputted to the output shaft 3 through the first carrier.
[0034] For illustration purposes, the rotational direction of the output shaft 3 is defined as a normal direction and the opposite direction is defined as an inverse direction hereafter.
[0035] Because the engine 7 is stopped, the second motor generator 9 connected with the second sun gear is rotated in the inverse direction without torque.
[0036] As the second motor generator 9 that has rotated in the inverse direction in the electric vehicle mode is rotated in the normal direction as shown in FIG. 3 , the engine 7 increases in rotational velocity, can be started and generate torque and thus power supplied from the first motor generator 11 and power supplied from the engine 7 are simultaneously outputted to the output shaft 5 , thereby achieving a first hybrid mode.
[0037] In the first hybrid mode, the first brake 13 is engaged while the second brake 15 and the clutch 17 are disengaged.
[0038] In the above operation, the second motor generator 9 functions as a generator that provides a reaction force according to the torque of the engine 7 , thereby substantially controlling the shift ratio.
[0039] The first motor generator 1 cannot control the shift ratio because the first ring gear is fixed by the first brake 13 , such that it only functions as a motor that transmits torque to the output shaft 3 through the first carrier.
[0040] FIG. 4 illustrates a second hybrid mode that is different from the first hybrid mode, in which the first hybrid mode is changed to the second hybrid mode by engaging the clutch 17 and disengaging the first brake 13 after controlling the shift ratio such that the velocity of the second sun gear reaches 0.
[0041] As the clutch 17 is disengaged as described above, both the first planetary gear set 5 and the second planetary gear set 11 make a lever on a single straight line in the lever analysis diagram.
[0042] Here, the first motor generator 1 functions as a motor, rotating in the inverse direction, and the second motor generator 9 functions as a generator, thereby achieving the second hybrid mode different from the first hybrid mode.
[0043] FIG. 5 shows a engine mode that can be provided by the power train of the invention, in which the first motor generator 1 is stopped.
[0044] After the velocities of the first ring gear and second sun gear reach 0 by controlling the shift ratio in the second hybrid mode, when the torque of the first motor generator 1 and the second motor generator 9 is removed by engaging the second brake 15 and disengaging the clutch 17 , torque is applied only in the second planetary gear set, thereby achieving the engine mode in which the vehicle is driven substantially by the torque of the engine 7 .
[0045] That is, referring to the lever analysis diagram of FIG. 5 , the first motor generator 1 is fixed and the second motor generator 9 is also fixed by the second brake 15 . Accordingly, the first motor generator 1 and the second motor generator 9 are substantially stopped, such that a mechanical point with the highest efficiency is achieved without energy loss due to changes between mechanical energy and electric energy.
[0046] Since the rotational velocity of the output shaft 3 is larger than the rotational velocity supplied from the engine 7 to the second carrier, an overdrive shift ratio is formed, which makes it possible to reduce a significant amount of fuel consumption especially when a vehicle is traveling at a high speed for a long time.
[0047] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. | A power train according to an embodiment of the invention includes two sets of planetary gear set, one clutch, and two brakes, such that it provides one electric vehicle mode, two hybrid modes, and one engine mode of overdrive shift ratio. Further, the power train of a hybrid vehicle has a simple configuration, high power performance, and reduced weight and fuel consumption, while being easily equipped in the vehicle. In particular, since an engine mode that makes it possible to reduce a significant amount of fuel consumption especially when a vehicle is traveling at a constant high-velocity. | 1 |
TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates, in general, to equipment utilized in conjunction with operations performed in subterranean wells and, in particular, to sand control screen assemblies having integral connector rings and methods for making same.
BACKGROUND OF THE INVENTION
[0002] Without limiting the scope of the present invention, its background will be described with reference to producing fluid from a hydrocarbon bearing subterranean formation, as an example.
[0003] Since the beginning of oil production from subsurface formations, the industry has been concerned with efficient control of the movement of unconsolidated formation particles, such as sand, into the wellbore. For example, such formation movement commonly occurs during production from completions in loose sandstone or following hydraulic fracture of a formation. Production of these materials causes numerous problems in the operation of oil, gas or water wells. These problems include plugged formations, tubing and subsurface flow lines, as well as erosion of casing, downhole equipment and surface equipment. These problems lead to high maintenance costs and unacceptable well downtime. Accordingly, numerous methods have been utilized to control the movement of these unconsolidated formation particles during the production of fluids.
[0004] For example, one or more sand control screen assemblies are commonly included in the completion string to control the movement of formation particles. Such sand control screen assemblies are commonly constructed by installing one or more screen jackets on a perforated base pipe. The screen jackets typically include a single wire wrapped around a plurality of longitudinally extending ribs. Once installed on the base pipe, the ribs provide certain strength to the wire wrap and stand-off between the wire wrap and the base pipe for fluid travel. Conventionally, screen jackets have been secured to the base pipe by welding.
[0005] It has been found, however, that the process of welding a screen jacket to a base pipe is sometimes very difficult due to the difference in metallurgy of the components. For example, the material used for the base pipe may be 13 chrome while the material used for the screen jacket may be a special alloy such as 304L stainless steel, 316L stainless steel, Inconel, Hastelloy or Monel. Due to the difficulty of the welding process and the post-weld heat treatment, numerous types of failures have been observed in sand control screen assemblies. For example, it has been found, that the screen wire of the screen jacket may be damaged due to the heat of the welding process.
[0006] Accordingly, a need has arisen for an apparatus for attaching a screen jacket to a base pipe that does not require welding incompatibly different materials. A need has also arisen for such an apparatus that is simple and cost-effective to manufacture and that is capable of withstanding severe downhole conditions during installation and production.
SUMMARY OF THE INVENTION
[0007] The present invention disclosed herein comprises a sand control screen assembly for preventing the inflow of formation particles during production. The sand control screen assembly of the present invention does not require welding incompatibly different materials to connect a screen jacket to the base pipe. In addition, the sand control screen assembly of the present invention is simple and cost-effective to manufacture and is capable of withstanding severe downhole conditions during installation and production.
[0008] In one aspect, the present invention is directed to a screen jacket assembly for positioning around a base pipe to form a sand control screen. The screen jacket assembly includes a screen jacket formed from a plurality of circumferentially distributed axially extending ribs and a screen wire wrapped therearound. A pair of oppositely disposed connector rings is at least partially positionable around the first and second ends of the screen jacket. The connector rings each have a plurality of openings in a sidewall portion thereof that are circumferentially alignable with at least a portion of the ribs such that the connector rings are integrally connectable with the aligned ribs via the openings.
[0009] In one embodiment, the connector rings may be shrink rings that are heated prior to positioning around the screen jacket such that upon cooling, a sand tight seal is created between the shrink rings and the screen jacket. In certain embodiments, the number of openings in each of the connector rings has a one to one relationship with the number of ribs. In other embodiments, the number of openings in each of the connector rings has a less than one to one relationship with the number of ribs including embodiment wherein the number of openings in each of the connector rings has a no more than one half to one relationship with the number of ribs. Once constructed, the ribs are operable to share a load between the connector rings, such as a torsional load, a tensile load, a compression load or the like. In certain embodiments, there are welded connections between the connector rings and the aligned ribs via the openings.
[0010] In another aspect, the present invention is directed to a sand control screen assembly that includes a base pipe and a screen jacket operably positionable around the base pipe. The screen jacket includes a plurality of circumferentially distributed axially extending ribs and a screen wire wrapped around the ribs. A pair of oppositely disposed connector rings is at least partially positionable around the first and second ends of the screen jacket. The connector rings each have a plurality of openings in a sidewall portion thereof that are circumferentially alignable with at least a portion of the ribs such that the connector rings are integrally connectable with the aligned ribs via the openings. The connector rings are operably positionable around the base pipe.
[0011] In a further aspect, the present invention is directed to a method for manufacturing a screen jacket assembly for positioning around a base pipe to form a sand control screen. The method includes forming a screen jacket including a plurality of circumferentially distributed axially extending ribs and a screen wire wrapped therearound, positioning a pair of connector rings at least partially around first and second ends, respectively, of the screen jacket, circumferentially aligning openings formed in a sidewall portion of each connector ring with at least a portion of the ribs and integrally connecting the connector rings with the aligned ribs via the openings.
[0012] The method may also include heating the connector rings prior to positioning the connector rings at least partially around first and second ends of the screen jacket, cooling the connector rings after positioning the connector rings at least partially around first and second ends of the screen jacket to form a sand tight seal, sharing a torsional load between the connector rings with the ribs, sharing a tensile load between the connector rings with the ribs or weldably connecting the connector rings with the aligned ribs via the openings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
[0014] FIG. 1 is a schematic illustration of a well system operating a plurality of sand control screen assemblies according to an embodiment of the present invention;
[0015] FIGS. 2A-2C are quarter sectional view of successive axial sections of a sand control screen assembly according to an embodiment of the present invention;
[0016] FIGS. 2D is a cross sectional view of a portion of a sand control screen assembly according to an embodiment of the present invention;
[0017] FIG. 3 is a side view partially cut away and partially in cross section of a sand control screen assembly according to an embodiment of the present invention;
[0018] FIG. 4 isometric view of one embodiment of a connector ring for use in a sand control screen assembly of the present invention;
[0019] FIG. 5 isometric view of one embodiment of a connector ring for use in a sand control screen assembly of the present invention; and
[0020] FIG. 6 isometric view of one embodiment of a connector ring for use in a sand control screen assembly of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the present invention.
[0022] Referring initially to FIG. 1 , therein is depicted a well system including a plurality of sand control screens embodying principles of the present invention that is schematically illustrated and generally designated 10 . In the illustrated embodiment, a wellbore 12 extends through the various earth strata. Wellbore 12 has a substantially vertical section 14 , the upper portion of which has cemented therein a casing string 16 . Wellbore also has a substantially horizontal section 18 that extends through a hydrocarbon bearing subterranean formation 20 . As illustrated, substantially horizontal section 18 of wellbore 12 is open hole.
[0023] Positioned within wellbore 12 and extending from the surface is a tubing string 22 . Tubing string 22 provides a conduit for formation fluids to travel from formation 20 to the surface. At its lower end, tubing string 22 is coupled to a completions string that has been installed in wellbore 12 and divides the completion interval into various production intervals adjacent to formation 20 . The completion string includes a plurality of sand control screens 24 , each of which is positioned between a pair of packers 26 that provides a fluid seal between the completion string 22 and wellbore 12 , thereby defining the production intervals. Sand control screens 24 serve the primary functions of filtering particulate matter out of the production fluid stream. In the illustrated embodiment, sand control screens 24 may also be useful in controlling the flow rate of the production fluid stream.
[0024] Even though FIG. 1 depicts the sand control screens of the present invention in an open hole environment, it should be understood by those skilled in the art that the flow control screens of the present invention are equally well suited for use in cased wells. Also, even though FIG. 1 depicts one sand control screen in each production interval, it should be understood by those skilled in the art that any number of sand control screens of the present invention may be deployed within a production interval without departing from the principles of the present invention. Further, even though FIG. 1 depicts each sand control screen as having a single screen jacket, it should be understood by those skilled in the art that any number of screen jackets may be installed on a single sand control screen of the present invention without departing from the principles of the present invention.
[0025] In addition, even though FIG. 1 depicts the sand control screens of the present invention in a horizontal section of the wellbore, it should be understood by those skilled in the art that the sand control screens of the present invention are equally well suited for use in deviated wellbores, vertical wellbores, multilateral wellbore and the like. Accordingly, it should be understood by those skilled in the art that the use of directional terms such as above, below, upper, lower, upward, downward, uphole, downhole and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure, the uphole direction being toward the surface of the well and the downhole direction being toward the toe of the well.
[0026] Referring next to FIGS. 2A-2D , therein is depicted successive axial sections of a sand control screen assembly according to the present invention that is representatively illustrated and generally designated 100 . Sand control screen assembly 100 may be suitably coupled to other similar sand control screen assemblies, production packers, locating nipples, production tubulars or other downhole tools to form a completions string such as that described above. Sand control screen assembly 100 includes a base pipe 102 that has a blank pipe section 104 and a perforated section 106 including a plurality of production ports 108 . Positioned around an upper portion of blank pipe section 104 is a screen jacket 112 that serves as a filter medium and may be in the form of a single layer wire wrap screen, a multilayer wire wrap screen, a prepacked screen, a woven wire mesh screen or the like, designed to allow fluids to flow therethrough but prevent particulate matter of a predetermined size from flowing therethrough. In the illustrated embodiment, screen jacket 112 includes a plurality of circumferentially distributed axially extending ribs 114 with a screen wire 116 wrapped around the ribs.
[0027] A connector ring 118 is positioned around the uphole end of screen jacket 112 . Connector ring 118 has a plurality of openings 120 in a sidewall portion thereof that are circumferentially aligned with ribs 114 of screen jacket 112 . Connector ring 118 is integrally connected with ribs 114 via welded connections 122 through openings 120 . Preferably, connector ring 118 is a shrink ring that is heated prior to positioning around screen jacket 112 such that upon cooling, a sand tight seal is created between connector ring 118 and screen jacket 112 . In the illustrated embodiment, connector ring 118 is operably associated with base pipe 102 in the form of a securable connection illustrated as weld 124 . The material of connector ring 118 is selected based upon factors including its thermal properties, its chemical resistance, its compatibility to be welded to base pipe 102 , its compatibility to be welded to screen jacket 112 and the like. Even though the material of screen jacket 112 may be incompatible for welding to base pipe 102 , the use of connector ring 118 as an intermediate device between screen jacket 112 and base pipe 102 enables welding of connector ring 118 to both base pipe 102 and screen jacket 112 . For example, suitable materials for connector ring 118 include 13 chrome, 304L stainless steel, 316L stainless steel, 420 stainless steel, 410 stainless steel, Incoloy 825 or similar alloys. In certain embodiments, connector ring 118 may be the same material of base pipe 102 , which eliminates any material incompatibility for welding. In other embodiments, connector ring 118 may be the same material of screen wire 116 , which eliminates welding directly between screen jacket 112 and base pipe 102 . In still other embodiment, connector ring 118 may be a material that is different from that of both base pipe 102 and screen wire 116 .
[0028] A connector ring 126 is positioned around the downhole end of screen jacket 112 . Connector ring 126 has a plurality of openings 128 , only one being visible in FIG. 2A , in a sidewall portion thereof that are circumferentially aligned with ribs 114 of screen jacket 112 . Connector ring 126 is integrally connected with ribs 114 via welded connections 130 through openings 128 , as best seen in FIG. 2D . Preferably, connector ring 126 is a shrink ring that is heated prior to positioning around screen jacket 112 such that upon cooling, a sand tight seal is created between connector ring 126 and screen jacket 112 . In the illustrated embodiment, connector ring 126 is operably associated with base pipe 102 forming a fluid passageway 132 therebetween. The material of connector ring 126 is selected based upon factors including its thermal properties, its chemical resistance, its compatibility to be welded to other sand control screen components and the like.
[0029] Positioned downhole of screen jacket 112 is a screen interface housing 134 that forms an annulus 136 with base pipe 102 . Preferably, screen interface housing 134 and connector ring 126 are operably associated with one another in the form of a securable connection illustrated as weld 138 . Securably connected to the downhole end of screen interface housing 134 is a sleeve housing 140 . At its downhole end, sleeve housing 140 is securably connected to a flow tube housing 142 . Flow tube housing 142 is preferably securably connected or sealably coupled to base pipe 102 to prevent fluid flow therebetween. Toward its downhole end, flow tube housing 142 is securably connected to a lower housing 144 which is preferably welded to base pipe 102 at its downhole end as indicated at 146 . The various connections of the housing sections may be made in any suitable fashion including welding, threading and the like as well as through the use of fasteners such as pins, set screws and the like. Together, the housing sections create a generally annular fluid flow path between screen jacket 112 and production ports 108 of base pipe 102 .
[0030] Positioned in the annular region between housing sleeve 140 and base pipe 102 is a split ring spacer 148 . Positioned within axial openings 150 in flow tube housing 142 is a plurality of flow tubes 152 . The illustrated embodiment includes six axial openings 150 and six flow tubes 152 , only one being visible, however, those skilled in the art will recognize that other numbers of flow tubes both greater than and less than six could alternatively be used and would be considered within the scope of the present invention. Each of the flow tubes 152 is secured within flow tube housing 142 by a threaded retaining sleeve 154 . One or more of the flow tube 152 may have a threaded cap or a plug (not pictured) associated therewith to inhibit or stop flow therethrough. The use of plugs and flow tubes 152 having various inner diameters allow an operator to adjust the pressure drop rating of each sand control screen 100 to a desired level such that a completion string including a plurality of sand control screens 100 is operable to counteract heel-toe effects in long horizontal completions, balance inflow in highly deviated and fractured wells, reduce annular sand transportation and reduce water/gas influx, thereby lengthening the productive life of the well.
[0031] Referring next to FIG. 3 , therein is depicted a screen jacket assembly of the present invention that is generally designated 200 . Screen jacket assembly 200 includes a screen jacket 202 that serves as a filter medium designed to allow fluids to flow therethrough but prevent particulate matter of a predetermined size from flowing therethrough. Screen jacket 202 includes a plurality of circumferentially distributed axially extending ribs 204 with a screen wire 206 wrapped around the ribs. A pair of connector rings 208 , 210 is positioned at opposite ends of screen jacket 202 . Connector ring 208 has a plurality of openings 212 in a sidewall portion thereof that are circumferentially aligned with ribs 204 of screen jacket 202 . Connector ring 208 is integrally connected with ribs 204 via welded connections 214 through openings 212 . Similarly, connector ring 210 has a plurality of openings 216 in a sidewall portion thereof that are circumferentially aligned with ribs 204 of screen jacket 202 . Connector ring 210 is integrally connected with ribs 204 via welded connections 218 through openings 216 .
[0032] As discussed above, connector rings 208 , 210 may be shrink rings that are heated prior to positioning around screen jacket 202 . Once in place such that openings 212 , 216 properly align with ribs 204 , connector rings 208 , 210 may be allowed to cool forming a sand tight seal between connector rings 208 , 210 and screen jacket 202 . Thereafter, in the illustrated embodiment, each of the ribs 204 is integrally connected to connector ring 208 and connector ring 210 . Specifically, connector ring 208 is integrally connected to ribs 204 via welds 214 using a tungsten inert gas (TIG) welding process, a metal inert gas (MIG) welding process or other suitable welding process or connecting process. Likewise, connector ring 210 is integrally connected to ribs 204 via welds 218 . The integral connection between connector rings 208 , 210 and ribs 204 enables ribs 204 to share a load between connector rings 208 , 210 , such as a torsional load, a tensile load, a compression load or the like that may be applied between connector rings 208 , 210 when a sand control screen assembly including screen jacket 202 is run in the well.
[0033] Referring next to FIG. 4 , therein is depicted a connector ring of the present invention that is generally designated 300 . Connector ring 300 may be used in conjunction with screen jacket 202 and is representative of connector ring 208 and connector ring 210 . Connector ring 300 has a substantially cylindrical body 302 . In the illustrated embodiment, connector ring 300 has a radially stepped inner profile 304 having a shoulder 306 between a radially thicker portion 308 and a radially thinner portion 310 . Preferably, shoulder 306 serves a stop and provides for axial alignment when connector ring 300 is positioned around a screen jacket. In the illustrated embodiment, connector ring 300 includes thirty openings 312 formed in the sidewall portion thereof. Once connector ring 300 is axially positioned around a screen jacket, openings 312 are preferably circumferentially aligned with an equal number of ribs of the screen jacket. Thereafter, connector ring 300 is integrally coupled to the screen jacket by, for example, welding the ribs to connector ring 300 through openings 312 .
[0034] Even though connector rings 118 , 126 , 208 , 210 , 300 have been depicted and described as having a thirty openings, it should be understood by those skilled in the art that the connector rings of the present invention could have different numbers of openings either greater than or less than thirty, without departing from the principles of the present invention. The required number of openings will depend upon factors such as the diameter and design of the screen jacket. In addition, even though FIGS. 2-4 have depicted and described connector rings 118 , 126 , 208 , 210 , 300 as having a one to one relationship between the number of openings of a connector ring and the number of ribs, it should be understood by those skilled in the art that the number openings of the connector rings of the present invention could have a different relationship to the number of ribs of the screen jacket.
[0035] For example, as best seen in FIG. 5 , connector ring 400 may be used in conjunction with screen jacket 202 and may replace connector ring 208 or connector ring 210 . Connector ring 400 has a substantially cylindrical body 402 . In the illustrated embodiment, connector ring 400 has a radially stepped inner profile 404 having a shoulder 406 between a radially thicker portion 408 and a radially thinner portion 410 . In the illustrated embodiment, connector ring 400 includes twenty openings 412 formed in the sidewall portion thereof. Once connector ring 400 is axially positioned around a screen jacket, openings 412 are preferably circumferentially aligned with an equal number of ribs of the screen jacket, which may be a subset of all the ribs of the screen jacket. Thereafter, connector ring 400 is integrally coupled to the screen jacket by, for example, welding the ribs to connector ring 400 through opening 412 .
[0036] As another example, as best seen in FIG. 6 , connector ring 500 may be used in conjunction with screen jacket 202 and may replace connector ring 208 or connector ring 210 . Connector ring 500 has a substantially cylindrical body 502 . In the illustrated embodiment, connector ring 500 has a radially stepped inner profile 504 having a shoulder 506 between a radially thicker portion 508 and a radially thinner portion 510 . In the illustrated embodiment, connector ring 500 includes fifteen openings 512 formed in the sidewall portion thereof. Once connector ring 500 is axially positioned around a screen jacket, openings 512 are preferably circumferentially aligned with an equal number of ribs of the screen jacket, which may be a subset of all the ribs of the screen jacket. Thereafter, connector ring 500 is integrally coupled to the screen jacket by, for example, welding the ribs to connector ring 500 through opening 512 .
[0037] While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments. | A screen jacket assembly for positioning around a base pipe ( 102 ) to form a sand control screen ( 100 ). The screen jacket assembly includes a screen jacket ( 112 ) formed from a plurality of circumferentially distributed axially extending ribs ( 114 ) and a screen wire ( 116 ) wrapped therearound. A pair of oppositely disposed connector rings ( 118, 126 ) is at least partially positionable around the first and second ends, respectively, of the screen jacket ( 112 ). The connector rings ( 118, 126 ) each have a plurality of openings ( 120, 128 ) in a sidewall portion thereof that are circumferentially alignable with at least a portion of the ribs ( 114 ) such that the connector rings ( 118, 126 ) are integrally connectable with the aligned ribs ( 114 ) via the openings ( 120, 128 ). | 8 |
FIELD OF THE INVENTION
This invention relates to sanitizing lotions having antimicrobial properties; and particularly to a highly persistent antimicrobial hand sanitizing lotion which displays unique barrier properties.
BACKGROUND OF THE INVENTION
Hand washing has long been recognized as a particularly effective method for reducing the transmission of communicable diseases. In hospitals, where patients are in a weakened condition, it is most important for health-care professionals to utilize an antimicrobial hand cleaning composition to prevent the spread of various pathogenic microorganisms. Furthermore, it is necessary to treat parts of the skin and mucous membranes antiseptically prior to any type of surgical procedure, injection, or puncture so as to prevent the transmission of infectious microorganisms. In such environments, compositions such as alcohols are effective antimicrobials. However, the defatting properties of alcohols cause chapping and cracking to occur to the skin of the user. The resultant damaged skin is then more prone to additional infectious contamination, since pathogenic microorganisms can enter and evade sanitizing materials by residing within the cracked epidermal layer. Additionally, the presence of alcohols inhibits the foaming action of various detergent compositions which are likely to be used in combination therewith. Various antimicrobials are known for use in such formulations, for example, iodophors, iodine formulations, phenolic compounds, e.g. hexachlorophene, and bisbiguanides, e.g. chlorhexidene gluconate. Such antimicrobial ingredients are also well-known additives for a variety of products, such as deodorant soap bars, underarm deodorants, liquid soaps and fabric treatments.
In order to form an efficacious antimicrobial product which is not injurious to the user's skin, various proposals have been made. Improvements in mildness and skin after-feel have called for the addition of such additives as glycerin, sorbitol, vitamin E, coco fatty acid derivatives and their salts, alkyl quaternary salts and sugar esters.
DESCRIPTION OF THE PRIOR ART
U.S. Pat. No. 5,173,216 discloses a composition for decontaminating and/or disinfecting the hands comprising an amphoteric-cationic surfactant, a cationic surfactant, a wetting agent which is compatible with the cationic surfactant, and a nonionic regressing agent. The composition exhibits both bacteriostatic and fungistatic effectiveness at varying concentrations.
U.S. Pat. No. 5,719,113 discloses an antimicrobial cleansing composition containing chlorhexidine, a nonionic surfactant which does not include polyoxypropylene/polyoxyethylene block copolymers, an amphoteric surfactant, and an alkyl polyglucoside. Additionally included are viscosifiers or thickeners, emollients, fragrances, perfumes, coloring agents, preservatives, foaming agents, vitamins and fungicides.
U.S. Pat. No. 5,259,984 discloses a cleansing composition containing a storage-stable volatile polymer gel solution and a cleaning agent including an alkali metal hydroxide. In a preferred embodiment, the polymer gel solution includes a hydroxypropylmethylcellulose polymer. The composition is formed by forming a pre-mixed cleaning agent and a pre-mixed volatile aqueous gel solution. These pre-mixed components are then intermixed to form the final cleaner composition.
U.S. Pat. No. 5,562,912 discloses a cleansing composition containing an EO/PO/EO tri-block nonionic copolymer surfactant in conjunction with a generic skin cleanser composition.
U.S. Pat. No. 5,629,006 discloses a cleansing composition containing an alcohol, a block copolymer, a foaming surfactant, an emulsifier, a cleaning agent, a polyalkylene glycol, an emollient and water. Stepwise addition of the components with continuous mixing to a point of homogeneity is utilized in the method of formulation.
U.S. Pat. No. 5,728,662 discloses a cleansing composition which consists essentially of a d-limonene, a solvent, a C 11 alcohol ethoxylate, polyoxyethylene (20) sorbitan monooleate, a water-soluble acrylic polymer, sodium hydroxide, mixed isothioazolinones, 2,6-di-tert--butyl-p-cresol and water.
U.S. Pat. No. 5,767,163 discloses a cleansing composition and method for its use as a hand antiseptic. The composition is an alcoholic solution containing cetyl alcohol, glycolic acid, benzalkonium chloride and isopropyl alcohol as its major constituent.
U.S. Pat. No. 5,750,579 is drawn to a cleansing composition which is useful for the hands and fingers. The composition is in the form of a solution which comprises a disinfecting medicament in an alcohol and a thickening agent consisting of a combination of a carboxyvinyl polymer and a water-soluble, high molecular weight cellulose compound. The process of manufacture requires that various of the ingredients are blended to a point of homogeneity, resulting in a final, homogeneous composition.
U.S. Pat. No. 5,591,442 is drawn to an antiseptic and disinfectant hand cleaning composition containing a synergistic mixture of an alkyl alcohol component and a glycerol monoalkyl ether.
U.S. Pat. No. 5,650,143 drawn to a deodorant cosmetic stick composition provides a deodorant cosmetic stick product which has a translucent or transparent light transmitting appearance. The cosmetic stick contains propylene glycol, sodium stearate, dimethicone copolyol, TRICLOSAN, PENTADOXYNOL-200, and water.
U.S. Pat. No. 5772640 drawn to TRICLOSAN-containing medical devices, discloses polymeric medical articles containing the antiinfective agents chlorhexidine and TRICLOSAN. The patent discloses a synergistic relationship between these compounds which permits the use of relatively low levels of both agents, while achieving effective antimicrobial activity when these compounds are contained in either hydrophilic or hydrophobic polymers.
The prior art formulations suffer from the fact that increased use of various surfactants and lipid-restoring compositions reduce the effectiveness of the antimicrobial active ingredient. Therefore, if a composition including skin barrier properties and persistent anti-microbial characteristics could be formulated in such a way that both enhanced skin-care and increased antimicrobial effectiveness resulted, a long-felt need in the art would be satisfied.
SUMMARY OF THE INVENTION
The present invention describes an antimicrobial hand sanitizing lotion in the form of a medicated polymer/emulsion based product and the method by which it is produced. The product is intended to be used as a topical antimicrobial lotion. 2,4,4′-trichloro-2′-hydroxydiphenyl ether, available under the tradename TRICLOSAN or IRGASAN DP 300 from the Ciba Geigy Corp., is the antimicrobial agent of choice in the present formulation. TRICLOSAN has demonstrated efficacy against the following gram-positive and gram-negative bacteria, plus fungi and yeasts:
GRAM-POSITIVE BACTERIA
Bacillus subtilis
Bacillus megatherium
Bacillus cereus
Bacillus cereus var. mycoides
Clostridium botulinum
Clostridium tetani
corynebacterium diphtheriae
Corynebacterium acnes *
Diplococcus pneumonise
Lactobacillus arabinosus
Lactobacillus fermenti
Mycobacterium tuberculosis
Mycobacterium smegmatis
Mycobacterium phlei
Sarcina lutea
Sarcina ureae
staphylococcus aureas
Staphylococcus albus
streptococcus agalactiae
streptococcus haemolyticus A
streptococcus faecalis
streptococcus pyogenes
* Propionibacterium acnes
GRAM-NEGATIVE BACTERIA
Aerobacter aerogenes
Alraligenes; faecalis
Brucella intermedia
Brucella abortus
Brucella melitensis
Brucella suis
cloaca cloacae
Escherichia coli
Haemophilus Influenzae
Klebsiella edwardsii
Klebsiella aerogenes
Klebsiella pneumoniae
Loeffierella mallei
Loeffierella pseudomallei
Moraxells duplex
Moraxella glucidolytica
Moraxella lwoffi
Neisseria catarrhilis
Pasteurella septica
Pasteurella pseuclotuberculosis
Proteus vulgaris
proteus mirabills
Pseudomonas aeruginosa
Pseudomonas fluorescens
Salmonella enteritidis
Salmonella typhimurium
salmonella typhi
Salmonella paratyphi A
salmonella paratyphi B
Salmonella pullorum
Serratia marcescens
Shigella flexneri
Shigella sonnei
Shigelle dysenteriae
Vibrio cholerae
Vibrio eltor
FUNGI AND YEASTS
Aspergillus niger
Aspergillus furnigatus
Candida albicans
Epidermophyton floccosum
Keratinomyces ajelloi
Tochophylon mentagrophytes
Trichophylon rubrum
Trichophyton tonsurans
It has been discovered that incorporation of TRICLOSAN in a topical lotion comprised of a Surfactant Phase, and a Wax Phase results in a product which is particularly effective in preventing cross-contamination of pathogenic microorganisms in the workplace. The product is persistent in that it significantly reduces the incidence of bacteria on skin surfaces for a period of about 3-4 hours. It is applicable to any area of intact skin, and will kill pathogenic bacteria on contact and remain effective for extended periods of time. The specially formulated antiseptic handwash of the invention is a non-toxic and hypoallergenic lotion containing a broad spectrum antimicrobial which forms a polymeric film on healthy skin. It is a completely safe and long lasting product which will not rub off on food or the like due to its unique bonding agent. The hydrophobic portion of the process utilizes a USP White Wax in combination with the acrylic carbomer. The wax in solution in co-ordination with the product backbone (CARBOPOL 934-P), melts through the heat of the hand. The wax phase spreads over the skin with the CARBOPOL theorized to act in two ways. The acrylate chains are theorized to intercalate into the wax matrix and stabilize the wax by adding support to the horizontal spreading and layering of the wax. Further, the CARBOPOL is theorized to interact with the skin surface relative to the horizontal wax layer. The combination of these interactions forms a physical hydrophobic layer which resides on the skin surface and provides a barrier which would inhibit penetration of liquids which are primarily hydrophilic in nature. The wax is solubilized and dispersed with the aid of surfactants and dimethicone within an alcohol/glycerol base. Stearic acid, particularly triple pressed, is noted as being critical to affecting complete solubilization of the raw materials in the wax phase. At appropriate concentration ranges of the antimicrobial ingredient, the product is efficacious for use by healthcare professionals in that it is a highly effective, broad spectrum bactericidal composition.
One of the unique properties of the product is its ability to protect the skin from relatively strong acids and bases. Tests conducted on metallic surfaces demonstrated enhanced longevity of the metallic substrates when exposed to corrosive environments. The barrier properties of the instant composition further increase the efficiency of bacterial removal from the skin's surface. The product is further characterized by exhibiting a highly persistent antimicrobial action. This persistence may be attributed to the stability of the wax/carbomer hydrophobic layer which allows for a unique physical presentation of the antimicrobial, e.g. TRICLOSAN, molecule. The stabilized barrier composition is stabilized by the CARBOPOL chains orientated into the wax phase. TRICLOSAN, being a hydrophobic molecule, would orientate with respect to the barrier layer, resulting in a product which maintains persistent skin contact and antimicrobial action. In combination, these properties result in a product having enhanced effectiveness in the removal of surface bacteria compared to washing with soap and water. This effectiveness persists for the duration of the presence of the product formulation on the skin. Application of this product prior to a soap and water hand washing has been clinically proven to enhance hand washing with a statistically significant increase in the removal of harmful bacteria from the skin surface, compared to ordinary hand washing without prior application of the product.
When used in combination with latex gloves, the product inhibits the growth of microorganisms underneath the latex gloves, protects hands from contamination should the gloves become damaged, moisturizes and soothes the skin to combat the potential damaging effects of latex, harsh soaps and frequent washing.
When processing the lotion of the present invention, the surfactant and wax phases are each formulated according to particular concentration and processing parameters, and then blended to form a Final Phase, resulting in a unique topical antimicrobial sanitizing and skin care product.
Accordingly, it is an objective of the instant invention to teach an antimicrobial sanitizing lotion, especially effective as a hand sanitizer, which is efficacious for a broad range of microorganisms and is characterized by unique skin protective barrier properties and enhanced persistence.
It is a further objective of the instant invention to teach a method for producing a sanitizing lotion wherein adherence to particular process parameters results in a unique final product.
It is yet another objective of the instant invention to teach a skin protective and sanitizing lotion wherein contact with the skin results in destruction of microbial contaminants and simultaneous formation of a hydrophobic skin protective surface layer.
It is a still further objective of the invention teach a skin protective and sanitizing lotion that enhances the capabilities of soaps and related skin-cleansers.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.
The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
DETAILED DESCRIPTION OF THE INVENTION
Production of the antimicrobial sanitizing lotion of the present invention relies upon strict adherence to a particular set of process parameters in order to arrive at a unique final product. In carrying out the process, particular attention must be given to the order of addition of the various components. Additionally, it is necessary that rigorous homogenization be carried out to form a “grain” free product. Finally, the various steps must be carried out within particular temperature ranges which are critical to the outcome of the process.
The product contains, as its active ingredient, TRICLOSAN (a Class III topical antimicrobial active ingredient. The finished product strength for TRICLOSAN ranges from (all percentages are percent by weight) 0.10%-0.35%, with a particularly preferred range being 0.117%-0.143% for general and food service usage and 0.27%-0.33% for the health care environment. The product is a viscous, flowing liquid polymer emulsion which is opaque and white in color, having a mild characteristic odor. The specific gravity of the product ranges from 0.960-0.980 at 25° C. and the pH of a 10% by volume aqueous solution is within the range of 6.5-7.1.
The excipients which are useful in forming the antimicrobial and skin protective lotion of the present invention are deionized water, in a range of 75-85 wt. %, VERSENE-100, in a range of 0.136-0.184 wt. %, CARBOPOL 934-P in a range of 0.245-0.455 wt. %, TRITON X-100 in a range of 2.55-3.45 wt. %, Propylene Glycol U.S.P. in a range of 0.85-1.15 wt. %, TERGITOL NP-9 in a range of 1.7-2.3 wt. %, DOWCIDE-A, in a range of 0.10-0.50 wt. %, Triethanolamine 85 % n.f, in a range of 0.85-1.15 wt. %, Chlorhexidine Digluconate 20 %, in a range of 0.16-0.75 wt. %, Alpha Tocopherol (Vitamin E U.S.P.), in a range of 0.09-0.11 wt. %, Stearic Acid—triple pressed in a range of 2.55-3.45 wt. %, Cetyl Alcohol n.f., in a range of 1.35-1.65 wt. %, Ethylene Glycol Monostearate, in a range of 0.675-0.825 wt. %, Dimethicone 1-45-350 cstks,in a range of 1.7-2.3 wt. %, U.S.P. White Wax in a range of 0.213-0.288 wt. %, and PARAGON MEPB in a range of 1.0-3.0 wt. %.
EXAMPLE 1
The following formulation was produced in accordance with the instant invention.
Excipients useful in the manufacture of this product were added in the following amounts:
EXCIPIENT
% BY WEIGHT
(1)
DEIONIZED WATER
83.50
(2)
VERSENE-100
0.16
(3)
CARBOPOL 934-P
0.35
(4)
TRITON X-100
3.00
(5)
PROPYLENE GLYCOL U.S.P.
1.00
(6)
TERGITOL NP-9
2.00
(7)
DOWCIDE - A
0.10
(8)
TRIETHANOLAMINE 85% N.F
1.00
(9)
CHLORHEXIDINE DIGLUCONATE 20%
0.16
(10)
ALPHA TOCOPHEROL (VITAMIN E USP)
0.10
(11)
STEARIC ACID - TRIPLE PRESSED
3.00
(12)
CETYL ALCOHOL N.F.
1.50
(13)
ETHYLENE GLYCOL MONOSTEARATE
0.75
(14)
DIMETHICONE L-45-350 CSTKS
2.00
(15)
USP WHITE WAX
0.25
(16)
PARAGON MEPB
1.00
In formulating a 4,050 pound batch of the antimicrobial sanitizing and skin protective lotion of the invention, the following method steps were followed:
(A) A Surfactant Phase is formulated by combining the following ingredients:
1) Deionized Water of reagent grade exhibiting less than 1 microohm resistivity is first added to a mixing tank in an amount of 405.40 gallons (3,382.59 lbs.)
2) VERSENE 100 (or a like equivalent EDTA Sodium Salt)(6.06 lbs.) is added; followed by
3) CARBOPOL 934 P (or a like equivalent Acrylic Polymer) (14.18 lbs.)
The mixer is engaged in the reverse mode while the circulating pump is turned on to full open, yielding a flow rate of about 110-150 gpm at a pressure of about 60-110 psi, for recirculation of the mixture. Engagement of the pump in the reverse mode causes mixing to occur in a bottom to top direction within the tank. This reverse mode pumping coupled with the forceful agitation of the recirculating pump is critical in solubilizing the Carbopol 934 in the mixture.
Homogenization of the above-mentioned ingredients is then carried out for about 30-40 minutes utilizing a stator-bladed motor driven homogenizer under flow conditions of about 110-150 gpm and at a pressure of about 60-110 psi, which conditions are sufficiently rigorous to yield a “grain” free and highly uniform product.
The remaining raw materials:
4)TRITON X-100 Surfactant (or a like equivalent Octyl Phenyoxypolyethoxy non-ionic surfactant) 121.5 lbs
5)Propylene Glycol (USP) 40.50 lbs.
6)TERGITOL NP-9 Surfactant (or a like equivalent Nonylphenol polyethylene glycol ether non-ionic surfactant) 81.00 lbs.
7)DOWCIDE-A (or a like equivalent Sodium O-Phenylphenatetetrahydrate) 4.05 lbs.
8)IRGASAN DP300 (2,4,4′-trichloro-2′-hydroxydiphenyl ether)
4)
TRITON X-100 Surfactant (or a like equivalent Octyl
121.5
lbs
Phenyoxypolyethoxy non-ionic surfactant)
5)
Propylene Glycol (USP)
40.50
lbs.
6)
TERGITOL NP-9 Surfactant (or a like equivalent
81.00
lbs.
Nonylphenol polyethylene glycol ether
non-ionic surfactant
7)
DOWCIDE-A (or a like equivalent Sodium O-
4.05
lbs.
Phenylphenatetetrahydrate)
8)
IRGASAN DP300
5.25
lbs.
(2,4,4′-trichloro-2′-hydroxydiphenyl ether)
9)
Triethanolamine 85% N.F.
40.50
lbs.
10)
Chlorhexidine Digluconate 20%
6.06
lbs.
11)
Alpha Tocopherol
4.05
lbs.
are weighed and added to the mixture.
It is noted that the hydrophilic portion of the product is modified by the use of the non-ionic surfactant (TRITON X-100) in a propylene glycol base. The hydrophilic phase is further modified due to the inclusion of TERGITOL NP-9 which includes the nonoxyl class of compounds.
Inclusion of Alpha Tocopherol (Alpha Tocopherol Acetate) commonly known as Vitamin E has a two-fold benefit. Its presence inhibits oxidation of the product as well as providing additional skin conditioning properties. Since tocopherols are freely soluble in alcohols and lipids, they easily penetrate the skin layer and provide conditioning benefits.
After all ingredients have been blended, the Surfactant Phase is then heated to within a range of about 70° C.-85° C., and maintained within this temperature range while mixing and pump recirculation are continued at about 110-150 gpm at a pressure of about 60-110 psi.
(B) The Wax Phase is next formulated by adding the following ingredients:
Stearic Acid - Triple Pressed
121.50
lbs.
Cetyl Alcohol N.F.
60.75
lbs.
Ethylene Glycol Monostearate
30.38
lbs.
Dimethicone L-45-350 cstks
81.00
lbs.
White Wax (BARECO BE SQUARE)
10.13
lbs.;
heating to within a range of about 70° C.-85° C., ideally about 77° C.-80° C.; and
maintaining the temperature of the Wax Phase within this temperature range, while mixing at about 1500-1700 rpm using a direct drive mixer.
The use of a wax, e.g. BARECO BE SQUARE, or a like equivalent which is a USP grade White Wax having a melting point in the range of 70° C.-85° C., provides a unique property. The wax, which is in solution in coordination with the Carbopol-934-P, melts through contact with the heat of the hands. This in turn forms a physical hydrophobic layer and provides a barrier which appears to inhibit penetration of liquids which are primarily hydrophilic in nature. This property helps protect the user from injury due to contact injurious materials, e.g. with acids and/or bases. The wax is apparently solubilized and dispersed with the aid of the surfactants and Dimethicone within an alcohol/glycerol base. The presence of Stearic acid, particularly triple pressed, is critical to effecting the complete solubilization of the remaining Wax Phase materials. While not wishing to be bound to any particular theory, it is believed that the wax flattens to form a neutral and hydrophobic barrier. The carbomers are believed to support the wax layer in the horizontal plane and in attachment to the skin. The carbomer molecule, which is believed to physically intercalate within the wax phase, thereby reinforcing the wax layer, is also believed to interact with the skin thereby having a stabilizing effect upon the wax layer, which results in the enhanced persistence characteristic of the product. Lastly, it is believed that the processing steps orient the TRICLOSAN molecules to yield an optimum level of antimicrobial activity.
(C) The Final Phase is formed by adding the Wax Phase to the Surfactant Phase.
At the time of mixing, the Wax Phase is being maintained at approximately 85° C. and the surfactant Phase is maintained at 80° C. The mixing takes place by using homogenization, recirculation and pressure. Pressure generation is accomplished by restricting the outlet side of the pump, thus limiting the flow therethrough. This restriction keeps the pump stators full at all times, so as to avoid burn out of the pump. Such conditions are maintained for 45-60 minutes using a 20 HP pump, at a rate of about 100-150 gal/min, at about 60-110 psi, in reverse mode, restricting the outlet and recirculating the batch. After approximately 60 minutes, the temperature is then lowered to less than 50° C. so that the PARAGON MEPB Parabens materials can be safely added.
PARAGON MEPB (a mixture of Methyl, Ethyl, Propyl, and Butyl Parabenzene in a Phenoxy Ethanol solvent, or a like equivalent mixture) is then added (40.50 lbs.) and homogenization is continued for an additional 20-30 minutes with the recirculation pump on full open. In a particular embodiment, the MEPB mixture had about 16% methyl paraben, about 4% ethyl paraben, about 2% propyl paraben, about 6% butyl paraben and the remainder, about 72% of phenoxy-ethanol solvent.
It is theorized that inclusion of DOWCIDE-A, Chlorhexidine gluconate and the Parabens species in a Phenoxy-Ethanol solvent act as phenolic based preservatives to further increase hydrophobic solubility and thereby potentiate the active biocidal properties of the product.
It is further theorized that the propylene glycol, cetyl alcohol, phenoxyethyl alcohol, parabens, and octyl phenol act as permeability barriers to the bacterial lipid cell wall; that the TRITON-X 100 and triethanolamine offer an ionic approach to cell wall disruption via a chelation mechanism; and that the phenoxyethyl alcohol, parabens and DOWCIDE-A further provide cytoplasmic membrane permeation.
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and drawings. | The present invention is directed toward an antimicrobial hand sanitizing lotion in the form of a medicated polymer/emulsion based product and the method by which it is produced. The product is intended to be used as a topical antimicrobial and skin protective lotion and contains 2,4,4′-trichloro-2′-hydroxydiphenyl ether as the antimicrobial agent of choice in a base which forms a hydrophobic protective barrier, having persistent antimicrobial properties, upon application to the skin. | 0 |
FIELD AND BACKGROUND OF THE INVENTION
[0001] Embodiments of the current invention are related to the gearing and derailleur mechanism of a bicycle. More specifically, embodiments of the present invention are directed to an electro mechanical derailleur actuator system and method thereof.
[0002] Bicycles are a well-established means for self transportation and for commuting. Since their introduction in the 19th century, bicycles have been widely accepted. Today they number about one billion worldwide, twice as many as automobiles. Bicycles are the principal means of transportation in many regions of the world. They also provide a popular form of recreation and sport, and a means of daily commuting to and from work.
[0003] The advent of the bicycle has had a major impact on society, both in terms of culture and of advancing modern industrial methods. Several bicycle components have been adapted and have eventually played a key role in the development of the automobile. Examples include: ball bearings; pneumatic tires; chain-driven sprockets; spoke-tensioned wheels, etc.
[0004] Reference is presently made to FIG. 1 , which is a schematic side view of a prior art bicycle 10 having a frame 12 , and showing major typical components of the prior art bicycle. FIG. 1 is introduced to generally define terms used in the specification and claims which follow. Frame 12 includes: handlebars 14 ; a cross bar 16 ; seat tube 18 ; a down tube 20 ; a seat stay 21 , and a chain stay 22 —all as indicated in the figure. Front and rear wheels 24 and 26 , respectively, are supported by the frame, as known in the art. Typically, prior art bicycle 10 travels with front and rear wheels touching the ground (not shown) defining the direction “down”, (ie. towards the ground) with the opposing direction defined as “up” (ie, away from the ground). The typical direction in which prior art bicycle advances is defined as “forward” with the opposing direction defined as “rear” or backward.
[0005] A drive chain 30 (otherwise known as simply “chain”) typically engages a chainring 32 , which is driven by a crank arm 34 , as known in the art). A secondary chainring 33 may be engaged by drive chain 30 , as described hereinbelow. Some modern bicycles have more than one or two chainrings driven by the crank arm and the gear wheels are respectively engaged by the chain, as known in the art. Furthermore, although not shown in the figure, most modern bicycles have additional chainrings mounted on the axis of rear wheel 26 . Finally the terms “sprocket” and “gear wheel” may be interchanged and are equivalent with “chainring”.
[0006] Chain 30 is displaced from chainring 32 to chainring 34 by the action of a front derailleur 35 as known in the art. Furthermore, chain 30 is displaced between/among the additional chainrings mounted on the axis (not shown in the figure) of rear wheel 26 by the action of a rear derailleur 36 , also as known in the art. An important aspect of modern bicycles is the “gears” or “gearing”—terms used in the specification and claims which follow intended to mean the configuration of the bicycle's gear wheels. Chain 30 interacts with the gears in a controlled manner, as known in the art, to enable a cyclist to maintain an approximately fixed pedaling speed while affording the cyclist a mechanical advantage versus the speed of the bicycle wheels (ie the speed of the bicycle on the terrain) and the cyclist/rider load.
[0007] In the specification and claims which follow, the term “chaining” is intended to mean the controlled displacement of the chain from one gear wheel to another gear wheel, effecting “gear changing”, “gear shifting”, or “changing gears” on a bicycle. Chaining is typically accomplished by a biasing movement of a derailleur against the chain, to yield the controlled chain movement described hereinabove, as known in the art. The expression “cogset” is intended to mean in the specification and claims which follow a combination of chainrings, whether associated with the crank arm or the rear wheel, as known in the art. Therefore, it may be said that chaining is typically accomplished on a cogset with the aid of the derailleur.
[0008] Typically, gear shifting is accomplished by means of a handlebar or stay-mounted shifter (not shown in the figure) having a cable 38 (for front derailleur 34 ) and a cable 39 (for rear derailleur 36 ), which serve to transfer the pull movement of the shifter to the respective derailleurs to shift gears, as known in the art.
[0009] Prior art bicycle gear shifting involves no small amount of cyclist/rider attention, which can detract from the riding experience and can even pose a safety concern. Many producers have attempted to manufacture automatic or electrically assisted bicycle gear actuation systems, but only few have succeeded in partially addressing problems such as: integration; operation; size; reliability; performance; and weight—inter alia.
[0010] One example of such prior art is U.S. Pat. No. 5,266,065 by Restelli, whose disclosure is incorporated herein by reference. Restelli describes an automated bicycle transmission comprising an actuator for movement into predetermined positions of a sprocket change mechanism member moving to engage a chain for transmission of motion opposite a predetermined sprocket among a plurality of coaxial sprockets of different diameter. The actuator is controlled by an electronic control device to which is connected a plurality of sensors including a sensor for detection of bicycle speed, as sensor for longitudinal slope or inclination of the bicycle and optionally a sensor of stress transmitted by the cyclist to the pedals. Restelli's description focuses solely on the rear wheel/rear derailleur and he gives no details of the actuator mechanism employed.
[0011] Another example is U.S. Pat. No. 5,577,969 by Watarai, whose disclosure is incorporated herein by reference. A multispeed bicycle having a shifting apparatus operable by a single manual lever to actuate the front and rear derailleurs is described. The shifting apparatus includes two actuating mechanisms for actuating front and rear derailleurs, respectively, and a shift controller for controlling the actuating mechanisms.
[0012] A third example is that of Ichida et al. In US patent application publications no. US 2008/0132364, whose disclosure is incorporated herein by reference. Ichida describes an electric derailleur motor unit provided for a motorized derailleur assembly. The electric derailleur motor unit has a derailleur motor support, a derailleur motor, a drive train and an output shaft. The output shaft, inter alia, has an output gear engaged with a worm gear of the drive train shaft.
[0013] The prior art cited generally addresses derailleur motor units or similar assisted shifting mechanisms using a worm gear. In all cases, the devices described are integral, meaning the bicycle employing the described devices must be either manufactured integrally and/or must have serious modifications made to a conventional bicycle-derailleur configuration to allow the devices to function correctly. One serious modification noted includes: cutting; shortening; rerouting; lengthening, removing; and replacing of the existing derailleur cable or cables.
[0014] There is therefore a need for a reliable and simplified electro mechanical derailleur actuation system that can be readily retrofitted to existing conventional derailleur gear shifting configurations without cable modification.
SUMMARY OF THE INVENTION
[0015] According to the teachings of the present invention there is provided an electro mechanical bicycle derailleur actuator system, retrofittable to a bicycle having gearing and at least one derailleur, the derailleur having a cable, the system comprising: at least one derailleur actuator module (DAM) connectable to the bicycle and to the cable; a cyclist interface module (CIM) connectable to the bicycle for cyclist interface with the system; and a control and power module (CPM) connectable to the bicycle serving to control and power the system, wherein the bicycle gearing is shiftable by the system without derailleur cable modification. Preferably, derailleur cable modification includes one chosen from the list including: cutting; shortening; rerouting; lengthening, removing; and replacing of the cable. Most preferably, the at least one DAM further comprises: a mounting connectable to a stay of the bicycle and having positional adjustment in two degrees of freedom and a cable displacement unit (CDU) connectable to the mounting and the cable, the CDU having positional adjustment in a third degree of freedom. Typically, the CDU includes a motor having an axis, the motor adapted to drive a lead screw on which a rider is configured and wherein the rider is attachable to the cable, the rider adaptable to displace the cable to effect gear changes. Most typically, the CDU further includes an encoder attachable to the axis, the encoder adapted to provide feedback regarding cable displacement by the rider.
[0016] Preferably, the CDU additionally includes means to: receive commands from the CPM; transfer information regarding cable displacement to the CPM; and receive power from the CPM. Most preferably, the CIM includes on board power and a means to transfer commands to the CPM including one chosen from the list including: wireless and wired. Typically, the CPM includes on-board power and wiring to transfer the power to the CDU and means to transfer commands to and receive information from the CDU. Typically, means to transfer commands and receive information to and receive information from the CDU includes one chosen from list including: wireless and wired. Most typically, the system is commandable to allow bicycle gear shifting not by the system.
[0017] According to the teachings of the present invention there is further provided a method of retrofitting an electro mechanical bicycle derailleur actuator system to a bicycle having gearing and at least one derailleur the derailleur having a cable, the method comprising the steps of: connecting at least one derailleur actuator module (DAM) to the bicycle and to the cable; connecting a cyclist interface module (CIM) to the bicycle for cyclist interface with the system; and connecting a power module (CPM) to the bicycle serving to control and power the system, wherein the bicycle gearing is shifted by the system without derailleur cable modification. Preferably, derailleur cable modification includes one chosen from the list including: cutting; shortening; rerouting; lengthening, removing; and replacing of the cable. Most preferably, the at least one DAM further comprises: a mounting connected to a stay of the bicycle and having positional adjustment in two degrees of freedom and a cable displacement unit (CDU) connected to the mounting and the cable, the CDU having positional adjustment in a third degree of freedom. Typically, the CDU includes a motor having an axis, the motor driving a lead screw on which a rider is configured and wherein the rider is attached to the cable, the rider displacing the cable to effect gear changes.
[0018] According to the teachings of the present invention there is further provided an electro mechanical bicycle derailleur actuator system connected to a bicycle having gearing and at least one derailleur, the derailleur having a cable, the system comprising: at least one derailleur actuator module (DAM) connectable to the bicycle and to the cable, the DAM comprising a rider to which the cable is attachable, the rider configurable onto a lead screw, the lead screw rotatable to displace the rider and the cable to effect gear changes, wherein the bicycle gearing is shiftable by the system.
BRIEF DESCRIPTION OF THE DRAWINGS AND APPENDICES
[0019] The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
[0020] FIG. 1 is a schematic side view of a prior art bicycle having a frame, and showing major typical components of the prior art bicycle;
[0021] FIG. 2 is a schematic side view of the prior art bicycle shown in FIG. 1 with an electro-mechanical actuator system installed thereupon, in accordance with an embodiment of the current invention.
[0022] FIG. 3 is a pictorial representation of a derailleur actuator module (DAM) installed on the bicycle stay, in accordance with an embodiment of the current invention;
[0023] FIGS. 4A-C are: a pictorial representation of the DAM of FIG. 3 without the cover, a side view of the DAM without the cover, and a pictorial representation of the mounting of the cable displacement unit (CDU) of FIG. 3 , respectively, in accordance with an embodiment of the current invention;
[0024] FIG. 5 is a pictorial view of the cyclist interface module (CIM) of FIG. 2 installed on the handlebar, in accordance with an embodiment of the current invention;
[0025] FIG. 6 is a pictorial view of the control and power module (CPM) of FIG. 2 installed on the down tube, in accordance with an embodiment of the current invention; and
[0026] FIG. 7 is a flow chart showing the interaction of components of the electro-mechanical actuator system of FIG. 2 , in accordance with an embodiment of the current invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] The current invention relates to gearing and derailleur mechanism of a bicycle. More specifically, embodiments of the present invention are directed to electro mechanical derailleur actuation and methods thereof.
[0028] Reference is currently made to FIG. 2 , which is a schematic side view of part of prior art bicycle 10 shown in FIG. 1 , with an electro-mechanical actuator system 100 installed thereupon, in accordance with an embodiment of the current invention. Apart from differences described below, prior art bicycle 10 is identical in notation, configuration, and functionality to that shown in FIG. 1 , and elements indicated by the same reference numerals and/or letters are generally identical in configuration, operation, and functionality as described hereinabove. Electro-mechanical actuator system 100 includes: a cyclist interface module (CIM) 105 , a control and power module (CPM) 110 , and derailleur actuator modules (DAM) 120 and 122 . Cyclist interface module (CIM) 105 is shown in the figure mounted to handlebars 14 , but may be alternatively or optionally mounted on down tube 20 . Details of the CIM and its functionality are further discussed hereinbelow. Control and power module (CIM) 110 , is typically mounted on down tube 20 and it has insulated power cables (not show in the figure) connecting it to derailleur actuator modules (DAM) 120 and 122 . The DAM's are mounted on down tube 20 and chain stay 22 , respectively, in the vicinity of front and rear derailleurs 34 and 36 , respectively. Respective DAM's are mechanically attached to cables 38 and 39 , as described hereinbelow. Alternatively or optionally, system 100 may employ only one DAM, however a more typical configuration is that of one DAM dedicated to one respective derailleur—yielding two DAM's for most bicycles employing two derailleurs.
[0029] The descriptions hereinbelow discuss one DAM (specifically DAM 122 ), however it is understood that the following description is applicable to two DAM's, mutatis mutandis.
[0030] Reference is currently made to FIG. 3 , which is a pictorial representation of DAM 122 of FIG. 2 installed on down tube 20 of bicycle 10 , in accordance with an embodiment of the current invention. Apart from differences described below, DAM 122 is identical in notation, configuration, and functionality to that shown in FIG. 2 , and elements indicated by the same reference numerals and/or letters are generally identical in configuration, operation, and functionality as described hereinabove. DAM 122 includes: a cable displacement unit (CDU) 124 with a cover 125 in position; and CDU mounting 126 , which is mechanically secured to chain stay 22 . The CDU is mechanically attached to mounting. Details regarding CDU mounting 126 and the CDU follow hereinbelow. As previously noted, DAM 122 is positioned on stay 22 to enable connection of the DAM to cable 39 , as discussed hereinbelow. Although not shown in the figures, some bicycle configurations have cable 39 routed along seat stay 21 (instead of along chain stay 22 as shown in the figures). In such configurations, it would be appropriate to mount DAM 122 onto seat stay 21 , and the following description would be modified, substituting seat stay 21 for chain stay 22 , as appropriate.
[0031] Reference is currently made to FIGS. 4A-C , which are a pictorial representation of DAM 122 of FIG. 3 without cover 125 , a side view of the DAM without CDU cover 125 , and a pictorial representation of CDU mounting 126 of FIG. 3 , respectively, in accordance with an embodiment of the current invention. Apart from differences described below, DAM 122 is identical in notation, configuration, and functionality to that shown in FIG. 3 , and elements indicated by the same reference numerals and/or letters are generally identical in configuration, operation, and functionality as described hereinabove.
[0032] In viewing FIGS. 4A-C , it can be seen that CDU 124 has a housing 130 , which is mechanically attached to the CDU mounting 126 through two vertically-elongated slots 132 in the CDU mounting. Two threaded bolts 136 pass through slots 132 from behind the CDU mounting and connect into holes 138 in the base of housing 130 thereby securing the housing to the mounting. It can be seen that by way of the slots, the housing may be adjusted in an up-and-down direction before being fixed in place. Furthermore, since slots 132 are formed with a dimension somewhat larger than the diameter of bolts 136 , a limited clockwise and/or counter-clockwise direction of adjustment is also afforded, before the housing is fixed in place by tightening the bolts. CDU mounting 126 is mechanically attached to chain stay 22 by two bands 139 . Further details regarding the CDU mounting follow hereinbelow.
[0033] CDU 124 further includes an electric motor 140 , which is attached to a gear box 144 , which drives main gear 146 . Main gear 146 drives pinion 148 , which is mechanically attached to one end of lead screw 150 , as shown. The other end of lead screw 150 is fixed in position, but may rotate freely. Rider 152 rides along lead screw 150 , having a matched threading to that of the lead screw, as known in the art. As such, rider 152 moves from right to left and back, in response to motor 140 and resultant pinion 148 rotations. Rider 152 is formed to have an extended narrower surface 153 . A clamp surface 154 , which opposes narrower surface 153 , has a screw 156 , which passes through the clamp surface and is accepted into a threaded hole (not seen in the figure) in narrower surface 153 . When cable 39 is positioned between clamp surface 154 and narrower surface 153 and when screw 156 is tightened, the two surfaces are biased together against the cable, serving to mechanically fix the rider to cable 39 . In an embodiment of the current invention, screw 156 takes the form of a quick release screw, as know in the art, allowing the cable to be easily fixed and released, as necessary, without tools. It can be seen in FIG. 4A that extended narrower surface 153 passes through an elongated slot 158 in the upper surface of housing 130 , the slot allowing the rider to move left and right, thereby displacing mechanically fixed cable 39 left and right.
[0034] Returning to housing 130 , it can further be seen that rotary encoder 160 is attached to an axis common to main gear 146 . Alternatively or optionally, rotary encoder may be positioned on the axis common to the main gear on the reverse side (not shown in the figure) of motor 140 . Rotary encoder 160 and encoder sensor may include technologies known in the art, such as, but not limited to: optical, IR, and magnetic. Rotary encoder 160 is read by encoder sensor 166 , as known in the art. Sensor information is fed back to the control and power module (CPM) 110 noted hereinabove in FIG. 2 (and which is further described hereinbelow) to provide feedback and control of the motor rotation and resultant rider and clamp displacement of cable 39 . Cable harness 170 provides wiring (not shown in the figure) to the CDU from the CPM, the wiring which provides power and command and control signals to the motor. Cover 125 is held in position on housing 130 by threaded holes 172 in the housing, as known in the art.
[0035] Referring to FIG. 4C , CDU mounting 126 includes an L-shaped support bracket 200 , in which slots 132 are formed (as described hereinabove) and in which two elongated slots 212 are formed in the shorter leg of the L-shape. A back plate 210 is secured to the support bracket by two threaded bolts 214 . Back plate 210 is formed to have a shape generally matching that of stay 22 to allow a relatively snug fit of the back plate to stay 22 when bands 139 are tightened by tightening screws 220 . It can be seen that elongated slots 212 , allow support bracket 200 to be adjusted in the direction towards and away from stay 22 before the bracket is fixed in place. Furthermore, since slots 212 are formed with a dimension somewhat larger than the diameter of bolts 214 , a limited clockwise and/or counter-clockwise direction of adjustment is also afforded, before the bracket is fixed in place by tightening the bolts. Bands 139 may be completely released, to remove the mounting or to aid in retrofit (as described hereinbelow) by loosening tightening screws 220 .
[0036] Attaching DAM 122 to Bicycle 10 —Retrofit Procedure
[0037] An embodiment of the current invention employs the following retrofit procedure to attach DAM 122 to stay 22 , referring initially to FIG. 4C , followed by FIGS. 4A and 4B . It is again noted that while the following description refers to DAM 122 and to stay 22 , it is can be understood that the following description is likewise applicable to DAM 120 , stay 20 , and cable 38 , mutatis mutandis, as well as to attaching DAM 122 to seat stay 21 .
1. Detach CDU mounting 126 completely from CDU 124 (ie. two threaded bolts 136 are loosened). 2. Loosen tightening screws 220 to release bands 139 . 3. Position the CDU mounting behind stay 22 as shown in the figure and route bands 139 around the stay and between the stay and cable 39 , reattaching the bands into back plate 210 . (In this way, the bands will circumvent only the stay and not the stay along with the cable—which is incorrect.) 4. Tighten screws 220 to tighten the bands and ensure a snug fit of back plate 210 onto stay 22 . 5. On CDU 124 , loosen screw 156 to allow a space between clamp surface 154 and narrower surface 152 . 6. Attach CDU 124 to CDU mounting 126 using two threaded bolts 136 . Partially tighten threaded bolts 136 and 214 to allow CDU 124 to be adjusted, as below. 7. Position cable 39 in the space between clamp surface 154 and narrower surface 152 . When the cable is in position, tighten screw 156 to fix cable 39 tightly between the two surfaces. 8. Adjust CDU 124 orientation to allow the clamp and narrower surfaces to move as collinearly as possible with cable 39 . This can be done by moving the CDU with regard to the CDU mounting, taking advantage of slots 132 and 212 (and their associated threaded bolts, 136 and 214 ). Slots 132 allow the CDU to be moved substantially perpendicular to the cable, up and down and/or rotated somewhat in the plane substantially parallel to wheels 24 and 26 . Slots 212 allow the CDU to be moved substantially perpendicular to the cable and parallel to the rear wheel axis, and/or rotated somewhat in the plane substantially parallel to the ground.
After rechecking the movement of clamp and narrower surfaces 154 and 152 and cable 39 movement when the motor 140 is commanded to move the cable back and forth, make sure threaded bolts, 136 and 214 are tightened, thereby locking the position/orientation of the CDU in place.
[0047] If it is desired to remove DAM 122 from bicycle 10 , follow the above steps in reverse.
[0048] Reference is currently made to FIG. 5 , which is a pictorial view of cyclist interface module (CIM) 130 installed on handlebar 14 , in accordance with an embodiment of the current invention. Apart from differences described below, CIM 130 is identical in notation, configuration, and functionality to that shown in FIG. 2 , and elements indicated by the same reference numerals and/or letters are generally identical in configuration, operation, and functionality as described hereinabove. Essentially, CIM 130 provides user interface with system 100 . Elements of CIM 130 include: a connecting band 230 ; down and up control buttons 232 and 234 , respectively; front and rear derailleur rocker selector switch 236 ; a power button 238 ; an operation indicator 240 ; and a communications and power module (not shown in the figure) to provide on board power and to enable communications to and from the CIM, as described hereinbelow. Connecting band 230 connects the CIM to the handlebars and may have a configuration similar to that shown hereinabove for bands 139 in FIGS. 4A-C . Down and up control buttons 232 and 234 , respectively, are used to command the system to shift a gear up or down. If the respective control button is pushed twice in succession (ie “down”, “down”), the command is to shift two gears down, etc. Front and rear derailleur rocker selector switch 236 is used to indicate to the system on which derailleur (ie front or rear) to shift gears.
[0049] Power button 238 is used to activate and deactivate the system. When the system is deactivated, to use the bicycle in conventional, prior art gear shifting mode, clamp 154 is released (refer to FIGS. 4A-C ) which releases cable 39 , thereby allowing the conventional operation of the cable and the derailleur. Pressing the power button to activate the system and reattaching clamp 154 to cable 39 allows system operation of gear shifting, as described hereinabove.
[0050] An operation indicator 240 provides visual and/or audible feedback to indicate system operation. The CIM has on-board capability to transfer commands and receive feedback (ie “telemetry”) from control and power module (CPM) 110 . A preferred mode of transferring commands and receiving feedback to/from CIM 130 is by wireless means, although wired means (not shown in the figure) may optionally or alternatively be employed. Additional description of CIM 130 and system operation follows hereinbelow.
[0051] Reference is currently made to FIG. 6 , which is a pictorial view of CPM 110 of FIG. 2 , installed on down tube 20 , in accordance with an embodiment of the current invention. Apart from differences described below, CPM 110 is identical in notation, configuration, and functionality to that shown in FIG. 2 , and elements indicated by the same reference numerals and/or letters are generally identical in configuration, operation, and functionality as described hereinabove. While the following description refers to CPM 110 and to down tube 20 , it is can be understood that the following description is likewise applicable to the CPM being installed on seat tube 18 and cross bar 16 , mutatis mutandis. CPM 110 includes: connecting bands 305 ; a control and power module 310 ; and a control and power harness 320 . Connecting bands 305 connect the CPM to down tube 20 and may have a configuration similar to that shown hereinabove for bands 139 in FIGS. 4A-C . Control and power module 310 includes communications and control electronics to allow CPM 110 to communicate with CIM 130 and with DAM's 120 , 122 (as installed in the system) as further described hereinbelow, and a power source (not shown in the figure) to provide power for the CPM and the DAM's. The power source may be batteries, as known in the art. Control and power harness 320 connects with DAM's 120 , 122 to provide both power and communications with the DAM's. Alternatively or optionally, communications with the DAM's may be by wireless means. Additional description of CPM 110 and how it interacts with components of system 100 and system operation follow hereinbelow.
[0052] Reference is currently made to FIG. 7 , which is a flow chart showing the interaction of components of electro-mechanical actuator system 100 of FIG. 2 , in accordance with an embodiment of the current invention. Apart from differences described below, system 100 is identical in notation, configuration, and functionality to that shown in FIG. 2 , and elements indicated by the same reference numerals and/or letters are generally identical in configuration, operation, and functionality as described hereinabove.
[0053] CIM commands 410 include: wake up from standby/sleep 430 and; change gear command 440 . In step 430 , when any of the buttons or switches of the CIM are touched by the cyclist the system “wakes up”, meaning it terminates a standby power-conserving mode (described hereinbelow) and begins to operate in a normal power mode. In step 440 , a forward/rear derailleur is chosen and the command of shifting up or down is entered. One or more commands to shift may be entered.
[0054] Control is currently transferred to the CPM and the DAM. CPM and DAM processing 445 includes: CPM registers new gear command 450 ; CPM commands DAM to shift one gear and decrement 460 ; check if the number of gear shifts is complete 470 ; and go to standby/sleep mode. Once one or more gear change commands have been given from the CIM in step 440 , the CPM erases previous gear commands and registers the near gear command/commands in step 450 . An exemplary gear command could be: front derailleur, shift up, twice (the “up” bottom of the CIM was pushed twice). A counter is initiated with the total number of gear shifts. In the specific example used herein, the counter initial value would be 2.
[0055] In step 460 , the CPM then commands the DAM to shift one gear. The DAM proceeds to perform one gear shift. Shifting of a gear is verified by the DAM by sensors in the CDU (sensing cable tension and/or CDU motor/encoder status) and alternatively or optionally by sensors which may be located on a respective derailleur to feed back gear status. Gear shift status is transferred to the CPM from the DAM. The CPM then decrements the gear shift counter by one, in step 460 .
[0056] In step 470 , the counter is checked to see if its value is not zero. A non-zero value indicates that not all of the gear shifts are complete and control is shifted to step 460 , for another gear shift. If the counter value is presently zero, indicative of completion of gear shifts, control is passed to step 480 . In step 480 , a timer is started and the system is then set to a power savings standby/sleep mode after a predetermined time without subsequent commands and control is returned back to step 430 , for the next cycle of gear shift commands from the CIM. The predetermined time may typically be 10 seconds, but a longer or shorter time interval may be programmed into the system.
[0057] It will be appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the scope of the present invention as defined in the appended claims. | An electro mechanical bicycle derailleur actuator system, retrofittable to a bicycle having gearing and at least one derailleur, the derailleur having a cable, the system comprising: at least one derailleur actuator module (DAM) connectable to the bicycle and to the cable; a cyclist interface module (CIM) connectable to the bicycle for cyclist interface with the system; and a control and power module (CPM) connectable to the bicycle serving to control and power the system, wherein the bicycle gearing is shiftable by the system without derailleur cable modification. | 8 |
RELATED APPLICATION
[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2010-0090614 filed in the Korean Intellectual Property Office on Sep. 15, 2010, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] The described technology generally relates to a laser irradiation apparatus and a sealing method of an organic light emitting display element using the same.
[0004] 2. Description of the Related Technology
[0005] In general, an organic light emitting display element is most widely used among organic semiconductor elements, and has a relatively simple structure. The organic display element is self-emissive unlike a liquid crystal display (LCD), and thus it does not require an additional back light so that an organic light emitting diode (OLED) display has advantages of a slim thickness and a reduced weight. Thus, recently, the OLED display has been actively developed as a display panel of portable data terminals such as mobile computers, portable cellular phones, portable game devices, electronic books.
SUMMARY
[0006] One aspect is a laser irradiation apparatus that can shorten a sealing process time of the organic light emitting display element and a sealing method of the organic display element using the same.
[0007] Another aspect is a laser irradiation apparatus that can easily correspond to variation of a cell size of an organic light emitting display element by arranging output heads of the laser irradiation apparatus in a zigzag form, and a sealing method of the organic display element using the same.
[0008] Another aspect is a laser irradiation apparatus which includes: an X-axis location control board configured to move a plurality of drivers in an X-axis direction; a plurality of output heads cooperatively arranged with the drivers and configured to move with movement of the drivers, wherein the output heads are configured to receive laser beams; and a Z-axis location control board cooperatively arranged with the X-axis location control board and configured to move the X-axis location control board in an Z-axis direction. The output heads alternatively protrude with different lengths along an Y-axis direction.
[0009] The output heads are arranged in a zigzag form in the X-axis location control board along the Y-axis direction.
[0010] The drivers and the output heads may be respectively connected with each other by brackets, and the brackets may protrude toward the Y-axis direction with different lengths for each alternation corresponding to the plurality of output heads.
[0011] The brackets and the drivers may be fixed by a holder assembly. The holder assembly may include a first holder connected to the bracket and a second holder combined to the first holder and fixing the output heads.
[0012] The first holder may be mounted in the shape of a plate extended along the Z-axis direction, and one side thereof may be connected with the bracket and the second holder may be mounted on the other side.
[0013] The second holder may protrude to the first holder and a penetration hole may be formed in the second holder for insertion fixing of the output heads.
[0014] Another aspect is a sealing method of an organic light emitting diode (OLED) display which includes: (a) providing a first substrate including a pixel area where an organic electric field light emitting element is formed and a non-pixel area; (b) providing a second substrate attached on one area including the pixel area of the first substrate; (c) forming frits arranged in a plurality of rows and columns along the periphery area of the second substrate corresponding to the non-pixel area of the first substrate; (d) forming a sealant in the second substrate of an external side of the frit; (e) attaching the first and second substrates to each other and hardening the sealant; (e) attaching the first and second substrates to each other and hardening the sealant; (g) applying the laser beam to the next row of the frit by changing a direction to a vertical direction of the frit when laser beam irradiation to the row direction of the frit in step of (f) is terminated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a diagram of a laser irradiation apparatus according to an embodiment.
[0016] FIG. 2 schematically shows an output head portion of FIG. 1 in the mounted state.
[0017] FIG. 3 shows a protruded state of the output head portion of FIG. 1 to a length direction of a bracket.
[0018] FIG. 4 is a flowchart of a sealing method of an organic light emitting diode (OLED) display according to an embodiment.
[0019] FIG. 5 shows a laser beam irradiation to organic light emitting display elements arranged in a plurality of rows and a plurality of columns.
DETAILED DESCRIPTION
[0020] When moisture or oxygen is introduced into an organic light emitting element, the life span of the element is reduced due to oxidation or exfoliation of an electrode material, light efficiency is deteriorated, and color fidelity degrades.
[0021] Therefore, a sealing treatment is typically performed to isolate an element and prevent moisture from being introduced in the organic light emitting display element in the manufacturing process. For sealing treatment of the display element, a sealing method that coats a frit on a glass substrate is used.
[0022] When the display element is sealed using the frit, the frit is coated on a sealing portion of each of the organic display elements, a laser beam is irradiated to the sealing portion of the element using an output head of a laser irradiation apparatus, and then the frit is hardened.
[0023] Here, when the cell size of the display element is increased, output heads of the laser irradiation apparatus should maintain a large gap therebetween corresponding to the cell size.
[0024] However, the output heads of the laser irradiation apparatus are arranged in one line and thus interference may be generated when the gap between the output heads is increased more than a predetermined distance, and therefore it is difficult to increase the gap between the output heads greater than a predetermined distance. Accordingly, when the cell size of the organic light emitting display element becomes greater than a predetermined size, the hardening of the frit using the laser irradiation apparatus cannot be smoothly performed.
[0025] Hereinafter, embodiments will be described with reference to the accompanied drawings. As those skilled in the art would realize, the described embodiments may be modified in various different ways.
[0026] In addition, the size and thickness of each component shown in the drawings may be arbitrarily shown for understanding and ease of description. In the drawings, the thickness of layers, films, panels, regions, etc. may be exaggerated for clarity.
[0027] FIG. 1 schematically shows a laser irradiation apparatus according to an embodiment.
[0028] Hereinafter, the present embodiment is applied to a sealing process of an organic light emitting diode (OLED) display, but it may be applied to other display devices that use sealing of a plurality of glass plates.
[0029] As shown in FIG. 1 , a plurality of organic light emitting display elements 17 are disposed on a first substrate 11 and a second substrate 13 . In addition, a sealing member 15 seals the first and second substrates 11 and 13 to prevent foreign particles from being introduced into the display elements 17 . In one embodiment, the sealing member 15 is doped with one or more transition metal and thus an absorption characteristic with respect to a specific wavelength is enforced so that it can be easily softened. In the present embodiment, the sealing member 15 may be formed with a frit. Hereinafter, the sealing member and the frit use the same reference numeral 15 .
[0030] A plurality of output heads 30 are disposed on the substrates 11 and 13 to irradiate laser beams to the sealing member 15 such that the first substrate 11 and the second substrate 13 are sealed. Hereinafter, a configuration of the laser irradiation apparatus 100 according to the embodiment will be described in further detail.
[0031] As shown in FIG. 1 , the laser irradiation apparatus 100 includes an X-axis location control board 20 on which a plurality of driving units 10 are slidably mounted, the output heads 30 coupled to the driving units 10 and slid with movement of the driving units 10 and to which laser beams are irradiated, and a Z-axis location control board 21 coupled with the X-axis location control board 20 and moving the X-axis location control board 20 to the Z-axis direction.
[0032] The X-axis location control board 20 is formed extending along the X-axis direction, and enables the driver 10 to move a length direction thereof. In addition, the Z-axis location control board 21 is coupled to the X-axis location control board 20 using a ball screw. The Z-axis location control board 21 controls a location of the X-axis location control board 20 , and the plurality of output heads 30 are substantially simultaneously focused such that laser beams with substantially uniform density can be irradiated.
[0033] FIG. 2 shows the output heads of FIG. 1 in the mounted state.
[0034] As shown in FIG. 2 , the output head 30 receives an output for irradiation of a laser beam 31 a through a laser oscillation unit 31 and irradiates the laser beam 31 a.
[0035] Hereinafter, irradiation of the laser beam 31 a through the output head 30 will be described in further detail.
[0036] The laser beam 31 a is irradiated from the laser oscillation unit 31 .
[0037] In addition, the irradiated laser beam 31 a is incident on flexible channels 33 . The flexible channels 33 refer to beam path members, and the laser beam 31 a is input to one end and output operation is performed through the other end. In one embodiment, the laser beam 31 a is passed through a plurality of lenses (not shown) before being incident on the flexible channels 33 to make the laser beam 31 a enter to the flexible channel 33 by substantially uniforming the density of the laser beam 31 a . The laser beam 31 a output from the flexible channel 33 is finally irradiated in the output head 30 .
[0038] The output head 30 irradiates the laser beam 31 a to a region to which the substrates 11 and 13 of the OLED display are to be sealed. A condenser lens 35 is mounted on the output head 30 so that the laser beam 31 a output from the flexible channels 33 can be substantially uniformly condensed. For this, the condenser lens 35 may include a convex lens. The output heads 30 can be movably mounted on the X-axis location control board 20 .
[0039] Combination of the output head 30 and the X-axis location control board 20 will now be described in further detail.
[0040] In one embodiment, the driver 10 is sildably mounted on the X-axis location control board 20 by motor driving. In one embodiment, the driver 10 is mounted as a linear motor for movement on the X-axis location control board 20 without vibration. The driver 10 can be individually driven for distance control between the output heads 30 . In addition, a holder assembly 50 is connected to the driver 10 using brackets 40 and 40 a.
[0041] FIG. 3 shows the output head of FIG. 1 in the protruding state along a length change of the bracket.
[0042] As shown in FIG. 2 and FIG. 3 , the holder assembly 50 includes a first holder 51 connected with the brackets 40 and 40 a and a second holder 53 coupled to the first holder 51 and fixing the output head 30 . The first holder 51 is directly connected to the brackets 40 and 40 a forms a plate shape. The second holder 53 is mounted on the first holder 51 and fixes the output head 30 . In one embodiment, the second holder 53 includes a penetration hole (not shown) and the condenser lens 35 is inserted to the penetration hole such that the output head 30 can be fixed.
[0043] Protruded lengths of the holder assemblies 50 in the respective drivers 10 may be different from each other through the length adjustment of the brackets 40 and 40 a . In one embodiment, as shown in FIG. 1 , the length of an even-numbered bracket 40 a among the brackets 40 and 40 a is longer by a predetermined length than that of an odd-numbered bracket 40 . In this embodiment, an even-numbered output head 30 protrudes further to the Y-axis direction than an odd-numbered output head 30 among the output heads 30 . In one embodiment, as shown in FIG. 1 , the output heads 30 are disposed in a substantially zigzag form. As the output heads 30 are arranged in the zigzag form, the distance between the output heads 30 may be freely set. That is, when the output heads 30 are disposed in one line as in a typical alignment, interference is generated between adjacent output heads 30 so that a gap greater than a predetermined distance cannot be maintained therebetween. However, as in the present embodiment, the distance between the output heads 30 can be easily controlled when the output heads 30 are arranged in substantially the zigzag form. Thus, the distance between the output heads 30 can be controlled substantially corresponding to the size of a cell in the organic light emitting display element so that the sealing time of the substrates 11 and 13 can be shortened, thereby shortening a manufacturing time of the OLED display.
[0044] FIG. 4 is a flowchart of a sealing method of an organic light emitting diode (OLED) display according to an embodiment, and FIG. 5 schematically shows irradiation of a laser beam to organic light emitting display elements arranged in a plurality of rows and a plurality of columns.
[0045] Referring to FIG. 4 and FIG. 5 , a sealing method of the OLED display will now be described in further detail.
[0046] First, a first substrate 11 including a pixel area where an organic light emitting element 17 is formed and a non-pixel area is provided (S 10 ). The pixel area is a portion where a display screen is displayed, and the non-pixel area is all the portions excluding the pixel area.
[0047] Next, a second substrate 13 attached on an area including the pixel area is provided (S 20 ). Here, the first substrate 11 is a lower substrate and the second substrate 13 is an upper substrate.
[0048] Frits 15 arranged in a plurality of rows and columns are formed along a periphery area of the second substrate 13 substantially corresponding to the non-pixel area of the first substrate 11 (S 30 ). The frits 15 prevent foreign particles from being introduced into the organic light emitting display element 17 .
[0049] A sealant is formed in the second substrate 13 at an external side of the frit 15 (S 40 ).
[0050] Next, the first substrate 11 and the second substrate 13 are attached to each other and the sealant is hardened (S 50 ).
[0051] Subsequently, a plurality of output heads 30 of a laser irradiation apparatus 100 are arranged in a substantially zigzag direction corresponding to the frits 15 in step of S 30 , and a laser beam is irradiated to the row direction of the frit 15 (S 60 ).
[0052] Step S 60 will be described in further detail with reference to FIG. 5 . In FIG. 5 , organic light emitting display elements 17 are arranged in a plurality of rows and a plurality of columns in the substrates 11 and 13 .
[0053] First, the output heads 30 of the laser irradiation apparatus 100 , arranged in the substantially zigzag shape are placed corresponding to the organic light emitting display elements of FIG. 5 , arranged in the rows and columns.
[0054] The output heads 30 of the laser irradiation apparatus 100 move along the row direction and irradiate laser beams to the frits of the organic light emitting display elements. Here, since the output heads 30 are arranged in the substantially zigzag direction according to the present embodiment, locations of the output heads 30 can be smoothly controlled without generating interference between the output heads 30 when controlling distances between the output heads 30 corresponding to the size of the organic light emitting display element.
[0055] When the irradiation of the laser beam to the row direction of the frit 15 is terminated (S 60 ), the laser beam is irradiated to the next row of the frit 15 by changing the irradiation direction to a substantially vertical direction of the frit 15 (S 70 ). Accordingly, a laser beam 31 a can be irradiated to the frit 15 without an influence depending on the size of a cell of the organic light emitting display element so that a manufacturing time of the OLED display can be shortened. In the above-stated embodiments, the output heads 30 can move and irradiate the laser beam to the frits 15 while the substrates 11 and 13 are fixed, and the substrates 11 and 13 can move and the laser beam 31 a can be irradiated to the frits 15 while the output heads 30 are fixed. When the substrates 11 and 13 are moving, a stage (not shown) for the movement may be mounted on a lower portion of the substrates 11 and 13 .
[0056] According to at least one of the disclosed embodiments, the output heads of the laser irradiation apparatus are arranged in a substantially zigzag form so that the gap between the output heads can be controlled without an interference of the output heads, and accordingly hardening of the frit can be smoothly performed corresponding to a cell size of the organic light emitting display element.
[0057] Embodiments have been described with reference to the accompanied drawings. It is to be understood that the disclosed embodiments are not considered limiting, and are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A laser irradiation apparatus is disclosed. In one embodiment, the apparatus includes i) an X-axis location control board configured to move a plurality of drivers in an X-axis direction and ii) a plurality of output heads cooperatively arranged with the drivers and configured to move with movement of the drivers, wherein the output heads are configured to receive laser beams. The apparatus may further include a Z-axis location control board cooperatively arranged with the X-axis location control board and configured to move the X-axis location control board in an Z-axis direction, wherein the output heads alternatively protrude with different lengths along an Y-axis direction. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a portable mailbox cover and more particularly to a portable mailbox cover featuring a three dimensional object, preferably an object representing a sport or a particular collegiate or professional athletic team, for adding aesthetic appeal to a mailbox while providing support for the particular sporting event or team.
2. Description of the Prior Art
One of the major problems with mailboxes is that they are permanently installed and often lack an attractive appearance. For example, U.S. Pat. No. 5,435,484 features a mailbox formed by an upright hollow housing closed by a top door and having a trap door intermediate with its height separating the hollow housing into an upper compartment and a lower compartment. This mailbox has the appearance of a large square trashcan with a top lid and an intermediate trap door.
U.S. Pat. No. 5,351,883 comprises a mail access section large enough to receive and support letters and packages. A mail containment section supports the access section above the ground and receives the mail as it is inserted through the access section. This mailbox has a standard everyday mailbox appearance and would not be an enhancement to the neighborhood.
The present invention features not only portability but also a very attractive appearance and an enhancement for every neighborhood. For these reasons it is seen that the previous efforts do not provide the benefits intended with the present invention. Additionally, prior techniques do not suggest the present inventive combination of component elements as disclosed and claimed herein. The present invention achieves its intended purposes, objectives and advantages over the prior art through a new, useful, and unobvious combination of component elements, which is simple to use, with the utilization of a minimum number of functioning parts, at a reasonable cost to manufacture, assemble, test and by employing only readily available material.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be constructed to be merely illustrative of some of the more prominent features and application of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different or modifying the invention within the scope of the disclosure. Accordingly, a fuller understanding of the invention may be had by referring to the detailed description of the preferred embodiments in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
The present invention is a mailbox cover featuring a three-dimensional object or structure secured thereto. The use of three-dimension object being secured to a mailbox will provide for an overall product that adds to the aesthetic appeal of an ordinary product.
In the first embodiment of the present invention, the cover comprises a three-dimensional object or structure having an attaching device secured thereto. This will provide for the object to be secured to a conventional mailbox via the attaching device.
For a more permanent attachment to the conventional mailbox, bolts or the like can be used as the attaching device. In this arrangement, holes are tapped into the existing mailbox; the bolts are inserted therein and secured interiorly to the mailbox by-way of nuts, wing nuts or the like.
To provide for a portable unit, a strap can be used as an attaching device. In this arrangement, a strap would be located on one side of the three dimensional object or structure, while a securing unit for accepting the strap is located on the opposite side of the three dimensional object. This will provide for the strap to wrap under the conventional mailbox and enable the three dimensional object to be secured thereto. The use of the strap provides an adjustable system, which enables the mailbox cover to be installed over an existing regular mailbox, quickly and easily. It is noted that the use of zip ties has utilized to produce favorably results.
In an alternative arrangement, a base can be provided. This base will include two separate types of attaching devices. The first attaching device will be adapted to removably receive the three dimensional object, while the second attaching device will be allow attachment of the base to the conventional mailbox. Such an arrangement provides for a unit that provides interchangeable objects, and thus permits for the user to change to any desired object, such as enabling a snowman for winter, a pumpkin for the fall, the American flag for the summer, and a football helmet of a particular team during homecoming.
This ornamental structure is designed and depicted so as to add interest and versatility to the overall product. Accordingly, this ornamental structure can represent any sporting event, such as, but not limited to collegiate, professional, or amateur football; collegiate, professional, or amateur basketball; collegiate, professional, or amateur baseball; collegiate, professional, or amateur hockey; collegiate, professional, or amateur soccer; collegiate, professional, or amateur auto racing; collegiate, professional, or amateur wrestling; collegiate, professional, or amateur golfing; animals; famous and well known figurines, characters, animated objects; seasonal items, or the like. By way of example, if the mailbox owner is a football fan, the top portion of the container could be shaped as a football or optionally as a helmet, sporting the name and logo of the owner's favorite team on the sidewall. This unique arrangement is unlimited in design structure by enabling any desirable structure to be secured to the conventional mailbox.
Accordingly, it is an object of the present invention to provide for a mailbox cover which will overcome the deficiencies, shortcomings and drawbacks of prior mailbox covers and methods thereof.
Another object of the present invention is to provide the user the opportunity to publicly support his sporting interest, personal interest, and seasonal display opportunities.
Still another object of the present invention is to enhance the appearance of the neighborhood due to the pleasant and eye-catching appearance of the portable mailbox cover.
Yet another object of the instant invention is to provide for portability and interchangeability of various mailbox covers.
Although there have been other inventions related to mailbox covers, none of the inventions have become sufficiently compact, low cost, and reliable enough to become commonly used. The present invention meets the requirements of the simplified design, compact size, low initial cost, low operating cost, ease of installation and maintainability, and minimal amount of training to successfully employ the invention.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and application of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, a fuller understanding of the invention may be had by referring to the detailed description of the preferred embodiments in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side planar view of the mailbox cover device of the present invention, illustrating a sporting theme for the three-dimensional object and being secured via a first attaching device.
FIG. 2 is a front planar view of the mailbox cover device of the present invention, illustrating a sporting theme for the three dimensional object and being secured via a second attaching device for producing a portable attaching device.
FIG. 3 a is a side planar view of the mailbox cover device of the present invention, illustrating an alternative three-dimensional objected secured thereto.
FIG. 3 b is a front planar view of the mailbox cover device of the present invention, illustrating the front portion of the three-dimensional object secured to the lid of the present invention.
FIG. 3 c is a cross-sectional view of first portion of the mailbox cover device secured to the lid of a conventional mailbox.
FIG. 4 is an exploded view of the second embodiment of the present invention, illustrating a base used to removably receive a three dimensional object.
FIG. 5 is a front view of an alternative construction of the base used in the second embodiment of the present invention.
Similar reference numerals refer to similar parts throughout the several views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention, shown in FIG. 1 -FIG. 4, is a mailbox cover apparatus, generally denoted by reference numeral 10 and is designed and configured to be used and secured to conventional mailboxes. By conventional mailboxes, it is to be understood that these are standard, U.S. Postal Service approved mailboxes.
The object of the present invention is to enable the mailbox to function in its intended and normal state, as well as provide for a product that is aesthetically pleasing. Ultimately providing for a device which is not obtrusive when placing items in or out of the conventional mailbox.
As seen in the FIG. 1 and FIG. 3 a the apparatus of the present invention 10 comprises an ornamental three-dimensional object 12 that will be secured to a conventional mailbox M. The three dimensional object 12 includes two portions. The two portions comprises a front or first portion 14 which is to be secured to the lid of the mailbox and a rear or second portion 16 , which is to be secured to the housing portion of the conventional mailbox. This will provide for the ornamental object to appear to be continuous and non-disruptive.
The front portion 14 and rear portion 16 , combined, will give the appearance of a singular three-dimensional object or structure. The front portion 14 will be secured to the lid and thus will have a handle 18 for enabling access to the interior of the mailbox. The handle 18 can be an integral component of the object, as seen in FIG. 1 or can be a separate member of the object as seen in FIG. 3 a.
In FIG. 1, the mask will act as the handle, and when a user pulls down on the mask (handle), the lid L of the conventional mailbox will be lowered, thus rendering access therein. A handle can be added as seen in FIG. 3 a , and thus protrudes out from the front of the three dimensional object.
The unique nature of the present invention enables any type or style object to be used. As seen in FIG. 1, since the object is three dimensional, the front portion may protrude outwardly. To accommodate this protrusion, at least one support rod 20 (illustrated in outlined) is used to secure the front portion 14 of the object to the lid. This support rod 20 is secured to the front portion of the object and is secured to the lid L of the conventional mailbox via conventional attaching means 22 , such as the use of a bolt and nut, or the like. Other conventional securing devices, such as adhesives, or the like, can be used. For added security, other areas contacting the outer surface of the lid can be secured to the lid via conventional devices as discussed above.
As seen in FIGS. 3 b and 3 c the front portion is a more substantial unit, and it includes two support rods 20 that are used for supporting the overall structure of the front portion of the object, as well as enable the front portion 14 to be secured to the lid L of the mailbox. This particular first portion is solid and can include additional attaching devices 22 for allowing attachment to occur successfully. The attaching devices 22 can be any conventional attaching devices as discussed above.
Since the use of the object may add additional weight to the lid, closure units can be used to ensure closure of the lid of the mailbox when desired. As seen in FIGS. 1 and 2, hooks 21 are attached to the second portion 16 of the object. The first portion is received within these hooks, thus allowing for the lid to be snapped into a closed and locked position when desired, yet permit easy access to the interior by merely gently pulling on the handle 18 . Other conventional closures can be used and can be secured interioraly within the interior section of the conventional mailbox.
The second portion of the object 12 is hollow and thus will engulf and receive the top and side surfaces of the conventional mailbox, as seen in FIGS. 1, 2 and 3 a . This hollow portion can include a conventional flag 24 , as shown in FIG. 1, for indication mail is located therein. The flag is pivotally secured to the second portion and stops 26 can be used to prevent the flag from extending too far during pivotal rotation.
This hollow second portion can include supports, though not illustrated, for added structural stability to the overall construction of the three dimensional object 12 . Also included on this second portion is a second attaching device used for attaching the second portion to the conventional mailbox.
The attaching device can be any conventional attaching device. Preferably, and what has proven successful, is the used of nuts and bolts, or the like, for attaching the second portion to the conventional mailbox M. This arrangement is more permanent and is shown in FIGS. 1 and 3 a . As seen in this figure the second attaching devices 28 provides for a more permanent attachment. In order to accomplish this type of attachment, holes are tapped through the existing mailbox. The holes can be either located on the top and/or side(s) of the mailbox. Holes will be provided within the second portion.
Once the holes are located through the mailbox M, the holes are aligned with the holes from the second portion 12 . Once aligned, the securing device (such as a bolt) is inserted therein and secured via a nut, wing nut or the like.
Another example of attaching the second portion to the existing mailbox is the use of straps. This method will prevent the mailbox owner from tapping holes, and thus provides for a more convenient means of attachment, as well as a portable means of attachment. This type of attachment is illustrated in FIG. 2 . As seen in this figure, a strap 28 would be located on one side of the three dimensional object or structure, while a securing unit 30 for accepting the strap is located on the opposite side of the three dimensional object. This will provide for the strap to wrap under the conventional mailbox and enable the three dimensional object to be secured thereto. The use of the strap provides an adjustable system, which enables the mailbox cover to be installed over an existing regular mailbox, quickly and easily. It is noted that the use of conventional zip ties has been utilized to produce favorably results. In the case of zip ties, at least two were coupled together for providing the adequate amount of length for strapping and securing the second portion 16 to the conventional mailbox.
Alternatively, the objects 12 can be designed and configured to be interchangeable. In this configuration the use can change the object whenever desired and thus provide for a plurality of covers to be utilized. For the interchangeable configuration, a base 32 , as seen in FIG. 4, is used. This base 32 has substantially the same cross-sectional shape as a conventional mailbox, and thus will provide for a snug fit when secured thereto. This base is fabricated from a durable, yet flexible material, such as, but not limited to, metal, plastic or the like.
Removably secured to the base 32 is the second portion 16 of the object 12 . To allow for removable securement, the base includes a conventional securing device 34 externally located. A corresponding securing device 36 is secured interiorly in the second portion. This will provide for the second portion to be secured to the base via the securing device. The securing device can be any conventional securing device, such as, but not limited to snaps, VELCRO, bolts, threaded members, or the like.
The base can be altered to provide for a more secure fit on the conventional mailbox. This alteration is shown in FIG. 5 . As seen, the base includes an upper portion 38 and a lower portion 40 . The upper portion is substantially the same as disclosed in FIG. 4 . The lower portion extends slightly inward and when attached to a conventional mailbox will be located under the base of the mailbox. This arrangement will prevent the base from dislodging from the conventional mailbox.
Additional features can be added to the base illustrated in FIG. 4 or 5 , such as a support 42 or an additional attaching device 44 , such as a strap. These features will add structural stability to the cover when secured to a conventional mailbox.
This ornamental structure is designed and depicted so as to add interest and versatility to the overall product. Accordingly, this ornamental structure can represent any sporting event, such as, but not limited to collegiate, professional, or amateur football; collegiate, professional, or amateur basketball; collegiate, professional, or amateur baseball; collegiate, professional, or amateur hockey; collegiate, professional, or amateur soccer; collegiate, professional, or amateur auto racing; collegiate, professional, or amateur wrestling; collegiate, professional, or amateur golfing; animals; famous and well known figurines, characters, animated objects; seasonal items, or the like. By way of example, if the mailbox owner is a football fan, the top portion of the container could be shaped as a football or optionally as a helmet, sporting the name and logo of the owner's favorite team on the sidewall. This unique arrangement is unlimited in design structure by enabling any desirable structure to be secured to the conventional mailbox.
While the invention has been particularly shown and described with reference to an embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention. | A mailbox cover featuring a three-dimensional object or structure secured thereto is disclosed. The use of three-dimension object being secured to a mailbox will provide for an overall product that adds to the aesthetic appeal of an ordinary product. The object includes a front portion that is secured to the lid of a mailbox and a rear portion that is secured to the back of a mailbox. Each portion is secured via a conventional attaching device. Alternatively, a base can be used to secure the second portion to the mailbox. This will provide for the secure portion to be removably secured to the base and thus enable interchangeable objects to be placed on the base and ultimately on the mailbox. | 0 |
REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of pending International Patent Application PCT/KR2009/007617 filed on Dec. 19, 2009, which designates the United States and claims priority of Korean Patent Application No. 10-2009-0004247 filed on Jan. 19, 2009, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an intrusion sensor net used for an unmanned outdoor security system. More particularly, the present invention relates to an intrusion sensor net for an unmanned outdoor security system, which does not easily undo and is easy to install on the spot, and a weaving machine for the same.
BACKGROUND OF THE INVENTION
[0003] Various facilities, such as military camps, airports, power plants, detention facilities, and so on, may not guarantee the national security or cause huge losses to the public society when enemies invade, outsiders trespass or insiders escape. Accordingly, security facilities to prevent intrusion or escape are essential. For such security facilities, security fences made of wire mesh as shown in FIG. 1 have been widely installed. However, only the security fences are difficult to monitor and prevent someone's intrusion through jumping over a wall or cutting the fence. Therefore, an intrusion monitoring system that is mounted on the security fence to monitor such intrusion has been developed and operated.
[0004] Various kinds of sensing methods and devices, such as surveillance cameras, hot-wire sensors, and optical fibers, have been used for the intrusion sensing system, and the optical fiber sensors out of the above are widely utilized. The optical fiber sensors are to sense an attempt of an intrusion at regions where security is needed by mesh-type optical fiber nets attached and installed to the security fence. As shown in FIG. 2 , the optical fiber net is woven in such a fashion that optical fibers simply cross each other and is installed on poles 120 of the existing fence. After that, an input control part 100 sends a predetermined optical signal to the optical fiber net 130 , and an output control part 110 receives the optical signal passing through the optical fiber net 130 . When an intruder opens or cuts the optical fiber net 130 , the optical signal is changed, and the system senses the change in optical signal, and then, checks whether or not there is any attempt of intrusion and takes proper countermeasures.
[0005] The optical fiber net has an advantage in that it is difficult for the intruder to open or break the net because it is sensitive of the attempt for intrusion, but may cause misjudgment because it is also sensitive of natural phenomena such as wind or rainfall, collision with animals, and so on. Furthermore, the optical fiber net is mounted on the security fence in such a fashion that the edge of the net is tied to the poles of the fence via fastening means. Hence, someone may intrude by cutting the fastening means. In the meantime, without using the fastening means, it is not easy to install the optical fiber net, which is previously manufactured in a factory, to the poles of the security fence by winding the optical fiber net on the poles of the security fence. The reason is that the optical fiber net must be installed at the same time with the installation of the security fence or the existing security fence is reinstalled in order to install the optical fiber net in such a fashion that the optical fiber is wound on the poles of the security fence. Accordingly, such installation work requires excessive manpower, and the optical fiber net cannot be firmly installed to the security fence because the optical fiber is not flexible.
SUMMARY OF THE INVENTION
[0006] Accordingly, the present invention has been made in an effort to solve the above-mentioned problems occurring in the prior arts, and it is an object of the present invention to provide an intrusion sensor net for an unmanned outdoor security system, which does not make misjudgment on intrusion and is not easy to be dismantled, and a weaving machine for weaving the intrusion sensor net.
[0007] Another object of the present invention is to provide an intrusion sensor net, which is easy to be installed on the installation spot, and a weaving machine for weaving the intrusion sensor net.
[0008] To achieve the above objects, the present invention provides an intrusion sensor net, which is woven with a single sensing line and has a predetermined repeated weaving pattern, comprising: a first support line; a first zigzag-shaped line that starts from an end portion of the first support line and ends at the other end portion of the first support line and all the vertices of one side thereof are connected by the first support line; a second support line for connecting all the vertices of the other side of the first zigzag-shaped line; and a second zigzag-shaped line that is formed in symmetry with the first zigzag-shaped line relative to the second support line, wherein two sensing lines corresponding to the first zigzag-shaped line and the second zigzag-shaped line are interlaced with each other at an intersection where the first zigzag-shaped line and the second zigzag-shaped line meet each other.
[0009] Moreover, the two sensing lines corresponding to the first zigzag-shaped line and the second zigzag-shaped line are interlaced with the first support line or the second support line at the intersection where the first zigzag-shaped line and the second zigzag-shaped line meet each other in such a fashion that the first support line or the second support line goes under one side of the zigzag-shaped line and over the other side of the zigzag-shaped line, so that the first support line or the second support line gets curved.
[0010] Furthermore, the intrusion sensor net further includes a first spare sensing line formed at a starting part of weaving and a second spare sensing line formed at an ending part of weaving.
[0011] Additionally, a plurality of fixtures are mounted on the edge of the sensor net, and each of the fixtures includes: a through hole and a sensing line fixing hole perforated in each of the fixtures, the through hole and the sensing line fixing hole having different directions of central axes from each other; and a slit formed in the sensing line fixing hole for allowing the sensing line to be inserted thereinto from the outside and seated on the sensing line fixing hole, and wherein at least one of the sensing lines of the first zigzag-shaped line and the second zigzag-shaped line sensing lines goes through the sensing line fixing hole.
[0012] In addition, the single sensing line passes through the through holes of the plural fixtures in order along the edge of the intrusion sensor net.
[0013] Moreover, the through hole is mounted at an inner portion than the sensing line fixing hole toward the center of the intrusion sensor net.
[0014] Furthermore, central axes of the through hole and the sensing line fixing hole are perpendicular to each other.
[0015] Additionally, inside the edge of the intrusion sensor net, a clip is mounted at the intersection where the first zigzag-shaped sensing line and the second zigzag-shaped sensing line meet each other in order to fasten the sensing lines corresponding to the first and second zigzag-shaped lines and the sensing line corresponding to the first support line or the second support line together.
[0016] In addition, the sensing line is a coaxial cable.
[0017] In another aspect of the present invention, the present invention provides a method of weaving an intrusion sensor net with a single sensing line using a plurality of fixtures, each of which includes first and second holes having different central axes from each other and a slit formed in the second hole and extending to the outer end portion of the fixture, the weaving method comprising: a first step of deploying a line of fixtures; a second step of passing a sensing line through the second hole of the first fixture of the deployed fixtures and passing the sensing line through the second holes of the other fixtures in order so that the sensing line passing through the fixtures forms a first zigzag shape and the fixtures are respectively located at the vertices of one side of the first zigzag shape; a third step of further deploying a fixture at a location facing the final fixture of the second step and passing the sensing line through the second hole of the deployed fixture; a fourth step of forming a first central line while passing through the vertices of the other side of the first zigzag shape in order in an alternating fashion that the sensing line goes under one of the two lines, which form each vertex of the first zigzag shape, and goes over the other one of the two lines near each vertex of the first zigzag shape; a fifth step of further deploying a fixture at a location facing the first fixture and passing the sensing line through the second hole of the fixture and the second hole of the first fixture, and then forming a second zigzag-shaped line in such a fashion that the sensing line interlaces all of the line, which forms the vertices of the other side of the first zigzag shape, and the first central line at an intersection between the sensing line and the first central line and is symmetric with the first zigzag-shaped line relative to the first central line; and a sixth step of forming a second central line by passing the sensing line through the vertices of the second zigzag shape, which do not meet the first central line, in order in an alternating fashion that the sensing line goes under one of the two lines, which form each vertex of the second zigzag shape, and goes over the other one of the two lines.
[0018] Moreover, the fixture is deployed in such a way that the first hole faces the inside of the intrusion sensor net, which will be woven.
[0019] Furthermore, the fixtures deployed in one line in the first step are in even number.
[0020] In a further aspect of the present invention, the present invention provides a weaving machine, which includes a rotatable cylindrical body and driving means for rotating the cylindrical body, wherein the cylindrical body includes: a plurality of columns of pins protrudingly formed along the outer circumference of the cylindrical body, and wherein the plurality of the columns of pins comprises a first column in which a plurality of pins are deployed in a line and a second column that is adjacent to the first column at a predetermined interval from the first column and that has a plurality of pins deployed at the locations facing the region in-between the pins of the first column, and wherein the first column and the second column are repeatedly deployed in an alternating fashion.
[0021] Additionally, the intervals between the pins formed on the cylindrical body are all identical and intervals between the columns are all identical.
[0022] In addition, the pins of the second column are deployed at the locations corresponding to central points between the neighboring pins of the first column.
[0023] Moreover, the weaving machine further includes a winding rod that winds the intrusion sensor net, which is woven in the cylindrical body, while rotating in interlock with the cylindrical body.
[0024] Furthermore, the cylindrical shape of the cylindrical body is formed by a plurality of pin support rods mounted along the outer circumference thereof and the pins are protrudingly formed on the pin support rods.
[0025] As described above, the intrusion sensor net according to the present invention has the following effects.
[0026] First, the intrusion sensor net is not easily dismantled because the zigzag-shaped sensing lines and the central line engage with one another. Moreover, anybody cannot intrude without damaging the sensor net because it is not easy to open the gaps of the woven sensor net, and hence, the intrusion sensor net can perfectly sense an attempt for intrusion.
[0027] Second, the intrusion sensor net according to the present invention is easy to be installed on the installation spot because the sensor net includes the spare sensing lines necessary for on-site installation work and the fixtures having the through holes for allowing passing of the spare sensing lines.
[0028] Third, even though the intrusion sensor net is woven with the single sensing line, the intrusion sensor net is firmly installed to the security fence by being bound to the poles of the security fence while the spare sensing line passes through the through holes of the fixtures mounted along the edge of the sensor net. Therefore, the sensor net cannot be separated from the security facility without an abnormal signal and provide an excellent sensing effect once the sensor net is closely attached to the security fence.
[0029] Fourth, the intrusion sensor net senses only a signal related with cutoff of the sensing line because the entire sensor net is woven with the single sensing line and the gaps of the woven net are not opened or widened. Hence, the intrusion sensor net according to the present invention does not make misjudgment due to contact with animals or external shock, such as a gust of wind.
[0030] Furthermore, the weaving machine according to the present invention can keep the entire structure and provide effective work till the intrusion sensor net is completely finished, so that the weaving work of the intrusion sensor net is progressed easily and effectively.
[0031] Moreover, the weaving machine according to the present invention can produce intrusion sensor nets of various sizes and dimensions according to consumers' demands because it can control the sizes and dimensions of the woven sensor net according to heights and lengths of the intrusion sensor net, which will be installed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 illustrates a security fence according to a prior art.
[0033] FIG. 2 illustrates an intrusion sensor using an optical sensor net according to another prior art.
[0034] FIG. 3 illustrates an intrusion sensor net according to the present invention.
[0035] FIGS. 4 to 7 illustrate a method of weaving the intrusion sensor net according to the present invention.
[0036] FIG. 8 illustrates a fixture mounted on the intrusion sensor net according to the present invention.
[0037] FIG. 9 illustrates a clip mounted on the intrusion sensor net according to the present invention.
[0038] FIG. 10 illustrates a spread state of the intrusion sensor net after being woven in a weaving machine.
[0039] FIG. 11 is a front view of the weaving machine for making the intrusion sensor net.
[0040] FIG. 12 is a plan view of the weaving machine for making the intrusion sensor net.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Reference will be now made in detail to the preferred embodiment of the present invention with reference to the attached drawings.
[0042] FIG. 3 is a schematic diagram of an intrusion sensor net 10 according to the present invention.
[0043] The intrusion sensor net 10 according to the present invention is attached on a security fence illustrated in FIG. 1 to sense someone's intrusion due to cutting or separation of the intrusion sensor net 10 occurring when there is an attempt for intrusion. The intrusion sensor net 10 of the present invention is woven in correspondence with dimensions of an upper part, a lower part or an underground part of a security facility, such as the security fence shown in FIG. 1 , and then, is attached to the security facility in order. Accordingly, nobody can intrude through the security facility without cutting or destroying the intrusion sensor net or the system according to the present invention. For ease of security, the intrusion sensor net of a predetermined length, for instance, 30 m, is attached to the security facility in a longitudinal direction in order. When the attached intrusion sensor net 10 is cut, a sensor 40 senses a change of a sensing signal, and the signal sensed by the sensor 40 is transmitted to a central control center through communication means. The central control center can take proper steps, such as check of the situation through a monitoring camera installed in each zone, sending a guard, impartment of emergency situations, and so on.
[0044] The intrusion sensor net 10 illustrated in FIG. 3 is woven with a single sensing line 15 in such a fashion that the intrusion sensor net 10 is not cut off from a starting part 11 to an ending part 12 . The intrusion sensor net is woven with a predetermined consistent weaving pattern. Moreover, as shown in FIG. 3 , the woven intrusion sensor net is generally formed in a rectangular shape and has a plurality of knot portions 13 formed on the outer edges thereof.
[0045] The predetermined consistent weaving pattern includes: a first support line 16 ; a first zigzag-shaped line 17 that starts from an end portion of the first support line and ends at the other end portion of the first support line and enables the first support line to connect all the vertices of one side thereof; a second support line 18 for connecting all the vertices of the other side of the first zigzag-shaped line; and a second zigzag-shaped line 19 that is formed in symmetry with the first zigzag-shaped line relative to the second support line 18 .
[0046] The starting part 11 and the ending part 12 are spare sensing line remaining after weaving, and are connected to the sensor 40 in such a way as to respectively serve as an input part and an output part of the sensing signal, and the sensing signal of the sensor 40 is connected to the central control center and a communication net. It is preferable that the intrusion sensor net 10 is woven with a coaxial cable 15 . The coaxial cable can compensate the shortcomings of the optical sensor lines, which are too sensitive to shock by wind or animals, and is a combination of a main conductor and a cylindrical conductor surrounding the main conductor. The coaxial cable is less affected by simple shock or external disturbing signals, generates a sensing signal when it is cut off, and does not come undone or broken because it is woven according to the weaving method, which will be described later.
[0047] In the case that the intrusion sensor net is made with the coaxial cable, as described above, the starting part 11 and the ending part 12 are all introduced into the sensor 40 , and hence, the sensing signal is transferable using the main conductor. Moreover, even though only one of the starting part 11 and the ending part 12 is introduced into the sensor 40 and the other electrically fastens the main conductor of an end portion thereof and the cylindrical conductor surrounding the main conductor with each other, the sensing signal can be inputted and outputted to the entire sensor net through the main conductor and the cylindrical conductor.
[0048] The reference numeral 13 designates a part to fasten a joint part 14 to a pole or a wire mesh of the security facility when the intrusion sensor net 10 is attached to the security facility on the spot after the intrusion sensor net 10 is completely woven. Therefore, the intrusion sensor net 10 finished in a manufacturing plant must have a spare length of the sensing line 15 of the starting part 11 or the ending part 12 , so that it can be attached to the security facility on the spot. A plurality of the joint parts 14 are formed along the circumference of the intrusion sensor net, and each joint part 14 has a fixture 20 as illustrated in FIG. 8 , and hence, it can be easily attached to the security facility by the spare line of the starting part 11 or the ending part 12 .
[0049] FIGS. 4 to 6 concretely show a method of weaving the intrusion sensor net 10 according to the present invention.
[0050] First, as shown in FIG. 4 , a plurality of pins 22 are mounted in columns in the first line (line 1 ), and a plurality of pins 22 are mounted between the pins of the first line in the second line (line 2 ). A plurality of the pin columns are formed along the circumference of a cylindrical body 50 of the weaving machine, which produces the sensor net according to the present invention, by a repeatedly alternating deployment. The sets of the pins may be mounted on a flat surface as well as the cylindrical form, but it is preferable that the intrusion sensor net is woven while the cylindrical body 50 is rotated in a state that the pins are mounted on the surface of the cylindrical body rather than on the flat surface because the sensor net 10 must be woven in length of several tens of meters.
[0051] One of the fixtures 20 is mounted on the pin located at the outermost position of the intrusion sensor net 10 , which will be woven. A concrete structure of the fixture 20 is illustrated in FIG. 8 , and the fixture 20 includes a through hole 23 for inserting the pin 22 thereinto and is mounted on the cylindrical body. The fixture 20 further includes a sensing line fixing hole 24 that has a direction of a central axis, which is not identical to a direction of a central axis of the through hole 23 , preferably, that is mounted at right angles to the direction of the central axis of the through hole 23 . As shown in FIG. 8 , a slit 25 is formed on one side of the sensing line fixing hole 24 . When the sensing line, for instance the coaxial cable, is fit into the sensing line fixing hole 24 , the slit 25 is opened, and the sensing line is put into the sensing line fixing hole 24 , so that the sensing line can be caught to the sensing line fixing hole 24 .
[0052] First, as shown in the upper part of FIG. 4 , the sensing line 11 passes through the sensing line fixing hole 24 of the first fixture 20 a of the line 1 , and then is caught to the first pin 22 a of the line 2 . After that, the sensing line 11 passes through the sensing line fixing hole 24 of the second fixture 20 b , and then is caught to the second pin 22 b of the line 2 . The operation continuously progresses in the above fashion in order, and then, the sensing line passes through the sensing line fixing holes 24 of the rightmost pins of the line 1 and the line 3 in order.
[0053] After that, as shown in the central part of FIG. 4 , the ongoing sensing line 15 a and the spare sensing line 15 b move in an arrow direction together. In this instance, the sensing line goes over the zigzag-shaped sensing line, which is mounted previously, at the intersection where the first pin 22 c is mounted, (refer to the circled part in the drawing) and goes under the zigzag-shaped sensing line near the next pin 22 d (refer to the circled part in the drawing), and then, goes over the zigzag-shaped sensing line near the next pin 22 e . The above work is repeated in an alternating fashion.
[0054] After that, as shown in the lower part of FIG. 4 , the ongoing sensing line 15 a , which is moved to the leftmost side, and the spare sensing line 15 b are respectively caught to the sensing line fixing holes 24 of the leftmost fixtures 20 a and 20 f . In this instance, the ongoing sensing line 15 a and the spare sensing line 15 b are respectively twisted once as shown in the drawing, and then, caught to the fixtures.
[0055] When the above work is finished, the ongoing sensing line 15 a becomes the central line that connects the vertices of the zigzag shape. After that, as shown in the upper part of FIG. 5 , the spare sensing line 15 b is caught to the pins 22 f and 22 g of the line 3 in order. In this instance, the spare sensing line 15 b is caught to the pins 22 f and 22 g in such a way as to have the structures illustrated in the enlarged figures of the central part of FIG. 3 . In other words, the spare sensing line 15 b is caught to the pin 22 f after being pulled over the central line, and then, caught to the pin 22 g after being pulled under the central line, and the sensing line 15 a is caught to all the pins of the line 3 by alternatingly repeating the above steps. Through the above process, one of the zigzag-shaped sensing lines can be interlaced not only with the other zigzag-shaped sensing lines but also with the central line. Furthermore, the woven pattern of the present invention has a structure that the zigzag-shaped sensing lines adjacent to the pins 22 j , 22 k , . . . prop one side of the central line up but press down the other side of the central line, and hence, a weaving form that the central line is curved adjacent to the pins 22 j , 22 k , . . . can be made. In other words, referring to the two circled enlarged figures, which illustrate the weaving forms adjacent to the pins 22 j and 22 k , in the central part of FIG. 5 , in the enlarged figure of the region of the pin 22 j , the central line is pressed down because the two zigzag-shaped sensing lines go over the central line at the left of the central line. Additionally, at the right of the central line, the central line is propped up because the two zigzag-shaped sensing lines go under the central line. Accordingly, the central line is vertically curved near the pin 22 j.
[0056] In the meantime, in the enlarged figure of the region of the pin 22 k , the central line is pressed down at the right of the central line but is propped up at the left of the central line, and hence, the central line is vertically curved near the pin 22 j.
[0057] Due to the curves of the central line, the zigzag-shaped sensing lines that are interlaced with each other near the pins 22 j , 22 k , . . . are in a state where it is difficult that they slide from side to side along the central line. Therefore, the sensor net according to the present invention has a structure that it is difficult to open or widen the intervals formed between the sensing lines when someone tries to intrusion.
[0058] The above weaving pattern is formed in the case that the fixtures 20 a , 20 b , 20 c , . . . deployed in the line 1 are even numbers. If the fixtures are deployed in odd numbers, as shown in the circled enlarged figures of FIG. 7 , a weaving pattern that the central line is not curved and the zigzag-shaped sensing lines are interlaced with the central line as well as each other is formed.
[0059] After the work is started, as shown in the lower part of FIG. 5 , the ongoing sensing line is wound and fastened to the rightmost fixture 20 g of the line 3 . After that, the ongoing sensing line 15 c and the spare sensing line 15 d are formed, and they continue work in the arrow direction. While the work progresses in the arrow direction, the sensing line goes over one of the two lines of the zigzag-shaped line formed by the pin and goes under the other one of the two lines, and goes under one of the two lines of the zigzag-shaped line formed by the next pin and goes over the other one of the two lines, (refer to the enlarged figures of FIG. 5 ), and then, the sensing line goes through all vertices of the zigzag-shaped line in order in an alternating fashion.
[0060] After that, the sensing line 15 passes through the sensing line fixing hole 24 of the leftmost fixture 20 h of the line 3 , and then, the spare sensing line 15 d is caught to the first pin 22 h and the second pin 22 i of the line 4 . In this instance, like the weaving pattern illustrated in the enlarged figure of the upper part of FIG. 6 , the spare sensing line 15 d is caught to the pin after being pulled over the central line, and then, caught to the pin after being pulled under the central line, and the sensing line 15 a is caught to all the pins of the line 4 by alternatingly repeating the above steps.
[0061] As described above, after the sensing line is caught to all the pins of the line 4 , the sensing line passes through the sensing line fixing holes 24 of the fixture 20 i of the line 3 and the fixture 20 j of the line 5 .
[0062] After that, the ongoing sensing line and the spare sensing line are woven as shown in the central part of FIG. 4 while they go in the arrow direction, and the above steps are alternatingly repeated.
[0063] As a result of the weaving work, the sensor net is woven into a wanted length, and then, finishing work is carried out. That is, as shown in the lower part of FIG. 6 , fixtures 20 are deployed to all the pins of the final line, and the sensing line is caught and fixed not to the pin but to the sensing line fixing hole 24 of the fixture 20 , and then, the sensing line, which passed through the final fixture, is remained as the spare sensing line 12 of a predetermined length.
[0064] The spare sensing line must pass through the through hole 23 of the fixture 20 , which will be mounted on the circumference, and must be tied to form knot portions 13 along the edge of the sensor net on the spot, and hence, it is preferable that the spare sensing line has a spare length of more than 120 cm in consideration of steps, which will be described later, in the case of the intrusion sensor net that is about 30 m long.
[0065] FIG. 9 illustrates a clip 30 that is mounted at the intersection of the inner sensing line of the intrusion sensor net 10 . The intersection nodes of the sensing lines formed at the pins 22 a and 22 b are not loosened or tangled by themselves even though the intrusion sensor net is separated from the pins because the sensing lines are twisted mutually. However, in order to more firmly hold the position and form of the intersections, the clips 30 may be mounted.
[0066] Each of the clip 30 is in a plate type having a hole 31 formed at the center thereof and a split portion 32 formed on one side thereof, so that the sensing line is seated on the hole 31 of the clip through the split portion 32 at the intersection of the sensing lines. In this instance, because the diameter of the hole 31 is not large, when the sensing line is forcedly seated and tightened on the hole, the sensing line is firmly fastened not to be moved.
[0067] FIG. 10 illustrates a spread state of the finished intrusion sensor net 10 .
[0068] Now, the intrusion sensor net 10 of the spread state is examined. After that, on the spot, the spare sensing lines 11 and 12 bind the through hole 23 of each fixture and the pole of the security facility together in order, and thereby, the intrusion sensor net is installed. Meanwhile, in order to keep the entire shape of the intrusion sensor net and form a stronger sensor net which is not untied or does not get loose, it is preferable that finishing work that the spare sensing lines 11 and 12 pass through the through holes 23 of the fixtures along the edge of the intrusion sensor net is carried out.
[0069] The finishing work is carried out in such a fashion that one of the spare sensing line 12 passes through the through hole 23 , which is the hole where the pin is inserted during the weaving work, along the edge of the sensor net from the fixture 21 b to the fixture 21 k in order. When the spare sensing line 12 passes through the through hole 23 , the steps of passing the spare sensing line from the top to the bottom and passing it from the bottom to the top are alternatingly repeated. After the spare sensing line 12 passes through the through hole 23 of the final fixture 21 k , it retraces the steps. Accordingly, the spare sensing line 12 passes through the through holes 23 again in a reverse direction.
[0070] Moreover, the other spare sensing line 11 also passes through the through hole 23 of the fixture 21 a from the top to the bottom and passes through the through hole 23 of the next fixture from the bottom to the top, and the spare sensing line 11 passes through all the through holes 23 from the fixture 211 to the fixture 21 l to 21 a along the edge of the sensor net in order by alternatingly repeating the above steps. After the spare sensing line 11 passes through the through hole 23 of the final fixture 21 a , it retraces the steps. Accordingly, the spare sensing line 11 passes through the through holes 23 again in a reverse direction.
[0071] Through the above process, the spare sensing line going from the top to the bottom and the spare sensing line going from the bottom to the top are mounted at the through hole 23 of the fixture. Furthermore, such a weaving pattern serves to firmly hold the spare sensing lines such that the sensing lines of a ring shape collected to the edge portion during the weaving process do not get loose. For instance, as shown in the central part of FIG. 6 , in case of the rings formed on the three sensing lines collected to the fixture 20 i , the spare sensing line first passes through the through hole 23 of the fixture 20 i from the top to the bottom, and then, second passes through the through hole 23 from the bottom to the top, so that the weaving pattern, in which the three rings of the sensing line cannot be separated or loosened, can be formed. In this instance, the through hole 23 of the fixture 20 must be located at the inner position where it is interlaced by all the three rings of the sensing line, namely, in an inward direction of the intrusion sensor net (refer to the position of the hole formed in the fixture 20 i ).
[0072] After the above process, the intrusion sensor net is completed, and then, the finished intrusion sensor net is installed on the spot using the spare sensing line. The step of passing the spare sensing line from the fixture 21 b to the fixture 21 k and from the 21 l to the 21 a is carried out in any one of the clockwise direction and the counterclockwise direction along one half of the entire edge of the sensor net and carried out in the reverse direction along the other half of the edge of the sensor net. The intrusion sensor net manufactured by the above weaving work has the structure that does not come undone and it is difficult to open or widen the gaps of the sensor net.
[0073] When the intrusion sensor net 10 is attached to the security facility in the spot where the security facility such as a security fence is installed, the intrusion sensor net 10 is located in a good attachment position, and then, the steps of binding the poles of the security facility and the through holes 23 of the fixtures 20 together along the edge of the intrusion sensor net 10 using the spare sensing lines 11 and 12 are carried out in order.
[0074] As described above, the fixture 20 is mounted at the point 14 of the edge of the intrusion sensor net 10 where the sensing lines are collected.
[0075] FIG. 3 briefly shows how to install the intrusion sensor net 10 . As shown in FIG. 3 , the knot portions 13 for binding the through holes 23 of the fixtures 20 and the security facility with each other are formed as many as the number of the fixtures mounted on the edge of the intrusion sensor net 10 , and hence, the intrusion sensor net 10 can be firmly mounted on the security facility.
[0076] After the intrusion sensor net 10 is attached to the security facility, the spare sensing lines 11 and 12 are connected to the sensor 40 for sensing a change of a signal of the sensing lines due to cutoff of the sensing lines.
[0077] In the case that the sensing lines are double-line cables like the coaxial cable, it is not necessary to connect all of the two spare sensing lines 11 and 12 , but one of the spare sensing lines is connected to the sensor and the other one is configured in such a fashion that the double lines inside the cable are electrically connected with each other.
[0078] In the meantime, FIGS. 11 and 12 illustrate a weaving machine for weaving the intrusion sensor net 10 .
[0079] A support 80 , which is a body of the weaving machine, serves as a body for supporting all components of the weaving machine and supports a cylindrical body 50 , where the intrusion sensor net 10 is woven, in such a way that the cylindrical body 50 is rotated by a bearing 65 .
[0080] A gear 63 is joined to a shaft of the cylindrical body 50 at one side of the cylindrical body 50 . The gear 63 is connected with a gear 61 joined to a rotary axis of a driving motor 60 via a chain 62 , so that the cylindrical body 50 is rotated according to the rotation of the driving motor 60 .
[0081] Because the weaving work of the intrusion sensor net 10 inside the cylindrical body 50 is finished by the unit of the lines, where the pins are deployed, it is preferable that the cylindrical body 50 is rotated as much as a predetermined interval whenever the weaving work of one or two lines is finished. Therefore, it is preferable that the driving motor 60 is a step motor. Moreover, the cylindrical body 50 is rotated as much as a fixed distance in such a fashion that the driving motor works whenever a user pushes a motor switch 69 once.
[0082] As shown in FIG. 11 , the cylindrical body 50 has a plurality of columns of pins (D) formed along the circumference thereof. One of the columns is formed by a plurality of pins deployed in one line, and another column located adjacent to the first column has pins deployed at the locations facing the region in-between the pins of the first column. Furthermore, the plurality of the pin columns are formed by alternatingly repeating the deployment of the above columns (refer to the deployment of the pins of the cylindrical body illustrated in FIG. 11 ).
[0083] It is preferable that gaps between the pins and gaps between the columns formed on the cylindrical body are all identical and that the columns are deployed in such a fashion that the pins are deployed at the locations corresponding to the region in-between the pins of the neighboring columns.
[0084] Additionally, the cylindrical body is molded in a drum shape and the plurality of the pins are protrudingly formed on the surface of the cylindrical body. However, in order to make manufacturing of the weaving machine easy, a plurality of pin support rods 51 , each of which has one column of the pins, are deployed between disc bodies 52 and 53 along the circumferences of disc bodies 52 and 53 , such that the cylindrical body can be made. Such a manufacturing method can remove inconvenience that the pins are fixed on the surface of the drum body.
[0085] The width of the intrusion sensor net 10 woven by the weaving machine is determined by the width woven in the cylindrical body. Accordingly, the width of the woven intrusion sensor net 10 can be controlled by the number of the pins 22 mounted on the fixtures 20 as necessary.
[0086] Meanwhile, a manual rotator 64 is mounted on the shaft of the cylindrical body 50 to prepare for an emergency that the driving motor does not work.
[0087] Furthermore, a working interval indicator 67 is mounted on the other side of the cylindrical body 50 in interlock with the shaft of the cylindrical body 50 . Additionally, an alarm 68 sounding for the end of work is connected to the working interval indicator 67 to indicate the progress of work, such as a rotational amount of the cylindrical body 50 , a converted length of the intrusion sensor net, and so on, and to raise the alarm at a previously set completion time, for instance, at a predetermined length, so that the user can end the weaving work.
[0088] In the weaving machine having the above structure, the intrusion sensor net 10 is woven in the previously described weaving method while being rotated by a fixed quantity according the working speed of the cylindrical body 50 . When the length of the intrusion sensor net 10 increases as the weaving work progresses, the woven intrusion sensor net 10 goes over the circumference of the cylindrical body 50 . After that, the intrusion sensor net 10 backwardly went over the cylindrical body 50 is automatically separated from the cylindrical body 50 at a predetermined point by the rotation of the cylindrical body. The reason is that the separated sensor net 10 is rolled on a winding rod 70 that is located adjacent to the cylindrical body and rotates in interlock with the cylindrical body 50 . The above action occurs because the fixtures 20 mounted in the line 1 of the cylindrical body 50 are respectively caught to the pins 74 of the winding rod 70 and the winding rod 70 rolls the intrusion sensor net 10 while rotating, after the intrusion sensor net 10 is woven into a predetermined length. Moreover, the intrusion sensor net 10 woven in the cylindrical body 50 is automatically separated from the pins in a state where it is rotated at a predetermined angle or more along the circumference of the cylindrical body 50 .
[0089] Meanwhile, a connection gear 66 is mounted at an end portion of the shaft of the cylindrical body 50 . The connection gear 66 is connected with the winding rod 70 , which winds the woven intrusion sensor net 10 thereon, via a belt or a chain, so that the winding rod 70 is rotated in interlock with the cylindrical body 50 .
[0090] However, because the length that the woven intrusion sensor net 10 is separated from the cylindrical body 50 and the length that the intrusion sensor net 10 is wound on the winding rod 70 are not identical with each other and the entire diameter of the winding rod is gradually increased as an amount of the intrusion sensor net 10 wound on the winding rod is increased, it is necessary to control a rotation rate of the cylindrical body 50 and the winding rod 70 as the weaving work progresses (the rotation rate of the winding rod is gradually reduced because the diameter of the winding rod increases due to an increase of the amount of the sensor net 10 wound on the winding rod 70 as the weaving work progresses). Accordingly, a controller is additionally mounted to control the rotational speed and the rotational rate of the cylindrical body 50 or a transmission gear 71 is mounted to reduce the rotational speed of the winding rod 70 according to the progress of the weaving work.
[0091] The intrusion sensor net 10 wound on the winding rod 70 is rewound on a bar 75 of an appropriate length after the weaving work is ended. The bar 75 on which the intrusion sensor net 10 is wound is moved to a different place and spread out for inspection or finishing work. According to circumstances, the bar 75 can be moved to an installation spot and the intrusion sensor net 10 is attached to the security facility.
[0092] As described above, the intrusion sensor net used for the unmanned outdoor security system according to the present invention is installed to security facilities, such as security fences, to prevent someone's intrusion and monitor the surrounding environments. Therefore, it can be widely installed and utilized in various places, such as military camps, detention facilities, restricted areas, and so on. | The present invention relates to an intrusion sensing net of a structure that does not allow the sensing net to be disassembled or dissolved easily but does enable easy installation at the site, and to a weaving machine that weaves the same. The invention relates to an intrusion sensing net the entirety whereof is woven with one sensing line, that includes a repeating and consistent weaving pattern; wherein the consistent weaving pattern comprises a support line, a line of a zigzag shape that enables the support line to connect all the vertices of one side starting from one end of the support line and ending at the other end, and another line of a zigzag shape that is formed in symmetry with the zigzag shape based on the another support line, wherein at the point where the line of a zigzag shape meets with the another line of a zigzag shape, two sensing lines corresponding to each line wind and hold one another. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to games played on a board where indicia on the board defines steps or stations and a piece, symbol or man is progressively advanced along a designated path defined by the steps or stations. The board game is a bicycle race game having a track or path, over an area on the game board, with interim hazards, to a finish.
[0003] 2. Prior Art
[0004] Games, played on a board defining an area or track of play are well known. Several examples of issued US patent on game boards include:
U.S. Pat. No. 5,482,288 issued to Cedeno 1996 U.S. Pat. No. 5,350,178 issued to Hollar 1994 U.S. Pat. No. 4,729,568 issued to Welsh 1988 U.S. Pat. No. 4,550,917 issued to Ferris et al 1985 U.S. Pat. No. 4,346,889 issued to Barlow et al 1982
[0005] U.S. Pat. No. 5,482,288 ('288) teaches a board game that is a race-to-the-finish, with obstacles and set-back stations. A plurality of stations, which are fixed indicia on the board, define a fixed track along which a player moves a token, progressively. The track includes hazard stations. Each player has two tokens, one representing himself and a second token representing a public servant. When the “self” token is advanced along the track and lands on a certain hazard or designated event station, the self token must remain on that station until receiving assistance in the form of the second token or public servant token. When the self token lands on other designated event stations, the path of the self token is diverted, favorably or unfavorably, according to the designated event. Dice are used to determine advancement of a token along the track.
[0006] U.S. Pat. No. 5,350,178 teaches an automobile race game in which a board game simulates an automobile race track for one of more players. The game board, which is a flexible member, has fixed race track paths printed on both sides of the board, one relatively large and one relatively small. The flexibility of the board permits the board to be placed on a non-flat or uneven surface so that either track may simulate a banked track. The flexibility of the board and the making of an uneven or non-flat surface defining a race track changes the orientation of the track but the tracks over which the races are run, remain fixed. A plurality of charts determine the course and type of movement along the track. A pair of dice are used to determine advancement of the vehicle along the track as well as selection of a chart. Although the board may be flexible, the track on the board is fixed.
[0007] The U.S. Pat. No. 4,729,568 teaches a horse race game played on a board. The game includes a fixed game board having a plurality of tracks printed thereon, a pair of gaming dice for determining the play of the game and a plurality of pieces which are moved along the respective racing tracks during play of the game. Prior of the race, but as part of the game, dice are rolled to determine which one of a predetermined number of playing pieces are to be “scratched” for the subsequent race. The remaining playing pieces are placed in starting positions on the respective tracks and are advanced along tracks, in accordance with the roll of the dice. Cards, from a plurality of sets of cards, are randomly dealt to the players. Each set of cards is composed of a plurality of numbered cards corresponding to the numbers of the respective ones of the playing pieces. The first playing piece to reach the “finish line” is declared the winner and the players share a central pot representing a purse.
[0008] U.S. Pat. No. 4,550,917 teaches a tiled board racing game. The track consists of a plurality of shiftable or sideway movable straight segments of track positioned between fixed curved segments of track. The fixed curved sections are offset with respect to each other, so that a movable straight track may be aligned with either adjacent fixed curved segment. Players are permitted to shift track segments to assist the advancement of the player's own piece or to interfere with the advancement of the opponent player's piece.
[0009] U.S. Pat. No. 4,346,889 teaches a movable tile board game with a path or track created in the tiles for a vehicle. The game is played on a board with a plurality of generally rectangular tiles. Each tile is slidable with respect to other tiles on a board base. The tiles are captured on the board and form a rectangular pattern with at least one vacant space, equal to the size of one tile. Grooves of different orientation are formed in the surface of the tiles and the tiles must be shifted to define a continuous track. The groves on each tile extend between the mid-point of side edges of the tile supporting the groove. A continuous path or track from tile to tile may be formed by orienting tiles on the board. A self-propelled vehicle is provided to move along the track created across the face of tiles, following the track formed by the adjacent tiles. An alarm on the vehicle is sounded when the vehicle reaches the unconnected edge of a tile.
[0010] U.S. patents to Brown, U.S. Pat. No. 4,185,823 and to Mazza et al, U.S. Pat. No. 5,149,101 each teach apparatus game, Brown teaches an apparatus for playing a movable vehicle game. The game may be played using one vehicle or two vehicles. A movable vehicle, when played as a single vehicle game, is moved by the apparatus and can release a plug or similar object, during such movement, so as to drop the plug on a target. When the apparatus is played with dual vehicles a lead vehicle can use a trailing line, for temporary detachment by a pursuer vehicle. Mazza et al teach an apparatus for playing a horse racing game on a game board. The game board is formed with fixed spaced game path spaces. A spring loaded apparatus provides a starting gate for the game.
SUMMARY OF THE INVENTION
[0011] The present invention provides a board game that simulates a bicycle race, known as a “tour”, with an improved game board. A bicycle tour race is a bicycle race that takes place or is run over a predetermined track within a predetermined geographic area. For example, the race may be run along a “track” established in a geographic area of France, or a geographic area of Italy, or of Spain, or any other country or countries, such as Belgium and Holland, for example. The “track” or path on which the race is usually defined by selected public roads of the geographical area. Since the “track” of the race extends through a relatively large geographic area of a country, the “track” may pass through or pass close to places of interest and/or sites within the particular geographic area in which the race is run. For this reason, and the fact that spectators of the race may often travel through and/or “tour” the geographic area in which the race is run, this type of race has become known as a “tour”. Typically, when such race is run in France the race is known as “Tour de France”. When such race is run in Italy, the race is known or as Tour de Italy”, and so forth. In other words the race is a “tour” of the geographic area through which the race is held or run.
[0012] In accordance with the nature of the sport simulated by the present invention, a game board or playing area is provided which includes a track or path printed or otherwise fabricated on the game board. The path of the race or “tour” established on the board of the game includes a geographic area with individual sites and/or places or things of interest within the geographic area defined.
[0013] In accordance with the present invention, the game board or playing area provides a virtual geographic area, through which the race or tour is run. The track on which the race is run, passes through the geographic area fabricated on the game board so that an illusion or fantasy of the “tour” is created for the players of the game. In addition, a player may create a team of cyclists of the player's selection, essentially forming a fantasy team with which to play the game. In a preferred embodiment of the game and also in a preferred embodiment of the game board, one or more strips or sections of the track are provided, wherein each separate strip or section of the track defines a unique geographic area, complete with sites and/or places of interest within the particular geographic area, with each unique geographic area of a strip different from the geographic area on the basic game board and different from the geographic area on other geographic area strips. A selected geographic area strip may be substituted for or lain over the basic or current geographic area strip thereby creating a “tour” of another geographic area. Any number of geographic area strips may be provided, each with a different geographic area and/or different sites and/or places of interest within the particular geographic area. A substitute strip which defines a different geographic area may be positioned or set in overlay on the game board and held on the game board by a clip, for example. Preferably, the game board is provided with a set of receiving and retaining slots, into which the strip defining the different geographic area is inserted and thereby held on the game board.
[0014] The novel board game is played by two or more persons, each of whom begin playing the game with three selected pieces or cyclists which represent a team of cyclists running the race or tour. Tracks through the tour are established on the board so that as many as two through eight teams may run the tour or race together. The Rules of the Game establish “stages” for each geographic area through which the tour is run. The roll of a die, by each player establishes the order of play and, during play, the advancement of the player's team of cyclists along the route of the tour. Hazards and/or penalties are encountered along the tour which may slow down or reverse advancement of a cyclist in a team. There are cash awards, in the form of play money for sprint bonus and mountain bonus, along with stage winners, sprint king elevation, mountain king elevation, tour winner and best team. The tour winner captures the winning prize of the purse. The object of the game is to make the tour in the shortest accumulated time, as advancement of a cyclist is calculated in time increments. Colored shirts, shorts and head gear of the cyclist team are used to enhance excitement and fun.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a representation of a game board on which the tour game is played;
[0016] [0016]FIG. 2 is a representation of a strip attachable to the game board showing a different geographic area and local sites from the geographic area and local sites on the game board of FIG. 1;
[0017] [0017]FIG. 2 a is a representation of part of a game board such as represented in FIG. 1, with receiving and retaining slots for holding an attachable strip as represented in FIG. 2;
[0018] [0018]FIG. 2 b is a representation of a clip which may be used for holding an attachable strip to a game board in lieu of the receiving and retaining slots represented in FIG. 2 a;
[0019] [0019]FIG. 3 is a representation of a cyclist or piece used by a player of the game;
[0020] [0020]FIG. 4 is a set of rules for playing the novel board game;
[0021] [0021]FIG. 5 is a representation of a set of rules establishing the stages in various geographic areas;
[0022] [0022]FIG. 6 is a representation of a set of rules establishing awards for the game;
[0023] [0023]FIG. 7 is a representation of a stage time card usable with the game;
[0024] [0024]FIG. 8 is a representation of a Final Standing card usable with the game;
[0025] [0025]FIG. 9 a is a representation of a sprint bonus chip usable in the game; FIG. 9 b is a representation of a penalty chip usable in the game;
[0026] [0026]FIG. 9 c is a representation of a mountain bonus chip usable in the game;
[0027] [0027]FIG. 9 d is a representation of a die used for playing the game; and
[0028] [0028]FIG. 9 e is a representation of play money usable in the game.
DETAILED DESCRIPTION OF THE INVENTION
[0029] As used hereinafter, the term, tour, is defined as a bicycle race of two or more teams of two or more cyclists racing over a continuous track or path which includes public roads in urban and suburban areas, open country road, roads through villages, up, over and down mountains and through valleys of a selected geographic area. The tour has a starting point and a finish point and the continuous track or path of the race may be several hundred miles from the starting point to the finish point. An actual Tour de France, for example, may take place over several days, with intermittent, designated stops along the route. The object of the race is to complete the race, in as many stages as required, in the shortest accumulated time. The present invention is a board game that represents a tour or bicycle race.
[0030] Referring to FIG. 1, the board game of the present invention is played on a game board 10 . The board has indicia thereon which sets out a STARTING LINE 15 /FINISH LINE 12 . The track of the tour is defined by intervals or advancement steps set out in seconds with five (5) sets of tracks around the internal periphery of the game board. A geographic area 14 is established along one side of the game board, through which the five sets of tracks pass. A fixed geographic area is represented on the game board as France so that the fixed or basic tour game is in France and the race played on the game board as represented would simulate the Tour de France. The invention provides for other geographic areas to be substituted for the basic geographic area on the game board so that the board game may be played as a race in another geographic area.
[0031] Rules for playing the game are set forth in FIG. 4 and are believed to be self explanatory.
[0032] Since a tour may be run in any one of several geographic area, there is provided, with the game board, one or more substitute geographic area strips, suitable for overlay, over the established geographic area on the game board. Such a substitute geographic area strip is represented in FIG. 2 at 30 . The substitute geographic area strip 30 may be placed in overlay over the section 14 on the game board 10 of FIG. 1 thereby virtually changing the geographic area through which the tour is run. The substitute strip 30 may be held in place on the game board 10 by a binder clip such as 25 in FIG. 2 b , or any other paper clip or clip means, for example. Preferably the game board 10 includes a set of receiving and retaining slots such as represented in FIG. 2 a . FIG. 2 a includes a representation of part of a game board 10 a. Located at the ends of the geographic area on the game board are short vertical strips 28 (only one show) and, along the bottom of the geographic area of the game board, an horizontal strip 29 . A substitute geographic area strip 30 a , such as represented in FIG. 2 a , for example, suitable for overlay, over the established geographic area on the basic game board, may be slid into the set of receiving and retaining slots 28 and 29 , thereby establishing another, different geographic area through which the tour may be run. In an alternate embodiment the horizontal slot 29 may be eliminated. Opposing vertical slots, coupled to both ends of the geographic area of the board, may be made sufficiently tight for holding and retaining any substitute geographic strip slid into the opposing slots, without using a horizontal slot, such as 29 .
[0033] In a preferred embodiment of the elements of the game, at least eight (8) substitute geographic area strips are provided. FIG. 5, which represents apart of the rules of the game establishes the number of stages to be run for each geographic area through which the tour may be run. With a basic or fixed geographic area established on the game board, a selection of other geographic areas, in the form of substitute strips, is provides for playing the game on or over one of nine (9) geographic areas. It will be appreciated that fewer or more substitute geographic area strips may be provided and/or used, if desired.
[0034] In order to play the board game, FANTASY TOUR, a player selects a team of three (3) playing pieces or cyclists. A playing piece or cyclist, usable in playing the board game, is represented in FIG. 3. Three (3) playing pieces or cyclists form a team. The base 35 of the cyclist or piece is sufficient to support the figure which represents a cyclist on a bicycle. The base 35 may include identifying indicia, such as the country of the team, and other identification, for example. The shirt or jersey 37 , shorts 38 and head gear 39 may be colored in team colors. Known cyclists, from different times and places may race together, as a fantasy team. A player may name, number and/or identify a cyclist and/or team of cyclists with which the player is playing the board game, with the name, number and/or identity of a contemporary or former bicycle racer, effectively making the cyclist and/or team a fantasy cyclist or team and the race a fantasy tour. Each team is allocated a track around the game board, of which five (5) tracks are shown. More of fewer tracks may be used, if desired.
[0035] Referring to FIG. 1, a SPRINT LINE is established at 16 , where a SPRINT BONUS chip, represented in FIG. 9 a and cash awards, in the form of play money, represented in FIG. 9 e , are collected when selected cyclists or pieces reach or pass the corner 18 . A MOUNTAIN LINE is established at the corner 20 where a MOUNTAIN CHIP, represented in FIG. 9 c and additional cash awards are collected when selected cyclists reach or pass corner 20 . The space 22 and 24 each represent a hazard in the form of a FLAT TIRE, and penalty for a cyclist that may stop on that space. A FLAT TIRE chip is represented in FIG. 9 b . FIG. 6 provides a schedule for prize money, payable with play money, FIG. 9 e.
[0036] A die, FIG. 9 d is used when playing the board game, to determine order of play and for advancement of the cyclists in a team. The elements of the game include 28 playing cyclists and one non-playing yellow cyclist. The 28 playing cyclists are consecutively numbered and may have colorful attire. A player selects three cyclists, which define a starting team. The game is played in STAGES and the first cyclist to land on or cross the FINISH LINE is a STAGE WINNER. The symbolic Yellow Jersey is awarded to the player whose cyclist is the leader of the race after each STAGE. A yellow, non-playing cyclist is used to represent the symbolic Yellow Jersey. SPRINT BONUS chips and MOUNTAIN BONUS chips are selectively awarded to cyclists who land on or cross an established SPRINT LINE, in the second corner 18 and an established MOUNTAIN LINE in the third corner 20 , during a STAGE. Prize money is awarded for SPRINT BONUS chips and MOUNTAIN BONUS chips collected during the tour. “Pink” and “Green” play money is awarded according to the chips collected. The player collecting the most “Pink” money is proclaimed KING of the MOUNTAIN. The player collecting the most “Green” money is proclaimed SPRINT KING. Prize play money is distributed according to a schedule shown in FIG. 6. A Stage Card, FIG. 7 is used for recording timing of cyclists of a team. The FINAL STANDINGS, FIG. 8, are recorded for the tour run.
[0037] A novel board game has been described in the drawings and defined in a description thereof. Those familiar with the sport of tour racing will understand the connotation and denotation of terms used herein as such terms relate to sport of tour racing. In the foregoing description of the invention, no unnecessary limitations are to be implied from or because of the terms used, beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Furthermore, the description and illustration of the invention are by way of example, and the scope of the invention is not limited to the exact details shown, represented or described.
[0038] Having now described a preferred embodiment of the invention, along with certain alternative construction and suggested changes, other changes that may become apparent to those skilled in the art may be made, without departing from the scope of the invention defined in the appended claims. | A board game used for playing a bicycle or tour race with an improved game board. The game board includes indicia thereon which defines a plurality of parallel tracks which extend along an interior periphery of the game board, the tracks extending around the entire game board. At least a section of the parallel tracks pass through indicia on the game board defining a geographic area which includes indicia defining sites and places of interest within the geographic area defined. Overlay strips, defining other geographic areas with sites and places of interest within the other geographic area are provided, for changing the geographic area on the game board. The board includes a set of receiving and retaining slots for receiving and retaining overlay strips for changing the geographic area through which the tracks of the race pass. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/854,123 filed May 26, 2004, the disclosure of which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
FIELD OF INVENTION
This invention relates to continuous digesters for wood chips in the papermaking industry.
BACKGROUND OF INVENTION
As commonly practiced in the prior art relating to papermaking, wood chips and alkali liquor (white liquor) are pumped into the top of a hydraulic cooking vessel (digester, approximately 180 feet high and approximately 23 feet in diameter) that is operated at high pressure (165 psig) and temperature (325 degrees F.). A chip cooking process proceeds over the time that it takes the saturated chip column to move down through the digester where the discharge rate of the chips to a blow line at the bottom of the digester is matched to the feed rate at the top so as to maintain a constant level and retention time of the chips in the digester.
In the cooking process (delignification of wood chips), approximately 50% of the organic chip mass is dissolved in the cooking liquor. At 1 to 3 locations above the lower section of the digester, liquor containing the dissolved solids is removed from the vessel by extracting liquor through sets of screens in the circumferential wall of the digester, the screens being aligned with the inner wall of the digester vessel. The screens are 3 to 4 feet in height. The wash screens are the lowest (often the only) set of screens in a continuous digester and are located 10 to 20 feet up from the bottom of the digester. The screen plates are made from stainless steel with multiple slots cut in them that are 0.12 to 0.35 inch wide by 3 to 4 inches long depending on the location in the digester. The liquor that is extracted can be sent to a chemical recovery system where the liquor solids are concentrated and the organic solids burned in a chemical recovery boiler. The chemicals (inorganic solids) are recovered in the bottom of the recovery boiler and re-used to produce white liquor for the cooking process.
Just prior to discharge from the digester bottom, the chip mass is washed and cooled by cold (120 to 150 degrees F.) filtrate which is generated externally of the digester (from black liquor for example) and introduced into the wash zone of the digester. As much as possible remaining organic/inorganic material dissolved in the cooking liquor is removed from the chip column by a displacement and diffusion wash in the bottom of the digester by extraction of high-dissolved-solids hot liquor through the wash screens. To displace the high-solids hot liquor and to cool the chip mass, cooled black liquor filtrate is added to the bottom of the digester at several locations in the wash zone.
In some instances, some of the liquor extracted and/or a combination of lower solids liquors (black liquor and/or white liquor) is added to a center pipe (downcomer) in the digester that discharges in the center of the chip column adjacent to a given set of screens. The liquor added to the center pipe at least partially displaces the liquor being pulled through the extraction screens at such given set of screens.
In summary, the purpose of the wash screens is to remove high solids filtrate from the chip column as it passes these screens by the efficient displacement and diffusion wash with cooler and cleaner liquor added to counter wash nozzles, to ring dilution nozzles and/or to the center of the chip mass via a downcomer that discharges adjacent to these screens. The efficiency of the wash is measured by the extent to which there is maintained optimum low temperature of the chip mass discharged from the digester with concomitant minimization of the cooling of the wash liquor added to the wash zone.
Because of the nature of the compaction of the chip column, it is difficult to predict and/or control the uniform flow of re-circulation flows or free liquor upflows or downflows through the chip mass in a large diameter continuous digester of the prior art. In the wash zone, there is a tendency for upflows to short circuit up the sides of the digester and for liquor contained in the chip mass to be carried down with the chip mass only to be displaced from the chip mass at the very bottom of the wash zone.
Temperature and alkali uniformity in the wash zone are impacted by flows at the bottom of the wash zone and in the wash zone of the digester. The temperature and alkali uniformity in the wash zone are key factors in achieving uniform cook (delignification) across the column. Uniform delignification reduces cellulose (pulp fiber) attack, helping to achieve overall maximum pulp fiber strength and yield. Cook non-uniformity across the column profile, with accompanying non-uniform retention of lignin on the individual fibers is a common deficiency of known prior art digesters.
As noted, in the prior art, The liquor added to the bottom of the chip mass passes through the chip column via paths of least resistance to the wash screens. The wash screens accommodate this process anomaly by removing the most easily removable flow to support the total wash screens flow. This results in poor displacement and diffusion of dissolved solids (poor wash efficiency) in the chip mass to the wash screens and poor heat transfer in some portions of the chip column. The poor wash efficiency causes downstream problems in the brown stock treatment and bleaching processes. The poor heat transfer in the chip column at the bottom of the digester increases the energy costs in these two affected process areas. Also, during operation, individual wash screens tend to plug off completely with the other screens picking up the flow. Continuous digesters are only shut down for maintenance on an annual basis, due to cost of such shutdowns. In some cases it has been observed that one or two wash screens will plug and remain plugged for the remainder of the year only to be unplugged during the annual shut down. The chip column adjacent to plugged wash screens leads to poor wash efficiency and poor heat transfer.
Thus, the prior art is deficient in that:
1. The flow through each of the wash screens is variable and dependent on the path of least resistance flow of wash filtrate added to the bottom of the digester. This is observed physically by the wide variance in wash screen exit nozzle temperatures. 2. There is no known current method to control the individual wash screen flow and temperature in order to break up the pattern of path of least resistance flow of cold blow wash filtrate. Further, there is currently no known method to unplug the wash screens other than when the digester is empty during the annual shut down. 3. The upflow through the wash zone is operated at higher than optimum for alkali and temperature profile uniformity because of the current inability to manage and maintain an acceptable wash efficiency in the bottom of the digester. 4. There is no known current method for adjusting the amount of free liquor upflow through the wash zone in order to maintain uniformity of temperature and alkali in the wash zone where the highest percentage of the cook (time at temperature) is completed with the highest potential for product non-uniformity to be affected. Currently, in the prior art, a higher free liquor upflow is maintained in order to compensate for the non-uniformity of the operation of the wash screens. Whereas this higher free liquor upflow helps to manage the dissolved solids level in the digester discharge, such flow has a negative impact on the temperature and alkali profiles in the wash zone.
SUMMARY OF INVENTION
In accordance with one aspect of the present invention, the total volume of liquor withdrawn from the digester through the wash screens within the wash zone of the digester is uniformly and automatically distributed between all of the wash screens. To this end, in accordance with the present invention there are installed individual temperature measurement, flow measurement and flow control valves in association with each of the wash screen to control the flow through such wash screen to maximize energy and wash efficiency. Further, this feature provides for sensing of a screen in difficulty and individual isolation of a screen by closing it's flow control valve to allow the down flowing chip column to wipe a screen thereby cleaning and avoiding total plugging of the screen as occurs in the prior art.
Additionally, in the present invention, there is provided a central downcomer within the digester. This downcomer includes side discharge ports adjacent to the bottom end of the downcomer through which filtrate liquor is discharged into the digester. These discharge ports of the downcomer are disposed substantially radially of the surrounding wash screens such that the discharge streams of filtrate liquor from the ports are directed substantially radially toward the surrounding screens, thereby creating a layer of filtrate liquor flowing perpendicularly from the center of the digester toward all the screens. This flow pattern of liquor filtrate is directed across the downward flow of the chip mass and has been found to break up or discourage formation of upflow/downflow streams of filtrate liquor within the area of the screens.
As desired, the piping associated with the wash screens may be provided with automatic or manual back flush apparatus to allow reverse flow of filtrate through the screens to assist in clearing a screen that is showing signs of plugging.
Still further, in accordance with one aspect of the present invention the present inventors have found that reducing the wash zone free liquor upflow ((for example, from about the current 0.25 gpm/ADt/d (US gallons per minute per air dry tonne per day to a 0.007 gpm/ADt/d of free liquor upflow or downflow)), provides improved uniformity of the product leaving the wash zone.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing, as well as other objects and advantages of the invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like reference characters designate like parts throughout the several views, and wherein:
FIG. 1 is a schematic representation of a typical wood chip digester embodying various of the features of the present invention;
FIG. 2 is a schematic representation of a portion of the digester depicted in FIG. 1 and taken along the circle 2 of FIG. 1 ;
FIG. 3 is a schematic representation of various piping elements and flow directions of fluids into the digester from a downcomer and out of the digester via control elements associated with the present invention; and
FIG. 4 is detailed side view of the distal end of a downcomer as depicted in FIG. 1 .
DETAILED DESCRIPTION OF INVENTION
In the embodiment of the present invention depicted in FIGS. 1 and 2 , as noted hereinabove, approximately 50% of the organic chip mass 10 is dissolved in the looking liquor. The depicted digester 14 includes an upper zone 13 into which the chip mass is loaded. This is also the cooking zone. A set 16 of screens, twelve screens 18 in a typical embodiment, are disposed about the inner circumferential wall 20 of the digester at a location just below the cooking zone 13 and above a wash zone 24 which is disposed at the bottom end of the digester.
Liquor containing dissolved solids is extracted from the interior of the digester through the screens. The liquor extracted through the individual screens is conveyed to a discharge header 28 which encircles the girth of the digester externally of the digester in the region of the screens and is conveyed, as by a pump system 30 , to a chemical recovery station 32 or is selectively returned in part to the digester via a downcomer 54 . As desired, a heater may be interposed within the piping between the pump station and the downcomer to heat the filtrate prior to its return to the digester. The downcomer is located centrally of the digester and includes discharge ports 38 adjacent the lowermost end of the downcomer. As depicted in FIG. 1 , these ports are disposed substantially radially equidistant from the surrounding screens such that the filtrate liquor discharged through the ports is directed substantially radially outwardly (see arrows of FIG. 1 ) from the downcomer ports thereby ensuring that the filtrate liquor discharged from the downcomer flows simultaneously and substantially uniformly radially toward all of the screens. When the filtrate liquor discharged into the chip mass adjacent the wash screens is heated to about the cook filtrate liquor temperature, and by reason of the radially lateral flow of the discharge filtrate liquor, upflow or downflow of the liquor through the chip mass in the area of the screens is prevented or discouraged.
As needed or desired, black liquor from one or more known sources in a papermaking facility may be added to the filtrate liquor which is extracted from the screens and fed to the downcomer.
In the depicted digester, there is provided a single set 16 of wash screens includes multiple separate screens 18 covering the digester circumference. As noted, these screens serve to permit the withdrawal of hot liquor containing dissolved organic/inorganic solids from the digester for reuse or recovery of the individual components of the extracted filtrate. In accordance with one aspect of the present invention, and referring to FIGS. 1 and 2 , conveyance of extracted filtrate from each screen 18 is effected by means of a stub pipe 26 disposed behind each screen 18 and serves to accept the liquor extracted from the digester by the screen and to convey the same away from the screen. This stub pipe is in fluid flow communication with a discharge ring header 28 which encircles the digester outside of and along the outer wall 42 of the digester and which serves to convey the filtrate from the several screens to a pump station.
With specific reference to FIGS. 2 and 3 , in accordance with the present invention, a continuous digester 14 having a set 16 of screens 18 disposed about its inner circumference 20 for withdrawal from the digester through the screen solids-bearing hot liquor, is provided with a combination of elements associated with the stub pipe 26 which is in fluid communication between each screen and a generally circular discharge collection header 28 disposed externally about the outer circumference of the digester. In the depicted embodiment of the invention, these elements are interposed along the length of the stub pipe and between the outer wall of the digester and the header. Each such combination of elements includes a first manual valve 50 located adjacent the digester outer wall, a temperature sensor 52 next to the first manual valve, an electronically controlled valve 54 next to the temperature sensor, a flowmeter 56 next to the electronically controlled valve, and a second manually operated valve 58 adjacent the header. As seen in FIG. 1 , the header is in fluid communication with a pump 30 which functions to draw the hot liquor extracted by each screen through the header to remote locations such as a chemical recovery station 32 , etc.
FIG. 3 schematically depicts the combination of elements referenced above and shows the association of a combination of elements associated with each individual screen. In this FIG. 3 , the valves associated with back wash of each screen, as seen in FIG. 2 , have been omitted for purposes of clarity.
In the present invention, hot liquor extracted from the digester through a given screen flows through the combination of elements which are interposed between the digester and the header. In the depicted embodiment, the discharge flow of hot liquor initially encounters the first manual valve 50 . This valve is manually operable to provide a means for manually adjusting the outflow from a given screen to either full flow, partial flow, or no flow. Next in line, the discharge flow encounters the temperature sensor 52 which includes an electrical lead 60 that passes to a controller 62 . Next in line, the discharge flow encounters the electronically controlled valve 54 having an electrical lead 64 that passes to the controller. Next in line, the discharge flow encounters the flowmeter 56 which also includes an electrical lead 66 which passes to the controller. Finally in line, the discharge flow encounters the second manually operated valve 58 and then flows into the header 28 . In the depicted embodiment there is provided a conduit 68 which intersects the stub pipe at a location between the flowmeter and the second manual valve. This conduit is provided with a third manually operated valve 70 .
Operationally, the first manually operated valve 50 functions to allow manual control over the flow through the stub pipe (irrespective of direction of flow) as either full flow, partial flow or no flow. Thus, this first valve functions as a type of override to any automatic control over the flow between the digester and the header, and in a backwash situation to assist in the flow control of backwash liquid to a screen. For back washing of a screen, the automatic control of the flow of discharge liquor from the screen toward the header is deactivated (as by the controller), the second manual valve 58 is closed to close off all flow to the header, and the third valve 70 is opened to admit backwash liquid into the stub pipe, thence to the screen at a flow rate which can be selected by either or both of the first and third manual valves.
During normal operation of the digester, with the second and third manual valves closed, and the first manual valve open, the outflow of hot liquor through each of the screens of the set of screens is selected automatically via the controller. Specifically, as hot liquor is withdrawn through a given screen, under the influence of the pump 30 , this discharge liquor encounters the temperature sensor 52 which senses the temperature of the discharge flow and develops an electrical signal which is representative of such flow and transmits such signal to the controller. Like signals representative of the temperature of the discharge flow from each of the screens are fed into the controller where these temperatures are compared to one another and to a temperature which is representative of the desired flow from each screen and which serves as a standard against which each of the discharge flows of each of the screens is compared. Variations in the temperature of the discharge flow from a given screen from the standard temperature are indicative, first, of the existence of flow from the screen, and, second, of the possible existence of cool upflow liquor from the wash zone reaching the screen without passing through the chip mass as a disbursed stream.
After the discharge flow passes the temperature sensor, it encounters the electronically controlled valve 54 which functions to adjust the rate of discharge flow to a value which is determined by the controller.
Downstream of the electronically controlled valve, the discharge flow encounters the flowmeter whose function is to sense the rate of flow of the discharge liquor through the stub pipe, generate an electrical signal representative of the sensed rate of flow and transmit such signal to the controller via the electrical lead 66 .
From the foregoing, it will be evident that if a screen is fully plugged, all flow of hot liquor through the screen will be halted. In this event, the there is no flowing hot liquor to contribute to the temperature sensed by the temperature sensor so this sensor will report to the controller a relatively cool temperature. Within the controller this cooler temperature will be compared to the normal hot liquor temperature, or other set temperature, and generate a signal to the operator to alert the operator to this undesirable condition. Likewise, the flowmeter will signal the controller that there is no flow through the stub pipe, this condition also possibly being the result of a plugged screen. In the present system, to avoid actual full plugging of a screen, the controller may be set to alert the operator when there is only a small drop in the temperature of hot liquor and/or small drop in the flow rate of the hot liquor passing through the stub pipe so that the operator may take remedial action immediately to remedy the plugging of the screen. This combination of a reduction in the anticipated flow rate through a stub pipe as sensed by the flowmeter which also sends to the controller a signal representative of such reduced flow to the controller, with the sensed reduction in temperature of the flowing hot liquor provides a novel improved concept for monitoring the operability of each individual screen. Thus, the signal from the flowmeter provides the controller with a signal, which compliments the signal to the controller from the temperature sensor.
In like manner, if the temperature within the stub pipe is within a range recognized by the controller as acceptable, but the flow rate of hot liquor through a given stub pipe increases above a standard value set in the controller, such conditions may indicate that more than anticipated hot liquor is flowing through the given stub pipe. This condition can be indicative of the lack of contribution to the overall desired discharge rate of hot liquor from the digester by one or more of the other screens, for example, and an alert to the operator to at least investigate the digester operating conditions and, if needed, take remedial action. Thus, it is seen that the combination of the temperature sensor and the flow meter are essential to the successful functioning of the present invention.
Further, if the rate of flow of hot liquor through the stub pipe is within a range set in the controller, but the temperature of the flow of hot liquor is lower than anticipated, such condition may be indicative of relative cool wash liquor moving upwardly of the digester into the area of the screens, such flow of cool wash water being possibly due to too much wash water being added to the bottom end of the digester or the existence of excess upflow of the wash liquor to a given screen or screens.
Other combinations of sensed temperature and independently sensed flow rate may be indicative of other operating conditions within the digester which may call for operator interdiction. For example, since the flow of hot liquor from each screen is monitored, both for temperature and flow rate, independently of every other screen, it may be readily determined if one or more screens is not functioning as desired, and importantly, which one or more screens is involved, thereby localizing a malfunction within the digester.
The present invention provides prompt and early indication of a source of possible trouble with respect to the outflow of hot liquor from the digester. In this respect, if a given screen or screens is noted to be plugging, the operator can close down outflow from such screen or screens, thereby allowing the downflowing chip stream to sweep the surface of the screen interiorly of the digester and remove all or part of any material which is attempting to plug the screen or screens. If this technique is unsuccessful, the operator further has the option of back washing the screen or screens individually employing the first, second and third manually operable valve which are associated with the stub pipe of each screen.
In accordance with one aspect of the present invention, hot liquor withdrawn from the digester through the screens and after being subjected to chemical recovery, is reintroduced to the interior of the digester through the downcomer which is aligned with the vertical centerline 74 . In the present invention, contrary to the prior art, the discharge ports in the bottom end of the downcomer are disposed both centrally of the interior of the digester and radially aligned with the screens which surround the downcomer. In this manner, the present inventors provide for the injection into the chip mass of a substantially circular sheet of fresh hot liquor which flows from the downcomer ports radially toward the screens. This flowing sheet of hot liquor has been found to eliminate or substantially discourage the development of upflows or downflows within the chip mass at substantially all points radially between the downcomer and the screens in the digester wall. This effect has been particularly noted in the regions of the perpendicular cross-section of the digester at the level of the screens and adjacent the screens for reasons not fully understood.
In addition to the recycling of treated hot liquor which has been withdrawn from the digester via the discharge header and fed back into the digester via the downcomer, cold filtrate (below the cooking temperature of the chip mass in the digester) from black liquor sources common in a papermaking facility, may be introduced into the bottom end of the digester as wash liquor as by a pump and associated piping as is known in the art. As desired or needed, such black liquor may be added to the digester through the downcomer, either as a substitute for hot liquor from the chemical recovery station or as an additive to the hot liquor from the recovery station.
Control over the flow of black liquor into the digester may be controlled through the controller, and a plurality of electrically operable valves, such as valves 73 , 76 and 78 . Each of these, and all others of the electrically operable valves includes a respective electrical lead between the controller and each such valve. In the Figures, the the electrical leads from these and others of the electrically responsive elements are indicated in dashed lines for purposes of clarity, but in all instances these electrical leads extend between the respective valve or element and the controller. | A continuous digester comprises a wash zone having a plurality of individual wash screens disposed about an inner wall of the digester for the withdrawal of co-current downflow liquor from the wash zone. A conduit is connected in fluid communication between each of the wash screens and a collector for co-current downflow liquor withdrawn from the wash zone of the digester. A valve is interposed along the length of the conduit leading from each of the wash screens. The valve is operable between open and closed positions in response to a signal received from a temperature sensor associated with the conduit leading from each of the wash screens. The signal represent changes in temperature of a corresponding co-current down flow liquor through a corresponding conduit wherein a corresponding valve permits adjustment of a corresponding flow rate of liquor through said corresponding conduit to a flow rate that is substantially equal to each of the other flow rates of co-current downflow liquor through each of the other conduits. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a division of U.S. patent application Ser. No. 13/934,600, filed Jul. 3, 2013, entitled “PRE-STRESSED PRESSURE DEVICE”, which is currently pending.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a device and system for treating a patient. Specifically, the invention relates to a pre-stressed pressure device that applies pressure to a wound and/or scar to promote healing and reduce the appearance of scars and to a system for making and using the pre-stressed pressure device.
[0004] 2. Description of the Related Art
[0005] Applying pressure to a patient's wound is beneficial because pressure provides immediate hemostasis and decreases swelling and bruising associated with the wound. An added benefit for traumatic or surgical wounds that require sutures is diminished swelling resulting in less tension across the suture lines. This facilitates healing and improves the quality of the final scar by decreasing suture marks and irregularities formed in the skin as the tissue surrounding the wound heals.
[0006] Wounds may take many forms. Herein, “wound” is intended to be as broadly inclusive as possible and means one or more injuries to at least the skin of a person. Wound may mean cuts and lacerations that are self-treated by a patient. It may also mean serious wounds caused by traumatic injuries that are treated in a medical setting; wounds caused by surgery; or vascular cutaneous puncture sites such as intravenous catheter, arterial catheter, or the like.
[0007] As wounds heal, applying pressure prevents scarring. The skin at any site of the body comprises an intrinsic tension that stretches the marginal area of the skin surrounding the wound. The actual amount of tension may vary, depending upon the person, age, skin type, and wound location. Pre-existing skin conditions, such as scarring, may also affect the intrinsic tension. During the intermediate phase of a wound healing process (between 2 weeks and 12 weeks), the edges of a healing incision or wound, are pulled in different directions by surrounding skin, causing formation of the scar tissue.
[0008] Even after scarring has formed, applying pressure is an integral component of a scar reduction regimen. Typically, a silicone gel sheet is fastened to a patient using a bandage wrapped tightly around the patient's limb or torso. When combined with glucocorticoid steroids, the result reduces the appearance of hypertrophic (thick) scars.
[0009] Herein, “scar” and/or “scarring” is intended to be as broadly inclusive as possible and means at last one or more temporary or permanent deformations of any part of the skin due to injury to the skin.
[0010] Unfortunately, to date, the various technologies available for providing pressure on a wound and/or scar require bulky or impractical devices. Thus, what is desired is a wound and scar treatment that provides pressure to a wound and/or scar and that is compact and a system for making and using that treatment.
SUMMARY OF THE INVENTION
[0011] These and other objectives are met by the present invention.
[0012] In accordance with one or more embodiments of the present invention, a pre-stressed pressure device is preferably configured as a pressure bandage for treating a wound or to reduce scarring of the skin of a patient. The pressure bandage includes a substrate assembly having a first surface, a pressure member having a curve in a central portion, the pressure member being secured to the substrate assembly; a treatment device for exerting a pressure on the wound or the scarring, the treatment device being connected to a first area of the first surface; and an adhesive for applying the pressure bandage to the skin, the adhesive being disposed on a second area of the first surface, the first and second areas being non-overlapping.
[0013] In accordance with one or more embodiments of the present invention, a pre-stressed pressure device is preferably configured as a pressure bandage for treating a patient. The pressure bandage includes a substrate assembly, a treatment device mounted on the substrate assembly, an adhesive disposed on the substrate assembly, the adhesive for securing the pressure bandage to the patient, and a pressure member secured to the substrate assembly. Therein, the pressure member is in a substantially curved state when the pressure bandage is not secured to the patient.
[0014] The pressure member includes a center portion and an end portion, which have a different thickness or a different width from each other.
[0015] The pressure member includes a plurality of disconnected portions disposed in a plurality of planes.
[0016] A system for treating a wound or scarring of a patient includes a pressure bandage comprising a pressure member having a pre-tension, a 3D printer for printing the pressure member, and a heater for selective heating an area of the pressure member to impart the pre-tension.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 a is a schematic plan view of a wound and scar being treated by the present invention.
[0018] FIG. 1 b is a cross-sectional area view of the wound of FIG. 1 a being treated by the present invention and a pressure diagram associated with the present invention.
[0019] FIG. 2 a is a top plan view of a pre-stressed pressure device that is configured as a bandage in accordance with one or more embodiments of the present invention.
[0020] FIG. 2 b is a bottom plan view of the bandage of FIG. 2 a.
[0021] FIG. 2 c is a longitudinal side view of the bandage of FIG. 2 b.
[0022] FIG. 2 d is a first transverse cross-sectional view of the bandage of FIG. 2 a.
[0023] FIG. 2 e is a second transverse cross-sectional view of the bandage of FIG. 2 a.
[0024] FIG. 2 f is a longitudinal cross-sectional view of the bandage of FIG. 2 a.
[0025] FIG. 3 a is a schematic view of the bandage of the present invention of FIG. 2 a prior to being applied to the wound of FIGS. 1 a and 1 b.
[0026] FIG. 3 b is a detail view of the treatment device of the present invention of FIG. 2 a after being applied to the wound of FIGS. 1 a and 1 b.
[0027] FIG. 3 c is a schematic view of the present invention of FIG. 2 a after being applied to the wound of FIGS. 1 a and 1 b and pressure diagrams associated with the present invention.
[0028] FIG. 4 a is a longitudinal cross-sectional view of the pressure member of the bandage of FIG. 2 a.
[0029] FIG. 4 b is a first transverse cross-sectional view of the pressure member of FIG. 4 a.
[0030] FIG. 4 c is a second transverse cross-sectional view of the pressure member of FIG. 4 a.
[0031] FIG. 5 a is a top plan view of a bandage in accordance with one or more embodiments of the present invention.
[0032] FIG. 5 b is a bottom plan view of the bandage of FIG. 5 a.
[0033] FIG. 5 c is a longitudinal side view of the bandage of FIG. 5 b.
[0034] FIG. 6 a is a top plan view of a bandage in accordance with one or more embodiments of the present invention.
[0035] FIG. 6 b is a bottom plan view of the bandage of FIG. 6 a.
[0036] FIG. 6 c is a longitudinal side view of the bandage of FIG. 6 b.
[0037] FIG. 7 a is a plan view of a pressure member in accordance with one or more embodiments of the present invention.
[0038] FIG. 7 b is a cross-sectional view of the pressure member of FIG. 7 a.
[0039] FIG. 7 c is a first alternate cross-sectional view of the pressure member of FIG. 7 a.
[0040] FIG. 7 d is a second alternate cross-sectional view of the pressure member of FIG. 7 a.
[0041] FIG. 7 e is a plan view of a pressure member in accordance with one or more embodiments of the present invention.
[0042] FIG. 7 f is a plan view of a pressure member in accordance with one or more embodiments of the present invention.
[0043] FIG. 8 a is a plan view of a pressure member in accordance with one or more embodiments of the present invention.
[0044] FIG. 8 b is a longitudinal cross-sectional view of the pressure member of FIG. 8 a.
[0045] FIG. 8 c is an alternate longitudinal cross-sectional view of the pressure member of FIG. 8 a.
[0046] FIG. 9 a is a plan view of a pressure member in accordance with one or more embodiments of the present invention.
[0047] FIG. 9 b is a plan view of a pressure member in accordance with one or more embodiments of the present invention.
[0048] FIG. 9 c is a longitudinal cross-sectional view of the pressure member of FIG. 9 b.
[0049] FIGS. 10 a - 10 c and 11 a - 11 c are, respectively, plan, side, and side on skin views of a bandage in accordance with one or more embodiments of the present invention.
[0050] FIG. 12 a is a longitudinal side view of a pre-stressed pressure device that is configured as a stress guard prior to being applied to a patient in accordance with one or more embodiments of the present invention.
[0051] FIG. 12 b is a longitudinal side view of the stress guard of FIG. 12 a applied to a patient when initially applied to an open incision site.
[0052] FIG. 12 c is a longitudinal side view of the stress guard of FIG. 12 a after being stressed.
[0053] FIG. 12 d is a first detail view of the stress guard of FIG. 12 a.
[0054] FIG. 12 e is a second detail view of the stress guard of FIG. 12 a.
[0055] FIG. 13 is a diagram illustrating a treatment system for making a pre-stressed pressure device for treating a wound and/or reducing scarring in accordance with one or more embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0056] The following detailed description is of the best mode or modes of the invention presently contemplated. Such description is not intended to be understood in a limiting sense, but to be an example of the invention presented solely for illustration thereof, and by reference to which in connection with the following description and the accompanying drawings one skilled in the art may be advised of the advantages and construction of the invention. In the various views of the drawings, like reference characters designate like or similar parts.
[0057] FIG. 1 a is a schematic plan of a wound and scar being treated by the present invention. FIG. 1 b is a cross-sectional area of the wound of FIG. 1 a being treated by the present invention and a pressure diagram associated with the present invention.
[0058] Therein, a patient 100 has sustained a wound 110 as is commonly understood and at least as defined in the Description of the Related Art. The wound 110 has a wound area 112 that is determined by the type and cause of the wound and a treatment area 114 . The treatment area extends from a regularized margin 116 of the wound to encompass the wound and an area most likely to be scarred by scarring 118 , such as hypertrophic, as determined by a patient, but preferably by a qualified medical practitioner. A “regularized margin” herein means a theoretical margin of the wound that extends in a regular geometric pattern of an ellipse or a circle about the wound and touches the furthest extent of the actual margin of the wound at at least three points. To treat the wound 110 and prevent likely scarring 118 , a pressure P, shown as exemplary pressure 190 in the pressure diagram of FIG. 1 b , is applied by a treatment device (not shown) on at least the treatment area 114 using a pressure bandage 10 .
[0059] It should be understood that the present invention may also be applied to only a scar. Therein, the wound area 112 is nil and the treatment area 114 extends to encompass the area scarred by scarring 118 , such as hypertrophic scarring, as determined by a patient, but preferably by a qualified medical practitioner. To treat scarring 118 , pressure P, is applied by a treatment device on at least the treatment area 114 using a pressure bandage 10 .
[0060] Pressure P is preferably non-uniform and is greater over the treatment area 114 than in other areas where the pressure bandage is applied. The particular diagrammatic shape and/or amount of pressure P are dependent on the shape of a pressure member in plan view, thickness, and amount, i.e., degree of pre-stressing.
[0061] FIG. 2 a is a top plan view of a pre-stressed pressure device that is configured as a bandage in accordance with one or more embodiments of the present invention. FIG. 2 b is a bottom plan view of the bandage of FIG. 2 a . FIG. 2 c is a longitudinal side view of the bandage of FIG. 2 b . FIG. 2 d is a first transverse cross-sectional view of the bandage of FIG. 2 a . FIG. 2 e is a second transverse cross-sectional view of the bandage of FIG. 2 a . FIG. 2 f is a longitudinal cross-sectional view of the bandage of FIG. 2 a.
[0062] FIG. 3 a is a schematic view of the bandage of the present invention of FIG. 2 a prior to being applied to the wound of FIGS. 1 a and 1 b . FIG. 3 b is a detail view of the treatment device of the present invention of FIG. 2 a after being applied to the wound of FIGS. 1 a and 1 b . FIG. 3 c is a schematic view of the present invention of FIG. 2 a after being applied to the wound of FIGS. 1 a and 1 b and pressure diagrams associated with the present invention.
[0063] FIG. 4 a is a longitudinal cross-sectional view of the pressure member of the bandage of FIG. 2 a . FIG. 4 b is a first transverse cross-sectional view of the pressure member of FIG. 4 a . FIG. 4 c is a second transverse cross-sectional view of the pressure member of FIG. 4 a.
[0064] In accordance with one or more embodiments of the present invention, a pre-stressed pressure device is configured as a pressure bandage 10 . The pressure bandage 10 is preferably used for treating the wound 110 and comprises a pressure member 14 , a substrate assembly 16 , and a treatment device 22 joined to the substrate assembly. The pressure member 14 is secured to the substrate assembly 16 and applies a force to the treatment device 22 . In turn, the treatment device 22 applies pressure P, i.e., the pressure 190 , within at least the treatment area 114 of patient 100 to promote healing and/or reduce scarring when the bandage 10 is secured to the skin of the patient 100 .
[0065] The pressure member 14 comprises one or more layers of one or more pressure materials.
[0066] A pressure material may be any suitable material that is elastic and capable of holding an initial non-flat shape, preferably a curved shape. However, preferably, the pressure material is a polymer material. More preferably, the pressure material is selected from the group of polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS); nylon polymers including polyamide 6, polyamide 66, homopolymers, and co-polymers; polyester resin; low-density polyethylene terephthalate (PET); low-density polyethylene, high-density polystyrene; high-density polyethylene; and rubberized and/or plasticized PVC.
[0067] The pressure member 14 comprises, but not necessarily, a generally rectangular shape in plan view having end portions 14 a (each defined as being generally, but not necessarily, the one-third end area in plan view of the pressure member) spaced distal from a central portion 14 b (defined as being generally, but not necessarily, the center one third area in plan view of the pressure member) and has a thickness 14 c . The thickness 14 c is preferably sufficient to prevent the longitudinal edges of the pressure member 14 from curling inwards towards the longitudinal centerline of the pressure member. That is, the thickness 14 c is chosen such that the pressure member remains rigid in a cross-section perpendicular to the longitudinal centerline of the pressure member.
[0068] Therein, the thickness 14 c may be varied as needed for the specific embodiment of the bandage 10 and may be non-uniform and variable in thickness across the width and/or along the length of the pressure member 14 . The thickness preferably also provides the bandage 10 with sufficient load carrying capacity to achieve the desired pressure strains needed for the therapeutic effect on the wound 110 and/or the scarring 118 . The thickness 14 c of the pressure member 14 may be tapered near the edges for added comfort and/or safety of use.
[0069] The pressure member 14 normally has a curved shape in at least part of the central portion 14 b while the end portions 14 a are straight. In other words, the pressure member 14 has a normally curved state 15 a , i.e., first state. This state occurs prior to the pressure bandage 10 being applied to the skin of the user.
[0070] The curved shape in at least part of the central portion 14 b may be achieved by casting, extruding, and/or forming central portion to be curved. Therein, the central portion 14 b may have any suitable curve while the end portions 14 a are straight.
[0071] The curved shape may also be made by pre-stressing the pressure member in a pre-stressed area 14 d ( FIG. 4 a ), such as being heat-treated. Therein, the pre-stressed area 14 d is preferably disposed in the central portion 14 b . In the pre-stressed area, the pressure member has been stressed increasing the compression side 14 e , moving the neutral axis 14 f in the pre-stressed area 14 d , and causing the tension side 14 g to be reduced.
[0072] In the curved state 15 a , the pressure member 14 is curved in the pre-stressed area 14 d , i.e., at least part or all of the central portion 14 b , while the end portions 14 a are straight. Therein, the end portions 14 a are preferably, but not necessarily, equidistant from the central portion 14 b in lateral and offset directions and are curved in the same direction. When the pressure member 14 is in the curved state 15 a , the bandage 10 generally follows the same curved contour as the pressure member 14 and also is in the curved state 15 a.
[0073] When the bandage 10 has been applied to the patient 100 , the pressure member 14 will be in a non-curved, substantially non-curved state 15 b , i.e., second state. When the pressure member 14 is in substantially the non-curved state 15 b , the bandage 10 generally follows the same contour as the pressure member 14 and also is in substantially the non-curved state 15 b . The non-curved state 15 b may be a flat state or contour, and/or may be one where the pressure member, i.e., pressure bandage, follows the contour of the skin.
[0074] In the substantially non-curved state 15 b , the pressure member 14 exerts a force F 1 . The force F 1 has end forces F 1 a and F 1 b directed away from the patient 100 and a central force F 1 c directed toward the patient 100 and forcing the treatment device 22 onto at least the treatment area 114 . That is, when the pressure member 14 is straightened, the region of the pressure member 14 that has not been pre-stressed will pull upwards with forces F 1 a and F 1 b in an evenly dispersed manner while the force F 1 c in the region that has been pre-stressed, i.e., the central portion 14 b , will be applied downward with a force equal to the sum of the forces F 1 a and F 1 b . The force F 1 c will be at maximum at the center the pressure member vary along the central portion 14 b.
[0075] Advantageously, the pressure material may be pre-stressed to a predetermined amount, and thus, the amount of curvature may be selectively predetermined to the pressure member 14 . In turn, by varying the curvature, the central portion 14 b can be predetermined to exert a specific force F 1 c on the wound 110 . In addition or in the alternative, the shape and/or the thickness 14 c of the pressure member may be selected, as taught further herein, to provide further predetermined refinement of the force F 1 c . For example, by increasing the size of the edge portions 14 a relative to the central portion 14 b , a greater force F 1 c will be generated. The force F 1 c is transferred as pressure to the patient via the treatment device, since pressure is force per unit area.
[0076] Therein, increasing the force F 1 c will yield an increase in pressure applied to at least the treatment area 114 via the treatment device.
[0077] The pressure member 14 may have a thickness of 100 microns to at least 1 mm, but preferably with a range of about 220 microns to about 500 microns, or more preferably 300 microns to 400 microns.
[0078] The substrate assembly 16 comprises at least two substrate members 18 a , 18 b and an adhesive 20 a applied in an adhesive area 20 b of the substrate assembly 16 . Substrate members 18 a , 18 b may be made of any suitable material 19 a that is durable, stretchable, and resiliently flexible as is known in the art for adhesive bandages.
[0079] However, preferably, each substrate member, when made of a single layer, comprises or consists of a material 19 a and, when made of a multilayer structure, comprises a covering made of a material 19 a and one or more support layers made of a material 19 b . The material 19 a used may be made entirely of or comprise a woven material such as cloth in any suitable weave strength and may metal-detectable fabric, such as metal fibers, to permit the use of the bandage 10 in food service and/or processing industry. The material 19 a may also be a light woven material for comfort or a heavy woven material for protection. The material may be chosen such that it is air permeable to permit air to access the wound 110 and/or the treatment area 114 .
[0080] The material 19 a may also be made entirely of or comprise a plastic material or rubber material as is known in the art for adhesive bandages due to their excellent stretchability, costs, and/or wearability.
[0081] The substrate members 18 a and 18 b may also comprise a multilayer structure. Therein, one or more material layers comprise or consist of a material 19 b , which may be cotton, artificial and/or natural fibers, artificial and/or natural gel materials, natural or artificial foamed rubber and/or vinyl, or a combination thereof may be added to the covering.
[0082] The adhesive 20 a may be one or more suitable pressure-sensitive adhesives as is known in the art for adhesive bandages. Due to their excellent adhesion strength, usability, costs, and/or length of use, the adhesive 20 a is preferably selected from the group of acrylic, silicone, butyl rubber, nitrile, styrene block copolymers (SBC), ethylene-vinyl acetate (EVA), or a combination thereof. In addition or in the alternative, the adhesive 20 a may be a polyacrylate-based, polyisobutylene-based, and/or silicone-based pressure-sensitive adhesive; or a synthetic rubber, acrylic, hydrocolloid, or a like compound adhesive. In addition or in the alternative, the adhesive 20 a may also be a light-curable or heat-curable adhesive.
[0083] Preferably, regardless of type, the adhesive 20 a comprises a T-peel release force of in the range of 0.45 N/cm to at least 19 N/cm. Therein, the T-peel release force and blunt probe tack force of pressure-sensitive adhesives is in accordance with ASTM D1876 and ASTM D2979 or other appropriate methods.
[0084] The adhesive 20 a is applied in the adhesive area 20 b to the substrate assembly. Therein, the adhesive area 20 b is preferably a marginal area of the substrate assembly 16 that surrounds the treatment device 22 and is non-overlapping with the treatment device 22 , which is also attached to the substrate assembly 16 , to provide maximum adhesion to the skin of the patient 100 .
[0085] The substrate members 18 a and 18 b are preferably sized similarly and define the maximum extent of both the bandage 10 and the substrate assembly 16 in plan view. In accordance with one or more embodiments of the present invention, a pressure bandage 10 exerts a pressure P having a pressure component 190 and one or more pressure components 191 . The pressure component 190 is the result of the force F 1 and F 2 and each pressure component 191 is the result of only the force F 2 .
[0086] The minimum size of the substrate assembly 16 is determined by the size of the adhesive area 20 b needed for an adhesive 20 a to create the force F 2 to overcome the forces F 1 a and F 1 b of the pressure member and to adhere the bandage 10 to the skin with sufficient forces to overcome unintended removal of the bandage 10 from the skin. Thus, when the bandage 10 has been applied to the patient 100 , at least the force F 1 c is exerted onto the treatment device 22 , in turn, creating the pressure 190 onto at least the treatment area 114 .
[0087] In accordance with one or more other embodiments of the present invention, the size of the substrate assembly 16 may be determined by the size of adhesive area 20 b needed for the adhesive 20 a to create the force F 2 to overcome at least the forces F 1 a and F 1 b of the pressure member, to adhere the bandage 10 the skin of the patient with sufficient forces to overcome unintended removal of the bandage 10 from the skin, and, further to add to the pressure applied by the pressure member 14 to the treatment device. Thus, preferably, the adhesive placed in the adhesive area 20 b exerts a force F 2 onto the substrate assembly 16 , or more specifically, to the pressure member 14 to prevent the pressure member from removing the bandage from the skin of the patient. Thus, when the bandage 10 has been applied to the patient 100 , the force F 1 c and a portion of the force F 2 is exerted onto the treatment device 22 , in turn, creating the pressure 190 onto at least the treatment area 114 .
[0088] The pressure member 14 may be disposed in the substrate assembly 16 by being embedded or sandwiched between the substrate members 18 a and 18 b and additionally may be secured as described below. However, the pressure member 14 may also be disposed or embedded solely within one of the substrate members or may be embedded such that a longitudinally-extending or laterally-extending portion of the pressure member is embedded solely in one substrate member. The other longitudinally-extending or laterally-extending portion of the pressure member is then embedded in the other substrate member or when three or more substrate members are present in one or more of the other substrate members.
[0089] In addition, the pressure member 14 may be joined to, joined with, disposed in, or disposed on, or embedded in the substrate using an adhesive, sonic welding, heating, stamping, or any other suitable means that aids in avoiding unintended movement of the pressure member 14 relative to the substrate assembly 16 .
[0090] Regardless of how the pressure member 14 is disposed in the substrate assembly 16 , the substrate assembly 16 comprises a marginal edge area 18 c in plan view between a perimeter of the pressure member and a perimeter of the substrate assembly. The marginal edge area 18 c also advantageously aids in keeping the pressure member 14 securely located relative to the substrate assembly 16 .
[0091] The substrate members 18 a and 18 b may be secured to each other by using an adhesive, sonic welding, heating, stamping, or any other suitable means that aids in avoiding unintended movement of the substrate members relative to each other. Moreover, the perimeter and/or a perimeter margin of the substrate assembly 16 may have a finished and reduced thickness relative to other portions of the substrate assembly 16 by crimping, flattening, sonically welding, and/or stamping the perimeters of the substrate members 18 a , 18 b . This advantageously prevents the unintended separation of the substrate members from each other.
[0092] The treatment device 22 is joined to the substrate assembly 16 using an adhesive, sonic welding, heating, stamping, or any other suitable means that aids in avoiding unintended dislocation of the treatment device relative to the substrate assembly.
[0093] In accordance with one embodiment of the present invention, the treatment device 22 may comprise or consist of an absorbent pad made from cotton gauze or fabric, but the treatment device 22 may also comprise or consist of an absorbent material impregnated with one or more anti-bacterial agents or substances generally known in the art.
[0094] The treatment device 22 may also may comprise or consist of one or more scar reducing materials such as silicone formed into a pad.
[0095] The treatment device 22 may also comprise or consist of a combination pad wherein a skin proximal layer is an absorbent material joined to a skin distal layer made of one or more scar reducing materials. This advantageously immediately permits hemostasis and initiates a regimen of scar reduction.
[0096] In accordance with one or more embodiments of the present invention, the treatment device 22 for a wound may comprise an absorbent material and may have a thickness of approximately 220-500 microns at a center of the pad for maximum comfort and absorbency while marinating a clinically suitable pressure on the wound. The treatment device 22 may have a silicone pad for scar reduction and may achieve a pressure of 10 to 25 mm Hg, i.e., 10 to 25 Torr, of pressure under the pad for a clinically suitable pressure to reduce scarring.
[0097] In accordance with one or more embodiments of the present invention, the treatment device 22 may comprise one or more therapeutic agents beneficial to wound healing and/or scar reduction that may be disposed in or on the absorbent pad of the treatment device, but also packaged with bandage 10 in a kit. For example, therapeutic agents may be Vitamin E and/or one or more hemostatic and/or coagulative agents. Hemostatic and/or coagulative agents may comprise epinephrine, calcium alginate, calcium-loaded zeolite, cellulose, microfibrillar collagen, fibrinogen, glucosamine, thrombin, coagulation factors (e.g. II, VI, VII, X, XIII, VWF), procoagulants, antifibrinolytics (e.g. epsilon aminocaproic acid), and/or similar compounds.
[0098] A therapeutic agent may also be an antibiotic disposed in or on the treatment device, but also packaged with the bandage 10 in a kit. A therapeutic agent may be, but is not limited to, cephalosporins, polymyxin B sulfate, bacitracin, neomycin, polysporin), antiseptics (such as iodine solutions, silver sulfadiazine, chlorhexidine) and/or other treatments (e.g. botulism toxin, growth factors).
[0099] The bandage 10 preferably includes a pair of protective sheets disposed on the side proximal to the treatment device as are generally known in the art.
[0100] The bandage 10 may also be packaged in a sterile packaging that is easily removable by peeling two protecting sheets apart as is generally known in the art.
[0101] Since the bandage 10 generally follows the same curved contour as the pressure member 14 in the curved state 15 a , the curved shape of the bandage, advantageously, permits nested packaging.
[0102] A plurality of the bandages 10 may be packaged to have treatment regimen starting with control of the wound using the bandages having treatment devices consisting of absorbent pads to bandages having treatment devices consisting of combination pads and ending with bandages having treatment devices having only scar reducing materials.
[0103] In accordance with one or more embodiments of the present invention, the bandage 10 may also be used for treatment of skin-related conditions such as skin injuries, including for example, incisions, acute or chronic wounds, ulcers, and venopuncture areas; preventing or reducing the incidence of wound infections, swelling and hematoma formation; treatment of skin irritation and sensitivity, skin paresthesia, allodynia, dermatitis, warts, rashes, acne, and psoriasis; management of arteriovenous malformations; treatment or improvement of wrinkles, scars, stretch marks or other skin irregularities; and/or delivering a drug to the skin or through the skin.
[0104] In accordance with one or more embodiments of the present invention, the bandage 10 further comprises, in any convenient location, one or more designs, logos, advertisements, treatment information, contact names and numbers, and/or marketing information.
[0105] In accordance with one or more embodiments of the present invention, the bandage 10 , as for example, illustrated in FIGS. 2 a - 2 f and 3 a - 3 c , comprises a length 11 a of approximately 50 mm to 190 mm and a width 11 b of 22 mm to 100 mm. The bandage further comprises a thickness 11 c in the range of 100 microns to at least 1 mm. Greater thicknesses may be possible depending on the thickness of the pressure member and generally vary between 1 mm to 3 mm.
[0106] Other bandages 10 may be suitably dimensioned in accordance with needs associated with a wound 110 or scarring 118 .
[0107] FIG. 5 a is a top plan view of a bandage in accordance with one or more embodiments of the present invention. FIG. 5 b is a bottom plan view of the bandage of FIG. 5 a . FIG. 5 c is a longitudinal side view of the bandage of FIG. 5 b.
[0108] In accordance with one or more embodiments of the present invention, a bandage 10 a is constructed similarly to bandage 10 except that the substrate assembly 16 has been replaced with a substrate assembly 16 a , which comprises a single substrate member 18 a . The single substrate member, preferably, comprises one or more layers made of material 19 b and at least one covering made of material 19 a . However, preferably, two coverings made of material 19 a sandwich the one or more layer made of material 19 b . Therein, the pressure member 14 may be disposed within the single substrate member in a manner taught above.
[0109] The substrate member 18 a may also consist of a single structural layer made of material 19 a . Then, the pressure member 14 is joined to an underside of the substrate member 18 a , i.e., the substrate assembly 16 , using an adhesive, sonic welding, heating, stamping, or any other suitable means that aids in avoiding unintended removal of the pressure member.
[0110] The treatment device 22 is then secured directly to the pressure member by an adhesive, sonic welding, heating, stamping, or any other suitable means that aids in avoiding unintended movement of the treatment device relative to pressure member.
[0111] Thus, the adhesive area 20 b is disposed directly on the underside of the substrate member 18 a and may also be disposed at least partially on an area of the pressure member 14 that is not covered by the treatment device 22 .
[0112] Advantageously, the bandage 10 a provides a simple and cost effective construction.
[0113] FIG. 6 a is a top plan view of a bandage in accordance with one or more embodiments of the present invention. FIG. 6 b is a bottom plan view of the bandage of FIG. 6 a . FIG. 6 c is a longitudinal side view of the bandage of FIG. 6 b.
[0114] In accordance with one or more embodiments of the present invention, a bandage 10 b is constructed similarly to bandage 10 except that the pressure member 14 is secured to the substrate assembly 16 on a side opposite to a side to which the treatment device 22 are secured.
[0115] Therein, the pressure member 14 is secured to a first side 16 b of the substrate assembly 16 . The substrate assembly 16 may be any substrate assembly as taught above, but, preferably, the substrate assembly 16 comprises a single substrate member 18 a that, in turn, consists of a single structural layer made of material 19 a . The pressure member is secured to the first side by an adhesive, sonic welding, heating, stamping, or any other suitable means that aids in avoiding unintended movement of the pressure member relative to the substrate assembly.
[0116] The treatment device 22 is secured directly to a second side 16 c of the substrate assembly 16 by an adhesive, sonic welding, heating, stamping, or any other suitable means that aids in avoiding unintended movement of the treatment device relative to pressure member.
[0117] The adhesive area 20 b is disposed directly on the underside of the substrate member 18 a , i.e., substrate assembly 16 , in an area not covered by the treatment device 22 .
[0118] FIG. 7 a is a plan view of a pressure member in accordance with one or more embodiments of the present invention. FIG. 7 b is a cross-sectional view of the pressure member of FIG. 7 a . FIG. 7 c is a first alternate cross-sectional view of the pressure member of FIG. 7 a . FIG. 7 d is a second alternate cross-sectional view of the pressure member of FIG. 7 a.
[0119] Therein, a pressure member 202 is substantially identical to the pressure member 14 and may be used in any of the bandages taught above. However, the pressure member 202 comprises end portions 202 a , which correspond to end portions 14 a , that are wider laterally than central portion 202 b , which corresponds to the central portion 14 b . Advantageously, the configuration permits increasing the forces F 1 a and F 1 b and placing the force F 1 c over a smaller surface area. Since pressure is the force per unit area, the force F 1 c will thus be able to increase pressure the treatment device by concentrating the pressure over a smaller area.
[0120] In addition or in the alternative, the pressure member 202 comprises ridges 202 c that may be squared, rounded, or peaked and aid in increasing the amount of pre-tensioning possible and increasing the force F 1 c.
[0121] FIG. 7 e is a plan view of a pressure member in accordance with one or more embodiments of the present invention. Therein, a pressure member 204 is substantially identical to pressure member 14 and may be used in any of the bandages taught above. However, pressure member 204 comprises end portions 204 a , which correspond to end portions 14 a , that are wider laterally than the central portion 204 b , which corresponds to central portion 14 b . End portions 204 a include one or more indentations 204 c , which permits the pressure member 204 to be more flexible at the end portions and be fitted in unusual anatomical situations to a patient.
[0122] FIG. 7 f is a plan view of a pressure member in accordance with one or more embodiments of the present invention. Therein, a pressure member 206 is substantially identical to pressure member 14 and may be used in any of the bandages taught above. However, the pressure member 206 comprises end portions 206 a and central portions 206 b , all of which have been widened, but have portions that connect them and that are not as wide as the portions 206 a and 206 b.
[0123] FIG. 8 a is a plan view of a pressure member in accordance with one or more embodiments of the present invention. FIG. 8 b is a longitudinal cross-sectional view of the pressure member of FIG. 8 a . FIG. 8 c is an alternate longitudinal cross-sectional view of the pressure member of FIG. 8 a.
[0124] Therein, a pressure member 208 is substantially identical to pressure member 14 and may be used in any of the bandages taught above. However, the pressure member 208 comprises end portions 208 a , which correspond to end portions 14 a , that are wider laterally than central portion 208 b , which corresponds to central portion 14 b . End members 208 a may also have a greater thickness than central portion 208 b . The difference in thickness may be distributed relative to one or both sides of the central portion. Advantageously, the configuration permits increasing forces F 1 a and F 1 b and placing force F 1 c over a smaller surface area. Since pressure is the force per unit area, force F 1 c will thus be able to increase pressure the treatment device by concentrating the pressure over a smaller area.
[0125] FIG. 9 a is a plan view of a pressure member in accordance with one or more embodiments of the present invention. FIG. 9 b is a plan view of a pressure member in accordance with one or more embodiments of the present invention. FIG. 9 c is a longitudinal cross-sectional view of the pressure member of FIG. 9 b.
[0126] Therein, a pressure member 210 is substantially identical to pressure member 14 and may be used in any of the bandages taught above. However, the pressure member 210 comprises a plurality of disconnected strips 210 a that may be arranged in one or more planes. This permits the pressure member to be more flexible.
[0127] The pressure member 210 may also comprise a plurality of disconnected strips 210 a and 210 b that may be arranged in one or more planes and/or may be stacked on top of each other.
[0128] The strips 210 b are preferably, but not necessarily, arranged at the end portions of the pressure member 210 causing the pressure member to have a greater thickness at one or more end portions than a central portion. This permits the pressure member to be more flexible as well as increasing the forces F 1 a and F 1 b and placing the force F 1 c over a smaller surface area. Since pressure is the force per unit area, the force F 1 c will thus be able to increase pressure on the treatment device.
[0129] FIGS. 10 a - 10 c and 11 a - 11 c are, respectively, plan, side, and side on skin views of a bandage in accordance with one or more embodiments of the present invention. Therein, a bandage 10 d or 10 e comprises a plurality of pressure members 14 that are arranged to overlap and/or have a woven configuration. This permits the bandages 10 d and 10 e to conform in not flat situations, such as the antecubital fossa.
[0130] FIG. 12 a is a longitudinal side view of a pre-stressed pressure device is configured as a stress guard prior to being applied to a patient in accordance with one or more embodiments of the present invention. FIG. 12 b is a longitudinal side view of the stress guard of FIG. 12 a applied to a patient when initially applied to an open incision site. FIG. 12 c is a longitudinal side view of the stress guard of FIG. 12 a after being stressed. FIG. 12 d is a first detail view of the stress guard of FIG. 12 a . FIG. 12 e is a second detail of the stress guard of FIG. 12 a.
[0131] A pre-stressed pressure device is configured as a stress guard 40 . Returning to FIG. 1 a , the stress guard 40 is preferably used to treat the wound 110 , which may be a wound caused by a surgical incision, and prevent scarring associated with the wound. Therein, the wound 110 typically will be sutured, and, thus, the wound area 112 is nil and the treatment area 114 extends to encompass the area scarred by scarring 118 . To treat the wound 110 and prevent likely scarring 118 , a pressure 192 , i.e., a stress 192 is applied by a treatment device on at least a portion of the treatment area 114 using the stress guard 40 .
[0132] Therein, the stress guard 40 is preferably pre-stressed with a curve designed to maximize inward force while applied to the skin with preferably a peelable adhesive disposed on end portions of the stress guard but not on the central portion. The stress guard can be manually strained and applied flat to the skin. The stress at the wound site may be reduced to the levels below that experienced by normal skin.
[0133] In accordance with one or more embodiments of the present invention, the stress guard 40 comprises a pressure member 44 , which exerts pressure 192 on the wound 110 to close the wound area 112 , if open, and/or relieve stress in the wound area 112 , and an adhesive 46 a applied in one or more adhesive areas 46 b.
[0134] The pressure member 44 comprises one or more layers of one or more pressure materials. A pressure material may be any suitable material that is elastic and capable of holding an initial non-flat shape, preferably a curved shape. However, preferably, the pressure material is a polymer material. More preferably, the pressure material is selected from the group of polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS); nylon polymers including polyamide 6, polyamide 66, homopolymers, and co-polymers; polyester resin; low-density polyethylene terephthalate (PET); low-density polyethylene, high-density polystyrene; high-density polyethylene; and rubberized and/or plasticized PVC.
[0135] The pressure member 44 comprises, but not necessarily, a generally rectangular shape in plan view having end portions 44 a (each defined as being generally, but not necessarily, the one-third end area in side view of the pressure member) spaced distal from a central portion 44 b (defined as being generally, but not necessarily, the center one third area in side view of the pressure member) and has a thickness 44 c . The thickness 44 c is preferably sufficient to prevent the longitudinal edges of the pressure member 44 from curling inwards towards a longitudinal centerline of the pressure member. That is, the thickness 44 c is chosen such that the pressure member remains rigid in a cross-section perpendicular to the longitudinal centerline of the pressure member.
[0136] Therein, the thickness 44 c may be varied as needed for the specific embodiment of the stress guard 40 and may be non-uniform and variable in thickness across the width and/or along the length of the pressure member 44 . The thickness preferably also provides stress guard with sufficient load carrying capacity to achieve the desired pressure 192 . The thickness 44 c of the pressure member 44 may be tapered near the edges for added comfort and/or safety of use.
[0137] The pressure member 44 normally has a curved shape in at least part of the central portion 44 b while the end portions 44 a are straight. In other words, the pressure member 44 has a normally curved state 45 a , i.e., first state. This state occurs prior to the stress guard 40 being applied to the skin of the user.
[0138] The curved shape in at least part of the central portion 44 b may be achieved by casting, extruding, and/or forming central portion to be curved. Therein, the central portion 44 b may have any suitable curve while the end portions 44 a are straight.
[0139] The curved shape may also be made by pre-tensioning the pressure member in a pre-stressed area (not shown), such as being heat-treating. Therein, the pre-stressed area is preferably disposed in the central portion 14 b . In the pre-stressed area, the pressure member has been stressed increasing a compression side, moving the neutral axis in the pre-stressed area, and causing a tension side to be reduced.
[0140] In the curved state 45 a , the pressure member 44 is curved in the pre-stressed area, while the end portions 44 a are straight. Therein, the end portions 44 a are preferably, but not necessarily, equidistant from the central portion 44 b in lateral and offset directions and are curved in the same direction. When the pressure member 44 is in the curved state 45 a , the stress guard 40 generally follows the same curved contour as the pressure member 44 and also is in the curved state 45 a.
[0141] In accordance with one or more embodiments of the present invention, one or more hinges 43 define the boundary between the central portion 44 b and respective end portions 44 a . Therein, the hinge 43 may be a plastic hinge or hinge having a groove or a channel 43 a . The groove or channel 43 a may be formed to be a V opening wherein each leg of the V has equal length, or has an unequal length.
[0142] Preferably, the adhesive 46 a may be one or more suitable pressure-sensitive adhesives as is known in the art for adhesive bandages. Due to their excellent adhesion strength, usability, costs, and/or length of use, the adhesive 46 a is preferably selected from the group of acrylic, silicone, butyl rubber, nitrile, styrene block copolymers (SBC), ethylene-vinyl acetate (EVA), or a combination thereof. In addition or in the alternative, the adhesive 46 a may be a polyacrylate-based, polyisobutylene-based, and/or silicone-based pressure-sensitive adhesive; or a synthetic rubber, acrylic, hydrocolloid, or a like compound adhesive. In addition or in the alternative, adhesive 46 a may also be a light-curable or heat-curable adhesive.
[0143] Preferably, regardless of type, adhesive 46 a comprises a T-peel release force of in the range of 0.45 N/cm to at least 19 N/cm. Therein, the T-peel release force and blunt probe tack force of pressure-sensitive adhesives is in accordance with ASTM D1876 and ASTM D2979 or other appropriate methods.
[0144] The adhesive 46 a is applied in the adhesive area 46 b , which is preferably a portion of or all of end portions 44 a . The adhesive 46 a is preferably not applied in the central portion 44 b.
[0145] The stress guard 40 is applied to the patient 100 , for example, by straining it manually and then using the adhesive 46 a to secure it to skin of the patient. Therein, the pressure member 44 will be in a non-curved, substantially the non-curved state 45 b , i.e., second state. When the pressure member 44 is in substantially non-curved state 45 b , the stress guard 40 follows the same contour as the pressure member 44 and also is in substantially the non-curved state 45 b . Substantially non-curved state 45 b may be a flat state or contour, and/or may be one where the pressure member, i.e., stress guard, follows the contour of the skin.
[0146] In either curved state 45 a or substantially the non-curved state 45 b , the pressure member 44 has the forces F 3 and F 4 , which combine as pressure 192 and are directed toward each other to pull the wound 110 closed. That is, when the pressure member 44 is curved, the forces F 3 and F 4 pull toward each other closing the wound 110 or keeping the marginal edges of the wound closed.
[0147] Preferably, a stress guard 40 is selected so that it is sufficiently sized, for example, by laying in a substantially non-curved state 45 b when applied to a wound, as shown in FIG. 12 b , and the wound's edges are being pulled toward each other to close the wound area 112 , if open, and/or relieve stress in the wound area 112 . As the wound heals, the wound area 112 becomes nil and the stress guard changes to a substantially curved state 45 a.
[0148] Advantageously, the pressure material may be pre-stressed to a predetermined amount, and thus, the amount of curvature may be selectively predetermined to the pressure member 44 . In turn, by varying the curvature, the central portion 44 b can be predetermined to exert specific forces F 3 and F 4 on the wound 110 . In addition or in the alternative, the shape and/or the thickness 44 c of the pressure member may be selected, as taught further herein, to provide further predetermined refinement of forces F 3 and F 4 . Forces F 3 and F 4 are transferred as pressures to the patient via the treatment device, since pressure is force per unit area.
[0149] Therein, increasing forces F 3 and F 4 will yield an increase in pressure applied to at least the treatment area 114 via the treatment device.
[0150] The pressure member 44 may have a thickness of 100 microns to at least 2 mm, but preferably with a range of about 220 microns to about 500 microns, or more preferably 300 microns to 400 microns. The pressure member 44 preferably has a length of approximately 10 mm to 190 mm, i.e., 1 cm to 19 cm, and/or a width of 8 mm to 100 mm, i.e., 0.8 cm to 10 cm.
[0151] In accordance with one or more embodiments of the present invention, a kit for treating the wound 110 of the patient 100 comprises two different types pre-stressed pressure devices, i.e., the pressure bandage 10 and the stress guard 40 , used at different times during the treatment for effective wound healing and to reduce the possibility of scarring. The pressure bandage 10 is indicated for use during the acute and late wound phases. These phases are immediately after the occurrence of the wound and up to 2 weeks after the occurrence of the wound. To treat the wound during the intermediate phase, between 2 and 12 weeks, the stress guard 40 is indicated. Therein, the system offers an ultimate solution to the skin wound treatment and scar tissue relief.
[0152] FIG. 13 is a diagram illustrating a treatment system for making a pre-stressed pressure device for treating a wound and/or reducing scarring in accordance with one or more embodiments of the present invention. Therein, the treatment system 500 for treating a wound and/or reducing scarring comprises an imaging device 502 , a computing device 504 executing a computer-readable software 506 stored on a non-transitory computer readable media 508 , a 3D printer 510 , a supply 512 of pressure material, a heating device 514 , a supply 516 of substrate members 18 a and 18 b , and a supply 518 of treatment device 22 .
[0153] Therein, when a patient 100 presents with a wound 110 or with scarring, a user of the system, who preferably, but not necessarily a qualified medical professional, uses imaging device 502 , such as a digital camera, smartphone camera, ultraviolet imaging apparatus, to take an image of the wound or scarring and/or the contours of the area surrounding the wound or scarring. Using a network or a storage device, the image is then transferred to a computing device 504 such as a computer, mainframe device, tablet computer, smartphone, or other device. The network herein may be any kind of network including a cellular, wireless, Wi-Fi, LAN, Ethernet, internet, private, public, or a combination thereof.
[0154] In accordance with one or more embodiments of the present invention, the image is utilized by the user to define treatment area 114 . Software 506 stored on a non-transitory computer readable media 508 , such as CD-ROM or DVD, uses the defined treatment and/or contours of the surrounding area to design the pressure member 14 , including the shape of the end portions 14 a , the central portion 14 b , the thickness 14 c for any portion and any variations therein as taught above, and transmits that information, preferably over a network, to the 3D printer 510 . The software then also calculates the amount of pre-tensioning required and transmits that information, preferably over a network, to heating device 514 .
[0155] Therein, the 3D printer 510 may be any suitable additive manufacturing printer. The printer 510 , using supply 512 of the pressure material, manufactures the pressure member 14 according to the information sent by computing device. The same user or another user then places the pressure member in the heating device 514 .
[0156] The heating device 514 may be any kind of suitable device that imparts energy into the pressure member 14 . Thus, heating device 514 may be a microwave, a radiant heater, a sonic welding device, or a combination thereof. Using the information sent by the computing device, the heating device 514 heats the pressure device 14 in the pre-stressed area 14 d to impart the pre-tensioning. In order to prevent unintended heating, a protective layer may be printed on areas of the pressure device other than the pre-stressed area 14 d.
[0157] In addition or in the alternative, the pressure member 14 may also be made to be curved in the printer 512 and heating with the heating device 514 may not be necessary.
[0158] After the pre-tensioning has been imparted in the pressure member 14 , it is joined to one or more substrate members 18 a and 18 b that are provided via a supply 516 and a treatment device 22 from the supply 518 . If necessary, the substrate members 18 a and 18 b and the treatment device 22 may be sized according to sizing information provided by the computing device 504 to produce a pre-stressed pressure device configured, for example, as the bandage 10 that may be applied to the patient. Similarly, the stress guard 40 may be produced by the treatment system 500 by itself and/or in conjunction with the pressure bandage 10 .
[0159] While the invention has been described in conjunction with specific embodiments, it is to be understood that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. | A pre-stressed pressure device for treating a wound or reducing scarring of a skin of a patient. the pre-stressed pressure device is composed of a pressure member having a curved state and a non-curved state, the pressure member having an inner surface and an outer surface. The pressure member has a central portion and first and second end portions, the central portion having a curved shape when the pressure member is in the curved state. The pre-stressed pressure device also contains a substrate assembly having a first surface side and a second surface side, the first surface side of the substrate assembly being secured to the inner surface of the pressure member and wherein the substrate assembly is no shorter than the pressure member. Further included is a treatment device connected to the second surface side of the substrate assembly, wherein the first and second end portions of the substrate assembly extend beyond a first and a second end of the treatment device; and an adhesive is located on the first and second end portions of the substrate assembly on the second surface side of the substrate assembly for applying the pre-stressed pressure device to the skin of the patient. The pressure member exerts end forces directed away from the patient and a central force directed towards the patient. | 0 |
This is a continuation of application Ser. No. 385,528, filed July 27, 1989, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor memory device having a redundant structure, and more particularly to a system for detecting the memory cell positions using the redundant structure.
2. Description of the Related Art
Memory capacity of semiconductor memory device has been remarkably increasing. With the increase in the capacity of semiconductor memories, redundant circuit technology has been introduced. The redundant circuit has a redundant column or row of memory cells which are added for a normal memory cell array and a redundant decoder for selecting the redundant column or row of memory cells. If the normal memory cell array contains any defective memory cells in a column or a row, the address corresponding to the defective column or row of memory cells is programmed into the redundant decoder in a known manner, thereby replacing the defective column or row of memory cells with the redundant column or row of memory cells, and thus enabling the defective chip to be relieved.
A memory device having such a redundant circuit involves necessity to know information about relief of the memory cell, that is whether or not the redundant circuit has been actually used, and the address of a defective part in the normal memory cell array which has been replaced with the redundant column or row, when the memory is evaluated or tested. Conventional practices therefor include a roll call circuit which is arranged such that a special circuit is provided in a memory chip to obtain relief information.
One approach for indicating whether the redundant circuit is actually used and which address of the normal memory array is replaced by the redundant structure is disclosed in the U.S. Pat. No. 4,731,759 issued to Watanabe. According to this U.S. Patent, a series circuit of field effect transistors is inserted between two power voltage terminals (Vcc and GND). The series circuit causes a DC current flowing the two power voltage when the redundant circuit is used for replacing the defective portion of the normal memory array. Therefore, by checking an amount of the DC current flowing through the two power voltage terminals, the usage of the redundant circuit can be known.
However, it is difficult to accurately measure the current flowing through the series circuit, because the memory circuit consumes an operating current which also flows between the two power voltage terminals. Moreover, the series circuit always consumes some current flowing therethrough at least when the memory circuit is enabled in a case where the redundant circuit is used. This consumes a wasteful power.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a semiconductor memory device provided with a novel system for detecting the usage of the redundant circuit with ease.
It is another object of the present invention to provide a semiconductor memory device having an improved system for detecting the memory position replaced with the redundant circuit operable without causing any wasteful current consumption.
A semiconductor memory device according to the present invention comprises a plurality of normal memory cells arranged in an array, at least one redundant memory cell, means for receiving address information, a selection circuit coupled to the array of the normal memory cells and the redundant memory cell, the selection circuit operatively selecting one memory cell from the array of the normal memory cells in accordance with the address information when the normal memory cell corresponding to the address information is operable and selecting the redundant memory cell when the normal memory cell corresponding to the address information is defective, a read-write circuit coupled to the selection circuit for performing a read operation of the selected memory cell in a read mode and a write operation to the selected memory cell in a write operation, a power voltage terminal for receiving a power voltage, a detection circuit coupled to the power voltage terminal for generating a detection signal when the power voltage is initiated to be applied the power voltage terminal, a first initializing circuit for setting the normal memory cells at a first logic state in response to the detection signal, and a second initializing circuit for setting the redundant memory cell at a second logic state different from the first logic state in response to the detection signal.
According to the present invention, the normal memory cells and the redundant memory cell are automatically initialized in different logic states, respectively upon the application of the power voltage to the memory circuit. Therefore, the address of the defective memory cell which is replaced by the redundant memory cell can be detected by simply checking read-out data. Any wasteful current does not flow for showing the using state of the redundant memory cell.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and further objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a schematic block diagram of an indicator circuit for a redundant circuit in the prior art;
FIG. 2 is a schematic block diagram showing a memory device according to one embodiment of the present invention;
FIG. 3 is a timing diagram showing an operation of a power-on detection circuit employed in the memory device of FIG. 2;
FIG. 4 is a schematic circuit diagram showing a memory cell;
FIG. 5 is a schematic block diagram showing a memory device according to another embodiment of the present invention; and
FIG. 6 is a schematic circuit diagram of a redundant memory cell employed in the memory of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
Prior Art
A conventional indicator circuit for indicating a using state of a redundant circuit in a memory circuit will be explained with reference to FIG. 1.
A program circuit 1 includes a series connection of a fuse F and an N-channel MOS field effect transistor Q 1 connected between a power voltage terminal Vcc and a reference voltage terminal (GND) and a feed-back inverter IV 1 to form a fuse type flip-flop.
The fuse F is cut when a redundant circuit including a redundant word line WLR, a redundant row decoder 4, a gate 5 and an inverter IV 2 is utilized for replacing a defective word of a normal memory cell array (not shown in FIG. 1). Therefore, a signal EN is set at a high level. To the contrary, when the normal memory array is perfectly good and the redundant circuit is not used, the fuse F is not cut to produce a low level of the signal EN. When the redundant circuit is used, the address of a defective part, e.g. word line to be replaced with a redundant word line WLR is programmed in the redundant decoder 4 in a known way. Accordingly, when address information AR indicates the address of the defective part, the output of the redundant decoder 4 is selected to select the redundant word line through the gate 5 and the inverter IV 2 in response to the high level of EN. A first roll-call circuit 2 having a P-channel MOS (PMOS) transistor Q 3 and an N-channel MOS (NMOS) transistor Q 4 causes a current flowing therethrough between Vcc and GND when the signal EN is at the high level. A second roll-call circuit 3 including a PMOS transistor Q 5 and an NMOS transistor Q 6 connected between Vcc and GND and causes a current flowing between Vcc and GND when the redundant word line is selected.
Thus, in the case where the redundant circuit is used, the signal EN is at the high level and therefore Q 4 is ON, so that the roll call circuit 2 constantly generates a current from the power supply to the ground (GND). For this reason, the current consumption is greater than in a memory in which the redundant circuit is not used by an amount corresponding to the current flowing through the roll call circuit 2.
In the memory wherein a redundant circuit is used, when the address of the defective part which has been replaced with the redundant circuit is selected, the output of the redundant decoder 4 is at a high level and the redundant word line WLR is at a high level. As a result, Q 6 turns ON and the roll call circuit 3 generates a current from the power supply Vcc to the ground. When another address is selected, the output of the redundant decoder 4 is at a low level and WLR is also at a low level, so that Q 6 turns OFF. Therefore, no current flows through the roll call circuit 3. Accordingly, the current consumption at the time when the address of a defective part replaced with the redundant circuit is selected is greater than that in the case where another address is selected. Thus, by checking the current consumption of the memory and the current that is consumed when each address is selected, it is possible to obtain information about whether or not the redundant circuit has been used and information about the address of a defective part replaced with the redundant column or row.
The above-described prior art has the disadvantages that the current consumption of the memory is increased because of the use of the redundant circuit and it is time-consuming since it is necessary to check, for all the addresses, the current that is consumed when each address is selected.
Embodiments
With reference to FIG. 2, the memory device according to a first embodiment of the present invention will be explained below.
The memory device comprises a normal memory array having a plurality of normal memory cells MC, a plurality of word lines WL l - WL m arranged in rows, and a plurality of pairs of bit lines BL, BL (in the drawing, only i-th pair of bit lines BL i , BL i are representatively shown), and a redundant array of redundant memory cells MC' coupled to the word lines WL l - WL m and a pair of redundant bit lines BL R , BL R . Thus, in this memory, a redundant column of memory cell MC' are provided for replacing a defective column of memory cells of the normal memory array. Each of the memory cells MC and the redundant memory cells MC' is constructed as shown in FIG. 4. Namely, the memory cells MC and MC' include a flip-flop composed of load resistors R1, R2 and a pair of NMOS transistors Q M1 , Q M1 , and a pair of transfer gate NMOS transistors Q M3 , Q M4 coupled to one word line WL and a pair of bit lines BL, BL.
A plurality of row decoders 11-l to 11-m are provided for selecting the word lines WL l - WL m , respectively. The pairs of bit lines BL i , BL i , BL R , BL R are connected to a pair of bus lines DB, DB connected to a read-write circuit 13 connected to an input/output terminal I/O through a plurality of pairs of transfer gate NMOS transistors QY i , QY i ', QY R , QY R '. Each pair of transfer gate transistors (QY i , QY i ') are selected by the corresponding column decoder (12-i) and the pair of transistors QY R , QY R ' for the redundant column are selected by the redundant column decoder 12-R. The redundant column decoder 12-R is enabled in response to the high level of the signal EN generated from the program circuit 1 such as shown in FIG. 1 and generates an active (high) level of output Y R when column address information ARY indicates a defective column of the normal array. The selective level of Y R inhibits operations of the normal column decoders such as 12-i. The memory circuit also includes a power-on detection circuit 10 including PMOS transistor Q 11 and NMOS transistors Q 12 , Q 13 connected in series between Vcc and GND and inverters IV 3 and IV 4 . The power-on detection 10 a high level pulse signal FC and a low level pulse signal FC when the power voltage Vcc is switched on, as will be explained in detail later.
Each of the row decoders 11-l to 11-m includes a NAND gate AGl receiving row address signals ARX, PMOS transistors Q 14 , Q 15 , Q 16 and NMOS transistors Q 17 to Q 19 and is enabled to select its corresponding word line in accordance with ARX in response to a low level of a control signal XE and selects its corresponding word line irrespective of ARX when the pulse signal FC is at the low level. In the normal memory array, as shown in by way of the pair of bit lines BL i , BL i , an NMOS transistor Q 22 receiving FC at its gate is connected between the true bit line BL i and the ground voltage source and a PMOS transistor Q 33 having a gate receiving FC is connected between Vcc and the ground voltage source. While a PMOS transistor having a gate receiving FC and an NMOS transistor receiving FC at its gate are connected between the true bit line BL R and Vcc and the complementary bit line BL R and the ground voltage source, respectively.
Load PMOS transistors Q 20 , Q 21 , Q 24 , Q 25 for the bit lines BL i , BL i , BL R , BL R are controlled by FC.
The operation of the power-on detection circuit 10 will first be explained with reference to FIG. 3. The threshold voltage VTN of the NMOSFET transistors Q 12 , Q 13 is set so as to be greater than the absolute value |VTP| of the threshold voltage of the PMOSFET transistor Q 11 , i.e., |VTP| < VTN. When the power supply voltage Vcc which gradually rises from OV and becomes equal to |VTP| at a time t0, Q 11 turns ON, so that the node Nl rises to a potential which is equal to Vcc. When Vcc becomes equal to 2VTN + Δv at a time t1, Q 12 and Q 13 turn ON in addition to Q 15 , wherein Δv is an increase in the threshold voltage of the NMOSFET transistors caused by the substrate bias effect of Q 12 . If Q 12 and Q 13 which are series-connected have an extremely greater current capacity than that of Q 11 , the potential at Nl falls at the time t1, as shown in FIG. 3. As has been described above, in the process of the gradual rise of the power supply voltage Vcc from 0 V, the potential at the node Nl forms a pulse signal such as that shown in FIG. 3. Accordingly, FC which is a pulse signal of the same phase as Nl, and FC which is a pulse signal of the opposite phase to Nl are generated. The following is a description of the circuit operation by which "0" and "1" are respectively written into normal memory cells MC and the redundant memory cells MC' in synchronism with the pulse signals FC and FC which are generated when it is detected that the power supply has been turned ON. When FC change from the low level to the high level and FC changes from the high level to the low level as a result of the detection that the power supply has been turned ON, Q 16 of the row decoders turns ON, while Q 16 turns OFF. Thus, the word lines WL l - WL m are forcedly raised to the high level irrespective of the address ARX and the level of XE. As FC changes from the low level to the high level, Q 20 and Q 21 turn OFF, while Q 22 and Q 23 turn ON. Accordingly, BL i is set at the GND level, while BL i is set at the Vcc level. Thus, "0" is written into the normal memory cells MC. Similarly, Q 24 and Q 25 turn OFF, while Q 26 and Q 27 turn ON, so that BL R is set at the Vcc level, while BL R is set at the GND level. Thus, "1" is written into the redundant memory cells MC'. Then, when FC changes from the low level to the high level, while FC changes from the high level to the low level, Q 16 , Q 22 , Q 23 , Q 26 and Q 27 turn OFF, while Q 19 to Q 21 , Q 24 and Q 25 turn ON, so that the row decoders and memory cell peripheral circuits become equivalent to those in ordinary memories. Thus, it is possible to effect read and write operations.
As has been described above, after the power supply has been turned ON, "0" and "1" are respectively written into all the normal memory cells and all the redundant memory cells and, thereafter, the operation mode is shifted to an ordinary read or write mode.
By virtue of the above-described operation, if information stored in the memory is read out in the address order without performing a write operation after the power supply has been turned ON, "1" is output from an address where the normal memory cell has been replaced with a redundant memory cell, while "0" is output from an address where the normal memory cell has not been replaced. It is therefore possible to obtain information about the address of a normal memory cell replaced and information about whether or not the redundant circuit has been used, that is, memory relief information, by checking read-out information in the address order.
Although all the word lines WL l - WL m are selected upon the power-on of Vcc in the memory of FIG. 2, it is also possible to select a predetermined one word line. In this case, it is necessary to select this predetermined word line for checking the address replaced by the redundant column.
With reference to FIGS. 5 and 6, a memory circuit according to a second embodiment of the present invention will be explained. In the memory of this embodiment, a redundant row of memory cells MC" are provided for replacing a defective row of memory cells MC in a normal memory cell array. In FIGS. 5 and 6, elements or portions corresponding to those in the previous drawings are denoted by the same or similar references. The normal memory cells MC have the same structure as those in FIG. 2, as shown in FIG. 4. The redundant row of memory cells MC" are constructed as shown in FIG. 6. Namely, NMOS transistors Q M5 and Q M6 connected to a control line WL' and a pair of data set lines BL' and BL' of the corresponding column are provided in addition to the memory cells MC shown in FIG. 4.
The normal row decoders such as 11-j for the normal memory array (MC) have the same structure as those 11-l to 11-m of FIG. 2, while a redundant row decoder 11-R includes PMOS transistors Q 31 - Q 33 and NMOS transistors Q 34 - Q 36 and is enabled in response to the low level of XE. The output (i.e. WL R ) of the redundant row decoder is forcibly set at the low level in response to the high level of FC.
When FC changes from the high level to the low level, while FC changes from the low level to the high level, as a result of the detection that the power supply has been turned ON, Q 33 in the redundant row decoder 11-R turns OFF, while Q 36 therein turns ON, so that the redundant word line WLR in the redundant memory cells MC" is forcedly shifted to the low level irrespective of the address input ARX and the level of XE. On the other hand, the other word line WL' which is paired with WLR is raised to the high level. The word lines such as WLj in the normal memory cell array are forcedly raised to the high level in the same way as in the first embodiment. Simultaneously, Q 20 and Q 21 turn OFF, while Q 22 and Q 23 turn ON, so that the bit lines BL l - BL n are set at the GND level, while the bit lines BL l - BL n are set at the Vcc level. Thus, "0" is written into all the normal memory cells MC. While the transistors Q 24 and Q 25 turn OFF, and Q 26 and Q 27 turn ON, so that the data set lines BL' l - BL' n for the redundant memory cells MC" are at the Vcc level, while the data set lines BL' l - BL' n are set at the GND level. Thus, "1" is written into all the redundant memory cells MC. When FC changes from the low level to the high level, while FC changes from the high level to the low level, Q 36 , Q 22 , Q 23 , Q 26 and Q 27 turn OFF, while Q 33 , Q 20 , Q 21 , Q 24 and Q 25 turn ON. Accordingly, the normal and redundant row decoders and peripheral circuits become equivalent to those in ordinary memories and it is therefore possible to carry out read and write operations in the same way as in the first embodiment.
The method of obtaining memory relief information in this memory is the same as in the first embodiment, and the memory having a redundant row in this embodiment also exhibits advantageous effects similar to those of the memory having a spare column in the first embodiment.
As has been described above, the present invention provides a memory circuit having a redundant circuit, comprising a power-on detection circuit which generates a pulse signal when detecting that the power supply has been turned on, and a circuit capable of writing "0" (or "1") into all normal memory cells and "1" (or "0") into all redundant memory cells in synchronism with the pulse signal, whereby it is possible to obtain memory relief information within a short period of time by such an easy method that information stored in the memory cells is read out in the address order after the power supply is switched ON, without any increase in the current consumption which has heretofore been caused by a circuit provided to obtain relief information. | A semiconductor memory device provided with an improved system for detecting an address of a defective column or row of memory cells replaced by a redundant column or row of memory cells through an output port comprises normal memory cells, at least one redundant memory cell, a power-on detection for generating a detection signal when a power supply to the memory circuit is switched on, a first circuit for initializing the normal memory cells at a first logic state in response to the detection signal, and a second circuit for initializing the redundant memory cell at a second logic state different from the first logic state in response to the detection signal. | 6 |
[0001] The present invention relates to welding, and more particularly, to the combination of laser welding, special fixturing, the machined geometries and various methods being employed, to minimize the distortion of cast components as a result of the welding process. The invention minimizes the distortion of cast components and permits a change in the standard assembly sequence of machine, weld, machine again and clean to machine, clean, and finish weld components.
BACKGROUND OF THE INVENTION
[0002] Over the years, the nuclear power industry has seen dramatic improvements in fuel designs. At present, there is a greater expectation that fuel will operate without failures. Some of the most common nuclear fuel failure mechanisms include: (1) debris fretting, (2) cladding corrosion, (3) pellet cladding interaction, and (4) failure due to manufacturing defects. One device that is used to prevent debris fretting is a Generation III Defender debris filter, which prevents the entry of debris into a nuclear reactor's fuel bundle, a problem that has previously caused fuel failures in reactors. The Defender debris filter is used in the BWR fleet, a series of boiling water nuclear reactors operating in the United States, Mexico, Japan, India, and several European countries.
[0003] Gas tungsten arc welding, also known as tungsten inert gas (“TIG”) welding, is an arc welding process that uses a non-consumable tungsten electrode to produce a weld. The weld area is protected from atmospheric contamination by a shielding gas, such as the inert gas argon. A filler metal is typically used, though some welds do not require it. A constant current welding power supply 55 produces energy, which is conducted across an arc through a column of highly ionized gas and metal vapors called plasma.
[0004] TIG welding is commonly used to weld thin sections of stainless steel and light metals, such as aluminum, magnesium and copper alloys. TIG welding allows for stronger, higher quality welds; however, the process is complex and significantly slower than other welding techniques. TIG welding is also used to weld cast plates, such as stainless steel cast surfaces. However, the process can create excessive distortion in such cast plates due to the heat generated in the welding process.
[0005] TIG welding has been used is in the manufacture of BWR fuel assembly lower tie plates. One of the difficulties with the use of TIG welding of cast components like the lower tie plates has been the distortion encountered when welding cast halves or machined components together in an assembly process. The distortion encountered is typically extreme enough to require final machining of the component due to the distortion.
BRIEF DESCRIPTION OF THE INVENTION
[0006] The present invention is directed to the use of laser welding to minimize distortion on cast stainless steel components as a result of welding. More specifically, the present invention is directed to the process of using laser welding in the assembly of boiling water reactor fuel debris filters, such as the Defender debris filter. The laser welding process minimizes the distortion of pre-machined cast surfaces on the Defender debris filter lower tie plate by applying minimal heat during the welding of a cover plate to the lower tie plate.
[0007] During the laser welding process, a laser beam is applied symmetrically about a centerline between weld flanges on the cover plate and the lower tie plate. This concentration of light energy at the centerline between the cover plate weld flanges and the lower tie plate generates heat that is conducted within the joint formed between the cover plate and the lower tie plate, causing the metals from which the plates are formed to change from a solid state, into a liquid state of molten metal, and thereby, combine the centerline between the weld flanges on the cover plate and the lower tie plate. After the centerline of the two metal plates change back into a solid state, the two plates are then said to be welded together so as to form a butt welded joint between the cover plate and the lower tie plate.
[0008] The welding process of the present invention utilizes a fixture designed to hold the debris filter lower tie plate through four degrees of motion under a fixed focused laser source during welding. Applying laser welding in the assembly of the lower tie plate minimizes distortion during the process of installing the debris filter within the pre-machined cast lower tie plate. The application of the laser weld subsequent to final machining of components provides a finished product that differs from typical high heat (Energy) input techniques (TIG). The techniques differ by; 1) no further machining of areas distorted by welding, 2) debris free cleaning, ensuring the exclusion of foreign material, and 3) resulting weldment geometry designed to minimize the concern of stress corrosion cracking.
[0009] The present invention is also directed to the reduction of stress corrosion cracking resulting from crevices in partial penetration welds that might occur in the laser welding process. A specified minimum weld penetration along with reliefs behind the cover plate weld flange geometry, are intended to eliminate any possibility of cervices being created during the welding process at the interface between the cover plate and the lower tie plate. The resistance of the Defender weldment to stress corrosion cracking is preserved if the depth of weld penetration is equal to or greater than 70% of the weld joint.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view of the principal components to be joined together and the overall layout of the Defender debris filter lower tie plate assembly.
[0011] FIG. 2 is a front elevation view of the debris filter lower tie plate, showing the cover plate attached to the lower tie plate and the location of the laser welds used to attach the cover plate to the lower tie plate.
[0012] FIG. 3 is a front view showing the locations of the tack welds used to hold the cover plate to the lower tie plate prior to laser welding the cover plate to the lower tie plate.
[0013] FIG. 4 is a drawing of a tack weld station including a fixture for compressing the filter while holding the cover plate on the lower tie plate for purposes of tack welding the cover plate to the lower tie plate.
[0014] FIG. 5A is a drawing of the laser power supply and controls which provides laser power to the tie plate weld station.
[0015] FIG. 5B is a drawing of the laser weld station used to weld the cover plate to the lower tie plate.
[0016] FIG. 6 is a picture of a tie plate pre-weld location with jog Z & Y crosshairs placed in a start position for the laser welding of the cover plate to the lower tie plate.
[0017] FIG. 7 is a drawing of a fixture for holding the lower tie plate through four degrees of axis motion in front of a focused laser source.
[0018] FIG. 8A is a schematic cross-sectional end view of the cover plate and lower tie plate weld joints showing the top and the bottom joints.
[0019] FIG. 8B is another schematic cross-sectional view of weld joints at one end of the cover plate and the lower tie plate.
[0020] FIG. 9A is a top-down, rear perspective view of the cover plate showing weld surfaces and weld reliefs.
[0021] FIG. 9B is a bottom-down rear perspective view of the cover plate showing weld surfaces and weld reliefs.
[0022] FIG. 10 is a perspective view of the lower tie plate showing weld surfaces in the opening through which a defender debris filter assembly is inserted.
[0023] FIG. 11A is a metallographic cross section from the top horizontal weld joint.
[0024] FIG. 11B is a metallographic cross section from the bottom horizontal weld joint.
[0025] FIG. 12 is a metallographic cross section showing mechanical loading by the debris filter once compressed within the cavity of the lower tie plate.
[0026] FIG. 13 is a graph showing stress intensity in cover plate welds relative to penetration of the weld.
[0027] FIG. 14 is a drawing showing the horizontal and vertical weld joint configurations for welding the cover plate to the lower tie plate.
DETAILED DESCRIPTION OF THE INVENTION
[0028] FIG. 1 is a perspective view of the various components that make-up a Defender debris filter lower tie plate assembly 10 . The Defender debris filter lower tie plate assembly 10 consists of a machined lower tie plate 14 with a machined cast inlet 13 , a filter plate assembly 12 inserted into a rectangular cavity 25 within lower tie plate 14 , and a cover plate 16 that is welded to lower tie plate 14 . The cover plate 16 includes a finger spring pocket 17 . The lower tie plate 14 includes a plurality of fluid flow holes 15 and nuclear fuel pin holes 9 , with an opening 11 in one of its sides, through which the filter plate assembly 12 is inserted into the rectangular pocket 25 within lower tie plate 14 . The filter plate assembly 12 is a rectangular assembly comprised of a plurality of wavy stainless steel plates 18 welded together. Filter plate assembly 12 must be compressed slightly when installed within the lower tie plate 14 to prevent flow-induced vibration during reactor operations. The cover plate 16 retains the filter plate assembly 12 within the lower tie plate 14 and prevents coolant leakage from being diverted from the reactor's fuel bundle, after the welding process that seals the cover plate 16 to the lower tie plate 14 . The cover plate 16 is welded to lower tie plate 14 along two vertical weld joints 20 and two horizontal weld joints 21 extending around the perimeter of the cover plate 16 , as shown in FIG. 2 .
[0029] After the filter plate assembly 12 is inserted into tie plate 14 , cover plate 16 is fitted over the opening 11 leading to rectangular cavity 25 and tack welded preferably at two locations 22 and 24 shown in FIG. 3 , although it should be understood that more than two tack welds can be used, if desired. The tack welds 22 and 24 are made as small as possible by developed parameters, while retaining the filter plate assembly 12 under compression within the lower tie plate 14 , but with enough strength to hold the cover plate 16 in position with respect to the lower tie plate 14 for subsequent laser welding. The tack welds 22 and 24 are fully consumed during the subsequent laser welding process. It should be noted that the tack welds are made using the TIG process. The tacks are made utilizing a precision power supply 55 noted for its stable arc starting capabilities, for producing a strong, low heat input, yet small profile tack weld, as needed for this application.
[0030] FIG. 4 shows a tie plate tack welding station 50 for tack welding the cover plate 16 to the lower tie plate 14 . The tie plate tack welding station 50 is a foreign material exclusion control area designed to minimize the intrusion of foreign materials into the lower tie plate's inner cavity 25 . Tack welding station 50 includes a digital TIG tack welding power supply 55 , a manual loading and unloading clamp/ram 53 , that has a poly insulator 54 that retains the inlet end 23 of the lower tie plate 14 when clamped within the tack welding station 50 . Attached between the loading and unloading clamp 53 and the poly insulator 54 is the support plate 51 with a push rod 47 attached by a locking device 45 . A copper chill block 49 attached to a tie plate fixture 52 , that's affixed upon a manual arbor press 60 that's adjustable in the “Y” axis and load cell/sensor 62 that's adjustable in the “Z” axis, that's to be used with an alignment tool 64 .
[0031] Prior to welding the weld joints between the cover plate 16 and the lower tie plate 14 are wiped with acetone or alcohol to ensure all the components a clean and contaminate free, including all work surfaces. The filter plate assembly 12 is orientated into the lower tie plate's cavity 25 and then placed into the tack weld station 50 . The copper chill block 49 that faces the lower tie plate 14 base, contains several precise locating pins that are made to fit snug into either the nuclear fuel pin holes 9 and/or the fuel flow holes 15 that are located on the surface base 31 of the lower tie plate 14 . Copper chill block 49 has a negative grounding cable that's attached from the Digital TIG tack welding power supply 55 . The lower tie plate 14 is then clamped into the copper chill block 49 by the manual loading and unloading clamp/ram 53 . The filter plate assembly 12 is inserted into the lower tie plate cavity 25 until it bottoms on the opposite wall. The preferred orientation of the filter assembly 12 within the lower tie plate cavity 25 utilizes the compressive nature of the filter assembly 12 . The push rod 47 locates the filter 12 and seats the filter within the inner cavity 25 . The push rod is locked in place using locking device 45 to avoid filter 12 slippage and proper engagement of cover plate wedge 37 . Thereafter, a fixture guide plate 56 is installed and held in place by the two palm-grip hand knobs 48 , that are attached to the top side of the lower tie plate fixture 52 . Once the fixture guide plate 56 is aligned with an edge of the tie plate's rectangular cavity 25 /opening 11 , an alignment tool 64 is then used to set a cover plate clamp 58 a predetermined distance from the guide face edge. Preferably, this distance is approximately 010″. Alignment tool 64 is placed on edge against the inner front surface of the fixture guide plate 56 , with the two palm-grip hand knobs 48 remaining loose enough for final adjustment of cover plate 16 gap clearance. Alignment tool 64 surface “A” 63 will come to rest upon horizontal weld surface 19 within cavity/opening 11 , while surfaces “B” 61 of the alignment tool 64 will come to rest upon the top surface of the fixture guide plate 56 . The alignment tool 64 is pulled against the inner surface of the fixture guide plate 56 and tightened into a final position by the two palm grip hand knobs 48 . The cover plate 16 is then installed and compressed with a manual arbor press 60 by way of the arbor press handle 57 . Before seating the cover plate 16 , a minimum force of 30 lbs must be indicated by the load cell 62 . The cover plate 16 is fully seated with additional arbor press force to minimize gap between the cover plate 16 and the tie plate 14 and to seat the cover plate 16 completely. If the load sensor 62 located on the “Z” axis reads above 30 pounds, but less than 1,000 pounds, the amount of force being used to compress the filter assembly 12 is within an acceptable range. Once cover plate 16 has been seated, the guide plate 56 is removed and the cover plate 16 is visually inspected to ensure that it is properly seated. If necessary, a small rubber mallet can be used with light taps to re-center the cover plate 16 in the lower tie plate 14 rectangular cavity/opening 11 . Preferably, the maximum gap between the cover plate 16 and the lower tie plate 14 is 0.010″ with a maximum gap on the two vertical joints 20 at 0.003″. While maintaining a load on the cover plate 16 and filter 12 with the arbor press 60 the final position of the filter 12 is inspected for proper positioning below the cover plate wedge 37 . Once this determination is made, two light tack welds 22 and 24 are made, as shown in FIG. 3 . After tack welding, the lower tie plate assembly 10 is checked for overall final dimensions prior to laser welding using an envelope gage.
[0032] The welding station FIG. 5B where cover plate 16 is laser welded to lower tie plate 14 is a foreign material exclusion control area. Typically, the laser welding system, in addition to the laser system 75 , would include a power supply 70 , a master control panel 72 , a main laser power switch (not shown), heat controls (not shown) and a chiller control (not shown). There would also be a computer switch (not shown) that controls the operation of the laser system 75 . In a typical welding procedure, the main power switch for the laser is turned on and then the laser que switch at the laser is also turned on. The laser control panel 72 is turned to a CNC mode. CNC is the computer numerical control that is used to control the power output and path of the laser. The chiller and heating control switches are then turned on, as are the main power switch to the lower tie plate welder and the computer is turned on. Thereafter, air, helium, vacuum (not shown) and water circulator (not shown) are turned on and a check is done to ensure that the laser lens 33 ( FIG. 14 ) of laser welding system 75 is in the center of its focus range. A program for operating the laser welding system 75 is then loaded. The lower tie plate 14 and cover 16 are positioned inside of the laser welding system 75 , whereupon the laser system 75 door 77 is closed and a switch is actuated to move the tie plate 14 and cover 16 to a pre-weld location. As shown in FIG. 6 , jog Z&Y crosshairs 80 and 82 are placed in a start position 84 between plates 14 and 16 and a verification is run prior to starting the laser welding sequence. After path verification, the weld sequence is started, during which a fixture 74 , shown in FIG. 7 , which holds lower tie plate 14 , is moved to facilitate the welding of the cover plate 16 to the tie plate 14 . A back purging gas line 79 is attached to the copper chill block 78 that has several precise locating pins attached, that are made to provide a slip fit into either the nuclear fuel pin holes 9 and/or the fuel flow holes 15 , that are located on the surface base 31 of the lower tie plate 14 . The purge gas insures that the inner welded surfaces of the lower tie plate 14 are not contaminated during the laser welding operation when full penetration is meet. The fixture 74 is designed to hold lower tie plate 14 through four degrees of motion under a collimated laser beam 35 ( FIG. 14 ) within laser system 75 during the welding of cover plate 16 to lower tie plate 14 .
[0033] The locations and configurations of the welded butt joints are shown in FIGS. 2 , 8 A and 8 B of the present application. FIG. 2 is a front elevation view of the debris filter lower tie plate assembly 10 showing cover plate 16 attached to lower tie plate 14 and the location of the laser welds 20 and 21 used to attach cover plate 16 to tie plate 14 . As shown in FIG. 2 , cover plate 16 is welded to lower tie plate 14 along two vertical weld joints 20 and two horizontal weld joints 21 extending around the perimeter of the cover plate 16 .
[0034] FIG. 8A is a schematic view of horizontal weld joints 21 at the top and the bottom of cover plate 16 , along with reliefs 28 behind weld flanges 26 ( FIGS. 9A & 9B ). FIG. 8B is another schematic view of one of the vertical weld joints 20 at the end of cover plate 16 , again with a relief 28 behind a weld flange 26 and weld joint 20 engaging flange 26 and tie plate 14 . It should be noted that another weld flange 26 and a vertical weld joint 20 are located at the other end of cover plate 16 , again with a relief 28 behind the weld flange 26 and weld joint 20 .
[0035] FIG. 9A is a top rear perspective view of the cover plate 16 showing weld flanges 26 , weld surfaces 29 and backside relief 28 . FIG. 9B is a bottom rear perspective view of the cover plate 16 also showing weld flanges 26 , weld surfaces 29 and backside relief 28 . FIG. 10 is a perspective view of the Defender debris filter lower tie plate assembly 10 , similar to FIG. 1 , but showing weld surfaces 19 in rectangular cavity/opening 11 through which filter plate assembly 12 is inserted into the lower tie plate 14 . The weld surfaces 19 in rectangular cavity/opening 11 are recessed surfaces engaged by the weld flanges 26 of cover plate 16 when cover plate 16 is inserted into cavity opening 11 and during the welding of cover plate 16 to lower tie plate 14 .
[0036] The reliefs 28 behind the cover plate weld flanges 26 , along with complete joint weld penetration are intended to eliminate any possibility of cervices at the interface between cover plate 16 and lower tie plate 14 , and thereby, reduce stress corrosion cracking resulting from crevices in partial penetration welds that might otherwise occur in the laser welding process.
[0037] During the laser welding process of the present invention, the laser beam is applied symmetrically about a centerline between weld flanges 26 on cover plate 16 and lower tie plate 14 onto weld surfaces 29 on the cover plate 16 and weld surfaces 19 on the lower tie plate 14 . The focused coherent laser energy between the cover plate weld flanges 26 and the lower tie plate 14 generates heat that is conducted into weld joints 20 / 21 formed between the cover plate 16 and the lower tie plate 14 , causing the metal from which the plates are formed to change from a solid to a liquid, so as to combine the two separate liquid plate metals into one. After the two metals change back to a solid, the two plates 14 and 16 are welded together so as to form butt weld joints 20 / 21 between the two plates 14 and 16 .
[0038] The present invention is also directed to the reduction of stress corrosion cracking resulting from crevices in partial penetration welds that might occur in a welding process. As noted above, complete joint weld penetration, along with reliefs 28 behind the cover plate weld flanges are intended to eliminate any possibility of cervices at the interface between the cover plate 16 and the lower tie plate 14 .
[0039] Partial penetration welds, such as welds 40 and 42 shown in FIGS. 11A and 11B , respectively, result in crevices 41 and 43 that increase the risk of stress corrosion cracking. Although the welding process of the present invention for joining the cover 16 and tie plate 14 is designed to result in full penetration welds, such penetration can be affected by mechanical loading on the welds 20 and 21 attaching cover plate 16 to lower tie plate 14 . Direct forces on the cover welds come from compression of the filter plate assembly 12 during attachment of the cover plate 16 to the tie plate 14 and from the coolant pressure differential during operation of the debris filter lower tie plate assembly 10 . The principal component of loading is the residual stress from shrinkage of the weld metal during solidification and cooling of the welds, combined with the stiffness of the cast cover plate 16 and tie plates 14 . Full penetration joint welds avoid crevices at the weld roots 44 and 46 , and, thereby, minimize the likelihood of stress corrosion cracking in creviced regions.
[0040] In a preferred embodiment of the debris filter lower tie plate assembly 10 , the filter plate assembly 12 is constructed from an austenitic stainless steel. Preferably, the lower tie plate 14 is a solution annealed CF3 casting stainless steel. Preferably, the cover plate 16 and each of wavy stainless steel plates 18 forming the filter plate assembly 12 are made from solution annealed 316L stainless steel. Preferably, the lower tie plate 14 and cover plate 16 are machined after annealing without subsequent heat treatment. Preferably, the filter element 12 is re-annealed after assembly and welding of the wavy stainless steel plates 18 and before insertion of the filter plate assembly 12 into the lower tie plate 14 .
[0041] Stress corrosion cracking is not an issue with respect to the lower tie plate 14 , due to the material used in its construction, i.e., cast, low-carbon stainless steel. Similarly, crevice-induced stress corrosion cracking is not an issue with the filter element 12 due to the high rate of coolant flow through the Defender debris filter lower tie plate assembly 10 . Crevice-induced stress corrosion is an issue in the cover plate 16 in the region of the laser welds 20 and 21 used to attach cover plate 16 to lower tie plate 14 , if the welds are not full penetration welds that include crevices.
[0042] The stress rule index, given in equation (1), provides a means for assessing the potential effect of weld crevices on the likelihood of stress corrosion cracking.
[0000]
P
m
+
P
b
S
y
+
Q
+
F
+
R
≤
A
S
y
+
0.002
E
(
1
)
[0000] where
A=1.0 for cast austenitic stainless steel (e.g., weld metal) and 0.7 for wrought 316L in a creviced condition, P m =Primary membrane stress, P b =Primary bending stress, S y =Yield strength at temperature, Q=Secondary stress R=Residual stress, E=Modulus of elasticity at temperature.
[0050] A lack of fusion at the weld roots 44 and 46 shown in FIGS. 11A and 11B is a structural discontinuity that increases the stress in the adjacent material. The severest case is shown in FIG. 11A , where the cover and lower tie plates 16 and 14 connect with no discernible gap and no discernible radius at the tip of the unfused region. Stress concentration factors for such partially fused butt welds are given by the empirically based relationship given in equation (2).
[0000]
σ
max
σ
=
max
[
C
0
,
C
1
+
C
2
(
b
/
a
)
]
(
2
)
[0000] where
a=Non-fused (crack) length, b=Overall section width, c 0 =4.5 (minimum concentration factor for short cracks), c 1 =1.0, c 2 =14.7, σ=Average stress away from concentration, σ max =Maximum stress at concentration.
[0058] The stress concentration factors from equation (2) range from 4.5 to 8.3 for weld penetrations of slightly less than 100% to 50%, respectively. For reference, the stress concentration factor from elastic theory for the joint in FIG. 11B is 3.6. The larger values given by equation (2) are a conservative approximation that eliminates the uncertainty of crack width and tip radius from stress calculations. The stress concentration factor is applied to both normal and shear loading of the welded joint.
[0059] The nature of the mechanical loading differs between the top and bottom welds 21 (horizontal) and end welds 20 (vertical) between plates 16 and 14 . That is, the forces needed to satisfy equilibrium create primarily a shear stress in the horizontal welds 20 and a tensile stress in the vertical welds 21 . In both types of welds, shrinkage during post-weld cooling creates primarily tensile stress in the weld material.
[0060] The resistive force of the filter plate assembly 12 against the welded cover plate 16 varies with component dimensions. It is measured during installation of the cover plate 16 and ranges from 30 lbs. to a maximum of 1,000 lbs. The upper end of this range leads to plastic deformation of the filter element 12 within the lower tie plate inner cavity 25 . The coolant pressure difference between the fuel bundle inlet and the bypass region is approximately 10 psi. Residual welding stresses approach the yield strength of the cover plate 16 and tie plate 14 due to shrinkage of the weld metal during solidification of the weld joints and the geometry of the joints. The force due to compression of the filter element 12 and residual weld stresses relax during operation of the Defender debris filter lower tie plate assembly 10 due to thermal and irradiation-based processes. The force due to the coolant pressure differential varies with flow conditions during bundle operation, but remains throughout the operational life of the filter plate assembly 12 , i.e., in the range of 6-9 years.
[0061] The loading and stresses in the weld joints 30 and 32 are shown schematically in FIG. 12 . These simplifications are consistent with the stress rule given in equation (1), i.e., partitioning the stress into primary and secondary components. The primary components are the stress resultants needed to satisfy force equilibrium and are affected by the joint geometry and the resulting stress concentration. The secondary components are the stresses that are self-relieving. The dominant secondary component results from weld shrinkage and the stiffness of the cover and tie plates 16 and 14 . The secondary stress arises from shrinkage during cooling of the weld metal from the approximate mid-point to the annealing temperature range to room temperature, i.e., the cooling from 1070° C. to 20° C. The resulting, average thermal strain in the weld metal is slightly greater than 2%, which is approximately 10 times the strain for the onset of plastic deformation. The residual stress in the weld at the completion of assembly operations is the average yield strength of 316L at room temperature, namely, 33.8 ksi.
[0062] The primary stress due to compression of the filter plate assembly 12 within the lower tie plate 14 and the residual welding stress relax due to thermal and irradiation effects. Thermal relaxation and relaxation due to the fast neutron flux in the region of the welds 20 and 21 reduces the stresses by additional amounts.
[0063] The calculated stress indices are shown relative to penetration and limiting values in FIG. 13 . Based on the stress relaxation during initial operation, weld penetration should be greater than or equal to 70% for the cover plate 16 adjacent to the weld. Although the weld metal is loaded directly based on the joint geometry shown in FIG. 11A , the region at the edge of the weld has been found to undergo large plastic strains during welding and to be susceptible to stress corrosion cracking. Thus, it is preferred that partial fusion of the butt welds 20 and 21 , which connect the cover plate 16 and lower tie plate 14 in the debris filter lower tie plate 10 , will not affect the resistance of the weldment to stress corrosion cracking if the weld penetration is greater than or equal to 70% of the weld joint.
[0064] FIG. 14 shows the laser welding used by the method of the present invention to weld the cover plate 16 to the lower tie plate 14 . As shown in FIG. 14 , there is a laser beam 35 that is focused by a laser lens 33 to a focal point 34 , which is followed by a defocal point 36 . The laser beam is used with a power level that achieves a weld penetration greater than or equal to 70% of the weld joint. A focused beam 38 is used for horizontal weld joints 21 and a defocused beam 39 is used for vertical weld joints 20 . The laser beam 35 is defocused 39 preferably on vertical sections.
[0065] The method of the present invention can be used to weld metal components other than the lower tie plate 14 and the cover plate 16 that are part of the Defender debris filter lower tie plate assembly 10 . The thickness of the particular metal components to be welded together will affect the parameters selected for the operation of the laser welder. For weld joints of a given thickness, the power level, focal length and speed for the laser beam are preferably set to result in a laser beam power density and weld speed needed to achieve sufficient weld joint penetration to preclude crevice—induced stress corrosion cracking, while minimizing the distortion of the metal pieces to be welded together so as to be within final acceptance specifications, thereby requiring no post weld machining of the metal components to be considered a final product. The inert gas flow is set to maximize cooling and minimize weld oxidation. Preferably, there is no wire brushing of the weld after completion to comply with foreign material exclusion methods.
[0066] After completion of the welding, the fixture 74 holding the debris filter lower tie plate assembly 10 moves via CNC to an unload position, whereupon soot is vacuumed from the debris filter lower tie plate assembly 10 before it is removed from laser system 75 . The debris filter lower tie plate assembly 10 is unloaded and wiped to remove excess soot with a clean wipe and filtered compressed air. A wire brush or other mechanically abrasive means are never used to clean the welds 20 and 21 . Filtered compressed air is then blown through both ends of the tie plate 14 for at least 15 seconds and wiped clean with alcohol and a clean wipe.
[0067] In the welding process of the present invention, the Defender debris filter lower tie plate assembly 10 and the weld area is cleaned and bagged in a foreign material exclusion area.
[0068] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A process of using laser welding in the assembly of boiling water reactor fuel debris filters is disclosed. The laser welding process minimizes the distortion of the debris filter cast lower tie plate by applying minimal heat during the welding. Fixtures hold the cast lower tie plate through four degrees of motion under a constant controlled laser source during welding. The welding process also reduces the potential for stress corrosion cracking resulting from crevices in partial penetration welds that might occur in a laser welding process. | 1 |
TECHNICAL FIELD
[0001] This application relates to computer systems, and more particularly, to using kernel-level techniques to simulate various abnormal conditions during development testing to improve application robustness.
BACKGROUND
[0002] During black-box software testing, a wide range of scenarios is not evaluated due to the difficulties of simulating the system conditions that provide those scenarios. For instance, creating abnormal or high-load system conditions such as the unreliable network, memory pressure, or lack of disk space conditions in a real working computer system may negatively impact all other projects that happen to use the same system. Creating such conditions on a real working computer system may also cause damages to the real system, entailing additional costs in the system management and administration. Accordingly, it would be desirable to be able to simulate abnormal system conditions so that software modules may be tested more thoroughly against a wide range of abnormal system conditions, yet other software or projects running on the same system may continue to be run under the normal system conditions.
SUMMARY
[0003] A method of simulating testing conditions at a kernel-level is provided. The method in one aspect includes intercepting an operating system call from an application at a kernel-level. In the kernel-level, a determination is made as to whether the operating system call was invoked from a process that was identified for failure emulation. If the operating system call was invoked from a process that was identified for failure emulation, user loaded rules are consulted and results to the operating system call according to the user loaded rules are generated and returned to the calling application. If the operating system call was not invoked from a process that was identified for failure emulation, a native operating system service routine associated with the operating system call is called and normal processing takes place.
[0004] The system for simulating testing conditions at a kernel-level in one aspect includes a user-space module operable to transmit one or more process identifiers and one or more rules associated with the process identifiers for emulating failure conditions at a kernel-level and a kernel-level module operable to intercept system call, and further operable to determine whether the system call was invoked from one or more processes identified by the one or more process identifiers and if the system call was invoked from the one or more processes identified by the one or more process identifiers, the kernel-level module further operable to generate a return result according to the one or more rules, and if the system call was not invoked from the one or more processes identified by the one or more process identifiers, the kernel-level module further operable to call native operating system service routine associated with the system call.
[0005] In one embodiment, the intercepting of the system calls by the emulator module at the kernel level is transparent to the processes that invoke the system calls.
[0006] Further features as well as the structure and operation of various embodiments are described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 illustrates the logic of processing in the failure emulator kernel module in one embodiment.
[0008] FIG. 2 is a flow diagram illustrating method for activating failure simulation in one embodiment.
[0009] FIG. 3 is a block diagram illustrating the kernel-level components and user-space setup utility components in one embodiment.
DETAILED DESCRIPTION
[0010] In one embodiment, a kernel-level module simulates test environments on a selective basis, for example, on a per process basis. FIG. 1 illustrates the logic of processing in the failure emulator kernel module in one embodiment. At 102 , when a process is called, it is determined whether the process is subject to failure emulator processing. This may be done, for example, by checking the identity of the called process, and whether the process's identity was previously downloaded from the user-space and identified as being the process for failure emulation.
[0011] At 104 , if a failure emulator is to be used, for example, the process is identified as a process for failure emulation as determined at 102 , syscall-dependent pre-syscall processing is performed at 106 . Pre-syscall processing may include maintaining any statistics that the failure emulator may choose to provide and any emulator-specific logic such as checking a counter for emulating intermittent failures, for example, a failure in 50 percent of calls can be approximated by condition (count % 2)==0. There are various design approaches which will depend on the particular system call, for example, a short read may be emulated by truncating the size of a read request before the call to the original syscall handler (that is, as part of pre-syscall processing) or by just returning part of the buffer of a full read. In some cases, it may not be necessary to call the original syscall handler at all.
[0012] At 108 , the original syscall handler is called and the results from the call is saved. At 110 , post-syscall processing is performed. Examples of post-syscall processing include generating syscall result as provided by failure rules, generating error codes as provided by failure rules, and updating system call statistics. Maintaining system call statistics may help setting up and conducting tests.
[0013] At 104 , if failure emulator is not being used, at 112 the original syscall handler is called and the call results are saved. At 114 , syscall returns to its caller with appropriate results and/or error codes.
[0014] In one embodiment, the kernel module uses kernel-intercept technology where system calls are intercepted. The result of a particular system call executed by an application under testing depends on a set of rules downloaded to the kernel module using a user-level binary, for example, a user-space set up utility module.
[0015] The user-level binary provides control over what is simulated and how, for instance, intermittent short reads, occasional failure of memory allocations. Intermittent and occasional failures can be emulated by maintaining a set of counters for each system call and using a type of pseudo random number generator. The user level binary is used to communicate selected failure types and patterns to the kernel module that simulates them.
[0016] In one embodiment, failure characterization are system call-based, for example, “make 50 percent of read calls from a process with pid 1211 fail pseudo-randomly with a short read error”. Each failure can be described by the system call, percentage of times it should fail and exact type of failure possible for the system call in question. Process identifiers of the target processes (for example, process owner, group owner, pid) can be downloaded to the failure emulator kernel module by a separate API call. The failure patterns (rules) may be selected by the user based on his scope of interest and what is available or implemented in the failure emulator kernel module.
[0017] The simulation may be done without requiring any modifications of the applications being tested. Thus, it is possible to test the exact application binary before the application is released to customers.
[0018] In one embodiment, a testing person may activate failure simulation for a particular process or group of processes by issuing a command that provides process identification to the kernel module together with a chosen set of failures and their patterns. FIG. 2 is a flow diagram illustrating a method for activating failure simulation in one embodiment. At 202 , the group attribute of the process, for which the failure condition is to be emulated, is set to one particular group. This way, one particular group may have the group ownership of the executable file that spawns the process. For example, for a file called netdaemon:
groupadd failtest chgrp failtest netdaemon
make the file netdaemon owned by failtest.
[0021] At 204 , the identities of the processes that are to fail are downloaded to the failure emulator module. For example, the command line: fem_control-i-g failtest will download the identities to the failure emulator module called fem_control. At 206 , failure test patterns are downloaded as follows: fem_control-c 3-t 1, where -c 3 requests call # 3 (read), -t 1 requests read failure of type 1. Failure type 1 may, for example, be short reads. At 208 failure emulation is started, for example, by the following command: fem_control -a 1. Here, the parameter “-a 1 ” sets active flag on, enabling the kernel-level emulation module.
[0022] At 210 , the returned test failure patterns may be observed, for example, to check how the process responds to the failure. For example, once simulation is activated, a tester may observe program behavior correlating observations with requested type of failure. At 212 , the failure emulation may be stopped, for example, by a command: fem_control -a 0.
[0023] In one embodiment, the kernel-level simulation system disclosed in the present application includes kernel-level components and user-space setup utility components. FIG. 3 is a block diagram illustrating the kernel-level components and user-space setup utility components in one embodiment. The kernel-level components may be a library statically linked into the kernel during the kernel build. The kernel-level components may also be dynamically loaded as a module.
[0024] In the following discussion, both types are referred to as a failure emulator kernel module. The arrows in FIG. 3 illustrate control/data paths when failure emulator is active. In one embodiment, all service calls from user programs 302 304 go through the system call dispatch 306 to the failure emulator kernel module 310 which then calls the original system call handler 312 . In one embodiment, the failure emulator module is completely transparent. The test pattern rules 308 are consulted for each process to be tested to see what kind of failure is requested.
[0025] The user-space setup utility components communicate setup data to the kernel-level components. User-space setup utility 314 in one embodiment is a program that is used to set up and control the kernel emulation module 310 . It communicates with the kernel emulation module 310 via its own system call that is installed during the kernel module startup in a spare system call table slot 316 . In one embodiment, the failure emulator API 315 is based around that system call. The user-space setup utility 314 parses the command line, sets up the parameters for and makes an API call 315 . The API call 315 communicates with the kernel emulation module 310 using the system call 316 .
[0026] In one aspect, operating service calls from the user-level 302 , 304 are intercepted at the system call table level 306 , by replacing the addresses of original system call handlers with addresses of functions in the failure emulator kernel module 310 , then modifies their behavior for the calling processes, consulting the rules 308 uploaded by the user-space control utility.
[0027] A typical system call wrapper in the failure emulator kernel module has code similar to the following for a read system call:
if (caller is a target_process) { if (rules[__NR_read].enabled) { rc = (*orig_read_sycall) (arg1, arg2, arg3) ; switch (rules[[__NR_read].type) { case SHORT_READ: rc >>= 1 ; SET_ERRNO(0) ; break ; case INTRD_READ: rc = −1 ; SET_ERRNO(EINTR) ; break ; default: rc = −1 ; SET_ERRNO(EINTR) ; break ; } return rc ; } else { return (*orig_read_sycall) (arg1, arg2, arg3) ; } } else { return (*orig_read_sycall) (arg1, arg2, arg3) ; }
[0028] For all other processes running on the same system, native operating system service routines are processed normally as shown in the above example.
[0029] The system and method of the present disclosure may be implemented and run on a general-purpose computer. The embodiments described above are illustrative examples and it should not be construed that the present invention is limited to these particular embodiments. Although the description was provided using the UNIX system call table as an example, it should be understood that the method and system disclosed in the present application may apply to other operating systems. Thus, various changes and modifications may be effected by one skilled in the art without departing from the spirit or scope of the invention as defined in the appended claims. | A method and system for simulating system conditions at a kernel-level is provided. In one aspect, process identifiers of processes for which simulation is to be performed are transmitted along with simulation pattern or rules from a user-space to a kernel space. Emulator in the kernel space intercepts system calls invoked by processes running in the user space. If the system calls originated from the one or more processes for which emulation was to be performed, return results according to the simulation pattern are generated and returned to the calling process. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to the stabilization of halogen-containing polymers against degradation on exposure to heat. More particularly, it relates to improving the thermal stability of halogen-containing polymers by incorporating therein an effective amount of a combination of a dithioketal of a carbonyl compound and a divalent metal salt, or mixture of divalent metal salts, of a carboxylic acid, or mixture of carboxylic acids, of 7 to 20 carbon atoms.
It is well known that halogen-containing polymers deteriorate upon exposure to elevated temperatures and that such deterioration is manifested by progressive discoloration of the polymer, generally from clear color-ess to pale yellow to reddish-brown to black. It is known to inhibit such thermal degradation by the addition of organotion stabilizers, such as those disclosed in U.S. Pat. No. 3,544,510 by Stapfer. Illustrative of such stabilizers are combinations of a mercaptal, such as distearyl 3,3'-(cyclohexylidenedithio) propionate, and a stannoic acid, such as butylstannoic acid, or alkylthiostannoic acid, such as butylthiostannoic acid. However, since all such stabilizer combinations found to date suffer from one deficiency or another, the search continues to discover better thermal stabilizer combinations for halogen-containing polymers.
SUMMARY OF THE INVENTION
In accordance with the present invention, it has been discovered that thermal stabilization of halogen-containing polymers can be achieved by incorporation therein of an effective amount of a combination of (a) a compound of the formula (I): ##STR2## wherein R 1 R 2 are independently selected from hydrogen, alkyl, aryl, alkyl or alkoxy-substituted aryl, aralkyl, alkyl- or alkoxy-substituted aralkyl, or taken together form an alkylene radical of 3 to 9 carbon atoms; R 3 and R 4 are independently selected from alkyl of at least 4 carbon atoms, carb- alkoxyalkyl, aryl, alkyl- or alkoxy-substituted aryl, aralkyl, alkyl- or alkoxy-substituted aralkyl, or taken together form thiodimethylene, an ortho-arylene radical, an alkyl-or alkoxy-substituted ortho-arylene radical, or an alkylene radical of 2 to 4 carbon atoms, with (b) a divalent metal salt of a carboxylic acid of 7 or 20 carbon atoms or mixture of such metal salts.
Preferred compounds within the above definition are those represented by formula (II): ##STR3## wherein R 3 R 4 are as previously defined and said salt is selected from calcium, magnesium, barium, or zinc benzoate, laurate, oleate, or stearate, or mixtures thereof.
Especially preferred compounds are those compounds represented by formula (II) wherein R 3 and R 4 are the same and are selected from alkyl of 8 to 18 carbon atoms, monocarbocyclic aryl and alkyl-substituted aryl, benzyl, and carbalkoxyalkyl, wherein the alkoxy group has 8 to 18 carbon atoms.
DESCRIPTION OF PREFERRED EMBODIMENTS
Representative compounds of formula (I), useful in the practice of the present invention, include the following:
1,1-bis(octadecylthio)cyclohexane
1,1-bis(hexadecylthio)cyclohexane
1,1-bis(dodecylthio)cyclohexane
1,1-bis(octylthio)cyclohexane
1,1-bis(butylthio)cyclohexane
1,1-bis(octylthio)cyclodecane
1,1-bis(phenylthio)cyclohexane
1,1-bis[(p-tert-butylphenyl)thio]cyclohexane
1,1`-bis[(p-methoxyphenyl)thio]cyclohexane
1,1-bis[(p-dodecylphenyl)thio]cyclohexane
1,1-bis(phenylmethylthio)cyclohexane
1,1-bis[[(p-tert-butylphenyl)methyl]thio]cyclohexane
1,1-bis[[(p-octadecylphenyl)methyl]thio]cyclohexane
1,1-bis[[(o-methoxyphenyl)methyl]thio]cyclohexane
1,1-bis[[(p-dodecyloxyphenyl)methyl]thio]cyclohexane
dimethyl 3,3'-(cyclohexylidenedithio)propionate
dioctyl 3,3'-(cyclohexylidenedithio)propionate
dioctadecyl 3,3'-(cyclohexylidenedithio)propionate
1,3-dithiolane
spiro(1,3-dithiolane-2,1'-cyclohexane)
2,2-dimethyl-1,3-dithiolane
4-methyl-2-phenyl-1,3-dithiolane
2,2-diphenyl-1,3-dithiolane
1,3-dithiane
2-phenyl-1,3-dithiane
2,2-diphenyl-1,3-dithiane
s-trithiane
1,1-bis(octadecylthio)-1-phenylethane
bis[[(p-tert-butylphenyl)methyl]thio]phenylmethane
bis[(p-dodecylphenyl)thio]methane
bis(hexadecylthio)methane
spiro (1,3-benzodithiole-2,1'-cyclohexane)
spiro (1,3-benzodithiole-2,1'-5',5'-dimethyl-cyclohexane
spiro[naphtho(2,3-d)-1,3-dithiole-2,1'-cyclohexane]
naphtho(2,3-d)-1,3-dithiole, and the like
In general, the compounds of the present invention can be prepared by condensation of a suitable ketone or aldehyde with 2 moles of a suitable thiol, or mixture of thiols, or 1 mole of a suitable dithiol, in the presence of an acid catalyst such as hydrogen chloride or para-toluene-sulfonic acid. The 3,3'-(cyclohexylidenedithio) propionic acid esters are prepared by condensing a ketone or aldehyde with a beta-mercaptopropionic acid ester in the presence of an acid catalyst such as hydrogen chloride or para-toluene-sulfonic acid. The preparation of bis(alkylthio) and bis(arylthio)methanes is disclosed by Lapkin et al, Zh. Org. Khim 3 (11), 2009 (1967), see Chemical Abstracts 68, 8695OY. The preparation of s-trithiane is disclosed by Yamamura et al, Japanese Pat. No. 7,007,060, see Chemical Abstracts 73, 3944d (1970) and by Mansfeld, Berichte 19, 696-702(1886). The preparation of various alkyl and aryl substituted s-tri-thianes is disclosed by Behringer et al, Ann. 600, 23-34 (1956), see Chemical Abstracts 51, 4311 h (1957). The preparation of various 2,2-substituted 1,3-dithiolanes is disclosed by Fuhrer et al in Helv. Chim. Acta. 45, 2036 (1962), see Chemical Abstracts 58:5482 h (1963).
Illustrative examples of suitable ketones and aldehydes which may be used to prepare the compounds of formula (I) are as follows:
cyclobutanone
cyclopentanone
cyclohexanone
cyclodecanone
benzophenone
acetophenone
benzaldehyde
4-methoxybenzophenone
formaldehyde
acetaldehyde
2-butanone
acetone
2-heptanone
4-octanone
2-undecanone
4-methoxybenzophenone
4,4'-dimethoxybenzophenone
2 -methylbenzophenone
4-n-dodecylbenzophenone
4-phenyl-2-butanone
1,3-diphenylacetone
4-p-methoxyphenyl-2-butanone
1,3-bis(4-t-butylphenyl)acetone
Illustrative examples of suitable thiols, or dithiols, which may be employed to prepare the compounds of formula (I) are the following:
benzenethiol
p-tert-butylbenzenethiol
p-methoxybenzenethiol
p-dodecylbenzenethiol
phenylmethanethiol
p-tert-butylphenylmethanethiol
p-octadecylphenylmethanethiol
o-methoxyphenylmethanethiol
p-dodecyloxyphenylmethanethiol
methyl-3-mercaptopropionate
octyl-3-mercaptopropionate
octadecyl-3-mercaptopropionate
1,2-ethanedithiol
1,4-butanedithiol
1,3-propanedithiol
1,2-propanedithiol
1,1'-thiodimethanedithiol
1-octadecanethiol
1-dodecanethiol
1-octadecanethiol
1-hexadecanethiol
1-cyclohexanethiol
1-butanethiol
1,2-benzenedithiol
2,3-naphthalenedithiol, and the like
In accordance with the present invention, halogen-containing polymers, such as homopolymers and copolymers of vinyl chloride, vinylidene chloride, chlorinated polyolefins, and the like, particularly vinyl chloride and copolymers thereof containing at least 50 percent by weight of vinyl chloride units, can be stabilized against thermal degradation by the incorporation therein of compounds of formula (I) in admixture with a divalent metal salt of a carboxylic acid or mixture of carboxylic acids of 7 to 20 carbon atoms, preferably 12 to 20 carbon atoms, the weight ratio of said divalent metal salt to said compound being from about 1:20 to about 2:1, said compound being used in an amount of about 0.5 to about 5.0 percent, preferably about 1.0 to about 3.0 percent, on the weight of said halogen-containing polymer. Representative examples of suitable divalent metal salts include magnesium benzoate, calcium stearate, calcium laurate, zinc stearate, calcium oleate, calcium octoate, calcium 2-ethylhexoate, calcium ricinolate, calcium palmitate, barium stearate, magnesium stearate, barium laurate, and the like, and mixtures thereof.
Other additives also may be present in the halogen-containing polymer to modify it for its intended application, such as fillers, antioxidants, anti-static agents, lubricants, light stabilizers, pigments, dyes plasticizers, etc., as is conventional practice.
The compounds of this invention, along with other additives, if used, are readily incorporated into halogen-containing polymers by such conventional processes as casting, molding, extruding, milling, mixing, and the like.
The following examples are given to illustrate the present invention. All parts are by weight unless otherwise specified.
EXAMPLE 1
A solution of 4-t-butylthiophenol (33.2 grams; 0.2 mole) in cyclohexanone (9.8 grams; 0.1 mole) was cooled to 5° C and hydrogen chloride gas was bubbled into the solution while allowing the temperature to rise to 15-20° C. The addition of hydrogen chloride was then stopped while the solution was cooled to 5° C. The addition of hydrogen chloride was then initiated and the temperature was again allowed to rise to 15°-20° C. The solution was again cooled to 5° C and treated with hydrogen chloride. This was continued until no reaction exotherm was observed at which point the addition of hydrogen chloride was continued for another hour. The reaction mixture was dissolved in 150 mls. of diethyl ether and the ethereal solution was washed successively with aqueous sodium hydroxide until the aqueous layer remained basic and with water until the aqueous layer was neutral. The ethereal layer was dried over anhydrous magnesium sulfate and the ether was evaporated to obtain a yellow oil.
The yellow oil was chromatographed on a column of alumina using hexane as an eluant to obtain a white solid which was identified as 1,1-bis[(p-tert-butylphenyl) thio]cyclohexane; m.p. 74°-76° C after recrystallization from isopropanol.
Analysis: - Calculated for C 26 H 36 S 2 (percent): C, 75.66; H, 8.80; S, 15.54. Found (percent): C, 76.10; H, 8.99; S, 15.39.
EXAMPLE 2
A solution containing benzophenone (45.5 grams; 0.25 mole), 1,2-ethanedithiol (23.5 grams; 0.25 mole), and p-toluenesulfonic acid (1 gram) in 150 mls. of dry benzene was heated at reflux until no more water was azeotroped off. The remaining benzene was then evaporated and the residue was dissolved in diethyl ether. The ethereal solution was then washed with water, dried over anhydrous magnesium sulfate, filtered and evaporated to obtain 2,2-diphenyl-1,3-dithiolane, a white crystalline solid which melted at 104°-105° C. A different preparation of this same compound is described in Fasbender, Berichte 21, 1473-7, (1888), wherein the melting point is reported as 106° C.
EXAMPLE 3
The procedure of Example 1 was used to react cyclohexanone (9.8 grams; 0.1 mole) and 1-octadecanethiol (57.2 grams; 0.2 mole) except that the solution was warmed to 35° C prior to adding hydrogen chloride and the temperature was allowed to rise to 50° C. The addition of hydrogen chloride was continued until no exotherm was observed. At this point 50 mls. of hexane were added, the solution was cooled to 35° C and addition of hydrogen chloride was continued until solidification occurred. The solid was dissolved in a mixture of chloroform and diethyl ether, washed with aqueous caustic and then with water until neutral. The ethereal solution was then dried over magnesium sulfate, filtered and evaporated to obtain a white solid which was identified as 1,1-bis(octadecylthio)cyclohexane, melting point 49-51° C after recrystallization from hexane.
Analysis: Calculated for C 42 H 84 S 2 (percent): C, 77.22; H, 12.96; S, 9.82. Found (percent): C, 77.50, H, 12.89; S, 9.61.
EXAMPLE 4
The procedure of Example 1 was used to react cyclohexanone (8.15 grams; 0.083 mole) and 1-octanethiol (24.2 grams; 0.166 mole). After evaporating the ether a very pale yellow liquid was obtained which was identified as 1,1-bis(octylthio)cyclohexane.
Analysis: Calculated for C 22 H 44 S 2 (percent): C, 70.93; H, 11.89; S, 17.18. Found (percent): C, 71.40; H, 11.79; S, 16.91.
EXAMPLE 5
The procedure of Example 1 was used to react cyclohexanone (12.5 grams; 0.127 mole) and α-toluenethiol (31.0 grams; 0.249 mole). After evaporating the ether the residual oil was distilled under vacuum and the fraction boiling at 197°-199° C at 0.15 mm. was collected and identified as 1,1-bis(phenylmethylenethio)cyclohexane.
Analysis: Calculated for C 20 H 24 S 2 (percent): C, 73.11, H, 7.36; S, 19.52. Found (percent): C, 73.13; H, 7.09; S, 20.30.
EXAMPLES 6 TO 10
To each of five different 16.7% of Geon® 103EP polyvinyl chloride in tetrahydrofuran was added an amount of a compound of Examples 1 to 5, respectively, to provide 3% by weight of compound on the weight of polyvinyl chloride and a film was cast therefrom and dried. Each film was then exposed to heat at 193.3° C (380° F) in a press under a pressure of fifteen tons for twenty minutes, after which each film was observed for discoloration. As noted before, thermal degradation of polyvinyl chloride is accompanied by progressive discoloration of the polymer from clear colorless through various stages to black.
After exposure to heat the films containing 3% by weight of the compounds of Examples 1 to 4 inclusive were colored reddish-brown; the film containing 3% by weight of the compound of Example 5 was a pale brown color. In all cases control films similarly made and tested without addition of any such compound were colored reddish-brown. It is thus seen that, when used alone, these compounds are incapable of effectively stabilizing polyvinyl chloride against thermal degradation.
EXAMPLES 11 TO 15
The procedure of Examples 6 to 10 was used to test the combinations of each of the compounds of Examples 1 to 5 with a mixture containing 36% by weight calcium stearate, 20% by weight magnesium benzoate, 8% by weight zinc stearate and 36% by weight pentaerythritol. The concentration of each of the compounds of Examples 1 to 5, was between 1 and 2% on the weight of polyvinyl chloride with sufficient of said mixture containing the metal salts being added to obtain a total concentration of 3% of the total combination on the weight of the polyvinyl chloride.
In all cases the films were found to be colorless after exposure to heat by the test described in Examples 6 to 10. Control films similarly made and tested which contained 1 to 2% by weight of the mixture containing the calcium stearate, magnesium benzoate, zinc stearate and pentaerythritol, described hereinabove, on the weight of polyvinyl chloride were colored pale red-brown. It is thus seen that, although the mixture containing the metal salts was ineffective, the combinations thereof with the compounds of Examples 1 to 5 were very effective as thermal stabilizers for polyvinyl chloride.
EXAMPLES 16 to 19
The procedure of Examples 6 to 10 was used to test s-trithiane or dioctyl 3,3'-(cyclohexylidenedithio)-dipropionate in combination with the mixture of metal salts described in Examples 11 to 15. The concentration of s-trithiane or dioctyl 3,3'-(cyclohexylidenedithio)dipropionate employed was either 1 or 2% on the weight of polyvinyl chloride with sufficient of said mixture containing said metal salts and pentaerythritol being added to obtain a total concentration of each conbination of 3% on the weight of the polyvinyl chloride. The results obtained are shown below in Table I.
Table I______________________________________Example Additive Color of Film______________________________________16 2% s-trithiane colorless17 1% s-trithiane colorless18 2% dioctyl 3,3'-(cyclo- colorless hexylidenedithio)di- propionate19 1% dioctyl 3,3'-(cyclo- colorless hexylidenedithio- propionate______________________________________
Control films, containing only the additive, similarly made and tested, are colored reddish-brown. It is thus seen that these two additives, each in combination with the metal salts, are also effective thermal stabilizers for polyvinyl chloride.
EXAMPLES 20 to 22
The procedure of Examples 6 to 10 was used to test the combinations of the compound of Example 1 with calcium stearate or magnesium benzoate. The results obtained are reported in Table II below.
Table II______________________________________Example Additive Color of Film______________________________________20 2.6% Product of Example colorless 1; 0.4% Calcium Stearate21 2.8% Product of Example colorless 1; 0.2% Magnesium Benzoate22 2.4% Product of Example colorless 1; 0.6% Magnesium Benzoate______________________________________
It is thus seen that the combination stabilizers useful for thermally stabilizing polyvinyl chloride (a) need not contain pentaerythritol and (b) can contain only a single metal salt rather than a mixture of metal salts and still achieve effective thermal stabilization. | Thermal stability of halogen-containing polymers is improved by incorporation therein of (a) a compound of the formula: ##STR1## wherein R 1 and R 2 are independently selected from hydrogen, alkyl, aryl, alkyl- or alkoxy-substituted aryl, aralkyl, alkyl- or alkoxy-substituted aralkyl, or taken together form an alkylene radical of 3 to 9 carbon atoms; R 3 and R 4 are independently selected from alkyl of at least 4 carbon atoms, carbalkoxyalkyl, aryl, alkyl- or alkoxy-substituted aryl, aralkyl, alkyl- or alkoxy-substituted aralkyl or taken together form thiodimethylene, an ortho-arylene radical, an alkyl- or alkoxy-substituted ortho-arylene radical, or an alkylene radical of 2 to 4 carbon atoms; in combination with (b) a divalent metal salt of a carboxylic acid of 7 to 20 carbon atoms, or mixture of such metal salts. | 2 |
FIELD OF INVENTION
The present invention concerns a method of manufacturing strong acid cation exchange resins by pressurized sulfonation. More particularly, the present invention concerns the sulfonation of styrene-divinylbenzene or other crosslinked vinyl copolymer beads in the presence of a swelling solvent at superatmospheric pressure.
BACKGROUND OF THE INVENTION
Cation exchange resins, which are commercially useful in water treatment applications, are conventionally prepared by sulfonating styrene-divinylbenzene copolymers or other crosslinked vinyl copolymers having aromatic rings in the presence of a swelling solvent. In general, sulfonated cation exchange resins are prepared by contacting the copolymer beads in the presence of a swelling agent with a sulfonating agent at an elevated temperature for a time sufficient to achieve the desired degree of sulfonation. U.S. Pat. No. 5,081,160 teaches that suitable swelling agents are halogenated hydrocarbons such as, for example, methylene chloride or ethylene dichloride. Sulfonation is known to progress by a shell progressive mechanism in which sulfonic acid groups are substituted substantially within a continuous shell that is disposed about a central, unfunctionalized copolymer core; see G. Schmuckler et al. in Ion Exchange and Solvent Extraction, Vol. 7, Chapter 1, pp. 1-27, Marcel Dekker Inc., 1974. The use of a swelling agent usually produces a smoother interface between sulfonated and unsulfonated portions of the copolymer beads and facilitates attaining a high ion exchange capacity, i.e., a high degree of functionalization.
U.S. Pat. No. 4,209,592 recognizes that halogenated hydrocarbon swelling agents are useful for avoiding a high degree of resin bead fragmentation encountered in sulfonation conducted in the absence of the halogenated hydrocarbon. U.S. Pat. No. 5,523,327 teaches that the same effect can be achieved with saturated hydrocarbon swelling agents. Both patents disclose that sulfonation is usually carried out at atmospheric pressure; however, when high boiling saturated hydrocarbon swelling agents are used, the sulfonation is preferably conducted under reduced pressure. Conventional wisdom suggests that conducting sulfonations under increased pressures would seriously compromise product quality, i.e., increase bead rupture.
In addition to water treatment, cation exchange resins are used in certain applications, e.g., as a pharmaceutical useful for controlling potassium in kidney dialysis patients, in which bead color and appearance are important. But conventional sulfonation procedures do not give a product of consistent color and appearance. It would be desirable to have a sulfonation process that provides consistently light colored product. As with all manufacturing operations, it is also desirable to have a process that has shorter cycle times and requires less energy while maintaining or improving product quality.
SUMMARY OF THE INVENTION
The present invention concerns an improved sulfonation process for manufacturing cation exchange resins in which copolymer beads of a monovinylidene aromatic monomer and a polyvinylidene crosslinking monomer are contacted with a sulfonating agent in the presence of a swelling solvent wherein the improvement comprises conducting the sulfonation under pressure. Pressure increases the boiling point of the swelling solvent and delays its boil off. By keeping the copolymer swelled at temperatures above the swelling solvent's normal boiling point, sulfonation proceeds at significantly lower temperatures. The lower temperatures in turn allow the consistent production of light colored resin. By running the reaction at lower temperature, both heat up and cool down times are shortened, reducing the overall cycle time and increasing plant capacity. Pressure also helps keep foaming to a minimum, particularly during the removal of the swelling solvent. Pressure sulfonation imparts all of the advantages of using a high boiling swelling solvent without the disadvantages associated with the recovery of high boiling solvents in general and without compromising product quality.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, cation exchange resins are obtained by sulfonating copolymer beads of a monovinylidene aromatic monomer and a polyvinylidene crosslinking monomer with a sulfonating agent in the presence of a swelling solvent under pressure.
Cation exchange resins refer to copolymer beads containing aromatic rings substituted with sulfonic acid groups or the corresponding sulfonate salts.
The method used to prepare the copolymer beads is not critical to realize the benefits of this invention. As such, the copolymer beads may be prepared by any process known in the art. Such methods include, for example, a single-stage suspension polymerization process as described by F. Helfferich, Ion-Exchange, (McCraw-Hill, 1962) at pages 35 and 36, wherein a water-immiscible monomer phase is suspension polymerized in a continuous aqueous phase to produce spheroidal copolymer beads. Also suitable for preparing the copolymer bead matrix is a multi-staged, or seeded, suspension polymerization process. A multi-stage polymerization adds monomers in two or more increments. Each increment is followed by substantial polymerization of the monomers before adding a subsequent increment. Seeded polymerizations, as well as continuous or semicontinuous staged polymerizations, are described in U.S. Pat. Nos. 4,419,245 and 4,564,644.
Monomers suitable for preparing copolymer beads are addition polymerizable ethylenically unsaturated compounds. Typically, a major portion of at least one monovinylidene aromatic compound is polymerized with a minor portion of an addition polymerizable polyvinylidene compound which acts as a crosslinking monomer. Of particular interest are water-insoluble monovinylidene aromatics such as styrene, vinyltoluene, ethylvinylbenzene, vinylnaphthalene and vinylbenzyl chloride and polyvinylidene crosslinkers such as divinylbenzene and trivinylbenzene. Preferred monovinylidene aromatic monomers are styrene, ethylvinylbenzene and mixtures thereof. The preferred polyvinylidene crosslinking monomer is divinylbenzene.
The copolymer beads are prepared from monomer mixtures which include at least one monovinylidene aromatic monomer in an amount of from about 88 to about 99.5 weight percent, preferably from about 90 to about 98.5 weight percent, and more preferably from about 92 to about 98 weight percent based on the weight of monomers in the mixture, with the balance of the monomers being a polyvinylidene crosslinking monomer. Such monomer mixtures typically include free-radical polymerization initiators which are well-known in the art, such as azo compounds like azobisisobutyronitrile and peroxy compounds like benzoyl peroxide, t-butyl peroctoate, t-butyl perbenzoate and isopropyl percarbonate.
A diluent which is substantially inert under polymerization conditions may also be incorporated into the monomer phase to obtain macroporous copolymer beads. The term "macroporous" (also referred to as macroreticular) is well-known in the art and, in general, refers to resins prepared from copolymer beads which have regions of densely packed polymer chains exhibiting molecular-sized porosity which are separated by copolymer-free voids, often referred to as mesopores (5-20 nanometers (nm)) and macropores (>20 nm). In contrast, microporous, or gel-type, resins have pores generally of molecular-size (less than about 5 nm) and are prepared from monomer mixtures which do not employ an inert diluent. Macroporous and gel resins are further described in U.S. Pat. Nos. 4,224,415 and 4,382,124.
Suitable inert diluents are those which are a solvent for the monomer mixture, but not the resulting copolymer. Accordingly, use of an inert diluent results in phase separation of the copolymer from the monomer phase during polymerization. Inert diluents are generally organic compounds having boiling points greater than about 60° C. and include, for example, aromatic hydrocarbons, aliphatic hydrocarbons, alcohols, and halogenated hydrocarbons. Preparation of macroporous copolymer beads is well-known in the art. The benefits of the present invention are obtained with either macroporous or gel copolymer beads.
In general, sulfonated cation-exchange resins are prepared by contacting the copolymer beads with a sulfonating agent at an elevated temperature and for a time sufficient to achieve a desired degree of sulfonation. Suitable sulfonating agents include concentrated sulfuric acid, i.e., acid having a sulfuric acid concentration greater than about 90 percent based on total weight; oleum; chlorosulfonic acid; or sulfur trioxide. A preferred sulfonating agent is sulfuric acid, preferably 98 percent sulfuric acid. The amount of concentrated sulfuric acid employed is advantageously that which is sufficient to provide adequate mixing during reaction, with a weight ratio of acid to beads of from about 4.5:1 to about 16:1 being generally sufficient. The preferred weight ratio of acid to beads is about 5:1 to about 6.5:1. Suitable temperatures for sulfonation with sulfuric acid are from about 20° to about 150° C. It is desirable to maintain a temperature of from about 40° to about 140° C., preferably from about 60° to about 130° C., and most preferably from about 70° to about 110° C.
Sulfonation of the copolymer beads with sulfuric acid is preferably conducted in the presence of a swelling solvent. Suitable swelling solvents are known in the art and include, for example, halogenated hydrocarbons like methylene chloride and ethylene dichloride and saturated hydrocarbons like cyclohexane and iso-octane. The amount of swelling solvent is preferably sufficient to give a weight ratio of swelling solvent to copolymer beads from about 0.1 to about 1.6, most preferably from about 0.2 to about 0.5. Typically, the copolymer beads are contacted with the swelling agent prior to sulfonation for a time sufficient to substantially swell the beads, generally at least about 10 minutes.
The gist of the present invention is directed to conducting the sulfonation under pressure. By "under pressure" is meant operation at pressures greater than atmospheric pressure. The advantage of operating under superatmospheric pressure is to effectively increase the boiling point of the swelling solvent to keep the copolymer swelled at temperatures above the swelling solvent's normal boiling point. Too high a pressure, however, can promote bead rupture. While operation at pressures above, for example, 100 pounds per square inch gauge (psig) 790 kilopascals (kPa)! may not be detrimental, neither is it any more beneficial for the usual swelling solvents employed. External pressure can be applied; however, it is preferable to run the reaction under autogenous pressure, i.e., under the pressure naturally developed by conducting the sulfonation in a closed or partially closed vessel.
After sulfonation, the reaction vessel is vented and the resin is hydrated and, if desired, converted to a metal salt. Alternatively, some pressure can be released during the sulfonation reaction for ease of other process considerations, such as improving cycle time.
In a typical reaction, a pressure reactor is loaded with sulfonating agent, copolymer and swelling solvent and is then purged with nitrogen, evacuated and sealed. The contents of the reactor are heated to the desired temperature until reaction is complete, generally in from about 0.25 to about 3 hours. A fixed pressure can be maintained by releasing some of the swelling solvent during the reaction. After completion of the reaction, the pressure is slowly released and the swelling solvent is removed. After cooling, the resin is hydrated and recovered.
The following examples further illustrate the present invention.
EXAMPLE 1
A 1-liter (L) Hastelloy B or C pressure reactor was equipped with a process controller and a pressure relief device set at 75 psig (627 kPa). Reactor temperature was controlled by external electric heating and water cooling. Reactor pressure was monitored by a transducer and controlled by a pressure regulating valve. The reactor was loaded with 100 parts of a 10 percent divinylbenzene (DVB) copolymer of styrene, 500 parts of 98 percent H 2 SO 4 and from 10 to 160 parts of methylene chloride (MeCl 2 ) as the swelling solvent. The reactor was purged with nitrogen, evacuated and sealed. The reactor was heated to the reaction temperature and held at that temperature for a prescribed time. The pressure was released and the solvent was removed using reduced pressure to speed up the final stages of removal. The resin was hydrated, washed and dried. Dry weight capacity (DWC) was determined by titration and compared to theoretical DWC 5.32 milliequivalents per gram (meg/g)! to calculate degree of sulfonation (DWC/theoretical DWC). The results are summarized in Table I.
TABLE I______________________________________Pressure Sulfonation Data for 10 percentDVB Copolymer of StyreneRun Temp. P.sub.max Time MeCl.sub.2 PercentNo. °C. psig kPa Hr. Parts Sulfonation______________________________________1 70 20 238 0.5 80 932 70 25 272 2 80 953 80 10 169 0.5 40 914 80 14 196 1 40 965 80 24 265 1 40 966 90 45 410 2 160 977 90 35 341 2 80 978 90 18 224 0.5 80 979 90 10 169 1 50 9710 90 24 265 1 40 9711 90 20 238 1 40 9712 90 10 169 1 40 9713 90 30 306 1.5 40 9714 90 18 224 1.5 40 9715 90 22 251 0.5 40 9716 90 17 217 0.5 30 9517 90 14 196 0.5 20 9118 90 11 176 0.5 10 8019 95 24 265 1 40 9720 100 45 410 1 40 9721 100 25 272 1 40 9722 100 10 169 0.5 40 97______________________________________
EXAMPLE 2
The procedure of Example 1 was repeated using an 8 percent DVB copolymer of styrene and from 30 to 40 parts MeCl 2 as the swelling solvent. The theoretical DWC was 5.34 meq/g. The results are summarized in Table II.
TABLE II______________________________________Pressure Sulfonation Data For 8 PercentDVB Copolymer of StyreneRun Temp. P.sub.max Time MeCl.sub.2 PercentNo. °C. psig kPa Hr. Parts Sulfonation______________________________________1 90 20 238 1 40 992 90 20 238 0.5 40 983 90 10 169 2 40 994 90 10 169 1 40 985 90 10 169 0.5 40 986 90 10 169 0.5 30 967 80 14 196 0.5 40 978 80 10 169 0.5 40 96______________________________________
EXAMPLE 3
The procedure of Example 1 was repeated using a 5.7 percent DVB copolymer of styrene and from 20 to 40 parts MeCl 2 as the swelling solvent. The theoretical DWC was 5.37 meq/g. The results are summarized in Table III.
TABLE III______________________________________Pressure Sulfonation Data For 5.7 PercentDVB Copolymer of StyreneRun Temp. P.sub.max Time MeCl.sub.2 PercentNo. °C. psig kPa Hr. Parts Sulfonation______________________________________1 90 20 238 1 40 992 90 20 238 0.5 40 993 90 10 169 1 40 994 90 10 169 1 30 995 90 10 169 1 20 986 90 10 169 0.5 40 997 80 14 196 1 40 978 80 10 169 1 40 97______________________________________ | Cation exchange resins are prepared by sulfonating copolymer beads in the presence of a swelling solvent under pressure. Pressure sulfonation shortens cycle times and requires less energy while maintaining or improving product quality. | 2 |
FIELD OF THE INVENTION
The present invention relates to a waveform equalization system for a data transmission line which can be suitably used in a signal processing system for a magnetic disk apparatus.
BACKGROUND OF THE INVENTION
An arrangement of a prior art decision feedback equalization circuit will be explained in connection with FIG. 1.
In a digital signal transmission system, a signal received through a transmission line generally comprises a transmitted signal distorted by intersymbol interference and noise.
The received signal passed through a transmission system with a relatively narrow band as transmission band has such intersymbol interference that affects the previous and subsequent transmission bits. In this specification, such interference which affects bits of the received signal at times antecedent to a received bit will be referred to as the forward interference, while such interference which affects bits of the received signal at times subsequent to the received bit will be referred to as the backward interference.
Noise is a general term for random disturbances independent of signals. For the purpose of removing intersymbol interference from such a received signal, an equalization circuit is used, A decision feedback equalization circuit comprises a linear equalizer 2 for eliminating forward interference in bits of the received signal, an intersymbol interference estimator 80 for eliminating backward interference in the signal bits, a subtracter 4, and a detector 6.
Explanation will next be made as to the operational principle of the decision feedback equalization circuit by referring to FIG. 2. To simplify explanation, it is herein assumed that a received signal 1 received in the decision feedback equalization circuit is a digital data signal of levels "0" and "1" distorted by intersymbol interference and disturbance. It is further assumed that a transmitted signal 33 is an isolated impulse signal having a level "1" at a transmission time corresponding to a reception time k and a level "0" at the other times. The received signal 1 is first subjected at the linear equalizer 2 to removal of forward interference antecedent to the received time k. The received signal is then subjected at the subtracter 4 to subtraction of a feedback signal 9. The feedback signal 9 is an estimate of the backward interference from the currently received bit and the backward interference is removed by subtracting the backward interference estimate for the subsequent bits. Whether to perform the subtraction for removal of the backward interference for the subsequent bits is determined by a decision signal "0" or "1" of the detector 6. That is, when determining the presence of an impulse signal at the received time k, the detector 6 performs a backward interference removing operation over the subsequent bits; whereas, when determining the absence of an impulse signal, the detector 6 performs no backward interference removing operation. The detector 6 generates a detected signal 7 as its output result and applies it to the intersymbol interference estimator 80. An output 9 of the intersymbol interference estimator 80 corresponds to an estimate of the backward interference contained in a signal to be next received from the past received data sequence. The feedback signal 9 generated by the intersymbol interference estimator 80 is applied to a minus input of the subtracter 4 to remove the backward interference applied to the next-received signal. Thereafter, these operations are repeated. An example of such a decision feedback equalization circuit is described in, for example, Jan W. M. Bergmans, "Decision Feedback Equalization for Magnetic Recording Systems", IEEE Trans. Magn. pp. 683, Vol. 24, No. 1, January, 1988.
The timing of operation of the prior art decision feedback equalization circuit is shown in FIG. 3. A main clock period 24 is a period with which a received signal is applied to the decision feedback equalization circuit. It is impossible to set the main clock period 24 to be shorter than a time 25 corresponding to a total sum of a delay time 17 of the subtracter 4, a delay time 18 of the detector 6 and a delay time 19 of the intersymbol interference estimator 80.
In a digital data transmission field, a higher data transmission rate has been always demanded. When a decision feedback equalizer is used as an equalizing means, a decision result is used to estimate an interference and a negative feedback circuit is provided at an input of a decider or detector, which results in that it is impossible to set a data transmission period to be shorter than a delay time of the feedback circuit. Accordingly, for the purpose of shortening the delay time of the feedback circuit to increase the data transmission rate, elements constituted of the feedback circuit are required to be of a high speed type.
It is therefore an object of the present invention to provide an inexpensive, high-speed decision feedback equalization circuit in which a feedback circuit can be made fast in operation while eliminating the need for requiring all elements of the feedback circuit to be of a high speed type.
SUMMARY OF THE INVENTION
In accordance with the present invention, when it is first assumed that a detector has M possible outputs (M being an integer of 2 or more), there may be provided M subtracters for subtracting outputs of feedback-signal selection estimator means from a received signal, M data memories for holding therein outputs of the M subtracters, and a selector for selecting one of data held in the M data memories.
The above feedback-signal selection estimator means may comprise a single feedback-signal selection estimator.
The above feedback-signal selection estimator means may comprise M feedback-signal selection estimators.
In the prior art, when it is first assumed that a detector has M possible outputs, a decision at a time (t) causes determination of a feedback signal to the received signal at a next time (t+1) from acquisition of a decision output. However, in accordance with the present invention, when a decision result at a time (t-1) is obtained, M feedback signal candidates at the time (t) of obtaining the M decision results are previously prepared so that, when the decision result at the time (t) is obtained, one feedback signal corresponding to the decision result is selected from the M feedback signal candidates and fed back. This shortens the time taken from the decision to the feedback of the feedback signal over that of the prior art decision feedback equalization circuit.
In the decision feedback equalization circuit, it is impossible to make a signal input/output period shorter than the delay time of the feedback circuit. In the prior art decision feedback equalization circuit, the delay time of the feedback circuit corresponds to a sum of the delay time of the subtracters, the delay time of the detector and the delay time of the feedback-signal selection estimator.
The signal input/output period of the decision feedback equalization circuit in accordance with the present invention is required to be set larger than one of a sum of the delay time of the subtracter, the delay time of the detector, the delay time of the data memory and the delay time of the selector; or a time necessary for deciding the M feedback signal candidates.
Therefore, the signal input/output period of the decision feedback equalization circuit of the present invention can be set to be shorter than the signal input/output period of the prior art decision feedback equalization circuit; by a time of the shorter one of a time corresponding a subtraction of the delay times of the data memory and selector from a time necessary for the decision of the M feedback signal candidates, and a sum of the delay times of the subtracter and detector.
In accordance with the present invention, M feedback signal candidates corresponding to acquisition of M possible decision results at the time (t) are found at the time of obtaining a decision result at the time (t-1), M subtracters are used to previously prepare negative feedback results of the M feedback signal candidates, one of which is selected corresponding to the decision result obtained at the time (t) and applied to the detector. Thus, the time between 2 consecutive decisions of the decision feedback equalization circuit can be made shorter than that of the prior art decision feedback equalization circuit, by a time of the shorter one of a time corresponding to a subtraction of a sum of the delay times of the detector and intersymbol interference estimator from a sum of the delay times of the intersymbol interference estimator and subtracter, and a time corresponding to a subtraction of half of a sum of the delay times of the detector, intersymbol interference estimator, subtracter, data memory and selector from a sum of the delay times of the detector, intersymbol interference estimator and subtracter.
In accordance with the present invention, in place of the intersymbol interference estimator forming the feedback-signal selection estimator being made up of high-speed elements, the data memory and selector comprise high-speed elements, whereby the operation of the circuit can be made fast with a low cost.
Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred and alternate embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in conjunction with certain drawings which are for the purpose of illustrating the preferred and alternate embodiments of the invention only, and not for the purpose of limiting the same, and wherein:
FIG. 1 is an arrangement of a prior art decision feedback equalization circuit;
FIG. 2 shows diagrams for explaining waveform equalizing processes in the decision feedback equalization circuit;
FIG. 3 is an operational timing chart for explaining the operation of the prior art decision feedback equalization circuit;
FIG. 4 is a diagram for explaining the first embodiment of the present invention;
FIG. 5 is a diagram for explaining a first example of a feedback-signal selection estimator in first and second embodiments of the present invention;
FIG. 6 is a diagram for explaining a second example of the feedback-signal selection estimator in first and second embodiments of the present invention;
FIG. 7 is a diagram for explaining a third example of the feedback-signal selection estimator in first and second embodiments of the present invention;
FIG. 8 is a diagram for explaining a fourth example of the feedback-signal selection estimator in first and second embodiments of the present invention;
FIG. 9 is a diagram for explaining a fifth example of the feedback-signal selection estimator in first and second embodiments of the present invention;
FIG. 10 is a timing chart for explaining the operation of the first embodiment of the present invention in which the example of FIG. 6, 8 or 9 is employed for the feedback-signal selection estimator;
FIG. 11 is a timing chart for explaining the operation of the first embodiment of the present invention in which the example of FIG. 5 or 7 is employed for the feedback-signal selection estimator;
FIG. 12 is a diagram for explaining the second embodiment of the present invention;
FIG. 13 is a timing chart for explaining the operation of the second embodiment of the present invention in which the example of FIG. 6, 8 or 9 is employed for the feedback-signal selection estimator;
FIG. 14 is a timing chart for explaining the operation of the second embodiment of the present invention in which the example of FIG. 5 or 7 is employed for the feedback-signal selection estimator;
FIG. 15 is a block diagram of the first embodiment of the present invention in which a 2-bit detector is used;
FIG. 16 shows diagrams for explaining the operation of the first embodiment of the present invention in which the 2-bit detector is used;
FIG. 17 shows diagrams for explaining received signals without noise; and
FIG. 18 is a graph showing a bit error rate reduction effect when a plural-bit detector is used in the first embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will be explained with reference to the accompanying drawings. As shown in FIG. 4, the present embodiment comprises a linear equalizer 2, a subtracter 4, a detector 6, an estimator 8 for selection of feedback signal, data memories 15a and 15b, and a selector 14. In the present embodiment, to simplify the following account, it is assumed that a received signal 1 corresponds to a binary signal of levels of "0" and "1" distorted by intersymbol interference and other disturbance.
Explanation will be made as to the operation of decision feedback equalization circuit of the present embodiment by referring to FIG. 4. The received signal 1 is input to the linear equalizer 2. In the linear equalizer 2, the input signal is subjected to removal of forward interference. An output 3 of the linear equalizer 2 is applied to an plus input of the subtracter 4. The subtracter 4 acts to subtract a feedback signal 9 from the output 3 of the linear equalizer 2. An output 5 of the subtracter 4 is sent to the detector 6 which in turn performs its detecting operation of "0" or "1" over the input signal. An output 7 of the detector 6, which becomes a final output of the decision feedback equalization circuit, is also applied to the estimator 8 for selection of feedback signal candidates and to the selector 14. The selector 14 has 3 inputs, 2 of which receive to-be-selected signals and the remaining one of which receives a selection control signal. The selector 14 selects and determines as its output either one of the to-be-selected signals on the basis of the state "0" or "1" of the selection control signal. In the illustrated example, the output 7 of the detector 6 is used as the selection control signal while outputs of the data memories 15a and 15b are used as the to-be-selected signals. When the selector 14 holds as feedback signal selections or candidates a feedback signal 13a when determining "0" as its decision result and a feedback signal 13b when determining "1" as its decision result, it selects and outputs one of the feedback signal candidates corresponding to the actually obtained decision result. Meanwhile, the estimator 8 for selection of feedback signal candidates generates the feedback signal 13a when the selector 14 determines "0" and the feedback signal 13b when the selector 14 determines "1". The above operations are repeated.
In FIG. 4, reference numeral 40 denotes a part which functions to executing a function of receiving the output of the linear equalizer 2 and the outputs of the estimator 8 for selection of feedback signal candidates to obtain a decision result for the received signal at a predetermined time.
The estimator 8 for selection of feedback signal candidates in the present embodiment may comprise such a single estimator 80 for intersymbol interference as shown in FIG. 5. In this case, the intersymbol interference estimator 80 generates an intersymbol interference when the selector 14 determines "0" as its decision result and the decision result "0" is held in a second data memory 34, and subsequently generates an intersymbol interference when the selector 14 determines "1" as its decision result. In this way, such an arrangement as to use the single intersymbol interference estimator can realize a high speed operation while eliminating the need for increasing the number of circuit elements to a large extent.
In such an embodiment having the estimator 8 for selection of feedback signal candidates made up of the single intersymbol interference estimator as mentioned above, the intersymbol interference estimator 80 may comprise a shift register 10 for holding therein a history of decision results and a data memory 12 using respective bits of the shift register as its addresses, as shown in FIG. 7. Such an arrangement as to use the above memory can eliminate interference dependent on recording pattern.
Shown in FIG. 11 is a timing chart for explaining the operation of the aforementioned embodiment including the estimator 8 for selection of feedback signal candidates made up of the single intersymbol interference estimator.
The estimator 8 for selection of feedback signal candidates in the present embodiment may comprise 2 intersymbol interference estimators 80a and 80b as shown in FIG. 6. In this case, the 2 intersymbol interference estimators simultaneously generate an intersymbol interference at the time of the first decision result and an intersymbol interference at the time of the next decision result ("0" or "1" in the present embodiment). In this way, such an arrangement using the 2 intersymbol interference estimators can realize a higher speed operation than in the arrangement using the single intersymbol interference estimator.
In the aforementioned embodiment having the feedback-signal selection estimator 8 made up of the 2 intersymbol interference estimators, the intersymbol interference estimators 80a and 80b may comprise shift registers 10a and 10b for holding therein a history of decision results and data memories 12a and 12b using respective bits of the shift registers as their addresses respectively, as shown in FIG. 8. The arrangement using such memories can remove interference dependent on recording pattern.
FIG. 10 shows a timing chart for explaining the operation of the above embodiment having the feedback-signal selection estimator 8 made up of the 2 intersymbol interference estimators. In the present embodiment, a main clock period in the present invention can be made shorter than a main clock period in the prior art, by a time 22 corresponding to a subtraction of a delay time 32 of the data memories and a delay time 21 of the selector from a delay time 19 of the intersymbol interference estimators 80a and 80b.
The feedback-signal selection estimator 8 in the present embodiment may comprise, as shown in FIG. 9, a shift register 10 for holding therein a history of decision results, coefficient memories 10' for holding therein coefficients to be multiplied by values held in respective bits of the shift register, multipliers 26 for performing multiplication of the values held in the shift register and the coefficients held in the coefficient memories, a first adder 28 for calculating a sum of outputs of the respective multipliers, and a second adder 28' for adding a coefficient to an output of the first adder 28 to obtain a feedback signal candidate when the next decision result is "1". The timing of the then operation is also shown in FIG. 10. In the present embodiment, a main clock period in the present invention can be made shorter than a main clock period in the prior art, by a time 22 corresponding to a subtraction of a delay time 32 of the data memories and a delay time 21 of the selector from a delay time 19 of an intersymbol interference estimator 81.
Another embodiment of the present invention will be explained by referring mainly to FIGS. 12 to 14. The present embodiment comprises a linear equalizer 2, subtracters 4a and 4b, a detector 6, a feedback-signal selection estimator 8, data memories 15a and 15b, and a selector 14. A received signal in the present embodiment is assumed to be similar to that in the first embodiment.
The operation of a decision feedback equalization circuit of the present embodiment will be explained with reference to FIG. 12. A received signal 1 is applied to the linear equalizer 2. The linear equalizer 2 eliminates forward interference from the received signal. An output 3 of the linear equalizer 2 is applied to plus inputs of the subtracters 4a and 4b. The subtracters 4a and 4b subtract feedback signal candidates 13a and 13b from the output 3 of the linear equalizer 2 respectively. The feedback signal candidates 13a and 13b are feedback signals when the decision results are "0" and "1" respectively. Outputs of the subtracters 4a and 4b are applied to respective data memories 15a and 15b. Outputs of the data memories 15a and 15b are applied to the selector 14. The selector 14 issues an output of the data memory 15a when a decision result 7 is "0" and issues an output of the data memory 15b when the decision result is "1". The selector 14 sends its output to the detector 6. The detector 6 decides whether the decision result is "0" or "1". An output of the detector 6, which is the final output of the decision feedback equalization circuit, is also applied to the feedback-signal selection estimator 8 and the selector 14. The feedback-signal selection estimator 8 generates the feedback signal 13a when the decision result is "0" and the feedback signal 13b when the next decision result is "1", and applies these feedback signals 13a and 13b to minus inputs of the respective subtracters 4a and 4b.
In the case where such an arrangement is employed, when one of the outputs of the subtracters 4a and 4b is determined to be much apart from an expected value through the comparison between the outputs of the subtracters 4a and 4b, the other output can be selected regardless of the decision result to improve reliability in the decision.
The feedback-signal selection estimator 8 in the present embodiment may comprise such a single intersymbol interference estimator 80 as shown in FIG. 5. In this case, the intersymbol interference estimator 80 generates an intersymbol interference when the next decision result is "0" and the generated intersymbol interference is held in the second data memory 34; while the intersymbol interference estimator 80 generates an intersymbol interference when the next decision result is "1". In this way, the above arrangement using the single intersymbol interference estimator can realize a high speed operation while eliminating the need for increasing the number of circuit elements to a large extent.
In the foregoing embodiment having the feedback-signal selection estimator 8 formed as the single intersymbol interference estimator, the intersymbol interference estimator 80 may comprise a shift register 10 for holding a history of decision results and data memory 12 using respective bits of the shift register as its addresses, as shown in FIG. 7. The arrangement using such a memory can remove interference dependent on recording pattern.
Shown in FIG. 13 is a timing chart for explaining the operation of the above embodiment having the feedback-signal selection estimator 8 formed as the single intersymbol interference estimator.
The feedback-signal selection estimator 8 in the present embodiment may comprise 2 intersymbol interference estimators 80a and 80b as shown in FIG. 6. In this case, the 2 intersymbol interference estimators simultaneously generate an intersymbol interference at the time of the first decision result and an intersymbol interference at the time of the next decision result ("0" or "1" in the present embodiment). In this way, such an arrangement using the 2 intersymbol interference estimators can realize a higher speed operation than in the arrangement using the single intersymbol interference estimator.
In the aforementioned embodiment having the feedback-signal selection estimator 8 made up of the 2 intersymbol interference estimators, the intersymbol interference estimators 80a and 80b may comprise shift registers 10a and 10b for holding therein a history of decision results and data memories 12a and 12b using respective bits of the shift registers as their addresses respectively, as shown in FIG. 8. The arrangement using such memories can remove interference dependent on recording pattern.
FIG. 14 shows a timing chart for explaining the operation of the above embodiment having the feedback-signal selection estimator 8 made up of the 2 intersymbol interference estimators. In the present embodiment, a main clock period in the present invention can be made shorter than a main clock period in the prior art, by a time 22 corresponding to a subtraction of a delay time 32 of the data memories and a delay time 21 of the selector from a delay time 19 of the intersymbol interference estimators 80a and 80b.
The feedback-signal selection estimator 8 in the present embodiment may comprise, as shown in FIG. 9, a shift register 10 for holding therein a history of decision results, coefficient memories 10' for holding therein coefficients to be multiplied by values held in respective bits of the shift register, multipliers 26 for performing multiplication of the values held in the shift register and the coefficients held in the coefficient memories, a first adder 28 for calculating a sum of outputs of the respective multipliers, and a second adder 28' for adding a coefficient to an output of the first adder 28 to obtain a feedback signal candidate when the next decision result is "1". The timing of the then operation is also shown in FIG. 14. In the present embodiment, a main clock period in the present invention can be made shorter than a main clock period in the prior art, by a time 22 corresponding to a subtraction of a delay time 32 of the data memories and a delay time 21 of the selector from a delay time 19 of an intersymbol interference estimator 81.
In the first and second embodiments of the present invention, the detector may perform its detecting or deciding operation with use of a plurality of bits of information. The operational principle of such a detector as to be able to perform its deciding operation on a plurality of bits of information will be explained in connection with FIGS. 15 to 18. For the purpose of simplifying the explanation, explanation will be made as to the case where such a detector performs its deciding operation with use of information on a bit to be decided and on a successive bit at a next time (which detector will be referred to as the 2-bit detector, hereinafter) is used in the first embodiment of the present invention. A decision feedback equalizer using such a 2-bit detector is described, for example, in J. Moon and L. R. Carley, "Performance comparison of detection methods in magnetic recording", IEEE Trans. Magn. Vol. 26, No. 6, pp. 3155-3172, November 1990.
FIG. 15 shows a block diagram of an embodiment of the present invention in which a 2-bit detector 6' is used in the first embodiment.
FIG. 16 shows diagrams for explaining the operation of the embodiment of the present invention in which the 2-bit detector 6' is used in the first embodiment. For the sake of the convenience of explanation, it is assumed here that delay times of elements in a circuit of FIG. 15 are sufficiently small and negligible. A transmitted signal 33 is an isolated impulse signal which takes a level "1" at a time k and a level "0" at the other times; whereas the received signal 1 received through a channel has such a spread that each 2 bits are present after and before a peak value corresponding to the transmitted signal 33 of "1", which results in an intersymbol interference. The linear equalizer 2 can eliminate a forward interference from the intersymbol interference. The output 3 of the linear equalizer 2 is subtracted at the subtracter 4 by a feedback signal 9'. The 2-bit detector 6', when detecting or deciding a signal at the time k, utilizes the signal at a next time k+1 containing interference from the signal at the time k. The 2-bit detector 6', with use of these 2 bits, decides that the signal at the time k has a level "1" and eliminates the intersymbol interference contained by the signal "1" at the time k from the signal at the next time k+1 to thereby obtain an output 7.
Explanation will then be made as to the detecting or deciding principle of the 2-bit detector 6' by referring to FIGS. 15 to 17. An output 5' of the subtracter is applied to the 2-bit detector 6'. The then output is assumed to have levels of fr(k) and fr(k+1) at times k and k+1 as transmitted signals fr(k) and fr(k+1). The transmitted signals fr(k) and fr(k+1) have only 4 combinations of (0,0), (0,1), (1,0) and (1,1). Hence, ideal received signals f0,0; f0,1; f1,0; and f1,1 without noise are prepared for the 4 combinations of the transmitted signals, and a square error E is calculated using these signals in accordance with the following equation.
E={fm,n(k)-fr(k)}2+{fm,n(k+1)-fr(k+1)}2
where, m=0,1 and n=0,1.
In the illustrated example, since the error becomes smallest for f1, 0, the 2-bit detector 6' decides that fr(k) has "1" and subtraction of f1,0(k+1) is carried out for fr(k+1) and later. When decision is carried out by the 2-bit detector in this way, error becomes much less than the 1-bit decision case. Similarly, the more the number of bits is increased the less the error occurs, as shown in the example given in FIG. 18. FIG. 18 shows comparative results of bit error rate when the detector utilizes 1-, 2- and 3-bits. The "bit error rate", which represents a rate of bits at which an error occurs on an average, is expressed in the ordinate; while a signal-to-noise ratio (SN ratio) for the received signal is expressed in the abscissa. It will be seen from FIG. 18 that the more the number of bits used in the decision is increased the more the bit error rate is decreased.
Even when such a detector for performing decision with use of information on a plurality of bits is used in the second embodiment of the present invention, the effect of reducing the bit error rate is also as shown in FIG. 18.
Likewise, the operational timing, for when such a detector with use of information on a plurality of bits is used in the first and second embodiments of the invention, is also similar to the case of using the 1-bit detector.
In accordance with the present invention, the operation of the decision feedback equalization circuit can be made fast with a low cost. | A decision feedback equalization circuit which can be operated at a high speed with a low cost as well as a high-speed digital data communication system and a high-speed digital data recording system using the equalization circuit are disclosed. The decision feedback equalization circuit has data memories which correspond to the number of available values in decision result and in which feedback signals corresponding to all the next decision results are previously prepared as candidates so that a suitable one of the feedback signal candidates is selected and fed back based on the obtained decision result, thus realizing high-speed operation of a feedback loop. | 7 |
[0001] The present invention relates to a firearm support system to provide a support for the firearm to assist in hunting activities, and more particularly, a firearm support system that allows a hunter to transport and easily install the firearm support system in tree or tree stand.
[0002] Currently, most hunters do not have a support system that holds the firearms steady while hunting or they use a stationary gun holder that is either mounted directly to the tree stand or tree. However, both of these options are not very satisfactory when sitting in a tree or tree stand for many hours while waiting the for the game to come by the hunter. Additionally, the stationary holder does not allow for easy transport to a different location if the hunter decides to hunt at another location, unless other holders are mounted at the other locations. If the hunter does not have a steady aim on the animal, the hunter may miss the animal or simply injure the animal rather than kill it quickly.
[0003] Accordingly, the present invention is directed to a firearm support system that substantially obviates one or more of the problems and disadvantages in the prior art. Additional features and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the apparatus and process particularly pointed out in the written description and claims, as well as the appended drawings.
SUMMARY OF THE INVENTION
[0004] To achieve these and other advantages and in accordance with the purpose of the invention as embodied and broadly described herein, the invention is directed to a firearm support system comprising an extendable arm, a support element attached to the extendable arm, and a support attachment member to engage a fixed structure and configured to accept at least a portion of the extendable arm.
[0005] In yet another aspect, the invention is directed to a firearm support system comprising an extendable arm, the extendable arm having a first end configured to engage a support structure, and a support element attached to a second end of the extendable arm.
[0006] In another aspect, the present invention is directed to a firearm support system comprising, an arm configured to be attached to a support structure, and a support element attached to the arm, the support element having a plurality of rest members spaced from one other along the support element to support a firearm.
[0007] It is to be understood that 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.
[0008] The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification. The drawings illustrate several embodiments of the invention and together with the description serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an elevational view of a firearm support system ferrule according to one embodiment of the present invention;
[0010] FIG. 2 is a side elevational view of the firearm support system of FIG. 1 in a folded position;
[0011] FIG. 3 is the other side view of the firearm support system of FIG. 1 in a folded position;
[0012] FIG. 4 is a side elevational view of the firearm support system of FIG. 1 in a partially unfolded position;
[0013] FIG. 5 is an enlarged partial view of the firearm support system of FIG. 1 illustrating the storage of one embodiment of a support attachment member;
[0014] FIG. 6 is an end view of the portion of the support attachment member of FIG. 5 ;
[0015] FIG. 7 is a plan view of the support attachment member installed in a fixed structure according to one embodiment of the present invention;
[0016] FIG. 8 is a perspective view of an alternative embodiment of a support attachment member according to the present invention;
[0017] FIG. 9 is an end view of the support attachment member of FIG. 8 ;
[0018] FIG. 10 is a perspective view of another alternative embodiment of a support attachment member according to the present invention strapped to a fixed structure;
[0019] FIG. 11 is a perspective view of an alternative embodiment of a support attachment member according to the present invention;
[0020] FIG. 12 is an end view of the support attachment member of FIG. 11 ;
[0021] FIG. 13 is an elevational view of a firearm support system ferrule according to another embodiment of the present invention in a folded configuration;
[0022] FIG. 14 is an elevational view of a firearm support system ferrule according to another embodiment of the present invention;
[0023] FIG. 15 is an elevational view of the firearm support system of FIG. 12 in a contracted configuration;
[0024] FIG. 16 is an elevational view of a firearm support system ferrule according to another embodiment of the present invention;
[0025] FIG. 17 is an alternative embodiment of a rest member with screws stored therein;
[0026] FIG. 18 is a partial view of an end of an arm segment of a firearm support system with screws stored therein; and
[0027] FIG. 19 is an elevational view of an alternative embodiment of a support element according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] As illustrated in FIGS. 1-7 , a firearm support system 10 has an extendable arm 12 that preferably has three arm segments 12 a , 12 b , 12 c rotatably connected to one another. The firearm support system 10 also has a projection 14 attached to a first end 16 of the extendable arm 12 . The projection 14 is preferably configured as a cylindrical member, as best illustrated in FIG. 5 . The projection 14 slides into support attachment member 18 , which in turn attaches to a fixed support structure 20 . The fixed support structure 20 is preferably a tree, but it can be any fixed object, including a bush, a tree stand in a tree or on the ground, a building, etc. The extendable arm 12 also has a support element 22 that is attached to a second end 24 of the extendable arm 12 . The support element 22 preferably has two fibrous elements 26 that extend from second end 24 and have a plurality of rest members 28 . The fibrous elements 26 are preferably made of nylon, but could be made of any durable material such as cotton string, leather or could even be a non-flexible member as described below. The rest members 28 are preferable elongated cylindrical members, but could be of any shape and size. For example, the rest members 28 could have a square, oval, or any other shape cross section. The two fibrous elements 26 are attached at either end of the rest members 28 to secure them at predetermined distances from each other. The rest members 28 are spaced from one another such that the firearm could be rested on the rest members 28 between the two fibrous elements 26 , or the hunter's hand could rest on them with the firearm resting on the hunter's hand or arm on the outside of the two fibrous elements 26 . It should also be noted that while the rest members 28 are attached that their ends to the two fibrous elements 26 , they could extend beyond the two fibrous elements 26 and still be within the scope of the present invention. The support element 22 could also have a single central support member that engages rest members 28 to support the firearm as illustrated in FIG. 17 .
[0029] Since the projection 14 is preferably a cylindrical member and the support attachment member 18 has a central lumen 30 that is appropriately sized to slidingly receive the projection 14 , the extendable arm 12 is able to pivot about the central lumen 30 in the support attachment member 18 . This allows the hunter to move the firearm (and the firearm support system 10 ) within the hunter's field of view. With a plurality of rest members 28 spaced along the length of the support element 22 , the hunter may alter the angle of the firearm with the ground, depending on the distance of the target from the hunter's position by utilizing the different rest members 28 .
[0030] The support attachment member 18 preferably includes two holes 32 in a base plate 36 to receive screws 34 . The hunter typically screws the screws 34 through the base plate 36 and into the fixed support structure 20 using a screw driver head 38 attached to one of the three arm segments 12 a , 12 b , 12 c. As shown best in FIGS. 2 & 3 , the screw driver head 38 is attached to one end of the arm segment 12 b. The hunter then slides the projection 14 into the central lumen 30 of support attachment member 18 . The firearm support system 10 is then ready to use
[0031] An alternative support attachment member 18 ′ is illustrated in FIGS. 8 and 9 . The support attachment member 18 ′ is similar to the support attachment member 18 , but has a reduced sized by having the screws 34 and holes 32 ′ through support attachment member 18 and the central lumen 30 ′. By inserting the screws 34 through the holes 32 and the support attachment member 18 ′, it supports the screws 34 in two places during insertion into the fixed support structure 20 . This configuration allows for more support of the screws 34 and easier insertion of the screws 34 into the fixed support structure 20 . Another alternative support attachment member is illustrated in FIG. 10 . The support attachment member 18 ″ has straps 40 rather than screws 34 to secure it to the fixed support structure 20 . The straps 40 are wrapped around the tree and then secured. This method of attaching support attachment member 18 to the fixed support structure 20 eliminates putting holes into the structure.
[0032] Another support attachment member 18 ′″ is illustrated in FIGS. 11 and 12 . The support attachment member 18 ′″ is similar to the members described above, but has a rectangular tubular portion 36 ′ rather than the base plate 36 . In this embodiment, the holes 32 ″ are only through the rectangular tubular portion 36 ′, and not through the cylindrical portion of the support attachment member 18 ′″. As the screws 34 ″ must pass through both sides of the rectangular tubular portion 36 ′, the screws 34 ″ are preferably longer than the screws in other embodiments to account for the thickness of the rectangular tubular portion 36 ′ and still penetrate the support structure a sufficient distance. The screws 34 ″ are supported more with the two sides of the rectangular tubular portion 36 ′, making it easier for the user to drive the screws 34 ″ into the tree using only one hand. The holes 32 ″ are preferably countersunk on the side nearest to the cylindrical portion, to eliminate any potential interference of the screws 34 ′ with the projection 14 .
[0033] It should be noted that the hunter may decide to leave the support attachment member 18 in the tree or other fixed support structure 20 for the next hunting trip. Additionally, the hunter could place several of the support attachment members 18 in various locations so as not to have to continually install and remove the support attachment members 18 each time.
[0034] The extendable arm 12 preferably has three arms 12 a , 12 b, 12 c that are rotatably connected to one another, which allows the extendable arm 12 to be folded up and easily carried to and from the hunter's stand. See FIGS. 2 & 3 . To fold the firearm support system 10 , the three arms 12 a , 12 b , 12 c are rotated over and onto one another as illustrated in FIG. 4 . In the embodiment in FIGS. 1-7 , the pivoting of the three arms 12 a , 12 b , 12 c are about the bolts 42 . Once the three arms 12 a , 12 b , 12 c are folded, the support attachment member 18 can be mounted to the underside of arm 12 c. Mounting of support attachment member 18 includes inserting the screws 34 into apertures 44 on the underside of arm 12 c. Then two hook and loop type straps 46 are used to hold the support attachment member 18 to the firearm support system 10 . As shown in FIGS. 2 & 3 , the straps 46 also cover the screws 34 to ensure that they do not fall out during transport and storage of firearm support system 10 . The two hook and loop type straps 46 are preferably secured to the firearm support system 10 so that they do not fall off or become lost during use of the firearm support system 10 . In the preferred embodiment, the straps 46 are riveted to arm 12 b, but they may be secured in any manner, e.g., glued, screwed, welded, with an adhesive, etc. The straps 46 also assist in keeping the firearm support system 10 in a folded configuration.
[0035] The support element 22 can then be wrapped around the firearm support system 10 as illustrated in FIGS. 2 and 3 . Wrapping the support element 22 around the firearm support system 10 also assists with keeping the firearm support system 10 in a folded configuration in addition to making firearm support system 10 more compact overall. While the support element 22 is wrapped around the firearm support system 10 in the figures, it could also simply be gathered and then secured to the firearm support system 10 with the strap 48 . In the compact configuration, firearm support system 10 can be easily transported in a fanny pack or other tote.
[0036] As illustrated in FIG. 4 , extra screws 34 could be stored in the bottom rest member 28 (or any of the rest members 28 ). The extra screws 34 are screwed into the bottom rest member 28 , but may also be stored in a hollow rest member 28 ′ as illustrated in FIG. 15 . Alternatively, the screws 34 could also be stored inside arm 12 a as shown in FIG. 16 . It should be noted that the two fibrous elements 26 , which are attached to extendable arm 12 at the second end 24 by knotting each end, block the end of the extendable arm 12 b, keeping the screws 34 inside the second end 24 . Access to the extra screws 34 is as easy as pulling the knotted ends of the two fibrous elements 26 out of the second end 24 of extendable arm 12 . The screws 34 will then fall out of the extendable arm 12 b.
[0037] The three arms 12 a , 12 b , 12 c are attached to one another by bolts 42 . The bolts 42 are tightened so that the extendable arm 12 does not easily close or collapse during use. While the tight bolts 42 make it hard for the extendable arm 12 to close, it may also be difficult for the hunter to extend the arms 12 a , 12 b , 12 c. Therefore, in FIG. 11 an alternative extendable arm 12 ′ is provided with wing nuts 52 that can be easily loosened during extension and folding, and then tightened to ensure that the alternative extendable arm 12 ′ does not unexpectedly fold during use. The heads of the bolts 54 with the wing nuts 52 are disposed within the arm 12 b′ , allowing the arms to all be the same length since the heads of the bolts 54 are inside the arm 12 b. Additionally, since the heads of bolts 54 are no longer external to the arm 12 b′ , the projection 14 ′ can be oriented so that is does not extend downward away from the extendable arm 12 as in the previous embodiment. This configuration makes for a more compact device.
[0038] A portion of another alternative embodiment of a firearm support system according to the present invention is illustrated in FIG. 12 . An extendable arm 56 extends in a telescopic manner rather than in a folding manner as in the previous embodiments. While the preferred embodiment has three arms 56 a , 56 b , 56 c that are telescopically connected to one another there could be any number of arms or segments. The extendable arm 56 may also have a projection attached to one end to engage a support attachment member as in the previous embodiment. A screw driver 58 head may be installed on the other end of the extendable arm 56 for installing screws into a fixed support structure 20 . The extendable arm 56 would also have a support element (not shown) as in the prior embodiments.
[0039] Another embodiment of firearm support system according to the present invention is illustrated in FIG. 14 . The extendable arm 58 would be a unitary (not foldable or telescoping) member that can be secured to the support attachment member with projection and support attachment member as in the prior embodiments, or with the end 60 as illustrated in FIG. 14 . The end 60 has threads 62 located on its periphery to allow the extendable arm 58 to be screwed directly into the fixed support structure. Alternatively, extendable arm 58 may also have the other attachment elements (e.g., the projection and support attachment member) discussed above with respect to the other embodiments.
[0040] It will be apparent to those skilled in the art that various modifications and variations can be made in the firearm support system 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. | A firearm support system is provided to support a firearm or a portion of person that in turn holds the firearm to make a steady shot. The firearm support system is particularly adaptable for use in a tree stand or tree. The firearm support system can be attached directly to the tree stand or tree and is pivotable thereto, allowing for a wide field of view and use. The firearm support system is collapsible, either by folding or telescoping, making for a more compact unit that can be easily carried to the hunting location. | 5 |
RELATED APPLICATIONS
This application is a continuation-in-part application of Ser. No. 08/890,802, filed Jul. 11, 1997.
The present invention relates to novel bioabsorbable polymeric compositions based upon AB polyester polyether or related diblocks. Compositions according to the present invention may be used in medical applications, for example, for reducing or preventing adhesion formation subsequent to medical procedures such as surgery, for producing surgical articles including stents and grafts, as coatings, sealants, lubricants, as transient barriers in the body, for materials which control the release of bioactive agents in the body, for wound and burn dressings and producing biodegradable articles, among numerous others.
BACKGROUND OF THE INVENTION
The desire to find improved polymeric compositions which can be used for specific medical and environmental applications is ever present. There is a continuous search for new, improved biodegradable polymers to provide enhanced materials which are biocompatible, have good bioabsorbtive/biodegrable properties, appropriate mechanical and physical properties and related structural characteristics which find use in the prescribed application. Materials which provide superior characteristics as well as flexibility in formulation and manufacture are especially desirable.
Early biodegradable/bioabsorbable polymers focused on polylactic and/or polyglycolic acid homopolymers or copolymers which were used primarily in bioabsorbable sutures. These early polymers suffered from the disadvantage that the polymers tended to be hard or stiff and often brittle with little flexibility. In addition, the kinetics of their degradation tended to be slow in certain applications, necessitating research on polymers with faster degradation profiles.
A number of other copolymers utilizing lactic acid, glycolic acid, ε-caprolactone, poly(orthoesters) and poly(orthocarbonates), poly(esteramides) and related polymers have been synthesized and utilized in medical applications with some measure of success. The polymers tend to be limited, however, by disadvantages which appear in one or more of the following characteristics: flexibility, strength, extensibility, hardness/softness, biocompatability, biodegradability, sterilizability, ease of formulation over a wide range of applications and tissue reactivity.
Recent investigative attention has centered on the production of ACA triblock polymeric compositions which are derived from blocks of poly(oxy)alkylene and polyhydroxycarboxylic acids. These formulations, among others have exhibited favorable characteristics for use to reduce and/or prevent adhesion formulation secondary to surgery and other medical applications.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide novel polymeric materials which may be used in a variety of medical, environmental and other applications where biodegradability/bioerodability is an important feature of the application.
It is an additional object of the invention to provide polymeric materials which may be manufactured in film form and other solid structures such as rods, cylinders, porous structures such as foams, dispersions, viscous solutions, liquid polymers, pastes, sprays or gels which may be administered easily or adapted for use in a wide range of applications.
It is yet another object of the invention to provide polymeric materials which may be used to substantially prevent adhesions and which may be effective for delivering bioactive agents.
It is yet an additional object of the invention to provide bioabsorbable polymeric materials which can be produced in a variety of formulations which have acceptable strength, may be reactive or non-reactive with patient tissue depending upon the desired application and are bioabsorbable.
It is yet another object of the present invention to provide polymeric barriers which can be used in various forms, e.g., films, other structures such as rods and cylinders, foams, gels, dispersions, liquid polymers, pastes, sprays or viscous solutions, to provide flexibility in administration and use in a variety of applications, including medical applications, environmental applications and other applications.
These and/or other objects of the invention may be readily gleaned from the detailed description of the present invention which follows.
SUMMARY OF THE INVENTION
The present invention relates to multiblock polymeric materials which utilize AB diblocks as building blocks for the polymeric materials.
The present invention preferably relates to polymeric compositions comprising coupled or crosslinked poly(ester)/polyether AB or related AB diblocks, where A is a polyester unit derived from the polymerization of monomers and B is a monofinctional hydroxyl, amine or carboxyl containing molecule (which may be monomeric or polymeric) which is end-capped with a non-reactive group, such that the hydroxyl, amine or carboxyl-containing molecule initiates the polymerization of the monomers to form the polyester unit (A block). In preferred embodiments according to the present invention, the polyester unit A is derived from the polymerization of monomers selected from the group consisting of lactic acid, lactide, glycolic acid, glycolide, β-propiolactone, ε-caprolactone, δ-glutarolactone, δ-valerolactone, β-butyrolactone, pivalolactone, α,α-diethylpropiolactone, ethylene carbonate, trimethylene carbonate, γ-butyrolactone, p-dioxanone, 1,4-dioxepan-2-one, 3-methyl-1,4-dioxane-2,5-dione, 3,3,-dimethyl-1-4-dioxane-2,5-dione, cyclic esters of α-hydroxybutyric acid, α-hydroxyvaleric acid, α-hydroxyisovaleric acid, α-hydroxycaproic acid, α-hydroxy-α-ethylbutyric acid, α-hydroxyisocaproic acid, α-hydroxy-α-methyl valeric acid, α-hydroxyheptanoic acid, α-hydroxystearic acid, α-hydroxylignoceric acid, salicylic acid and mixtures, thereof. B may be derived from any monofunctional hydroxyl, amine or carboxyl containing molecule which is capable of initiating polymerization of the monomers which comprise the A block. In preferred aspects of the present invention, the monofunctional molecule (which is also referred to as a “monofinctional initiator molecule”) is a C 1 to C 12 amine, alcohol or carboxylic acid. The alcohol, amine or carboxylic acid may be an alkyl amine, alcohol or carboxylic acid, an aryl amine, alcohol or carboxylic acid, an aralkyl amine, alcohol or carboxylic acid or a substituted alkyl arnine, alcohol or carboxylic acid, substituted aryl amine, alcohol or carboxylic acid or a substituted aralkyl amine, alcohol or carboxylic acid. In alternative embodiments, the monofunctional initiator molecule is a poly(oxyalkylene) molecule or a poly(oxyalkylene)-containing molecule, preferably poly (ethylene glycol), varying in molecular weight from as low as 100 (diethylene glycol) to hundreds of thousands or more, with a preferred molecular weight ranging from about 550 to about 5,000 or more.
The AB diblocks described above may be utilized without further modification, or preferably, they may be coupled with a chain-extender or coupling agent as described in more detail herein to produce coupled diblocks or multiblocks according to the present invention. Polymeric compositions according to the present invention are advantageously end-capped with inert groups, i.e. they preferably do not contain any reactive groups at their ends which will participate in any reaction. By relying on end-capping with inert groups, the present compositions unexpectedly attain a storage stability, whether in solid form or solution, which is significantly enhanced compared to compositions which are end-capped with reactive groups such as hydroxyl, amine or carboxylic acid groups.
The present invention relates to a polymer of the chemical structure:
where a is a positive integer,
X is a C 1 -C 8 alkylene group, preferably a C 1 (CH) alkylene group,
R 1 is H or CH 3 , preferably H when X is a C 2 -C 8 alkylene group and Z is derived from an amine- or hydroxyl-containing monofunctional monomeric or polymeric compound end-capped with an amine or hydroxyl group, the amine- or alcohol-containing compound preferably being selected from an alkyl (preferably, C 1 to C 12 ) amine or alcohol, an aryl amine or alcohol, an aralkyl amine or alcohol or a substituted alkyl (preferably, C 1 to C 12 ) amine or alcohol, a substituted aryl amine or alcohol, a substituted aralkyl amine or alcohol, a blocking group or a C═C containing group.
Z is preferably represented by the structure M—(O—R—) m —Y,
where m is a positive integer,
Y is O or NH,
R is a C 2 to C 10 alkylene group and is preferably an ethylene group and/or propylene group, and
M is a non-reactive group or a group containing a blocking group or a —C═C— group, preferably a group selected from a C 1 to C 12 alkyl group, an aryl group, an aralkyl group or a substituted C 1 to C 12 alkyl group, aryl group, aralkyl group, a blocking group or a C═C containing group.
The present invention also relates to a polymeric composition of the chemical structure:
where a is a positive integer,
Z is derived from an amine- or hydroxyl-containing monofunctional monomeric or polymeric compound end-capped with an amine or hydroxyl group, the amine- or alcohol-containing compound preferably being selected from an alkyl (preferably, C 1 to C 12 ) amine or alcohol, an aryl amine or alcohol, an aralkyl amine or alcohol or a substituted alkyl (preferably, C 1 to C 12 ) amine or alcohol, a substituted aryl amine or alcohol, or a substituted aralkyl amine or alcohol, a blocking group or a C═C containing group,
X is a C 1 -C 8 alkylene group, preferably a C 1 (CH) alkylene group,
R″ is a C 0 to C 12 alkylene group or a hydroxyl or carboxylic acid substituted alkyl group, a cycloalkyl, a hydroxyl-containing cycloalkyl, or cycloalkyl-containing group, an aryl or aryl-containing group, an oligoester or polyester, or a polyoxyalkylene chain-containing group, preferably comprised of poly(ethylene oxide), poly(ethylene oxide)-co-poly(propylene oxide) or a poly(ethylene oxide) rich chain, and R 1 is H or CH 3 , preferably H when X is a C 2 -C 8 alkylene group.
Z is preferably represented by the structure M—(O—R—) m —Y,
where m is a positive integer,
Y is O or NH,
R is a C 2 to C 10 alkylene group, preferably an ethylene group (C 2 ) and/or propylene group (C 3 ), M is a non-reactive group or a group containing a blocking group or a —C═C— group, preferably, a C 1 to C 12 alkyl group, an aryl group, an aralkyl group or a substituted C 1 to C 12 alkyl group, an aryl group, an aralkyl group, a blocking group or a C═C containing group. More preferably, M is methyl or ethyl.
The present invention also relates to a polymeric composition according to the chemical structure:
where a is a positive integer,
Z is derived from an amine- or hydroxyl-containing monofunctional monomeric or polymeric compound end-capped with an amine or hydroxyl group, the amine- or alcohol-containing compound preferably being selected from an alkyl (preferably, C 1 to C 12 ) amine or alcohol, an aryl amine or alcohol, an aralkyl amine or alcohol or a substituted alkyl (preferably, C 1 to C 12 ) amine or alcohol, a substituted aryl amine or alcohol, or a substituted aralkyl amine or alcohol, a blocking group or a C═C containing group,
X is a C 1 -C 8 alkylene group, preferably a C 1 (CH) alkylene group,
R′ is a C 2 to C 12 alkylene group, a cycloalkyl or cycloalkyl-containing group, an aryl or aryl-containing group, 4,4′-diphenylmethane, toluene, naphthalene, 4,4′-dicyclohexylmethane, cyclohexyl, 3,3′-dimethylphenyl, 3,3′-dimethyl-diphenylmethane, 4,6′-xylylene, 3,5,5-trimethylcyclohexyl, 2,2,4-trimethylhexamethylene or p-phenylene or a poly(ethylene oxide) containing or poly(ethylene oxide) rich chain and R 1 is H or CH 3 , preferably H when X is a C 2 -C 8 alkylene group.
Z is preferably represented by the structure M—(O—R—) m —Y,
where m is a positive integer,
Y is O or NH,
R is a C 2 to C 10 alkylene group, preferably an ethylene group and/or propylene group and M is a non-reactive group or a group containing a blocking group or a —C═C— group, preferably, a C 1 to C 12 alkyl group, an aryl group, an aralkyl group or a substituted C 1 to C 12 alkyl group, an aryl group, an aralkyl group, a blocking group or a C═C containing group. More preferably,
M is methyl or ethyl.
The present invention also relates to a polymeric composition according to the chemical structure:
where a is a positive integer,
Z is derived from an amine- or hydroxyl-containing monofunctional monomeric or polymeric compound end-capped with an amine or hydroxyl group, the amine- or alcohol-containing compound preferably being selected from an alkyl (preferably, C 1 to C 12 ) amine or alcohol, an aryl amine or alcohol, an aralkyl amine or alcohol or a substituted alkyl (preferably, C 1 to C 12 ) amine or alcohol, a substituted aryl amine or alcohol, or a substituted aralkyl amine or alcohol, a blocking group or a C═C containing group,
X is a C 1 -C 8 alkylene group, preferably a C 1 (CH) alkylene group,
R′ is a C 2 to C 12 alkylene group, a cycloalkyl or cycloalkyl-containing group, an aryl or aryl-containing group, 4,4′-diphenylmethane, toluene, naphthalene, 4,4′-dicyclohexylmethane, cyclohexyl, 3,3′-dimethylphenyl, 3,3′-dimethyl-diphenylmethane, 4,6′-xylylene, 3,5,5-trimethylcyclohexyl, 2,2,4-trimethylhexamethylene, p-phenylene or a poly(ethylene oxide) containing or poly(ethylene oxide) rich chain, R′″ is selected from or derived from the group consisting of a diol, which generates urethane groups upon reaction with a diisocyanate, a diamine, which generates urea groups upon reaction with a diisocyanate or a dicarboxylic acid which generates amide groups upon reaction with a diisocyanate, said diol preferably being selected from the group consisting of C 2 to C 24 (preferably, C 2 to C 12 ) diols such as ethylene glycol and butanediol, a poly(oxyalkylene) diol compound of the structure —(O—R) m —O— where R is a C 2 to C 10 alkylene group (preferably an ethylene group and/or propylene group) and m is a positive integer, poly(oxyalkylene)-rich diols especially including poly(ethylene oxide)-rich diols, a OH-terminated polycaprolactone or other OH-terminated polyesters, oligoesters or an ACA triblock, wherein in said ACA triblock, A is a polyester unit and C is selected from the group consisting of poly(ethylene oxide), poly(ethylene oxide)-co-poly(propylene oxide), a poly(ethylene oxide) rich chain, a diol and a diamine as set forth above, said diamine being preferably selected from the group consisting of C 2 to C 24 (preferably, C 2 to C 12 ) diamines, more preferably ethylene diamine and hexamethylene diamine, amino acids, and oligopeptides,
said dicarboxylic acid preferably being selected from the group consisting of C 0 to C 24 (preferably, C 2 to C 12 ) dicarboxylic acids, succinic acid, sebacic acid, adipic acid, malic acid, tartaric acid, oxalic acid, maleic acid, fumaric acid, COOH-terminated polycaprolactone, and COOH-terminated polyesters or oligoesters, and R 1 is H or CH 3 , preferably H when X is a C 2 -C 8 alkylene group.
Z is preferably represented by the structure M—(O—R—) m —Y,
where m is a positive integer,
Y is O or NH,
R is a C 2 to C 10 alkylene group, preferably an ethylene group and/or propylene group and M is a non-reactive group or a group containing a blocking group or a —C═C— group, preferably, a C 1 to C 12 alkyl group, an aryl group, an aralkyl group or a substituted C 1 to C 12 alkyl group, an aryl group, an aralkyl group or a blocking group or a C═C containing group. More preferably,
M is methyl or ethyl.
The present invention also relates to a composition comprising a polymer of the chemical structure:
where a is a positive integer,
Z is derived from an amine- or hydroxyl-containing monoflinctional monomeric or polymeric compound end-capped with an amine or hydroxyl group, the amine- or alcohol-containing compound preferably being selected from an alkyl (preferably, C 1 to C 12 ) amine or alcohol, an aryl amine or alcohol, an aralkyl amine or alcohol or a substituted alkyl (preferably, C 1 to C 12 ) amine or alcohol, a substituted aryl amine or alcohol, or a substituted aralkyl amine or alcohol, a blocking group or a C═C containing group,
X is a C 1 -C 8 alkylene group, preferably a C 1 (CH) alkylenegroup,
R 1 is a hydrogen or methyl group, preferably H when X is a C 2 -C 8 alkylene group,
R″ is a C 0 to C 12 alkylene group or a hydroxyl or carboxylic acid substituted alkyl group, a cycloalkyl, a hydroxyl-containing cycloalkyl, or cycloalkyl-containing group, an aryl or aryl-containing group, a carboxyl-terminated oligoester or polyester, or a polyoxyalkylene chain-containing group preferably comprised of poly(ethylene oxide), poly(ethylene oxide)-co-poly(propylene oxide) or a poly(ethylene oxide) rich chain, and
R 2 is selected from or derived from the group consisting of a diol, which generates urethane groups upon reaction with a diisocyanate, a diamine, which generates urea groups upon reaction with a diisocyanate or a dicarboxylic acid which generates amide groups upon reaction with a diisocyanate, said diol preferably being selected from the group consisting of C 2 to C 24 (preferably, C 2 to C 12 ) diols such as ethylene glycol and butanediol, a poly(oxyalkylene) diol compound of the structure —(O—R) m —O— where R is a C 2 to C 10 alkylene group (preferably an ethylene group and/or propylene group) and m is a positive integer, poly(oxyalkylene)-rich diols especially including poly(ethylene oxide)-rich diols, a OH-terminated polycaprolactone or other OH-terminated polyesters, oligoesters or an ACA triblock, wherein in said ACA triblock, A is a polyester unit and C is selected from the group consisting of poly(ethylene oxide), poly(ethylene oxide)-co-poly(propylene oxde), a poly(ethylene oxide) rich chain, a diol and a diamine as set forth above,
said diamine being preferably selected from the group consisting of C 2 to C 24 (preferably, C 2 to C 12 ) diamines, more preferably ethylene diamine and hexamethylene diamine, amino acids, and oligopeptides,
said dicarboxylic acid preferably being selected from the group consisting of C 0 to C 24 (preferably, C 2 to C 12 ) dicarboxylic acids, succinic acid, sebacic acid, adipic acid, malic acid, tartaric acid, oxalic acid, maleic acid, fumaric acid, COOH-terminated polycaprolactone, and COOH-terminated polyesters or oligoesters.
Z is preferably represented by the structure M—(O—R—) m —Y,
where m is a positive integer,
Y is O or NH,
R is a C 2 to C 10 alkylene group, preferably an ethylene group and/or propylene group and M is a non-reactive group or a group containing a blocking group or a —C═C— group, preferably, a C 1 to C 12 alkyl group, an aryl group, an aralkyl group or a substituted C 1 to C 12 alkyl group, an aryl group, an aralkyl group or a blocking group or a C═C containing group. More preferably,
M is methyl or ethyl.
Other embodiments of the present invention are directed to a composition comprising a polymer of the chemical structure:
where a is a positive integer,
Z is derived from an amine- or hydroxyl-containing monofinctional monomeric or polymeric compound end-capped with an amine or hydroxyl group, the amine- or alcohol-containing compound preferably being selected from an alkyl (preferably, C 1 to C 12 ) amine or alcohol, an aryl amine or alcohol, an aralkyl amine or alcohol or a substituted alkyl (preferably, C 1 to C 12 ) amine or alcohol, a substituted aryl amine or alcohol, or a substituted aralkyl amine or alcohol, a blocking group or a C═C containing group,
X is a C 1 -C 8 alkylene group, preferably a C 1 (CH) alkylenegroup,
R′ is a C 2 to C 12 alkylene group, a cycloalkyl or cycloalkyl-containing group, an aryl or aryl-containing group, 4,4′-diphenylmethane, toluene, naphthalene, 4,4′-dicyclohexylmethane, cyclohexyl, 3,3′-dimethylphenyl, 3,3′-dimethyl-diphenylmethane, 4,6′-xylylene, 3,5,5-trimethylcyclohexyl, 2,2,4-trimethylhexamethylene, p-phenylene, or a poly(oxyalkylene) chain, including a poly(ethylene oxide) containing or poly(ethylene oxide) rich chain, R′″ is selected from or derived from the group consisting of a diol, which generates urethane groups upon reaction with a diisocyanate, a diamine, which generates urea groups upon reaction with a diisocyanate or a dicarboxylic acid which generates amide groups upon reaction with a diisocyanate, said diol preferably being selected from the group consisting of C 2 to C 24 (preferably, C 2 to C 12 ) diols such as ethylene glycol and butanediol, a poly(oxyalkylene) diol compound of the structure —(O—R) m —O— where R is a C 2 to C 10 alkylene group (preferably an ethylene group and/or propylene group) and m is a positive integer, poly(oxyalkylene)-rich diols especially including poly(ethylene oxide)-rich diols, a OH-terminatsed polycaprolactone or other OH-terminated polyesters, oligoesters or an ACA triblock, wherein in said ACA triblock, A is a polyester unit and C is selected from the group consisting of poly(ethylene oxide), poly(ethylene oxide)-co-poly(propylene oxde), a poly(ethylene oxide) rich chain, a diol and a diamine as set forth above,
said diamine being preferably selected from the group consisting of C 2 to C 24 (preferably, C 2 to C 12 ) diamines, more preferably ethylene diamine and hexamethylene diamine, amino acids, and oligopeptides,
said dicarboxylic acid preferably being selected from the group consisting of C 0 to C 24 (preferably, C 2 to C 2 ) dicarboxylic acids, succinic acid, sebacic acid, adipic acid, malic acid, tartaric acid, oxalic acid, maleic acid, fumaric acid, COOH-terminated polycaprolactone, and COOH-terminated polyesters or oligoesters,
and R 1 is H or CH 3 , preferably H when X is a C 2 -C 8 alkylene group and preferably CH 3 when X is C 1 .
Z is preferably represented by the structure M—(O—R—) m —Y,
where m is a positive integer,
Y is O or NH,
R is a C 2 to C 10 alkylene group, preferably an ethylene group and/or propylene group and M is a non-reactive group or a group containing a blocking group or a —C═C— group, preferably, a C 1 to C 12 alkyl group, an aryl group, an aralkyl group or a substituted C 1 to C 12 alkyl group, an aryl group, an aralkyl group or a blocking group or a C═C containing group. More preferably,
M is methyl or ethyl.
Other embodiments of the present invention are directed to a composition comprising a polymer of the chemical structure:
where a is a positive integer,
Z is derived from an amine- or hydroxyl-containing monofunctional monomeric or polymeric compound end-capped with an amine or hydroxyl group, the amine- or alcohol-containing compound preferably being selected from an alkyl (preferably, C 1 to C 12 ) amine or alcohol, an aryl amine or alcohol, an aralkyl amine or alcohol or a substituted alkyl (preferably, C 1 to C 12 ) amine or alcohol, a substituted aryl amine or alcohol, or a substituted aralkyl amine or alcohol, a blocking group or a C═C containing group,
X is a C 1 -C 8 alkylene group, preferably a C 1 (CH) alkylenegroup,
R′ is a C 2 to C 12 alkylene group, a cycloalkyl or cycloalkyl-containing group, an aryl or aryl-containing group, 4,4′-diphenylmethane, toluene, naphthalene, 4,4′-dicyclohexylmethane, cyclohexyl, 3,3′-dimethylphenyl, 3,3′-dimethyl-diphenylmethane, 4,6′-xylylene, 3,5,5-trimethylcyclohexyl, 2,2,4-trimethylhexamethylene, p-phenylene, or a poly(oxyalkylene) chain, including a poly(ethylene oxide) containing or poly(ethylene oxide) rich chain,
R′″ is selected from or derived from the group consisting of a diol, which generates urethane groups upon reaction with a diisocyanate, a diamine, which generates urea groups upon reaction with a diisocyanate or a dicarboxylic acid which generates amide groups upon reaction with a diisocyanate, said diol preferably being selected from the group consisting of C 2 to C 24 (preferably, C 2 to C 12 ) diols such as ethylene glycol and butanediol, a poly(oxyalkylene) diol compound of the structure —(O—R) m —O— where R is a C 2 to C 10 alkylene group (preferably an ethylene group and/or propylene group) and m is a positive integer, poly(oxyalkylene)-rich diols especially including poly(ethylene oxide)-rich diols, a OH-terminated polycaprolactone or other OH-terminated polyesters, oligoesters or an ACA triblock, wherein in said ACA triblock, A is a polyester unit and C is selected from the group consisting of poly(ethylene oxide), poly(ethylene oxide)-co-poly(propylene oxde), a poly(ethylene oxide) rich chain, a diol and a diamine as set forth above,
said diamine being preferably selected from the group consisting of C 2 to C 24 (preferably, C 2 to C 12 ) diamines, more preferably ethylene diamine and hexamethylene diamine, amino acids, and oligopeptides,
said dicarboxylic acid preferably being selected from the group consisting of C 0 to C 24 (preferably, C 2 to C 12 ) dicarboxylic acids, succinic acid, sebacic acid, adipic acid, malic acid, tartaric acid, oxalic acid, maleic acid, fumaric acid, COOH-terminated polycaprolactone, and COOH-terminated polyesters or oligoesters,
and R 1 is H or CH 3 , preferably H when X is a C 2 -C 8 alkylene group and preferably CH 3 when X is C 1 .
Z is preferably represented by the structure M—(O—R—) m —Y,
where m is a positive integer,
Y is O or NH,
R is a C 2 to C 10 alkylene group, preferably an ethylene group and/or propylene group and M is a non-reactive group or a group containing a blocking group or a —C═C— group, preferably, a C 1 to C 12 alkyl group, an aryl group, an aralkyl group or a substituted C 1 to C 12 alkyl group, an aryl group, an aralkyl group or a blocking group or a C═C containing group. More preferably,
M is methyl or ethyl.
It is noted that in each of the above polymeric chemical formulas Z may also be derived from a monolinctional carboxylic acid. In such formulations, the chemical structure of the resulting polymer will reflect that initiation. Thus, AB diblocks which result from the intiation of a polyester chain by a monofunctional acid will be end-capped with a carboxylate (carboxylic acid) group and then coupled with a diisocyanate (to produce a resulting amide-containing group), a diol (to produce an ester-containing group) a diamine (to produce an amide-containig group) or, in certain instances, a hydroxylamine (which produces an ester group on one end of the hydroxyl amine and an amide group on the other end of the hydroxylamine. Accordingly, multiblocks which are based upon AB diblocks and coupled with complex couplers, will produce polymers which are analogus to those which are set forth hereinabove. One of ordinary skill in the art, within the teachings of the scope of the present invention, may readily produce numerous polymeric compounds which have chemical structures which are analogous to those which are set forth in detail hereinabove, but which utilize a monofunction carboxylic acid compound to initiate polymerization of the polyester A block.
The present invention also relates to polymeric compositions comprising the reaction product of a diol, diamine or dicarboxylic acid (as otherwise defined in the present invention) with a coupling agent in about a 1:2 mole ratio, with the resulting product being reacted with a monofunctional hydroxyl, amine or carboxylic acid containing compound to produce a pentamer. The diol, diamine or dicarboxylic acid in this aspect of the present invention may be any compound (including monomeric or polymeric compounds) which contain two functional groups and is reactive with one or more chain-extenders or coupling agents. In this aspect of the present invention, the chain-extender or coupling agent is used in a molar excess, preferably in a molar ratio of about 1 mole of diol, diamine or dicarboxylic acid to about 2 moles chain extender or coupling agent. The resulting intermediate product, which contains two reactive groups from the chain extender or coupling agent is thereafter reacted with a monofunctional alcohol, amine or carboxylic compound (which may be monomeric or polymeric) to produce a pentameric product according to the present invention. It is noted that in this aspect of the present invention, the diol, diamine or dicarboxylic acid compound which is used may be a ACA triblock, where A is a polyester unit and C is a compound selected from the group consisting of a diol, a diamine and a dicarboxylic acid compound. In this aspect of the invention, the diol is preferably selected from the group consisting of C 2 to C 24 (preferably, C 2 to C 12 ) diols including ethylene glycol and butanediol, a poly(oxyalkylene) diol compound of the structure —(O—R) m —O— where R is a C 2 to C 10 alkylene group (preferably an ethylene group and/or propylene group) and m is a positive integer, poly(oxyalkylene)-rich diols especially including poly(ethylene oxide)-rich diols, OH-terminated polycaprolactone, OH-terminated polyesters or oligoesters, the diamine is preferably selected from the group consisting of C 2 to C 24 (preferably, C 2 to C 12 ) diamines including ethylene diamine and hexamethylene diamine, amino acids, and oligopeptides and the dicarboxylic acid is preferably selected from the group consisting of C 2 to C 24 (preferably, C 2 to C 12 ) dicarboxylic acids, including succinic acid, pimelic acid, azelaic acid, sebacic acid, adipic acid, malic acid, tartaric acid oxalic acid, maleic acid, fumaric acid, COOH-terminated polycaprolactone, and COOH-terminated polyesters or oligoesters. In preferred aspects of this invention, the ACA triblock is comprised of A blocks which are comprised of oligoesters or polyesters and C blocks which are comprised of poly(oxy)alkylene.
In a particular method aspect according to the present invention, in one aspect, the present invention comprises administering or affixing to an area in a patient's body at risk of developing adhesions, a polymeric composition comprising AB diblocks (preferably, as di-diblocks, as discussed in greater detail herein) or ACA triblocks which are chain-extended, coupled and/or crosslinked and contain sufficient polyethylene oxide character to promote anti-adhesion characteristics. In this aspect of the present invention, preferably, the A blocks comprise aliphatic ester units, more preferably derived from hydroxy acid units or their cyclic dimers and the like, even more preferably α-hydroxy acid units. In many embodiments, the method comprises administering the instant polymer compositions to a site within the patient's body which has been subjected to surgical repair or excision. In the present invention, the polymeric material provides a barrier to prevent adhesions from forming. After this period of protection, the polymer will degrade and will be resorbed within the patient's body and/or excreted from the patient's body. According to the present method, problems associated with non-absorption or foreign body reactions are significantly reduced or prevented.
The polymers according to the present invention may be used in various forms such as films, other structures including rods, cylinders, foams, pastes, dispersions, viscous solutions, liquid polymers, sprays or gels. Polymers according to the present invention may be used in a broad array of applications, including, for example, in medical applications, for example, for reducing or preventing adhesion formation subsequent to medical procedures such as surgery, for producing surgical articles including stents and grafts, as coatings, sealants, lubricants, as transient barriers in the body, for materials which control the release of bioactive agents in the body, wound and bum dressings and producing biodegradable articles, among numerous others.
The form a polymer takes will obviously depend upon the application for which such polymer is used. In the case of preventing or reducing the occurrence of adhesion at a surgical site, the form a polymer takes at the surgical site will depend upon the type of surgery which has been performed or the condition which is to be treated and the site to be treated. In addition, the need to deliver the polymer to a particular site within the body may be determinitive of the form in which the polymer is delivered. In certain aspects according to the present invention, the present method may be used after surgery to prevent tissue adhesion which occurs during the initial phases of post-surgical repair. Thus, in all applications where tissue is being repaired or excised, certain polymers according to the present invention find utility to prevent adhesions. In certain applications according to the present invention, the polymers are may be used to prevent tissue to tissue adhesion and adhesions between tissues and implants or devices, which occur after surgical procedures, as well as other conditions, including certain disease states.
In the anti-adhesion aspects according to the present invention, the present polymers preferably are based on polyester/poly(oxyalkylene) ACA triblocks or AB diblocks (including AB multiblocks, thereof), where A is a polymer preferably comprising aliphatic ester units, which are preferably derived from hydroxy acid units or their cyclic dimers and the like, even more preferably α-hydroxy acid units or their cyclic dimers and the like, such as a related ester or lactone. Preferably, the A block comprises α-hydroxy acid units derived from an aliphatic α-hydroxy carboxylic acid or a related acid, ester or similar compound such as, for example, lactic acid, lactide, glycolic acid, glycolide, or a related aliphatic hydroxycarboxylic acid or ester (lactone) such as, for example, β-propiolactone, ε-caprolactone, δ-glutarolactone, δ-valerolactone, β-butyrolactone, pivalolactone, α,α-diethylpropiolactone, ethylene carbonate, trimethylene carbonate, γ-butyrolactone, p-dioxanone, 1,4-dioxepan-2-one, 3-methyl-1,4-dioxane-2,5-dione, 3,3,-dimethyl-1-4-dioxane-2,5-dione, cyclic esters of α-hydroxybutyric acid, α-hydroxyvaleric acid, α-hydroxyisovaleric acid, α-hydroxycaproic acid, α-hydroxy-α-ethylbutyric acid, α-hydroxyisocaproic acid, α-hydroxy-α-methyl valeric acid, α-hydroxyheptanoic acid, α-hydroxystearic acid, α-hydroxylignoceric acid, salicylic acid and mixtures, thereof. The use of α-hydroxyacids in the present invention is preferred. The A block of the triblocks and diblocks (and multiblocks, thereof) used in the present invention preferably comprises a poly(α-hydroxy-carboxylic acid), for example, poly(glycolic acid), poly(L-lactic acid) and poly(D,L-lactic acid), because these polymers will degrade and produce monomeric units which may be metabolized by the patient. In this anti-adhesion method aspect of the present invention, the B block in the triblocks used in the present invention is preferably a hydroxyl, carboxylic acid or amine terminated poly(oxyalkylene) block (preferably, hydroxyl terminated) and is more preferably either a poly(ethylene oxide) homopolymer or poly(ethylene oxide)-co-poly(propylene oxide) block copolymer.
The triblocks or diblocks (including multiblocks, thereof) described above are preferably end-capped with hydroxyl or amine groups and are chain-extended or coupled using difunctional chain extenders such as diisocyanates, dicarboxylates, diesters or diacyl halide groups in order to couple the triblocks or diblocks into high molecular weight chains. In the case of diblocks, these are coupled with difunctional chain extenders in much the same way that triblocks are chain extended with the same chain extenders. Alternatively, the triblocks may be end-capped with groups such as carboxylic acid moieties or ester groups (which may be reacted directly as ester groups, activated as “active” ester groups or converted to active acyl groups such as acyl halides) or isocyanate groups and then reacted with difunctional chain extenders such as diols, diamines, hydroxylamines, or polyoxyethylene (polyethylene glycol) or poly(ethylene oxide)-co-poly(propylene oxide) block copolymer chain extenders (especially, in the case of water soluble or water dispersible gels, dispersions or viscous solutions) among others, to produce chain extended polymers preferably having high molecular weight. Coupled diblocks and soluble multiblocks according to the present invention are particularly useful for providing polymers in reduced viscosity applications according to the present invention or for producing star or comb polymers according to the present invention.
In certain aspects of the present invention which relates to reducing or preventing adhesion after surgery, preferred polymers for use in the present invention have the following characteristics: they are prepolymerized, chain-extended (in the case of triblocks), coupled (in the case of diblocks and some polymers), some polymers may be substantially non-crosslinked and biodegradable and/or bioabsorbable. In other aspects, the polymers may be crosslinked, especially where diblocks are used to produce star polymers. Preferred polymers may be reactive or non-reactive with animal, including human tissue. In general, preferred polymers according to the present invention do not produce an unintended or adverse tissue reaction. The present polymers are advantageously used as barrier materials to reduce or prevent adhesion as well as in numerous other applications including as coatings, sealants, lubricants, and in numerous non-medical applications. Polymers used in various preformed structures such as films according to the present invention are sufficiently flexible to enable the polymer to substantially conform to the surface of the tissue to be treated, yet at the same time have sufficient strength to function as an integral and therefore, effective barrier to allow suturing the material to tissue. Polymers used in other forms such as gels, dispersions, pastes and viscous solutions according to the present invention also have sufficient structural integrity to be delivered to a site within the body and prevent adhesions at the same time that the polymers are water soluble and/or water dispersible in order to be delivered.
In the present invention, PELA is the generic name used to denote certain preferred polymers which are used in anti-adhesion methods according to the present invention which comprise poly(ethylene oxide) and poly(lactic acid) blocks, which are chain extended with a diisocyanate, most preferably hexamethylene diisocyanate. PELA polymers are generally designated with respect to their composition by the average molecular weight of the poly(ethylene oxide) chain and by their (EO/LA) ratio, where EO is the number of ethylene oxide units present and LA is the total number of lactoyl units (ester units) present. A general definition of EO/LA ratio is presented hereinbelow.
In an anti-adhesion aspect of the present invention, the ACA triblock is preferably a substantially non-water soluble unit comprising poly(hydroxy acid) blocks and poly(oxyalkylene blocks), preferably poly(α-hydroxy acid) blocks and ethylene glycol, diethylene glycol and poly(ethylene oxide) chains or poly(ethylene oxide)-co-poly(propylene oxide) block copolymers. The A block of the ACA triblocks of the present polymers is biodegradable and ranges in size from one monomeric unit (a monomeric unit within the A block being considered lactic acid, glycolic acid or a related hydroxy acid (ester) unit even where lactide and/or glycolide or related reactants containing more than one hydroxyacid unit are used to produce the A block) up to about 400 or more monomeric units, with a preferred size ranging from about 4 to about 50 units, more preferably about 6 to about 30 units, even more preferably about 8 to about 16 monomeric units, which length depends upon the length or molecular weight of the C block combined with the A block in triblocks according to the present invention. It is to be noted that the size of the A block may well fall outside of the above range, depending upon the overall physical characteristics of the ACA triblock formed and the size of the C block.
The A block of AB diblocks and multiblocks according to the present invention ranges in size from one monomeric (ester) unit up to about 500 units or more, depending upon the application for the which the end product will be used. For those applications in which a low molecular is desirable (lower viscosity), the molecular weight of the A block will preferably be of a lower molecular weight, for example from one monomeric unit to about 20 monomeric units.
In ACA triblocks and AB diblocks according to the present invention which are used in an anti-adhesion method, the A block is derived preferably from an α-hydroxy acid as described above, more preferably from units of glycolic acid, lactic acid (preferably L or D,L mixtures to promote bioabsorbability) or mixtures thereof, in the form of glycolide or lactide reactants (as explained in greater detail hereinbelow). In the final polymers to be used to reduce or prevent post-operative adhesion, the A blocks tend to create hard domains in the matrix and generally provide strength and structural integrity to the polymer. The A block is non-water soluble and is sized in combination preferably with the more water soluble/water dispersible B or C block in order to preferably promote phase separation between the the A and C blocks in the ACA triblock and the final polymer to be used to prevent or reduce adhesions. Thus, the A block instills the final polymer with essential structural characteristics, which, in combination with the B or C block, results in a polymer which has excellent anti-adhesion characteristics (believed to be instilled by the B or C block) in combination with strength, structural integrity and biodegradability instilled by the A block. In addition, in certain embodiments according to the present invention, the length of the A block is believed to be important for providing a material with a phase separated microstructure.
In certain aspects of the present invention which relate to the treatment of adhesion, the B block (in the case of AB diblocks) and the C block (in the case of ACA triblocks) preferably comprises poly(ethylene oxide) or poly(ethylene oxide)-co-poly(propylene oxide) block copolymers and other PEO-rich chains which fall in the molecular weight (M w ) range as defined hereinbelow. The B or C block may preferably vary in size from about 100 Da (dalton units) up to about 200,000 Da or higher, with a more preferred range of about 400 Da up to about 20,000 Da. Even more preferably, the B or C block is a poly(ethylene oxide) ranging in size from about 400 to about 10,000 Da. Based upon the teachings of the present invention, one of ordinary skill will now know to vary the length of the B or C block and the A block to provide polymers having excellent anti-adhesion properties, depending upon the type of final formulation desired and its delivery characteristics.
In the anti-adhesion aspect according to the present invention, the ACA triblocks and AB diblocks (including some multiblocks) according to the present invention are described according to the length (number of monomeric repeating units) of the B or C block [preferably, poly(ethylene oxide), the repeating unit being in this case ethylene oxide units] divided by the total number of monomeric units in both A blocks (preferably, an α-hydroxy acid such as lactic acid) of the ACA triblock or the A block of the AB diblock. This ratio is referred to as the EO/LA ratio. Polymers comprised of ACA triblocks or AB diblocks which are chain extended, coupled or crosslinked pursuant to the present invention also may be described in terms of an EO/LA ratio for the polymer, in which case the EO/LA ratio simply represents the ratio of oxyalkylene units to monomeric units in the entire polymer. The EO/LA ratio of the entire polymer may be determined by NMR analysis. These polymers may also be designated with respect to their composition by the average molecular weight of the poly(ethylene oxide) (PEG) chain or chains and by the weight percentage of the PEG chain or chains in the triblock, diblock or total polymer. It should be noted, however, that in instances where the chain extender, coupler or crosslinking agent comprises a poly(ethylene oxide) chain, the EO/LA ratio for the polymer may vary considerably from the EO/LA ratio found in the ACA triblock, AB diblock or multiblock (the total amount of EO may become considerably larger because of contribution of EO from the chain extender, and consequently, the EO/LA ratio for the polymer may be considerably larger than it is for the ACA triblock, AB diblock or multiblock). Likewise, the weight percentage of PEG found in such a polymer may also be quite different from that found in the ACA triblock or AB diblock.
Without being limited by way of presentation, the concept of the EO/LA ratio may be exemplified by a polymer described as a poly(ethylene oxide)-lactic acid block copolymer (PELA) 6,000/3.8, which is a hexamethylene diisocyanate chain extended ACA triblock copolymer comprising PEG chains having an average molecular weight of 6,000 and an EO/LA ratio of 3.8. The triblock in this polymer comprises, therefore, a 6,000 molecular weight PEG segment for the B block containing approximately 136 ethylene oxide units and two A blocks each containing, on average, approximately 18 LA units. Alternatively, the same polymer can be designated as 6,000/69.8%, where 6,000 is the average molecular weight of the PEG chains, and 69.8% is the weight percentage of PEG in the ACA triblock. For this PELA 6,000/3.8 polymer, the molecular weight of the triblock is approximately 8592 (6,000 for the PEG chain and two poly (lactic acid) A blocks each having a molecular weight of approximately 1296, for a total for the two A blocks of 2592). The weight percentage of the PEG block in this triblock is, accordingly, 69.8% (6,000/8592).
Alternatively, by way of example, the ACA triblock described above may be chain extended with, for example, the following chain extender: HDI-PEG4000-HDI, which is formed by reacting a poly(ethylene oxide) chain of molecular weight 4000 with two moles of hexamethylene diisocyanate. The repeating unit, after reaction of this chain extender with the ACA triblock described in the paragraph above is [(LA) 18 -PEG6000-(LA) 18 -HDI-PEG4000HDI-]. The molecular weight of the triblock 8592 (6000+2×18×72=2592) and that of the macrodiisocyanate chain extender is 2×168 (for the two HDI molceules)+4000 for the PEG chain. The MW of the repeating unit is therefore, 8592+4336=12928. The weight % of PEG in the repeating unit is 77.4% (6000+4000=10,000; 10,000/12928). In terms of the EO/LA ratio of the repeating unit, we have a total PEG MW of 10000, which comprises 10000/44 EO units=227.3 EO units. These units, divided by the 36 LA units present gives us a ratio of 6.3. Because it is difficult to define an average PEG MW in certain instances, since we could get, for the example above, an average MW of approximately 6000, which could be the result of PEG 10000 in the triblocks and 2000 in the chain extenders, or the result of simply having PEG chains of 6000 in each of the triblock and chain extender. The exemplary polymer we describe above is a PELA 6000/4000/77.4%.
The preferred EO/LA ratio for polymers which are used in the anti-adhesion aspect according to the present invention ranges from about 0.1 to about 100 or more, preferably about 0.5 to about 30, more preferably from about 0.5 to about 10.0, more preferably about 1.0 to about 5.0, more preferably about 1.5 to about 4.5, even more preferably about 2.5 to about 3.5 and most preferably about 3.0. In certain instances, the EO/LA ratio may fall outside of these ranges, depending upon the final characteristics of the polymers which are desired. Preferred EO/LA ratios for individual polymers may also vary according to the size of the B block and the type of chain-extender which is used. In certain embodiments, as the size (molecular weight) of the B block in the triblocks increases, the preferred EO/LA ratio will tend to be somewhat less than in triblocks and polymers where the size of the B block is less.
Tailoring the general properties of polymeric compositions according to the present invention is based upon choosing the individual components of the compositions in keeping with the application in which such composition is to be used, and the desired characteristics of the final composition, for example, the molecular weight of the composition, the form the final composition is to take, other physical properties of the composition, the biodegradability or bioerodability of the composition, the chemical or solubility characteristics of the composition e.g. the chemical requirements that enable the composition to be compatible with bioactive agents for controlled release delivery, etc. In the present invention, the use of the present polymers allows for improved physical characteristics compared to polymers which do not have the same type of chemistry.
Polymeric compositions according to the present invention may be changed or tailored to promote residence time and to enhance or delay the rate of biodegradation, to improve the physical/mechanical properties of solid and liquid polymers and in certain applications which utilize polymeric compositions in solution, to improve the rheological characteristics of the polymers. Because the chemistry of the present polymers may make use of a number of groups which may promote hydrogen bonding, the present polymers may also have greater interaction with, for example, tissue surfaces, proteins, and related molecules, cells and/or surfaces, a characteristic which may be advantageously employed in certain aspects of the present invention which relate to the use of the present polymers in biological and/or medical applications. In addition, increased hydrogen bonding may instill certain physical or mechanical characteristics to films according to the present invention, or alternatively, may improve the physical characteristics of liquid polymers or polymers in solution.
In the case of an anti-adhesion aspect according to the present invention, tailoring the properties of the antiadhesion barriers generated by the present polymers is based upon combining (a) the enhanced antiadhesion properties attributed, by way of theory, by the PEG (B block) segments; (b) the biodegradability of the polyester, preferably poly(hydroxy acid) A blocks; (c) the physical and/or mechanical properties derived from the partially phase separated microstructure of the polymeric matrix.; and in certain instances, where relevant (d) the Theological characteristics of the various materials.
In certain aspects, the PEG (B block) content is related to the efficaciousness of the polymer as an antiadhesion barrier. Higher PEG content may give rise to greater antiadhesion activity, but with fast polymer degradation. Since there is a requirement for the barrier to stay in place separating the relevant tissues for a determined period of time, there is an optimal EO/LA ratio which combines maximum PEG content with the biologically required residence time. In agreement with these basic considerations, preliminary animal data indicate that polymers of the present invention comprising PEG chains of a 6,000 molecular weight and having an EO/LA ratio of approximately 1.0-3.0, preferably about 1.5 display optimal properties as antiadhesion barriers.
Based upon the teachings of the present invention, one of ordinary skill in the art will now know to vary the length of the A block to the B block in a manner which provides polymers having excellent structural integrity, biodegradability and activity which substantially inhibits post-operative adhesion.
The polymers according to the present invention are prepolymerized, chain-extended coupled and preferably attain high molecular weight. The polymers may be non-crosslinked or crosslinked. In order to increase the molecular weight of the polymers produced, the AB diblock (which may be end-capped with hydroxyl, amine or carboxylic acid groups) is chain-extended or coupled using difunctional compounds such as diisocyanate, dicarboxylic acid compounds or derivatives of dicarboxylic acids such as diacyl halides. The product which is formed from the reaction of the chain extender, coupling agent or crosslinking agent with the ACA triblock or AB diblock according to the present invention will depend upon the chemical nature of the nucleophilic (or electrophilic) moieties on the ACA triblock or AB diblock (or related multi diblocks) and the electrophilic (or nucleophilic) moieties on the chain extender, coupling agent or crosslinking agent. The reaction products can vary widely to produce different moieties, such as urethane groups, ester groups, urea groups and amide groups, among numerous others. For example, in the case of an ACA triblock or AB diblock which is hydroxyl terminated, reacting with diisocyanate chain extenders, produces a product containing urethane groups. In the case of amine groups terminating the ACA triblocks or AB diblocks reacted with diisocyanate chain extenders, the product contains urea groups. In the case of carboxylic acid groups terminating the ACA triblocks or AB diblocks (which can be converted to anhydrides or acyl halides) reacting with an amine terminated chain extender or crosslinking agent, the product contains amide groups. Alternatively, the reaction of a carboxylate-terminated triblock or diblock with an isocyanate also produces a product contains amide groups. Preferably, the nucleophilic end-capped triblocks ro diblocks are chain-extended with diisocyanate compounds in order to produce chain-extended polymers according to the present invention, although the chemical approaches, as explained above, may vary greatly. In the case of structures such as films, the chain extenders are used to provide greater molecular weight to the triblocks, thus enhancing structural integrity. In the case of gels, liquid polymers and/or viscous solutions, the chain extenders, coupling agents or crosslinking agents may provide not only high molecular weight, viscosity control and structural integrity, but also a degree of water solubility/dispersibility consistent with the solubility and/or dispersibility of these polymers in water and the delivery of these polymers to a site within the patient's body. Thus, the chain extenders, coupling agents and crosslinkers may be used to provide a number of benefits hampering the beneficial morphological, mechanical and rheological effects.
The final polymers according to the present invention may be non-water soluble or in certain liquid, viscous solution and/or gel applications may absorb significant quantities of water. Certain polymers according to the present invention are water soluble, especially where the polymer has a high EO/LA ratio.
The polymers according to the present invention may be crosslinked in addition to being chain-extended or coupled. Crosslinking agents may be similar to the chain extenders and coupling agents used in the present invention, with the exception that the crosslinking agents contain at least three reactive functional groups, in contrast with chain extenders or coupling agents, which generally contain only two reactive functional groups. In the case of using crosslinking agents with diblock polymers, the resulting polymer may be a star-like or comb-like structure.
In addition to chain extenders, coupling agents and crosslinkers, end-capping agents, which contain only one functional group (i.e., they are monofinctional) may also be used in the present invention to end-cap triblocks, diblocks or multiblocks according to the present invention. By end-capping the polymers according to the present invention, the storage stability and shelf-life of the polymers increases significantly over polymers which are end-capped with reactive groups such as hydroxyl or amine groups.
DETAILED DESCRIPTION OF THE INVENTION
The following terms shall be used throughout the specification to describe the present invention.
The term “non-reactive” is used throughout the specification to describe compounds or portions of molecules (moieties) which do not participate in the reaction(s) to form an intermediate or polymer according to the present invention. Examples of non-reactive groups for use in the present invention include, for example, alkyl, aryl or aralkyl groups or substituted alkyl, aryl or aralkyl groups. It is noted here that most of the reactions to produce intermediates or polymers according to the present invention proceed through a heat initiated nucleophilic/electrophilic polymerization reaction as opposed to a radical initiated polymerization reaction. Consequently, those moieties which are preferably non-reactive fall within this definition. It is noted here that in certain instances, hydroxyethyl methacrylate (HEMA) or other —C═C— containing monomer or a group containing a blocking group (which can be removed to produce a reactive entity subsequent to intermediate or polmer formation) may also be used, for example, to initiate polymerization of monomers to produce an A block, or for inclusion in one or more other segments of triblocks, diblocks, multiblocks or polymers according to the present invention. Such a —C═C— containing moiety may be used in a subsequent coupling or crosslinking reaction to produce polymer compositions according to the present invention. Despite such reactivity in “radical polymerizable reactions”, these monomers may be used in “non-reactive groups” according to the present invention. Non-reactive groups may also be “inert”, i.e., they contain groups which are not reactive under any conditions. Examples of such inert non-reactive groups are alkyl groups, aralkyl groups or aryl groups, whether substituted or unsubstituted, which do not contain blocking groups, —C═C— groups or other groups which can reactive further.
The term “diol” is used throughout the specification to describe any molecule or compound (such term including monomers, oligomers and polymers) containing two alcohol groups which can react with electrophilic groups (e.g., isocyanates, esters, acyl halides, activated esters, etc.) to produce compounds according to the present invention. Representative diols for use in the present include, for example, C 2 to C 24 (preferably, C 2 to C 12 ) diols, alkanols, aryl alcohols, aralkyl alcohols, substituted alkyl, substituted aryl and substituted aralkyl alcoholes, including for example, ethylene glycol and butanediol, OH-terminated polycaprolactone and other OH-terminated polyesters and oligoesters, polyethers, such as poly(oxyalkylene) including poly(ethylene glycol), poly(propylene glycol), poly(ethylene glycol)-co-poly(propylene glycol) and other hydroxyl-containing compounds such as, for example, proteins, enzymes, growth factors, bioactive agents, polysaccharides and ACA triblocks, where A is a polyester unit and C is itself a diol, including a poly(oxyalkylene).
The term “diamine” is used throughout the specification to describe any molecule or compound (such term including monomers, oligomers and polymers) containing two amine groups (including primary and secondary amines, but preferably primary amines) which can react with electrophilic groups to produce compounds according to the present invention. Representative diamines for use in the present invention preferably include, for example, C 2 to C 24 (preferably, C 2 to C 12 ) diamines including alkyl amines, aryl amines, aralkyl amines, substituted alkyl, substituted aryl and substituted aralkyl amines, amino acids, oligopeptides and polypeptides, proteins, enzymes, bioactive agents. Lysine, oligolysine and polylysine may be used preferably as amino acids, oligopeptides and polypeptides in the present invention.
The term “dicarboxylic acid” is used throughout the specification to describe any molecule or compound (such term including monomers, oligomers and polymers) containing two carboxylic acid groups which can react with electrophilic groups or be converted to an electrophilic group such as an activated ester or acyl halide for reaction with nucleophilic groups to produce compounds according to the present invention. Representative dicarboxylic acids for use in the present invention preferably include, for example, C 0 to C 24 (more preferably, C 0 to C 12 ) dicarboxylic acids, including alkyl carboxylic acid, aryl carboxylic acid, aralkyl carboxylic acid, substituted alkyl, substituted aryl and substituted aralkyl carboxylic acid, including succinic acid, sebacic acid, adipic acid, malic acid, oxalic acid, maleic acid, fumaric acid, COOH-terminated polycaprolactone, and COOH-terminated polyesters or oligoesters.
The term “polymer” is used to describe compositions according to the present invention. Polymers according to the present invention may range in molecular weight (average molecular weight) from about 1,000-3,000 to several million or more and as described, include oligomers of relatively low molecular weight.
The terms “poly(ethlyene glycol)”, “poly(oxyethylene)” and poly(ethylene oxide) are used interchangably to describe certain aspects of the present invention. These polymers, of varying weights, may be used in the B block of ACA triblocks and AB diblocks and multiblocks, thereof according to the present invention as well as in chain extenders, coupling agents and crosslinking agents which may also be used in the present invention. The terms “poly(oxyalkylene) containing” and “poly(ethylene oxide) containing” and are used to describe certain polymeric chains which contain at least some amount of poly(oxyalkylene) or poly(ethylene oxide). The terms “poly(oxyalkylene) rich” and “poly(ethylene oxide) rich” are used to describe certain polymeric chains containing at least 50% by weight (of the total weight of the polymeric chain described) poly(oxyalkylene) or poly(ethylene oxide).
The term “polyester” is used to describe polyester compounds found in A blocks of AB diblocks, multiblocks, or ACA triblocks or, although not present in diblocks, multiblocks or triblocks are nonenthleless present in polymeric compositions according to the present invention where the “polyester” is a polymeric unit which may be derived from an aliphatic hydroxy carboxylic acid or a related ester, lactone, dimeric ester, carbonate, anhydride, dioxanone or related monomer and may be preferably derived from an aliphatic hydroxy carboxylic acid or related ester, such units derived from the following: including, for example, lactic acid, lactide, caprolactone, glycolic acid, glycolide, or a related aliphatic hydroxycarboxylic acid, ester (lactone), dimeric acid or related compound such as, for example, β-propiolactone, ε-caprolactone, δ-glutarolactone, δ-valerolactone, β-butyrolactone, pivalolactone, α,α-diethylpropiolactone, ethylene carbonate, trimethylene carbonate, γ-butyrolactone, p-dioxanone, 1,4-dioxepan-2-one, 3-methyl-1,4-dioxane-2,5-dione, 3,3,-dimethyl-1-4-dioxane-2,5-dione, cyclic esters of α-hydroxybutyric acid, α-hydroxyvaleric acid, α-hydroxyisovaleric acid, α-hydroxycaproic acid, α-hydroxy-α-ethylbutyric acid, α-hydroxyisocaproic acid, α-hydroxy-α-methyl valeric acid, α-hydroxyheptanoic acid, α-hydroxystearic acid, α-hydroxylignoceric acid, salicylic acid and mixtures, thereof. The use of α-hydroxyacids or related hydroxy acids and their corresponding cylic dimeric esters, especially lactide, glycolide and caprolactone in the present invention, is preferred. It is noted that in using certain of the described monomers according to the present invention, the monomeric units which are produced are not specifically ester groups, but may include such groups as carbonate groups, urethane groups, anhydride groups and related groups which are derived from the above-described monomers. It will be understood that the term polyester shall encompass polymers which are derived from all of the above monomers, with those which actually produce ester units being preferred. Preferably, polyesters which are used in the present invention are biodegradable and/or bioabsorbable. The term “oligoester” is used to describe compounds which contain at least two ester groups (diester) to about 10 or more ester groups and are used in the present invention. Oligoesters tend to be shorter (have lower molecular weights) and contain fewer ester groups than polyesters.
The terms “poly(hydroxy carboxylic acid)” or “poly(α-hydroxy carboxylic acid)” are used to describe polyester A blocks of AB diblocks, ACA triblocks or multiblocks, thereof used in polymeric compositions according to the present invention where A is a polymeric polyester unit derived from an aliphatic hydroxy carboxylic acid or a related ester, dimeric ester or oligoester and is preferably derived from an aliphatic α-hydroxy carboxylic acid or related ester, including a cyclic dimeric ester, such as, for example, lactic acid, lactide, glycolic acid, glycolide, or a related aliphatic hydroxycarboxylic acid or ester (lactone) such as, for example, ε-caprolactone, δ-glutarolactone, δ-valerolactone, γ-butyrolactone and mixtures, thereof, among numerous others as set forth herein. The use of α-hydroxyacids and their corresponding cylic dimeric esters, especially lactide and glycolide in the present invention, is preferred.
The term “diblock” is used to describe polymeric units which comprise an A block and a B block as described in general hereinabove. AB diblocks according to the present invention comprise a first polyester A block [preferably, a poly(hydroxy carboxylic acid) polyester] covalently linked to a B block which is comprised of a monofunctional amine, hydroxyl or carboxyl containing monomeric or polymeric compound, in certain aspects, preferably comprising poly(oxyalkylene) as described above. In the present invention, diblocks may be formed, for example, by initiating a polymerization of hydroxy carboxylic acid (or equivalent monomeric, dimeric or related building blocks) with a hydroxyl, amine or carboxyl-terminated compound block which is end-capped (on one end of the polymer) with a non-reactive group (for example, an alkyl, aryl or aralkyl group or E substituted alkyl, aryl or aralkyl group, preferably, a C 1 -C 12 alkyl group or an equivalent, or a protecting group which can be removed to provide a free nucleophilic moiety at a later time). The diblocks which are produced may then be further reacted with coupling reagents in a coupling reaction (preferably, in which the coupling agent and diblock are reacted in a 1:2 molar ratio), crosslinking agents and the like to produce polymers according to the present invention having favorable EO/LA ratios for use in reducing and/or preventing adhesion or for numerous other uses. Diblocks may be used in much the same way that ACA triblocks are used in the present invention, i.e., as building polymeric units of the polymers according to the present invention.
The term “di-diblock” is used to describe compounds according to the present invention which are produced by coupling (using a coupling agent) two AB diblocks pursuant to the present invention. The terms di-diblock and coupled di-blocks are used synonymously to describe the present invention. Di-diblocks according to the present invention may be represented by the general structure:
BA-W-AB,
where W is derived from a simple diisocyanate or diacid (or related ester, activated ester or acyl halide), if B initiated polymerization to produce A using a hydroxyl or amine group (the A block has a terminal hydroxyl group to perform the coupling reaction in this case). Alternatively, W may be derived from a simple diisocyanate, or a diol or diamine, if B initiated polymerization of the A block using a carboxylate (carboxylic acid) as the initiating group.
The term “multi-diblock” is used to describe compounds which contain AB diblocks according to the present invention which have been linked through complex couplers to produce multiblocks according to the structure:
AB-V-BA,
where V is a variety of more complex “couplers” which could be any one or more of the following:
an isocyanate or acid terminated triblock or other molecule (which may be monomeric, oligomeric or polymeric), if the polymerization of the A block is initiated using a hydroxyl or amine terminated B block (after polymerization, the A block is terminated with a hydroxyl group which can be used to perform the coupling reaction);
an isocyanate, amine or hydroxyl terminated triblock or molecule (which may be monomeric, oligomeric or polymeric), if the polymerization of A is initiated using a COOH-terminated B block (after polymerization, the A block is terminated with a COOH group to perform the coupling reaction).
The term “triblock” is used to describe polymeric units which are used in certain embodiments to produce the polymers according to the present invention which comprise a first polyester A block covalently linked to a diol, diamine or dicarboxylic acid compound C block (which block, in certain applications preferably includes poly(oxyalkylene) which is, in turn, covalently linked to a second polyester A block. Triblocks according to the present invention may be terminated by hydroxyl, amine, or carboxyl moieties, but in preferred embodiments, are terminated with hydroxyl groups which can be readily covalently linked to chain extenders, crosslinking agents or other groups which contain electrophilic moieties, to produce the final polymers which are used in the present invention. It is noted that the use of the term ACA to designate a triblock, in contrast to the term AB for a diblock is done to merely distinguish between the di-functionality of the C block of the ACA triblock and monofunctionality of the B block of the diblock. Whereas the C block is derived from a difunctional diol, diamine or dicarboxylic acid molecule, the B block by design (other than in cases where the B block contains for example, a blocking group or a —C═C— group, which may participate in additional reactions after an intermediate or polymer is first synthesized) is monofunctional (i.e., is derived from a compound containing only one hydroxyl, amine or carboxylic acid moiety which participates in a reaction to initiate the polymerization of or bond to an A block).
The term “star-like molecule” or “star polymer” is used throughout the specification to refer to a type of molecule which is star-like in character. This type of compound may be made by using a tri- or higher function B block (e.g. an oligopeptide with at least three amine groups) such that each functional group initiates the formation of an A block. Without further modification, the resulting product is a star polymer. Alternatively, if AB diblocks are reacted with higher functional crosslinking agents or the formation of the A block is initiated with a tri- or polyfunctional agent, such as trimethylolpropane, the result will also be a star polymer. If we start with a polyfunctional agent, for example, polyHEMA, or other polyfunctional molecule such a poly acrylic acid to initiate the A block polymerization, the result would be a star or “comb” polymer, if the A block was simply generated. If the A blocks are coupled, the result would be crosslinked materials.
The term “non-water soluble” or “substantially non-water soluble” is used to describe certain preferred ACA triblocks or AB diblocks used in various forms according to the present invention. In the present invention, in forms such as viscous solutions, gels, pastes or emulsions in which the polymers are substantially water soluble, the AB diblocks, AB multiblocks or ACA triblocks may be water soluble or non-water soluble. Non-water soluble diblocks or triblocks according to the present invention are soluble in water up to a limit of no more than about 0.5-0.6 g per 100 ml of water, preferably less than about 0.2 g per 100 ml of water. In determining water solubility, diblocks or triblocks according to the present invention are dissolved in, agitated or mixed in water at room temperature (i.e., at a temperature of about 20-23 ° C.) for a period of two hours. It is noted that in the present invention, chain extended triblocks which are used to produce structures such as films according to the present invention are also preferably substantially non-water soluble, i.e, they are limited in water solubility to no more than about 0.2 mg/ml. This limitation of water solubility reflects the fact that in certain embodiments according to the present invention which relate to the anti-adhesion aspect of the present invention, substantially non-soluble triblocks or diblocks which are preferably used in the present invention comprise at least about 25-30% by weight of A blocks.
An amount of the A blocks in the AB diblocks or ACA triblocks comprising at least about 25-30% by weight generally renders the triblocks or diblocks according to the present invention substantially non-water soluble. It is to be noted that water solubility or the absence of water solubility of the triblocks or diblocks may depend upon the molecular weight of the material. This characteristic is advantageous in the present polymeric compositions because the length and/or size of the A block instills structural integrity and biodegradability to the final polymer, but also, by virtue of the relative hydrophobicity of the block, tends to reduce the water solubility of the AB diblock or ACA triblock. Consequently, polymeric compositions according to the present invention which contain a proper balance of A block or blocks to B block have a slow rate of biodegradability and consequently, a longer period of interaction with tissue to be protected from adhesion formation. In aspects according to the present invention which utilize a B block which contains (poly)ethylene oxide, this is reflected overall in the EO/LA ratio of the polymers according to the present invention.
Polymers to be used in viscous solutions, dispersions and/or gels according to the present invention are preferably water soluble and/or water dispersible and may use many of the same or similar AB diblocks or ACA triblocks used in polymeric structures such as films according to the present invention. In certain applications of the present invention in an anti-adhesion method, in particular, in producing a liquid version which is substantially non-water soluble, having acceptable viscosity and flow characteristics for favorable administration, the polymers are actually substantially non-water soluble. Consequently, in applications such as films as well as in certain embodiments of the gel, dispersion and viscous solution applications, regardless of the way the polymers are administered, the ACA triblocks or AB diblocks which are preferably used are substantially non-water soluble. In certain alternative embodiments of the gels, dispersions and viscous solutions of the present invention, especially where the polymers are to be readily water dispersible, water solubility of the AB diblocks or ACA triblocks may be an advantageous characteristic, in which case, the inclusion of A blocks which comprise as little as about 1-5% by weight of the AB diblock or ACA triblock may be useful in the present invention.
The term “storage stable” is used to describe polymeric compositions according to the present invention in solid, liquid, gel or related forms. Polymeric compositions which are end-capped with non-reactive groups (i.e., cannot further participate in a reaction) tend to be significantly more stable than polymers which are end-capped with reactive groups, particularly hydroxyl, amine or carboxylic acid groups. In the present polymers, the non-reactive groups which cannot further participate in reactions such as transesterification or tranamidation reactions, where the polymer may change in chemical and/or physical character over time, and consequently are preferably long-term storage stable, i.e., stable for a period of at least one month, preferably at least 6 months, a year or even longer, are preferred. Storage stable polymer compositions according to the present invention may also more easily comply with quality control.
The term “adhesion” is used to describe abnormal attachments between tissues or organs or between tissues and implants (prosthetic devices) which form after an inflammatory stimulus, most commonly surgery, and in most instances produce considerable pain and discomfort. When adhesions affect normal tissue function, they are considered a complication of surgery. These tissue linkages often occur between two surfaces of tissue during the initial phases of post-operative repair or part of the healing process. Adhesions are fibrous structures that connect tissues or organs which are not normally joined. Common post-operative adhesions to which the present invention is directed include, for example, intraperitoneal or intra abdominal adhesions and pelvic adhesions. The term adhesion is also used with reference to all types of surgery including, for example, musculoskeletal surgery, abdominal surgery, gynecological surgery, ophthalmic, orthopedic, central nervous system, cardiovascular and intrauterine repair. Adhesions may produce bowel obstruction or intestinal loops following abdominal surgery, infertility following gynecological surgery as a result of adhesions forming between pelvic structures, restricted limb motion (tendon adhesions) following musculoskeletal surgery, cardiovascular complications including impairing the normal movement of the heart following cardiac surgery, an increase in intracranial bleeding, infection and cerebrospinal fluid leakage and pain following many surgeries, especially including spinal surgery which produces low back pain, leg pain and sphincter disturbance.
The term “EO/LA ratio” is used to describe the relative amount of poly(ethylene oxide) or poly(ethylene oxide)-co-poly(propylene oxide) and ester units (such term including monomeric units which are not technically ester units, as described in greater detail herein but preferably, are hydroxy carboxylic acid units, even more preferably, α-hydroxy carboxylic acid units and most preferably, lactic acid units) which are used in AB diblock or ACA triblock copolymers and chain-extended or coupled polymers according to the present invention. This term refers to the length (number of monomeric units) of the B or C block [preferably, poly(ethylene oxide), the monomeric units being ethylene oxide units] divided by the total number of hydroxy acid (ester) units in both A blocks (preferably, lactic acid) of the ACA triblock or in the A block of the AB diblock as described hereinabove. Polymers comprised of AB diblocks or ACA triblocks which contain significant (poly) ethylene oxide (in B or C blocks or in other components of the present composition) which are chain extended pursuant to the present invention are also described in terms of an EO/LA ratio. The EO/LA ratio for preferred polymers for use in the anti-adhesion aspect according to the present invention generally ranges from about 0.1 to about 100 or more, preferably ranges from about 0.5 to about 30 or more, more preferably from about 0.5 to about 10.0, more preferably about 1.0 to about 5.0, more preferably about 1.5 to about 4.5, even more preferably about 2.5 to about 3.5 and most preferably about 3.0. In certain instances, the EO/LA ratio may fall outside of these ranges, depending upon the final characteristics of the polymers which are desired and the application for which the polymer is used. In the case of polymeric films to be utilized in anti-adhesion aspects according to the present invention, the EO/LA ratio preferably ranges from about 0.1 to about 25 or more, more preferably about 0.5 to about 10, even more preferably about 1.0 to 5.0, even more preferably about 1.5 to about 4.5 and even more preferably about 2.5 to 3.5, with about 3.0 within this range being particularly preferred. In the case of viscous solutions, dispersions and/or gels which are utilized in the anti-adhesion aspect, the polymers may contain EO/LA ratios which range up to 30 or more. It is noted that in the case where a hydrophobic unit is used in the B or C block (for example a propylene oxide unit or higher alkylene oxide unit, this unit is considered as being a component in the denominator (LA) of the EO/LA ratio.
The term “prepolymerized” is used to describe the polymers according to the present invention which have been completely reacted before being introduced or administered in an application, for example, to a patient to be treated. Prepolymerized polymers according to the present invention stand in contrast to polymers which may be polymerized in situ, i.e., at the site of administration in the patient. Prepolymerized polymers of the present invention are utilized to create both preformed structures, e.g., compositions having three-dimensional structure such as films, cylinders, spheres, rods, blocks, tubes, beads, foam or rings, etc. and related structures, and non-preformed compositions such as sprays, gels, liquid polymers, pastes, viscous solutions and dispersions, among others.
The term “crosslinked” or “crosslinker” is used to describe agents which covalently bond the ACA triblocks or AB diblocks to other triblocks, diblocks or other moieties in the present polymers. As used herein, a crosslinker refers to a chemical compound which contains at least three (3) reactive moieties, for example, nucleophilic and/or electrophilic moieties, or moieties such as double-bonds, which can react through a radical initiated mechanism. In preferred embodiments, crosslinking agents according to the present invention have at least three of the same type of moieties, for example nucleophilic, electrophilic or radical-initiated moieties in order to facilitate the reaction of the crosslinker with triblocks and diblocks according to the present invention. In many respects, crosslinking agents are related to chain-extending agents in the present invention except that chain-extending agents contain only two reactive moieties, whereas crosslinking agents contain at least three reactive moieties. Exemplary crosslinking agents which can be used in the present invention include those which contain at least three isocyanate moieties, for example, isocyanurate, among numerous others, or a mixture of reactive moieties, such as carboxylic acid and hydroxylic groups (an example being citric acid or tartaric acid, among numerous others) and amine groups. One of ordinary skill in the art will be able to readily determine the type and amount of crosslinking agent which may be used in the present invention in order to facilitate the therapeutic method according to the present invention and the delivery of the polymers to a treatment site in a patient.
In the present invention, reaction of an AB diblock with a crosslinking agent may produce a star molecule or, in other instances, different structures such as a comb polymer, for example, but not a crosslinked system per se. Inasmuch as the AB diblock will generally contain only one reactive moiety per molecule (except in the case where one of the two blocks contains a blocking group which may be removed and then reacted subsequent to the initial formation of the AB diblock), the use of crosslinkers will produce predetermined structures such as star or comb molecules. The inclusion or incorporation of an additional moiety in the diblock to which a crosslinking agent can react will generate a more elaborate crosslinked system akin to that produced with the ACA triblocks of the present invention.
The term “non-crosslinked”, “substantially non-crosslinked”, “crosslinked” or “substantially crosslinked” are used to describe the polymers according to the present invention which exhibit or display a substantial absence of crosslinking or, in other embodiments, substantial crosslinking. Polymers according to the present invention are advantageously associated with substantial post-surgical adhesion prevention or reduction as well as numerous other applications. In certain embodiments, the present polymers actually prevent adhesions. Polymers according to the present invention which are considered substantially non-crosslinked preferably contain less than about 1.0% crosslinking, more preferably less than about 0.5% by weight crosslinking, even more preferably less than about 0.1% by weight crosslinking, most preferably less than about 0.05% by weight crosslinking are advantageously employed in the present invention. As used herein, reference to 1.0%, 0.5%, 0.1% etc. crosslinking refers to the amount by weight of a crosslinker which may be found in the polymers of the present invention. In other embodiments, polymers may be crosslinked, i.e., they may contain substantially more crosslinking agent than 1.0% by weight crosslinking agent.
The polymeric compositions according to the present invention may be chain-extended or coupled rather than crosslinked, but may be crosslinked in addition to being chain extended or coupled. It is also possible to produce crosslinked, non-chain extended polymers according to the present invention, but these polymers, if used in anti-adhesion aspects of the present invention, are preferably crosslinked with more hydrophilic chain extenders in order to maintain a favorable EO/LA ratio. In certain preferred embodiments, the polymers may be both chain extended and crosslinked. In the present compositions, chain extension provides the type of structural integrity and uniformity associated with the exceptional performance of the polymers of the present invention as anti-adhesion barriers. While not being limited by way of theory, it is believed that chain extension alone or in combination with crosslinking, in contrast to mere crosslinking with hydrophobic chain extenders without chain extension, allows a degree of mobility and flexibility of the hydrophilic B block which is consistent with anti-adhesion activity. In the anti-adhesion aspect of the present invention, the polymeric compositions according to the present invention provide an environment in which the A blocks (of the ACA triblock or AB diblock) will form hydrophobic, and often partially crystalline, hard microphases of high structural integrity and the B or C blocks will form hydrophilic, flexible phases, which are believed to be primarily responsible for good anti-adhesion activity. The formation of this microstructure, which is believed to be associated with polymeric compositions according to this invention and in particular, the flexibility of the PEG B or C blocks where used, produces excellent barriers for the reduction or prevention of post-surgical adhesions. Hydrophobic crosslinking of the triblocks according to the present invention without chain-extension (in contrast to hydrophilic crosslinking which may be used advantageously) not only limits molecular mobility, of special importance being its effect on the PEG segments, but also hampers or in certain instances, is believed to prevent microphase segregation from taking place. These two phenomena are believed to be associated with the production of less successful anti-adhesion barriers.
In certain polymers according to the present invention which are used in the anti-adhesion aspect according to the present invention, crosslinking, especially if crosslinking density is high, prevents or at least substantially limits phase separation and to a greater extent, crystallization. In the present invention, the limitation of phase separation and crystallization will depend on the crosslinking density which is a function not only of the number of trimers which are crosslinked to those which are chain extended, but also on the molecular weight of the diblock or triblock and MW weight of its different components. In addition, the degree to which crosslinking will limit phase separation (and also crystallization) will depend on the molecular weight and flexibility of the crosslinker. Clearly, the shorter the crosslinker, the greater the decrease in molecular mobility and therefore, phase separation. The effect of the crosslinker being hydrophobic or hydrophilic on phase separation and molecular or segmental mobility is two-fold: a) hydration will render the crosslinker more flexible and b) if the crosslinker is crystalline, its crystallinity will be destroyed by hydration. One is therefore, not limited to relatively low molecular weights of the crosslinker where, due to perturbations of the short chain, the polymer is unable to crystallize.
The term “coupler” is used to describe a difunctional compound which couples two AB diblocks together to produce coupled di-diblocks or multi-blocks according to the present invention. Couplers and chain-extenders are similar compounds, but a coupler is a difunctional compound which couples two diblocks together, whereas a chain-extender is used to extend the ACA triblocks into very high molecular weight polymeric chains.
As used in the present invention, the AB diblocks or ACA triblocks used in the present polymers are preferably chain extended or coupled. The chain extenders or couplers which are used are difunctional compounds (nucleophilic or electrophilic) which react with the end-cap reactive group of the diblocks or triblocks to produce di-diblocks, multiblocks or chain extended triblocks according to the present invention. Electrophilic couplers include, for example, diisocyanates, diacids, diesters, active diesters and acyl halides (all of which may be derived from dicarboxylic acids), among others, and nucleophilic couplers, which may include diols, diamines (as otherwise described herein) and hydroxyl amines. Electrophilic couplers are useful for coupling hydroxyl or amine-capped diblocks or triblocks, the resulting products containing urethane groups, urea groups (from the diisocyanate) and ester groups or amide groups (from the diacids, diesters, or related coupling agents). In addition, diisocyanates are useful for coupling or chain-extending diblocks or triblocks which are capped with carboxylic groups, such coupling reaction resulting in the formation of an amide group. Nucleophilic couplers such as diols and diamine are useful for coupling diblocks or triblocks which are end-capped with carboxyl groups, the resulting products containing ester groups or amide groups. Couplers may be simple, e.g., a simple monomeric compound containing two functional groups, or complex, e.g., containing oligomeric or polymeric moieties such as polyesters or polyethers, or may be based upon the reaction of a number of coupling agents to such as diols or diamines and diisocyanates or diacids, etc. to produce complex coupling agents.
In the present invention, the amount of coupling agent or chain extender which is included within the polymers according to the present invention may vary. In the case of polymers which incorporate an ACA trimer, the molar ratio of chain extender or coupler to ACA triblock in the present polymers varies from about 1.25 to about 2.:1, more preferably about 1.5:1 to about 2:1, most preferbly about 2:1. In the case of AB diblocks, the coupler is used preferably in a molar ratio of about 2:1 (AB diblock to coupler) in order that virtually all or nearly all of the functional groups on the end of the diblock are reacted with coupling agent.
In the case of diblocks, the preferred molar ratio of coupling agent to AB diblock varies from about 0.25 to about 1.0, with a more preferred ratio of about 0.5 to 1.0. When used with diblocks, the couplers form a di-diblock. It is noted that in synthesizing the present chain-extended polymers, the amount of chain extender which is reacted with AB diblock or ACA triblock to produce compositions according to the present invention is generally slightly higher than the amount which is expected to be included in the final synthesized polymers.
Chain extenders or couplers which are used in the present invention, preferably contain no more than about 1% by weight of a crosslinking compound (such term signifying a compound containing at least 3 functional groups which can react with the end-cap group of the triblock and which generally appear in a chain extender sample as a side product of the synthesis or production of the chain extender), more preferably, less than about 0.5% by weight of a trifunctional compound and even more preferably less than 0.1% by weight. In certain embodiments, it is preferable to employ a difunctional chain extender which contains as little trifunctional (or higher functionality) compound as is practical. Also, the occurrence of side reactions which would lead to crosslinking of the polymers is negligible, due to both compositional as well as experimental parameters of the synthesis of the polymers of the present invention. Of course, in certain embodiments which separately employ crosslinking agents (either alone or in addition to chain extenders), the inclusion of weight percentages of crosslinking agents outside of the above-described weight ranges is within the scope of the present invention.
In the case of polymers which are used in structures such as films, the chain extenders are preferably non-water soluble. In the case of polymers which are used in systems such as water soluble gels, dispersions or viscous solutions, the chain-extenders are preferably highly water soluble. Preferred water soluble chain-extenders include, for example, polyethylene glycol diisocyanates or poly(ethylene oxide)-co-poly(propylene oxide) copolymer diisocyanates, with the polyethylene glycol or poly(ethylene oxide)-co-poly(propylene oxide) copolymer chain ranging in molecular weight from about 200 to about 20,000 or more with a preferred molecular weight ranging from about 600 to about 15,000, even more preferably about 600 to about 10,000. In cases where the preferred embodiment is a non-water soluble polymer in a liquid form, the chain extenders may also be substantially non-water soluble. The role of the chain extenders in the gels and/or viscous solutions according to the present invention is to promote the water solubility/dispersibility of the polymers and affect their viscosity in an effort to provide polymers which are readily deliverable to a site in a patient's body and also to fine tune the kinetics of degradation, the dilution and/or the solubilization of these polymers, to obtain optimal residence time and enhance the performance of the polymer as a barrier between tissue planes.
As an advantageous feature of the present invention, certain preferred polymers of the present invention are employed in the present invention to substantially reduce or prevent adhesions. While not being limited by way of theory, it is believed that the polymers according to the present invention which have a favorable EO/LA ratio allow greater mobility of polyoxyalkylene blocks (and in particular, polyethylene oxide blocks) within the AB diblock or ACA triblocks used in the present invention, a condition which is believed to at least partially explain the favorable results obtained by the present polymers in substantially reducing or preventing adhesions. Chain extended polymers according to the present invention are more likely to enhance phase separation of the distinct A and B blocks which comprise the triblocks, a condition which is associated with the superior performance of the polymers of this invention as anti-adhesion barriers. It is preferred that the polymers of the present invention should be chain extended and substantially non-crosslinked, or chain extended and crosslinked while maintaining a favorable EO/LA ratio of the entire polymer as well as preserving flexibility and segmental mobility, as much as possible. Polymers which are simply crosslinked (without chain extension) are also useful in the present invention, provided that the crosslinking agent is substantially hydrophilic in composition and allows the retention of the required degree of flexibility and segmental mobility.
The term “integral” is used to describe polymers according to the present invention which are substantially non-permeable to mesenchymal cells, platelets, blood cells and other cells which are involved in the biology of adhesion formation. Integral polymers preclude cells which are involved in the adhesion process from crossing the polymer barrier and initiating the adhesion process. Integral polymers also exhibit favorable physical characteristics and mechanical properties consistent with substantially reducing or eliminating adhesions.
The term “coupled” or “chain-extended” is used to describe polymers according to the present invention wherein the basic diblock or triblock is reacted with a difunctional (preferably, containing two electrophilic groups such as isocyanates, activated esters and acyl halides, among others, but also possibly containing two nucleophilic groups such as alcohols, amines and carboxylates) chain extender to increase the molecular weight of the present polymers. Preferred chain extenders or couplers for use in the present invention include, for example, diisocyanates, activated esters or acyl halides, but may include diols, diamines, dicarboxylates and hydroxylamines, among others. In certain preferred embodiments, especially in the form of films, the present polymers may be substantially non-crosslinked and are instead, chain-extended to provide sufficiently high molecular weight polymer chains to enhance the strength and integrity of the final polymer film compositions as well as affecting the rate of degradation. It is noted that chain extension of the polymers provides adequate strength and integrity of the final films and other structures, yet allows a degree of motility of the individual polyoxyalkylene B blocks within the ACA triblock or AB diblock in order to maximize the adhesion inhibiting characteristics of the films. In contrast, hydrophobically crosslinked polymers which are not chain extended, provide a more rigid structure which may limit movement of the individual polymeric blocks.
Preferred chain extenders or couplers for use in the present invention include diisocyanates of the general formula:
where R′ is a C 2 to C 12 , preferably a C 2 to C 8 alkylene group, a cycloalkyl or cycloalkyl-containing group, an aryl or aryl-containing group, 4,4′-diphenylmethane, toluene, naphthalene, 4,4′-dicyclohexylmethane, cyclohexyl, 3,3′-dimethylphenyl, 3,3′-dimethyl-diphenylmethane, 4,6′-xylylene, 3,5,5-trimethylcyclohexyl, 2,2,4-trimethylhexamethylene or p-phenylene. Equivalents of diisocyanates may also be used as chain extenders in the present invention. Additional chain extenders may include macrodiisocyanates including isocyanate terminated poly(oxyalkylene) including isocyanate terminated polymers comprising poly(ethylene oxide) and polyethylene oxide)-co-poly(propylene oxide), among others.
Additional preferred chain extenders for use in the present invention include, for example, those according to the formula:
where R″ is a C 0 to C 12 , preferably a C 2 to C 8 , alkylene group or a hydroxyl or carboxylic acid substituted alkylene group, alkene, a cycloalkyl, hydroxyl or carboxylic acid-containing cycloalkyl or cycloalkyl-containing group, an aryl or aryl-containing group or a polyoxyalkylene chain comprised of poly(ethylene oxide), poly(ethylene oxide)-co-poly(propylene oxide) or other poly(ethylene oxide) rich chains and L is hydroxyl, a halide such as Cl, I or Br or an ester group which can be prepared from a hydroxyl group such as an alkyl, phenyl, benzyl or substituted alkyl, phenyl or benzyl group, including activated ester groups such as a tosyl group, mesyl group or related activating groups.
The moiety
may be derived from numerous di- and tricarboxylic acids including, for example, citric acid, malic acid and tartaric acid, among numerous others such as oxalic acid, malonic acid, succinic acid, 2,3-dimethylsuccinic acid, glutaric acid, 3,3-dimethylglutaric acid, 3,3-dimethylglutaric acid, 3-methyladipic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, maleic acid, fumaric acid, diglycolic acid, hydromuconic acid, among others, including equivalents of these acids. These di- and tricarboxylic acids may be used to chain extend or couple the AB diblocks or ACA triblocks under controlled conditions so that crosslinking is substantially prevented. Alternatively, the use of the tricarboxylic acids may result in substantial crosslinking in certain aspects of the present invention. In the case of using dicarboxylic acids containing additional carboxylic acid groups and/or other polar groups such as hydroxyl groups, as in the case of citric acid or malic acid, among others, these will tend to enhance the water solubility of the final polymeric compositions.
The term “biodegradable” relates to the characteristic whereby a polymer will degrade. Preferred polymers according to present invention are biodegradable. Preferred polymers according to the present invention which are utilized in vivo readily degrade in vivo and breakdown readily into monomeric units such as hydroxy acids. In the case of the use of PEG chains (B or C blocks) with polymers which are utilized within the body, although these chains are not biodegradable, they are readily excreted by the patient upon degradation of the A block. The degradation of the present polymers mainly takes place through the hydrolysis of reactive bonds in the A block, such as aliphatic esters. The hydrolysis reaction is generally dependent upon pH. The rate constant for hydrolysis tends to be much higher at high pH (greater than 9.0) and low pH (less than 3.0) than at neutral pH (6.0 to 8.0). The rate constant for hydrolysis tends to be higher under basic conditions than under acidic conditions.
The A blocks of the diblocks and triblocks of the present polymers tend to be biodegradable, whereas the B or C blocks of the triblocks, diblocks and chain extenders tend not to be biodegradable. In the case of water-soluble chain extenders and crosslinking agents which are preferably utilized in gels and viscous solutions according to the present invention, these chain extenders and crosslinking agents, which generally are highly water soluble, tend not to be biodegradable. In addition, when using polymers containing A blocks derived from α-hydroxy acids, the polymeric A blocks will degrade to individual α-hydroxy acids which are biosynthetically useful and may be involved in the patient's “biochemistry”. In contrast, however, although the poly(oxyalkylene) polymeric B or C blocks are biocompatible, they are neither biodegradable nor bioabsorbable. Thus, in using the polymers according to the present invention it is recognized that the poly(oxyalkylene) blocks will remain as polymeric units in vivo until such time as the blocks are excreted. Consequently, the choice of an upper molecular weight range of the polyoxyalkylene block in the polymers according to the present invention which are to be used in vivo will very much depend on the ability of the body to excrete or otherwise rid the body of the material.
The term “strength”, “mechanical strength” or “sufficient suture-holding ablity” describes favorable mechanical and/or physical characteristics of the present polymers and reflects the fact that preferred polymers for use in the present invention (generally, as films) having a mechanical strength which is sufficient to allow a suture to be used to anchor the polymer to a tissue site without appreciable tearing or ripping of the film. These preferred polymers according to the present invention have an Ultimate Tensile Strength value preferably within the range of about 5-35 MPa and Elongation at Break values generally within the range of about 400-2000%.
The term “flexible” is used with respect to a physical description of the polymers of the present invention to reflect the fact that the present polymers are essentially non-rigid and non-brittle, and generally display an elastomeric behavior and tend to be conformable to a tissue surface to be treated. That is, the present polymers contain sufficient flexibility and are pliable enough to substantially conform to the contours of the tissue surfaces to be treated. Thus, polymeric compositions according to the present invention have a Young's Modulus preferably within the range of about 50-150 MPa.
The term “homogeneous” is used to describe preferred polymers according to the present invention. The term homogeneous is associated with the inclusion in the final polymer compositions of a population of diblocks and triblocks which are generally of the same size and preferably have a polydispersity of between about 1.0 and 2.0, more preferably about 1.1 to about 1.5 and even more preferably about 1.1 to about 1.2. Homogeneous triblocks and diblocks are associated with reproducible mechanical and physical characteristics and favorably consistent biodegradability.
The term “structure” is used to describe polymers according to the present invention which have form, size and dimensions which are established outside the body and will not significantly change upon being placed inside the body of the patient to be treated. The term structure embraces not only flat surfaced structures (i.e., films) in the traditional manner, but also cylinders, tubes and other three dimensional structures which are not substantially changed by the anatomy of the patient into which the structure has been placed.
The term “gels” is used to describe dispersions or suspensions of polymer which have been formed by dissolving, suspending or dispersing polymer in an aqueous solution for delivery to a site within the patient's body in order to prevent adhesions. Gels of the present invention typically contain polymer in a sterile aqueous solution (such solution comprising saline solution, sterile water or a water/ethanol mixture) at a viscosity ranging from about 100 to about 150,000 or more, preferably about 500 centipoise units up to about 50,000 centipoise units or more. More preferably, the gels are delivered in sterile, isotonic saline solution at a viscosity ranging from about 2000 centipoise units up to about 30,000 centipoise units depending upon the application. In certain aspects according to the present invention, liquid polymeric compositions comprising non-water soluble polymers may also be used.
Gels according to the present invention may be used in numerous applications to reduce or prevent adhesions, but preferably are employed to reduce or prevent adhesions following general surgical procedures and related surgeries which are minimally invasive. Gels may utilize non-water soluble ACA triblocks which are chain extended with water-soluble or hydrophilic chain extenders in order to render the overall polymeric composition water dispersible or water soluble. AB diblocks may also be used in this gel aspect according to the present invention without limitation. Certain phases within the gel polymer compositions will be advantageously non-water soluble in order to promote the structural integrity and reduce the overall rate of biodegradability of the gel formulations in the body.
The term “viscous solution or suspension” is used to describe free-flowing solutions or suspensions of polymers according to the present invention wherein the solution has a viscosity which is greater than about 1 centipoise unit and less than about 60,000 or more centipoise units, more preferably about 1000 centipoise units to about 40,000 centipoise units or more, even more preferably about 2,000 centipoise units to about 20,000 centipoise units and above within this range. Viscous solutions or suspensions of polymers according tso the present invention at viscosities approaching the high end of the range of viscosities may be indistinguishable from gels at the low end of a viscosity range. The present invention also contemplates liquid polymeric compositions having appropriate viscosity and flow characteristics and their use to reduce and/or prevent adhesions.
In the anti-adhesion aspect of the present invention, the AB diblock or ACA triblock is a unit which is preferably comprised of ester units derived from a variety of monomers as described hereinabove and preferably comprises poly(hydroxy acid) polymers in the A block and poly(oxyalkyelene) polymers in the B or C block. The A block is however, substantially biodegradable and ranges in size from one monomeric unit up to about 400 or more monomeric units, with a preferred size ranging from about 4 to about 50 units, more preferably about 6 to about 30 units, even more preferably about 8 to 16 units. In this aspect of the present invention, the A block preferably is derived from an alpha-hydroxy acid or a related ester or lactone which produces monomer units of alpha-hydroxy acid within the polymeric chain as will be described in greater detail below. More preferably, the A block is derived from units of glycolic acid, lactic acid or mixtures thereof, in the form of glycolide or lactide reactants (dimeric α-hydroxy acids as explained in greater detail hereinbelow). In this anti-adhesion aspect of the present invention, the B or C block preferably comprises poly(ethylene oxide) or poly(ethylene oxide)-co-poly(propyleneoxide) block copolymers. In certain aspects of the present invention, for example, where a polymer comprises a sufficient weight percent of poly(ethylene oxide) units in chain extenders and/or crosslinking agents to instill the overall polymer with a favorable EO/LA ratio, the B or C block may be hydrophobic or hydrophilic and derived from, for example, diols, diamines and dicarboxylic acids, among other equivalent compounds.
In certain preferred aspects according to the present invention, for example, where the polymer is used in an anti-adhesion application in vivo, examples of diol, diamine and dicarboxylic acid compounds which may be used in the present invention include, for example, OH-terminated diol molecules such as ethylene glycol, butanediol (generally a C 2 to C 12 unsubstituted or substituted, saturated or unsatured, preferably a saturated, linear diol), OH-terminated polycaprolactone chains ranging in molecular weight from several hundred up to several thousand or more (4,000+), poly(propylene glycol) also ranging in molecular weight from several hundred to several thousand or more (4000+), OH-terminated polyesters or oligoesters such as OH-terminated poly(ethylene succinate) or poly(hexamethyleneadipate) or polyfunctional diols such as tartaric acid (containing two OH groups which are reactive with isocyanates and two carboxylic acid groups, which, in carboxylate form, will function to enhance the overall hydrophilicity of the composition and can serve to provide a material with pH dependent water solubility). Additional examples of such compounds include amine-containing compounds (preferably, a C 2 to C 12 diamine) such as ethylene diamine, hexamethylene diamine, amino acids, such as lysine(where two amine groups react leaving an unreacted carboxylic acid group) and oligopeptides (such term including compounds containig from one to 100 peptide units) with two reactive amino groups, among numerous others. Examples of difunctional carboxylic acid-containing compounds include, for example any C 2 to C 24 , preferably a C 2 to C 12 , saturated or unsaturated dicarboxylic acid, including succinic acid, sebacic acid, among numerous others, including adipic acid, succinic acid, malic acid, or fuimaric acid, maleic acid, COOH-terminated polycaprolactone, COOH-terminated polyesters or oligoesters such as COOH-terminated poly(ethylene succinate) or poly(hexamethylene adipate). Additional examples of such compounds include, for example, C═C containing groups such as fumaric acid (trans) and maleic acid (cis), among others which react with the diisocyanates via their COOH groups which leave unreacted double bonds available for further derivation by different mechanisms. Indeed, a large number of molecules are able to start the polymerization step including polyaminoacids, saccharides, etc. One example may be a polymer where lactide dimer (LD) is not started by a PEG chain, but rather by butane diol. A pentamer will be formed with HDI and chain-extended using, for example, PEG 6000. Alternatively, one can generate the HDI-PEG6000-HDI macrodiisocyanate and react such a molecule with, for example, (LA)-BD-(LA)4 triblock to produce the material —(HDI)-(LA)-BD-(LA)4-HDI-PEG6000—. A huge number of alternative embodiments are contemplated by the present invention.
When such compounds are used to make AB diblocks, the difunctional diol, diamine or dicarboxylic acid compounds may be terminated with an unreactive or blocking group at one end of the compound, or, alternatively, the compound may simply be end-capped with an unreactive group such as an alkyl, cycloalkyl, aryl, aralkyl or related group including a substituted alkyl, cycloalkyl, aryl or aralkyl group. In such a case where a blocking group is used, the blocking group may be “deblocked” thus producing an AB diblock which has reactive groups at the terminal end of the A block and at the terminal end of the B block. Alternatively and preferably, where the B block is simply end-capped with an unreactive, inert group, the resulting AB diblock will have but one functional group at the terminal end of the A block, which is chain-extended, coupled or crosslinked to multi-diblocks according to the present invention.
The B or C block may vary in size from about 100 Da (dalton units) up to about 200,000 Da or higher, with a preferred range of about 1,000 Da up to about 20,000 Da. Most preferably, the B block is a poly(ethylene oxide) ranging in size from about 3,000 to about 10,000 Da. It is unexpectedly found that the poly(ethyleneoxide) B (or C) block provides the greatest inhibition or reduction in adhesion in the present invention.
The AB diblock or ACA triblock is preferably end-capped with nucleophilic moieties such as hydroxyl or amine groups. Alternatively, these diblocks and triblocks may be end-capped with carboxyl groups as well. With the preferred nucleophilic end-capping groups in place, the AB diblock or ACA triblock may be readily coupled or chain extended using difunctional electrophilic compounds such as diisocyanate or dicarboxylic acid compounds (or derivatives of dicarboxylic acids such as esters or diacyl halides). More preferably, the diblocks and triblocks are end-capped with hydroxyl groups and coupled or chain extended with diisocyanate compounds in order to produce the preferred polymers according to the present invention.
In one aspect, therefore, the present invention relates to a method of substantially reducing or preventing tissue adhesions in patients comprising exposing damaged tissue in a patient to a polymeric composition in a structure such as a film, gel, dispersion, liquid polymer, spray or viscous solution form comprising a multiblock polymer according to the present invention. Structures such as films which incorporate the polymers according to the present invention are preferably characterized by their favorable flexibility, mechanical strength and suture-holding ability as well as being substantially non-water soluble, chain extended, integral and biodegradable. Other structures used in the present invention, as well as gels, viscous solutions and emulsions, in certain aspects, may be preferably water soluble. In all aspects according to the present invention, certain embodiments may be substantially non-water soluble or water soluble, depending upon a variety of factors which may be influenced by treatment and/or delivery of the present compositions to a site of activity.
Preferably, the molecular weight of triblocks, diblocks and polymers used in the present invention are relatively homogeneous which provides for advantageous characteristics in films and related structures, gels, dispersions, sprays, liquid polymers and solutions/emulsions.
In various materials according to the present invention which are included in preformed and non-preformed materials such as films, viscous solutions, suspensions and gels, among others, the polymers may comprise ACA triblocks or AB diblocks as disclosed hereinabove, which may be chain extended, coupled and/or crosslinked using a highly water soluble/water dispersible chain extender or crosslinking agent. Although in many preferred embodiments the B (or C) block of the ACA triblock or AB diblock is hydrophilic and will have a high degree of compatability with water, thus allowing certain of the polymeric films according to the present invention to absorb large quantities of water or dissolve in water, it is the hydrophilic chain extender or coupler used in various polymers according to the present invention which utilize hydrophobic and hydrophilic B blocks, which allows delivery of these polymer compositions in aqueous solutions. Although in certain aspects of the present invention the ACA triblocks and AB diblocks are preferably non-water soluble (especially, for example, in the case of films and in other aspects of the present invention), in a number of aspects of the present invention including films, or other preformed structures, and in viscous solutions, gels, dispersions and sprays, the use of ACA triblocks and AB diblocks which are substantially water soluble may be advantageous. One of ordinary skill will readily know how to modify the polymers according to the present teachings in an effort to adjust the formulations to maximize delivery within a particular treatment context.
In the present application, the following chain extenders or coupling agents find use in preparing pre-polymerized, non-preformed polymers such as gels and viscous solutions having desirable characteristics for reducing or preventing post-operative adhesion:
where R′ is a C 2 to C 12 , preferably a C 2 to C 8 alkylene group, a cycloalkyl or cycloalkyl-containing group, an aryl or aryl-containing group, 4,4′-diphenylmethane, toluene, naphthalene, 4,4′-dicyclohexylmethane, cyclohexyl, 3,3′-dimethylphenyl, 3,3′-dimethyl-diphenylmethane, 4,6′-xylylene, 3,5,5-trimethylcyclohexyl, 2,2,4-trimethylhexamethylene or p-phenylene. Equivalents of diisocyanates may also be used as chain extenders in the present invention. Preferred chain extenders may include water soluble macrodiisocyanates including isocyanate terminated poly(oxyalkylene) diisocyanates or isocyanate-terminated polymers comprising poly(ethylene oxide), polyethylene oxide)-co-poly(propylene oxide) and poly(ethylene oxide) containing and poly(ethylene oxide) rich schains, which may be water-soluble or non-water soluble, among others.
Additional preferred chain extenders for use in the present invention include, example those according to the formula:
where R″ is a C 0 to C 12 , preferably a C 2 to C 8 , alkylene group or a hydroxyl or carboxylic acid substituted alkylene group, alkene, a cycloalkyl, hydroxyl or carboxylic acid containing cycloalkyl or cycloalkyl-containing group, an aryl or aryl-containing group or a poly(oxyalkylene) chain comprised of poly(ethylene oxide), poly(ethylene oxide)-co-poly(propylene oxide) or other poly(ethylene oxide) containing or poly(ethylene oxide) rich chains [i.e., where poly(ethylene oxide) is included in an amount ranging from at least about 50% by weight of the polymeric chain and] L is hydroxyl, a halide such as Cl, I or Br or an ester group which can be prepared from a hydroxyl group such as an alkyl, phenyl, benzyl or substituted alkyl, phenyl or benzyl group, include activated ester groups such as a tosyl group, mesyl group or related activated groups. It is noted that diacids according to this aspect of the present invention may also find use as C blocks in certain ACA triblocks and AB diblocks according to the present invention.
It is noted that in choosing ACA triblocks or AB diblocks for formulating viscous solutions and gels according to the present invention, care must be given to providing a good balance of strength/structural integrity and biodegradability from the A block, hydrophilicity/anti-adhesion activity from the C block and further hydrophilicity in the form of water solubility/water dispersibility from the chain extender, coupling agent and/or crosslinking agent, where such agent is used. Notwithstanding certain of the embodiments previously discussed, in the present invention, non-water soluble triblocks or diblocks such as are utilized in film applications according to the present invention also may be advantageously employed in viscous solution/gel applications.
The above-described chemical formulas provide insight into the chain extended and crosslinked polymers which are used in the present invention. In the case of polymers which are preferably used in non-preformed polymers such as gels, dispersions, sprays and/or viscous solutions according to the present invention, the ultimate polymeric composition is preferably water soluble/dispersible and the polymers are preferably chain extended or crosslinked utilizing hydrophilic chain extenders or crosslinking agents, for example, diisocyanate terminated poly(alkylene glycol) chains comprising a central polyalkylene glycol chain such as poly(ethylene oxide), capped by two diisocyanate compounds, among numerous others. Examples include the use of poly(ethylene glycol) chains with a molecular range between 200 and 20,000, hexamethylene diisocyanate or a related diiisocyanate as previously described being the diisocyanate. By employing non-water soluble or water soluble ACA triblocks or AB diblocks and preferably employing water soluble/dispersible chain extenders and/or crosslinking agents, polymer compositions which are used in viscous solution and gel applications provide favorable strength and structural integrity, biodegradability (the rate of which may be influenced by the length and hydrophobicity of the A block and the overall hydrophilicity of the polymer), flexibility and anti-adhesion activity from the PEG segments in the polymer and water solubility/dispersibility from the selective chain extenders which are used.
In addition to being useful for substantially reducing or preventing adhesions, the present polymers may also be used to deliver bioactive compositions to a site of activity within the patient's body. This aspect of the present invention is secondary to the anti-adhesion characteristics of the inventive polymers. It is particularly advantageous that the present polymers may be used to deliver bioactive agents which may serve to enhance the healing of the wounds created by a surgical procedure, a disease state or other condition associated with the tissue to be treated.
Exemplary bioactive agents which may be delivered pursuant to the methods according to the present invention include, for example, anticoagulants, for example heparin and chondroitin sulphate, fibrinolytics such as tPA, plasmin, streptokinase, urokinase and elastase, steroidal and non-steroidal anti-inflammatory agents such as hydrocortisone, dexamethasone, prednisolone, methylprednisolone, promethazine, aspirin, ibuprofen, indomethacin, ketoralac, meclofenamate, tolmetin, calcium channel blockers such as diltiazem, nifedipine, verapamil, antioxidants such as ascorbic acid, carotenes and alpha-tocopherol, allopurinol, trimetazidine, antibiotics, especially noxythiolin and other antibiotics to prevent infection, prokinetic agents to promote bowel motility, agents to prevent collagen crosslinking such as cis-hydroxyproline and D-penicillamine, and agents which prevent mast cell degranulation such as disodium chromolglycate, among numerous others.
In addition to the above agents, which generally exhibit favorable pharmacological activity related to promoting wound healing, reducing infection or otherwise reducing the likelihood that an adhesion will occur, other bioactive agents may be delivered by the polymers of the present invention include, for example, amino acids, peptides, proteins, including enzymes, carbohydrates, antibiotics (treat a specific microbial infection), anti-cancer agents, neurotransmitters, hormones, immunological agents including antibodies, nucleic acids including antisense agents, fertility drugs, psychoactive drugs and local anesthetics, among numerous additional agents.
The delivery of these agents will depend upon the pharmacological activity of the agent, the site of activity within the body and the physicochemical characteristics of the agent to be delivered, the therapeutic index of the agent, among other factors. One of ordinary skill in the art will be able to readily adjust the physicochemical characteristics of the present polymers and the hydrophobicity/hydrophilicity of the agent to be delivered in order to produce the intended effect. In this aspect of the invention, bioactive agents are administered in concentrations or amounts which are effective to produce an intended result. It is noted that the chemistry of polymeric composition according to the present invention can be modified to accommodate a broad range of hydrophilic and hydrophobic bioactive agents and their delivery to sites in the patient.
Synthesis of Polymers According to the Present Invention
In general, the synthesis of the present polymers proceeds by first synthesizing an AB diblock. In this general reaction, a monofinctional amine, alcohol or carboxyl containing compound is (which preferably includes a compound containing a polyoxyalkylene group) is preferably reacted with a hydroxy acid, its cyclic dimer or a related monomer as previously described herein, to produce the AB diblock. Essentially, the monofinctional amine, alcohol or carboxyl containing compound reacts with the hydroxy acid or its cyclic dimer to produce an AB diblock which is end-capped with a hydroxyl group or other functional group(s) capable of reacting with a coupling agent or crosslinking agent.
Once the AB diblock is formed, the hydroxyl groups at the end(s) of the molecule are reacted with difunctional chain extenders or couplers, for example, diisocyanates. This reaction produces a chain extended polymer (e.g. a diblock or a star or comb polymer) which is readily used to prepare films and various related structures, gels, dispersions, suspensions, pastes and viscous solutions of the present invention. In the case of certain polymers, these are of sufficiently low molecular weight so that they are in liquid form without the need to add additional solvent.
Generally, during the first stage of the reaction in which the low molecular weight AB diblock is formed, the overall molecular weight and the length of the different segments will be determined by the molecular weight of the B block chosen to initiate the reaction, by the number of moles of hydroxy acid, its cyclic dimer or related compounds used to form the A block, which is reacted with the B block. Thereafter, the AB diblock is chain extended, coupled and/or crosslinked to produce polymers containing AB diblocks.
In the case of the use of ACA triblocks, the triblock is first synthesized utilizing a C block which is difunctional diol, diamine or dicarboxylic compound, preferably, a (poly)oxyalkylene diol, most preferably a (poly)ethylene oxide-containing diol which is preferably reacted with a hydroxy acid, its cyclic dimer or a related monomer as previously described herein, to produce the ACA triblock. Once the triblock is formed, it is reacted with a molar excess (most preferably, a 2:1 molar ratio) of chain-extender or coupling agent to produce an intermediate ACA block which is end-capped with coupling agent having on each end a reactive group, which is further reacted with a monofunctional amine, alcohol or carboxyl containing molecule to produce an ACA triblock containing pentameric polymer composition. In this reaction, essentially, the monofunctional amine, alcohol or carboxyl containing compound reacts with chain-extended or coupled ACA triblock to produce the pentamer accordingly.
A particularly preferred synthesis according to the present invention relies on the use of the cyclic ester or lactone of lactic acid and glycolic acid. The use of lactide or glycolide as the reactant will enhance the production of ACA triblocks or AB diblocks which have relatively narrow molecular weight distributions and low polydispersity.
In this preferred method, lactide or glycolide (the cyclic dimer of lactic acid or glycolic acid, respectively), rather than lactic acid or glycolic acid, is first used to synthesize the ACA triblock or AB diblock from the starting poly(oxyalkylene) block. Once the triblock or diblock is obtained, the hydroxyl end-capped triblock or diblock is reacted with a diisocyanate, preferably hexamethylene diisocyanate.
The synthesis of the ACA triblock or Ab diblock preferably proceeds by way of a ring-opening mechanism, whereby the ring opening of the lactide or glycolide is initiated by the hydroxyl end groups of the diol, diamine or dicarboxyl (preferably, PEG) chain under the influence of a catalyst such as stannous octoate. An ACA type triblock or AB type diblock is generated at this point, the molecular weight of which is a function of both the molecular weight of the central Bor C block, preferably a PEG chain, and the length of the polyester, preferably PLA, lateral block(s). Typically, the molecular weight of the triblock ranges from about 4,000 to about 30,000 (but may be as low as 1,000 or less and as high as 250,000 or more). In the case if the diblock, the molecular weight may range as low as several hundred to upwards of 50,000 or more. After synthesis of the ACA triblock or AB diblock, the final polymer is preferably obtained by chain extending the hydroxyl terminated triblocks with difunctional reactants such as isocyanates, most preferably hexamethylene diisocyanate.
The chemical and physical properties of the different polymers will vary as a function of different parameters, the molecular weight and composition of the B (or C) block and A block segments along the backbone of the AB diblocks and ACA triblocks being of particular importance.
The preferred method has several advantageous characteristics including:
1. a rapid, nearly quantitative reaction which is complete in from 1 to 3 hours;
2. the reaction takes place under moderate reaction conditions (140° C.) thus minimizing side reactions;
3. the resulting triblock or diblock contains an extremely narrow polydispersity (P=1.3-1.4 or better; and
4. the triblock or diblock contains little or no homopolymer.
Preparation of Adhesion Barrier Structures
Barrier structures (which term includes films as well as cylinders and related three-dimensional structures) for use in the present invention are prepared by first producing the polymer according to the present invention and then dissolving the polymer in a solvent, such as chloroform, methylene chloride or a related organic solvent. Films, for example, are preferably prepared by placing the solution containing polymer in a mold or a related receptable and then allowing the solvent to evaporate. The resulting film is homogeneous and of uniform thickness and density. The film may be used as prepared or cut into segments for application to a desired site in a patient. In addition to the above-described solvent cast method, a continuous solvent cast process, a thermal cast method or related methods well known in the art may be used to make films and other structures according to the present invention.
In order to prepare other three dimensional structures of polymer, such as cylinders and related shapes, these may be cast or molded using various techniques, starting with solid polymer. Methods to produce these structures using these techniques are well known in the art.
Preparation of Gels, Viscous Solutions and Dispersions
In order to prepare the gels, viscous solutions, pastes and dispersions according to the present invention, polymer in powder, flakes or other related form is dissolved or suspended in an aqueous solution, preferably sterile isotonic saline solution, generally at room temperature and then mixed in the solution to produce the final gel, viscous solution or dispersion. Viscosity of the system is readily adjusted by adding fulrther polymer or aqueous solution. The gels, viscous solutions, pastes and dispersions are utilized under sterile conditions when they are applied in medical applications.
While not being limited by way of theory, it is believed that the chain extended polymers of the present invention form integral layers in films, gels or viscous solutions when applied to tissue for surgical applications. The resulting integral polymers provide an excellent barrier which substantially reduces the formation of post-operative adhesions.
Having generally described the invention, reference is now made to the following examples intended to illustrate preferred embodiments and comparisons but which are not to be construed as limiting to the scope of this invention as more broadly set forth above and in the appended claims.
EXAMPLES
The synthesis of the polymers is presented in the following examples. In general, where solvent is used, it is dried and distilled prior to use. Nitrogen is used dry at all times. All other materials are dried and distilled prior to use.
Example 1
Synthesis of [MPEG 750-d,lLA4]2-HDI
The synthesis consisted of two consecutive stages, namely the diblock synthesis and the consequent di-diblock formation.
1. Diblock Synthesis
80 gr. of poly(ethylene glycol) methyl ether of molecular weight 750 (MPEG 750), was dried under vacuum at 100° C. for 1 hour, under constant stirring. 32.26 gr. of (d,l)lactide were then added, corresponding to an LA:PEG molar ratio 4:1, including an excess of 5%. Catalyst (stannous 2-ethyl hexanoate) was added at a molar ratio of 1/400 of the amount of added lacitide, i.e. 0.3 gr. The reaction was carried out in a sealed flask, under a dry nitrogensaturated atmosphere, for two hours at 145° C.
2. Di-block formation
The diblock obtained in the first step was reacted with 17.92 gr. of hexamethylene diisocyanate (HDI) (at a molar ratio of 1:2) in a three-necked flask for 1 hour under mechanical stirring and dry nitrogen atmosphere, at 85° C.
The material is a water-soluable viscous liquid, at room temperature.
Example 2
Synthesis of [MPEG 750-d,lLA8]2-HDI
Same as in EXAMPLE 1, except for the use of 64.51 gr. of (d,l)lactide, corresponding to an LA:PEG molar ratio of 8:1, and 0.43 gr. of catalyst, in the first stage of the synthesis.
The material is a water-soluable viscous liquid, at room temperature.
Example 3
Synthesis of [MPEG 750-d,lLA12]2-HDI
Same as EXAMPLE 1, except for the use of 96.77 gr. of (d,l)lactide corresponding to an LA:PEG molar ratio of 8:1 and 0.68 gr. of catalyst, in the first stage of the synthesis.
The material is a water-insoluable viscous liquid, which does not flow at room temperature.
Example 4
Synthesis of [MPEG 550-(l)LA4-HDI]2-PEG 400
The synthesis consisted of three stages as follows:
1. Diblock Synthesis
70 gr. of poly (ethylene glycol) methyl ether of molecular weight 500 (MPEG 550), was dried under vacuum at 100° C. for 1 hour, under constant stirring. 42.15 gr. of (l)lactide were then added, corresponding to an LA:PEG molar ratio of 4:1, including an excess of 15%. Catalyst (stannous 2-ethyl hexanoate) was added at a molar ration of 1/400 of the amount of added lactide, i.e. 0.296 gr. The reaction was carried out in a sealed flask, under dry nitrogen-saturated atmosphere, for 150 min. at 150° C.
2. Macrodiisocyanate Formation
23.87 gr. of dried poly(ethylene glycol) of molecular weight 400 (PEG 400) were reacted with 20.07 gr. of HDI (corresponding to a 1:2 molar ratio, including a 10% excess of HDI, by adding the PEG 400 to the HDI in a three-necked flask, under mechanical stirring (80rpm) at room temperature and the reaction was carried out for 10 min. under a dry nitrogen atmosphere, at 75° C.
3. Addition of Diblock
100 gr. of dried diblock were added to the macrodiisocyanate, corresponding to a 2:1 molar ratio. Catalyst (stannous 2-ethyl hexanoate) was added simultaneously at a molar ratio of 1/100 of the amount of the added diblock, i.e. 0.48 gr. The reaction took place under the same conditions as described in step 2.
Thermal analysis of the material showed a glass transition temperature around −41° C. The viscosity of this material was 22000 cps and 5000 cps at 22° C. and 37° C. respectively. The product exhibited a translucid, yellowish color. NMR analysis showed the average number of LA units as 4.06.
Example 5
Synthesis of [MPEG 550-(l)LA2-HDI]2-PEG 400
The synthesis consisted of three stages as follows:
1. Diblock Synthesis
55 gr. of monomethyl ether-terminated poly(ethylene glycol) of molecular weight 550 (MPEG 550), was dried under vacuum at 100° C. for 1 hour, under constant stirring. 14.4 gr. of (l)lactide were then added, corresponding to a molar ratio LA:PEG of 2:1, including an excess of 15%. Catalyst (stannous 2-ethyl hexanoate) was added at a molar ratio of 1/400 of the amount of added lactide, i.e. 0.1 gr. The reaction was carried out in a sealed flask, under dry, nitrogen-saturated atmosphere, for 150 min. at 140° C.
2. Macrodiisocyanate Formation
20 gr. of dried PEG 400 were reacted with 16.82 gr. of HDI (corresponding to a 1:2 molar ratio, by adding the PEG 400 at the HDI in a three-necked flask, under mechanical stirring and nitrogen atmosphere, at 70° C. The reaction was carried out for 4 min.
3. Addition of Diblock
69.4 gr. of diblock were added to the macrodiisocyanate, corresponding to a 2:1 molar ratio. The reaction took place under the same condition as described in step 2, for one hour. The product was a yellowish liquid at room temperature.
Example 6
Synthesis of [MPEG 550-(l)LA6-HDI]2-PEG 600
The synthesis consisted of three steps as follows:
1. Diblock Synthesis
140 gr. of poly(ethylene glycol) methyl ether weight 550 (MPEG 550), was dried under vacuum at 100° C. for 1 hour, under constant stirring. 126 gr. of L lactide were then added, corresponding to an LA:PEG molar ratio of 6:1, including an excess of 15%. Catalyst (stannous 2-ethyl hexanoate) was added at a molar ratio of 1/400 of the amount of added lactide, i.e. 0.89 gr. The reaction was carried out in a sealed flask, under a dry, nitrogen-saturated astmosphere, for 150 min. at 150° C.
2. Macrodiisocyanate Formation
61 gr. of dried PEG 400 were reacted with 37.62 gr. of HDI (corresponding to a 1:2 molar ratio, including a 10% excess of HDI, by adding the PEG 600 to the HDI in a three-necked flask, under mechanical stirring at 80 rpm and dry nitrogen atmosphere, at 85° C. The reaction was carried out for 10 min.
3. Addition of Diblock
200 gr. of dried diblock were added to the macrodiisocyanate, corresponding to a 2:1 molar ratio. Catalyst (stannous 2-ethyl hexanoate) was added simultaneously at a molar ratio of 1/100 of the amount of added diblock, i.e. 0.82 gr. The reaction took place under the same conditions as described in step 2.
Example 7
Synthesis of [MPEG 550-HDI]2-[(l)LA4-PPG1000-LA4]
The synthesis consisted of three stages as follows:
1. Triblock Synthesis
40 gr. of poly(propylene glycol) of molecular weight 1000 (PPG 1000), were dried under vacuum at 100° C. for 1 hour, under constant stirring. 25.8 gr. of (l)lactide were then added, corresponding to an LA:PEG molar ratio of 8:1, including an excess of 12%. Catalyst (stannous 2-ethyl hexanoate) was added at a molar ratio of 1/400 of the amount of added lactide, i.e. 0.181 gr. The reaction was carried out in a sealed flask, under a dry, nitrogen-saturated atmosphere, for 150 min. at 150° C.
2. Macroisocyanate Formation
34.87 gr. of dried MPEG 550 were reacted with 11.2 gr. of HDI (corresponding to a 1:1 molar ratio, by adding the MPEG 550 to the HDI in a three-necked flask, under mechanical stirring and dry nitrogen atmosphere, at 75° C. Catalyst (stannous 2-ethyl hexanoate) was added at a molar ratio of 1/100 of the amount of added diblock, i.e. 0.82 gr. The reaction was carried out for an hour.
3. Addition of Triblock
50 gr. of dried diblock were added to the macroisocyanate corresponding to a 1:2 molar ratio. The reaction took place under the same conditions as described in step 2.
Thermal analysis of the triblock showed a glass transition temperature around −44° C. and two melting endotherms at 11° C. and 34° C. The viscosity was 43000 cps at 27° C. The product exhibited a translucid white color.
Example 8
Synthesis of (MPEG 550-(d,l)LA30-HDI)2-PCL 1250
The synthesis consisted of three stages as follows:
1. Diblock Synthesis
4.4 gr. of poly(ethylene glycol) methyl ether of molecular weight 550 (MPEG 550), was dried under vacuum at 100° C. for 1 hour, under constant stirring. 19.8 gr. of (d,l)lactide were then added, corresponding to a molar ratio LA:PEG of 30:1, including an excess of 15%. Catalyst (stannous 2-ethyl hexanoate) was added at a molar ratio of 1/400 of the amount of added lactide, i.e. 0.12 gr.
The reaction was carried out in a sealed flask, under a dry, nitrogen-saturated atmosphere, for 150 min. at 140° C.
2. Macrodiiisocyanate Formation
5 gr. of dried polycaprolactone of molecular weight 1250 (PCL 1250) were reacted with 1.34 gr. of HDI (corresponding to a 1:2 molar ratio, by adding the PCL 1250 to the HDI in a three-necked flask, under mechanical stirring and dry nitrogen atmosphere, at 70° C. The reaction was carried out for 30 min.
3. Addition of Diblock
24.2 gr of dried diblock were added to the macrodiisocyanate, corresponding to a 2:1 molar ratio. The reaction took place under the same condition as described in step 2, for one hour.
The NMR spectrum showed a 1:4 ratio and the product exhibited a viscosity of 40000 cps at 80° C. At room temperature it appeared as a hard sticky solid.
Example 9
Synthesis of [MPEG 750-(HDI-(l)LA4-PEG400-(l)LA4-HD)]2-[PEG1000]
The synthesis consisted of four stages as follows:
1. Triblock LA4-PEG400-LA4 synthesis
Same as described as in EXAMPLE 4
2. Macrodiisocyanate Formation
17 gr. of triblock were reacted with 6.26 gr. of HDI (corresponding to a 1:2 molar ratio, including a 7% excess of HDI, by adding the triblock to the HDI in a three-necked flask, under mechanical stirring and a dry nitrogen atmosphere, at 85° C.). The reaction was carried of for one hour.
3. Reaction Between Macrodiisocyanate and PEG 1000
8.71 gr. of dried PEG 1000 were added to the reaction, corresponding to a 1:2 molar ratio, and reacted under the same conditions as described in step 2.
4. Addition of MPEG750
13.05 gr. of dried PEG750M were added to the reaction, corresponding to a 2:1 molar ratio, and reacted under the same conditions as described in step 2.
Example 10
Synthesis of [(HexOH-LA12-HD)]2-PCL4000
Same as EXAMPLE 4, except for the use of 4.73 gr. of hexanol and 40 gr. of (d,l)lactide, corresponding to a hexanol:lactide molar ratio of 1:12 and 0.28 gr. of catalyst in the first stage, the use of 20 gr. of PCL 4000 and 1.68 gr. of HDI in the second stage, to which 44.73 gr. of triblock were added in the third stage.
Example 11
Synthesis of [MPEG 550-d,lLA12-HDI]2-PCL2000
Same as EXAMPLE, except for the use of 20 gr. of MPEG 500 and 36.13 gr. of (d,l)lactide, corresponding to a hexanol:lactide molar ratio of 1:12 and 0.21 gr. of catalyst in the first stage, the use of 20 gr. of PCL 2000 and 3.36 gr. of HDI in the second stage, to which 56.13 gr. of triblock were added in the third stage.
Example 12
Synthesis od [MPEG 750-HDI-PEG6000-HDI]2-[(I)LA4-PEG400-(I)LA44]
The synthesis consisted of four stages as follows:
1. Triblock LA4-PEG400-LA4 synthesis
35 gr. of PEG 400 were dried as in EXAMPLE 1, to which 55.9 gr. of (l)lactide were added, including an excess of 5% 0.0355 gr. of catalyst (stannous 2-ethyl hexanoate) were added at a molar ratio of 1/400 of the amount of added lactide. Reaction was carried out under the same conditions as described in EXAMPLE 1.
2. Macrodiisocyanate Formation
30.72 gr. of dried PEG 6000 were reacted with 2.94 gr. of HDI (corresponding to a 1:2 molar ratio, including a 7% excess of HDI), by adding the PEG 6000 to the HDI in a three-necked flask, under mechanical stirring and nitrogen atmosphere, at 85° C. The reaction was carried out for an hour.
3. Reaction Between Macrodiiscoanate and Triblock
2.5 gr. of triblock were added to the macrodiiscoanate corresponding to a 1:2 molar ratio and reacted under the same conditions as described in step 2.
4. Addition of MPEG750
3.84 gr. of dried MPEG750 were added to the reaction, corresponding to a 2:1 molar ratio, and reacted under same conditions described in step 2.
The material is a white, crystilline, water-soluble solid at room temperature, displaying a melting endotherm at 56° C.
Example 13
Synthesis of [MPEG 750-HDI-PEG2000-HDI]2-[(I)LA4-PEG400-(l)LA4]
The synthesis consisted of four stages as EXAMPLE 4, except for the use of 41 gr. of dried PEG 2000 and 7.38 gr. of HDI in the second stage, 10 gr. of triblock LA4-PEG400-LA4 in the third stage and 15.38 gr. of dried PEG 750M in the fourth stage. Molar ratios between reagents were the same as in EXAMPLE 4, absolute amounts, however, were normal zed to enable the use of 10 gr. of triblock, for convenience purposes
The material is a white, crystilline, water-soluable solid at room temperature displaying a melting endotherm at 50° C.
Example 14
Synthesis of [MPEG 750-HDI-PEG1000-HDI]2-[(l)LA4-PEG400-(I)LA4]
The synthesis consisted of four stages as in EXAMPLE 1, except for the use of 40 gr. of dried PEG 1000 and 14.38 gr. of HDI in the second stage, 19.52 gr. of triblock LA4-PEG400-LA4 in the third stage and 30 gr. of dried PEG 750M in the fourth stage.
The material is a yellowish, crystilline, water-soluable solid at room temperature, displaying a melting endotherm at 43° C.
Example 15
Synthesis of [MPEG 750-HDI-PEG600-HDI]2-[(l)LA4-PEG400-(l)LA4]
The synthesis consisted of four stages as in EXAMPLE 4, except for the use of 35 gr. of dried PEG 600 and 20.96 gr. of HDI in the second stage, 28.45 gr. of triblock LA4-PEG400-LA4 in the third stage and 43.73 gr. of dried PEG 750M in the fourth stage.
The material is a yellowish, water-soluable solid at room temperature, displaying a melting endotherm at 22° C.
Example 16
Synthesis of [MPEG 750-HDI-PEG400-HDI]2-[(l)LA4-PEG400-(l)LA]
The synthesis consisted of four stages as in EXAMPLE 4, except for the use of 24 gr. of dried PEG 400 and 22.47 gr. of HDI in the second stage, 30.5 gr. of triblock LA4-PEG400-LA4 in the third stage and 46.88 gr. of dried PEG 750M in the fourth stage.
The material is a yellowish, water-soluable solid at room temperature, displaying a melting endotherm at 19° C.
Example 17
Synthesis of [MPEG 750-HDI-PEG400-HDI]2-[(d,l)LA4-PEG400-(d,l)LA4]
The synthesis consisted of four stages as in EXAMPLE 4, except for the use of (d,l)lactide for the triblock preparation, instead of (l)lactide.
Example 18
Synthesis of {PEG600-(HDI-(d,l)LA4-PPG1000-(d,l)LA4-HDI)-PEG600]2-[HDI]
The synthesis consisted of four stages as follows:
1. Triblock Synthesis
40 gr. of poly (propylene glycol) of molecular weight 1000 (PPG 1000), were dried under vacuum at 100° C. for 1 hour, under constant stirring. 25.8 gr. of (d,l)lactide were then added, corresponding to a molar ration LA:PEG of 8:1, including excess of 12%. Catalyst (stannous 2-ethyl hexanoate) was added at a molar ratio of 1/400 of the amount of added lactide, i.e. 0.181 gr. The reaction was carried out in a sealed flask, under a dry, nitrogen-saturated atmosphere, for 150 min at 150° C.
2. Macrodiisocyanate Formation
20 gr. of dried triblock were reacted with 4.57 gr. of HDI (corresponding to a 1:2 molar ratio), by adding the triblock to the HDI (+1 ml of chloroform, used to quantitatively add the HDI and catalyst) in a three-necked flask, under mechanical stirring and dry nitrogen atmosphere, at 75° C. Catalyst (stannous 2-ethyl hexanoate) was added at a molar ratio of 1/50 of the amount of added lactide, i.e. 0.103 gr. The reaction was carried out for 15 min.
3. Addition of PEG 600
15.23 gr. of dried PEG 600 were addded to the macrodiisocyanate, corresponding to a 2:1 molar ratio. The reaction took place under the same conditions as described in step 2.
4. Addition of HDI
1.14 gr. of HDI, corresponding to a 2:1 molar ratio in relation with the triblock, including an excess of 7% were added (+1 ml of chloroform, used to quantitatively add the HDI and catalyst) and reacted for an hour as described before.
The material exhibited a translucid white color. The triblock showed a glass transition temperature of −39° C., the average number of LA units being 5.2, as determined by NMR.
It is to be understood that the examples and embodiments described hereinabove are for the purposes of providing a description of thepresent invention by way of example and are not to be viewed as limiting the present invention in any way. Various modifications or changes that may be made to that described hereinabove by those of ordinary skill in the art are also contemplated by the present invention and are to be included within the spirit and purview of this application and the following claims. | The present invention relates to novel bioabsorbable polymeric compositions based upon AB polyester polyether or related diblocks and triblocks. Compositions according to the present invention may be used in medical applications, for example, for reducing or preventing adhesion formation subsequent to medical procedures such as surgery, for producing surgical articles including stents and grafts, as coatings, sealants, lubricants, as transient barriers in the body, for materials which control the release of bioactive agents in the body, for wound and bum dressings and producing biodegradable articles, among numerous others. | 2 |
BACKGROUND OF THE INVENTION
1. Field of Art
The invention relates to a method for the operation of a combustion device, in which liquid hydrocarbons are mixed with primary air and the mixture is conducted into a reaction chamber where it is contacted with shaped metal bodies and subjected to elevated temperature to convert the mixture into a soot-free fuel gas mixture containing carbon monoxide, hydrogen and gaseous hydrocarbons which is mixed with secondary air and fed into the combustion device.
2. Prior Art
In the combustion of liquid fuels in combustion devices such as burners or internal-combustion engines, uneven mixing and combustion of the fuel with the air leads to high emission of harmful substances in the exhaust gas. If these fuels contain lead, or aromatics, these substances which are injurious to health are also contained in the exhaust gas. It is known that the emission of harmful substances can be lowered if the combustion device is preceded by a gas generator in which the fuels are reacted with primary air under heavy air deficiency forming a fuel gas. Such a procedure is described, in detail in U.S. Pat. No. 3,828,736 in which liquid hydrocarbons are gasified, and the resulting gasified hydrocarbons are mixed with air. The resultant hydrocarbon/air mixture is conducted over nickel sponge or platinum catalyst arranged in the reaction chamber.
Unleaded straight-run gasoline with a low octane number can be used and can also be converted into a fuel gas with a high octane number. Using the procedure of U.S. Pat. No. 3,828,736 the fuel gas so formed can be burned in the internal combustion engine with excess air, in which the formation of nitrogen oxides, and the emission of carbon monoxide and other products of an arrested combustion are largely avoided.
A number of catalytically active fillings for the reaction chamber of reformed-gas generators have also been developed which make possible a soot-free reaction of hydrocarbons with air under heavy air deficiency. These fillings usually consist of a ceramic carrier material which contains a particular aluminum oxide. This aluminum oxide is preferably present in thermally unstable catalytically active modifications since the thermally stable α-Al 2 O 3 only has very little catalytic activity for the partial oxidation. Accordingly, the unstable modification effectively aids the activity of the catalytically active components of the fillings which are usually metal oxides.
It is extremely advantageous to be able to use small amounts of primary air without formation of soot. However, in such situations, known nickel or nickel-containing metal alloys favor the formation of soot. This leads to disturbances in the operation of the combustion device and to contamination of the catalyst which reduces its effectiveness. Also, the catalyst systems described above with ceramic carrier matter cannot suppress soot formation reliably unless the fuel is carefully evaporated before entering the hot reactor. The operation of such known reformed-gas generators requires careful control of the air number since the reaction temperature in the gas generator rises if the amounts of primary air are too large, and the thermally unstable catalysts are damaged. Another disadvantage is that many known catalysts which are used in the prior art processes are sensitive to the use of sulphur-containing fuels. A further disadvantage is that use of the known catalysts required careful control of the process in order to maintain the optimum operating temperature. This is because the known catalysts have relatively low thermal conductivities and, therefore, the danger of uneven temperature distribution and, incomplete conversion in the reaction chamber exists.
It is therefore an object of this invention to provide an improved method for the soot-free conversion of liquid hydrocarbons into a fuel gas which contains carbon-monoxide, hydrogen and gaseous hydrocarbons.
It is another object of this invention to provide an improved method which requires minimum outside control.
It is still another object of this invention to provide an improved method in which sulfur containing hydrocarbons can be used without the possibility of contaminating the environment.
Still other objects and advantages of the present invention will be obvious and apparent to those of skill in the art from the specifications and the appended claims.
SUMMARY OF THE INVENTION
These and other objects which are apparent to those of skill in the art from a consideration of the specification and appended claims are achieved by the method of the present invention. This invention is directed to a method of operating combustion devices which comprises:
mixing liquid hydrocarbons with air;
conducting said hydrocarbons/air mixture to a reaction chamber wherein said mixture is contacted with one or more shaped metal bodies composed of an aluminum alloy which contains from about 15 to about 35 weight percent silicon at elevated temperatures, thereby converting said mixture into a soot-free fuel gas mixture containing carbon monoxide, gaseous hydrocarbons and hydrogen;
mixing said soot-free fuel gas mixture with more air to form a fuel gas/air mixture
conducting said fuel gas/air mixture to a combustion device.
In the initial step of the method of this invention, liquid hydrocarbons are mixed with air. This air is hereinafter referred to as "primary air". The amount of primary air used is from about 5 to about 30 percent of the quantity of air required for the stoichiometric combustion of the hydrocarbons in the mixture.
In the second step of the method of this invention, the liquid hydrocarbon/primary air mixture is contacted with one or more shaped metal bodies at an elevated temperature. These bodies are composed of an aluminum alloy which contains silicon. The contacting step converts the mixture into a soot-free fuel gas mixture of carbon monoxide, hydrogen and gaseous hydrocarbon. As used herein gaseous hydrocarbons are those hydrocarbons which are gaseous under normal conditions. Representative of such hydrocarbons are those which include from 3 to 4 carbon atoms per molecule.
The aluminum alloy contains from about 15 to about 35 weight percent silicon. In the preferred embodiments of this invention, the aluminum alloy includes from about 20 to about 25% by weight of silicon. In the preferred embodiment of this invention, metal bodies of Al/Si eutectic are used with a primary phase of silicon distributed therein.
The shaped metal bodies can be comminuted fragments of an AlSi casting. Such AlSi castings are known, as for example as the material of which the housing of reciprocating engines are constructed. These materials are commercially available. The shaped metal bodies can also be made by preparing an alloy powder and molding it into the metal bodies. During the operation of the method of this invention, the shaped metal bodies are subjected at elevated temperatures, preferably at a temperature of between 600° and 800° C., to a stream of gas which contains air (oxygen) and gaseous or gasified hydrocarbons. This procedure which results in the formation of carbon monoxide, carbon dioxide and hydrogen, also results in the catalytic activity of the shaped bodies.
Thus, during the first hours of operation of the method of this invention, a heat treatment of the metal bodies takes place, which leads to structural changes and which leads to the formation of catalytic properties of the shaped bodies. During the first hours of operation it is preferable to choose the air numbers so that during the heat treatment, the ratio of the number of carbon atoms in the hydrocarbon to the number of oxygen molecules in the air is between 2 and 8, and preferably between 4 and 6.5. In this manner, from about 5% to about 30% by weight of the aluminum present in the shaped metal bodies is converted to α-Al 2 O 3 , and from about 1% to about 10% of the silicon present in the shaped metal bodies is converted into β-SiC, during the first hours of operation.
The shaped bodies used in the method of this invention can also be subjected to such a heat treatment before the reactor is placed into operation. For example, they can be treated before they are placed into the reaction chamber. When pre-treated the shaped bodies are subjected for at least about 10 hours to an elevated temperature of between 600° and 800° C. in the presence of an oxidizing atmosphere which leads to the formation of the earlier noted amount of α-Al 2 O 3 and, in the presence of a hydrocarbon-containing atmosphere which leads to the formation of the earlier noted amount β-SiC. Both steps can be performed simultaneously by treatment for at least about 10 hours in an appropriate gas stream e.g., containing air and hydrocarbon or sequentially, i.e., in separate atmospheres.
These metal bodies exhibit high thermal conductivity. Temperature differences in the reaction chamber are therefore largely and automatically equalized. The bodies are insensitive to temperature fluctuations and exhibit stable catalytic activity after air break-in. While a very slight amount of soot formation can be detected during the first hours of operation, this soot formation is so small that no visible soot is produced and the catalytic activity is not impaired. If sulfur-containing fuels are used, part of the sulfur is absorbed on the metal bodies during the first hours of operation, but the absorbed amount of sulfur does not increase during the extended periods of operation, and does not lead to an impairment of the process. This makes it possible to operate domestic and industrial burners with nondesulfurized heating oils. The use of light as well as the use of heavy heating oil is also possible. It is also possible to operate internal combustion engines, for example a motor vehicle, with straight-run gasoline or diesel oil through use of the method of this invention. By pre-gasifying the fuel according to the invention, the emission of harmful substances of internal-combustion engines can be lowered substantially. Also, when operating domestic burners, the possibility exists that burners which are designed for a higher maximum output can be operated and controlled continuously with low throughputs, if the demand for heat is lower.
An important advantage of the claimed invention is that it is possible to work with small amounts of primary air to convert the liquid hydrocarbon into soot-free fuel gas. For example, air numbers of from about 0.05 to about 0.3 can be used. In the preferred embodiments air numbers of from about 0.09 to 0.1 are used. Using small amounts of air has the advantage of resulting in minimal energy loss during the gasification step. The combustion in the combustion device can likewise take place with relatively small air numbers. The air employed in the combustion step, is hereafter referred to as "secondary air." Thus, the total amount of air in the method according to this invention for both the gasification and combustion steps can be limited to air numbers between 1 and 1.2 which is slightly over stoichiometric. Smaller amounts of air, preferably having air numbers between 1 and 1.07 can also be used in the gasification and combustion steps.
In the case of motor vehicle engines, this means that no unnecessary excess air is driven through the engine as ballast in the combustion mixture yet the leaning-out is still sufficient to prevent emission of unburned harmful substances. In addition, small amounts of air do not cause misfiring or sluggishness if load changes occur. The low air numbers also allow for high combustion temperatures in domestic and industrial burners. The chief advantages are increased heat, and that no appreciable emissions of nitrogen oxides or sulfur oxides are observed at these high temperatures even when sulfur-containing fuels are used.
Through the heat treatment, preferably from 5 to 30% of the aluminum present is converted into Al 2 O 3 , and preferably from 1 to 10% of the silicon present is converted into β-SiC. A small percentage of the silicon, not detectable in the polished section, is also converted into silicon nitride. Various other components, silicon oxides, aluminum carbides, aluminum silicates, aluminum silicon carbides and sulfur compounds which are formed by heat treatment are also not detectable.
The formation of Al 2 O 3 and SiC is accompanied by an increase in weight, which can be explained to a certain extent by an initial formation of traces of soot. The quantity of soot can be determined by burning off, however, it is not visible because it is deposited in voids of the material. The soot content is less than about 3% by weight of the total weight of the catalyst. After long periods of operation (more than 2,000 hours) practically no further increase in weight and no further formation of soot could be observed. If sulfur-containing hydrocarbons are used, a certain amount of sulfur absorption analogous to the soot formation is observed. However, sulfur absorption does not cause an impairment of catalytic activity and does not exceed a very low threshold value even over extended periods of operation.
Surprisingly no substantial increases in the activity is achieved by increasing the porosity (surface) of the shaped catalytic bodies. Therefore, to obtain high activity, it is not necessary to increase the surface of catalysts which have been prepared by comminution of a casting by special manufacturing steps beyond the value occurring naturally in the manufacture of the castings. The surface area is normally in the range of 0.03 to 0.2 m 2 /g. The high activity of the catalyst according to the invention is highly surprising since known catalysts of Al 2 O 3 or aluminum silicon ceramics exhibit no appreciable activity and are normally used only as carriers for other catalytically active components.
An AlSi alloy would also be expected to be unsuitable as a catalyst for the above indicated reaction, since the melting point of the eutectic is low and the reaction temperature high and, therefore, this catalyst should be particularly temperature-sensitive. However, contrary to this expectation, it has been observed that the catalyst withstands at least short temperature increases without damage and that high reaction rates can be obtained at temperatures of about 600° to 800° C., while the reaction temperatures for known catalysts are usually at least 50° C. higher.
The catalyst according to the invention is further distinguished from known catalysts by the fact that the CO 2 - and H 2 O-content in the product fuel gas can be kept relatively low. This is caused by the fact that the catalyst is particularly rugged with respect to soot formation and requires no measures for preventing soot. This indicates that mainly endothermic processes are being catalyzed. As taught in British Pat. No. 1,517,129, exothermic processes start at lower operating temperatures in the catalytic oxidation of hydrocarbons with air deficiency. These processes lead to a first splitting of the hydrocarbons and have a large amount of reaction heat. At higher reaction temperatures endothermic secondary reactions set in and can be recognized by a decrease in the reaction heat. Upon a further increase of the reaction temperature, endothermic processes set in again which eventually lead to the complete decomposition of the hydrocarbons and to an approximation of the thermodynamic equilibrium (formation of H 2 O, CO 2 and soot). When using the catalyst according to this invention, the endothermic reactions are initiated at low operating temperatures. This causes a particularly effective suppression of soot formation, and low content of CO 2 and H 2 O are observed. Such oxidation end products as may have been produced can be used up again, in some circumstances. The catalyst is, therefore, also largely insensitive to contact with liquid fuel droplets.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments of this invention, and the preferred uses thereof, will be described in greater detail in conjunction with the accompanying diagrammatic representations. It should be understood that the means of carrying out the preferred embodiments exemplified by the figures are not limiting, but rather illustrative and representative of many other embodiments and uses which fall within the spirit of the invention, and that various modifications of the following constructive and operational detail apparent to a person of skill in the art, are within the scope of this invention.
FIG. 1 is a schematic diagram of a device for reacting liquid hydrocarbons with air, and for operating a combustion device with the fuel gas produced.
FIG. 2 is a micro-polished section of an Al-Si shaped body perpendicular to the edge of the Al-Si shaped body, before the shaped body is subjected to a hydrocarbon/air gas stream.
FIG. 3 is an enlarged section of FIG. 2.
FIG. 4 is an embodiment similar to FIG. 2 after the shaped body was exposed to the hydrocarbon/air gas stream.
FIG. 5 is a graph of the composition of the fuel gas produced as a function of the reaction temperature.
FIG. 6 is a graph of the composition of the fuel gas produced as a function of the loading of the catalyst.
FIG. 7 is a graph showing the conversion obtained as a function of the operating time for long-time operation.
FIG. 8 is a graph showing the deposited quantity of soot as a function of the operating time for long-time operation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The metal bodies 1 of the catalyst of this invention for converting the hydrocarbons are arranged in the reaction chamber 2 of a gas generator 3. For example, bodies 1 can be in the form of a bed which is held together by perforated plates 4. The gas generator 3 used here for test purposes, has relatively large and thick walls and a small bed volume and, therefore, has heat losses so high that the reaction temperature necessary for conversion can only be maintained by external heating of the reaction chamber 2. This external heating is provided by heating jacket 5 which in this embodiment is heated electrically by means of a control device 7 which is controlled by a temperature sensor 6 arranged in the reaction chamber 2. The entrance of the reaction chamber 2 is preceded by a mixing chamber 8 into which lead feed lines 9 and 10 for hydrocarbon and air. These feed lines 9 and 10 contain metering valves 11 for adjusting the hydrocarbon throughput and the air numbers. Feed lines 9 and 10 also include heating devices 12, for instance, heat exchangers, for preheating the reaction gases. The fuel gas produced can be taken and analyzed from the outlet line 13 of the gas generator 3 either via a test line 14, or the fuel gas is mixed with combustion air introduced by way of secondary air line 15 and the resultant mixture taken to combustion device 16. In this embodiment, the combustion device serves as a domestic burner. However, it should be appreciated that the combustion device can be an internal combustion engine, for instance, a motor vehicle engine or a gas turbine.
To produce the metal bodies 1, a commercially available casting of an aluminum silicon alloy is broken into fragments of about 5 mm diameter. The starting material designated by the manufacturer as "aluminum silicide" exhibits in the analysis, besides aluminum, 22% by weight of silicon, 0.1% by weight of titanium, 0.1% by weight of vanadium and 0.1% by weight of nickel. Aluminum and silicon are present as a eutectic with a Si primary phase, as far as can be determined by the analysis. For the aluminum, the lattice constant was determined within the error limits as the lattice constant of pure aluminum. Only a very small Si-content is therefore dissolved in the Al phase. Such an alloy is obtained, for instance, by slow cooling of a melt of the two components. The pore volume of the fragments was 0.05 to 0.15 ml/g; pores from a diameter of 8 nm on were included. The mean pore radius was 10 nm and the surface 0.1 m 2 /g.
From the same starting material, fragments of different Si contents and exhibiting other porosities were produced, for example, by dissolving part of the aluminum from the structure. Also, an alloy powder was made by milling the fragments. The fragments were mixed with 2 weight percent graphite as a plasticizing lubricant and cold pressed in tabletting press at a pressure of 750 kg/cm 2 . Such pellets have a considerably higher porosity but exhibit substantially the same catalytic behavior as the first-mentioned fragments to which the results described in the following refer.
A mixture of heating oil and air is introduced over the first mentioned fragments in the reactor. For a long-term test, heating oil "extra light", density 0.85, C-content 85.7 weight %, was used. However, medium or heavier heating oil having a density of 0.92 or 0.98, and a carbon content of 85.3 and 84.9 weight %, respectively, can also be used. Such medium or heavier heating oil can be used for operating a burner. Also, cracking of unleaded "straight run" gasoline was carried out successfully in the operation of an internal combustion engine connected thereto.
The heating oil was pre-heated to about 415° C., and the air number of the mixture was set to 0.09±0.01. The loading of the reactor charge was 12 liters of heating oil per liter of bed volume and hour.
Before the reactor was started up for the first time, a sample of the metal bodies was taken and examined by X-rays, analytically and in the micro by means of the microprobe and a light microscope. FIGS. 2 and 3 show the findings of the light microscope.
From FIGS. 2 and 3, it is apparent that in front of the dark background 20, isolated cracks and pores 21 can be seen. The main mass consists of the bright phase 22 of the largely aluminum-containing eutectic. Embedded therein are needle or beam-shaped crystals 23 which are the primary phase of the silicon. FIGS. 2 and 3 also show as an impurity, a light-gray iron phase 24, the composition of which corresponds approximately to the intermetallic body compound Al 9 Fe 2 Si 2 and which also contains small amounts of Mn and Ni. The Mn and Ni impurities, were also determined analytically in extremely small amounts in the other zones of the material.
After 12 hours in the reactor, another sample of the metal bodies was taken and analyzed in the aforementioned manner, by light microscope. FIG. 4 indicates the findings. FIG. 4 shows a distinctly bright, largely aluminum-containing phase 22, and the embedded, gray Si-phase 23. In addition, very fine-grained zones 26 are observed which contain oxygen. It turns out that this is a very fine-grained Al 2 O 3 phase with occlusions of different components, mainly aluminum and silicon. Particularly in the outer zones of the particles, medium-gray small precipitates 27 were also observed which were identified as SiC. The catalyst is now formed for long-term operation.
Further investigations after 200 to 2000 operating hours show that with increasing operating periods, during which the activity of the catalyst no longer changes appreciably, the formation of Al 2 O 3 -containing zones is gradually increased. The structure of these zones is very inhomogeneous. The Al 2 O 3 is partially present in nearly pure alpha-form. Frequently it is permeated by different structure components in extremely fine distribution. Si and SiC containing as well as heavily Al-containing structure components occur. In addition, also the heavily Al-containing eutectic particles are surrounded by a dark-gray Al 2 O 3 -containing layer. In between, there are particles which consist predominantly of Si and contain dark-gray Al 2 O 3 precipitates as well as medium-gray β-SiC precipitates. Agglomerations of these precipitates occur particularly in the outer zones of the particles and along the cracks and pores. With increasing operating time, the size of the SiC precipitates seems to grow very slowly. It was further determined that small amounts of sulfur are accumulated in the pores within an oxidic outer zone as well as in the pores in the interior of the particles.
In principle the same results were obtained also when n-heptane and diesel oils were used.
Several times, excess air got into the reaction chamber due to a disturbance in the operation. Although an air break-in is accompanied by temperatures which are considerably above the melting point of the eutectic, it was surprising that for all practical purposes no sintering-together or other changes of the catalyst structure were observed. Only slightly rounded zones due to melting and solidification were found at the surface. Apparently the Al 2 O 3 and SiC formed give increased structural stability to the metal bodies, like a highly heat-resistant matrix.
In FIG. 5, the gas composition is given as a function of the reaction temperature if heating oil "extra light" is reacted in the reaction chamber with a loading of 12 liters per liter of bed volume per hour and with air numbers around 0.09. The gas contents are given in volume %, based on the gas volume produced (excluding condensable, unreacted hydro-carbon residues). The remainder is nitrogen.
An increasing percentage of the oxygen of the added air is used up in forming carbon monoxide, and the conversion increases with increasing reaction temperature. Only a small amount of CO 2 is produced. In addition to hydrogen, methane as well as C 2 and C 3 -containing hydrocarbons are generated. A component designated with C 4 + which is not differentiated with respect to its hydrogen content was also generated. It is worthy of note that no generation of acetylene was observed which is unstable at these temperatures and would decompose, forming soot.
In FIG. 6, the gas composition is given as a function of through-put. The reaction temperature was maintained at a constant 750° C. and various catalyst loadings are set. FIG. 6 shows that the rate of conversion decreases with increasing through-put. This can be recognized from the decrease of the CO-content and the increase of non-spent oxygen in the gas mixture produced. In this gas mixture part of the liquid hydrocarbons present is in the form of fuel which is not reacted or only partially reacted, and is merely evaporated, yet it is still suited for most applications at such high catalyst loadings as 18 liter/1. hr.
In FIG. 7, the percentage of the liquid fuel which was converted into low molecular weight hydro-carbons, which are gaseous under normal conditions, is shown as a function of the operating hours. The air number was approximately 0.09, the catalyst load 12 l/1 hr. and the catalyst temperature 750° C. First, the untreated metal bodies, not subjected to a hydrocarbon air stream, were put into the reactor. After the first 12 operating hours, the catalyst has been formed into the structure shown in FIG. 4. After initial fluctuations, a conversion degree of about 70% is obtained. The aforementioned air break-ins into the catalyst are designated by the arrows 60. In the first air break-in, the degree of conversion remains practically constant. After the second air break-in, a temporary decrease to about 60% is apparent which, however, is followed by a slow rise to the previous value. These curves contain innumerable on and off switching actions of the installation. For switching off, no particular measures had to be taken to protect the catalyst while it was cooling off slowly, from inflowing air. Starting-up the reaction charge was accomplished by electrically evaporating the heating oil and heating it to a maximum of 415° C. This was accomplished by switching on the external heater of the reactor and additionally pre-heating the evaporating air electrically to 560° C. After at most 8 minutes, it was possible to turn off the heating of the evaporating air, since the heating power of the external reactor heating was sufficient to maintain a stable reaction temperature of 750° C. This relatively long starting time can be shortened for instance, by increasing the air number and carrying out in the reactor more exothermic reactions with correspondingly higher heats of reaction. In order to test the suitability of Al-Si metal bodies for the conversion at small air numbers, such additional measures were dispensed with.
As was already mentioned, the formation of small amounts of soot at the catalyst can be shown. FIG. 8 shows the amount of soot deposited at the catalyst in weight % based on the weight of the metal bodies prior to use. As can be seen from FIG. 8, even after 2000 operating hours, the soot formation was less than 3%. The soot is not visible, but presumably deposited in the pores. Parallel with the soot formation, a slight absorption of sulfur in the pores of the metal bodies was observed. However, neither soot nor sulfur impaired the activity of the catalyst. The catalyst can be used with fuels having a higher sulfur content. No formation of SO 3 or other detrimental sulfur oxides occurred either in the fuel gas or in the exhaust gas of the combustion device fed with the fuel gas. | A method for the operation of combustion devices such as burners and internal-combustion engines, in which liquid hydrocarbon such as straight-run gasoline, heating oil and diesel fuel, are mixed with gasification primary air, and the resulting mixture is conducted into a reaction chamber containing metal bodies composed of an Al-Si eutectic with a primary phase of form about 15 to about 35 weight percent of silicon distributed therein, and in which from about 5 to about 30 weight percent of the aluminum is in the form of α-Al 2 O 3 , and in which from about 1 to about 10 weight percent of the silicon is in the form of β-SiC, where the liquid hydrocarbon is partially oxidized at elevated temperatures into a soot-free fuel gas mixture containing carbon monoxide, hydrogen and gaseous hydrocarbons, and the fuel gas mixture is mixed with secondary air and the fuel gas/secondary air mixture is conducted into the combustion device. | 2 |
FIELD OF THE INVENTION
The invention relates to a substrate for an electronic circuit.
The invention further relates to an electronic circuit.
BACKGROUND OF THE INVENTION
Many semiconductor devices of electronic circuits or integrated circuits are housed or cast into plastic or resin in order to protect the semiconductor devices against environmental influences like humidity or dirt. An upper surface of a semiconductor crystal, e.g. silicon or another semiconducting material like germanium, gallium-arsenic or gallium-nitrogen, supports a number of structured thin layers, in particular one or more electrically conductive layers or conductors comprising aluminium, aluminium-silicon, aluminium-silicon-copper or gold, and one or more electrically insulating layers or passivating layers. These semiconductor devices are generally produced on wafers and may be subsequently singularized, e.g. by sawing the wafer. The electrically insulating layers may consist of silicon-oxide, silicon-nitride, and silicon-oxide-nitride. Furthermore, the electrically conductive layers comprise so-called contact pads, which can be connected to external terminals or bond pads of the semiconductor device. In the course of the mounting of a semiconductor package comprising the semiconductor device the semiconductor device, called crystal or chip as well, is mounted on a carrier or carrier pad, and the bond pads and terminals of the package, e.g. a lead frame of the package, are electrically connected by bonding, e.g. by bondwires. Afterwards the package or chip is cast into a resin or plastic material which forms an envelope protecting the chip against humidity dirt or the like. The cast material also sticks to the thin conductive or non-conductive layers described above.
A possible connecting of the semiconductor devices, e.g. base and emitter areas or regions of a bipolar transistor, may be based on a mesh-like structure of conductor paths formed in such a way that contact areas or vias, which are connected to the semiconductor devices, are contacted by the conductor paths. These conductor paths are made of metallic material and are formed on the contact areas, contact pads or vias and are guided through dielectric areas formed as an insulating layer around the contact areas. The contact areas may be connected to respective semiconductor devices by using wires or conductor paths formed through vias.
However, the metal conductor paths in the known packages may separate or delaminate from the non-conductive layer formed around the contact areas. Such a separation may cause failure of the package and is thus a matter of present research. To decrease the probability of delamination variation of known deposition or structuring procedures are performed. For example, it is attempted to decrease the delamination probability by increasing etching temperatures of the non-conductive areas or by doping the structured non-conductive areas.
OBJECT AND SUMMARY OF THE INVENTION
It may be an object of the invention to provide a substrate having an alternative arrangement of conductor paths for active zones of the substrate, wherein the arrangement of the conductor paths may lead to a decreased probability of delamination or may ensure an improved performance of a semiconductor device or electronic circuit the substrate is used in.
In order to achieve the object defined above, a substrate for an electronic circuit and an electronic circuit, e.g. a semiconductor circuit or device, according to the independent claims are provided.
According to an exemplary embodiment of the invention a substrate for an electronic circuit is provided wherein the substrate comprises a plurality of contact areas, a plurality of dielectric areas, and a conductor path, wherein each of the plurality of contact areas is surrounded by a respective one of the dielectric areas, and wherein at least two of the contact areas are connected with each other by the conductor path. Furthermore, the conductor path is formed at the dielectric area in such a way that it completely covers the dielectric area. In particular, the conductor path may be formed by a metallic component and may form a path connecting the plurality of contact areas with each other.
According to an exemplary embodiment of the invention an electronic circuit is provided which comprises a substrate according to an exemplary embodiment of the invention and a plurality of semiconductor devices, wherein the semiconductor devices are electrically connected to the contact areas. In particular, at least some of the semiconductor devices are formed by transistors, in particular bipolar transistors. Furthermore, the dielectric areas may be formed by a base-emitter oxide.
In this application the term “contact areas” may particularly denote any kind of area or region on a substrate which may be adapted to electrically contact elements, e.g. transistors or the like, formed on the substrate. These contact areas may be formed by vias filled with electrically conductive material or may be formed by so-called contact pads.
In this application the term “completely cover” may particularly denote the fact that a layer, e.g. the conductor path, may be arranged in such a way on a layer underneath that the conductor path forms a blanket or covering layer on the underneath layer. For example, in case the lower layer has a circular form of a first diameter, the conductor path, which completely covers the lower layer, may have a width or a diameter which is at least the same size or greater than the first diameter. Thus, in a process the lower layer may be formed and in a step directly afterwards or after some intermediate steps the conductor path may be formed on the lower layer so that no part of the lower layer is exposed to the environment any more. It should be noted that “lower” is not meant in a restrictive sense and in particular not with respect to any specific reference system.
By providing a conductor path which completely covers contact areas and surrounding non-conductive areas, e.g. oxide layers used to passivate the contact areas, it may be possible to avoid so-called crossovers of the conductor paths and the non-conductive areas. That is, it may be possible to avoid intersections of these two layers which intersections may otherwise facilitate a delamination process or facilitate an underetching of the conductor path at the intersection areas or regions. Such underetching would possibly facilitate the formation of so-called necks, i.e. thinned portions of the conductor path. These necks may cause weakening of the structure in known semiconductor devices which may be avoided by using a substrate according to an exemplary embodiment having conductor paths which completely cover the underlying non-conductive area, e.g. an oxide used for structuring the substrate or passivating layers of the substrate. Thus, the use of a substrate according to an exemplary embodiment may provide for an electronic circuit or integrated circuit having an improved lifetime, performance and quality.
A substrate according to an exemplary embodiment may reduce the probability of occurrence of underetching or generating of necks in further processing steps of the substrate without implementing new, complex and costly new processing steps, like increased temperatures, ion doping, dry etching or the use of different masks. Furthermore, it may be possible to increase the performance of electronic circuits using such a substrate. Additionally, it may be possible to transfer higher current densities for a given conductor path width or a smaller width of the conductor path may be chosen for the same current density.
A gist of an exemplary aspect of the invention may be seen in providing a substrate, e.g. a semiconductor substrate, which may be used for an electronic circuit, e.g. an integrated circuit, wherein a crossover or intersection of a conductor path and non-conductive areas formed around contact areas to be connected by the conductor paths are avoided. This avoiding may be performed by entirely covering the non-conductive or dielectric areas by the conductor paths, e.g. metal conductor paths. Thus, it may be possible to avoid interfaces where conductor paths and non-conductive areas come in direct contact to environmental layers, i.e. a third area or layer.
Next, further exemplary embodiments of the substrate for an electronic circuit are described. However, these embodiments also apply to the electronic circuit.
According to another exemplary embodiment the
According to another exemplary embodiment of the substrate the contact areas are formed by contact vias. In particular, the dielectric areas may be formed circularly around the contact areas and may have a first diameter while the conductor path may comprise circularly portions having a second diameter which is greater than the first diameter. Moreover, the circularly portions of the conductor path may be formed on the dielectric areas. Thus, the dielectric areas or non-conductive areas may form a passivation layer around the contact areas. For example, the non-conductive areas may form an oxide, e.g. a silicon-oxide, silicon nitride or silicon-oxide-nitrogen, structuring a base-emitter of a bipolar-transistor.
According to another exemplary embodiment the substrate further comprises a plurality of conductor paths. In particular, the plurality of conductor paths may form a mesh-like structure or a line structure. The conductor paths may comprise or may be formed by metallic material, like aluminum, aluminum-silicon, aluminum-silicon-copper, gold other suitable metals. The conductor paths may be formed on a base surface of the substrate or may even be formed in vias leading from the base surface to an upper surface of the substrate on which upper surface semiconductor elements may be formed. Thus, the conductor paths may not only form layers connecting contact areas of a substrate with each other but may also form electrically contacting elements adapted to connect different layers or levels of an electronic package through a via or contact whole.
According to another exemplary embodiment of the substrate the conductor path comprises an elongated portion and a bulge portion, wherein the elongated portion is arranged between dielectric areas, and wherein the bulge portion is arranged over the dielectric area. In particular, the bulge portion or bulge area may form a substantially circular portion in case the non-conductive area is of a substantially circular shape as well. In general, the bulge portion may have a form or shape which is similar to the shape of the non-conductive area or passivation area. However, the size of the bulge area is chosen to be greater than the size of the passivation area so that it is possible that the bulge area completely covers the passivation area.
According to another exemplary embodiment of the substrate the bulge portion comprises circular segments corresponding to a first diameter, wherein the dielectric areas comprises circular segments corresponding to a second diameter, and wherein the second diameter is smaller than the first diameter. In particular, the bulge portions may have a substantially circular shape however at partitions the elongated portions and the bulge portions met each other the circular shape is deviated from.
According to another exemplary embodiment of the substrate a width of the elongated portion is adapted to an expected current flow through the conductor path. In particular, the width may be chosen smaller than in known substrates since according to the exemplary embodiment of the present invention the probability of weaknesses like necks or underetching is reduced. However, according to known structures these weaknesses are dealt with by providing conductor paths having a greater width than necessary for a given current. Thus, according to exemplary embodiments of the inventions it may be possible to reduce the width of the conductor paths in the elongated regions since the probability of occurrences of weaknesses is reduced.
According to another exemplary embodiment of the substrate the conductor path has a constant width along its extension. In particular, the width may be measured in a direction substantially perpendicular to a longitudinal extension of the conductor path. Moreover, the width may be constant along the whole extension or at least substantially along the whole extension. In particular, the conductor path may not comprise or may be free of bulge portions in which the width of the conductor path is increased or recess areas in which the width of the conductor path is decreased. Thus, a conductor path having a constant width may be provided, possibly leading to the fact that the manufacturing process of the conductor path may be simplified. However, it should be noted that the width of the conductor path is adapted to entirely cover the dielectric areas.
That is, the constant width of the conductor path may be greater than the width or diameter of the dielectric areas surrounding the contact areas.
According to another exemplary embodiment of the substrate the contact areas are formed by vias. In particular, the contact areas may be formed by conductive material used to fill the vias to provide an electrically conductive path through the substrate, e.g. for contacting a different level of an electronic package or for contacting electronic elements arranged on top of the substrate while the conductor paths are formed on the bottom or base of the substrate.
Summarizing, a gist of an exemplary aspect of the present invention may be seen in the provision of a mesh-like structured semiconductor circuit having metal conductor paths for concurrently contacting base contacts or contact areas of the semiconductor circuit. The conductor paths may be passed over the base contacts and may form electrical contacts for the base terminal of a bipolar transistor, wherein material of the conductor paths are also filled in the vias. The base contacts may be structured by two oxide layers, i.e. a so-called base-emitter oxide, which is formed annularly around the base contact, and a so-called contact oxide which provides in openings electrical contact of the metal conductor paths to active zones of the semiconductor circuit. For connecting the base contacts the conductor path crosses the base-emitter oxide which is formed around the base contact and which forms a step or stage. In known semiconductor circuits these steps formed by the base-emitter oxide introduce weaknesses since the adhesion between the conductor path and the base-emitter oxide is significantly reduced leading to underetching and neck formation when further processing is performed. According to the exemplary aspect of the invention this weaknesses are reduced by omitting the crossovers or intersection between the conductor paths and the base-emitter oxide by providing a conductor path having such a size that it totally covers the base-emitter oxide.
Thus, in general using periodic, especially mesh-like emitter structures, the device's performance, especially the current capability, the device's resistance and the noise properties can be significantly improved for bipolar semiconductor transistor devices. Metal conductor paths or lanes crossing the oxide edges at these periodic structures, as present in known substrates, are inherently undergoing severe adhesion problems at the oxide edges, which lead to metal underetching, especially the formation of metal grooves of the interconnection lanes. These grooves have severe impact on the device's performance and quality. By using a substrate according to exemplary embodiments of the invention having metal interconnection lanes around these base connection areas the crossing of metal lanes and oxides edges may be avoidable, which leads to higher device quality and performance and design flexibility.
The aspects and exemplary embodiments defined above and further aspects of the invention are apparent from the example of embodiment to be described hereinafter and are explained with reference to these examples of embodiment. It should be noted that features described in connection with one exemplary embodiment or exemplary aspect may be combined with other exemplary embodiments and other exemplary aspects.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited.
FIG. 1 schematically illustrates a base view of a mesh-like semiconductor circuit.
FIG. 2 shows a microscopic view of a known conductor path contacting a contact area.
FIG. 3 schematically illustrates a base view of a contacting area according to a first exemplary embodiment of the invention.
FIG. 4 schematically illustrates a base view of a contacting area according to a second exemplary embodiment of the invention.
FIG. 5 schematically illustrates a base view of a contacting area according to a third exemplary embodiment of the invention.
DESCRIPTION OF EMBODIMENTS
The illustration in the drawing is schematically. In different drawings, similar or identical elements are provided with similar or identical reference signs.
FIG. 1 shows a schematically base view of a substrate 100 for an array of mesh-structured bipolar-transistors. The mesh-structure comprises a plurality of conductor paths 101 , 102 and 103 formed by a metallic material. The conductor path 101 connects contact areas or contact vias 104 , 105 , 106 , for example. The contact areas 104 , 105 , and 106 are surrounded by the so-called base-emitter oxide 107 , 108 , 109 forming a layer surrounding the contact areas or base contacts. Furthermore, the substrate comprises so-called contact oxide layers 110 , 111 , 112 and 113 which forms a hull of the contact vias or into which the vias are formed. A difference between the so-called base-emitter oxide and the contact oxide may be seen in the fact that the contact oxide may be formed by material of the substrate itself, while the so-called base-emitter oxide is formed by an additional layer formed on the base side of the substrate. According to the structure shown in FIG. 1 the conductor paths does not cover the whole base-emitter oxides, i.e. a crossover between conductor paths and the base-emitter oxide is present, so that a weakness in form of a neck or underetching may be formed during further processing of the structure.
In FIG. 2 a microscopic image of a contact area of FIG. 1 is shown. In particular, FIG. 2A shows a substrate 200 comprising a conductor path 201 . Furthermore, a contact area 204 can be seen which is contacted by the conductor path 201 . Moreover, a base-emitter oxide 207 can be seen which is crossed or intersected by the conductor path 201 . As can be seen in the image depicted in FIG. 2A necks or lateral contractions and underetching 214 and 215 are formed in the regions the conductor path 201 is deposited onto the base-emitter oxide 207 . In particular, the necks are basically formed only in the regions and starting from the regions in which the conductor path 201 reaches the base-emitter oxide, i.e. at the step which is formed by the base-emitter oxide. FIG. 2B shows a detailed view of the underetching and neck 214 which is induced by a reduced adhesion of the metal of the conductor path 201 on the step of the base-emitter oxide.
FIG. 3 schematically illustrates a first exemplary embodiment of a substrate or structure for an electronic circuit. For sake of clarity only a region around a single via is depicted in FIG. 3 . However, a mesh-like structure as depicted in FIG. 1 is also possible for the substrate according to the first exemplary embodiment. In particular, FIG. 3 shows a conductor path 301 arranged on a contact oxide layer 310 . Furthermore, a contact area or 304 surrounded by a base-emitter oxide 307 is shown in FIG. 3 . The contact area may be adapted to be connectable to a bipolar transistor. In contrast to the conductor paths shown in FIG. 1 the conductor path 301 shown in FIG. 3 comprises an elongated portion 316 and a bulge portion 317 . The bulge portion 317 is substantially circular and has a diameter or width which is greater than the diameter of the base-emitter oxide 307 . Thus, no crossover is present between the conductor path 301 and the base-emitter oxide 307 but the base-emitter oxide 307 is completely covered by the conductor path 301 , in particular by the bulge portion of the conductor path 301 . However, it should be noted that the conductor path 301 lies completely in the region of the contact oxide layer 310 so that no crossover is provided between these two layers. Since no crossovers are provided and the step generated by the base-emitter oxide 307 is not intersected by the conductor path, the probability of generating necks or underetching in the further processing is reduced.
FIG. 4 schematically illustrates a second exemplary embodiment of a substrate or structure for an electronic circuit which is similar to the one shown in FIG. 3 . For sake of clarity only a region around a single via is depicted in FIG. 4 . However, a mesh-like structure as depicted in FIG. 1 is also possible for the substrate according to the second exemplary embodiment. In particular, FIG. 4 shows a conductor path 401 arranged on a contact oxide layer 410 . Furthermore, a contact area or 404 surrounded by a base-emitter oxide 407 is shown in FIG. 4 . In contrast to the conductor paths shown in FIG. 1 the conductor path 401 shown in FIG. 4 comprises an elongated portion 416 and a bulge portion 417 . The bulge portion 417 is substantially circular and has a diameter or width which is greater than the diameter of the base-emitter oxide 407 . Thus, no crossover is present between the conductor path 401 and the base-emitter oxide 407 but the base-emitter oxide 407 is completely covered by the conductor path 401 , in particular by the bulge portion of the conductor path 401 . However, compared to the elongated portion of the conductor path 301 in FIG. 3 the elongated portion 416 of the conductor path 401 and the contact oxide layer 410 has a reduced width indicated by the arrows 418 . The elongated portion 416 which forms the connection between contact areas or vias may have a smaller width than in known substrates since the probability of forming of necks is reduced so that the width may be adapted to a specific maximum current density in the conductor path. The maximum current density may be chosen so that electromigration is reduced to a suitable level. Thus, according to an embodiment of the invention it may be possible to produce substrates having conductor paths with smaller widths. The saved areas may be used to increase the contact areas or even the number of contact areas provided on a substrate having the same size. By increasing the size of the contact areas of a substrate it may be possible to increase the performance of an electronic circuit using the substrate. In particular, the current may be increased while the resistance may be decreased.
However, it should be noted that the conductor path 401 lies completely in the region of the contact oxide layer 410 so that no crossover is provided between these two layers. Since no crossovers are provided and the step generated by the base-emitter oxide 407 is not intersected by the conductor path, the probability of generating necks or underetching in the further processing is reduced.
FIG. 5 schematically illustrates a third exemplary embodiment of a substrate or structure for an electronic circuit which is similar to the one shown in FIG. 3 . For sake of clarity only a region around a single via is depicted in FIG. 5 . However, a mesh-like structure as depicted in FIG. 1 is also possible for the substrate according to the third exemplary embodiment. In particular, FIG. 5 shows a conductor path 501 arranged on a contact oxide layer 510 . Furthermore, a contact area or 504 surrounded by a base-emitter oxide 507 is shown in FIG. 5 . In contrast to the conductor paths shown in FIG. 3 the conductor path 501 shown in FIG. 5 comprises no elongated portion and no bulge portion. On contrast, the conductor path 501 has a constant width and is adapted in such a way that it is identical or greater than the diameter of the base-emitter oxide 507 . Thus, no crossover is present between the conductor path 501 and the base-emitter oxide 507 but the base-emitter oxide 507 is completely covered by the conductor path 501 . In particular, the manufacturing process for a substrate shown in FIG. 5 may be simplified due to the fact that the conductor path 501 has a constant width.
However, it should be noted that the conductor path 501 lies completely in the region of the contact oxide layer 510 so that no crossover is provided between these two layers. Since no crossovers are provided and the step generated by the base-emitter oxide 507 is not intersected by the conductor path, the probability of generating necks or underetching in the further processing is reduced.
Finally, it should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined by the appended claims. In the claims, any reference signs placed in parentheses shall not be construed as limiting the claims. The word “comprising” and “comprises”, and the like, does not exclude the presence of elements or steps other than those listed in any claim or the specification as a whole. The singular reference of an element does not exclude the plural reference of such elements and vice-versa. In a device claim enumerating several means, several of these means may be embodied by one and the same item. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. | A substrate for an electronic circuit is provided wherein the substrate comprises a plurality of contact areas ( 304 ), a plurality of dielectric areas ( 307 ), and a conductor path ( 301 ), wherein each of the plurality of contact areas is surrounded by a respective one of the dielectric areas, and wherein at least two of the contact areas are connected with each other by the conductor path. Furthermore, the conductor path is formed at the dielectric area in such a way that it completely covers the dielectric area. | 7 |
The present invention relates to a granular high surface area sorbent for reducing the formaldehyde content of an atmosphere.
Formaldehyde has been reported to be one of the five most commonly used chemicals and in 1980, 5.77 billion pounds of formaldehyde were produced in the United States. Formaldehyde is found in products ranging from antiperspirants to wood products, principally particle board and plywood.
Formaldehyde is known to be a strong irritant and sensitizer. Exposure to formaldehyde at even low levels causes irritation of the eyes, nose, and throat. Repeated or long-term exposure to formaldehyde has resulted in prolonged eye, nose and throat irritation, coughing, wheezing, diarrhea, nausea, vomiting, headaches, dizziness, lethargy, irritability, disturbed sleep, olfactory fatigue and skin irritation. Persons sensitized to formaldehyde and persons with hyperactive airways may respond even more severely upon exposure to formaldehyde.
Commercial products for formaldehyde filtration are currently available. One such material is used as the active agent for room air purification and comprises granules of activated alumina impregnated with potassium permanganate and is available as Purafil Chemisorbent from Purafil Inc. The use of this material for air purification has been described in U.S. Pat. No. 3,049,399. The preparation of granular alumina impregnated with solid oxidizing agent such as potassium permanganate is described in U.S. Pat. No. 3,226,332. While those granules are somewhat effective in filtering formaldehyde vapors from ambient air, they have been found to have a short service life. A similar material is available as Unisorb Air Purification Spheres from Tegal Scientific, Inc.
Another commercially available material comprises activated carbon granules impregnated with copper and chromium salts and is available from Barnebey-Cheney as Activated Carbon Type CI sorbent (6×10 mesh). This material also suffered from a short service life to formaldehyde vapor.
Still another commercially available sorbent material, which showed some effectiveness in filtering formaldehyde vapors, comprises activated carbon granules impregnated with copper and chrome salts and is available from the Norton Company as formaldehyde cartridge number N 7500-5 (12×30 mesh).
Prior workers have reported various reactions of formaldehyde with amines, related compounds, sulfonate salts and sulfonamide derivatives in solution. See for example, Walker, Formaldehyde, Third Edition, Reinhold Publishing Corporation, 1964, Kirk-Othmer Encyclopedia of Chemical Technology, Second Edition, Vol. 19, p. 244, Interscience, New York 1969; Wood, et al, Journal of the Society of Chemical Industry, 346T (1933); and Walder, U.S. Pat. No. 2,321,958. Reaction products having utility as flame retardants and surfactants have been reported. Thus see Vollmer, German Pat. No. 2,432,271, Chem. Abstr., 84:150755y and Orthmer et al., U.S. Pat. No. 2,243,437, Chem. Abstr., 35:5600, 2.
Resinous materials prepared by reaction of formaldehyde with amino or phenolic compounds in the presence of sulfonic acid or sulfamate salts are known from Mayer, German OS No. 1,908,094, Chem. Abstr. 73:99596r and Keller, South African Pat. No. 68-07,095, Chem. Abstr. 71:82046x.
Air cleaning applications of sulfonic acid solutions and extrudates of sulfamates with clay binders have also been reported by Koetting in German OS No. 2,226,955, Chem. Abstr. 80:73897j; and Suzuki et al in Japanese Kokai No. 73-102,077, Chem Abstr. 80:136987m. Suzuki et al report in Japanese Kokai No. 73-102,078, Chem. Abstr. 81:16333u that one such extrudate has activity against formaldehyde. See also U.S. Pat. No. 3,400,079.
Other agents such as urea are known which react with formaldehyde in solution and on clay supports. See Hayashi, Japanese Kokai, No. 78-09,709, Chem. Abstr. 88:157843s.
Sorbents for removal of formaldehyde in gaseous systems made by impregnation of activated charcoal with various ammonium or hydrazinium salts have been described by Japanese workers in Sugai, et al., Japanese Kokai No. 78-29292, Chem Abstr. 89:11487c, and Yoshino, Japanese Kokai No. 73-93,580, Chem. Abstr. 80:99785w.
Granular carbon impregnated with alkali metal cyanides are reported to remove formaldehyde from exhaust gases, Fukunaga, Japanese Kokai No. 74-21,111, Chem. Abstr., 81:25092s.
Certain molecular sieves are also reported to absorb formaldehyde, see Chachulski, et al., Chemik 18, 252-5 (1965) Chem. Abstr. 64:9279g.
Reported methods for reducing the emission of formaldehyde from plywood, treated fabrics and the like include treatment of the article with sulfite salts, Miwa, Japanese Kokai No. 74-66,804, Chem. Abstr., 82:32698t, urea, Hojo, Japanese Kokai No. 74-75,709, Chem. Abstr., 82:32704s or multivalent metal salts, Okifuji, Japanese Pat. No. 74-14,440, Chem. Abstr. 83:61555v. Wrappings made from paper impregnated with ammonium sulfamate is also reported to reduce emission of formaldehyde containing plywood, Miwa, Japanese Kokai, No. 74-124,207, Chem. Abstr. 83:12586x.
Aqueous solutions of the tertiary amine urotropine have been used to collect gaseous formaldehyde. See Fadeev, et al., USSR Pat. No. 189,825, Chem. Abstr. 67:108214v.
A polyol (trimethylolpropane) has been reported as enhancing the formaldehyde absorbing capacity of sodium sulfite solution by Ishida et al., Japanese Kokai No. 73-85,484, Chem. Abstr. 80:87100f.
It has been reported that 2-amino-1-naphthyl hydrogen sulfate and formaldehyde react on charcoal to yield 2-methylamino and 2-formamido-1-naphthyl hydrogen sulfate, the reaction occurring in water solution, by Boyland et al., Biochemical Journal, (1966) 99, p. 189 et seq.
SUMMARY OF THE INVENTION
The present invention relates to a granular high surface area sorbent material for removing formaldehyde from ambient air at room temperature. The formaldehyde content of the air is reduced by reaction of the formaldehyde with the granular high surface area solid support impregnated with a water soluble, essentially non-volatile primary or secondary amine with equivalent weight less than about 400 and bearing either zero or two carbonyl substituents attached directly to the amino nitrogen atom.
The granular sorbent material of this invention is formulated by immersing granular high surface area solid support material in an impregnating solution, removing the excess solution by filtration and drying in an air circulating oven. The resulting granular product is particularly useful as the active component of respirators, powered air purifiers, room air purifiers, ventilation filters, exhaust filters, process gas filters and the like to effectively remove formaldehyde from an ambient atmosphere.
DETAILED DESCRIPTION OF THE INVENTION
Formaldehyde is a reactive chemical species capable of undergoing polymerization, condensation, addition, oxidation and reduction reactions. Although the chemistry of formaldehyde has been extensively studied, effective formaldehyde sorbent filter media for use in respirators, air filters and the like are not well known. This situation exists in spite of the serious health effects produced by human exposure to formaldehyde gas and the widespread use of materials containing free formaldehyde.
Although many compounds are known to react with formaldehyde in solution, an understanding of these solution reactions is not sufficient to predict the utility of reactants in gas phase sorbents made by depositing the reactants on high surface area supports. For example, strong acids, phenol in acid solution, urea, and strong alkalis are known to react readily with formaldehyde in solution but do not react with gas phase formaldehyde when deposited on activated carbon.
Some amino compounds are known to form methylolamines on reaction with formaldehyde in solution. These products may undergo further reactions, either with additional formaldehyde or by self-reaction. It has now been discovered that certain of these amino compounds are capable of reacting with gas phase formaldehyde when the amino compounds are deposited on high surface area supports and that these impregnated high surface area supports are useful as sorbent filter media for formaldehyde.
To provide a basis for comparison of different reactants as impregnating agents, one specific granular high surface area support was chosen, Witco 965 activated carbon 12×20 mesh size. Activated carbon of this particle size is useful as sorbent filter media for organic vapor respirators, but the raw carbon has little capacity for formaldehyde. The candidate sorbents were prepared by immersion of the carbon in a solution of the agent, removing excess solution by filtration, and drying in an air circulating oven. These granular impregnated sorbents were loaded into air purifying respirator type filter beds and evaluated under conditions similar to those used for bench testing of chemical cartridge respirators as described in Federal Register Vol. 37, No. 59, Part II (1972). Although this document does not specify test conditions for formaldehyde respirators, it does define standard conditions of air flow, temperature and relative humidity for testing sorbents and respirators against other gases and vapors such as carbon tetrachloride, several acid gases, ammonia and methylamine. A challenge concentration of 100 ppm formaldehyde was chosen for the bench test. This challenge is 33 times the current established OSHA permissible exposure limit, 50 toimes the ACGIH recommended exposure limit and 100 times the NIOSH recommended exposure limit for workplaces. The Federal Register tests set forth above utilize challenge concentrations of 20-500 times the permissible exposure limit for NIOSH certification of chemical cartridge respirators for the gases and vapors noted above.
Approximately 195 cc of the candidate sorbent material was loaded into a filter bed with a cross-sectional area of 61 cm 2 and a depth of 3.2 cm. Air containing 100 ppm formaldehyde and 50% relative humidity at 32° C. was passed through the filter bed at a constant flow rate of 64 liters per minute. Formaldehyde vapor was generated by metering a dilute formalin solution into a heated vaporization chamber in the test air line. Concentration of formaldehyde in the challenge air and downstream from the filter was measured using a commercial formaldehyde in air monitor (CEA Model 555 available from CEA Instruments, Inc.). The initial formaldehyde concentration in air downstream from the filter was zero. Service life of the test sample was recorded in minutes required for the formaldehyde level in the effluent air to react 1 ppm.
The observed service life depends on the reactivity of the impregnating agent deposited on the high surface area support toward gas phase or weakly adsorbed formaldehyde. Reactivity in solution cannot be strictly related to reactivity on the solid support towards gas phase formaldehyde. In order to be classified as a practical sorbent, the reactivity of the deposited agent should be sufficient to significantly increase service life of the impregnated sorbent over the untreated solid support. For air purifying respirators, the sorbent filter should effectively reduce contaminant level in breathing air from a hazardous ambient level to zero. Respirator filter design may dictate the use of various different particle size sorbents. The observed service life will also depend on sorbent particle size, filter area, sorbent bed depth and the concentration of impregnating solution. For practical application, sorbent reactivity and respirator design should provide service life, as measured by the above bench test, of at least 90 minutes and preferably 120 minutes or more.
The invention will become more readily apparent from the following examples:
EXAMPLES 1-26
100 parts of activated carbon (Witco 965, 12×20 mesh from Witco Chemical Company) was added to 200 parts of an aqueous solution generally containing 20% by weight of the impregnating agent. After soaking for about sixty minutes, the excess solution (about 60% of the original 200 parts) was filtered from the solid particles and the moist carbon granules were dried in trays in an air circulating oven at 100°-110° C. until the remaining moisture content was 2% or less. Service life was determined by the bench test described above and reported in the table below.
______________________________________Example Impregnating Agent Service Life______________________________________1 Sulfamic acid sodium salt 2602 Taurine sodium salt 1953 N--methyl taurine sodium salt 1694 Sulfanilic acid sodium salt 154+5 Metanilic acid sodium salt 1546 β-Alanine sodium salt 120+7 p-Aminobenzoic acid sodium salt 120+8 2-Amino-1-butanol 120+9 Diethanol amine 120+10 Methane sulfonamide 120+11 6-Amino-1,3-naphthalene disulfonic 132 acid disodium salt12 Succinimide 120+13 10% p-Phenylene diamine (from 120+ methanol)14 Glutamic acid disodium salt 120+15 Acetamide <516 13% N--cyanoacetamide <517 Saccharine sodium salt <518 Urea <519 15% p-Dimethylamino benzoic acid <5 sodium salt20 10% Triethanol amine <521 Nitrilotriacetic acid trisodium salt <522 5% Triethylene diamine <523 2-Acrylamido-2-methylpropane sul- <5 fonic acid sodium salt24 Sulfamic acid <525 Glycine <526 Untreated carbon-control <5______________________________________
In addition to reactivity toward formaldehyde, practical utility requires that the impregnating amino compound have high solubility in water and either low vapor pressure or high affinity for the solid support. Water solubility is necessary because organic solvents are expensive, difficult to process and may compete with the impregnating amino compound for adsorption sites on the solid support. High support affinity is required because weakly adsorbed or volatile agents would be desorbed during use as air passes through the filter media resulting in loss of reactive capacity for formaldehyde and release of another material into the air. An equivalent weight of less than about 400 g/reactive amine group is also a practical limit on the impregnating agent to ensure adequate capacity for formaldehyde.
Amino compounds with polar or ionic substituent groups satisfy both of the above requirements. Compounds with substituent groups such as amino, hydroxyl or acid salts provide both high water solubility and low volatility as well as high reactivity toward formaldehyde gas in the adsorbed state. However, not all substituent groups show sufficiently high formaldehyde activity. For example, amino compounds with acidic substituents exist in a zwitterionic or internal salt form and the protonated amino group of this form is not reactive toward formaldehyde (Examples 24 and 25). However, the acid neutralized salt forms of both sulfonic and carboxylic acid substituted amino compounds are useful (Examples 1-7, and 11).
Hydroxyl and amino substituents also are useful (Examples 8, 9 and 13). The reactive amino site may be either primary or secondary (Examples 1-9, and 11) but not tertiary (Examples 19-22). Single carbonyl substitution at the nitrogen atom to form amides (Examples 15, 16, 18 and 23) inhibits activity but double carbonyl substitution promotes reactivity (Example 12). Also, sulfonyl substitution at the nitrogen atom to form sulfonamides (Example 10) promotes reactivity.
Untreated activated carbon tested against formaldehyde using the respirator bench test had very poor service life (Example 26).
EXAMPLES 27-30
Sorbents were prepared as in Example 1 except that the concentration of the sodium sulfamate impregnating agent was varied from 5% to 40%. Service life was tested as described earlier. Results given below show that service life increases with the amount of sodium sulfamate deposited on the activated carbon and that sodium sulfamate is effective even at low levels.
______________________________________Example Sodium Sulfamate Concentration Service Life______________________________________27 5% 80 min.28 10% 127 1 20% 26029 30% 34330 40% 575______________________________________
EXAMPLES 31-32
Sorbents were prepared using 20% sodium sulfamate as in Example 1 using different high surface area solids in place of activated carbon. Silica gel dessicant from Davison Chemical was 6×12 inch. Activated alumina (F-1 from Alcoa) was 8×14 mesh. Results of service life tests show the effectiveness of sodium sulfamate on these solid supports.
______________________________________Example Solid Support Service Life______________________________________31 Silica Gel 231 min.32 Activated Alumina 175 min.______________________________________
EXAMPLE 33
100 parts of activated carbon (Witco 965, 12×20 mesh) was added to 200 parts of a solution containing 10% phenol and 2% sulfuric acid; after 60 minutes the excess solution was filtered off and the sorbent dried until moisture content was less than 2%. Service life of the sorbent tested as described in previous examples was less than 5 minutes. | Granular sorbent material comprising a granular high surface area support impregnated with a water soluble, essentially non-volatile primary or secondary amine with equivalent weight less than about 400 and bearing either zero or two carbonyl substituents attached directly to the amino nitrogen atom is disclosed. The resulting material can be used as the filtration media in respirators, powered air purifiers, room air purifiers, ventilation filters, exhaust filters, process gas filters and the like to reduce the formaldehyde content of air. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/576,908, filed Dec. 16, 2011. The disclosure of the foregoing United States patent application is specifically incorporated by reference herein in its entirety for all purposes.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates, in general, to methods and systems of communication networks, especially methods for efficiently transmitting medium access control (MAC) header data by devices of the network. More particularly, the invention relates to (but is not limited to) wireless communication networks operating in the Sub-1 GHz band, especially networks using the emerging IEEE standard 802.11 ah.
[0004] 2. Relevant Background.
[0005] Many types of communication networks, both wired and wireless, transmit and receive packets of data by organizing transmitted signals into frames for coordination, synchronization and relaying of the transmissions. Ethernet is an example of a wired protocol for such signaling; examples of wireless networks include systems using the 802.11 protocols. One advantage to frames is to allow multiple devices to access to the same physical medium. But a disadvantage is that extra information, such as intended recipient, frame type, etc., must also be transmitted with the desired end user data in order to accomplish the coordination, synchronization and relaying. In many cases, such as with Ethernet and current 802.11 systems, this overhead information imposes a relatively light burden because data carrying frames often carry quite a bit of data, and the system uses a high proportion of such data carrying frames.
[0006] But in some systems which transmit relatively small amounts of data, on a less frequent basis, on channels (wired or wireless) with limited bandwidth, the overhead information can impose a large burden. An example of such a system is a wireless sensor network, with a large number of sensors. An IEEE 802.11 BSS or Wi-Fi system typically has a central device to communicate with perhaps tens of nearby users, each needing large data volumes (e.g., for viewing video, web pages, etc.) over time periods of seconds or less. In contrast, a sensor network could have hundreds, perhaps thousands, of widely dispersed sensors, each needing to send or receive small amounts of data to a central device, within time periods of minutes or even days. The amount overhead information needed to be sent with each frame, just for correct addressing of so many users, could seriously degrade the sensor network's capabilities.
[0007] To address this problem, as well as for efficient use of the radio spectrum, the Institute of Electrical and Electronic Engineers (IEEE) created Task Group ah (TGah) to develop standards so that wireless networks can transmit in a frequency band of 902 MHz to 928 MHz, called the Sub-1 GHz band. An advantage of this band is that greater range can be achieved. Also, there is typically less interference from intervening objects.
[0008] A third advantage of the Sub-1 GHz band is that no legacy systems with different protocols need to be accommodated. So communication systems and devices for this band can be designed to optimize overhead efficiency, rather than to optimize interoperability. In particular, the overhead information included in a transmitted frame can be reduced. In frame-based communication systems, the actual data packet to be transmitted to the receiving station and end user, called the payload, is included with other needed information, called header data. The header data allows the radio receiver to find the start of the frame, to determine the addressee of the payload, to check for errors, and to perform other system operations. Current standard communication protocols specify how the frames are to be structured into fields, which are often further structured with subfields. Also, for effective coordination of the system, some frames are designed only to send information for control and coordination of the transmissions, such as scheduling of transmission times by the various system devices. For example, in the 802.11 standards, there are three types of frames: control, data and management. The detailed terminology of frames and frame-based communications are specified in the standard IEEE 802.11-2012. The standard is cited as a reference for terminology and background information about frame transmission, and does not imply that the communication networks of this disclosure necessarily use the physical wireless transmission methods described therein.
[0009] FIG. 1 shows standard arrangements of data and management frames known from the IEEE 802.11a/b/g/n standards. In a data frame, the header consists of up to ten fields with a total size of 36+4 octets (or bytes). The Frame Control field conveys information on signaling and the type of frame being sent. Typically three MAC address fields, and sometimes four, are needed to distinguish the source device of the data, the data's destination device, and possible intermediate transmitter and receiver devices. The QoS, HT Control, Duration/ID fields convey information for coordinating channel access among the devices in the network. Finally, a Frame Check Sequence field typically includes the bits of a Cyclic Redundancy Check code used to ensure the frame header fields have been received correctly. The header of a management frame comprises many of the same fields, and three MAC address fields. The current inventions implement methods and systems for reducing this inefficiency.
[0010] 3. Glossary and Acronyms
[0011] As a convenient reference in describing the invention herein, the following glossary of terms is provided. Because of the introductory and summary nature of this glossary, these terms must also be interpreted more precisely by the context of the detailed description in which they are discussed.
ACK Acknowledgement
AID Association Identifier
AP Access Point
CH Compressed Header
CH_MAC Compressed Header Medium Access Control
CRC Cyclic Redundancy Check
DA/SA/RA Destination Address/Source Address/Receiver Address
DS Distribution System
EOSP End of Service Period
FCS Frame Check Sequence
FHC Frame Header Compression
HT High Throughput
HTC High Throughput Control
LTF Long Training Field
MAC Medium Access Control
MMPDU MAC Management Protocol Data Unit
MPDU MAC Protocol Data Unit
MSDU MAC Service Data Unit
PLCP Physical Layer Convergence Procedure
PPDU PLCP Protocol Data Unit
RA Receiver Address
RD Reverse Direction
RDG Reverse Direction Grant
SIG Signal
STA Station
STF Short Training Field
TA Transmitter Address
TDLS Tunneled Direct-Link Setup
TIM Traffic Identification Map
VHTC Very High Throughput Control
SUMMARY OF THE INVENTION
[0012] The exemplary embodiments disclosed herein are methods for use in, and systems of, communication networks, and specify forms of header information and fields of management and data frames, and which specify how and when communication networks can use these forms of headers. In certain embodiments, the header fields are reduced in size from the analogous fields specified in the 802.11a/b/e/g/n standards, and some of those standard fields are removed.
[0013] In a first family of embodiments, methods and systems are presented for using frame-based communications within a network in which an access point (AP) device communicates directly with other station (STA) devices, in a point-to-multipoint topology. The AP and the STAs form a basic service set (BSS). Data frames which carry end user data have compressed header fields, totaling at most 16 octets. Two fields of a data frame are used for addressing and routing: a 2-octet association identifier/compressed header field (AID/CH), and a BSS identifier (BSSID) field of 6 octets. In a preferred embodiment, the AID/CH field comprises an AID subfield which identifies the STA corresponding to the frame, and a CH Identifier subfield which represents additional compressed information, e.g. the Address 3 (DA or RA) of the frame. The matching between CH Identifier and the additional compressed information is established between a station and the AP through frame header compression negotiation.
[0014] In further embodiments, a data frame comprises a Frame Control field, a Sequence Control field, and a Quality of Service (QoS). In a preferred embodiment the lengths of these fields are respectively 2 octets, 1 octet, and 1 octet. In another embodiment, a data frame comprises a Frame Check Sequence (FCS) field, which can be used to provide error correction capabilities. In one embodiment the FCS has 4 octets, and in another embodiment it has 2 octets. In the latter case the FCS can comprise a two octet cyclic redundancy check code, such as a CRC-16-CCITT.
[0015] In order to compress more information in a frame header, a second family of embodiments discloses methods and systems in which the AP and the STAs can transmit signals to negotiate whether compressed headers can be used for transmission of a data frame. A CH Identifier (e.g. 3-bit length) can be used to indicate source or destination MAC address. In one embodiment, a CH Identification Request frame is transmitted from a STA (or from the AP) that would like to send a subsequent data frame using compressed header fields to the AP (respectively, to a STA). The CH Identification Request frame preferentially comprises a Category field, an Action Value field, a Dialog Token field, and at least one pair of fields, the pair of fields comprising a CH Identifier field of 1 octet and a DA/SA MAC address field of 12 octets. A further embodiment also comprises a CH Identification Response frame, of size at most 5 octets.
[0016] In a third family of embodiments, methods and systems are presented for using frame-based communications within a network in which an AP device communicates directly with other STAs, in a point-to-multipoint topology. In this family of embodiments, management frames, which transmit management information for network services, have compressed header fields, totaling at most 16 octets. Two fields of a management frame are used for addressing and routing: a 2-octet association identifier/compressed header field (AID/CH), and a Basic Service Set Identifier (BSSID) field of 6 octets. In a preferred embodiment, the AID field identifies the STA corresponding to the frame.
[0017] In further embodiments, the header fields of a management frame comprise a Frame Control field, a Sequence Control field and a FCS field. In a preferred embodiment, the Frame Control field uses 2 octets, and the Sequence Control field uses 1 octet. In two further embodiments the FCS uses either 2 or 4 octets, and can be used to convey error detection and correction information, often using cyclic redundancy check coding.
[0018] In two further families of embodiments, the Frame Control field of a data frame or a management frame is used for conveying information regarding whether compressed headers are being used. In the first of these families, either a new Protocol Version bit set (in the Protocol Version field) is used, or else a new Type and SubType value combination in the Type and SubType subfields is used. In the second of these families, a From DS field (indicating whether the frame is to/from a Distribution System) is created within the Frame Control field to convey the order of the BSSID and AID fields within the compressed header fields.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The figures described below illustrate exemplary embodiments of the invention, and do not limit the scope of the claims.
[0020] FIG. 1 shows a standard organization of the MAC header fields of data and management frames, as known in the art.
[0021] FIG. 2 shows a standard organization of subfields in a Frame Control Field.
[0022] FIG. 3 shows a standard organization of the fields in a Physical Layer Convergence Procedure Protocol Data Unit, including the SIG field.
[0023] FIG. 4 shows the organization of the fields and subfields in compressed header data frames, according to embodiments of the invention.
[0024] FIG. 5 shows an organization of the fields and subfields of a CH Identification Request frame, and the fields of a CH Identification Response frame, according to embodiments of the invention.
[0025] FIG. 6 shows a signaling process by which a transmitter (either a STA or an AP) negotiates use of compressed MAC header formats for data frames with a receiver (respectively, either an AP or a STA), according to embodiments of the invention.
[0026] FIG. 7 shows compressed header MAC fields for management frames, according to embodiments of the invention.
[0027] FIG. 8 shows two embodiments of the Frame Control field of the compressed header management frame, according to embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] In the description and claims that follow, the word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements.
[0029] Many types of communication networks have an architecture in which devices in the network communicate through one device, called an access point (AP). The AP is often connected to another network, such as the interne. The other devices in the network, called stations (STAB), route most or all of their transmissions through the AP. As discussed above, for transmissions to be coordinated and sent to the correct device, the information to be transmitted is often broken into packets and the packets of digital data are sequentially encapsulated with other data for addressing and synchronization. The combination is called a frame.
[0030] Examples of such frame-based communications networks are specified in the standards 802.11. These standards specify three types of frames: data, management and control frames. FIG. 1 shows the structure of how information is encapsulated into the first two types of frames, according to these standards. The Frame Body contains a packet of the information that a STA or AP wishes to transmit. The other components of the frames, called fields or elements, are of specified length (in octets, also called bytes), and contain the necessary extra information needed for routing the information and coordinating transmissions within and out of the network. This extra information is called medium access control (MAC) header information, and the extra fields are called frame header fields. The entire frame is termed the MAC Protocol Data Unit (MPDU). As shown in FIG. 3 , the entire MPDU is itself enclosed in a Physical Layer Convergence Procedure Protocol Data Unit (PPDU), which is used for physical synchronization of the transmitter and receiver. In some cases, multiple MPDSUs are transmitted in the data field of FIG. 3 ; these are Aggregated MPDUs (A-MPDU). FIG. 2 shows a standard arrangement of the subfields of the Frame Control field. The standards are cited as a reference for terminology and background information about frame transmission, and do not imply that the communication networks of this disclosure necessarily use the physical wireless transmission methods described therein.
[0031] There are situations where it is desirable to use the general structure of such a frame-based communication network, but where it would be inefficient to include all the detailed information included in all the fields of FIG. 1 . An example of such a situation is in a wireless sensor network, particularly for one using the Sub-1 GHz band. In the United States, this band is 902 MHz to 928 MHz. For such a network, efficiency of transmission is of primary importance for a variety of reasons: the bandwidth is limited, STAs (e.g., a sensor) typically need to transmit and receive only small amounts of data on an intermittent basis, and there may be upwards of thousands of STAs. Finally, in the case of networks using the Sub-1 GHz band, backwards compatibility with 802.11a/b/g/n is not needed.
[0032] The exemplary embodiments detailed herein improve transmission efficiency in a frame-based communication network by allowing the use of a compressed set of frame header fields. Other embodiments specify signaling processes by which STAs and the AP can negotiate whether to use such a compressed frame header format.
[0033] Address fields of a data frame in the 802.11 standards are the Receiver Address (RA), Transmitter Address (TA), Source Address (SA), and the Destination Address (DA). The Address fields of a management frame in the 802.11 standards are Address 1 (RA), Address 2 (TA), and Address 3. All are 6-octet MAC addresses. The AID can be used to identify the STA. The RA and TA of a frame are always used to identify the receiver and the transmitter in the BSS. The SA and DA are used to identify the source or the destination of the frame which may be outside the BSS. Once a STA is associated with an AP, the AP will allocate an Association Identifier (AID) to the STA. The AID can be used to replace the MAC address in MAC header fields.
[0034] In a sensor network, only limited amounts of data will need to be transmitted between the AP and the STAs, and the AP will coordinate communication with any distribution system (DS). Using all four address fields of a data frame would not be necessary in a data frame within a sensor network, especially from a STA to the AP. STAs, and APs, only need to send enough information in the header fields so the intended receiver knows the frame is intended for it. Some fields/subfields in standard MAC headers also might not be required for some cases, e.g. TXOP Limit/QueueSize subfields, Address 3 in a management frame. Further, some fields/subfields can be compressed. The transmitter or the receiver of a frame can be identified by the AID of the transmitter or the receiver. By removing some fields/subfields in a frame header and compressing some fields/subfields, the MAC overhead can be decreased. One such embodiment is to transmit only one AID to replace the TA and RA, and one MAC address in the header fields.
[0035] FIG. 4 shows a particular embodiment of a compressed set of MAC frame header fields, to be used with data frames, according to the present invention. The transmitter and the receiver of the data frame are not identified by two MAC Addresses. Instead, a MAC address Basic Service Set Identifier (BSSID) field, comprising the AP's MAC address, of 6 octets, and one AID field, of 2 octets, is used to identify the transmitter and the receiver. The BSSID field is used to identify whether the frame is in the same BSS. The BSSID is also used to avoid wrong reception of the frames. For example, when a STA in another BSS with the same AID as the AID in the compressed data frame receives the compressed data frame, the STA will discard the frame. The reason is that the BSSID in the frame is not the same as the BSSID of the AP that the STA is associated with.
[0036] A data frame includes a Frame Control field, as is known in the art, and shown in FIG. 2 . Two subfields can be used with the compressed header format just described. In one embodiment, if the From DS bit is 1 and the To DS bit is 0, the BSSID is the transmitter identifier and AID is the receiver identifier. When “From DS” bit is 0 and the “To DS” bit is 1, the BSSID is the receiver identifier and the AID is the transmitter identifier. But when the “From DS” bit in Frame Control field is 1 and the “To DS” bit in Frame Control field is also 1, the compressed header is not used. In this embodiment, tunneled direct link setup (TDLS) is not to be used.
[0037] In another embodiment, a final Frame Check Sequence (FCS) field is included among the compressed data frame headers to implement correction of possible transmission errors of the bits in the frame. A preferred embodiment is to use a cyclic redundancy check (CRC) error correcting code. Using a 4-octet CRC is known in the art, and can be used in the present embodiments. But since in the embodiment shown in FIG. 4 the size of the header fields is reduced, the FCS can use a shorter, 2-octet, CRC code, such as the 16-CRC-16-CCITT.
[0038] To signal whether the data frame is normal or compressed, a number of options are possible. In a first embodiment, a new protocol version in the Protocol Version subfield can be used. Presently, 00 is the protocol version used by the non-compressed frame. A non-compressed data frame will never include the new protocol version in the frame's Protocol Version subfield. Once a data frame includes the new protocol version in Protocol Version subfield, the frame is a compressed frame. In a second embodiment, one bit in the signal (SIG) field of the Physical (PHY) Layer Convergence Procedure (PLCP) frame, shown in FIG. 3 , can be used. A non-compressed data frame will set the selected bit in the signal (SIG) field of the PLCP to 0. Once a data frame sets the selected bit in the SIG field of the PLCP to 1, the frame is a compressed frame. In a third embodiment, a new MPDU Type/SubType value combination in the Type and SubType subfields can be used. A non-compressed data frame will never include the new MPDU Type/SubType value combination in the frame's Type and SubType subfields.
[0039] In networks with at most 6000 STAs in a BSS, such as in a network of 802.11ah, 13 bits suffice to indicate the AID. Then in the field there are still 3 bits left in a 2-byte field. The three remaining bits can be used to identify the source or the destination of the frame that was originally identified by 6-byte SA and 6-byte DA. This can further decrease the frame header length. The field can be named as AID/CH identifier field, and includes 13-bit AID and 3-bit CH identifier. A particular embodiment is shown in FIG. 4 . In this embodiment, in the case that From DS subfield in the Frame Control field is 0, and the To DS subfield is 1, then bits 13 to 15 (inclusively) are the DA identifier. In the case that the From DS subfield is 1, and the To DS subfield is 0, then bits 13 to 15 (inclusively) are the SA identifier. As described below, CH Identification Request/Response action frames are used to match the CH Identifier to the DA/SA MAC address. The 3-bit SA/DA identifier is normally enough since for a given RA/TA pair (one STA and its associated AP), the possible SAs or DAs are the STA, edge router/bridge, AAA server, policy server, or signup server.
[0040] To manage DA/SA Identification, a non-AP STA sends a CH Identification Request action frame to the AP to indicate the mapping between CH Identifiers and DA/SA MAC Addresses. An embodiment of such frame is shown in FIG. 5 . At most eight pairs of CH Identifiers and DA/SA MAC Addresses can be included. After receiving a CH Identification Request frame, the AP sends a CH Identification Response frame to acknowledge the mapping between a CH Identifier and a DA/SA MAC Address. An embodiment of such a CH Identification Response frame is also shown in FIG. 5 .
[0041] FIG. 6 illustrates the signaling of the CH Identification Request and the CH Identification Response messages.
[0042] The Duration/ID field in standard 802.11 frames carries the remaining duration of the transmit opportunity (TXOP). A STA that receives the frame will not try to contend the wireless medium (count down the backoff timer or transmit the frames when the backoff timer becomes to 0) during the remaining TXOP. This can avoid collisions even if the STA can't detect the following acknowledge frame. 802.11 ah adds a 2-bit ACK Indication in the SIG field. With the ACK Indication help, a neighbor STA that receives the frame but can't detect the acknowledgement will not try to contend for the wireless medium access during the transmission of the acknowledgement. Because a 2-bit ACK Indication is added to the SIG field PHY layer fields, the Duration/ID field can be eliminated. A 2-octet QoS Control field in non-compressed frames includes various subfields: 3-bit TID, End of Service Period (EOSP), 2-bit ACK Policy, 1-bit A-MSDU Present, and 8-bit TXOP Limit/Queue Size. The EOSP, 1-bit A-MSDU Present, and 8-bit TXOP Limit/Queue Size subfields can be removed from compressed frames since they are not important to the compressed frame. In a further embodiment, the QoS Control field is reduced to 1 octet, and in a preferred embodiment, 4 bits of it are used to indicate the Traffic Identification Map (TID) of the frame, 2 bits are used to indicate the acknowledgement policy (ACK), and the other bits are reserved. A 2-octet Sequence Control field in non-compressed frames can help the receiver detect a duplicate frame. Given that a sensor STA has lower data rate, a one-octet Sequence Control field is long enough to detect a duplicate frame. So in another embodiment, a single octet Sequence Control field is used.
[0043] Other families of embodiments use the Compressed Management Frame Header fields shown in FIG. 7 . By using a reduced set of frames for the header fields, greater transmission efficiency can be achieved. The Address3, Duration, and HT Control field are removed from standard management frame header fields shown in FIG. 1 to make the compressed MAC header of FIG. 7 . The HT control field can be removed to make the compressed management MAC header. This means that the compressed frame will not do the functionality related with HT Control fields. As stated above, 802.11ah adds a 2-bit ACK Indication in the SIG field PHY layer fields. With the ACK Indication help, a neighbor STA that receives the frame but can't detect the acknowledgement will not try to contend the wireless medium during the transmission of the acknowledgement. So the Duration/ID field can be eliminated since a 2-bit ACK Indication is added to the SIG field PHY layer fields. Only one Address field, of size 6 octets, and one AID field, of size 2 octets, are used to identify the transmitter and the receiver. In some known methods, a STA uses Address3 to decide whether a group management frame should be accepted. Given that the TA is the same as Address3 in group management frames, it is safe to remove Address3 to make the compressed management frames. The remaining fields of the Compressed Management Frame Header fields comprise a Frame Control (2 octets), a Sequence Control field (2 octets) and a Frame Check Sequence field (either 2 or 4 octets).
[0044] In one embodiment, the AID field is used to identify the destination of the management frame. This embodiment is used when the From DS subfield in the Frame Control field is 1.
[0045] In another embodiment, the AID field is used to identify the source of the management frame. This embodiment is used when the From DS subfield in the Frame Control field is 0.
[0046] Different embodiments involve variations in the information carried in the Frame Control field.
[0047] In one family of embodiments, the Frame Control field comprises a Type and a SubType Field.
[0048] To signal whether the management frame is normal or compressed, a number of options are possible. In one embodiment, a new protocol version in the Protocol Version subfield can be used. A non-compressed management frame will never include the new protocol version in the frame's Protocol Version subfield. Once a management frame includes the new protocol version in Protocol Version subfield, the frame is a compressed frame. In another embodiment, one bit in the signal (SIG) field of the Physical (PHY) Layer Convergence Procedure (PLCP) frame can be used. A non-compressed management frame will set the selected bit in the signal (SIG) field of the Physical (PHY) Layer Convergence Procedure (PLCP) to 0. Once a management frame sets the selected bit in the signal (SIG) field of the Physical (PHY) Layer Convergence Procedure (PLCP) to 1, the frame is a compressed frame. In a third embodiment, a new MPDU Type/SubType value combination in the Type and SubType subfields can be used. A non-compressed management frame will never include the new MPDU Type/SubType value combination in the frame's Type and SubType subfields.
[0049] In some embodiments a final Frame Check Sequence field of 2 or 4 octets is included to implement correction of possible transmission errors of the bits in the compressed header fields. A preferred embodiment is to use a cyclic redundancy check (CRC) error correcting code: CRC-16-CCITT, though other 2 octet codes can be used.
[0050] Yet other embodiments reduce the size of, or remove altogether, at least one of the standard 802.11 MAC header fields to form the header fields for data or management frames. As would be apparent based on the explanations and embodiments disclosed above, in a network, such as a sensor network, with an AP and a plurality of STAs directly communicating, the modified and remaining forms of the MAC header fields used to transmit the data or management frame only need to be able to identify the receiver (AP or STA) and the transmitter (respectively the STA or the AP), and whether the frame is being transmitted using the modified header fields.
[0051] Although the invention has been described and illustrated with a certain degree of particularity, it is understood that the present disclosure has been made only by way of exemplary embodiments, and that numerous changes in the combination and arrangement of elements will be apparent to those skilled in the art without departing from the spirit and scope of the invention, as hereinafter claimed. | Methods and systems are disclosed specifying the arrangement and content of the fields in data and management frames, which allow for greater payload efficiency in frame-based communication networks. The content of the fields is changed from the standard 802.11 arrangement to meet of the needs of networks such as Sub-1GHz networks, including those of the 802.11 ah standard, and sensor networks with a large number of stations transmitting at low data rates. In some embodiments, MAC header fields are reduced from standard 802.11 header fields by using only two fields for addressing and eliminating standard fields that are not used in sensor networks. | 7 |
FIELD
This application relates to Computer-Aided Design (CAD), and more particularly, to the reuse of data constructs within a 3D CAD model.
BACKGROUND OF THE INVENTION
Computer-aided design (CAD) software allows a user to construct and manipulate complex three-dimensional (3D) models. A number of different modeling techniques can be used to create a 3D model. One such technique is a solid modeling technique, which provides for topological 3D models where the 3D model is a collection of interconnected topological entities (e.g., vertices, edges, and faces). The topological entities have corresponding supporting geometrical entities (e.g., points, trimmed curves, and trimmed surfaces). The trimmed surfaces correspond to the topological faces bounded by the edges. CAD systems may combine solid modeling and other modeling techniques, such as parametric modeling techniques. Parametric modeling techniques can be used to define various parameters for different features and components of a model, and to define relationships between those features and components based on relationships between the various parameters.
A design engineer is a typical user of a 3D CAD system. The design engineer designs physical and aesthetic aspects of 3D models, and is skilled in 3D modeling techniques. The design engineer creates parts and may assemble the parts into a subassembly. Parts and subassemblies may be used to design an assembly.
A solid modeling system may be a feature-based 3D CAD system wherein a part is constructed using various features. Examples of features include bosses, fillets, chamfers, cuts, holes, shells, lofts, and sweeps. Commercially available feature-based modeling systems include the SolidWorks® 2007 software system available from SolidWorks Corporation of Concord, Mass. SolidWorks software and other commercially available CAD systems store the contents of parts, subassemblies, and assemblies in a data file. In addition to features, the contents of CAD data files may include design profiles, layouts, internal components (e.g., bodies), and graphical entities.
Often, new or modified product designs evolve from existing designs, and thus, a design engineer constructs a model that has similar characteristics to a model that has previously been built. However, entities that make up the similar characteristics may not be readily available to use again in a design. The previously built model may be stored in a data file created by a legacy CAD system and not readable by a CAD system currently in use. On the other hand, the currently used CAD system may be able to read the data file created by a legacy system, but the contents of the data file may not be assessable in the granularity desired by the design engineer. Thus, the design engineer may need to construct the same data entities again in their entirety.
Some CAD systems, such as SolidWorks 2007 software, allow design engineers to specify design data that may be used for future designs. Once design data is specified, the design data may be organized for reuse, including for example, specifying and saving data as two-dimensional sketch blocks or library features. To reuse data stored as sketch blocks or library features, a design engineer must have the forethought that the data may be needed again in another design and must proactively specify the appropriate data for later use. Moreover, after saving the design data for reuse, the design data may only be used again after being located. Locating the saved design data may require using a file browser to conduct an extensive manual search in relevant CAD files for the saved data. Once the saved design data is located, the design engineer may select a name of a feature or sketch block and drag the name into the window area in which the part appears, at which time the saved data will graphically appear in the part.
In addition to feature libraries and sketch blocks, CAD systems may also provide feature recognition capabilities. In general, feature recognition capabilities are based on heuristics and identify features of a part created by a non-native CAD system. Moreover, feature recognition techniques do not necessarily capture the design intent because information on how a feature is created may be lacking. Feature recognition techniques may also be limited in scope. For example, a feature recognition process may only recognize features in a currently opened CAD file requiring the user to find the appropriate CAD file, open the file, and then initiate the feature recognition process.
Other methods of locating previously designed CAD data include search mechanisms. SolidWorks 2007 software provides a search mechanism using a textual search technique that locates a part file using a text string. However, the software accesses and opens the entire part rather than a specific entity therein. This is analogous to a web search technique that locates a web page given a text string and opens an entire web page that contains the text.
Time-saving advantages and enhancements to state of the art CAD systems could be achieved by providing an efficient means that allows design engineers to automatically locate needed design data whatever the granularity without having to first proactively save specific segments of design data for reuse, manually browse a file system for the specific segment of design data for reuse, and open the entire file that contains the reusable design data.
SUMMARY OF THE INVENTION
In general, in one aspect, the invention features a computer-implemented method for reusing design data in a computer-aided design model. A computer-aided design file is automatically decomposed into elements. To decompose the design file into elements, the computer-aided design file is analyzed to identify each element and information corresponding to each element is stored for later retrieval to reproduce one of the elements. The information is data that indicates a location in the design file of an element or data that explicitly defines an element. When information is retrieved, the corresponding elements are presented in a user interface. One of the elements presented can be selected and included in the computer-aided design model. Constructing the computer-aided design model includes incorporating the selected element in the computer-aided design model.
A search criterion determines the information to retrieve. In some embodiments, the search criterion specifies at least a filename and/or an element name; and the information retrieved is identified by the filename and/or the element name.
The plurality of elements includes any one of a feature, a profile, a sketch entity, a connected set of lines, a spline, a surface, and internal file property, a two-dimensional block, a drawing view, a layer, and an annotation. The internal file property specifies any one of a texture, a material, a bump map, a color, a configuration value, a numerical value, a text string, and a behavioral property.
The presentation of the corresponding elements in a user interface may include the display of a respective graphical image of each element and/or the display of filenames associated with the elements. The display of the graphical image may include rendering a part defined by the computer-aided design file in a transparency mode except the subject corresponding elements included in the part. A thumbnail image of the part may also be generated.
In one embodiment, a user selects one or more of the presented elements for inclusion in the computer-aided design model by graphical user interface operations, such as dragging the desired presented element from a user interface region and dropping the subject element into a modeling portion of a window.
In other embodiments, the invention method further includes the steps of storing tag data corresponding to an identified element, searching for the stored tag data to locate the identified element, retrieving the stored information corresponding to the identified element, and presenting a graphical image of the identified element in the user interface.
According to another embodiment, the present invention provides a computer-readable data storage medium comprising computer instructions for reusing design data in a computer-aided design model. The computer instructions cause a computer to execute a process that automatically identifies one or more computer-aided design components defined in a design file used for construction of a first computer-aided design model. Next the computer stores data for re-creating the computer-aided design components, wherein the stored data comprises a unique dataset associated with each of the computer-aided design components. The computer instructions further cause the computer to search the stored data for the unique dataset matching a search criterion without opening the design file. The computer presents as a reusable CAD entity the computer-aided design component associated with the unique dataset matching the search criterion. The computer allows for user selection of the reusable CAD entity.
The unique dataset associated with each one of the computer-aided design components may be a pointer to the computer-aided design component and/or a copy of the computer-aided design component. In turn, the computer instructions cause the computer to generate a copy of the reusable CAD entity upon user selection of the reusable CAD entity and to include the copy of the reusable CAD entity in a second computer-aided design model. Further, the computer presents the reusable CAD entity by displaying a graphical image of the reusable CAD entity and/or by displaying a filename associated with the reusable CAD entity. The computer instructions cause the computer to select the graphical image and/or the filename, search the stored data to locate one or more lower-level entities used to generate the reusable CAD entity, present the one or more lower-level entities, enable selection of one or more lower-level entities and include a selected one of the lower-level entities in the second computer-aided design model.
In some embodiments, the invention method or system distinguishes a kind of component during the process of automatically identifying computer-aided design components. A filter means filters the graphical image of the reusable CAD entity according to the kind of component. The filtered graphical image of the reusable CAD entity is then displayable. The kind of component or component types include a cut feature, an extruded feature, a sketch block, a drawing view, and a layer.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description that follows. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
FIG. 1 is an illustration of a computer-generated model and a feature manager portion of the user interface displayed in a window in one embodiment of the present invention.
FIG. 2 is an illustration of a computer-generated model and the invention user interface containing a representation of the computer-generated model shown in FIG. 1 and a feature thereof.
FIG. 3 is an illustration of a computer-generated model and the invention user interface.
FIG. 4 is an illustration of the computer-generated model of FIG. 3 and the invention user interface containing representations of features from the computer-generated model shown in FIG. 1 .
FIG. 5 is an illustration of the computer-generated model of FIG. 3 and the invention user interface containing representations of sketch entities from the computer-generated model of FIG. 1 .
FIG. 6 is an illustration of the invention user interface and filters that may be applied to search results.
FIG. 7 is an illustration of a computer-generated drawing of a model and the invention user interface containing representations of design entities in the drawing.
FIG. 8 is a schematic diagram depicting the data flow between components in an embodiment of the present invention.
FIG. 9 is a schematic diagram of a computer system in which embodiments of the present invention are implemented.
DETAILED DESCRIPTION OF THE INVENTION
A description of example embodiments of the invention follows.
The present invention enables design engineers of all experience levels to easily reuse design data. The reusable design data may be a low-level design construct such as a curve or a higher-level design construct such as a sub-assembly. The reusable design data may also be a design property, a graphical attribute such as a material appearance, a bitmap (e.g., a company logo), or an annotation. The present invention identifies reusable design data by decomposing a design document (e.g., a part, assembly, or drawing file). Extracting identified design data from a decomposed design document and organizing the extracted design data in searchable memory allows the design data to be easily incorporated into a new design.
Referring now to FIG. 1 , a window 102 displayed on a computer monitor is shown. The window 102 is generated by modeling software executed by a computerized modeling system, an example of which is later shown with reference to FIGS. 8 and 9 . The window 102 is a conventional computer-generated window that can be programmed by one of ordinary skill in the art using conventional, commercially available, software programming tools, such as those available from Microsoft Corporation of Redmond, Wash.
A computer-generated 3D model 104 is displayed within a modeling portion 106 of the window 102 . Among other design elements, the model 104 includes an extruded cut 110 . Implementations of the present invention also may include other window areas, such as a FeatureManager® window panel 108 in which the structure of an opened component, assembly, or drawing is listed to help the design engineer visualize and manipulate the 3D model 104 , as well as components of the 3D model 104 . The FeatureManager window panel 108 may present the feature history to the design engineer as a hierarchical collection of features. The design engineer may be able to highlight a feature by selecting the name of the feature or an icon representing a feature in the FeatureManager window panel 108 . U.S. Pat. No. 5,815,154 to Hirschtick et al discloses a system for modifying a model by allowing a user to graphically manipulate a hierarchical collection of features.
Referring now to FIG. 2 , a 3D model of an object 202 is shown in the window 102 . The model of the object 202 may be used as a foundation for a new model. To reuse a previously designed CAD element that is a particular extruded cut, the design engineer may search for an extruded cut by typing extruded cut's name in a search window 206 . The results of the search appear as thumbnail images in a search result panel 204 . As shown in the search result panel 204 , the feature named “Cut-Extrude1” and the model 104 that is shown in FIG. 1 and which contains the named feature, are displayed in the search result panel 204 . The search result panel 204 informs the design engineer that two items were found—a cut feature and a document that contains the cut.
As shown in FIG. 3 , after a file document named bracket.SLDPRT is searched, the search result panel 204 displays thumbnail images of numerous features of model 104 . Using a mouse, a thumbnail image may be dragged and dropped into the modeling portion 106 of the window 102 for reuse. When the search result panel 204 cannot accommodate all the images in the available space, scrollable bars 302 allow the design engineer to view more CAD elements returned by the search operation. Additionally, an implementation may arrange the results in pages and allow the design engineer to select a page to view in the search result panel 204 . Moreover, the pages may be arranged depending on the types of CAD elements. For example, one page may show features, another page sketch entities, and yet another page annotations. The present invention may also display a tag window 304 , as is shown in the lower part of the window 102 in FIG. 3 . The tag window 304 enables the design engineer to associate meaningful text to a CAD element. For example, the Cut-Extrude1 feature 306 may be tagged with the text “standard connector.” Text entered into the tag window 304 may later be used in a search specification to retrieve the CAD element.
FIG. 4 and FIG. 5 show the model of the object 202 after the inclusion of additional CAD entities that are reusable according to embodiments of the present invention. The additional CAD entities are a cylinder 402 , extruded cut 406 , and a sketch entity 410 . Referring to FIG. 4 , the cylinder 402 and the extruded cut 406 were included in the model of the object 202 after the design engineer selected then dragged and dropped a corresponding image of the cylinder 404 and a corresponding image of the extruded cut 408 , respectively, from the search result panel 204 . The images of the CAD entities shown in the search result panel 204 in FIG. 4 represent the results of a search of a design document (i.e., a file) that defines a part named bracket.SLDPRT. As seen in the search window 206 , the text “bracket.SLDPRT” was entered into the search window 206 to initiate the search process.
The CAD entity corresponding to the sketch entity 410 is not shown in FIG. 4 because the corresponding image of the sketch entity 502 is displayed on another page of the search results panel 204 , as shown in FIG. 5 . The present invention automatically collects information about CAD entities during a decomposition process. This information is then used to filter and rank results displayed in the search results panel 204 . Referring back to FIG. 4 , a filter identified three kinds of CAD entities in the bracket.SLDPRT document—Sketch, Extrusion, and Cut. Beside the identified kinds of entities is a numeral indicating the number of each entity type in the search results. To filter the search results, the design engineer may select a filter name in the upper area 412 of the search result panel 204 . If the design engineer selects the text “Sketch” in the upper area 412 , the sketches in bracket.SLDPRT document will be displayed, as shown in FIG. 5 . The inclusion of sketch entity 410 in the model of the object 202 occurred after the corresponding image of the sketch entity 502 was selected and dragged from the search result panel 204 shown in FIG. 5 and dropped on the face 506 . Moreover, the search window 206 in FIG. 5 reflects the entire search context by including the text “Kind: Sketch” to indicate that the kind of CAD entities displayed in the search results panel 204 are sketch entities. Essentially, the search window 206 is combination of a user interface file browser and a filter 504 to be applied to the results of a file browsing operation.
Referring now to FIG. 6 , a search result panel 204 is shown. A search window 206 displayed above the search result panel 204 indicates that a folder named “data” located on a disk drive E was searched. To make the search results easier to comprehend, the present invention groups heterogeneous files and presents the groupings to the design engineer. A document type list 602 indicates that several document types were found, including 168 SolidWorks part documents. A kind list 604 indicates that the data folder on drive E contains 199 documents and five folders. In the lower portion of the search result panel 204 , thumbnail images of SolidWorks part documents 606 are shown. Beside each thumbnail image is a filename.
An embodiment of the present invention automatically performs a search within a folder or a file when the design engineer double clicks a mouse button while pointing to a thumbnail image or corresponding filename in the search result panel 204 . Double-clicking on a folder causes that folder to be searched, while double-clicking on a filename or image causes that file to be searched. Results from the search are then displayed in the search result panel 204 . This pattern of behavior can occur with all entities that contain other entities capable of being decomposed thereby enabling a design engineer to drill down to basic entities in a CAD file. For example, double-clicking on a filename or image that is a part document causes that part document to be searched; search results are then displayed as thumbnail sketches and/or filenames in the search result panel 204 . Likewise, double-clicking on a feature defined in a part document causes that feature to be searched and perhaps then causes thumbnail images of a sketches or blocks used to construct that feature to appear in the search result panel 204 .
As illustrated in FIG. 7 , the present invention not only decomposes 3D part files, but additionally decomposes 2D drawing files for reuse in a new 2D drawing or in a 3D model. The window 102 shown in FIG. 7 contains a 2D drawing 702 and the search result panel 204 . Not only are the images of 2D CAD entities displayed in the search result panel 204 , the names of the files that define those entities are also displayed.
FIG. 8 is a diagram of a framework 800 implemented by an embodiment of the present invention. The framework 800 enables the reuse of design data by automatically reducing designs stored in design documents to reusable CAD entities. No user intervention is required to reduce designs into reusable CAD entities. Two processes in the framework 800 run in the background of a modeling system. One background process is a search and indexing service 802 . The search and indexing service 802 reads one or more design documents 812 (located on local or networked disks, or in cache memory) and creates a search service table 814 that provides links that optimize the retrieval of reusable design data. The links associate text strings with the design documents 812 . Commercially available software such as Microsoft Windows Desktop Search may be used for the search and indexing service 802 .
The second background process in the framework 800 is a decomposition service 804 . A first component 806 of the decomposition service 804 decomposes one or more design documents 812 by performing a detailed analysis of the design data and identifying CAD entities, which are logical data sets. A CAD entity is a particular CAD element, and by way of non-limiting example may be a feature, a profile (which may be a sketch), an internal file property (e.g., a texture), a user-created table, a material, or an annotation. A CAD entity may also be a group of connected lines or a sketch block in a 2D drawing document.
The detailed analysis of the design data may employ numerous techniques and the techniques used are dependent on the document format. For example, one technique employs particular headers that identify CAD elements for known file formats. Another technique employs feature recognition methods to identify CAD features, which is useful for decomposing unknown file formats. Yet other techniques recognize data types to aid in the identification of tables, annotations, and dimensions. To identify 2D CAD elements, the detection of various line segments having common endpoints may reveal a CAD entity. Furthermore, drawing views may be discovered using methods such as those described in U.S. Pat. No. 6,603,486 to Baran et al. Moreover, 2D CAD elements such as layers and blocks may be identified using software libraries available through the Open Design Alliance.
A second component 808 of the decomposition service 804 performs an actual or a virtual extraction of each identified CAD entity. Whereas an actual extraction of the CAD entities creates a copy of each CAD entity, a virtual extraction does not reproduce any design data. Rather, pointers to the locations of each CAD entity are generated and stored in cached memory along with an indication of the byte size of the corresponding CAD entity.
A third component 810 of the decomposition service 804 caches the actual extracted CAD entities or the pointers and accompanying size data in a decomposition service table 816 , which may reside in disk memory or in non-permanent memory. The decomposition service table 816 also stores other identifying information for each CAD entity, such as the file from which the particular CAD entity was extracted and parent-child relationships. The decomposition service table 816 is accessed when a design engineer initiates a modeling search operation 818 .
The design engineer initiates a search by providing user search criteria to a modeling search process 818 . The modeling search process locates one or more folders, files, or CAD elements identified in the search criteria. The modeling search process 818 finds the text (which by way of non-limiting example may be a pathname, a tag, or a feature name) in the search service table 814 and retrieves the names of files that meet the search criteria. Then, the modeling search process 818 looks up the names of the files retrieved from the search service table 814 in the decomposition service table 816 to locate the entities or pointers thereto 820 belonging to the named files. After the search process 818 locates the desired CAD entities 820 , the CAD entities are presented to the design engineer as search results 822 such as in search results panel 204 discussed above in FIGS. 2-7 .
The search results 822 are shown graphically, and may be displayed as thumbnail images. In an embodiment search results that are features are displayed by making the entire part in which the feature belongs transparent except the feature. Furthermore, a different color may be assigned to the feature to highlight the feature. The part is then sized such that only the feature and the immediate surrounding region of the feature fit in the area allotted for a thumbnail image.
As previously discussed, double clicking a CAD entity or the filename associated with the CAD entity initiates another search. Within the framework 800 , the modeling search process 818 fetches information from the decomposition service table 816 only, to produce another set of entities or pointers thereto 820 . Information does not need to be retrieved from the search service table 814 in this case. The other identifying information with each CAD entity (e.g., the file from which the particular CAD entity was extracted and parent-child relationships) is utilized to determine lower-level entities belonging to the CAD entity.
CAD entities displayed as search results 822 may be selected and incorporated in a new or an existing model. An intuitive means for accomplishing this is for the computerized modeling system to allow the design engineer to select, drag, and drop a CAD entity to incorporate that CAD entity in a model. If a selected CAD entity is a copy of an extracted CAD entity, then the selected CAD entity is simply included in the model. If a selected CAD entity is a pointer to the extracted CAD entity, then the selected CAD entity is created by locating the extracted CAD entity, extracting a specified amount of data (e.g., determined by byte size), and creating a copy of the extracted CAD entity to include in the model.
Referring now to FIG. 9 , a computerized modeling system 900 is shown and includes a CPU 902 , a computer monitor 904 , a keyboard input device 906 , a mouse input device 908 , and a storage device 910 . The CPU 902 , computer monitor 904 , keyboard 906 , mouse 908 , and storage device 910 can include commonly available computer hardware devices. For example, the CPU 902 can include a Pentium-based processor. The mouse 908 may have conventional left and right buttons that the user may press to issue a command to a software program being executed by the CPU 902 . As an alternative or in addition to the mouse 908 , the computerized modeling system 900 can include a pointing device such as a trackball, touch-sensitive pad, or pointing device and buttons built into the keyboard 906 . Those of ordinary skill in the art appreciate that the same results described herein with reference to a mouse device can be achieved using another available pointing device. Other appropriate computer hardware platforms are suitable as will become apparent from the discussion that follows. Such computer hardware platforms are preferably capable of operating the Microsoft Windows NT, Windows 98, Windows 2000, Windows XP, Windows ME, UNIX, Linux, or MAC OS operating systems.
Additional computer processing units and hardware devices (e.g., rapid prototyping, video, and printer devices) may be included in the computerized modeling system 900 . Furthermore, the computerized modeling system 900 may include network hardware and software thereby enabling communication to a hardware platform 912 , and facilitating communication between numerous computer systems that include a CPU and a storage system, among other computer components.
Computer-aided modeling software of the present invention may be stored on the storage device 910 and loaded into and executed by the CPU 902 . The modeling software allows a user to create and modify a 3D model and implements aspects of the invention described herein. The CPU 902 uses the computer monitor 904 to display a 3D model and other aspects thereof as described. Using the keyboard 906 and the mouse 908 , the user can enter and modify data associated with the 3D model. The CPU 902 accepts and processes input from the keyboard 906 and mouse 908 . The CPU 902 processes the input along with the data associated with the 3D model and makes corresponding and appropriate changes to that which is displayed on the computer monitor 904 as commanded by the modeling software. In one embodiment, the modeling software is based on a solid modeling system that may be used to construct a 3D model consisting of one or more solid and surface bodies.
The invention may be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations thereof. Apparatus of the invention may be implemented in a computer program product tangibly embodied in a machine-readable storage device for execution by a programmable processor; and method steps of the invention may be performed by a programmable processor executing a program of instructions to perform functions of the invention by operating on input data and generating output. The invention may advantageously be implemented in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Each computer program may be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language if desired; in any case, the language may be a compiled or interpreted language. Suitable processors include, by way of non-limiting example, both general and special purpose microprocessors. Generally, a processor will receive instructions and data from a read-only memory and/or a random access memory and in some embodiments instructions and data may be downloaded through a global network. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM disks. Any of the foregoing may be supplemented by, or incorporated in, custom-designed ASICs (application-specific integrated circuits).
An advantage of the present invention is that reusable design data can save organizations time, money, and opportunity costs. Given that a design engineer will not need to recreate many unchanged features, parts, and other CAD components, product cycle times may be shortened. Moreover, product branding features may be captured for reuse, such as specific curves and profiles that are identifiable within an overall product line. Additionally, CAD databases may represent a large investment for a company and allowing items in that database to be reused may increase the return on investment for the company.
Yet another advantage is that the present invention enhances collaboration between design engineers by providing a means to easily share data. A design engineer who recently joined a company can search significant amounts of design data with very little knowledge of how another design engineer created earlier designs. The present invention allows a design engineer to find, understand, and extract the appropriate data from files that that design engineer did not previously create.
Other advantages of the present invention include giving the design engineer the ability to find CAD parts and have design data within one or more of those CAD parts presented in an easily reusable way, and giving the design engineer the ability to readily reuse design data without the design engineer having to preprocess design data that may be useful later in the same model or in future models.
A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, implementations may change the order in which operations are performed. Furthermore, depending on the needs of an implementation, particular operations described herein may be implemented as a combined operation, eliminated, added to, or otherwise rearranged. Particular user interface operations relative to a mouse (e.g., click, drag, drop, etc.) are by way of illustration and not limitation. Other user interface operations for selecting, moving, placing, etc. model or design data are suitable. Additionally, an embodiment may apply filters to the decomposition procedure to limit the number of CAD entities extracted.
While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. | Reusing design data in a computer-aided design model includes automatically analyzing a computer-aided design file to identify a set of elements, storing information corresponding to each element in a manner enabling querying and retrieval of the information, presenting one element in a user interface upon retrieval of the information corresponding to the one element, selecting the presented element for inclusion in the model, and constructing the model by incorporating the presented element in the model. The information identifies corresponding elements to facilitate reproduction of at least one element. The information is data indicating a location in the computer-aided design file or data defining at least one of the elements. The stored information allows querying and searching for elements matching a search criterion in a manner free of opening the design file. | 1 |
FIELD OF THE INVENTION
The invention relates to phenylquinoxaline copolymers having polar partial structures, and to their use in the production of highly heat-resistant dielectrics.
BACKGROUND OF THE INVENTION
When applied as dielectrics for multilayer interconnections having a high switching rate, polyphenylquinoxalines demonstrate better thermal and electrical properties than conventional, highly heat-resistant protective and insulation layers based on polyimide (c.f.: 35th Electronic Components Conference, Washington (U.S.), May 20-22 (1985) Conference Report 1985, pp. 192-198); (c.f.: First European Technical Symposium on Polyimides, Montpellier, May 10-11 (1989) - Proceedings vol. 1, pp. B-2/1-B-2/12). In order for the polymers to be processed into the required thin layers, they must be soluble in those solvents which can be applied in production lines without adversely affecting the environment. Another requirement is that the polymer layers must adhere well to the substrates used in microelectronics. However, neither of these two requirements is met by polyphenylquinoxalines. These polymers are soluble only in very toxic, phenolic solvents, such as cresol or chlorinated hydrocarbons, and demonstrate insufficient adherence to typical semiconductor surfaces, such as silicon oxide and silicon nitride.
SUMMARY OF THE INVENTION
The object of the invention is to provide polymers, which can be used to produce highly heat-resistant organic dielectrics having good thermal and electrical properties and which can be processed thereby in non-toxic solvents.
This is achieved according to the invention by means of phenylquinoxaline copolymers, which have polar partial structures and are of the following general formula: ##STR2## where m=0 or 1, and n=1 to 10,
where the following applies: ##STR3## where p=1 to 18 and q=1 to 10,
and Z=alkyl with 2 through 10 C-atoms or aryl;
R'=H, F or Cl; ##STR4## where Q=H or OR",
where R" is hydrogen (H) or an olefinically unsaturated residue, and where the residue R' on the aromatic grouping adjacent to the CO group can be a COOH group, ##STR5## where r=0 or 1,
and T=--O--, --CO-- or ##STR6## where the following applies: ##STR7##
DETAILED DESCRIPTION OF THE INVENTION
Besides phenylquinoxaline structures, the copolymers according to the invention exhibit precursors of oxazoles (1), imides (1), imidazoles (2) and so-called pyrones (3), that is imidazopyrrolones as co-components having polar partial structures. While substantially retaining the good thermal and electrical properties of polyphenylquinoxalines, these copolymers demonstrate good solubility in common non-toxic solvents, such as γ-butyrolactone and N-methylpyrrolidone, as well as a good adhesion to semiconductor substrates, such as silicon oxide and silicon nitride. The processibility in non-toxic solvents and the improved adhesion to semiconductor substrates are achieved by introducing the polar partial structures.
The copolymers according to the invention cyclize when heated to approximately 400° C. and--under the formation of benzoxazole-, imide-, benzimidazole- and pyrone partial structures--become insoluble in all organic solvents. Surprisingly, the good thermal and electrical property spectrum of polyphenylquinoxaline is retained after the cyclization. Therefore, these copolymers are extremely well suited for producing highly heat-resistant dielectrics. Compared to polyimides, another advantage is that the reduction in the layer thickness amounts merely to 10 to 20% and, consequently, clearly lies under the 30 to 50% of the polyimides.
Another advantage of the copolymers according to the invention is that photosensitive precursors are able to be produced by introducing photochemically reactive groups, for example by adding unsaturated epoxides to OH-, NH 2 - or COOH groups. R" thereby preferably represents one of the following olefinically unsaturated residues: ##STR8## where
A=-CH 2 - and -CH 2 -O-[(CH 2 ) s -O] t -(CH 2 ) 3 -.
D=H, CH 3 , Cl, Br and CN,
and
s=2 to 16,
t=1 to 10.
As already explained, the cyclization of the copolymers according to the invention leads to copolymers with benzoxazole-, imide-, benzimidazole- or pyrone units. These copolymers have the following structure, for example: ##STR9##
When copolymers with imide structures, are prepared the residue R' which is on the aromatic grouping adjacent to the CO-NH group, must be a COOH group. This means that, in this case, the aromatic grouping merely exhibits two residues R', which are H, F or Cl.
Exemplary embodiments of the invention will be described in greater detail in the following Examples.
EXAMPLE 1
Copolymer of Phenylquinoxaline and of a Benzoxazole Precursor
By condensing oxydibenzil (1 mole) with 3,4diaminobenzoic acid (2 moles), a dicarboxylic acid with phenylquinoxaline units is obtained. The corresponding acid chloride is prepared from this dicarboxylic acid. Thionyl chloride can be used for this purpose. The dicarboxylic acid chloride is subsequently reacted with 3,3'-dihydroxy-4,4'diaminobiphenyl (1 mole) to form a copolymer that has both phenylquinoxaline units, as well as o-hydroxy-amide groupings (CO-NH-). The copolymer can also be prepared by means of a so-called chloride-free synthesis (c.f. U.S. Pat. No. 5,096,999).
Resist films are able to be produced from a solution of the copolymer. They split off water when annealed at approximately 400° C., whereby the o-hydroxy-amide groupings cyclize into benzoxazole structures.
EXAMPLE 2
Copolymer of Phenylquinoxaline and of an Imide Precursor
One proceeds in accordance with Example 1, where in place of 3,4-diaminobenzoic acid, 4,5-diaminophthalic acid is used, and in place of 3,3'-dihydroxy-4,4'-diaminobiphenyl, 4.4'- diaminobiphenyl is used. Via tetracarboxylic acid, or the corresponding acid chloride, as an intermediate stage, a copolymer with phenylquinoxaline units and o-carboxyamide groupings (-CO-NH-) is thereby obtained. When annealed to approximately 400° C., they cyclize into imide structures.
If in place of 4,4'- diaminobiphenyl, 3,3'-dihydroxy4,4'-diaminobiphenyl is used, a copolymer with hydroxyimide structures is obtained in a corresponding manner.
EXAMPLE 3
Copolymer of Phenylquinoxaline and of a Benzimidazole Precursor
By condensing oxydibenzil and isophthalaldehyde (molar ratio 1:1) with the double molar quantity 3,3',4,4'-tetraaminobiphenyl in a suitable solvent, such as N-methylpyrrolidone, one obtains a soluble copolymer that exhibits both phenylquinoxaline units as well as o-amino-azomethine groupings (--N═CH--).
The copolymer is able to be processed into films. When the polymer films are annealed at approximately 400° C., the o-amino-azomethine groupings are cyclized into benzimidazole structures.
EXAMPLE 4
Copolymer of Phenylquinoxaline and of a Pyrone Precursor
3,3',4,4'-Tetraaminobiphenyl and benzophenone tetracarboxylic acid dianhydride are converted in the molar ratio of 6:1 into an oligomeric amidocarboxylic acid having terminal o-diamino functions. This amidocarboxylic acid is subsequently condensed with oxydibenzil in the molar ratio 6:5 into a copolymer that has both phenylquinoxaline units as well as o-amino-o'-carboxy- amide groupings (--CO--NH--).
Films produced from the copolymer split off water when annealed at approximately 400° C., whereby the o-amino-o'-carboxy-amide groupings cyclize into pyrone structures.
All of the above-described copolymers are very good soluble in strong polar solvents, such as dimethyl formamide, dimethylsulfoxide, dimethylacetamide and N-methylpyrrolidone. The substrates, for example silicone wafers, are coated with solutions of the copolymers in N-methylpyrrolidone using a spinon deposition process. The resist films were dried for 1 h at approximately 70° C. and subsequently annealed for 1 h at approximately 400° C.
Contrary to the phenylquinoxaline polymers, a loss in layer thickness occurs in the case of the copolymers during the annealing process. This is because, in this case, non-cyclized prepolymer units are present in part, which are only converted into the highly heat resistant structures after undergoing the annealing process (400° C./1 h). The volume shrinkage of approximately 10 to 20% which occurs is clearly less than it is for polyimides (30 to 50%).
Compared to polyimides, the copolymers according to the invention are distinguished by a clearly higher thermal resistance. A loss in weight does not occur until a temperature of above 500° C. The thermal characteristic was determined thermogravimetrically, where the copolymers were heated at a heating rate of 10° C./min from room temperature to 700° C., and the loss in weight was recorded.
The copolymers according to the invention demonstrate very good insulation properties. The following characteristic electrical values were determined:
______________________________________Copolymer ε tan δ × 10.sup.3 ρ(Ω × cm)______________________________________Example 1 3.03 1.3 1.3 × 10.sup.18Example 3 3.33 3.25 7 × 10.sup.17Example 4 3.08 2.0 1.6 × 10.sup.18______________________________________
The dielectric properties were determined by taking a capacitance measurement at 25° C. (atmospheric humidity: 0%) at a measuring frequency of 1 kHz. A polymer film was applied to a Cr/Ni-coated silicone wafer, and a gold layer was vapor-deposited on as a counter-electrode; the film thickness amounted to approx. 6 μm.
With respect to the thermal and dielectric characteristic values, the copolymers according to the invention behave similarly to the phenylquinoxaline polymers. In addition, because of the solubilizing OH-, NH 2 - and COOH-groups, these copolymers demonstrate a good solubility in non-toxic solvents, such as γ-butyrolactone and N-methylpyrrolidone. At the same time, the polar groups in the copolymers result in an improvement in the bonding properties on substrate surfaces, such as SiO 2 and Si 3 N 4 .
Furthermore, the copolymers according to the invention have the advantage of being receptive to a photostructuring process. This can take place indirectly using a two-layer technique with O 2 /RIE, or directly with photosensitively adjusted precursors. Mixtures composed of the copolymers, which contain chemically bonded, photoreactive groups, and of sensitizers and/or photoinitiators are applied, whereby a positive or negative structuring with light follows, preferably with a wavelength of >400 nm. As sensitizers, one can apply compounds based on diazochinone, or rather diazoketone, for example, as employed in conventional positive resists. | Phenylquinoxaline copolymers of the general formula: ##STR1## are described where R* signifies a polar unit. The application of these copolymers for producing highly heat-resistant dielectrics is also described. | 2 |
FIELD OF THE INVENTION
[0001] The invention relates to a heat shield arrangement for a component guiding a hot gas, which comprises a number of heat shield elements disposed next to each other on a supporting structure with gaps in between. A heat shield element can be mounted on the supporting structure such that an internal space is formed, which is delimited in areas by a hot gas wall to be cooled, with an inlet channel for admitting a coolant into the internal space. The invention also relates to a combustion chamber with an internal combustion chamber lining, which has such a heat shield arrangement, and a gas turbine with such a combustion chamber.
BACKGROUND OF THE INVENTION
[0002] The high temperatures in hot gas channels and other hot gas spaces mean that it is necessary for the internal wall of a hot gas channel to be configured with the highest level of temperature-resistance possible. Materials with a high level of heat resistance, such as ceramic materials, are suitable for this purpose. But ceramic materials have the disadvantage that they are both very brittle and they also have unfavorable thermal and temperature conducting characteristics. Metal alloys with a high level of heat resistance and an iron, chromium, nickel or cobalt base are possible alternatives to ceramic materials. As the operating temperature of metal alloys with a high level of heat resistance is however significantly below the maximum operating temperature of ceramic materials, it is necessary to cool metallic heat shields in hot gas channels.
[0003] A heat shield arrangement, in particular for structural elements of gas turbine units, is disclosed in EP 0 224 817 B1. The heat shield arrangement is used to protect a supporting structure against a hot fluid, in particular to protect a hot gas channel wall in gas turbine units. The heat shield arrangement has an internal lining made of heat-resistant material, which generally comprises heat shield elements fixed to the supporting structure. These heat shield elements are disposed next to each other leaving gaps for the passage of cooling fluid and are able to move due to thermal influences. Each of these heat shield elements has a top part and a stem part in the manner of a mushroom. The top part is a flat or three-dimensional, polygonal flat element with straight or curved boundary lines. The stem part connects the central area of the flat element to the supporting structure. The top part is preferably triangular in form, so that an internal lining of almost any geometry can be produced using identical top parts. The top parts and optionally other parts of the heat shield elements are made of a material with a high level of heat resistance, in particular a steel. The supporting structure has holes, through which a cooling fluid, in particular air, can be admitted into an intermediate space between the top part and the supporting structure and from there can be admitted through the gaps for passage of the cooling fluid into a spatial area surrounded by the heat shield elements, for example a combustion chamber of a gas turbine unit. This flow of cooling fluid reduces the penetration of hot gas into the intermediate space.
[0004] A metallic lining for a combustion chamber is described in U.S. Pat. No. 5,216,886. This lining comprises a number of cube-shaped hollow elements (cells) disposed next to each other, which are welded or soldered to a common metal plate. The common metal plate has precisely one opening assigned to each cube-shaped cell to admit cooling fluid. The cube-shaped cells are disposed next to each other leaving a gap in between. On every side wall in the vicinity of the common metal plate they have a respective opening for the discharge of cooling fluid. The cooling fluid enters the gap between adjacent cube-shaped cells, flows through said gap and forms a cooling film on a surface of the cells, which is oriented parallel to the metal plate and can be exposed to a hot gas. With the type of wall structure described in U.S. Pat. No. 5,216,886 an open cooling system is defined, in which cooling air passes via a wall structure through the cells into the inside of the combustion chamber. The cooling air is then lost for further cooling purposes.
[0005] A wall, in particular for gas turbine units, having cooling fluid channels, is described in DE 35 42 532 A1. In the case of gas turbine units the wall is preferably disposed between a hot space and a cooling fluid space. It is joined together from individual wall elements, each of the wall elements being a plate-type body made from material with a high level of heat resistance. Each plate-type body has parallel cooling channels distributed over its base surface, with one end of said cooling channels communicating with a cooling fluid space and the other end with the hot space. The cooling fluid admitted into the hot space and guided by the cooling fluid channels forms a cooling fluid film on the surface of the wall element facing the hot space and/or adjacent wall elements.
[0006] A cooling system for cooling a combustion chamber wall is shown in GB-A-849255. The combustion chamber wall is formed by wall elements. Each wall element has a hot gas wall with an outside that can be subject to the action of hot gas and an inside. Nozzles are disposed at right angles to the inside. Cooling fluid in the form of a concentrated flow is discharged from these nozzles and strikes the inside. This cools the hot gas wall. The cooling fluid is collected in a collection chamber and removed from the collection chamber.
[0007] To summarize, all these heat shield arrangements, in particular those for gas turbine combustion chambers, are based on the principle that compressor air is used both as the cooling medium for the combustion chamber and its lining and as sealing air. The cooling and sealing air enters the combustion chamber, without having been involved in combustion. This cold air mixes with the hot gas. This causes the temperature at the combustion chamber exit to drop. As a result the output of the gas turbine drops as does the efficiency of the thermodynamic process. This can be compensated for to some extent by setting a higher flame temperature. However this then gives rise to material problems and higher emission values have to be accepted. Another disadvantage of the specified arrangements is that the admission of a not insignificant mass flow of cooling fluid into the combustion chamber causes pressure losses in the air supplied to the burner.
[0008] To prevent coolant blowing out into the combustion chamber, complex systems are known with pressurized cooling fluid control, in which the cooling fluid is guided in a closed circuit with a supply system and a return system. Such closed cooling concepts with pressurized cooling fluid control are described for example in WO 98/13645 A1, EP 0 928 396 B1 and EP 1 005 620 B1.
SUMMARY OF THE INVENTION
[0009] The object of the invention is to specify a heat shield arrangement, which can be cooled with a coolant, such that little cooling fluid is lost when the heat shield arrangement is cooled. It should be possible to deploy the heat shield arrangement in a combustion chamber of a gas turbine.
[0010] This object is achieved according to the invention by a heat shield arrangement for a component guiding a hot gas, which comprises a number of heat shield elements disposed next to each other on a supporting structure with gaps in between. A heat shield element can be mounted on the supporting structure such that an internal space is formed, which is delimited in areas by a hot gas wall to be cooled, with an inlet channel for admitting a coolant into the internal space, with a coolant discharge channel being provided for the controlled discharge of coolant from the internal space, said channel discharging from the internal space into the gap.
[0011] The invention is based on the consideration that the very high flame temperatures in hot gas channels or other hot gas spaces, for example in combustion chambers of stationary gas turbines, mean that the components guiding the hot gas have to be actively cooled. A very wide range of cooling technologies—or even combinations thereof—can be used for this purpose. The most frequently used cooling concepts are convection cooling, convection cooling with measures to increase turbulence and impact cooling. Because of the very intensive efforts to reduce pollutant emissions in particular from systems with open cooling, for example combustion chambers with open cooling in gas turbines, cooling air economy is a particularly important factor in achieving these objectives—in this instance greater NO x reductions. The objective for cooling concepts with open cooling is therefore to minimize the mass flow of cooling air required. With the conventional, open cooling concepts discussed in more detail above, after completing its cooling task the cooling air finally escapes through the gap between adjacent heat shield elements, to enter the combustion chamber. Discharge of the cooling air protects the system from penetration of hot gas into the gaps. The uncontrolled blowing out of the cooling air however means that more cooling air is used to seal the gaps than is required for the cooling task. This increase in quantity leads to excessive cooling air consumption with disadvantageous consequences for the overall efficiency of the unit and pollutant emissions from the combustion system producing the hot gas.
[0012] Based on this knowledge with the heat shield arrangement of the invention a controlled and tailored discharge of the coolant for an open cooling system is proposed after completion of the cooling task at the hot gas wall to be cooled. The heat shield arrangement can thereby be implemented particularly simply and is associated structurally with significantly lower manufacturing outlay than closed cooling concepts with coolant return. The controlled coolant discharge into the gap means that coolant, e.g. cooling air, can be used more economically compared with the conventional concepts, whilst at the same time achieving a significant reduction in pollutant emissions, in particular NO x emissions. This is achieved by providing a coolant discharge channel for the controlled discharge of coolant from the internal space, said channel discharging from the internal space into the gap.
[0013] A particularly high level of cooling efficiency and sealing effect of the coolant against the action of a hot gas in the gap on the supporting structure is advantageously achieved in the gap by the tailored and metered application of coolant to the gap. The controlled discharge of coolant from the internal space can thereby be achieved in a simple manner by corresponding dimensioning of the coolant discharge channel, for example in respect of the channel cross-section and the channel length.
[0014] In a preferred embodiment the heat shield element has a side wall, which is inclined in the direction of the supporting structure in relation to the hot gas wall. As a result the basic geometry of the heat shield element is configured as a single-shell hollow element, which can be mounted on the supporting structure, thereby forming the internal space. The internal space is thereby delimited or defined in just one direction by the supporting structure and in the other spatial directions by the heat shield element itself.
[0015] In a particularly preferred embodiment the coolant discharge channel penetrates the side wall. The coolant discharge channel can thereby be configured simply as a hole through the side wall, with the internal space being connected to the gap space formed by the gap. Coolant can thus be discharged in a controlled manner from the internal space through the coolant discharge channel due to the pressure difference between the internal space and the gap space defined by the gap.
[0016] To prevent residual coolant leaks from the internal space, a sealing element is preferably fitted between the side wall and the supporting structure. By inclining the side wall in the direction of the supporting structure, if the heat shield is fixed to the supporting structure in a detachable manner, a gap can be provided for thermomechanical reasons, which can result in unwanted coolant leaks. It is therefore particularly advantageous to seal off those gaps, which may cause an uncontrolled blowing out of coolant from the internal space, using suitable sealing measures. This provides a leak-tight connection between the heat shield element and the supporting structure. The sealing element between the side wall and the supporting structure is thereby a particularly simple but effective measure to reduce coolant consumption further. Also, depending on the embodiment, the sealing element can have a damping function, such that the heat shield elements of the heat shield arrangement are mounted on the supporting structure in a mechanically damped manner.
[0017] An impact cooling mechanism is preferably assigned to the internal space of a heat shield element, such that the hot gas wall can be cooled by impact cooling. Impact cooling is thereby a particularly effective method for cooling the heat shield arrangement, with the coolant striking the hot gas wall in a number of discrete coolant jets at right angles to the hot gas wall and cooling the hot gas wall correspondingly from the internal space in an efficient manner.
[0018] The impact cooling mechanism is thereby formed by a number of coolant inlet channels, integrated in the supporting structure. A cooling impact mechanism is already provided in a simple manner by a corresponding number of inlet channels discharging into an internal space of a heat shield element. As well as the function of supporting the heat shield arrangement, the supporting structure also has a coolant distribution function via the number of coolant inlet channels integrated in the supporting structure. The inlet channels can thereby be configured as holes in the wall of the supporting structure.
[0019] In a preferred embodiment the heat shield element is made of a metal or a metal alloy. Metal alloys with a high level of heat resistance with an iron, chromium, nickel or cobalt base are particularly suitable for this purpose. As metals or metal alloys are particularly suitable for a casting process, the heat shield element is advantageously configured as a cast part.
[0020] In a particularly preferred embodiment the heat shield arrangement is suitable for use in a combustion chamber lining of a combustion chamber. Such a combustion chamber provided with a heat shield arrangement is preferably suitable as a combustion chamber of a gas turbine, in particular a stationary gas turbine.
[0021] The advantages of such a gas turbine and such a combustion chamber are clear from the above details relating to the heat shield arrangement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention is described in more detail below based on examples with reference to the schematic and in some instances highly simplified drawings, in which:
[0023] FIG. 1 shows a half section through a gas turbine,
[0024] FIG. 2 shows a sectional view of a heat shield arrangement according to the invention,
[0025] FIG. 3 shows a detailed view of the detail III in the heat shield arrangement shown in FIG. 2 ,
[0026] FIG. 4 shows an alternative embodiment of the heat shield arrangement shown in FIG. 3 .
[0027] The same reference characters have the same significance in the individual figures.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The gas turbine 1 according to FIG. 1 has a compressor 2 for the combustion air, a combustion chamber 4 and a turbine 6 to drive a compressor 2 and a generator or machine (not shown in further detail here). To this end the turbine 6 and compressor 2 are disposed on a common turbine shaft 8 also referred to as a turbine rotor, to which the generator or machine is also connected, and which is supported such that it can be rotated about its central axis 9 . The combustion chamber 4 configured in the manner of an annular combustion chamber is fitted with a number of burners 10 to burn a fluid or gaseous fuel.
[0029] The turbine 6 has a number of rotating blades 12 connected to the turbine shaft 8 . The blades 12 are disposed in a rim shape on the turbine shaft 8 , thereby forming a number of rows of blades. The turbine 6 also has a number of fixed vanes 14 , which are also fixed in a rim shape, forming rows of vanes on an internal housing 16 of the turbine 6 . The blades 12 thereby serve to drive the turbine shaft by pulse transmission of the hot medium flowing through the turbine 6 , the working medium or the hot gas M. The vanes 14 on the other hand serve to guide the flow of the working medium M between two successive rows of blades or blade rims when viewed in the direction of flow of the working medium M. A successive pair from a rim of vanes 14 or a vane 3 and from a rim of blades 12 or a row of blades is thereby also referred to as a turbine stage.
[0030] Each vane 14 has a platform 18 also referred to as a vane base, which is disposed as a wall element to fix the respective vane 14 to the internal housing 16 of the turbine 6 . The platform 18 is thereby a component that is subject to a comparatively high level of thermal loading and forms the outer limit of a hot gas channel for the working medium M flowing through the turbine 6 . Each blade 12 is fixed in a similar manner to the turbine shaft 8 via a platform 20 also referred to as a blade base.
[0031] A guide ring 21 is disposed on the internal housing 16 of the turbine 6 between the platforms 18 of the vanes 14 of two adjacent rows of vanes, said platforms being disposed at a distance from each other. The outer surface of each guide ring 21 is thereby also exposed to the hot working medium M flowing through the turbine 6 and separated radially from the outer end 22 of the blade 12 opposite by a gap. The guide rings 21 disposed between adjacent rows of vanes thereby serve in particular as cover elements, protecting the internal wall 16 or other integral parts of the housing from thermal overload due to the hot working medium M, the hot gas, flowing through the turbine 6 .
[0032] The combustion chamber 4 is delimited by a combustion chamber housing 29 , with a combustion chamber wall 24 being formed on the combustion chamber side. In the exemplary embodiment the combustion chamber 4 is configured as a so-called annular combustion chamber, whose number of burners 10 disposed in a peripheral direction around the turbine shaft 8 discharge in a common combustion chamber space. To this end the combustion chamber 4 is generally configured as an annular structure, positioned around the turbine shaft 8 .
[0033] To achieve a comparatively high level of a efficiency, the combustion chamber is designed for a comparatively high temperature of the working medium M of around 1200° C. to 1500° C. To achieve a comparatively long operating life, even with such unfavorable operating parameters for the materials, the side of the combustion chamber wall 24 facing the working medium M is provided with a heat shield arrangement 26 , which forms a combustion chamber lining. Because of the high temperatures inside the combustion chamber 4 a cooling system is also provided for the heat shield arrangement 26 . The cooling system is thereby based on the principle of impact cooling, in which cooling air is blown under pressure as the coolant K at sufficiently high pressure at a number of points onto the component to be cooled at right angles to its component surface. Alternatively the cooling system can also be based on the principle of convective cooling or can make use of this cooling principle in addition to impact cooling.
[0034] The cooling system is designed to be of simple structure for reliable application of coolant K to a large area of the heat shield arrangement and also for the lowest possible coolant consumption.
[0035] To illustrate and describe the cooling concept of the invention in more detail, FIG. 2 shows a heat shield arrangement 26 , which is particularly suitable for use as a heat-resistant lining of a combustion chamber 4 of a gas turbine 1 . The heat shield arrangement 26 comprises heat shield elements 26 A, 26 B, which are disposed next to each other on a supporting structure 31 leaving gaps 45 . The heat shield elements 26 A, 26 B have a hot gas wall 39 to be cooled, which has a hot side 35 facing the hot gas M and subject to the action of the hot gas M during operation and a cold side 33 opposite the hot side 35 .
[0036] For cooling purposes the heat shield elements 26 A, 26 B are cooled from their cold side 33 by a coolant K, for example cooling air, which is delivered to the internal space 37 formed between the heat shield elements 26 A, 26 B and the supporting structure 31 via suitable inlet channels 41 , 41 A, 41 B, 41 C and guided in a direction at right angles to the cold side 33 of a respective heat shield element 26 A, 26 B. The principle of open cooling is used here. After completion of the cooling task at the heat shield elements 26 A, 26 B, the at least partly warmed air is mixed with the hot gas M. For controlled discharge and precise metering of coolant K from the internal space, a coolant discharge channel 43 is provided, which discharges from the internal space 37 into the gap 45 . This means that a precisely predefinable mass flow of coolant K can be delivered to the gap 45 . The number of inlet channels 41 , 41 A, 41 B, 41 C, each assigned to an internal space 37 of a respective heat shield element 26 A, 26 B, form an impact cooling mechanism 53 , such that the hot gas wall 39 can be cooled particularly effectively by means of impact cooling. The inlet channels 41 , 41 A, 41 B, 41 C for the coolant K are hereby integrated by means of corresponding holes in the wall 47 of the supporting structure. The inlet channels 41 , 41 A, 41 B, 41 C thereby discharge into the internal space 37 such that the coolant strikes the hot gas wall 39 at right angles. After the hot gas wall 39 has been undergone impact cooling, the coolant K is discharged from the internal space 37 in a controlled manner through the correspondingly dimensioned coolant discharge channel 43 into the gap 45 , where a sealing effect is achieved in respect of the hot gas M, protecting the critical components, such as the supporting structure 31 .
[0037] FIG. 3 shows an enlarged illustration of the detail III in the heat shield arrangement shown in FIG. 2 . The heat shield element 26 A has a side wall 49 , which is inclined in the direction of the supporting structure 31 in relation to the hot gas wall 39 . The heat shield element 26 B disposed adjacent to the heat shield element 26 A is configured in the same manner with a side wall 49 . The coolant discharge channel 43 is configured as a hole through the side wall 43 of the heat shield element 26 A, which discharges through the side wall 43 at an oblique angle rising slightly in the direction of the hot side into the gap 45 . The oblique discharge means that, after establishing a sealing effect in the gap 45 , the coolant K leaves the gap 45 , where possible forming a cooling film of coolant K along the hot side 35 of the heat shield element 26 B adjacent to the heat shield element 26 A. This additional film cooling effect, achieved with the tailored supply of the coolant K into the gap 45 , advantageously means that the coolant K is used in a multiple manner for different cooling purposes in the heat shield arrangement 26 .
[0038] So that the heat shield elements 26 A, 26 B can be fixed in a manner that is tolerant of thermal expansion, the side walls 49 are not in direct contact with the supporting structure 31 but are connected to the supporting structure 31 via a respective sealing element 51 . The sealing elements thereby satisfy both a sealing function for the coolant K and a mechanical damping function for the heat shield arrangement 26 . The sealing element 51 means that the coolant K cannot pass from the internal space 37 into the gap 45 in an uncontrolled manner and be blown in the direction of the hot side 35 . Rather the sealing element 51 brings about an additional reduction in the quantity of coolant K needed to cool the heat shield arrangement 26 . The combination of sealing element 51 and coolant discharge channel 43 allows a particularly favorable coolant balance to be achieved. Also a longitudinal flow along the bottom of the wall 47 of the supporting structure 31 facing the internal space 37 is achieved by means of the sealing elements 51 assigned respectively to the internal space 37 . The leak-tight connection between the heat shield element 26 A, 26 B and the supporting structure 31 via the sealing element 51 is a particularly simple and effective measure for reducing coolant consumption further.
[0039] It is also possible, although more complex from a manufacturing point of view—as shown in FIG. 4 —for the coolant discharge channel 43 to extend through the wall 47 of the supporting structure 31 . This embodiment also allows tailored delivery of the coolant K into the gap 45 after completion of the cooling task at a heat shield element 26 A. The gap 45 and the sealing elements 51 delimiting the gap 45 in the vicinity of the discharge point of the coolant discharge channel 43 are cooled as a result. In particular the side walls 49 delimiting the gap 45 are also cooled by convection. | The invention relates to a heat shield arrangement for a hot gas (m)-guiding component, which comprises a number of heat shield elements arranged side-by-side on a supporting structure while leaving a gap there between. A heat shield element can be mounted on the supporting structure whereby forming an interior space which is delimited in areas by a hot gas wall to be cooled, with an inlet channel for admitting a coolant into the interior space. According to the invention, a coolant discharge channel is provided for the controlled discharge of coolant from the interior space and, from the interior space, leads into the gap. Coolant can be saved and efficiently used by the specific coolant discharge via the coolant discharge channel, and reduction in pollutant emissions can also be achieved. The heat shield arrangement is particularly suited for linking a combustion chamber of a gas turbine. | 5 |
SUMMARY OF THE INVENTION
The present invention is directed to a compound of the formula: ##STR2## wherein R 1 represents lower alkyl, lower alkoxy, nitro, amino, cyano, trifluoromethyl, acetyl, methylthio, methylsulfinyl, methylsulfonyl, benzoyl, substituted benzoyl, aminosulfonyl or halogen; and R 2 and R 3 are the same or different and are selected from the group consisting of hydrogen, lower alkyl, lower alkoxy, amino, cyano, trifluoromethyl, acetyl, methylthio, methylsulfinyl, methylsulfonyl, benzoyl, substituted benzoyl, aminosulfonyl or halogen. The invention also includes the pharmaceutically-acceptable salts of the compounds described herein.
As used herein, the term "halogen" represents bromo, chloro or fluoro; "lower alkyl" refers to an alkyl group having from 1 to 3 carbon atoms, such as methyl, ethyl, propyl or isopropyl; "lower alkoxy" refers to an alkoxy group having from 1 to 3 carbon atoms such as methoxy, ethoxy, propoxy or isopropoxy; "substituted benzoyl" refers to a benzoyl group in which the benzene ring is monosubstituted, disubstituted or trisubstituted with substituents selected from the group consisting of bromo, chloro or methyl; and "pharmaceutically-acceptable salts" refers to the acid addition salts of those bases which will form a salt with the benzenesulfonic acid and which will not cause an adverse physiological effect when administered to an animal at dosages consistent with good pharmacological activity. Suitable bases thus include the alkali metal and alkaline earth metal hydroxides, carbonates and bicarbonates, such as sodium hydroxide, potassium hydroxide, calcium hydroxide, potassium carbonate, sodium bicarbonate and magnesium carbonate.
In general, the compounds within the scope of the invention are solids having some water solubility and varying solubility in organic solvents such as methylene chloride, methanol and ethanol. The compounds disclosed herein exhibit antiviral activity and thus can be used to inhibit viral replication by contacting a virus and, preferably, virus host cells with an effective amount of the appropriate subject compound. The present invention is further directed to methods of using the compounds of the invention as antiviral agents in which a virus or virus host cell (i.e., a cell susceptible to infection by the virus) is contacted with an effective amount of one or more of the subject compounds. The present invention is also directed to antiviral compositions which can contain from about 0.00001 percent (%) or less to about 99% by weight of the active compound in combination with a pharmaceutically-acceptable carrier. Typically, in those compositions employing a low percentage of active compound, the pharmaceutically-acceptable carrier is in liquid form, therefore a composition containing 0.00001% or less by weight of active compound is equivalent to a composition containing about 0.1 microgram (μg) or less of the active compound per milliliter (ml) of carrier.
DETAILED DESCRIPTION OF THE INVENTION
Compounds within the scope of the present invention are prepared by reacting a compound of the formula: ##STR3## (sulfanilic acid, i.e. 4-aminobenzenesulfonic acid, when the desired subject compound is a 4-(((substituted-phenyl)methyl)amino)benzenesulfonic acid derivative or metanilic acid, i.e. 3-aminobenzenesulfonic acid when a 3-(((substituted-phenyl)methyl)amino)benzenesulfonic acid derivative is desired) with a ring substituted benzyl halide of the formula: ##STR4## wherein X represents halide, generally bromide or chloride; and R 1 , R 2 and R 3 have the same meanings as previously defined herein.
The reaction proceeds when the above reactants (preferably, in approximately equimolar concentrations) are contacted and mixed in water, and heated to a temperature, generally from about 40° C. to about 90° C. in the presence of a base, such as sodium hydroxide, for a time sufficient to obtain the desired subject compound as a salt, usually from about 3 hours to about 8 hours, although longer reaction times may be required.
The free acid is obtained by treating the salt with an appropriate acid, such as hydrochloric acid. The salt of free acid is recovered from the reaction mixture by conventional procedures such as filtration, centrifugation and decantation. Purification of the product is accomplished by procedures well known in the art, such as recrystallization.
Alternatively, compounds within the scope of the invention can be prepared by adding the preselected ring-substituted benzyl halide (usually, as a solution of the benzyl halide in acetonitrile) to a mixture of the compound of formula II (i.e., sulfanilic acid or metanilic acid) in water and acetonitrile in the presence of a base such as sodium acetate or sodium acetate trihydrate. The resulting mixture is refluxed for a time sufficient to obtain the desired subject compound as a salt. Usually a reflux time of about 2 to about 7 hrs. is sufficient. The free acid can be obtained and recovered as previously described herein.
The following examples are included to further illustrate the invention but are not to be construed as a limitation thereon.
EXAMPLE 1
Sodium 4-(((3-Chlorophenyl)methyl)amino)benzenesulfonate
A mixture of 17.2 g of sulfanilic acid, 100 ml of 5 Normal (N) sodium hydroxide solution, 100 ml of water and 16.1 g of 3-chlorobenzyl chloride was stirred in a 500-ml Erlenmeyer flask and heated to about 40°-50° C. After 5 days, a small portion of the reaction mixture was poured into dilute hydrochloric acid. A white precipitate formed which was insoluble in boiling water. The remaining portion of the reaction mixture was poured over 800 ml of ice-water, acidified with concentrated hydrochloric acid, and then filtered through a sintered glass funnel. After filtering, about 50 ml of slurry remained in the funnel. This slurry was put in a beaker, 200 ml of ethanol was added and the mixture was warmed to about 50° C. A solution of 5N sodium hydroxide was added dropwise until solution was achieved. The solution was carbon treated and filtered. Concentration of the filtrate gave a gummy semisolid which was recrystallized from 200 ml of acetic acid containing a small quantity of water. After vacuum oven drying, 5.4 g of the purified product, sodium 4-(((3-chlorophenyl)methyl)amino)benzenesulfonate, was obtained as an off-white solid having a melting point (mp) greater than 280° C.
A nuclear magnetic resonance spectrum confirmed the structure.
EXAMPLE 2
Sodium 4-(((4-Fluorophenyl)methyl)amino)benzenesulfonate
To 17.3 g (0.1 mole) of sulfanilic acid, 100 ml of 5N sodium hydroxide solution and 100 ml of water was added 14.4 g (0.1 mole) of 4-fluorobenzyl chloride which was then mixed and heated to about 45°-55° C. in a 500-ml Erlenmeyer flask for 48 hours. After heating, the reaction mixture was poured over approximately 1 liter of cold water and acidified with concentrated hydrochloric acid. The resulting slurry was slowly filtered through a fine sintered glass funnel and a top clear yellow solution which did not pass through the filter was decanted away and discarded. The remaining off-white solid was mixed with 100 ml of ethanol and aqueous NaOH solution was added slowly until solution was achieved. The solution was then carbon treated, filtered and concentrated under reduced pressure to obtain 9.0 g of the crude product. Recrystallization from 80 ml of glacial acetic acid, followed by vacuum oven drying gave 2.4 g of the purified product, sodium 4-(((4-fluorophenyl)methyl)amino)benzenesulfonate, as white crystals which decomposed at 275° C.
The structure was confirmed by nuclear magnetic resonance spectroscopy.
EXAMPLE 3
Sodium 4-(((3,4-Dimethylphenyl)methyl)amino)benzenesulfonate
To 17.3 g of sulfanilic acid, 100 ml of 5N sodium hydroxide solution and 100 ml of water was added 15.5 g of 3,4-dimethylbenzyl chloride and the resulting mixture was then heated to about 50°-60° C. in a 500-ml Erlenmeyer flask for 72 hours. The reaction mixture was poured over approximately 1 liter of ice-water and acidified with concentrated hydrochloric acid to give a solid. The solid was collected by filtration and washed with 100 ml of diethyl ether. Then the product was slurried in hot water and filtered again. After drying, 6.4 g of solid was obtained. The solid was slurried in ethanol and one equivalent of an aqueous sodium hydroxide solution added. Upon removal of the solvent under reduced pressure, 8.2 g of a tan semi-solid was obtained. Recrystallization from an ethanol/water solution gave 1.4 grams of the purified product, sodium 4-(((3,4-dimethylphenyl)methyl)amino)benzenesulfonate, as pale yellow crystals having a melting point of greater than 280° C. Nuclear magnetic resonance spectroscopy confirmed the structure.
EXAMPLE 4
4-(((4-Bromophenyl)methyl)amino)benzenesulfonic Acid
A mixture of 27.7 g (0.16 mole) of sulfanilic acid, about 28 grams of 50% sodium hydroxide solution, approximately 400 ml of water and 50 grams (0.20 mole) of 4-bromobenzyl bromide were stirred and heated to about 80°-85° C. for 5 hours (hrs). Upon cooling to room temperature, a solid formed which was removed by vacuum filtration. The solid was added to water and the resulting mixture heated and then acidified with concentrated hydrochloric acid. The mixture was filtered while still warm, about 50° C., and the white amorphous solid remaining was air-dried to give 14.8 g of the purified product, 4-(((4-bromophenyl)methyl)amino)benzenesulfonic acid, as a white powder having a melting point greater than 260° C.
An infrared spectrum (potassium bromide pellet) showed broad stretching from 3150-2300 cm -1 , and intense signals at 1620, 1590, 1435, 1240, 1155, 1120, 1035, 1010, 825 and 680 cm -1 . A nuclear magnetic resonance spectrum (dimethylsulfoxide-d 6 solution) was as follows: δ 9.82 (S, 2H, NH and SO 3 H), 7.65-7.25 (m, 6H, aromatic), 6.85 (d, J=8 Hz, 2H, aromatic), 4.40 (S, 2H, CH 2 ).
EXAMPLE 5
4-(((4-Chlorophenyl)methyl)amino)benzenesulfonic Acid
To a stirred mixture of 76.6 g (0.44 mole) of sulfanilic acid in 300 ml of water was added 75 g (0.93 mole) of 50% sodium hydroxide solution. The mixture was heated to 80° C. and 100 g (0.62 mole) of 4-chlorobenzyl chloride was added. The dark mixture was stirred at about 80°-85° C. for 4 hours.
After the reaction mixture cooled overnight, the excess 4-chlorobenzyl chloride was removed from the reaction mixture by extracting with diethyl ether. Acidificaton with approximately 40 ml of concentrated hydrochloric acid resulted in the precipitation of a fine tan solid which was removed by filtration. A portion of the solid was recrystallized from 95% ethanol to yield the purified product, 4-(((4-chlorophenyl)methyl)amino)benzenesulfonic acid, having a melting point greater than 270° C.
EXAMPLE 6
4-(((2-Fluorophenyl)methyl)amino)benzenesulfonic Acid
To a mixture of 42.8 g (0.247 mole) of sulfanilic acid in 200 ml of water was added 20 g (0.25 mole) of 50% sodium hydroxide solution. To the resulting dark solution, 50 g (0.345 mole) of 2-fluorobenzyl chloride was added. The mixture was stirred and heated to about80° C. for 33/4 hours. The reaction mixture was cooled to 50° C. and then vacuum filtered which resulted in the recovery of a light green powder. The powder was stirred in 700 ml of hot water and the mixture was acidified with concentrated hydrochloric acid and then cooled to 40° C. and vacuum filtered leaving 37.7 grams of solid.
A portio of the solid, 28 g, was mixed with ethanol and 50% sodium hydroxide added, utilizing the methodology previously described herein to obtain the sodium salt, sodium-4-(((2-fluorophenyl)methyl)amino)benzenesulfonate having a melting point of greater than 275° C.
The remaining 9.7 g of solid was recrystallized to give the purified product 4-(((2-fluorophenyl)methyl)amino)benzenesulfonic acid, having a melting point greater than 270° C.
Other subject compounds prepared essentially as described herein are:
EXAMPLE 7
4-(((4-Methylphenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 270° C.
EXAMPLE 8
4-(((2,6-Dichlorophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 270° C.
EXAMPLE 9
4-(((3,4-Dichlorophenyl)methyl)amino)benzenesulfonic Acid, decomposition at 280° C.
EXAMPLE 10
4-(((3-Fluorophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 11
4-(((4-Nitrophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 12
4-(((3-(Trifluoromethyl)phenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 13
4-(((3-Nitrophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 14
4-(((2,5-Dimethylphenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 15
4-(((2,4,6-Trimethylphenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 16
4-(((3-Bromophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 17
4-(((4-(1-Methylethyl)phenyl)methyl)amino)benzenesulfonic Acid
To a 1-liter (1) 3-necked round-bottomed flask equipped with an overhead stirrer, reflux condenser and dropping funnel and containing a stirred mixture of 52.0 g (0.30 mole) of sulfanilic acid in 225 ml of warm (˜65° C.) water was added 83.0 g (0.61 mole) of sodium acetate trihydrate and 75 ml of acetonitrile. The temperature of the resulting yellow solution was stabilized at about 70° C. and a solution of 33.8 g (0.20 mole) of 4-(1-methylethyl)benzyl chloride in 75 ml of acetonitrile was added over 70 minutes. The solution was then refluxed for an additional 31/2 hrs, and 95 ml of acetonitrile was removed by distillation over a 30 minute period, during which time 50 ml of concentrated hydrochloric acid (con. HCl) was added dropwise. The resulting mixture was filtered hot (˜80° C.) and the collected solids were slurried in 300 ml of boiling methanol for 15 min. and then vacuum filtered. The slurrying and vacuum filtration process was repeated first with 300 ml of warm (65° C.) water and then again with 300 ml of boiling methanol. Air-drying of the collected solids gave 12.51 g (20.5% yield) of purified 4-(((4-(1-methylethyl)phenyl)methyl)amino)benzenesulfonic acid as a white powder, having a melting point greater than 275° C.
EXAMPLE 18
4-(((2,4-Dichlorophenyl)methyl)amino)benzenesulfonic Acid
To a mixture of 52.0 g (0.30 mole) of sulfanilic acid in 225 ml of warm water was added 83 g (0.61 mole) of sodium acetate trihydrate and 75 ml of acetonitrile. Then a solution of 37.1 g (0.19 mole) of 2,4-dichlorobenzyl chloride in 75 ml of acetonitrile was added and the resulting solution refluxed for 31/2 hrs, followed by the dropwise addition of 50 ml of conc. HCl while simultaneously removing 75 ml of acetonitrile by distillation. The reaction mixture was filtered while hot (80° C.) and the same purification sequence utilized as described in the previous example, which gave 34.91 g (55.3% yield) of purified 4-(((2,4-dichlorophenyl)methyl)amino)benzenesulfonic acid as a white powder having a melting point greater than 275° C.
EXAMPLE 19
4-(((4-Benzoylphenyl)methyl)amino)benzenesulfonic Acid
To a stirred melt of 75.0 g (0.38 mole) of 4-methylbenzophenone maintained at a temperature of approximately 150° C. in a 500-ml 3-necked round-bottomed flask equipped with overhead stirrer, reflux condenser and dropping funnel was added 61 g (19.7 ml, 0.38 mole) of bromine. The dark mixture was stirred at 150° C. for an additional hour and then allowed to cool to about 90° C. The mixture was then poured into water, resulting in the formation of an oil which solidified upon standing overnight, affording about 70 g of a cream-colored solid. The cream-colored solid was recrystallized from absolute ethanol to give 42.6 g of tan needles, mp 81°-85° C. A second recrystallization from 95% ethanol afforded 36.3 g of purified 4-(bromomethyl)benzophenone as tan flakes, mp 85°-89° C.
To a 1-liter 3-necked round-bottomed flask equipped with overhead stirrer, reflux condenser, dropping funnel and thermometer and containing a stirred slurry of 33.8 g (0.195 mole) of sulfanilic acid in 150 ml of warm (60° C.) water was added 55 g (0.404 mole) of sodium acetate trihydrate and 50 ml of acetonitrile. The resulting yellow solution was heated to 70° C. and a solution of 35 g (0.127 mole) of the 4-(bromomethyl)benzophenone prepared above in 80 ml of acetonitrile was added dropwise over 11/2 hrs. The resulting solution was then refluxed for 5 hrs. Approximately 75 ml of acetonitrile was then removed by distillation at the same time that a dropwise addition of 32 ml of conc. HCl (over a 20 minute period) was made. The mixture was then vacuum filtered at 80° C. which gave a pale yellow powder. The powder was then slurried in 250 ml of water for 15 minutes and again isolated by vacuum filtration. The resulting solids were reslurried in 250 ml of methanol and isolated by vacuum filtration which afforded 25.28 g (54.2%) of purified 4-(((4-benzoylphenyl)methyl)amino)benzenesulfonic acid as a pale yellow powder, which decomposed at 257°-259° C.
EXAMPLE 20
4-(((-4-(Methylsulfonyl)phenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 260° C.
The compound of example 20 was prepared essentially as described in the preceding examples.
EXAMPLE 21
3-(((3,4-Dichlorophenyl)methyl)amino)benzenesulfonic Acid
To a warm (˜65° C.) mixture of 52.0 g (0.30 mole) of 3-aminobenzenesulfonic acid in 225 ml of water was added 50.3 g (0.61 mole) of sodium acetate, and 75 ml of acetonitrile. The resulting dark solution was warmed to approximately 70° C., and a solution of 39.1 g (0.20 mole) of 3,4-dichlorobenzyl chloride in 75 ml of acetonitrile was added dropwise over 55 minutes. The dark solution was then heated at reflux for 21/2 hrs. To this solution was then added 48 ml of conc. HCl dropwise over 30 minutes at the same time that 85 ml of acetonitrile was removed by distillation.
The resulting mixture was vacuum filtered at 80° C. and air-dried to give 53.14 g of off-white powder. The powder was slurried in 200 ml of water at 80° C. for 20 minutes, and then isolated by vacuum filtration. The resulting solids were reslurried in 200 ml of boiling methanol for 20 minutes, and then isolated by vacuum filtration. The solids were then dried overnight in vacuo at 50° C. which afforded 36.2 g (54.8%) of purified 3-(((3,4-dichlorophenyl)methyl)amino)benzenesulfonic acid as a white powder having a melting point greater than 275° C.
EXAMPLE 22
3-(((3-(Trifluoromethyl)phenyl)methyl)amino)benzenesulfonic Acid
To 52.0 g (0.30 mole) of 3-aminobenzenesulfonic acid in 225 ml of water was added 83.0 g (0.61 mole) of sodium acetate trihydrate and 75 ml of acetonitrile. The solution was stabilized at about 70° C. and a solution of 38.92 g (0.20mole) of 3-(trifluoromethyl)benzyl chloride in 75 ml of acetonitrile was added dropwise. The resulting orange solution was refluxed for 4 hrs, then acidified by the dropwise addition of 42 ml of conc. HCl while simultaneously removing 105 ml of acetonitrile by distillation. After standing overnight, a flocculent cream-colored solid crystalized which was removed by vacuum filtration. The collected solids were then slurried in 300 ml of warm (60° C.) water for 20 minutes and then filtered. The slurrying process was repeated using 300 ml of boiling methanol and the solids isolated by vacuum filtration. Air-drying in vacuo at about 60° C. gave 15.4 g (23.2% yield) of purified 3-(((3-(trifluoromethyl)phenyl)methyl)amino)benzenesulfonic acid as a white powder having a melting point greater than 275° C.
EXAMPLE 23
3-(((4-Nitrophenyl)methyl)amino)benzenesulfonic Acid
After 52.0 g (0.30 mole) of 3-aminobenzenesulfonic acid in 225 ml of warm (65° C.) water and 83.0 (0.61 mole) of sodium acetate trihydrate in 75 ml of acetonitrile was combined and the temperature stabilized at approximately 68°-70° C., 43.2 g (0.20 mole) of 4-nitrobenzyl bromide in 85 ml of warmed acetonitrile was added dropwise over 70 minutes. The orange-red solution was then refluxed for 2 hrs, then acidified with 42 ml of conc. HCl over 40 minutes while simultaneously distilling off 110 ml of acetonitrile. The mixture was filtered hot (70° C.) which gave a light yellow powder. The powder was slurried in 275 ml of hot (75° C.) water for 20 minutes and then filtered. The slurrying process was repeated with water and then with methanol which gave a cream-colored powder. The cream-colored powder was dried in vacuo overnight at 50° C. to afford 35.33 g (57.3% yield) of purified 3-(((4-nitrophenyl)methyl)amino)benzenesulfonic acid as a cream-colored powder having a melting point greater than 275° C.
EXAMPLE 24
3-(((2,5-Dimethylphenyl)methyl)amino)benzenesulfonic Acid
To a stirred slurry of 52.0 g (0.30 mole) of 3-aminobenzenesulfonic acid in 225 ml of hot (65° C.) water was added 83.0 g (0.61 mole) of sodium acetate trihydrate and 75 ml of acetonitrile. The temperature was stabilized at approximately 67°-68° C. and a solution of 30.93 g (0.20 mole) of 2,5-dimethylbenzyl chloride in 75 ml of acetonitrile added dropwise over 1 hr. The resulting orange solution was refluxed for 31/2 hrs, then acidified with 40 ml of conc. HCl while simultaneously distilling off 80 ml of acetonitrile. After placing the reaction mixture in a refrigerator a flocculent cream-colored precipitate formed which was collected by vacuum filtration, washed with water and air-dried. The collected solids were then slurried in 400 ml of boiling methanol for 20 minutes, then vacuum filtered and then dried in vacuo at about 60° C., which afforded 30.86 g (53.0% yield) of purified 3-(((2,5-dimethylphenyl)methyl)amino)benzenesulfonic acid as a white powder having a melting point greater than 275° C.
EXAMPLE 25
3-(((2,4,6-Trimethylphenyl)methyl)amino)benzenesulfonic Acid
A mixture of 52.0 g (0.30 mole) of 3-aminobenzenesulfonic acid, 83.0 g (0.61 mole) of sodium acetate trihydrate, 33.7 g (0.20 mole) of 2,4,6-trimethylbenzyl chloride, 225 ml of water and 150 ml of acetonitrile was refluxed for 4 hrs, then acidified by the dropwise addition of 40 ml of conc. HCl over 30 minutes during which time approximately 100 ml of acetonitrile was distilled off. The resulting mixture was vacuum filtered while hot (80° C.) and a grayish-white powder obtained which was then slurried in 300 ml of hot (65° C.) water for 20 minutes and vacuum filtered. The slurrying process was repeated with water and then with 300 ml of boiling methanol for 20 minutes. Vacuum filtration followed by drying in vacuo at about 60° C. afforded 24.85 g (40.7% yield) of purified 3-(((2,4,6-trimethylphenyl)methyl)amino)benzenesulfonic acid as a white powder having a melting point greater than 275° C.
Other subject compounds prepared essentially as described herein are:
EXAMPLE 26
3-(((3-Bromophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 27
3-(((3-Chlorophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 28
3-(((4-Chlorophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 285° C.
EXAMPLE 29
3-(((2,6-Dichlorophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 30
3-(((3-Nitrophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 31
3-(((4-Methylphenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 285° C.
EXAMPLE 32
3-(((2,4-Dimethylphenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 33
3-(((4-Fluorophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 285° C.
EXAMPLE 34
3-(((4-Bromophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 285° C.
EXAMPLE 35
3-(((2-Chlorophenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
EXAMPLE 36
3-(((4-(1-Methylethyl)phenyl)methyl)amino)benzenesulfonic Acid, melting point greater than 275° C.
The physical properties of the above examples are summarized in Table 1.
TABLE 1__________________________________________________________________________CompoundExample Calculated % Found %Number % Yield mp, °C. C H N C H N__________________________________________________________________________1 17.5 >280 48.84 3.47 4.38 48.8 3.58 4.572 29.7 275 decomp. 51.49 3.66 4.62 51.5 3.71 4.813 21.9 >280 *4 22.4 >260 45.62 3.54 4.09 45.64 3.65 3.955 1.1 >270 52.43 4.06 4.70 52.71 4.10 4.686 34.1 >270 55.50 4.30 4.98 55.3 4.35 5.057 11.5 >270 60.63 5.45 5.05 60.35 5.77 5.168 33.6 >270 47.00 3.34 4.22 46.75 3.59 4.199 63.3 280 decomp. 47.00 3.34 4.22 46.83 3.32 4.2010 13.4 >275 55.50 4.30 4.98 55.38 4.41 5.0211 73.4 >275 50.64 3.92 9.09 50.34 3.91 8.8412 57.3 >275 50.75 3.65 4.23 50.57 3.81 4.4513 30.8 >275 50.64 3.92 9.09 50.34 4.11 9.0714 59.4 >275 61.83 5.88 4.81 61.62 5.72 4.6715 43.6 >275 62.92 6.27 4.59 62.67 6.38 4.2916 61.4 >275 45.62 3.54 4.09 45.53 3.47 4.1417 20.5 >275 62.92 6.27 4.59 63.23 6.34 4.7918 55.3 >275 47.00 3.34 4.22 46.73 3.46 4.2019 54.2 257-259 decomp. 65.37 4.66 3.81 65.64 4.57 3.8020 62.1 >260 49.25 4.43 4.10 49.49 4.30 3.9821 54.8 >275 47.00 3.34 4.22 46.77 3.45 4.1822 23.2 >275 50.75 3.65 4.23 50.95 3.78 4.2723 57.3 >275 50.64 3.92 9.09 50.37 3.93 8.8524 53.0 >275 *25 40.7 >275 62.92 6.27 4.59 63.15 6.37 4.3926 53.1 >275 45.62 3.54 4.09 45.53 3.47 4.1427 35.8 >275 52.43 4.06 4.70 52.17 4.09 4.8028 48.3 >285 *29 63.5 >275 47.00 3.34 4.22 47.19 3.30 4.1730 62.3 >275 50.64 3.92 9.09 50.36 4.04 8.8631 13.2 >285 60.63 5.45 5.05 60.36 5.31 5.3332 25.1 >275 61.83 5.88 4.81 61.59 5.72 4.5133 30.3 >285 55.50 4.30 4.98 55.29 4.32 5.1534 37.8 >285 45.62 3.54 4.09 45.52 3.60 3.9835 43.9 >275 52.43 4.06 4.70 52.68 4.13 4.6936 20.5 >275 62.92 6.27 4.59 63.23 6.34 4.79__________________________________________________________________________ *The structure of the indicated test compound was confirmed by infrared spectroscopy and/or nuclear magnetic resonance spectroscopy.
Antiviral activity for the subject compounds was demonstrated utilizing the following tissue culture testing procedure:
Monolayered HeLa cells in 16 millimeter (mm) tissue culture dishes were treated with 1 ml of culture medium (Eagles medium supplemented with fetal calf serum) containing subject compound at an appropriate concentration or containing no compound at all. Culture media such as those described herein are more fully described in standard texts, as for example, Kuchler's Biochemical Methods in Cell Culture and Virology, Dowden, Hutchinson and Ross, Inc., Stroudsberg, PA. (1977). Following treatment, cells were challenged with 0.05 ml of rhinovirus type 1A (RV-1A), rhinovirus type 2 (RV-2) or Coxsackie A 21 virus (Cox A 21 ) in culture medium. Some of the compounds were also tested against rhinovirus type 5 (RV-5), rhinovirus type 8 (RV-8) or rhinovirus type 64 (RV-64). Cell controls received no viruses. Cultures were observed for compound cytotoxicity and viral cytopathic effect (CPE) at 48 and 72 hours post-treatment.
Some of the subject compounds were also tested in animals as follows:
Swiss male mice, 10-12 grams in weight, were challenged intraperitonially (IP) with 0.2 ml of a normally lethal dose, i.e. a virus dose sufficient to cause ≅80-100% mortality in infected animals within 10 days of challenge of Cox A 21 virus in phosphate buffered saline containing heat inactivated fetal calf serum. Three hours later mice were treated IP or orally (PO) with 0.2 ml of compound suspended in 0.5% hydroxypropyl methylcellulose (Methocel) or with 0.2 ml of Methocel alone. Compound suspensions had a concentration of 7.5 milligrams/milliliter (mg/ml) which as administered to the animal was equivalent to a dosage of 150 milligrams/kilogram (mg/kg); 20 mg/ml (400 mg/kg); or 30 mg/ml (600 mg/kg). Mice were observed daily for 7-10 days post-challenge and deaths recorded. A modified Mantel-Haenzel combined chi-square (χ 2 ) procedure was used to determine significant difference between virus control and treated groups. Chi-square values greater than 3.84 and considered significant (95% confidence level) in this test.
Results obtained from the above-noted testing are summarized in Table 2.
TABLE 2__________________________________________________________________________Com- Cyto- Animal Testingpoundtoxic- ip poExampleity* Tissue Culture Testing** Dose DoseNumber(μg/ml) RV-1A RV-2 Cox A.sub.21 RV-5 RV-8 RV-64 (mg/kg) X.sup.2 (mg/kg) X.sup.2__________________________________________________________________________1 >200 1.25 25 25 400 11.049 600 4.82 >200 1.25 200 50 400 21.467 600 13.23 >200 1.25 100 25 150 1.0864 >100 <6.25 ≦12.5 ≦12.5 600 0.2015 >100 0.156 50 <6.25 600 5.346 >100 ≦6.25 NA NA 600 1.1337 >100 <6.25 25 25 600 1.318 ≧100 NA NA 100 600 0.299 >100 <6.25 ≦6.25 12.5 25 NA <6.25 600 0.26410 >100 <6.25 NA NA 600 5.2211 >100 <<6.25 6.25 6.25 NA NA <6.2512 >100 <6.25 6.25 50 NA NA <<6.2513 >100 <6.25 50 <6.25 NA NA 12.514 >100 <6.25 NA 10015 100 <6.25 NA 5016 >100 <<6.25 25 5017 >100 12.5 25 NA18 >100 <6.25 50 10019 >100 <<6 6 10020 >400 200 NA NA21 >100 <6.25 12.5 25 25 NA 6.25 600 ***9.63 toxic22 >100 <6.25 50 10023 >100 <6.25 12.5 ±10024 >100 <6.25 ±100 10025 50 <<6.25 12.5 25 600 0.00726 >100 <<6.25 100 50 600 0.00427 >100 <6.25 50 NA28 >100 <6.25 ≦6.25 NA NA NA 12.5 600 ***12.029 toxic29 >100 ≦6.25 100 NA30 >100 ≦6.25 NA NA 600 0.11031 >100 <6.25 ≦6.25 100 6.25 NA 12.5 600 0.10832 >100 <<6.25 12.5 >100 600 0.12333 >100 <6.25 25 NA34 >100 <6.25 <6.25 100 100 NA 6.25 600 0.20935 >100 <6.25 50 NA36 >100 ±100 100 NA__________________________________________________________________________ *Cytotoxicity figures represent the concentration of the compound, micrograms/milliliter (μg/ml) found to be toxic to the cell. **Lowest concentration of the compound (μg/ml) necessary to cause a 50 percent reduction in cytopathic effect. ***The test compound was significantly toxic at the indicated dosage. The symbol "NA" indicates that the compound was not active against that particular virus at the standard test conditions; "<" means "less than"; "≦" means "less than or equal to"; "> " means "greater than"; "≧" means "greater than or equal to"; "±" means "approximately" and "<<" means "considerably less than".
The data in Table 2 demonstrate the antiviral activity of representative compounds falling within the scope of the present invention.
The test data indicate that all of the tested compounds are active against at least one of the test viruses, (RV-1A, RV-2, RV-5, RV-8, RV-64 or Cox A 21 ). In additon, several of the subject compounds (at the 95% confidence level) are active antiviral compounds in testing with mice. When tested in another tissue culture testing system, the compound 4-(((4-bromophenyl)meythyl)amino)benzenesulfonic acid (Example 4) inhibited fifteen of the twenty rhinovirus types it was tested against when the compound was used at a 100 μg/ml concentration. Because of their demonstrated antiviral activity compounds of the formula ##STR5## or a pharmaceutically-acceptable salt thereof wherein R 1 represents halogen; R 2 represents halogen or hydrogen; and R 3 represents hydrogen are preferred.
In using the compounds of the invention, a virus or virus host cell is contacted with an amount of one or more of the compounds effective to inhibit the virus. Although the invention should not be construed as limited to any particular theory of action, it appears that the compounds act to inhibit virus in host cells, rather than by direct chemical or physical inactivation of the virus particle apart from the cell. In antiviral applications carried out in non-living environments, contacting should be carried out in a manner which ensures continued presence of an effective amount of the compound when subsequent contact with host cells occurs. Preferably, the compounds are used by contacting the host cells with an effective antiviral amount (i.e., the amount which must be employed to achieve significant viral inhibition) of one or more of the compounds. The contacting can be carried out directly, as by addition of the compound to cells in tissue culture, to inhibit contaminating picornaviruses. Contacting can also be carried out by administering an antiviral dosage of a compound of the invention to an animal (preferably a mammal). The compounds can be administered to animals parenterally (for example, by intraperitoneal, subcutaneous or intravenous injection) or orally, and the oral antiviral activity of certain of the compounds is a feature of the invention. In such applications, an effective antiviral dose of one or more of the compounds is administered to an animal. Selection of the compound or compounds for administration to animals in particular cases is dictated by considerations such as toxicity, mutagenicity, ease of administration, antiviral activity (potency), stability, compatibility with suitable carriers, etc.
The exact amount of the compound or compounds to be employed, i.e., the amount of the subject compound or compounds sufficient to provide the desired effect, depends on various factors such as the compound employed; type of contacting or administration; the size, age and species of animal; the route, time and frequency of administration; the virus or viruses involved, and whether or not the compound is administered prophylactically or is administered to an infected animal to inhibit the infecting virus. In particular cases, the amount to be administered can be ascertained by conventional range finding techniques, for example, by observing the effect produced at different rates using conventional virus assay procedures.
The compounds are preferably administered in the form of a composition comprising the compound in admixture with a pharmaceutically-acceptable carrier, i.e., a carrier which is chemically inert to the active compound and which has no detrimental side effects or toxicity under the conditions of use. As shown above, the compounds when administered to tissue culture medium exhibit significant antiviral activity at low concentrations, such as, for example, the 0.156 μg/ml of 4-(((4-chlorophenyl)methyl)amino)benzenesulfonic acid (Example 5) which caused a 50% reduction in cytopathic effect in testing against test virus RV-1A.
Such compositions can contain from about 0.1 microgram or less of the active compound per milliliter of carrier to about 99 percent by weight of the active compound in combination with a pharmaceutically-acceptable carrier.
Preferred compositions include compositions containing from about 0.1 μg of active compound per milliliter of carrier to about 0.0025 to about 0.05 to about 0.25 to about 0.5 to about one to about 10 to about 25 to about 50 percent by weight of active compound in a pharmaceutically-acceptable carrier.
The compositions can be in solid forms such as tablets, capsules, granulations, feed mixes, feed supplements and concentrates, powders, granules or the like; as well as liquid forms such as sterile injectable suspensions, orally administered suspensions, or solutions. The pharmaceutically-acceptable carriers can include excipients, such as surface active dispersing agents, suspending agents, tableting binders, lubricants, flavors and colorants. Suitable excipients are disclosed, for example, in texts such as Remington's Pharmaceutical Manufacturing Thirteenth Edition, Mack Publishing Co., Easton, PA. (1965). | Novel (((substituted-phenyl)methyl)amino)benzenesulfonic acids having antiviral activity are disclosed. Compounds within the scope of the invention have the formula ##STR1## wherein R 1 represents lower alkyl, lower alkoxy, nitro, amino, cyano, trifluoromethyl, acetyl, methylthio, methylsulfinyl, methylsulfonyl, benzoyl, substituted benzoyl, aminosulfonyl or halogen; and R 2 and R 3 are the same or different and are selected from the group consisting of hydrogen, lower alkyl, lower alkoxy, amino, cyano, trifluoromethyl, acetyl, methylthio, methylsulfinyl, methylsulfonyl, benzoyl, substituted benzoyl, aminosulfonyl or halogen. The invention also includes the pharmaceutically-acceptable salts of the novel (((substituted-phenyl)methyl)amino)benzenesulfonic acids. Methods of using the compounds as antiviral agents are also disclosed, as well as compositions which comprise a carrier in combination with a suitable antiviral active compound. | 2 |
[0001] The present invention relates to a method of producing esters from formates and olefinically unsaturated compounds by carbonylation with catalysts based on palladium-containing compounds. The invention further discloses a multiphasic reaction mixture and also nonoic acid methyl ester mixtures obtained by the method of the present invention.
RELATED ART
[0002] Esters, especially esters bearing linear moieties of preferably 8, 9 and 10 carbon atoms, are industrially important for use as plasticizers. Linear and branched esters are also produced for a multiplicity of applications as specialty and fine chemicals such as drugs, scents and insecticides. The esterification of carboxylic acids and the direct methoxycarbonylation of olefins in the presence of carbon monoxide and a palladium catalyst are the most important methods used in industry for production of linear esters (see FIG. 1 ).
[0003] The methodology of carbonylating with formates is reviewed in Appl. Catal. A 1995 p. 25-44. Altogether, esters are manufactured by carbonylation at a rate of more than 120 000 metric tons a year.
[0004] In the literature, there are very few research results in the carbonylation with formates. The catalysts generally used in this context contain ruthenium, iridium or palladium in the presence of various additives, such as promoters, ligands or acids. Ethylene is used as the sole olefin source in almost all the reactions which are known. As the number of carbon atoms in the olefin increases, all processes suffer an enormous reduction in activity, accompanied by enormous losses in chemoselectivity. Since the systems which are known for carbonylation with formates are mostly ligand-free systems, poor regioselectivities are obtained here with higher olefins as well as poor activity and chemoselectivity.
[0005] The analogous production of esters from carbon monoxide and methanol is a thoroughly investigated process. Its disadvantages are the need to use costly high-pressure apparatus and the use of pure carbon monoxide, which is quite costly and highly toxic and is produced from fossil resources.
[0006] In summary, no hydroesterification process is known for reacting higher olefins than ethylene as well as ethylene, especially olefin-containing mixtures, with good chemoselectivities (>95%), good regioselectivities (>90%), good activities (TOF>100 h −1 ) and—when olefin-containing mixtures comprising internal carbon-carbon double bonds are used—under isomerizing conditions while not using carbon monoxide as a reactant. It is necessary to hit these numbers if industrial conversions are to be achieved.
PURPOSE OF THE INVENTION
[0007] For the abovementioned reasons there is an immense need for novel improved methods of carbonylating olefinically unsaturated compounds, especially olefin-containing mixtures comprising internal as well as other carbon-carbon double bonds, with formates. A particular purpose is to make even long-chain olefins having more than 2 carbon atoms accessible to carbonylation with formates, i.e. without use of carbon monoxide as a reactant. An accompanying objective is the achievement of high n-selectivities, i.e. the formation of n-terminal esters even from olefin-containing mixtures, and of such activity levels as are required for industrial application.
SUMMARY OF THE INVENTION
[0008] In contrast to the thoroughly investigated production of esters from carbon monoxide and methanol, the method presented herein requires only one substrate, and that is in the liquid state. This substrate, the formate, is an adduct formed from carbon monoxide and an alcohol. It is obtainable from the hydrogenation of CO 2 and thus involves a chemical process which helps to reduce greenhouse gases. The production of esters from carbon monoxide and methanol, by contrast, gets its carbon monoxide raw material mainly from fossil resources, such as coal gasification.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The invention provides a method of producing esters by carbonylation, characterized in that it is carried out
[0010] i) using at least one palladium-containing compound,
[0011] ii) at least one olefinically unsaturated compound,
[0012] iii) at least one phosphorus-containing ligand,
[0013] iv) at least one formate,
[0014] v) at least one alcohol,
[0015] vi) at least one acid,
[0016] vii) in a temperature range of 80° C. to 120° C.,
[0017] viii) at a reaction pressure of 0.1 to 0.6 MPa.
[0018] The palladium-containing catalyst comprises a phosphorus-containing ligand and an acid in a palladium:ligand ratio ranging from 1:1.1 to 1:100 and a palladium:acid ratio ranging from 1:1 to 1:1000 and all ratios are molar ratios.
[0019] The target reaction has a preference for temperatures of 60 to 180° C., more preferably 80 to 120° C.
[0020] The method of the present invention may also utilize solvents for the catalyst. The solvents used are generally polar inert organic solvents, water or the alcohol corresponding to the particular formate, for example methanol in the case of methyl formate and ethanol in the case of ethyl formate. Examples include dipolar aprotic solvents, aliphatic ethers, amides, aromatic compounds, alcohols and esters and also mixtures thereof. The alcohols corresponding to the particular formate are particularly preferable.
[0021] Useful sources of palladium include any palladium-containing salts and complexes in the form of a precursor which form palladium-hydride complexes under the reaction conditions. Examples include Pd(II) halides (e.g. Pd(II)Cl 2 ), Pd(II) complexes (e.g. Pd(II) acetylacetonate, Pd(II) acetate, Pd(II) dibenzylideneacetone), Pd(0) complexes (e.g. Pd(0)[PPh 3 ] 4 ). The palladium compounds can be in different oxidation states from 0 to +II which react with the acid and the formate to form the corresponding active palladium-hydride complexes.
[0022] Palladium acetylacetonate is a particularly preferred precursor.
[0023] To achieve the desired catalytic selectivities and catalytic activities, a phosphorus-containing ligand has to be added. The present method employs this ligand in excess relative to the palladium. The palladium-to-ligand ratio is preferably between 1:2 to 1:50.
[0024] Useful ligands include any desired ligands comprising trivalent phosphorus and capable of forming a coordinative bond with the central palladium atom. A suitable example is α,α′-bis(di-t-butylphosphino)-o-xylene, represented by formula 1 and hereinbelow abbreviated as BuPoX. The binding of ligands can be not only monodentate but also multidentate. Bidentate ligands are preferred.
[0025] A particularly preferred ligand is α,α′-bis(di-t-butylphosphino)-o-xylene, represented by formula 1:
[0000]
[0026] Useful acids include strong acids of pKa below 4, preferably sulphonic acids. Particular preference is given to methanesulphonic acid and p-toluenesulphonic acid from the group of sulphonic acids.
[0027] Olefins are unsaturated compounds capable of being selectively reacted using the catalyst systems mentioned. Terminal alkenes and aromatic olefins having between 2 and 20 carbon atoms, and mixtures thereof, are particularly preferred. Olefins of 6 to 12 carbon atoms and mixtures thereof are particularly preferred. Branched and internal olefins can likewise be reacted.
[0028] The method of the present invention will prove particularly advantageous for the production of esters having 3 to 21 carbon atoms. The production of esters having 7 to 13 carbon atoms is preferred in particular.
[0029] The olefins may be in a functionalized state and include not only carbon and hydrogen but also further, hetero atoms, for example nitrogen and/or oxygen. Without claim to completeness, unsaturated alcohols, ethers, amines, esters, carboxylic acids, amides, urethanes, halides, aldehydes, ketones and epoxides may be mentioned here as useful substrates.
[0030] The invention further provides a multiphasic reaction mixture containing at least one olefinically unsaturated compound and at least one ester formed by the method of the present invention.
[0031] The method of the present invention achieves turnover number values [(TON)=product (mol)/palladium (mol)] for the catalysts on the order of 3400 or more in batch operation. Therefore, between 0.038 mol % of palladium (based on olefin substrate) is typically used.
[0032] Because the catalyst activities are good, the method of the present invention can use very small amounts of catalyst.
[0033] The method of the present invention is particularly surprising and novel in that no comparatively long-chain and highly stereo- and regioselective esters of olefins with sufficient activity have been described in the past. The method described herein shows for the first time that good yields and n-selectivities of n-terminal esters are possible under the conditions of the present invention. The particular advantages of the novel method are that no gases, especially no carbon monoxide, are any longer needed as a reactant, to perform a carbonylation.
[0034] It is additionally possible to produce the formates from the greenhouse gas CO 2 . This enables esters to be produced using an environmentally friendly and less complex process.
[0035] Catalyst activities likewise have to be high for industrial use. The method of the present invention provides them. 1-Octene for instance at a turnover frequency or reaction rate constant of above 209 h −1 and a turnover number of 3400 in batch operation. The result was accordingly a space-time yield of 16.2 g/(l*h) or 0.016 t/(m 3 *h).
[0036] The esters obtained according to the present invention are useful inter alia as intermediates for plasticizer alcohols and for pharmaceuticals and agrochemicals and also as building blocks for polymers.
EXAMPLES
[0037] The examples which follow illustrate the method of the present invention.
[0038] General protocol for production of esters from formate and olefinically unsaturated compounds using a palladium/phosphine/acid catalyst:
[0039] A 100 ml stainless steel autoclave is charged with 54.5 mmol of 1-octene (8.5 ml), Pd(acac) 2 , 0.038 mol % (6.3 mg), 0.13 mol % of BuPoX (28.4 mg), 10 ml of methyl 25 formate, 10 ml of methanol and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C. to establish a final pressure of 0.51 MPa, followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography.
[0040] General information see note [a] in Table 1.
[0041] Table 1 hereinbelow shows changes of some reaction parameters, for example the variation of ligands having the following structures:
[0000]
[0042] The possible product spectrum which the method of the present invention provides on using 1-octene and methyl formate is apparent from reaction (1):
[0000]
[0043] The invention further provides a nonoic acid methyl ester mixture obtained by the method of the present invention.
[0000]
TABLE 1
Palladium-catalysed methoxycarbonylation of 1-octene.
Ex-
T
MeOH/MF
Yield
n-Sel.
ample
Ligand
Acid
[° C.]
[ml/ml]
[%] [b]
[%]
1
1
MeSO 3 H
100
10/10
46 [c]
95
2
1
pTsOH
100
10/10
36 [C]
95
3
1
HOAc
100
10/10
0
—
4
1
—
100
10/10
0
—
5
1
MeSO 3 H
80
10/10
34
95
6
1
MeSO 3 H
100
10/10
98
94
7
1
MeSO 3 H
120
10/10
79
93
8
1
MeSO 3 H
100
0/10
28
95
9
1
MeSO 3 H
100
10/10
98
94
10
2
MeSO 3 H
100
10/10
0
—
11
3
MeSO 3 H
100
10/10
0
—
12
4
MeSO 3 H
100
10/10
0
—
13
5
MeSO 3 H
100
10/10
0
—
14
6
MeSO 3 H
100
10/10
0
—
[0044] [a] unless otherwise stated, the reactions were carried out at 100° C. with 0.038 mol %, of Pd(acac) 2 , UPd=4 (L=BuPoX=1),10 ml of methylformate, 10 ml of methanol, acid/L=4 (=20 μl MeSO 3 H), 54 mmol of olefin. [b] determined by gas chromatography using an internal standard. [c] yields following a reaction time of 5.5 h.
Example 1
[0045] A 100 ml stainless steel autoclave is charged with 54.5 mmol of 1-octene (8.5 ml), Pd(acac) 2 , 0.038 mol % (6.3 mg), 0.13 mol % of BuPoX (28.4 mg), 10 ml of methyl formate, 10 ml of methanol and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C. to establish a final pressure of 5.1 bar, followed by stirring at that temperature for 5.5 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of n-product, i.e. methyl nonanoate, is 43.7%. The yield of branched products (methyl 2-methyloctanoate, methyl 2-ethylheptanoate and methyl 2-propylhexanoate) is altogether 2.3%. The total yield of methyl esters is accordingly 46% with an n:iso ratio of 95:5.
Example 2
[0046] A 100 ml stainless steel autoclave is charged with 54.5 mmol of 1-octene (8.5 ml), Pd(acac) 2 , 0.038 mol % (6.3 mg), 0.13 mol % of BuPoX (28.4 mg), 10 ml of methyl formate, 10 ml of methanol and 58 mg of p-toluenesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C. to establish a final pressure of 5.1 bar, followed by stirring at that temperature for 5.5 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of branched products (methyl 2-methyloctanoate, methyl 2-ethylheptanoate and methyl 2-propylhexanoate) is altogether 1.8%. The total yield of methyl esters is accordingly 36% with an n:iso ratio of 95:5.
Example 3
[0047] A 100 ml stainless steel autoclave is charged with 54.5 mmol of 1-octene (8.5 ml), Pd(acac) 2 , 0.038 mol % (6.3 mg), 0.13 mol % of BuPoX (28.4 mg), 10 ml of methyl formate, 10 ml of methanol and 17.6 μl of acetic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C. to establish a final pressure of 5.1 bar, followed by stirring at that temperature for 5.5 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of methyl nonanoate is 0%.
Example 4
[0048] A 100 ml stainless steel autoclave is charged with 54.5 mmol of 1-octene (8.5 ml), Pd(acac) 2 , 0.038 mol % (6.3 mg), 0.13 mol % of BuPoX (28.4 mg), 10 ml of methyl formate, 10 ml of methanol and no acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C. to establish a final pressure of 5.1 bar, followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of methyl nonanoate is 0%.
Example 5
[0049] A 100 ml stainless steel autoclave is charged with 54.5 mmol of 1-octene (8.5 ml), Pd(acac) 2 , 0.038 mol % (6.3 mg), 0.13 mol % of BuPoX (28.4 mg), 10 ml of methyl formate, 10 ml of methanol and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 80° C., followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of n-product, i.e. methyl nonanoate, is 32.3%. The yield of branched products (methyl 2-methyloctanoate, methyl 2-ethylheptanoate and methyl 2-propylhexanoate) is altogether 1.7%. The total yield of methyl esters is accordingly 34% with an n:iso ratio of 95:5.
Example 6
[0050] A 100 ml stainless steel autoclave is charged with 54.5 mmol of 1-octene (8.5 ml), Pd(acac) 2 , 0.038 mol % (6.3 mg), 0.13 mol % of BuPoX (28.4 mg), 10 ml of methyl formate, 10 ml of methanol and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C. to establish a final pressure of 5.1 bar, followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of n-product, i.e. methyl nonanoate, is 92.1%. The yield of branched products (methyl 2-methyloctanoate, methyl 2-ethylheptanoate and methyl 2-propylhexanoate) is altogether 5.9%. The total yield of methyl esters is accordingly 98% with an n:iso ratio of 94:6.
Example 7
[0051] A 100 ml stainless steel autoclave is charged with 54.5 mmol of 1-octene (8.5 ml), Pd(acac) 2 , 0.038 mol % (6.3 mg), 0.13 mol % of BuPoX (28.4 mg), 10 ml of methyl formate, 10 ml of methanol and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 120° C. to establish a final pressure of 5.1 bar, followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of n-product, i.e. methyl nonanoate, is 73.5%. The yield of branched products (methyl 2-methyloctanoate, methyl 2-ethylheptanoate and methyl 2-propylhexanoate) is altogether 5.5%. The total yield of methyl esters is accordingly 79% with an n:iso ratio of 93:7.
Example 8
[0052] A 100 ml stainless steel autoclave is charged with 54.5 mmol of 1-octene (8.5 ml), Pd(acac) 2 , 0.038 mol % (6.3 mg), 0.13 mol % of BuPoX (28.4 mg), 10 ml of methyl formate and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C., followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of methyl nonanoate is 28% with an n:iso ratio of 95:5.
Example 9
[0053] corresponds to Example 6
Examples 10-14
[0054] A 100 ml stainless steel autoclave is charged with 54.5 mmol of 1-octene (8.5 ml), Pd(acac) 2 , 0.038 mol % (6.3 mg), ligand (Example 10: 55 mg of ligand 2; Example 11: 116 mg of ligand 3; Example 12: 163 mg of ligand 4; Example 13: 44.6 mg of ligand 5; Example 14: 39.2 mg of ligand 6), 10 ml of methyl formate, 10 ml of methanol and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C. to establish a final pressure of 5.1 bar, followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of methyl nonanoate is 0% in all cases.
[0055] Since olefin mixtures are frequently used in the industry, one core competency of an industrially useful catalyst is good isomerization of olefins coupled with highly selective n-terminal functionalization.
[0056] One particular embodiment of the invention utilizes an olefin-containing mixture comprising internal carbon-carbon double bonds as olefinically unsaturated compound. The performance capability of the proposed system is demonstrated on such a technical-grade mixture in FIG. 2 ; see also Example 16.
[0057] The invention further provides a nonoic acid methyl ester mixture obtained by the method of the present invention.
[0058] Reaction (2) indicates the general course.
[0059] The substituents R 1 , R 2 and R 3 correspond to the groups or portions of the compounds shown in the “Olefin” and “Product” columns of Examples 15 to 23 hereinbelow.
[0000]
[0060] The examples in Table 2 show the unsaturated starting compounds (olefin and formate) and the products obtained. The n-selectivity column indicates the proportions of product having an n-terminal ester group.
[0000]
TABLE 2
n-
Ex-
Formate
Yield
Selecti-
ample
Olefin
ester
[%] [b]
vity
Product
15
98
94
16
80
94
17
99
95
18
86
92
19
46
93
20
86
95
21 [e]
82
88
22 [c]
98
89
23 [c]
81
>99
24 [c]
56
>99
[a] reactions were at 100° C. with 6.3 mg (0.038 mol % when using 54 mmol of olefin) of Pd(acac) 2 , L/Pd = 4 (L = BuPoX), 10 ml of formate, 10 ml of alcohol (alcohol corresponding to formate used), acid/L = 4 (=20 μl of MeSO 3 H), 54 mmol of olefin.
[b] determined by gas chromatography using an internal standard.
[c] 27 mmol of olefin.
[d] formate screening conditions.
[e] 10 mmol of methyl oleates, 0.3 mol % of Pd(acac) 2 , reaction tim 166 h.
Example 15
[0061] corresponds to Example 6
Example 16
[0062] A 100 ml stainless steel autoclave is charged with 54.5 mmol of octene mixture (8.5 ml consisting of: 2% of 1-octene, 11% of 2-octene, 28% of 3-octene, 59% of 4-octene), Pd(acac) 2 , 0.038 mol % (6.3 mg), 0.13 mol % of BuPoX (28.4 mg), 10 ml of methyl formate, 10 ml of methanol and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C. to establish a final pressure of 5.1 bar, followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of n-product, i.e. methyl nonanoate, is 75.2%. The yield of branched products (methyl 2-methyloctanoate, methyl 2-ethylheptanoate and methyl 2-propylhexanoate) is altogether 4.8%. The total yield of methyl esters is accordingly 80% with an n:iso ratio of 94:6.
Example 17
[0063] A 100 ml stainless steel autoclave is charged with 19.3 mmol of 1-octene (3 ml), Pd(acac) 2 , 0.16 mol % (9.4 mg), 124 μmol of BuPoX (49 mg), 10 ml of ethyl formate, 10 ml of ethanol and 28 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 120° C., followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of n-product, i.e. ethyl nonanoate, is 94.1%. The yield of branched products (ethyl 2-methyloctanoate, ethyl 2-ethylheptanoate and ethyl 2-propylhexanoate) is altogether 4.9%. The total yield of ethyl esters is accordingly 99% with an n:iso ratio of 95:5.
Example 18
[0064] A 100 ml stainless steel autoclave is charged with 19.3 mmol of 1-octene (3 ml), Pd(acac) 2 , 0.16 mol % (9.4 mg), 124 μmol of BuPoX (49 mg), 10 ml of benzyl formate, 10 ml of benzyl alcohol and 28 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 120° C., followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of branched products (benzyl 2-methyloctanoate, benzyl 2-ethylheptanoate and benzyl 2-propylhexanoate) is altogether 6.9%. The total yield of benzyl esters is accordingly 86% with an n:iso ratio of 92:8.
Example 19
[0065] A 100 ml stainless steel autoclave is charged with 19.3 mmol of 1-octene (3 ml), Pd(acac) 2 , 0.16 mol % (9.4 mg), 124 μmol of BuPoX (49 mg), 10 ml of phenyl formate, 10 ml of phenol and 28 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 90° C., followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of n-product, i.e. phenyl nonanoate, is 42.8%. The yield of branched products (phenyl 2-methyloctanoate, phenyl 2-ethylheptanoate and phenyl 2-propylhexanoate) is altogether 3.2%. The total yield of phenyl esters is accordingly 46% with an n:iso ratio of 93:7.
Example 20
[0066] A 100 ml stainless steel autoclave is charged with 54.8 mmol of 1-hexene (6.8 ml), Pd(acac) 2 , 0.038 mol % (6.3 mg), 0.13 mol % of BuPoX (28.4 mg), 10 ml of methyl formate, 10 ml of methanol and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C., followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of n-product, i.e. methyl heptanoate, is 81.7%. The yield of branched products (methyl 2-methylhexanoate and methyl 2-ethylpentanoate) is altogether 4.3%. The total yield of methyl esters is accordingly 86% with an n:iso ratio of 95:5.
Example 21
[0067] A 100 ml stainless steel autoclave is charged with 10 mmol of methyl oleate (3.4 ml), 9.4 mg of Pd(acac) 2 , 124 μmol of BuPoX (49 mg), 10 ml of methyl formate, 10 ml of methanol and 26 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C., followed by stirring at that temperature for 166 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. The product has precipitated as a solid. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and methanol is added until all of it has dissolved. The mixture is then analysed by gas chromatography. The yield of n-product, i.e. dimethyl eicosanedioate, is 72.2%. The yield of branched products (for example dimethyl 2-methylnonadecanedioate, dimethyl 2-ethyloctadecanedioate) is altogether 9.8%. The total yield of methyl esters is accordingly 82% with an n:iso ratio of 88:12.
Example 22
[0068] A 100 ml stainless steel autoclave is charged with 27 mmol of styrene (3.1 ml), Pd(acac) 2 , 0.08 mol % (6.3 mg), 28.4 mg of BuPoX, 10 ml of methyl formate, 10 ml of methanol and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C., followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of n-product, i.e. methyl 3-phenylpropionoate, is 87.2%. The yield of the branched product methyl 2-phenylpropionate is 10.8%. The total yield of methyl esters is accordingly 98% with an n:iso ratio of 89:11.
Example 23
[0069] A 100 ml stainless steel autoclave is charged with 27.2 mmol of methyl methacrylate (2.9 ml), Pd(acac) 2 , 0.08 mol % (6.3 mg), 28.4 mg of BuPoX, 10 ml of methyl formate, 10 ml of methanol and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C., followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of n-product, i.e. dimethyl 2-methylsuccinate, is 81%. Branched products were not detectable. The total yield of methyl esters is accordingly 81% with an n:iso ratio of 100:0.
Example 24
[0070] A 100 ml stainless steel autoclave is charged with 27 mmol of N-vinylphthalimide, Pd(acac) 2 , 0.08 mol % (6.3 mg), 28.4 mg of BuPoX, 10 ml of methyl formate, 10 ml of methanol and 20 μl of methanesulphonic acid under a protective gas (argon or nitrogen for example). The autoclave is heated to 100° C., followed by stirring at that temperature for 20 h. The autoclave is subsequently cooled down to room temperature and the residual pressure is released. A 5 ml quantity of isooctane is added to the reaction solution as an internal standard and the mixture is analysed by gas chromatography. The yield of n-product, i.e. the methyl ester of N-phthaloyl-β-alanine, is 56%. Branched products were not detectable. The total yield of methyl esters is accordingly 56% with an n:iso ratio of 100:0.
[0071] The very good yields and selectivities of the method according to the present invention are clear from the examples. | The invention provides a process for preparing esters from formates and olefinically unsaturated compounds with catalysts based on palladium compounds. In addition, the invention discloses a polyphasic reaction mixture and nonyl methyl ester mixtures prepared by the process according to the invention. | 2 |
This application is a division of application Ser. No. 07/462,525 filed Jan. 9, 1990, now U.S. Pat. No. 5,060,043.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor wafer and, more specifically, to an improvement of a mark for identifying crystal orientation of a semiconductor wafer provided on the semiconductor wafer for identifying a specific crystal orientation of the semiconductor wafer.
2. Description of the Background Art
An orientation flat serving as a reference for identifying the crystal orientation is provided on a semiconductor wafer. FIG. 6 is a plan view of a semiconductor wafer having the orientation flat. The orientation of a main surface 2 of the semiconductor wafer 1 is (100). One crystal orientation <110> of the semiconductor wafer 1 is in the direction shown by A and in the direction shown by B which is orthogonally intersecting the direction shown by A. An orientation flat 3 is provided on the semiconductor wafer 1 by cutting a portion of an outer periphery of the semiconductor wafer 1 along the direction shown by A. The orientation flat 3 has the following two functions.
First, the orientation flat 3 serves as a reference for alignment in lithography during the manufacturing process of the semiconductor.
Secondly, the orientation flat 3 serves as a reference in dicing the semiconductor wafer into semiconductor chips.
However, provision of the orientation flat on the semiconductor wafer exhibits the following drawbacks. As described above, the orientation flat serves as a reference for alignment. In order to realize precise alignment, the orientation flat must be of some length. Consequently, a large area of the semiconductor wafer is cut away in providing the orientation flat on the semiconductor wafer. Accordingly, the number of semiconductor chips which can be formed on one semiconductor wafer is reduced.
As the orientation flat is provided on the semiconductor wafer, the peripheral portion of the semiconductor wafer comes to be defined by a curve and a line. When the semiconductor wafer having the orientation flat is thermally processed, the outer peripheral portion of the semiconductor wafer does not expand uniformly, thereby causing stress in the semiconductor wafer. Now, when a force is applied to a member having a portion at which the shape of the member is abruptly changed, the stress is concentrated at that portion. As to the semiconductor wafer having the orientation flat, the shape of the semiconductor wafer is abruptly changed at the portion of the orientation flat. Therefore, when the semiconductor wafer is thermally processed, stress is concentrated on the portion having the orientation flat. Consequently, crystal defects are generated at the portion of the orientation flat of the semiconductor wafer. The crystal defects can be seen as slip lines.
FIG. 7 is a plan view of a semiconductor wafer on which slip lines are generated. The orientation of a main surface 5 of a semiconductor wafer 4 is (100). One crystal orientation <110> of the semiconductor wafer 4 is in the direction shown by C and in the direction shown by D which is orthogonal to the direction shown by C. The orientation flat 6 is formed by cutting away a portion of the outer periphery of the semiconductor wafer 4 along the direction of C. Slip lines 7 are generated at the portion of the orientation flat 6 of the semiconductor wafer 4. The slip lines 7 extend in the direction of D. The portion which is discontinued from the curve defining the outer periphery of the semiconductor wafer 4, that is, the portion of the orientation flat 6, must be long to some extent as mentioned above. Therefore, stress is concentrated at a relatively wide range during thermal processing of the semiconductor wafer 4, so that the slip lines 7 are generated in the wide range.
The following two prior art references disclose semiconductor wafers having marks, other than the orientation flat, for identifying the crystal orientation. One is disclosed in Japanese Patent Laying-Open No. 60-119709. In this prior art, a through hole, a semicircular notch or the like is provided on the semiconductor wafer, which is used as a mark for identifying the crystal orientation of the semiconductor wafer.
The specific content will be described in the following. Japanese Patent Laying-Open No. 60-119709 discloses three semiconductor wafers. The first one shown in FIG. 8 has a through hole 9 serving as a mark for identifying the crystal orientation at the center of the semiconductor wafer 8 whose outer periphery is circular. The through hole 9 is an isosceles triangle. A portion at which two sides having the same length intersect with each other is a vertex 10 of the isosceles triangle. A side 11 is facing the vertex 10. A line coupling the side 11 with the vertex 10 seems to identify the crystal orientation of the semiconductor wafer 8.
In the semiconductor wafer 8 shown in FIG. 8, the area of the through hole 9 is made smaller than the area of the wafer which is cut off for providing the orientation flat. Therefore, the consequential loss of the semiconductor wafer 8 can be made smaller than that of the semiconductor wafer having the orientation flat. However, since the distance between the vertex 10 and the side 11 is short, the through hole 9 does not exactly indicate the crystal orientation.
Since the outer periphery of the semiconductor wafer 8 is circular, the outer periphery of the semiconductor wafer 8 expands uniformly when it is thermally processed. Consequently, no stress is generated in the semiconductor wafer 8, and accordingly no slip line is generated in the semiconductor wafer 8.
Another semiconductor wafer disclosed in the Japanese Patent Laying-Open No. 60-119709 is as shown in FIG. 9, which has a through hole and a notch serving as marks for identifying the crystal orientation provided on a semiconductor wafer having circular outer periphery. A circular through hole 13 is provided at the center of the semiconductor wafer 12. A semicircular notch 14 is provided on the outer periphery of the semiconductor wafer 12. A line coupling the through hole 13 and the notch 14 seems to indicate a specific crystal orientation of the semiconductor wafer 12. The loss of the semiconductor wafer 12 is only the areas at both ends of the line, namely, the portion of the through hole 13 and the notch 14. The through hole 13 and the notch 14 may be small, since they are used only for defining a line serving as a reference for identifying crystal orientation. Compared with the orientation flat, the area loss of the semiconductor wafer can be reduced by these marks for identifying the crystal orientation.
As mentioned above, the notch 14 may be small. Therefore, the outer periphery of the semiconductor wafer 12 is approximately circular, so that the outer portions of the semiconductor wafer 12 are expanded approximately uniformly when it is thermally processed. Accordingly, the stress generated in the semiconductor wafer 12 is small, and therefore slip lines are less frequently generated even if the stress is concentrated at the notch 14.
A further semiconductor wafer disclosed in the Japanese Patent Laying-Open No. 60-119709 is as shown in FIG. 10, which has through holes serving as marks for identifying crystal orientation provided on a semiconductor wafer 15 whose outer periphery is circular. Through holes 16 and 17 are provided near the outer periphery of the semiconductor wafer 15, which through holes 16 and 17 are both circular. A line coupling the through holes 16 and 17 seems to identify the crystal orientation of the semiconductor wafer 15. The area loss of the semiconductor wafer 15 can be reduced for the same reason as described above with reference to the semiconductor wafer 12 shown in FIG. 9. Slip lines are not generated in the semiconductor wafer 15 from the same reason as described above with reference to the semiconductor wafer 8 shown in FIG. 8.
Another example of prior art relating to a semiconductor wafer, having a mark other than an orientation flat for identifying the crystal orientation, is disclosed in Japanese Patent Laying-Open No. 63-148614. In the prior art, a mark for identifying the crystal orientation is provided on a semiconductor wafer in the following manner. First, a main surface of a semiconductor wafer having circular outer periphery is irradiated from above by X-ray. The diffracted X-ray is measured by a detector, whereby the crystal orientation of the semiconductor wafer is detected. A mark indicating the crystal orientation is applied on the surface of the semiconductor wafer. Since a mark indicating the crystal orientation is applied on the surface of the semiconductor wafer, there is no area loss of the semiconductor wafer. The outer periphery of the semiconductor wafer is circular, so that the outer periphery of the semiconductor wafer expands uniformly when it is thermally processed. Therefore, no stress is generated in the semiconductor wafer, and accordingly no slip line is generated in the semiconductor wafer.
Semiconductor wafers are manufactured by slicing a bar semiconductor. Since the bar is considerably long, it is difficult to provide a through hole in the longitudinal direction of the bar. Therefore, in the prior art disclosed in the Japanese Patent Laying-Open No. 60-119709 in which a through hole is provided on a semiconductor wafer as a mark for identifying the crystal orientation, the through hole must be provided on the semiconductor wafer after it is sliced. Provision of a through hole in a number of the semiconductor wafer one by one takes much time, reducing efficiency in the producing of semiconductor devices.
As to the prior art examples disclosed in the Japanese Patent Laying-Open No. 60-119709, the mark for identifying the crystal orientation shown in FIG. 8 does not precisely indicate the crystal orientation of the semiconductor wafer, compared with the orientation flat. The following is also a reason of the lower precision in indicating the crystal orientation of this mark for identifying the crystal orientation. Namely, the mark for identifying the crystal orientation shown in FIG. 8 indicates a specific crystal orientation by a line coupling the side 11 and the vertex 10. However, there are two lines coupling the side 11 and the vertex 10. Consequently, the crystal orientation cannot be uniquely indicated by the mark for identifying the crystal orientation. It is the same in the case of the mark for identifying the crystal orientation shown in FIG. 9. Namely, there can be a number of lines coupling the circular through hole 13 and the semicircular notch 14 because of their finite size, so that the crystal orientation cannot be precisely indicated. It is also the same in the case circular marks of finite size, as shown in FIG. 10.
The prior art disclosed in the Japanese Patent Laying-Open No. 63-148614 provides a mark indicating the crystal orientation on the surface of the semiconductor wafer, as described above. Since such a mark cannot not be applied on the bar member before slicing, the mark must be applied on individual semiconductor wafers produced by slicing the bar. Namely, in this prior art also, marks must be applied on the semiconductor wafer one by one, reducing the efficiency in producing semiconductor devices.
In addition, specific disclosure is not given in the Japanese Patent Laying-Open No. 63-148614 about the mark for identifying the crystal orientation applied on the semiconductor wafer. Whether or not the crystal orientation can be precisely indicated by the mark cannot be determined.
SUMMARY OF THE INVENTION
The present invention was made to solve the above described problems and its object is to provide a semiconductor wafer having a mark for identifying specified crystal orientation which mark can be readily provided to the bar member before slicing, which reduces area loss of the semiconductor wafer and suppresses generation of slip lines.
Another object of the present invention is to provide a semiconductor wafer having a mark which precisely identifies the crystal orientation of the semiconductor wafer.
A further object of the present invention is to provide a method of effectively providing marks for identifying specified crystal orientation of the semiconductor wafer on the semiconductor wafers.
The present invention relates to a semiconductor wafer having a mark for identifying a specified crystal orientation. The semiconductor wafer in accordance with the present invention has a circular outer periphery.
In accordance with a first aspect of the present invention, first and second angular notches, each defined by a pair of intersecting surfaces are provided spaced apart from each other on the outer periphery of the semiconductor wafer. A line coupling the vertices of the first and second notches serves as a reference for identifying a specified crystal orientation.
In accordance with a second aspect of the present invention, a notch serving as a mark for identifying the crystal orientation is provided on the outer periphery of the semiconductor wafer. The notch has its shape defined by two orthogonally intersecting notched surfaces.
In accordance with the first aspect of the present invention, first and second notches are provided spaced apart from each other on the outer periphery of the semiconductor wafer. A line coupling the first and second notches serves as a reference for identifying a specified crystal orientation. The area loss of the semiconductor wafer is only the portions on both ends of the line, namely, the portions of the notches. The notches may be small, since they are only to define a line serving as a reference for identifying the crystal orientation. Therefore, in accordance with the first aspect of the present invention, the area loss of the semiconductor wafer can be reduced compared with that of the semiconductor wafer having an orientation flat.
As described in the foregoing, the notch may be small. Therefore, the outer periphery of the semiconductor wafer is nearly circular. Consequently, the outer periphery of the semiconductor wafer expands approximately uniformly when it is thermally processed, so that the stress generated in the semiconductor wafer is small. Accordingly, slip lines are less frequently generated even if the stress is concentrated to the notch.
In addition, since the notches are provided on the outer periphery of the semiconductor wafer, they can be provided on the bar member before slicing. By using the notch as the mark for identifying the crystal orientation, the efficiency in producing semiconductor devices can be improved as compared with alternative techniques wherein through holes or a mark on the surface of the semiconductor wafer are used as marks for identifying the crystal orientation.
In accordance with the second aspect of the present invention, a notch serving as a mark for identifying the crystal orientation is provided on the outer periphery of the semiconductor wafer. The notch has its shape defined by two notched surfaces orthogonally intersecting with each other. Line formed by the intersection of the two notched surfaces defining the notch and the main surface of the semiconductor wafer serves as references for identifying the specified crystal orientation.
In order to reduce area loss, the notch cannot be made very large. Therefore, the lines formed by the intersection of the notched surfaces and the main surface of the semiconductor wafer cannot be made very long. Consequently, the precision in alignment for lithography is lower than that of the orientation flat. However, a line (hereinafter referred to as a first reference line) formed by the intersection of one of the notched surfaces and the main surface of the semiconductor wafer encounters in the orthogonal direction a line (hereinafter referred to as a second reference line) formed by the intersection of the other one of the notched surfaces and the main surface of the semiconductor wafer. Therefore, it is convenient in dicing the semiconductor wafer into chips. More specifically, the dicing can be carried out in the following manner. A number of cut lines are provided on the surface of the semiconductor wafer parallel to each other, referring to the first reference line. Thereafter, a number of cut lines are provided parallel to each other on the surface of the semiconductor wafer referring to the second reference line. The semiconductor wafer is separated into chips by applying a bending stress thereto.
As described above, the notch is not very large. Therefore, slip lines are less frequently generated at the notch during thermal processing of the semiconductor wafer, as in the first aspect of the present invention.
Since the mark for identifying the crystal orientation is a notch, it can be provided easily on the bar member before slicing. Therefore, compared with the cases where through holes and marks provided on the surface of the semiconductor wafers are used as the marks for identifying crystal orientation, the efficiency in producing semiconductor devices can be improved. Especially in the second aspect of the present invention, only one notch is provided on the semiconductor wafer, so that the efficiency in producing semiconductor devices can be further improved compared with the first aspect of the present invention.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a first embodiment of the semiconductor wafer in accordance with the present invention;
FIG. 2 is a plan view of a second embodiment of the semiconductor wafer in accordance with the present invention;
FIG. 3 is a plan view of a third embodiment of the semiconductor wafer in accordance with the present invention;
FIG. 4 is a plan view of a fourth embodiment of the semiconductor wafer in accordance with the present invention;
FIGS. 5A to 5D show, in this order, a method of manufacturing the semiconductor wafer in accordance with the present invention;
FIG. 6 is a plan view of a conventional semiconductor wafer having an orientation flat serving as a mark for identifying crystal orientation;
FIG. 7 shows slip lines generated on the portion of the orientation flat; and
FIGS. 8 to 10 are plan views of conventional semiconductor wafers having through holes and the like serving as marks for identifying crystal orientation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the semiconductor wafer in accordance with the present invention will be described with reference to FIG. 1. An outer periphery of a semiconductor wafer 21 is circular. The diameter of the circle is, for example 200 mm. The semiconductor wafer 21 is formed of silicon, with the orientation of the main surface 22 being (100). First and second notches 23 and 24 are provided on the outer periphery of the semiconductor wafer 21. The first and the second notches 23 and 24 are both V shaped. The vertex of the V shape of the first notch 23 is 25. The vertex of the V shape of the second notch 24 is 26. A line 27 coupling the vertices 25 and 26 is on the diameter of the circle defining the outer periphery of the semiconductor wafer 21. Therefore, the line 27 coupling the vertices 25 and 26 has approximately the same length as the diameter of the circle defining then outer periphery of the semiconductor wafer 21. The line 27 coupling the vertices 25 and 26 indicates one crystal orientation <110> of the semiconductor wafer 21, represented by E. The line 27 is an imaginary line. The line 27 is not directly drawn on the semiconductor wafer 21. How to form the first and the second notches 23 and 24 serving as marks for identifying the orientation <110> on the semiconductor wafer 21 will be described in the following with reference to FIGS. 5A to 5D.
First, referring to FIG. 5A, a single crystal silicon bar 27 is prepared. The single crystal silicon bar 27 has its outer surface polished.
Thereafter, referring to FIG. 5B, the single crystal silicon bar 271 is irradiated by X-ray, and the crystal orientation <110> is detected by the X-ray diffraction. The first notch 23 and the second notch 24 are provided on the outer periphery of the single crystal silicon bar 271 such that the line coupling the vertex 25 of the first notch 23 and the vertex 26 of the second notch 24 indicates the crystal orientation <110>. The first and second notches 23 and 24 are provided along a generating line of the single crystal silicon bar. The second notch 24 is not shown in FIG. 5B.
Thereafter, referring to FIG. 5C, both ends of the single crystal silicon bar 271 are cut. The surface 22 having the orientation of (100) is exposed.
Then, referring to FIG. 5D, the single crystal silicon bar 271 is sliced to provide semiconductor wafers 21. By the above described process, a semiconductor wafer 21 having first and second notches 23 and 24 serving as marks for identifying the crystal orientation <110> is manufactured.
Particular effects of this embodiment will be described in the following. As shown in FIG. 1, the first and second notches 23 and 24 are V shaped, so that the vertices 25 and 26 are defined unequivocally. Accordingly, the line 27 coupling the bottom portions 25 and 26 indicating the crystal orientation of the semiconductor wafer 21 is defined uniquely. Consequently, in accordance with this embodiment, the crystal orientation of the semiconductor wafer 21 can be indicated exactly.
In this embodiment, the line 27 coupling the vertices 25 and 26 indicates the specified crystal orientation of the semiconductor wafer 21. Compared with a case in which notches are provided such that a line coupling the both bottom portions intersect, by a predetermined angle, with the specified crystal orientation of the semiconductor wafer, alignment in lithography is facilitated.
The line 27 coupling the vertices 25 and 26 has approximately the same length as the diameter of the circle defining the outer periphery of the semiconductor wafer 21 in this embodiment. It is longer than a common orientation flat. Therefore, alignment for lithography can be carried out more precisely.
When a semiconductor wafer having an orientation flat is thermally processed, the semiconductor wafer may possibly be warped, since the outer periphery of the semiconductor wafer does not expand uniformly. The warp of the wafer cannot be neglected when the diameter of the circle defining the outer periphery of the semiconductor wafer is 200 mm or larger. However, in the present embodiment, the outer periphery of the semiconductor wafer is approximately circular, so that the outer periphery of the wafer expands uniformly during thermal processing. Therefore, even when the diameter of the circle defining the outer periphery of the semiconductor wafer is large, the problem of the warp is not very serious.
Although the first and the second notches 23 and 24 are provided such that the line 27 coupling the vertices 25 and 26 approximately corresponds to a diameter of the circle defining the outer periphery of the semiconductor wafer 21 in the foregoing, locations for the notches are not limited thereto, and notches may be provided such that the line coupling the bottom portions is not on the diameter of the circle defining the outer periphery of the semiconductor wafer.
Since the first and the second notches 23 and 24 are to specify both ends of the line 27 serving as a reference for identifying the specified crystal orientation, 1 mm may be enough as the depth of the first and second notches.
A second embodiment of the semiconductor wafer in accordance with the present invention will be described in the following with reference to FIG. 2. A semiconductor wafer 31 has a circular outer periphery, and the semiconductor wafer 31 is formed of silicon with the orientation of the main surface 32 being (100) First and second notches 33 and 34 are provided on the outer periphery of the semiconductor wafer 31. The first and second notches 33 and 34 are both V shaped. The vertex of the V shape of the first notch 33 is 35. The vertex of the V shape of the second notch 34 is 36. A line coupling the vertices 35 and 36 is on the diameter of the circle defining the outer periphery of the semiconductor wafer 31. Consequently, the line 37 coupling the vertices 35 and 36 has approximately the same length as the diameter of the circle defining the outer periphery of the semiconductor wafer 31. The first and the second notches 33 and 34 are provided such that the line 37 coupling the vertices 35 and 36 intersect a crystal orientation <110> of the semiconductor wafer 31 shown by F by a prescribed angle. This is the only difference between the second embodiment and the first embodiment. The line 37 is an imaginary line and is not directly drawn on the semiconductor wafer 31.
When the notches are provided at such positions, the generation of the slip lines can be suppressed compared with the semiconductor wafer having an orientation flat, even if the stress is concentrated to the notch during thermal processing of the semiconductor wafer.
A third embodiment of the semiconductor wafer in accordance with the present invention will be described in the following with reference to FIG. 3. The semiconductor wafer 41 has a circular outer periphery. The orientation of the main surface 42 is (100). First and second notches 43 and 44 are provided on the outer periphery of the semiconductor wafer 41. The first notch 43 is defined by a notched surface 47 and a notched surface 48. The notched surfaces 47 and 48 abut each other orthogonally. The orthogonal intersecting point is the vertex 45. The second notch 44 is defined by notched surfaces 49 and 50. The notched surfaces 49 and 50 abut each other orthogonally. The orthogonal intersecting point is the vertex 46.
A line 58 coupling the vertices 45 and 46 indicates one crystal orientation <110> of the semiconductor wafer 41 shown by H. The notched surfaces 48 and 50 are on the same plane. A line formed by the intersection of the notched surfaces 48 and 50 with the main surface 42 of the semiconductor wafer 41 also indicates one crystal orientation <110> of the semiconductor wafer 41 shown by H.
The line 59 which is an extension of the line formed by the intersection of the notched surface 47 and the main surface 42 shows one crystal orientation <110> of the semiconductor wafer 41 shown by G. The line 60 which is an extension of a line formed by the intersection of the notched surface 49 with the main surface 42 also shows one crystal orientation <110> of the semiconductor wafer 41 shown by G.
A particular effects of the present embodiment will be described in the following. As shown in FIG. 6, in case of a semiconductor wafer 1 having the orientation flat 3, the identification of the crystal orientation <110> shown by B is realized by searching an orthogonal direction to the orientation flat 3. In third embodiment of the present invention, the line 58 indicates the crystal orientation <110> as shown in FIG. 3, while lines 59 and 60 indicate the crystal orientation <110> shown by G. The lines 58, 59 and 60 are imaginary lines and not actually drawn on the semiconductor wafers 41.
A fourth embodiment of the semiconductor wafer in accordance with the present invention will be described in the following. The semiconductor wafer 51 has a circular outer periphery. The semiconductor wafer 51 is formed of silicon with the orientation of the main surface 52 being (100) A notch 53 is provided on the outer periphery of the wafer 51. The notch 53 is defined by a first notched surface 54 and a second notched surface 55. The first notched surface 54 and the second notched surface 55 abut orthogonally each other. The line 56 which is an extension of a line formed by the intersection of the first notched surface 54 and the main surface 52 indicates one crystal orientation <110> of the semiconductor wafer 51 shown by I. The line 57 which is an extension of a line formed by the intersection of the second notched surface 55 and the main surface 52 indicates one crystal orientation <110> of the semiconductor wafer 51 shown by J. The lines 56 and 57 are imaginary lines and not actually drawn on the semiconductor wafer 51.
In this embodiment, the crystal orientation <110> shown by I and the crystal orientation <110> shown by J can be identified by one notch. Therefore, the semiconductor wafer 51 is diced into chips by the following method. First, a number of cut lines are provided in parallel to each other on the surface of the semiconductor wafer 51 along the line 56. Thereafter, a number of cut lines are provided in parallel to each other on the surface of the semiconductor wafer 51 along the line 57. A bending stress is applied to the semiconductor wafer 51 so that the wafer is divided into chips.
In this embodiment, the line 56 indicates the crystal orientation <110> represented by I while the line 57 indicates the crystal orientation <110> represented by J. However, the present invention is not limited to this embodiment and the notches may be provided such that the line 56 intersects the crystal orientation <110> represented by I by a prescribed angle, and the line 57 intersects the crystal orientation <110> represented by J by a prescribed angle.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims. | A semiconductor wafer having a mark indicating a specified crystal orientation is disclosed. In a preferred embodiment, first and second notches are provided on a circular outer periphery of the semiconductor wafer. A line coupling the vertices of the first and second notches indicates the crystal orientation of the semiconductor wafer. By using such notches as marks for identifying the crystal orientation, the loss of useful area of the semiconductor wafer can be reduced. Generation of slip lines which are crystal defects can be suppressed. Such notches can be formed on the bar member before slicing. By providing the notches on the bar member before individual wafers are cut therefrom, it becomes unnecessary to provide notches on the individual semiconductor wafers one by one. | 8 |
TECHNICAL FIELD
The present invention relates to an improved method for enzymatic acylation. In particular, the invention relates to the preparation of β-lactam antibiotics by enzymatic acylation of the parent amino β-lactam moiety with an acylating agent which is an activated derivative of the side chain acid.
BACKGROUND ART
Enzymatic production of semisynthetic β-lactam antibiotics by acylation of the parent amino β-lactam moiety with the side chain acid or an activated derivative, such as an amide or an ester thereof, is known e.g. from West German patent application having publication No. 2,163,792, Austrian Patent No. 243,986, Dutch patent application No. 70-09138, West German patent application having publication No. 2,621,618, European patent application having publication No. 339,751, international patent application having publication No. WO 92/01061 and from international patent application having publication No. WO 93/12250.
From West German patent application having publication No. 3,507,403 it is known to add a lower aliphatic alcohol to the reaction mixture in order to improve the yield. According to said invention, the acylation is preferably carried out in a solvent which is water containing from about 5 to about 40 % (w/w) of methanol or ethanol. Presumably, the alcohol added lowers the activity of the water in the reaction mixture and thus the extent of the hydrolysis of the acylating agent and the desired product.
In the present specification, the moiety of the β-lactam antibiotic molecule which is a condensed ring system comprising a four-membered β-lactam ring which has an exocyclic amino group and a five- or six-membered ring with a sulphur atom in it and sharing a nitrogen atom with the β-lactam ring is referred to as the β-lactam moiety. The amino β-lactam obtained on deacylation of the exocyclic amino group is referred to as the parent amino β-lactam. Similarly, the acyl group to be introduced into the amino group of an amino β-lactam in order to produce a β-lactam antibiotic is referred to as the β-lactam side chain or just the side chain. The acid corresponding to the side chain is designated the side chain acid.
The parent amino β-lactams such as 6-aminopenicillanic acid (6-APA) and 7-aminodesacetoxycephalosporanic acid (7-ADCA) are commonly produced by enzymatic hydrolysis of a fermented penicillin (for example penicillin V or penicillin G). Besides impurities originating from the fermentation, the resulting crude solution typically contains unreacted traces of the β-lactam antibiotic used as starting material at a concentration of 150-200 mM. The crude solution can be purified and crystallized to obtain pure 6-APA or 7-ADCA (in the 7-ADCA case, the fermented penicillin has to go through a rearrangement process before the hydrolysis step).
A drawback of the known methods for enzymatic production of β-lactam antibiotics by acylation of the parent amino β-lactam with an activated derivative of the side chain acid is that under the reaction conditions used part of the acylating agent hydrolyses before it has reacted with the amino β-lactam. Thus, when the amide of the side chain acid is used as acylating agent, some free side chain acid and an equivalent amount of ammonia will be generated in the reaction mixture as a result of this hydrolysis. Similarly, when an ester of the side chain acid is used as acylating agent, some free side chain acid and an equivalent amount of the alcohol corresponding to the ester will be generated in the reaction mixture as a result of the hydrolysis. Also, the desired product formed hydrolyses to form free side chain acid and the parent amino β-lactam.
The loss of acylating agent and of the desired product due to hydrolysis leads to a reduced yield of the process, to a more laborious work up procedure and ultimately to an economy of the process which is less than optimal. Accordingly, it is desired to find a method of avoiding or reducing the loss of acylating agent and/or desired product.
SUMMARY OF THE INVENTION
It has now, surprisingly, been found that certain modulators, i.e. compounds different from the reactants and the reaction product, can be added to a reaction mixture in which enzymatic synthesis of a β-lactam antibiotic takes place in a concentration which is lower than that of the reactants, preferably lower than about 100 mM, to suppress the reaction in such a way that the hydrolysis of the acylating agent--when an activated derivative of the side chain acid is used as acylating agent--and of the desired product is suppressed more than the synthesis of the desired product.
Accordingly, in its broadest aspect the present invention relates to a method of providing a semisynthetic β-lactam antibiotic by enzymatic acylation of the parent β-lactam with an activated derivative of the side chain acid wherein a modulator which suppresses the hydrolysis of the acylating agent and the desired product more than it suppresses the synthesis of the desired product is added to or present in the reaction mixture.
Examples of β-lactam antibiotics which can be produced by the process of this invention are ampicillin, amoxicillin, ticarcillin, cefaclor, cefatrizine, cefaparol, cephradine, cephalexin, cefadroxil, cephaloglycin and cephalothin.
The acylating agent to be used in the method of this invention is an activated derivative of the side chain acid such as a lower alkyl (methyl, ethyl, n-propyl or isopropyl) ester or an amide. The amide can be unsubstituted in the --NH 2 group which is preferred, or it can be substituted by one or two lower alkyl groups--identical or different--selected from the group comprising methyl, ethyl, propyl and isopropyl. The derivative may be used in the form of a salt, for example, the hydrochloride or the sulphate. Examples of side chain acids are D-phenylglycine or D-p-hydroxyphenylglycine.
Examples of parent amino β-lactams which can be acylated by the method of this invention are 6-aminopenicillanic acid (6-APA), 7-aminodesacetoxycephalosporanic acid (7-ADCA), 7-aminocephalosporanic acid (7-ACA) and 7-amino-3-chloro-3-cephem-4-carboxylate.
Examples of modulators are given in the examples and in the claims.
DETAILED DESCRIPTION OF THE INVENTION
The method of the present invention can be used in combination with suitable methods of the known art. Thus, it can, for example, be combined with the methods described in international patent application having publication No. WO 92/01061 and in international patent application having publication No. WO 93/12250. The contents of both of said applications is hereby incorporated in its entirety by reference.
The amount of modulator to be added to the reaction mixture in order to achieve the desired effect depends i.a. on the identity of the modulator and on the amount of enzyme present in the reaction mixture. Some guidance to this can be found in the examples and in the claims. It is thus important to notice that a too high concentration of the modulator will prevent the desired reaction from taking place. Under all circumstances the useful concentration of modulator in the reaction mixture is so low that it does not influence the water activity in the reaction mixture. In any case, it will be lower than that of the reactants, preferably lower than 100 mM.
The enzyme to be used in the process of this invention may be any enzyme catalyzing the reaction in question. Such enzymes have been known since around 1966. Enzymes to be used are, for example, termed penicillin amidase or penicillin acylase and classified as E.C. 3.5.1.11. A number of microbial enzymes are known to have this activity, derived from for example Acetobacter, Xanthomonas, Mycoplana, Protaminobacter, Aeromonas (West German patent application having publication No. 2,163,792) Pseudomonas (Austrian Patent No. 243986), Flavobacterium (Dutch patent application No. 70-09138), Aphanocladium, Cephalosporium (West German patent application having publication No. 2,621,618), Acetobacter pasteurianum, Bacillus megaterium, Xanthomonas citrii (European patent application having publication No. 339,751), Kluyvera citrophila (Agr.Biol.Chem. 37 (1973), 2797-2804) and Escherichia coli (West German patent application having publication No. 2,930,794). The Escherichia coli enzyme is commercially available. The enzyme may also be a so-called ampicillin hydrolase, acylase or amidase. In this connection, reference is, inter alia, made to Hakko to Kogyo 38 (1980), 216 et seq., the contents of which is incorporated by reference.
It is preferred to use the enzyme in a reusable form, for example, in entrapped or immobilized form. Immobilization may be done by any known method. Immobilized Escherichia coli enzyme is commercially available from Boehringer Mannheim GmbH, Germany, under the trade name Enzygel.
The process of this invention is generally carried out in a system containing water. If desired, an organic solvent may be added.
The solubility of the acylating agent such as the D-phenylglycine or D-p-hydroxyphenylglycine derivative or originating from the D,L mixtures as described in EP-A-339751, will vary with the identity of the derivative and with the composition of the reaction medium. In an aqueous system as used in the examples, the solubility of the hydrochloride of D-phenylglycine amide is typically approximately 450 mM. However, the solubility is very dependent on the salt components in the solution, as well as on the pH value and the temperature of the solution. In some embodiments of the process of this invention, the initial reaction mixture is a slurry containing undissolved acylating agent and/or amino β-lactam, which will dissolve partly or fully during the course of the reaction. The β-lactam antibiotic formed may precipitate during the reaction and, also, the hydrolysis products of the acylating agent such as D-phenylglycine and D-p-hydroxyphenylglycine, may precipitate. Hence, in some cases the reaction mixture will be a slurry throughout the duration of the reaction.
The amino β-lactam, for example 6-APA or 7-ADCA, used in the process of this invention may be obtained by enzymatic hydrolysis of the fermented penicillins or cephalosporins (for example penicillin V, penicillin G or cephalosporin C), or their ring enlarged analogues (for example V-DCA and G-DCA) or derivatives thereof followed by removal of the hydrolysis by-product, if desired (phenoxyacetic acid etc.). In some cases, the crude solution can be used directly without further purification or dilution.
Generally, the reaction temperature of the process of this invention may vary between about 0° C. and about 35° C., especially between about 5° C. and about 30° C. Temperatures in the range about 20°-30° C. may be preferred for convenient operation. The pH value which is optimal depends on the type and purity of enzyme. Using Escherichia coli enzyme, the optimal pH value is typically in the range from about 5.5 to about 7.5, preferably in the range from about 6.1 to about 7. For the preparation of amoxicillin, a pH value in the range from about 5.5 to about 6.4 is preferred. Control of the pH value may be used. Suitable reaction times are from several minutes to several hours, in particular from about 1/2 hour to about 8 hours. Suitable enzyme concentrations may be from about 1 U/ml to about 100 U/ml (1 U=one unit of enzyme activity, see below).
Using the method according this invention, unusually high yields of the desired β-lactam antibiotic can be obtained. The high yields are obtained using the teachings of this invention and properly selecting the concentration of the acylating agent, the ratio between the concentration of acylating agent and the starting amino β-lactam, the pH value, the enzyme and the identity and amount of modulator.
Recovery and purification of the product can be achieved by methods known per se, for example by crystallisation.
The present invention is further illustrated by the following examples which, however, are not to be construed as limiting the scope of protection. The features disclosed in the foregoing description and in the following examples may, both separately and in any combination thereof, be material for realising the invention in diverse forms thereof.
EXAMPLES
DEFINITIONS AND METHODS OF ANALYSIS
Abbreviations
D-HPGA is D-p-hydroxyphenylglycine amide, D-HPG is D-p-hydroxyphenylglycine, 6-APA is 6-aminopenicillanic acid, Amox is amoxicillin, Phox is phenoxyacetic acid, and Phyl is phenylacetic acid.
V 0 (Amox) is the initial velocity of Amox formation, and V 0 (D-HPG) is the initial velocity of D-HPG formation, specified as μmoles/min/g enzyme, μmoles/min/ml reaction mixture, or nmoles/min/U (enzyme activity).
Enzyme Activity
The following definition of penicillin G acylase activity is used: one unit (U) corresponds to the amount of enzyme that hydrolyses per minute 1 μmole of penicillin G under standard conditions (5% penicillin G, 0.2M sodium phosphate buffer, pH 8.0, 28° C).
The Synthetic vs. Hydrolytic Ratio X
The ratio X is defined as the number of moles of D-HPGA consumed per mole of Amox produced. For practical use this can be transformed to X=1+moles D-HPG/moles Amox, wherein "moles D-HPG" is the molar amount of D-HPG produced by hydrolysis of the acylating agent and the desired product and "moles Amox" is the molar amount of Amox present in the reaction mixture. Thus, if X is 1 this means that only the desired synthesis takes place, no hydrolysis. If X is 2, this means that D-HPG and Amox are formed in equal amounts (on a molar basis). If X is 3, this means that twice as much D-HPG as Amox is present in the reaction mixture (on a molar basis). The ratio X can be calculated at any time during reaction, but in the following examples X is calculated at the reaction stop time, which is defined as the time at which 90 % of the theoretical yield of Amox is present in the reaction mixture (based on the inserted amount of 6-APA). Square brackets are used to designate molar concentrations.
HPLC Analysis of Reaction Components
Column: C 18 , YMC 120 Å, 5 μm (4.6×250 mm)
Elution with mixture of 96% 25 mM sodium phosphate buffer, pH value 6.5 and 4% acetonitrile.
Flow: 1 ml/min.
Detection: UV at 230 nm
Preparation of samples for analysis: the samples taken from the reaction mixtures were diluted with 25 mM sodium phosphate buffer to 400 times their volume. At this dilution all samples were fully dissolved.
Retention times in minutes: 2.6 (D-HPG), 3.5 (D-HPGA), 5.0 (6-APA), 13.5 (Amox).
Standard Reaction Conditions
In Examples 1-8 the following standard conditions for enzymatic amoxicillin synthesis have been used (see patent application No. WO 92/01061 for further details):
D-HPGA! start =650 mM
6-APA! start =200 mM
Temp.=25° C.
pH=6.0
During the reactions, the pH value of the reaction mixtures was kept constant by titration with 2M sulphuric acid.
Representative samples of the reaction mixtures including solid constituents were taken at regular intervals during the reactions and analyzed by HPLC.
Example 1
Enzymatic Synthesis of Amoxicillin Using a Fixed Dosage of Immobilized Pen G Acylase and Varying the Phox Concentration in the Reaction Mixture from 2.6 to 61.7 μM
Experiment A (reference)
A standard synthesis (immobilized penicillin G acylase from E. coli; enzyme dosing 8.6 U/ml) was carried out with no Phox added. The Phox level was 2.6 μM in the reaction mixture due to a residual Phox content of 0.0009% w/w in the 6-APA used. The results obtained are reported in Table 1.
Experiments B-E
Same conditions as in Experiment A were employed, except that Phox was added to the reaction mixture at the beginning of the experiment in amounts so that the concentrations specified in Table 1 were obtained. The results are reported in Table 1.
TABLE 1______________________________________ Initial velocity Phox! (μM) (μmoles/min/g) X at reac- Reaction in reaction V.sub.0 V.sub.0 tion stop stop timeExperiment mixt. (Amox) (D-HPG) time (h)______________________________________A 2.6 17.7 25.0 2.9 2.1B 9.9 13.1 16.5 2.7 3.3C 16.8 11.9 13.8 2.55 4.1D 31.0 8.8 8.8 2.35 5.7E 61.7 6.5 5.4 2.05 9.5______________________________________
Example 2
Enzymatic Synthesis of Amoxicillin Using a Fixed Dosage of Immobilized Pen G Acylase and Varying the Phyl Concentration in the Reaction Mixture from 32.9 to 127 μM
Experiment A (reference)
A standard synthesis (immobilized penicillin G acylase from E. coli; enzyme dosing 8.6 U/ml) was carried out with no Phyl added. The Phox level in the reaction mixture was 2.6 μM. The results are reported in Table 2.
Experiments B-D
Same conditions as in Experiment A were employed, except that Phyl was added to the reaction mixture at the beginning of the experiment in amounts so that the concentrations specified in Table 2 were obtained. The Phox background level was 2.6 μM. The results are reported in Table 2.
TABLE 2______________________________________ Phox! Phyl! Initial velocity X at Reaction(μM) in (μM) in (μmoles/min/g) reaction stopExperi reaction reaction V.sub.0 V.sub.0 stop timement mixture mixture (Amox) (D-HPG) time (h)______________________________________A 2.6 0 17.7 25.0 2.9 2.1B 2.6 32.9 10.8 13.8 2.7 4.2C 2.6 63.3 8.1 8.8 2.5 5.1D 2.6 127 5.2 5.4 2.2 5.8______________________________________
Example 3
Enzymatic Synthesis of Amoxicillin Using Various Immobilized Preparations of Pen G Acylase and Varying the Phox Concentration in the Reaction Mixture from 2.6 to 56.8 μM
Four different immobilized Pen G acylase preparations were used: a) immobilized penicillin G acylase from E. coli; enzyme dosing 8.6 U/ml; b) agarose based immobilizate, dosing 12.0 U/ml; c) immobilizate obtained from Recordati, dosing 12.0 U/ml; and d) immobilizate obtained from Boehringer Mannheim (experimental preparation), dosing 11.5 U/ml.
Each immobilizate was tested under standard synthesis conditions in presence of Phox 2.6, 28.4 and 56.8 μM, respectively. The results obtained are presented in Table 3.
TABLE 3______________________________________Ratio X at reaction stop time. Phox! (μM) in reaction mixtureImmobilizate 2.6 28.4 56.8______________________________________a 2.9 2.35 2.05b 2.4 1.85 1.7c 2.3 1.9 1.95d 2.5 1.95 1.9______________________________________
Example 4
Enzymatic Synthesis of Amoxicillin Using Varying Amounts of Enzyme and a Constant Concentration of Phox
An agarose based penicillin G acylase immobilizate was employed in the following experiments. The immobilizate which was kept in water was drained of excess water on a filter by applying suction for 1 min. Phox was added to a concentration of 31 μM in the reaction mixture. The results are reported in Table 4.
TABLE 4______________________________________ Initial velocity Phox! (μM) Enzyme (μmoles/min/ml) in reaction dosage V.sub.0 V.sub.0 X at stopExperiment mixture (U/ml) (Amox) (D-HPG) time______________________________________A 31 11.9 1.17 0.60 1.75B 31 23.8 2.97 1.85 1.8C 31 47.5 6.6 ca. 5.6 ca. 2.0______________________________________
Example 5
Enzymatic Synthesis of Amoxicillin by Using Soluble Pen G Acylase (Two Different Suppliers) and Varying the Phox Concentration in the Reaction Mixture from 2.6 to 142 μM
Soluble Pen G acylase preparations were obtained from Calbiochem, art. No. 516329, ca. 1500 U/ml, and from GBF, ca. 300 U/ml. An enzyme dosage of 60 or 61 U/ml were employed in the two series. The results are reported in Table 5.
TABLE 5______________________________________ Initial velocityEnzyme Phox! (μM) (nmoles/min/U) X atSoluble Pen dosage in reaction V.sub.0 V.sub.0 reactionG acylase (U/ml) mixture (Amox) (D-HPG) stop time______________________________________Calbiochem 61 2.6 52.2 33.4 2.1 61 56.8 11.0 6.8 1.8 61 142 5.5 ca. 4.4 ca. 1.7GBF 60 2.6 61.1 50.0 2.1 60 56.8 21.7 14.4 1.8 60 142 6.3 3.6 1.7______________________________________
Example 6
Enzymatic Synthesis of Amoxicillin by Using Immobilized Pen G Acylase and Varying the Concentration of L-(+)-Mandelic Acid from 0.64 to 36.1 mM
Experiment A (reference)
A standard synthesis (immobilized penicillin G acylase from E. coli; enzyme dosing 12.0 U/ml) was carried out with no L-(+)-mandelic acid added. The Phox background level was <0.6 μM in the reaction mixture. The results obtained are reported in Table 6.
Experiments B-G
Same conditions as in Experiment A were employed, except that L-(+)-mandelic acid was added to the reaction mixture at the beginning of the experiment in amounts as specified in Table 6. The results are reported in Table 6. A side product obtained was α-hydroxybenzylpenicillin.
TABLE 6______________________________________ Initial velocity L-(+)-Mandelic (nmoles/min/U) X at ReactionExperi acid! (mM) in V.sub.0 V.sub.0 reaction stop timement reaction mixture (Amox) (D-HPG) stop time (h)______________________________________A 0 180 270 3.0 1.7B 0.64 156 207 2.9 2.4C 3.3 137 174 2.8 2.8D 6.7 119 146 2.65 3.0E 13.3 89 110 2.65 4.7F 14.2 80 106 2.8 4.2G 36.1 49 68 2.8 5.5______________________________________
With respect to minimization of the ratio X, the optimal L-(+)-mandelic acid concentration under the conditions chosen are thus in the interval 3.3-14.2 mM.
Example 7
Enzymatic Synthesis of Amoxicillin by Using Immobilized Pen G Acylase and Varying the 2-Thiopheneacetic Acid Concentration from 0.03 to 0.3 mM in the Reaction Mixture
Experiment A (reference)
A standard synthesis (Boehringer Mannheim immobilized penicillin G acylase, experimental preparation; enzyme dosing 12 U/ml) was carried out with no 2-thiopheneacetic acid added. The Phox background level in the reaction mixture was below 0.6 μM. The results obtained are reported in Table 7.
Experiments B-C
Same conditions as in Experiment A were employed, except that 2-thiopheneacetic acid was added to the reaction mixture at the beginning of the experiment in amounts as specified in Table 7. The results obtained are reported in Table 7.
TABLE 7______________________________________ Initial velocity Thiopheneacetic (μmoles/min/ml) X at ReactionExperi acid! (mM) in the V.sub.0 V.sub.0 reaction stop timement reaction mixture (Amox) (D-HPG) stop time (h)______________________________________A 0 3.28 4.90 3.0 1.5B 0.03 1.68 1.95 2.7 2.3C 0.3 0.15 0.058 1.6 12______________________________________
Example 8
Enzymatic Synthesis of Amoxicillin Using Immobilized Pen G Acylase and Various Enzyme Modulators
The compounds listed below improve synthesis performance (standard synthesis conditions, immobilized penicillin G acylase from E. coli; enzyme dosing 13 U/ml) in the sense that when they are present in the reaction mixture in a concentration within the interval specified, synthesis of the desired β-lactam antibiotic is favoured as compared to hydrolysis of the acylating agent:
______________________________________Concentration interval where improvement of ratio X is found______________________________________Penicillin G 2-1000 μMPenicillin V 2-1000 μmPenicillin G sulfoxide 2-500 μMp-Hydroxyphenoxyacetic acid 2-500 μM(Phenylthio)acetic acid 2-1000 μM2-Hydroxy-5-nitrobenzyl bromide 10-500 μMPhenylmethylsulfonyl fluoride 0.2-10 μM______________________________________ | A method for providing a semisynthetic β-lactam antibiotic by enzyme catalyzed acylation of the parent β-lactam with an activated derivative of the side chain acid wherein a modulator, which consists of one or more compounds different from the reactants and the reaction product and which suppresses the hydrolysis of the activated derivative of the side chain acid and the desired product more than it suppresses the synthesis of the desired product, is added to the reaction mixture, at the beginning of the reaction process, in a concentration from about 0.2 to 100×10 3 μm. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
This is a continuation-in-part application of U.S. patent application Ser. No. 633,334 filed Dec. 27, 1990.
TECHNICAL FIELD
The present invention relates in general to a combustion chamber which more efficiently burns fuel with fewer undesirable emissions, and in particular to an improved combustion chamber useful for heating aggregate in an asphalt plant.
BACKGROUND ART
No single component is more important in the manufacture of hot mix asphalt than the aggregate dryer and its exhaust system. One problem encountered with the use of such apparatus is pollution in the form of NO x compounds produced by the burner flame. It is known that the formation of NO x compounds may be inhibited by more efficient combustion of the available fuel; reducing the amount of nitrogen in the fuel; reducing the flame temperature; reducing the amount of air available for combustion; and reducing the time that combustion gases spend at elevated temperatures.
It is common in the steam generation industry to lower flame temperature by recirculating flue gas to the burner and thereby reducing NO x emissions. This reduction in flame temperature is further augmented by staged combustion in which the flame is initially oxygen poor (and therefore cooler) and is charged with additional oxygen a short time later to complete combustion. Multiple stages are preferably utilized to obtain the best results.
Experience has taught, however, that methods useful in the steam industry for reducing the formation of NO x compounds are not applicable to equipment used in the production of asphaltic products, such as aggregate dryers. This is because the two processes utilize different types of flames to provide heat and because aggregate dryers generally are of a shorter dimension unsuitable for implementing staged combustion techniques having multiple stages. Steam generation plants typically utilize lengthy staged combustion and a flame characterized as long and lazy. Lengthy, multiple staged combustion set-ups and long, lazy flames cannot be used in aggregate dryers because aggregate dryers typically provide a smaller combustion area than do steam plants.
The recirculation of gases in rotary heating equipment for purposes other than to reduce the level of NO x is known in the art. U.S. Pat. No. 4,190,370 discloses a drum mixer having a temperature control system for regulating the temperature of the asphalt-aggregate mix by varying the flow of hot gases through the drum mixer. The system is also disclosed in connection with an aggregate dryer. The temperature control system withdraws gases exiting the drum before they pass through a baghouse and recirculates them to an input manifold on the drum mixer. This recirculation system reduces the temperature of the burner flame and the energy required to heat the gases within the drum mixer, but does not suggest any effect on NO x emissions.
U.S. Reissue Pat. No. Re. 29,496 discloses another rotary heating device in which combustion gases are recirculated from the outlet of a drum mixer to a burner assembly located at the inlet of the drum mixer. The recirculation gases are passed through a heating or a cooling heat exchanger before being routed to the burner. This recirculation scheme is said to provide a somewhat isothermal air flow to the burner and to allow more energy efficient operation, but the patent does not discuss any reduction in either flame temperature or flame length. Nor does the patent suggest that the scheme operates to reduce NO x emissions.
Other examples of rotary heating devices incorporating various gas recirculating schemes are disclosed in U.S. Pat. Nos. 3,963,416; 4,143,972; 4,309,113; 4,332,478; 4,600,379; and 4,892,411. However, none of these recirculation methods are directed to the reduction of NO x emissions.
Therefore, there remains a need for an improved rotary heating device for use in the production of asphaltic paving materials having reduced NO x emissions, and in particular for a combustion chamber which consumes fuel in a manner which results in fewer NO x emissions.
SUMMARY OF THE INVENTION
The present invention solves the above-discussed need in the art by providing an improved combustion chamber and a method of flowing gases through a combustion chamber which enhances the mixing of fuel and air to allow more efficient operation, to promote greater flame stability and to reduce the level of NO x emissions created in the combustion process.
Generally described, the present invention comprises a combustion chamber having improved heating efficiency and reduced NO x emissions, comprising an enclosure defining a first end and a second end, and capable of having a main current of gases flowing from the first end to the second end, the internal cross section of the enclosure including a throat positioned at the first end and having a first cross-sectional area; a first expansion adjacent and interior to the throat, having a cross-sectional area greater than the first cross-sectional area of the throat for promoting a vortexlike motion of gas flow within the enclosure which runs contrary to the main current in part of the first expansion; and a second expansion adjacent and interior to the first expansion having a cross-sectional area greater than the cross-sectional area of the first expansion for promoting a vortexlike motion of gas flow within the enclosure which runs contrary to the main current in part of the second expansion.
The present invention may also provide more than two expansions in the cross-sectional area of the chamber and is particularly useful when used in connection with aggregate dryers, but can also be used with other heating apparatus.
In another aspect of the present invention, there is provided a method for increasing heating efficiency and reducing NO x production in a combustion chamber, comprising the steps of introducing a main current of combustion gases into a first cross-sectional area; passing the main current of gases from the first cross-sectional area into a second cross-sectional area having a cross-sectional area greater than the first cross-sectional area such that a first portion of gases is separated from the main current and directed to run contrary to the main current in part of the second cross-sectional area; and passing the main current of gases from the second cross-sectional area into a third cross-sectional area having a cross-sectional area greater than the second cross-sectional area such that a second portion of gases is separated from the main current and is directed to run contrary to the main current in part of the third cross-sectional area.
This method may also provide more than two expansions in the cross-sectional area and is particularly useful with combustion chambers used in connection with aggregate dryers, but can also be used with other heating apparatus.
Accordingly, it is an object of the present invention to provide an improved combustion chamber.
Another object of the present invention is to provide a combustion chamber which minimizes the amount of NO x emissions associated with its operation.
It is yet another object of the present invention to provide a combustion chamber which reduces the production of NO x compounds by influencing the flow of gases through the chamber.
A further object of the present invention is to provide a combustion chamber having flow characteristics which increase the proportion of the volume of the chamber having turbulent flow.
A still further object of the present invention is to provide a combustion chamber which provides the formation eddy currents within the combustion chamber to improve heating efficiency, promote flame stability and reduce NO x emissions.
Yet another object of the present invention is to provide an aggregate dryer having reduced NO x emissions.
Still another object of the present invention is to provide a method for increasing the heating efficiency and reducing the production of NO x of a combustion chamber.
These and other objects, features and advantages of the present invention will become apparent from a review of the following detailed description of the disclosed embodiment and the appended drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of the present invention.
FIG. 2 is a schematic diagram of the device shown in FIG. 1.
FIG. 3 is a cross-sectional view of the combustion chamber of FIG. 1.
FIG. 4 is a diagrammatic cross-sectional view of the combustion chamber showing the flow pattern of gases through the chamber.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, in which like numerals indicate like parts, throughout the several views, FIG. 1 shows a counter-flow aggregate dryer 10 adjacent a baghouse 12 and a virgin aggregate bin 14. The aggregate is fed by a conveyor belt 18 from the bin 14 for delivery into the dryer 10 in a manner well known in the art. The baghouse 12 filters gases which have passed through the dryer 10, also in a conventional manner.
Referring now to FIGS. 1 and 2, the dryer 10 includes an elongate drum 20 rotatably mounted on a support frame 22. Pivotally attached at one end of the support frame 22 are a pair of support legs 24. Attached at the other end of the support frame 22 are a pair of extendable support legs 26. The length of the legs 26 may be adjusted by various methods known in the art, but preferably hydraulically. In their unextended configuration, the legs 26 are generally of a shorter length than the legs 24, which are adjacent to the aggregate feed conveyor 18. In this configuration, the drum 20 is mounted at an angle inclined from horizontal. As the legs 26 are extended, the angle of inclination of the drum 20 is reduced. However, it is desirable that the drum 20 always be maintained at some inclined angle so that material fed into the drum by the conveyor 18 will feed down the length of the drum 20 due to the affect of gravity as the drum is rotated. The adjustability of the legs 26 therefore provides a means for controlling the rate at which material will feed down the length of the drum 20 at a particular rate of rotation of the drum.
Located at the lower end of the dryer 10 is a flame source, such as a conventional gas burner 28. The burner 28 projects a flame 30 having a temperature of between about 2,200° and 3,000° F. into a refractory combustion chamber 32, shown in more detail in FIG. 3. A discharge manifold 31 is located between the refractory combustion chamber 32 and the drum 20 for discharge of heated aggregate to a hot mix pugmill coater 34 located adjacent the dryer. The hot mix coater 34 is of known construction and operation, as shown in U.S. Pat. No. 4,616,934, incorporated herein by reference.
The pugmill coater 34 is positioned adjacent to and below the combustion chamber 32 with its longitudinal axis sloping with respect to horizontal. The lower end 29 of the pugmill coater is disposed below and adjacent to the discharge manifold 31 so that the dried aggregate from the dryer 10 falls by gravity directly into the pugmill coater 34. Recyclable material may also be introduced into the pugmill coater by a recycle conveyor 27, in a manner well known in the art and recovered fines may also be introduced through a particle return duct 53, described below. Conventional apparatus for heating and conveying liquid asphalt to the pugmill coater is also provided.
Referring now to FIGS. 3 and 4, the refractory combustion chamber 32 is a stepped chamber designed to aid the mixing of recirculated gases and reduce NO x emissions, as explained below. The combustion chamber 32 is preferably a steel shell 33 lined with a castable refractory material 35 such as Greencast 97-L available from A. P. Greencast, Mexico, Mo. To provide a more turbulent flame 30, the chamber 32 is configured to have a stepped configuration including a reduced diameter throat 36 at a first or exterior end 38 of the chamber located closest to the burner 28 and a step 37 located downstream of the throat. The throat has an annular surface 21 which forms a flowpath for gases through the throat. A radially extending, annular connecting surface 23 connects the throat to the expanded cross-sectional area provided by the step 37.
Referring further to FIG. 3, the following measurements set forth in Table 1 illustrate the preferred dimensions of the interior of the chamber 32. It should be noted however, that it is the general relative dimensions provide the preferred flow characteristics.
TABLE 1______________________________________Distance Approximate Measurement (ft)______________________________________A 8.0B 1.0C 1.0D 1.5E 2.0F 1.0G 8.0H 0.5I 0.5J 0.5K 3.5______________________________________
The reduced throat and stepped construction allows, on its own, for decreased NO x production with increased efficiency and drying capabilities. The chamber construction provides enhanced mixing of fuel and air which results in a more turbulent, more stable flame. The shape of the chamber also creates back-swirl or eddy currents 15 and 16 as shown in FIG. 4 which aid in the mixing of combustion gases.
Referring further to FIG. 4, there is shown a main current 17 of gases entering the combustion chamber through the throat 36. A beveled surface 39 is provided at the throat entrance to reduce the effect of the sudden contraction of the throat on the flow of gas. The beveled surface 39 eliminates the sharp comer that would otherwise be present to induce vortice formation along the inner surface of the throat. Such vortices would promote better mixing of gases, but would also increase the pressure drop through the throat to an undesirable level for the present embodiment. The throat of the embodiment shown in FIG. 3 has a pressure drop of about 8 inches water gauge. It will be understood, however, that for some applications the beveled surface 39 may be omitted. Additionally, for some applications, a beveled surface (not shown) may be provided on the throat exit to alter flow characteristics. As shown in FIG. 4, an angle Z exists between the throat surface 21 and the connecting surface 23 and has a value of about 90° . It will be understood that the angle Z is not necessarily a 90° angle and need not form a sharp corner at this point. The most important characteristic of the chamber is the provision of successive enlargements of the cross-sectional area to promote the formation of vortexlike currents which run contrary to the main current to allow better mixing of the combustion gases. However, by making the throat surface 21 a beveled surface or inclining the surface 23 and thus reducing angle Z preferably not to less than about 7° , vortice formation along the connecting surface 23 may also be induced. Likewise, it will also be understood that the step 37 need not be a 90° comer.
In the embodiment of FIG. 4, the velocity of the main current 17 of gases increases during passage through the throat 36. Upon exiting the throat, the main current 17 encounters successive enlargements of the cross-sectional area of the chamber 32 and experiences a decrease in velocity. When the main current encounters a first expansion V of the cross-sectional area created by the step 37 wherein the diameter of the chamber increases from E to 2D+E (shown in FIG. 3), a portion of the flow separates from the main current into a first set of eddy currents 15 which are drawn toward the perimeter of the chamber and run contrary to the main current in the outer parts of the first expansion V. As the main current progresses toward a second expansion W of the cross-sectional area downstream and adjacent the step 37 wherein the diameter increases from 2D+E to G, an additional portion of the flow separates from the main current into a second set of eddy currents 16 which are drawn towards the perimeter of the chamber in the second area of expansion and run contrary to the main current in this area. It will be appreciated that the flow characteristics of the main current may be different along the length of the chamber, as the eddy currents formed in each area serve to alter the flow of the main current.
The formation of eddy currents is known to occur whenever a flow encounters a sudden increase in cross-sectional area. It has been observed, however, that by shaping the interior of the chamber such that the cross-sectional area of the chamber is increased in successive steps rather than all at once, the efficiency of the chamber is increased. For example, it has been experienced that a combustion chamber made in accordance with the measurements of Table 1 enhances heating efficiency by allowing more complete combustion. Visual observations of a flame within a combustion chamber made in accordance with Table 1 indicates more complete combustion as evidenced by the chamber having a translucent volume without distinguishable, individual flame edges. It is believed that this increase in flame stability and efficiency results from enhanced formation of eddy currents, as shown in FIG. 4, which result from the combination of the reduced diameter throat and stepped configuration of the chamber.
To further reduce NO x emissions, gases may be introduced to the end of the flame to act in a "quenching" manner or to provide an abbreviated version of staged combustion. The steel shell 33 of the chamber 32 is surrounded by an annular duct 40 which is supplied with recirculated gases in a manner described below. A series of quenching holes or nozzles 42 extend through the refractory material 35 to communicate with the interior of the chamber 32 at a second end 41 of the chamber which opens to the drum 20. The nozzles 42 provide a "quenching ring" for introducing cooler exhaust gases to cool and reduce the length of the flame or may be used as conduits for adding air for staged combustion. As will be explained further, the annular duct 40 is preferably adapted to conduct recirculated gases through the nozzles 42 and direct them generally toward the center of the chamber at a velocity sufficient to penetrate the flame 30. This further promotes turbulence and mixing of the recirculated gases with the end of the flame 30 and reduces the temperature and length of the flame. Experience has taught that a velocity of about 10,000 feet per minute is suitable and may be obtained using a fan or blower generating a pressure of about 16 inches H 2 O through thirty-six uniformly spaced 2 inch diameter nozzles.
The heated gases from the burner 28 pass from the chamber 32 into the drum 20 to heat and dry the virgin aggregate 14. An exhaust manifold 46 is provided at the upper end of the drum 20 for conducting gases from the drum 20. The exhaust manifold 46 is connected to a separator duct 48 for conducting gases and suspended particulate matter (such as small aggregate particles) away from the exhaust manifold. The duct 48 leads to a conventional cyclone separator 50 located above the drum 20 for removal of particulate matter, such as aggregate fines, from the exhaust gases. The removed particulate matter is conducted to the pugmill coater 34 by a particle return duct 53 which leads from the bottom of the cyclone separator 50 to the pugmill coater 34. A baghouse duct 54 conducts the separated gases to the baghouse 12 for further particulate removal.
The baghouse 12 is of a design well known in the art and includes an internal filter chamber 56 within which extend a number of fiber filter collectors in the form of filter bags (not shown). Air How through the baghouse 12 is provided by an exhaust fan 58 having an inlet duct connected to a plenum chamber of the baghouse (not shown). The output of the exhaust fan 58 is connected to an exhaust stack 64 which opens to the atmosphere. A recirculating duct 66 is connected to the exhaust stack 64 for routing an amount of the exhaust gases through the recirculating duct. A manual diverter damper 68 is provided on the exhaust stack 64 to route a percentage of the exhaust gases to the recirculating duct 66 according to the damper setting. A modulating control damper 70 is provided on the recirculating duct to vary the flow of gases through the recirculating duct 66 in proportion to the fuel flow to the burner 28. The modulating control damper 70 receives a control signal from a burner controller (not shown) of a type which is well known in the art for controlling the amount of fuel and air introduced to the burner 28. The modulating controller may be calibrated and operated to provide a flow consistent with the values set forth in Tables 2 and 4.
The exhaust gases routed to the recirculating duct 66 may be routed to the burner 28 or to the quenching nozzles 42, or both. A "Y" duct 72 is provided along the recirculating duct 66 to permit the desired routing of the exhaust gases, as explained below.
The recirculating duct 66 is split at the "Y" duct 72 into a primary exhaust gas recirculating ("EGR") feed duct 74 and a quenching EGR feed duct 76. Manual control dampers 78 and 80 are provided on the primary EGR feed duct 74 and the quenching EGR feed duct 76, respectively. Manipulation of the dampers 78 and 80 allows the desired amount of exhaust gas to be routed through each of the ducts 74 and 76. A primary ambient air duct 82 having a manual control damper 84 and a staging ambient air duct 86 having a manual control damper 88 are provided just downstream of the "Y" duct 72 for introducing ambient air to the primary air feed duct 74 and the quenching air feed duct 76, respectively. The flow rates of gases through each of the ducts 74, 76, 82 and 86 are preferably monitored utilizing conventional pitot tube apparatus (not shown) downstream of the dampers 78, 80, 84 and 88, respectively.
Additionally, it will be understood that each of the manual control dampers 68, 78, 80, 84 and 88 may be replaced with electronic control dampers, whose operation may be controlled responsive to signals from the pitot tubes, utilizing conventional microprocessor equipment well known in the art for automatic process control.
The contributions of the primary EGR feed duct 74 and the primary ambient air duct 82 are combined at point R to form a primary EGR duct 75. Likewise, the contributions of the quenching EGR feed duct 76 and the staging ambient air duct 86 are combined at point S to form a quenching EGR duct 79. The primary EGR duct 75 extends to a conventional primary air inlet 77 on the burner 28. For combustion to occur, air and fuel must be supplied to the burner 28 in appropriate amounts. Combustion air is defined as the air or gases required for complete combustion of the available fuel. Excess air is defined as the air or gases supplied in addition to the combustion air. Combustion and excess air may be supplied to the burner 28 utilizing the primary EGR duct 75 and/or a tertiary air duct 89. A primary fan 90, and a tertiary fan 94 are provided along each of the respective ducts 75 and 89 to render available the desired amount of gases from each duct. The quenching EGR duct 79 extends via an inlet duct 81 to communicate with the annular duct 40 of the combustion chamber. A quenching fan 92 is provided along the quenching EGR duct 79 to transmit the desired amount of gases through the quenching EGR duct 79. To obtain the maximum flow rates shown in Example 1 below, a 100 horsepower centrifugal fan was utilized for the primary fan 90; a 40 horsepower centrifugal fan was utilized for the quenching fan 92; and a 150 horsepower axial flow fan was utilized for the tertiary fan 89.
The dryer 10 operates as follows. A continuous supply of virgin aggregate is introduced into the drum 20 by the conveyor 18. The flame 30 from the burner 28 provides combustion gases to the refractory combustion chamber 32. These gases exit the drum 20 via the exhaust manifold 48 and are routed to the cyclone separator 50 for removal of particulate matter and then to the baghouse 12 for further removal of particulate matter.
It is noted that gases exiting the baghouse 12 are more humid and at a lower temperature than gases within the dryer 10. The present invention uses these cooler, moister gases emerging from the baghouse 12 to accomplish a reduction in the formation of NO x compounds. The dryer 10 thereby is a conventional counter-flow aggregate dryer except for the novel features described herein.
It is found that combustion efficiency may be improved, and hence NO x production may be reduced, by providing a stepped configuration within the combustion chamber which promotes the formation of eddy currents. It is also found that NO x emissions may be reduced by maintaining a highly turbulent, short flame 30 while reducing the maximum temperature of the flame and the time that the gases spend at a temperature where NO x is readily created. The dryer 10 operates to produce this second set of conditions by taking the gases from downstream of the exhaust fan 58 and recirculating them to the burner 28 via the primary EGR duct 75 and to the end of the flame 30 via the quenching duct 79, as discussed above. While it will be understood that ambient air or gases recirculated from the exhaust manifold 46 may be used, it is preferred to use air recirculated from after the baghouse 12. Additional benefits of using air recirculated from after the baghouse 12 include the elimination of the back-flow of excessively hot furnace gases through the primary fan 90 and the quenching fan 92, and the elimination of dust loading from the fans 90 and 92.
A flow of recirculated gases through the primary EGR duct 75 and the quenching duct 79 may be established by the primary fan 90 and the quenching fan 92, respectively. These moister, cooler recirculated gases are routed to the burner 28 by the primary EGR duct 75 and to the end of the flame 30 via the quenching EGR duct 79 which directs gases to the nozzles 42. Introduction of recirculated gases to the burner 28 and the quenching ring 38 reduces the flame temperature, the flame length, and the free oxygen content. These reductions result in a lower rate of NO x production. As stated before, it is preferable to recirculate gases from after the baghouse 12, because the gases are cleaner and less damaging to the blowers 90 and 92. The trade-off for this benefit of cleaner gases is the disadvantage of a more oxygen rich and cooler recirculation gas stream, because baghouse filtration increases oxygen content. It will be understood that a less oxygen rich exhaust gas stream may be obtained by recirculating the exhaust gas from before the baghouse 12. This, however, has the disadvantage of a more dust laden gas stream.
The amount of exhaust gas recirculated is determined as a mass percentage of the "total gases" supplied by the Primary EGR duct 75, the quenching EGR duct 79, and the tertiary air duct 89. Combustion air is the amount of air or gases needed for combustion of the available fuel. Excess air is the amount of air or gases supplied in excess of the combustion air.
In the preferred operation of the dryer 10, all of the combustion air and some of the excess air is supplied by the primary EGR duct 75 in combination with the tertiary air duct 89). In this mode, the quenching EGR duct 79 supplies exhaust gases to the nozzles 42 at a velocity sufficient to penetrate the flame 30.
As stated above, the term "total gases" is defined as the sum of all recirculated gases and fresh air supplied by the primary EGR duct 75, the quenching EGR duct 79, and the tertiary air duct 89. In the preferred operating mode, the contributions and compositions of the various gases and air ducts preferably fall within the following ranges set forth in Table 2.
TABLE 2______________________________________ Approximate Approximate % by % by mass mass in duct whichDuct Description of total gases is recirculated gas______________________________________66 Recirculation 5 to 50 10074 Primary EGR Feed 0 to 95 10082 Primary ambient air 0 to 95 075 Primary EGR 28 to 95 5 to 10076 Quenching EGR Feed 5 to 30 10086 Staging Ambient Air 0 079 Quenching EGR 5 to 30 10089 Tertiary Air 0 to 67 0______________________________________
TABLE 2______________________________________ Approximate Approximate % by % by mass mass in duct whichDuct Description of total gases is recirculated gas______________________________________66 Recirculation 5 to 50 10074 Primary EGR Feed 0 to 95 10082 Primary ambient air 0 to 95 075 Primary EGR 28 to 95 5 to 10076 Quenching EGR Feed 5 to 30 10086 Staging Ambient Air 0 079 Quenching EGR 5 to 30 10089 Tertiary Air 0 to 67 0______________________________________
EXAMPLE 1
The below Table 3 sets forth maximum flow rates anticipated to be utilized to perform tests of a dryer embodying the invention. The results of the planned tests are expected to indicate an average reduction in NO x emissions, as measured at the exhaust stack 64, from approximately 0.024 pounds per ton of aggregate to approximately 0.158 pounds per ton of aggregate.
TABLE 3______________________________________ Maximum Flow Actual Rate cubic Actual Operating feet per min. at Operating PressureDuct Description 60° F. and 1 atm Temp (°F.) (inch H.sub.2 O)______________________________________64 Exhaust to 44,750 250 -5.0Atmosphere66 Recirculation 13,350 250 -5.074 Primary 10,146 250 -5.0EGR Feed82 Primary 10,146 ambient -0.1Ambient Air75 Primary 10,680 250 -5.0EGR76 Quenching 8010 250 -5.0EGR Feed86 Staging 0 ambient -0.1Ambient Air79 Quenching 8010 250 -5.0EGR89 Tertiary Air 16,020 ambient -0.1______________________________________
The above description discloses a mode of operation in which sufficient oxygen is provided to the burner 28 to allow complete combustion. The gases supplied by the quenching nozzles 42 are provided to reduce flame temperature and length. It will be understood, however, that other modes of operation may be practiced to reduce flame temperature and length. For example, the flow rates and the percentage of recirculated gases and fresh air in each duct may be varied to achieve the desired effects. For example, an abbreviated form of staged combustion may be accomplished by supplying insufficient combustion air to the burner. The remaining air required for combustion of the available fuel may then be supplied by the quenching nozzles 42. When operating in the staged combustion mode, the contributions and compositions of the gases and air ducts preferably fall within the ranges given in Table 4:
TABLE 4______________________________________ Approximate Approximate % by % by mass mass in duct whichDuct Description of total gases is recirculated gas______________________________________66 Recirculation 0 to 30 10074 Primary EGR Feed 0 to 95 10082 Primary Ambient Air 0 to 95 075 Primary EGR 28 to 95 0 to 10076 Quenching EGR Feed 0 10086 Staging Ambient Air 5 to 30 079 Quenching EGR 5 to 30 089 Tertiary Air 0 to 67 0______________________________________
It will further be noted that the novel design of the combustion chamber 32 is capable of reducing NO x emissions independent of the introduction of recirculated gas or staged combustion. This result occurs because of the superior mixing of fuel and air obtained by the geometry of the chamber. Thus, the duct 40 and nozzles 42 may be eliminated in some applications. However, if recirculated gases are provided, the chamber geometry aids in mixing recirculated gases with fuel and air.
While the foregoing description relates to a counter-flow aggregate dryer, it will also be understood that the foregoing invention may also be utilized to reduce NO x emissions in connection with parallel flow dryers drum mixers, and other heating apparatus.
The foregoing description relates to preferred embodiments of the present invention, and modifications or alterations may be made without departing from the spirit and scope of the invention as defined in the following claims. | A combustion chamber having improved heating efficiency and reduced NO x emissions includes a reduced diameter throat and a stepped configuration within the chamber. The chamber configuration encourages efficient combustion to reduce NO x production by promoting the formation of eddy currents within the chamber. A method for increasing heating efficiency and reducing NO x production is provided and involves passing combustion gases through such a combustion chamber. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to devices for use in imaging organs and tissues of a body. More specifically, the invention relates to an apparatus for securing such an imaging device to a body so the imaging device will remain in a fixed position relative to the body yet the body will be able to move freely during the imaging process.
2. History of the Prior Art
Imaging devices are routinely used in medicine to obtain images of body organs and tissues. Such devices include conventional "X-ray" devices, positron emission tomography (PET) detectors, single positron emission computed tomography (SPECT) detectors, fast computed tomography (cine-CT) detectors, gamma cameras, and the like. Although used in different contexts and with different organs, all imaging devices presently used in medical applications share the requirement that the body to be imaged remain as stationary as possible with respect to the device so an accurate image may be obtained.
However, it is not possible to completely immobilize the human chest and abdomen for imaging of organs such as the heart due to involuntary movement (e.g., heartbeat). To compensate for such movement, several images may be obtained from which a composite image of the organ may be extrapolated. For example, cine-CT scanners typically obtain multiple images of organs in a matter of seconds. Through mathematical calculations and image manipulation, the series of images is combined into a single image. However, the utility of the image is limited by loss of information during the image combination step and dissipation of contrast agent from spaces within the organ (e.g., cardiac ventricles).
The problem of movement is particularly acute when evaluating heart function under stress. For example, radioisotopic imaging of the heart is a routine diagnostic procedure used to evaluate patients for coronary artery disease (CAD). In patients with CAD, ventricular function and myocardial perfusion (arterial blood flow) rates may be within normal ranges at rest, but become abnormal during physical stress. For that reason, CAD is commonly evaluated immediately after the patient has exercised (e.g., the treadmill stress test) or after the patient has received drugs to simulate the effects of exercise.
However, because the heart cannot be adequately imaged while the patient is in motion, patients may be instructed to stop moving before the images are taken. Under this approach, no information is obtained directly from the heart at peak stress or while stress on the heart develops. In an effort to obtain such information, patients may be instructed to grip or press their chest against the imaging device while exercising.
The difficulties inherent in attempting to stabilize a moving body against a stationary imaging device are apparent. Not only is the patient's freedom of movement compromised, but it is not uncommon for the patient to collide with the device during motion, thus potentially compromising the latter's accuracy. Yet the alternative of moving the imaging device with the patient's body is made difficult, if not impossible, by the weight and size of such devices. Indeed, conventional Anger gamma cameras (so named after their inventor) are typically so heavy that they must be attached to a motorized gantry to allow the camera to be moved into position for imaging.
In an effort to obtain information for use in evaluating ventricular function during stress on the heart, several researchers have attempted to use radioisotopic probes to assess heart function without imaging. For example, one approach strapped such a probe directly onto the patient's chest, presumably over the position of the left ventricle. However, without images to use for confirmation, it proved difficult to be certain that the probe was properly positioned. Moreover, although such a probe could (if properly positioned) assess ventricular function in terms of ejection fraction (EF), it cannot be used to assess regional movement of the ventricular wall. Therefore, although easily moved and attached to a body, radioisotopic probes have proven to have limited usefulness.
Thus, a need exists for an apparatus which will allow medical quality images to be obtained of body organs while the body is in movement or otherwise under stress. The present invention addresses that need.
SUMMARY OF THE INVENTION
The invention is an apparatus which will securely support an imaging device on a body so that medical quality images of body organs can be obtained notwithstanding movement by the body during the imaging process. The preferred imaging device for use with the apparatus of the invention is a gamma camera, preferably one weighing less than about 30 pounds. According to the invention, the imaging device is removably attached to the body in a secure position with respect to the organ to be imaged. The combination of the inventive apparatus and preferred lightweight gamma camera permits the body to move relatively freely while images are obtained. As a result, the invention is particularly useful for obtaining images of the body under maximum stress; e.g., to obtain images of the heart during exercise.
In one preferred embodiment of the invention, the imaging device is secured to the body by a harness. The harness is securely fastened to a body so the imaging device is immobilized over the region of the body to be imaged. Further support for the imaging device is preferably provided by means to suspend or otherwise support the imaging device in the harness.
To minimize movement of the imaging device relative to the organ to be imaged, the harness will preferably include a pocket into which the imaging device is placed. Alternatively, the imaging device may be held in place by contraction of the harness against the body.
In one aspect of the invention, the means for providing further support to the imaging device consists of a suspension mechanism comprising an adjustable weight and pulley mechanism whereby the weight of the imaging device is counterbalanced by a weight of approximately equal weight to the imaging device.
In another aspect of the invention, the weight of the imaging device is supported by an extendible bar (such as a retractable spring or gas piston) which is attached to, and supports, the imaging device.
In another aspect of the invention, the imaging device is suspended by a fixed suspension mechanism, such as a wire or beam.
In another aspect of the invention, the imaging device is supported by a bar which is pivotably mounted in balance with the weight of the imaging device.
In another aspect of the invention, the imaging device is entirely supported against the body by the harness. The preferred imaging device for use in this embodiment of the invention is one which weighs less than about 30 pounds, thus minimizing the strain of carrying the device on the body. Most preferably, the dimensions of the imaging device will be less than about 16 inches along each side.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a (prior art) Anger gamma camera with gantry.
FIG. 2 is a side view of a preferred embodiment of the invention, showing the pouch and imaging device being supported by an adjustable weight and pulley system.
FIG. 3 is a side view of an alternative embodiment of the invention, showing the weight of the imaging device being supported by a pivotable bar.
Like numerals refer to like elements in FIGS. 2 and 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Many of the advantages of the apparatus of the invention over prior art mechanisms for supporting an imaging device are apparent in a comparison of the invention to the prior art camera and gantry arrangement shown in FIG. 1. As shown in FIG. 1, a conventional Anger gamma camera is a large, relatively heavy imaging head 1 attached to a movable mechanical gantry 2. As a consequence of its lead shielding, device 1 may weigh in excess of several hundred pounds. Given their size and design, devices such as the one shown in FIG. 1 cannot follow movement of a patient's body.
For comparison, imaging devices used with the invention are removably secured to a body to be imaged in such a way that movement of the imaging device with respect to the body is minimized; i.e., so that medically useful images of a body part such as the heart can be obtained even though the body is in motion. For purposes of discussion, the imaging device for use with the invention will be referred to as a gamma camera, although those of ordinary skill in the art will understand that other imaging devices may also be readily used in the inventive apparatus. Also, for the sake of convenience, the description of the invention refers to use of the apparatus by a human. However, it will be understood that the apparatus may be adapted for use by other mammals, such as livestock and pet animals.
All of the embodiments of the invention share the advantage of supporting an imaging device while stabilizing it against a body. Each embodiment permits some range of movement by the body while minimizing movement of the imaging device with respect to the part of the body to be imaged. For purposes of this disclosure, movement of the body within such range of movement shall be referred to as movement "freely" by the body. The term "freely" will be understood to mean movement by the body to the fullest extent permitted by the dimensions of the inventive apparatus (e.g., the length and/or extendibility of support mechanisms present in the apparatus with respect to the radius about such support mechanism in which the body is to be moved).
As shown in the FIGS, the most common use of the apparatus of the invention will likely be to obtain first pass images of the heart (over the left ventricle), particularly during physical exercise. However, it can be readily appreciated that the apparatus of the invention may also be used to image other organs of the body. For example, if body 10 shown in the FIGS. 2-3 was facing away from rather than toward stand 20, gamma camera 5 could be positioned along the back of body 10 to image, for example, the kidneys. Thus, the invention will be understood not to be limited to use for imaging a specific organ or with a specific imaging device, but rather is defined by the scope of the appended claims.
A preferred embodiment of the invention is shown in FIG. 2. In FIG. 2, the imaging device is represented by gamma camera 5, which is secured to a human body 10. To ease the strain of carrying the imaging device on body 10, gamma camera 5 will weigh no more than about 100 pounds, most preferably no more than about 20 pounds. Similarly, gamma camera 5 will preferably be no wider or longer than the chest of the person with whom it is to be used, which will typically be no more than about 16 inches along each side. Further, so gamma camera 5 will readily follow the body in motion, the mass of the gamma camera should not substantially exceed that of the body part against which it is placed (e.g., the chest).
Such a gamma camera is described in co-pending, commonly owned U.S. patent application Ser. No. 08/372,807 (filed Dec. 23, 1994), the disclosure of which is incorporated herein by this reference to illustrate the structure and form of a preferred imaging device for use with the apparatus of the invention. A commercial embodiment of the gamma camera claimed in the '807 Application is also being made available by DIGIRAD, Inc. of San Diego, Calif.
For use with the inventive apparatus, gamma camera 5 is placed into harness 6. Harness 6 may secure camera 5 against body 10 by contraction of a piece of fabric stretched snugly over gamma camera 5 in at least two opposing directions (to form a strap) or may cover gamma camera 5 as shown in FIG. 3. The camera may also be placed snugly within a sack-like structure in the front of the harness (e.g., a pocket 7, containing the camera shown partially in phantom in FIG. 2).
Preferably, harness 6 will be a relatively durable material, such as cotton canvas, plastic, rubber or nylon. Also, depending on the structure of the imaging device, harness 6 may also include a rigid cup or bracket at the posterior end of pocket 7 into which the imaging device will be seated. Any such rigid cup or bracket may be attached to the posterior of pocket 7 by any suitable fastening means, such as snaps or stitching. Alternatively, where camera 5 is secured within harness 6 by a stretch of fabric as shown in FIG. 2, any rigid cup or bracket present will be attached by suitable fastening means to the inner surface of harness 6 so as to extend beneath, and provide additional stability to, the posterior end of gamma camera 5.
So pocket 6 may be adjusted to fit onto different size bodies at desired locations, it will preferably be secured to body 10 by adjustable attachment means, such as slidable straps. For example, as shown in FIG. 2, harness 6 is attached to body 10 by adjustable straps 11 which extend over each shoulder and connect to a belt 13 intended to circle the waist. The posterior end 8 of pocket 7 is securely attached to belt 13 in a removable or permanent fashion. For better support and comfort, belt 13 is preferably a lumbar support belt; i.e., a belt which is sufficiently wide to encompass the lumbar region of the wearer's back. When fitted tight around the waist, a lumbar support belt will provide support to the wearer's lower back. Such belts are commercially available and well-known in the art for medical and industrial uses.
For additional stability, harness 6 may also be secured to body 10 by additional attachment means, such as straps extending beneath the wearer's arms which attach to straps 11 behind the wearer's back, and may also extend completely around the wearer's back. Any such straps used as attachment means will preferably be adjustable by use of adjustment means such as slides, buckles or fastening fabric (e.g., VELCRO® adhesive tape) so the straps may be fixed in place on body 10.
Other configurations of harness 6, as well as alternative attachment means, will be apparent to those of ordinary skill in the art. For example, harness 6 may be attached to the body as part of a fitted vest or jacket. Further, to ensure proper positioning of gamma camera 5, it may be secured in a fixed position within harness 6 by fasteners such as VELCRO® fasteners to attach the camera to the patient's chest. For example, where harness 6 includes a sack-like structure such as pocket 7, fasteners may be mated between the outer surface of pocket 7 (between the pouch and the body) and a surface between pocket 7 and the body (such as a strap or inner vest). Alternatively, where the camera is secured within harness 6 by contraction of a stretch of fabric larger in diameter than the camera, the fabric will extend around the camera in at least two directions and attach directly to a surface (such as a strap or inner vest) worn on the body. For example, gamma camera 5 may be placed between the front surface of harness 6 and the body. Using a VELCRO®-type hook and loop fabric fastener, the inner surface of the front of harness 6 which extends beyond camera 5 would then be secured to body 10 by joining the fabric fasteners on harness 6 to complementary fabric fasteners attached to a cloth vest worn on the body. Gamma camera 5 can be secured more closely to the body by tightening harness 6 around the body's girth.
Advantageously, the inventive apparatus is used to retain a gamma camera at a desired point with respect to body 10 while body 10 is in movement during, for example, a cardiac stress treadmill test. To relieve the body being imaged of the camera's weight while the body is under stress, substantially all of the weight of the camera is supported by one or more of the means for supporting the camera described below.
A preferred embodiment to provide support to gamma camera 5 by a mechanism separate from the harness is shown in FIG. 2. According to this embodiment, gamma camera 5 is suspended in harness 6 from a rope (preferably a flexible wire or the like) 15 hanging from a structure raised above body 10, such as the vertical arm 22 of the stand 20 shown in FIG. 2. Opposite its attachment to vertical arm 22, rope 15 is connected to gamma camera 5 by any fastener of sufficient strength to support gamma camera 5 (notwithstanding moderate movement of body 10).
To accommodate movement by body 10, rope 15 is preferably slidably engaged with one or more pulleys along vertical arm 22 of stand 20 to allow rope 15 to shorten and lengthen as required to accommodate movement of body 10 (for example, on exercise equipment such as treadmill 30, a stairstepper or indoor bicycle).
To balance gamma camera 5, a counterweight 16 is attached to rope 15 opposite the point of attachment of gamma camera 5; i.e., so that counterweight 16 hangs from rope 15 along vertical spine 23 of stand 20. Thus, although movement of body 10 is accommodated by movement of rope 15, gamma camera 5 is stabilized in position in harness 6 by the tendency of the camera and counterweight 16 to remain in equilibrium (i.e., balance) with respect to one another as well as by compression of the camera against body 10.
Gamma camera 5 may also be suspended from vertical arm 22 by a length of extendible material, preferably a spring, an elastic cord, or a highly compressible and extendible gas piston (e.g., such as the hydraulic cylinders commonly used to permit the "steps" of stairstepper exercise machines to be compressed then returned to a neutral position). In this embodiment of the invention, pulleys 21 will not be included on stand 20. Instead, movement by body 10 will be accommodated by flex, compression and extension of the spring or other extendible material. Alternatively, harness 6 may be attached to vertical arm 22 by any of the means described above in lieu of suspending gamma camera 5 from vertical arm 22.
The weight of gamma camera 5 can also be relieved by providing support from below the camera. An example of a preferred support stand 40 for use in this embodiment of the invention is shown in FIG. 3. In FIG. 3, a bar 35 is pivotably mounted on stand 40 at a midpoint between the distal end 36 and proximal end 37 of the bar. Preferably, bar 35 will be mounted on stand 50 so bar 35 may extend upward to about a 45° angle from vertical at its proximal end. Proximal end 37 is detachably attached to harness 6 at its bottom or midpoint. Camera 5 will be stabilized in position against body 10 by tightening of harness 6 and may be further stabilized by attachment of camera 5 to rope 15 (with or without counterbalance) or to a extendible material (such as a spring or elastic cord).
To balance the weight of camera 5, a counterbalance 38 of about equal weight to camera 5 will be attached to distal end 36 of bar 35. Further, being pivotably mounted on stand 40, bar 35 will move upward and downward in response to movement by body 10. Thus, this embodiment of the invention is particularly well suited for use with exercise equipment that may cause vertical movement of the body, such as a stairstepper apparatus.
The invention having been fully described, modifications thereto which meet the intended use and scope of the invention will become apparent to those of ordinary skill in the art. All such modifications are within the scope of the invention being claimed. | A system and apparatus for obtaining medical quality images of a body under stress, such as a body in motion, are disclosed. The apparatus preferably consists of a harness into which the imaging device may be removably placed and securely positioned with respect to a body part, even when the body is in motion. The system preferably further comprises a small, light weight gamma camera. The imaging device is preferably supported by a mechanism which is separate from the harness. In each embodiment of the invention, movement of the imaging device relative to the body is minimized, yet the body is permitted to move relatively freely. Methods for use of the apparatus and system to obtain medical images of a body are also described. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to a process for preparing polyisocyanates that can be used as a curing agent for two-pack urethane resins usable in the fields of paint, adhesives and molding materials.
More specifically, this invention relates to a process for preparing polyisocyanates of the isocyanurate type which is derived from a diisocyanate compound mainly composed of hexamethylene diisocyanate and which can be used as a curing agent for two-pack urethane resins.
The isocyanurate-type polyisocyanates, which are derived from hexamethylene diisocyanate through isocyanuration reaction, are important since they are more durable curing agents for two-pack urethane resins than conventional biuret-type or adduct-type polyisocyanates due to the high chemical stability of the isocyanurate ring contained therein.
Also, since the isocyanurate-type polyisocyanates have in the molecules no such bonds as urethane bonds which cause hydrogen bonding, they are considered good curing agents for two-pack urethane resins used in paints and adhesives due to their low viscosity and good dissolving power in various organic solvents.
However, in the process for preparing isocyanurate-type polyisocyanates with an isocyanuration catalyst, hexamethylene diisocyanate has different properties than those of aromatic diisocyanate compounds such as tolylene diisocyanate, indicating high selectivity for the catalyst and tending to involve side reactions, e.g., carbodiimide formation, that readily take place causing coloration or the like. Therefore, isocyanuration catalysts having particularly high performance are required in this process.
Furthermore, the isocyanurate-type polyisocyanates derived from hexamethylene diisocyanate when used as a curing agent for two-pack urethane resins are known to have somewhat poor compatibility with acrylic polyols which are widely used as a major component of the curing agent. Accordingly, to prepare isocyanurate-type polyisocyanates having improved compatibility with the acrylic polyols, they must be polyisocyanates which have a low molecular weight and in which the content of the compounds containing only a single isocyanurate ring (hereafter, referred to as "mononuclear" polyisocyanates or compounds) is high. That is why isocyanuration catalysts having improved performance are required.
However, since hexamethylene diisocyanate has high selectivity for catalysts, conventional isocyanuration catalysts (i.e., various tertiary amine compounds and phosphines) that are efficient for aromatic diisocyanate compounds such as tolylene diisocyanate cannot be used in the isocyanuration of hexamethylene diisocyanate. Accordingly, there has been an ongoing need to develop other efficient isocyanuration catalysts useful for the purpose.
As the results of extensive studies conducted recently on the catalysts useful in the isocyanuration of hexamethylene diisocyanate, N-(2-hydroxyalkyl)-quaternary ammonium aliphatic carboxylate was proposed as a catalyst with high catalytic activity. Japanese Patent Publication (Kokai) No. 55-143978 discloses use of the catalyst in amounts of from 200 to 1,000 ppm to prepare isocyanurate-type polyisocyanates. Although this process using a quaternary ammonium compound catalyst is more advanced when compared as the preceding proposals, the isocyanuration reaction performed using hexamethylene diisocyanate alone causes coloration of the resin due to accompanied side reactions, failing to provide isocyanurate-type polyisocyanates having a light color and acceptable quality.
Very recently, the present inventors have found in their study that N-(2-hydroxyalkyl)-quaternary ammonium aromatic carboxylate is an efficient isocyanuration catalyst with high activity (Japanese Patent Publication (Kokai) No. 60-181078). However, the process of the preceding proposals proved inadequate to suppress the coloration which occurred during the isocyanuration reaction when hexamethylene diisocyanate was used alone. Thus far, light color, high-quality isocyanurate-type polyisocyanates with a high content of a mononuclear polyisocyanate compound have been difficult to prepare at comparatively low conversions.
As previously mentioned, the conventional processes proved insufficient for preparing light color, high-quality isocyanurate-type polyisocyanates using hexamethylene diisocyanate alone.
SUMMARY OF THE INVENTION
In light of the above-mentioned situation, extensive research has been made with view to developing a catalyst that would effectively promote the isocyanuration reaction of hexamethylene diisocyanate, and as the result it has now been found that use of a specified isocyanuration catalyst is effective, thus completing the invention.
Therefore, this invention provides a process for preparing isocyanurate-type polyisocyanates characterized by reacting an aliphatic or alicyclic diisocyanate compound comprising hexamethylene diisocyanate as a major component in the presence of an isocyanuration catalyst represented by general formula [I], ##STR2## wherein R 1 , R 2 and R 3 independently represent a hydrocarbon group containing 1 to 20 carbon atoms, or a hydrocarbon group containing one or more hetero atoms; at least two of R 1 , R 2 and R 3 may be linked to each other; R 4 indicates a hydrogen atom or a hydrocarbon group containing 1 to 20 carbon atoms; and R 5 , R 6 and R 7 independently represent a hydrocarbon group containing 1 to 20 carbon atoms.
Also, this invention provides a process for preparing diol-modified isocyanurate-type polyisocyanates characterized by reacting an aliphatic or alicyclic diisocyanate compound comprising hexamethylene diisocyanate as a major component in the presence of
(a) an isocyanuration catalyst represented by general formula [I], wherein R 1 , R 2 and R 3 independently represent a hydrocarbon group containing 1 to 20 carbon atoms, or a hydrocarbon group containing one or more hetero atoms; at least two of R 1 , R 2 and R 3 may be linked to each other; R 4 indicates a hydrogen atom or a hydrocarbon group containing 1 to 20 carbon atoms; and R 5 , R 6 and R 7 independently represent a hydrocarbon group containing 1 to 20 carbon atoms, and
(b) a hydrocarbon diol.
The processes of this invention are advantageous in that they can produce isocyanurate-type polyisocyanates which have a light color and high quality and are of a high industrial value using a small amount of catalyst since they use a catalyst having improved performance as compared with the conventional processes.
DETAILED DESCRIPTION OF THE INVENTION
In general formula [I] above, the hetero atom may be, for example, a nitrogen atom to which an alkyl group such as a methyl group may be attached.
The resulting isocyanurate-type polyisocyanates or diol-modified isocyanurate-type polyisocyanates contain preferably at least 65% by weight of a mononuclear polyisocyanate compound. When the content of the mononuclear polyisocyanate compound is below 65% by weight, the compound does not mix well.
Typical examples of the isocyanuration catalyst, i.e., N-(2-hydroxyalkyl)-quaternary ammonium tertiary aliphatic carboxylate represented by general formula [I] above as used in this invention include compounds with structures [Ia] to [Ik] shown below. ##STR3##
The compounds represented by general formula [I] and typically represented by formulae [Ia] to [Ik] above, are readily available through the established processes of Bechara or its modification as described in Japanese Patent Publication (Kokai) No. 52-17484.
The amount of the isocyanuration catalyst to be used is preferably from 20 to 200 ppm based on the weight of the charged diisocyanate compound which is mainly composed of hexamethylene diisocyanate. When the amount of the catalyst is smaller than 20 ppm, the reaction tends to proceed unsatisfactorily and on the other hand, the reaction tends to proceed excessively when the catalyst is used in an amount greater than 200 ppm and it will sometimes be difficult to control the reaction.
In general, the isocyanuration catalyst is used after diluting it with an organic solvent in which the catalyst is soluble. Dimethylacetamide, N-methylpyrrolidone or butyl Cellosolve acetate can be used as the solvent, and various kinds of alcohols such as ethyl alcohol, n-butyl alcohol, t-butyl alcohol, 2-ethylhexyl alcohol, benzyl alcohol, butyl Cellosolve, propylene glycol or 1,3-butanediol can be used.
For practical application of this invention, active hydrogen compounds such as alcohols, e.g., 1,3-butanediol and 2,2,4-trimethyl-1,3-pentandiol, and phenols, e.g., p-t-butylphenol and 2,6-dimethyl-4-t-butylphenol can be used as a co-catalyst.
Since the catalyst of this invention represented by general formula [I] above has a high catalytic activity, high-quality isocyanurate-type polyisocyanates can readily be obtained without using a co-catalyst. However, use of the above active hydrogen compounds as the co-catalyst will not depart from the scope of present invention.
The isocyanuration reaction of this invention normally proceeds at temperatures of from 30° to 120° C. The reaction at temperatures exceeding 120° C. is not favorable because the catalyst is deactivated or the quality of the product deteriorates as by coloration of polyisocyanate.
Since the isocyanuration catalyst represented by general formula [I] features high performance, the isocyanuration reaction of hexamethylene diisocyanate can be smoothly be promoted at the above temperatures (e.g., 60° C.). At the same time, the rate of formation of the isocyanurate-type polyisocyanates as the reaction proceeds can be evaluated by measuring the change in the refractive index of the reaction system. This is particularly effective and helpful in preparing low-molecular weight isocyanurate-type polyisocyanates with a high content of the mononuclear polyisocyanates.
Therefore, the conversion of the isocyanuration reaction is kept in the range of preferably from 8 to 65% by weight, and more preferably from 10 to 45% by weight, for obtaining isocyanurate-type polyisocyanates with a high content of the mononuclear polyisocyanates.
Thus, after the isocyanuration reaction, the isocyanuration catalyst used can be deactivated by using appropriate deactivators (e.g., acids such as dodecylbenzenesulfonic acid and monochloroacetic acid or organic acid halides such as benzoyl chloride).
Among the deactivators mentioned above, monochloroacetic acid is preferred since it can be refined with ease.
The isocyanurate-type polyisocyanates can readily be obtained by removing unreacted diisocyanate compounds from the reaction mixture containing the already deactivated catalyst using various types of molecular distillation still (e.g., rotary blade or rotary disc type).
The isocyanurate-type polyisocyanates resulting from hexamethylene diisocyanate are expressed by general formula [II] as follows: ##STR4## among which polyisocyanate compounds expressed by general formula [III], are composed of a mononuclear polyisocyanate in amounts of at least 65% by weight. ##STR5##
The resulting isocyanurate-type polyisocyanates can be used in their pure state or diluted state by using organic solvents such as toluene, xylene, ethyl acetate, butyl acetate or petroleum aromatic hydrocarbon solvents (e.g., Swasol 1000 produced by the Maruzene Petroleum Co.).
In the present invention, isocyanurate-type polyisocyanates obtained from hexamethylene diisocyanate as a major raw material are conceived as the primary subject. If desired, up to 40% by weight, preferably up to 30% by weight, of other raw materials such as aliphatic diisocyanate compounds, e.g., 2,2,4-trimethylhexamethylene diisocyanate and dodecamethylene diisocyanate or alicyclic diisocyanate compounds such as 1,4-cyclohexanediisocyanate and 1,3-bis(isocyanatomethyl)-cyclohexane can be added to the hexamethylene diisocyanate system.
In the process of preparing isocyanurate-type poly-isocyanates according to this invention, hydrocarbon diols such as 1,3-butanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, and cyclohexanedimethanol can if desired be used together with the catalyst in the isocyanuration reaction to prepare the diol-modified isocyanurate-type polyisocyanates. This process of preparing the modified type product is also included within the scope of the present invention. The amount of diol modification in the process of preparing the diol-modified isocyanurate-type polyisocyanates is preferably up to 30% by weight and more preferably up to 20%, based on the weight of the diisocyanate compound charged.
The isocyanurate-type polyisocyanates prepared according to the process of this invention play an important industrial role as a curing agent for polyurethane resins, and are particularly effective curing agents for use together with not only polyester polyol, which is a major ingredient of polyurethane resins but also acrylic polyol.
The acrylic polyol with a hydroxyl number of from 40 to 160 and a molecular weight of from 5,000 to 25,000 is commonly used, and modified acrylic polyol grafted with cellulose acetate butyrate (CAB) is also suitable for use in combination with the polyisocyanate used in this invention. In addition, fluoropolyol, which is soluble in organic solvents, can be used together with polyisocyanates obtained according to the process of this invention.
The polyisocyanates thus-obtained by the present invention in combination with the previously mentioned polyols can be applied to the fields of paint, adhesives, and molding materials.
EXAMPLES
This invention will be described in greater detail with reference to the following examples which are not construed as limiting this invention. All percentages are by weight unless otherwise indicated specifically.
EXAMPLE 1
A 5-liter four-necked glass flask (equipped with a stirrer, a nitrogen gas supply tube, an air cooling tube, and a thermometer) was charged with 3,500 g of hexamethylene diisocyanate (HDI) in a nitrogen gas atmosphere. While stirring, the temperature of the flask was raised to 55° C. in an oil bath, then a 20%-butyl Cellosolve solution of N,N,N-trimethyl-N-2-hydroxypropylammonium pivalate (molecular weight: 219), expressed by formula [1b] above, was added as an isocyanuration catalyst. When a total of 1.8 g of catalyst solution was added (103 ppm against charged HDI), the temperature inside the reactor rose to 63° C.
After the exothermic reaction ended, the reaction was constantly monitored by observing changes in the refractive index (n 25 D) of the reaction mixture with controlling the temperature controlled at 60° C. When the refractive index of the reaction mixture reached 1.4625, 2.5 g of a 6.8%-xylene solution of monochloroacetic acid (molecular weight: 94.5) was added as a catalyst deactivator to terminate the reaction.
Then, the reaction mixture was cooled to room temperature. The deactivated reaction mixture had light color, indicating a Hazen color unit of 10 to 20.
Subsequently, a 1,000 g aliquot of the reaction mixture was subjected to molecular distillation to obtain 249.8 g (conversion: 25.0%) of polyisocyanate as a reaction residue, and 748.6 g (recovery ratio 75.0%) of HDI as a distillate.
The resulting polyisocyanate solution has a light color (Hazen color unit 40) and a Gardner viscosity at 25° C. (the same hereinafter) of W to X. The isocyanate group content (abbreviate as "NCO %") was 23.0%. The polyisocyanate (P-1) was confirmed to be an isocyanurate-type polyisocyanate from the infra-red absorption spectrum and 13C nuclear magnetic resonance spectrum analyses.
Also, the content of the product having a mononuclear polyisocyanate group in the molecule expressed by formula [III] above, which corresponded to general formula [II] in which n=1, was determined to be 70% using high-performance gel permeation chromatography, and the measured number-average molecular weight was 560.
The polyisocyanate (P-1) indicated good compatibility with acrylic polyol "ACRYDIC A-801" (produced by Dainippon Ink & Chemicals, Inc.; non-volatile content=50%, Gardner viscosity=P to T, acid value<3, hydroxyl number=50+2, solvent=toluene, butyl acetate) at an NCO/OH equivalent ratio of 1.0. When the resulting varnish was coated on a glass plate, a very cohesive, cured film was obtained.
Separately, a resin varnish was prepared by mixing the polyisocyanate solution with acrylic polyol (B) (glass transition temperature=50° C., non-volatile content=50%, molecular weight=15,000, acid value=1, hydroxyl number=50, solvent=butyl acetate), which was prepared in trial by using conventional radical polymerization from methyl methacrylate, styrene, ethyl acrylate, and β-hydroxyethyl methacrylate. When the resulting varnish was coated on a glass plate, a very cohesive, cured film was obtained.
EXAMPLE 2
The same procedure as described in Example 1 was performed except for the following. As the isocyanuration catalyst, a 20%-butyl Cellosolve solution of N,N,N-triethyl-N-2-hydroxypropylammonium pivalate (molecular weight 261), expressed by formula [1c] above, was introduced in a flask in portions. When a total of 1.6 g (91 ppm) of the catalyst solution was added, the temperature inside the reactor rose to 64° C. While maintaining the temperature at 60° C. when the refractive index of the reaction mixture reached 1,4625, 1.8 g of a 6.8%-xylene solution with monochloroacetic acid was added inside the reactor to terminate the reaction. The cooled reaction mixture had a light color with a Hazen color unit of 10.
Subsequently, a 1,000 g aliquot of the reaction mixture was subjected to molecular distillation to obtain 249.5 g (conversion 25.0%) of the aimed polyisocyanate as a reaction residue and, on the other hand, 750.2 g (recovery ratio 75.0%) of HDI as a distillate.
The resulting polyisocyanate (P-2) solution had a light color (Hazen color unit 30), Gardner viscosity of W, and NCO% of 23.3%. The polyisocyanate (P-2) was confirmed to be an isocyanurate-type polyisocyanate, containing 72% of the mononuclear polyisocyanate group with a number-average molecular weight of 540 (as determined through the same instrument analysis as in Example 1).
The polyisocyanate (P-2) indicated good compatibility with each of acrylic polyol: "ACRYDIC A-801" and the trial-made acrylic polyol (B). When the resulting varnish was coated on a glass plate, a very cohesive, cured film was obtained.
EXAMPLE 3
The same procedure as described in Example 1 was performed except for the following. As the isocyanuration catalyst, a 20%-butyl Cellosolve solution of N,N,N-dimethyl-N-cyclohexyl-N-2-hydroxypropylammonium pivalate (molecular weight: 287), expressed by formula [1e] above, was added. When a total of 2.5 g (143 ppm) of catalyst solution was added, a reaction started and was continued at a temperature of 60° C. When the refractive index of the reaction mixture reached 1.4625, 2.7 g of a 6.8% -xylol solution of monochloroacetic acid was added to terminate the reaction. The cooled reaction mixture had a light color with a Hazen color unit of 10 to 20.
Subsequently, a 1,000 g aliquot of the reaction mixture was subjected to molecular distillation to obtain 249.7 g (conversion: 25.0%) of the sought polyisocyanate as a reaction residue and, on the other hand, 749.9 g (recovery ratio 75.0%) of HDI as a distillate.
The resulting polyisocyanate (P-3) solution had a light color (Hazen color unit 40), Gardner viscosity of W, and NCO% of 23.3.%. The polyisocyanate (P-3) was confirmed to be an isocyanurate-type polyisocyanate, containing 72% of the mononuclear polyisocyanate group with a number-average molecular weight of 550 (as determined through the same instrument analysis as in Example 1).
The polyisocyanate (P-3) indicated good compatibility with each of acrylic polyol: "ACRYDIC A-801" and the trial-made acrylic polyol (B).
EXAMPLE 4
The same procedure as described in Example 1 was performed except for the following. As the isocyanuration catalyst, a 20%-butyl Cellosolve solution of N,N-dimethyl-N-cyclohexyl-N-2-hydroxypropylammonium 2-methyl-2-ethyl-butanoate (molecular weight 315), expressed by formula [1h] above, was added. When a total of 2.2 g (126 ppm) of catalyst solution was added, a reaction started and was continued at a temperature of 60° C. When the refractive index of the reaction mixture reached 1.4625, 2.2 g of a 6.8%-xylol solution of monochloroacetic acid was added to terminate the reaction. The resulting cooled reaction mixture had a light color, indicating a Hazen color unit of 10 to 12.
Subsequently, a 1,000 g aliquot of the reaction mixture was subjected to molecular distillation to obtain 249.5 g (conversion: 25.0%) of the sought polyisocyanate as a reaction residue and, on the other hand, 749.6 g (recovery ratio 75.0%) of HDI as a distillate.
The resulting polyisocyanate (P-4) solution had a light color (Hazen color unit 40), Gardner viscosity of W, and NCO% of 23.0. The polyisocyanate (P-4) was confirmed to be an isocyanurate-type polyisocyanate, containing 72% of the mononuclear polyisocyanate group with a number-average molecular weight of 550 (as determined through the same instrument analysis as in Example 1).
The polyisocyanate (P-4) indicated good compatibility with each of acrylic polyol: "ACRYDIC A-801" and trial-made acrylic polyol (B).
EXAMPLE 5
The same procedure as described in Example 1 was performed except for the following. As the isocyanuration catalyst, a 20%-butyl Cellosolve solution of N,N-dimethyl-N-cyclohexyl-N-2-hydroxypropylammonium 2.2-dimethylpentanoate (molecular weight: 315), expressed by formula [1i] above, was added. When a total of 1.9 g (109 ppm) of catalyst solution was added, a reaction started and was continued at a temperature of 60° C. When the refractive index of the reaction mixture reached 1.4625, 2.2 g of a 6.8%-xylol solution of monochloroacetic acid was added to terminate the reaction. The resulting cooled reaction mixture had a light color, indicating a Hazen color unit of 10.
Subsequently, a 1,000 g aliquot of the reaction mixture was subjected to molecular distillation to obtain 249.8 g (conversion: 25.0%) of the sought polyisocyanate as a reaction residue and, on the other hand, 749.2 g (recovery ratio: 75.0%) of HDI as a distillate.
The resulting polyisocyanate (P-5) solution had a light color (Hazen color unit 30), Gardner viscosity of W, and NCO% of 23.2%. The polyisocyanate (P-5) was confirmed to be an isocyanurate-type polyisocyanate, containing 71% of the mononuclear polyisocyanate group with a number-average molecular weight of 550 (as determined through the same instrument analysis as in Example 1).
The polyisocyanate (P-5) indicated good compatibility with each of acrylic polyol: "ACRIDIC A-801" and trial-made acrylic polyol (B).
EXAMPLE 6
The same procedure as described in Example 1 was performed except for the following. As the isocyanuration catalyst, 2.0 g (114 ppm) of a 20%-butyl Cellosolve solution of [1b] (same solution as used in Example 1) consisting of 2,800 g of hexamethylene diisocyanate (HDI) and 700 g of 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI) as raw material was used to promote reaction in the system. When the refractive index of the reaction mixture reached 1.4690, 2.8 g of a 6.85-xylol solution of monochloroacetic acid was used to deactivate the reaction. The resulting reaction mixture had a light color, indicating a Hazen color unit of 10 to 12.
Subsequently, a 1,000 g aliquot of the reaction mixture was subjected to molecular distillation to obtain 258.7 g (conversion: 26.0%) of the sought polyisocyanate as a reaction residue and, on the other hand, 736.3 g (recovery ratio: 74%) of HDI as a distillate.
The resulting polyisocyanate (P-6) solution had a light color (Hazen color unit 30) and NCO% of 22.5%. The polyisocyanate (P-6) was confirmed to be an isocyanurate-type polyisocyanate consisting of HDI and H6XDI, containing 71% of the mononuclear polyisocyanate group with a number-average molecular weight of 570 (as determined through the same instrument analysis as in Example 1).
The polyisocyanate (P-6) indicated good compatibility with each of acrylic polyol: "ACRYDIC A-801" and trial-made acrylic polyol (B). When the clear varnish prepared by the equivalent mixture ratio was coated on a glass plate, a very cohesive, cured film was obtained.
EXAMPLE 7
The same procedure as described in Example 1 was performed except for the following. As the isocyanuration catalyst, 0.72 g (41 ppm) of a 20%-butyl Cellosolve solution of [1b] (same solution as used in Example 1) consisting of 3,500 g of hexamethylene diisocyanate (HDI) and 125 g of 2,2,4-trimethyl-1,3-pentanediol (TMPD) as raw materials was used to promote reaction in the system. When the refractive index of the reaction mixture reached 1.4662, 1.0 g of a 6.8%-xylol solution of monochloroacetic acid was used to deactivate the reaction. The resulting reaction mixture had a light color, indicating a Hazen color unit of less than 10.
Subsequently, a 1,000 g aliquot of the reaction mixture was subjected to molecular distillation to obtain 342.9 g (conversion: 34.5%) of the sought polyisocyanate as a reaction residue and, on the other hand, 651.1 g (recovery ratio: 65.5%) of HDI as a distillate.
The resulting polyisocyanate (P-7) solution had a light color (Hazen color unit 20) and NCO% of 20.8%. The polyisocyanate (P-7) was confirmed to be a diol-modified isocyanurate-type polyisocyanate having isocyanurate rings and an adduct of TMPD with a number-average molecular weight of 620 (as determined through the same instrument analysis as in Example 1).
The polyisocyanate (P-7) indicated good compatibility with each of acrylic polyol: "ACRIDIC A-801" and the trial-made acrylic polyol (B). When the clear varnish prepared by the equivalent mixture ratio was coated and left on a glass plate, a very cohesive, cured film was obtained.
COMPARATIVE EXAMPLE 1
In the same process as described in Example 1, a 20%-butyl Cellosolve solution of well-known N,N,N,-trimethyl-N-2-hydroxypropylammonium octanoate (molecular weight: 271; ref. Patent Publication (Kokai)No. 55-143978) was used as the isocyanuration catalyst. The solution was added in portions. When the total added amount became 7.9 g (451 ppm), a reaction started Continuing the reaction at a temperature of 60° C. until the refractive index of the reaction mixture reached 1.4625, 8.6 g of a 6.8%-xylol solution of monochloroacetic acid was added to terminate the reaction. The resulting cooled reaction mixture was colored, indicating a Hazen color unit of 220.
Subsequently, a 1,000 g aliquot of the reaction mixture was subjected to molecular distillation to obtain 248.9 g (conversion 24.9%) of the sought polyisocyanate as a reaction residue, and 750.1 g (recovery ratio 75.0%) of HDI as a distillate.
The resulting polyisocyanate (S-1) solution was colored, indicating a Hazen color unit of 340 to 360, Gardner viscosity of W, and NCO% of 22.9%. The polyisocyanate (S-1) was confirmed to be an isocyanurate-type polyisocyanate containing 68% of a polyisocyanate ring with a number-average molecular weight of 580 (as determined through the same instrument analysis as in Example 1).
The polyisocyanate (S-1) indicated good compatibility with acrylic polyol "ACRYDIC A-801" and the trial-made acrylic polyol (B), but the quality was poor due to excessive coloration.
COMPARATIVE EXAMPLE 2
In the same process as described in Example 1, a 20%-butyl Cellosolve solution of well-known N,N,N-trimethyl-N-2-hydroxypropylammonium p-t-butylbenzoate (molecular weight: 295; ref. Patent Publication (Kokai) No. 60-181078) was used as the isocyanuration catalyst. The solution was added in portions. When the total added amount became 5.2 g (297 ppm), a reaction started. Due to slow reaction at 60° C., 0.8 g (46 ppm) of the catalyst solution was added to promote the reaction. When the refractive index of the reaction mixture reached 1.4625, 6.0 g of a 6.8%-xylol solution of monochloroacetic acid was added to terminate the reaction. The resulting cooled reaction mixture was colored, indicating a Hazen color unit of 160.
Subsequently, a 1,000 g aliquot of the reaction mixture was subjected to molecular distillation to obtain 249.3 g (conversion: 25.0%) of the sought polyisocyanate as a reaction residue, on the other hand, and 749.8 g (recovery ratio: 75.0%) of HDI as a distillate.
The resulting polyisocyanate (S-2) solution was colored, indicating a Hazen color unit of 260, viscosity of X, and NCO% of 22.8. The polyisocyanate (S-2) was confirmed to be an isocyanurate-type polyisocyanate containing 68% of a isocyanurate ring with a number-average molecular weight of 580 (as determined through instrument analysis).
The polyisocyanate (S-2) indicated good compatibility with acrylic polyol "ACRIDIC A-801" and the trial-made acrylic polyol (B), but the quality was poor due to excessive coloration. | Disclosed is a process for preparing isocyanurate-type polyisocyanates characterized by reacting an aliphatic or alicyclic diisocyanate compound comprising hexamethylene diisocyanate as a major component in the presence of an isocyanuration catalyst represented by general formula [I], ##STR1## wherein R 1 , R 2 and R 3 independently represent a hydrocarbon group containing 1 to 20 carbon atoms, or a hydrocarbon group containing one or more hetero atoms; at least two of R 1 , R 2 and R 3 may be linked to each other; R 4 indicates a hydrogen atom or a hydrocarbon group containing 1 to 20 carbon atoms; and R 5 , R 6 and R 7 independently represent a hydrocarbon group containing 1 to 20 carbon atoms. Diol-modified isocyanurate-type polyisocyanates can be prepared additionally using a hydrocarbon diol in the process. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to urological warming and cooling devices and more particularly to a warming catheter and method of warming the urethra of a patient during ablative surgery. The apparatus is particularly useful in cryosurgery to prevent damage to tissues surrounding a surgical site from the extremely cold temperatures employed therein. The apparatus is especially useful during transperineal cryoablation of the prostate gland in human males to maintain the temperature of the urethral tissues and thereby prevent urethral sloughing. The apparatus may also have utility where it is desired to lower the temperature of surrounding tissues, such as during laser ablation.
[0003] 2. Description of the Related Art
[0004] Cryosurgical probes are used to treat a variety of diseases. The cryosurgical probes quickly freeze diseased body tissue, causing the tissue to die after which it will be absorbed by the body, expelled by the body or sloughed off. Cryothermal treatment is currently used to treat prostate cancer and benign prostate disease, breast tumors and breast cancer, liver tumors and liver cancer, glaucoma and other eye diseases. Cryosurgery is also proposed for the treatment of a number of other diseases.
[0005] The use of cryosurgical probes for cryoablation of the prostate is described in, for example, Onik, Ultrasound - Guided Cryosurgery, Scientific American at 62 (January 1996). Cryosurgical probe systems are manufactured by present assignee, Endocare, Inc. of Irvine, Calif. In cryosurgical ablation procedures generally several cryosurgical probes are inserted through the skin in the perineal area (between the scrotum and the anus), which provides the easiest access to the prostate. The probes are pushed into the prostate gland through previously placed cannulas. Placement of the probes within the prostate gland is typically visualized with an ultrasound imaging probe placed in the rectum. The probes are quickly cooled to temperatures typically below −120° C. The prostate tissue is killed by the freezing, and any tumor or cancer within the prostate is also killed. The body absorbs some of the dead tissue over a period of several weeks. However, other necrosed tissue may slough off and pass through the urethra, often causing undesirable blockage. Thus, it is often desirable to avoid cryoinjury to the urethra during cryoablation of the prostate. This may be done by placing a warming catheter in the urethra and continuously flushing the catheter with warm fluid to keep the urethra from freezing.
[0006] Devices for warming the urethra have been available for quite some time. In 1911, U.S. Pat. No. 1,011,606 issued for an “Appliance For Subjecting Portions Of The Human System To Heat Or Cold.” This device was a coaxial dual lumen catheter intended for the application of therapeutic cooling or heating to the urethra and bladder. Devices for warming other body parts have also been proposed, such as U.S. Pat. No. 4,244,377, issued Jan. 13, 1981 to Grams entitled “Ear Probe For Use In Closed-Loop Caloric Irrigation”, which shows a coaxial dual lumen cannula intended for the application of therapeutic heating inside the ear.
[0007] U.S. Pat. No. 5,437,673, issued on Aug. 1, 1995 to Baust, et al., entitled “Closed Circulation Tissue Warming Apparatus and Method of Using the Same in Prostate Surgery” illustrates use of a urethral warming catheter which is used to protect the urethra from cryothermal damage during cryosurgical treatment of the prostate for benign prostate hyperplasia. The Baust patent discloses a coaxial three lumen catheter in which warm saline passes through an outside lumen and is returned through a coaxial second lumen. A third lumen is a urinary drainage lumen centrally disposed within the other two lumens. The catheter is used to heat the urethra while the prostate is being frozen with cryosurgical probes.
[0008] A very similar device to that disclosed in U.S. Pat. No. 5,437,673 is disclosed in U.S. Pat. No. 5,624,392, issued on Apr. 29, 1997 to Saab, entitled “Heat Transfer Catheter and Methods of Making and Using Same.”
[0009] U.S. Pat. No. 5,257,977, issued on Nov. 2, 1993 to Eshel, entitled “Technique for Localized Thermal Treatment of Mammals,” shows a catheter that delivers heated saline flow to provide therapeutic hyperthermia treatment of the prostate. Like the Baust patent, Eshel shows a three lumen catheter with a centrally located urinary drainage lumen.
[0010] Still other devices have been described for importing fluid into the body and allowing a means for removing fluid from the body. One such device is described in U.S. Pat. 3,087,493, issued Apr. 27, 1960 to Schossow, entitled “Endotracheal Tube”. Schossow describes a device employed to intubate the human trachea. The device is connected with ducts and/or tubes outside the patient for the purpose of, for example, drawing off from the patient's respiratory tract undesirable liquids and/or introducing beneficial liquids into the trachea. The device comprises an outer tube, which fits inside the patient's trachea, and a two layered inner tube. The lumen of the inner tube is open to be connected with devices or ducts through which suction may be applied or fluids injected into the trachea. The distal portion of the inner tube is vented with ports or openings that create a “sprinkler” effect inside the tube.
[0011] During cryoablation, the prostate tissue is killed by freezing temperatures in the cryogenic temperature range, typically −120° C. and below. The hot fluid used for the warming catheter is supplied at about 30° C. to 50° C. Warm fluid is pumped through the urethral warming catheter, such as the catheter described in Baust et al. Using this catheter, as the warm fluid travels the length of the urethral catheter disposed within the cryosurgically-cooled urethra, it is cooled by the surrounding freezing tissue. By the time the hot water has traveled from the bladder neck sphincter to the external sphincter, it has been significantly cooled by the surrounding frozen prostate. As a result, the urethral tissue near the bladder neck sphincter (near the hot water outlet) is heated more than the urethral tissue near the external sphincter, creating a strong thermal gradient in the prostatic urethra and an uneven heating effect. By the time the hot water reaches the external sphincter, it may have lost so much heat to the upper region of the urethra that it is not warm enough to protect the external sphincter from freezing. In order for the tissue at the bladder neck sphincter to be adequately warmed, hotter water must be pumped in, risking urethral damage due to scalded tissue, or more water must be pumped at higher rates and pressures, increasing the material requirements of the hot water supply system and the warming catheter.
[0012] U.S. Pat. No. 6,017,361, issued to Mikus et al, entitled “Urethral Warming Catheter,” discloses an improved method and means for maintaining the temperature of urethral tissues during cryoablation of the prostate gland and thereby eliminates or reduces the sloughing of dead cells into the urethra. Diffuser holes or ports, much like a “sprinkler,” are drilled into the inner tube of the warming catheter. The holes create an advantage over the prior art of achieving improved uniformity of fluid flow and temperature, utilizing a lower initial temperature and resulting in a more even application of thermal treatment to the urethral tissues. The apparatus may find additional utility in other areas of surgery where thermal treatment or maintenance of tissues is required with or without the capability of drainage.
SUMMARY OF THE INVENTION
[0013] In one broad aspect the present invention is a heat exchange catheter that includes an inflow housing assembly, an outflow housing assembly, a discharge tube, an inner balloon, an outer balloon, and flow separation means. The inflow housing assembly includes an inflow housing main section having a central axis; and, an inflow housing inlet section coupled to the inflow housing main section for providing an inlet flow of heat exchange fluid to the inflow housing main section, the inflow housing main section and the inflow housing inlet section having respective openings therein for providing for the inlet flow. The outflow housing assembly includes an outflow housing main section having a central axis which is along the central axis of the inflow housing main section. The outflow housing main section is coupled to the inflow housing main section. An outflow housing outlet section is coupled to the outflow housing main section for receiving an outlet flow of heat exchange fluid from the outflow housing main section. The outflow housing main section and the outflow housing outlet section have respective openings for the inlet flow and the outlet flow. The discharge tube is positioned within respective openings of the inflow housing assembly and the outflow housing assembly, the discharge tube being positioned along the central axis. The inner balloon is positioned about the discharge tube and coupled to the outflow housing assembly. The inner balloon is in a position offset from the central axis. The outer balloon is positioned about the inner balloon and connected at a first end to the outflow housing assembly. A second end thereof is securely attached to a distal portion of the discharge tube. The inner balloon is shorter than the outer balloon. Flow separation means for separating the inlet flow of heat exchange fluid from the outlet flow of warming fluid. During operation, the inlet flow of heat exchange fluid flows from the inflow housing inlet section, and through the inflow housing main section, then through an inlet fluid passageway formed between the inner balloon and the discharge tube, the flow continuing around a distal end of the inner balloon, thus becoming the outlet flow of the heat exchange fluid which is directed through an outlet fluid passageway formed between the inner balloon and the outer balloon, then through the outflow housing main section and finally discharged through the outflow housing outlet section.
[0014] The heat exchange catheter is particularly useful as a warming catheter for prostatic cryosurgical procedures where cryosurgical probes are used and it is desired to maintain the temperature of the urethral tissues to prevent urethral sloughing.
[0015] Offset positioning of the inner balloon, in contrast to any coaxial relationship of this inner balloon to the outer balloon and the discharge tube (such as disclosed in U.S. Pat. Nos. 5,437,673 and 5,624,392) has certain advantages. An offset relationship enhances the fluid dynamic properties of the catheter. It provides an increased turbulence, which, in turn, maximizes the heat exchange efficiency.
[0016] Furthermore, this offset positioning provides the ability to have a discharge tube of minimal thickness and thus enhanced flexibility, which is important, for example, for application in the urethra in which the catheter must be able to bend around the pubic bone when inserted through the urethra.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of a first embodiment of the heat exchange catheter of the present invention.
[0018] FIG. 2 is a bottom plan view of the embodiment of FIG. 1 .
[0019] FIG. 3 is a cross-sectional view taken along line 3 - 3 of FIG. 2 .
[0020] FIG. 4 is an enlarged cross-sectional view of the invention.
[0021] FIG. 5 is a sectional view taken along lines 5 - 5 of FIG. 4 .
[0022] FIG. 6 is a perspective view of the distal portion of the heat exchange catheter.
[0023] FIG. 7 is a perspective view of a second embodiment of the heat exchange catheter of the present invention.
[0024] FIG. 8 is a bottom plan view of the embodiment of FIG. 7 .
[0025] FIG. 9 is a cross-sectional view taken along line 9 - 9 of FIG. 8 .
[0026] FIG. 10 is an enlarged cross-sectional view of the second embodiment of the invention.
[0027] FIG. 11 is a sectional view taken along lines 11 - 11 of FIG. 10 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Referring now to the drawings and the characters of reference marked thereon, FIGS. 1-6 illustrate a first embodiment of the heat exchange catheter of the present invention, designated generally as 10 . The catheter 10 includes an inflow housing assembly, designated generally as 12 and an outflow housing assembly, designated generally as 14 . The generally cylindrical housing assemblies 12 , 14 are coupled to each other and are serially positioned along a common central axis 16 . An outer balloon 18 projects from the distal end of the outflow housing assembly 14 . A discharge tube 20 is also positioned along the central axis 16 and extends beyond the end of the outer balloon 18 .
[0029] As best seen with reference to FIG. 4 , the inflow housing assembly 12 includes an inflow housing main section 22 and an inflow housing inlet section 24 coupled to the inflow housing main section for providing an inlet flow of warming fluid to the inflow housing main section. The inflow housing main section 22 and the inflow housing inlet section 24 have respective openings therein for providing for the inlet flow, designated by arrows 26 . In the embodiment shown, the inflow housing main section 22 and the inflow housing inlet section 24 together comprise an integral, molded plastic part.
[0030] The outflow housing assembly 14 includes an outflow housing main section 28 , which is along the central axis 16 of the inflow housing main section 28 . The outflow housing main section 28 is coupled to the inflow housing main section 22 via a divider element, designated generally as 30 . An outflow housing outlet section 32 is coupled to the outflow housing main section 28 for receiving an outlet flow of warming fluid from the outflow housing main section 28 , the outlet flow, designated by arrows 34 . The outflow housing main section 28 and the outflow housing outlet section 32 have respective openings for the inlet flow 26 and the outlet flow 34 .
[0031] The divider element 30 includes a proximal axially oriented portion 36 secured to a distal end of the inflow housing main section 22 and to a proximal end of the outflow housing main section 28 . A radially inwardly extending portion 38 depends from a distal end of the proximal axially oriented portion 36 . The radially inward extending portion 38 is radially off center from the central axis 16 . A distal axially oriented portion 40 depends from the radially inwardly extending portion 38 . The distal axially oriented portion 40 is secured to a proximal end of an inner balloon 42 thus positioning the inner balloon 42 in an offset position from the central axis 16 . The outflow housing main section 28 includes an axial extension 44 . The outer balloon 18 is secured between the outer surface of the axial extension 44 and strain relief element 48 . Although FIG. 4 illustrates the inner balloon 42 being secured to the inner surface of the distal axially oriented portion 40 it may be secured in other locations such as the outer surface of the distal axially oriented portion 40 .
[0032] A luer 46 extends rearwardly from a proximal end of the inflow housing main section 22 for providing access to the discharge tube 20 . The discharge tube 20 may provide access for the discharge of bladder fluid or may, for example, provide access for a guide wire or endoscope.
[0033] The balloons 18 and 42 are preferably made from a flexible, relatively non-stretchable, polyester film such as polyethylene terephthalate (PET), outer balloon 18 having a fixed diameter upon introduction of fluid therein. Preferably, this diameter is about 22 French, which corresponds to the average diameter of the urethra in adult male humans. The length of the balloons may be on the order of, for example, from about 12 inches to about 24 inches. The inner balloon may have an outside diameter of about 0.162 inches and an inside diameter of about 0.160 inches. The outer balloon may have an outside diameter of about 0.284 inches and an inside diameter of about 0.281 inches.
[0034] The discharge tube 20 may be formed of, for example, a suitable plastic such as polyamide. It may, for example, have an outside diameter of about 0.107 inches and an inside diameter of about 0.058 inches. Therefore, the thickness of the discharge tube may be, for example, about 0.0245 inches. This is much thinner than present commercially sold products, having a thickness of about 0.052 inches. Thus, the discharge tube 20 of the present invention is much more flexible.
[0035] As protection against damage due to excessive flexing, a strain relief element 48 in the form of a length of heavier gauge plastic tubing is attached to the outflow housing assembly 14 by telescoping a portion of the tubing over the outer surface of barbed axial extension 44 . Strain relief element 48 extends a distance of approximately five centimeters beyond the end of axial extension 44 .
[0036] In a specific example of operation, to warm a urethra of a patient during cryosurgical ablative surgery, ablative devices are inserted into the prostate region of a patient. The heat exchange catheter 10 , operating as a warming catheter, is inserted through the patient's urethra at least to the bladder neck and generally into the bladder. Warming fluid is delivered through the catheter 10 during operation of the ablative surgical devices. The warming fluid is delivered into the bladder. The urethra is warmed by the warming fluid to preserve living tissue thereof.
[0037] The ablative devices are preferably cryosurgical probes such as manufactured and marketed by Endocare, Inc., of Irvine, Calif. Generally, six cryosurgical probes are used as well as four temperature probes. Alternatively, other ablative devices may be used, for example, radio frequency electrodes, laser fibers, microwave catheters, or high-intensity focused ultrasound. In such instances the heat exchange fluid is cool so as to prevent the urethra from the heating by the ablative elements.
[0038] Although not shown, the inflow housing assembly 12 receives heat exchanges fluid from a pump and warmer, which are, in turn, connected to a reservoir. The warming fluid should be supplied at temperatures sufficient cool so as to not thermally damage the urethra. Appropriate fluids include sterile water, physiological saline, and the like and should be such fluids as are biocompatible and physiologically benign in the event of inadvertent rupture of the balloons 18 , 42 .
[0039] The warming fluid passes through the inflow housing assembly 12 , as shown by arrows 26 , and into the outflow housing assembly 14 within the inlet fluid passageway formed within the inner balloon 42 . As the flow reaches the distal end of the inner balloon it is turned, as indicated by arrows 50 (shown in FIGS. 4 and 6 ), and is directed in the outlet fluid passageway formed between the outer balloon 18 and the inner balloon 42 as indicated by arrows 34 . It is then discharged through the outflow housing outlet section 32 . Thus, a closed fluid circulation path is provided as the fluid is returned to the reservoir. The countercurrent flow of incoming and outgoing fluid allows the warmer incoming fluid in inner balloon 42 to warm the cooler outgoing fluid in outer balloon 22 . The thermal exchange is even along the length of catheter 10 . Even though from the figures (e.g. FIG. 5 ) it appears as if there may be some attachment of the outer balloon 18 and the inner balloon 42 , they are not attached, and indeed there is a generally a gap between the two balloons even in the proximity in which they appear to be very close to each other.
[0040] The entire apparatus of the catheter 10 may be constructed in larger or smaller sizes as needed depending on the criteria of patient and use. For example, a catheter 10 for use on a child will be smaller than that used on an adult. Similarly, a catheter 10 for use elsewhere in the body may be smaller or larger than that used in the urethra.
[0041] Referring now to FIGS. 7-11 , another embodiment of the present is illustrated, designated generally as 52 . In this instance, the inflow housing assembly 54 includes an inflow housing main section 56 that comprises an inflow block. Similarly, the outflow housing assembly 58 includes an outflow housing main section 60 that comprises an outflow block.
[0042] The inflow block has a first axial extension 62 having a decreased diameter and a second axial extension 64 having a further decreased diameter. A mating surface is formed by the presentation of the first axial extension 62 being offset from the central axis 66 . An inner radial surface of the second axial extension 64 is secured to an outer surface of the inner balloon 68 . The outer balloon 70 may be secured to an inner surface of an axial extension 72 of the outflow housing main section 60 , as shown in this figure. Alternatively, it may be secured to an outer surface of the axial extension 72 .
[0043] A luer 74 is secured to and extends from a proximal end of the inflow housing main section 56 for providing access to a discharge tube 76 . In this embodiment, the inflow housing inlet section 78 and outflow housing outlet section 80 are separate pieces from their respective main sections 56 , 58 . They are threaded into their positions relative to their associated main sections. The flow separation means in this embodiment is the material that forms the blocks 56 , 58 . Inlet fluid passageways and outlet fluid passageways are provided within these blocks.
[0044] This embodiment operates in the same manner as that described above with respect to the first embodiment with inlet flow, designated by arrows 82 , passing through the inflow housing assembly 54 , around the distal end of the inner balloon as shown by arrow 84 . The flow thus becomes an output flow 86 that flows through the outflow housing assembly 58 .
[0045] Although the examples discussed above refer to the use of a warming fluid it is understood that if the ablative devices are for heating rather than for cooling, the heat exchange fluid would be a cooling fluid.
[0046] The heat exchange catheter may find additional utility in other areas of surgery where thermal treatment of maintenance of tissues is required with or without the capability of drainage. For example, an extended length catheter may be used for thermal treatment within the intestinal tract or the esophagus. Shorter versions may find utility in other areas such as nasal passages, otic areas, joints, i.e. arthroscopy, or the like, where adjacent tissues may be undergoing cryogenic or other thermal treatment. Indeed, varied forms of the apparatus and method may be used in virtually any body cavity where tissues are exposed to thermal extremes and damage to adjacent tissues is to be avoided. They may find particular utility anywhere cryogenic probe devices are being used to destroy and/or remove tumerous growths.
[0047] The molded embodiment of FIGS. 1-6 has fewer parts than the block embodiment of FIGS. 7-11 and therefore has manufacturing advantages. Molding rather than using machined and standard off the shelf components results in cost advantages. The block embodiment of FIGS. 7-11 has the advantage of obviating up front tooling expenses.
[0048] The reservoir used is preferably a removable and disposable plastic container, such as an intravenous bag or a rigid container, which may be prepackaged with a fixed volume of sterile fluid, for example one liter. Clearly, just as larger or smaller catheters may be used in different situations, such larger and smaller catheters will require larger or smaller volumes of fluid. Appropriate fluids include sterile water, physiological saline, and the like and should be such fluids as are biocompatible and physiologically benign in the event of inadvertent rupture of the balloons. To allow for removal and return of the fluid in the closed system, the reservoir includes two fittings for connection of the inflow housing inlet section and outflow housing outlet section. These fittings may be standard piercable IV bag fittings.
[0049] A heating block is configured to removably accept and hold reservoir so as to heat the fluid contained therein. Preferably the heating block includes a vertical slot or window, which permits volume indicia on the reservoir to be viewed. The heating block itself may be a simple resistance heating means or an infrared heater or any other suitable heater capable of raising the temperature of the fluid within reservoir to approximately 42 degrees C. Heating the circulation fluid to this level has been found to provide sufficient warmth within the balloons to counter the cold of a cryoprobe and maintain the urethral tissues at about normal body temperature during cryogenic surgery of the prostate. Suitable heater control means allows the operator to select the desired temperature for heater block.
[0050] Downstream from the heating block is a pump, which provides motive force to the fluid to maintain a constant and even flow through the system. Once the desired flow rate and temperature are set, automatic control means are activated to maintain these levels. The automatic controls include monitoring sensors for supply temperature, return temperature and flow rate. In addition to the sensors and control means, pump and heater activating switches are included and electrically linked through a control circuit to their respective units as is a low flow alarm.
[0051] Thus, while the preferred embodiments of the devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the invention. Other embodiments and configurations may be devised without departing from the spirit of the invention and the scope of the appended claims. | An inlet flow of heat exchange fluid flows from an inflow housing inlet section, and through an inflow housing main section. It then flows through an inlet fluid passageway formed between an inner balloon and a discharge tube. The flow continues around a distal end of the inner balloon, thus becoming an outlet flow of the heat exchange fluid which is directed through an outlet fluid passageway formed between the inner balloon and an outer balloon, then through an outflow housing main section and finally discharged through an outflow housing outlet section. The inner balloon is in a position offset from the central axis of the catheter. The offset relationship enhances the fluid dynamic properties of the catheter. It provides an increased turbulence, which, in turn, maximizes the heat exchange efficiency. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. application Ser. No. 11/393,021 filed Mar. 30, 2006, which claims benefit of Provisional Application Ser. No. 60/672,733 filed Apr. 19, 2005, which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a display stand for certain types of consumer products. More particularly, this invention relates to a display stand for disposable serving ware containers, such as paper or plastic plates, platters, deep dishes or bowls that will display the containers in a vertical position so the face of the container can be readily viewed by the consumer at the point of purchase.
BRIEF SUMMARY OF THE INVENTION
[0003] Serving containers, such as paper or plastic plates are typically packaged in nested form in a plastic outer wrap. The containers are transported from the manufacturer ultimately to a retail outlet for purchase by the consumer. At the retail outlet, the containers are typically stacked horizontally on the shelves such that the consumer only sees the edge of the stack of packaged containers. For most purposes this arrangement is acceptable. However, some containers include decorative designs on the face of the container and some even include a theme such as animals. See for example U.S. Patent Publication No. U.S. 2004/0069788, the disclosure of which is incorporated herein by reference. When stacked horizontally on store shelves, the aesthetic appeal of these types of decorative containers is not readily apparent to the customer. In order to allow the store to stack these types of containers so that the decorative face of the container is readily apparent to the customer, a display stand for the containers that will hold them upright is required.
[0004] In order for the display stand to be economically viable, it must allow the footprint of the package to remain small and it must allow the various packages of the containers to be nested. This minimizes the space needed to transport the packaged containers and display stands and allows the retail outlet to display a large number of such packaged containers and display stands on the shelves. This in turn minimizes the frequency that the store shelves need to be restocked with those items. In addition, the display stand should be easily manufactured and combined with the consumer product to be displayed with the display stand to allow easy incorporation into the manufacturing process of the consumer products. This will minimize cost for the consumer product manufacturer. The display stand should also work with the retail outlets' current display system to avoid costly retrofitting of the retail outlets' current display system and to avoid the need for the retail outlets to purchase new display systems.
[0005] The display stand of this invention is preferably formed from a paperboard blank that is folded together to define an interior portion for accommodating a certain number of disposable containers. When the containers are placed in the display stand, the display stand holds the containers in a vertical position so the face of the container can be directed to the consumer at the point of purchase. The display stand has an open bottom and is defined by a straight bottom edge where the edges are substantially aligned with each other and generally perpendicular to a vertical axial line extending through the display stand. This straight bottom edge provides a flat surface on which the display stand rests to give the display stand, with the containers therein, stability. The front and rear portions of the display stand preferably have a concavely curved top edge such that the radius of curvature of the concavely curved portions are substantially similar to the radius of curvature of the face portion of the container. This provides the consumer with an unobstructed view of the decorative face of the container. It also provides a shoulder on which the rear of the container can rest so the edges of the containers do not extend below the bottom edge of the display stand, which could adversely affect the stability of the assembled package. The two sides of the display stand can be generally perpendicular to the front and rear portions of the display stand. Alternatively, each of the two sides can be formed from two angled portions so that each end defines a generally V-shaped configuration with the apex of the V pointing away from the containers. These sides of the display stand may also provide a shoulder on which the sides of the container can rest to also help prevent the bottom edge of the containers from extending below the bottom edge of the display stand to thus improve the stability of the package.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The invention will be described in detail in the following description of preferred embodiments with reference to the following figures in which like reference numbers refer to like parts and wherein:
[0007] FIG. 1 is a front perspective view of a first embodiment of the display stand of this invention with a plurality of disposable plates packed therein where the plates have an example of an aesthetic design on the face thereof;
[0008] FIG. 2 is a rear perspective view of the first embodiment of the display stand of this invention with a plurality of disposable plates packed therein;
[0009] FIG. 3A is a top perspective view of the first embodiment of the display stand of this invention;
[0010] FIG. 3B is a bottom perspective view of the first embodiment of the display stand of this invention clearly showing the open bottom therein;
[0011] FIG. 4 is a plan view of the blank used to form the first embodiment of the display stand of this invention;
[0012] FIG. 5 is a front perspective view of a second embodiment of the display stand of this invention with a plurality of disposable plates packed therein where the plates have an example of an aesthetic design on the face thereof;
[0013] FIG. 6 is a rear perspective view of the second embodiment of the display stand of this invention with a plurality of disposable plates packed therein;
[0014] FIG. 7A is a top perspective view of the second embodiment of the display stand of this invention;
[0015] FIG. 7B is a bottom perspective view of the second embodiment of the display stand of this invention clearly showing the open bottom therein; and
[0016] FIG. 8 is a plan view of the blank used to form the second embodiment of the display stand of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The display stand 100 of this invention is preferably formed from a paperboard blank that is folded together to define an interior portion for accommodating a certain number of disposable containers 600 therein. Preferably, display stand 100 can be formed from any paper-based material such as folding carton stock and corrugated paperboard, more specifically micro-flute corrugated paperboard. Display stand 100 defines an open bottom 200 , which in turn is defined by the straight bottom edge 300 of the various flaps forming display stand 100 . Straight bottom edge 300 provides a flat surface on which display stand 100 rests to give display stand 100 , with the containers therein, stability. Typically the paperboard blank is cut from a larger piece of the paperboard on a standard flatbed die-cutting piece of equipment.
[0018] Preferably, the front and rear portions of display stand 100 have a concavely curved portion 110 such that the radius of curvature of the concavely curved portions 110 is similar to, or generally the same as, the radius of curvature of the outer circumference 605 of the face portion 610 of the container 615 . This is generally located adjacent to the rim 620 of the paper plate and can in some cases be considered the interface 625 therebetween. The degree of similarity between the radii of curvature should be such that display stand 100 provides the consumer with an unobstructed view of the aesthetic design, i.e. the decorative face, of the container. Thus the radius of curvature of concavely curved portion 110 can be less or greater than that of the face portion of the container as long as the face is not obstructed. Concavely curved portion 110 also provides a shoulder on which the rear of the container can rest so the edges of the containers do not extend below the bottom edge of the display stand, which would adversely affect the stability of the assembled package. See FIGS. 2 and 6 . In addition, the concavely curved portion 110 on the rear of display stand 100 allows the face of one package to nest with the rear of another package to minimize the amount of space needed to pack and ship a large quantity of display stands 100 with containers packaged therein. Although it is possible to configure only one of the front panel or the rear panel with a curved top edge, this is not the preferred arrangement. In addition, although a concavely curved configuration is preferred for the top edge of the front panel and the rear panel, any other configuration, such as a linear, angular or scalloped or some other complex curved configuration, could be used as long as the configuration provides a clear view of the face of the container to display the decorative features of the container. Also the configuration should provide (i) some type of shoulder on which the rear of the container can rest and (ii) space to allow multiple packages to nest and minimize the footprint requirements of the display stand with the containers packed therein.
[0019] The depth of display stand 100 is determined by the dimensions of the container and the number of containers to be packaged in display stand 100 . Preferably the width of display 100 stand is less than the width of the containers to be packaged in display stand 100 . This allows the ends of display stand 100 to provide another shoulder 120 on which the sides of the containers can rest to prevent the bottom of the container from extending below the bottom of display stand 100 , thus adversely affecting the stability of the assembled package. See FIGS. 1 and 2 . The two sides of display stand 100 can be generally perpendicular to the front and rear portions of display stand 100 . See FIGS. 1-3 . Alternatively, each of the two sides can be formed from two angled portions so that each end defines a generally V-shaped configuration 130 with the apex of the V pointing away from the containers. See FIGS. 5-7 . Where such a V-shaped configuration 130 is provided for the ends of display stand 100 ′, preferably the apex of the V is inside of the tangent to the outermost side portion on the container or at most is aligned with the tangent to that outermost side portion.
[0020] The blank for the first embodiment of display stand 100 has a continuous straight bottom edge 300 , a connection tab 410 , a front flap 420 , a first end flap 430 , a rear flap 440 and a second end flap 450 . As seen in FIG. 4 , connection tab 410 is connected along its right edge to the left edge of front flap 420 along a first vertical fold line 415 . Front flap 420 is connected along its right edge to the left edge of first end flap 430 along a second vertical fold line 425 . First end flap 430 is connected along its right edge to the left edge of rear flap 440 along a third vertical fold line 435 . Rear flap 440 is connected along its right edge to the left edge of second end flap 450 along a fourth vertical fold line 445 . To assemble the blank into display stand 100 , each vertical fold line is folded so that each portion of the blank is perpendicular to the adjacent portion. This allows connection tab 410 to overlap a portion of second end flap 450 and can be adhered thereto by any standard means such as an adhesive, staples or other mechanical interlocking means.
[0021] The blank for the second embodiment of display stand 100 ′ has a continuous straight bottom edge 300 , first rear flap 510 , a first end flap 520 , a second end flap 530 , a front flap 540 , a third end flap 550 , a fourth end flap 560 and a second rear flap 570 . As seen in FIG. 8 , first rear flap 510 is connected along its right edge to the left edge of first end flap 520 along a first vertical fold line 515 . First end flap 520 is connected along its right edge to the left edge of second end flap 530 along a second vertical fold line 525 . Second end flap 530 is connected along its right edge to the left edge of front flap 540 along a third vertical fold line 535 . Front flap 540 is connected along its right edge to the left edge of third end flap 550 along a fourth vertical fold line 545 . Third end flap 550 is connected along its right edge to the left edge of fourth end flap 560 along a fifth vertical fold line 555 . Fourth end flap 560 is connected along its right edge to the left edge of second rear flap 570 along a sixth vertical fold line 565 . To assemble the blank into display stand 100 ′ each vertical fold line is folded so that each portion of the blank is at an angle to the adjacent portion to allow first and second rear flaps 510 , 570 to be aligned with, and preferably overlap, each other. This allows a portion of first and second rear flaps 510 , 570 to be adhered to each other by any standard means such as an adhesive, staples or other mechanical interlocking means.
[0022] Thus, it is seen that a display stand is provided that is stable, economical, easy to manufacture and use with various consumer products, such as disposable serving ware, and that has a small footprint and allows for unobstructed viewing of the front face of the product. | A display stand with disposable serving ware containers, such as paper or plastic plates, platters, deep dishes or bowls, displaying the containers in a vertical position so the face of the front container is readily viewed by the consumer at the point of purchase. | 0 |
FIELD OF INVENTION
The invention pertains to modems. More particularly, the invention pertains to modems designed to operate in accordance with the CCITT V.90 and V.90PLUS standardized protocols.
BACKGROUND OF THE INVENTION
Modems are transceiver devices that allow digital data to be transmitted between pieces of digital equipment, e.g., computers, via the telephone lines. The transmitting modem receives serial digital data from a computer (typically passed from the computer to the modem through a UART (Universal Asynchronous Receiver Transmitter) in order to convert it from parallel to serial format. The modem converts the data to a signal form that can be transmitted effectively via the public telephone system. The receiving modem receives that data and converts it back to serial digital format and passes it to the receiving computer (typically through another UART, which converts the data back to parallel).
Over the past few decades, several protocol standards for modems have been developed. One of the more recent standards has been promulgated by the ITU (International Telecommunications Union) formerly known as the CCITT and is known as ITU-T recommendation V.90, incorporated herein by reference. Earlier generation standards developed by the ITU/CCITT include V.22, V.22bis, V.32, V.34, V.42 and V.42bis.
In the relevant industries, communication in the transmit direction from a network node, such as a telephone or a modem, in the direction of the telephone company central office is termed the upstream direction. Receive direction communications from the network towards a node is termed the downstream direction. In accordance with the V.90 protocol, the data format is different in the downstream direction than it is in the upstream direction. In the V.90 standard, modem transmission in the upstream direction is an analog signal in accordance with the older V.34 standard. However, downstream communication is a PCM (pulse code modulated) signal.
There also is a proposed V.90PLUS recommendation, also incorporated herein by reference, which presently is not in commercial use. In the V.90PLUS standard, PCM is used in both the upstream and downstream directions.
FIG. 1 is a block diagram generally illustrating modem to modem communications through a public telephone network. The system will be described in connection with a public telephone network customer exchanging data with his Internet service provider (ISP) through the public telephone network. For purposes of fully illustrating the various factors contributing to noise in this type of communication, let us assume the customer and his ISP are coupled to different central offices of the public telephone network.
The customer at computer 12 inputs and sends data to the ISP at 28 . The computer 12 includes a built-in UART and, therefore, sends out a serial digital signal to the modem 14 . The modem converts the serial digital signal to comply with the V.90 standard (which, in the upstream direction, is the analog V.34 standard) and puts it out on the public telephone network 20 .
Under the V.34 standard, data rates as great as 31.2 kilobits per second (Kbps) can be achieved.
Within the telephone network, telephony communications between central offices are digital, rather than analog. Accordingly, the analog signal is encoded by a codec 22 into a 64 Kbps signal. In particular, the received analog signal is sampled at a rate of 8 KHz and digitized at an 8 bit resolution to produce a 64 kbps digital PCM signal. The 64 kbps standard is known in the United States as the μ-law standard and in Europe as the A-law standard. The information is digitally transmitted between central office 24 and central office 26 .
For voice and data communications between two normal customers of the public telephone network, the digital signals received at central office 26 from other central offices on the network, e.g., central office 24 , would be passed through another codec (not shown) to be decoded back to analog form. The decoded analog signals would then be forwarded to the receiving customer. However, a high volume customer of the public telephone network, such as an ISP 28 , would likely have a high bandwidth digital connection to the central office 26 , such as a T-1 line 30 . Accordingly, ISP 28 would not use a codec in central office 26 , but instead would receive the data in digital form over a digital link, such as a T1 line 30 .
In the opposite direction, ISP 28 outputs digital data to central office 26 via T1 line 30 . This data is transmitted in digital form to central office 24 . Codec 22 in central office 24 decodes the digital data to a PCM analog version of the digital signal in accordance with the V.90 protocol and transmits it to the customer. The customer's modem 14 receives the data and converts it to a serial digital data format detectable by computer 12 . Finally, the UART in computer 12 converts the data from serial to parallel. In the downstream direction, data can be received at rates as great as 56 Kbps.
As can be seen, under the V.90 standard, upstream communications are at a different data rate, i.e., 31.2 Kbps, than downstream communications, i.e., 56 kbps. Further, the communications in the upstream direction, is in an analog format, i.e., V.34, and, in the downstream direction, are in PCM format.
FIG. 2 is a more detailed block diagram of the interface between a customer's modem 14 and the local central office 24 . As shown, the modem 14 accepts transmit data from the computer's UART 201 on a transmit data path 202 and sends data to the computer's UART 201 on a receive data path 204 . In the transmit (upstream) direction, V.90 transmitter 203 in modem module 206 of modem 14 converts data between the serial digital format generated by the UART 201 to the analog V.34 format. Codec 209 converts the data from digital to analog for transmission over the telephone lines. In the receive direction (i.e., downstream), V.90 receiver 205 in modem module 206 converts data from the V.90 PCM format to the serial digital format used by UART 201 . Codec 209 converts data from analog to digital in the receive direction.
The customer's equipment (to the left of hybrid circuitry 208 in FIG. 2) is a four wire system. That is, there are two wires for the transmit direction (i.e., each of lines 202 and 204 comprises two wires) and two wires for the receive direction (i.e., each lines 204 and 207 comprises two wires). The public telephone network, however, is a two wire system in which the transmit data and the receive data are transmitted over the same wire pair. Accordingly, a hybrid circuit 208 interfaces between the codec 209 and the public telephone network 210 . In the transmit direction, it takes the transmit data from the codec and places it on the two wires 211 (tip and ring) of the telephone network. In the receive direction, it selects and isolates the receive data from wires 211 and forwards it to the modem module 206 on the receive wire pair 207 . There is almost always an impedance mismatch between the customer's telephone equipment and the public telephone network. This impedance mismatch has the unfortunate effect of causing an echo at the hybrid circuit. The echo occurs in both directions. For instance, data transmitted from the computer 12 through the modem module 206 to the hybrid 208 is reflected back on the receive wire pair 207 to the modem module 206 and computer 12 . Likewise, data received from the public telephone network over the tip and ring wire pair 211 also is reflected back onto the public telephone network.
At the central office, there is another hybrid circuit 224 and codec circuit 226 serving essentially the same functions. Hybrid circuit 224 also creates echos in both directions. The echo from hybrid circuit 224 passes back through hybrid circuit 208 and reach the receive data path 204 , 207 . Such echoes are not particularly bothersome for voice communications, which can bear a significant amount of noise and still provide signal quality acceptable to the human ear. However, echo signals of large enough amplitude can corrupt digital data that is being received simultaneously with the echo on the receive data path 204 , 207 .
FIG. 3 is a block diagram illustrating a customer-to-customer link through a public telephone network between an individual using a PC with a V.90 modem and his ISP having an all digital connection to the network. FIG. 3 illustrates echo effects.
In this example, the two customers are geographically distant from each other so that they are coupled to different central offices. Accordingly, transmissions in the upstream direction pass from the first customer's transmission circuitry 302 over transmit data path 303 through his hybrid circuit 304 onto two wire portion 316 of the public telephone network and through the hybrid circuit 306 in central office 308 to re-separate the transmit and receive direction data for the four wire digital network portion 310 . The data is converted to digital and then transmitted over the digital, inter-central-office network portion 310 to central office 312 where it is forwarded, still in digital form, to modem 314 of ISP 316 .
Thus, the first customer's telephone equipment has a hybrid circuit 304 for converting from four wire to two wire. His local central office also has a hybrid circuit 306 for converting from two wire back to four wire for the digital network 310 . In the upstream direction, the customer experiences a near echo 333 a from hybrid circuit 304 and a near echo 333 b from hybrid circuitry 306 . Because the hybrid circuit 304 in the customer's own equipment as well as the hybrid circuit 306 in his local central office are physically close to him, the near echo is almost simultaneous with the actual transmission of the data. Accordingly, in most circumstances it can be ignored without significant adverse effect in voice communication. However, in data communication, a near echo canceller is required in client modem 301 to remove the near echo in order to achieve better performance.
The ISP's modem 314 experiences a far echo 333 c from hybrid circuit 306 in far central office 308 and a far echo 333 d from the customer's hybrid circuit 304 . Receipt of the far echos at a modem such as modem 314 may be, and commonly are, sufficiently delayed from the original transmission of the data that created the echo to corrupt data on the receive data path of modem 314 .
In order to minimize the effect of far echo, therefore, a digital loss of approximately 6 decibels (dB) is incorporated into hybrid circuits so as to reduce echo amplitude. However, even with the incorporation of digital loss, far echo sometimes can still create sufficient noise to corrupt data.
Thus, in order to further compensate for echo, digital communications equipment (e.g., modems) commonly include an echo canceller circuit. FIG. 4 is a block diagram of an echo canceller circuit of the prior art. The transmit signal from transmitter 400 on transmit path 401 is fed out to the digital network 402 . The transmit signal also is fed into an echo cancellation circuit 403 . The echo canceller circuit includes a bulk delay line buffer 404 and a Finite Impulse Response (FIR) circuit 406 . FIR circuit 406 receives the transmit signal from transmit wire pair 401 through bulk delay line buffer 404 and generates an echo cancellation signal that can be used to cancel the far echo signal portion that returns from the network. The FIR circuit determines, at the beginning of each call, the channel response for the call (e.g., attenuation of echoes, etc.), emulates it and applies it to the data transmitted from transmitter 400 so that the echo cancellation signal emulates the echo signal. The bulk delay line buffer 404 is the circuit that determines and causes the necessary delay in order to cause the output from the FIR circuit 406 to be simultaneous with the receipt of the far echo.
As is well known in the art, significant handshaking takes place between the central office interface circuit and the customer's modem. From that handshaking, the round trip delay of the far echo as well as the channel response for any given telephone call can be readily determined. Accordingly, a processor 412 in the modem determines the round trip delay and the necessary coefficients for the FIR circuit 406 from the handshaking data and sends the data to the bulk delay line buffer 404 and the FIR circuit, respectively. The delay circuit 404 will then delay passing the transmit data from transmit path 401 to the FIR circuit 406 for the appropriate duration, namely, the round trip delay, and the FIR will attenuate and otherwise condition the transmit signal to emulate the echo signal. Subtractor 410 subtracts the output of FIR circuit 406 from the receive data path 408 in order to cancel the far echo component that appears on receive data path 408 . It should be noted that the far central office and the receiving customer's equipment are typically geographically close to each other such that the difference in delay between the two can be ignored and the far echo treated as a single far echo signal.
Another noise factor inherent in telephony communications is “robbed bit” noise. In particular, in the digital network portion between telephone company central offices, the least significant bit (LSB) of every sixth data sample is utilized for synchronization. In the United States, for instance, there is one type of robbed bit loss, termed type A. In type A robbed bit systems, the LSB of every sixth data sample (each data sample comprises 8 bits) is forced to digital one regardless of the actual data content. There also are other types of robbed bit protocols. Further, if a connection is routed through a plurality of central offices between the two termination points of the connection, a robbed bit may be inserted for each central office through which a particular call is routed such that there may be several robbed bits every six samples. As will become clear from the discussion below, the present invention is applicable regardless of the particular robbed bit protocol utilized or the number of robbed bits inserted.
In voice communications, for which, of course, the telephone network was originally constructed, the loss of that bit is imperceptible to the listener and, therefore, unimportant. The echo effect of the robbed bit also is acceptable in connection with analog data transmissions such as in accordance with the V.34 modem standard. However, in PCM data communications over the telephone network, the robbed bit must be taken into consideration. Particularly, data cannot be sent in that bit position since it will be corrupted in the digital portion of the network.
Further, the far echo that comes back through the digital network includes the robbed bit. Accordingly, the echo cancellation signal generated by echo cancellation circuit 403 will not exactly match the echo signal portion. Specifically, the signal echoed back to the transmitting equipment contains the robbed bit, whereas the signal that was transmitted on transmit path 401 , and, therefore, was used to create the echo cancellation signal did not contain the robbed bit.
However, the robbed bit is generated in the inter-central-office digital portion of the telephone network. Accordingly, the PCM output signal from the central office codec does not include the robbed bit, which is added later. Accordingly, the signal that is sent from the central PCM modem to the echo canceller circuit does not include the robbed bit information. Accordingly, the echo canceller cannot cancel the robbed bit which is received in the echo.
Accordingly, it is the object of the present invention to provide an improved far echo cancellation method and apparatus.
SUMMARY OF THE INVENTION
In accordance with the present invention, a PCM modem is provided with a far echo canceller circuit which includes a robbed bit generator to compensate for the robbed bit which will appear in the far echo signal received over a telephone network.
In particular, during the handshaking which occurs at the initiation of a telephone call, the transmitting PCM modem determines from the modem at the receiving end the position of the robbed bit added by the telephone network. Based on this information, the position of every robbed bit during the telephone call is known, since it occurs at regular intervals. The robbed bit position information is provided to a robbed bit generator circuit in the echo canceller of the PCM modem which then incorporates the robbed bit into the echo cancellation signal to compensate for the far echo signal, including the robbed bit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram generally illustrating modem to modem communications through a public telephone network in accordance with the prior art.
FIG. 2 is a more detailed block diagram of the interface between a customer's modem and the local central office in accordance with the prior art.
FIG. 3 is a block diagram illustrating echo in customer-to-customer communications through a public telephone network in accordance with the prior art.
FIG. 4 is a block diagram of an echo cancellation circuit in accordance with the prior art.
FIG. 5 is a block diagram of a far echo cancellation circuit in accordance with the present invention.
FIG. 6 is a circuit diagram of an exemplary embodiment of the robbed bit generator of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 5 is a block diagram of the front end of a V.90 standard central modem. As used herein, the term central modem refers to a modem that transmits in PCM format, such as might be found in the facilities of an ISP or other large-scale telephony customer that can hook directly to the digital portion of the telephone network. Thus, for example, referring to FIG. 1, the central modem would be the modem of ISP 28 , which transmits in PCM.
As noted above, at least in the United States, almost all communications over the digital portion of the public telephone network (between central offices) utilizes robbed bit synchronization. Accordingly, the central modem transmits data on transmission wire pair 502 to the digital network 504 . The digital network modifies the signal to insert the robbed bit once every six samples. Thus, when the far echo comes back from the hybrid circuit at the far central office on receive wire pair 506 and the hybrid circuit of the customer's modem, the echo typically is different due to the addition of the robbed bit to the original signal.
A robbed bit may be added in the downstream signal as well as in the echo of the upstream signal. In fact, if a call is routed through several central offices between termination points, several robbed bits may be inserted in each direction. The echoed upstream robbed bit(s) is of less significance because of the presence of the digital loss circuitry which attenuates the echo. Specifically, by the time an upstream robbed bit returns in an echo to the transmission source, it has gone through at least one digital loss circuit and is therefore of almost negligible amplitude. The down stream robbed bit does not experience the digital loss. Thus, the robbed bit(s) in the downstream data is the one that is of major concern to the performance of central PCM modems.
The front end of the central PCM modem includes a far echo canceller circuit 510 . This far echo canceller comprises a robbed bit generator 512 , a bulk delay line buffer 514 , a FIR circuit 516 and a subtractor 518 .
In order to incorporate robbed bit correction into the FIR circuit 516 , the location of the robbed bit is determined by the central PCM modem. The information necessary to determine the position of the robbed bit is obtained from the customer's modem during the initial handshaking that occurs between the central PCM modem and the customer's modem at the commencement of a communication link. This is done independently of the present invention since the central PCM modem needs to determine the location of the robbed bit for synchronizing to the network in the first place.
Particularly, the central PCM modem sends a training signal to the customer's modem during initialization. In connection with the receipt of the training signal, the customer's modem detects the position of the robbed bit. The customer's modem then sends the information of the position of the robbed bit back to the central PCM modem. That information is used by the robbed bit generator circuit 512 to modify the signals it receives from the central PCM modem transmitter to add in the effect of the robbed bit. That modified signal is then sent to the bulk delay line buffer 514 .
The robbed bit generator circuit may take on any number of forms. In essence, it performs the exact same function as the robbed bit generating circuitry of the communications network itself. Thus, there are numerous well known circuits for this purpose that can be utilized. Any of those circuit designs could be used for the present invention.
However, FIG. 6 illustrates one very simple embodiment of robbed bit generator 512 . It comprises a counter 602 set to circularly count to 48 (6×8), a programmable logic circuit 604 and an OR gate 606 . After the processor has determined the position of the robbed bit, it places data indicating the position of the robbed bit relative to some reference point in the data transmission on line 610 . In a TDM network, for instance, the reference point may be the start of a frame as indicated by receipt of the frame synchronization pulse and the position information is the number of bits from the frame start to the position of the first robbed bit in the frame. If we assume that we are concerned only with the downstream robbed bit and that only one downstream robbed bit is inserted, the robbed bit will be the LSB of one of the sample bytes and must occur every 6 samples as previously discussed, this number will be 8, 16, 24, 32, 40 or 48. The counter 602 is reset by the frame synchronization signal at the start of every frame and then counts to 48 circularly until reset again. The programmable logic circuitry 604 is designed to output a one in the bit position corresponding to the position provided to it on line 610 by the processor and a 0 in the other 47 positions. OR gate 606 is coupled to receive the output of the programmable logic circuit at one input and the transmit data from the transmit data path 502 at the other input. Accordingly, the bits transmit data stream corresponding to the positions of the robbed bits are converted to 1 by the robbed bit generator circuit while all other bits remain unaffected.
In alternate embodiments either or both of upstream and downstream robbed bits can be detected and canceled. Also, if the particular connection passes through several central offices such that more than one robbed bit is inserted in either or both directions, the invention would detect and compensate for all of the robbed bits.
During the initialization handshaking, the central PCM modem also determines the time delay of the far echo by measuring the round trip delay during a portion of the start up protocol in which the customer's modem is not transmitting any data. This allows the central PCM modem to receive back the far echo signal without any other data being placed on the line. This measurement is well known in the prior art and forms no part of the present invention. The bulk delay line buffer 514 then delays the output of the modified signal to the FIR circuit 516 for the determined amount of time (termed “round trip delay”). The FIR circuit 516 then applies the channel response to the signal and outputs an echo cancellation signal to subtractor 518 in order to overlap and cancel the far echo received from the digital data network 504 on receive line 506 . The output on line 520 , termed the residual signal, is then forwarded to the receiver 524 of the central PCM modem. As illustrated by feedback line 526 , the FIR circuit includes feedback for continuously correcting the FIR circuit.
Accordingly, the central PCM modem can readily identify the echo and determine the round trip delay as well as the positions of the robbed bits. Once the position of one robbed bit is determined, then the position of all robbed bits is known since they occur at regular intervals. The central PCM modem digital signal processor 528 must also determine what type of robbed bit protocol is being used on the network. This information also is typically determined during training and is well known in the art. Alternately, the PCM modem may simply be pre-set to a particular type of robbed bit compensation since, frequently, it is known in advance what type of public telephone network the modem would be used in connection with and particularly what type of robbed bit protocol is used on that network.
In the PCM V.90PLUS protocol, during initialization handshaking, the position of the downstream robbed bit is detected by the client modem and that position information is given to the central modem. The position of the robbed bit in the upstream direction can be determined by the central modem itself in the V.90PLUS protocol.
Having thus described a few particular embodiments of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements as are made obvious by this disclosure are intended to be part of this description though not expressly stated herein, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only, and not limiting. The invention is limited only as defined in the following claims and equivalents thereto. | A pulse code modulation modem having a far echo canceller that compensates for robbed bit echo noise by polling the receiving modem for robbed bit position information and incorporating that information into its far echo cancellation circuitry. | 7 |
BACKGROUND OF THE INVETION
[0001] 1. Field of the Invention
[0002] The present invention relates to an air inflation device, and in particular, an inflation device which draws air externally and cool the air cylinder and the motor.
[0003] 2. Description of the Prior Art
[0004] Conventional DIY air inflation device has the drawbacks of insufficient inflation pressure, and excessive noise. FIG. 1 shows a conventional mini size air inflation device A 1 that can solve the drawback of excessive noise. However, the heat dissipated by the motor in the course of operation has affected seriously the efficiency of the motor. In other words, this conventional air inflation device has a very short live of use. Besides, in the course of operation of the air inflation device, heat dissipation to the motor is not provided to the motor and the cylinder. In some cases, the excessive heat and current overload will damage the socket for cigarette lighter within the vehicle. Accordingly, it is an object of the present invention to provide an improved structure of an inflation device, which mitigates the above drawbacks.
SUMMARY OF THE PRESENT INVENTION
[0005] The present invention relates to an air inflation device, and in particular, an inflation device which draws air externally and cool the air cylinder and the motor.
[0006] Accordingly it is a main object of the present invention to provide an improved structure of an inflation device having a motor, a mini-sized button-type air filter, a front mounting seat, a muffling pad, a muffling board seat, an air cylinder mounting, a piston, a cylinder body, an cylinder cover and a pressure gauze, characterized in that the motor has a sealing mounting seat provided with one or more than one through hole disposed with the air filter, the front mounting seat is locked with a covering cap, and a cylinder seat mounting plate of the motor is also provided with a through hole to lead air into the cylinder body, and the piston within the cylinder body is connected to the main shaft of the motor so that reciprocation movement is obtained, the piston is provided with an air-inlet hole and the top of the air-inlet hole is provided with an air-sealing pad, and an air discharge hole is provided within the interior of a through slot of the cylinder cover and the top face of the air discharge hole is also provided with a sealing pad, thereby when the reciprocating movement is initiated, air inflation is obtained and the motor and the cylinder body are provided with cooling air.
[0007] Another object of the present invention is to provide an improved structure of an inflation device, wherein the device is provided with excellent heat dissipation so that the excessive heat caused the burning of the motor is mitigated.
[0008] Yet another object of the present invention is to provide an improved structure of an air inflation device, wherein the cost of manufacturing is low and the longevity of the device is extended. The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.
[0009] Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a plan and partial sectional view of a conventional air inflation device.
[0011] [0011]FIG. 2 is a perspective view of a preferred embodiment of the present invention.
[0012] [0012]FIG. 3 is a perspective exploded view of the various parts of the present invention.
[0013] [0013]FIG. 4 is a perspective view of the air filter in accordance with the present invention.
[0014] [0014]FIG. 5 is another preferred embodiment of air filter in accordance with the present invention.
[0015] [0015]FIG. 5A is another preferred embodiment of an air filter in accordance with the present invention.
[0016] [0016]FIG. 6 is a sectional view of the air filter in accordance with the present invention.
[0017] [0017]FIG. 7 is a sectional view of the present invention.
[0018] [0018]FIG. 8 is a sectional enlarged view of the air discharging sealing pad of the present invention.
[0019] [0019]FIG. 9 is a sectional enlarged view of the air inlet sealing pad of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.
[0021] Referring to FIGS. 2 and 3 there is shown an improved structure of an air inflation device comprising a motor 1 , a mini-sized button-type air filter 2 , a front mounting seat 3 , a muffling pad 4 , a muffling board seat 5 , an air cylinder mounting 6 , a piston 7 , a cylinder body 8 , an cylinder cover 9 and a pressure gauze 10 , characterized in that the motor 1 has a sealing mounting seat 11 for sealing the opening at the rear of the motor 1 . The mounting sear 11 is extended to a bottom-bending leg seat 12 . The motor 1 is provided with forward opening which is directly shut by the air cylinder seat 13 at the front opening of the motor 1 such that the motor and the air cylinder seat 13 are combined as one unit. The sealing mounting seat 11 of the motor 1 is provided with one or more than one through hole 111 disposed with the air filter 2 , allowing external air to be withdrawn. The cylinder seat locking plate 132 is provided with through holes 133 of equal number and the through hole 133 can directly communicate with the cylinder body B so as to draw air. This is shown in FIG. 7.
[0022] As shown in FIGS. 2 and 3, the opening end 131 of the cylinder seat 13 is provided with a muffling plate seat 5 having mounted with a muffling pad 4 to seat off the opening end 131 . The muffling end 5 is provided with bended leg seat 51 so as to correspond to the leg seat 12 of the sealing mounting seat. The top section of the cylinder 13 is provided with an air cylinder mounting 6 , pistons 7 , cylinder body 8 and cylinder cover 9 to form into an entire cylinder body B. The piston 7 has an eccentric block 71 connected to the main shaft 110 such that the piston 7 can form reciprocation movement within the cylinder body B. The lateral side of the air cylinder cover 9 is mounted with pressure gauze 10 to show the pressure reading.
[0023] As shown in FIGS. 8 and 9, the piston 7 within the cylinder body B is connected to the main shaft 110 of the motor 1 so that reciprocation movement is obtained. The piston 7 is provided with an air-inlet hole 72 and the top of the air-inlet hole 72 is provided with an air-inlet sealing pad 73 , and an air discharge hole 91 is provided within the interior of a through slot of the cylinder cover 9 and the top face of the air discharge hole 91 is also provided with an air-discharge sealing pad 92 .
[0024] When the motor 1 is in operation, the rapid rotation of the rotor 112 provides turbulent air and together with the rapid reciprocation movement of the piston 7 , the absorbing force that produced will lead air passed through the motor 1 to the cylinder B so as to obtain heat dispersion effect. When the piston 7 moves downward, the pressure that produced at that instance pushes the air inlet sealing pad 73 and the air is lead to the cylinder mounting 6 . When the piston 7 moves upward the compressed will push away the air discharge sealing pad 92 at the air inlet hole 91 . At this instance the sealing pad 73 is in a sealing status and the compressed air can be rapidly discharged away. Thereby when the reciprocating movement is initiated, air inflation is obtained and the motor and the cylinder body are provided with cooling air. Therefore the operation capability of motor is lengthened.
[0025] Referring to FIGS. 4, 5 and 5 A, the air filter 2 is positioned at the through hole 111 of the sealing mounting seat to provide leading external air for heat dispersion. The external of the installed filter 2 is locked and covered by the front mounting seat 3 such that the air filter 3 is concealed and hidden. In accordance with the present invention, the air filter 2 includes a top cover 21 and a cup body 22 and the face of the top cover 21 is provided with air holes 211 and the outer circumferential edge is provided with a water sealing edge 212 to prevent water drops into the air holes 211 . The cup body 22 is provided with an insertion section 221 and an air communication slot 222 for filling of air filtering material 23 for air purification. Referring to FIGS. 5 and 5- 1 , the insertion section is provided with a snap engagement or a screw-typed lock. These mounting methods are of similar function.
[0026] It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.
[0027] While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. | An improved structure of an air inflation device is disclosed. External air is drawn to the motor and cylinder to provide rapid cooling so that the efficiency of the motor is maintained. In the present invention, a plurality of air filters is used to filter air. Thereby the air inflation device is useful and practical. | 5 |
PRIORITY CLAIM
[0001] This application is a Continuation-in-Part of PCT Patent Application No. PCT/AU2009/000137 entitled “DUST COLLECTOR CONTROL SYSTEM” filed on Feb. 5, 2009, which claims the benefit of Australian Patent Application No. 2008900515 filed on Feb. 5, 2008.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to air filtration systems and in particular to dust collectors and to monitor and control systems for dust collectors.
[0004] 2. Description of the Relevant Art
[0005] Dust collectors are used by a variety of industries such as mining, pharmaceutical, power industry, sawmills, small to large workshops (i.e. schools, hospitals, art gallery), furniture manufacturers, cement, chemical, food industries and such. Historically, filtering of air on commercial premises was done using scrubbers and precipitators. These filters have been more suitable in high temperature plants. Dust collectors may employ the use of either tubular filter bags or cartridges to retain fine dust particles. One popular type of filter is made from fabric. Fabric filters have higher efficiency in dust collection and clean air emissions compared to other filter types. Dust collectors operate like giant vacuum cleaners with a number of collection bags, called baghouses. Dust particles are drawn into fabric bag filters and trapped by the walls of the filter bag.
[0006] For the bags to filter at an optimal level they must be cleaned regularly. In order to provide continuous filtered air, dust particles trapped by the filters need to be removed whilst the plant is operating. In one method, this is achieved by periodical shaking of the filters. The filters are shaken either mechanically (for example, between every 5 to 15 seconds) or blasted with compressed air. The dust particles then fall from the filters and are collected below in a hopper which is regularly emptied. Too much shaking is to be avoided where possible as it can cause unnecessary wear to the filters.
SUMMARY OF THE INVENTION
[0007] According to a first embodiment there is provided a method of determining a state of a dust filter unit having an air inlet conduit for directing air to be filtered to a filter and an air outlet conduit for receiving filtered air from the filter, the air to be filtered being caused to flow from the inlet to the outlet through the filter and wherein the filter is subjected to cleaning cycles, the method includes:
detecting the concentration of dust in the outlet conduit following one of the cleaning cycles of the filter, the detected concentration of dust being indicative of the state of the dust filter unit.
[0009] In one form, the method includes, after the detecting step, of comparing the detected concentration of dust with a baseline dust concentration, wherein a detected dust concentration which is greater than the baseline dust concentration indicates a possible leak in the dust filter. In a particular embodiment, the comparing step may be performed within a predetermined time after the cleaning of the filter. Alternatively, the comparing step may be performed after the cleaning cycle within a predetermined percentage of time of a single complete cleaning cycle.
[0010] In one form, the cleaning cycle includes forcing air through the filter, opposite the direction of flow of air to be filtered, for a predetermined time period or until a predetermined volume of air has passed through the filter. In a particular form, the step of forcing air through the filter includes forcing the air through the filter as a pulse of air at a pressure higher than the pressure of air flowing through the filter from the inlet conduit to the outlet conduit.
[0011] The cleaning cycle may include shaking the filter.
[0012] In one form, the filter unit may include a plurality of filters and the method is employed to detect a leak in at least one of the filters or one filter in a group of filters. The filter unit may also include an outlet manifold, wherein the or each filter is connected to the manifold and the outlet conduit is in fluid communication with the manifold. In one form, the filter unit may include a plurality of said outlet manifolds, each manifold having at least one of said filters connected thereto and being in communication with the outlet conduit. The detecting step may be applied to each respective manifold at different times. Optionally, the method may be employed to detect a leak in at least one filter of a group of filters connected to one of the manifolds.
[0013] In a particular form, the or each filter is a bag filter or cartridge filter.
[0014] In one form, when a leak is detected in the filter unit, the flow of air through the filter is stopped.
[0015] In one form, there is provided the further step of establishing the differential in air pressure across the filter to indicate a further state of the dust filter unit. In a particular form the differential in air pressure is indicative of whether the filter requires cleaning.
[0016] In a further aspect, there is provided a method of determining a state of a dust filter unit having an air inlet conduit for directing air to be filtered to a filter and an air outlet conduit for receiving filtered air from the filter, the air to be filtered being caused to flow from the inlet to the outlet through the filter and wherein the filter is subjected to cleaning cycles, the method includes:
establishing the differential in air pressure across the filter to indicate the state of the dust filter unit.
[0018] In a particular form, a characteristic of the cleaning cycle is established utilizing the established differential in air pressure across the filter. The characteristic of the cleaning cycle may be the duration of the cycle, the strength of the cycle and/or the timing of the activation of the cleaning cycle.
[0019] In a particular form, where the characteristic is the timing of the activation of the cleaning cycle, the cleaning cycle is activated when the established differential is above a predetermined threshold.
[0020] According to a further embodiment there is provided a monitoring system for a dust filter unit, the unit including an air inlet conduit for directing air to be filtered to a filter and an air outlet conduit for receiving filtered air from the filter, the air to be filtered being caused to flow from the inlet to the outlet through the filter and wherein the filter is subjected to cleaning cycles, the system including:
a dust detector configured to be associated with and for detecting a concentration of dust in the outlet conduit; and a controller configured to identify the detected dust concentration following one of the cleaning cycles such that the detected concentration of dust can be compared with a baseline dust concentration.
[0023] In one form, the system further includes a comparator module arranged to compare the detected concentration with the baseline concentration so as to determine the state of the filter unit; and an output module arranged to issue an alert signal responsive to the comparator module determining that the state of the filter unit is exhibiting one or more characteristics.
[0024] In one form the one or more characteristics includes a possible leak in the filter.
[0025] In yet a further aspect, there is provided a control system for a dust filter unit, the unit including an air inlet conduit for directing air to be filtered to a filter and an air outlet conduit for receiving filtered air from the filter, the air to be filtered being caused to flow from the inlet to the outlet through the filter and wherein the filter is subjected to cleaning cycles, the system including:
a device for detecting the differential in air pressure across the filter; and a controller operable to control one or more characteristics of the cleaning cycle in response to the differential in air pressure being at a threshold level.
[0028] According to a fourth embodiment there is provided a method of detecting a leak in a dust filter unit having an air inlet conduit for directing air to be filtered to a filter and an air outlet conduit for receiving filtered air from the filter, the air to be filtered being caused to flow from the inlet to the outlet through the filter and wherein the filter is subjected to cleaning cycles, the method including:
performing a cleaning cycle by agitating the filter to dislodge at least some of the residue therefrom; stopping the agitation step; after stopping the agitation step, detecting the concentration of dust in the outlet conduit; and comparing the detected concentration of dust with a baseline dust concentration, wherein a detected dust concentration which is greater than the baseline dust concentration indicates an undesired leak in the dust filter unit.
[0033] According to a further embodiment there is provided a method for determining a state of a cleaning cycle system of a dust collector, the dust collector having an air inlet conduit for directing air to be filtered to one or more filters and an air outlet conduit for receiving filtered air from the one or more filters, the air to be filtered being caused to flow from the inlet to the outlet through the one or more filters and wherein the one or more filters are subjected to cleaning cycles by the cleaning cycle system, the cleaning cycle system periodically providing cleaning air from a cleaning air source via a valve system through the one or more filters, the method includes:
measuring a pressure profile of the cleaning air in the cleaning air source during at least a portion of one of the cleaning cycles and comparing the profile against a predetermined profile, wherein a difference of more than a predetermined amount between the cleaning air pressure profile and the predetermined profile indicates a changed state of the cleaning cycle system.
[0035] In one form, the changed state includes an undesired condition of one or more of the valves of the valve system. Optionally, the underside may include a failure of one or more of the valves to open or to close. The difference may be determined by the difference between the gradient of the predetermined profile and the gradient of the cleaning air pressure profile.
[0036] In a particular form, the cleaning air source includes an air receiver and the step of measuring the cleaning air pressure profile includes measuring the cleaning air pressure profile of the air in the air receiver.
[0037] According to another embodiment there is provided a system for determining a state of a cleaning cycle system of a dust collector, the dust collector having an air inlet conduit for directing air to be filtered to one or more filters and an air outlet conduit for receiving filtered air from the one or more filters, the air to be filtered being caused to flow from the inlet to the outlet through the one or more filters and wherein the one or more filters are subjected to cleaning cycles by the cleaning cycle system, the cleaning cycle system periodically providing cleaning air from a cleaning air source via a valve system through the one or more filters, the system including:
a valve between the cleaning air source and the dust collector, the valve being operable to provide cleaning air to the one or more filters; a pressure measuring device for measuring the pressure over time in the cleaning air source; a device for determining a pressure profile of the cleaning air in the cleaning air source during at least a portion of one of the cleaning cycles; and a device for comparing the cleaning air pressure profile against a predetermined profile, wherein a difference of more than a predetermined amount between the cleaning air pressure profile and the predetermined profile indicates a changed state of the cleaning cycle system.
[0042] In one form, the system includes a controller for controlling the cleaning cycle system and the valve. The cleaning air source may include an air receiver.
[0043] In a particular form, when a difference of more than the predetermined amount is detected, the cleaning cycle system is interrupted. Also, when a difference of more than the predetermined amount is detected, an alarm may be activated.
[0044] In one form, the controller is connected to and remotely accessible via a computer network. The controller may be in communication with the computer network via the Internet.
[0045] According to yet a further embodiment a method is provided for controlling a cleaning cycle of a dust filter system including one or more filters, the cleaning cycle having start and stop criterion associated with a characteristic of the dust filter system, the method including:
adjusting at least one of the start and stop criteria in response to a predefined state of the dust filter system being determined.
[0047] In one form the characteristic for at least one of the start and stop criterion is a pressure differential detected across one or more filters of the dust filter system.
[0048] In one form the start criterion is that the pressure differential across the one or more filters has reached a first predefined value. In one form the stop criterion is that the pressure differential across the one or more filters has fallen below a second predefined value which is lower than the first predefined value.
[0049] In one form a value of at least one of the start and stop pressure criterion is adjusted in response to a duration of a previous or current cleaning cycle exceeding a predefined value.
[0050] In one form a value of at least one of the start and stop pressure criterion is adjusted in response to determining that at least one filter of the filter system has reached a predefined age and/or filtration state.
[0051] In one form, in response to adjusting the value of the stop criterion when the duration of the current cleaning cycle exceeds a predefined value, the value of the start criterion is adjusted by a predefined amount.
[0052] In one form the value of at least one of the start and stop criterion is increased by a fixed amount. In another form the values of at least one of the start and stop criterion is increased by an amount dependent on at least one of: an age of the filter(s); a state of the filter(s); a particulate size of the filtered material; and a system loading.
[0053] In yet a further embodiment a controller is provided for a dust filter system including one or more filters, the controller being arranged to implement a cleaning cycle having start and stop criterion associated with a characteristic of the dust filter system, the controller being further arranged to adjust at least one of the start and stop criteria in response to determining a predefined state of the dust filter system.
[0054] In one form the characteristic for at least one of the start and stop criterion is a pressure differential detected across one or more filters of the dust filter system.
[0055] In one form the start criterion is that the pressure differential has reached a first predefined value. In one form the stop criterion is that the pressure differential has fallen below a second predefined value which is lower than the first predefined value.
[0056] In one form the controller is arranged to adjust a value of at least one of the start and stop criterion in response to determining that a duration of a previous or current cleaning cycle exceeds a predefined value.
[0057] In one form a value of at least one of the start and stop criterion is adjusted by the controller in response to determining that the one or more filters has reached a predefined age and/or filtration state.
[0058] In one form, in response to the value of the stop criterion being adjusted, the controller is further arranged to adjust the value of the start criterion by a corresponding amount.
[0059] In one form the value of at least one of the start and stop criterion is increased by a fixed amount.
[0060] In one form the values of the start and stop criterion are adjusted by an amount dependent on at least one of: an age of the filter(s); a state of the filter(s); a particulate size of the filtered material; and a system loading.
[0061] In yet a further embodiment a controller is provided for a dust filter system including at least one dust filter, the controller being arranged to implement a plurality of cleaning cycles over a period of time, the cleaning cycles having start and stop threshold values associated with a characteristic of the dust filter system, the controller being further arranged to incrementally increase the respective start and stop threshold values over the period of time.
[0062] In one form the controller is arranged to implement each incremental increase in response to a predefined state of the filter system being determined.
[0063] In one form the predefined state is that the duration of a current or previous cleaning cycle has exceeded a predefined value. In one form the characteristic is the pressure differential measured across one or more of the filters.
[0064] According to yet another embodiment, computer program code is provided which when executed by a processor implements the method according to any one of the aforementioned aspects.
[0065] According to another embodiment a computer readable medium including the program code of the aforementioned aspect is provided.
[0066] According to another embodiment, a data signal carrying the program code of the aforementioned aspect is provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0067] Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
[0068] FIG. 1 is a sectional side elevation of a dust control system according to an embodiment;
[0069] FIG. 2 is a schematic illustration of a dust control system according to an embodiment;
[0070] FIG. 2A is a schematic of a controller in accordance with an embodiment;
[0071] FIGS. 3 a - c illustrate simplified theoretical graphical representations of header air receiver pressure profiles under different valve fault conditions; and
[0072] FIG. 4 is a table illustrating an on-demand cleaning cycle implemented by the controller of FIG. 2A .
[0073] While the invention may be susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. The drawings may not be to scale. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but to the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0074] It is to be understood the present invention is not limited to particular devices or methods, which may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include singular and plural referents unless the content clearly dictates otherwise. Furthermore, the word “may” is used throughout this application in a permissive sense (i.e., having the potential to, being able to), not in a mandatory sense (i.e., must). The term “include,” and derivations thereof, mean “including, but not limited to.” The term “coupled” means directly or indirectly connected.
[0075] Referring to the figures, a preferred embodiment includes a dust filter monitoring/control system. In this embodiment, the system includes one or more dust filter units 10 of the type which includes a plurality of banks 12 of filters in the form of filter bags 14 , preferably fabric filter bags 14 . Each bank 12 includes five filter bags 14 , although in alternative embodiments, different respective banks may include more or fewer filter bags 14 . Also in this embodiment, as illustrated in FIG. 2 , there are four banks 12 , but in alternative embodiments there may be more or fewer than four banks 12 . The number of banks and/or filter bags employed will depend on the quality and/or volume of the air to be filtered.
[0076] Each bank 12 includes a respective outlet manifold 15 on which the filter bags 14 are held. The manifolds 15 are sealingly connected to a hopper 16 , in such a manner that the filter bags 14 are contained within a sealed chamber defined by the manifolds 15 and the hopper 16 . An air inlet 18 is in fluid communication with the hopper 16 to provide air to be cleaned to the filter bags 14 . Each manifold 15 is in turn in fluid communication with a clean air outlet conduit 22 . A fan 24 is operatively connected to the outlet conduit 22 to draw air from the inlet 18 through the filter bags 14 and manifolds 15 to the outlet conduit 22 .
[0077] Each bank 12 of filter bags 14 is cleaned periodically (or on demand, as described in more detail in subsequent paragraphs) in a cleaning cycle by providing a burst of relatively higher pressure air from a header air receiver 25 , the air of which is supplied to the air receiver 25 by a compressor 26 via a non-return valve 27 . A burst of air is provided from the air receiver 25 through the filter bags 14 in a direction opposite to the filtration direction of flow of the air at a pressure higher than the pressure of the air being drawn through the filters. This results in dislodging residue from the filters into a collection chamber 28 at the bottom of the hopper 16 . The collection chamber 28 can be manually emptied for disposal of the residue. Also in this embodiment, there is a sensor 32 in the collection chamber which determines when the volume of residue in the collection chamber 28 reaches a predetermined amount. An alarm may then be activated to inform a supervisor that the chamber 28 needs to be emptied. Alternatively, emptying of the chamber 28 may be automated using an auger which feeds the collected duct from the hopper to a removal conveyor.
[0078] The filtration system is provided with a controller 33 which is configured to provide several functions. One function is to arrange the cleaning of the filter bags 14 . With additional reference to FIG. 2A , the controller 33 includes a microprocessor 60 which implements a valve control module 62 programmed to control various pulse inlet and manifold valves (e.g. by way of various solenoids or the like) for affecting a cleaning cycle. In one embodiment this involves controlling operation of pulse inlet valves 34 and manifold valves 36 , based on program code stored in memory 64 . In the illustrated embodiment, each manifold 15 has one of said pulse inlet valves 34 and one of said manifold valves 36 associated therewith. To perform a cleaning function, the manifold valves 36 are actuated to close and the pulse inlet valves 34 are actuated to open on command of the controller 33 . This forces a pulse of air back through the filter bags 14 as described above. In practice, it is often desirable to continue the filtration process, regardless of the cleaning of the filter bags 14 . Therefore, in this embodiment, the controller 33 is configured to allow for the cleaning of one bank 12 of filter bags 14 at a time to allow the remaining banks 12 to continue filtering. This is achieved using a staged sequential, scheduled, or ad hoc cleaning cycle or by a cleaning cycle that is activated in response to a state of the filters. In alternative embodiments, depending on the requirements of the user of the filtration system, all or more than one bank of filter bags may be cleaned at once.
[0079] In this embodiment, it is possible to monitor the filter unit to determine states of the dust filter unit 10 , one state to be determined in this embodiment being the integrity of the filter bags 14 , another being whether the bags require cleaning.
[0080] In determining the integrity of the bags, it is possible to determine whether one or more of the banks 12 contain one or more broken or damaged or otherwise non-integral filter bags 14 . This is achieved by the use of a dust particle monitor 38 located in the outlet conduit 22 . In this embodiment, the dust particle monitor 38 detects the concentration of dust particles in the outlet conduit 22 during cleaning and filtration of the air and communicates the readings to a comparator module 66 implemented by the controller 33 , for subsequent analysis. The comparator module 66 then compares the readings to a baseline concentration stored in memory 64 , the baseline concentration being the desired maximum concentration of particulate matter in the filtered air. If the comparator module 66 detects a concentration of dust particles above the baseline level, and in particular above a predetermined percentage tolerance above the baseline level, it is assumed at least one filter bag 14 has an undesirable leak. For example, the baseline level may be 99.9% removal of all particulate matter having a mean particle diameter of 1 μm from the air by the unit 10 . Also, the predetermined tolerance may be 0.9%, such that if the comparator module 66 determines that less than 99% of particulate matter is removed from the air by the unit 10 , then it is deemed that one of the filter bags 14 has a leak.
[0081] The inventor has recognised that when a filter bag has a leak, the leak may be blocked by filtered residue that has built up over time thus reducing the amount of undesired particulate matter passing through the filter, sometimes to a level which is difficult to accurately detect. However, immediately after a cleaning cycle, the residue blocking the undesirable leak is removed and the amount of undesirable particulate matter passing through the leaking filter is subsequently increased until residue again builds upon the undesirable leak point. Therefore, it has been determined that the preferred time to compare the amount of particulate matter with the baseline concentration for a given bank 12 is immediately after a cleaning cycle has been performed on the given bank 12 of filter bags 14 , given that it is generally easier to detect undesired particulate matter in the outlet conduit 22 at that time. Also, given that the cleaning of each bank 12 is sequential, if an increase in particulate matter is detected by the comparator module 66 immediately after the cleaning of one particular bank, then it can be assumed that at least one of the filter bags 14 in the cleaned bank 12 has an undesired leak. A supervisor or other delegated person can then stop filtration through the bank 12 detected to contain the leaking filter bag to check the bags of the bank 12 and replace or repair the non-integral or damaged filter.
[0082] Alternatively, on detection of a leak, an automated system employing the controller 33 can be employed to stop filtration through the bank 12 which contains the leaking filter bag. In an embodiment, this is achieved by way of the valve control module 62 which is additionally operable to close a valve 42 on the filtered air side of the bank 12 with the damaged filter bag, again based on program code stored in memory 64 . In this way, the dust filter unit 10 can continue to filter the incoming air through the remaining operating banks 12 . The bank 12 with the damaged filter bag(s) may then be isolated and visually inspected for damage. As will be understood, this is particularly useful when attempting to locate a fault or leak in one filter bag 14 in systems which employ the use of hundreds or thousands of filter bags 14 in one or more units 10 . Also, this embodiment has the advantage that only one dust particle monitor 38 is required for each unit 10 , reducing capital and operating costs.
[0083] In an embodiment the controller 33 also communicates with a pressure sensor 50 to determine the pressure differential across the filter bags at any given time. The pressure differential may be used by the controller 33 to determine when and how best to control a cleaning cycle. For the setup illustrated in FIG. 1 , the pressure differential may, for example, range from between 0-2.5 KPa, depending on the state and age of the filter bags. The pressure differential readings can then be communicated to a pressure control module 70 implemented by the controller 33 which utilises the readings to control characteristics of the cleaning cycle, such as the timing of the activation of the cleaning cycle (i.e. for on demand cleaning), its duration and/or its strength. The advantage of such a system is that the life of the bags may be extended by reducing the need for unnecessary cleaning, and can improve performance of the system. Where the on demand cleaning option has been enabled (i.e. as opposed to the periodically controlled option), the pressure control module 70 may be configured to activate a cleaning cycle in response to some predefined start criterion associated with a characteristic of the filter system being met. For example, the criterion may be that a predefined pressure differential threshold has been exceeded. The predefined pressure differential threshold may be set at a level which is indicative that the filter bags 14 are clogged and are in need of cleaning. For example, the pressure control module 70 may be programmed to compare a current pressure differential reading received from the pressure sensor 50 to a first threshold pressure level which is stored in memory 64 . The controller 33 will then initiate a cleaning cycle which will continue until a stop criterion associated with a system characteristic has been met. The stop criterion may, for example, be that the pressure differential falls below a second threshold pressure level (also stored in memory 64 ) which is indicative that the bags are sufficiently clean to continue filtering. It will be understood by persons skilled in the art, however, that the system characteristic may be other than the pressure differential. For example, the characteristic may be operational time, filter state, etc.
[0084] It will be appreciated that during high use periods, where the particulate levels present in the incoming air are particularly high, the pressure differential measured by the pressure control module 70 may rise sharply and in turn quickly surpass the first threshold pressure level 92 . In such situations a normal cleaning cycle may not be sufficient to bring the pressure differential down in a suitable timeframe. To accommodate for such high use periods, a third threshold level which is higher than that of the first threshold level may be programmed into the pressure control module 70 and which, once exceeded, causes the controller 33 to implement an intensive cleaning cycle. In an embodiment, the intensive cleaning cycle may pulse more frequently than a standard cleaning cycle (as previously described) and/or have an increased pulsing pressure. Other variations which increase the effective cleaning capability are envisaged and should not be seen as limited to those variants described above.
[0085] The present inventor has recognised that, by virtue of their construction, certain filter bags 14 may, over time, increasingly retain particulates after each cleaning cycle. Thus, irrespective of how many or how often the cleaning cycles are implemented by the controller 33 , the differential pressure of the system will gradually rise and the thresholds described above for such filter bags may no longer be appropriate. For example, if the thresholds remained constant for such systems the differential pressure for the system would gradually reach a point where the cleaning cycle would be continually “on” (i.e. pulsing is continuous) which would cause the filter bags to wear prematurely and thus defeat the on demand cleaning feature, as previously described. To avoid such a situation, the pressure control module 70 may, in an embodiment, advantageously implement dynamic thresholds which increase in value over the life of the bags.
[0086] In an embodiment the dynamic thresholds may be set to increase when the pressure control module 70 determines that the cleaning cycle has been continually on for a period of time T which is greater than some predefined time period stored in memory. For example, if the system has been continuously pulsing for greater than two hours, then the pressure control module 70 may increase the second threshold (being the pressure level at which the cleaning cycle is stopped) such that it meets or exceeds the current system differential pressure. The first and third thresholds may at the same time be increased by a corresponding amount. It will, of course, be appreciated that the continuous pulsing time which triggers the adjustment in threshold value may be more or less than two hours depending on the actual implementation (i.e. type of filters being used, particle size, etc.). In an embodiment the stage and/or age of the filter bags 14 may additionally, or alternatively, be taken into consideration by the pressure control module 70 when determining when and by how much to increase the thresholds. In an embodiment the timing and/or amount by which the thresholds are increased may also be dependent on various system parameters such as the type of filter bags 14 , the size of the particulates being filtered by the system as well as any other relevant system parameters. In another embodiment, the amount by which the thresholds is increased is a predefined fixed amount. Such a stepped increase in threshold levels is shown in FIG. 4 . According to FIG. 4 , the measured pressure differential is designated by reference numeral 90 , while the first, second and third pressure differential levels are designated by reference numerals 92 , 94 and 96 respectively. The pulsing intervals for a cleaning cycle are also shown and designated by reference numeral 98 . The pressure control module 70 may continue to increase the thresholds until the first threshold level is within some distance of an alarm pressure differential level 100 (e.g. the first threshold level has reached 90% of the alarm level). At this point the pressure control module 70 may be configured to issue an appropriate warning (e.g. audible or visible alarm) to an operator that the filter bags 14 need to be changed.
[0087] In another embodiment, which may be used in conjunction with or separately to the above described embodiments, the state to be determined by the controller 33 is whether one or more of the pulse inlet valves 34 are undesirably stuck open or closed. This may occur due to a mechanical fault, such as build up of dust at the valve not allowing it to open or close, or an electrical fault, for example where an electrical connection operatively engaged with the valve in question has short circuited. This state is determined by measuring a pressure profile of the air pressure in the air receiver 25 during a cleaning cycle using pressure transducer 40 , which is in communication with the pressure control module 70 . This air pressure is much higher than that detected across the filters and is typically in the order of 550-800 KPa. As will be understood, the measured profile during a cleaning cycle should decrease with time, as illustrated in FIG. 3 a , where the air pressure during a cleaning cycle is denoted as 44 and the air pressure between cleaning cycles is denoted as 46 . The pressure rises between cleaning cycles as air is supplied by the compressor 26 to the air receiver 25 . The pressure control module 70 monitors the air pressure in the receiver 25 and is operable to stop air supply to the air receiver 25 once the pressure reaches a predetermined maximum pressure. The pressure profile 44 of the change in pressure in the air receiver 25 during a cleaning cycle may be taken as a predetermined or desired pressure profile (i.e. stored in memory 64 ), indicating that the cleaning system valves ( 34 ) are working as expected.
[0088] Referring to FIG. 3 b , if a pulse air inlet valve 34 opens during one cleaning cycle ( 44 ′) and fails to close, the gradient of the air pressure profile ( 44 ″) of the following cleaning cycle will be relatively flatter, since the starting pressure will be lower due to leaking of the cleaning air through the pulse inlet valve 34 . While the pressure control module 70 notes that the air pressure in the air receiver 25 is too low and so directs the air compressor 26 to continue to supply air to the receiver, the open pulse air inlet valve 34 continues to leak air, and thus the pressure either falls (as illustrated in FIG. 3 b ), will remain unchanging, or will rise slightly over time, depending on by how much the valve 34 is open. Therefore, there is a difference between the desired pressure profile indicated as 44 in FIG. 3 a and the measured pressure profile indicated by 44 ″ in FIG. 3 b . This indicates a failure of the valve 34 to close.
[0089] Similarly, referring to FIG. 3 c , if the pulse air inlet valve 34 fails to open, there would be no drop in pressure during the succeeding cleaning cycles, and the pressure profile would resemble the profile indicated by 44 ″' in FIG. 3 c . Again, there will be a difference between the desired pressure profile indicated as 46 in FIG. 3 a and the measured pressure profile indicated by 44 ″′ in FIG. 3 c . This would indicate a failure of the valve 34 to open. The absolute value of the pressure indicates whether the failure is due to the valve not opening or not closing. For example, comparing the pressure profiles in FIGS. 3 b and 3 c where the valves 34 have failed to close and open respectively, the air pressure of the air receiver 25 with the closed valve is relatively higher than the air pressure of the air receiver 25 with the open valve. As will be understood, if any one of the pulse inlet valves 34 is stuck fully open or closed, this is an extreme fault situation.
[0090] If any of the pulse air inlet valves 34 are determined to be stuck open or closed, they are first tested to determine if they are stuck open or closed by an electrical fault. In this embodiment, a test module implemented by the controller 33 is operable to supply an electrical current to each valve 34 at fault. If the current is above a predetermined level, it is implied that there is an undesired short circuit across the valve. If the current is below a predetermined amount, or zero, it is implied that there is an undesired open circuit across the valve. If no open or short circuit is detected, it is implied that the fault with the valve(s) 34 in question is a mechanical fault. The valve can then be isolated and visually inspected. Any visually detected obstructions (eg dust build up) can then be removed, or the faulty valve repaired or replaced as needed.
[0091] While the present embodiment applies to cleaning units 10 which are monitored by an on-site supervisor, in another embodiment, being a variation on each of the above described embodiments, the controller 33 is remotely accessible by a computer via the Internet, or some other suitable communications network. In this way, the operation of the dust filter units 10 can be monitored and/or controlled off site. For example, if it is determined that the cleaning cycle needs to be modified a control signal could be sent to the control module 33 which causes the cleaning cycle program code stored in memory 64 to be suitably modified. In the embodiment illustrated in FIG. 2A , the controller 33 includes a modem 82 for communicating with the remote computer across a secured private network denoted by reference number 84 .
[0092] As will be understood, unless the context requires or suggests otherwise, features of any one of the above described embodiments may be used in conjunction with another one or more of the above described embodiments.
[0093] While the invention has been described in reference to its preferred embodiments, it is to be understood that the words which have been used are words of description rather than limitation and that changes may be made to the invention without departing from its scope as defined by the appended claims.
[0094] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.
[0095] A reference herein to prior art information is not an admission that the information forms part of the common general knowledge in the art in Australia or in any other country. | System for a dust filter unit includes dust detector to measure dust concentration in an outlet conduit of the filter unit. A controller establishes the detected dust concentration following a cleaning cycle of a filter of the unit and in one form compares that detected concentration to a baseline concentration to identify whether there is possible leak in the filter. The system also includes monitoring arrangements to measure pressure profiles in the unit to assess the state of values and/or filters in the unit. Methods of detecting the state of a filter unit are also described. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a division of application Ser. No. 363,596, filed May 24, 1973 now U.S. Pat. No. 3,881,550.
BACKGROUND OF THE INVENTION
The present invention relates in general to the art of oil recovery and, more in particular, to recovery of hydrocarbons from heavy crudes or bitumens by stimulation.
There are large petroleum deposits in the form of very viscous crudes or bitumens. These deposits may be residuals from naturally developed fields or deposits which have never been produced. An example of very viscous tar deposits is in the Peace River and Athabasca regions of Canada. These tars have a gravity of from 6° to 20° API, a clean oil viscosity of to 20,000 cps, and an emulsion viscosity of to more than 100,000 cps. The asphaltene content of these deposits is up to 30 percent and sulfur up to 6 percent. Because these tars are so viscous, they cannot be recovered by natural techniques and must be stimulated.
Stimulation of petroleum deposits by steam flowing is a known and tested technique. In this type of stimulation, high pressure and temperature steam is injected into injection wells for recovery of petroleum from production wells. During steam stimulation, steam heats a deposit in a steam zone. Values are distilled there and are forced by steam pressure away from the injection wells towards the production wells. Some of the distilled hydrocarbons will condense in the steam zone because of heat loss from the zone to surrounding strata. Some of the distilled hydrocarbons will reach a front between a hot condensate zone and the steam zone and condense there. The driving force of the steam pressure, however, continuously advances the condensed hydrocarbons towards the production wells. The hot condensate zone itself fronts on a cold water zone more remote from the steam zone. Finally, there is an oil zone bordering the cold water zone which is the formation unaffected by stimulation. In typical steam flooding, the cold water zone is water flooded and oil is removed by this known technique to the water flooding saturation level. The advancement of the hot condensate zone itself stimulates recovery by lowering viscosity of the oil and by thermal expansion of the oil. Within the steam zone, recovery is promoted, in addition to distillation, by the temperature produced agencies of viscosity reduction and formation swelling. Hydrocarbons are usually recovered at the production wells in primarily liquid form. The considerable driving force of the steam flooding technique is ultimately lost when breakthrough occurs at a production well. This is an event where the steam front advances to the production well and steam pressure is largely dissipated in the well. The well becomes a short circuit. After steam stimulation, the usual practice is to produce without stimulation until further stimulation is necessitated or production terminated.
Obviously, in the steam flooding technique distillation plays only a modest role at best for very heavy crudes such as the Peace River bitumens because they do not contain any considerable light values. Consequently, the action of steam in stimulating recovery from deposits such as the Peace River bitumens must be by viscosity reduction from heating, thermal expansion of the formation, and the driving force of the steam. Even then, recovery can be modest because of channeling resulting from the permeability of the deposits, fractures, and gravity override between the steam and liquid in the hot and cold zones.
Importantly also, is the effect of even modest distillation on bitumens or tars. With these crudes, the boiling away of lights will cause the residual crude to become so viscous that no further recovery would be possible, even with the viscosity lowering effect of high temperature from the steam.
Consequently, it has been thought that steam drive recovery is limited to deposits with an API gravity of 20° or greater.
Cold solvent stimulation of oil deposits has improved recovery. Solvents can repair organic and inorganic damage, clean deposited asphaltenes and waxes out from around well bores, and lower the viscosity of the hydrocarbons in the deposit by cutting and demulsification. Demulsification reduces the viscosity of the hydrocarbon deposit because emulsions of water-in-oil and oil-in-water have higher viscosities than oil alone. Solvent stimulation also removes asphaltenes from the deposits. Removal of asphaltenes is especially good with aromatics.
The removal of crude oil from the deposit, however, can create a situation where the solubility of remaining asphaltenes is reduced. Remaining asphaltenes precipitate on surfaces of the deposit and block the passage of crude. Accordingly, to prevent asphaltene precipitation and blockage of the deposit, surfactants have been added to maintain the wetability of deposit surfaces, which prevents blockage.
One of the major drawbacks of solvent stimulation is the high cost of solvent. Quite obviously, if the cost of solvent required to produce effective stimulation of a deposit becomes too great, then solvent stimulation cannot be practiced. Heretofore it has been the practice to produce at least most of the solvents away from the stimulation site. This is so especially with aromatic solvents which are very useful in dissolving asphaltenes.
SUMMARY OF THE INVENTION
The present invention provides solvent stimulation of hydrocarbon deposits having extremely high viscosities, such as found in the Peace River region of Canada.
In brief, the present invention contemplates the use of a hot solvent generated from product on site to recover hydrocarbon product values from heavy crudes or bitumens. The hot solvent is injected into the deposit and functions to reduce deposit viscosity by demulsifying viscous emulsions of crude-in-water and water-in-crude, solvent cutting of crude, and raising the temperature of the crude. The solvent also solubilizes production restricting precipitated waxes and asphaltenes. The solvent can be used to remove scale deposited from produced water, sand deposited around well bores, and drilling and completion damage. The solvent is introduced at a temperature of from about 200° to about 650° F. and is preferably depentanized naphtha of up to about an 800° F. end point. This naphtha has substantial quantities of aromatics, the aromatics being useful in the dissolving of asphaltenes and waxes. The solvent may be manufactured from recovered bitumen by topping or by a combination of topping with visbreaking or reforming. Surfactants may be added to the solvent to prevent deposition of asphaltenes on deposit formations by keeping surfaces in the formation water wetable. Suitable surfactants are butylamines or mixed alkyl phenols.
The presently preferred embodiment of the present invention contemplates the use of both solvent and steam extraction of hydrocarbon values from tars or bitumens typified by the Peace River deposits. This is done by either injecting steam and solvent vapors and liquids continuously into the formation or by cyclic injection of steam and hot solvent. With steam, thermal reduction in crude viscosity results and reservoir fluids expand. There will be some, though small, distillation of hydrocarbons by the steam from heat and partial pressure reduction. With the decrease in viscosity, gravity drainage is promoted. The steam pressure, say, 1500 p.s.i.a. at injection, will strongly drive crude towards production wells.
The steam-solvent process retains the production resulting from thermal stimulation of deposits by the steam while eliminating or minimizing production restrictions occasioned by viscous emulsions, precipitated waxes and asphaltenes, scale and sand deposition, and drilling and completion damage.
When steam and solvent are used together, the difficult problem of solvent-crude mixing is not present because the steam is a low viscosity fluid which will rapidly fill all available voids in the reservoir and carry solvent with it. The solvent can then function more completely throughout the formation.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 illustrates schematically a prior art steam driving technique for the recovery of hydrocarbons as it would apply in tar deposits in the Peace River type;
FIG. 2 illustrates schematically steam and solvent recovery of hydrocarbon values in a deposit of the Peace River type; and
FIG. 3 is a flow diagram of a plant for the implementation of the process of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates schematically a typical steam drive system which has been implemented before the present invention. Its description is helpful in understanding the principles behind the process of the invention.
In the Figure, injection wells 10 are provided through overburden and to and through tar sands 12. The overburden is, say 2000 feet and the production interval is, say, 100 feet. In the Peace River deposit, the production interval varies from about 50 to about 1000 feet. Production wells 14 are also provided through the overburden and the production interval.
Steam of a quality of 70 to 80 percent, and at a pressure up to about 2500 p.s.i.a. and at about 668° F. is injected into the injection wells. A pressure seat in the overburden prevents backflow of this steam from either the injection wells or production wells.
The gravity of the tars or bitumen in the Peace River deposits is from about 6° to about 20° API. The clean oil viscosity is up to about 20,000 cps. In the emulsion, however, the viscosity increases to more than 100,000 cps. The asphaltic content of the Peace River type of tars is up to about 30 percent. The sulfur content is also high, being up to about 6 percent. The tar sands may be bottomed by a water zone indicated at 16.
Steam injected through the injection wells will progress from that well radially toward the production wells. During the steam drive, a steam zone 18 will continuously expand radially away from the steam injection well. Within the steam zone hydrocarbon vapors will be generated, but immobile hydrocarbons wil remain. Owing to temperature rise, the deposit will also expand and there will be a reduction in viscosity. A steam front 20 separates a hot condensate zone 22 from the steam zone. Along this front and into the hot condensate zone condensation of hydrocarbon vapors will occur as steam condenses. Within the hot condensate zone, the temperature varies from steam temperature to reservoir temperature. The hot condensate zone, as in the case in the steam zone, progressively increases with time. Reservoir heating in the hot condensate zone is augmented by the latent heat of the steam and condensing hydrocarbon vapors. A cold water zone 24 is ahead of the hot condensate zone and receives some heat from fluids passing into it from the hot condensate zone. The balance of the reservoir indicated at 26 and is at the original reservoir temperature. As will be seen, with a steam drive system alone, no production occurs from this zone because the hydrocarbons are too immobile to be recovered at the original reservoir temperature.
A production mechanism in the steam drive system illustrated in FIG. 1 is the steam distillation of hydrocarbons in the steam zone. The transfer of the heat energy from the steam to the reservoir deposits will thermally expand these deposits which also results in the production of hydrocarbons. The heating of the deposit also reduces viscosity which makes the oil values there more mobile and results in production. The heated hydrocarbons will drain by gravity and be recovered at the production wells which may have bottom hole pumps. A driving force from the pressure differential between the injection wells and the production wells will continuously force hydrocarbons towards the latter for recovery.
Prior techniques of steam stimulation also include the so-called "huff" and "puff" system. In this system, steam is injected for a considerable period of time into a well without attendant oil production. The injection of steam is eventually stopped and oil production commences with the stimulation by steam improving the production rate from the well for a time. Ultimately, the well may be restimulated or not, depending on economics. This technique is an alternative to that known as the "steam drive" discussed above.
FIG. 1 also shows a condition which is known as steam breakthrough during steam drive. Steam breakthrough occurs when steam appears at the production wells. The result of this phenomenon is the loss of the driving pressure of the steam and a marked diminution in the efficiency of the system. A second phenomenom is also illustrated in FIG. 1, and that is steam channeling. It will be noted that the steam zone breaks through at a production well along a very short vertical distance. This channeling is the result of gravity override, permeable strata and horizontal fractures in the reservoir. Gravity override results from the different densities of the steam and the condensate, with the latter tending by gravity toward lower depths. When steam breakthrough occurs, economy precludes continued steam injection, for excessive heat is lost to surrounding strata and is vented up the casing of the production well, this notwithstanding continued gravity drainage due to the rise in temperature of hydrocarbon values in the reservoir. Other problems associated in the steam drive system is the production of extremely viscous emulsions of oil-in-water and water-in-oil. As previously mentioned, emulsion viscosities can exceed 100,000 cps.
The problem of hydrocarbon immobility from excess viscosity is compounded by removal of distillates from the formation by the steam distillation in the steam zone.
The precipitation of waxes and asphaltenes can effectively block recovery of hydrocarbon values and this precipitation can occur when lighter hydrocarbons are taken from the reservoir. Scale deposition from produced water can also reduce recovery. Steaming can also result in sand deposition around well bores with the result that recoveries are adversely affected. Finally, drilling and completion damage adversely affect recovery.
These problems are reduced by the implementation of hot solvent stimulation of the present invention. The solvent is produced at the production site. With reference to FIG. 2, injection wells 28 are formed in the same manner as the injection wells of FIG. 1. Similarly, production wells 30 are formed in the same manner. The overburden and production zones and water zones are the same. In FIG. 2, production of hydrocarbons is affected by the injection of a mixture of steam and solvent vapors and liquid. The solvent is in two phases, that is, both liquid and vapor. Since the steam has a quality of less than 100 percent a water phase is also present.
An important aspect of the present invention is the manufacture of solvent on site. The solvent should have a relatively low viscosity and a high aeromatic content. An ideal solvent is depentanized naphtha having a maximum end point of up to about 800° F.
The production mechanism of the FIG. 2 system includes an increase in mobility of the hydrocarbons through viscosity reduction. Viscosity reduction, as in the steam drive system, results from temperature rise. But in addition to the purely thermal effects from viscosity reduction, an important reduction in viscosity will also be the result of solvent cutting or mixing with the hydrocarbons of the reservoir and the demulsification of the extremely viscous emulsions within the reservoir. This production mechanism also results in thermal expansion of the reservoir fluids due to their heating by both the steam and the solvent. The thermal expansion results in the release of hydrocarbons for recovery. The steam-solvent system also recovers values by gravity drainage. The reduction in viscosity and increased mobility allows hydrocarbon values to drain for recovery. Again there is a driving force because of the pressure differential between the injection fluid at the injection well and the produced fluid at the production well. The steam may act as a solvent carrier to expose a considerable amount of the deposit to the solvent.
Steam channeling will again occur due to the factors previously set forth, gravity override, permeability of strata, and horizontal fractures. However, the steam channeling may be effectively used to disperse solvent throughout the reservoir. This solvent also prevents precipitation of waxes and asphaltenes at the well bores and washes out scale, sand, and drilling and completion damage.
In FIG. 2, a hot vapor zone 32 is illustrated and it has a front with a cold water and solvent zone 34. The unaffected portion of the reservoir is shown at 36 and it has the originally constituted hydrocarbons at original reservoir temperature. It should be noted that the use of both steam and hot solvent as recovery vehicles results in greater recovery. The hot solvent conditions the deposit for greater thermally induced recovery over that which would result from steam alone.
Initially, with deposits such as in Peace River, about 10 to about 25 percent of the gross product is recycled as hot solvent, after the solvent is made by the processing steps set out below. As the process continues, the gross product increases because the injected solvent is being recovered with the crude. It is possible that product solvent will be left over.
The making of the solvent on site is inexpensive and, with surplus product solvent acid with crude, the quality of the crude increases. Solvent purchased for stimulation, say, cyclohexane, is normally much more expensive than the products produced.
In the simultaneous injection of steam and solvent, in general for each barrel of crude produced and removed from the reservoir, there then may be used about 32/3 barrels of water converted to steam and about one-third barrel of solvent produced. This ratio, however, is no wise limiting and any ratio of steam to solvent may be employed depending on conditions and process economics.
The solvent produced, such as depentanized naphtha having a high aromatic content, should be heavy enough to dissolve the heavier hydrocarbons of the bitumen, but not so heavy as to create mobility problems and remain in the formation. The preferred solvent has a boiling point range of from about 200° to about 800° F. An acceptable range is from about 200° to about 500° F. The solvent must have a high aromatic content to dissolve asphaltenes. Small quantities of non-ionic surfactants may be used with the solvent. These surfactants are useful in maintaining the wetability of the deposit being processed so that precipitated asphaltenes will not prevent recovery.
As was previously mentioned, hot aromatic solvent will break highly viscous emulsions in the reservoir. They also increase crude temperature and, as such, further decrease the viscosity of the crude.
The present invention also contemplates the cyclic introduction of steam and solvent. The steam stimulates in the manner previously described, i.e., primarily by viscosity reduction and formation swelling, resultant gravity drainage, and pressure drive. In the steam zone, distillation of some values will occur. These values form a solvent slug.
After steam termination the solvent is injected hot at from about 200° to about 650° F, to stimulate the steam flooded formation by demulsification, solvent cutting and temperature effects. The solvent cleans up the deposit by removing asphaltenes, waxes, sand and the like. With demulsification, solvent cutting and removal of asphaltenes, the residual crude is conditioned for processing again by steam.
As indicated steam is injected first and steam injection continues until breakthrough at a production well. Steam injection is then terminated and hot solvent injection commenced. Solvent injection is continued until the solvent-to-crude ratio is about 1 to 3. Steam is then injected again until breakthrough. Steam is always injected last to recover solvent from the deposit. As an alternative the huff and puff technique may be employed with solvent and steam, or steam followed by hot solvent injected into the well for a period of time during which production is periodically terminated while stimulation occurs.
The present invention also contemplates recovery of hydrocarbons from highly viscous deposits of tars or bitumens by hot solvent stimulation alone. The solvent is injected into the injection wells at a temperature of from about 200° to about 650° F. The solvent is produced from recovered crude at the site and is preferably depentanized naphtha having an end point of less than about 800° F. The solvent has a high aromatic content for the solubilizing of asphaltenes. The production mechanism is demulsification of oil-in-water and water-in-oil emulsions, solvent cutting of heavy components of the crude, some formation heating, and removal of physical and chemical impediments to production in the formation.
With reference to FIG. 3, a system to implement the present invention is illustrated. Again there are a series of production wells that may be bottom-hole pumped. These wells are indicated by the single line 40. A series of steam injection wells are produced at 42. A production zone or interval 43 is the same as in the previous Figures, that is, it varies from 50 feet to 1000 feet and is very heavy in tars of the type found in the Peace River deposits. The production zone has a fairly thick overburden 44 on it and is bottomed by a water zone 46.
Product from the recovery leaves the deposit as a stream 48 and consists of heavy crude or tar, water and sand. Stream 48 is introduced at the well head into a separator 50. The separation is of the gaseous constituents of the product and steam from liquid product, sand and water. The gaseous constituents are H 2 S, CO 2 , steam and light hydrocarbons and they leave the separator as a stream 52. The well head separator is provided to measure the production streams and also provides a preliminary breakup of emulsions, which may be by known chemical treatment with the addition of heat, if required. Stream 52 is compressed for a compressor 54 and a compressed stream 56 is introduced into a stream 58 from an emulsion breaker 60 to form a new stream 62. The stream from the emulsion breaker contains crude oil. The united streams enter a topping unit 64, such as a distillation column.
A crude oil, sand and water stream 68 leaves well head separator 50, passes through a pump 72 before entering line 74. The stream 74 is combined with a recycled stream of light hydrocarbons 76 as a diluent to constitute a stream 78 which passes through heater 80 into a desander 82. A sand and sludge stream 84 from the desander goes to disposal. A stream 86 from a desander enters emulsion breaker 60 where the emulsion is further broken. The requisite input for emulsion breaking is indicated by the flow arrow 88. Emulsion breaking may consist of chemical dehydration, chemical-electrical treaters, flotation and skimming, filtration, centrifuging, or a combination of these methods.
Crude oil stream 58 from the emulsion breaker combines with gas stream 56 to form a stream 62 which is introduced into topping unit 64, which may include a visbreaking and/or reforming unit to increase the aromaticity of the solvent produced.
A water and oil stream 89 leaves the emulsion breaker and is introduced into a flotation cell 90. In the flotation cell, air is introduced at 92 and the water and oil are separated. In addition, any residual sand is separated from the water and oil, as indicated by an egress sand stream 94. The separated water stream 96 from flotation cell 90 enters a water treater 98. There, the water may be treated in such a manner as to be suitable for disposal or, alternatively, for makeup water for a steam generator. Alternate streams for these purposes are indicated at 100 and 102, respectively. The oil stream leaving the flotation cell is a recycle stream and it passes by pump 104 for recycling as stream 76.
Sand slurry 94 is pumped to settling ponds where sand will be precipitated and retained water and oil returned to the process plant. Surplus water not required for the sand slurry mix is directed to settling ponds for skimming remaining oil contaminants and for final settling before being returned to a feed water treatment facility of the plant or a water disposal facility.
Water pumped to flotation cell 90 is air injected to cause any remaining oil particles or sediment to float to the surface. These oil particles or sediment are skimmed resulting in very clean water. Water can be further purified by pumping it through diatomaceous earth filters. Water treatment may also include its softening to zero hardness.
Stream 62 entering topping unit 64 provides on-site generation of solvent for the recovery process. The topping unit may also employ visbreaking and reforming, the latter operations being employed to increase the aromaticity of the solvent and provide, where necessary, a sufficient volume of solvent to recover very heavy tars such as 6° to 8° A.P.I. tars. The products of the topping unit include heavy crude or tar, which leave the topping unit as a stream 106. The generated solvent leaves the topping unit as a stream 108 and goes to a solvent storage facility 110. This solvent is high in aromatic content. The high aromaticity is valuable in removal of asphaltenes from the deposit. A heavy pitch stream 112 from the topping unit provides fuel for a steam generator 114 and/or fired tubular heater 115. Noncondensable gases are taken from the topping unit as a stream 116. These gases can be used as fuel or can be disposed of in any other suitable manner. An excess reflux stream 118 is introduced into stream 76 to provide a diluent for the stream entering emulsion breaker 60.
Excess solvent may be taken from solvent storage as a stream 120, or earlier, as product solvent, which may be commingled with the heavy crude as tar or sold separately.
Steam from steam generator 114 passes through a line 122 and may be:
a. combined with solvent in the recovery of values from the deposit,
b. used in cyclic flooding of the deposit with steam and solvent, or,
c. used to heat solvent for the introduction of hot solvent in a solvent flooding production process.
For the production of hot solvent, steam passes through line 122, which is valved at 124, and into a heat exchanger 126 where it passes in heat exchange relationship with the aromatic solvent pumped through the heat exchanger from storage 110 by a pump 128. The solvent is heated to a temperature of from about 200° to 650° F. The hot aromatic solvent is then introduced through a line 130 and into a line 132 downstream of a valve 134 in line 132. Line 132 goes to the injection wells. Stream in the heat exchanger is condensed and the steam condensate stream 138 is used as makeup for the steam generator and is introduced to the generator in a stream 140.
Another alternative is to introduce the steam and solvent together. This may be done by a line 142 from solvent storage 110 which bypasses heat exchanger 126 and joins line 130 to the injection wells. In this instance a valve 144 in line 130 is closed and a valve 146 in line 142 is open. On the steam side, valve 124 is closed and valve 134 is open. The result is that both steam and solvent pass through line 132 to the injection wells.
For the introduction of steam and solvent in a cycle, valves 124 and 134 are alternately opened and closed on the steam side, and on the solvent side valves 144 and 146 are alternately opened and closed.
The steam generated from generator 114 is at high temperature and pressure and is of a quality substantially lower than 100 percent, say, 80 percent. The reason for this quality is that the water can prevent scale buildup in the steam generator and ancillary lines.
The maximum introduction pressure of steam into the formation is set by formation and overburden characteristics and for 2000 feet of overburden will average about 1500 p.s.i.g. This requires that the steam generator have a maximum working pressure of about 2500 p.s.i.g.
In cases where hot solvent alone is used to stimulate the reservoir the solvent may be heated in a fixed tubular heater 115 and this will, in general, be required if the solvent is employed at high introduction temperatures. Fired tubular heater 115 may be used in conjunction with steam heating of the solvent, in most instances steam and/or solvent temperatures should be maximized for maximum stimulation.
While the process has been described in terms of Canadian tar sands, the process of this invention is useful in recovery of carbonaceous values from many other deposits. Tar sands are found in the United States, Venezuela and other countries.
The process of this invention may also be employed to recover values from old oil fields which have been depleted by primary production i.e., natural production followed by water flooding. These systems do not recover the tars present. These fields may still contain from 40 to 90 percent of their original carbonaceous values as tars.
Yet another example are oil and tar deposits in which the crude is too viscous to process by conventional means or which would be uneconomic to process. | Hydrocarbon products from viscous tar sands are recovered by continuously injecting a hot solvent containing relatively large amounts of aromatics into the formation. Alternatively, steam and solvent are cyclically and continuously injected into the formation to recover the values. The last stimulation is by steam so that solvent is recovered. A third alternative is to continuously inject a mixture of steam and solvent vapors and liquid into the formation. In all cases, the solvent, except perhaps for startup, is produced at the site, as in a conventional topping unit, which alternatively is combined with a conventional visbreaking or reforming unit to increase the volume and/or aromaticity of the solvent produced. | 4 |
[0001] This invention was made with Government support under Cooperative Agreement DE-FG36-07G017007 awarded by DOE. The Government has certain rights in this invention.
FIELD OF THE INVENTION
[0002] This disclosure relates to methods of making anhanced activity nanostructured thin film catalyst by radation annealing, typically laser annealing, typically under inert atmosphere.
BACKGROUND OF THE DISCLOSURE
[0003] U.S. Pat. No. 5,879,827, the disclosure of which is incorporated herein by reference, discloses nanostructured elements comprising acicular microstructured support whiskers bearing acicular nanoscopic catalyst particles. The catalyst particles may comprise alternating layers of different catalyst materials which may differ in composition, in degree of alloying or in degree of crystallinity.
[0004] U.S. Pat. No. 6,482,763, the disclosure of which is incorporated herein by reference, discloses fuel cell electrode catalysts comprising alternating platinum-containing layers and layers containing suboxides of a second metal that display an early onset of CO oxidation.
[0005] U.S. Pat. Nos. 5,338,430, 5,879,828, 6,040,077 and 6,319,293, the disclosures of which are incorporated herein by reference, also concern nanostructured thin film catalysts.
[0006] U.S. Pat. Nos. 4,812,352, 5,039,561, 5,176,786, and 5,336,558, the disclosures of which are incorporated herein by reference, concern microstructures.
[0007] U.S. Pat. No. 7,419,741, the disclosure of which is incorporated herein by reference, discloses fuel cell cathode catalysts comprising nanostructures formed by depositing alternating layers of platinum and a second layer onto a microstructure support, which may form a ternary catalyst.
[0008] U.S. Pat. No. 7,622,217, the disclosure of which is incorporated herein by reference, discloses fuel cell cathode catalysts comprising microstructured support whiskers bearing nanoscopic catalyst particles comprising platinum and manganese and at least one other metal at specified volume ratios and Mn content, where other metal is typically Ni or Co.
SUMMARY OF THE DISCLOSURE
[0009] Briefly, the present disclosure provides a method of making an enhanced activity catalyst comprising the steps of: a) providing a nanostructured thin film catalyst; and b) radiation annealing the nanostructured thin film catalyst under an inert gas having a residual oxygen level of 100 ppm or less by irradiation at an incident energy fluence of at least 30 mJ/mm 2 . In some embodiments, the inert gas has a residual oxygen level of 50 ppm or less. In some embodiments, the incident energy fluence is between 35 and 40 mJ/mm 2 . In some embodiments, step b) of radiation annealing is laser annealing. In some embodiments, step b) of radiation annealing is laser annealing by use of a CO 2 laser. In some embodiments, step b) of radiation annealing is electron beam annealing. In some embodiments, the nanostructured thin film catalyst is provided on a continuous web.
[0010] In this application:
[0011] “membrane electrode assembly” means a structure comprising a membrane that includes an electrolyte, typically a polymer electrolyte, and at least one but more typically two or more electrodes adjoining the membrane;
[0012] “nanostructured element” means an acicular, discrete, microscopic structure comprising a catalytic material on at least a portion of its surface;
[0013] “nanoscopic catalyst particle” means a particle of catalyst material having at least one dimension equal to or smaller than about 15 nm or having a crystallite size of about 15 nm or less, as measured from diffraction peak half widths of standard 2-theta x-ray diffraction scans;
[0014] “thin film of nanoscopic catalyst particles” includes films of discrete nanoscopic catalyst particles, films of fused nanoscopic catalyst particles, and films of nanoscopic catalyst grains which are crystalline or amorphous; typically films of discrete or fused nanoscopic catalyst particles, and most typically films of discrete nanoscopic catalyst particles;
[0015] “acicular” means having a ratio of length to average cross-sectional width of greater than or equal to 3;
[0016] “discrete” refers to distinct elements, having a separate identity, but does not preclude elements from being in contact with one another;
[0017] “microscopic” means having at least one dimension equal to or smaller than about a micrometer;
[0018] “planar equivalent thickness” means, in regard to a layer distributed on a surface, which may be distributed unevenly, and which surface may be an uneven surface (such as a layer of snow distributed across a landscape, or a layer of atoms distributed in a process of vacuum deposition), a thickness calculated on the assumption that the total mass of the layer was spread evenly over a plane covering the same area as the projected area of the surface (noting that the projected area covered by the surface is less than or equal to the total surface area of the surface, once uneven features and convolutions are ignored);
[0019] “bilayer planar equivalent thickness” means the total planar equivalent thickness of a first layer (as described herein) and the next occurring second layer (as described herein).
[0020] It is an advantage of the present disclosure to provide catalysts for use in fuel cells. Objects and advantages of this disclosure are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this disclosure.
BRIEF DESCRIPTION OF THE DRAWING
[0021] FIG. 1 is a graph of nominal laser power at the processing plane for a laser beam used in an embodiment of a process according to the present disclosure, where the beam is at least partly obstructed by a razor blade, where the x-axis represents the blade position starting from a starting position blocking all of the beam until completely out of the laser beam path.
[0022] FIG. 2 is a schematic diagram of an apparatus used in performing one embodiment of the process of the present disclosure.
[0023] FIG. 3 is a graph of Pt fcc (hkl) grain size as measured by X-ray diffraction for the catalysts from Set #3, plotted as a function of the laser scan speed used to treat the catalysts, as discussed in Example 1.
[0024] FIGS. 4A and 4B are graphs of specific activity (4A) fuel cell mass activity (4B) plotted as a function of fluence, as discussed in Example 1.
[0025] FIG. 5A is a graph demonstrating XRF measurement of the Pt loading remaining on laser treated samples exposed under air or N2 at 4 or 4.5 m/sec, as discussed in Example 2.
[0026] FIG. 5B is a graph demonstrating XRF calibration curve from samples made with 0.05, 0.10 and 0.15 mg/cm 2 of Pt in PtCoMn, as discussed in Example 2.
[0027] FIGS. 6A and 6B are graphs of mass activity vs. gas type and fluence, as discussed in Example 2.
[0028] FIGS. 7A and 7B are graphs of mass specific surface area vs. gas type and fluence, as discussed in Example 2.
[0029] FIGS. 8A and 8B are graphs of specific activity vs. gas type and fluence, as discussed in Example 2.
[0030] FIGS. 9A and 9B are graphs of Pt grain sizes and lattice constants, as discussed in Example 2.
[0031] FIG. 10 is a graph of mass specific surface area vs. gas type for four catalyst types, as discussed in Example 3.
[0032] FIG. 11 is a graph of specific activity vs. gas type for four catalyst types, as discussed in Example 3.
[0033] FIG. 12 is a graph of mass activity vs. gas type for four catalyst types, as discussed in Example 3.
[0034] FIG. 13A represents galvanodynamic polarization curves in the kinetic and mid-current density regions from catalyst samples made with Pt 30 Ni 70 as discussed in Example 4.
[0035] FIGS. 13B to 13E compare ORR metrics for three sample types and untreated controls as discussed in Example 4.
[0036] FIG. 14A is a chart of the Pt face centered cubic (111) lattice parameter of PtCoMn alloy catalyst as a function of electron beam radiation exposure, as deduced from X-ray diffraction, for samples discussed in Example 5.
[0037] FIG. 14B is a chart demonstrating variation of Pt fcc[111] crystallite size of PtCoMn alloy catalyst as a function of electron beam radiation exposure, as deduced from X-ray diffraction, for samples discussed in Example 5.
[0038] FIG. 14C represents galvanodynamic polarization curves for catalyst samples discussed in Example 5.
[0039] FIG. 14D represents oxygen reduction reaction (ORR) fuel cell metrics measured for catalyst samples discussed in Example 5.
DETAILED DESCRIPTION
[0040] This disclosure describes a post-fabrication process to increase the activity for oxygen reduction of the nanostructured thin film (NSTF) PEM fuel cell electrocatalysts. It consists of laser annealing, electron beam annealing, or other radiation annealing of the catalyst alloy coated NSTF whiskers in an inert gas, with minimal residual oxygen level of 100 ppm or less, with an incident fluence of at least 30 mJ/mm 2 . The result is a 50% increase in mass activity (A/mgp t ) of NSTF-PtCoMn alloy using a scanning CO 2 laser at 4 m/sec. It is compatible with a moving web process.
[0041] Pt based alloys are currently the best electrocatalysts for the use on the cathodes of PEM fuel cells under development for automotive applications. There are two basic types of catalysts in use, the standard being dispersed Pt nanoparticles supported on carbon black. The newer alternative is the nanostructured thin film catalyst, referred to as NSTF. This disclosure demonstrates a method to increase the mass activity of the as-made catalyst, by exposing the catalyst coated whiskers on a web under an inert gas atmosphere such as Ar to a scanning laser, such as an industrial CO 2 laser. Under the right energy fluence between 35 and 40 mJ/mm 2 , and with residual oxygen levels below about 50 ppm, the mass activity is increased from an average of 0.175 A/mg to 0.265 A/mg. Significant gains in the Pt fcc crystallite grain size and surface area are also observed. The process of the present disclosure is readily adaptable to a roll-good process.
[0042] Objects and advantages of this disclosure are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this disclosure.
EXAMPLES
NSTF Catalyst Preparation
[0043] NSTF PtCoMn alloy catalysts were prepared on the PR149 whisker supports as described in recently issued and allowed patents, U.S. Pat. No. 7,419,741, 2005/0069755 and 60854US02. Samples with as-made Pt loadings of 0.10 mg Pt /cm 2 on 2200-3 standard PR 149 whiskers were prepared. Rectangular shaped sample pieces were cut 5″×8″ and mounted between two metal frames with open centers for laser exposure.
Laser Set-up and Scanning Conditions
[0044] For the laser processing of the fuel cell catalyst, the following equipment was used. The CO 2 laser from Coherent, Inc. (5100 Patrick Henry Drive, Santa Clara, Calif. 95054) was Model Diamond C-55A. The scanner from Nutfield Technology, Inc. (49 Range Road, Windham, N.H. 03087) was Model XLR8-15 mm 2-axis scan head. These two pieces equipment were controlled with a computer using the Waverunner laser and scanner control software interface and the Pipeline Control Rack, both also from Nutfield Technology, Inc.
[0045] The scanner was set up to process a field size of 266 mm square with a focused spot at a working distance of approximately 390 mm. For processing the fuel cell catalyst samples, the material was placed above this focused plane by approximately 75 mm, that is at a working distance of 315 mm. In the processing plane, the laser spot size was roughly 1 mm in diameter. This beam shape was characterized by passing a razor through the beam in the plane at 315 mm working distance. The nominal beam size was identified between the limits of 15% and 85% of total power being eclipsed by the razor blade. The raw data is shown in FIG. 1 of laser power versus razor blade position. FIG. 1 is a chart of nominal power measurements for the laser beam at the processing plane as a razor blade moves from a starting position blocking all of the beam until completely out of the laser beam path. Measurements in the orthogonal direction replicated this curve shape.
[0046] The laser output was turned on and then scanned horizontally across the sample from the point of view looking down on the sample. The laser output was momentarily stopped while the scanner incremented a small distance orthogonal to the scan direction.
[0047] Then the laser output was turned on again and horizontally scanned in the reverse direction. This process, or raster scanning, was repeated until the entire sample was exposed.
[0048] The laser processing conditions for these samples were set by entering parameters in the software control interface for laser power, scanning speed, and orthogonal offset distance or “hatch” separation. For the laser power, the pulse length of 30 microseconds and repetition rate of 20 kHz created an average power delivered to the sample of 37 Watts. The laser scanning speed was varied to effect different incident fluences or energy density delivered to the catalyst surface, where this speed is of the laser beam in the focused plane. The actual speed of the laser beam in the processing plane is approximately 80% of this value since the laser beam is on shorter scanning radius at the decreased working distance. The scanning speed recorded in this Record of Disclosure is that in the focal plane. For the “hatch” separation, that parameter was set selected to be 0.25 mm for the samples in Examples 1 and 2, which gave a 0.20 mm displacement in the processing plane.)
[0049] FIG. 2 presents one embodiment of an apparatus for laser annealing the sample films under a controlled ambient environment with residual oxygen analysis. FIG. 2 illustrates the laser set up used for rastering the laser beam over the sample surface in a rectangular pattern under a controlled ambient environment as well as air. A METEK TM-1B oxygen analyzer was used to monitor the residual oxygen in the sample chamber when inert gases were flowed into the sealed sample chamber.
[0050] An MKS mass flow controller was used to control the rate of gas flow into the sealed sample chamber at the rate of 100 slm. The residual O 2 level was monitored after introducing the gas of choice until the O 2 level fell below about 40 ppm, at which time the laser was triggered to scan a rectangular pattern over the sample of ˜5″ square.
[0051] Five sets of catalyst samples were treated in order to investigate the effects on fuel cell performance. For the first two sets, the laser was scanned at rates between 2.5 and 7.5 m/sec and variable translation rates (hatch) with ambient air environment, in order to first find the incident fluence (energy per unit area) and scanning conditions that would introduce a change in the catalyst layer, as evidenced by either complete ablation of the catalyst coated whiskers off the MCTS substrate, or increases in the Pt crystallite grain sizes as revealed by X-ray diffraction. SEM images of the first and second sets of laser exposed samples did not show any apparent change in the NSTF whiskers up to 50,000 magnification. No statistically significant changes in the fuel cell performance curves or kinetic activity metrics could be identified with the conditions used for the first two sample sets.
[0052] For the third set of samples it was determined that in some embodiments preferred scan rates were 4 to 4.5 m/sec with a 0.25 mm translation on each return path of the laser beam. This delivered an estimated fluence of 34.55 to 38.5 mJ/mm 2 to the catalyst surface. XRD characterization of the 3 rd set showed a clear dependence of Pt(hk1) grain size on fluence (Example 1 below). In all samples, the laser scan direction was maintained parallel to the down-web direction of the catalyst samples or parallel to the MCTS substrate grooves. Fuel cell testing indicated a small but statistically significant increase in ORR activity with incident fluence, but other parameters were insensitive. TEM imaging of NSTF catalyst coated whiskers from a treated (#3-4 in Table 1) vs. an untreated sample suggest a very small amount of surface smoothing at the highest levels of magnification. Characterization by TEM of the atomic planes of the fcc(111) vs. other (hkl) facets on the catalyst surface is ongoing since this may be the level at which the surface is being changed to induce the changes in fuel cell activity observed in the 4 th series.
[0053] For the 4 th set of samples, the ambient gas environment was varied. Fuel cell testing was completed for this 4 th set. XRD results were consistent with those in Ex. 1 in that the higher the fluence the larger the crystallite grain size. The primary variables for the 4 th set were the type of ambient gas, viz. air, N 2 , Ar and Ar+4% H 2 , and two scan rates, 4 and 4.5 m/sec. Significant increases in ORR activity, surface area, and specific activity were observed as a function of the type of inert gas and incident fluence (Example 2 below.) During the laser exposure, clear visible trails of smoke emanated from the surface, with more apparent at the 4 m/sec higher fluence condition. Another key observation was that during the laser scan, the O 2 level dropped from its steady state value by about 50% at the 4 m/sec scan rate and 30% at the 4.5 m/sec scan rate. This indicates the Pt surface was being cleaned and made more reactive for oxygen adsorption, acting in effect as a getter material. This suggested that some Pt might be being removed from the surface at the conditions used, which would affect the mass activity measurements. Additional samples were then exposed under air and N 2 at both 4 and 4.5 m/s scan rates for XRF characterization of the amount of Pt lost. For this XRF measurement, a scanning unit made by NDC Infrared Engineering was used to measure the average residual Pt. This unit averages over an area defined by a 1.25″ circle translated 2 inches. Those results were reported in Example 2 below and used to determine the actual mass activity and mass specific surface area of the samples.
[0054] A 5 th set of samples used He and He+4% H 2 gases as well, and PtNi alloys were also treated. The purpose of the He is to see if the gas thermal conductivity is important. The PtNi alloys had different atomic percentages of transition metals. Preliminary data suggested that the laser annealing significantly improved the high current density performance of the high Ni containing alloy versus the as-made alloy.
Fuel Cell Testing
[0055] For fuel cell testing, the laser treated samples were used as the cathodes in a three layer catalyst coated membrane electrode assembly (CCM). The anode catalyst was standard NSTF PtCoMn at a Pt loading of 0.05 mgPt/cm 2 , and all taken from the same roll-good lot of material, P409140B. The membranes used for all samples were 20 micron thick 850 EW proton exchange membrane, cast from methanol. The anode and cathode gas diffusion layers (GDL's) were identical. The catalysts and membrane were laminated together to form the CCM at 350° F. and 150 psig. The 5-layer MEA's were mounted in standard 50 cm 2 test cells with quad-serpentine flow fields with gaskets selected to give 15% compression of the MEA. All samples for sample sets 3 and 4 were measured on a single test station, number 6. After conditioning the MEA's using the NSTF standard thermal cycling protocol, the cathode surface area and ORR activity at 900 mV under saturated 150 kPa H 2 /O 2 was measured. Various performance metrics were also recorded, including the potentiodynamic current density at 813 mV on the back scan, and galvanodynamic polarization potentials at 20 mA/cm 2 , 0.32 A/cm 2 , 1 A/cm 2 , 1.46 A/cm 2 and 2 A/cm 2 .
Example 1
[0056] In this example, a series of samples from sample set #3 were exposed under air with varying incident fluence to determine the impact on the Pt crystallite grain sizes. Scan rates of 3.5, 4, 5, 6 and 7.5 m/sec were compared to the unexposed sample. FIG. 3 is a graph of Pt fcc (111(1) grain size as measured by X-ray diffraction for the catalysts from Set #3, plotted as a function of the laser scan speed used to treat the catalysts. FIG. 3 shows the effect of the laser scan speed on the XRD determined crystallite grain sizes. The maximum grain size occurs at the scan rate of 4 m/sec, corresponding to an estimated fluence of 38.5 mJ/mm 2 . At slower scan rates, higher fluence, the catalyst coated whiskers are observed to be ablated off the surface in substantial areas of the exposed sample region and this may be affecting the apparent crystallite size due to excessive heating and rapid cooling. These results indicate that a laser scan rate from about 4.5 to 4.0 m/sec would be sufficient to induce significant melting of the surface catalyst.
[0057] FIGS. 4A and 4B show the mass and specific activity from this set as a function of fluence. The fuel cell results indicated only a marginal effect of the laser annealing from this set, despite the clear effect on the Pt grain size in FIG. 3 . The other fuel cell metrics were similar in showing no statistically significant or a marginal effect only. The reason for this lack of effect was suspected to be due to the presence of oxygen in the ambient air that would prevent the catalyst surface structure from annealing properly. So for the 4 th set of samples, the primary variant was the ambient gas type, with oxygen minimized and monitored. For the air samples, it must also be considered that it contained ambient water vapor, which the inert gas environments did not.
Example 2
[0058] In this example a series of samples were exposed under controlled ambient gases with the relative fluence and residual O 2 levels identified in Table II.
[0000]
TABLE II
Sample parameters for laser annealing set 4 (Example 2)
Residual
Sample
Catalyst
Relative
Oxygen
FC Analysis
#
Lot
Gas
Fluence
(ppm)
Status
4-0
P409075A
N 2
38.4
<40
done
4-1
P409075A
N 2
38.4
37
done
4-2
P409075A
N 2
38.4
38
done
4-3
P409075A
N 2
34.55
36
done
4-4
P409272
N 2
34.55
38
done
4-5
P409272
Ar
38.4
35
done
4-6
P409272
Ar
34.55
36
done
4-7
P409272
Ar
34.55
34
done
4-8
P409272
Ar
38.4
35
done
4-9
P409272
Ar/4%H 2
34.55
<40
Sample
ripped
4-10
P409272
Ar/4%H 2
34.55
<40
done
4-11
P409272
Ar/4%H 2
38.4
<40
done
4-12
P409272
Ar/4%H 2
38.4
<40
done
[0059] FIG. 5A is a graph demonstrating XRF measurement of the Pt loading remaining on laser treated samples exposed under air or N2 at 4 or 4.5 m/sec. FIG. 5B is a graph demonstrating XRF calibration curve from samples made with 0.05, 0.10 and 0.15 mg/cm 2 of Pt in PtCoMn.
[0060] FIGS. 5A and 5B show the results of the XRF calibration and measurement of the residual Pt remaining on laser treated samples in air and N 2 at fluences of 38.4 mJ/mm 2 (4 m/sec) and 34.55 mJ/mm 2 (4.5 m/sec). The initial mass loading of 0.10 mg/cm 2 of Pt was reduced by 15 -20%. These values were used to correct the loadings used for calculating the mass activity and mass specific surface area for the samples in set #4. The same mass change measured for the samples exposed under N 2 is assumed to apply to the Ar and Ar+4% H 2 as well.
[0061] FIG. 6 shows the measured mass activity from the set #4 samples as a function of the gas type for the two fluence levels. The loading corrected mass activity means the absolute activity was divided by the XRF determined mass loading from FIG. 5 . The error bars reflect a 1 sigma standard deviation of the XRF loading measurement. 4 m/sec (38.4 mJ/mm 2 ) is more effective than 4.5 m/sec (34.55 mJ/mm 2 ). It is apparent in FIG. 6 that treatment in air is less effective than in inert gases, Ar appears more effective than N 2 which is more effective than air. The presence of 4% H 2 does not appear to provide any benefit over pure Ar. A maximum gain in mass activity of ˜50% is obtained by the laser treatment under Ar or Ar+4%H 2 at 4 m/sec.
[0062] FIG. 7 shows similarly the loading corrected mass specific surface area for laser set #4 as a function of the gas type and fluence. Similar to the mass activity, 4 m/sec (38.4 mJ/mm 2 ) was more effective than 4.5 m/sec (34.55 mJ/mm 2 ), treatment in air is less effective than in inert gases, Ar appears more effective than N 2 which is more effective than air, and the presence of 4% H 2 does not appear to provide any benefit over pure Ar. A maximum gain in ECSA of ˜25-30% was obtained by the laser treatment.
[0063] FIG. 8 shows the specific activity (A/cm 2 of Pt surface area) vs. gas type and fluence for laser set #4. Similar to mass activity and specific surface area, 4 m/sec (38.4 mJ/mm 2 ) is more effective than 4.5 m/sec (34.55 mJ/mm 2 ), treatment in air is less effective than in inert gases, Ar appears more effective than N 2 which is more effective than air, and the presence of 4% H 2 does not appear to provide any benefit over pure Ar. A maximum gain in Specific Activity of ˜18% is obtained by the laser treatment at the highest fluence level.
[0064] Finally, FIG. 9 shows the Pt grain sizes in the [hkl] directions and the lattice constants for the samples of laser set #4. There appeared to be a consistent trend that the higher fluence (4 m/sec scan rate) generated slightly higher grain sizes than the 4.5 m/sec rate. It is not clear if there is a consistent gas type dependence.
Example 3
[0065] In this example a series of thirty-six samples from set #5 were exposed under controlled ambient gases with the catalyst type, laser scan rate, gas type, and residual O 2 levels identified in Table III.
[0000] TABLE III Sample parameters for laser annealing set 5. Resid- Resid- ual ual Scan Oxygen Oxygen Gas Rate at start at end Sam- Catalyst Catalyst (100 (m/ of scan of scan ple # Lot Type slm) sec) (ppm) (ppm) 5-1 P409272 PtCoMn air 4 NA NA 5-2 P409272 PtCoMn air 4.5 NA NA 5-3 P409272 PtCoMn He 4.5 35 5-4 P409272 PtCoMn He 4 52 38 5-5 P409272 PtCoMn He + 4.5 38 NA 4% H2 5-6 P409272 PtCoMn He + 4 38 NA 4% H2 5-7 P4D09308A PtNi(0.6) air 4.5 NA NA 5-8 P4D09308A PtNi(0.6) air 4.5 NA NA 5-9 P4D09308A PtNi(0.6) N 2 4 39 10 5-10 P4D09308A PtNi(0.6) N 2 4.5 41 28 5-11 P4D09308A PtNi(0.6) Ar/ 4.5 40 NA 4% H 2 5-12 P4D09308A PtNi(0.6) Ar/ 4.5 38 NA 4% H 2 5-13 P4D09308A PtNi(0.6) He + 4.5 39 NA 4% H 2 5-14 P4D09308A PtNi(0.6) He + 4.5 39 NA 4% H 2 5-15 P4D09308B PtNi(4.2) air 4.5 NA NA 5-16 P4D09308B PtNi(4.2) air 4.5 NA NA 5-17 P4D09308B PtNi(4.2) N 2 4.5 39 30 5-18 P4D09308B PtNi(4.2) N 2 4.5 39 28 5-19 P4D09308B PtNi(4.2) Ar/ 4.5 38 NA 4% H 2 5-20 P4D09308B PtNi(4.2) Ar/ 4.5 39 NA 4% H 2 5-21 P4D09308B PtNi(4.2) He + 4.5 26 NA 4% H 2 5-22 P4D09308B PtNi(4.2) He + 4.5 30 NA 4% H 2 5-23 ML091109-1 PtNi(0.6) He + 4.5 32 NA 4% H 2 5-24 ML091109-1 PtNi(0.6) He + 4.5 33 NA 4% H 2 5-25 ML091117-1 PtCo(0.45) Ar 4.5 53 48 5-26 ML091117-1 PtCo(0.45) Ar 4.5 52 45 5-27 ML091117-1 PtCo(0.45) Ar 4.5 54 45 5-28 ML091117-1 PtCo(0.45) Ar 4 54 28 5-29 ML091117-1 PtCo(0.45) Ar 4 53 29 5-30 ML091117-1 PtCo(0.45) Ar 4 54 29 5-31 P4D09308A PtNi(0.6) Ar 4.5 54 44 5-32 P4D09308A PtNi(0.6) Ar 4.5 53 43 5-33 P4D09308A PtNi(0.6) Ar 4 49 24 5-34 P4D09308A PtNi(0.6) Ar 4 53 27 5-35 P4D09308A PtNi(0.6) Ar 4.5 54 48 5-36 P4D09308A PtNi(0.6) Ar 4 54 30
For comparison to earlier examples, laser scan rates of 4 m/sec correspond to fluences of 38.4 mJ/mm 2 and 4.5 m/sec to 34.55 mJ/mm 2 . FIGS. 10-12 summarize the resulting effect of the laser annealing on the catalyst activity metrics for the four types of catalyst compositions under the various gases at atmospheric pressure.
[0066] FIG. 10 shows that the laser treatment with a fluence of 34.5 mJ/mm 2 under all gases increased the surface area of all the catalyst types. It shows also that treatment of the high Ni containing Pt 30 Ni 70 catalyst under the inert gases containing some H 2 increased the surface area substantially more than treatment under air for the inert gases, while the effect under the inert or inert+hydrogen gases was much less for the higher Pt containing catalysts.
[0067] FIG. 11 shows that the specific activity for oxygen reduction was increased by as much as 25% over the untreated Pt 30 Ni 70 catalyst under Ar+4% H 2 by the laser annealing at atmospheric pressure. The other catalyst compositions showed lesser amounts of increases over the as-made, untreated condition.
[0068] FIG. 12 shows that the high Ni containing catalyst's mass activity was increased by as much as 50% over the untreated control by the laser treatment under the inert gases containing some hydrogen. The low Ni containing catalyst, Pt 75 Ni 25 , was not increased as much. The mass activity is the product of the mass specific surface area ( FIG. 10 ) and the specific activity ( FIG. 11 ), and so the percentage increases in both of those quantities combines to give the larger increase in this mass activity.
Example 4
[0069] In this example a series of samples from set #6 were exposed under a sub-atmospheric pressure of a mixture of Ar+4% H 2 or N 2 +4% H 2 . The catalyst types and loadings of Pt, are identified in Table 4.1. For these exposures, the chamber shown in FIG. 2 was replaced with a vacuum chamber. The gaseous environment within the chamber was determined by the rate of inlet gas flow and the rate of pumping by a standard mechanical vacuum pump. The gaseous pressure was measured with a diaphragm vacuum gauge so it was independent of the gas type. The incident laser was introduced through a ZnSe window at the top of the chamber. For these samples of set #6, the gas inlet and outlet pump throttle valves were adjusted to maintain a steady pressure, e.g.10 ton to 750 Ton, in the chamber during the laser scan over the 50 cm 2 area of the sample. A major reason for using a subatmospheric gas pressure is to affect the rate of cooling of the catalyst areas heated by the passing laser beam. For these samples, the scan rate of the laser and the laser power was varied as well.
[0000]
TABLE 4.I
LASER annealed sample Set #6.
Vacuum Conditions: 10 Torr with dynamic flow of Ar + 4% H 2
Laser Conditions
scan rate = 4
250 micron
0.25 mm
30
m/sec
spot size
hatch
20 kHz
microsec.
Pen 1
Catalyst
Gas Flowing
Scan Rate
Pt
Beam
Pressure
Number
Sample #
Catalyst Lot
Type
at 10 Torr
(m/sec)
Loading
Power
(Torr)
Passes
LASER Sample Set #6
22 Mar. 2010
6-1
P409272
PtCoMn
Ar + 4% H2
4
0.1
33%
10
1
6-2
P409272
PtCoMn
Ar + 4% H2
4
0.1
33%
10
1
6-3
P409272
PtCoMn
Ar + 4% H2
4
0.1
33%
10
1
6-4
P410061A
Pt3Ni7
Ar + 4% H2
4
0.1
33%
10
1
6-5
P410061A
Pt3Ni7
Ar + 4% H2
4
0.1
33%
10
1
6-6
P410061A
Pt3Ni7
Ar + 4% H2
4
0.1
33%
10
1
6-7
P1X100126
Pt on +40 C.
Ar + 4% H2
4
0.15
33%
10
1
6-8
P1X100126
Pt on +40 C.
Ar + 4% H2
4
0.15
33%
10
1
6-9
P1X100126
Pt on +40 C.
Ar + 4% H2
4
0.15
33%
10
1
2nd set
13 Apr. 2010
6-10
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
750
1
6-11
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
750
1
6-12
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
330
1
6-13
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
330
1
6-14
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
100
1
6-15
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
100
1
6-16
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
32
1
6-17
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
33
1
6-18
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
750
2
6-19
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
750
2
6-20
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
750
4
6-21
P410061A
Pt 3 Ni 7
Ar + 4% H2
4
0.1
33%
750
4
3rd set
16 Apr. 2010
6-22
P410061A
Pt 3 Ni 7
N 2 + 4% H 2
3.8
0.1
33%
600
1
6-23
P410061A
Pt 3 Ni 7
N 2 + 4% H 2
3.6
0.1
33%
600
1
6-24
P410061A
Pt 3 Ni 7
N 2 + 4% H 2
4.5
0.1
60%
600
1
6-25
P410061A
Pt 3 Ni 7
N 2 + 4% H 2
4.5
0.1
55%
600
1
6-26**
P410061A
Pt 3 Ni 7
N 2 + 4% H 2
4.5
0.1
55%
600
1
6-27
P410061A
Pt 3 Ni 7
N 2 + 4% H 2
4.5
0.1
55%
600
1
**Inadvertently laser exposed with MCTS grooves perpendicular to scan direction. So rotated sampled 90° and re-exposed again. Very little indication of exposure after 1st scan with grooves perpendicular.
[0070] FIG. 13A shows only slight differences in the fuel cell polarization curves in the kinetic region and mid-current density region for the samples shown. FIGS. 13B to 13E compare more specific ORR metrics for three sample types with the untreated controls. It is apparent in FIGS. 13B to 13E that LA6-25 had the highest mass activity and surface area as a result of the laser annealing conditions used.
[0071] FIG. 13E shows that the sample exposed under N2+4% H2 at 600 Ton total pressure (80 kPa) with 55% laser power at 4.5 m/sec scan rate has the highest increase in mass activity.
Example 5
[0072] In this example, a series of fuel cell NSTF catalysts were exposed to an electron beam as a way to post-treat the catalysts with energy. For these samples PtCoMn catalysts with a 0.1 mg/cm 2 Pt loading coated onto the NSTF whiskers as in previous examples were used. The 3M CRPL e-beam processing line designated at CB300 was used to expose the samples:
[0073] Sample: Catalyst roll PE4145B—PtCoMn (90:10, 20, 2,1, 0.15 mg Pt /cm 2 )
[0000]
TABLE 5-I
Samples Exposed in the CB 300
Dose-
Num-
Sam-
Web
Beam
Beam
age
ber of
ple #
Size
Speed
Voltage
Current
(Mrad)
Passes
1
4″ × 11″
20 ft/min
120 keV
15 mA
14.5
1
2
6″ × 11″
10 ft/min
120 keV
7.5 mA
15.5
1
3
13″ × 11″
20 ft/min
120 keV
15 mA
14.3
5
[0074] There was no visible effect on the samples from any of the exposures, although they felt slightly warmer when removed from the carrier web. Samples were submitted for X-ray diffraction characterization to see if there is any change in grain size or lattice parameter, with the results shown in FIGS. 14A and 14B . FIG. 14A is a chart of the Pt face centered cubic (111) lattice parameter of PtCoMn alloy catalyst as a function of electron beam radiation exposure, as deduced from X-ray diffraction. FIG. 14B is a chart disclosing variation of Pt fcc[111] crystallite size of PtCoMn alloy catalyst as a function of electron beam radiation exposure, as deduced from X-ray diffraction.
[0075] FIG. 14A shows that the lattice parameter of the catalyst was unchanged by the e-beam radiation exposure. FIG. 14B shows that the Pt crystallite grain size in the Pt[111] direction decreased with increasing radiation exposure. However there was no systematic change in the crystallite sizes in the Pt(200), Pt(220), or Pt(311) directions. This indicates that the crystallites have an aspect ratio greater than one in the [111] direction and the effect of the e-beam treatment was to decrease the aspect ratio slightly.
[0076] Fuel cell membrane electrode assemblies (MEA's) were made from samples 2, 3 and a control (untreated) for fuel cell characterization. FIG. 14C compares the galvanodynamic polarization curves from duplicates of the samples 7-2 and 7-3 in Table 5.1, as well as untreated controls designated at samples 7-4. Other comparison MEA's are included as well. The fuel cell performance was seen to be essentially the same for these three types.
[0077] FIG. 14D represents oxygen reduction reaction (ORR) fuel cell metrics measured for the samples 7-2 and 7-3 in Table 5.1 and untreated controls. FIG. 14D compares the samples’ oxygen reduction reaction fuel cell metrics, including the absolute activity, surface area and specific activity. The surface area and absolute activity were essentially unchanged by the e-beam treatment, but the specific activity was reduced compared to the average of the controls.
[0078] Various modifications and alterations of this disclosure will become apparent to those skilled in the art without departing from the scope and principles of this disclosure, and it should be understood that this disclosure is not to be unduly limited to the illustrative embodiments set forth hereinabove. | This disclosure provides methods of making an enhanced activity nanostructured thin film catalyst by radiation annealing, typically laser annealing, typically tinder inert atmosphere, Typically the inert gas has a residual oxygen level of 100 ppm. Typically the irradiation has an incident energy fluence of at least 30 mJ/mm 2 . In some embodiments, the radiation annealing is accomplished by laser annealing. In some embodiments, the nanostructured thin film catalyst is provided on a continuous web. | 1 |
This application is the national phase under 35 U.S.C.§371 of PCT International Application No. PCT/JP2009/003580 which has an International filing date of Jul. 29, 2009 and designated the United States of America.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a control apparatus utilizing an application program and a platform program. Especially, the present invention relates to a control apparatus, a control method and a computer program, which implement utilizing a part of platform program for overcoming the difference of hardware resources, implement improving the reusability, implement shortening the development process and implement reducing the development load.
2. Description of Related Art
Recently, several fields adopt a system where plural control apparatuses are connected to exchange data with each other, each of which is provided with a communication function, and a functional role is assigned to each control apparatus. Such the system can make the plural control apparatuses associate with each other and then perform several processes. For example, in a field of on-vehicle local area network (LAN) arranged on a vehicle, an electronic control unit (ECU; electronic control apparatus) is provided with such the communication function, each of ECUs implements assigned functional role and exchanges data to another ECU, and then the system can perform several processes (e.g., patent document 1).
In the case that plural control apparatuses are associated with each other and performs several processes, each control apparatus can be configured to implement an assigned functional role similar to the assigned function of another control apparatus and said another control apparatus may substitute for the control apparatus based on the setting for implementing the assigned functional role of the control apparatus, instead of focusing on the specialization of the assigned functional role of each control apparatus. Particularly, it may be configured to separate a common function from an application program that implements the functional role assigned to each control apparatus, respectively, and configured to implement the separated common function with utilizing a platform program. For example, the common function consists of storing or updating data utilized for executing the application program, communicating with another apparatus, or the like.
When a definition of communication specifications is changed in such the configuration, the platform program may be changed and then each control apparatus may be made to execute the changed platform program. On the contrary, it is not required to change the application program in accordance with the change of communication specifications. Even with the unchanged application program, it is possible to communicate with another control apparatus with performing the process similar to the process performed before the change of application program. Thus, it does not require complicated works, such as the preparation of plural kinds of application programs based on the difference of definition of communication specifcations. The application program may be configured just for implementing the assigned functional role, and then the reusability of application program is improved better.
[Patent Document 1] Japanese Patent Application Laid-Open No. 2007-329578
SUMMARY OF THE INVENTION
The configuration of platform program differs in accordance with the difference of hardware resource. As an ECU includes a storage device, it is considered that the storage device may be, for example, an EEPROM or a flash memory. Actual physical processes are different between for the EEPROM and for the flash memory. However, the important thing is to actually write desired data into such the storage device, and it is not important about which physical process is actually performed.
In the case that it is necessary to change the platform program in accordance with the type of configurations or specifications of hardware resource, the reusability of platform program is decreased. Furthermore, it is hard to improve the complex works of development process required for the control apparatus itself and it is hard to improve the complex works of development process required for the large-scale system utilizing plural control apparatuses that have different hardware resources, respectively. Thus, it is hard to shorten the development process and to reduce the development load.
The present invention is made in view of such circumstances, and has an object to provide a control apparatus, a control method, and a computer program, which implement separating the functions of platform program into a functional part for logically controlling the hardware resources and a functional part for physically controlling the hardware resources based on the type of the hardware resources, implement improving the reusability of the platform program, implement shortening the development process and implement reducing the development load.
A control apparatus of a first aspect according to the present invention has a first executing means for executing one or more application programs and a second executing means for executing a platform program to control a hardware resource in accordance with a request from the application programs, wherein the second executing means comprises: an indicating means for indicating to obtain information from the hardware resource in accordance with the request from the application program or for indicating the hardware resources to perform an operation; and a controlling means for controlling data input into or output from the hardware resources in accordance with a content indicated by the indicating means, and the controlling means comprises a plurality of function implementing means.
A control apparatus of a second aspect according to the present invention has one of the function implementing means that comprises: a means for determining whether or not there is a hardware resource corresponding to the indicated operation, and a means for emulating the operation of the hardware resource and responding to the indicating means, when it is determined that there is not the hardware resource corresponding to the indicated operation.
A control apparatus of a third aspect according to the present invention further comprises: a means for detecting an indication of application program to be executed by the first executing means, an indication to be executed by the indicating means and the controlling means of the second executing means, or executing conditions of the application program and implementing conditions of each function through the first and second executing means.
A control method of a fourth aspect according to the present invention is for controlling hardware resources, with executing one or more application programs and executing a platform program, which controls the hardware resources, in accordance with a request from the application program, and comprises steps of: indicating the hardware resources to obtain information or the hardware resources to perform an operation in accordance with the request from the application program, and controlling data input into and output from the hardware resources, which are performed independently from each other by a process of the plat form program, and further controlling the data input into and output from the hardware resources, which are based on the respective hardware resources and performed independently from each other by a process of the plat form program.
A computer program of a fifth aspect according to the present invention is for making a computer control an operation of hardware resource in accordance with a request from an application program when the computer executes one or more application programs, wherein plural computer parts are included which are separated by predetermined functional units, and each computer part makes the computer respectively implement: a function for indicating to obtain information from the hardware resource in accordance with a request from the application program, or for indicating the hardware resource to perform an operation; and a function for controlling data input into and output from the hardware resource.
In the first aspect, the fourth aspect and the fifth aspect, two means are independently provided, one of the means is for performing a logical access, such as instruction for obtaining information from a hardware resource in accordance with a request from an application program or instruction for making the hardware resource perform an operation, and the other of the means is for performing a physical access that controls input into and output from the hardware resource, such as actual access to an I/O memory of the hardware resource. The type difference of hardware resources is addressed by the functional part which performs the physical access. It is possible input and output desired data, although another functional part performing the logical access does not require to recognize the type of hardware resource and the physical part of hardware resource performing the data input and the data output.
Furthermore, at least the means for performing the physical access is configured to include a functional module that implements a function independently. Thus, it is possible to select and combine functional modules based on the type of hardware resources and the desired specifications. Therefore, it is not required to change whole of the platform program itself based on the type of hardware resources.
In the second aspect, the function for implementing the physical access contributes in emulating the operation of hardware resource when there is no hardware resource corresponding to the request from the application program which indicates to perform an operation, and thus the response is replied as if there is the hardware resource corresponding to the request. Hence, the functional part for implementing the logical access can respond to the request from the application program which indicates to perform the operation, regardless of the presence of corresponding hardware resource. Therefore, it is not required to particularly change whole of the platform program in accordance with the individual specifications of hardware resource.
In the third aspect, it is further possible to change the function implemented by the application program and the platform program, in accordance with several conditions of whole of the control apparatus. Furthermore, the situations of respective programs can be detected by the corresponding executing means, and thus it is possible to select the control function of hardware resources in accordance with the conditions executing the application program.
According to the present invention, the platform program is configured with the functional part for implementing the logical access and another functional part for implementing the physical access. These functional parts are separated from each other, and the functional part for implementing the logical access is configured to be independent from the physical handle of hardware resource. Thus, it is not required to particularly change the whole of platform program in accordance with the individual specifications of hardware resource. Only the functional part for implementing the physical access may be changed in accordance with the type of hardware resource. It is possible to improve the reusability, since the functional part for implementing the logical access can be shared by several hardware resources. Therefore, it is possible to shorten the development process and reduce the development load.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
FIG. 1 is a block diagram showing a configuration of an ECU according to the present embodiment.
FIG. 2 is an explanation view conceptually showing a function implemented by a CPU of ECU according to the present embodiment.
FIG. 3 is a flowchart showing an example of process performed by a resource manager layer and a resource controller layer in accordance with an operation request.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, an embodiment of the present invention is described in detail with reference to drawings.
In the embodiment described below, a control apparatus according to the present invention is described in the context of an electronic control unit (ECU), which is mounted on a car and performs several controls, in reference to a control system where plural ECUs are connected to associate with each other via communication line and perform processes.
FIG. 1 is a block diagram showing a configuration of the ECU according to the present embodiment. The ECU 1 is connected to another ECU via a communication line 2 and is configured to be able to communicate with another ECU. The ECU 1 is additionally connected to a sensor 3 and an actuator 4 . The ECU 1 is provided with a specific function, such as a function for operating the actuator 4 based on the information obtained through the process performed by the ECU 1 in accordance with the information obtained from the sensor 3 or operating the actuator 4 based on the information obtained through the process performed by another ECU. Although the ECU 1 is connected both to the sensor 3 and to the actuator 4 , the ECU 1 may be alternatively connected to any one of both or connected to none of both.
The ECU 1 includes a central processing unit (CPU) 11 that controls operations of each component, a ROM 12 configured with a non-volatile memory, a microcomputer 10 provided with a RAM 13 which implements high speed access, a storing unit 14 configured with a non-volatile memory, a communicating unit 15 configured with a network controller, and an I/O unit 16 which is an interface for the sensor 3 and the actuator 4 .
The storing unit 14 is a memory having a relatively large storage capacity, such as a flash memory and an electrically erasable and programmable ROM (EEPROM). The storing unit 14 stores information obtained through the process performed by the microcomputer 10 executing application programs 17 , 17 , which is described later. The stored information is system information, such as condition information of the ECU 1 and condition information of vehicle mounting the ECU 1 . Additionally, the storing unit 14 stores data obtained from the sensor 3 by the microcomputer 10 , data received from another ECU and the like.
The communicating unit 15 implements the communication with another ECU which is performed through the communication line 2 by the microcomputer 10 . The communicating unit 15 particularly implements the communication based on a protocol of control area network (CAN), a protocol of local interconnect network (LIN), a protocol of Flex Ray (registered trademark) or the like. The communicating unit 15 may be configured as a part of microcomputer 10 , alternatively.
The I/O unit 16 is the interface for the sensor 3 and the actuator 4 , as described above. In the case of connecting to the sensor 3 , the I/O unit 16 acquires a signal representing, for example, a measured value output from the sensor 3 , and then outputs the signal to the microcomputer 10 . In the case of connecting to the actuator 4 , the I/O unit 16 outputs a control signal to the actuator 4 , as the control signal is required for the actuator 4 and output by the microcomputer 10 . The I/O unit 16 may be provided with a function for the D/A conversion and A/D conversion.
The central processing unit (CPU) 11 of microcomputer 10 implements a specific function that controls each component through reading out a control program 1 P stored in the ROM 12 onto the RAM 13 and executing the read control program 1 P.
The ROM 12 is a memory, such as a mask ROM, a flash memory, a programmable ROM (PROM), an erasable and programmable ROM (EPROM), or an electrically EPROM (EEPROM). Although storing the control program 1 P as described above, the ROM 12 may further store control data utilized for controlling.
The RAM 13 is a memory, such as a dynamic random access memory (DRAM) or a static random access memory (SRAM). The RAM 13 is configured to temporally store respective information that are generated through the process performed by the CPU 11 .
The control program 1 P stored in the ROM 12 is configured to include: application programs 17 , 17 , . . . for making the microcomputer 10 perform a process specific to the ECU 1 ; a platform program 18 for implementing a function common with another ECU, such as a controlling function of hardware resource and a communicating function; a middleware program 19 for mediating the application programs 17 , 17 , . . . and the platform program 18 ; and a system manager program 20 for controlling whole of the ECU 1 in order to perform a process based on each program.
The application programs 17 , 17 , . . . include several programs for making the ECU 1 implement the specific function, such as a program for implementing a control process of engine mounted on the car, and a program for implementing a switch process of door lock ON/OFF and of head light ON/OFF.
The platform program 18 includes a program for implementing a process performed by each hardware resource in accordance with an operation request sent from the microcomputer 10 to each hardware resource based on the application programs 17 , 17 , . . . , such as a process of writing data into the storing unit 14 , a process of reading out data from the storing unit 14 , and a process of sending data through the communicating unit 15 . Particularly, the platform program 18 includes: a resource manager part corresponding to a device driver for implementing a logical data access based on the operation request sent from the CPU 11 executing the application programs 17 , 17 , . . . ; and a resource control part corresponding to a basic input/output system (BIOS) for implementing a physical data access based on the implementation of respective hardware resources.
The middleware program 19 includes a program for implementing an interpreter function, such as a program for converting the operation request sent from the application programs 17 , 17 , . . . to conform to the platform program 18 and then for sending the converted operation request to the platform program 18 . Particularly, the middleware program 19 includes an output type process function for receiving an output request based on the application programs 17 , 17 , . . . from the CPU 11 , for converting the received output request to conform to the platform program 18 and for sending the converted output request to the platform program 18 . The output request is, for example a request to write data in the storing unit 14 or a request to send data through the communicating unit 15 . Additionally, the middleware program 19 includes an input type process function for receiving data input from the platform program 18 , for converting the received data to conform to the application program 17 and for sending the converted data to the application programs 17 , 17 , . . . . The middleware program 19 further implements a management type process function for sending management information to the application programs 17 , 17 , . . . . The management information is received from the CPU 11 based on a system manager program 20 described later.
The system manager program 20 is a program for adjusting whole of the processes performed by the CPU 11 , such as the process based on the application programs 17 , 17 , . . . , the process based on the platform program 18 and the process based on the system manager program 20 , in order to correspond to a situation where the ECU 1 should work properly and to control the ECU 1 . For example, the system manager program 20 implements a function for changing the process performed on the basis of each program, in accordance with the difference of situations, such as a situation where the ECU 1 should perform an operation for a test phase before shipping or a situation where the ECU 1 should perform an operation during maintenance. For example, the system manager program 20 implements a function for changing the process performed on the basis of each program, in accordance with the difference of situations, such as a situation where the ECU 1 should correspond to a car utilizing Japanese specifications or a situation where the ECU 1 should correspond to a car utilizing North American specifications. For example, the system manager program 20 implements a function for changing the physical control method of hardware resource, in accordance with the performed application programs 17 , 17 , . . . .
FIG. 2 is an explanation view conceptually showing a function implemented by the CPU 11 of ECU 1 according to the present embodiment. The CPU 11 reads out the control program 1 P onto the RAM 13 , which is stored in the ROM 12 , and then executes the read control program 1 P. As described above, the control program 1 P includes the application programs 17 , 17 , . . . , the platform program 18 , the middleware program 19 and the system manager program 20 . The CPU 11 performs an operation with a software configuration separated into three layers based on the respective programs included in the control program 1 P; an application layer 107 , a middleware layer 109 ; and a platform layer 108 .
In the uppermost application layer 107 , the CPU 11 works as respective applications (application A, application B, application C, . . . ) based on the application programs 17 , 17 , . . . .
In the middleware layer 109 , the CPU 11 implements respective functional modules 112 , 112 , . . . based on the middleware program 19 , as the functional modules 112 , 112 , . . . are for receiving operation requests from respective applications in the application layer 107 or for sending data from the platform layer 108 to the application layer 107 . For example, the respective functional modules 112 , 112 , . . . include an input type functional module 112 that sends data obtained from the platform layer 108 to the application layer 107 , an output type functional module 112 that sends the output from the application layer 107 , and a management type functional module that sends the management information showing an indication from the system manager 110 described later. Thus, in the middleware layer 109 , interfaces 111 , 111 , . . . are implemented on the basis of the middleware program 19 , as the interfaces 111 , 111 , . . . correspond to several application programs 17 , 17 .
In the lowermost platform layer 108 , the CPU 11 actually controls a group of hardware 14 , 15 , 16 , . . . based on the platform program 18 . Several functions are implemented in the lowermost platform layer 108 , for example, a function for reading and writing data with the storing unit 14 , a function for transmitting data with the communicating unit 15 , and the like. The platform layer 108 is further hierarchized into a resource manager layer 108 a and a resource controller layer 108 b . The resource manager layer 108 a is configured to implement functions 181 a , 182 a , 183 a , . . . for performing the logical access, for example, that leads indicating which data should be read out from the storing unit 14 . The resource controller layer 108 b is configured to implement functions 181 b , 182 b , 183 b , . . . for performing the physical access, for example, that leads to actual writing of data to be sent into the I/O memory of communicating unit 15 .
For example, a memory management function 181 a is implemented in the resource manager layer 108 a and a memory control function 181 b is implemented in the resource controller layer 108 b , for reading and writing data of memory (e.g., storing unit 14 ). The memory management function 181 a determines, in accordance with the request from the application layer 107 , which data should be read out from the memory and which data should be written into the memory. The memory control function 181 b identifies the address in the memory for the determined data, actually reads out the determined data and then actually writes the determined data. Furthermore, a communication management function 182 a is implemented in the resource manager layer 108 a and a communication control function 182 b is implemented in the resource controller layer 108 b . The communication management function 182 a instructs the communicating unit 15 to send data, for example. The communication control function 182 b actually performs data input into and data output from the communicating unit 15 . Similarly, a sensor management function 183 a is implemented in the resource manager layer 108 a and a sensor control function 183 b is implemented in the resource controller layer 108 b . The sensor management function 183 a instructs to read out data obtained from the sensor. The sensor control function 183 b actually receives the signal from the sensor.
It will be described below about the advantages of platform layer 108 hierarchized into the resource manager layer 108 a and the resource controller layer 108 b . For example, an application in the application layer 107 sends a request to read out data from the storing unit 14 , and the platform layer 108 receives the operation request. It is simply required in the platform layer 108 that the resource manager layer 108 a can read out the requested data from the storing unit 14 and input the read data into the application, regardless of whether the memory of storing unit 14 is the EEPROM or the flash memory. On the other hand, there are differences in the actual data reading method based on the specifications of respective hardware resources, i.e., whether the memory of storing unit 14 is the EEPROM or the flash memory. The memory control function 181 b in the resource controller layer 108 b modifies the read method in consideration of these differences, and sends the read data to the memory management function 181 a in the resource manager layer 108 a . Therefore, the memory management function 181 a in the resource manager layer 108 a can send the data, in response to the operation request from the application, to the application layer 107 side, regardless of memory type and the like.
It is possible to consider similarly about the case that the application sends a request for sending data from the communicating unit 15 . It is simply required in the resource manager layer 108 a that the requested data can be sent from the communicating unit 15 to a device, such as another ECU, regardless of whether the ECU 1 is connected to the CAN, LIN or Flex Ray. On the other hand, it is necessary to add information based on the type of protocol onto the data to be sent, when the data is actually sent from the communicating unit 15 . The communication control function 182 b in the resource controller layer 108 b modifies the data to be sent in consideration of the protocol type. Therefore, the communication management function 182 a in the resource manager layer 108 a can respond to the data sending request from the application, regardless of the protocol type.
In addition, the resource controller layer 108 b includes a function for performing a process based on the presence of hardware resource. Particularly, there are control functions 181 b , 182 b , 183 b , . . . corresponding to respective hardware resources, and these control functions are respectively provided with emulator functions that emulate operations for the corresponding hardware resources and return the emulated operations to the upper layer, i.e., the resource manager layer 108 a when the corresponding hardware resources is not present. For example, it is assumed that the resource manager layer 108 a requests to send the data for recognizing whether the “headlight” is ON or OFF. In the case that the sensor control function 183 b cannot obtain the signal for directly recognizing whether the “headlight” is ON or OFF because the “headlight” is not connected, the sensor control function 183 b utilizes e.g., the information capable of obtaining from another ECU for recognizing whether the “small light” is ON or OFF, instead of the information for recognizing whether the “headlight” is ON or OFF, and sends the information about the “small light” as the information about the “headlight”. The emulator functions contribute to make the resource manager layer 108 a be capable of performing processes, regardless of the presence of corresponding hardware resources. Alternatively, the resource controller layer 108 b includes a virtualization function independently implementing to emulate, and respective emulator functions are not included in the control functions 181 b , 182 b , 183 b , . . . corresponding to respective hardware resources.
Respective functions in the resource controller layer 108 b are affected by the type or specifications of hardware resources and by the presence of hardware resources. Thus, the respective functions in the resource controller layer 108 b should be adjusted in conformity to the hardware resources. On the other hand, the respective functions implemented in the resource manager layer 108 a are configured independently of the physical access control for the hardware resources. Thus, the respective functions in the resource manager layer 108 a are not affected by the type or specifications of hardware resources and by the presence of hardware resources. Therefore, it is possible to combine the resource controller layer 108 b and respective functions in the resource manager layer 108 a , although the resource controller layer 108 b is designed in conformity to several hardware resources and the resource manager layer 108 a is common to several hardware resources.
Furthermore, the CPU 11 reads out and executes the system manager program 20 , and thus the function of system manager 110 is implemented with the interface shared by the platform layer 108 . The system manager 110 implements a system monitoring function 113 that detects conditions of three layers, operation conditions of respective applications in the application layer 107 , operation conditions of functional modules 112 , 112 , . . . in the middleware layer 109 which correspond to the operating application and then that keeps the information, and implements a function management function 114 that identifies the type, shipping destination and grade of car on which the ECU 1 should be mounted, the application, functional module, operated hardware resource implemented in each layer corresponding to the change of ECU 1 function, and the like. It is noted that the system manager 110 is not limited to the configuration shown in FIG. 2 where the interface is shared with the platform layer 108 . Alternatively, the system manager 110 may be configured to directly transmit information with the functions of respective layers.
An example of applications implemented in the application layer 107 is a signal control, condition judgment, load control that controls loads (such as an actuator 4 ) or the like. Respective application programs 17 , 17 , . . . executed in the application layer 107 are determined in accordance with the management information sent from the system manager 110 through the management type functional module in the middleware layer 109 . For example, the CPU 11 reads out the management information from the middleware layer 109 in accordance with the application program 17 executed by the application layer 107 , selects another of application programs 17 , 17 , . . . to be executed in accordance with the read management information, and executes the selected application program. The management information includes, for example, information showing conditions or situations of ECU 1 , and information for identifying the application programs 17 , 17 , . . . to be executed in accordance with the conditions or situations of ECU 1 . For example, the management information includes information showing that the ECU 1 is in the test phase before shipping and information for identifying the application programs 17 , 17 , . . . to be executed in the case that the ECU 1 is in the test phase before shipping. Thus, the application layer 107 can select and execute a proper application program 17 based on the management information. Therefore, it is possible to perform proper processes based on the situations.
An example of functional modules 112 , 112 , . . . in the middleware layer 109 is an input type relay function that relays information obtained from the platform layer 108 into the application in the application layer 107 . In the input type relay function, the CPU 11 sends the information required by the application in the application layer 107 , among the information obtained from the platform layer 108 . In addition, there is an output type relay function that relays the data output from the application of the application layer 107 into the platform layer 108 . In the output type relay function, the CPU 11 selects an output destination in the platform layer 108 for the information output from the application in the application layer 107 , in accordance with the intended use of this output information, selects a proper interface from the platform interface 108 c and sends the output information to the selected interface.
For example, when the information output from the application is data to be sent to an external apparatus, the function of output type module 112 corresponding to the platform layer 108 selects a proper interface from the platform interface 108 c in order to send the data from the communication hardware corresponding to the proper protocol. Thus, the destination of sent data is selected. For example, when the information output from the application is data to be input into the storing unit 14 , the function of output type module 112 selects a proper interface in order to access to the storing unit 14 .
FIG. 3 is a flowchart showing an example of process performed by the resource manager layer 108 a and the resource controller layer 108 b in accordance with the operation request.
The middleware layer 109 selects a function, as an output destination, among the functions in the resource manager layer 108 a . The selected function receives an operation request from the application in application layer 107 (step S 1 ). A function in resource manager layer 108 a generates an instruction based on the operation request and sends the generated instruction to the resource controller layer 108 b (step S 2 ). In the case that the application requests to read out data, the memory management function in the resource manager layer 108 a described above identifies the data to be read out and instructs the resource controller layer 108 b to read out the identified data.
A function in the resource controller layer 108 b receives the instruction from the resource manager layer 108 a (step S 3 ), determines whether there is a hardware resource based on the instruction or not (step S 4 ). When having determined that such the hardware resource is not there (S 4 : YES), the physical control for the hardware resource is performed in accordance with the instruction (step S 5 ), and the response is returned (step S 6 ). In the example case of memory control function 181 b described above, the storing unit 14 is directly instructed to read out the data based on the identified data address, the data is read out from the I/O memory of the storing unit, and the like.
When having determined that there is not the hardware resource (S 4 : NO), the operation is emulated (step S 7 ) and the response is returned (S 6 ). In the example case of memory control function 181 b described above, the communicating unit 15 may receive the instruction when there is no memory storing the identified data. Then, the communicating unit 15 may return data temporary stored in the communicating unit 15 as the data to be read out. In the example case of sensor control function 183 b , the communicating unit 15 may return data received by the communicating unit 15 as the data sent from the sensor, when there is no sensor to which the data based on the read-out instruction should be output. Therefore, it looks like as if there is the connected sensor.
The resource manager layer 108 a detects the response from the resource controller layer 108 b (step S 8 ), and returns the detected response to the application from which the operation request has been sent (step S 9 ). Then, the procedure is completed.
As described above, the platform layer 108 is configured with the resource manager layer 108 a and the resource controller layer 108 b which are separated and work independently from each other. Based on the platform program 18 of control program 1 P included in the ECU 1 according to the present embodiment, the resource manager layer 108 a implements the function for the logical access and the resource controller layer 108 b implements the function for the physical access which is affected by the type of hardware resource. Thus, the resource manager layer 108 a can implement the function, regardless of the types or specifications of hardware resources and the presence of hardware resource. Therefore, it is not required to change the part of program corresponding to the resource manager layer 108 a in accordance with the types, specifications and presences of hardware resources connected to the ECU 1 . The part of program corresponding to the recourse controller layer 108 b may be simply adjusted to the type of hardware resources. Since the program part corresponding to the resource manager layer 108 a can be commonly conformed to and utilized for several hardware resources, it is possible to improve the reusability. Therefore, it is possible to obtain several advantages, such as shortening the development process and reducing the development load.
In the case that plural ECUs associate with each other and perform several processes, it might be configured to make respective ECUs utilize hardware resources having different types or specifications from each other. When the platform program 18 of each ECU must be changed in conformity to the hardware resource in that configuration, it happens to cause the complicated program management and the non-effective development. On the other hand, the configuration of platform layer 108 according to the present embodiment can contribute to utilize a common resource manager layer 108 a even for several hardware resources having the types or specifications different from each other and connected to respective ECUs. Thus, it is possible to improve the versatility. Therefore, it is possible to obtain several advantages, such as not only shortening the development process but also preventing the complexity of program management for the large-scale development.
Furthermore, the respective control functions 181 b , 182 b , 183 b , . . . of resource controller layer 108 b can implement the emulator function when the corresponding hardware resource is not present, and thus it looks like as if the corresponding hardware resource is present. Thus, it is possible to utilize the same resource manager layer 108 a for the case that there are differences not only in types or specifications but also in the presence of hardware resources connected to respective ECUs. Hence, it is possible to improve the versatility and reusability. Therefore, it is possible to obtain several advantages, such as shortening the development process and reducing the development load.
The embodiment described above shows an example where the present invention is applied to the ECU mounted on the vehicle. However, the present invention is not limited to that example. The present invention may be applied to several computer apparatuses that perform several controls.
As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims. | Functions of platform layer based on platform program are separated into a resource manager layer that performs logical controls for hardware resources and a resource controller layer that performs physical controls for the hardware resources. The resource manager layer requires identifying a desired data based on an application program, but does not require knowing the actual address of the desired data in a storing unit. The resource controller layer knows the actual address, and physically reads out and replies the data instructed by the resource controller layer. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a method for modifying surface properties of a shaped article of a silicone or, in particular, to a method for imparting durable affinity to water to the surface of a silicone rubber article.
Shaped articles of silicones, e.g. silicone resins and silicone rubbers, are widely used in various fields of industry in general owing to their excellent properties such as anti-weathering resistance, heat resistance, workability, mechanical properties, electrical properties and the like. Recently, silicone products have become a promising material and used in the medical field by virtue of their physiological inertness to the human body.
A problem in the use of silicone products is that the surface of a silicone article is generally water-repellent inherently so that the use of silicone products is necessarily limited when the surface of the article is desired to be wetted with water as is frequently the case in the medical field or others.
Such a problem of poor affinity to water and a problem of accumulation of static electricity on the surface are not limited to the silicone products but are generally encountered in most of synthetic polymer products. Several attempts have been made hitherto to modify the surface properties of shaped articles of plastic materials to be imparted with increased affinity to water. One of the approaches is to coat the surface of the article with an anti-static agent. This method is effective when the anti-static effect is desired to be instantly exhibited but is defective in the poor durability of the effect and the stickiness on the surface with eventual blocking of the coated articles in contact with each other. Alternatively, a method is proposed in which the shaped articles are fabricated with the resin or rubber composition admixed with an anti-static agent. The effect of this method is considerably durable and the surface resistivity of the shaped articles can be decreased to some extent but this method is impractical due to the insufficient affinity to water of the surface and low anti-static effect. An attempt to increase the amount of the anti-static agent in the resin or rubber composition is unsuccessful because of the appearance of stickiness on the surface leading to eventual blocking of the articles and the problem of bleeding or blooming of the anti-static agent per se on the surface in addition to the lowering of the heat resistance and workability as well as the surface coloring and increased susceptibility to stain.
It has been recently disclosed that the affinity to water of the surface of a plastic shaped article can be increased when the surface is exposed to an atmosphere of low temperature plasma leading to the decrease in the static electricity on the surface. This method of plasma treatment has not yet been established because of the relatively low effectiveness of the method. Moreover, when the surface of a silicone product is treated with low temperature plasma, affinity to water is indeed increased to some extent but the durability of the effect is low so that the once obtained affinity to water is rapidly lost in the lapse of days as has been recognized in the experiments by the inventors.
SUMMARY OF THE INVENTION
Thus, it is an object of the present invention to provide a novel and improved method for imparting very high and durable affinity to water to the surface of a shaped article of a silicone or, in particular, a silicone rubber free from the above described problems in the prior art methods.
The method of the invention, established as a result of the extensive investigations undertaken by the inventors for improving the surface properties of a shaped article made of a silicone, comprises the steps of (a) subjecting the surface of the shaped article of a silicone to exposure to low temperature plasma of an inorganic gas, and (b) bringing the thus plasma-treated surface of the shaped article into contact with a liquid inert to the silicone and containing a surface active agent.
Despite the simplicity of the method, the effectiveness of the inventive method is so remarkable and durable that the surface of the shaped article subjected to the treatment in accordance with the invention remains hydrophilic even after 6 months.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
What is meant by the term of silicone in this invention includes any kinds of organopolysiloxane materials well known in the art of organosilicon chemistry or technology. Various kinds of shaped articles can be the objective body of the inventive method. For example, shaped articles are prepared with a so-called silicone molding compound or a silicone rubber composition. The method of the present invention is applicable not only to the shaped articles prepared with the above mentioned silicone molding compound or silicone rubber composition but also to the surface coated with a silicone-based coating composition such as a silicone varnish. Furthermore, modified silicones such as epoxy-modified silicones and the like are also suitable for the application of the inventive method provided that the main constituent thereof is a silicone. The shape of the articles subjected to the method of the present invention is not limitative in so far as the whole surface thereof can be uniformly exposed to the low temperature plasma of a gas.
In the method of the present invention, the surface of the shaped article of a silicone is fist subjected to exposure to low temperature plasma of an inorganic gas. Low temperature plasma here implied is well known in the art as a gaseous atmosphere full of electrically charged species, where the temperature of the gaseous atmosphere is not excessively high in comparison with the ambient temperature irrespective of the energies of the charged species per se. Low temperature plasma is produced mainly by glow discharge in a gaseous atmosphere of a pressure in the range from about 0.001 to 10 Torr where the frequency of the electric power supply for the discharge is not limitative ranging from direct current to the microwave region. In particular, a frequency of the so-called high frequency is recommended due to the possibility of obtaining stable discharge. For example, a frequency of 13.56 MHz or 27.12 MHz is recommended since these frequencies are relatively free from statutory regulations for radio waves.
The shapes and arrangement of the electrodes for the plasma discharge are not limitative in so far as a stable plasma discharge can be ensured within the space in which the surface of the shaped article is exposed to the plasma atmosphere. Thus, a pair of exterior electrodes and a coiled electrode may be used in addition to a pair of inside electrodes according to particular types of the apparatuses for plasma generation. The electrodes may be connected to the high frequency generator either by capacitive coupling or by inductive coupling.
The intensity or power density of the low temperature plasma and the time for the plasma treatment are mutually interrelated parameters but extreme difficulties are encountered when the power density of low temperature plasma is to be determined explicitly. This is because of the very complicated nature of the plasma atmosphere which is beyond the understanding in the present status of the art. Therefore it is best to determine the time for the plasma treatment in advance by trial runs corresponding to the electric power supply and the particular articles under treatment. With a power density obtained in most of the currently available apparatuses for plasma generation, a time ranging between a few seconds and several tens of minutes is usually sufficient to obtain the desired effect of the inventive method. At any rate, it is a least requirement that the surface of the plasma-treated articles never undergoes thermal degradation by the heat evolved by the plasma discharge.
The other parameters that should be considered in the plasma treatment are the kind of the gaseous constituent and the pressure of the gaseous atmosphere in which low temperature plasma is generated. To ensure stability of the plasma discharge, the pressure of the gaseous atmosphere within the apparatus for plasma generation should be maintained in the range from about 0.001 to 10 Torr or, preferably, from about 0.01 to 1.0 Torr.
The gases to fill the apparatus for plasma generation should be inorganic since organic gases are liable to produce polymeric matters in the plasma condition which deposit on the surface of the article under treatment. Suitable inorganic gases are exemplified by helium, neon, argon, nitrogen, nitrous oxide, nitrogen dioxide, oxygen, air, chlorine, hydrogen chloride, carbon monoxide, carbon dioxide, hydrogen and the like. These gases may be used either singly or as a mixture of two kinds or more according to need. Among the above named gases, carbon monoxide gas or a gaseous mixture containing carbon monoxide is preferred because of the higher efficiency for an unknown reason.
The shaped article of the silicone having been exposed to low temperature plasma is then brought into contact with a liquid which is inert to the silicone, i.e. a liquid in which the silicone is not dissolved nor swollen. Such an inert liquid is exemplified by an aqueous solution containing a surface active agent, although water, methyl alcohol, ethyl alcohol, dioxane and the like can be used.
The temperature of the inert liquid when the plasma-treated shaped article is in contact therewith is preferably in the range from 0° C. to 50° C. but, most conveniently, the contacting is carried out at room temperature. The duration of contacting with the inert liquid is in the range from a few second to several minutes or at least 1 second although an excessively long time exerts no adverse effects. It is not always necessary that the shaped article after completion of the plasma treatment is immediately brought into contact with the inert liquid and the effectiveness is almost unchanged when the plasma-treated article is brought into contact with the liquid within 24 hours after completion of the plasma treatment.
The type of the surface active agent used in the inert liquid aqueous solution is not particularly limited and includes cationic, anionic, non-ionic and amphoteric surface active agents.
The cationic surface active agents suitable for use are exemplified by salts of primary amines, salts of secondary amines, salts of tertiary amines, quaternary ammonium salts and pyridinium salts and the anionic surface active agents are exemplified by sulfonated oils, soaps, sulfonated ester oils, sulfonated amide oils, sulfonated ester salts of olefins, sulfonated ester salts of aliphatic alcohols, ester salts of alkylsufuric acids, ethylsulfonic acid salts of fatty acids, salts of alkylsulfonic acids, salts of alkylnaphthalenesulfonic acids, salts of alkylbenzenesulfonic acids, succinic acid ester sulfonates and salts of phosphoric acid esters. The non-ionic surface active agents are exemplified by addition products of ethylene oxide with fatty acids, aliphatic amides, alkylphenols, alkylnaphthols, partial carboxylic acid esters of polyvalent alcohols and the like and block copolymers of ethylene oxide and propylene oxide and the amphoteric surface active agents are exemplified by derivatives of carboxylic acids and derivatives of imidazolines. These surface active agents are dissolved, dispersed or emulsified in water or a mixed solvent of water and an alcohol in a concentration of about 0.01 to 50% by weight or, preferably, 0.01 to 10% by weight.
No particular explanation may be necessary of the manner in which the plasma-treated shaped article of a silicone is brought into contact with the inert liquid. For example, the plasma-treated shaped article is contacted with the inert liquid by dipping, brushing, spraying, steaming or any other conventional method and the shaped article wet with the inert liquid is, if necessary, washed with water and dried completely at room temperature or at an elevated temperature.
The shaped article of the silicone treated as described above in accordance with the invention is imparted with very remarkably improved surface characteristics, in particular, affinity to water, as mentioned before so that the fields of application of silicone shaped articles are further enlarged to a great extent.
Following are the examples to illustrate the method of the present invention in further detail. In the examples, the affinity to water was evaluated by the contact angle of water on the surface. All of the "parts" in the examples are given for "parts by weight".
EXAMPLE 1
A silicone rubber composition was prepared by blending 100 parts of a methylvinylpolysiloxane gum containing 0.15% by moles (based on the total number of the organic groups) of vinyl groups, 60 parts of acetylene black and 0.7 part of dicumyl peroxide and an electroconductive silicone rubber sheet of 0.5 mm thickness was obtained by compression molding of the above composition at 170° C. for 5 minutes.
The above silicone rubber sheet was placed in a plasma generating chamber in which low temperature plasma was generated by applying high frequency electric power of 150 watts at 13.56 MHz while gaseous atmosphere in the chamber was kept under a pressure of 0.4 Torr by passing carbon monoxide gas under a reduced pressure so as that the surface of the silicone rubber sheet was exposed to the plasma atmosphere for about 10 minutes.
The thus plasma-treated silicone rubber sheet was dipped in an aqueous solution containing a sodium alkylbenzenesulfonate-higher alcohol surface active agent in a concentration of 1% for 1 minute followed by rinsing of the surface with water and complete air drying.
The contact angle of water was determined on the plasma-treated silicone rubber sheets without or with following treatment with the aqueous solution of the surface active agent. The measurement was carried out either immediately after the treatment or after lapse of days up to 6 months to give the results set out in Table 1 below.
EXAMPLE 2
The conditions for the preparation of the silicone rubber sheets and the plasma treatment of the sheet were about the same as in Example 1 except that the silicone rubber composition was composed of 100 parts of a emthylvinylpolysiloxane gum containing 0.2% by moles of vinyl groups, 40 parts of a fumed silica filler and 0.5 part of dicumyl peroxide and the high frequency electric power supply for the plasma generation was increased to 300 watts along with the decrease of the atmospheric pressure of carbon monoxide gas to 0.2 Torr.
The aqueous solution used for the treatment of the plasma-treated silicone rubber sheet contained 5% of a triethanolamine laurylsulfate surface active agent. The results of the determination of the contact angle of water on the plasma-treated silicone rubber sheets without or with following treatment with the aqueous solution are set out in Table 1 below.
EXAMPLE 3
The conditions for the preparation of the silicone rubber sheets and the plasma treatment of the sheet were about the same as in Example 1 except that the silicone rubber composition was composed of 100 parts of a methylvinylpolysiloxane gum containing 0.13% by moles of vinyl groups, 50 parts of a fumed silica filler and 0.8 part of dicumyl peroxide and the low temperature plasma was generated with increased power supply of 500 watts in an atmosphere under a pressure of 0.7 Torr kept by passing a gaseous mixture of 20:80 by volume of carbon monoxide and argon.
The aqueous solution used for the treatment of the plasma-treated silicone rubber sheets contained 3% of an alkylamine surface active agent. The results of the determination of the contact angle of water on the surfaces of the plasma-treated silicone rubber sheets without or with following treatment with the aqueous solution were as set out in Table 1 below for the sheets immediately after the treatment and after lapse of days up to 6 months.
TABLE 1______________________________________Treatment (contact angle of water)Example with aqueous Initial After After AfterNo. solution value 1 month 3 months 6 months______________________________________1 No 50° 72° 80° 93° Yes 22° 30° 36° 39°2 No 56° 80° 96° 108° Yes 32° 38° 42° 50°3 No 45° 60° 73° 91° Yes 28° 32° 38° 41°______________________________________ | A novel method is proposed for improving the surface properties or, in particular, for increasing the affinity to water of the surface of a shaped article made of a silicone, e.g. a silicone rubber. The inventive method comprises first exposing the surface of the shaped article of the silicone to low temperature plasma of an inorganic gas and then bringing the plasma-treated surface into contact with a liquid inert to the silicone which is an aqueous solution containing a surface active agent. The treated surface retains sufficient affinity to water even 6 months after the treatment. | 2 |
FIELD OF THE INVENTION
This invention relates generally to coinjection molding and particularly relates to an improved apparatus for simultaneously molding a plurality of multi-layered articles.
DEFINITIONS
As used herein:
"First and second materials" is intended to cover at least two materials which are sequentially supplied to an injection mold, it being entirely possible that one or more other materials may be sequentially supplied before, between, or after the first and second materials;
"Balanced Hot Runner" is a temperature controlled heated uninterrupted material conveying system extending from a single input (e.g. a material source or metering valve) to a plurality of outputs (e.g. metering valves or injection mold cavities) comprising a single passage branched into a plurality of passages with each of said plurality of passages, communicating with one of the plurality of outputs, for conveying material therethrough to simultaneously supply equal quantities of the material to each of the outputs;
"Unbalanced Hot Runner" is a temperature controlled heated material conveying system, for the passage of material from an input (e.g. material supply source) to a plurality of outputs (e.g. metering valves for metering the material for supply of metered quantities of the material to injection mold cavities), which is not branched to provide passages of identical cross-section and length and does not divide the supplied material into equal quantities for the simultaneous supply of these quantities each to one of outputs.
BACKGROUND OF THE INVENTION
The manufacture of pure, or virgin, resin preforms for blow molding containers is well known within the prior art. But since the advent of recycling, it is now possible to manufacture preforms with materials that are compositionally less pure than virgin materials. Such degraded, or recycled, materials not only yield positive environmental benefits in an ecologically fragile era but provide manufacturers with an alternative manufacturing method which allows for substantial reductions in costs.
But, since recycled materials are obtained from post consumer solid waste, certain new manufacturing problems have been encountered that were heretofore previously unknown. For example, manufacturers must now provide, at increased costs, additional equipment for keeping the virgin and recycled materials separate from each other. In addition, multi-layered articles, such as preforms, that are eventually used to form containers for food stuffs, have even further impediments by way of rigid statutory guidelines. The guidelines, enacted by the Food and Drug Administration (FDA), require that certain minimums must be met, or exceeded, before the containers can be approved as "qualified" to contain food stuffs and before the foods are allowed to be distributed to the consumer population. One extremely noteworthy FDA provision enacted theretowards provides for the assurance of product "cleanliness".
Currently, in order to meet the FDA cleanliness standards, a container must be configured such that only surfaces of virgin materials contact the foods and beverages therein. Other container surfaces, such as areas for contacting the human mouth, e.g. the dispensing orifice on a soda container, also require virgin material surfaces. As a result, it is economically desirable to provide manufacturers with a apparatus capable of utilizing recycled materials within containers while, at the same time, preventing recycled materials from contacting the very foods and liquids that are to be distributed to, and consumed by, the public.
Some advances towards the aforementioned goal have been attained by using coinjection molding techniques to manufacture multi-layered containers. The multi-layered containers thence produced have interior and exterior surfaces of the container comprised of virgin materials while the fill and support materials located within the interior of the container walls comprise the degraded, less than pure, recycled materials. Consequently, the economies and conservation of utilizing recycled materials is thereby achieved while simultaneously meeting the strict FDA statutory requirements.
Prior art coinjection molding techniques that produce the multi-layered containers described above, often first manufacture a multi-layered preform and then blow mold the preform into the final container. The formation of multi-layered containers are described in detail, for example, in Applicant's U.S. Pat. Nos. 4,550,043 and 5,221,507.
Typically, the preforms are injection molded in multi-cavity molds which may have as many as 96 cavities. These preforms are then simultaneously produced by injecting appropriate amounts of a first and second material, i.e. virgin and recycled, into each of the cavities. To this end, the mold defines a manifold arrangement to convey the two materials to each of the singular cavities. Such an arrangement, as in Applicant's prior patents, is known to convey each of the first and second materials into a singular hot runner before contiguously conveying the materials to the cavities. The combination then allows for a reduction in equipment costs due to the singular hot runner arrangement. The singular conduit repeatedly divides the materials flowing therein into a plurality of flow paths for delivery to each cavity and to thereby ultimately provide each cavity with a substantially equal amount of metered material at substantially the same temperature and at substantially the same time as every other cavity. Yet, with mold arrangements containing large numbers of cavities, such as with forty-eight and ninety-six cavities, the two materials contiguously flowing within a singular conduit have been known to have interface boundary problems between the virgin and recycled materials when conveyed over lengthy distances.
Other prior art multi-cavity mold apparatus, that use coinjection molding to form multi-layered preforms, utilize molds in which a completely separate manifold system for each material, i.e. virgin and recycled, is used to separately convey that specific material to the singular cavities. The separate materials are then, either, injected simultaneously into the cavities using concentric nozzles or injected sequentially into the cavities utilizing a valve arrangement closely adjacent each cavity to control the flow from the separate manifolds into the multi-orifice nozzles. Such arrangements result in molds that are expensive and complex. In addition, such molds result in difficulties in controlling the temperature of the material to be injected into the cavity in a manner such that each mold receives an accurately metered quantity of material at substantially the same temperature.
Prior art injection molding systems for molding preforms simultaneously, with molding material supplied by way of a balanced hot runner, in a plurality of like cavities have utilized cavities in multiples of two in order to simplify the simultaneous supply of the materials, in equal amounts, to the cavities.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a method and apparatus that yields a delivery method for a first and second material that delivers the respective materials at substantially the same temperature and at reduced costs while conveying substantially equal amounts of the respective materials at substantially simultaneous delivery times.
It is a further object of the present invention to provide a more distinct division between the recycled and pure materials being contiguously conveyed within the same conduit to the individual mold cavities in order to more accurately provide a substantially equivalent amount of molding materials to each cavity.
It is a further object of the present invention to provide a method and apparatus using a multi-cavity coinjection mold which avoids the complex construction and expense of prior art multi-cavity coinjection molds and which provides a low cost, relatively simple, easy to regulate mold which is suitable for use on existing machinery at minimal conversion costs.
It is a further object of the invention to facilitate the use of injection molding systems for molding preforms simultaneously in pluralities of cavities of any number, odd as well as even (e.g. 4, 5, 10, 11, etc.).
These and other objects are achieved by providing an apparatus and method that utilizes a first hot runner manifold system which keeps at least one of a plurality of molding materials, virgin and recycled, for example, physically separated until they have been conveyed to locations adjacent individual cavities. Once conveyed to these locations, the molding materials are combined by a timed valve distribution mechanism, one per cavity, to produce a contiguous sequence of molding material comprised of metered quantities of the different materials. The contiguous quantities of material may then be conveyed through a second hot runner manifold system for injection simultaneously and sequentially into the individual cavities in desired amounts of the materials to produce a plurality of similar multi-layered preforms.
According to the invention there is provided a multi-cavity coinjection mold for simultaneously producing a plurality of multi-layered articles comprising: a mold structure defining a plurality of mold cavities; a first supply source for supplying a first molding material; a second supply source for supplying a second molding material; a hot runner system in communication with said first and second supply sources for conveying said first and said second materials separately to a region proximate each cavity; a valve mechanism per cavity for receiving said first and said second materials from said first hot runner system and for sequentially supplying desired quantities of said first and said second materials contiguously to a hot runner for each cavity, wherein each hot runner communicates with a single cavity only; and a temperature control means for maintaining the desired respective temperatures of said hot runner system, hot runners and said cavities.
Also according to the invention there is provided a multi-cavity coinjection mold for simultaneously producing a plurality of multi-layered articles comprising: a mold structure defining a plurality of mold cavities; a first supply source for supplying a first molding material; a second supply source for supplying a second molding material; a hot runner system in communication with said first and second supply sources for conveying said first and said second materials separately to a region proximate each cavity, the hot runner system comprising at least one unbalanced hot runner; a valve mechanism per cavity, each valve mechanism being arranged to receive said first and said second materials from said hot runner system and for sequentially supplying desired quantities of said first and said second materials contiguously to its associated cavity; and a temperature control means for maintaining the desired respective temperatures of said hot runner system and said cavities.
Also according to the invention there is provided a method of multi-cavity coinjection molding for simultaneously producing a plurality of multi-layered articles comprising the steps of: providing a mold structure defining a plurality of mold cavities; providing a first supply source for supplying a first molding material; providing a second supply source for supplying a second molding material; separately conveying said first and second material through a hot runner system from said first and second supply sources to a valve mechanism individual to and proximate each cavity; operating the valve mechanisms to sequentially supply desired quantities of said first and said second materials contiguously to a hot runner individual to each cavity; and controlling the temperatures of said hot runner system, hot runners and said cavities.
Also according to the invention there is provided a method of multi-cavity molding simultaneously producing a plurality of multi-layered articles comprising the steps of: providing a mold structure defining a plurality of mold cavities; providing a first supply source for supplying a first molding material; providing a second supply source for supplying a second molding material; separately conveying said first and second materials through an hot runner system, comprising at least one unbalanced hot runner from said first and second supply sources to a valve mechanism individual to and proximate each cavity; operating the valve mechanisms to sequentially supply desired quantities of said first and said second materials contiguously to each cavity; and controlling the temperatures of said hot runner system and said cavities.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a diagrammatic cross-section of a multi-cavity sequential coinjection mold system according to one embodiment of the invention;
FIG. 2 is a diagrammatic representation of a valve to cavity variation from that shown in FIG. 1; and
FIG. 3 is a diagrammatic illustration of another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the embodiment of FIG. 1, a cavity mold 10 for the sequential coinjection molding of multi-layered preforms for the blow molding of multi-layered containers comprising interior and exterior surfaces of a virgin material (e.g. polyethylene terephthalate, PET) is illustrated as having four cavities 12. It will be appreciated by those skilled in the art that, in practice, the multi-cavity mold 10 depicted may have a greater number of cavities including both odd (e.g. 71) or even (e.g. 96) numbers. Four cavities 12 are used in this example to simplify explanation of the present invention which is applicable to molds having any number of cavities. Each cavity 12 is itself well known to those skilled in the art and is not described in detail herein. At the base of each cavity is a gate 14 through which passes the materials which will form the preform in that particular cavity. Connected to each gate 14 is a nozzle 16 having a cross section area of decreasing magnitude the nearer the cross section of nozzle 16 is to gate 14. The particular cross section is a function of the properties of materials conveyed and of how much material is to be injected. All of which are well known within the art.
The mold 10 defines a plurality of hot runners 18 each for conveying sequential quantities of alternating first and second molding materials contiguously from a timed valve mechanism 20, one for each cavity.
In operation, each timed valve mechanism 20, which provides the materials to the hot runners 18, receives first and second materials through a manifold system 24 which comprises unbalanced hot runners 25 and 27. The first and second materials are supplied by plasticizers 26 and 28 under control of ram pots 30 and 32, respectively. Each timed valve mechanism 20 switches between two discrete positions corresponding to runners 25 and 27 so that the two materials are sequentially supplied contiguously to the hot runner 18 of the associated cavity. Each valve mechanism 20 may also switch back and forth between a third discrete position wherein no material is allowed to flow by valve mechanism 20 to its hot runner 18. Also, if more than two materials are utilized each valve mechanism would have operating positions corresponding to the number of materials used.
The valve mechanisms 20 are closely adjacent their respective cavities 12. It will be appreciated that separate conveyance of the first and second materials to the valve mechanisms proximate their, respective cavities will minimize any interface boundary difficulties between the first and second materials since the two materials are not contiguous within a singular conduit prior to reaching the valve mechanisms. Once combined by the valve mechanisms 20, the distance traveled by the contiguous first and second materials within the hot runners 18 is minimal and the difficulties of lengthy contiguous travel are minimized. Simultaneously, equipment cost advantages are realized since each hot runner 18 is a single undivided channel dedicated to a single cavity. In addition, hot runner manifold system 24 need not be a balanced conveyance system.
Timing control mechanism 40 facilitates the coordination of simultaneous switching of the plurality of valve mechanisms 20 so that substantially equal amounts of the materials will be supplied simultaneously to each individual cavity 12. Timing mechanism 40 may be any one of a variety of electromechanical mechanisms as will be well known to those skilled in the art and will not be described here in detail.
Further construction details of mold 10, particularly its hot runners, together with the heating and cooling arrangements therefore are also conventional within this technology and will be readily apparent to those skilled in the art. Likewise, the plasticizers and ram pots are of conventional construction as are the general engineering details of valve mechanisms. Accordingly, these matters are again not described herein in detail.
It will be further appreciated by those skilled in the art that the separate and distinct hot runners 25, 27 may be used to convey different materials from respective plasticizers 26 and 28 wherein the materials supplied from the plasticizers are of substantially different processing temperatures. Such an alternative arrangement, while providing distinct hot runners for materials of differing temperatures, may also be used if the materials are of the same processing temperature. The temperature control means used for each hot runner system 24 would then be adjusted to the same temperatures. In either event, the conveyance of the specific materials are again kept separate until conveyed to the appropriate proximate cavity regions. Conveyed first and second materials are then likewise supplied to a timed valve distribution system 20 for combining the materials into hot runners 18, nozzles 16 and eventually to the appropriate individual cavity 12.
In FIG. 2, the nozzle 16 is closely adjacent the valve mechanism 20 with the passage between the nozzle 16 and the gate 14 leading to the cavity 12 being part of the hot runner 18.
FIG. 3 illustrates another embodiment in which reference number 90 indicates, in diagrammatic form, an assembly comprising a cavity, gate, nozzle, hot runner and valve mechanisms similar to those numbered 12, 14, 16, 18 and 20 in FIG. 1.
In this embodiment, four plasticizers 70, 72, 74 and 76, which may have associated ram pots (not shown in FIG. 5), separately supply a plurality of up to four different materials to diverter valves 78 and 80 for metering and supply to balanced hot runners 82 and 84 for the contiguous supply of materials from plasticizers 70, 76 and 72, 74, respectively, to the valve mechanism of the assemblies 90, for metering thereby to provide the contiguous supply thereof through the hot runners of the assemblies 90 to the cavities thereof in a manner substantially as previously described herein with respect to the embodiment of FIG. 1. As mentioned materials from different plasticizers could be the same.
Although the embodiment of FIG. 3 illustrates the use of four plasticizers 70, 72, 74 and 76 and two balanced hot runners 82, 84 associated respectively with diverter valves 78, 80, it will be appreciated that two or more plasticizers could be arranged to supply two or more different plastics materials to a combination of unbalanced and balanced hot runners with each balanced hot runner being supplied with plastics materials by way of a diverter valve (e.g. 78, 80).
In an embodiment employing an unbalanced hot runner and a balanced hot runner the plasticizers may provide three different materials, for example, virgin PET recycled PET and another material, such as a barrier material. Alternatively, two of the plasticizers could supply virgin PET. In either circumstance virgin PET is supplied separately by way of the unbalanced hot runner to the valve mechanisms of the assemblies 90 while the other materials are metered by a diverter valve to the balanced hot runner for contiguous flow therethrough to supply the materials simultaneously and sequentially in equal quantities to the valve mechanisms of the assemblies 90 for metering, with the virgin PET from the unbalanced hot runner, to provide the contiguous supply of the materials from the valve mechanisms of the assemblies 90. Operation of all of the valves is preferably synchronized to ensure appropriate material metering.
In the event of the material from two of the materials both being virgin PET, this arrangement can advantageously be used to supply virgin PET through an unbalanced hot runner to valve mechanisms of the assemblies 90 without any possible contamination by the recycled PET, thereby to facilitate the formation of the inner surface of a multi-later article molded in the cavities and to supply virgin and recycled PET through a balanced hot runner for use in the article where contamination of the virgin PET is less critical.
It will be appreciated that, for example, a single plasticizer could be used to supply the same material to both the unbalanced hot runner and the diverter valve of the balanced hot runner and that similar variations are possible in other embodiments. In addition the balanced hot runners 82, 84 may be identical, in order to balance the contiguous supply of metered material therethrough, or may be different from each other and/or controlled at different temperatures to provide desired characteristics of material flow to the cavities.
The valve mechanisms may be provided with an "off" or closed position as well as a position for the introduction of each material sequentially and contiguously into the manifold 33.
Of course it will be appreciated that diverter valve operation could be adjusted, if injection molding in different cavity groups is unbalanced thereby causing non-uniform layers and or parts from cavity group to cavity group, by sequentially operating the valves and/or changing valve timing to adjust material flow from one cavity group to another, for example, so that cavity groups that would receive the most material would have their diverter valve operation delayed to compensate and balance the flow of material to the groups.
One of the materials may be recycled PET or a barrier material e.g. ethylene vinyl alcohol (EVOH) disposed intermediate polyester layers of the article.
In arrangements utilizing an unbalanced hot runner system for supplying the diverter valves 20 as illustrated in FIG. 1, the possibility of providing the diverter valves 20 at or closely adjacent the gates 14 and of utilizing thermal diverter valves at the gates emerges. | A multi-cavity coinjection mold and method for simultaneously producing a plurality of multi-layered articles comprising: a mold structure defining a plurality of mold cavities; a first supply source for supplying metered amounts of a first molding material; a second supply source for supplying metered amounts of a second molding material; a hot runner system in communication with the first and second supply sources for conveying the metered amounts of the first and the second materials separately to a region proximate each of the cavities; a valve mechanism per cavity for receiving the metered amounts of the first and second materials from the hot runner system and for sequentially supplying desired quantity of the first and second materials contiguously to each cavity. | 1 |
BACKGROUND OF THE INVENTION
The present invention pertains to a courtesy light for use in a vehicle, and particularly to a multipurpose courtesy light for use both for general lighting and as a directionally adjustable spotlight.
Courtesy lights are commonly used in vehicles to provide interior lighting for vehicles such as for entering and exiting a vehicle. These lights are intended to generally light the interior of the vehicle so that a person entering the vehicle can easily see to safely enter the vehicle and also confirm that an intruder is not present in the vehicle. Additional lights ar typically provided to provide a more focused light for reading maps and the like. These additional lights emit a more focused spot-type light which increases light intensity and also prevents the light from spreading around the vehicle interior thus reducing a driver's ability to see out of the vehicle. In order to accommodate both requirements, two different systems of lighting are generally employed. This is both inefficient and costly. U.S. Pat. No. 4,686,609 issued on Aug. 11, 1987, and assigned to the present assignee, discloses a dual light system used to provide both a spotlight and a floodlight by selectively sliding a lens in front of an otherwise flood-type light. Although such system provides a desired dual characteristic light, it requires additional space for the sliding storage of the lens when not over the light.
SUMMARY
The apparatus of the present invention provides a courtesy light in a vehicle which has both an unfocused or flood position and a focused or spotlighting position. In the focused position the light can be rotatably tilted thus directing the light in a desired direction. The apparatus includes a carrier which mounts within the vehicle, and a bulb holder and reflector which cooperate within the carrier to provide a source of both unfocused light and tiltable, adjustable focused light. In the preferred embodiment, the bulb holder includes a spherically shaped section and a protruding end that provides means for tilting, extending and retaining the reflector. In the preferred embodiment, the reflector provides a finger grip for pulling the reflector to an extended position and for limiting the angle of tilt attainable.
Such an apparatus provides a compact and efficient dual system of lighting which reduces the complexity and cost of the apparatus. Further, the apparatus offers advantages of convenience and simplicity of assembly and operation. These and other features, objects, and advantages of the present invention will become apparent upon reading the following description thereof together with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective exploded view of the courtesy light of the present invention;
FIG. 2 is a side elevational view of one of the components in FIG. 1;
FIG. 3 is a cross-sectional view taken through section line III--III in FIG. 2;
FIG. 4 is an enlarged vertical cross-sectional view of the apparatus of FIG. 1 fully assembled and shown in a first position for providing floodlighting;
FIG. 5 is a vertical cross-sectional view of the apparatus of FIG. 4 shown in a second position for providing spotlighting; and
FIG. 6 is a vertical cross-sectional view of the apparatus of FIG. 5 shown in the second position and tilted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIGS. 1 and 4, there is shown a courtesy light 10 embodying the present invention which is particularly adapted for mounting within the interior passenger compartment of a vehicle such as an automobile. In the preferred embodiment, courtesy light 10 is designed to fit into a roof or wall panel such as header 12 and extend downwardly slightly into the passenger compartment of the vehicle, although it could be used in other areas of the vehicle. In the preferred embodiment, courtesy light 10 comprises a carrier 14, a swivel bulb holder 16 which mounts within the carrier 14 and swivels or tilts therein a reflector 18 which mounts through carrier 14 into bulb holder 16, a bulb 20, a lens 22 and a lens holder bezel 24 which provides a finger grip for extension and movement of the reflector.
Courtesy light 10 (FIGS. 1 and 4) is secured to the under surface of sheet metal roof 26 of the vehicle by insertion of courtesy light 10 into an aperture 28 in headliner 30 and an aligned aperture 32 in the sheet metal 26. Carrier 14 is provided with standoffs 34 which align carrier 14 within holes 28 and 32. Staggered tangs 36 positioned around carrier 14 elastically deform inwardly as carrier 14 is pushed upwardly into place in the roof and then spring outwardly into position gripping the top surface of sheet metal roof 26 for holding carrier 14 in place in the roof. An indexing rib 38 rotationally locates and locks carrier 14 by engaging a notch 40 at the edge of mounting aperture 28 in the sheet metal 26. In the installed position, a generally elliptical peripheral flange 42, integrally formed on carrier 14, engages the lower surface of headliner 30 and together with tangs 36 hold carrier 14 firmly in place. The downwardly opening face 43 of carrier 14 is generally cup-shaped with a central opening 46 (FIG. 4) for receiving the reflector 18.
Carrier 14 also integrally includes upwardly extending curved fingers 48 defining a socket for receiving the bulb holder 16. Fingers 48 are defined in part by slots 50 and have an inside surface 52 which is spherically shaped allowing fingers 48 to mateably receive and retain swivel bulb holder 16. Flange 42 includes a decorative outer surface facing the interior of the vehicle, and the ends of the elliptical flange provide protection for the headliner 30 when the light position is changed as described below. Carrier 14, as well as the remaining elements of the light assembly, is integrally molded of a suitable polymeric material such as polycarbonate.
Swivel bulb holder 16 (best shown in FIGS. 2-3) includes a curved central ring 54, an upwardly projecting external collar portion 55, and an internal downwardly extending collar 62. Collar 62 is located centrally within portion 55 and has a generally hollow cylindrical opening 58 and terminates at the bottom in an integrally formed bulb socket 70. The outside surface 63 of collar 62 and the inside surface 56 of ring 54 are spaced to define an annular space 59 (FIG. 3) designed to slidingly receive the cylindrically shaped mating end 86 of reflector 18 as best seen in FIGS. 4-6 and as described below. A vertically extending slot 64 is formed laterally outwardly through the ring and collar 54 and 55, respectively, and receives a pin 90 of reflector 18 to control the sliding extension of the reflector 18 as described in greater detail below. Also extending outwardly from ring 54 of swivel bulb holder 16 are one or more antirotational pins 76 which permit holder 16 to tilt in multiple directions away from an axis located centrally through carrier 14, but prevent the swivel bulb holder 15 from rotating with respect to the centrally located axis. For such purpose, pins 76 fit between fingers 48 in slots 50 of carrier 14.
The opening 58 located centrally on portion 55 is designed to allow electrical contacts 7 to extend from the upper end of opening 58 to bulb socket 70 and to retain contacts 72 in position (FIG. 4). Electrical conductors 74 connect to contacts 72 at the top of portion 55 and are routed away as desired. Electrical power from the vehicle power supply is selectively applied to a bulb 20 mounted in bulb socket 70 and in contact with contacts 7 through the electrical conductors which may be coupled to suitable courtesy lamp switches in a conventional manner.
Reflector 18 is generally parabolic in shape and is defined by an exterior surface 80, an interior surface 82, locking ledge 84 and upper telescoping end 86. Exterior surface 80 is designed to mateably fit into and be received by the downwardly oriented cup-shaped face 46 of carrier 14. Interior surface 82 is parabolically shaped such that when lighted bulb 20 is positioned at the focal point of reflector 18 as seen in FIGS. 4 and 5, the resulting emanating light is focused to provide spotlighting. Alternatively, when reflector 18 is positioned as seen in FIG. 4., the filament of bulb 20 no longer is located at the focal point of the reflective surface 82 of member 18 and the emanating light takes on a floodlight pattern. The telescoping end 86 of reflector 18 is a hollow cylindrically-shaped structure which mateably fits into swivel bulb holder 1 between curved ring 54 and telescoping collar 62. Telescoping end 86 has a retention pin or tang 90 which mateably fits within slot 64. Tang 90 is properly positioned to snappingly engage retention slot 64 on member 16 such that reflector 18 may be inserted in a fully inserted position wherein tang 90 is positioned at upper end 92 of slot 64, or reflector 18 may be extended downwardly until retention tang 90 mechanically strikes the lower end 94 of slot 90. Collar 62 has a relief or slot 95 to allow tang 90 to slide into position.
Covering the downwardly facing open end of reflector 18 is a lens assembly 22 having a pillow optics lens portion 100 with outwardly extended retention ledges 102 and a retainer bezel and finger grip 24. Ledges 102 are mateably positioned against locking ledges 84 of reflector 18. Lens assembly 22 covers the downwardly opening end 78 of reflector 18, both esthetically closing off the courtesy lamp assembly 10 and also reducing glare by more uniformly dispersing light emanating from bulb 20.
Finger grip 24 is a ring-shaped structure having an exterior surface 104 designed to be esthetically pleasing and functional to the touch and an interior surface 106 having locking ridges 108. Finger grip 24 is designed to receive lens 100 such that retention ledges 102 align with locking ridges 108 and permit grip 24 to be installed on and twisted to lock onto locking ledge 84 of reflector 18. An interior annular surface 110 provides a support surface for holding the lower edges of ledges 102 on lens 100 for holding the lens between member 24 and reflector 18 in a vertically aligned position.
Having described the components of the preferred embodiment, the operation and use of this apparatus should become clear. Initially electrical conductors 74 are soldered or otherwise attached to contacts 72 which extend downwardly to make contact with and receive the male end of bulb 20 as is commonly known in the art. Swivel bulb holder 16 is then inserted into the backside (upper end) of central opening 52 on carrier 14 such that fingers 48 of carrier 14 receive and grip swivel bulb holder 16. As installed, antirotation pins 76 fit mateably between adjacent fingers 48 in slots 50 of carrier 14. Reflector 18 is then inserted into the lower end of carrier 14 with telescoping end 86 inserting mateably onto telescoping collar 62 of swivel bulb holder 16. Bulb 20 is then inserted into bulb socket 70, and lens 100 is then placed within lens holder/finger grip 24, and grip 24 is inserted onto reflector 18 and rotated such that locking ridges 108 lockingly engage locking ledges 84 of reflector 18.
Courtesy light 10 is normally positioned with reflector 18 in a fully inserted upwardly position such that finger grip 24 extends adjacent to and against headliner 30. In this upward inserted position (FIG. 4), courtesy light 10 gives off an unfocused flooded light pattern due to the fact that lighted bulb 20 is not at the focal point of the parabolically-shaped silvered reflective interior surface 82 of reflector 18.
When an operator wishes to focus the light from courtesy light 10, the operator grabs finger grip 24 beside ears 49 of flange 42 and pulls downwardly. This causes reflector 18 to slide downwardly on swivel bulb holder assembly 16 with end 86 of reflector 18 sliding telescopingly downwardly in telescoping collar 62 of swivel bulb holder 16. Reflector 18 slides downwardly until retention tangs 90 strike the lower end 94 of slot 64. In this extended position, the lens assembly 22 no longer lays interferingly adjacent to headliner 30, and reflector exterior surface 80 clears the interior cup-shaped face 46 of carrier 14 such that swivel bulb holder 16 and reflector 18 operate as a unit and may be tilted angularly laterally in any direction. Antirotation pins 76 located on the exterior surface 56 of swivel bulb holder 16 ride up and down within slots 50 between fingers 48 of carrier 14 as bulb holder 16 is pivoted thus preventing rotation and preventing wires 74 from being twistedly broken away from contacts 72.
When the operator is done using the spotlight, the user reverses the above procedure by centering the reflector 18 on carrier 14 and pushing upwardly, thus reinserting reflector 18 into swivel bulb holder 16 on telescoping tower 62. Retention tang 90 exerts sufficient lateral forces to combine with telescoping tower 62 in creating sufficient friction to hold reflector 18 in the uppermost position. Where increased friction is desired, surface imperfections can be added to the sliding surfaces of telescoping tower 62. Other devices commonly known in the art such as springs, detents and the like may be used for urging or holding reflector 18 to a fully inserted, upward position.
Thus, it is seen with the courtesy light of the present invention, a compact, efficient and cost effective lighting system is provided for a vehicle. The courtesy light provides both a focused and unfocused position, the focused position offering the ability to direct a focused spotlight in a desired direction. In the preferred embodiment, the bulb holder, reflector and carrier cooperate to provide a means for retaining the parts in an assembly, for extending a portion of the assembly, and for tilting a portion of the assembly such that the direction of the spotlight is controllable. In the preferred embodiment, the reflector provides a finger grip for pulling the reflector to an extended position and for limiting the angle of tilt.
It will become apparent to those skilled in the art that various modifications to the preferred embodiment can be made without departing from the spirit and scope thereof as defined by the appended claims. | A directional courtesy light for a vehicle includes a reflector which is moveable with respect to a bulb between a first position for providing unfocused light to a second position for providing focused light. In the second position, the reflector can be tilted to direct the focused light in a specific direction. The courtesy light may include a lens to further control the light. The reflector is mounted to a bulb holder for translation with respect to a bulb therein and the bulb holder is mounted to a carrier attached to the vehicle for pivoting the holder with respect to the carrier. The courtesy light components snap together and snaps in place in the vehicle for quick assembly and installation. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to power generation systems, and more particularly, to integrated gasification combined cycle systems.
BACKGROUND OF THE INVENTION
[0002] Integrated Gasification Combined Cycle (IGCC) systems are an economically attractive alternative to Natural Gas Combined Cycle systems (NGCC), as the systems can use more abundant fuel sources such as coal or biomass. IGCC systems gasify the low heating value fuel and produce a mixture comprising hydrogen and carbon monoxide. IGCC systems also have greater potential for efficiency improvement and a decrease in undesirable emissions compared to conventional coal-fired steam power plants.
[0003] IGCC power plants having oxygen-blown gasifiers to generate syngas require a relatively pure stream of oxygen gas. Production of this oxygen supply can be achieved by various means. A well-known technique is the cryogenic air separation method, in which the partial pressure differences between oxygen and other air constituents is exploited at a very low temperature and an elevated pressure to effect phase differences that are used to separate the air components. One disadvantage of using cryogenic systems for oxygen separation is that the compression stage requires significant power consumption. This reduces the plant output and net efficiency. Another air separation technology involves use of an Ion Transport Membrane (ITM) to remove oxygen from a high temperature, pressurized air stream. The resulting ITM system output streams are: (i) an oxygen-enriched gas supply delivered at a high temperature and ambient pressure, and (ii) an oxygen-depleted air supply delivered at a high temperature and a high pressure. A compressor and an air pre-heater are generally employed to provide the high temperature, high pressure air stream, adding significant equipment installation and operational cost for deployment of the ITM technology in IGCC systems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Features of the invention will be best understood when the following detailed description is read in conjunction with the accompanying drawings, wherein:
[0005] FIG. 1 is a schematic representation of a conventional Integrated Gasification Combined Cycle (IGCC) system;
[0006] FIG. 2 is a schematic representation of an IGCC system according to an embodiment of the invention; and
[0007] FIG. 3 is a schematic representation of an IGCC system according to another embodiment of the invention.
[0008] In accord with common practice, the various described device features are not drawn to scale, but are drawn to emphasize specific features relevant to the invention. Like reference characters denote like elements throughout the figures and text.
DETAILED DESCRIPTION OF THE INVENTION
[0009] IGCC systems employing the ITM air separation technology require two compressed air streams, one for the ITM air separation process and one for combustion of the fuel mixture in a gas combustor. The ITM process requires compressed air, generally in the range of 150-500 psia. The gas combustor of the IGCC gas turbine system requires compressed air, generally in the range of 120 psia-475 psia. It is now recognized as advantageous to generate two compressed air streams from a single compressor. This approach, using, for example, a compressor having multipressure outlets, reduces capital equipment costs as well as the operational costs of IGCC systems.
[0010] In the past, high pressure oxygen-depleted air produced by the ITM has been injected into the fuel mixture entering the combustor of the IGCC gas turbine system. This facilitates temperature control and NO x emission reduction. The pressure of the oxygen-depleted air relative to the compressed air supplied to the ITM ASU is reduced, due to frictional losses in the ITM system and in return piping. The pressure of the depleted air as it is injected into the fuel flow is lower than the pressure of compressed air that is routed directly from the gas turbine compressor to the combustor. In order to equalize the pressure of the two streams, the higher pressure stream of air from the compressor has been throttled, but this results in a loss of gas turbine efficiency.
[0011] By way of example, to avoid this loss in efficiency, a compressor having multipressure outlets may be integrated with a gas turbine system and a gasification system. Two compressed air streams can be generated, each at a different pressure. The integrated system eliminates the need for throttling of the gas turbine compressor outlet stream that is routed to the combustor. The lower pressure air stream output from the compressor is mixed with the oxygen-depleted air from the ITM prior to introduction to the combustor.
[0012] A conventional IGCC system 100 , shown in FIG. 1 , comprises a gasification system 1 , a gas turbine system 2 , a heat recovery steam generator (HRSG) 3 , and a steam turbine system 4 . The gasification system 1 includes a carbonaceous fuel 106 , such as a coal slurry, a gasifier 108 and an ITM Air Separation Unit (ASU) 110 . The gas turbine system 2 includes an air-compressor 130 , a throttle valve 132 , a combustor 134 , a gas turbine 136 , and an electrical generator 140 . The HRSG 3 comprises an economizer 172 , a steam drum 174 , an evaporator 176 , and a super heater 178 . The steam turbine system 4 includes a steam turbine 160 , an electrical generator 162 , a condenser 164 and a feed-water pump 166 .
[0013] In the gasification system 1 , oxygen 109 , e.g., in an oxygen-enriched gas supply, is provided to the gasifier 108 from the ITM ASU 110 . The ASU 110 produces oxygen-enriched gas 109 while operating in a temperature range of about 1300-1700° F. and with an oxygen partial pressure differential across an ion transport membrane of 160 to 285 psia. The compressor 130 in the gas turbine system 2 develops a stream of high pressure air 131 from ambient air 129 . A portion 111 of the high pressure air 131 is delivered to the pre-heater 112 , where the membrane operating temperature is achieved by heat exchange to extract sensible heat from one or more sources, including the hot gas 137 exiting the gas turbine 136 . In the gasifier 108 , the carbonaceous fuel 106 undergoes partial oxidation with the oxygen-enriched gas 109 to generate syngas 117 , which primarily comprises carbon monoxide and hydrogen, in a highly exothermic reaction, generally in the temperature range of about 2000° F.-2800° F. To meet air quality requirements, impurities such as sulfides, nitrous components, and dust particles are removed in the gas clean-up unit 120 . The syngas cooler 118 reduces the syngas temperature before introduction to the gas clean-up unit 120 . The cooler 118 may, as illustrated, use a portion 191 of feed-water 167 from the steam turbine system 4 to recover the syngas heat. The steam 192 produced from the feed-water 191 by the syngas cooler 118 can be sent to the steam chest 152 . The cleaned syngas 124 is mixed with steam 126 from the steam chest 152 to regulate the combustion process temperature, the internal combustor temperature profile, and the combustor exit temperature by varying the steam flow rate. The mixture 128 of steam 126 and syngas 124 flows through the fuel manifold 123 and into the combustor 134 of the gas turbine system 2 .
[0014] In the gas turbine system, the compressed air 131 produced by the compressor 130 is mixed with oxygen-depleted air 127 from the ITM ASU 110 , forming a high pressure air mixture 133 directed to the combustor 134 . Mixing with oxygen-depleted air 127 helps to control the flame temperature and reduce the formation of NO x in the combustor 134 . Due to frictional losses in the piping 107 and in the ITM ASU 110 , the pressure of the oxygen-depleted air 127 can be lower than the pressure of the air stream 131 coming directly from the compressor 130 . In order to prevent back-flow of oxygen-depleted air 127 , the stream of pressurized air 131 exiting the compressor 130 is throttled by a valve 132 , leading to a significant loss of gas turbine efficiency. The fuel mixture 128 entering the gas combustor 134 reacts with the high pressure air mixture 133 to produce a hot, pressurized gas 135 which powers gas turbine 136 and turns the rotor shaft 138 to drive both the compressor 130 and the electrical generator 140 . As a result of having been expanded in the turbine 136 , the temperature of the exhaust gas 135 from the turbine 136 is considerably lower than the temperature of the hot gas 135 entering the turbine 136 . The exhaust gas 135 , typically in the range of 850° F.-1100° F., is directed from the turbine 136 to the air pre-heater 112 of the gasification system 1 for transfer of sensible heat to the compressed air 111 supplied from the compressor 130 . The cooled gas 135 exiting the pre-heater 112 , still relatively hot (typically in the range of 750° F.-1000° F.), is sent to the HRSG 3 for further recovery of heat.
[0015] The HRSG 3 receives feed-water 167 sent from the steam turbine system 4 by the feed-water pump 166 . The feed-water 167 is heated with heat transferred from the relatively hot gas 135 exiting the gas turbine system 2 . The feed-water 167 first flows through the heat transfer tubes of the economizer 172 , where its temperature is raised to near the boiling point and is then directed to the steam drum 174 from which the water is circulated through the heat transfer tubes of the evaporator 176 where the heated feed-water 167 is converted into saturated steam 177 . The steam temperature is further elevated as it flows through the superheater 178 before entering the steam chest 152 . After flowing through the HRSG 3 , the cooled, expanded gas 135 is then discharged to atmosphere via a stack 156 .
[0016] In the steam turbine system 4 , steam 192 from the syngas cooler 118 of the gasification system 1 and steam 177 from the HRSG 3 are merged in the steam chest 152 . Steam 153 flows from the steam chest 152 to the steam turbine 160 and steam 126 flows from the steam chest 152 to the fuel supply line 125 for entry to the fuel manifold 123 with the cleaned syngas 124 as the fuel mixture 128 . Within the steam turbine 160 , the steam 153 expands, turning the rotor shaft 161 to drive the electrical generator 162 . In other designs, the steam turbine 160 may be coupled to the shaft 138 and generator 140 of the gas turbine system 2 . After passing through the turbine 160 the cooled, expanded steam 163 enters the condenser 164 for recycling as feed-water 167 . Fresh water 165 is supplied to the condenser 164 to compensate for water loss in the system 100 .
[0017] In the embodiment of FIG. 2 , an IGCC system 200 generates compressed air 211 for an ITM process and compressed air 231 for combustion from a compressor 230 having multipressure outlets 203 and 204 . The system 200 comprises a HRSG 3 , and a steam turbine system 4 as described with respect to FIG. 1 , a gasification system 5 , and a gas turbine system 6 .
[0018] The gasification system 5 includes a gasifier 208 which receives a fuel source 206 and an oxygen-enriched gas supply 209 from an ITM ASU 210 . Syngas 217 produced in the gasifier 208 is sent to a syngas cooler 218 to reduce the syngas temperature prior to clean-up of impurities, e.g., sulfur, nitrous oxide, and dust particles in a gas clean-up unit 220 . The cleaned syngas 224 is mixed with steam 126 from the steam chest 152 of the steam turbine system 4 to form a fuel mixture 228 which flows through the manifold 223 and passes through multiple ports 239 thereof, into the gas combustor 234 of the gas turbine system 2 . A supply of compressed air 211 delivered to an ASU 210 first passes through a syngas cooler 218 where it receives sufficient heat from hot syngas 217 to elevate the temperature as required for ITM oxygen separation. After being separated from the air 213 in the ASU 210 , oxygen-enriched gas 209 is delivered to a gasifier 208 and oxygen-depleted air 227 is delivered to an air chest 214 in the gas turbine system 6 . Although not shown, the syngas cooler 218 may include an additional heat exchanger to generate steam from a portion of the feed-water 167 .
[0019] Still referring to FIG. 2 , the compressor 230 in the gas turbine system 6 receives ambient air 229 to generate the source of high pressure air 211 exiting the first outlet 203 , generally in the range of 200-300 psia, and a source of low pressure air 231 exiting the second outlet 204 , having substantially same pressure as the oxygen-depleted air 227 , e.g., generally in the range of 160-285 psia. The high pressure stream of air 211 is extracted from a high pressure port 203 of the compressor 230 and is delivered to the syngas cooler 218 for heat exchange prior to entering the ITM ASU 210 for oxygen separation. The low pressure air stream 231 is routed to the air chest 214 where it is mixed with the oxygen-depleted air 227 traveling from the ASU 210 through a line 207 , generating an air mixture 233 . The air mixture 233 is delivered to the combustor 234 to react with the fuel mixture 228 to produce a hot, pressurized gas 235 which powers the gas turbine 236 , turning the rotor shaft 238 to drive both the compressor 230 and the electrical generator 240 . As a result of having been expanded in the turbine 236 , the temperature of the exhaust gas 237 exiting from the turbine 236 is considerably lower than the temperature of the hot gas 235 entering the turbine 236 . The exhaust gas 237 , typically in the range of 850° F.-1100° F., is directed to the HRSG 3 for recovery of heat. After flowing through the HRSG 3 , the cooled, expanded gas is discharged to the atmosphere via a stack 156 .
[0020] In the embodiment of FIG. 3 , an IGCC system 300 generates a supply of low pressure compressed air 331 for combustion from a supply of high pressure compressed air 311 with an air turbine 341 . The system 300 comprises a HRSG 3 , a steam turbine system 4 , a gasification system 5 , each as described with respect to FIG. 1 and FIG. 2 , and a gas turbine system 7 .
[0021] In the gas turbine system 7 , a compressor 330 generates a supply of high pressure air 311 , generally at 200-300 psia. The high pressure air 311 passes through the syngas cooler 218 in the gasification system 5 where it receives sufficient heat from hot syngas 217 to elevate the temperature as required for ITM oxygen separation in the ASU 210 . After being separated from the air 213 in the ASU 210 , oxygen-enriched gas 209 is delivered to the gasifier 208 in the gasification system 5 and oxygen-depleted air 227 is delivered to an air chest 314 in the gas turbine system 7 . Although not shown, the syngas cooler 218 may include an additional heat exchanger to generate steam from a portion of the feed-water 167 .
[0022] A portion 312 of the air 311 is delivered to the air turbine 341 to produce a stream of lower pressure air required for combustion in a combustor 334 . The high pressure air 312 expands in the air turbine 341 and turns a rotor shaft 338 coupled to drive both the compressor 330 and the electrical generator 340 . The air turbine 341 , in other designs, may be coupled to a separate rotor shaft and a separate generator. The air 331 exiting the air turbine 341 , generally at 160-285 psia, is routed to an air chest 314 .
[0023] Pressurized, oxygen-depleted air 227 from the ITM ASU 210 of the gasification system 5 mixes with the air 331 in the air chest 314 , providing an air mixture 333 . The air mixture 333 is delivered to the combustor 334 to react with the fuel mixture 228 to produce a hot, pressurized gas 335 which powers a gas turbine 336 , turning the rotor shaft 338 to drive both the compressor 330 and the electrical generator 340 . As a result of having been expanded in the turbine 336 , the temperature of the exhaust gas 337 exiting the turbine 336 is considerably lower than the temperature of the gas 335 entering the turbine 336 . The exhaust gas 337 exiting from the turbine 336 , typically in the range of 850° F.-1100° F., is directed to the HRSG 3 for recovery of heat. After flowing through the HRSG 3 , the cooled, expanded gas is then discharged to the atmosphere via a stack 156 .
[0024] While the preferred embodiments of the invention have been illustrated and described, it will be clear that the invention is not so limited. Numerous modifications, changes, variations, substitutions and equivalents will occur to those skilled in the art without departing from the spirit and scope of the present invention as described in the claims. | An integrated gasification combined cycle system. In one embodiment (FIG. 2 ) a system ( 200 ) includes an ion transport membrane air separation unit ( 210 ) for producing oxygen-enriched gas ( 209 ) and oxygen-depleted air ( 227 ), a gasification system ( 5 ) for generating syngas with the oxygen-enriched gas ( 209 ), a gas combustor ( 234 ) for reacting the syngas ( 224 ), and a subsystem configured to provide a first stream of air to the combustor ( 234 ) at a first pressure and to provide a second stream of air to the air separation unit ( 210 ) at a second pressure greater than the first pressure. The subsystem includes a compressor ( 230 ) having multi-pressure outlets ( 203, 204 ). | 8 |
TECHNICAL FIELD
[0001] The present invention relates generally to methods of making nonwoven fabrics, and more particularly to a method of manufacturing three-dimensional imaged nonwoven fabrics exhibiting flame-retardant characteristics while retaining aesthetic appeal, abrasion resistance, and fabric strength, these properties permitting use of the fabric in wall cover applications.
BACKGROUND OF THE INVESTIGATION
[0002] Significant quantities of textile fabric are employed in the construction of domestic and business furnishings, room dividers and acoustic panels. Manufactures of such textile fabrics are cognizant of the end-use of their materials in these constructions and have looked to improve the aesthetic qualities of the fabrics. Further, manufactures have also taken safety into consideration and looked to ways in which the textile fabric can be imparted with improved levels of flame retardancy.
[0003] The production of conventional textile fabrics is known to be a complex, multi-step process. The production of fabrics from staple fibers begins with the carding process where the fibers are opened and aligned into a feedstock known as sliver. Several strands of sliver are then drawn multiple times on drawing frames to further align the fibers, blend, improve uniformity as well as reduce the diameter of the sliver. The drawn sliver is then fed into a roving frame to produce roving by further reducing its diameter as well as imparting a slight false twist. The roving is then fed into the spinning frame where it is spun into yarn. The yarns are next placed onto a winder where they are transferred into larger packages. The yarn is then ready to be used to create a fabric.
[0004] For a woven fabric, the yarns are designated for specific use as warp or fill yarns. The fill yarn packages (which run in the cross direction and are known as picks) are taken straight to the loom for weaving. The warp yarns (which run on in the machine direction and are known as ends) must be further processed. The packages of warp yams are used to build a warp beam. Here the packages are placed onto a warper, which feeds multiple yam ends onto the beam in a parallel array. The warp beam yams are then run through a slasher where a water-soluble sizing is applied to the yams to stiffen them and improve abrasion resistance during the remainder of the weaving process. The yams are wound onto a loom beam as they exit the slasher, which is then mounted onto the back of the loom. Here the warp and fill yams are interwoven in a complex process to produce yardages of textile fabric.
[0005] In contrast, the production of nonwoven fabrics from staple fibers is known to be more efficient than traditional textile processes as the fabrics are produced directly from the carding process with a topical treatment of the nonwoven fabric readily being applied.
[0006] Nonwoven fabrics are suitable for use in a wide-variety of applications where the efficiency with which the fabrics can be manufactured provides a significant economic advantage for these fabrics versus traditional textiles. However, nonwoven fabrics have commonly been disadvantaged when fabric properties are compared, particularly in terms of surface abrasion, pilling and durability in multiple-use applications. Hydroentangled fabrics have been developed with improved properties, which are a result of the entanglement of the fibers or filaments in the fabric providing improved fabric integrity. Subsequent to entanglement, fabric durability can be further enhanced by the application of binder compositions and/or by thermal stabilization of the entangled fibrous matrix. However, the use of such means to obtain fabric durability comes at the cost of a stiffer and less appealing fabric.
[0007] The resulting textile or nonwoven fabric requires further processing before a suitable material is available for the construction of furnishings. Fabric constructed by either mechanism is essentially planar, having little in way of macroscopic asperities, let alone, a three-dimensional aesthetic quality. It has been necessary in the art to further treat the fabric with embossing techniques or complex foaming agents in order to impart the fabric with a multi-planar, aesthetic quality. In addition, depending upon whether or not the textile fabric was woven from costly flame-retardant staple fiber, a subsequent topical treatment containing an appropriate flame-retardant chemistry is required.
[0008] U.S. Pat. No. 3,485,706, to Evans, hereby incorporated by reference, discloses processes for effecting hydroentanglement of nonwoven fabrics. More recently, hydroentanglement techniques have been developed which impart images or patterns to the entangled fabric by effecting hydroentanglement on three-dimensional image transfer devices. Such three-dimensional image transfer devices are disclosed in U.S. Pat. No. 5,098,764, hereby incorporated by reference, with the use of such image transfer devices being desirable for providing a fabric with enhanced physical properties as well as an aesthetically pleasing appearance.
[0009] In preparing an imaged nonwoven material by the present invention for use in furnishings, the material has also been found to have inherent physical properties that render the material eminently suitable for wall coverings, window coverings, upholstery, and drapery applications, which are hereby referenced as co-pending applications.
[0010] Heretofore, attempts have been made to develop flame-retardant nonwoven fabrics exhibiting the necessary aesthetic and physical properties for durable consumer applications.
[0011] U.S. Pat. No. 4,320,163, to Schwartz, hereby incorporated by reference, discloses a three-dimensional ceiling board facing. This patent contemplates selectively coating a flame-retardant substrate with a print paste consisting of a foamable plastisol. By then exposing said-coated substrate to an elevated temperature, the plastisol increases variably in height under the influence of expanding thermoplastic microspheres, forming a roughened or “pebbled” surface.
[0012] A construct is disclosed in U.S. Pat. No. 4,830,897, to Seward, whereby an initial woven textile fabrics receives thereupon a heat dissipating metallic foil followed by a fibrous batt. The application of a subsequent mechanical needling procedure integrates the layers into a unitary construct.
[0013] There are a number of Japanese patents directed to nonwoven fabrics used as a component in wall covering fabrication. JP10168756 to Kawano, et al., utilizes a flame-retardant spunbond containing diguanidine phosphate laminated to a wallpaper backing. A wallpaper is disclosed in JP10131097 to Takeuchi, et al., whereby a nonowoven fabric is adhesively bonded to wallpaper backing, the adhesive containing a significant amount of a high specific gravity fireproofing agent. JP3251452 to Nakakawara, et al., discloses an alternate foam texturing process wherein a uniform foam layer is initially applied to a nonwoven substrate, then a solvent is printed thereon to reductively pattern the laminate. A final patent of interest is JP11335958 to Nanbae, et al., whereby a two layered nonwoven fabric, each layer consisting of less than 20% thermally fusible fibers is subjected to an embossing process.
[0014] As can be seen in the prior art, there has not been an effective melding of three-dimensional aesthetic qualities with flame-retardant properties in a fabric suitable for furnishing, window covering, and wall covering applications.
SUMMARY OF THE INVENTION
[0015] In accordance with the present invention, a method of making a nonwoven fabric embodying the present invention includes the steps of providing a precursor web comprising a fibrous matrix. While use of staple length fibers is typical, the fibrous matrix may comprise substantially continuous filaments and combinations thereof. In a particularly preferred form, a staple length fibrous matrix is carded and cross-lapped to form a precursor web. It is also preferred that the precursor web be subjected to pre-entangling on a foraminous forming surface prior to imaging and patterning.
[0016] The present method further contemplates the provision of a three-dimensional image transfer device having a movable imaging surface. In a typical configuration, the image transfer device may comprise a drum-like apparatus that is rotatable with respect to one or more hydroentangling manifolds.
[0017] The precursor web is advanced onto the imaging surface of the image transfer device so that the web moves together with the imaging surface. Hydroentanglement of the precursor web is effected to form an imaged and patterned fabric.
[0018] After hydroentanglement, the imaged and patterned fabric is treated with a flame-retardant binder composition. The treated and imaged nonwoven fabric may then be subjected to one or more variety of post-entanglement treatments. Such treatments include dyeing of the fabric by conventional textile dyeing methods.
[0019] A method of making the present durable nonwoven fabric comprises the steps of providing a precursor web that is subjected to hydroentangling. Fibrous precursor webs, in either homogeneous form or in a blend with other polymeric and/or natural fibers or webs, have been found to desirably yield soft hand and good fabric drapeability. The precursor web is formed into an imaged and patterned nonwoven fabric by hydroentanglement on a three-dimensional image transfer device. The image transfer device defines three-dimensional elements against which the precursor web is forced during hydroentangling, whereby the fibrous constituents of the web are imaged and patterned by movement into regions between the three-dimensional elements of the transfer device.
[0020] In the preferred form, the precursor web is hydroentangled on a foraminous surface prior to hydroentangling on the image transfer device. This pre-entangling of the precursor web acts to partially integrate the fibrous components of the web, but does not impart imaging and patterning as can be achieved through the use of the three-dimensional image transfer device.
[0021] After hydroentangling, the imaged and patterned nonwoven fabric is treated with a flame-retardant binder finish to lend further integrity to the fabric structure. The polymeric binder composition is selected to enhance flame-retardancy and durability characteristics of the fabric, while maintaining the desired softness and drapeability of the patterned and imaged fabric.
[0022] Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The invention will be more easily understood by a detailed explanation of the invention including drawings. Accordingly, drawings, which are particularly suited for explaining the invention, are attached herewith; however, it should be understood that such drawings are for explanation purposes only and are not necessarily to scale. The drawings are briefly described as follows:
[0024] [0024]FIG. 1 is a diagrammatic view of an apparatus for manufacturing a durable nonwoven fabric, embodying the principles of the present invention;
[0025] [0025]FIG. 2 is a diagrammatic view of an apparatus for the application of a flame-retardant finish onto a nonwoven fabric, embodying the principles of the present invention;
[0026] [0026]FIG. 3 is a fragmentary top plan view of a three-dimensional image transfer device of the type used for practicing the present invention, referred to as “stubs”;
[0027] [0027]FIG. 4 is a fragmentary top plan view of a three-dimensional image transfer device of the type used for practicing the present invention, referred to as “cross stubs”;
[0028] [0028]FIG. 5 is a photograph of the resultant material utilizing the image transfer device depicted in FIG. 3; and
[0029] [0029]FIG. 6 is a photograph of the resultant material utilizing the image transfer device depicted in FIG. 5.
DETAILED DESCRIPTION
[0030] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
[0031] In accordance with the present invention, a durable flame-retardant nonwoven fabric can be produced which can be employed in a wide variety of wall coverings described as applied to wallpaper. It should be understood, however, that upon suitable modification the invention can be adapted for use with cloth, wood veneer, plastic or combinations thereof, as exemplified by U.S. Pat. No. 3,663,269 to Fischer et al., hereby incorporated by reference, with the fabric exhibiting sufficient flame-retardancy, drapeability, abrasion resistance, strength, and tear resistance, with colorfastness to light. It has been difficult to develop nonwoven fabrics that achieve the desired hand, drape, and pill resistance that are inherent in woven fabrics.
[0032] In the case where nonwoven fabrics are produced using staple length fibers, the fabric typically has a degree of exposed surface fibers that will abrade or “pill” if not sufficiently entangled, and/or not treated with the appropriate polymer chemistries subsequent to hydroentanglement. The present invention provides a finished fabric that can be conveniently cut, sewn, and packaged for retail sale or utilized as a component in the fabrication of a more complex article. The cost associated with designing/weaving, fabric preparation, dyeing and finishing steps can be desirably reduced.
[0033] With reference to FIG. 1, therein is illustrated an apparatus for practicing the present method for forming a nonwoven fabric. The fabric is formed from a fibrous matrix preferably comprising staple length fibers, but it is within the purview of the present invention that different types of fibers, or fiber blends, can be employed. The fibrous matrix is preferably carded and cross-lapped to form a precursor web, designated P. In current embodiments, the precursor web comprises staple length polyester fibers, particularly polyester having an independent level of flame-retardancy.
[0034] [0034]FIG. 1 illustrates a hydroentangling apparatus for forming nonwoven fabrics in accordance with the present invention. The apparatus includes a foraminous forming surface in the form of belt 12 upon which the precursor web P is positioned for pre-entangling by entangling manifold 14 .
[0035] The entangling apparatus of FIG. 1 further includes an imaging and patterning drum 18 comprising a three-dimensional image transfer device for effecting imaging and patterning of the lightly entangled precursor web. The image transfer device includes a moveable imaging surface which moves relative to a plurality of entangling manifolds 22 which act in cooperation with three-dimensional elements defined by the imaging surface of the image transfer device to effect imaging and patterning of the fabric being formed.
[0036] Manufacture of a durable nonwoven fabric embodying the principles of the present invention is initiated by providing the precursor nonwoven web, preferably in the form of a 100% flame-retardant polyester or polyester blend. The use of the polyester desirably provides drape, which upon treatment with the specific binder formulation listed herein, results in a material with improved flame retardant properties at relatively low cost. During invention development, fibrous layers comprising flame-retardant polyester, standard polyester, p-aramid, n-aramid, melamine, and modacrylic fibers in blend ratios between about 100% by weight to 20% by weight minor component to 80% by weight major component were found effective. Such blending of the layers in the precursor web was also found to yield aesthetically pleasing color variations due to the differential absorption of dyes during the optional dyeing steps.
[0037] After formation and integration of the imaged and patterned nonwoven fabric, a flame-retardant binder finish is applied. The flame-retardant binder finish includes chemistries to render the treated fabric the ability to resist advanced thermal degradation and flame progression when exposed to combustion temperatures. A preferred chemistry employed herein is based on a halogenated derivative of a polyurethane backbone. Additional chemistries, including metallic salt extinguisants, can be used in conjunction with the halogenated polyurethane.
[0038] Upon application and curing of the flame-retardant binder finish on the imaged nonwoven fabric, the resulting fabric can be dyed by conventional textile dying methods. Various dyeing methods commonly known in the art are applicable including nip, pad, and jet, with the use of a jet apparatus and disperse dyes, as represented by U.S. Pat. Nos. 5,440,771 and 3,966,406, both hereby incorporated by reference, being most preferred.
EXAMPLES
Example 1
[0039] Using a forming apparatus as illustrated in FIG. 1, a nonwoven fabric was made in accordance with the present invention by providing a carded, randomized precursor fibrous batt comprising Type DPL 535 flame-retardant polyester fiber, 1.5 denier by 1.5 inch staple length, as obtained from Fiber Innovation Technology of North Carolina. The web had a basis weight of 2.8 ounces per square yard (plus or minus 7%).
[0040] Prior to patterning and imaging of the precursor web, the web was entangled by a series of entangling manifolds such as diagrammatically illustrated in FIG. 1. FIG. 1 illustrates disposition of precursor web P on a foraminous forming surface in the form of belt 12 , with the web acted upon by entangling manifolds 14 . In the present examples, each of the entangling manifolds included three each 120 micron orifices spaced at 42.3 per inch, with the manifolds successively operated at 3 strips each at 100, 300, 800 and 800 psi, at a line speed of 60 feet per minute.
[0041] The entangling apparatus of FIG. 1 further includes an imaging and patterning drum 18 comprising a three-dimensional image transfer device for effecting imaging and patterning of the now-entangled precursor web. The entangling apparatus includes a plurality of entangling manifolds 22 that act in cooperation with the three-dimensional image transfer device of drum 18 to effect patterning of the fabric. In the present example, the three entangling manifolds 22 were operated at 2800 psi, at a line speed which was the same as that used during pre-entanglement.
[0042] The three-dimensional image transfer device of drum 24 was configured as a so-called cross-slubs, as illustrated in FIG. 4.
[0043] Subsequent to patterned hydroentanglement, the fabric was dried on three consecutive steam cans at about 275° F., then received a substantially uniform application by dip and nip saturation of a flame-retardant binder composition at application station 40 in FIG. 2. The web was then directed through three consecutive steam cans 41 , operated at about 250° F.
[0044] In the present example, the pre-dye finish composition was applied at a line speed of 60 feet per minute, with a nip pressure of 32 pounds per square inch and percent wet pick up of approximately 125%.
[0045] The flame retardant finish formulation, by weight percent of bath, was as follows:
[0046] Water 90%
[0047] Vycar 460×46 [vinyl chloride acrylic co-polymer binder] 10%
[0048] As is registered to and can be obtained from B.F. Goodrich of Akron, Ohio
Example 2
[0049] A fabric as made in the manner described in EXAMPLE 1, whereby in the alternative the flame-retardant binder composition formulation, by weight percent of bath, was as follows:
Chemwet MQ-2 [wetting agent] 0.25% Defoam 525 [silicone anti-foam] 0.25% Pyron 6135 [halogenated polyurethane] 16.0% Chemonic TH-22 [thickener] 1.0%
[0050] The above being registered to and can be obtained from Chemonic Industries, of North Carolina.
[0051] Ammonium hydroxide, Aqueous 0.50%
[0052] As is registered to and can be obtained from B.F. Goodrich, of Ohio
[0053] Water 82.0%
Example 3
[0054] A fabric as made in the manner described in EXAMPLE 1, whereby in the alternative 20.0% Pyron 6139 was used in place of 16% Pyron 6135 and 78.0% water was used in place of 82.0% water.
[0055] The following benchmarks have been established in connection with nonwoven fabrics, which exhibit the desired combination of durability, softness, abrasion resistance, etc., for certain home use applications.
Vertical Flame Test NFPA-701 Fabric Strength/Elongation ASTM D5034 Absorbency-Capacity ASTM D1117 Elmendorf Tear ASTM D5734 Handle-o-meter ASTM D2923 Stiffness-Cantilever Bend ASTM D5732 Fabric Weight ASTM D3776 Martindale Abrasion Test ASTM D4970 Colorfastness To Crocking AATCC 8-1988
[0056] The test data in the attached tables shows that nonwoven fabrics approaching, meeting, or exceeding the various above-described benchmarks for fabric performance in general, and to commercially available products in specific, can be achieved with fabrics formed in accordance with the present invention. For many applications, fabrics having basis weights between about 2.0 ounces per square yard and 6.0 ounces per square yard are preferred, with fabrics having basis weights of about 2.5 ounces per square yard to about 3.5 ounces per square yard being most preferred. Fabrics formed in accordance with the present invention are flame-retardant, durable and drapeable and are suitable for decorative wall cover applications.
[0057] For upholstery and drapery applications, fabrics having basis weights between about 2.0 ounces per square yard and 10.0 ounces per square yard are preferred, with fabrics having basis weights of about 3.0 ounces per square yard to about 6.0 ounces per square yard being most preferred. Fabrics formed in accordance with the present invention are flame-retardant, durable and drapeable, and are not only suitable for covering or upholstering furniture such as chairs, couches, love seats, and the like, but also draperies or hanging fabric that prevents the admittance of any ambient light through the fabric.
[0058] For window covering applications, fabrics having basis weights between about 0.5 ounces per square yard and 6.0 ounces per square yard are preferred, with fabrics having basis weights of about 1.0 ounces per square yard to about 4.0 ounces per square yard being most preferred. Fabrics formed in accordance with the present invention are flame-retardant, durable and drapeable, and are suitable for window covering applications. Window coverings of the present invention are those coverings that allow for the admittance of ambient light through the fabric, such as sheets, shades, or blinds including, but not limited to cellular, vertical, roman, soft vertical, and soft horizontal.
[0059] From the foregoing, it will be observed that numerous modifications and variations can be affected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims. | A method of forming flame-retardant nonwoven fabrics by hydroentanglement includes providing a precursor web. The precursor web is subjected to hydroentanglement on a three-dimensional image transfer device to create a patterned and imaged fabric. Treatment with a flame-retardant binder enhances the integrity of the fabric, permitting the nonwoven to exhibit desired physical characteristics, including strength, durability, softness, and drapeability. The treated nonwoven may then be dyed by means applicable to conventional wovens. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
SEQUENCE LISTING OR PROGRAM
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of Invention
[0005] This invention relates to a portable hand-held pleating apparatus of the type adapted to create pleats within any fabric material.
[0006] 2. Prior Art
[0007] Inventors have discovered several industrial methods to create pleats within (1) draperies, such as U.S. Pat. Nos. 3,824,964 to Ryan (1974), 4,042,155 to Sprong (1977), and 4,157,775 to Soto (1979); (2) fabric materials, such as U.S. Pat. Nos. 2,906,441 to Liebeskind (1959), 4,917,277 to Hibbard (1990), and 5,114,056 to Frye (1992); (3) paper, such as U.S. Pat. No. 7,465,267 to Goodrich (2008); and (4) sheet-like material, such as U.S. Pat. No. 6,231,493 to Kato (2001). All of these inventions are large, bulky and meant mainly for industrial use. All of these differ greatly from the hand-held pleating apparatus described herein where the objective is a compact light-weight pleating apparatus for use by any individual anywhere.
[0008] Additionally, inventors have established methods for creating the appearance of pleats within draperies such as U.S. Pat. Nos. 3,191,665 to Rosenbaum (1965), 4,170,053 to Rosenzweig (1979), and 6,041,481 to Martin (2000). These inventions only create an illusion of pleated fabric material and do not provide a method for actually generating uniform pleats within any fabric.
[0009] No compact portable apparatuses are known for creating uniform pleats within fabric material. Additionally, there is no known mechanism to aid in the proper wearing of a traditional sari, dhoti, or long scarf where many meters of fabric must be pleated for the garment to be worn.
OBJECTS AND ADVANTAGES
[0010] The primary object of this invention is to provide a hand-held pleating apparatus that overcomes the above-mentioned problem associated with no known portable hand-held tool for creating pleats and which, nevertheless, provides a straightforward mechanism of creating uniform pleats of varying widths within any fabric material in a facile way. One form of fabric material is a sari, dhoti, sarong or long scarf where many meters of fabric material are required to be pleated to be worn.
[0011] Currently a sari, usually between 5.5 to 8 meters long, is worn with multiple uniform pleats being created manually and many times with aid from an additional person. Wearing a sari requires frequent practice and dexterity and there is no tool to assist this process. With this invention, fabric material such as a sari is manually tucked around the body whereby the hand-held pleating apparatus is then used to create uniform pleats of all required material, is removed from the fabric material, and the resulting pleats are then tucked and secured with aid from a safety pin or broach resulting in proper wearing of the garment.
[0012] More specifically, it is an object of this invention to provide a pleating apparatus construction, which includes a pleat creating attachment in the form of fingers adapted to facilitate insertion of fabric material of varying thickness to be woven through the pleating apparatus by the user. The two rigid support arms are designed such that the narrower arm can slide within the wider arm and lock at varying widths with the narrowest resulting pleat width exceeding the width of a single arm. Each arm of the pleating apparatus contains five to ten laterally spaced fingers that allow for insertion of any fabric material to be woven alternatively through opposing and adjacent fingers to form multiple uniform pleats. The pleating apparatus is portable, compact, and can be carried in a pocket or handbag. Embodiments of the pleating apparatus could exist as two sliding arms with fingers that fold for compact handling, pull apart through pressure fits and separate into three or four segments, or exist as a single solid unit in multiple increasing sizes.
SUMMARY
[0013] In accordance with the present invention a portable hand-held pleating apparatus comprises a central rigid body and two sets of opposing multiple finger elements adapted for weaving a selected section of any fabric material alternatively between and around adjacent and opposing fingers to create pleats within said fabric.
DRAWINGS
Figures
[0014] Other objects, features, and advantages of the present invention will become apparent from the following description and accompanying drawings, in which:
[0015] FIG. 1 is a fragmentary front elevational view of a fabric material having pleats formed therein by means of the hand-held pleating apparatus of the present invention.
[0016] FIG. 2 is a top plan view of the pleated fabric material shown in FIG. 1 .
[0017] FIG. 3 is a side elevational view of pleating apparatus with rigid member attachment mounted thereon and one embodiment of the locking mechanism demonstrated.
[0018] FIG. 4 is a top plan view of the pleating apparatus.
[0019] FIG. 5 is a side elevational view of the wider arm of the pleating apparatus.
[0020] FIG. 6 is a front elevational view of the wider arm of the pleating apparatus.
[0021] FIG. 7 is a top plan view of the wider arm of the pleating apparatus.
[0022] FIG. 8 is a side elevational view of the narrower arm of the pleating apparatus.
[0023] FIG. 9 is a front elevational view of the narrower arm of the pleating apparatus.
[0024] FIG. 10 is a top plan view of the narrower arm of the pleating apparatus.
[0025] FIG. 11 is a side elevational view of an alternate embodiment of the pleating apparatus.
[0026] FIG. 12 is a side elevational view of the pleating apparatus with an illustrative fabric shown.
[0027] FIG. 13 A-D is an illustrative diagram on wearing a sari (saree).
[0028] FIG. 14 is a side elevational view of an alternate embodiment of the pleating apparatus.
[0029] FIG. 15 is a top plan view of an alternate embodiment of the pleating apparatus.
DETAILED DESCRIPTION
Preferred Embodiment
[0030] Referring first to FIGS. 5 through 7 , the hand-held pleating apparatus of the present invention is preferably formed by a first of two rigid support arms, designated 20 , and includes five to ten fingers coated with an agglutinative substance taken from a group consisting essentially of but not limited to plastic, rubberized, and flocking, illustrated as eight fingers designated M ( 22 , 24 , 26 , 28 , 30 , 32 , 34 , 36 ). All fingers are arranged laterally and imbedded into arm 20 at a preferred 90 degree right angle. As shown in FIG. 6 , fingers M flare slightly outwardly in an upward direction. Likewise, as shown in FIG. 5 in one embodiment the outer fingers 22 and 36 can slope slightly rearwardly relative to the plane of the inner fingers 24 , 26 , 28 , 30 , 32 , 34 in an upward direction.
[0031] FIG. 6 illustrates how arm 20 is wider and curves up and over the said second arm, designated 21 , in FIG. 8 . This feature prevents the pleating apparatus from twisting resulting in asymmetrical pleats. Additionally, one preferred embodiment shown in FIGS. 5 to 7 , the arm has a slit or small clip, designated 40 , which can grip a corner of the fabric material to be pleated. FIGS. 5 and 7 also illustrate one preferred embodiment having an aperture within arm 20 applied to adjust the width of the pleating apparatus and thusly affecting the width of the resulting pleats. An alternative embodiment is illustrated in FIG. 11 where arm 20 is modified to having alternating a plurality of protrusions and aperatures designated 58 , 59 , 60 , 61 , 62 , 63 .
[0032] Referring to FIGS. 8 through 10 , the hand-held pleating apparatus of the present invention is preferably formed by a second rigid support arm, designated 21 , and includes five to ten fingers coated with a substance to increase tackiness taken from a group consisting essentially of but not limited to plastic, rubberize and flock, illustrated as eight fingers designated N ( 23 , 25 , 27 , 29 , 31 , 33 , 35 , 37 ). All fingers are arranged laterally and imbedded into arm 21 at a preferred 90 degree right angle. As shown in FIG. 9 , fingers N flare slightly outwardly in an upward direction. Likewise, as shown in FIG. 8 in one embodiment the outer fingers 23 and 37 can slope slightly rearwardly relative to the plane of the inner fingers 25 , 27 , 29 , 31 , 33 , 35 in an upward direction.
[0033] FIG. 9 illustrates how this arm, designated 21 , is slightly narrower than the first arm of the pleating apparatus and can fit within the curve of the wider arm 20 . This feature prevents the pleating apparatus from twisting resulting in asymmetrical pleats. Additionally, one preferred embodiment shown in FIGS. 8 to 10 , the arm has a slit or small clip designated 41 that can grip a corner of the fabric material to be pleated. FIGS. 8 and 10 also illustrate one preferred embodiment having a plurality of apertures parallel to the lateral edge of the arm designated 43 , 45 , 47 , 49 , 51 , 53 , 55 , 57 are applied to adjust the width of the pleating apparatus and thusly affecting the width of the resulting pleats. Additional embodiments may allow for rigid support arm 21 to slide within arm 20 and lock into place at varying widths.
[0034] Referring to FIGS. 6 and 9 , the cross-section width of a single finger M and N is not critical but a preferred embodiment is to be thin and any shape circular, square, and hexagonal. The nubbin at the end of each finger is optional and is applied to prevent snagging of fabric. The length of each finger is optional and all fingers M and N are preferred to be uniform in dimension. The resultant pleat penetrates into a certain length of fabric and is dependent upon the length of fingers M and N. The lateral spacing between fingers must be slightly larger than at least two times the thickness of the fabric to be pleated to provide for ease of insertion and weaving. In alternate embodiments the fingers M and N can fold, pull or separate making the apparatus conveniently portable.
[0035] FIGS. 3 and 4 show the assembled hand-held pleating apparatus where the narrower arm 21 is inserted within the wider arm 20 . Aligning apertures and inserting a releasable locking mechanism not limited to a screw with washer/nut, locking ring, velcro, and having protrusions with corresponding apertures adjust the width of the ensemble. Illustrated in FIGS. 3 and 4 is alignment of aperture 42 with 49 . Fabric material is woven alternately through opposing and adjacent fingers contained within rigid arms 20 and 21 .
[0036] The invention includes various alternative embodiments that may be constructed of a variety of the same or different materials. In one embodiment the hand-held pleating apparatus consists of a single molded plastic device in which the finger elements are integral with the central gripping section as illustrated in FIGS. 14 and 15 . In another embodiment the apparatus may consist of metal prongs embedded in a penetrable material such as a wood block or drilled material for pressure fitting the prongs. Still other embodiments may be constructed of multiple components with the finger elements releasably attached to the central gripping member. Alternatively, the finger elements may be attached by hinged devices to provide a foldable apparatus. In one-piece devices such as the single molded plastic, illustrated in FIGS. 14 and 15 , the pleating width is predetermined by the distance chosen for the center gripping section between the opposing finger-like elements. Any suitable distance may be chosen though generally for a sari the distance will be between about three to eight inches. In still other embodiments with multiple components, the distance between the opposing finger elements may be adjustable to allow for producing pleated fabric of different pleat widths depending on the setting of the adjustable center section. Additionally, other means for varying the distance between the respective finger elements may be employed as are readily available to those skilled in the art.
[0037] Obviously the apparatus of the invention may be fitted with or constructed from decorative elements and may be combined with other functional elements such as a lint brush or other surface attached to the central gripping portion. All of such optional devices are intended to be included within the scope of the invention.
[0038] FIG. 12 illustrates weaving a fabric material through the pleating apparatus to create accordion pleats. Select the desired pleat width for appearance purposes by sliding and locking rigid support arm 21 within arm 20 . Starting with one corner of the fabric to be woven, secure the end within clip 40 and weave through finger 22 . The lateral edge O of the fabric is maintained parallel to the plane of interlocked support arms 20 and 21 throughout the weaving process. The fabric is then wrapped around opposing finger 23 and woven between adjacent fingers 22 and 24 . The pleat created within the fabric penetrates the length of fingers 22 and 23 . The fabric is then wrapped around opposing finger 24 and woven between adjacent fingers 23 and 25 . The third pleat is created by wrapping the fabric around opposing finger 25 and weaving between adjacent fingers 24 and 26 . The fabric is then woven around finger 26 and back across to opposed and adjacent fingers 25 and 27 . Wrapping around finger 27 and weaving between opposed and adjacent fingers 26 and 28 illustrate continuation of the motion. As viewed from the front, the pleat thus formed has the appearance illustrated in FIG. 1 . As viewed from the top, the pleat thus formed has the appearance of FIG. 2 .
[0039] One form of fabric material for immediate application with the herein described pleating apparatus is a sari. The traditional steps to wearing a sari are illustrated in FIG. 13 . A sari is bought and sold as a one-size-fits-all garment and can vary from 5.5 to 8 meters in length. Saris are composed of fabric material ranging from cotton, silk, chiffon, georgette, and polyester blends. The wearer customizes the fit of the sari for her body by modifying the pleat width and number of pleats taken with the fabric material. FIG. 13A shows that a sari is worn by beginning to tuck edge O into the right side of a petticoat. The lower edge of the sari, P, should be grazing the floor. The sari is tucked around the waist into the petticoat. Next the entire length of the sari is wrapped around the body once coming back in front on the right side. FIG. 13B illustrates creating five to eight uniform pleats of equal width, approximately 5 inches wide, and gathering the pleats together ensuring that the lower edge of the pleats are uniform as well. The pleats may be secured with a safety pin to prevent the pleats from scattering. The pleats, along edge O, are then tucked within the petticoat. The herein described pleating apparatus will play an essential role in this step. Creating uniform pleats requires practice, dexterity and patience. The pleating apparatus will assist the user by quickly creating uniform pleats within the fabric material. Drape the remaining fabric around the hips once more from left to right and bring the material to the front holding the top edge O of the sari as shown in FIG. 13C . The width of the sari is then manually pleated and brought up and over the left shoulder so that the end Q of the sari falls to the back of the knees as shown in FIG. 13D . The herein described pleating apparatus will also play an essential role in this step by increasing the ease at which uniform accordion pleats will be created. The sari may be secured to the shoulder by a small safety pin or broach. | A portable hand-held pleating apparatus for fabric material consisting of two halves containing a total of ten to twenty fingers adapted to allow fabric material to be pleated into numerous uniform pleats, specifically accordion pleats. The pleating apparatus can hold fabric material to allow for pleating by any user weaving said material through said fingers and then being removed by a simple upward motion. The pleating apparatus can be adjusted to enable variable pleat widths in a facile way. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] This invention relates to a method and apparatus for attaching line to a unique fastener device. The inventive fastener has a unique line attachment portion which is constructed by shaping the end or ends of a shaft of metal or other material into a coiled or pigtail configuration. The pigtailed or coiled end-portion(s) may be provided with a springing action which would allow the coiled portion to be biased toward the shaft thereby frictionally engaging any line which has been attached to the fastener using the unique line attachment methods which will be described in detail below.
[0004] Previous line fastener devices typically required the user to have somewhat fine motor skills and manual dexterity in order to quickly and properly thread and knot the line to the fastener. Furthermore, in addition to requiring skill and dexterity, in order to properly thread and tie a line to prior fastener types, the user of the hook must use both hands to properly complete the tying procedure. In addition, the nature and function of most fastener devices require that any knot formed between the fastener and the line be permanent, thus necessitating a cutting of the line in order to subsequently remove the fastener therefrom. Besides the damage associated with cutting the line, these fastener devices may otherwise place undesirable wear and tear on line as a consequence of their use. Finally, many fasteners are known which may allow line to slip or loosen which may be undesirable as well as dangerous.
[0005] The present pigtail fastener overcomes all of the well known shortcomings described above. The present pigtail fastener is designed to allow a user to quickly and easily tie a line to the fastener in a manner which results in a secure, non-slip line attachment which may just as quickly and easily be untied with minimal damage to the line.
[0006] The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. §1.56(a) exists.
BRIEF SUMMARY OF THE INVENTION
[0007] The invention provides for a shaft, particularly a shaft of a metal implement such as a fishhook, tent stake, carabineer or other device which one may desire to have a line attached to. The shaft has an end which is shaped into a pigtail configuration. The unique pigtail fastener will typically include a tightly coiled end portion of the implement shaft which is configured so that at least one point from the coiled portion contacts or is immediately adjacent to the shaft.
[0008] The attachment device may allow for a space between the coiled portion and the shaft or the coiled portion and shaft may be pressed together as a result of the tension provided by the coiled portion. Where a space is provided for, the space may be uniformly narrow or may include a more constricted portion. The space provided must be sufficiently narrow so that when line is drawn into the space as described herein, the various loops of line will be tightened against one another as a result of the close proximity of the coiled portion and the shaft. In this later embodiment the coiled portion and the shaft may exhibit some springing characteristics but will preferably be fairly rigid relative to one another.
[0009] The attachment device is constructed so that the coiled portion exhibits a sufficient amount of tension toward the shaft so that when line is drawn between the coiled portion and the shaft the line will be pinched and securely held as a result of the tension provided. The present pigtail fastener allows the user to secure line to the attachment device without the need to form a permanent knot with the line. An example of an appropriate material from which to construct the pigtail fastener is spring steel.
[0010] In the various alternative embodiments of the pigtail fastener, the fastener may be further configured to include a lip or line guide to further assist a user in attaching a line to the fastener. In such an embodiment at least a section of the coiled portion is spaced slightly outward from the shaft, thereby providing an initial enlarged opening between the coiled portion and the shaft wherein the line will more readily be received into. The opening which receives the line then narrows to pinch the line in between the coiled portion and the shaft. The coiled portion may also be configured to include a line securement area which is which functions to lock line into a predetermined position.
[0011] In all of the embodiments of the present pigtail fastener, a line attachment device is provided for which allows a user to quickly affix a line to the fastener without the need to tie a permanent knot with the line. The pigtail fastener and the associated methods for affixing a line thereto also provide the user with the ability to secure a line to the attachment device with only limited manual dexterity and skill.
[0012] The present pigtail fastener is designed to facilitate a uniquely user friendly, highly effective method of affixing a line thereto simply by winding a length of line around the implement shaft and then pulling the wound line into the coiled portion in the manners described below.
[0013] The present attachment device may be utilized with other devices besides those mentioned above. For example, in the embodiment wherein the pigtail fastener is applied to a fishhook, other fishing related devices such as lures, weights, floats, etc, may be constructed to include the present attachment device. As a result, one or more devices could be attached to a given length of fishing line. On a larger scale, tent stakes, which may include pigtail fastener ends, could be secured to one end of a line while the other end is secured to a pigtail fastener or other device located on the tent surface. The pigtail fastener may be affixed to the ends of securement straps, ropes or cords to provide a strap which may be readily adjusted in length by securing an end pigtail fastener along the length of the strap. Many other devices may be incorporated or used in combination with the present pigtail fastener. Such devices will be apparent to one of ordinary skill in the art and are included within the scope of the present invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] A detailed description of the invention is hereafter described with specific reference being made to the drawings in which:
[0015] [0015]FIG. 1 is a perspective view of a fishhook embodiment of the present pigtail fastener;
[0016] [0016]FIG. 2 is a close up view of a preferred embodiment of the pigtail fastener;
[0017] FIGS. 3 - 7 show the various steps of a first inventive method for securing a line to the pigtail fastener shown in FIG. 2;
[0018] [0018]FIG. 8 is a perspective view of the preferred embodiment of the pigtail fastener and the line secured at the apex of the pigtail fastener;
[0019] [0019]FIG. 9 is a side view of the pigtail fastener shown in FIG. 8 showing the line in cross section;
[0020] [0020]FIG. 10 is a side view of an embodiment of the pigtail fastener wherein the coils of the coiled portion are spaced apart a predetermined distance and the coiled portion includes an outwardly raised coil lip to assist in receiving line into the coiled portion;
[0021] [0021]FIG. 11 is a perspective view of an embodiment of the pigtail fastener having a line securement area at the apex of the coiled portion;
[0022] [0022]FIG. 12 is a top down view of the embodiment of the pigtail fastener shown in FIG. 11;
[0023] FIGS. 13 - 16 show in a rear perspective, the various steps of a second inventive method for securing a line to an embodiment of the pigtail fastener having a raised coil lip to assist in receiving line into the coiled portion;
[0024] FIGS. 17 - 20 show in a front perspective, the various steps of the line securing method shown in FIGS. 13 - 16 ;
[0025] [0025]FIG. 21 shows a perspective view of an embodiment of the pigtail fastener which includes two coiled portions;
[0026] [0026]FIG. 22 shows the embodiment of the pigtail fastener shown in FIG. 22 with separate line ends secured to each coiled portion;
[0027] [0027]FIG. 23 shows a side view of an embodiment of the pigtail fastener wherein the shaft is bent or molded to include line diameter guides along a length of the shaft;
[0028] [0028]FIG. 24 shows a perspective view an embodiment of the pigtail fastener wherein the shaft has a flattened region, the flattened region including line diameter guides incorporated;
[0029] [0029]FIG. 25 shows a side view of an embodiment of the pigtail fastener wherein the coiled portion has a narrowed end region which as a reduced diameter relative to the remaining region of the coiled portion;
[0030] [0030]FIG. 26 shows a perspective view of the embodiment of the pigtailed fastener shown in FIG. 25;
[0031] [0031]FIG. 27 shows a top down view of an embodiment of the pigtail fastener wherein part of the coiled portion is shaped to form a line securement area at the apex of the coiled portion;
[0032] [0032]FIG. 28 shows an embodiment of the present invention wherein a cord length may be adjusted with pigtail fasteners located at each end of the cord, the pigtail fasteners being equipped with hooks having blunted ends;
[0033] [0033]FIG. 29 shows a close up view of an end of the cord and a respective pigtail fastener shown in FIG. 28; and
[0034] [0034]FIG. 30 shows a close up view of a clip used in conjunction with the embodiment shown in FIG. 28 wherein the clip may retain excess cord which may result from the length of the cord being shortened.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The inventive aspect of the present pigtail fastener focuses upon a unique coiled region located at the distal end of an elongate shaft which is constructed to pinch and secure a line therein. As shown in the various figures, the pigtail fastener is preferably a coiled shaft portion of a metal implement. However, it should be noted that an implement could be retrofitted to include a pigtail fastener. The pigtail fastener is preferably constructed from a metal such as spring steel which has been tightly coiled and is immediately proximate to the shaft.
[0036] [0036]FIG. 1 shows the present pigtail fastener as incorporated into a fishhook embodiment. The fishhook 10 has a hook or barbed portion 12 , a shaft 14 and a pigtail fastener 20 . As better seen in FIG. 2 the preferred embodiment of the pigtail fastener 20 includes a shaft 14 that has been configured into a coil 22 . The terms coil or coiled portion herein defines an extension of the shaft that has been shaped or molded or otherwise formed into an arc of at least 450 degrees. Preferably, the coil defines an arc which is 540 degrees or more. The arc which defines the coil may also be described as being roughly 1½ turns or loops of material extending from shaft 14 . A coil which is within the parameters described provides a biasing force throughout the length of the arc defined and ensures that the apex 28 of the fastener has sufficient tension force to biasedly trap the line therein.
[0037] A first method for attaching a line to the pigtail fastener may be broken up into a series of steps as shown in FIGS. 3 - 7 . FIG. 3 shows the initial step of winding a length of line 30 around the shaft 14 to form a plurality of loops 32 thereabout. FIG. 4 shows the second step which includes crossing the first end of the line 34 (the end of the line which may be secured to a fishing pole or other device) and the second end of the line 36 (the free end of the line) across each other relative to the loops 32 upon the shaft 14 . This step may be accomplished by simply flipping the orientation of the fishhook 180 degrees relative to the initial placement of the first end of the line 34 and the second end of the line 36 . Alternatively, if the fishhook is held in place by the user, the second end of the line 36 may be drawn toward the barb 12 and held against the fishhook by the user's thumb or finger(s) leaving the first end of the line 34 free to be drawn across the loops 32 .
[0038] The third step of the line attachment method is shown in FIG. 5 and includes pulling the first end of the line 34 along the shaft 14 toward the pigtail fastener 20 . A sufficient amount of tension must be placed upon the second end of the line 36 in order to prevent the line 30 from simply unwinding from the shaft 14 as the first end of the line 34 is pulled.
[0039] [0039]FIG. 6 shows the continued pulling of the first end of the line 34 toward the pigtail fastener 20 . FIG. 6 also illustrates the tendency of the loops 32 to begin to entangle or bunch-up as the first end of the line 34 is pulled.
[0040] In FIG. 7, it can be seen that loops 32 have become bound together as a result of crossing and pulling both ends of the line, as well as a result of the tension provided by coil 22 pushing against the line and shaft 14 . As a result of this tension or pinching action, and in combination with the constriction of loops 32 , the line 30 begins to form a somewhat entangled mass 38 that is secured within coil 22 or between coil 22 and shaft 14 .
[0041] In FIG. 8 the line is pulled taut in a direction toward coil 22 (away from shaft 14 ) and the line is continuously held tight by the pigtail fastener 20 . The pinching action between the coil 22 and the shaft 14 secures allows the line 32 to be held securely within the pigtail fastener 20 . Continued pulling upon the line 30 away from the shaft 14 will cause the entangled mass 38 to advance toward the apex 28 of the pigtail fastener 20 and to further tighten itself within the coil 22 .
[0042] It should be noted that because of the unique shape and construction of the present invention, in all embodiments of the pigtail fastener, line may be pinched within the coil itself or between the shaft and that part of the coil immediately adjacent to the shaft. Where it is stated that the line is located or pinched between the coil and shaft it should be understood that the line may just as easily be held directly within the confines of the coil.
[0043] [0043]FIG. 9 further shows a cross-sectional view of the entangled mass 38 and helps to illustrate the tightening effect upon the various loops 32 resulting from continued pulling on the line.
[0044] As previously stated, the pigtail fastener may be embodied in several different forms incorporating a wide range of features. FIG. 10 shows an embodiment of the pigtail fastener which includes a lip portion 24 of coil 22 which is bent outward and protrudes away from the shaft 14 . Lip portion 24 functions as a line guide which allows the coil 22 to readily catch and receive line which the user may desire to have pinched within the coil 22 but not necessarily against the shaft 14 . As seen and described above, the method of attaching the line to the fastener shown in FIGS. 13 - 20 , may employ a pigtail fastener having a lip portion such as is shown, or may employ alternative embodiments of the pigtail fastener such as the embodiment shown in FIG. 2.
[0045] It should also be noted that in an alternative embodiment the entire coil, as opposed to a lip portion alone, may be configured to be initially spaced away from the shaft to more readily catch and receive line between the coil and shaft.
[0046] The pigtail fastener shown in FIG. 10 also includes a coil 22 which is spaced away from the shaft 14 at apex 28 to define a gap 26 . The gap 26 has a width which may be determined based on the diameter of line which is to be used with the pigtail fastener. An entangled mass of relatively large diameter line, such as described in the line tying methods above may require a larger gap 26 to ensure that the line will be pinched and held within the coil 22 without damaging the line or distorting coil 22 . In a preferred embodiment where the pigtail fastener is constructed from spring steel, the coil 22 is intended to hold entangled mass of line 38 by providing a biasing force toward shaft 14 . An undesirably large diameter line inserted into the pigtail fastener as described herein could distort and damage coil 22 . By providing a gap 26 of appropriate width such potential damage and wear to the line and coil is avoided.
[0047] Turning now to FIGS. 13 - 20 , a second inventive tying method is shown which is best utilized with a pigtail fastener having a lip portion as described above. FIGS. 13 - 16 show the various steps of the tying method from a rear perspective view of the pigtail fastener, while FIGS. 17 - 20 show the corresponding steps in a front perspective view of the pigtail fastener.
[0048] Unlike the previously discussed tying method shown in FIGS. 3 - 7 , the present method does require that the line be threaded through the eyelet 42 of the coil 22 . However, because the present tying method is highly suitable for use with relatively large embodiments of the pigtail fastener such as could be used with tent stakes, boating cleats, carabineers, etc, the eyelet 42 will typically be of such size that the speed and ease of tying the line to the fastener will not be reduced.
[0049] As seen in FIGS. 13 and 17 the first step in tying a line 30 to the pigtail fastener 20 is to insert or thread the line 30 through the eyelet 42 of the coil 22 . Preferably the first end of the line 34 is inserted into the eyelet 42 from the shaft-side of the pigtail fastener to the coil side as shown.
[0050] [0050]FIGS. 14 and 18 show the second step in the present tying method. The first end of the line 34 is pulled through the eyelet 42 to provide a length of line sufficient to lie against a portion of the shaft 14 below the coil 22 . The user may secure the first end of the line 34 against the shaft 14 by any means. For example: if the user is holding the pigtail fastener by the shaft, the user could simply slide the first end of the line between his or her finger or thumb and press the line against the shaft. Once the first end of the line 34 is laid against the shaft 14 , the second end of the line 36 is wound about the shaft 14 and the first end of the line 34 one or more times, preferably two or three times, as best seen in FIGS. 15 and 19.
[0051] [0051]FIGS. 16 and 20 show the final step in the present tying method. After winding the second end of the line 36 about the shaft 14 and the first end of the line 34 as shown, the second end of the line 36 is drawn over the wound loops of line 44 and upward toward the coil 22 . The second end of the line 36 is inserted into the coil 22 by being pulled between the lip portion 24 and the coil 22 . The second end of the line 36 is drawn to its final position at the apex 28 of the coil 22 .
[0052] The line 30 is easily removed from the coil 22 by pulling the second end of the line 36 downward from the lip portion 24 . Once the second end of the line 36 is no longer retained by the coil 22 the line is simply unwound.
[0053] The tying method shown in FIGS. 13 - 20 and described above is especially appropriate when used with larger embodiments of the pigtail fastener which would utilize line such as relatively thick rope or cord.
[0054] The pigtail fastener and tying methods described above are an improvement over prior art fastener devices and tying methods. The embodiment disclosed provides a device which can be fastened to a line with relative ease requiring little manual dexterity or coordination from the user while still providing a strong secure connection between the fastener and line. In addition, the method of tying a line to the present pigtail fastener allows a user to tie a line to the fastener in just a few seconds regardless of external conditions.
[0055] In a further embodiment of the pigtail fastener as shown in FIGS. 11 and 12, a line securement area 40 is notched or otherwise formed at a predetermined point within the coil 22 . The line securement area provides a widened area which helps to secure the line 30 (seen only in FIG. 11). In the embodiment shown, the line securement area 40 corresponds with the apex 28 to ensure that the line 22 is guided in the direction opposite to the orientation of the shaft 14 . The line securement area 40 is sized appropriately to retain a predetermined diameter of line therein. The location of the line securement area 40 at the apex 28 also helps secure the line within the coil 22 by reventing the line 22 from slipping in either direction away from the line securement area 40 even when force is not applied to the line as described in the tying method described above. In FIG. 27, an alternative embodiment is shown where line securment area 40 is formed by shaping or molding coil 22 to a desired shape and diameter, rather than forming the line securment area by notching the coil as previously shown in FIGS. 11 and 12. An advantage of the embodiment shown in FIG. 27 is that possible damage to the line resulting from friction and compression is further minimized as a result of the relatively smooth surface and contour of the shaped line securement area 40 .
[0056] In the preferred embodiment where the coil is constructed from spring steel, the line may be slid into the line securement area by pulling the line upward toward the apex to momentarily distort the diameter of the line securement area so it may flexibly receive the line. The line may be removed from the line securement area by pulling on the line in a direction away from the line securement area with sufficient force to overcome the biasing force of the coil, thereby sliding the line out of the line securement area without damage to either the line or to the coil.
[0057] [0057]FIG. 21 shows an embodiment of the pigtail fastener wherein two coiled portions 46 , 48 have been joined along a common shaft 50 . Such an embodiment can be used to join multiple lines together. The embodiment shown can be used to connect an initial line 52 to a secondary line 54 as best shown by FIG. 22. The initial line 52 may be tied to the coiled portion 46 . The secondary line 54 is tied to the coiled portion 48 . The respective coiled portions and lines may be tied utilizing any tying method known but preferably with the methods described herein.
[0058] It should be understood by one of ordinary skill in the art that a multiple coiled portion embodiment of the pigtail fastener is not limited to only joining two coiled portions as described and shown herein. It may be desirable to attach numerous implements or lines to a common location. As such it is possible to join several coiled portions together around a common axial point or around a support ring or other device (not shown) either fixedly or moveably to provide for such common joining.
[0059] [0059]FIGS. 23 and 24 show in detail a line sizing feature which could be incorporated into nearly any embodiment of the present pigtail fastener. The line sizing feature includes one or more sizing areas 56 which correspond to the diameter of line which may or may not be properly used with the coiled portion (not shown) as described above. In FIG. 23 the sizing areas 56 are the result of bending the shaft 14 to the diameter desired. In the embodiment shown in FIG. 24 the shaft 14 has a flattened area 58 which includes the sizing areas 56 . The sizing areas 56 may be cut, etched or otherwise placed into the flattened area 58 . In the embodiment shown in FIG. 24 the sizing areas 56 , may also be utilized as line cutters or trimmers by simply applying downward pressure against a line as it rests against the sizing area 56 .
[0060] In certain applications of the present invention. It may be desirable to use relatively fine or small diameter line with the pigtail fastener. An example of such an application may include the fishhook embodiment such as shown in FIG. 1. In such an application, coil 22 may have insufficient flexibility to adequately secure the reduced diameter line to the pigtail fastener 10 because the coil may be fairly rigid as a consequence of having a uniform and relatively large diameter when compared to the line. In order to provide the coil with adequate flexibility and springiness the coil may be equipped with an end region which has been flattened or reduced in diameter as illustrated in the embodiment shown in FIGS. 25 - 26 .
[0061] In the embodiment shown in FIGS. 25 and 26 coil 22 is characterized has having a reduced diameter region and an initial region. Reduced diameter region 60 is characterized as being more flexible and more springy relative to initial region 62 . As a result of these characteristics, the reduced diameter region will be more prone to push against initial region 62 than a coil having a larger uniform diameter. In the preferred embodiment shown reduced diameter region 60 defines an arc of at least 400 degrees however, in alternative embodiments this value may vary greatly depending on the diameter of the line, the physical characteristics of line being used, the method of attaching the line to the fastener, etc. Alternatively, it may be possible to retain reduced diameter line in an embodiment of the pigtail fastener which has a coil or region of the coil, whether reduced in diameter or not, manufactured from a material which is more flexible and springy than either the shaft or the initial region.
[0062] In yet another embodiment of the present invention, an adjustable length securement strap, indicated generally at 70 , is formed by combining a line with two pigtailed fasteners as shown in FIGS. 28 and 29. The line is preferably a shock or bungee cord 72 having a predetermined length, and is equipped with two pigtail fasteners 74 , 76 . The length of the securement strap may be infinitely adjusted by attaching the pigtail fasteners at desired points along the length of the bungee cord. In the embodiment shown, the bungee cord 72 is attached to the pigtail fasteners 74 , 76 utilizing the method of attachment shown in FIGS. 13 - 20 and described above. However any method of attachment may be used. Excess cord 78 may be allowed to hang freely or is more preferably retained substantially parallel to bungee cord 72 by one or more retaining clips such as clip 80 shown in FIGS. 28 and 30.
[0063] As seen in FIGS. 28 and 29 the pigtail fasteners used in the securement strap embodiment preferably are equipped with a blunted hook 82 at the end of shaft 14 . By providing the pigtail fasteners 74 , 76 with blunted hooks 82 the securement strap may be hooked to a variety of surfaces without scratching or otherwise damaging such surfaces. In order to further ensure that the blunted hooks do not scratch or harm surfaces to which they are hooked, each blunted hook 82 may be equipped with a protective cap 84 . Protective cap 84 may be constructed out of any suitable material such as plastic, rubber, etc.
[0064] It should be understood that in the embodiment shown in FIGS. 28 - 30 any type of line, pigtail fasteners and clips can be utilized.
[0065] This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
[0066] While this invention may be embodied in many different forms, there are shown in the drawings and described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. | The present invention includes an inventive pigtail fastener and the associated method of attaching line thereto. The pigtail fastener is comprised of an elongated shaft at the proximal end of the device and a tightly coiled portion of the shaft at the distal end of the device. The pigtail fastener is constructed and arranged in such a manner so as to provide an amount of tension sufficient to pinch and thereby secure a quantity of line between the coiled portion and the shaft. The tension being provided as a result of the narrow confines of the space between the shaft and the coiled portion or alternatively as a result of the coiled portion being biased against a portion of the shaft. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO A SEQUENCE LISTING, ETC.
Not Applicable
BACKGROUND OF THE INVENTION
Large store systems typically are laid out in an enclosed rectangular space, with shelving for merchandise and aisles for shoppers arranged along lines parallel to the exterior walls of the store building. The shopper typically progresses through the store by going down one aisle and up the next. To go directly from the first aisle to the last requires that customer travel the length of the store.
After selecting all the items desired, the shopper must proceed to a checkout area, where all the parallel checkout lanes are located in a confined space. This area is often crowded with lines of other shoppers, not only making it difficult to proceed directly to a given checkout counter but also making it difficult for shoppers who are still shopping to get from one aisle to another. Both shoppers waiting in line to check out and those trying to get from one aisle to another can become frustrated with the congestion and develop a negative impression of their shopping experience.
The entrance and exit of such stores are typically singular in number and may or may not be near each other, but either arrangement can make parking a motor vehicle in the establishment's parking lot a frustrating experience for a shopper, who usually prefers to park as close to both as possible, especially in inclement weather. When the store entrance and exit are located next to each other, the parking spaces in their vicinity quickly get taken up, thus concentrating traffic in the precise area where shoppers are walking to and from their cars. Those shoppers who cannot find a parking space close to the entrance and exit do not enter or leave with a favorable impression of the store.
In some stores, the entrance and exit are separated by a good distance. In such an arrangement, there are no parking spaces that are convenient to both store entrance and store exit. Such an arrangement also can frustrate shoppers, who must walk some distance either just before or just after the shopping experience in the store. In such situations, the preferred parking spaces are midway between entrance and exit, which causes those areas in the parking lot to become most congested and dangerous for drivers and pedestrians alike.
A new arrangement for a store system not only would improve movement within the store and alleviate congestion at checkout areas but also would lessen parking congestion and reduce dangerous traffic patterns in the parking lot surrounding the store building.
SUMMARY OF THE INVENTION
In accordance with one embodiment of the present invention, a revolutionary store system is provided, whose floor plan is essentially circumscribed by a circle or a polygon of many sides. This system involves arranging the shelving units and aisles between them in a radial fashion on a floor structure, with a hub area at the center of the store facilitating movement among the various aisles. The checkout counters are spaced at regular intervals all around the outer edge of the store and are located just inside the outside wall of the store and oriented more or less at right angles to the aisles in the vicinity. With this configuration, lines of shoppers waiting to check out align themselves more or less around the periphery of the store, and in this way do not interfere with customers still shopping and moving around the end of one aisle to reach another. Entrances and exits to the store are arranged near all checkout stations, which are spaced at regular enough intervals to be convenient to every aisle but sufficiently far apart so that entrances are not blocked by lines of shoppers waiting to check out. The parking lot of the circular store is more or less annular in configuration, thus distributing parking spaces all around the structure. All parking space locations are equally convenient, since an entrance and exit will always be located nearby, a very desirable feature in inclement weather. In one embodiment, the entire store is mounted on a slowly revolving floor structure, much as is done with a revolving restaurant, thus providing a distinctive identifying feature to attract customers and also bringing every entrance to and exit from the store in even closer proximity to every parking space in the surrounding parking lot.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic top view of one embodiment of a radial store system.
FIG. 2 is a schematic top view of a staging area between shelving or display units, making them accessible for restocking from the side away from the customer aisles.
FIG. 3 is a schematic top view of a radial store system and its surrounding parking lot.
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of the present invention is represented in FIG. 1, which shows the schematic the floor plan of a store contained within a structure of more or less circular geometry. This arrangement can support the usual components of a typical supermarket, which will be used as an illustrative system. In order to contain 50,000 gross square feet of floor space, which is taken here as the size of a representative store, the diameter of the circular store would have to be about 250 feet, which is not an unreasonable size.
The shelving 1 on which the merchandise is displayed is arranged substantially radially on the substantially circular floor 2 , but it does not extend fully to the center or to the outer edge of the store, to allow room around the periphery for checkout lines and counters 3 and to allow room in the center hub area 4 of the store for movement between aisles and other uses, as will be described below. Because of the nature of the geometry of a circle, the radially aligned shelving will be wider at the outer end 5 than at the inner end 6 . This variation in shelving depth can be turned to advantage by shelving large, heavy, and bulky items like packages of disposable diapers, bags of dog food, and bottled drinks on or near the deeper portion 7 of a shelf and small, light, and compact items like spices, teas, and cans of tuna fish on or near the shallower portion 8 of a shelf. If the edges of the shelves 9 are strictly radial, then also the aisles 10 would necessarily be wider at the outer end 11 and narrower at the inner end 12 . The minimum practical aisle width desired by the store would fix the distance between the shelving on either side of an aisle, or the shelving layout could deviate from the true radial to allow more flexibility in shelf and aisle width.
The width of the aisles will also depend upon how far from the center of the store the shelving terminates. This in turn will depend on the store's desired use of the hub area 4 and the surrounding annular area 13 . One possible option is to leave the center hub completely open, so that shoppers can move virtually unimpeded from the inner end of any aisle to the inner end of any to any other aisle in the store. Another possible use of the hub area is as a kind of “public square,” where shoppers can stop to talk with friends and acquaintances that they encounter as they move from one aisle to another across the “square.” Alternately, a coffee shop with tables and chairs can be located at the center of the “square” to promote and encourage such encounters and thus enhance the shopping experience. Still another option is for the store to locate its service and information desk 14 at the center of the store, making it equally convenient to shoppers approaching from any aisle. The store could also locate the manager's office or a security office in an elevated space atop the hub. From such a vantage point, every aisle would be in clear view, and the entire store could be watched with ease, allowing quick detection of wet or dirty floors, fallen merchandise, or shoplifting activity. Other uses of the hub area are also possible.
Not all aisles in a typical supermarket are flanked by plain shelving, of course. Produce, dairy, frozen food, and other special climate sections must necessarily be accommodated. As suggested in FIG. 2, this can be done within a radial arrangement of shelves as easily as it is done in a conventional rectilinear store layout. Where the presence of attendants or clerks is required, as it is in meat, fish, delicatessen, and like sections, the aisle 15 between two shelving units can be closed off at its ends (except for an access door 16 to the interior space) and fitted with tables 17 and other elevated surfaces used for the preparation and packaging of the items sold in that section. Instead of shelving units enclosing the work area, it is surrounded with display cases 18 , which are specialized for meats, cheeses, vegetables, prepared foods, and the like and can be accessed by clerks or restocked from within the work area. A floor opening within the work area 15 provides access 19 to the stockroom located in the lower level.
As shown in FIG. 1, checkout counters 3 in the circular store are located at regular intervals all around the outer edge 20 of the substantially circular store (practical construction considerations would likely dictate a polygonal periphery), so that wherever a shopper finished up selecting items there would be a checkout counter nearby. The checkout counters would be aligned more or less at right angles to the shelving 1 in the area and more or less parallel to the tangent to the nearby outer edge of the store 20 , and spaced sufficiently far apart so that lines of customers waiting at the checkout counters would form more or less parallel to the outer edge 20 of the store. In this way, shoppers waiting in a line to check out would not block the passage of other shoppers moving from aisle to aisle around the outer end 5 of a shelving unit. Extensive use of automated self-service checkout stations and anti-theft systems would allow for the plurality of peripheral checkout stations to remain open even during periods of slow business.
Between each pair of checkout counters is a set of entrance and exit doors 21 . As indicated in FIG. 3, with this arrangement no shopper would ever have to walk very far from a parking space 22 in the annular parking lot 23 surrounding a circular store. Indeed, a shopper driving up to the store could see through its encircling plate glass windows and doors where the various sections of the store were located and could park accordingly. After shopping, customers can walk around the store's periphery until reaching an exit that is near their car in the parking lot. This will be especially convenient when it is raining or the weather is otherwise inclement.
The only parts of the all-surrounding parking lot that are not available for parking are the shopping basket return areas 24 and the entrance 25 to a ramp driveway leading down into a tunnel through which vehicles gain access to the basement space beneath the store. This access serves delivery, maintenance, and other vehicles needing to gain access to the area housing heating, air conditioning, refrigerating, and other mechanical equipment, as well as a loading dock serving the stockroom for the store.
The stockroom would typically be more or less congruent with the store level, and the stock could be arranged more or less in the same relative positions as the items are on the shelves in the store above. With the stock so logically arranged, it could be readily located even by inexperienced stockroom clerks, and it could be delivered as needed to the store level for replenishing items taken off the shelves by shoppers. The method of delivery of stock from the basement stockroom to the store level could take many forms, including one akin to baggage handling at major airports. Boxes of goods in the basement storage area could be loaded onto conveyor belts that would carry them up to a carrousel rotating around the hub 4 of the store. Such an embodiment would necessarily occupy space in the hub area not then available for other uses, but this carrousel space could also be enclosed within a circular wall, leaving the annular space 13 between it and the inner ends 6 of the shelves available for the variety of uses described above.
Other means of transporting fresh stock from the stockroom to the store level are also possible. Among these can be the use of conveyor belts within the openings 19 to carry stock from the lower level stockroom up into staging areas concealed behind back-to-back shelving segments, as in FIG. 2, thus allowing shelves or display cases to be restocked from behind. This has the advantage of not obstructing aisles with boxes, stock carts, and stock persons. The geometry of such stock staging areas could be adjusted by having the shelf line deviate slightly from the true radial, which could also have the added advantage of making aisles of constant width from inner to outer ends.
As an additional means of distinguishing such a radially arranged store from establishments laid out according to the prior art, and also as a means of providing further conveniences of use for customers, the radial store system can be mounted on a revolving platform, much like a revolving restaurant. The state of the art of revolving restaurants located atop tall buildings is such that the mechanical equipment needed to support and rotate such a structure are well within existing capabilities. If the store makes as much as one complete revolution every fifteen minutes, then the periphery of the floor structure will be moving relative to the ground at approximately one-half mile per hour, which is well within the experience of ordinary people in mounting such devices as chair lifts, amusement park rides, escalators, and moving sidewalks.
With a revolving store, every entrance and exit would at some time in the cycle be conveniently located for every lane 26 in the parking lot. This would tend to distribute parked cars uniformly around the parking lot, thus reducing frustration among drivers looking for a good parking space and minimizing traffic congestion at any single location.
The mechanical- and stockroom need not revolve with the shopping level of a revolving store. Stock transferred from a stationary lower level to a rotating upper one would not present insurmountable technical obstacles, given the state of the art of baggage handling in airports.
In an alternate embodiment, only a portion of the entire floor of the store revolves. The hub area, for example, could remain stationary, for the purposes of the café, service, office, surveillance, or other use to which it was put. Alternately or also, an outer ring area of the store, on which the checkout counters are located, could be stationary, allowing for a conventional ground mounted structural framing system capable of supporting a long-span roof and a curtain wall encircling the building. In this way the revolving floor system would not bear any of the dead load of the enclosing structure. Whether enclosed in such a ground-based structure or carrying the structure on the revolving platform, any transitions between stationary and revolving portions of the floor of the store can be based on the technology used in revolving restaurants. | This invention relates to store systems laid out with shelves and aisles radiating, out from a central hub area. The arrangement of the shelves and aisles allows a customer to enter and begin shopping at any one of a plurality of places around the periphery of the store and to move easily and directly from any aisle to any other aisle through the central hub area. The arrangement lends itself to having unobstructive checkout lines located at a variety of locations around the periphery of the store. The layout extends to the parking lot, whose lanes are also laid out in a radial fashion. The store layout lends itself to being mounted on a revolving structure, which serves to showcase all sections of the store, attract customers to the store, make every parking space equally convenient and appealing to shoppers, and reduce congestion and danger in the parking lot. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of pending International patent application PCT/EP2006/006167 filed on Jun. 27, 2006 which designates the United States and claims priority from Italian patent application UD2005A000111 filed on Jul. 1, 2005 and Italian patent application UD2006A000028 filed Feb. 8, 2006, the content of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] 1. Technical Field
[0003] This invention relates to a smart card as a universal electronic card, whose characteristics correspond to the precharacterizing part of the main claim.
[0004] 2. Use
[0005] The use is substantially directed to the electronic service of data treatment, to the sector of telecommunications and to everything connected with electronic data processing.
BACKGROUND OF THE INVENTION
Background Art
[0006] At present smart cards or intelligent cards are known and in use which can carry out a very great number of functions, such as for identification, for payments and collections, as well as for a plurality of other services.
[0007] At present the USB keys are known which can carry out many functions physically connecting at least to one of the electronic apparatus.
EXAMPLES OF PRIOR ART
[0008] US2003/019942 A1 (BLOSSOM GEORGE W.)
[0009] US2004/203352 A1 (HALL ERIC S ET ALL)
[0010] GB2407189 A (VODAFONE GROUP PLC)
[0011] EP1326196 A (NAGNEK CORPORATION)
PROBLEMS AND DRAWBACKS OF THE PRIOR ART
[0012] The problems and drawbacks of the prior art refer substantially to a limitation of functions.
[0013] In other words the current cards have a limited use for certain services, other services being satisfied by other devices generally of different form.
SUMMARY OF THE INVENTION
Scope of the invention
[0014] The scope of the invention is to solve the above-mentioned problems and drawbacks and supply an intelligent card able to carry out a large amount of functions and able to assure identity check of the user.
SOLUTION OF THE PROBLEM AND IDENTIFICATION OF THE FEATURES OF THE INVENTION
[0015] The problem is solved with the characteristics of the main claim.
[0016] The sub-claims represent advantageous preferred solutions that supply a better performance and secure personalization.
ADVANTAGES
[0017] In this way there is the advantage of having a card able to carry out a large variety of functions at present unavailable.
[0018] In particular it can also be noticed that such a card can be associated to the performance of the common USB key.
[0019] Moreover, if one loses the card or it is thieved for example, a third person cannot use it because only the fingerprint of the true owner can authorize the use.
BRIEF DESCRIPTION OF THE DRAWINGS
Description of the Preferred Solution
[0020] For a better understanding the invention is described in preferred solution with the help of attached figures, wherein:
[0021] FIG. 1 —it represents the plan-view of a card in one possible form with the respective uncovered hardware inserts.
[0022] FIG. 2 —it represents the sectional view of the card of FIG. 1 .
[0023] FIG. 3 —it represents the view of the card of FIG. 1 with partial removal of the coating plastic covering.
[0024] FIG. 4 —it represents the view of a block diagram of the card in a first form of solution.
[0025] FIG. 5 —it represents the view of a block diagram of the card in a second form of solution.
[0026] FIG. 6 —it represents the view of a block diagram of the card in a third form of solution that substantially integrates the first two.
[0027] FIG. 7 —it represents the schematic view of an operative-functional block diagram.
[0028] FIG. 1 A—it represents the block schematic top-view of the most secure smart card having the fingerprint reader module.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Detailed description of the invention in relation to the first solutions is represented in FIGS. 1 to 7 .
[0030] According to the figures it can be observed that the invention refers to a universal electronic card, or universal smart card with telecommunication means.
[0031] In the figures it can be seen that the new card looks like a very common credit card (sizes about mm 850×550×30), the reduced sizes of internal components will allow to produce a plasticized card and aesthetically able to be customized with prints of logos, images or other.
[0032] The same has a support basis in integrated-circuit plastic material ( 1 ) with the respective components such as microprocessor or CPU ( 2 ), memory ( 6 ), transmission module ( 3 ), battery ( 4 ), eventual LCD screen ( 8 ) and ON/OFF button (b).
[0033] The card thereinafter for simplicity called card or smart card, will be able to receive, memorize and transfer multiple data and information simply approaching the electronic apparatus equipped with Wi-Fi and bluetooth technology or higher or similar communication standard. Therefore, it can communicate with different apparatus in commerce as computers, portable pc, palmtops, cell phones, satellitaire connectors, electronic apparatus in general etc.
[0034] Moreover the card using the radio communication with no need of cables or USB connection can be employed for many uses or applications.
[0035] Card model bluetooth FIG. 4
[0036] It consist of:
Bluetooth module ( 31 ); microcontroller ( 7 ) that includes CPU processor ( 2 ) and static memory ( 6 ); battery ( 4 ); antenna ( 5 ); Optional LCD screen ( 8 ).
[0042] Therefore, it consists of five elements: Bluetooth module that allows the communication with all the apparatus equipped with Bluetooth technology; a microcontroller ( 7 ) that allows to store new data and to transmit those which it already contains and a battery ( 4 ) allowing the card to work, which contains an antenna ( 5 ). Moreover, it will be possible to add an LCD screen ( 8 ) for data reading.
[0043] In this way the transmission and data reception are ensured, as well as every gender of apparatus equipped with Bluetooth technology, without the need of using any connecting cable of easy use and available to all.
[0044] Card model Wi-Fi FIG. 5
[0045] It is composed of:
Wi-Fi module with transceiver and Baseband ( 3 ); CPU ( 2 ); memory ( 6 ); battery ( 4 ); antenna ( 5 ); Optional LCD screen ( 8 ).
[0052] Consequently, this solution is composed of six elements: Wi-Fi module ( 3 ) that allows the communication with all the apparatus equipped with Wi-Fi technology; a CPU ( 2 ) that allows to store new data and to transmit those which it already contains, a memory ( 6 ) that can vary on the basis of the needs and a battery ( 4 ) allowing the card to work, which contains an antenna ( 5 ). Moreover, it will be possible to add a LCD screen ( 8 ) for data reading.
[0053] The transmission and data reception between the card and every gender of apparatus equipped with Wi-Fi technology occurs without the need of using any connecting cable of easy use and available to all.
[0054] Card model bluetooth/Wi-Fi FIG. 6
[0055] The card consists of:
Bluetooth module ( 31 ); Wi-Fi module ( 32 ); processor ( 2 ) and memory ( 6 ) (if necessary integrated in microcontroller ( 7 ), as from FIG. 4 ); battery ( 4 ); antenna ( 5 ); Optional LCD screen ( 8 ).
[0062] This solution consists of five elements: Wi-Fi module ( 32 ), Bluetooth module ( 21 ) that allows the communication with all the apparatus equipped with Wi-Fi and Bluetooth technology; a CPU ( 2 ) that allows to store new data and to transmit those which it already contains, a memory ( 6 ) and a battery ( 4 ) allowing the card to work, which contains an antenna ( 5 ). Moreover, it will be possible to add a LCD screen for data reading.
[0063] Transmission and data reception between the card and every gender of apparatus equipped with Bluetooth technology and Wi-Fi technology, without the need of using any connecting cable.
[0064] Furthermore, this solution allows to make the converter function between the two communication systems.
[0065] Uses and Applications
[0066] Uses and applications can be quite different e.g. not limitative:
[0067] Business cards,
[0068] Presentation of firms and services, price-list,
[0069] Data base,
[0070] Index-book,
[0071] Music, games and music patterns,
[0072] Pre-paid cards, electronic record accounting device, electronic payment instruments in general,
[0073] Service card, authentication cards, subscriptions,
[0074] Identification cards, sanitary data, personal data, attendance cards,
[0075] Lunch cards, payment ticket, bus subscription, railways, and similar,
[0076] Automatic delivery machines, copy machines,
[0077] Control and communication with electronic apparatus,
[0078] Telematic service supply, access to PC or other,
[0079] Message, file, data, fingerprint and digital signature coding
[0080] Telematic and e.commerce recognition, protected internet services,
[0081] Info mobility, motorways pass, parking card, Tele-pass,
[0082] access-control, Memorisation and data transfer, images, photos, etc.
[0083] Example of Use
[0084] The USC card can be utilized as a safe and secure electronic business card.
[0085] As regards aesthetic features, it will be possible to personalize it with the logo of the Company, and thanks to the incorporated chip inside it we can find the data of the company itself:
heading; addresses of various seats; telephone numbers; number of Fax; e-mail; Website; VAT number; description of services that the company offers.
[0094] The data can be used immediately from the receiving apparatus as the card is approached with the advantage that the data are not introduced in the receiving apparatus with the keyboard.
[0095] When the card is approached to a cellular phone endowed with Bluetooth technology, the telephone number of the Company will appear on the display of the phone and the call can be immediately sent; moreover we can immediately memorize the telephone number in the index-book of the cell-phone.
[0096] Instead, when the card is approached to a computer endowed with Bluetooth technology, the system will show the data contained in the card requiring the reading and the memorisation of the private-data in the different archives (private-data for invoicing program, mail for outlook, lists and/or services offered by the company, other).
[0097] One can also use the card for inserting the destination in the GPS apparatus equipped with Bluetooth technology without having to digit the address, for inserting possible stops as hotels, restaurants or for organizing a pre-defined route.
[0098] A particularity is that for the description of services that the Company offers it will be possible to memorize it in several languages and to show it according to the needs of the user.
[0099] The card can also be utilized by the financial bank sector, by the public administration, in the field of transports and by the enterprises as a substitutive product of current Card or Smart card in general.
[0100] Technical Specifications
[0101] Therefore, the main object of the card (cordless) is that of communicating with different types of devices, for instance cellular telephones, palmtops, computer, notebook, or other electronic devices, etc.
[0102] On the basis of the data amount to transmit/receive, the devices will utilize a different technology (Wireless or Bluetooth).
[0103] When the data flux to transmit/receive is low (as in the cell-phones and palmtops), the used technology will be the Bluetooth (or new similar communication standard or higher), while for the transfer/reception of a larger data amount (as in the file exchange between computers), the indicated standard will be the Wi-Fi (Wireless Fidelity—IEEE 802.11b or new similar or higher communication standard, example 802.11a/b/i/g).
[0104] Naturally it will be possible to realise different product typologies with different prices, the product will vary according to the type of connected device and data amount to transmit
[0105] General Structure
[0106] Bluetooth Card
[0107] The Card consists of a Bluetooth module managed by a central processor, connected to a memory.
[0108] The Bluetooth module will allow the cordless communication between the card and the other devices.
[0109] In the memory the data of clients are stored.
[0110] In the most advantageous solution a single microcontroller component ( 7 ) is used for integrating the processor ( 2 ) and the memory ( 6 ). The power supply by means of the battery ( 4 ) is realised during the transmission of data and after having pressed the key for receiving or transmitting (b).
[0111] For some specific use e.g. the pre-paid card or the debit/credit cards, in the card one can add a device to LCD liquid crystals ( 8 ) to verify the data e.g. the residual credit.
[0112] Components
[0113] Examples of components with sizes are described in the enclosed table 01 :
[0114] Table 01
[0115] Dimension component Ref.
[0116] National Instruments LMX9820
[0117] Nluetooth Module port serial 10.1×14.0×1.9 mm 31
[0118] Motorola MC68HC908QT1 5.50×8.20×2.05 mm CPU 2
[0119] Varta battery CR2032 Diameter 20.0 mm 4
[0120] WIFI card
[0121] In case of the use of the Wi-Fi standard instead of the Bluetooth, it will be possible to transfer a larger amount of data and consequently the card can be used to support larger files as audio, video, etc. communicating especially with computers by means of the WLAN cordless net (Local Wireless Network area).
[0122] As the need for memory of each user is variable depending on the naturalness of stored files, in this case one can choose to add a card memory (SD Card, compact Flash).
[0123] The most significant physical change is the implementation of the Wi-Fi module instead of the Bluetooth module.
[0124] In table 02 the necessary components for the IEEE standard radio 802.11b are described as well as a suggestion of memory, with their prices and sizes.
[0125] For some specific use e.g. the pre-paid card or the debit/credit cards, in the card one can add a device to LCD liquid crystals ( 8 ) to verify the data e.g. the residual credit.
[0126] Components
[0127] Table 02
[0128] Dimension component Ref.
[0129] Texas TNETW1100B-MAC/Baseband 12.0×12.0 mm 32
[0130] Maxim MAX2822-802.11b Transceiver 7.0×7.0 mm 32
[0131] Memory SD Card 64 MB 32.0×24.0 mm 6
[0132] The cost and sizes of the components are similar to the previous ones, except for the memory of high capacity that should be added according to the need of the user.
[0133] The processor and the battery could be replaced with similar components with higher speed and capacity respectively.
[0134] Card Bluetooth/WIFI
[0135] In order to reach all the possible wireless devices, the hybrid card is the indicated one, using the Wi-Fi and Bluetooth modules together.
[0136] Its general structure is illustrated in FIG. 6 . Obviously the cost and the power consumption are equivalent to the whole components previously described.
[0137] Description of the Working System
[0138] The description of the working of the card is illustrated in the block diagram of FIG. 7 . Start happens when the energy source is connected to the circuit.
[0139] At this time the card is off, thus it does not consume energy.
[0140] The activation can be carried out by the programming key or the transmission key.
[0141] When the programming key is activated, the card comes into programming modality, which means that the received data are stored in the memory.
[0142] When the reception and the storing are completed, the card will stop going OFF automatically.
[0143] Otherwise when one presses the transmission key, the data contained in the memory start to be transmitted.
[0144] At the end of the transmission the card goes OFF for saving energy and returns to the initial state.
[0145] Advanced Personal Solution
[0146] As regards now the most advanced solution referred to in FIG. 1A , it must be observed that the most advanced solution refers to the same universal electronic card, or universal smart card but it has a personalization module ( 80 ). The card has the preferred format of 80×55×3 mm, in metallic or plastic material, that includes the following elements:
[0147] ( 10 ) Module Wi-Fi: It realizes the cordless connection by means of standard IEEE 802.11b.
[0148] ( 20 ) Bluetooth module: It realizes the cordless connection by means of standard Bluetooth.
[0149] ( 30 ) USB pin connector: It connects the device to the USB gate, allowing the reload of the battery and the data exchange.
[0150] ( 40 ) Rechargeable battery: Its autonomy is monitored, indicating to the user the recharge moment.
[0151] ( 50 ) Internal memory: it records the settings of the user.
[0152] ( 60 ) Microprocessor: it is responsible for managing all the peripherals.
[0153] ( 70 ) Card flash memory connector: It allows the use of an external storage, adapting the capacity to the needs (till 2 GB).
[0154] ( 80 ) Fingerprint module: it detects the fingerprint of the user, checking its authenticity, and it also acts as navigator of the menu.
[0155] ( 90 ) LCD display: It allows the view of the menu and of operations in progress.
[0156] Obviously the same is integrated with antenna.
[0157] In the user interface obviously together with the components ( 80 , 90 ) there will also be a series of key caps with control functions, and/or input.
[0158] The novelty and originality is the association of all the said elements and in particular: addition of the fingerprint reader ( 80 ) for checking, identification and access permission to all the functions.
[0159] In the figures it can be seen that the new card looks like a very common credit card, the reduced sizes of internal components will allow to produce a plasticized card and aesthetically able to be customized with prints of logos, images or other.
[0160] The same has a support basis in integrated-circuit plastic material with the said components such as microprocessor or CPU, memory, transmission module, battery, LCD screen and ON/OFF button.
[0161] As the previous one, the smart card can receive, memorize and transfer multiple data and information simply approaching the electronic apparatus equipped with bluetooth technology and Wi-Fi or higher or similar communication standard, therefore similarly it can communicate with different apparatus in commerce as computers, laptops, palmtops, mobile or cell phones, satellite devices, and other electronic apparatus.
[0162] In a similar way, using the radio communication with no need of cables or USB connection, the card can be employed for different uses or applications, but having the USB connection it can also can carry out similar functions of any USB.
[0163] The working of the personal fingerprint reader card is illustrated in the block diagram of FIG. 1A .
[0164] Start happens when the energy source is connected to the circuit.
[0165] At this time the card is off, thus it does not consume energy.
[0166] The activation can be carried out through a programming key or by transmission key.
[0167] When the programming key is activated, the card comes into programming modality, which means that the received data are stored in the memory.
[0168] When the reception and the storing are completed, the card will stop automatically.
[0169] Otherwise when one presses the transmission key, the data contained in the memory start to be transmitted.
[0170] At the end of the transmission the card goes OFF for saving energy and returns to the initial state. | Universal electronic card, of the smart card or intelligent card type, similar to a form of plastic card, with integrated circuital elements which are integrated in the thickness of the stratified card and with in it at least one microchip, structured integrally with: i—a microprocessor associated to a memory; ii—an interchangeable flat battery within the card-thickness able to power-supply the said microprocessor and the said memory; iii—at least one data transmission device connected to the said microprocessor and/or to the said memory; iv—one fingerprint reader device integrated in it and to the processor system to read the imprint of the user, checking its authenticity before allowing the access at its various functions. | 6 |
This is a divisional of U.S. patent aplication Ser. No. 08/661,437, filed Jun. 11, 1996, now U.S. Pat. No. 5,801,453.
TECHNICAL FIELD
This invention relates to gas generating and/or propellant compounds, and more particularly to the preparation of energetic compounds such as ammonium dinitramide in substantially spherical form.
BACKGROUND OF THE INVENTION
Ammonium dinitramide is a non-chlorine containing oxidizer useful in rocket propellant and gas generating devices such as air bag inflators. For example, in U.S. Pat. No. 5,324,075, ammonium dinitramide is described as a preferred gas generator for air bags. In U.S. Pat. No. 5,316,749, a process for producing stable ammonium dinitramide salts is disclosed for use in a smokeless rocket propellant. While ammonium dinitramide compounds have useful functional properties, they suffer from physical limitations which renders their use impractical.
For example, ammonium dinitramide ("ADN") crystallizes naturally in the form of needles or plates which are not readily amendable to subsequent processing. For use as a propellant or gas generator, it is necessary to use solid particulate ammonium dinitramide of controlled size to obtain predictable results. Particles in the range of about 10 to 1,000 microns are considered useful. However, efforts to control crystallization or to physically process solid ADN to obtain a selected particle size have been unsuccessful, as solid ADN cannot be ground or subject to other physical processing due to its low stability.
One method for producing particulate ammonium dinitramide is to melt ADN in a non-solvent fluid, vigorously stirring to disburse the ADN, then rapidly cooling the mixture before the melted ADN coagulates.
This process is not suitable because melted ADN can decompose violently if it remains melted for too long a period of time. Also, to minimize the potential damage if decomposition were to occur, the total amount of ADN in the fluid must be minimized. While possibly adequate for producing laboratory size quantities of ADN, such a method cannot be used to produce the large quantities of material necessary, i.e. for use as a propellant.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a substantially spherical solid energetic compound such as ADN of controlled size, with a limited melt processing time.
It is a further object to provide a continuous process for producing substantially spherical energetic compounds such as ADN in large scale processing equipment, to produce large quantities of useful material.
These and other objects of the present invention are achieved by a method of producing a substantially spherical energetic compound comprising:
providing a solid energetic compound;
feeding the solid energetic compound in a continuous controlled rate to a heating means;
melting the energetic compound in the heating means;
providing an agitated cooling fluid maintained at a temperature below the temperature of solidification of the energetic compound; and
adding the melted energetic compound in a rate comparable to the controlled feed rate, into the agitated cooling fluid such that the energetic compound forms droplets after entering the fluid, which solidify in substantially spherical form.
The agitated cooling fluid is stirred in an amount sufficient to disperse the liquid energetic compound into droplets of the desired size. A stream of the cooling fluid is fed to a filtration device to remove the spherical energetic compound, with return of the fluid for continued use in the process.
Utilizing the inventive method, the amount of the energetic compound, such as ADN, which is melted at any one time is minimized, and the energetic compound is in a melted state for a very short time. This minimizes the potential for decomposition. Further the energetic compound is readily separated from the cooling fluid by filtration, and subsequently washed, dried and stored for use. By controlling the fluid temperature, rate of addition, and degree of agitation, it is possible to obtain a fairly consistent particle size in the preferred range of from about 10 to about 1,000 microns.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the process of the present invention.
FIG. 2 is an alternative process according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
This invention, while hereinafter described in relation to ammonium dinitramide, is also applicable to other energetic compounds which are those that are potentially unstable and difficult to process into substantially spherical form. For example, 1, 3, 3-Trinitroazetidine is an energetic compound which may be processed in accordance with the present invention, and the invention is not limited to ADN.
The terms "spherical" and "substantially spherical" are used interchangeably refer to the formation of grains or particles of the energetic compound, as typically classified by percent of passage through a particular mesh screen. As is well known, such particles are classified by the amount of material which passes through a screen having a known open area. A perfect sphere shape is not necessary but rather a substantially spherical particle size.
The energetic compound, such as ammonium dinitramide, may be obtained through known processes. For example, U.S. Pat. No. 3,428,667 to Hamill et al. describes the reaction of an ionic nitronium salt with a primary organic nitramine to form N, N-dinitramine having the general formula R- N (NO 2 ) 2 ! n where n is 1-2 and r is a monovalent or divalent organic radical.
Referring to FIG. 1, a solid energetic compound 1 in powdered form, is placed in a fed hopper 2 which is connected to a conveyor 3. The conveyor may be of any suitable type such as a screw conveyor, belt conveyor, etc. for transporting solid materials at a controlled rate. Controllability is necessary to assure delivery of a selected quantity of the compound at a selected rate.
A heating device is located at a discharge end of the conveyor. The heating device shown is a double pipe heat exchanger 4, having two co-axial pipes, an inner pipe 5 through which the compound is processed, and an outer pipe 6, defining a space 7 between the pipes, to form a jacket, through which a heating fluid 8 is passed, heating the contents of the inner pipe. The heat exchanger 4 is operated at a temperature sufficient to melt the delivered quantity of the energetic compound. The energetic compound enters the pipe as a solid powder and then is melted within the inner pipe. Once melted, the compound flows to an outlet end 10 of the inner pipe. For example, ADN melts at a temperature of about 1000° C., and it is preferred to maintain the heating device at from about 100° C. to about 110° C. so as to avoid overheating of the energetic compound material as it passes through the heating device.
The heating device is preferably placed at a downward angle towards the outlet end to allow gravity flow of the melted energetic compound, from the entrance end to the exit end 10 of the heat exchanger. The exit end is positioned over an opening 12 above a cooling tank 13.
The cooling tank 13 contains a non-solvent fluid 14 subject to mixing by an agitator 15. The cooling fluid is maintained at a temperature below the melt temperature of the energetic compound so that near immediate solidification occurs when the melted energetic compound enters the cooling fluid. Preferably, the cooling fluid is maintained at a temperature of about 20° C. when processing ADN.
After the energetic compound has entered the cooling fluid, and before solidification, it is dispersed into substantially spherical droplets of the desired size by the agitator, which shears and distributes the droplets prior to solidification. The agitation also maintains the separation of the droplets until solidification occurs.
A portion of the cooling fluid is then fed by a pump 18 to a filtration device 19 where the solid substantially spherical energetic compound 20 is captured. The cooling fluid is then fed by a pump 21 back to the cooling tank.
Preferably a second filtration device 22 is available so as to allow continuous operation in the production of the spherical particles, with the second filtration device brought on line to allow washing, drying and removal of the solid spherical energetic compound from the first filtration device 19.
Utilizing the present invention, a continuous process for producing an energetic compound, particularly ADN is achieved. Further, the amount of energetic compound subject to melting is minimized, as is the time during which the compound is in liquid form.
Referring to FIG. 2, an alternative embodiment of the present invention is shown.
In this method, the energetic compound 23 is placed in a carrier fluid 24 contained in a tank 25. The carrier fluid is preferably identical to the non-solvent cooling fluid. Thus, the energetic compound is mixed with the carrier fluid to produce a slurry within which the solid energetic compound is dispersed. Preferably, the liquid is continuously stirred by an agitator 26 to maintain the dispersion of the energetic compound within the liquid. Then, a portion of the slurry is fed to a heat exchanger 27, such as the double pipe heat exchanger described above. As previously, a heating fluid 28 heats the mixture in the inner pipe above the melting point of the energetic compound, causing the compound to melt. Since the energetic compound is not soluble in the carrier fluid, it separates into a second liquid phase 29. The two phase fluid can then be fed from an outlet end 29 in a controlled liquid rate to a stirred cooling tank 31 where the energetic compound phase is dispersed by the agitator into droplets 32 which solidify in a cooling fluid 33, again producing a substantially spherical particle product. As described above, a stream of cooling fluid containing the solid spherical particles can be fed to a filtration device for recovery of the solid energetic compound and return of the cooling fluid to the process.
Various non-solvent fluids can be used to contain the solid energetic compound, such as mineral oil, fluorocarbon oil, silicone oil, etc. Any non-solvent fluid of sufficiently high boiling point may be used, "non-solvent" meaning that the energetic compound will not react with the non-solvent at or above its melting temperature.
Utilizing the present invention, energetic compounds, such as ADN, can be obtained in sizes of from about 10 to about 1,000 microns with the range dependent on the cooling fluid temperature, rate of addition, agitation speed, drop location, etc. For example, if fed closer to the agitator, more physical disruption of the droplet size is likely, reducing the particle size. On the other hand, less agitation combined with a higher rate of addition, will allow larger droplets to form and solidify without breakage. For use as a propellant, it is preferred that ADN be produced with a particle size below about 425 micron, preferably with the majority of particles in the 10-200 micron range.
EXAMPLE
One kilogram of powdered ADN containing 0.1 to 2% of stabilizer (hexamine) was placed in a feed hopper. A Teflon coated screw feed conveyor was used to deliver 100 grams per hour of ADN to a double tube heat exchanger. Hot water circulated through the heat exchanger at a temperature of about 100° C., allowing the ADN to melt. A 1.5 millimeter capillary end was fitted to the exit end of the heat exchanger, to promote droplet formation. The heat exchanger was placed at an angle of about 20° C. to promote gravity flow of the melted ADN to the exit end. A cooling tank containing mineral oil was positioned below the exit end, the tank having cooling coils for maintaining the temperature of the tank at about 20° C. A baffle was provided adjacent to the capillary end to maintain a constant stirred environment adjacent to the droplet entry point. The agitator was of variable speed to adjust the degree of agitation in the baffle area, having an adjustment range of 2,000-4,000 rpm. The agitator was set at a speed of about 3,400 rpm, the agitator having a diameter of 13/4". Using the apparatus described, of the solids produced 65% was the diameter of choice, substantially spherical ADN having a particle size of less than 425 microns.
The experiment was repeated with a 21/2 diameter agitator, set at 2,300 rpm, to generate the same tip speed for shearing the droplets and the same amount of substantially spherical ADN, having a particle size of less than 425 microns was obtained.
Using the present invention, a continuous process for producing spherical energetic compounds such as ammonium dinitramide is provided, allowing production of large quantities of spherical material with a minimum melt quantity maintained at the melting temperature for a minimum time. The parameters for adjusting particle size are easily controlled, i.e. by increasing agitation speed to adjust the processing for producing different size products, with total recycle of the cooling fluid. Thus, material and equipment costs are minimized while safety is enhanced using the process of the invention. | A method for producing substantially spherical energetic compounds such as ammonium dinitramide (ADN) which minimizes the time during which the ADN is melted involves providing solid ADN, feeding the ADN at a controlled continuous rate to a heating means, melting the ADN, the melted ADN being fed continuously to a non-solvent cooling fluid maintained at a temperature below the temperature of solidification of the ADN, the cooling fluid agitated in a manner which promotes the formation of droplets of controlled size which solidify in the cooling fluid to produce substantially spherical ammonium dinitramide in a particle size corresponding to the droplet size. APPARATUS FOR PREPARING SPHERICAL ENERGETIC COMPOUNDS | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is related to French Patent Application Ser. No. 10 60625 filed Dec. 16, 2010 and takes priority therefrom.
FIELD OF THE INVENTION
The present invention relates to a device for applying epilation wax, allowing for a precise application from the standpoint of thickness as well as dimensions of the application.
BACKGROUND OF THE INVENTION
Wax dispensers which are constituted of a head mounted on a flexible container are known. The container ensures the containment of the wax and the head ensures the distribution of the wax thus stored in the container.
The wax generally used is adapted to be made more fluid by a temperature increase. This fluidity is limited so as to enable an application of the wax in a thin layer, but without running, while also ensuring a sufficient wettability vis-à-vis the hairs and/or fine hairs to be removed. When cooling, the wax imprisons the hairs. The wax is adapted not to adhere to the skin. The wax thus deposited then only has to be removed by traction to ensure the hairs imprisoned within the wax are pulled out.
To facilitate this pulling operation, it is possible to lay a small strip of mesh or non-woven material on the laid out wax, immediately after application, when the latter is still sticky and has a “tacking” power, so the small strip is also imprisoned in the cooling wax matrix, becoming affixed to this small strip. A traction on the strip facilitates grasping and makes pulling out the wax/hairs assembly including the hairs possible.
Waxes are presently of a different nature, based on synthesis polymers. More and more, these new waxes are based on natural, sugar-based polymers. The advantages of these waxes are numerous. First, these waxes use sugars which are known to originate from agricultural products and are thus renewable. In addition, these products are naturally biodegradable, and require no recycling. The cleaning is carried out with water, and therefore without necessitating any sort of solvent and without generating any waste.
However, there still remains the problem of the wax application and practicality of this operation. This wax application and removal operation must indeed be simple, fast, precise, without requiring skill, and, most importantly, with no risk to the user. Another constraint is cleaning the device since the device must be reusable after a first use in a simple and fast manner without requiring complex cleaning or disassembly.
The device according to the invention not only targets the above objections, but, also targets other industrial objectives: simplicity of fabrication to limit costs, increased affordability of the device, a limited number of pieces to facilitate its assembly and its automation on a conveyor, and durable and reliable functioning, without blockages.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 : a perspective view of the device according to the present invention, in an application state;
FIG. 2 : an exploded, perspective view of the device according to the present invention;
FIG. 3 : a top, perspective view, providing details of the application head;
FIG. 4 : a bottom, perspective view, providing details of the application head;
FIG. 5 : a detailed view of the movable applicator;
FIG. 6 : a cross-sectional detailed view of the head screwed on the body of the device.
DETAILED DESCRIPTION OF THE INVENTION
The device according to the present invention will now be described in detail according to a particular, non-limiting embodiment; this description being made with reference to the annexed drawings.
FIG. 1 shows a complete device for applying wax according to the invention. This device comprises a body 10 and an applicator head 12 attached to said body. This body 10 is made in a known manner out of plastic. The shape is obtained by extrusion blow molding, for example. A preform or parison made of plastic material is placed in a mold and the body is formed by molding, possibly by blowing air under pressure. In this case, the body 10 has a substantially cylindrical shape with upper 14 and lower 16 ends, FIG. 2 . This hollow body 10 comprises an open neck 18 placing the inner volume of the body 10 out in the open, this open neck being provided with an outer screw thread 20 , as shown in FIG. 2 , located on a shoulder 22 , constituting the upper end 14 of the body 10 .
The lower end 16 remains opened after being removed from the mold so as to enable the filling of the device according to the invention with the product to be dispensed, epilation wax in the present case. The filling is carried out with a covering of said open neck 18 with a conventional cap, the applicator head 12 being made separately and mounted immediately before use, in lieu of the cap.
Once the body has been filled, this body 10 is sealed at the lower end 16 by flattening followed by border to border welding, constituting a segment substantially equal to the diameter of the body before flattening, measured perpendicular to this end. The body 10 can have a different shape than that illustrated, the drawn shape having, however, satisfactory design and ergonomics while providing a suitable capacity. The nature of the plastic material used is compatible with the wax which it contains so that, on the one hand, the wax does not adhere and, on the other hand, it allows the wax to be placed at the temperature of use, as explained later.
The head 12 is composed of two pieces, shown in detail in FIGS. 3 , 4 , and 5 , namely a base 26 and a movable applicator 28 . The base 26 in FIGS. 3 and 4 comprises a peripheral envelope 30 with an open housing 32 having a substantially rectangular shape. The housing 32 thus comprises two longitudinal lateral surfaces 34 - 1 and 34 - 2 and two transverse lateral surfaces 36 - 1 and 36 - 2 and a bottom 38 . The longitudinal lateral surfaces 34 - 1 and 34 - 2 each have an arc-shaped upper border with a large radius of curvature, whereas the two transverse lateral surfaces 36 - 1 and 36 - 2 have rectilinear borders.
Generally, the edge 37 of these 4 borders is rounded and the angles also have a curvature in order to avoid any harm to the skin during application as will be explained later. Each of the longitudinal lateral surfaces 34 - 1 and 34 - 2 is provided, perpendicular to the apex of the arch, with a groove 40 - 1 and 40 - 2 ( FIG. 6 ), open toward the free border of each of the surfaces and closed toward the inside of the housing, the shape being semi-circular. Each groove 40 - 1 and 40 - 2 bears, immediately perpendicular to the border of said longitudinal lateral surface 34 - 1 and 34 - 2 , a lip 42 - 1 and 42 - 2 , having a triangular section, with a slope oriented toward the bottom 38 of the housing, facilitating the insertion and blocking the removal. Thus, each groove 40 - 1 and 40 - 2 is delimited to form a bearing 44 - 1 and 44 - 2 . The bottom 38 of the housing is flat with a channel perpendicular to the angles between said bottom and the transverse and longitudinal lateral surfaces.
The bottom 38 bears at its center a hole 46 for communication between the body 10 and the open housing 32 . Under the bottom 38 , as shown in detail in FIG. 6 also, a skirt 51 is provided comprising a screw thread 48 , produced by molding, adapted to cooperate in a sealed manner with the external screw head 20 of the open neck 18 .
The movable applicator 28 is a wheel 50 comprising a peripheral rolling surface 52 and two domed surfaces 54 - 1 and 54 - 2 . This wheel 50 is provided with two cylindrical tabs 56 - 1 and 56 - 2 projecting perpendicularly to the rotation axis, forming a rotating shaft, arranged on both sides of the median plane. These tabs 56 - 1 and 56 - 2 have a shape adapted to cooperate in rotation with the bearings 44 - 1 and 44 - 2 of the longitudinal lateral walls 34 - 1 and 34 - 2 provided to receive them. The surface 52 for peripheral rolling of the wheel 50 comprises transverse grooves 58 having a sinusoidal cross-section, if the succession of grooves on the periphery in the median plane is considered. The depth of these grooves depends on the properties of the wax at application temperature as will be explained later.
Therefore, assembling the head is simple since the wheel 50 is inserted in the open housing 32 , the tabs 56 - 1 and 56 - 2 are in abutment on the lips 42 - 1 and 42 - 2 and an additional pressure causes the passage of the tabs beyond the lips to lodge themselves by ratcheting in bearings 44 - 1 and 44 - 2 . The tabs are thus maintained in these bearings and are free in rotation. The base 26 bearing the movable applicator 28 can thus be screwed on the body 10 . The three pieces are thus assembled to form the device according to the invention shown in FIG. 1 .
The device according to the invention is filled with a suitable wax, particularly, but not exclusively, sugar-based. To use it, the body 10 of the device is placed in a water bath, for example, or in any other hot water container with a conventional cap, the cap being advantageously oriented downward. The applicator head 12 is mounted only at the time of use. The first advantage is to dissolve the possible wax drippings resulting from a previous use. In parallel, the volume of wax contained is heated to the temperature suited to its application.
It then suffices to unscrew the conventional cap to mount the applicator head by screwing and placing the wheel in contact with the skin on the area to be epilated, and then roll the wheel by translational displacement while maintaining pressure to deposit the wax on the desired area. The wheel ensures the dosage at the same time as the spreading. Indeed, placing the wheel 50 in rotation makes it possible to circulate the wax coming from the body 10 which passes through the hole 46 to come out in the space situated between the wheel and the bottom 38 . The wheel functions as a mini wheel with blades, the blades being the transverse grooves 58 which ensure the distribution of wax at a suitable volume.
Similarly, the grooves in contact with the wax applied onto the skin allow for latching which sets said wheel into rotation, regulating the thickness of the applied wax. It must be noted that the contours can be followed precisely since the transverse borders do not hinder the maneuvers. The longitudinal lateral borders, being substantially perpendicular to the rotational axis of the wheel 50 are not a hindrance either. The wheel 50 is thus clear over more than half its circumference, which makes it very accessible. It must be noted that the wheel 50 rotates freely by creating in the open housing 32 a passage adapted for the wax to be expelled via the hole 46 . It must also be noted that the domed surfaces 54 - 1 and 54 - 2 prevent the wax from exiting the space created between one or the other of the lateral transverse surfaces 36 - 1 and 36 - 2 and the peripheral rolling surface 52 of the wheel, according to the displacement direction of the device. This allows a very precise, even dosing, with no gaps, proportional to the translational movement and thus proportional to the length of application.
In order to feed the wheel to dose the quantity of wax, a slight pressure must be exerted on the flexible body 10 . It must be noted here also that even if the exerted pressure is accidentally substantial, the volume distributed cannot be substantial since the static flow is very limited since the wheel must rotate to free the necessary applicable volume. At the end of use, the applicator head 12 is disassembled, then rinsed for a future application and the body 10 receives the conventional cap again to ensure the remaining volume of wax is preserved.
During the next use, the device is again ready to be put back in service by proceeding with the same steps as those carried out during the first use. | A device for applying epilation wax, allowing for a precise application from the stand-point of thickness as well as dimensions of the application, comprising a body ( 10 ) containing wax, a head comprising an open housing provided with longitudinal and transverse lateral walls, the housing receiving a movable applicator ( 28 ) mounted in rotation in the housing, characterized in that the movable applicator ( 28 ) is a wheel ( 50 ) whose lateral surfaces ( 54 - 1 and 54 - 2 ) are domed. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 08/808,020, filed Mar. 3, 1997, abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to enclosures for receiving and storing digitally coded discs and, more particularly, to an improved engagement means for holding such discs within such enclosures.
2. Description of the Prior Art
Various types of planar discs are in use at the present time to record and store information which is to be retrieved by various means, such as by optical or magnetic means. Typical of such discs are compact discs (CDs) in which information is digitally recorded by use of a laser beam and then read optically by a laser beam. Such discs are used to record audio information, such as musical renditions, video information such as visual images and digital information for use as read only and other memories for use in various applications, such as computer applications. In most instances, at the present time, such discs are sold with information already recorded thereon. In other applications, such discs are sold in blank form and are used by the customer to record information thereon. In the latter case, for example, optical discs are sold for use as computer storage media and are used in hard disc storage systems. In either case, optical imperfections in or on the surfaces of such discs interfere with both the recording and retrieval of information stored on the discs. Care must, therefore, be taken in the storage, moving and handling of such discs to avoid causing any such imperfections.
Compact discs containing laser recorded information are typically packaged in enclosures designed to hold one or more CDs for protecting the discs during storage and shipment. Enclosures commonly used at the present time comprise a three piece assembly consisting of a base or bottom element, an insert or tray in the base/bottom element for positioning and supporting the disc in the base/bottom element, e.g., by a center projection (commonly referred to as a "rosette") which engages the periphery of the aperture in the center of the disc, and a lid or cover which is hinged to the base/bottom element and is closed thereon after the disc is mounted therein on the tray. Other enclosures utilize only two pieces, omit the tray, and position and support the disc via the center projection directly on the base/bottom element. The enclosure is, typically, at least partially transparent and graphics relating to the disc and containing trademark and sales promotional information are usually inserted in such a manner as to be visible through the enclosure.
Most typically, the rosette comprises a raised hub which is formed integrally with the base/bottom element or tray, preferably by injection molding. The hub includes a plurality of small gripping teeth or fingers for radially engaging the central aperture in the CD. Generally, the central aperture of the CD is positioned over the rosette and a slight downward pressure is applied. Due to the relative dimensions of the central aperture and the rosette, the downward pressure causes the gripping teeth or fingers to deflect radially inwardly and to resiliently engage the central aperture of the CD. In this way the rosette engages and secures the CD in place during storage.
It has become conventional for the elements of the CD enclosures to be formed by injection molding. As a consequence the rosettes are formed of the same plastic material as the base or tray with which they are integrally molded. The base and/or tray elements and, therefore, the rosettes have typically been made from pigmented thermoplastic molding resins having sufficient impact resistance to withstand the forces attendant to mounting and unmounting CDs as well as the forces experienced during shipping and handling.
More recently there has arisen a growing demand for additional graphic display space on CD enclosures. As a consequence it has become desirable to provide a clear, see through tray or base so that a larger percentage of graphic area is visible to the consumer. In order to achieve a clear, see through tray or base, a transparent plastic material must be used. One material which has emerged as the material of choice is crystalline polystyrene. Although a functional CD tray or base can be molded with crystalline polystyrene using known injection molding techniques and existing molds without substantial change to the enclosure design, the brittleness of crystalline polystyrene has caused significant problems with the rosette. Specifically, the molded gripping teeth or fingers have evidenced a tendency to fracture and/or break away during mounting and unmounting of the CDs and during shipping and handling operations due to the brittleness of the crystalline polystyrene. This can result in a loss of engagement between the rosette and the central aperture of the CD, allowing the CD to move within the enclosure and to become damaged by impairing the recording media stored thereon. Alternatively, or in addition, the fractured teeth or fingers can become loose and move around in the enclosure, damaging the surface of the CD by scratching the surface and impairing the stored recording media thereon.
Efforts have been made to reinforce the teeth or fingers of the rosette. See, for example, U.S. Pat. No. 5,515,968 and U.S. Pat. No. 5,494,156. However, attempts to redesign the rosettes or to reinforce them suffer from one or more shortcomings which make the resulting rosette either unsatisfactory or not particularly desirable for use in a CD enclosure. Either the rosette is undesirable because it is uneconomical to manufacture or it is unsatisfactory because it remains susceptible to fracture in use and presents substantial risk of damaging the information bearing surface of the disc. Accordingly, there remains a need for a simple, inexpensive to manufacture and easy to use rosette for a CD enclosure which is configured to facilitate safe mounting and unmounting of the disc thereon and which does not present a damage risk for the disc's information bearing surface.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a rosette for a CD enclosure which permits its manufacture by injection molding using low impact strength plastics, such as crystalline polystyrene, which is configured to facilitate safe mounting and unmounting of the disc thereon and which does not present a damage risk for the disc's information bearing surface.
It is also an object of the present invention to provide an improved rosette for a CD enclosure which is simple, inexpensive to manufacture and easy to use.
It is another object of the present invention to provide a rosette for a CD enclosure which can be formed from a typically brittle plastic material yet which includes sufficiently durable and resilient fingers for safely and effectively engaging the central aperture of a CD for retaining it in place within a CD enclosure.
The foregoing and other objects are achieved in accordance with the present invention by providing engagement means for securing at least one disc shaped element having a central aperture, the engagement means comprising: a) a raised circular hub having a substantially cylindrical side wall, the hub projecting upward from a planar base; b) at least one resilient, arcuate, circumferentially extending finger integrally formed with the hub and extending along the perimeter of the hub, each finger being formed integrally with the hub at one end and free at the other end, the free ends of the fingers being resiliently deflectable arcuately inwardly from the perimeter of the hub; c) whereby the perimetric edge of the disc central aperture engages the fingers when the disc is placed on the hub causing the fingers to move arcuately inwardly from the perimeter of the hub to allow the disc central aperture to slide downwardly over the hub, the fingers resiliently engaging the perimetric edge of the disc central aperture to hold the disc in place on the hub.
Desirably, the engagement means further includes a radially extending protrusion on the free end of each finger projecting outwardly beyond the outside diameter of the hub for engaging a bottom perimetric edge of the disc central aperture when the disc is placed on the hub for causing the fingers to move arcuately inwardly, the protrusions being adapted to resiliently engage a top perimetric edge of the disc central aperture after the disc slides downwardly over the protrusions for removably securing the disk onto the hub. In addition, the engagement means also includes at least one aperture defined in the base, the number of apertures corresponding to the number of the fingers, the fingers being arranged so that the free ends thereof overhang the apertures for permitting the free ends to substantially unobstructedly deflect when the disc is inserted on the hub. The rosette of the invention can be further strengthened by providing at least one rib molded on the underside of each finger adjacent the fixed end thereof for reinforcing the finger without inhibiting the flexibility and freedom of movement of the free end of the finger.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodiment of the improved rosette of the present invention.
FIG. 2 is a plan view of the improved rosette of FIG. 1.
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2.
FIG. 4 is a perspective view of another embodiment of the improved rosette of the present invention.
FIG. 5 is a plan view of still another embodiment of the improved rosette of the present invention.
FIG. 6 is a sectional view taken along line 6--6 of FIG. 5.
FIG. 7 is a perspective view of the underside of the improved rosette of FIG. 5.
FIG. 8 is a plan view of yet another embodiment of the improved rosette of the present invention.
FIG. 9 is a sectional view taken along line 9--9 of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the present invention is illustrated in FIGS. 1, 2 and 3 in which there is illustrated an improved rosette or mounting hub 14 for a CD enclosure. Rosette 14 is generally positioned in the same location within CD enclosures as prior art rosettes, i.e., generally centrally located on the insert or tray of three piece enclosures or on the base of two piece enclosures. Desirably, rosette 14 is molded integrally with the base or tray of the enclosure. In the embodiment of FIGS. 1-3, rosette 14 is molded on raised CD seat 4 which, itself, is molded on tray or base 2. Raised seat 4 provides a circular surface on which the annular area of the CD which is immediately adjacent the central disc aperture can be supported above the base 2. This area of the CD typically contains no recorded information and, therefore, contact between the CD in this area and the raised seat will not damage the CD. The CD may optionally be peripherally supported at its outer edges which also, typically, contains no recorded information in order to provide further assurance that contact of the recorded areas of the CD with either the base or tray or the cover of the CD enclosure will be avoided. Extending upward from disc seat 4 is rosette 14 which is essentially a vertical cylindrical section divided by generally L-shaped slits 50 into a plurality of arcuate, circumferentially extending fingers 6. Each L-shaped slit in rosette 14 has a first leg slit 50a extending generally radially through circumferential side wall 11 of rosette 14 and a short distance across top wall 10 and a second leg slit 50b in the top wall 10 extending, from the end of the first leg slit, generally parallel to the circumferential side wall 11 of the rosette 14. In this way each L-shaped slit defines a circumferentially extending finger 6 having a radial thickness defined by the radial distance between side wall 11 and second leg slit 50b and a circumferential length defined by the length of second leg slit 50b. Each finger 6 is formed integrally with the rosette 14 at one end 6b and is free at the other end 6a. The free end 6a of each finger 6 overlies an opening 12 defined in raised seat 4 on which rosette 14 is positioned to allow free movement of the free end in an arcuate direction, i.e., generally toward the geometric center of rosette 14. Each of the fingers 6 is associated with each of the openings 12. Although five fingers and five openings are illustrated, it will be appreciated that any number of fingers and corresponding openings may be located at more or less regularly spaced intervals along the circumference of rosette 14. Preferably, rosette 14 comprises at least two fingers 6 and corresponding openings 12. Most desirably, rosette 14 comprises at least four fingers 6 and corresponding openings 12. The openings 12 may of any desirable or convenient shape consistent with their function which is to allow the free ends 6a of fingers 6 to deflect unobstructedly in response to a deforming force. Inasmuch as ends 6b of fingers 6 are integrally formed with the rosette, ends 6b are secured 5 while ends 6a are free to pivot or otherwise deflect in a plane parallel to base 2 in response to the force applied during mounting of a CD.
At the free end 6a of each finger 6 a protrusion 8 is formed which extends radially outwardly beyond the outer diameter of the rosette 14 with fingers 6 in their rest position and extends circumferentially along side wall 11 from the free end 6a toward fixed end 6b. As can be seen in FIG. 2, protrusion 8 desirably extends circumferentially only a short distance along side wall 11 although it may extend a greater distance, up to the entire circumferential length of finger 6, if desired. With reference to FIG. 3, it will be seen that in a vertical plane, such as A--A', protrusion 8 is formed as a complex curve gently extending from the outward and downward curvature of the radially outer edges 6c of the axial top surface of finger 6. Protrusion 8 extends outwardly and downwardly from merge point 8a with finger top surface outer edges 6c, along side wall 11 to curve apex 8b and then inwardly and downwardly to the point 8c where protrusion 8 merges with side wall 11. A protrusion configured generally in this manner provides a guide curvature which allows the CD to slip easily over rosette 14.
The outer diameter of rosette 14 measured to the radial edges of fingers 6 is slightly larger than the diameter of the disc central aperture. Protrusions 8 extend radially outwardly from the radial edges of the fingers which makes the outer diameter at the protrusions even larger than the outer diameter of the rosette 14. In use, the free ends 6a of fingers 6 deflect slightly inwardly from their rest position toward the center of rosette 14 under pressure from the perimetric edge of the central disc aperture in contact with protrusions 8 as the CD is fitted over the fingers onto the rosette. Pressure exerted as the CD is pressed vertically over the fingers 6 into contact with radial outer edge of the finger top surface 6c and the protrusions 8 between upper merge point 8a and apex 8c causes displacement of the free ends 6a of the fingers 6 radially inwardly along an inwardly directed arc. Thus, the effective diameter of the rosette temporarily decreases to accommodate the somewhat smaller diameter of the disc central aperture. After the disc has passed apex 8b of protrusions 8, fingers 6 begin to resiliently return toward their rest position. When the disc has passed merge point 8c, the side wall 11 of rosette 14 engages the perimetric edge of the disc central aperture to securely hold the disc in position. At this point, because rosette outer diameter is slightly larger than the diameter of the disc central aperture, the fingers 6 have not completely returned to their rest position and are, therefore, resiliently biased against and applying a light, secure, outward directed pressure to the perimetric edge of the disc central aperture. When the disc is fully seated on raised seat 4, it is securely held in place on rosette 14 by the radially outward directed pressure of the resilient fingers 6 and by the pressure of protrusions 8 along the upper surface of the perimetric edge of the disc central aperture. Removal of the disc from rosette 14 is accomplished simply by exerting a light upward pressure to the edge of the disc. The pressure of the disc against the protrusions between merge point 8c and apex 8b again causes displacement of the free ends 6a of the fingers 6 radially inwardly along an inwardly directed arc. Thus, the effective diameter of the rosette again temporarily decreases to accommodate the somewhat smaller diameter of the disc central aperture. After the disc has passed apex 8b of protrusions 8, a light continued upward pressure causes it to break free of rosette 14. The rosette of the present invention may, if desired, be of such a height that two or more CD's can be securely supported thereon, for example, one above the other.
A second embodiment of the rosette of the present invention is illustrated in FIG. 4 which is identical to the rosette 14 of FIGS. 1-3 except that in FIG. 4 rosette 18 is essentially a vertical cylindrical section having a central opening 16 in the center thereof. More specifically, rosette 18 extends upward from disc seat 24 which, in turn, is raised from base or tray 28. Rosette 18 comprises a plurality of arcuate, circumferentially extending fingers 20, the free end 20a of each of which overlies a corresponding opening 26 in raised seat 24. At the free end 20a of each finger 20 a protrusion 22 is formed which extends radially outwardly beyond the outer diameter of the fingers 20 in their rest position and extends circumferentially along side wall 29 of rosette 18 from the free end 20a toward fixed end 20b of fingers 20. In use, as with rosette 14, the free ends 20a of fingers 20 deflect slightly inwardly from their rest position toward the center of rosette 18 under pressure from the perimetric edge of the central disc aperture in contact with protrusions 22 as the CD is fitted over the fingers onto the rosette. Pressure exerted as the CD is pressed vertically over the fingers 20 causes displacement of the free ends 20a of the fingers 20 radially inwardly along an inwardly directed arc to temporarily decrease the effective diameter of the rosette to accommodate the somewhat smaller diameter of the disc central aperture. After the disc has passed the apex of protrusions 22, fingers 20 begin to resiliently return toward their rest position until the side wall 29 of rosette 18 engages the perimetric edge of the disc central aperture to securely hold the disc in position.
A third embodiment of the rosette of the present invention is illustrated in FIGS. 5-6 which is identical to the rosette 14 of FIGS. 1-3 except that in FIGS. 5-7 rosette 34 includes a plurality of ribs 44 integrally molded on the underside of each finger 36. More specifically, rosette 34 extends upward from disc seat 42 which, in turn, is raised from base or tray 40. Rosette 34 has a closed top wall 30 and comprises a plurality of arcuate, circumferentially extending fingers 36, the free end 36a of each of which overlies a corresponding opening 32 in raised seat 42. At the free end 36a of each finger 36 a protrusion 38 is formed which extends radially outwardly beyond the outer diameter of the fingers 36 in their rest position and extends circumferentially along side wall 39 of rosette 34 from the free end 36a toward fixed end 36b of fingers 36. A molded rib 44 on the underside of each finger 36 is positioned to extend radially through the fixed end 36b thereof from a point radially inward of the inner diameter of fingers 36 to a point radially outward of the outer diameter of fingers 36 in order that it may reinforce each finger without inhibiting the flexibility and freedom of movement of the free end 36a of finger 36. In use, as with rosette 14, the free ends 36a of fingers 36 deflect slightly inwardly from their rest position toward the center of rosette 34 under pressure from the perimetric edge of the central disc aperture in contact with protrusions 38 as the CD is fitted over the fingers onto the rosette. Pressure exerted as the CD is pressed vertically over the fingers 36 causes displacement of the free ends 36a of the fingers 36 radially inwardly along an inwardly directed arc to temporarily decrease the effective diameter of the rosette to accommodate the somewhat smaller diameter of the disc central aperture. After the disc has passed the apex of protrusions 38, fingers 36 begin to resiliently return toward their rest position until the side wall 39 of rosette 34 engages the perimetric edge of the disc central aperture to securely hold the disc in position.
A fourth embodiment of the rosette of the present invention is illustrated in FIGS. 8-9 which is identical to the rosette 34 of FIGS. 5-7 except that in FIGS. 8-9 rosette 34 is essentially a vertical cylindrical section having a central opening 46 in the center thereof.
The present invention is directed not only to the improved rosette described herein but also to an improved insert or tray for securing and storing one or more CDs, which insert or tray is particularly useful as an element of three piece CD enclosures. Typically, such an insert or tray comprises a substantially planar surface from which the improved rosette of the present invention projects upwardly. Desirably, the insert or tray includes a raised circular seat from which the rosette projects and on which the annular area of the CD which is immediately adjacent the central disc aperture can be supported. This area of the CD typically contains no recorded information and, therefore, contact between the CD in this area and the raised seat will not damage the CD. The insert or tray may also include a supporting raised surface for peripherally supporting the CD along its outer edges which also, typically, contain no recorded information and which will not be damaged by contact with the tray. Typically, the rosette of the present invention is positioned in the center of the insert or tray. However, if the insert or tray is substantially larger than the CD, is shaped to store other CDs or items other than CDs, or for other reasons, the rosette need not be positioned in the center of the insert or tray. CD three piece enclosures generally also include a base or bottom element in which the insert or tray may be removably secured and a lid or cover element which is hinged to the base or bottom element and is closed thereon after the disc is mounted therein on the rosette. Where the CD enclosure is of the two piece variety, the tray or insert generally comprises the base or bottom element of the enclosure to which the lid or cover is hinged.
The present invention is desirably employed for molding brittle or low impact resistant clear thermoplastic resins. However, it is equally applicable when any moldable thermoplastic resin, whether clear, translucent, opaque, pigmented, tinted or otherwise, low or high impact resistance, is utilized. The invention is particularly advantageous for the injection molding of crystalline polystyrene and other styrenic polymers, such as copolymers and terepolymers containing styrene copolymerized with other monomers or other brittle polymers.
While the present invention has been described in terms of specific embodiments thereof, it will be understood that no limitations are intended to the details of construction or design other than as defined in the appended claims. | An improved rosette for securing at least one disc shaped element having a central aperture includes a raised circular hub having a substantially cylindrical side wall, the hub projecting upward from a planar base; at least one resilient, arcuate, circumferentially extending finger integrally formed with the hub and extending along the perimeter of the hub, each finger being formed integrally with the hub at one end and free at the other end; at least one aperture defined in the base, the number of apertures corresponding to the number of fingers, the fingers being arranged so that the free ends thereof overhang the apertures for permitting the free ends to substantially unobstructedly deflect arcuately inwardly when the disc is inserted on the hub; and a radially extending protrusion on the free end of each finger projecting outwardly beyond the outside diameter of the hub. The perimetric edge of the disc central aperture engages the protrusions when the disc is placed on the hub, causing the fingers to move arcuately inwardly from the perimeter of the hub to allow the disc central aperture to slide downwardly over the hub, the fingers resiliently engaging the perimetric edge of the disc central aperture to hold the disc in place on the hub. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of PPA Serial No. 60/376,892, filed May 2, 2002 by the present inventor.
BACKGROUND OF THE INVENTION
1. Field
This invention relates to a quilting frame system that can be used for hand quilting or machine quilting.
2. Background of the Invention
Quilting frames are used for the purpose of both free hand and machine quilting. They typically consist of a pair of frame ends supporting three rods. The rods hold the material to be quilted. As the quilting process progresses, the material is wound onto one of the rods—the take-up rod. A steady tension is applied to each piece of material mounted on the rods. The tension is important for consistently creating patterns in the material being quilted.
As the material continues to collect on the take-up rod, its diameter increases. When used for machine quilting, the increase in diameter causes a downward pressure to increase drag on the sewing machine. To reduce drag, quilting frames should be adjustable for both tilt and height. The adjustment techniques should be simple and easy to perform, allowing for fine tension adjustment.
Current quilting frame systems are typically set up on a semi-permanent or permanent basis, due to their designs. In order to accommodate the growing home quilting market, a modern quilting frame system should be simple to erect and take down, provide a high degree of portability and be easy to adjust and operate.
Prior patents for quilting frames have presented techniques for tensioning the fabric. U.S. Pat. No. 843,269 discloses a hanging frame using a pin, through a hole in the frame, passing though holes in a disc attached to the end of the pole for tensioning. This tensioning system, while providing positive tension, does not allow for fine tension adjustment. It also requires the use of both hands in the tensioning process.
U.S. Pat. No. 940,070 discloses a floor frame for hand quilting, using a ratchet and pawl tension system. U.S. Pat. No. 988,913 discloses a hanging frame for hand quilting, using a ratchet and pawl arrangement for tensioning. U.S. Pat. No. 1,326,776 discloses a hand quilting device using a ratchet and pawl tension system. The ratchet and pawl tension system provides positive tension and allows for one-hand adjustment, but does not allow for fine tension adjustment.
U.S. Pat. No. 1,843,834 discloses a 2-pole hand quilting system using a radial spline arrangement for pivoting the frame and a friction system for tension adjustment. Friction tension adjustment allows for fine tension adjustment, but does not provide for positive tension adjustment. Over time the friction surfaces can wear down and reduce the effectiveness of such a system. This system requires both hands for tension adjustment.
U.S. Pat. No. 5,913,275 discloses a radial spline coupling approach for both ends of the rods, using a bolt and wing nut to pull the radial splines into engagement. While this approach provides for a finer tension adjustment than the previously stated ratchet and pawl systems, it requires the use of both hands in the tensioning process. One hand holds the rod in the rotated, tensioned position and the other hand tightens the wing nut.
In conclusion, insofar as I am aware, no home quilting frame system formerly developed provides for positive, fine tension adjustment; separate height and tilt adjustment; integral attachment system for clamping to the end of a table or rails. The present invention provides a high degree of portability, versatility and simplicity of operation for the growing number of home quilters.
SUMMARY
The invention, an improved quilting frame system, can be used for hand quilting or machine quilting. The frame is comprised of three spaced, parallel rods supported by a pair of parallel frame ends. The rods are located perpendicular to the frame ends. The frame ends allow for each of the three parallel rods to be individually rotated and individually locked in position for tensioning. The individual rotation and tensioning of the parallel rods is accomplished by attaching one end of each rod to a roller clutch assembly on one of the frame ends and a passive spindle on the other frame end. The top and bottom layers of the material to be quilted are attached to the rods, with the batting sandwiched between these two layers of material. The quilting area between the rods is kept taut to allow for proper quilting of the material.
A pair of vertical rods supports each of the end frames. The support rods attach to the side of the end frames in a manner that allows the end frames to slide vertically along the support rods when the support rod attachments are loose. These two support rods provide the independent height and tilt adjustment for the end frames.
The base of the support rods is a length of channeling. The channeling is oriented such that the open end can be slid over the end of a table, with the support rods resting on top of the channel. The channel also allows for attachment of a rail system for increased portability or extending the length of the quilt frame system for larger quilts. When used with the rail system for extending the quilting frame system, extending both the quilting rods and rails is accomplished by separate extension pieces with attachment devices.
DRAWINGS
FIG. 1 is a plan view of the quilting frame system according to the present invention.
FIG. 2 is a longitudinal sectional view taken along section line 2 of FIG. 1 illustrating arrangement of quilting rods, support rods and roller clutch assembly on active frame end, showing the direction of rotation for tensioning.
FIG. 3 is a side view taken along section line 3 of FIG. 1 of the frame ends illustrating quilting rods connecting between roller clutch assembly and passive spindle and frame ends clamped to a table.
FIG. 4 is an enlarged elevation view of a portion of the active frame end illustrating the roller clutch assembly and locking knob.
FIG. 5 is a side sectional view taken along section line 5 of FIG. 4 illustrating details of the roller clutch assembly and locking knob.
FIG. 6A is side sectional view of the roller clutch assembly illustrating the locking knob tightened against the roller clutch body.
FIG. 6B is side sectional view of the roller clutch assembly illustrating the locking knob loosened, allowing rotation of the roller clutch body.
FIG. 6C is side sectional view of the roller clutch assembly illustrating the locking knob recessed into the frame end, and the roller clutch assembly removed from frame.
FIG. 7 is an enlarged elevation view of a portion of the active frame end illustrating the main frame end support system.
FIG. 8 is a side sectional view taken along section line 8 of FIG. 7 illustrating the frame support system.
DESCRIPTION
FIG. 1 is a plan view of the quilt frame 50 of this invention. Three quilting rods 25 , 26 and 27 are each supported on the active frame end 21 by shaft 4 , which is part of the roller clutch assembly 55 . On the passive frame end 22 , the three quilting rods are each supported by a passive spindle 6 . Each of the frame ends is supported by two clamping systems 60 and 65 . These clamping systems are attached to vertical rods 13 and 20 respectively. Height is adjusted on each frame end by loosening knobs 16 and 9 , setting the proper height and then re-tightening. Adjusting tilt is performed using only knob 9 . The base of each of the support rods is a channel 14 . The channel is used for attachment of each frame end to a table end or rail system.
FIG. 2 is a longitudinal sectional view of the active frame end 21 illustrating the support rods 20 and 13 attached to the base 14 and supporting the active frame end. Knobs 23 provide the clamping force for attachment to the end of a table. The square end of the roller clutch shaft 4 engages the square quilting rods 25 , 26 and 27 allowing for control of rotation and tension. The roller clutch 3 is contained in the roller clutch body 2 . The lines 28 and 29 are provided to illustrate the direction of rotation for tensioning of fabric placed on the quilting rods 25 , 26 and 27 . Quilting rod 25 is the take up rod. Both the top layer fabric 28 and the bottom layer fabric 29 are wound onto rod 25 . The batting that is sandwiched between these layers is not shown in this illustration. The direction of rotation allowed by the roller clutches when the locking knob 5 is in locked position, as illustrated in FIG. 6A, is indicated by the arrows at the ends of 28 and 29 . Rotation of rods 25 , 26 and 27 when all three locking knobs 5 are in this position provides for fine tension adjustment. In order to advance the quilting material, locking knobs 5 for roller clutch assemblies associated with rods 26 and 27 must be in the unlocked position as illustrated by FIG. 6 B. The locking knob 5 for the roller clutch associated with rod 25 would be in locked position as illustrated in FIG. 6A, allowing it to roll the quilting material on to rod 25 .
FIG. 3 is a side view of the quilting frame system. Each frame end channel 14 is shown clamped to a table using knobs 23 . Only one of the quilting rods is shown for clarity. The square end of shaft 4 is engaged with the square quilting rod, allowing for rotation using knob 1 . The passive spindle 6 on the passive frame end 22 only provides support for the quilting rod.
FIGS. 4 and 5 illustrate the roller clutch assembly 55 and associated locking knob 5 in the frame end 21 . Since the frame ends can be fabricated from a relatively soft material such as wood or plastic, the use of a threaded insert 24 provides for a strong threaded receptacle for locking knob 5 . The roller clutch 3 is fixed to the roller clutch body 2 . When the roller clutch knob 5 is in the position illustrated (also shown in FIG. 6 B), the roller clutch body 2 is allowed to rotate freely in both directions within the frame end 21 . When the roller clutch knob 5 is tightened against the roller clutch body 2 , as illustrated in FIG. 6A, the roller clutch body 2 is pressed against frame 21 , disallowing its movement. In this position, the roller clutch 3 will only allow the shaft 4 to rotate in one direction.
FIGS. 7 and 8 illustrate the main frame end support system 65 . Both frame support systems 60 and 65 employ the same securing technique, so only the main support system 65 will be described. When securing the frame ends 21 and 22 in proper position, knob 16 (FIG. 8) is rotated, pulling the support body 19 against spacer 18 . The support rod 20 is held in place by the tension maintained by knob 16 on support body 19 . Due to the contact surface area between 19 and 20 , only a small amount of tensioning pressure is required to hold the frame end in place.
REFERENCE NUMERALS IN DRAWING
1 . Shaft Rotating Knob
2 . Roller Clutch Body
3 . Roller Clutch (one-way clutch)
4 . Quilt Rod Engaging Shaft
5 . Roller Clutch Locking Knob
6 . Passive Spindle
7 . Spacer
8 . Spindle Bolt
9 . Angle Knob
10 . Washer
11 . Washer
12 . Angle Support Body
13 . Vertical Support
14 . Channel
15 . None
16 . Height Knob
17 . Washer
18 . Height Support Body
19 . Height Support Body
20 . Vertical Support
21 . Active Frame End
22 . Passive Frame end
23 . Table Attachment Knob
24 . Threaded Insert
25 . Quilt Take-up Rod
26 . Quilt Top Rod
27 . Quilt Backing Rod
28 . Top Quilt Layer Illustrative Line
29 . Backing Illustrative Line
50 . Quilting Frame System
55 . Roller Clutch Assembly
60 . Tilt Clamping Assembly
65 . Height Clamping Assembly
OPERATION
Attach frame end bases 14 to opposite ends of the table and tighten knobs 23 . The length of rods 25 , 26 and 27 must be approximately equal to the length of the table.
Remove roller clutch assemblies 55 from frame end 21 by loosening the locking knob 5 to the position illustrated in FIG. 6 C.
Attach each of the rods 25 , 26 and 27 on passive frame 22 in turn by placing one end of each rod onto spindle 6 on frame 22 . Next attach the rod to the active frame end 21 , by inserting roller clutch assembly 55 into frame 21 while engaging shaft 4 with the rod end. Place the roller clutch assembly 55 back into the frame end 21 , and adjust locking knob 5 to the position illustrated in FIG. 6 B. This process is repeated until all three rods 25 , 26 and 27 are attached to both frame ends.
Attach cloth leaders to rods 25 , 26 , and 27 . This can be done with tape or other means.
Attach backing of quilt to leader attached to rod 27 using straight pins or other fabric attachment device. Tighten locking knob 5 for roller clutch assembly 55 associated with rod 27 to the position illustrated in FIG. 6 A and then roll backing onto rod 27 using knob 1 of roller clutch assembly 55 associated with rod 27 .
With quilt top facing up, attach top to rod 26 and in a similar manner roll fabric onto rod 26 .
Tighten knob 5 for the roller clutch assembly associated with rod 25 to the position illustrated by FIG. 6 A.
Place quilt batting in between rods 26 and 27 , sandwiching the batting between the quilt top and quilt bottom Loosen locking knobs 5 for roller clutch assemblies 55 associated with rods 26 and 27 to the position illustrated in FIG. 6B to allow for bi-directional rotation.
Attach all three front edges (backing, batting and top) to cloth leader on take up rod 25 . Tighten locking knobs 5 for roller clutch assembly 55 associated with rods 26 and 27 to the position illustrated in FIG. 6A to allow for only one direction of rotation only. If using frame for hand quilting, turn knobs 1 of roller clutch assembly 55 associated with rods 25 , 26 and 27 until proper tension is attained.
If frame is to be used with sewing machine on a moveable platform, loosen locking knob 5 for roller clutch assembly 55 associated with take up rod 25 to the position illustrated in FIG. 6 C. Remove roller clutch assembly 55 from frame end 21 , lift take up rod 25 slightly while pivoting on the associated passive spindle 6 on frame end 22 in order to pass rod 25 through the sewing machine throat. Reattach rod 25 to roller clutch assembly 55 and tighten associated locking knob 5 . After assuring all three locking knobs 5 are tightened, turn knobs 1 attached to rods 25 , 26 , and 27 in the direction allowed by the roller clutch until proper tension is achieved.
Adjust height of end frames 21 and 22 by loosening knob 9 of tilt adjustment assembly 60 and knob 16 of height adjustment assembly 65 on frame end 21 . Set height and tighten knob 16 . Repeat the process on the passive frame end 22 , matching the height of frame end 21 . With height adjustment set, adjust frame tilt by moving frame end 21 vertically at a point near rod 25 . When the desired position is found, tighten knob 9 and repeat process on frame end 22 .
Roll completed quilted areas onto take up rod 25 by loosening locking knobs 5 on roller clutch assemblies associated with rods 26 and 27 and rotate knob 1 of roller clutch assembly associated with roll take up rod 25 . Tighten locking knobs 5 on roller clutch assemblies associated with rods 26 and 27 and then selectively rotate all three rods 25 , 26 , and 27 until proper tension is achieved once more.
As the quilting process progresses, the amount of quilted material on rod 25 will increase. As this occurs, a further adjustment of the height and angle may be required for smooth operation.
To remove completed quilt from frame, loosen all three locking knobs 5 to the position illustrated in FIG. 6 B. Unpin back edges on quilt top and bottom from leader on rods 26 and 27 and unroll take up rod 25 until completed quilt is totally unrolled. Then unpin the front edge from the leader attached to take up rod 25 .
The foregoing should be considered as illustrative only of the principles of the invention. It is not desired to limit the invention to the exact construction and operation shown and described. Since modifications and changes will readily occur to those with skill in the field, all suitable modifications may be resorted to while falling within the scope of this invention. | A quilting frame for the purpose of both free hand and machine quilting consisting of a pair of frame ends ( 21 and 22 ) supporting three rods ( 25, 26, and 27 ). The rods ( 25, 26, and 27 ) hold material to be quilted. As the quilting process progresses, the material is wound onto the take-up rod ( 25 ). The proper tension for both hand and hand-machine guided quilting is applied to each piece of material mounted on the rods through clutch assemblies ( 55 ). The quilt frame is adjustable for both tilt and height using assemblies 60 and 65 respectively. The adjustment technique is simple and easy to perform, facilitating both hand and home machine quilting. | 3 |
BACKGROUND AND SUMMARY
The present disclosure generally pertains to power converters. Power converters, such as, for example, transformers, are typically used to convert electrical energy from one circuit into a suitable form for use in another circuit. Thus, power converters may be used to regulate voltage, current, or frequency between circuits. Typical power converters often utilize one or more input or primary coils positioned around a ferromagnetic core, and one or more output coils positioned around another portion of the core. The input coils are used to produce a magnetic flux in the core, which in turn produces an electromotive force, or voltage, in the output coil. However, due to the effect of Lenz's Law, the amount of output power produced by typical power converters does not exceed the amount of input power. Accordingly, a power converter which mitigates the effect of Lenz's Law on the input coils is desired.
Based on a standard demagnetization curve for permanent magnets, the flux density of the permanent magnet remains relatively constant until a magnetizing force sufficient to coerce the magnet is applied to the magnet, at which point the magnetic flux density drops quickly to zero. Thus, the permanent magnet acts as a constant magnetic flux generator until coerced. Furthermore, a variation of Kirchoff's current law states that magnetic flux in a series loop is constant. Therefore, the present disclosure sets forth an application of these principles wherein a permanent magnet is used to mitigate the effect of Lenz's Law in a power converter.
Embodiments of the present disclosure generally pertain to a magnetic power converter. A magnetic power converter in accordance with an exemplary embodiment of the present disclosure comprises a generally figure-8 shaped magnetic core having a plurality of legs. A toroid is positioned along at least one leg of the core and a permanent magnet is positioned along at least one leg of the core to provide a plurality of magnetic flux paths through the core, forming a balanced reluctance bridge. An output coil is positioned around one leg of the core, and at least one input coil is positioned around a portion of each toroid. When current is driven through the input coil, a control flux is induced in each toroid which remains captured in the toroid, increasing the flux density in the toroid and lowering the permeability of the core such that a virtual air gap is formed in each toroid. Such control flux in the toroid displaces the magnetic flux produced by the permanent magnet such that a portion of the magnetic flux from the permanent magnet flows through the third leg of the core.
The change in magnetic flux flowing through the third leg induces a current in the output coil which may be used to provide electrical power to a load. Thus, the control core acts as a variable reluctance shunt with respect to the magnet and the flow of electricity and none of the energy moderating the flux through the toroid is coupled to the output coil. Accordingly, the output coil is controlled by the input coils indirectly and the effect of Lenz's Law on the input coils is mitigated. Due to the absence of the effect of Lenz's Law on the input coils, any output loading is not reflected on the input. The output power may therefore be greater than the input power. Because of this ability to amplify input power, embodiments of the present disclosure may have wide applications in alternative energy and green energy generation.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure can be better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale relative to each other, emphasis instead being placed upon clearly illustrating the principles of the disclosure. Furthermore, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is a top plan view of a magnetic power converter according to an exemplary embodiment of the present disclosure.
FIG. 2 depicts the magnetic power converter of FIG. 1 illustrating input and output coils.
FIG. 2A depicts the input coils of FIG. 2 coupled in series to the power source of FIG. 2 .
FIG. 3 depicts magnetic flux paths within the magnetic power converter of FIG. 2 when no current flow through the input coils.
FIG. 4 depicts magnetic flux paths within the magnetic power converter of FIG. 2 when current flows through the input coils.
FIG. 5 is a chart relating a B-H curve for M19 electrical steel to permeability.
FIG. 6 is a schematic diagram depicts the load of FIG. 2 according to an exemplary embodiment of the present disclosure.
FIG. 7 depicts the input power signal and the output power signal in the test of Example I.
FIG. 8 depicts a magnetic power converter according to another exemplary embodiment of the present disclosure.
FIG. 9 depicts magnetic flux paths within the magnetic power converter of FIG. 8 when the magnet is removed and current flows through the input coils.
FIG. 10 depicts magnetic flux paths within the magnetic power converter of FIG. 8 when the magnet is present and no current flows through the input coils.
FIG. 11 depicts magnetic flux paths within the magnetic power converter of FIG. 8 when the magnet is present and current flows through the input coils.
FIG. 12 is a top plan view of a magnetic power converter according to an exemplary embodiment of the disclosure.
FIG. 13 is a top plan view of the top portion of the core of the magnetic power converter of FIG. 12 .
FIG. 14 is a top plan view of the magnetic power converter of FIG. 12 , with input and output coils installed.
FIG. 15 a is a top plan view of a bobbin according to an exemplary embodiment of the disclosure.
FIG. 15 b is a front plan view of the bobbin of FIG. 15 a.
FIG. 15 c is a cross sectional view of the bobbin of FIG. 15 a , taken along section lines A-A of FIG. 15 a.
FIG. 15 d is a right side plan view of the bobbin of FIG. 15 a.
FIG. 16 a is a top plan view of a clamp plate according to an exemplary embodiment of the present disclosure.
FIG. 16 b is a front plan view of the clamp plate of FIG. 16 a.
FIG. 16 c is a right side plan view of the clamp plate of FIG. 16 a.
FIG. 17 illustrates the installation of bobbins on the pinch points of the core.
FIG. 18 a is a top plan view of a right leg bobbin according to an exemplary embodiment of the disclosure.
FIG. 18 b is a front plan view of the bobbin of FIG. 18 a.
FIG. 18 c is a right side plan view of the bobbin of FIG. 18 a.
FIG. 19 is a top plan view of a right leg clamp plate according to an exemplary embodiment of the disclosure.
FIG. 20 is a top plan view of a magnetic power converter according to another exemplary embodiment of the disclosure.
FIG. 21 depicts magnetic flux paths within the magnetic power converter of FIG. 20 when the magnet is present and no current flows through the input coil.
FIG. 22 depicts magnetic flux paths within the magnetic power converter of FIG. 20 when the magnet is present and current flows through the input coil.
DETAILED DESCRIPTION
FIG. 1 is a top plan view of a magnetic power converter 10 according to an exemplary embodiment of the present disclosure. As shown by FIG. 1 , the magnetic power converter 10 comprises a generally figure-8 shaped magnetic core 12 having a plurality of legs and a plurality of transverse pieces. In one embodiment, the core 12 comprises one-inch thick stack of 29 gauge M19 electrical steel laminations having a C5 oxide coating. However, other isotropic steels, such as, for example, M14 electrical steel, of varying thicknesses may be utilized in the core 12 in other embodiments.
In one embodiment, the core 12 has a left leg 14 , a right leg 16 , a middle leg 18 , an upper transverse piece 20 and a lower transverse piece 22 . The widths (w 1 ) of the left leg 14 , the right leg 16 , the middle leg 18 , the upper transverse piece 20 and the lower transverse piece 22 are substantially equal. In one embodiment, such widths (w 1 ) are approximately one inch, although other widths are possible in other embodiments.
The upper transverse piece 20 is substantially parallel to the lower transverse piece 22 . The left leg 14 , right leg 16 , and middle leg 18 are substantially parallel to one another and are substantially perpendicular to the upper transverse piece 20 and the lower transverse piece 22 . Further, the upper transverse piece 20 , the lower transverse piece 22 , the left leg 14 , the right leg 16 , and the middle leg 18 are disposed in substantially the same plane.
The left leg 14 comprises a toroid 24 having a left portion 26 and a right portion 28 , and the right leg 16 comprises a toroid 32 having a left portion 36 and a right portion 38 . The left portion 26 and the right portion 28 lie in substantially the same plane as the left leg 14 . In the embodiment depicted by FIG. 1 , note that the core 12 is substantially symmetrical such that the orientation and dimensions of the core 12 mirror one another with respect to the middle leg 18 . Also note that the toroid 24 is substantially the same size as the toroid 32 , and each toroid 24 and 32 is symmetrical such that the respective left and right portions 26 , 28 , 36 , and 38 mirror one another with respect to the corresponding leg 14 and 16 . Furthermore, the widths (w 2 ) of the left portions 26 and 36 and the right portions 28 and 38 are substantially equal. For example, in one embodiment the width (w 2 ) of each left portion 26 and 36 and each right portion 28 and 38 is one-half (0.5) inches, although other widths are possible in other embodiments.
The left leg 14 further comprises a permanent magnet 40 positioned within the toroid 24 , and the right leg 16 further comprises a permanent magnet 42 positioned within the toroid 32 . The permanent magnets 40 and 42 induce magnetic flux through the core 12 . The permanent magnets 40 and 42 are oriented in the same direction such that the respective north poles 44 and 46 of the magnets 40 and 42 are oriented towards the upper transverse piece 20 . In one embodiment, the magnets 40 and 42 are in line with the left leg 14 and the right leg 16 , respectively, and are the same width (w 1 ) as the legs 14 and 16 . However, the magnets 40 and 42 may have different dimensions in other embodiments. In one embodiment, the permanent magnets 40 and 42 comprise rare earth magnets, such as, for example, neodymium iron boron magnets, but other types of permanent magnets 40 and 42 may be used in other embodiments. It is well-known that the permanent magnets 40 and 42 have stored potential energy (typically referred to as the “magnetic energy product”) which is measured in megagauss-oersteds (MGOe), discussed in more detail hereafter, and represents the amount of energy the magnets 40 and 42 can supply to a magnetic circuit. One MGOe is equivalent to approximately 7957.75 Joules per cubic meter (J/m 3 ). In one embodiment, the magnetic energy product of the neodymium iron boron permanent magnets 40 and 42 is fifty-two (52) MGOe, or approximately 4.13803×10 5 J/m 3 .
The left portion 26 of the toroid 24 comprises a pinch point 50 wherein the left portion 26 of the toroid 24 becomes narrow, and the right portion 28 of the toroid 24 also comprises a pinch point 52 . Similarly, the left portion 36 and the right portion 38 of the toroid 32 comprise pinch points 54 and 56 , respectively. In one embodiment, a ratio of the length (L) of each pinch point 50 , 52 , 54 , 56 to the corresponding depth (D) of the pinch point 50 , 52 , 54 , 56 along that length is 0.8:1. For example, in one embodiment, the length (L) of the pinch point 50 is 0.2 inches and the depth (D) of the pinch point 50 is 0.25 inches. However, other ratios involving different lengths and different depths are possible in other embodiments.
In the embodiment depicted by FIG. 1 , the core 12 comprises an upper section 57 and a lower section 58 . The upper section 57 comprises the upper transverse piece 20 and the upper half of the toroid 24 , the upper half of the middle leg 18 , and the upper half of the toroid 32 . Note that the pinch points 50 , 52 , 54 , 56 are located in the upper section 57 in the embodiment depicted by FIG. 1 but they may be located in the lower section 58 in other embodiments. The lower section 58 comprises the lower transverse piece 22 , the lower half of the toroid 24 , the lower half of the middle leg 18 , and the lower half of the toroid 32 . The upper section 57 abuts the lower section 58 with a plurality of precision ground butt joints (J), as shown by FIG. 1 , which allow for easy assembly. However, other types of joints are possible in other embodiments.
FIG. 2 depicts the magnetic power converter 10 of FIG. 1 having a plurality of input coils and an output coil positioned around the core 12 . As shown by FIG. 2 , the magnetic power converter 10 further comprises an input coil 60 , 62 , 64 , 66 positioned around each pinch point 50 , 52 , 54 , 56 , respectively. In one embodiment, each input coil 60 , 62 , 64 , 66 is wound around a bobbin (not shown) comprising insulative material, such as, for example, polyoxymethylene plastic (Delrin®). [Note, therefore, that the input coils 60 , 62 , 64 , 66 as shown in FIG. 2 are schematic representations of the coils, and do not depict the actual physical topography of the coils.] The bobbins (not shown) are positioned such that the coils 60 , 62 , 64 , 66 are positioned around the corresponding pinch points 50 , 52 , 54 , 56 , respectively. The input coils 60 , 62 , 64 , 66 are connected in series to an AC power source 59 , as is depicted by FIG. 2A . The power source 59 is configured to provide electrical current to the input coils 60 , 62 , 64 , 66 . In one embodiment, the power source 59 provides a bipolar sine wave input signal. When the power source 59 sends an input signal to the coils 60 , 62 , 64 , 66 , electrical current flows through the coils 60 , 62 , 64 , 66 and induces a magnetic flux in each toroid 24 and 32 ; however, no electrical current flows through the coils 60 , 62 , 64 , 66 when no input signal is sent by the power source 59 . The input coils 60 , 62 , 64 , 66 are configured to generate a magnetic flux in the core 12 when an electrical current passes through the coils 60 , 62 , 64 , 66 (i.e. when the power source 59 provides an input signal). In one embodiment, the input coil 60 and the input coil 64 are positioned such that the electromagnetic polarity of each coil 60 and 64 is oriented towards the lower transverse piece 22 , while the input coil 62 and the input coil 66 are positioned such that the electromagnetic polarity of each coil 62 and 66 is oriented towards the upper transverse piece 20 . Thus, the input coils 60 and 62 of the toroid 24 are oriented in opposite directions and the input coils 64 and 66 of the toroid 32 are oriented in opposite directions. Such orientations are significant for demonstrating that the placement of the permanent magnets 40 and 42 mitigate the effect of Lenz's Law on the input coils 60 , 62 , 64 , 66 , discussed in more detail hereafter. However, the input coils 60 , 62 , 64 , and 66 may be oriented in the same direction in other embodiments.
In one embodiment, each input coil 60 , 62 , 64 , 66 comprises insulated multifurcate wiring, such as, for example, twenty-two strands of number thirty-six (36) copper wire. Such multifurcate wiring reduces the overall resistance of the coils 60 , 62 , 64 , 66 while keeping the impedance of the coils 60 , 62 , 64 , 66 low, increasing the total power output of the magnetic power converter 10 . Other types of insulated multifurcate wiring are possible in other embodiments. In one embodiment, each of the coils 60 , 62 , 64 , 66 has 105 turns and a resistance of 0.76 Ohms (a), although different resistances and numbers of turns may be utilized in other embodiments.
The magnetic power converter 10 further comprises an output coil 69 positioned around the middle leg 18 of the core 12 . When a change in magnetic flux traveling through middle leg 18 occurs, an electromotive force is induced in the output coil 69 causing the output coil 69 to generate electrical power to a load 70 , described in more detail hereafter. The output coil 69 comprises insulated multifurcate wiring. In one embodiment, the output coil 69 comprises a dual coil having sixteen strands of number thirty-two (32) copper wire. Furthermore, the coil has six hundred (600) turns and a length of 5.08 centimeters (cm) in this embodiment, but different types of coils having more or fewer turns and varying lengths are possible in other embodiments. In one embodiment, the middle leg 18 of the core 12 is one inch wide, although the middle leg 18 may be narrower in other embodiments.
In one exemplary embodiment, the core 12 comprises M19 electrical steel and the permanent magnets 40 and 42 comprise neodymium iron boron magnets having a magnetic energy product of 52 MGOe. The length of each pinch point 50 , 52 , 54 , 56 is 0.2 inches and the depth of each pinch point 50 , 52 , 54 , 56 is 0.25 inches. Also, each input coil 60 , 62 , 64 , 66 comprises twenty-two (22) strands of number thirty-six (36) copper wire having one hundred five (105) turns and a resistance of 0.76Ω, and the output coil 69 comprises sixteen (16) strands of number thirty-two (32) copper wire having six hundred (600) turns. Furthermore, the coils 60 and 62 are oriented in opposite directions and the coils 64 and 66 are oriented in opposite directions. Finally, no input signal is provided by the power source 59 .
FIG. 3 illustrates magnetic flux produced by the permanent magnets 40 and 42 when no input power is applied to the core 12 . The magnetic flux travels through the core 12 along a plurality of magnetic flux paths 74 , 76 , and 78 . The magnetic flux path 74 moves away from the north pole 44 of the magnet 40 and up the left leg 14 to the upper transverse piece 20 . The magnetic flux path 74 further travels along the upper transverse piece 20 and down the middle leg 18 to the lower transverse piece 22 . The magnetic flux path 74 further travels along the lower transverse piece 22 towards the left leg 14 and up the left leg 14 to the south pole 45 of the magnet 40 . Approximately half of the magnetic flux produced by the magnet 40 travels along the magnetic flux path 74 when no input signal is provided by the power source 59 ( FIG. 2 ). The magnetic flux path 76 travels in a counter-clockwise direction away from the north pole 44 of the magnet 40 , through the left portion 26 of the toroid 24 , and back to the south pole 45 of the magnet 40 . Similarly, the magnetic flux path 78 travels in a clockwise direction away from the north pole 44 of the magnet 40 , through the right portion 28 of the toroid 24 , and back to the south pole 45 of the magnet 40 . Approximately one-fourth of the magnetic flux produced by the magnet 40 flows through the magnetic flux path 76 and approximately one-fourth of the magnetic flux produced by the magnet 40 flows through the magnetic flux path 78 when no input signal is provided by the power source 59 .
The permanent magnet 42 produces magnetic flux which travels through the core 12 along a plurality of magnetic flux paths 84 , 86 , and 88 . When no input signal is provided by the power source 59 , the magnetic flux path 84 moves away from the north pole 46 of the magnet 42 , up the right leg 16 to the upper transverse piece 20 , and along the upper transverse piece 20 to the middle leg 18 . The magnetic flux path 84 then travels down the middle leg 18 to the lower transverse piece 22 , along the lower transverse piece 22 to the right leg 16 , and up the right leg 16 to the south pole 47 of the magnet 42 . The magnetic flux path 86 travels away from the north pole 46 of the magnet 42 in a counter-clockwise direction through the left portion 36 of the toroid 32 and back to the south pole 47 of the magnet 42 . The magnetic flux path 88 travels in a clockwise direction from the north pole 46 of the magnet 42 , through the right portion 38 of the toroid 32 , and back to the south pole 46 of the magnet 42 . When no input signal is provided by the power source 59 , approximately half of the magnetic flux produced by the magnet 42 travels along the magnetic flux path 84 , approximately one-fourth of the magnetic flux produced by the magnet 42 travels along the magnetic flux path 86 , and approximately one-fourth of the magnetic flux produced by the magnet 42 travels along the magnetic flux path 88 . Thus, the permanent magnets 40 and 42 produce a constant magnetic flux which is distributed evenly throughout the core 12 when no input signal is provided by the power source 59 .
In the exemplary embodiment discussed above, the magnetic flux density (B m ) in each pinch point 50 , 52 , 54 , 56 is approximately 15 kilogauss (KG) and the magnetic flux density (B m ) in the middle leg 18 is approximately 9 KG when no electrical current flows through the coils 60 , 62 , 64 , 66 .
When the power source 59 provides an input signal to the input coils 60 , 62 , 64 , 66 ( FIG. 2 ), electrical current flows through the input coils 60 , 62 , 64 , 66 . It is well-known in the art that a variation of the formula for calculating electrical power is:
P=I 2 R
where P is power, I is current, and R is resistance. Thus, when electrical current flows through the coils 60 , 62 , 64 , 66 , the total input power (P in ) is defined by the equation:
P in =I in 2 R in
where I in is the input current and R in is the total input resistance. Thus, if the input current is 980 milliamps (mA) and the total input resistance of the input coils 60 , 62 , 64 , 66 is 3.04 Ohms (Ω), the input power (P in ) is set forth as
P in =(980 mA) 2 ×(3.04Ω).
Therefore, P in equals approximately 2.92 Watts (W).
FIG. 4 illustrates flux flowing through the core 12 when input power is applied to the core 12 . When current flows through the coil 60 ( FIG. 2 ), a control flux 90 is induced in the pinch point 50 ( FIG. 2 ) which travels in the same direction as the magnetic flux path 76 . The magnetomotive force (F c1 ) produced by the coil 60 is defined by the equation
F c1 =0.4 πN C1 I c1
where N c1 is the number of turns of the coil 60 and I c1 is the current flowing through the coil 60 . Thus, the magnetomotive force (F c1 ) produced by the coil 60 is defined by the equation
F c1 =(0.4π)×(105)×(0.980 A)
which equals approximately 129.3 gilberts (Gi). The magnetizing force produced by the coil 60 is set forth by the equation
H c 1 = 0.4 π N c 1 I c 1 L c 1
where N c1 is the number of turns (105), I c1 is the current through the coil 60 (0.980 A), and L c1 is the length of the coil 60 (0.508 centimeters (cm)). Therefore, H c1 equals approximately 254.54 oersteds (Oe).
FIG. 5 depicts a B-H curve for M19 electrical steel illustrating the relationship between permeability, magnetic flux density, and magnetizing force. The control flux 90 (Φ c1 ) induced by the coil 60 is defined by the equation
Φ c1 =B c1 A
where B c1 is the magnetic flux density through the pinch point 50 in KG, and A is the cross-sectional area of the core 12 through the pinch point 50 in square centimeters (1.6129 cm 2 ). In one embodiment, when 980 mA of current flows through the coil 60 , the magnetic flux density (B c1 ) through the pinch point 50 equals approximately 19.3 KG. Thus, Φ c1 is approximately equal to 31,937.4 maxwells (Mx).
The strong control flux 90 and the permanent magnet (PM) magnetic flux of the magnetic flux path 76 traveling in the same direction within the pinch point 50 cause the magnetic flux density in the pinch point 50 to increase such that the left portion 26 of the toroid 24 is driven to saturation. Referring to FIG. 5 , as the magnetizing force (H) applied to the M19 electrical steel increases, the magnetic flux density (B) increases significantly until the steel approaches saturation, at which point the permeability decreases drastically. Thus, when the magnetic flux density (B c1 ) through the pinch point 50 equals approximately 19.3 KG, the relative permeability (μ) approaches zero.
The relationship between reluctance (R) and permeability (μ) is defined as
R = L μ A
where L is the length of the magnetic path in centimeters (cm) and A is the cross-sectional area of the core 12 in square centimeters (cm 2 ). Thus, as the permeability decreases the reluctance increases greatly. Furthermore, as the cross-sectional area of the core 12 decreases the reluctance increases. Therefore, the combination of the small cross-sectional area (A) of the pinch point 50 and the low permeability (μ) in the pinch point 50 causes a significant increase in reluctance (R) in the pinch point 50 . Accordingly, at saturation, the reluctance in the left portion 26 is high such that further PM magnetic flux cannot enter the left portion 26 of the toroid 24 . Such low permeability creates a virtual air gap which causes a significant amount of the magnetic flux of the PM magnetic flux path 76 to flow through the magnetic flux path 74 .
Furthermore, as shown by FIG. 4 , when current flows through the coil 62 ( FIG. 2 ), a control flux 92 is induced in the pinch point 52 ( FIG. 2 ) which opposes the magnetic flux of the magnetic flux path 78 . The control flux 92 (Φ c2 ) is generally the same magnitude as the control flux 90 , which is 31,937.4 Mx. The magnetomotive force (F c2 ), the magnetizing force (H c2 ), and the magnetic flux density (B c2 ) introduced by the coil 62 are also equal in magnitude to F c1 , H c1 , and B c1 , respectively, but in an opposite direction with respect to the permanent magnet 40 . The control flux 92 opposes the magnetic flux in the pinch point 52 , lowering the permeability in the right portion 28 of the toroid 24 such that no flux travels through the right portion 28 and the magnetic flux density through the pinch point 52 becomes zero. Such a low permeability in the right portion 38 of the toroid 24 causes a high reluctance in the right portion 38 , creating a virtual air gap which diverts a significant amount of PM magnetic flux from the magnetic flux path 78 to the magnetic flux path 74 . A combination of the left portion 26 of the toroid 24 being driven to saturation and the right portion 28 of the toroid 24 allowing no flux to flow through the magnetic flux path 78 creates a high reluctance in the toroid 24 , causing a high percentage of the PM magnetic flux from the magnet 40 traveling along the magnetic flux path 76 and the magnetic flux path 78 to be displaced such that the PM magnetic flux now travels along the magnetic flux path 74 through the middle leg 18 . Such an increase in magnetic flux traveling through the middle leg 18 induces an electromotive force in the output coil 69 ( FIG. 2 ), which may be used to power the load 70 ( FIG. 2 ).
Similarly, when current flows through the coil 64 ( FIG. 2 ), a control flux 94 is induced in the pinch point 54 ( FIG. 2 ) which opposes the PM magnetic flux of the magnetic flux path 86 . The magnitude of the control flux 94 is equal to approximately 31,937.4 Mx, as discussed above with respect to the control flux 90 and 92 . Furthermore, the magnetomotive force (F c3 ), the magnetizing force (H c3 ), and the magnetic flux density (B c3 ) introduced by the coil 64 are also equal in magnitude to F c1 , H c1 , and B c1 , respectively. The control flux 92 opposes the PM magnetic flux of the magnetic flux path 86 , lowering the permeability of the pinch point 54 and creating a virtual air gap such that no magnetic flux flows through the left portion 36 of the toroid 32 . Thus, the magnetic flux density in the left portion 36 becomes zero. Accordingly, the PM magnetic flux is diverted from the magnetic flux path 86 to the magnetic flux path 84 .
When current flows through the coil 66 ( FIG. 2 ), a control flux 96 is induced in the pinch point 56 ( FIG. 2 ) which travels in the same direction as the magnetic flux of the magnetic flux path 88 . The magnitude of the control flux 96 is also approximately 31,937.4 Mx, as discussed above with respect to the control flux 90 , 92 , and 94 . The magnetomotive force (F c4 ), the magnetizing force (H c4 ), and the magnetic flux density (B c4 ) introduced by the coil 66 are also equal in magnitude to F c1 , H c1 , and B c1 , respectively. A combination of the control flux 96 and the magnetic flux of the magnetic flux path 88 flowing through the pinch point 56 causes the magnetic flux density in the pinch point 56 to increase until it reaches saturation. In one embodiment, the magnetic flux density in the pinch point 56 rises to 19.3 KG. Thus, the permeability of the pinch point 56 becomes low and the reluctance becomes high, creating a virtual air gap which causes the magnetic flux of the magnetic flux path 88 to flow through the magnetic flux path 84 .
When the magnetic flux from the magnetic flux paths 76 , 78 , 86 , 88 is diverted through the magnetic flux paths 74 and 84 , the magnetic flux flowing through the middle leg 18 increases significantly. According to Faraday's Law of induction, the induced electromotive force in any closed circuit is equal to the time rate of change of the magnetic flux through the circuit. Thus, the change in the magnetic flux traveling through the middle leg 18 induces an electromotive force in the output coil 69 , thereby converting the potential magnetic energy of the magnets 40 and 42 into kinetic electrical energy which may be used to provide electrical power to a load 70 . In one embodiment, the output signal resembles a full wave rectified sine wave which is twice the frequency of the input signal. Such an output signal shows that the output signal is indirectly controlled by the input signal, i.e., the output signal is not coupled to the input.
According to Lenz's Law, the polarity of the electromotive force induced in the output coil 69 ( FIG. 2 ) by a magnetic flux is such that it produces a current whose magnetic field, or magnetizing force, opposes the original change in flux. Thus, the induced current in the output coil 69 has a magnetizing force which opposes the flux flowing through the middle leg 18 .
The total magnetizing force (H 1TOTAL ) produced by the input coils 60 and 62 and the magnet 40 is set forth in the equation
H 1TOTAL =H m1 +H c1 +H c2
where H m1 is the magnetizing force produced by the magnet 40 , H c1 is the magnetizing force produced by the input coil 60 , and H c2 is the magnetizing force produced by the input coil 62 . Similarly, the total magnetizing force (H 2TOTAL ) produced by the input coils 64 and 66 and the permanent magnet 42 is set forth in the equation
H 2TOTAL =H m2 +H c3 +H c4
where H m2 is the magnetizing force produced by the magnet 42 , H c3 is the magnetizing force produced by the input coil 64 , and H c4 is the magnetizing force produced by the input coil 66 .
It is significant to note that the polarity of the input coil 60 and the polarity of the input coil 62 are in opposition to one another with respect to the output coil 69 , and the polarity of the input coil 64 and the polarity of the input coil 66 are also in opposition to one another with respect to the output coil 69 . Thus,
H 1TOTAL =H m1 +H c1 −H c2
and
H 2TOTAL =H m2 +H c3 +H c4 .
Therefore, H c1 and H c2 cancel one another out and H c3 and H c4 cancel one another out with respect to the output coil 69 such that
H 1TOTAL =H m1
and
H 2TOTAL =H m2 .
Accordingly, the magnetizing force produced by the current in the output coil 69 only opposes the flux from the magnets 40 and 42 and does not affect the input coils 60 , 62 , 64 , 66 since polarities of the input coils 60 and 62 and the input coils 64 and 66 are in opposition to one another with respect to the output coil 69 . Such orientation demonstrates that the input coils 60 , 62 , 64 , 66 indirectly control the output and are immune from the effect of Lenz's Law.
Furthermore, the standard equation for the transformer is
E out = 4.44 f N out B m A 10 8
where E out is the electromotive force in the output coil 69 , N out is the frequency, N out is the number of turns of the output coil 69 , B m is the magnetic flux density, and A is the cross-sectional area in cm 2 . The standard equation for the magnetizing force of the output coil 69
H out = 0.4 π N out I out L out
where N out is the number of turns of the output coil 69 , I out is the current through the coil 69 , and L out is the length of the coil 69 . Note that frequency is a component of the standard equation for the transformer but is not a component of the standard equation for magnetizing force. Thus, by increasing the frequency and maintaining the current flowing through the input coils 60 , 62 , 64 , 66 , the electromotive force in the output coil 69 is increased, but the opposing magnetizing force produced by the output coil 69 remains the same.
FIG. 6 is a schematic diagram depicting an exemplary embodiment of the load 70 of FIG. 2 . In one embodiment, the load 70 comprises a variable resistor 98 , such as, for example, a potentiometer, connected between the output coil 69 and ground 99 . The maximum power output delivered to the load 70 is determined by adjusting the variable resistor 98 such that the voltage across the variable resistor 98 is equal to approximately half of the no load voltage. Once the voltage across the variable resistor 98 is half of the no load voltage, the load impedance matches the source impedance. According to the maximum power theorem, when the load impedance matches the source impedance, maximum power is transferred to the load 70 .
Accordingly, when the voltage across the variable resistor 98 is half the no load voltage, the current flowing through the resistor is measured. The total power output is determined by the formula
P out =V out I out
where P out is the power output, V out is the voltage across the load 70 , and I out is the current through the load 70 . Thus, when the no load voltage is 64 V, the variable resistor 98 is adjusted until the load voltage is approximately 32 V. The current is then measured and multiplied by the load voltage to determine the power output (P out ).
Example I
Using the exemplary magnetic power converter 10 discussed above, a test was performed with the following parameters:
Input Input Frequency Power Output Power Power Boost (Hz) (W) (W) (%) 60 3.155 2.940 −6.8 70 3.079 3.011 −2.2 80 3.079 3.054 −0.8 90 3.082 3.130 1.5 100 3.053 3.180 4.2
Accordingly, as the input frequency increased, the output power (P out ) increased with no corresponding increase to the input power (P in ). FIG. 7 depicts the input signal 188 applied in this test, a bipolar sine wave, and the output signal 189 , which resembles a full wave rectified sine wave floating about a reference. Note that the output frequency is double that of the input.
FIG. 8 depicts a magnetic power converter 100 according to another exemplary embodiment of the present disclosure. The magnetic power converter 100 comprises a generally figure-8 shaped core 102 comprising a left leg 104 , a right leg 106 , a middle leg 108 , an upper transverse piece 110 , and a lower transverse piece 112 . The left leg 104 , the right leg 106 , and the middle leg 108 each extend from the upper transverse piece 110 to the lower transverse piece 112 . In one embodiment, the core 102 comprises a one-inch thick stack of 29 gauge M19 electrical steel laminations, but other isotropic materials, such as M14 electrical steel, involving varying depths may be utilized in the core 102 in other embodiments. The left leg 104 comprises a toroid 114 having a left portion 116 and a right portion 118 . The left portion 116 and the right portion 118 comprise pinch points 120 and 122 , respectively, wherein the toroid 114 becomes narrow. In one embodiment, a ratio of the length (L) of each pinch point 120 and 122 to the corresponding depth (D) of each pinch point 120 and 122 along that length is 0.8:1. For example, in one embodiment, the length (L) of the pinch point 120 is 0.2 inches and the depth (D) of the pinch point 120 is 0.25 inches. However, other pinch point 120 and 122 ratios involving other lengths and depths are possible in other embodiments.
The middle leg 108 comprises a permanent magnet 130 positioned within the middle leg 108 such that the north pole 134 of the magnet 130 is oriented towards the upper transverse piece 110 and the south pole 135 of the magnet is oriented towards the lower transverse piece 112 . The permanent magnet 130 provides a constant magnetic flux throughout the core 102 . In one embodiment, the permanent magnet 130 comprises a neodymium-iron-boron magnet having a magnetic energy product of fifty-two (52) MGOe, although other types of permanent magnets 130 having varying magnetic energy products are possible in other embodiments. The right leg 106 comprises a uniform width between the upper transverse piece 110 and the lower transverse piece 112 . In one embodiment, the right leg 106 is one inch wide, but other widths are possible in other embodiments.
The magnetic power converter 100 further comprises an input coil 140 positioned around the pinch point 120 and an input coil 142 positioned around the pinch point 122 . Each input coil 140 and 142 is wound around a bobbin (not shown) comprising insulative material, such as, for example, polyoxymethylene plastic (Delrin®). The bobbins (not shown) are positioned such that the coils 140 and 142 are positioned around the corresponding pinch points 120 and 122 , respectively. [Note, therefore, that the input coils 140 and 142 as shown in FIG. 8 are schematic representations of the coils, and do not depict the actual physical topography of the coils.] The input coil 140 is positioned such that the electromagnetic polarity of the coil 140 is oriented towards the lower transverse piece 112 , and the input coil 142 is positioned such that the electromagnetic polarity of the coil 142 is oriented towards the upper transverse piece 110 . The input coils 140 and 142 are connected in series to a power source 149 . The power source 149 is configured to provide electrical current to the input coils 140 and 142 . No electrical current flows through the coils 140 and 142 when no input signal is provided by the power source 149 . However, electrical current flows through the coils 140 and 142 and induces a control flux, discussed in more detail hereafter, in the toroid 114 when an input signal is provided by the power source 149 .
Each input coil 140 and 142 comprises insulated multifurcate wiring. In one embodiment, each input coil 140 and 142 comprises twenty-two strands of number thirty-six (36) copper wire. However, other types of wiring involving different numbers of strands are possible in other embodiments. In one embodiment, each of the coils 140 and 142 has 105 turns and a resistance of 0.76 Ohms (Ω), although different resistances and numbers of turns may be utilized in other embodiments.
The magnetic power converter 100 further comprises an output coil 159 positioned around the right leg 106 . When a change in magnetic flux traveling through right leg 106 occurs, an electromotive force is induced in the output coil 159 causing the output coil 159 to generate electrical power to a load 70 . The output coil 159 comprises insulated multifurcate wiring. In one embodiment, the output coil 159 comprises a dual coil having sixteen strands of number thirty-two (32) copper wire and six hundred (600) turns, but different types of coils having more or fewer turns are possible in other embodiments.
In one exemplary embodiment, assume that the core 102 comprises M19 electrical steel and the permanent magnet 130 is removed from the core 102 . Further assume that the length of the pinch points 120 and 122 is 0.2 inches and the depth of the pinch points 120 and 122 is 0.25 inches. Also assume that each input coil 140 and 142 comprises twenty-two (22) strands of number thirty-six (36) copper wire having one hundred five (105) turns and a resistance of 0.76Ω, and that the output coil 159 comprises sixteen (16) strands of number thirty-two (32) copper wire having six hundred (600) turns. Furthermore, assume that the coils 140 and 142 are oriented in opposite directions with respect to the output coil 159 . Finally, assume that an input signal is provided by the power source 149 such that the power source 149 provides 980 mA of current through the input coils 140 and 142 .
FIG. 9 depicts the control flux traveling through the toroid 114 if the permanent magnet 130 were removed from the core 12 and power source 149 ( FIG. 8 ) were providing an input signal to the input coils 140 and 142 . As shown by FIG. 9 , when power source 149 provides an input signal, the input coil 140 ( FIG. 8 ) induces a control flux 160 in the left portion 116 of the toroid 114 . Due to the orientation of the coil 140 , the control flux 160 travels down the left portion 116 in the direction indicated by directional arrow 164 . Furthermore, the input coil 142 ( FIG. 8 ) induces a control flux 162 in the right portion 118 of the toroid 114 which travels in the direction indicated by the directional arrow 165 . Accordingly, the control flux 160 induced by the input coil 140 and the control flux 162 induced by the input coil 142 are in opposition to one another with respect to the output coil 159 ( FIG. 8 ) but travel in the same circumferential direction within the toroid 114 .
When the power source 149 provides an input signal, the control flux 160 and 162 induced by the input coils 140 and 142 , respectively, thus travels in a counter-clockwise direction within the toroid 114 . Importantly, as shown by FIG. 9 , none of the control flux 160 and 162 escapes the toroid 114 to the right leg 106 . Thus, the ability of the control flux 160 and 162 to remain captive within the toroid 114 demonstrates the magnetic isolation of the input coils 140 and 142 from the output coil 159 , which is significant in indirectly controlling the output coil 159 and thereby mitigating the effect of Lenz's Law on the input coils 140 and 142 . In other embodiments, the input coils 140 and 142 may be oriented in opposite directions such that they produce control flux which travels in a clockwise direction within the toroid 114 .
FIG. 10 illustrates magnetic flux produced by the permanent magnet 130 when no input power is applied to the core 102 . The permanent magnet 130 is positioned within the middle leg 108 of the core 102 and the magnet 130 comprises a neodymium iron boron magnet having a magnetic energy product of 52 MGOe. No input signal is provided by the power source 149 . As shown by FIG. 10 , the permanent magnet 130 produces magnetic flux which travels through the core 102 along a plurality of magnetic flux paths 166 , 168 , and 170 . The magnetic flux of the magnetic flux path 166 travels from the north pole 134 of the magnet 130 , up the middle leg 108 , along the upper transverse piece 110 to the left leg 104 , down the left leg 104 through the left portion 116 of the toroid 114 , along the lower transverse piece 112 , and up the middle leg 108 to the south pole 135 . The magnetic flux of the magnetic flux path 168 travels up from the north pole 134 of the magnet 130 along the middle leg 108 to the upper transverse piece 110 , across the upper transverse piece 110 to the left leg 104 , down the left leg 104 through the right portion 118 of the toroid 114 to the lower transverse piece 112 , and through the lower transverse piece 112 to the south pole 135 of the magnet 130 via the middle leg 108 . The magnetic flux of the magnetic flux path 170 travels away from the north pole 134 of the magnet 130 , up the middle leg 108 to the upper transverse piece 110 , along the upper transverse piece 110 to the right leg 106 , down the right leg 106 and along the lower transverse piece 112 and back up the middle leg 108 to the south pole 135 of the magnet 130 . Thus, when no input signal is provided by the power source 149 , the magnetic flux of the magnetic flux paths 166 and 168 travels in a counter-clockwise direction and the magnetic flux of the magnetic flux path 170 travels in a clockwise direction.
In the embodiment described above, the magnetic flux density (B m ) in the pinch point 120 is approximately 9.8 KG, the magnetic flux density (B m ) in the pinch point 122 is approximately 9.8 kilogauss (KG), and the magnetic flux density (B m ) in the right leg 106 is approximately 7.7 KG when no input signal is provided by the power source 149 . Referring to FIG. 5 , when the magnetic flux density in the pinch points 120 and 122 is 9.8 KG, the respective relative permeability in each pinch point 120 and 122 is approximately 7,200, which is relatively high. Furthermore, when the magnetic flux density through the right leg 106 is 7.7 KG, the relative permeability through the right leg 106 is approximately 7,900, which is near the maximum permeability for M19 electrical steel. Accordingly, the reluctance through such magnetic flux paths 166 , 168 , and 170 is low when no input power is applied to the core 102 .
Significantly, the core 102 is dimensioned such that the lengths of the magnetic flux paths 166 , 168 , and 170 are approximately equal when no electrical current flows through the input coils 140 and 142 . Thus, magnetic flux traveling through the magnetic flux paths 166 and 168 travels generally the same distance as flux traveling through the magnetic flux path 170 . Such dimensions form a balanced reluctance bridge which allows the input coils 140 and 142 to be immune from the effect of Lenz's Law when no input signal is provided by the power source 149 .
Note however that the magnetic flux paths 166 and 168 are slightly longer than the magnetic flux path 170 . The effect of the shorter path 170 is offset by the larger cross-sectional area of the flux path 170 .
FIG. 11 illustrates flux flowing through the core 102 when input power is applied to the core 102 . The permanent magnet 130 is positioned within the middle leg 108 of the core 102 and the power source 149 ( FIG. 8 ) provides an input signal to the input coils 140 and 142 ( FIG. 8 ). As shown by FIG. 11 , when the power source 149 provides an input signal, electrical current flows through each input coil 140 and 142 ( FIG. 8 ) and induces the control flux 160 and 162 in the toroid 114 . When the electrical current is relatively small, such as for example, 100 mA, the control flux 160 and 162 is relatively low, the magnetic flux density in the pinch points 120 and 122 is relatively low, and a small amount of PM magnetic flux is displaced from the toroid 114 . However, when the electrical current is increased, the control flux 160 and 162 becomes relatively high. When the electrical current flowing through the coils 140 and 142 is increased to 980 mA, the magnetizing force (H c1 ) and (H c2 ) produced by each coil 140 and 142 is equal to approximately 254.54 Oe. Furthermore, the magnetic flux density (B c1 ) and (B c2 ) through each respective pinch point 120 is approximately 17.5 KG, while the magnetic flux density through the output (B out ) is equal to only approximately 11.7 KG. Thus, each control flux (φ c1 ) 160 and (Φ c2 ) 162 is equal to approximately 28,207.5 Mx. Referring to FIG. 5 , when the magnetic flux density is equal to approximately 17.5 KG, the relative permeability of the pinch points 120 and 122 is equal to approximately 60. Such low permeability causes the reluctance to become high, creating virtual air gaps in the pinch points 120 and 122 . When the magnetic flux density in the right leg 106 is equal to approximately 11.7 KG, however, the relative permeability in the right leg 106 is equal to approximately 4,800. Therefore, a significant amount of the magnetic flux produced by the permanent magnet flows through the magnetic flux path 170 rather than through the magnetic flux paths 166 and 168 since the permeability of the right leg 106 is significantly higher than the permeability of the pinch points 120 and 122 when current flows through the coils 140 and 142 .
When the magnetic flux from the magnetic flux paths 166 and 168 is diverted through the magnetic flux path 170 , the magnetic flux flowing through the right leg 106 increases significantly. According to Faraday's Law of induction, such a change in magnetic flux induces an electromotive force in the output coil 159 , thereby converting the potential magnetic energy of the magnet 130 into kinetic electrical energy which may be used to provide electrical power to a load 70 .
Furthermore, as set forth above, Lenz's Law states that the polarity of the electromotive force in the output coil 159 produces a current whose magnetizing force opposes the original change in flux. Thus, the magnitude of the opposing magnetizing force produced by the output coil 159 is equal to the magnitude of the total magnetizing force (H TOTAL ) produced by the input coils 140 and 142 and the magnet 130 . The total magnetizing force (H TOTAL ) is set forth in the equation
H TOTAL =H m +H c1 +H c2
where H m is the magnetizing force produced by the magnet 130 , H c1 is the magnetizing force produced by the input coil 140 , and H c2 is the magnetizing force produced by the input coil 142 . As set forth above, the magnetizing force (H c1 ) produced by the input coil 140 and the magnetizing force (H c2 ) produced by the input coil 142 are equal in magnitude. However, it is significant to note that the input coils 140 and 142 are opposite in polarity with respect to the output coil 159 . Thus,
H TOTAL =H m +H c1 −H c2 .
Since H c1 and H c2 are equal in magnitude, they cancel one another out with respect to the output coil 159 such that
H TOTAL =H m .
Accordingly, the opposing magnetizing force produced by the current in the output coil 159 only opposes the magnetizing force (H m ) of the magnet 130 , thereby effectively isolating the input coils 140 and 142 from the output coil 159 and immunizing the input coils 140 and 142 from the effect of Lenz's Law. However, due to the fact that the input coils 140 and 142 are indirectly controlling the permanent magnet 130 , the magnetizing force produced by the current in the output coil 159 only opposes the flux from the magnet 130 even if the input coils 140 and 142 are not in opposition. Thus, the opposing polarities of the input coils 140 and 142 are used to clearly demonstrate the isolation of the input coils 140 and 142 from the output coil 159 .
The total input power is defined by the equation
P in =I in 2 R in
where I in is the input current and R in is the total input resistance. Thus, when the input current (I in ) is equal to 980 mA, the total input power (P in ) of the magnetic power converter 100 is set forth in the equation
P in =(0.980 A) 2 ×(1.52Ω)
which equals approximately 1.46 W. As set forth above, frequency is a component of the standard equation for the transformer but is not a component of the standard equation for magnetizing force. Thus, by increasing the frequency of the current flowing through the input coils 140 and 142 , the electromotive force in the output coil 159 is increased, but the magnetizing force produced by the output coil 159 remains the same.
FIG. 12 is a top plan view of a magnetic power converter 200 according to another exemplary embodiment of the present disclosure. This embodiment has flux patterns substantially similar to the embodiment of FIGS. 8-11 discussed above, and has a slightly different physical topology. The magnetic power converter 200 comprises a generally figure-8 shaped core 202 comprising a left leg 204 , a right leg 206 , a middle leg 208 , an upper transverse piece 210 , and a lower transverse piece 212 . The left leg 204 , the right leg 206 , and the middle leg 208 each extend generally perpendicularly from the upper transverse piece 210 to the lower transverse piece 212 .
In one embodiment, the core 202 comprises uniformly one-inch thick stack of 29 gauge M19 electrical steel laminations. Other isotropic materials, such as M14 electrical steel, with varying depths may be utilized in the core 202 in other embodiments. The M19 electrical steel comprising the core 202 is comprised of multiple layers of 29G (0.014 inch thick) steel welded together in this embodiment.
The left leg 204 comprises a toroid 214 having a left portion 216 and a right portion 218 . The left portion 216 and the right portion 218 comprise pinch points 220 and 222 , respectively, wherein the toroid 214 becomes narrower. In one embodiment, a ratio of the length (L) of each pinch point 220 and 222 to the corresponding depth (D) of each pinch point 220 and 222 along that length is 0.8:1. For example, in one embodiment, the length (L) of the pinch point 220 is 0.2 inches and the depth (D) of the pinch point 220 is 0.25 inches. However, other pinch point 220 and 222 ratios involving other lengths and depths are possible in other embodiments.
The left leg 204 comprises a neck 258 disposed above the toroid 214 between the toroid 214 and the upper transverse piece 210 . The left leg 204 further comprises a neck 265 disposed below the toroid 214 between the toroid 214 and the lower transverse piece 212 . The neck has a width of approximately 1 inch in this embodiment.
The toroid 214 further comprises a left upper toroid surface 266 on the left portion 216 and a right upper toroid surface 267 on the right portion 218 . The left upper toroid surface 266 and the right upper toroid surface 267 are disposed beneath the neck 258 . The toroid 214 further comprises a left lower toroid surface 266 a on the left portion 216 and a right lower toroid surface 267 a on the right portion 218 . The left lower toroid surface 266 a and the right lower toroid surface 267 a are disposed above the neck 265 .
The left portion 216 of the toroid 214 is bounded by a left side surface 301 , which is generally flat. The right portion 218 of the toroid 214 is bounded by a right side surface 302 , which is generally flat.
The toroid 214 further comprises a central opening 306 , which is generally oblong and is bounded by a curved surface 262 , a curved surface 263 , a curved surface 262 a , a curved surface 263 a , an upper flat surface 304 , a lower flat surface 305 , a right vertical surface 307 , and a left vertical surface 308 . The right and left vertical surfaces 307 and 308 define the length (L) of the pinch point 222 and 220 , respectively.
The middle leg 208 comprises a permanent magnet 230 positioned within the middle leg 208 such that the north pole 234 of the magnet 230 is oriented towards the upper transverse piece 210 and the south pole 235 of the magnet is oriented towards the lower transverse piece 212 . The permanent magnet 230 provides a constant magnetic flux throughout the core 202 . In one embodiment, the permanent magnet 230 comprises a one inch cube of neodymium-iron-boron magnet having a magnetic energy product of fifty-two (52) MGOe, although other types of permanent magnets 230 having varying magnetic energy products are possible in other embodiments.
The right leg 206 has a substantially uniform width between the upper transverse piece 210 and the lower transverse piece 212 . In one embodiment, the right leg 206 is one inch wide, but other widths are possible in other embodiments.
Like the embodiment shown in FIG. 8 , the magnetic power converter 200 further comprises an input coil (not shown) positioned around the pinch point 220 and an input coil (not shown) positioned around the pinch point 222 . Each input coil is wound around a bobbin (not shown) comprising insulative material, such as, for example, polyoxymethylene plastic (Delrin®), and the input coils are in series with one another. The bobbins (not shown) are positioned such that the coils are surround the corresponding pinch points 220 and 222 . The polarity of the input coils in this embodiment is substantially similar to that of the input coils 120 and 122 of FIG. 8 .
Like the embodiment shown in FIG. 8 , the magnetic power converter 100 further comprises an output coil (not shown) positioned around the right leg 206 . When a change in magnetic flux traveling through right leg 206 occurs, an electromotive force is induced in the output coil causing the output coil to generate electrical power to a load (not shown).
In the illustrated embodiment, the core 202 is formed from two portions, an upper portion 203 and a lower portion 205 , which portions 203 and 205 are joined at a joint J 1 on the left portion 216 of the toroid 214 , at a joint J 2 on the right portion 218 of the toroid 214 , and at a joint J 3 on the right leg 206 . The upper portion 203 is joined to the lower portion 205 via clamps (not shown) built into the bobbins (not shown) on the left leg 204 and the right leg 206 , as further discussed herein.
The magnet 230 extends between a surface 275 of an extension 207 of the upper portion 203 and a surface 276 of an extension 209 on the lower portion 205 . The extension 207 , the magnet 230 , and the extension 209 form the middle leg 208 . The magnet 230 is held in place by the clamps (not shown) on the left leg 204 and the right leg 206 .
The upper portion 203 comprises a plurality of tooling holes 211 that extend through the core 202 and are used in assembling the upper portion 203 to the lower portion 205 . In the illustrated embodiment, the upper portion 203 comprises two (2) tooling holes 211 , though other embodiments may employ more or fewer tooling holes 211 . The tooling holes 211 in the illustrated embodiment comprise 0.255 diameter circular holes.
The lower portion 205 also comprises a plurality of tooling holes 213 that extend through the core 202 and are used in assembling the upper portion 203 to the lower portion 205 . In the illustrated embodiment, the lower portion 205 comprises two (2) tooling holes 213 , though other embodiments may employ more or fewer tooling holes 213 . The tooling holes 213 in the illustrated embodiment comprise 0.255 diameter circular holes.
FIG. 13 is a dimensioned top plan view of the top portion 203 of the core 202 ( FIG. 12 ) according to an exemplary embodiment of the disclosure. Note that the bottom portion 205 is substantially similar to and a mirror image of the top portion 203 in this embodiment.
The neck 258 is bounded by curved surfaces 256 and 257 . The curved surfaces 256 and 257 each comprise a 0.2 inch radius in this embodiment. The left portion 216 and the right portion 218 of the toroid 214 ( FIG. 12 ) are somewhat mirror imaged to one another. However, the left upper toroid surface 266 of the left portion 216 is slightly shorter than the right upper toroid surface 267 of the right portion 218 . In the illustrated embodiment, the upper toroid surface 266 of the left portion 216 is 0.700 wide and the upper toroid surface 267 of the right portion 218 is 0.800 wide. This difference in lengths is important because when flux (not shown) travels from the magnet 230 ( FIG. 12 ) through the left portion 216 and the right portion 218 , the flux needs to distribute equally between the left portion 216 and the right portion 218 . The flux path through the right portion 218 requires a sharper turn than the path through the left portion 216 , such that if the right portion 218 was identical to the left portion 216 , the left portion 216 would receive more flux than the right portion 218 . Shortening the upper toroid surface 266 offsets this difference and enables substantially identical flux flow through the left portion 216 and the right portion 218 .
The left portion 216 of the toroid 214 comprises a curved surface 262 with a 0.3 inch radius in this embodiment. The right portion 218 of the toroid 214 comprises a curved surface 263 with a 0.3 inch radius in this embodiment.
The extension 207 from the upper portion 203 comprises curved surfaces 259 which have a 0.4 in radius in this embodiment. Lips 260 and 261 extend from the extension 207 and bound right and left sides of the magnet 230 ( FIG. 12 ). The surface 275 bounds the north pole side of the magnet 230 .
FIG. 14 is a top plan view of the magnetic power converter 200 of FIG. 12 , with a bobbin 277 installed on the left portion 216 of the toroid 214 , a bobbin 278 installed on the right portion 218 of the toroid 214 , and a right leg bobbin 279 installed on the right leg 206 .
The bobbins 277 and 278 each comprise a plurality of insulated multifurcate wires 280 . In one embodiment, each of the wires 280 comprises twenty-two strands of number thirty-six (36) copper wire. However, other types of wiring involving different numbers of strands are possible in other embodiments. The wires 280 on the bobbin 277 comprise a left input coil 240 on the left portion 216 ( FIG. 12 ) of the toroid 214 ( FIG. 12 ). The left input coil 240 initiates at a lead point F 1 and terminates at a lead point S 1 . The wires 280 on the bobbin 278 comprise a right input coil 242 on the right portion 218 ( FIG. 12 ) of the toroid 214 ( FIG. 12 ). The right input coil 242 initiates at a lead point F 2 and terminates at a lead point S 2 . During operation of the magnetic power converter 200 , the lead point S 1 is connected directly to the lead point S 2 , such that the input coils 240 and 242 are in series.
In one embodiment, each of the coils 240 and 242 has 205 turns and a resistance of 0.76 Ohms (Ω), although different resistances and numbers of turns may be utilized in other embodiments.
The input coils 240 and 242 are connected in series to the AC power source 259 . The power source 259 is configured to provide electrical current to the input coils 240 and 242 . In one embodiment, the power source 259 provides a bipolar sine wave input signal.
The right leg bobbin 279 comprises a plurality of insulated multifurcate wires 280 that make up the output coil 299 . In one embodiment, the output coil comprises insulated multifurcate wiring comprising a dual coil having sixteen strands of number thirty-two (32) copper wire and six hundred (600) turns. Different types of coils having more or fewer turns are possible in other embodiments.
The output coil 299 initiates at a lead point F 3 and terminates at a lead point S 3 . The output coil is connected to a load (not shown).
FIG. 15 a is a top plan view of the bobbin 277 of FIG. 15 a . Note that the bobbin 278 of FIG. 14 is substantially similar to the bobbin 277 . An opening 805 extends through the bobbin 277 and is received by the pinch points 220 and 222 ( FIG. 12 ) when the bobbin 277 is installed on the core 202 ( FIG. 12 ). The opening 805 is centrally located in the bobbin 277 and is generally rectangular in shape.
The bobbin 277 further comprises a winding surface 804 that is similar in shape to the opening 805 and spaced apart from the opening 805 . The wires 280 ( FIG. 14 ) are wound around the winding surface 804 , which is generally rectangular. The dimensions of the winding surface are necessarily larger than the opening 805 .
FIG. 15 b is a front plan view of the bobbin 277 of FIG. 15 a . The bobbin 277 comprises an upper portion 806 and a lower portion 807 with an aperture 801 disposed between the upper portion 806 and the lower portion 807 . The winding surface 804 is disposed within the aperture and extends between the upper portion 806 and lower portion 807 .
The opening 805 extends generally vertically through the bobbin 277 and is received by the pinch points 220 and 222 ( FIG. 12 ) when the bobbin 277 is installed on the core 202 ( FIG. 12 ). In this regard, the opening 804 is generally rectangular in cross section, and is sized slightly larger than the pinch points 220 and 222 .
The upper portion 806 and the lower portion 807 of the bobbin 277 each comprise a plurality of openings 810 for receiving fasteners (not shown) for attaching the bobbin 277 to the core 202 ( FIG. 12 ). In this regard, the bobbin 277 acts as a clamp to join the upper portion 203 of the core 202 to the lower portion 205 of the core 202 , as further discussed herein.
FIG. 15 c is a cross-sectional view of the bobbin 277 of FIG. 15 a , taken along section lines A-A. Surface 802 defines a channel 808 ( FIG. 15 d ) that extends generally horizontally through the top portion 806 of the bobbin 277 . Surface 803 defines a channel 809 ( FIG. 15 d ) that extends generally horizontally through the bottom portion 807 of the bobbin 277 . Tapered walls 811 extend from the surfaces 802 and 803 to the opening 805 as shown. The tapered walls 811 help to guide the upper portion 203 ( FIG. 12 ) and lower portion 205 ( FIG. 12 ) of the core 202 ( FIG. 12 ) into place within the opening 805 when the bobbin 277 is being installed on the core 202 .
FIG. 15 d is a side plan view of the bobbin 277 of FIG. 15 a . The channel 808 is recessed into the top portion 806 of the bobbin 277 . Similarly, the channel 809 is recessed into the bottom portion 807 of the bobbin 277 . The width We of the channels 808 and 809 is necessarily slightly larger than the thickness of the core 202 ( FIG. 12 ), as the core 202 is disposed within the channels 808 and 809 when the bobbin 277 is installed on the core 202 .
FIG. 16 a is a top plan view of a clamp plate 820 according to an embodiment of the present disclosure. Two clamp plates 820 are used to couple the bobbin 277 ( FIG. 14 ) to the core 202 ( FIG. 14 ), as further discussed herein. Similarly, two clamp plates 820 are used to couple the bobbin 278 ( FIG. 14 ) to the core 202 ( FIG. 14 ).
Each clamp plate 820 comprises a unitary, generally rectangular plate with a generally smooth and generally flat top surface 823 and a generally smooth and generally flat bottom surface 832 ( FIG. 16 b ). The clamp plate 820 further comprises a plurality of openings 821 extending through the plate for receiving fasteners (not shown) that couple the clamp plate 820 with the bobbin 277 . In the illustrated embodiment, the openings 821 are standard countersunk holes for receiving standard, recessed-head threaded fasteners. The openings 821 are aligned with the openings 810 ( FIG. 15 a ) in the bobbin 277 ( FIG. 15 a ). The illustrated embodiment comprises (4) openings 821 and 810 , though more or fewer openings may be employed in other embodiments.
The clamp plate 820 further comprises a recessed area 822 flanked by two protrusions 825 and 826 on one side of the plate 820 . The recessed area 822 receives the core 202 ( FIG. 14 ) when the clamp plate 820 is installed on the magnetic power converter 200 . The recessed area 822 has a width Wcp that is thus necessarily slightly larger than the thickness of the core 202 . An angled surface 824 extends upwardly from the bottom surface 832 ( FIG. 16 b ) of the clamp plate 820 to the top surface 823 within the recessed area 822 , as shown. A top edge and a bottom edge 829 and 827 , respectively, of the clamp plate 820 are generally straight and generally parallel to one another. A left edge 828 of the clamp plate 820 is generally straight and generally perpendicular to the top edge and bottom edge 829 and 827 .
FIG. 16 b is a front side plan view of the clamp plate 820 of FIG. 16 a . The plate 820 is generally thin and flat, as shown.
FIG. 16C is a right side plan view of the clamp plate 820 of FIG. 16 a . When the clamp 820 is installed, the bottom surface 832 contacts the top surface 830 of both the bobbin 277 and the left upper toroid surface 266 ( FIG. 12 ), as illustrated in FIG. 17 .
FIG. 17 is a partial view of the magnetic power converter 200 of FIG. 14 illustrating the installation of the clamp plates 820 and the bobbins 277 and 278 onto the core 202 . The upper portion 203 of the core 202 is joined to the lower portion 205 of the core 202 as discussed herein, and secured together by the bobbins 277 , 278 and the clamp plates 280 . In order to assembly the magnetic power converter 200 in this fashion, the upper portion 203 and the lower portion 205 are installed into the bobbins 277 and 278 such that the pinch points 220 ( FIG. 12) and 222 ( FIG. 12 ) of the core 202 are received by the openings 805 in the bobbins 277 and 278 , respectively. The core 202 is received by the channels 808 and 809 ( FIG. 15 a ) in the bobbins 277 and 278 .
The clamp plates 820 are then installed by sliding the clamp plates 820 onto the left portion 216 and right portion 218 of the toroid 214 such that the bottom surfaces 832 of the clamp plates 820 rest against the toroid surfaces 266 , 266 a , 267 , and 267 a of the bobbins 277 and 278 . The fasteners (not shown) are then installed through the openings 821 of the clamp plates 820 and through the openings 810 on the bobbins 277 and 278 to secure the clamp plates 820 to the bobbins 277 and 278 . When the clamp plates 820 are rigidly affixed to the bobbins 277 and 278 , the bottom surfaces 832 of the clamp plates 820 press against the toroid surfaces 266 , 266 a , 267 , and 267 a of the bobbins 277 and 278 to rigidly hold the upper portion 203 and lower portion 205 of the core together.
FIG. 18 a is a top plan view of the right leg bobbin 279 according to an exemplary embodiment of the present disclosure. The right leg bobbin 279 comprises a central opening 851 that extends through the bobbin 279 . The opening 851 is generally rectangular in cross section and receives the right leg 206 ( FIG. 12 ) when the upper portion 203 ( FIG. 12 ) and lower portion 205 ( FIG. 12 ) of the core 202 ( FIG. 12 ) are joined together at joint J 3 ( FIG. 12 ). The opening 851 is thus necessarily slightly larger than the right leg 206 .
A plurality of openings 854 receive fasteners (not shown) for coupling a right leg clamp plate 750 ( FIG. 19 ) to the right leg bobbin 850 . A channel 856 is recessed into the right leg bobbin 850 for receiving the core 202 when the right leg bobbin 840 is installed, as further discussed herein.
FIG. 18 b is a front plan view of the right leg bobbin 850 of FIG. 18 a . A winding surface 852 is disposed in the center of the bobbin 850 , and the winding surface extends between a top portion 857 and a bottom portion 858 . The winding surface 850 is generally rectangular in cross section, and the wires 280 ( FIG. 14 ) are wound against the winding surface 850 .
FIG. 18 c is a right side plan view of the right leg bobbin 850 of FIG. 18 a . The channel 856 extends across the top portion 857 and bottom portion 858 and receives the core 202 when the magnetic power converter 200 ( FIG. 14 ) is assembled.
FIG. 19 is a top plan view of a right leg clamp plate 750 that joins the right leg bobbin 850 to the core 202 ( FIG. 14 ). The right leg clamp plate 750 comprises a plurality of openings 855 which receive fasteners (not shown) for coupling the right leg clamp plate 750 ( FIG. 19 ) to the right leg bobbin 850 .
The right leg bobbin 850 and right leg clamp plates 750 are installed in a manner similar to the manner of installing the bobbins 277 and 278 to the core 202 . The right leg clamp plates 750 , when installed, apply pressure to the top portion 203 and the bottom portion 205 of the core 202 to aid in rigidly coupling the top portion 203 to the bottom portion 205 .
FIG. 20 is a top plan view of a magnetic power converter 900 according to another exemplary embodiment of the present disclosure. This embodiment has a similar physical structure to the embodiment depicted by FIG. 12 . The magnetic power converter 900 comprises a generally figure-8 shaped core 902 comprising a left leg 904 , a right leg 906 , a middle leg 908 , an upper transverse piece 910 , and a lower transverse piece 912 . The left leg 904 , the right leg 906 , and the middle leg 908 each extend generally perpendicularly from the upper transverse piece 910 to the lower transverse piece 912 .
In one embodiment, the core 902 comprises uniformly one-inch thick stack of 29 gauge M19 electrical steel laminations. Other isotropic materials, such as M14 electrical steel, with varying depths may be utilized in the core 902 in other embodiments. The M19 electrical steel comprising the core 902 is comprised of multiple layers of 29G (0.014 inch thick) steel welded together in this embodiment.
The left leg 904 comprises a toroid 914 having a left portion 916 and a right portion 918 . The left portion 916 and the right portion 918 comprise pinch points 920 and 922 , respectively, wherein the toroid 214 becomes narrower. In one embodiment, a ratio of the length (L) of each pinch point 920 and 922 to the corresponding depth (D) of each pinch point 920 and 922 along that length is 0.8:1. For example, in one embodiment, the length (L) of the pinch point 920 is 0.2 inches and the depth (D) of the pinch point 920 is 0.25 inches. However, other pinch point 920 and 922 ratios involving other lengths and depths are possible in other embodiments. The other characteristics of the toroid 914 are similar to those of the toroid 214 ( FIG. 12 ) set forth above.
The middle leg 908 comprises a permanent magnet 930 positioned within the middle leg 908 such that the north pole 934 of the magnet 930 is oriented towards the upper transverse piece 910 and the south pole 935 of the magnet is oriented towards the lower transverse piece 912 . The permanent magnet 930 provides a constant magnetic flux throughout the core 902 . In one embodiment, the permanent magnet 930 comprises a one inch cube of neodymium-iron-boron magnet having a magnetic energy product of fifty-two (52) MGOe, although other types of permanent magnets 930 having varying magnetic energy products are possible in other embodiments.
The right leg 906 has a substantially uniform width between the upper transverse piece 910 and the lower transverse piece 912 . In one embodiment, the right leg 906 is one inch wide, but other widths are possible in other embodiments. Note that decreasing the cross-sectional area of the right leg 906 increases the amount of power generated by the magnetic power converter 900 .
The magnetic power converter 900 has a bobbin 977 installed on the left portion 916 of the toroid 914 and a right leg bobbin 979 installed on the right leg 906 . The bobbin 977 comprises a plurality of insulated multifurcate wires 980 . In one embodiment, each of the wires 980 comprises twenty-two strands of number thirty-six (36) copper wire. However, other types of wiring involving different numbers of strands are possible in other embodiments. The wires 980 on the bobbin 977 comprise an input coil 940 on the left portion 916 ( FIG. 12 ) of the toroid 914 ( FIG. 12 ). The input coil 940 initiates at a lead point F 1 and terminates at a lead point S 1 . In one embodiment, the coil 940 has 205 turns and a resistance of 0.76 Ohms (Ω), although different resistances and numbers of turns may be utilized in other embodiments. Note that the magnetic power converter 900 only comprises one input coil 940 , and the electromagnetic polarity of the coil 940 is oriented towards the upper transverse piece 910 .
The input coil 940 is connected to the AC power source 959 via a tank circuit (not shown). The power source 959 is configured to provide electrical current to the input coil 940 . In one embodiment, the power source 959 provides a bipolar sine wave input signal. Note that the input coil 940 should be operated at its resonance frequency. In one embodiment, the input coil 940 resonates at 500 Hz, although other frequencies are possible in other embodiments.
The right leg bobbin 979 comprises a plurality of insulated multifurcate wires 980 that make up the output coil 999 . In one embodiment, the output coil 999 comprises insulated multifurcate wiring comprising a dual coil having sixteen strands of number thirty-two (32) copper wire and six hundred (600) turns. Different types of coils having more or fewer turns are possible in other embodiments.
The output coil 999 initiates at a lead point F 2 and terminates at a lead point S 2 . The output coil 999 is connected to a load (not shown), as set forth above, via a tank circuit (not shown). The output coil 999 should also be operated at its resonance frequency.
FIG. 21 illustrates magnetic flux produced by the permanent magnet 930 when no input power is applied to the core 902 . The permanent magnet 930 is positioned within the middle leg 908 of the core 902 and the magnet 930 comprises a neodymium iron boron magnet having a magnetic energy product of 52 MGOe. No input signal is provided by the power source 959 . As shown by FIG. 21 , the permanent magnet 930 produces magnetic flux which travels through the core 902 along a plurality of magnetic flux paths 966 , 968 , and 970 . The magnetic flux of the magnetic flux path 966 travels from the north pole 934 of the magnet 930 , up the middle leg 908 , along the upper transverse piece 910 to the left leg 904 , down the left leg 904 through the left portion 916 of the toroid 914 , along the lower transverse piece 912 , and up the middle leg 908 to the south pole 935 . The magnetic flux of the magnetic flux path 968 travels up from the north pole 934 of the magnet 930 along the middle leg 908 to the upper transverse piece 910 , across the upper transverse piece 910 to the left leg 904 , down the left leg 904 through the right portion 918 of the toroid 914 to the lower transverse piece 912 , and through the lower transverse piece 912 to the south pole 935 of the magnet 930 via the middle leg 908 . The magnetic flux of the magnetic flux path 970 travels away from the north pole 934 of the magnet 930 , up the middle leg 908 to the upper transverse piece 910 , along the upper transverse piece 910 to the right leg 906 , down the right leg 906 and along the lower transverse piece 912 and back up the middle leg 908 to the south pole 935 of the magnet 930 . Thus, when no input signal is provided by the power source 959 , the magnetic flux of the magnetic flux paths 966 and 968 travels in a counter-clockwise direction and the magnetic flux of the magnetic flux path 970 travels in a clockwise direction. The reluctance through such magnetic flux paths 966 , 968 , and 970 is low when no input power is applied to the core 902 .
Significantly, the core 902 is dimensioned such that the lengths of the magnetic flux paths 966 , 968 , and 970 are approximately equal when no electrical current flows through the input coil 940 . Thus, magnetic flux traveling through the magnetic flux paths 966 and 968 travels generally the same distance as flux traveling through the magnetic flux path 970 . Such dimensions form a balanced reluctance bridge which allows the input coil 940 to be immune from the effect of Lenz's Law when an input signal is provided by the power source 949 .
FIG. 22 illustrates flux flowing through the core 902 of FIG. 20 when input power is applied to the core 902 . The permanent magnet 930 is positioned within the middle leg 908 of the core 902 and the power source 959 ( FIG. 20 ) provides an input signal to the input coil 940 ( FIG. 20 ). As shown by FIG. 22 , when the power source 959 provides an input signal, electrical current flows through the input coil 940 and induces the control flux 960 in the toroid 914 . When the electrical current is relatively small, such as for example, 100 mA, the control flux 960 is relatively low, the magnetic flux density in the pinch points 920 and 922 is relatively low, and a small amount of PM magnetic flux is displaced from the toroid 914 . However, when the electrical current is increased, the control flux 960 becomes relatively high and a majority of the control flux 960 remains captive in the toroid 914 , as shown by FIG. 22 . The control flux 960 remains captive in the toroid 914 due to the high reluctance created by the magnet 930 along the other flux paths 970
When the electrical current flowing through the coil 940 is increased, the magnetic flux density increases, and the relative permeability of the pinch points 920 and 922 decreases. Such low permeability causes the reluctance to become high, creating virtual air gaps in the pinch points 920 and 922 . When the magnetic flux density in the right leg 906 is equal to approximately 11.7 KG, however, the relative permeability in the right leg 906 is relatively high, such as, for example, approximately 4,800. Therefore, a significant amount of the magnetic flux produced by the permanent magnet flows through the magnetic flux path 970 rather than through the magnetic flux paths 966 and 968 ( FIG. 21 ) since the permeability of the right leg 906 is significantly higher than the permeability of the pinch points 920 and 922 when current flows through the coil 940 . Note that the magnetic flux paths 966 , 968 and 970 depicted by FIGS. 21 and 22 do not represent precise physical paths through the core 902 but instead represent the general paths of the magnetic flux from the permanent magnet 930 . Thus, more magnetic flux is flowing through the right leg 906 of the core 902 when electrical current is flowing through the input coil 940 than when no electrical current is flowing through the input coil 940 because the magnetic flux that was flowing through the magnetic flux paths 966 and 968 is now flowing through the magnetic flux path 970 .
When the magnetic flux from the magnetic flux paths 966 and 968 is diverted through the magnetic flux path 970 , the magnetic flux flowing through the right leg 906 increases significantly. According to Faraday's Law of induction, such a change in magnetic flux induces an electromotive force in the output coil 999 ( FIG. 20 ), thereby converting the potential magnetic energy of the magnet 930 into kinetic electrical energy which may be used to provide electrical power to a load (not shown), as set forth above.
Furthermore, as set forth above, Lenz's Law states that the polarity of the electromotive force in the output coil 999 produces a current whose magnetizing force opposes the original change in flux. However, as shown by FIG. 22 , the magnetic power converter 900 is a balanced reluctance bridge and the magnetic flux from the permanent magnet 930 is indirectly controlled by the input coil 940 . Therefore, the magnetizing force only opposes the magnet 930 rather than the input coil 940 since the input coil 940 is isolated from the output coil 999 . Such isolation has been demonstrated above with respect to the magnetic power converters 10 , 100 and 200 . Furthermore, the magnetizing force required to coerce the magnet 930 is relatively high such that the output coil 999 does not produce a force sufficient to coerce the magnet 930 .
The total input power is defined by the equation
P in =I in 2 R in
where I in is the input current and R in is the total input resistance. Thus, when the input current (I in ) is equal to 1010 mA and the input resistance (R in ) is equal to 0.899 Ohms, the total input power (P in ) of the magnetic power converter 900 is set forth in the equation
P in =(0.1010 A) 2 ×(0.899Ω)
which equals approximately 0.919 W. In such embodiment, the total output power (P out ) has been measured at 10.3 W. Accordingly, by indirectly controlling the magnetic flux from the permanent magnet 930 , which is a constant magnetic flux source until coerced, power is generated in the output coil 999 .
Note that the orientation of the electromagnetic polarity of the input coil 940 does not affect the performance of the magnetic power converter 900 . Thus, if the electromagnetic polarity of the input coil 940 is oriented towards the lower transverse piece 912 , the control flux 960 will complete its flux path through the permanent magnet 930 . However, none of the control flux 960 will reach the output coil 999 due to the high reluctance in the lower transverse piece 912 produced by the permanent magnet 930 , as shown by FIG. 22 . Furthermore, as set forth above, the magnetizing force produced by the output coil 999 only opposes the magnetizing force of the permanent magnet 930 thereby mitigating the effect of Lenz's Law. | A rare earth magnet is observed to function as a constant flux generator until coerced. To exploit this law, a Magnetic Power Converter is configured as a figure eight shaped balanced reluctance bridge where a rare earth magnet provides a source of constant flux employed as a working fluid. One side of the bridge drives an output coil and the other side is moderated by a toroid shaped control core acting as a variable reluctance shunt with respect to the magnet. Current in the control coil determines the rate and degree of flux variation across the bridge and therefore the resultant output voltage. Due to a mitigation of Lenz effect, full output loading is not reflected in the input; this property supports real power conversion efficiencies that may have wide applications in alternative energy and green energy generation. | 7 |
This application claims benefit of 60/092,961 filed Jul. 14, 1998.
The present invention is related in general to the field of semiconductor devices, and more specifically to integrated circuits that permit wire bonding to be performed directly over portions of the active circuit area.
BACKGROUND OF THE INVENTION
Two independent trends in semiconductor technology, both with a long history contribute to the urgency for the present invention. The first trend concerns certain processes in the assembly of a semiconductor chip.
It is well known in semiconductor technology that bond pads on silicon integrated circuits can be damaged during wafer probing using fine-tip tungsten needles, further during conventional thermosonic wire bonding to aluminum metallization on the circuits, or during solder ball attachment in chip-to-substrate devices of more recent assembly developments. In wire bonding, particularly suspect are the mechanical loadings and ultrasonic stresses applied by the tip of the bonding capillary to the bond pad. When the damage is not apparent during the bonding process, the defects may manifest themselves subsequently by succumbing to thermo-mechanical stresses generated during the plastic encapsulation, accelerated reliability testing, temperature cycling, and device operation. The damage appears in most cases as microcracks which may progress to fatal fractures in the underlying dielectric material, as chip-outs of brittle or mechanically weak dielectric films, often together with pieces of metal or silicon, or as lifted ball bonds, or as delamination of metal layers.
Recent technological developments in the semiconductor industry tend to aggravate the problem. For instance, newer dielectric materials such as silicon-containing hydrogen silsesquioxane (HSQ) are being preferred due to their lower dielectric constant which helps to reduce the capacitance C in the RC time constant and thus allows higher circuit speed. Since lower density and porosity of dielectric films reduce the dielectric constant, films with these characteristics are introduced even when they are mechanically weaker. Films made of aerogels, organic polyimides, and parylenes fall into the same category. These materials are mechanically weaker than previous standard insulators such as the plasma-enhanced chemical vapor deposited dielectrics. This trend even affects stacks of dielectric layers such as alternating layers of plasma-generated tetraethylorthosilicate (TEOS) oxide and HSQ, or plasma-generated TEOS oxide and ozone-TEOS oxide (which is susceptible to failure much like HSQ). Since these material are also used under the bond pad metal, they magnify the risk of device failure by cracking.
In addition, the spacing between bond pads is being progressively reduced to save valuable silicon real estate. Consequently, the bonding parameters have to become more aggressive to achieve stronger bonds in spite of smaller size. Bonding force and ultrasonic energy during bonding are being increased. Again, the risk of yield loss and lowered reliability is becoming greater.
For conventional bond pad metallization processes, a solution to the aforementioned problems was disclosed in patent application Ser. No. 08/847,239, filed May 1, 1997, titled “System and Method for Reinforcing a Band Pad”, assigned to Texas Instruments Incorporated. Some concepts and methods of this disclosure have been subsequently described in a publication entitled “Elimination of Bond-pad Damage through Structural Reinforcement of Intermetal Dielectrics” by M. Saran et al. (Internat. Reliab. Physics Symp., March 1998). In essence, a mechanically strong metal structure serves as a reinforcement for the mechanically weak dielectric layer. The metal is deposited and then etched to form “reservoirs” to be filled with the dielectric material, for example HSQ. For instance, the metal pattern thus formed may include grid-shaped or crucifix-shaped elements. The metal line widths and spacing are structured to confine much of the HSQ into the reservoirs while minimizing the area of each reservoir so that the HSQ layer is spared the direct mechanical impact of the bonding process.
Since HSQ is deposited by a spin-on process, the sizes of the reservoirs have to remain large enough to be filled controllably with the dielectric. This requirement is contrary to the industry trend for continued shrinking of all circuit feature sizes. Furthermore, the industry-wide trend towards smaller dimensions for increasing circuit speed brought the so-called damascene metallization process recently to wide acceptance. In this process flow, an insulator film is formed first; openings such as trenches are then etched into this film. Next, metal such as copper or aluminum is deposited to fill these openings. Whatever metal is deposited elsewhere on the surface, is removed by grinding and polishing, leaving only the metal embedded in the trenches. This process flow, however, is the inverse of the conventional process underlying the above cited patent application.
Wire bonding and solder ball flip-chip bonding over damascene metal pads are facing the same issues (transfer of mechanical and ultrasonic energies to the bond pads and risks of cracking weak dielectric layers) as in the case of conventional metallization. A patent disclosure titled “Fine-Pitch System and Method for Reinforcing Bond Pads in Semiconductor Devicee” (M. Saran et al., May 1998, assigned to Texas Instruments Incorporated) has been submitted for filing. It teaches the design and fabrication process for metal structures made with the damascene technique reinforcing weak dielectrics under the bond pads.
The second trend concerns aspects of manufacturing cost savings by conserving semiconductor “real estate”. In order to accommodate balls of bonding wires or solder, typical bond pads on silicon integrated circuits have to be of appropriate size (typically ranging from squares of 80×80 μm to squares of 150×150 μm) and therefore consume an area between approximately 1 and 20% of the circuit area, dependent on the number of bond pads and the size of the integrated circuit. For manufacturing and assembly reasons, the bond pads are arranged in rows along the periphery of the circuit, usually stringed along all four chip sides.
Until now, all semiconductor devices manufactured had to exclude the area covered by the bond pads from use for laying out actual circuit patterns because of the high risk of damaging the circuit structures due to the unavoidable forces needed in the bonding process. Evidently, considerable savings of silicon real estate can be obtained if circuit patterns could be allowed to be laid out under the bond pad metal. One way to achieve this would be to create another level of metallization dedicated solely to bond pad formation. This level would be built over a protective overcoat covering an active circuit area. In existing technology, however, a special stress buffer layer of polyimide has to be applied between the protective overcoat and the extra metal layer, as shown by K. G. Heinen et al. (“Wire Bonds over Active Circuits”, Proc. IEEE 44th Elect. Comp. Tech. Conf., 1994, pp. 922-928). The cost of applying this polyimide layer has so far prohibited the implementation of the bonds-over-active-circuit concept.
An urgent need has therefore arisen for a low-cost, reliable mass production system and method allowing the manufacture of wire and solder ball bonds directly over active integrated circuits areas. The system should provide stress-free, simple, and no-cost-added bond pads for flexible, tolerant bonding processes even when the bond pads are situated above one or more structurally and mechanically weak dielectric layers. The system and method should be applicable to a wide spectrum of design, material and process variations, leading to significant savings of silicon, as well as improved process yield and device reliability. Preferably, these innovations should be accomplished using the installed process and equipment base so that no investment in new manufacturing machines is needed.
SUMMARY OF THE INVENTION
The present invention is related to high density integrated circuits, especially those having high numbers of metallized inputs/outputs, or “bond pads”. These circuits can be found in many device families such as processors, digital and analog devices, memory and logic devices, high frequency and high power devices, and in both large and small area chip categories. The invention saves significant amounts of silicon real estate and thus permits the shrinking of integrated circuit chips. Consequently, the invention helps to alleviate the space constraint of continually shrinking applications such as cellular communications, pagers, hard disk drives, laptop computers and medical instrumentation.
In accordance with the present invention, a bond pad reinforcing system and method are provided which utilize specific portions of the actual integrated circuit as the means to reinforce weak dielectric layers under the bond pad and thus provide a system strong enough to withstand the mechanical forces required in the bonding process. In other words, the bond pad is placed over portions of the actual circuit, which, in turn, serves as the reinforcement needed for damage-free bonding to the bond pad.
Successful reinforcement requires these circuit portions to be designed and fabricated following certain rules developed by finite element stress modeling, and certain guidelines for applying fine-pattern reinforcing structures, so called “dummy” structures. As defined herein the term “dummy” structure refers to reinforcing structures inserted under the bond pad solely for the purpose of mechanical reinforcement without primarily being a portion of the integrated circuit. In general, these reinforcement rules will either limit the maximum area covered by solid blocks of metal and closely spaced metal patterns, and/or specify a much larger minimum metal pitch. For most circuit designs, these rules keep metal line widths to less than 50 μm and spaces between metal leads to less than 10 μm. Dummy patterns of similar geometries may serve as reinforcements under bond pads where actual circuit patterns are sparse.
The invention utilizes the sequence of processing steps applied to producing the integrated circuit. For any reinforcing structure, the invention accepts one of the following processing steps. When the damascene metallization process is used, the dielectric layers are deposited first and the trenches etched with design rules typical for integrated circuit features. These fine-pitch openings are then filled with metal such that metal and dielectrics are discretely confined to their respective regions. When the conventional metallization process is used, the metal layer is deposited first and then etched to form “reservoirs” to be filled with the dielectric material (for example, HSQ).
It is an object of the invention to reduce the cost of integrated circuit chips by reducing the silicon area consumed for the overall circuit design; this object is achieved through utilizing the areas underneath the (numerous) bond pads by positioning portions of the actual circuit under the bond pad areas while simultaneously exploiting the structural strength of these circuit portions in order to mechanically reinforce the dielectric layers under the bond pad metal.
Another object of the present invention is to advance the process and operation reliability of semiconductor probing, and wire bonded and solder-attached assemblies by structurally reinforcing the bond pad metallizations even for multilevel architectures under the bond pads.
Another object of the invention is to eliminate restrictions on the processes of probing and of wire bonding and solder attachment, thus minimizing the risks of inflicting cracking damage even to very brittle dielectrics.
Another object of the invention is to provide design and layout concepts and process methods which are flexible so that they can be applied to many families of semiconductor products, and are general, so that they can be applied to several generations of products.
Another object of the invention is to provide a low-cost and high-speed process for fabrication, testing and assembly.
Another object of the invention is to use only designs and processes most commonly used and accepted in the fabrication of integrated circuit devices, thus avoiding the cost of new capital investment and using the installed fabrication equipment base.
These objects have been achieved by the teachings of the invention concerning design concepts and process flows suitable for mass production. Various modifications have been successfully employed to satisfy different selections of product geometries and materials.
In one embodiment of the invention, at least one portion of the integrated circuit is disposed under the bond pad, occupying a substantial area under the bond pad. This circuit portion comprises at least one mechanically weak dielectric layer and a reinforcing patterned metal structure disposed in the dielectric layer. Examples for suitable circuit portions under the bond pad include interconnectors, resistors, capacitors, inductors, and electrostatic discharge structures.
In another embodiment of the invention, the circuit portion under the bond pad contains at least one dielectric stack of multiple dielectric layers; a reinforcing patterned structure of electrically conductive material is disposed in the dielectric stack.
In another embodiment of the invention, at least one portion of the integrated circuit is disposed under the bond pad, comprising a mechanically weak dielectric layer and a reinforcing patterned metal structure, and occupying a substantial area under the bond pad. In addition, another dielectric layer is disposed under the bond pad, containing another reinforcing patterned structure. The reinforcing patterned structure may be a joined or interconnected structure. In yet another embodiment of the invention, the reinforcing patterned structure may comprise disjoined or non-interconnected and repeating elements.
In another embodiment of the invention, a first portion of the integrated circuit is disposed under a portion of the bond pad. Furthermore, additional portions of the integrated circuit are disposed under portions of the bond pad. Each circuit portion comprises at least one weak dielectric layer and a reinforcing patterned structure disposed in the dielectric layer.
In yet another aspect of the invention, a method for reinforcing a bond pad in a semiconductor integrated circuit includes the steps of placing at least one portion of the integrated circuit under the bond pad, and providing this circuit portion with at least one dielectric layer and a reinforcing patterned electrically conductive structure disposed in that at least one dielectric layer. Typically, the reinforcing patterned electrically conductive structure comprises at least one metal layer. The process of providing at least one dielectric layer and at least one reinforcing patterned metal structure comprises in one embodiment of the invention the fabrication sequence of the conventional metallization, yet in another embodiment of the invention the fabrication sequence of the damascene metallization.
The technical advances represented by the invention, as well as the objects thereof, will become apparent from the following description of the preferred embodiments of the invention, when considered in conjunction with the accompanying drawings and the novel features set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 refers to prior art. FIG. 1 is a schematic top view of a dummy structure reinforcing the bond pad, made by conventional or damascene metallization processes.
FIG. 2 is a schematic and simplified cross section through a bond pad and its underlying multi-level reinforcing structures, comprising circuit portions and dummy structures according to an embodiment of the invention.
FIGS. 3 and 4 are schematic cross sections of examples of bond pads with underlying reinforcing portions of the integrated circuit in multi-level arrangement.
FIG. 5 is a simplified top view of a bond pad overlying circuit portions and dummy structures in a multi-level reinforcing arrangement according to another embodiment of the invention.
FIG. 6 is a schematic and simplified cross section through a bond pad and its underlying multi-level reinforcing structures, comprising circuit portions and dummy structures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is related to the input/output (I/O) terminals of integrated circuits, commonly referred to as “bond pads”. As defined herein, the term “bond pad” refers to the metallized I/Os of the circuits. A bond pad requires a substantial area of silicon “real estate” (from squares of 80×80 μm to squares of 150×150 μm) in order to serve as a contact to a metal ball in wire bonding or to a solder ball in reflow assembly. In modem circuits, the signal, power and ground needs call for numerous bond pads, ranging in number from 8 to over 1000, causing a significant sacrifice of precious silicon. Furthermore, the processes of wire bonding and solder reflow exert considerable mechanical stress onto the bond pads and their underlying materials so that especially insulators may be threatened by microcracks. The present invention solves both the area and the strength problems of the circuit bond pads.
While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention. The impact of the present invention can be most easily appreciated by highlighting the limitations of the known technology.
FIG. 1 illustrates an approach in known technology for reinforcing the material, especially the mechanically weak insulators, under the bond pad with the help of metallized structures. FIG. 1 shows a joined or interconnected grid structure 11 (made of metal or electrically conductive material) with a plurality of areas 12 for containing and accommodating a large portion of weak dielectric material herein. Accordingly, reinforcing structure 10 provides support and mechanical strength to the mechanically weak dielectric layer, or layers, so that incidents of cracking, cratering and other bonding-related and testing-related failures caused by wire-bonding, soldering, or probing are substantially suppressed.
By way of example, grid structure 11 may be made of copper. The walls of grid 11 are 0.5 μm thick. The grid may occupy a square-shaped area with side length 13 of 80 μm. If the dielectric material filling areas 12 is a stack of mostly HSQ with a thinner overlayer of oxide, each area 12 is square shaped with side length 14 of 3.0 μm. A variety of reinforcing structures are being used, for instance with or without a plurality of connected structural elements; with or without a plurality of repeating structural elements; in single-layer arrangement or in multi-layered stacks. These reinforcing structures can be fabricated in the process sequence of the standard metallization or the sequence of the damascene metallization.
In contrast to the reinforcing capabilities of metal structures like the one shown in FIG. 1, dummy structures still consume precious silicon area for accommodating the (numerous) bond pads and, therefore, do not address the urgent need to save silicon real estate.
This shortcoming of the known technology is eliminated by the present invention, as illustrated in the example of FIG. 2, depicting schematically a preferred embodiment of the invention. A small portion of an integrated circuit is shown as it is made over silicon substrate 200 and its first oxide 201 (thickness typically in the 200 to 1000 nm range). The hierarchy starts with first metal level 210 , which is frequently a sandwich of several metals, for instance sequentially titanium nitride 20 to 40 nm thick, copper-doped aluminum 300 to 600 mn thick, titanium nitride, 20 to 60 nm thick. It is followed by the first interlevel dielectric layer 202 , which may be made of a stack of 100 to 600 nm HSQ followed by 400 to 700 nm oxide. The hierarchy is continued with second metal level 220 of similar composition as metal level 210 , followed by the second interlevel dielectric layer 203 , which again comprises the mechanically weak material HSQ. There is often a third (and fourth, etc.) metal level 230 and a third (and fourth, etc.) interlevel dielectric 204 , before the metal level 240 for the bond pad is reached. For the purpose of illustration, these are all shown as identical dielectric stacks, but this does not need to be so.
As defined herein, the term “hierarchy” refers to a stack of insulating and/or electrically conductive layers positioned on top of each other and processed sequentially; The layers may contain features aligned to each other.
Commonly used techniques for depositing the dielectric layers include chemical vapor deposition, sputtering, or spin-on processes. Preferred materials include silicon dioxide, silicon nitride, oxy-nitride, fluoro-silicate glass (FSG), undoped silicate glass (USG), phosphor-silicate glass (PSG), plasma-generated tetraethylortho-silicate oxide (TEOS), and recently silicon-containing hydrogen silsesquioxane (HSQ), or even gels or a foamy substance, or an organic polymeric such as polyimide and parylene. Each material has its preferred regime for application; for instance, silicon nitride stops penetration by water molecules, phosphorus-doped glass offers lower reflow temperatures, HSQ exhibits very low dielectric constant. Often, however, the desirable characteristics are accompanied by undesirable ones; so are HSQ and gels structurally and mechanically weak, and polymerics may require polymerization at elevated temperatures and may be thermally unstable. The thickness of the layers can be varied widely (from 20 to 1000 nm), but is typically quite uniform across a wafer diameter.
Bond pad metal layer 240 typically comprises 400 to 1000 nm copper-doped aluminum, often over a thin (10 to 200 nm) underlayer of titanium (or titanium nitride, titanium-tungsten, tantalum, tantalum nitride, tantalum silicon nitride, tungsten nitride, or tungsten silicon nitride). It is covered by the moisture-impenetrable protective overcoat 205 a made of silicon nitride or silicon oxy nitride (commonly 200 to 1000 mn thick). The window 205 b (80 to 150 μm wide), opened in the protective overcoat, defines the width of the bond pad 241 , which is usually square shaped. The bond pad will receive the ball or wedge of the bonding wire (not shown), mostly gold, copper, or aluminum. If a ball of solder (some mixture of lead and tin, not shown) is to be affixed to the bond pad, it has to receive first an undermetal (not shown) of a thin film of a refractory metal and a film of a noble metal.
The present invention provides system and method of fabrication for the metal layers 210 , 220 , and 230 under the bond pad area. In FIG. 2, layer 210 comprises portions 211 of the integrated circuit; examples are interconnects, portions of protective structures against electrostatic discharge, precision resistors, capacitors and inductors. These circuit portions 211 occupy only part of the bond pad width; consequently, layer 210 further comprises portions 212 of reinforcing dummy structures, electrically isolated from the circuit patterns, such as described in FIG. 1 . For electrical biasing reasons, some parts of the circuit portions may have electrical connections 213 to diffused moats 214 or other connections 215 to the silicon substrate.
Metal layer 220 in FIG. 2 comprises other portions 221 a and 221 b of the integrated circuit. Examples again include interconnects, portions of protective structures against electrostatic discharge, precision resistors, capacitors and inductors. Care has been taken that the sum of portions 211 and 221 adds up to the complete area of the bond pad 241 . It can, therefore, be stated that bond pad 241 is located over active circuitry and does not consume additional silicon real estate. There may be optional electrical connections 222 between circuit portions 211 and 221 a and 221 b . The balance of metal layer 220 comprises reinforcing dummy structures 223 such as described in FIG. 1 .
Another embodiment of the invention, in which not the whole area of the bond pad is located over circuit portions, is described in FIG. 6 .
In the embodiment of FIG. 2, metal layer 230 is completely made of reinforcing dummy structures 231 , which may, for instance, be a connected grid structure such as described in FIG. 1 . By way of example, if the metallization technology of the integrated circuit calls for the damascene process, then layer 230 will be fabricated by depositing the dielectric material first; commonly used techniques include chemical vapor deposition, sputtering, or spin-on process. Preferred materials are ones mentioned above, including the mechanically weak HSQ. Openings or trenches are etched into this layer; commonly used techniques include sputter etching, and plasma etching. Since masks are typically used for this process, the widths of the openings so created follow the trend in the semiconductor industry towards fine feature sizes and fine line pitch. The widths of the openings ranges from approximately 100 to more than 600 nm for lines, and 40 to 150 μm for reservoirs between the lines.
Next, a suitable conductor, semiconductor, or metal such as aluminum (often doped with up to 2% copper and 1% silicon) or copper is deposited (usually by sputtering, electroplating, or chemical vapor deposition over a sputtered seed layer) over the whole surface, filling the openings/trenches uniformly and forming some blanket over the remainder of the surface. Other examples of conductive materials include a bottom layer made of a stack of titanium/titanium nitride, followed by a layer of aluminum. Note, if copper is used, the stack to be polished usually consists of tantalum nitride and sputtered copper followed by electroplated copper. The blanket is then carefully removed by grinding and polishing, generating a uniformly flat surface of alternating dielectric and metallic portions. The boundaries between the dielectric and the metallic portions are clearly defined, free of spurious material of either kind infringing onto the nearest neighbor portions.
On the other hand, if the metallization technology of the integrated circuit calls for the conventional metallization process, then layer 230 of FIG. 2 will be fabricated by depositing the metal layer first. Openings, or reservoirs, are then etched into the metal layer and filled with dielectric material. When the dielectric material is semiviscous and allows a spin-on technique for filling the openings/reservoirs, the size of the opening has to be large enough to ensure proper filling by the semiviscous dielectric material. In the process of filling, the semiviscous material forms a meniscus at the walls of the opening. Further, a thin film of dielectric is deposited on the remainder of the metal surface between the openings. Consequently, the resulting surface is not uniformly flat, and spurious dielectric material remains on the metal surface outside the openings.
Other preferred embodiments of the present invention are shown in FIGS. 3 and 4. These FIGURES are schematic cross sections through bond pads and the underlying hierarchies of layers reinforcing mechanically weak dielectrics for those applications when active elements of the integrated circuits are placed in the area under the bond pads. Such elements include for example MOS transistors. A comparison of FIG. 3 and FIG. 4 teaches the following design layout rules for successful bond pad reinforcement by active circuit elements:
When the circuit layout includes metal interconnections under the bond pad in addition to the active elements, additional insertion of metal dummy structures may not be necessary to achieve satisfactory reinforcement (example: FIG. 3 ).
When the circuit layout does not include metal interconnections under the bond pad in addition to the active elements, additional insertion of suitable metal dummy structures is needed to achieve satisfactory reinforcement (example: FIG. 4 ). An example is the mesh structure of FIG. 1 .
Dependent on the choice of metal of a continuous metal for the dummy structure, the maximum dimension of a continuous metal feature has to be determined by finite element strength analysis. In the example of FIG. 1 : Maximum width of copper lines 0.5 μm.
Dependent on the choice of dielectric material for the dummy structure, the maximum dimension of a continuous dielectric feature has to be determined by finite element strength analysis. In the example of FIG. 1 : HSQ reservoir side length 2.0 μm.
Referring now to FIG. 3, the bond pad 30 consists of an opening 300 a (for example, 80 μm wide), etched into protective overcoat 300 b (for example, silicon nitride of 500 to 1000 nm thickness), and comprises aluminum or copper about 200 to 1000 nm thick, often with a thin (about 10 to 500 nm) barrier underlayer 301 (made of titanium, titanium nitride, or titanium-tungsten, tantalum, tantalum nitride, tantalum silicon nitride, tungsten nitride, or tungsten silicon nitride). Dielectric layer 302 is typically made of TEOS oxide, silane oxide, FSG, polyimide, or other dielectric with low dielectric constant. Optional layer 303 is made of silicon nitride, silicon oxynitride, silicon carbide, or aluminum nitride (about 20 to 50 nm thick).
Dielectric layer 304 , about 200 to 1000 nm thick, comprises any good quality dielectric such as plasma oxide. It may also consist of FSG, USG, PSG oxides, or some polymeric such as polyimide. Layers 305 and 306 , about 20 to 50 nm thick, are made of nitride or oxynitride. Dielectric layer 307 , about 200 to 1000 nm thick, comprises material with low dielectric constant, such as HSQ, or a stack of oxide (FSG, USG, PSG oxides) and HSQ.
Crucial for the present invention are metal patterns 31 and 32 . They are, for instance, circuit interconnects made of copper, with dense layout rules. Widths 31 a and 32 a can vary from about 0.15 to 50 μm, and spacing 33 a is in the 0.1 to 1.0 range. Patterns 31 and 32 may be surrounded by thin barrier layers 308 similar to layer 301 . Metal patterns 31 and 32 may exhibit vias 31 b and 32 b , about 0.1 to 0.5 nm wide, which reach through pre-metal dielectric layer 309 (typically USG or PSG oxides) to various lower levels in order to make electrical connections to other active or passive circuit elements located under the bond pad area. In FIG. 3, via 31 b connects to poly-silicon layer 310 (about 100 to 300 nm thick and surrounded by sidewall spacer oxide or nitride 311 ), and via 32 b connects to silicide layer 312 . This silicide layer terminates in trench isolation 313 , which may be 50 to 300 nm wide and extend 200 to 500 nm deep into silicon substrate 314 . The gate width 310 a of the MOS transistor is often in the 0.1 to 0.5 μm range, while the overall transistor width is typically 0.5 to 1.0 μm.
Referring now to FIG. 4, the hierarchy of layers, their material compositions and geometries are analogous to those in FIG. 3 . In contrast to FIG. 3, though, the embodiment of FIG. 4 does not comprise the dense circuit pattern of metal interconnects (reference numerals 31 and 32 ) under bond pad 40 . It requires, therefore, metal dummy structures 41 to achieve reinforcement. Structure 41 is patterned in dielectric layer 43 , which may be a stack of a mechanically weak HSQ layer 43 a and an oxide layer 43 b . The bond pad may be connected by vias 42 with the metal dummy structure. In this case, the vias 42 traverse the dielectric layer 44 , which may be a stack of silicon nitride, oxide (FSG, USG, PSG oxides, or polymeric), and silicon nitride (or oxy-nitride) layers. Vias 42 do not have to be located at the periphery of bond pad 40 .
As another embodiment of the invention, FIG. 5 shows a simplified top view of a bond pad 50 overlying a multi-level reinforcing hierarchy of layers with circuit portions 51 and dummy structures 52 . Using identical reference numerals for the same entities, FIG. 6 illustrates a schematic and simplified cross section through the reinforcing hierarchy of layers. The dummy structures are laid out on two complete levels, while the circuit portion consumes part of the bond pad area on another level. As an example, the circuit portion may constitute part of a protection device against electrostatic discharge, especially its interconnection and resistor parts. Another example are interconnective and resistive portions of the circuit. The circuit portion may optionally be connected by via 53 to moat 54 diffused into the silicon substrate 55 .
Materials and geometries of the layers in FIG. 6 are similar to the respective layers in FIG. 2 . The major difference between the embodiments of FIG. 6 and FIG. 2 is the restriction of the circuit portions to a level different from the dummy structures. The goal, though, in both cases is to accommodate as many circuit portions as possible under the bond pad area while reinforcing any mechanically weak dielectrics, and, if necessary, achieve optimum reinforcement by adding reinforcing dummy structures. According to the teachings of the invention, this concept can be applied for both conventional metallization and damascene metallization processes.
While this invention has been described in reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments. | An architecture and method of fabrication for an integrated circuit having a reinforced bond pad comprising at least one portion of the integrated circuit disposed under the bond pad; and this at least one circuit portion comprises at least one dielectric layer and a patterned electrically conductive reinforcing structure disposed in this at least one dielectric layer. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Application No. 61/377,716, filed Aug. 27, 2010 which is hereby incorporated by reference in its entirety and is a Continuation-in-Part of U.S. Nonprovisional patent application Ser. No. 13/218,915, filed Aug. 26, 2011, entitled “A Method and Apparatus for Removing Liquid from a Gas Producing Well”.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIALS SUBMITTED ON A COMPACT DISK
[0003] Not Applicable
BACKGROUND
[0004] 1. Field of the Invention
[0005] This invention relates, in general, to the production of fluids from a hydrocarbon producing well. In particular, this invention relates to efforts to provide systems for the gathering of natural gas which use the space in and around the well site as efficiently as possible.
[0006] 2. Description of the Related Art
[0007] Fluids are produced from hydrocarbon producing formations under the Earth's surface. An example of a hydrocarbon producing formation is a coal seam. Coalbed Methane (CBM) is produced by drilling a well into a coal formation and collecting the entrapped methane gas located within the formation. While entrapped in the formation, the methane gas is under pressure. The gas naturally migrates to the low pressure area created by the well. Liquids such as water similarly migrate to this low pressure area.
[0008] Liquid Removal
[0009] The accumulated liquid must be removed so that gas can continue to flow from the well. In a typical pumping arrangement, the liquid is drawn to the surface through tubing running from a down-hole pump located at the bottom of the well to the surface. In some instances gas under pressure may be used to drive the liquid to the surface. Gas flows from the well through the annulus, the space between the well and the tubing. Once brought to the surface, the liquid must be removed from the well site. Currently, two methods are used to remove the liquid.
[0010] Liquid Removal by Truck
[0011] One method of gathering and disposing of the liquid is to pump fluids directly from the well into localized tanks or other holding facilities. Trucks then travel to and from the collection tank to dispose of the liquid. However, this method requires a great deal of man power, reliable roads, and expensive road maintenance. The weight and amount of travel from the trucks damages roads to well sites as well as any community roads which the trucks must travel on during the trip to the collection facility. Local communities often require gas producer to pay for maintenance of the community roads. The expense and liability of on-road fluid gathering and distribution can be costly and potentially unpopular within the community. In the winter snow and ice can create adverse road conditions that make it difficult for trucks to travel to and from the well site.
[0012] Liquid Removal by Pipeline
[0013] A second method of removing liquid is to install a pipeline for the liquid to enter as it exits the well. The pipeline could run from the well site to a collection facility. Conventionally, the pump jack and/or down-hole pump is the mechanism used to push the liquid through the pipeline because it has positive displacement capabilities far beyond what is necessary to simply bring fluids to the surface. The excess pressure capability can be utilized as the mechanism to push liquid through a pipeline network to the central collection facility. However, a disadvantage of using the pump-jack to force liquid through a pipeline is that the pump jack will cause a pressure surge or water hammer to move through the pipeline. Therefore, a larger diameter pipeline is required to accommodate these short duration surges, than would be required if the same total volume of liquid moved through the pipeline at a substantially constant flow rate.
[0014] Problems Caused by Gas/Liquid Mixtures
[0015] Fluid, brought to the surface by a well, typically contains a liquid component and a gas component. The presence of the gas component raises additional problems which are not fully addressed by conventional methods of gas and liquid separation and removal. When the fluid is pumped directly to the pipeline without conventional gas and liquid separation, any gas entrained in the liquid is typically lost. This problem is further compounded by a condition know as over-pumping. Over-pumping occurs when the pump operates more than is necessary to remove the liquid from the well. Once the liquid is removed from the well and the pump continues to run, natural gas is allowed to escape from the wellbore and is pumped into the tubing and into the liquid pipeline. The presence of gas in the liquid pipeline also makes it difficult to accurately measure the volume of liquid which is removed from the well because currently used methods for measuring flow through a pipeline cannot distinguish between gas flow and liquid flow.
[0016] When gas is introduced into a liquid pipeline the possibility of an air-locking condition is created. Air-locking occurs when gas gathers in the highest elevations in the pipeline and causes a complete or partial blockage of liquid flow. The gathering of gas can be from gas that separates from the fluid mixture or from gas that is introduced when the well is over-pumped. When air-locking occurs the liquid cannot be pushed past the gas blockage. As the pump continues to try to force liquid past the air-lock blockage, the pressure in the portion of the pipe before the blockage continues to increase. When the pressure reaches a pressure beyond the maximum rating of the pipeline, a rupture can occur. Pipeline ruptures can be difficult to diagnose and locate. Furthermore, ruptures can be expensive both in terms of costs associated with repairing damaged equipment and in cleaning up environmental damages from liquid which leaks from the ruptured pipeline.
[0017] In addition to the risk of pipeline rupture, the pump-jack also creates pressure on the wellhead itself and the packing surrounding the wellhead. The pump-jack is typically connected to the down-hole pump by steel rods that extend from the entire depth of the well. The rod connected to the pump-jack at the surface is known as the polish rod because of its smooth and polished surface. A packing material at the wellhead allows the polish rod to move up and down in the well while containing the pressure of the water in the tubing. This packing must be monitored frequently because it often leaks unexpectedly and has to be replaced on a frequent basis. In fact, spillage associated with packing leakage is difficult if not impossible to eliminate.
[0018] Cold Weather
[0019] Another problem associated with current methods of storing, removing, and transporting liquid such as water from a well site is the danger that the liquid will freeze during cold weather. The frozen water can limit well production and also rupture pipelines and promote wellhead spillage.
[0020] Installation and Servicing Concerns
[0021] Finally, current methods of setting up a pumping assembly at a well site take two to three days before the site is ready to begin pumping fluid from the well. Under the current method of installing a pumping assembly, the pump is assembled in a piecemeal fashion at the well site. As a result, even pumping assemblies located close together often are not constructed according to a uniform plan and do not use the same components. The piecemeal method of installation takes a long time to complete and makes maintenance and repair difficult. Furthermore, space within the pumping assembly is not utilized as efficiently as possible. As a result, the footprint of the installed pumping assembly is larger than is necessary to accomplish all functions of the assembly. Similarly, as a result of the lack of uniformity in gas well construction and large footprint area, gas wells generally do not have a uniform aesthetically pleasing appearance.
[0022] In addition to difficulties created by current installation practices, further difficulties arise because gas producing wells must be serviced regularly. To service the down-hole pump and other elements located within the well, a large truck hauling a gin pole and pulley system must drive up to the well site. The pulley system is used to hoist the down-hole portions of the pumping assembly from the well. The problems associated with building and maintaining access roads to the well site, described above for liquid transportation trucks, applies similarly to these service trucks which also must access the well site regularly.
[0023] For the reasons stated above, there is a need for a method and apparatus for removing liquid from a well site which can accomplish liquid removal without the use of hauling trucks or large diameter pipelines. Furthermore, the apparatus and method should prevent complications that lead to air-locking and pipeline ruptures. The method and apparatus should also address the problem of pipeline freezing so that it can be used in cold weather. Finally, there is a need for a method and apparatus for liquid removal which makes more efficient use of space in and around the wellhead and which can be installed more quickly so that pumping can begin in a more timely fashion. Furthermore, the gas well should have a uniform aesthetically pleasing appearance.
BRIEF SUMMARY
[0024] Pumping Fluid at a Wellhead
[0025] A method for pumping fluid at a wellhead according to the present invention requires forming a well center unit comprising: a pumping assembly for pumping fluid from a well which may be a mechanical pump directed to raising the fluid; a support structure for supporting the assembly; a holding tank positioned below the support structure, having an inflow port, connected to the pumping assembly, and an outflow port; and a holding tank pump and/or a compressor to compress the gas to drive fluid from the tank. The compressor can compress the gas before after it leaves the tank. The well center unit is connected to the wellhead and into the well. The well center unit could include a power source capable of operating the pumping assembly, the holding tank pump, and/or a gas compressor. The holding tank could allow for depressurization.
[0026] The invented method may further include: allowing the fluid in the holding tank to separate to a liquid component and, if a gas component is present, a gas component; removing the gas component from the holding tank through a gas outflow conduit; and forcing the gas component to a gas pipeline either by a pump or by compressed gas. The liquid component could similarly be removed from the holding tank at a substantially constant flow rate through an outflow port having a smaller cross-sectional area than the inflow port. The invention could further include warming the fluid in the holding tank so that the fluid will not freeze. Exhaust heat, vented from the power source, could be used to create the warming.
[0027] The well center unit could be anchored to the ground and also to the wellhead. In addition, the support structure could have a removable gin pole for servicing the well when necessary. Gas and water metering devices could be housed underneath the support structure. A gas conditioning device could also be located underneath the support structure. The well center could be enclosed with a guarding structure in order to prevent access from unwanted persons.
[0028] Well Management Center Unit
[0029] A well management center unit according to the present invention includes: a fluid forcing assembly which may be a mechanical pump to bring to the surface fluid from a well; a support structure for supporting the assembly; a holding tank positioned below the support structure, having an inflow port, connected to the fluid forcing assembly, and an outflow port; and a holding tank pump or compressed gas device. The well management center could further include a power source that operates both the fluid forcing assembly and the holding tank pump or compressed gas device. Exhaust heat from the power source could warm liquid in the holding tank. The well management center could further include a removable gin pole to be used when servicing the center. The gin pole is used for hoisting down-hole elements of the pumping apparatus from the well. The gin pole has a crank which could be turned by hand. The crank could also be powered by the same single power source which powers the down-hole pump, the holding tank pump, and the gas compressor. The well management center could be enclosed within a housing structure for security purposes. It could further include water and gas metering apparatus within the support structure. The well management center could include a gas conditioning device.
[0030] Removing Liquid
[0031] A method of removing a liquid from a gas producing well according to the present invention requires accepting a periodic surge of fluid, brought to the surface by a down-hole well pump driven by a power source or by compressed gas, into a holding tank located under the wellhead, through an inflow conduit having a cross-sectional area capable of accepting the surge. Once the fluid is in the holding tank, it is allowed to separate to a liquid component and, if there is a gas component present, a gas component. The holding tank could be warmed so that the fluid does not freeze. The liquid component is removed from the holding tank through an outflow conduit having a smaller cross-sectional area than the inflow conduit. A power source could be used to power both the down-hole pump or gas compressor and a holding tank pump or compressed gas for removing the liquid component from the holding tank. The gas component could, similarly, be removed from the holding tank through a gas outflow conduit and forced to a gas pipeline. Once it is removed from the holding tank, the liquid component is forced, at the substantially constant flow rate, from the outflow conduit through a pipeline, thereby removing the liquid from the well. The forcing could be performed by a pump other than the down-hole well pump or by gas under pressure fed into the holding tank.
[0032] Pumping Fluid
[0033] A method for pumping fluid at a wellhead according to the present invention requires forming a well center unit having: a pumping assembly for pumping fluid from a well or a gas compressor to pressurize gas to bring fluid to the surface or to allow the gas to enter the pipeline; a support structure for supporting the assembly; a holding tank positioned below the support structure, having an inflow port, connected to the pumping assembly, and an outflow port; and a holding tank pump or access to compressed gas. The well center unit could farther include a power source capable of operating both the pumping assembly, the holding tank pump and a gas compressor. Once the well center unit is formed, the well center unit is coupled to the wellhead and into the well. The well center unit could be anchored to the ground.
[0034] Elevating Apparatus
[0035] An apparatus for elevating a pumping assembly according to the present invention includes a pumping assembly for drawing fluid from a well. The pumping assembly is elevated by a support structure having a lower cavity underneath the support structure, A holding tank is located inside the lower cavity. The holding tank has an inflow port for receiving fluid from the pumping assembly and an outflow port wherein the total cross-sectional area of the inflow port is greater than the total cross-sectional area of the outflow port. A holding tank pump or compressed gas is connected to the outflow port for forcing fluid from the outflow port to a pipeline. The apparatus could further include a power source operably connected to the well pump and the holding tank pump for driving both the well pump, the holding tank pump and a gas compressor. The apparatus for elevating a pumping assembly is used according to the method for removing a liquid from a gas producing well described above,
[0036] Therefore, the general object of this invention is to provide an apparatus and method for pumping fluid at a wellhead more cheaply and without the problems, such as over-pumping, air-locking, wellhead packing, and pipeline rupture, associated with current methods. Specifically, an object of the invention is to allow for the use of a small diameter pipeline for removing liquid from a well site which continues to work effectively even in cold weather. Liquid should flow through the pipeline at a substantially constant flow rate so that liquid volume produced can be measured using currently available measuring devices. In addition, an object of the invention is to improve the efficiency of pumping by limiting the amount of natural gas which escapes through the liquid pipeline and by recovering as much of that gas as possible. A further object of the invention is to use the space around the wellhead more efficiently so that the footprint area of the pumping assembly is effectively reduced, Finally, since wells are constructed according to uniform designs, it is an object of this invention to reduce the time required to install a pumping assembly so that the pump can begin removing liquid from the well more quickly. A result of the decreased footprint size and more uniform design is that the gas wells, both individual wells and multiple wells located close together, will be more aesthetically pleasing than well designs which are currently available.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 shows a flow chart describing how the surge of a fluid is accepted from the down-hole pump. The flow chart traces the fluid from the down-hole pump, through separation in the holding tank, to removal from the well site by a pipeline,
[0038] FIG. 2 shows a flow chart tracing the formation of a well center unit from a plurality of components and how the well center unit is connected with the wellhead and into the well.
[0039] FIG. 3 shows an isomeric view of the apparatus for elevating a pumping assembly.
[0040] FIG. 4 shows an isomeric view of the support structure for the pumping assembly including the lower cavity in which the holding tank is located.
[0041] FIG. 5 shows an isomeric view of the holding tanks including the inflow and outflow ports and the holding tank pump for pumping liquid through a liquid pipeline.
[0042] FIG. 6 shows an isomeric view of the well center unit with the removable gin pole attached, which is used for providing maintenance services to the unit.
DETAILED DESCRIPTION
Examples and Explanatory Definitions
[0043] The examples and explanatory definitions provided below are inclusive and are not intended to limit what is within the meaning of these terms.
[0044] “gas producing well”—means a well for producing natural gas. Natural gas wells can be drilled into a number of rock formations. In one embodiment of the invention, the well could be drilled into a coal formation.
[0045] “fluid”—A fluid is a substance which continually deforms under an applied shear stress. Essentially, a fluid is able to flow when a shear stress is applied. A fluid may be a gas or a liquid or a mixture containing both liquid and gas components. A foam having gas bubbles within a liquid is an example of a fluid. A foam of natural gas and liquid is often brought to the surface by a gas producing well.
[0046] “well center unit”—The well center unit is an assembly capable of drawing fluid from a well, separating the fluid to a liquid component and a gas component, and removing the liquid component from the well site. Rather than building the assembly on the wellhead, the unit is pre-formed and installed to the wellhead as a single unit.
[0047] “forming”—Forming refers to the manufacturing and assembly process necessary to create the well center unit. In one embodiment of the instant invention, the unit would be formed offsite, for example at a manufacturing facility, and then transported to the well site for installation.
[0048] “pump”—A mechanical device using pressure or suction to raise or move fluids. A pump could be powered by a natural gas combustion engine or by an electric motor or any other power source.
[0049] “pumping assembly”—The pumping assembly includes the pump-jack, tubing, the rod string, the down-hole pump and any other apparatus necessary to move gas or fluids from the well to the surface.
[0050] “support structure”—The support structure is a base for anchoring and supporting the pump-jack and/or mast and pulley driver. The support structure also functions as an elevator for raising and reorienting the pump-jack.
[0051] “positioned below the support structure”—The support structure forms a lower cavity below the pump-jack. In one embodiment of the invention, the holding tank is located within the lower cavity.
[0052] “port”—A port is an orifice or conduit allowing a fluid to flow into or be removed from the holding tank. In the case of a liquid, the port could be a drain.
[0053] “holding tank pump”—A pump for moving liquid from the outflow conduit to a pipeline. The pump operates at a steady state meaning that when liquid is present in the holding tank, it will be pumped by the holding tank pump as a continuous flow having a substantially constant flow rate.
[0054] “coupling”—The well center unit is coupled to the wellhead and into the well by arranging the elements of the well center unit at the corrected locations in and around the well. For example, the down-hole pump is located in the well; the pump-jack is located at the wellhead; and the holding tank is positioned below the pump-jack.
[0055] “power source”—A device that provides energy sufficient to drive the holding tank pump, the down-hole pump, an auxiliary alternator, a gas compressor, a vapor recovery unit, and/or any other device requiring a mechanical driver. The power supply device could be an electrical engine, a combustion generator that provides electrical power, a combustion engine powered by natural gas, or any other device that provides power or energy. In this application typically the devices to be driven by the power source is/are located under the pumping assembly along with the tank pump, the down-hole pump, the gas compressor and/or the vapor recover unit. The power source could be used in connection with one or all of the above but all would be under the pump assembly.
[0056] “capable of operating”—The power supply should be powerful enough and arranged so that it can provide power to the down-hole pump, the holding tank pump and/or a gas compressor. However, the pumps should be able to operate independently so that the pumps can pump fluid at different rates and can turn on or off at different times independent of one another.
[0057] “depressurization”—Air-locking occurs when the down-hole pump can no longer draw fluid to the surface as a result of the increased pressure at the wellhead. Pressure near the wellhead increases as gas collects at the upper portions of the welt. Depressurization removes the collected gas to reduce the pressure and prevent air-locking.
[0058] “warming”—The fluid in the holding tank should be kept at a temperature above the freezing point of the liquid component of the fluid even in cold weather. The freezing point of water is 0 degrees Celsius. In the case of a liquid mixed with solid fines, the freezing point may be lower. Warming can be accomplished by positioning the holding tank near enough to a device which produces heat so that the residual heat from the device keeps the holding tank above the freezing level.
[0059] “exhaust heat”—Refers to heated exhaust gases which are vented away from a power source such as an internal combustion engine and, in one embodiment of the invention, used to warm the holding tank.
[0060] “forcing”—The fluid or gas is forced from the outflow conduit to a pipeline. A common method for forcing a fluid through a pipeline is by using a pump. In some cases, gravity could also be used to force the gas or liquid through the pipeline or compressed gas could be used for the purpose.
[0061] “separate”—The invention includes any means of separating the liquid and gas components of a mixture. In one embodiment of the invention, the separation is natural separation where gravity causes the mare dense material to collect at the bottom of the holding tank and less dense material to collect in the top portion of the tank. In the case of a natural gas and water foam, water would collect at the bottom of the tank and natural gas would collect at the top.
[0062] “liquid”—A liquid is a material in the state of matter having characteristics including a readiness to flow, little or no tendency to disperse, and a relatively high incompressibility. Liquids commonly drawn from a well include water and oil.
[0063] “inflow conduit”—Fluid enters the holding tank via the inflow conduit. The inflow conduit could be a pipe running from the wellhead to the holding tank. In an embodiment of the invention, the holding tank is positioned below the pump jack fluid flows.
[0064] “outflow conduit”—The outflow conduit is the port where separated gas or separated liquid is removed from the holding tank. In the case of a liquid, the outflow conduit could be a drain.
[0065] “holding tank”—The holding tank is a vessel for holding the fluid brought to the surface by the pump jack. The holding tank functions as a gas/liquid separation device which depressurizes the fluid.
[0066] “substantially constant flow rate”—The liquid or gas should be removed from the holding tank at a substantially constant flow rate. It is recognized that if the down-hole pump is not drawing fluid from the well, no fluid will be available to remove from the holding tank; however, when fluid is being supplied to the tank, the liquid component of the fluid should be removed from the tank as a substantially continuous flow at a constant rate. The intent is to avoid the periodic high volume, high flow rate surges which come from the wellhead.
[0067] “cross-sectional area”—The cross-sectional area of a conduit or pipe refers to the area outlined by the inner surface of the conduit. Cross-sectional area is, essentially, the area through which the fluid can flow. In the case of a circular pipe, cross-sectional area is equal to (II)*(inner radius) 2 .
[0068] “an outflow conduit having a smaller cross-sectional area than the inflow conduit”—The total cross-sectional area of the outflow must be less than the total cross-sectional area of the inflow. It is recognized that a holding tank could have a plurality of inflow or outflow conduits. In that case, the total cross-sectional area of the plurality of inflow conduits, rather than the cross-sectional area of any individual conduit, must be greater than the total cross-sectional area of the plurality of outflow conduits.
[0069] “removable gin pole”—A rigid pole with a pulley on the end used for lifting. In the instant invention, the gin pole is used to provide maintenance services to the well center unit when necessary. The gin pole is removable.
[0070] “service the well when necessary”—necessary service may include regularly scheduled maintenance activities as well as efforts to fix or replace broken elements of the apparatus.
[0071] “guarding structure”—The apparatus is encased within a guarding structure to reduce the likelihood that trespassers will vandalize the well management center unit or steal parts of the unit. The guarding structure could be a metal case surrounding the well management center.
[0072] “gas and water metering devices”—devices for measuring the volume of liquid (water) or gas (natural gas) flowing through a pipe. The present invention allows for the accurate measurement of the volume of liquid which flows through a pipeline because liquid flows through the pipeline at a substantially constant flow rate.
[0073] “gas conditioning device”—A device for conditioning natural gas so that the gas can be used by an internal combustion engine. Conditioning may include steps of both filtering the gas and drying the gas.
[0074] “gas compressor”—A device for compressing gas so that the exit pressure from the compressor is greater than the pressure of gas entering the compressor. Reference number 50 in FIG. 6 .
[0075] “periodic surge”—A surge of fluid drawn from a well. The surge can increase pressure in a pipeline and, in some circumstances, cause the pipeline to rupture. This type of fluid or pressure surge is often referred to as a “water hammer.”
[0076] “capable of accepting the surge”—As described above, the fluid drawn from the well arrives at the holding tank in a periodic fashion with alternating intervals of high and low volume. To be capable of accepting the surge, the cross-sectional area must be great enough so that the entire high volume surge can flow into the holding tank without backing up and, as a result, increasing the pressure at the wellhead making it more difficult for fluid to flow from the well.
[0077] “down-hole pump”—A down-hole pump is a tool used in the well which draws fluid from the well into tubing and lifts that fluid to the surface. The down-hole pump is located in the well. It is used in conjunction with the pump-jack located on the surface and the rod string which connects the pump-jack to the down-hole pump.
[0078] “pressurized gas”—gas that is pressurized by a gas compressor and which may be utilized to force gas into the pipe line.
[0079] “lower cavity”—The space below the support structure. In one embodiment of the invention, the lower cavity houses the holding tank.
[0080] “Vapor Recover Unit”—a compressor used to recover gas vapor. In this application this unit will be housed under the pump jack and will use the power source for its energy. It can be used to compress gas vapor liberated from condensate, oil or water. It can be used in conjunction with a larger gas compressor or a gas compressor with varying pressure capabilities. Reference number 52 in FIG. 6 .
DESCRIPTION
[0081] FIG. 1 shows a flow chart describing how the periodic surge 2 of a fluid is accepted from the down-hole pump. The flow chart traces the fluid as it is drawn from the well 24 , to the wellhead 22 , by the down-hole pump 23 ; through separation in the holding tank 6 ; to removal from the well site by a pipeline which can include the use of a compressor to compress the gas. The fluid is drawn from the well by a down-hole pump 23 with periodic surges 2 of a large volume of fluid. The fluid passes into the holding tank 6 through the inflow conduit 4 . The fluid is separated to a gas component and a liquid component in the holding tank 6 . The gas component is removed from the holding tank 6 through the outflow conduit for gas 8 . The gas could also be compressed by an air compressor in order to enable the gas to enter into the pipeline. The air compressor would be driven by the same power sources. The gas is forced into a pipeline. The liquid component is removed from the holding tank 6 through the outflow conduit for liquid 10 . The liquid is forced to a pipeline for liquid by the holding tank pump 12 .
[0082] FIG. 2 shows a flow chart tracing the formation of a well center unit 20 from a plurality of components and how the well center unit 20 is coupled with the wellhead 22 and into the well 24 . The well center unit 20 is formed from: a pumping assembly 14 ; a support structure 16 , a holding tank 6 with an inflow port 26 and a plurality of outflow ports 28 and 29 ; a holding tank pump or pressurized gas source 12 ; and a single power source 18 . After the well center unit 20 is formed, it is coupled to a wellhead 22 and into a well 24 .
[0083] FIG. 3 shows an isomeric view of the apparatus for elevating a pumping assembly 14 . The pumping assembly has a pump-jack 30 connected to a support structure 16 and a rod string 32 going through the wellhead 22 and into the well 24 . It will be appreciated that if compressed, pressurized gas is utilized to bring fluid up from the well bottom, the pump jack 30 and the rod string 32 will be removed and pressurized gas will be introduced in controlled gas lines through well head 22 . The support structure 16 forms a lower cavity 34 underneath the support structure 16 . A holding tank 6 is Located within the lower cavity 34 . A holding tank pump and a gas compressor together with a single source of power to operate them and the pump jack 30 are located in compartment 12 .
[0084] FIG. 4 shows an isomeric view of the support structure 16 for the pumping assembly 14 including the lower cavity 34 in which the holding tank 6 is located. There are also holding tank saddles 36 within the lower cavity for supporting the holding tank 6 .
[0085] FIG. 5 shows an isomeric view of the holding tanks 6 including the inflow port 26 , the outflow port for liquid 28 , and the outflow port for gas 29 . Liquid is removed through the outflow port 28 , to the conduit 10 , and is forced to a pipeline by the holding tank pump or by pressurized gas. Gas is removed from the holding tank 6 through the outflow port for gas 29 and into the outflow conduit for gas 11 .
[0086] FIG. 6 shows an elevational view of the well center unit 20 with the removable gin pole 38 attached, which is used for providing maintenance services to the unit. The figure depicts the pumping assembly 14 anchored to the support structure 16 . Elements including the holding tank 6 and the holding tank pump 12 are located beneath the pumping assembly 14 in the lower cavity 34 formed by the support structure 16 . The gin pole 38 is anchored to the support structure 16 . A cable 44 runs from the crank 40 , over the pulley 42 attached to the gin pole 38 , past the wellhead 22 , and into the well 24 .
[0087] It is important to note that function of the vapor recovery unit and or the compressor. These devices compress gas from the well. The gas compressor will compress gas from the well and allow it to enter into a pipeline. Sometimes the pipeline has high pressure so in order to get the gas from the storage tank and/or well bore to the well compression is required. It is novel and non-obvious for these compressor(s) to be placed under the pump jack and operated off of the power source. The vapor recovery unit will take the gas that previously may have been vented and/or incinerated on location and use it. Typically it can be gas recovered from condensate or light end oil. The gas recovery unit will also be located underneath the pump jack and can be operated off of the power source. It is important to note in this novel application the power source can power the pumping apparatus, the liquid pump, the gas compressor and the vapor recovery unit. The down hole pump, the liquid pump, the gas compressor and vapor will all be located under the pump jack and any other devices that need to be mechanically driven. There can be any combination of one or more down hole pump, liquid pump, gas compressor, vapor recovery unit, or any other devices that need to be mechanically driven by the power source and located under the pump jack.
[0088] FIGS. 1-6 show a person of ordinary skill in the art how to make and use the preferred embodiment of the invention. All teachings in the drawings are hereby incorporated by reference into the specification.
[0089] Various changes could be made in the above construction and method without departing from the scope of the invention as defined in the claims below. It is intended that all matters contained in the paragraphs above, as shown in the accompanying drawings, shall be interpreted as illustrative and not as a limitation. | A method for pumping fluid at a wellhead is provided. The invented method will improve liquid removal by eliminating the need to transport liquid produced from a well to containment facilities using trucks or large diameter pipelines capable of accommodating periodic surges of a high volume of fluid. The danger that the liquid will freeze in cold weather is also addressed. The invention removes liquid from the well site through a small diameter pipeline as a continuous flow at a constant flow rate. An apparatus for removing liquid from the well site is also provided. | 4 |
This application is a continuation application which claims the benefit of priority to U.S. patent application Ser. No. 10/922,300, filed Aug. 19, 2004 now U.S. Pat. No. 7,105,511 which is herein incorporated by reference in its entirety.
This invention was supported in part by funds from the U.S. government (NIEHS #ES06897) and the U.S. government may therefore have certain rights in the invention.
FIELD OF THE INVENTION
The present invention relates to a new class of fused-ring triazoles and methods for synthesis of these compounds. The present invention also relates to compositions comprising these fused-ring triazoles and methods for use of these compositions as anti-proliferative agents, anti-estrogenic agents, anti-microbial agents and/or anti-viral agents. These fused-ring triazoles have been found to be intensely fluorescent when excited at selected wavelengths. The fluorescent properties of these compounds are useful in tracking these compounds, for example in pharmacokinetic studies of these therapeutic agents. Their fluorescent properties also make them useful as fluorescent probes.
BACKGROUND OF THE INVENTION
The 1,2,4-triazole moiety is an important and versatile pharmacophore often found as a structural unit in diverse pharmaceutical classes. Antifungal imidazoles and indeed almost any important pharmaceutical, in which a five-membered nitrogen heterocyclic residue is incorporated, can be synthesized with a 1,2,4-triazole as a surrogate for that imidazole with retention of the model compound's original pharmacologic activity (Angibaud et al. Bioorg. Med. Chem. Lett. 2003 13:4361-4364). Biological pathways requiring histidine can be manipulated into accepting and incorporating the triazole analogue into the resulting protein (Ikeda et al. Protein Eng. 2003 16:699-706). Furthermore, the 1,2,4-triazole has been observed as a bioisostere for a phenyl ring in the PPARα agonists being explored as lipid-lowering drugs (Xu et al. J. Med. Chem. 2003 46:5121-5124).
A functionalized 1,2,4-triazole attached to a benzonitrile moiety is in clinical trials for breast cancer and is showing significant activity (Tominaga, T. and Suzuki, T. Anticancer Res. 2003 4:3533-3542). 1,2,4-Triazoles with alkylamino side chains were inhibitory against a host of malignant cell lines (Demirbas et al. Bioorg. Med. Chem. 2002 10:3717-3723). Dimers of 1,2,4-triazol-5-thiols were active against seven cancer types (Holla et al. Eur. J. Med. Chem. 2002 37:511-517). Both antitumor and anti-HIV activity were observed in triazoles fused to benzene sulfonamides (Pomarnacka E, Kozlarska-Kedra I, Farmaco 2003 58:423-429).
Fused ring systems in which the 1,2,4-triazole nucleus is the core of a larger heterocyclic pharmaceutical are showing considerable therapeutic promise. Catarzi reported that a triazole-quinoxaline class was potentially useful in neuroprotection (treatment and prevention of acute and chronic neurological disorders) (Catarzi et al. J. Med. Chem. 2004 47:262-272). Tourirte found modest inhibition of the replication of HIV by triazole-pyrimidines (Tourirte et al. Nucleosides Nucleotide Nucleic Acids. 2003 22:1985-1993).
Thus, the triazole nucleus is used widely in drug design and development.
SUMMARY OF THE INVENTION
A unique family of fused ring triazoles referred to herein as 3-R-7-(phenylmethylene)-s-triazolo[3,4-b] [1,3,4]-thiadiazines has now been synthesized. This new class of fluorescent fused triazoles is useful as fluorescent probes and in the treatment of proliferative disorders and as anti-estrogenic, antimicrobial and antiviral agents.
Accordingly, an object of the present invention is to provide a compound of Formula II:
wherein R is selected from the group consisting of a furyl group, a thienyl group, a pyridyl group, an alkyl group, and an aryl or arylalkyl group. Preferably R is an aryl or arylalkyl group selected from the group consisting of 1-(2-phenyl)-ethyl, 3-methoxyphenyl, 4-trifluoromethylphenyl and 4-fluorophenyl, or a pyridyl group selected from the group consisting of 2-pyridyl, 3-pyridyl, and 4-pyridyl.
Another object of the present invention is to provide methods for synthesizing a compound of Formula II.
In one embodiment, the method of synthesis comprises a single step wherein α-bromocinnamaldehyde is added to a solution comprising a mercaptoaminotriazole and a tertiary amine, and a compound of Formula II precipitates therefrom.
In another embodiment, the method of synthesis comprises a two-step process wherein a bromocinnamyl imine is derived from the condensation of a mercaptoaminotriazole with an aldehyde, preferably α-bromocinnamaldehyde. The bromocinnamyl imine is then converted to a compound of Formula II by treatment at reflux with a tertiary amine.
Another object of the present invention is to provide a method for inhibiting cell proliferation which comprises administering to the cell a compound of Formula II.
Another object of the present invention is to provide a pharmaceutical composition comprising a compound of Formula II and a pharmaceutically acceptable vehicle.
Another object of the present invention is to provide a method for treating a proliferative disorder which comprises administering to a subject suffering from a proliferative disorder a pharmaceutical composition comprising a compound of Formula II and a pharmaceutically acceptable vehicle.
Another object of the present invention is to provide a method for inhibiting estrogen-mediated growth of cancer cells such as estrogen-dependent breast cancer cells which comprises administering to a subject suffering and estrogen-mediated cancer a pharmaceutical composition comprising a compound of Formula II and a pharmaceutically acceptable vehicle.
Another object of the present invention is to provide a method for treating a viral or microbial infection in a subject which comprises administering to a subject suffering from a microbial or viral infection a pharmaceutical composition comprising a compound of Formula II and a pharmaceutically acceptable vehicle.
Another object of the present invention is to provide a disinfectant or antiseptic agent comprising a compound of Formula II.
Another object of the present invention is to provide a fluorescent probe comprising a probe molecule fluorescently labeled with a compound of Formula II.
Yet another object of the present invention is to provide a method for fluorescently tagging a molecule of interest such as a selected protein or nucleic acid sequence using a fluorescent probe comprising a compound of Formula II.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a novel class of fused ring triazole compounds represented by the following Formula II:
wherein R is selected from the group consisting of a furyl group, a thienyl group, a pyridyl group, an alkyl group, and an aryl or arylalkyl group. Preferably R is an aryl or arylalkyl group selected from the group consisting of 1-(2-phenyl)-ethyl, 3-methoxyphenyl, 4-trifluoromethylphenyl and 4-fluorophenyl, or a pyridyl group selected from the group consisting of 2-pyridyl, 3-pyridyl, and 4-pyridyl. This class of fused ring triazole compounds of the present invention is also referred to herein as 3-R-7-(phenylmethylene )-s-triazolo[3,4-b] [1,3,4]-thiadiazines.
Also provided in the present invention are methods for synthesizing 3-R-7-(phenylmethylene)-s-triazolo [3,4-b] [1,3,4]-thiadiazines of Formula II.
In one embodiment, these compounds are synthesized by a single-step process for preparation. The general scheme for this one-step preparation of a 3-R-7-(phenylmethylene)-s-triazolo[3,4-b] [1,3,4]-thiadiazine is depicted in Scheme I:
As shown in Scheme I, in this one-step synthesis, a solution of a mercaptoaminotriazole of Formula I, wherein R is selected from the group consisting of 2-pyridyl, 3-pyridyl, and 4-pyridyl, is prepared by refluxing with a tertiary amine such as triethylamine or pyridine in a solvent such as anhydrous ethanol or dioxane. An aldehyde, preferably an α-halocinnamaldehyde such as iodo-, bromo- or chloro-cinnamaldehyde, is then added to the solution and the resulting mixture is refluxed for several hours until a precipitate of the 3-R-7-(phenylmethylene)-s-triazolo[3,4-b ] [1,3,4]-thiadiazine forms.
This one-step synthetic method is particularly useful for synthesis of compounds of the present invention wherein R contains a basic moiety such as the nitrogen of a pyridyl or quinolinyl functionality. Yields ranging from about 50 to about 75% are generally achieved using this method. This one step-synthesis can also be applied to any mercaptoaminotriazole of Formula I wherein R is selected from the group consisting of a furyl group, a thienyl group, an alkyl group, or an aryl or arylalkyl group such as 1-(2-phenyl)-ethyl, 3-methoxyphenyl, 4-trifluoromethylphenyl or 4-fluorophenyl as long as an equivalent amount of a tertiary amine, such as triethylamine, is also used.
In another embodiment, compounds of the present invention are synthesized by a two-step process. The general scheme for this two-step preparation of a 3-R-7-(phenylmethylene) -s-triazolo[3,4-b] [1,3,4]-thiadiazine is depicted in Scheme II:
In step I, a bromocinnamyl imine is derived from the condensation of a mercaptoaminotriazole of Formula I with an aldehyde, preferably α-bromocinnamaldehyde, in accordance with procedures for preparation of 4-amino-3-mercapto-1,2,4-triazoles as set forth in WO 00/10564, which is herein incorporated by reference in its entirety. The resulting intermediate of bromocinnamyl imine (depicted in Formula III) has been isolated and characterized in >60% yields. These imines can be converted (step II) by treatment at reflux with an equivalent amount of a tertiary amine such as triethylamine or pyridine, in a solvent, preferably ethanol, to a 3-R-7-(phenylmethylene)-s-triazolo[3,4-b] [1,3,4]-thiadiazine of Formula II with completion of the reaction defined by the time at which no detectable residue of Formula III, as determined by thin layer chromatography, remains.
Exemplary triazole compounds of the present invention synthesized in accordance with the one-step and/or two-step processes described herein include, but are in no way limited to,
Compound IIa, viz., 3-(4-pyridyl)-7-(phenylmethylene)-s-triazolo[3,4-b] [1,3,4]-thiadiazine, wherein R is 4-pyridyl
Compound IIb, viz., 3-(2-pyridyl)-7-(phenylmethylene)-s-triazolo [3,4-b] [1,3,4]-thiadiazine, wherein R is 2 -pyridyl,
Compound IIc, viz., 3-(3-pyridyl)-7-(phenylmethylene)-s-triazolo[3,4-b] [1,3,4]-thiadiazine, wherein R is 3-pyridyl,
Compound IId, viz., 3-(2-thienyl)-7-(phenylmethylene)-s -triazolo[3,4-b] [1,3,4]-thiadiazine, wherein R is 2-thienyl,
Compound IIe, viz., 3-(2-furyl)-7-(phenylmethylene)-s -triazolo[3,4-b] [1,3,4]-thiadiazine, wherein R is 2-furyl,
Compound IIf, viz., 3-(2-phenylethyl)-7-(phenylmethylene)-s-triazolo[3,4b] [1,3,4]-thiadiazine, wherein R is 1-(2-phenyl)ethyl,
Compound IIg, viz., 3-(3-methoxyphenyl)-7-(phenylmethylene)-s-triazolo[3,4b] [1,3,4]-thiadiazine, wherein R is 3-methoxyphenyl,
Compound IIh, viz., 3-(4-trifluoromethylphenyl)-7-(phenylmethylene)-s-triazolo[3,4b] [1,3,4]-thiadiazine, wherein R is 4-trifluoromethylphenyl, and
Compound IIi, viz., 3-(4-fluoromethylphenyl)-7-(phenylmethylene)-s-triazolo[3,4b] [1,3,4]-thiadiazine, wherein R is 4-fluorophenyl.
The antiproliferative activity of compounds of the present invention was demonstrated in PAM 212 tumor cells. Experiments were performed in accordance with the procedure described by Yurkow and Laskin (Cancer Chemother. Pharmacol. 1991 27:315-319). In these experiments, tumor cells were maintained in culture in growth medium consisting of Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine. Tumor cells were plated at low density (5000 cells/well) in 6-well tissue culture dishes and allowed to adhere overnight. The medium was then replaced with phenol red-free DMEM supplemented with increasing concentrations of the compounds, with zero concentration of compound serving as the control. Six concentrations and a control were used for each inhibitor, and each concentration was tested in triplicate. After 5 days, cells were removed from the dishes and enumerated using a Coulter Counter (Coulter Electronics, Inc.). The controls and treated samples at each concentration were averaged. Data are presented as the percentage of control growth at each concentration of the compound, plus and minus the standard error. The IC 50 for growth inhibition was the concentration of each compound that inhibited growth by 50%. These are depicted in Table 1.
TABLE 1
Ability of Fused-Ring Triazoles to Inhibit Growth of Tumor Cells
IC50 of fused ring triazole
Cells type
IIa
IIb
IId
mouse PAM 212 keratinocytes
10 μM
18 μM
18 μM
mouse B16 melanoma
9 μM
15 μM
23 μM
human CX-1 colon cells
17 μM
30 μM
20 μM
human HeLa cervical carcinoma
4 μM
9 μM
28 μM
IC50 = Concentration of each compound inhibiting growth of cell line by 50%.
Accordingly, the compounds of the present invention are useful as anti-proliferative agents, particularly in the inhibition of tumor cell growth.
Further, triazole compounds are commonly used as anti-estrogens for example, to suppress estrogen mediated cancers such as estrogen-dependent breast cancer development in humans.
Thus, it is expected that pharmaceutical compositions comprising a compound of the present invention will be useful in the treatment of cancer as well as other proliferative disorders or diseases including but not limited to, macular degeneration, psoriasis, arteriosclerosis and restenosis and as anti-estrogenic agents.
Further, the inhibitory properties of these agents are expected to be useful against bacterial and viral infections as well, thus making these compounds also useful as anti-microbial and/or antiviral agents.
Compounds of the present invention are expected to be useful as antiproliferative, anti-estrogenic, antiviral and/or antimicrobial agents in all animals, including but not limited to, humans, dogs, cats, birds, horses, cows, sheep, swine (pigs and hogs), and other farm animals, as well as rodents and other animals seen in zoos. Thus, while the activities of these new compounds are believed to be particularly useful for inhibiting tumor growth and infectious diseases in humans, use of these compounds for veterinary purposes is also clearly within the scope of the instant invention.
Therefore, another aspect of the present invention relates to pharmaceutical compositions comprising a compound of Formula II. Pharmaceutical compositions of the invention may further include excipients, stabilizers, emulsifiers, therapeutic adjuvants, diluents and the like, referred to herein in general as pharmaceutically acceptable vehicles. Sustained-released and time-release formulations are also encompassed within the present invention.
Suitable solid or liquid formulations for use in the present invention are, for example, granules, powders, coated tablets, microcapsules, suppositories, syrups, elixirs, suspensions, emulsions, drops or injectable solutions. Commonly used additives in protracted release preparations are excipients, disintegrates, binders, coating agents, swelling agents, glidants or lubricants, flavors, sweeteners or solubilizers. More specifically, frequently used additives are, for example, magnesium stearate, magnesium carbonate, titanium dioxide, lactose, mannitol and other sugars, talc, lactalbumin, gelatin, starch, cellulose and its derivatives, animal and vegetable oils, polyethylene glycols and solvents. Common solvents include sterile water and monohydric or polyhydric alcohols such as glycerol. Acceptable carriers, agents, excipients, stabilizers, diluents and the like for therapeutic use are well known in the pharmaceutical field, and are described, for example, in Remington's Pharmaceutical Sciences, Mack Publishing Co., ed. A. R. Gennaro (1985). If appropriate, the compound may be administered in the form of a physiologically acceptable salt, for example, an acid-addition salt. The pharmaceutical compositions are preferably produced and administered in dosage units, each unit containing as an active component an effective dose of at least one compound of the present invention and/or at least one of its physiologically acceptable salts. The effective dose to treat diseases such as those discussed above typically ranges from about 1 to about 100 mg/kg of body weight per day.
The pharmaceutical compositions according to the invention are suitable for use as anti-proliferative, antimicrobial and/or antiviral agents in a subject, particularly a human patient or subject, and comprise an effective amount of a fused triazole compound according to the present invention and a pharmaceutically acceptable vehicle, carrier or diluent.
Such compositions may be administered by various routes selected in accordance with the condition to be treated. Exemplary routes of administration include, but are not limited, intravenously, orally, intramuscularly, parenterally, topically, bucally, via inhalation, and rectally.
For intravenous infusion or intravenous bolus injection, or parenteral or intramuscular injection, the active ingredient is dissolved in a pharmaceutically acceptable vehicle such as saline or phosphate buffered saline.
For oral treatment, administration of the active ingredient may be, for example, in the form of tablets, capsules, powders, syrups, or solutions. For tablet preparation, the usual tablet adjuvants such as cornstarch, potato starch, talcum, magnesium stearate, gelatin, lactose, gums, or the like may be employed, but any other pharmaceutical tableting adjuvants may also be used, provided only that they are compatible with the active ingredient. In general, an oral dosage regimen will include about 5 mg to about 50 mg, preferably from about 5 to about 10 mg, per kg of body weight. Such administration and selection of dosage and unit dosage will of course have to be determined according to established medical principles and under the supervision of the physician in charge of the therapy involved.
For topical applications, solutions or ointments may be prepared and employed. These may be formulated with any one of a number of pharmaceutically acceptable carriers, as is well known in the art. Topical formulations comprise an effective amount of the active ingredient per unit area. Preferably, the topical formulation is in the form of a one percent solution, suspension or ointment and is applied on the skin at about 0.1 mL per square centimeter. The formulations may contain a suitable carrier such as ethanol or any of the pharmaceutically acceptable carriers described supra.
The antiviral and/or antimicrobial activities of these compounds also render them useful as disinfectants or aseptic agents. The triazole compounds of the present invention, as disinfectants or antiseptic agents, are suitable for various uses including, but not limited to, water purifying agents, sanitizers and bactericides for use, for example, in room temperature methods for sterilizing a surface medical instruments or devices. Further, these compounds can be used to sterilize biological and medical fluids including, but not limited to blood, cerebrospinal fluid, and fluid replacements. The compounds can also be used to sterilize tissues, prosthetic implants or chemical compositions prior to administration, implantations or insertion during various medical procedures. For example, in one nonlimiting embodiment, the compound can be used to sterilize oral tissues prior to invasive dental procedures. In an alternative nonlimiting embodiment, the compound can be used to sterilize a chemical composition prior to administration into, for example, the vaginal canal to prevent the transmission of sexually transmitted diseases. Disinfectants or antiseptic agents of the present invention comprise a solution or suspension of a compound of Formula II. Other components of the solution or suspension may include those ingredients routinely incorporated into disinfectants and/or antiseptic agents and well known to those skilled in the art. Examples of additional components which can be included in the disinfectants or antiseptic agents include, but are in no way limited to alcohols, oxidizing agents such as hydrogen or benzoyl peroxide, halogens such as chlorides or iodides, heavy metals and quaternary ammonium compounds.
The triazole compounds of the present invention also exhibit a unique and intense fluorescent spectrum. Characteristics of their fluorescence spectra are shown in Table 2.
TABLE 2 Characteristics of Fluorescence Spectra of Representative Fused Ring Triazoles Compound Excitation peaks Emission peak IIa 224 nm, 286 nm 358 nm IIb 249 nm 320 nm
Excitation and emission spectra of a 10 micromolar solution of compounds IIa and IIb were determined using a Perkin-Elmer LS-5B Luminescence Spectrometer.
The fluorescent properties of these compounds are useful in tracking these compounds, for example in pharmacokinetic studies of these therapeutic agents. Their fluorescent properties also make them useful as fluorescent probes.
Accordingly, another aspect of the present invention relates to fluorescent probes comprising a compound of Formula II. Fluorescent probes are used extensively in cell and molecular biology and in clinical diagnosis to detect specific proteins and/or nucleic acid sequences such as DNA and RNA.
In one embodiment of the present invention, a fluorescent probe comprising a compound of Formula II is used to detect minute quantities of a selected protein or proteins or a nucleic acid sequence or sequences such as DNA and RNA in biological samples by covalently modifying the molecule of interest with the intensely fluorescent compound. Alternatively, a compound of Formula II can be attached or linked to a second agent, which directs binding of the probe to a selected molecule. Examples of second agents include, but are in no limited to, antibodies or other binding agent such as avidin, which can be used to detect selected molecules such as antigens. An additional example of a second agent is an agent that binds DNA, RNA or protein, for example, a dye that intercalates DNA and directs the fluorescent probe to a selected molecule such as a DNA, RNA or protein.
Fluorescence techniques are used increasingly in a variety of clinical assays.
For example, fluorescence techniques are used routinely in microscopy, whole animal imaging, fluorescence microplate readers and in flow cytometry in the detection of different types of cells of a tumor or in blood. The Fluorescence Activated Cell Sorter (FACS) was invented in the late 1960s by Bonner, Sweet, Hulett, Herzenberg, and others to do flow cytometry and cell sorting of viable cells and commercial machines were introduced by Becton Dickinson in the early 1970s. (Ehrenberg et al. Clin Chem. 2002 October;48(10):1819-27). Over the years, the number of measured FACS dimensions or parameters, as well as the speed of sorting, has been increased to where 12 fluorescent colors plus 2 scatter parameters can now be measured simultaneously. Flow cytometry via FACS thus has great utility as it allows for simultaneous staining and analysis, followed by sorting of cells from small samples of human blood cells. Analysis and sorting of multiple subpopulations of, for example, lymphocytes, by use of 8 to 12 colors can be performed. Alternatively, FACS and flow cytometry can be used in single cell sorting, for example, to clone and analyze hybridomas.
Fluorescence techniques are also used for chromosome analysis and/or molecular cytogenetics. The last 20 years have witnessed an astounding evolution of cytogenetic approaches to, for example cancer diagnosis and prognostication. Molecular techniques and, in particular, nonisotopically-labeled nucleic acid probes and fluorescence in situ hybridization (FISH)-based techniques have replaced the costly and potentially dangerous radioactive techniques used in research and the clinical detection of genetic alterations in tumor cells (Weier et al. Expert Rev Mol Diagn. 2002 March;2(2):109-19). Fluorescent DNA probes also enable the screening for very subtle chromosomal changes. Clinical laboratories now select from a growing number of FISH-based cytogenetic tests to support physician's diagnoses of the causes and the course of a disease. Depending on the specimen, state-of-the-art FISH techniques allow the localization and scoring of 10-24 different targets and overcome previous problems associated with target colocalization and detection system bandwidth. FISH-based analyses have been applied very successfully to the analysis of single cells and have demonstrated the existence of cell clones of different chromosomal make-up within human tumors. This information provides disease-specific information to the attending physician and should enable the design of patient-specific protocols for disease intervention.
Fluorescence techniques are also used in immunohistochemistry and western blotting for diagnosis, and in antigen and enzyme assays such as, for example, ELISA and other diagnostic immunoassays.
The unique fluorescent spectrum of the compounds, as exemplified in FIGS. 1 and 2, makes them useful alone in any of the above-described techniques or in combination with other fluorescent compounds allowing for multicolor analysis in any of the above-described techniques.
The following nonlimiting examples are provided to further illustrate the present invention.
EXAMPLES
Example 1
Preparation of Starting Materials
The mercaptoaminotriazoles (Formula I) employed herein were prepared as described in Reid and Heindel (Journal of Heterocyclic Chemistry 1976 13:925-926). Specifically, 4-amino-3-(2-pyridyl)-5-mercapto[4H]-1,2,4-triazole (Formula I wherein R is 2-pyridyl; mp 190-191° C.) and 4-amino-3-(3-pyridyl)-5-mercapto[4H]-1,2,4-triazole (Formula I wherein R is 3-pyridyl; mp=192-193° C.) were prepared and characterized in accordance with the procedure of Reid and Heindel (Journal of Heterocyclic Chemistry 1976 13:925-926). Melting points were obtained in capillaries in a MelTemp apparatus and are reported uncorrected. NMR analyses were performed in the solvents indicated on a Bruker 360 MHz NMR spectrometer. All solvents and reagents employed were of the highest commercially available purities.
Example 2
One-Step Synthesis of Compound IIa
To prepare Compound IIa by one-step preparation, 102 mg (0.53 mmol) of 4-amino-3-(4-pyridyl)-5-mercapto[4H]-1,2,4-triazole were refluxed with 740 μL (0.53 mmol) of triethylamine in 25 mL of anhydrous ethanol until complete dissolution. To this solution was added α-bromocinnamaldehyde (197 mg, 0.93 mmol) and the mixture was refluxed for 5 hours. Over time the product precipitated out of solution and, after cooling down the reaction to room temperature, it was isolated by filtration and washed with ethanol. Yellow crystals were obtained after recrystallization from ethanol/DMSO. 92 mg, 57%, mp=245-246° C. Anal. Calcd. for C 16 H 11 N 5 S: C, 62.93%; H, 3.63%; N, 22.93%. Found: C, 62.86%; H, 3.42%; N, 22.86%. 1 H NMR (d 6 -DMSO) δ: 7.47-7.63 (m, 6H, Ph and H γ ); 7.99 (dd, J=1.5 Hz, J′=4.5 Hz, 2H, H b ); 8.23 (s, 1H, H α ); 8.77 (dd, J=1.5 Hz, J′=4.5 Hz, 2H, H a )
Example 3
One-Step Synthesis of Compound IIb
To prepare Compound IIb by one-step preparation, 105 mg (0.54 mmol) of 4-amino-3-(2-pyridyl)-5-mercapto[4H]-1,2,4-triazole were refluxed with 760 μL (0.54 mmol) of triethylamine in 25 mL of anhydrous ethanol until complete dissolution. To this solution was added α-bromocinnamaldehyde (202 mg, 0.96 mmol) and the mixture was refluxed for 5 hours. Over time the product precipitated out of solution and, after cooling down the reaction to room temperature, it was isolated by filtration and washed with ethanol. Yellow crystals were obtained after recrystallization from ethanol/DMSO. 91 mg, 55%, mp=205-207° C. Anal. Calcd. for C 16 H 11 N 5 S: C, 62.93%; H, 3.63%; N, 22.93%. Found: C, 62.43%; H, 3.32%; N, 22.71%. 1 H NMR (d 6 -DMSO) δ: 7.47-7.64 (m, 7H, Ph, H c , H γ ); 7.93-7.96 (m, 1H, H d ); 7.99-8.04 (m, 1H, H b ); 8.17 (s, 1H, H α ); 8.76-8.78 (m, 1H, H a ).
Example 4
One-Step Synthesis of Compound IIc
To prepare Compound IIc by one-step preparation, 110 mg (0.57 mmol) of 4-amino-3-(3-pyridyl)-5-mercapto[4H]-1,2,4-triazole were refluxed with 800 μL (0.57 mmol) of triethylamine in 25 mL of anhydrous ethanol until complete dissolution. To this solution was added α-bromocinnamaldehyde (212 mg, 1.00 mmol) and the mixture was refluxed for 5 hours. Overtime the product precipitated out of solution and, after cooling down the reaction to room temperature, it was isolated by filtration and washed with ethanol. Yellow crystals were obtained after recrystallization from ethanol/DMSO. 104 mg, 60%, mp=228-229° C. Anal. Calcd. for C 16 H 11 N 5 S+0.8 H 2 O: C, 60.10%; H, 3.97%; N, 21.90%. Found: C, 60.01%; H, 3.61%; N, 21.40%. 1 H NMR (d 6 -DMSO) δ: 7.48-7.64 (m, 7H, Ph, H d , H γ ); 8.20 (s, 1H, H α ); 8.31-8.36 (m, 1H, H c ); 8.72-8.75 (m, 1H, H b ); 9.12 (s, 1H, H a )
Example 5
Two-Step Synthesis of Compound IId
To prepare Compound IId by a two-step synthetic process one must first prepare (step I) the imine from the condensation of the mercaptoaminotriazole of Formula I [in this case the 5-(2-thienyl)-analog] and α-bromocinnamaldehyde. The methodology is set forth in WO 00/10564 which is herein incorporated by reference in its entirety. Thereafter, (step II), 100 mg (0.26 mmol) of this 4-imino-(γ-bromocinnamyl)-3-mercapto-5-(2-thienyl)-4H-1,2,4-triazole were refluxed with 83 μL (1.02 mmol) of pyridine in 35 mL of anhydrous ethanol until no more of the starting triazole could be detected by thin layer chromatography (hexanes 70%/ethyl acetate 30%). The reaction mixture was evaporated to dryness and the residue obtained purified by flash silica gel column chromatography (hexanes 70%/ethyl acetate 30%) leading to the isolation of a yellow solid as the final product. 32 mg, 40%, mp=180-183° C. Anal. Calcd. for C 15 H 10 N 4 S 2 +0.2 H 2 O: C, 57.38%; H, 3.34%; N, 17.84%. Found: C, 57.66%; H, 3.35%; N, 17.20%. 1 H NMR (d 4 -MeOH) δ: 7.22 (dd, J=3.7 Hz, J′=5.0 Hz, 1H, H b ); 7.38-7.64 (m, 6H, Ph and H γ ); 7.70 (dd, J=1.2 Hz, J′=5.0 Hz, 1H, H c ); 8.01 (dd, J=1.2 Hz, J′=3.7 Hz, 2H, H a ); 8.04 (s, 1H, H α )
Example 6
One-Step Synthesis of Compound IId
To prepare compound IId by a one-step synthetic process, 117 mg (0.59 mmol) of 4-amino-3-(2-thienyl)-5-mercapto[4H]-1,2,4-triazole were refluxed with 83 μL (0.59 mmol) of triethylamine in 10 mL of anhydrous ethanol. To this solution was added α-bromocinnamaldehyde (218 mg, 1.03 mmol) and the mixture was refluxed until no more of the starting triazole could be detected by thin layer chromatography (hexanes 70%/ethyl acetate 30%). Over time the product precipitated out of solution and, after cooling down the reaction to room temperature, it was isolated by filtration and washed with ethanol. Yellow crystals were obtained, 129 mg (70%). Same physical characteristics as IId isolated through the two-step process.
Example 7
One-Step Synthesis of Compound IIe
To prepare compound IIe by a one-step synthetic process, 100 mg (0.55 mmol) of 4-amino-3-(2-furyl)-5-mercapto[4H]-1,2,4-triazole were refluxed with 76 μL (0.55 mmol) of triethylamine in 10 mL of anhydrous ethanol. To this solution was added α-bromocinnamaldehyde (203 mg, 0.96 mmol) and the mixture was reluxed until no more of the starting triazole could be detected by thin layer chromatography (hexanes 70%/ethyl acetate 30%). Over time the product precipitated out of solution and, after cooling down the reaction to room temperature, it was isolated by filtration and washed with ethanol. Yellow crystals were obtained, 125 mg (77%). 1 H NMR (d 6 -DMSO) δ: 6.74 (dd, J=3.5 Hz, J′=2.0 Hz, 1H, H b ); 7.23 (dd, J=1.0 Hz, J′=3.5 Hz, 1H, H c ); 7.46-7.62 (m, 6H, Ph and H γ ); 7.98 (dd, J=1.0 Hz, J′=2.0 Hz, 2H, H a ) 8.20 (d, J=0.5 Hz, 1H, H α ).
Example 8
One-Step Synthesis of Compound IIf
To prepare compound IIf by a one-step synthetic process, 103 mg (0.47 mmol) of 4-amino-3-{l-(2-phenyl)-ethyl}-5-mercapto[4H]-1,2,4-triazole were refluxed with 65 μL (0.47 mmol) of triethylamine in 10 mL of anhydrous ethanol. To this solution was added α-bromocinnamaldehyde (212 mg, 1.00 mmol) and the mixture was refluxed until no more of the starting triazole could be detected by thin layer chromatography (hexanes 70%/ethyl acetate 30%). Over time the product precipitated out of solution and, after cooling the reaction to room temperature, it was isolated by filtration and washed with ethanol. Pale yellow crystals were obtained, 98 mg (63%). Anal. Calcd. for C 19 H 16 N 4 S: N, 16.85%. Found: N, 16.64%. 1 H NMR (d 6 -DMSO) δ: 3.03 (t, J=7.8 Hz, H b ); 3.12 (t, J=7.8 Hz, H a ); 7.19-7.30 (m, 5H, Ph); 7.45-7.60 (m, 6H, Ph and H γ ); 8.10 (d, J=1.0 Hz, 1H, H α ).
Example 9
One-Step Synthesis of Compound IIg
To prepare compound IIg by a one-step synthetic process, 107 mg, (0.52 mmol) of 4-amino-3-(3-methoxyphenyl)-5-mercapto[4H]-1,2,4-triazole were refluxed with 72 μL (0.52 mmol) of triethylamine in 10 mL of anhydrous ethanol. To this solution was added α-bromocinnamaldehyde (167 mg, 0.79 mmol) and the mixture was refluxed until no more of the starting triazole could be detected by thin layer chromatography (chloroform 95%/methanol 5%). Over time the product precipitated out of solution and, after cooling the reaction to room temperature, it was isolated by filtration and washed with ethanol. tanned crystals were obtained after recrystallisation from acetone, 121 mg (70%), mp=202-203° C. Anal. Calcd. for C 15 H 10 N 4 S 2 +0.25 H 2 O: C, 63.79%; H, 4.31%; N, 16.53%. Found: C, 63.84%; H, 4.22%; N, 16.41%. 1 H NMR (d 6 -DMSO) δ: 3.82 (s, 3H, CH 3 ); 7.11-7.15 (m, 1H, H b ); 7.47-7.62 (m, 9H, Ph and H a/b/c//γ ); 8.19 (s, 1H, H α ).
Example 10
One-Step Synthesis of Compound IIh
To prepare compound IIh by a one-step synthetic process, 124 mg, (0.48 mmol) of 4-amino-3-(4-trifluoromethylphenyl)-5-mercapto[4H]-1,2,4-triazole were refluxed with 66 μL (0.48 mmol) of triethylamine in 10 mL of anhydrous ethanol. To this solution was added α-bromocinnamaldehyde (150 mg, 0.71 mmol) and the mixture was refluxed until no more of the starting triazole could be detected by thin layer chromatography (chloroform 95%/methanol 5%). Over time the product precipitated out of solution and, after cooling the reaction to room temperature, it was isolated by filtration and washed with ethanol. Yellow crystals were obtained after recrystallisation from acetone, 125 mg (70%), mp=246-247° C. Anal. Calcd. for C 15 H 10 N 4 S 2 +0.5 H 2 O: C, 56.69%; H, 3.17%; N, 14.69%. Found: C, 56.87%; H, 2.88%; N, 14.48%. 1 H NMR (d 6 -DMSO) δ: 7.47-7.64 (m, 6H, Ph and H γ ); 7.94 (d, J=8.4 Hz, 2H, H b ); 8.23 (s, 1H, H α ); 8.24 (d, J=8.4 Hz, 2H, H a ).
Example 11
One-Step Synthesis of Compound IIi
To prepare compound IIi by a one-step synthetic process, 152 mg (0.72 mmol) of 4-amino-3-(4-fluoromethylphenyl)-5-mercapto[4H]-1,2,4-triazole were refluxed with 100 μL (0.72 mmol) of triethylamine in 10 mL of anhydrous ethanol. To this solution was added α-bromocinnamaldehyde (267 mg, 1.27 mmol) and the mixture was refluxed until no more of the starting triazole could be detected by thin layer chromatography (chloroform 95%/methanol 5%). Over time the product precipitated out of solution and, after cooling the reaction to room temperature, it was isolated by filtration and washed with ethanol. Orange crystals were obtained after recrystallisation from acetone, 105 mg (45%), mp=254-255° C. 1 H NMR (d 6 -DMSO) δ: 7.40-7.64 (m, 8H, Ph and H b/γ ); 8.03-8.07 (m, 2H, H a ); 8.19 (s, 1H, H α ). | Fused-ring triazole compounds which inhibit proliferation of cells and exhibit a unique and intense fluorescence are provided. Also provided are methods for synthesizing these compounds and methods for using these compounds to inhibit cell proliferation and infection and to label and fluorescently detect selected molecules. | 2 |
FIELD OF THE INVENTION
This invention relates generally to a tool used to remove compressed rings from tubing joints. More specifically, this tool relates to the removal of crimped rings used to secure plastic plumbing pipe or tubing over a fitting.
BACKGROUND OF THE INVENTION
The introduction of plastic plumbing to the construction industry has resulted in a significant saving of time. The conduit used in plastic plumbing is referred by a variety of terms such as hose, piping or tubing. Steel piping requires a labor and time intensive fitting and threading process. Rigid copper piping avoids the threading process but replaces it with the need for soldering. Plastic tubing requires less fitting and the resulting joints are easy to complete. Tubing used for household plumbing is placed over a fitting's barbed or ribbed nipple and secured with a clamp of some sort.
It is known to crimp rings, such as annealed copper rings, over plastic plumbing tubing attached to the fitting's nipples, in order to provide a more secure joint. The tubing is resilient and is caused to deform over the ribs of the rigid nipple, preventing the tubing's removal therefrom. A number of tools have been developed to crimp the ring over the tubing and the nipple. One such tool is described in U.S. Pat. No. 5,289,712 to Haughian, wherein a lever type tool is used to apply pressure and reduce the diameter of the ring over the tubing, once positioned over a ribbed nipple. The tubing under the ring is permanently deformed.
Sometimes it is necessary to change the connection at the joint, to correct an error, alter the configuration, or merely to remove the fitting. Preferably the fitting is salvaged for reuse, due in part to economics but also to avoid the need to change all other joints on the affected fitting. Due to the deformation of the tubing at the old joint, the deformed part is usually cut off.
To change the joint, the crimped ring is removed before the tubing can be removed from the ribbed nipple. Currently, removal of these crimped rings presents a challenge, as most plumbers are forced to use a hacksaw to angle cut the ring from the tubing and the nipple. This may result in damage to the nipple as it is difficult to visualize the point at which the ring has been cut and the underlying nipple has not. The tubing offers little resistance to the hacksaw and one can cut through the tubing and into the nipple with little warning. Further, joints of this type are often too closely spaced or are located in areas with little space to maneuver a saw.
There are a number of tools used to hold and cut pipe or tubing, such as described in U.S. Pat. No. 287,378 to Herbert and U.S. Pat. No. 198,709 to Thornton. Generally, these pipe-cutting devices cut the pipe circumferentially. U.S. Pat. No. 45,496 describes a device which has a nearly tangential pipe thread cutting tooth. None of these tools could be used to remove a crimp ring from tubing. Further, tools which would apply a force perpendicular to the surface of the ring could result in deformation or damage to the fitting.
There is clearly a demonstrated need for a tool that can remove a crimped ring without damaging the underlying nipple and which is simple and easy to operate under a variety of conditions.
SUMMARY OF THE INVENTION
In a preferred embodiment, a device is provided for removing an annular ring from plastic tubing overlying a plumbing fitting. The device has the advantages of simplicity, ease of operation and does not risk injury to the fitting. In an embodiment implementing pivoting jaws and handles, the jaws are placed over the crimped ring and actuation of the handles allows one jaw to support the ring while the other cuts the ring on a path tangent to the inside circumference of the ring which thereby avoids injuring the fitting.
In a broad aspect then, apparatus is provided for cutting a crimped ring from an underlying cylindrical object, such as plastic tubing overlying a nipple, the apparatus comprising an annular recess for radially supporting at least a portion of the ring along its circumference and a ring-cutting chisel. Means are provided for actuating the chisel between resting and ring-cutting positions, preferably being a pair of pivoting levers, which form the recess and chisel portions. The chisel, when actuated from a resting position to a cutting position, engages and cuts through the ring across its width and along a path substantially tangent to the ring's inner circumference so as to leave the underlying circular object intact, the ring being supported by the annular recess.
Preferably, the actuating means are a pair of levers or a screw actuated chisel integrated into a unitary body. More preferably, serrations can be provided in the annular recess to prevent rotation of the ring while cutting.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a is a partial side, cross-sectional view of a conventional plumbing fitting, plastic tubing and crimped ring;
FIG. 1 b is a cross-sectional view of the fitting, tubing and ring along line I—I of FIG. 1 a;
FIG. 2 is a perspective view of a hacksaw example for removal of a crimped ring, according to the prior art;
FIG. 3 a is a side view of one embodiment of the invention illustrating the resting position prior to cutting of the ring;
FIG. 3 b is a side view according to FIG. 3 a , illustrating cutting position wherein the ring is severed;
FIG. 4 a is a partial perspective view of the embodiment according to FIG. 3 a illustrating a partial fitting, tubing and crimped ring prior to cutting;
FIG. 4 b is a perspective view of a crimped ring after it has been cut using an embodiment of the invention; and
FIG. 5 is a side cross-sectional view of a screw-type embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Having reference to FIGS. 1 a and 1 b , in conventional plumbing, fittings 1 are used at joints in resilient, tubular plastic tubing 2 . A contemporary example of such tubing is cross-linked polyethylene, most commonly used in configurations having ½″ and ¾″ inside diameters. The inside diameter or bore of the tubing 2 is placed over a cylindrical member 3 . The member 3 could be a rigid cylindrical plug or a nipple 3 extending from the fitting 1 . The member 3 has several barbs, serrations or circumferential ribs 4 spaced axially therealong. Hereinafter, the cylindrical member referred to herein is implemented as a nipple 3 having a bore for passing fluids coextensive with the tubing 2 . Together, the nipple 3 and overlying tubing 2 form a cylindrical object 5 .
The tubing 2 is secured to the nipple 3 with an annular ring 6 . The ring 6 is placed concentrically over the cylindrical object 5 and compressed or crimped with a conventional crimping tool (not shown). The crimped ring 6 radially compresses the tubing 2 onto the nipple 3 and deforms it over the nipple's ribs 4 . The crimped ring 6 is used only once and must be removed if the tubing 2 is to be separated from the nipple 3 .
As stated above, a known prior art means of ring removal, as seen in FIG. 2, is to use a hacksaw 7 to cut across the width w of the crimped ring 6 at an angle. There is a risk that in attempting to cut the ring 6 , both the tubing 2 and the nipple 3 may be cut requiring replacement of the fitting 1 and all three joints shown.
Having reference to FIGS. 3 a - 5 , the present invention provides a device 11 , which incorporates radial support means 8 for the ring 6 and a ring-cutting means 10 . A portion of the outer circumference of the ring 6 rests against the support means 8 for radially supporting the ring 6 . Actuating means 9 operate cutting means 10 between a resting position (FIG. 3 a ) and a ring-cutting position (FIG. 3 b ).
As shown in FIGS. 4 a and 5 , when actuated, the cutting means 10 are driven into the ring 6 , across its width w, and along a path P substantially tangent to the inside circumference of the annular ring 6 . Cutting reaction forces (including torque), imposed upon the ring 6 , tubing 2 and fitting 1 , are radially resisted by the support means 8 .
The arrangement of the support and cutting means 8 , 10 are described in detail as follows.
In one embodiment of the invention, shown in FIGS. 3 a through 4 a , a crimped-ring removal device 11 is shown. Support means 8 are shown to comprise a first lever 12 , on one end of which a ring support in the form of a supporting jaw 13 having a ring supporting surface 13 a thereon is formed, and on the other end a handle 14 is disclosed. A second lever 15 has a blade or chisel 16 formed on a chisel support 15 a at one end as the cutting means 10 , and on the other end is formed a handle 17 .
The two levers 12 , 15 are joined with a pivot 18 intermediate along their length which allows the device 11 to be actuated to drive the chisel 16 into the ring 6 . Slot 19 aids in placing the jaws over the ring 6 . The slot is inoperative during cutting. The ring 6 , the underlying tubing 2 , and the nipple 3 rest in an annular recess 20 in the supporting jaw 13 which acts as the support means 8 . The annular recess 20 and supporting jaw 13 provide support against the radial force resulting when the chisel 16 bears down on the ring 6 in the cutting position (FIG. 3 b ).
While the resulting frictional forces are significant and usually sufficient to prevent rotation of the ring 6 , the supporting jaw 13 optionally includes serrated teeth 21 to further prevent reactive rotation of the ring 6 during cutting (see FIGS. 4 a and 5 ).
Best shown in FIGS. 4 a and 4 b , the chisel 16 has a linear cutting edge 22 for making a single cut 23 through the annulus of and across the width w of the ring 6 . The resulting cut is substantially parallel to the axis of the ring 6 . Adding angle to the edge may assist in the cutting, but a greater stroke would be required between resting and cutting positions.
In operation, FIG. 3 a shows the device 11 in a non-actuated, or resting position. When the handles 14 , 17 of levers 12 , 15 are actuated by squeezing them together, the device is actuated to the cutting position.
Then, as shown in FIGS. 4 a and 3 b , the chisel 16 and pivot 18 are arranged so that when operated between the resting and cutting positions, the chisel 16 is pivoted to strike the ring 6 and proceed therethrough on a path P substantially tangent to the ring's inner diameter or circumference 23 . The cutting path P enables cutting of the ring 6 without cutting the underlying nipple 3 . The chisel 16 could encroach on the already deformed resilient tubing 2 .
In another embodiment of the invention, best seen in FIG. 5, the support means 8 , a supporting jaw 13 , and the chisel 16 are provided in a unitary C-shaped body 25 . Note that the same reference numerals are used when the elements have the same function as in the earlier embodiment.
The supporting jaw 13 is formed in the body's lower end 26 of the body 25 and the actuating means 9 is formed at the body's upper end 27 . The actuating means 9 comprises a linear screw actuator 28 , housed in a threaded bore 29 in the body's upper end 27 . As in the first embodiment, the cutting means 10 is a chisel 16 formed on a bit 30 . The bit 30 moves axially, but does not rotate, within bore 29 so as to ensure the chisel's cutting edge 22 cuts across the ring's width w. The bit 30 is prevented from rotating by guide means 31 formed in the body's upper end 27 , aligning the chisel's edge 22 substantially parallel to the ring's axis.
Means 34 connect the linear screw actuator 28 and the bit 30 so that the bit 30 both advances and retracts with the actuator. Connecting means 34 permits relative rotation of the rotating screw actuator and non-rotating bit.
One form of connection means 34 is shown as an annular groove 32 at the end of the bit 30 opposite the chisel 16 and having a transverse locking pin 33 installed through the screw actuator 28 to engage the annular groove 32 in the bit 30 .
Although several preferred embodiments of the present invention have been disclosed above, it is clear to those of ordinary skill in the art that other embodiments are possible which do not vary from the spirit and scope of the present invention. For example, other forms of actuating means are possible which support a ring and actuate the chisel along the described path; the chisel can be skewed slightly to increase the point load, yet still cut across the ring's width; or a spring return can be added to the chisel of the embodiment depicted in FIG. 5 rather than the connection means 34 . | Apparatus is provided for removing a crimped ring from plastic tubing installed over the nipple of a fitting. A supporting jaw radially supports the crimped ring while a chisel cuts the ring on a tangential path. One embodiment uses pair of levers joined and pivoted intermediate their ends. One lever forms the supporting jaw while the other forms the chisel. When actuated, the cutting jaw cuts the ring on a path tangent to the inside circumference of the ring, thereby avoiding injury to the fitting, the fitting therefore being reusable. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an air spray device, more particularly to an air spray device with a telescopic spray tube that is convenient to use and store.
2. Description of the Related Art
Referring to FIG. 1, a conventional air spray device is shown to include a barrel 1 with a passage 102 which has an inlet 103 and an outlet 104 , a valve body 3 which is disposed in the passage 102 between the inlet 103 and the outlet 104 and which has upper and lower O-rings 302 and an annular groove 301 , an actuator 5 which is pivotally disposed on the barrel 1 via a pivot pin 4 to actuate the valve body 3 so as to align the annular groove 301 with the inlet 103 and the outlet 104 in order to permit compressed air from the inlet 103 to flow through the outlet 104 and to spray out from a spray tube 6 that is connected to the outlet 104 so as to remove dust on an object for cleaning purposes, and a biasing member 2 which can bias the valve body 3 to align one of the upper and lower O-rings 302 with the inlet 103 and the outlet 104 to interrupt the fluid communication therebetween.
Since the length of the spray tube 6 is fixed, dust to be removed from the object may fly over the user during operation. This is particularly undesirable when the air spray device is applied in conjunction with a painting and coating device. In addition, after use, some painting and coating material may be left in the nozzle portion 61 , thereby resulting in inconvenient cleaning thereof. Moreover, numerous air spray devices are required for operating with different materials of painting, thereby resulting in inconvenience during usage.
SUMMARY OF THE INVENTION
The object of the present invention is to provide an air spray device in which a spray tube has a plurality of tube portions telescopically fitted over each other so as to be stretchable and retractable for added convenience during storage and use.
According to this invention, the air spray device comprises a barrel with an inner surrounding wall to define a passage which has an inlet and an outlet downstream of the inlet. A controlling member includes a valve body which is disposed in the passage between the inlet and the outlet, and a stem portion which has an inner end engaging the valve body and an outer end extending from the inner end and transversely and outwardly of the inner surrounding wall so as to be actuated to move the valve body to permit fluid communication between the inlet and the outlet. A biasing member is disposed to bias the valve body to interrupt the fluid communication between the inlet and the outlet. An actuator is disposed on the barrel to actuate the outer end of the stem portion to move the valve body against a biasing action of the biasing member. A spray tube includes first and second tube portions. The first tube portion has a first proximate end which is connected to and which is in fluid communication with the outlet, a first distal end opposite to the first proximate end in a longitudinal direction and downstream of the first proximate end, and a first intermediate tubular portion interposed between the first proximate and distal ends. The first intermediate tubular portion includes a first outer tubular wall surface, and a first inner tubular wall surface which defines a first conduit opposite to the first outer tubular wall surface radially and disposed between and communicating with the first proximate and distal ends. The second tube portion has a second proximate end which is inserted into the first conduit, a second distal end which is disposed opposite to the second proximate end in the longitudinal direction and downstream of the second proximate end and which extends outwardly of the first distal end, and a second intermediate tubular portion which is interposed between the second proximate and distal ends. The second intermediate tubular portion includes a second outer tubular wall surface to be telescopically fitted in the first conduit in the longitudinal direction and to be slidable between a stretched position, where the second proximate end is close to the first distal end, and a retracted position, where the second proximate end is close to the first proximate end, and a second inner tubular wall surface opposite to the second outer tubular wall surface radially and defining a second conduit that is in fluid communication with the first conduit. A nozzle portion is disposed outwardly of the second distal end and distal to the second proximate end, and is fluidly communicated with the second conduit. A first retaining member is disposed on and extends radially and inwardly from the first inner tubular wall surface proximate to the first proximate end so as to arrest further movement of the second proximate end toward the first proximate end in the retracted position. A second retaining member is disposed between the first distal end and the second outer tubular wall surface proximate to the second proximate end to arrest further movement of the second proximate end toward the first distal end in the stretched position.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which:
FIG. 1 is a sectional view of a conventional air spray device;
FIG. 2 is an exploded perspective view of a first preferred embodiment of a spray tube of an air spray device according to this invention;
FIG. 3 is a sectional view of the first preferred embodiment in a retracted state;
FIG. 4 is a sectional view of the first preferred embodiment in a stretched state;
FIG. 5 is a sectional view of a second preferred embodiment of this invention in a retracted state;
FIG. 6 is a sectional view of the second preferred embodiment in a stretched state;
FIG. 7 is a sectional view of a third preferred embodiment of this invention in a retracted state.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before the present invention is described in greater detail, it should be noted that same reference numerals have been used to denote like elements throughout the specification.
Referring to FIGS. 2, 3 and 4 , the first preferred embodiment of the air spray device according to the present invention is shown to comprise a barrel 10 , a biasing member 30 , an actuator 14 , a spray tube 40 , a nozzle portion 50 , and a plurality of retaining members.
The barrel 10 has an inner surrounding wall to define a passage 12 which has an inlet 121 and an outlet 122 downstream of the inlet 121 , and a controlling member which includes a valve body 20 disposed in the passage 12 between the inlet 121 and the outlet 122 , and a stem portion 201 which has an inner end that engages the valve body 20 and an outer end that extends from the inner end and transversely and outwardly of the inner surrounding wall so as to be actuated to move the valve body 20 to have an annular groove 25 aligned with the inlet 121 and the outlet 122 to establish fluid communication between the inlet 121 and the outlet 122 .
The biasing member 30 is disposed to bias the valve body 20 to interrupt the fluid communication between the inlet 121 and the outlet 122 via upper and lower O-rings 23 , 24 which are sleeved on the valve body 20 and which are disposed at opposite sides of the annular groove 25 .
The actuator 14 is disposed pivotally on the barrel 10 to actuate the outer end of the stem portion 201 to move the valve body 20 against a biasing action of the biasing member 30 .
In this embodiment, the spray tube 40 includes first, second and third tube portions 41 , 42 , 43 .
The first tube portion 41 has a first proximate end 411 , a bushing 48 which is inserted into the first proximate end 411 and which has an externally threaded portion 481 that engages threadedly an internally threaded portion 123 of the outlet 122 and that is in fluid communication with the outlet 122 , an O-ring 413 which is sleeved on the first proximate end 411 to provide an air-tight connection, a first distal end 412 which is disposed opposite to the first proximate end 411 in a longitudinal direction and downstream of the first proximate end 411 , and a first intermediate tubular portion which is interposed between the first proximate and distal ends 411 , 412 . The first intermediate tubular portion includes a first outer tubular wall surface 414 , and a first inner tubular wall surface 415 which defines a first conduit 416 opposite to the first outer tubular wall surface 415 radially and which is disposed between and which communicates with the first proximate and distal ends 411 , 412 .
The second tube portion 42 has a second proximate end 421 which is inserted into the first conduit 416 , a second distal end 422 which is disposed opposite to the second proximate end 421 in the longitudinal direction and downstream of the second proximate end 421 and which extends outwardly of the first distal end 412 , and a second intermediate tubular portion which is interposed between the second proximate and distal ends 421 , 422 . The second intermediate tubular portion includes a second outer tubular wall surface 424 of a diameter which is smaller than that of the first inner tubular wall surface 415 so as to be telescopically fitted in the first conduit 416 in the longitudinal direction and to be slidable between a stretched position (as shown in FIG. 4 ), where the second proximate end 421 is close to the first distal end 412 , and a retracted position (as shown in FIG. 3 ), where the second proximate end 421 is close to the first proximate end 411 , and a second inner tubular wall surface 425 which is disposed opposite to the second outer tubular wall surface 424 radially and which defines a second conduit 426 that is in fluid communication with the first conduit 416 .
The third tube portion 43 has a third proximate end 431 which is inserted into the second conduit 426 , a third distal end 432 which is disposed opposite to the third proximate end 431 in the longitudinal direction and downstream of the third proximate end 431 and which extends outwardly of the second distal end 422 , and a third intermediate tubular portion which is interposed between the third proximate and distal ends 431 , 432 . The third intermediate tubular portion includes a third outer tubular wall surface 434 of a diameter which is smaller than that of the second inner tubular wall surface 425 so as to be telescopically fitted in the second conduit 426 in the longitudinal direction, and a third inner tubular wall surface 435 which is disposed opposite to the third outer tubular wall surface 434 radially and which defines a third conduit 436 that is in fluid communication with the second conduit 426 .
In addition, each of the first and second distal ends 412 , 422 has a ring portion 4121 , 4221 which extends radially and inwardly therefrom to frictionally and slidably contact a respective one of the second and third outer tubular wall surfaces 424 , 434 so as to confine a respective one of clearances between the first inner and the second outer tubular wall surfaces 415 , 424 , and between the second inner and the third outer tubular wall surfaces 425 , 434 . Each of the second and third inner tubular wall surfaces 425 , 435 defines a pair of insert holes 4211 , 4311 to communicate with a respective one of the second and third outer tubular wall surfaces 424 , 434 .
The nozzle portion 50 is disposed on the third distal end 432 and distal to the third proximate end 431 , and is fluidly communicated with the third conduit 436 .
The retaining members includes a first retaining member 482 which is an abutment wall of the bushing 48 in this embodiment, and which extends radially and inwardly from the first inner tubular wall surface 415 proximate to the first proximate end 411 so as to arrest further movement of the second proximate end 421 toward the first proximate end 411 in the retracted position. A second retaining member and a fourth retaining member are disposed between the first distal end 412 and the second outer tubular wall surface 424 proximate to the second proximate end 421 , and between the second distal end 422 and the third outer tubular wall surface 434 proximate to the third proximate end 431 , respectively. Each of the second and fourth retaining members includes abutment portions 442 , 452 of a pair of retaining plates 44 , 45 which are disposed on and which extend outwardly and radially from the respective one of the second and third outer tubular wall surfaces 424 , 434 such that the abutment portions 442 , 452 are accommodated in the respective clearance and are movable relative to the respective one of the first and second inner tubular wall surfaces 415 , 425 so as to abut against the respective ring portion 4121 , 4221 in the stretched position, thereby arresting further movement of the second and third proximate ends 421 , 431 toward the first and second distal ends 412 , 422 , respectively. Each retaining plate 44 , 45 is detachably sleeved on the respective one of the second and third outer tubular wall surfaces 424 , 425 , and further has a connecting end opposite to the abutment portion 442 , 452 in the longitudinal direction and proximate to the respective one of the second and third proximate ends 421 , 431 . An insert member 441 , 451 is formed integrally on the retaining plate 44 , 45 proximate to the connecting end, and is received in the insert hole 4211 , 4311 . A third retaining member 4411 , 4511 is connected integrally to the insert member 441 , 451 , and extends radially and inwardly of the respective one of the second and third inner tubular wall surfaces 425 , 435 so as to arrest further movement of the third proximate end 431 toward the second proximate end 421 in the retracted position.
In use, the third tube portion 43 is pulled outwardly to abut the abutment portions 452 against the ring portion 4221 so as to permit the second tube portion 42 to be pulled outwardly until the abutment portions 442 abut against the ring portion 4121 to place the spray tube 40 in the stretched position, as shown in FIG. 4 . Thus, the distance between the barrel 10 and an opening 51 of the nozzle portion 50 is lengthened so as to prevent dust on an object from flying over the user during cleaning of the object.
When it is desired to retract the spray tube 40 for storing the air spray device, the nozzle portion 50 is forced to move the third tube portion 43 into the second conduit 426 so as to abut the third proximate end 431 against the third retaining member 441 such that the second tube portion 42 is moved inwardly of the first conduit 416 until the second proximate end 421 abuts against the first retaining member 482 .
As shown in FIGS. 5 and 6, the second preferred embodiment of the air spray device according to this invention is shown to be substantially similar to the first preferred embodiment in construction. Additionally, two bushings 46 , 47 are disposed respectively on the second and third tube portions 42 , 43 . Each bushing 46 , 47 includes an inner portion 461 , 471 which is disposed on a respective one of the second and third inner tubular wall surfaces 425 , 435 proximate to the second and third proximate ends 421 , 431 , and which has an abutment wall 4611 , 4711 to serve as the third retaining members, and an annular end 462 , 472 which extends outwardly and radially of and beyond the respective one of the second and third proximate ends 421 , 431 so as to frictionally and slidably contact a respective one of the first and second inner tubular wall surfaces 415 , 425 . A plurality of O-rings 466 , 464 , 476 , 474 are disposed between the annular ends 462 , 472 and the first and second inner tubular wall surfaces 415 , 425 , and between the inner portion 461 , 471 and the second and third inner tubular wall surfaces 425 , 435 so as to provide air-tight connection therebetween.
As shown in FIG. 7, the third preferred embodiment of the air spray device according to this invention is also shown to be substantially similar to the first preferred embodiment in construction. The nozzle portion 50 ′ has an internally threaded portion 52 ′ which engages threadedly and detachably an externally threaded portion of the third distal end 432 ′ of the third tube portion 43 ′ of the spray tube 40 ′. The nozzle portion 50 ′ has an opening 51 ′ downstream of the third conduit 436 ′, and an intake port 53 ′ which is disposed between and which is in fluid communication with the third conduit 436 ′ and the opening 51 ′. Thus, the intake port 53 ′, is adapted to be in fluid communication with a liquid container 60 ′, such as a painting container, to cause the liquid contained therein to be entrained in an air stream which flows from the third conduit 436 ′ and out of the opening 51 ′.
After use, the nozzle portion 50 ′ can be detached from the spray tube 40 ′ for convenient cleaning. In addition, the nozzle portion 50 ′ can be changed for operating with different colors of paint.
While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements. | An air spray device includes a barrel with a passage therein, a valve body disposed in the passage and actuated to move to permit fluid communication between an inlet and an outlet of the passage, spray tube with a first tube portion connected to the outlet, and a second tube portion telescopically fitted in the first tube portion, and a nozzle portion which is disposed outwardly of the second tube portion to generate a compressed air stream for removing dust from an object. Retaining members are disposed in the spray tube for retaining the spray tube in one of stretched and retracted positions. By the telescopic spray tube, the dust to be removed will not fly over the user, and the air spray device is convenient to store. | 1 |
RELATED PATENT APPLICATIONS
This application claims priority to U.S. provisional application Ser. No. 61/613,684 filed 21 Mar. 2012 entitled “Phase Change Material Evaporator Charging Control”. Furthermore, this application is related to application U.S. Ser. No. 12/481,933 filed 10 Jun. 2009 to E. Wolfe IV, et al. entitled “Evaporator Phase Change Thermal Siphon”, application U.S. Ser. No. 13/451,665 filed 20 Apr. 2012 to G. Vreeland et al. entitled “Evaporator Phase Change Thermal Siphon” and application U.S. Ser. No. 61/702,889 filed 19 Sep. 2012 to G. Vreeland et al. entitled “PCM Evaporator with Louvered Clam Shells”. All three aforesaid related applications are hereby incorporated herein by reference.
TECHNICAL FIELD OF INVENTION
The present invention relates to an evaporator for a vehicle air conditioning system; more particularly, to an evaporator having a phase change material; and still more particularly, to the control of the charging of the phase change material.
BACKGROUND OF THE INVENTION
Hybrid vehicles may employ Belt Alternator Starter (BAS) technology to gain energy efficiency. Coming to a stop at a traffic light or during an extended idle, the engine is turned off to achieve enhanced fuel economy. As the brake pedal is released, an electric motor/generator unit instantaneously restarts the engine, typically in less than half of a second time, making the auto start system essentially transparent to the driver. This is referred to as the Stop-Start strategy for enhancing fuel economy. A BAS vehicle can provide 15-20% fuel economy gain in the city and an overall fuel economy increase of 4˜7%. For a baseline gasoline vehicle with 30 mpg fuel economy, this is equivalent to an increase of 1.2˜2.1 mpg of Fuel economy improvement.
While the Stop-Start strategy improves fuel economy, it may compromise passenger comfort. Stopping the engine disables the belt-driven A/C system, resulting in interruption of cooling for the passenger compartment. Currently, vehicle OEM's currently rely on the thermal inertia of the air conditioning evaporator to provide some residual cooling during the period when the engine is stopped. The evaporator residual cooling time is typically limited to 25 seconds or less before the discharge temperature of the evaporator rises above a level that no longer provides the desired cooling. When the evaporator is warmed up to a specified air discharge temperature, the engine is restarted to drive the A/C system to provide cooling. This periodic restart under idle conditions undermines average fuel economy that can be achieved by the Hybrid vehicles.
BRIEF DESCRIPTION OF THE INVENTION
According to one aspect of the invention, a method of managing a phase change material (PCM) thermo-syphon evaporator includes the steps of determining the Evaporator Out Air Temperature (EOAT), and determining if the air conditioning (A/C) system is operating in transient cool-down mode or steady state mode, and finally determining the charging priority of the PCM evaporator over that of standard comfort maintenance. If the A/C system is operating in a transient cool-down mode, and PCM charging priority is higher than comfort maintenance, then the HVAC module blower voltage is overridden to a lower value than the standard comfort maintenance blower voltage to achieve a reduced evaporator temperature so as to achieve charging of the PCM material. Conversely, if the A/C system is operating in a steady-state mode, then a predetermined override blower voltage is selected as a function of Evaporator Out Air Temperature only, and a State of Charge Indicator is used to enable or disable the blower override, and consequently, the PCM charging.
These and other features and advantages of this invention will become apparent upon reading the following specification, which, along with the drawings, describes preferred and alternative embodiments of the invention in detail.
BRIEF DESCRIPTION OF DRAWINGS
This invention will be further described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 , illustrates a perspective view of a thermo-syphon PCM evaporator employed in the present invention;
FIG. 2 , illustrates an exploded, perspective view of the thermo-syphon PCM evaporator of FIG. 1 , depicting internal details thereof;
FIG. 3 , illustrates the PCM evaporator of FIG. 1 , employed within an HVAC module;
FIG. 4 , is a graph illustrating contrasting Vent Duct Temperature v Time characteristics of an HVAC module with and without a PCM evaporator;
FIG. 5 , illustrates a flow chart for managing the PCM charging during A/C transient operation;
FIG. 6 , illustrates a flow chart for monitoring and managing the steady state charging of the PCM evaporator of FIG. 1 ,
FIG. 7 , is a graph illustrating PCM Charge State (%) Control Set Point (Deg. C) v Time showing the cyclic charging of a PCM evaporator during Series Reheat Reduction (SSR) operation; and
FIG. 8 , illustrates a flow chart of an SSR compatible charging algorithm.
Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to illustrate and explain the present invention. The exemplification set forth herein illustrates an embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF INVENTION
To improve Stop-Start hybrid vehicle fuel economy, Phase Changing Materials (PCM) based Thermal Storage technologies have been created to bank the excessive cooling available during road load operations and release the stored cooling during traffic stop to provide passenger comfort. As indicated in FIG. 1 , PCM material is typically integrated into the top portion of the evaporator to provide cooling storage capability. Due to the fact that PCM materials' latent heat is significantly greater than their sensible heat, extended period of comfort can be provided to the passenger compartment before an engine restart is needed. The reduction in the frequency of restart, or the entire elimination thereof, during the majority of traffic stops, allows the Stop-Start strategy to achieve its full fuel economy potential.
Referring to FIG. 1 , illustrated is a preferred exemplary embodiment of an evaporator 100 having a plurality of PCM housings 12 in thermal communication with the upper region 14 of the refrigerant tubes 16 . The evaporator 10 includes an upper manifold 18 and a lower manifold 20 , in which the terms upper and lower are used with respect to the direction of gravity. Hydraulically connecting the upper manifold 18 with the lower manifold 20 are flat refrigerant tubes 16 which may be manufactured by any methods known to those of ordinary skill in the art, such as by extrusion, folding of a sheet of heat conductive material, or assembling two half plates having stamped features defining flow spaces. While flat tubes are shown, those of ordinary skill in the art would recognize that other refrigerant tube shapes may be utilized.
Referring to FIG. 2 , illustrated is a partially exploded view of the evaporator 10 , which is manufactured from a plurality stamped metallic plates 22 . The stamped metallic plates 22 include features known to those of ordinary skill in the art, such as openings, bosses about selected openings, and flanges. When stacked and brazed, the plurality of stamped metallic plates 22 define the upper manifold 18 , lower manifold 20 , and flat refrigerant tubes 16 hydraulically connecting the manifolds 18 , 20 . Inserted between adjacent flat refrigerant tubes 16 is a PCM housing 24 containing a phase change material. The PCM housing 24 may be defined by features on the stacked and brazed stamped metallic plates 22 , or may be manufactured separately and then assembled onto the evaporator 10 . A PCM housing 24 is disposed between adjacent flat refrigerant tubes 16 and is in thermal contact with only the upper region 14 of the flat refrigerant tubes 16 . The PCM housing 24 may surround part of the upper manifold 18 or, as an alternative, the PCM housing 24 may be separate from the upper manifold 18 and positioned in the upper region 14 of the flat refrigerant tubes 16 immediately below the upper manifold 18 . A heat conductive material such as metallic fins 12 or metallic particles or fibers may be added in the PCM housing 24 to increase the heat transfer efficiency. Corrugated fins 26 may be inserted between the adjacent flat refrigerant tubes 16 beneath the PCM housing 24 .
FIG. 3 indicates the application of a PCM evaporator 28 in an A/C system HVAC module 30 . The PCM evaporator 28 replaces the traditional non-PCM evaporators and becomes an integral part of the A/C system 30 . The PCM evaporator 28 is nestingly disposed within an HVAC air flow duct 32 such that air flowing there through, as indicated by arrows 34 , passes through the lower portion 36 of the PCM evaporator 28 . Airflow exiting the PCM evaporator 28 is selectively directed by a damper door 38 through a bypass passage 40 or a heater core 42 toward an outlet port 44 .
FIG. 4 graphically illustrates the impact of the PCM cooling storage in terms of the duration within which a sustained low vent outlet discharge temperature is achieved. Normally, the duration of useful discharge temperature is double or triple of the standard non-PCM equipped evaporators.
An embodiment of the invention focuses on the managed use of the PCM evaporator to achieve maximum fuel economy saving. The direct application of the present invention is on vehicles with automatic climate control systems. However, it is also applicable to enhanced manually controlled A/C systems.
The basis is the definition of a State of Charge Indicator. With the charging status known, it is possible to intelligently manage the charging process to increase the operational availability of the PCM cooling at a traffic stop and achieve improved fuel economy. Meanwhile, it also makes it possible to achieve operational compatibility with the Series Reheat Reduction (SRR) control methodology, allowing Mild Hybrid vehicles to gain the benefit of energy saving from both the PCM and SRR.
State of Charge Indicator
Herein one method of defining the State of Charge Indicator is provided. According to Max Planck (1858˜1947, Germany, Nobel Physics Prize Recipient, 1918), the liquid/solid phase change time for pure or homogeneous substances of specific shape with a single freezing/melting temperature can be determined with the following formula,
t
100
=
Δ
H
f
ρ
T
Freeze
-
T
∞
(
P
d
h
+
R
d
2
k
)
where
t 100 Time to achieve 100% phase change (minutes)
ΔH ƒ Latent heat of fusion (Btu/lb)
ρ Density: use liquid density for freezing and solid density for melting (1b/ft^3).
T Freeze Freezing temperature of the PCM (° F.)
T ∞ Surrounding medium temperature (° F.)
P, R Shape dependent constants, as given in Table 1
d Characteristic length: thickness of slab or diameter of cylinder or sphere (ft).
h Surrounding medium heat transfer coefficient (Btu/min-ft2-° F.)
k Material thermal conductivity: use solid conductivity for freezing and liquid thermal conductivity for melting
TABLE 1
Shape Dependent Constants for Plank's Equation
Shape
P
R
Infinite Slab
½
⅛
Infinite Cylinder
¼
1/16
Sphere
⅙
1/24
In the PCM thermo-syphon evaporator environment, the melting or freezing driving temperature is provided by the A/C system refrigerant. Normally there is no direct evaporator refrigerant temperature measurement in the vehicle. Thus the refrigerant temperature may be obtained indirectly. In most vehicles, the Evaporator Out Air Temperature (EOAT) is measured with a thermistor for A/C system control purposes. The EOAT temperature may be used to approximate the refrigerant temperature through the following equation, where C is a calibratible constant to account for the difference between the refrigerant temperature and the EOAT temperature. It is expected that improvement to the above formula may be obtained by those skilled in the art by way of heat transfer and thermodynamic principles.
T ∞ =T refrig =T eoa −C
During the freeze process, assuming the PCM material is subjected to the refrigerant temperature T refrig for an incremental amount of time δt, the percentage of PCM material frozen (or charged) can be indicated by δƒ p ,
δ
f
p
=
δ
t
t
100
=
δ
t
Δ
H
f
ρ
[
T
Freeze
-
T
eoa
(
t
)
-
C
]
(
P
d
h
+
R
d
2
k
)
Integrating δƒ p over the time during which the PCM material is exposed to the refrigerant temperature, the total percentage of PCM frozen, or the State of Charge Indicator, can be obtained,
f
p
=
∫
0
t
ⅆ
t
Δ
H
f
ρ
[
T
Freeze
-
T
eoa
(
t
)
-
C
]
(
P
d
h
+
R
d
2
k
)
Since most of the terms in the above equation are constants, and by defining the following constant K,
K
=
1
Δ
H
f
ρ
(
P
d
h
+
R
d
2
k
)
the percentage frozen function can be given as below and used as the State of Charge Indicator,
f
p
=
K
∫
0
t
[
T
Freeze
-
T
eoa
(
t
)
-
C
]
ⅆ
t
The following general boundary conditions apply during the integration process,
If ƒ p >1, ƒ p =1
If ƒ p <0, ƒ p =0
At engine start before a trip begins or at each traffic stop that lasts longer than the maximum capable time of the PCM evaporator, the percentage froze function is initialized to zero,
ƒ p =0
PCM Evaporator Initial Charging During Transient Soak and Cool-Down
The A/C system operation may be classified into two phases of operation. When the cabin is soaked to a high in-car temperature before the engine is started, the initial air conditioning objective is to bring the in-car temperature down as quickly as possible to achieve passenger comfort. This is normally classified as the transient A/C control. After the in-car temperature has been brought down to a preset comfort temperature, further A/C system operation is regulated to maintain the in-car comfort. This maintenance phase of the A/C system control is classified as the steady state control phase.
During the transient stage of the Soak and Cool-down, no charging can be obtained when the EOAT is considerably above the PCM freeze temperature. Charging will start when
T eoa ( t )− C<T Freeze
the state of charge can be tracked by real-time integrated ƒ p .
At certain point of the transient operation, the PCM charging may be accelerated by overriding the blower to a lower voltage such that the refrigerant temperature falls below T Freeze , or,
T eoa ( t )− C<<T Freeze
The blower voltage override to a lower value helps promote earlier or quicker charging of the PCM evaporator. However, if the priority is for accelerated transient in-car comfort, charging of the PCM evaporator can be delayed or avoided by overriding blower voltage to a higher level than the default setting. At the higher flow rate, the refrigerant temperature will be elevated along with the EOAT temperature, such that
T eoa ( t )− C>T Freeze
When this condition is met with control, it ensures that no charging of PCM will occur and the highest amount of cooling enthalpy will be delivered to the passenger compartment.
FIG. 5 provides the flowchart for managing the PCM evaporator charging during the transient phase of the A/C system operation. The flowchart commences with entering transient PCM charging at step 46 , which flows to logic step 48 . If the transient comfort has priority over PCM charging, flow passes to step 50 providing override to higher blower voltage Vhigh to bypass PCM charging, and passes on to exit step 52 . If the transient comfort does not have priority over PCM charging, flow passes to logic step 54 . If PCM charging does not have high priority, flow passes to step 56 , where normal ACC system prevails, and passes on to exit step 52 . If PCM charging has high priority, it flows to the step 58 of overriding ACC to lower blower voltage Vlow to improve PCM charging, and passes to exit step 52 .
PCM Evaporator Charging Under Steady State Conditions
For systems without Series Reheat Reduction (SRR), and under low to mid ambient temperatures, the refrigerant temperature may be naturally below the freezing temperature of PCM, and meeting the condition of,
T eoa ( t )< T Freeze +C
then charging will automatically occur. The State of Charge is tracked with ƒ p . Once charged, the PCM evaporator will remain charged and ready to be discharged at traffic stop.
However, if under steady state operating conditions, the refrigerant temperature is above the freeze temperature of PCM, such as when the car is operating in relatively high ambient temperatures (>30° C., e.g.), charging of PCM, if desired, can be accomplished by reducing the blower voltage below that commanded by the ACC system. Under the reduced blower voltage, lower refrigerant temperature may be obtained and hopefully below the PCM freeze temperature. The in-car comfort will be compromised to a limited extent, since at the reduced airflow rate the outlet discharge temperature will also be lowered. For such relatively high ambient temperatures, the override state may need to be maintained over time to ensure the readiness of the PCM evaporator for discharging.
One alternative is to allow certain amount of discharge to the PCM during steady state operation. For example, a minimum capacity of PCM is maintained at 75%. Whenever charging reaches 100%, as indicated by ƒ p , the override state is terminated and the Automatic Climate Control (ACC) system may return to normal operation. Discharge of PCM will occur under the normal operating condition. Once the threshold condition of 75% is reached, charging may be resumed by overriding the blower again.
Under even higher ambient conditions (>=40 C, e.g.), PCM charging temperature may be difficult to reach under the minimum allowable blower voltage. Under these conditions, the engine should not be turned off at the traffic stop for fuel saving purposes. Instead, the engine should remain on for comfort maintenance.
FIG. 6 shows the flowchart for monitoring and managing the steady state charging of the PCM evaporator. During steady state A/C system operation where cabin comfort has been achieved, natural charging is maintained. The rest of the branch manages the cyclic charging of the evaporator by blower override. In the event charging fails to occur after certain amount of time with the blower overridden, a failure to charge signal is provided to engine control to prevent engine from stopping during traffic stop.
The flowchart of FIG. 6 commences with entering steady state charging at step 60 , and flows to a logic step 62 determining if Tref exceeds Tfreeze. If Tref does not exceed Tfreeze, the State of Charge Function is integrated at step 64 and then flows to logic step 66 . In logic step 66 , if Blower Override is not true, the ACC control is maintained and PCM evaporator is charged at step 68 , and then flows to exit step 70 . Alternatively, if Blower Override is true, PMC charge state is determined at logic step 72 . If the PCM is not charged to 100%, flow is direct to exit step 70 with no action taken. If the PCM is charged to 100%, flow is to step 70 wherein Blower-Override flag is set to not true and then to exit step 70 . This disables the blower override. If Tref exceeds Tfreeze, flow is to a logic step 76 where Blower-Override state is evaluated. If Blower-Override is true, logic flow is to logic step 78 which determines if Override-Tmr has reached a calibrated set value. If Override-Tmr has not reached the set value, Override-Tmr+ is incremented by 1 at step 80 and logic flows to exit step 70 . If Override-Tmr has reached the set value, the State of Charge is assigned 0 and the PCM Charge is assigned to Failed at step 82 and logic flows to exit step 70 . If Blower Override is not true, logic flow is to a logic step 84 wherein if PCM Charge does not exceed 75%, logic flow is to step 86 setting Blower-Override=True and Override-Tmr=0 to initiate the blower override and start the timing of the override, and then to exit step 70 . Finally, if PCM Charge State exceeds 75%, logic flow is to Maintain ACC Control at step 88 and then to exit step 70 .
SRR Compatible PCM Evaporator Charging Under Steady State Conditions
For vehicle A/C systems with Series Reheat Reduction (SRR), the normal operating EOAT temperature may be above the freeze temperature of the PCM for ambient temperatures in the range of 5˜30 C. Typical EOAT temperature under SRR is around 10° C. This may make the steady state charging and maintenance of the PCM evaporator impossible due to that the melting temperature of the PCM is lower than the SRR set temperature. However, by taking advantage of the thermal inertia of the PCM evaporator and that of the airflow ducts, compatibility of SRR with PCM evaporator can be achieved.
As shown in FIG. 7 , the initial charging of the PCM evaporator is performed by overriding the SRR control to moisture freeze control EOAT temperature. Once charged and the State of Charge indicator is at 100%, the SRR control is executed to achieve improved A/C system energy efficiency. For the maintenance of the PCM evaporator, the SRR control is periodically overridden to maintain the charging state. For example, with the SRR EOAT control at 10° C. and the PCM freeze point at 5° C., the SRR operation may slowly discharge the PCM evaporator since the refrigerant temperature maybe higher than the PCM freeze point. At a pre-established State of Charge indicator level, such as 75% (defined to be the minimum required capacity level for Start Stop operation), the SRR will be overridden to evaporator freeze control for lowered refrigerant temperature to charge the PCM. For charging from 75% to 100%, the estimated charging time is about 25 seconds. Due to the thermal inertia of the evaporator, the air steam will likely not sense the temperature change during that period. Once the PCM charging indicator arrives at the 100% state, the SRR control assumes normal control of the A/C system. During the SRR high EOAT control period (such as 10° C.), the stored cooling in the PCM evaporator gradually gets discharged. This automatically translates into further reduced compressor load and result in additional energy saving more than that from the SRR algorithm alone. On average over the cycle, the extra energy used to charge the PCM in the SRR overriding period is balanced by the energy saving from the PCM evaporator during its discharge period. The net effect is that the PCM evaporator is at least maintained at 75% (as an example), and the SRR still achieves its own design objective.
FIG. 8 shows the flowchart for the SRR compatible PCM charging algorithm. In the event that the EOAT temperature decreases before the charging reaches 100%, charging of the PCM evaporator may be stopped early. For example, EOAT starts to decrease when PCM reaches 90%. The overall impact is that the charging and discharging will occur between 75% and 90%, and the cycling frequency for SRR override is in general increased.
The flow chart commences with entering steady state charging with SSR at step 90 and flowing to logic step 92 which determines if SSR is enabled. If SSR is not enabled, logic flows to step 94 which runs moisture freeze control and charge PCM. Logic then flows to a logic step 96 which determines if PCM is charged to 100%. If PCM is charged to 100%, logic flows to an exit step 98 . If PCM is not charged to 100%, logic feeds back to step 94 to re-run moisture freeze control and charge PCM. If the SSR is enabled at logic step 92 , logic flows to a logic step 100 which determines if PCM Charge State exceeds 75%. If PCM Charge State does not exceed 75%, logic flow returns to the input of step 94 . If PCM Charge State exceeds 75%, logic flow continues to step 102 which maintains SSR control and subsequently flows to exit step 98 .
The SRR overriding control can be further improved by monitoring the Discharge Air Temperature (DAT) sensor for cars equipped with such sensors. The charging of the PCM evaporator can be carried on until the DAT sensor senses the first sign of decrease in the discharge air temperature (such as 0.5 C decrease in discharge temperature decrease). Immediately afterwards the SRR control is resumed. The PCM State of Charge indicator is monitored. When it becomes 75%, or some other predefined value, the charging of the PCM evaporator should be initiated again. This is carried out periodically over time. The advantage of this method is that the thermal inertia of the air ducts is utilized to perhaps allow more charging time without impacting the discharge temperature commanded by the ACC system.
Another consideration in charging the PCM evaporator is City Traffic driving. A timer may be maintained between two consecutive stops and a record of the driving intervals is kept. As the frequency of the stops increases beyond certain point, a judgment is made that the car is driving in the city traffic. It is expected that more energy can be saved via stopping the engine than with the SRR. At this point, PCM charging will gradually take a higher priority than SRR. This is implemented algorithmically by reducing the set point of the SRR toward evaporator moisture freeze control.
While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.
It is to be understood that the invention has been described with reference to specific embodiments and variations to provide the features and advantages previously described and that the embodiments are susceptible of modification as will be apparent to those skilled in the art.
Furthermore, it is contemplated that many alternative, common inexpensive materials can be employed to construct the basis constituent components. Accordingly, the forgoing is not to be construed in a limiting sense.
The invention has been described in an illustrative manner, and 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.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, wherein reference numerals are merely for illustrative purposes and convenience and are not in any way limiting, the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the Doctrine of Equivalents, may be practiced otherwise than is specifically described. | An evaporator has a manifold and a plurality of refrigerant tubes extending downward in the direction of gravity from the manifold. The evaporator includes at least one PCM housing engaging the upper portion of the refrigerant tube for storing a phase change material. When operating in a first operating mode, heat is transferred from the phase change material to the refrigerant to freeze and cool the phase change material. When operating in a second operating mode, heat is transferred from the refrigerant to the frozen phase change material to condense the refrigerant. The condensed refrigerant falls downwardly through the tubes and receives heat from a flow of air to cool the air and evaporate the refrigerant. The evaporated refrigerant rises upwardly back to the low pressure of the cold manifold. | 1 |
BACKGROUND
1. Field
The present disclosed embodiments relate generally to web browser functionality, and more specifically to reordering of operations during browser pageload.
2. Background
With regard to web browser functionality, a “mainframe” is a document rendered by a web browser (e.g., and HTML document) that typically spans a web browser's window and can include one or more self-contained components such as IFrames. Most web-based advertisements are rendered within an IFrame, or some other independent object within a mainframe of a webpage. An IFrame is an HTML addition to the Frames toolbox that creates a frame within another webpage or mainframe, where the IFrame is filled with a second webpage. The mainframe and the IFrame each have their own URLs, thus enabling the mainframe and IFrame to have distinct and independent content and functionality. This ability allows the same webpage to be displayed at different times, to different users, and on different devices, and also includes ads tailored to the time, user, or device. Since an IFrame is a feature of HTML utilized in a variety of web browsers including, for example, Safari, Firefox, Internet Explorer, and Google's CHROME, to name a few, IFrames are often used to embed advertisements within webpages.
Typically the mainframe and IFrame download via a single communication channel and are processed on a single core (see top timing chart in FIG. 3 ). Gaps in the network activity often arise when the application processor must dedicate its resources to parsing and executing data packets before it can resume fetching further data packets. Similarly, gaps in the network activity can arise when the application processor must parse and execute data packets before it can determine which further data packets to fetch. The communication channel is therefore underutilized and remains active even when not in use. A pageload also takes longer because scheduling network activities and processing cannot occur in parallel. Mainframe and IFrame data packets also typically compete for preferred memory slots (e.g., cache vs RAM or virtual memory). There is therefore a need in the art for systems and methods to enable more efficient utilization of network, core, and memory resources.
SUMMARY
Embodiments disclosed herein address the above stated needs modifying the order in which IFrames, or other self-contained component within the mainframe, are transmitted via network resources, stored in memory resources, and processed in processor resources. The reordering conserves user device power and makes better use of network, processor, and memory resources. For instance, aspects of multicore processors and multichannel network connections are utilized to perform parallel operations on mainframe data packets and IFrame data packets when a webpage is downloaded. Since mainframes and IFrames are sourced from different URLs they can be received on separate communication channels and can be processed on different cores. Prioritization in memory storage between the two can also be used to enhance the speed with which the mainframe is loaded.
Some aspects of the disclosure can be characterized as a method of loading a webpage, the webpage having a mainframe and at least one self-contained component within the mainframe, the method comprising. The method can include receiving data packets in response to a request to load a webpage having the mainframe. The method can further include determining that the webpage includes the at least one self-contained component within the mainframe. Also, the method may include identifying those of the data packets that are mainframe data packets. Additionally, the method can include identifying those of the data packets that are data packets corresponding to the at least one self-contained component within the mainframe. The method may further include processing the mainframe data packets on a first core of an application processor. The method may yet further include processing data packets corresponding to the at least one self-contained component within the mainframe on a second core of the application processor. The method may also include rendering the mainframe from the mainframe data packets. The method may further include rendering the at least one self-contained component within the mainframe from the data packets corresponding to the at least one self-contained component within the mainframe.
Some aspects of the disclosure can also be characterized as a system comprising a network interface, an application processor, a memory, and a memory controller. The network interface can receive, in response to a request for a webpage, mainframe data packets for a webpage and data packets corresponding to one or more self-contained components of the webpage. The application processor can have a first core and a second core. The first core can process the mainframe data packets, and the second core can process the data packets corresponding to the one or more self-contained components of the webpage. The memory can have at least first and second levels of memory. The memory controller can oversee storage of the mainframe data packets and the data packets corresponding to the one or more self-contained components of the webpage in either or both of the first and second levels of the memory.
Other aspects of the disclosure can be characterized as a non-transitory, tangible computer readable storage medium, encoded with processor readable instructions to perform a method for downloading a webpage. The method can include receiving first data packets in response to a first request for a webpage. The method can also include parsing the first data packets to identify any self-contained components of the webpage. If one or more self-contained components are identified, then the method can store an indicator that the webpage includes one or more self-contained components. In this event the method can further process a second portion of the first data packets corresponding to the one or more self-contained components of the webpage on a second processor of the user device. Otherwise, the method can process the first data packets of the mainframe of the webpage on the first processor of the user device.
Further aspects of the disclosure can include a system. The system can include a means for receiving mainframe data packets interspersed with data packets of a self-contained component of the mainframe. The system can further include a means for processing the mainframe data packets. The system can also include means for storing the data packets of the self-contained component of the mainframe until the mainframe data packets are processed. The system can also include a means for processing the data packets of the self-contained component of the mainframe after the mainframe data packets have processed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates one embodiment of a system diagram for a user device;
FIG. 2 illustrates a method of downloading and processing webpage data packets in response to a request for a webpage;
FIG. 3 illustrates a method of downloading and processing webpage data packets in response to a request for a webpage;
FIG. 4 illustrates a timing diagram as known in the art compared to a timing diagram for the systems and methods herein disclosed;
FIG. 5 illustrates a timing diagram as known in the art compared to a timing diagram for the systems and methods herein disclosed; and
FIG. 6 shows a diagrammatic representation of one embodiment of a machine in the exemplary form of a computer system.
DETAILED DESCRIPTION
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.
To meet the needs described in the background, the present disclosure describes systems and methods for more efficient utilization of network resources, processor resources, and memory resources. In particular, an IFrame within a webpage (or mainframe) can be identified and processed separately from, and in parallel to, the mainframe such that the IFrame and the mainframe do not compete for network resources, processor power, or network bandwidth. Said another way, by sending mainframe and IFrame data packets to separate cores of an application processor, an IFrame data packet can be fetched while a mainframe data packet is being processed and vice versa, thus enabling earlier fetching of data packets. As a result, users experience faster pageloads, the modem can enter an idle state more quickly and more often, and processor resources are less taxed. This not only improves system performance, but also reduces power consumption. As used herein, processing includes parsing and executing a data packet.
Identification of an IFrame can involve parsing the HTML code of a webpage, and identifying an IFrame tag within the code. Once identified, the IFrame can be processed in parallel to the mainframe. In one aspect, packets corresponding to the mainframe can be processed on a first core of an application processor, and packets corresponding to the IFrame can be processed on a second core of the application processor (see FIGS. 4 and 5 ). In another aspect, packets corresponding to the IFrame can be downloaded and directed to a second core of the application processor during moments when packets corresponding to the mainframe are being processed by a first core of the application processor (see FIG. 4 ). Also, packets corresponding to the mainframe can be downloaded via a first communication channel, while packets corresponding to the IFrame can be downloaded via a second communication channel (see FIG. 5 ).
In situations where limited bandwidth and a single core configuration prevent either of the above parallel uses of the network to be implemented, data packets corresponding to the mainframe can be processed before any packets corresponding to the IFrame are processed. Traditionally, the data packets are interspersed and thus are processed on the single core in an interspersed order. Even though it may only take 2 ms to process mainframe data packets, since they are processed in the same interlaced order that they are received, along with the IFrame data packets, the mainframe takes longer than 2 ms to process. Since the mainframe is the more important component of a webpage rendering, data packets corresponding to the IFrame can be held in memory (e.g., a cache) until all data packets corresponding to the mainframe are processed, thus decreasing the time required to process and render the mainframe.
In another aspect of the disclosure, memory allocation can be prioritized such that packets corresponding to the mainframe can be stored in the same or faster types of memory than packets corresponding to the IFrame.
FIG. 1 illustrates one embodiment of a system diagram for a user device 100 . The user device 100 includes a network interface 120 , an application processor 102 , memory 112 , storage 116 , an IFrame identification module 122 with a browser parser module 123 , a browser engine 124 having a parallel processing module 125 , and a memory controller 126 . These various components are in communication with each other via a bus 140 (and the memory controller 126 has direct communication with the memory 112 in addition to communication via the bus 140 ). The network interface 120 transmits and receives data packets from the network 130 via a first channel 150 and/or a second channel 152 , and controls allocation of the first and second channels 150 , 152 .
Received data packets are passed via the bus 140 to the application processor 102 . The application processor 102 includes at least a first core 104 and second core 106 , along with at least a first cache 108 and a second cache 110 . A parallel processing module 125 can control how the first and second cores 104 , 106 are allocated to processing (e.g., parsing and executing) the received data packets. Data packets can be stored in a memory 112 and can be allocated to different levels of the memory 112 as dictated by a memory controller 126 . Different levels of memory 112 can include the first and second cache 108 , 110 , random access memory (RAM) 114 , and a portion of a hard drive (HDD) 118 allocated to the memory 112 as virtual memory 119 . Data packets can also be stored in the HDD 118 of the storage 116 without being part of the virtual memory 119 .
The network interface 120 can control which data packets are received via the first channel 150 and which are received via the second channel 152 . For instance, data packets corresponding to the mainframe can be allocated to the first channel 150 while data packets corresponding to the IFrame can be allocated to the second channel 152 , or vice versa. The first and second channels 150 , 152 can be implemented as different communication paths or protocols. For instance, one can be a Wi-Fi channel while the other is a cellular channel. In another example, one can be a wired channel while the other is a wireless channel. In yet another instance, one can use the 802.1n wireless protocol while the other uses 802.1g. Other types that the first and second channels 150 , 152 can take include, but are not limited to, 3G and 4G data, WiMAX, and ZIGBEE. The network 130 can include the public Internet, a private intranet, a cellular network, a satellite network, or a combination of these or these and other network types, to name a few.
The network interface 120 can also control an order in which data packets are received via the channels 150 , 152 . This is especially true in bandwidth-limited instances, or those where only a single channel is available. In such instances, the network interface 120 aligns the data packets such that all the data packets corresponding to the mainframe are downloaded before the first data packet corresponding to the IFrame downloads.
The IFrame identification module 122 can distinguish between data packets that correspond to the mainframe and data packets that correspond to the IFrame, for instance by identifying webpages having IFrames. In one embodiment, such webpages can be identified by an IFrame tag in the webpage's code (e.g., <IFrame . . . > in the HTML code). In some embodiments, a browser parser module 123 can aid in this identification by parsing the incoming data packets and identifying IFrame tags in the parsed data packets. Although only a single browser parser module 123 is shown, there may be a browser parser module 123 running on each of the first and second cores 104 , 106 and therefore there can be two or more browser parser modules 123 .
The browser engine 124 can be configured to control certain aspects of webpage download and processing. In particular, the parallel processing module 125 can be configured to control how the first and second cores 104 , 106 process the data packets. For instance, the parallel processing module 125 can direct the first core 104 to parse and execute mainframe data packets in parallel to the second core 106 parsing and executing IFrame data packets.
The memory controller 126 can dictate where and when data packets are written to the memory 112 . The importance of this control is that the memory 112 includes different levels of memory where each level has different read and write speeds. For purposes of this disclosure, the first cache 108 is at the highest level of the memory 112 and the RAM 114 is typically at the bottom of the memory 112 , with the second cache 110 in the middle. However, in some cases, the first and second caches 108 , 110 , and the RAM 114 may be filled such that further memory 112 is required. In such instances, a portion of the HDD 118 can be allocated to the memory 112 as virtual memory 119 . In such instance, the virtual memory 119 is at the lowest level of the memory 112 . Typically, the first cache 108 has faster read and write times than the second cache 110 , the second cache has faster read and write times than the RAM 114 , and the RAM 114 has faster read and write times than the virtual memory (or HDD 118 ), although these relations may not always hold true.
The IFrame identification module 122 and the parallel processing module 125 can be implemented as software, firmware, hardware, of a combination of the above. For instance, both modules 122 , 125 may be software operating on the application processor 102 . In an alternative example, the modules 122 , 125 may be firmware operating on an ASIC.
While the illustrated application processor 102 has a first and second core 104 , 106 , in other embodiments the application processor 102 can have more than two cores. Additionally, while the application processor 102 is illustrated as having only a first and second cache 108 , 110 , in other embodiments the application processor 102 can include more than two caches. While the first and second cache 108 , 110 are illustrated as being separate from the first and second core 104 , 106 , in other embodiments, one or more caches can be part of one or more of the cores. In some embodiments, the application processor 102 can be a single integrated circuit having multiple cores and multiple caches.
The user device 100 may be implemented as any of a variety of communication devices (e.g., cell phones, smart phones, tablet computers, to name a few) or computing devices (e.g., laptop computers, desktop computers, ultra books, to name a few). In the illustrated embodiment the user device 100 includes a single HDD 118 . However, in other embodiments two or more HDD's 118 can be implemented. The network interface 120 is illustrated as communicating with the network 130 via a first channel 150 and a second channel 152 , but in other embodiments three or more channels may be utilized.
In some embodiments, the IFrame identification module 122 and/or the browser engine 124 can run on the application processor 102 . A variety of other components of the user device 100 may also be implemented, but are not illustrated for the sake of clarity and simplicity of FIG. 1 . For instance, a baseband processor, a user input interface, and peripherals interfaces, are just a few components that would likely be found in the user device 100 , but are not illustrated.
The following discussions detail systems and method for (1) identifying IFrames, (2) allocating processor resources, (3) allocating network resources, and (4) allocating memory resources. This discussion will also describe aspects of FIG. 1 in conjunction with descriptions of method steps as illustrated in FIG. 2 .
Identifying Iframes
The first time that a webpage is downloaded to the user device 100 , data packets are received (Block 202 or 302 of the first download in FIG. 2 or 3 ) through the network interface 120 and the IFrame identification module 122 parses the incoming data packets (Block 204 or 304 ) to determine whether the webpage includes one or more IFrames (Block 206 or 306 ). If an IFrame is not detected, then the parallel processing module 125 instructs the first core 104 to process the data packets (Block 210 ). Alternatively, or at the same time, the memory controller 126 can instruct data packets corresponding to the webpage to be stored in a fastest memory (Block 310 ).
If an IFrame is detected, then the parallel processing module 125 determines which data packets correspond to the mainframe (Block 208 ) and which correspond to the IFrame. The parallel processing module 125 then instructs the first core 104 to process data packets corresponding to a mainframe of the webpage (Block 210 ) and instructs the second core 106 to process data packets corresponding to the IFrame (Block 212 ). Alternatively, or at the same time, the memory controller 126 can store data packets corresponding to the mainframe in a fastest memory (Block 310 ) and can store data packets corresponding to the one or more IFrames in a remaining memory (Block 312 ). Assuming that an IFrame is detected, an identifier of the webpage can be stored in the memory 112 (Block 214 or 314 ) so that subsequent downloads of the webpage can avoid the parsing the data packets (Block 204 or 304 ).
In particular, when a second download of the webpage begins (Blocks 250 and 350 ), the IFrame identification module 122 can scan the memory 112 to see if there is an identifier of the webpage in the memory 112 or on the HDD 118 (Block 252 or 352 ), thus indicating that the webpage has one or more IFrames. If the check (Block 252 or 352 ) indicates that the webpage has IFrames, then the parallel processing module 125 can instruct the first and second cores 104 , 106 to process the data packets corresponding to the mainframe and the one or more IFrames in parallel (Blocks 254 , 256 , 258 ). Alternatively, or at the same time, the memory controller 126 can store data packets corresponding to the mainframe in a fastest memory (Block 356 ) and data packets corresponding to the one or more IFrames in remaining memory (Block 358 ). In this fashion, the second download of the webpage can be performed faster than the first download since there is no need to parse the data packets (Block 204 or 304 ) to determine if one or more IFrames are present.
Processor Resources
Traditional methods for processing data packets for both mainframes and IFrames do not distinguish between the two, and therefore process both mainframes and IFrames on the same core even where multiple cores are available for processing. Many of today's application processors have two or more cores, and this disclosure takes advantage of such multicore processors by processing data packets associated with the mainframe on a first core while processing data packets associated with one or more IFrames on a second core (or third, fourth, fifth, etc).
The user device 100 can receive first data packets corresponding to a mainframe and second data packets corresponding to an IFrame (Block 202 ). Traditionally, both sets of data packets were processed on a single core. However, here, by identifying which data packets correspond to the mainframe and which correspond to the IFrame, (Blocks 208 , 254 ) the first data packets can be sent to and processed on the first core 104 (Blocks 210 , 256 ) while the second data packets can be sent to and processed on the second core 106 (Blocks 212 , 258 ). As a result, total processing time for the webpage is decreased, which reduces the pageload time and reduces the amount of time that a modem processor remains in an active state. This results in reduced power consumption and improved user experience. This also frees up the application processor 102 resources faster so that other user device 100 functions can utilize the application processor 102 .
Processor resources and pageload time can further be reduced during the second download and subsequent downloads since parsing of the data packets (Block 204 ) and the IFrame identification decisions (Block 206 ) can be avoided as discussed in the IDENTIFYING IFRAMES section above. Instead, the second and subsequent downloads can look to the identifier of a webpage stored in the memory 112 identifying a webpage as having one or more IFrames (Block 214 ).
Network Resources
Traditional methods for downloading packets utilize a single network channel and do not distinguish between mainframe and IFrame data packets (see FIG. 5 —PRIOR ART). As a result, the mainframe and IFrame data packets compete for network resources rather than utilizing them in a planned and organized fashion. Furthermore, since traditional methods process mainframes and IFrames on the same core, there is nothing to gain from using multiple communication channels.
This disclosure introduces the concept of parallel processing mainframe data packets and IFrame data packets on the first and second cores 104 , 106 (see FIGS. 4 and 5 ), which in turn also enables receiving data packets on two or more channels (see FIG. 5 ). In particular, the network interface 120 can dictate that data packets corresponding to the mainframe can be received on the first channel 150 and data packets corresponding to the IFrame can be received on the second channel 152 .
For instance, in FIG. 5 mainframe data packets are received on a first channel while IFrame data packets are received on a second channel. As compared to the PRIOR ART where a single channel is used, the parallel or dual channel method enables four data packets to arrive in half the time required for the four data packets to arrive in a traditional single-channel setup. What is more, in the parallel channel setup, since data packets corresponding to both the mainframe and IFrames arrive at the same time, they can be processed in parallel on a first and second core, which reduces the total pageload time (and total core activity time) as compared to a single channel and single core methodology.
Where only a single channel and a single core are available, such as in FIG. 4 —PRIOR ART, data packets cannot be downloaded and processed simultaneously since each data packet has to be processed before an application processor can know which data packets to download next. As such, gaps form in the network usage where the network is active, but no data is being downloaded. By providing mainframe data packets to a first core and IFrame data packets to a second core, data packets can be fetched more often and can be more closely spaced on the single channel, thus reducing the use of network resources, decreasing pageload times, and decreasing the time in which either of the two cores are actively processing the four illustrated data packets. This requires interlacing of the fetching and download of the mainframe and IFrame data packets—in other words, a mainframe data packet can be downloaded, sent to a first core for processing, and while being processed an IFrame data packet can be downloaded, and then sent to a second core for processing (see FIG. 4 ). This also enables the modem to be idled sooner than in the prior art since there is reduced network activity as compared to the art. Put another way, data packets corresponding to the mainframe are processed on the first core 104 as is usually done, but data packets corresponding to the IFrame are downloaded during moments when the channel is not in use for downloading mainframe data packets, and then these IFrame data packets are processed on the second core 106 .
Additionally, delays arise in bandwidth-limited situations where there is only a single channel, since the mainframe and IFrame data packets compete for space on the lone channel. Since mainframe and IFrame data packets traverse the channel in an interlaced fashion, they are processed in an interlaced fashion. Thus, to complete processing of mainframe data packets, at least some IFrame data packets are also processed, and thus the mainframe does not render as quickly as it could if processed without the IFrame data packets. The mainframe is typically more important than the IFrame (e.g., advertisements), so there is a desire to decrease the time of mainframe data packet processing even if at the expense of IFrame processing. One solution is to hold the IFrame data packets in a memory and to process all of the mainframe data packets before the first IFrame data packets is processed. Thus, given a bandwidth limited and single channel situation, the mainframe data packets can be downloaded before any of the IFrame data packets.
Memory Resources
Additionally, traditional methods for downloading data packets give mainframe and IFrame data packets equal priority in memory allocation. In this disclosure, the memory controller 126 directs data packets corresponding to the mainframe to be stored in the memory 112 with a greater priority than data packets corresponding to the IFrame. By greater priority it is meant that the data packets corresponding to the mainframe are generally written to faster memory types (or memory levels) than the data packets corresponding to the IFrame. For instance, if there is memory remaining in the first cache 108 and the second cache 110 after the memory controller 126 has allocated space to mainframe data packets (Blocks 310 and 356 ), then the remaining cache can be allocated to IFrame data packets (Block 312 and 358 ). If the data packets corresponding to the mainframe can all be allocated to the first cache 108 (Blocks 310 and 356 ) without filling the first cache 108 , then at least some of the data packets corresponding to the IFrame can also be allocated to remaining space on the first cache 108 (Block 312 and 358 ).
The method steps or operations illustrated in FIGS. 2 and 3 are not limited in order of operation to the order illustrated and these method steps can be interchanged without departing from the scope of the invention. In some instances, one or more of these operations can be carried out in parallel to or at the same time as another one or more of the operations.
The systems and methods described herein can be implemented in a machine such as a computer system in addition to the specific physical devices described herein. FIG. 6 shows a diagrammatic representation of one embodiment of a machine in the exemplary form of a computer system 600 within which a set of instructions can execute for causing a device (e.g., user device 100 ) to perform or execute any one or more of the aspects and/or methodologies of the present disclosure. The components in FIG. 6 are examples only and do not limit the scope of use or functionality of any hardware, software, embedded logic component, or a combination of two or more such components implementing particular embodiments.
Computer system 600 may include a processor 601 , a memory 603 , and a storage 608 that communicate with each other, and with other components, via a bus 640 . The bus 640 may also link a display 632 , one or more input devices 633 (which may, for example, include a keypad, a keyboard, a mouse, a stylus, etc.), one or more output devices 634 , one or more storage devices 635 , and various tangible storage media 636 . All of these elements may interface directly or via one or more interfaces or adaptors to the bus 640 . For instance, the various tangible storage media 636 can interface with the bus 640 via storage medium interface 626 . Computer system 600 may have any suitable physical form, including but not limited to one or more integrated circuits (ICs), printed circuit boards (PCBs), mobile handheld devices (such as mobile telephones or PDAs), laptop or notebook computers, distributed computer systems, computing grids, or servers.
Processor(s) 601 (or central processing unit(s) (CPU(s))) optionally contains a cache memory unit 602 for temporary local storage of instructions, data, computer addresses, or mainframe and IFrame data packets. Processor(s) 601 are configured to assist in execution of computer readable instructions such as those found in mainframe and IFrame data packets. Computer system 600 may provide functionality as a result of the processor(s) 601 executing software embodied in one or more tangible computer-readable storage media, such as memory 603 , storage 608 , storage devices 635 , and/or storage medium 636 . The computer-readable media may store software that implements particular embodiments, and processor(s) 601 may execute the software. For instance, the computer-readable media may store a browser engine (e.g., browser engine 124 ) that the processor(s) 601 executes. Memory 603 may read the software from one or more other computer-readable media (such as mass storage device(s) 635 , 636 ) or from one or more other sources through a suitable interface, such as network interface 620 . The software may cause processor(s) 601 to carry out one or more processes or one or more steps of one or more processes described or illustrated herein. As one example, the software may cause processor(s) 601 to execute an HTML file and pass rendering dat to the video interface 622 for rendering to the display 632 . Carrying out such processes or steps may include defining data structures stored in memory 603 and modifying the data structures as directed by the software.
The memory 603 may include various components (e.g., machine readable media) including, but not limited to, a random access memory component (e.g., RAM 604 ) (e.g., a static RAM “SRAM”, a dynamic RAM “DRAM, etc.), a read-only component (e.g., ROM 605 ), and any combinations thereof. ROM 605 may act to communicate data and instructions unidirectionally to processor(s) 601 , and RAM 604 may act to communicate data and instructions bidirectionally with processor(s) 601 . ROM 605 and RAM 604 may include any suitable tangible computer-readable media described below. In one example, a basic input/output system 606 (BIOS), including basic routines that help to transfer information between elements within computer system 600 , such as during start-up, may be stored in the memory 603 .
Fixed storage 608 is connected bidirectionally to processor(s) 601 , optionally through storage control unit 607 . Fixed storage 608 provides additional data storage capacity and may also include any suitable tangible computer-readable media described herein. Storage 608 may be used to store operating system 609 , EXECs 610 (executables), data 611 , API applications 612 (application programs), and the like. Often, although not always, storage 608 is a secondary storage medium (such as a hard disk) that is slower than primary storage (e.g., memory 603 ). Storage 608 can also include an optical disk drive, a solid-state memory device (e.g., flash-based systems), or a combination of any of the above. Information in storage 608 may, in appropriate cases, be incorporated as virtual memory in memory 603 . In some embodiments, a portion or all of the storage 608 can be located in “the cloud.” In other words, the storage 608 may partially reside on remote servers accessible via the network interface 620 and the network 630 .
In one example, storage device(s) 635 may be removably interfaced with computer system 600 (e.g., via an external port connector (not shown)) via a storage device interface 625 . Particularly, storage device(s) 635 and an associated machine-readable medium may provide nonvolatile and/or volatile storage of machine-readable instructions, data structures, program modules, and/or other data for the computer system 600 . In one example, software may reside, completely or partially, within a machine-readable medium on storage device(s) 635 . In another example, software may reside, completely or partially, within processor(s) 601 .
Bus 640 connects a wide variety of subsystems. Herein, reference to a bus may encompass one or more digital signal lines serving a common function, where appropriate. Bus 640 may be any of several types of bus structures including, but not limited to, a memory bus, a memory controller, a peripheral bus, a local bus, and any combinations thereof, using any of a variety of bus architectures. As an example and not by way of limitation, such architectures include an Industry Standard Architecture (ISA) bus, an Enhanced ISA (EISA) bus, a Micro Channel Architecture (MCA) bus, a Video Electronics Standards Association local bus (VLB), a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, an Accelerated Graphics Port (AGP) bus, HyperTransport (HTX) bus, serial advanced technology attachment (SATA) bus, and any combinations thereof.
Computer system 600 may also include an input device 633 . In one example, a user of computer system 600 may enter commands and/or other information into computer system 600 via input device(s) 633 . Examples of an input device(s) 633 include, but are not limited to, an alpha-numeric input device (e.g., a keyboard), a pointing device (e.g., a mouse or touchpad), a touchpad, a joystick, a gamepad, an audio input device (e.g., a microphone, a voice response system, etc.), an optical scanner, a video or still image capture device (e.g., a camera), and any combinations thereof. Input device(s) 633 may be interfaced to bus 640 via any of a variety of input interfaces 623 (e.g., input interface 623 ) including, but not limited to, serial, parallel, game port, USB, FIREWIRE, THUNDERBOLT, or any combination of the above.
In particular embodiments, when computer system 600 is connected to network 630 , computer system 600 may communicate with other devices, specifically mobile devices and enterprise systems, connected to network 630 . For instance, the computer system 600 may receive data packets from web servers via the network 630 in response to requests for webpages. Communications to and from computer system 600 may be sent through network interface 620 . For example, network interface 620 may receive incoming communications (such as requests or responses from other devices) in the form of one or more data packets (such as Internet Protocol (IP) packets) from network 630 , and computer system 600 may store the incoming communications in memory 603 for processing. Computer system 600 may similarly store outgoing communications (such as requests or responses to other devices) in the form of one or more packets in memory 603 and communicated to network 630 from network interface 620 . Processor(s) 601 may access these communication packets stored in memory 603 for processing.
Examples of the network interface 620 include, but are not limited to, a network interface card, a modem, and any combination thereof. Examples of a network 630 or network segment 630 include, but are not limited to, a wide area network (WAN) (e.g., the Internet, an enterprise network), a local area network (LAN) (e.g., a network associated with an office, a building, a campus or other relatively small geographic space), a telephone network, a direct connection between two computing devices, and any combinations thereof. A network, such as network 630 , may employ a wired and/or a wireless mode of communication. In general, any network topology may be used.
Information and data can be displayed through a display 632 . Examples of a display 632 include, but are not limited to, a liquid crystal display (LCD), an organic liquid crystal display (OLED), a cathode ray tube (CRT), a plasma display, and any combinations thereof. The display 632 can interface to the processor(s) 601 , memory 603 , and fixed storage 608 , as well as other devices, such as input device(s) 633 , via the bus 640 . The display 632 is linked to the bus 640 via a video interface 622 , and transport of data between the display 632 and the bus 640 can be controlled via the graphics control 621 .
In addition to a display 632 , computer system 600 may include one or more other peripheral output devices 634 including, but not limited to, an audio speaker, a printer, and any combinations thereof. Such peripheral output devices may be connected to the bus 640 via an output interface 624 . Examples of an output interface 624 include, but are not limited to, a serial port, a parallel connection, a USB port, a FIREWIRE port, a THUNDERBOLT port, and any combinations thereof.
In addition or as an alternative, computer system 600 may provide functionality as a result of logic hardwired or otherwise embodied in a circuit, which may operate in place of or together with software to execute one or more processes or one or more steps of one or more processes described or illustrated herein. Reference to software in this disclosure may encompass logic, and reference to logic may encompass software. Moreover, reference to a computer-readable medium may encompass a circuit (such as an IC) storing software for execution, a circuit embodying logic for execution, or both, where appropriate. The present disclosure encompasses any suitable combination of hardware, software, or both.
For purposes of this disclosure a communication channel is established between any two devices, and in particular between network interfaces of the two devices. The communication channel can be made via a wired connection, a wireless connection, or a combination of the two. The communication channel may be encrypted or non-encrypted. The communication channel is not limited to any particular protocol, so for instance, UMTS, CDMA, and WiFi are each equally applicable protocols for implementing the communication channel. As another example the communication channel can use either TCP or UDP protocols.
For purposes of this disclosure a data packet (or packet) is a formatted unit of data carried by a packet mode computer network. However in some embodiments, the herein disclosed communication methods can utilize non-packet-based transmissions for instance where series of bytes, characters, or bits alone are transmitted.
Those of skill in the art will understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
Those of skill will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. 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. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | Systems and methods are herein disclosed for reducing power consumption, processor activity, network activity, and for improving a user experience during web browsing. More particularly, an ordering of IFrames, or other self-contained component within the mainframe, is modified in terms of network resources, memory resources, and processor resources in order to conserve user device resources. For instance, aspects of multicore processors and multichannel network connections are utilized to perform parallel operations on mainframe data packets and IFrame data packets when a webpage is downloaded. Since mainframes and IFrames are sourced from different URLs they can be received on separate communication channels and can be processed on different cores. Prioritization in memory storage between the two can also be used to enhance the speed with which the mainframe is loaded. | 8 |
[0001] This application claims the benefit of Indian Patent Application No. 201641024792, filed Jul. 20, 2016, which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an improved process for the preparation of sofosbuvir. The present invention involves an environmental friendly process and use of reagents that are less expensive and easier to handle.
BACKGROUND OF THE INVENTION
[0003] Sofosbuvir (formerly PSI-7977 or GS-7977) is an approved drug for the treatment of hepatitis C. It was discovered at Pharmasset and then acquired for development by Gilead Sciences. Sofosbuvir is a prodrug that is metabolized to the active antiviral agent 2′-deoxy-2′-a-fluoro-β-C-methyluridine-5′-monophosphate. It is a nucleotide analogue inhibitor of the hepatitis C virus (HCV) polymerase.
[0004] Nucleoside phosphoramidate are inhibitors of RNA-dependent, RNA viral replication and are useful as inhibitors of HCV NS5B polymerase, as inhibitors of HCV replication and for treatment of hepatitis C infection in mammals.
[0005] Sofosbuvir is chemically known as isopropyl (25)-2-[[[(2R,3R,4R,5R)-5-(2,4-dioxopyrimidin-1-yl)-4-fluoro-3-hydroxy-4-methyl-tetrahydrofuran-2-yl] methoxy-phenoxy-phosphoryl] amino] propanoate of Formula (I).
[0000]
[0006] Sofosbuvir was first described in Example 25 of U.S. Pat. No. 7,964,580 B2, which corresponds to WO 2008/121634 A2 and also discloses other novel nucleoside phosphoramidates and their preparations and use as agents for treating viral diseases.
[0007] The process disclosed is provided below. The compound of formula VI is protected with a benzoyl group in the presence of benzoyl chloride and pyridine base to obtain the compound of formula V. The amino group of compound V is deprotected in the presence of 80% AcOH under reflux conditions and ammonia/methanol as a solvent was added to get a compound of formula III. The compound of formula III is reacted with a compound of formula IIa to obtain a diastereomeric mixture at “P” of Sp and Rp sofosbuvir. This on chiral resolution by Supercritical Fluid Chromatography (SFC) using 20% MeOH in CO 2 as a solvent yields sofosbuvir (I).
[0008] The process described herein leads to the production of nucleoside phosphoramidate prodrugs with less than 50% of the desired isomer, which requires additional purifications to get the desired isomer, which enhances the number of steps and cost. This reference does not provide a particular combination of solvents and bases which provides or increases the stereo selectivity during the reaction for the production of the desired Sp isomer.
[0009] The above process is schematically shown below.
[0000]
[0010] PCT publication no. WO 2011/123645 A2 discloses various crystalline forms and a process for the preparation of (S)-isopropyl 2-(S)-(((2R,3R,4R,5R)-5-(2,4-dioxo-3,4-dihydropyrimidin-1-(2H)-yl)-4-fluoro-3-hydroxy-4-methyltetrahydrofuran-2-yl)methoxy)(phenoxy)pho sphoryl)-amino)propanoate (sofosbuvir), shown below. A compound of formula (V) is deprotected in the presence of 70% AcOH followed by hydrolysis to obtain a compound of formula III. This is reacted with a compound of formula (II) in the presence of a Grignard reagent to obtain sofosbuvir.
[0000]
[0011] The condensation reaction of the compound of formula (III) with the compound of formula (II) in the presence of a Grignard reagent has low yield and a high impurity profile.
[0012] Hence, the use of a Grignard reagent may not be feasible and it is not economical for industrial scale production for the preparation of Sofosbuvir (I).
[0013] PCT publication no. WO 2006/012440 A2, WO 2008/045419 A1, WO 2006/031725 A2 and U.S. Pat. Nos. 7,601,820 B2 and 8,492,539 B2 disclose processes for the preparation of intermediates, which can be used for the preparation of sofosbuvir.
[0014] PCT publication no. WO 2010/135569 A1 discloses various processes for the preparation of sofosbuvir and its intermediates.
[0015] PCT publication no. WO 2014/08236 A1 discloses a process for the preparation of diastereomerically enriched phosphoramidate derivatives. WO 2014/047117 A1, CN103804446A and WO2014/056442 A1 disclose various processes for the preparation of intermediates and nucleoside phosphoramidates compounds.
[0016] In view of the foregoing, the present inventors have performed extensive experiments and found that sofosbuvir can be produced in high yield and purity in a simple, efficient, more economical and eco-friendly process.
SUMMARY OF THE INVENTION
[0017] The present invention relates to an improved, commercially viable and industrially advantageous process for the preparation of sofosbuvir.
[0018] One embedment of the present invention is a process for the preparation of sofosbuvir (I) comprising the step of (a) reacting a compound of formula (III) with a compound of formula (II) in the presence of a metallic salt, a base and a solvent to obtain a compound of formula (I)
[0000]
[0019] The compound of formula (III) may be prepared by
(i) deprotecting a compound of formula (V), preferably under acidic conditions, to obtain a compound of formula (IV)
[0000]
[0021] and
(ii) hydrolyzing the compound of formula (IV), preferably in the presence of a base and a solvent, to obtain a compound of formula (III)
[0000]
[0023] The process of the present invention can be performed without the use of a Grignard reagent and without the use of unsuitable temperatures (such as −20° C. to −15° C.). The process can be performed at room temperature which is advantageous for commercial production.
[0024] Yet another embodiment is a composition comprising sofosbuvir and a metallic salt. The metallic salt may be selected from magnesium chloride, magnesium bromide, magnesium iodide, lithium chloride, lithium bromide, lithium iodide, copper chloride, copper bromide, copper iodide, and mixtures thereof. In one embodiment, the metallic salt is magnesium chloride. In another embodiment, the composition comprises sofosbuvir and the metallic salt (such as magnesium chloride) at a weight ratio of at least 98:2, preferably at least 99.5:0.5, at least 99.8:0.2, at least 99.9:0.1, at least 99.95:0.05, or at least 99.98:0.02.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The present invention relates to an improved, commercially viable and industrially advantageous process for the preparation of sofosbuvir.
[0026] One embodiment is a process for preparing sofosbuvir (I) comprising the step of (a) reacting a compound of formula (III) with a compound of formula (II) in the presence of a metallic salt, a base and a solvent to obtain a compound of formula (I).
[0027] Another embodiment is a process preparing sofosbuvir (I) comprising the steps of:
(i) deprotecting a compound of formula (V), preferably under acidic conditions, to obtain a compound of formula (IV); (ii) hydrolyzing the compound of formula (IV), preferably in the presence of a base and a solvent, to obtain a compound of formula (III); and (a) reacting a compound of formula (III) with a compound of formula (II) in the presence of a metallic salt, a base and a solvent to obtain a compound of formula (I).
[0031] Step (i)
[0032] The deprotection of the compound of formula (V) in step (i) may be performed in the presence of a deprotection agent, such as a suitable acid. Suitable acids include, but are not limited to, trifluoroacetic acid, sulphuric acid, methane sulphonic acid, acetic acid, formic acid, hydrochloric acid (including, but not limited to, concentrated hydrochloric acid), and mixtures thereof. A preferred acid is acetic acid (e.g., 80% aqueous acid acid).
[0033] In one embodiment, the deprotection of the compound of formula (V) is performed under acidic conditions and under reflux conditions over night till completion of reaction. The reaction mixture can then be cooled to 15° C. and allowed to stir, and then the temperature raised to obtain the compound of formula (IV). The obtained, precipitated compound of formula (IV) can be filtered, washed with solvent and dried to obtain the desired product of formula (IV).
[0034] Step (ii)
[0035] The hydrolysis step may be performed in the presence of a base and a solvent. The reaction mixture can be allowed to stir at a reduced temperature (e.g., at 0° C. for 30 min), warmed to room temperature slowly and stirred at the same temperature for another 18-24 hours to obtain the compound of formula (III).
[0036] Suitable solvents include, but are not limited to, acetone, tetrahydrofuran (THF), acetonitrile, ethyl acetate, dimethylformamide (DMF), dichloromethane, methyl tertiary butyl ether, acetic acid, methanol, ethanol, isopropanol, water and mixtures thereof (such as a mixture of acetonitrile and ethyl acetate). A preferred solvent is methanol.
[0037] Suitable bases include, but are not limited to, triethylamine, diisopropylethylamine, diisopropylamine, pyridine, ammonium acetate, ammonium chloride, ammonium formate, ammonium sulfamate, ammonium phosphate, ammonium citrate, ammonium carbamate, ammonia, and mixtures thereof. A preferred base is ammonia. In another embodiment, the base is triethyl amine or diisopropylethylamine.
Step (a)
[0038] The compound of formula (III) may be reacted with the compound of formula (II) in the presence of a metallic salt, a base and a solvent. The reaction can be performed at room temperature under nitrogen atmosphere at 25-30° C. and allowed to stir for 2-6 hrs. at the same temperature. The resultant solvent in the reaction mixture can be distilled out at a suitable temperature and the product can be further purified with a suitable solvent (e.g., by recrystallization) to isolate the sofosbuvir of formula (I).
[0039] Suitable solvents include, but are not limited to, acetone, tetrahydrofuran, acetonitrile, ethyl acetate, dimethylformamide, dichloromethane, methyl tertiary butyl ether, acetic acid, methanol, ethanol, isopropanol, water and mixtures thereof (such as a mixture of acetonitrile and ethyl acetate). A preferred solvent is tetrahydrofuran.
[0040] Suitable bases include, but are not limited to, triethylamine, diisopropylethylamine, diisopropylamine, pyridine, ammonium acetate, ammonium chloride, ammonium formate, ammonium sulfamate, ammonium phosphate, ammonium citrate, ammonium carbamate, ammonia, and mixtures thereof. A preferred base is ammonium chloride (e.g., aqueous ammonium chloride). In another embodiment, the base is triethyl amine or diisopropylethylamine.
[0041] Suitable metallic salts include, but are not limited to, magnesium chloride, magnesium bromide, magnesium iodide, lithium chloride, lithium bromide, lithium iodide, copper chloride, copper bromide, copper iodide, and mixtures thereof. A preferred metallic salt is magnesium chloride.
[0042] In a preferred embodiment, step (a) is performed in the absence of a Grignard reagent.
[0043] The resulting sofosbuvir can be purified by techniques known in the art, such as the use of an anti-solvent, recrystallization, filtration and evaporation. In one embodiment, the sofosbuvir is subjected to recrystallization, for example in the presence of an ether solvent. Suitable ether solvents include, but are not limited to, diethyl ether, diisopropyl ether, MTBE (methyl tertiary butyl ether), and mixtures thereof. A preferred ether solvent is MTBE.
[0044] The present inventors have discovered that the condensation reaction of the compound of formula (III) with the compound of formula (II) carried out in the presence of a metallic salt is industrially feasible, eco-friendly and commercially advantageous for preparation of sofosbuvir and its analogues.
[0045] The following examples illustrate the present invention, but should not be construed as limiting the scope of the invention.
EXAMPLES
Example-1
Preparation of N 4 ,3′,5′-dibenzoyl-2′-Deoxy-2′-fluoro-2′-C-methyluridine
[0046] N 4 ,3′,5′-tribenzoyl-2′-Deoxy-2′-fluoro-2′-C-methylcytidine (20 gm) was added to 80% aqueous acetic acid (1 liter) and refluxed overnight till completion of the reaction. After cooling and standing at room temperature (15° C.), most of the product was precipitated and then filtered through a sintered funnel. The resultant precipitate was washed with water and co-evaporated with toluene to give a white solid of the titled product. (Yield: 85-90%)
Example-2
Preparation of 2′-deoxy-2′-fluoro-2′-C-methyluridine
[0047] To a solution of 3′,5′-dibenzoyl-2′-Deoxy-2′-fluoro-2′-C-methyluridine (10 gm) in MeOH (120 mL) was added to a solution of saturated ammonia in MeOH (60 mL). The reaction mixture was stirred at 0° C. for 30 min, warmed to room temperature slowly and then allow to stir for another 18 hours at the same temperature. The solvent in the resultant mixture was evaporated under reduced pressure to give a residue, which was recrystallized with methanol and water to afford the pure product. (Yield: 50-60%)
Example-3
Preparation of (S)-isopropyl-2-(((R)-[(2,3,4,5,6-pentafluoro-phenoxy)-phenoxy-phosphoryl amino]propanoate
[0048] To a 2 L three-necked round bottom flask fitted with a mechanic stirrer and low temperature thermometer was added 30 g of phenyl dichlorophosphate and 300 mL of anhydrous dichloromethane. The solution was cooled to 0° C. under a nitrogen atmosphere and L-alanine isopropyl ester hydrochloride (23.5 g) was added quickly as a solid. The mixture was stirred and cooled to −55° C. in a dry ice-acetone bath. A solution of 31 g of triethylamine in 150 mL of dichloromethane was added through an addition funnel over 70 minutes. The white cloudy mixture was stirred at −55° C. for half hour and then the temperature was raised to −5° C. slowly over 1.5 h. A pre-cooled mixture of pentafluorophenol and triethylamine in 100 mL of dichloromethane was added to the mixture via an addition funnel over 1 hour at 0° C. and the resulting mixture was stirred at 0° C. for 4 hours. The white precipitate (TEA.HCl) was filtered out and rinsed with dichloromethane. The filtrate was concentrated under reduced pressure and the white solid residue was triturated in 880 mL of t-butyl methyl ether (TBME) at room temperature for one hour. The white suspension was filtered and the solid was rinsed with TBME. The solid was distributed in a mixture of ethyl acetate and water. The organic layer was separated and washed with water. The organic layer was dried over MgSO4 and concentrated to afford a white feather solid. The obtained solid was dissolved in ethyl acetate, washed with water/brine and dried over MgSO4. The resultant solution was concentrated under reduced pressure to obtained title compound. (Yield: 70-80%)
Example-4
Preparation of Sofosbuvir
[0049] To a 4 L four-necked round bottom flask fitted with a mechanical stirrer and low temperature thermometer were added 100 gm of uridine intermediate from Example 2 and 1500 ml of tetrahydrofuran (THF) and the mixture was stirred for 5-10 min under nitrogen atmosphere at 25-30° C. 54.8 gm of MgCl 2 was added and the mixture was stirred for 2 hours. 261.0 gm of phosphramide intermediate from Example 3 was slowly added and the mixture was stirred for 8-10 hrs at the same temperature. After completion of the reaction (as determined by HPLC), the THF was distilled out at below 45° C. and the reaction mass was allowed to cool at 25-30° C. 1.0 L dichloromethane and 1.0 L of aqueous ammonium chloride solution was added to the reaction mass, and the solution was stirred at room temperature to separate the layers.
[0050] The obtained organic layer was distilled out completely to obtain a residue, followed by addition of 300 mL of MDC (dichloromethane) and 300 mL MTBE. The reaction mixture was stirred for 6 hrs. at 25-30° C. and then cooled to 10-15° C. and stirred again for 2 hrs. The resultant precipitated material was filtered, washed with a mixture of dichloromethane and MTBE (1:1) and dried under vacuum for 15 min at 50-60° C. to isolate the title product. (Yield: 70-80%)
Example-5
Preparation of Sofosbuvir
[0051] To a 4 L of four-necked round bottom flask fitted with a mechanical stirrer and low temperature thermometer were added 100 gm of uridine intermediate from Example 2 and 1500 mL of tetrahydrofuran (THF) and the reaction mixture was stirred for 5-10 min under nitrogen atmosphere at 25-30° C. 54.8 gm of LiCl 2 was added and the reaction mixture was stirred for 2 hours, followed by slow addition of 261.0 gm of phosphramide intermediate from Example 3 and stirring for 8-10 hrs. at the same temperature. After completion of the reaction (as determined by HPLC), the THF was distilled out at below 45° C. and the reaction mass was allowed to cool at 25-30° C. 1.0 L dichloromethane and 1.0 L of aqueous ammonium chloride solution was added to the reaction mass, and the solution was stirred at room temperature to separate the layers.
[0052] The obtained organic layer was distilled out completely to obtain a residue, followed by addition of 300 mL of MDC and 300 mL MTBE. The reaction mixture was stirred for 6 hrs. at 25-30° C. and then cooled to 10-15° C. and stir for 2 hrs. The resultant precipitated material was filtered, washed with a mixture of dichloromethane and MTBE (1:1) and dried under vacuum for 15 min at 50-60° C. to isolate the title product. (Yield: 60-70%)
[0053] Throughout this specification, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which the disclosed matter pertains. The references disclosed are also individually and specifically incorporated by reference herein for the material contained in them that is discussed in the sentence in which the reference is relied upon. | The present invention relates to an improved, commercially viable and industrially advantageous process for the preparation of sofosbuvir, which uses reagents that are less expensive and easier to handle. | 2 |
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to a hand tool and more particularly a hand tool for ripping through the shell of a hard boiled egg to facilitate peeling the same.
2. Description of the Prior Art
Devices are known for use in peeling the shell from a hard boiled egg and by way of example reference maybe had to the following U.S. Patents: U.S. Pat. No. 4,787,306 issued Nov. 29, 1988 to G. E. Johnson; U.S. Pat. No. 4,191,102 issued Mar. 4, 1980 to C. J. Cope; U.S. Pat. No. 4,182,234 issued Jan. 8, 1980 to W. H. Reed; U.S. Pat. No. 4,149,456 issued Apr. 17, 1979 to T. Gisonni; U.S. Pat. No. 4,117,774 issued Oct. 3, 1978 to E. R. Wilburn et al; U.S. Pat. No. 4,106,402 issued Aug. 15, 1978 to J. C. Gevas; U.S. Pat. No. 4,056,051 issued Nov. 1, 1977 to E. A. Brown; U.S. Pat. No. 3,552,458 issued Jan. 5, 1971 to J. C. Whitman; U.S. Pat. No. 3,612,122 issued Aug. 6, 1969 to R. C. Bjork; and U.S. Pat. No. 2,535,980 issued Dec. 26, 1950 to C. K. Yeamans.
None of the foregoing references while pertinent teach the unique features of the present invention. The only reference considered to be of some relevancy is U.S. Pat. No. 4,117,774 in that it discloses a pointed head in which the pointed end goes between the egg shell and the hard boiled egg white. Thereafter water under pressure is introduce by way of the device between the egg shell and the egg white to remove the shell. U.S. Pat. No. 4,149,456 discloses a sleeve having resiliently biased prongs projecting into the sleeve wherein each prong has a hooked end to ripe through the egg shell and thus remove it from the firm egg white. However, neither of the forgoing references suggest or disclose any means that engages and slides over the outer surface of the egg shell and controls the depth of penetration of the shell ripper as does the present invention.
SUMMARY OF INVENTION
A principal object of the present invention is to provide a simple hand tool that can be used to make gashes in the shell of a hard boiled egg so that the shell can easily be removed while at the same time the user can be reasonably assured, due to a depth control feature, there is little likelihood of making a gouge in the egg white.
A preferred embodiment of the instant invention provides a hand tool for use in removing the shell from a hard boiled egg. The tool includes a handle readily grasped by one hand with a first and a second spaced apart pair of egg shell abutment members connected to the handle. The egg shell abutment members have respective first and second contact surfaces for engaging the outer surface of the egg shell. A shell ripper is connected to the handle and disposed between the abutment members. The ripper has a leading end portion in a plane offset in a first direction from a plane containing the first and second contact surfaces on the egg shell abutment members and a portion spaced from the leading end portion that is offset from the plane in a direction opposite the first direction.
Moreover, an embodiment of the present invention provides a hand tool for use in removing the shell from a hard boiled egg. The tool includes a handle including a first and a second spaced apart pair of egg shell abutment guide tines connected to the handle and having respective first and second contact surfaces for engaging the outer surface of an egg shell. The handle includes a longitudinal distal end defining a shell ripper tine disposed in between the pair of guide tines and the ripper tine includes an upwardly extending projection or hump spaced from the leading end portion.
Furthermore, the instant invention may also define a hand tool for use in removing the shell from a hard boiled egg including a body, a handle extending form the body, at least one longitudinal member extending therefrom defining a shell ripper member having an upwardly extending projection spaced from a leading end portion, and at least one pair of guide members extending from the body opposite the handle on each side of the shell ripper member for engaging the outer surface of an egg shell.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like numerals refer to like parts throughout the several views and wherein:
FIG. 1 is an oblique view of a hand tool of the present invention for ripping through the shell of a hard boiled egg;
FIG. 2 is a side elevation of the tine portion of the tool;
FIG. 3 is top plan view of FIG. 2;
FIG. 4 is a right hand elevation view of FIG. 3;
FIG. 5 is a top plan view of an alternative embodiment; and
FIG. 6 is an elevational view of FIG. 5 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Illustrated in the drawings 1 - 6 is a hand tool for ripping through the shell of a hard boiled egg. The egg ripper tool 10 comprises a handle 20 connected by way of a stem 30 to an egg shell ripper member 40 at the distal end of the tool. The egg shell ripper member 40 comprises a spaced apart pair of guide tines 41 and 42 having respective lower i.e. bottom surfaces 44 and 45 that ride on the outer surface of the egg shell and a shell ripper tine 43 disposed between the tines 41 and 42 . Of course, a plurality of ripper tines or guide tines may be utilized with the instant invention as an option. The tines 41 and 42 effectively provide a depth gauge for the tool preventing the shell ripper tine 43 from gouging the surface of the cooked egg white. The ripper tine 43 has a free outer end (preferably rounded) tip 46 spaced rearwardly from the tips 47 and 48 of the respective tines 41 and 42 . The ripper tine 43 has an upper surface 49 which at the tip 46 is located in a plane offset, downwardly as viewed best in FIG. 2 from a plane containing the surfaces 44 and 45 of the outer tines 41 and 42 . The width of the ripper tine(s) and/or guide tine(s) may be chosen to provide optimal performance depending upon the size and/or curvature of the egg. Moreover, the ripper tine(s) and/or guide tine(s) may be of irregular width along the length thereof.
The handle provides means for gripping the tool in one hand leaving the other hand free to hold the egg. The handle should be comfortable to hold and push on in a direction toward the tines during use of the tool. The handle maybe the standard utensil handle shown or if desired some other suitable shape such as a loop, flange, or curved handle. For example, the handle maybe a closed loop connected to the stem 30 and the loop could be parallel to the plane containing the tine lower surfaces 44 and 45 or at selected angle thereto for example 90 degrees. Alternatively the handle maybe a rounded knob connected to the stem 30 or simply a bar or rod attached to the stem and disposed transversely thereto.
In the embodiment illustrated in FIGS. 1 to 4 the tool is moved during use relative to the egg, i.e., pushed toward the egg causing the tip 46 to pierce the shell of the egg. During further relative movement of the tool engaging the outer surface of the egg the tines 41 and 42 serve as runners gliding over the outer surface of the egg shell while the shell between the runners is ripped open by the ripper tine 43 . A raised portion defining an upper curvature or hump 50 on the upper surface of this ripper tine spreads the shell in the ripping process and ensures the shell is broken open. A spur, or plow shaped projection may be formed on the upper surface of the ripper tine to perform the same function as the hump 50 shown in the drawings. After a suitable gash or gashes have been made, the shell can be easily removed if it hasn't already dropped off.
As illustrated in FIGS. 5 and 6, an alternative embodiment is shown that is pulled toward the user rather than pushed away from the user. Moreover, this hand tool has a loop type handle 20 A having a stem 30 A connected by a pivot pin 301 to an egg shell ripper member 40 A. The ripper member 40 A comprises an arm 401 connected to the handle by the pivot pin 301 and having a cross member 302 providing a means for limiting the pivoting motion of the arm 401 . The arm 401 is reversely bent as indicated at 402 to provide an egg shell penetrating and ripping portion 403 that terminates at a tip end 405 . A pair of rollers 406 and 407 are journal led on a shaft 408 that is secured to the lever arm 401 . During use of the tool rollers 406 and 407 run on the outer surface of the egg shell and serve as a depth gauge controlling the depth of penetration of the tip 405 below the egg shell 60 preventing gouging the hard boiled egg white. If desired the pivot pin 301 can be eliminated in which case the arm 401 would be rigidly secured to the handle stem.
The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom, for modifications will become obvious to those skilled in the art based upon more recent disclosures and may be made without departing from the spirit of the invention and scope of the appended claims. | A hand tool to facilitate removing the shell from a hard boiled egg. The tool has an egg shell ripper prong disposed between a spaced apart pair of members that engage the outer surface of the egg shell and limit the depth of penetration of the ripper prong. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a position measurement technique, and more particularly to a capacitance sensation unit of plane position measurement device.
2. Description of the Related Art
U.S. Pat. No. RE27436 discloses a technique related to flat stepping motor. The basic structure of the flat stepping motor is mainly composed of a flat steel plate and a mover movable on the surface of the steel plate. The mover is able to interact with the magnetic field produced by multiple stator teeth two-dimensionally arranged on the surface of the steel plate in a checkerboard pattern. Accordingly, the mover can quickly and precisely move on the surface of the steel plate. However, such flat stepping motor necessitates a laser interferometer for performing position measurement. The laser interferometer is quite expensive and complicated so that the substantial application range of the flat stepping motor is greatly limited.
Many conventional sensation techniques have been disclosed and used for performing practical sensation and measurement of the position of the mover of the flat motor. For example, U.S. Pat. No. 6,476,601 discloses a compensation magnetic sensor on the basis of Hall sensation. Such sensor is too sensitive to the residual magnetization affection of the stator teeth. As a result, the practical application of such sensor is limited.
U.S. Pat. No. 6,175,169 discloses an improved electromagnetic sensor, which is integrated with the mover. The electromagnetic sensor has submicron-level sensation ability. However, the precision of such electromagnetic sensor is lowered with the crossmodulation effect, affection of magnetic flux of the mover and the defects of the stator teeth due to small-scale sensation. Therefore, such electromagnetic sensor is still not perfect.
U.S. Pat. No. 5,818,039 discloses a sensation device based on optical sensation technique. Such sensation device is able to detect the change of position through fluorescence. However, such sensation device has a quite large volume so that it is impossible to integrally arrange the sensation device in the mover. This limits the application of such sensation device in the field of flat motor. Also, such sensation device can hardly provide uniform dyeing concentration and is unable to remove the noise in the position signal. As a result, such sensation device cannot perform precise position measurement.
In the above different sensation techniques, the technical essences are all limited. Therefore, none of the above sensation techniques can provide an optimal position measurement for the flat motor. Thanks to the development of flat motor manufacturing technique, the flat motor can have a stable air gap. The stable air gap is a basis for the capacitance measurement technique. Accordingly, the capacitance measurement technique with nano-definition precision and insensitivity to magnetic flux has become a most often used technique for plane position measurement.
Concerning the capacitance measurement technique, U.S. Pat. No. 6,492,911 discloses a sensor based on rotational and linear capacitances. Such sensor can modulate the position through electrodes in a specific configuration. However, due to the specialness of the configuration, such sensor cannot be applied to the plane linear motor.
In addition, U.S. Pat. No. 4,893,071 discloses a capacitance sensation technique performing position measurement on the basis of the stator teeth. However, in such capacitance sensation technique, the harmonic wave distortion of the position sensation signal will greatly lower the precision. Also, the technique for rectifying and adjusting the relative motional position of the sensor is too complicated to integrate the sensor on the armature of the mover.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a capacitance sensation unit of plane position measurement device. The capacitance sensation unit is able to perform high-precision and high-definition uniaxial or multiaxial measurement of rotational position and angle.
To achieve the above and other objects, the capacitance sensation unit of plane position measurement device of the present invention includes a movable main body and a sensation section for performing one-dimensional sensation in a virtual sensation axis. The sensation section has multiple elongated sensation electrodes. The sensation electrodes are disposed on one face of the main body in parallel to each other at intervals with their lengthwise directions substantially normal to the sensation axis. The lengthwise directions of two ends of each of the sensation electrodes contain an angle unequal to 180 degrees.
In the above capacitance sensation unit, the angle contained between the lengthwise directions of two ends of each of the sensation electrodes is preferably an obtuse angle and each of the sensation electrodes has a V-shaped inclined configuration.
In the above capacitance sensation unit, the sensation electrodes have equal widths and are arranged at equal intervals.
In the above capacitance sensation unit, there are multiple sensation sections, which are disposed on one surface of the main body for enhancing the measurement precision.
In the above capacitance sensation unit, the sensation sections are sequentially arranged along a linear arrangement axis or Z-shaped non-single arrangement axes. In other words, according to different sensation requirements, the sensation sections can be arranged in a specific order to as enlarge the sensation range as possible and enhance the measurement precision.
In the above capacitance sensation unit, the sensation axes of the sensation sections are parallel to the arrangement axis, whereby the sensation directions of the sensation sections are directed in the same direction to achieve a one-dimensional sensation assembly.
In the above capacitance sensation unit, the sensation sections are sequentially arranged along the arrangement axis in a stepped pattern to increase the sample number and enlarge the sensation range.
In the above capacitance sensation unit, the sensation axes of two adjacent sensation sections are normal to each other to perform at least two-dimensional position sensation.
In the above capacitance sensation unit, there are at least two sensation sections, which are symmetrically disposed on one face of the main body about a geometrical center.
In the above capacitance sensation unit, the inclination directions of the sensation electrodes of the sensation section are reverse to each other.
In the above capacitance sensation unit, the rearmost sensation electrodes of the respective sensation sections in the inclination directions are correspondingly positioned where the geometrical center is positioned.
The present invention can be best understood through the following description and accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plane view of a first embodiment of the present invention;
FIG. 2 is a plane view showing the use of the first embodiment of the present invention;
FIG. 3 is a sectional view of the first embodiment of the present invention;
FIG. 4 is a plane view of a second embodiment of the present invention;
FIG. 5 is a bottom view of the second embodiment of the present invention;
FIG. 6 is a top view of the second embodiment of the present invention;
FIG. 7 is a schematic diagram showing that the second embodiment of the present invention is connected to a processing circuit;
FIG. 8 is a diagram of the sine wave according to the second embodiment of the present invention, output from the processing circuit;
FIG. 9 is a perspective view of a third embodiment of the present invention;
FIG. 10 is a plane view of the third embodiment of the present invention; and
FIG. 11 is a plane view of a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Please refer to FIG. 1 . According to a first embodiment, the capacitance sensation unit 10 of the plane position measurement device of the present invention includes a main body 20 and a sensation section 30 .
The main body 20 is a circuit board with a certain size for disposing the sensation section 30 thereon. The main body 20 has a connection circuit for electrically connecting an external circuit with the sensation section 30 .
The sensation section 30 has four elongated sensation electrodes 31 , 32 , 33 , 34 with equal width. The sensation electrodes 31 , 32 , 33 , 34 are disposed on one face of the main body 20 in parallel to each other at equal intervals. The lengthwise directions of two ends of each of the sensation electrodes 31 , 32 , 33 , 34 contain an obtuse angle α. Accordingly, two ends of each of the sensation electrodes 31 , 32 , 33 , 34 respectively obliquely extend from the center thereof to two lateral sides, whereby each of the sensation electrodes 31 , 32 , 33 , 34 has a substantially V-shaped configuration.
Accordingly, as shown in FIGS. 2 and 3 , the plane position measurement device with the capacitance sensation unit 10 is integrally arranged in the mover (not shown) of a flat motor 40 for sensing the displacement position of the mover relative to a flat stator 41 .
The flat motor 40 pertains to prior art. The stator 41 of the flat motor 40 has the form of a flat plate. The stator 41 has multiple conductive stator teeth 411 arranged in a checkerboard pattern. Also, in order to keep the surface of the stator 41 tidy and provide proper protection for the stator teeth 411 , an insulation packaging material such as epoxy is filled and distributed in the tooth spaces 412 between the stator teeth 411 . Under such circumstance, the surface of the stator 41 can keep tidy and the air gap formed between the stator 41 and the mover can have a stable size.
The capacitance sensation unit 10 is directly fixedly disposed on the mover via the main body 20 with the sensation section 30 positioned on one face of the mover that faces the stator 41 . Accordingly, the sensation electrodes 31 are spaced from the corresponding conductive stator teeth 411 by the air gaps to respectively produce corresponding capacitance C. A conventional processing circuit composed of a trigger circuit, measurement circuit and digital interpolator is used to process the sensation signals. The processing technique of the sensation signals is not the subject matter of the present invention and thus will not be further described hereinafter.
However, it should be specifically noted that in this embodiment, the sizes of the sensation electrodes 31 , 32 , 33 , 34 and the sizes of the stator teeth 411 have a certain corresponding relationship. Substantially, the sum of the size of one stator tooth 411 and the size of an adjacent tooth space 412 is a stator tooth period 42 . The sum of the size of one sensation electrode and the width of the interval between the sensation electrode and an adjacent sensation electrode is an electrode period 35 . The electrode period 35 is 3/4 the stator tooth period 42 , whereby the sensation section 30 precisely crosses over three stator tooth periods 42 .
Also, the thickness 36 of the sensation electrode 31 is minimized to provide a polished surface and reduce the parasitic capacitance.
Moreover, as shown in FIG. 2 , in the capacitance C 1 , C 2 , C 3 , C 4 respectively produced by the sensation electrodes 31 , 32 , 33 , 34 , the first capacitance C 1 has a maximum value, while the third capacitance C 3 has a minimum value.
Furthermore, the V-shaped inclined configurations of the sensation electrodes 31 , 32 , 33 , 34 help in suppressing the harmonic wave distortion to keep the linear state. In comparison with the conventional technique, the special configuration provided by the present invention is helpful in increasing the precision and sensitivity in position sensation.
According to the above arrangement, the capacitance sensation unit 10 of the plane position measurement device of the present invention is integrally disposed in the mover and movable along with the mover relative to stator 41 . When the capacitance sensation unit 10 is moved along with the mover, the sensation section 30 can perform one-dimensional sensation in a virtual sensation axis a. To speak more specifically, the sensation axis a is parallel to the connection line of the lengthwise central points of the sensation electrodes 31 , 32 , 33 , 34 . That is, in case of negligence of the angle α, the sensation axis a is normal to the lengthwise direction of the sensation electrodes 31 , 32 , 33 , 34 .
Please further refer to FIG. 4 . Inevitably, it often takes place that some of the numerous stator teeth 411 ′ are damaged or twisted to affect the stability of the size of the air gap and cause space noise. Therefore, once the structure of the stator teeth 411 ′ is deformed, chipped or otherwise damaged, the basis for the measurement scale will be affected to greatly lower the precision of the capacitance position measured by the sensation section 30 ′. In order to reduce the affection of the deformation and damage of the stator teeth on the sensation precision, in a second embodiment of the present invention, there are five capacitance sensation units 10 ′ sequentially arranged along a linearly extending arrangement axis b′ and the sensation axes a′ of the sensation sections 30 ′ are parallel to the arrangement axis b′. In addition, the sensation sections 30 ′ are arranged along the arrangement axis in a stepped pattern. Accordingly, the number of the measurement points of the sensation axes a′ is increased and the sensation sections 30 ′ are arranged in a stepped pattern to laterally expand the sensation range. Under such circumstance, the sensation sample number is greatly increased to lower the affection of the deformation of the stator teeth on the sensation precision.
Accordingly, as shown in FIG. 7 , in use of the one-dimensional sensation assembly 1 ′ composed of multiple sensation units 10 ′ with parallel sensation axes a′, a processing circuit 50 ′ is used to process the electronic signals produced by the one-dimensional sensation assembly 1 ′. However, the position sensation is not performed by directly measuring the respective capacitance values, but is performed on the basis of the voltage corresponding to the capacitance values. To speak more specifically, the sensation electrodes 31 , 32 , 33 , 34 of the respective sensation sections 30 ′ are pair by pair respectively electrically connected to the resistors 511 ′, 512 ′, 521 ′, 522 ′ of two electrical bridges 51 ′, 52 ′. The low points of the electrical bridges 51 ′, 52 ′ are the grounded surface of the stator 41 ′, while the high points of the electrical bridges 51 ′, 52 ′ are connected to the high-frequency trigger signal produced by an oscillator 53 ′. The voltage balance positioned in the branches of the electrical bridges 51 ′, 52 ′ are respectively measured by an amplifier 54 ′, 55 ′.
When the one-dimensional sensation assembly 1 ′ is moved with the operation of the mover, the capacitance corresponding to the one-dimensional sensation assembly 1 ′ is also changed therewith to change the voltage balance of the electrical bridges 51 ′, 52 ′. After processing the signal, a sine wave signal is produced as a calculation basis for the position measurement as shown in FIG. 8 .
Please now refer to FIGS. 9 and 10 . In a third embodiment, multiple one-dimensional sensation assemblies 1 ″ as the second embodiment are combined to perform three-dimensional sensation. In this case, the position and rotational angle on the plane can be measured.
Substantially, in this embodiment, there are three one-dimensional sensation assembles 1 a ″, 1 b ″, 1 c ″ are sequentially arranged along the arrangement axis b″. The sensation axis a″ of the first one-dimensional sensation assembly 1 a ″ in the middle is parallel to the arrangement axis b″, while the sensation axes a″ of the second and third one-dimensional sensation assemblies 1 b ″, 1 c ″ symmetrically arranged on two sides are parallel to each other and normal to the arrangement axis b″.
According to the above arrangement, the respective one-dimensional sensation assemblies 1 ″ can be used to perform position measurement in different directions. Due to the low sensitivity of the sensation sections 30 ″ in the direction normal to the sensation axes a″, the interference between the respective one-dimensional sensation assemblies normal to each other can be avoided so that the position sensation can be precisely performed.
Furthermore, in addition to the arrangement of the third embodiment, in order to achieve higher precision in measurement of rotational angle, a fourth embodiment of the present invention is provided as shown in FIG. 11 . In the fourth embodiment, a capacitance sensation unit 10 ″′ is based on the technique of the first embodiment and there are two sensation sections 30 ″′. The sensation axes a″′ of the sensation sections 30 ″′ are parallel to each other but directed in reverse directions. The sensation sections 30 ″′ are symmetrically disposed on one face of the main body 20 ″′ with a geometrical center serving as the symmetrical axis. In addition, the first sensation electrodes 31 ″′ of the respective sensation sections 30 ″′ are positioned on two sides of the geometrical center to measure the same stator tooth period 42 ″′.
The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention. | A capacitance sensation unit of plane position measurement device for performing measurement with submicron definition is able to measure both two-dimensional position and rotational angle relative to a plane object. The main application of the capacitance sensation unit is exemplified with the position measurement of the mover of a flat motor. The capacitance sensation unit is able to measure the position and rotational angle of the mover relative to the surface of a stator in the form of a flat plate. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage filing under 35 U.S.C. §371 based upon international application no. PCT/CA2009/001539, filed 26 Oct. 2009 and published in English on 6 May 2010 under international publication no. WO 2010/048709, which claims priority to U.S. provisional application nos. 61/108,619, filed 27 Oct. 2008 and 61/152,420, filed 13 Feb. 2009. All of the foregoing are hereby incorporated by reference as though fully set forth herein.
FIELD
The specification relates to pleatable materials, or fabrics, for use in filtration, and more particularly for use as pleated “filter bags” in baghouse-type dust collectors, for example.
BACKGROUND
A dust collector is an equipment to remove particles in an industrial fume. Typically the collector contains between hundreds to thousands of cylindrical elements referred to as bags. The bags are made of a filtration fabric that is porous. As the gas flows through, the porous filtration fabric collects particles. The particles can form a cake on the surface after minutes of operation, and the bags are typically cleaned by a reversed jet.
One of the important parameters of the filtration fabric is the filtration efficiency. The efficiency of filtration of bags is related to the total surface area. Typically, if the surface area is increased, then the velocity of gas and particles going through the fabric will be reduced, which decreases the probability of undesired particles going through the fabric and can consequently reduces the particle emissions. Moreover, a higher surface area can reduce the probability of particles getting embedded into the fabric in a manner where they resist the reversed jet, thereby increasing the lifespan of the filter. It is also possible, by increasing the surface area, to increase the capacity of a dust collector. It is thus generally sought to increase the surface area of the bags in dust collectors, where possible.
Typically, pleated bags have a greater surface area than non-pleated bags (i.e. simply cylindrical bags). Using pleated bags instead of non-pleated bags is thus one way of increasing the surface area without necessarily increasing the overall size of the dust collector system. In many cases, replacement of non-pleated bags by pleated bags can increase the surface area by two to three times.
Pleated bags can be made using a pleatable material which keeps its shape after pleating. The pleating can be done with a pleating machine. Some pleating machines operate at room temperature.
Alternately, for some materials which require thermosetting to retain their pleats, pleating machines having heating blades are used to fold the fabric and keep pressure on the pleats until the fabric is cooled back to room temperature. Heretofore, such processes have been used with polymers that can be thermally formed and have a relatively small density.
Some materials that are not thermally formable per se can be made so by adding a thermo-setting resin. An example of this is fiberglass felt impregnated with phenolic resin. The temperature of blades allow setting of the phenolic resin which subsequently acts to maintain the shape of the pleats. The reaction being irreversible, the pleats subsequently keep their shape even at high temperature.
However, even given the state of the art, some filtration materials could not be pleated by the known means and therefore remained known as being unpleatable. Nevertheless, given some desired characteristics, at least one of these ‘unpleatable’ filtration materials remained a popular choice for some specific applications despite the fact that it was not available in pleated form. There thus remained a strong need for an equivalent to such ‘unpleatable’ materials in pleated form due to the many advantages of pleats in filtration. This called for improvement.
SUMMARY
As it will appear from the description below, a filtration material such as a PTFE felt covered by an E-PTFE membrane, which was traditionally known as unpleatable, can now be made pleatable by felting with a pleatable scrim, more particularly a pleatable metallic scrim. There are many metals which are pleatable when provided in apertured sheets, and the pleatability of a metallic scrim can take precedence on the pleatability of both the felted PTFE and the E-PTFE membrane. Felting by hydro-entanglement (spunlacing) can be better suited than needle-felting when using a metallic scrim.
In accordance with one aspect, there is provided a pleatable filtration material comprising a felt having PTFE fibers felted onto a pleatable metallic scrim, a permeability of at least 20 l/dm 2 /minute at 12 mm of water gauge and a weight between 100 and 1000 g/m2, the felt having a density between 150 and 1000 g/m 2 and a permeability greater than that of the scrim and between 20 and 250 l/dm 2 /minute at 12 mm of water gauge; and a membrane laminated onto the felt, made of E-PTFE and having a permeability of between 3 and 75 l/dm 2 /minute at 12 mm of water gauge, preferably between 12 and 50 l/dm 2 /minute at 12 mm of water gauge; wherein the filtration material can be pleated using a traditional pleater at room temperature and thenceforth retain its pleats.
In accordance with one aspect, there is provided a process of making a pleatable filtration material comprising felting PTFE fibers onto a pleatable metallic scrim having resistance characteristics at least comparable to that of the PTFE fibers, a permeability of at least 20 l/dm 2 /minute at 12 mm of water gauge and a weight between 100 and 1000 g/m2, until a felt density between 150 and 1000 g/m 2 in addition to the density of the scrim and a permeability greater than that of the scrim and between 20 and 250 l/dm 2 /minute at 12 mm of water gauge are reached; and laminating an E-PTFE membrane having a permeability of between 3 and 75 l/dm 2 /minute at 12 mm of water gauge, preferably between 12 and 50 l/dm 2 /minute at 12 mm of water gauge onto a face of the felted PTFE fibers.
In accordance with one aspect, there is provided a pleated filter bag for use in a bag house dust collector, the filter bag being elongated and comprising a longitudinal hollow center with an open end, and a pleated filter wall transversally circumscribing the hollow center, the pleated filter wall having a felt felted onto an apertured and pleatable scrim and having a permeability lower than a permeability of the scrim and appropriate for filtration applications, and a membrane having a permeability substantially lower than the permeability of the felt and covering the felt on the outer side thereof facing the hollow center, wherein all of the scrim, the felt, and the membrane are resistant to a harsh filtration environment of the dust collector.
In accordance with another aspect, there is provided a filter fabric construction which incorporates a pleatable scrim to the base felt. The pleatability of the scrim takes precedence on the pleatability of the remaining components of the filter fabric, thereby rendering the filter fabric pleatable. This construction, or associated production method, can make pleatable a material such as PTFE, which was traditionally known as non-pleatable.
In accordance with another aspect, there is provided a pleatable filtration fabric having an E-PTFE laminated PTFE felt. This filtration fabric is made pleatable while at least substantially maintaining the thermal and chemical resistance characteristics of the PTFE by making the PTFE felt with a pleatable, heat-resistant and chemical-resistant scrim. The pleatability of the metallic scrim takes precedence in the combination and makes the entire material pleatable.
It will be understood that in the instant specification, the expression “pleatable” is to be understood in the context of operability in filtration. A pleatable filtration element will retain its pleats for a reasonable lifespan in the context of a normal or recommended use. For instance, a felt of polyester with a polyester scrim can be viewed as a non-pleatable fabric, whereas spunbounded polyester, which is denser and stiffer, can be viewed as pleatable.
DESCRIPTION OF THE FIGURES
In the appended figures,
FIG. 1 is a perspective view, fragmented, showing an example of a felt having a pleatable scrim.
DETAILED DESCRIPTION
One example of a material which was still used in unpleated form is polytetrafluoroethylene (PTFE), at least partly because of its exceptional thermal and chemical resistance characteristics which made the only viable choice for some harsh environments. An example of an application where unpleated PTFE-based bags were still used is dust collectors of waste incineration facilities. Incinerated wastes typically contain plastics which emit aggressive chemicals such as HCl, H2SO4, and HF during combustion. PTFE was appreciated for resisting to the combination of high temperatures (˜150 to 260° C.) and aggressive chemicals present in such waste incineration gaseous by-products. In applications such as waste incineration where tolerated emission levels were quite low, the PTFE fabric can be covered by a membrane to get a more efficient degree of filtration. A porous expanded PTFE membrane (E-PTFE) can be used to this end, laminated on the PTFE felt.
Tests attempting to pleat a PTFE felt (with or without catalyst) with a PTFE scrim failed. After pleating, the shape was not kept in a satisfactory way. Further, adding resins to the PTFE was found inefficient, at least partly due to the lack of adhesion and wetting by many of the tested resins on PTFE fibers.
The mere continued use of non-pleated PTFE filtration bags in dust collectors of applications such as waste incineration facilities, in itself demonstrates the former unavailability of this material in pleated form, considering the strong incentives for using pleated bags instead of cylindrical bags.
As will be detailed below, it will be understood how such materials and others can now be pleatable by felting the fabric onto a pleatable scrim. A type of pleatable scrim which can be used in making a PTFE felt pleatable is a metallic scrim.
FIG. 1 shows an exemplary sample of a PTFE felt spunlaced onto a metallic scrim. In this example, the metallic scrim is a square steel screen. As shown in the cut-out portion on the bottom and left-hand side corner of the sample, the metallic scrim is sandwiched between two layers of PTFE felt. In fact, during hydro-entanglement of the PTFE fibers, the fibers are placed on one side of the scrim, and partially pass through it, to the other side. The right-hand side of the sample is shown pleated. The E-PTFE membrane (not shown in the illustration), can later be laminated onto one face of the PTFE felt with metallic scrim. The PTFE felt can act as a support layer for the E-PTFE membrane which has a permeability substantially lower than the permeability of the felt. In use, the E-PTFE membrane faces the outside of the filtration bag and determines the relatively low permeability of the filtration material. The felt can thus be used to provide a cushioned support to the membrane, and, in combination with the metallic scrim, gives mechanical resistance to the membrane which acts as the actual “filter” during use but which is not practically usable alone. In fact, in many applications, the stresses which would be imparted to the E-PTFE membrane by the scrim during use if it was adhered directly thereto instead of being supported via felt, would result in an E-PTFE membrane having a very short useful life. The metallic scrim additionally provides pleatability to the filtration material because its higher pleatability takes precedence in the assembly.
The felt can be made of expanded porous or non-expanded PTFE fibers. The felt can be made by spunlacing the fibers onto the metallic scrim by a water jet—a process commonly referred to as hydro-entanglement. Hydro-entanglement can allow to avoid or reduce damage to the metallic scrim which could result if using conventional needle felting instead. The felt can have a density between 150 and 1000 g/m 2 , preferably between 250 and 700 g/m 2 , and a permeability between 20 and 250 l/dm 2 /minute at 12 mm of water gauge, preferably above 100 l/dm 2 /minute, for example.
The metallic scrim can be made of galvanized steel, stainless steel, aluminum, aluminium alloy, bronze, brass, copper, copper-based alloy, nickel, nickel-based alloy, or any suitable metal or alloy, provided it has suitable pleatability and resistance, and that it is ductile enough to be pleated without breaking. The metal can be a woven mesh, a punched metal sheet or any method that will create a metal sheet with suitable apertures in it. The permeability of the material should be greater than the permeability which is desired of the felt, preferably at least 20 l/dm 2 /minute at 12 mm of water gauge. The weight of the metal scrim can be between 100 and 1000 g/m 2 , preferably between 300 and 700 g/m 2 for example. Metallic scrims of various known types of metals can have chemical and temperature resistance characteristics suitable for harsh applications.
The felted support layer can be treated with a binder prior to lamination of the membrane, or the binder can be omitted. The fibers of the felt can act in a binding manner in certain applications. If used, the binder can be a fluorinated ethylene propylene copolymer (FEP) or a hexafluoropropylene-tetrafluorethylene copolymer, for example, or any other suitable binder. The binder can be provided at a concentration of between 25-50% by weight in a liquid suspension, and be either sprayed on a selected side of the support layer or transferred thereon using a roll. The material can then be heated in an oven at ˜120 to 240° C., to evaporate the solvent. After evaporation, the weight of transferred solid binder can represent a relative weight of between 1% and 10% (relative to the weight of the fabric).
The membrane, which can be made of commercially available E-PTFE, preferably has a permeability between 3 and 75 l/dm 2 /minute at 12 mm of water gauge, more preferably between 12 and 50 l/dm 2 /minute at 12 mm of water gauge. The membrane can be laminated on the side having the binder at a temperature of 270° C.
It will be noted that in some instances, PTFE felt for use in applications such as incinerators can have particles of catalyst deposited on the surface or embedded into the PTFE fibers. This can be desirable in a pleatable fabric and typically does not affect pleatability. For example, some catalysts help reducing emissions of dioxin, furan or nitrous oxide from waste incineration. The catalyst typically is typically provided a volume less than 20% of the volume of the PTFE fibers. Examples of catalysts include titanium dioxide (TiO 2 ), iron and cobalt (provided in the form of oxides), nickel, platinum and palladium. Other examples of catalysts include zeolith, copper oxide, tungsten oxide, aluminum oxide, chromium oxide, gold, silver, rhodium etc. If used, the catalyst should be provided in a particles size of less than 10 microns, but can be of any suitable shape, such as spheres, whiskers, plates, flakes, etc.
A resulting pleatable filtration material, or fabric, can include PTFE fibers spunlaced to a steel scrim, covered by a membrane. Such a fabric can be pleated using a traditional pleater operating at room temperature. The use of a pleatable metallic scrim can render the use of heated pleater blades unnecessary. An exemplary embodiment thereof is provided below:
EXAMPLE 1
PTFE fibers are spunlaced onto a 400 g/m 2 stainless steel scrim by hydro-entanglement. After entangling the total weight is 800 g/m 2 . The permeability of the material at this step is about 200 l/dm 2 /minute. The resulting felted support material is then sprayed with a suspension of FEP particles to add about 25 g/m of FEP particles after drying at 150° C. Then, an E-PTFE membrane is laminated thereon with the temperature of the FEP particles raised to 270° C. The resulting filtration material has a weight of 825 g/m 2 , and a permeability between 15 and 30 l/dm 2 /minute at 12 mm of water gauge, and is pleatable at room temperature.
EXAMPLE 2
Titanium dioxide particles of less than 10 microns in size are mixed with a PTFE dispersion. The titanium dioxide can correspond to 1-90% by volume, preferably 25-85% by volume, for example. The paste is extruded and calendered to form a tape. The tape is slitted along the length, expanded and processed over a rotating pinwheel to form fibers. These fibers with catalyst on the surface are spunlaced onto a 500 g/m2 stainless steel 316 scrim by hydroentanglement. After entangling the total weight is 900 g/m2. The E-PTFE membrane is laminated directly on the surface of the catalytic felt, the fibers acting as the binding agent. The resulting material has a weight of 900 g/m2, a permeability between 15 and 30 l/dm2/min at 12 mm of water gauge and is pleatable at room temperature.
It is to be understood that above example is given for illustrative purposes only. Alternate embodiments can be realized. For instance, thicker or thinner fabrics can be realized using more or less spunlaced PTFE, and different E-PTFE membranes. The pleatable metallic scrim can be applied to materials other than PTFE. Further, other scrim materials than metals can have similar pleatability and resistance characteristics. The use of a catalyst is optional. Given the above, the scope is indicated by the appended claims. | The pleated filter bag, which can be used in a bag-house type dust collector, is elongated and has a longitudinal hollow center with an open end, and a pleated filter wall circumscribing the hollow center. The pleated filter wall has a felt such as PTFE fibers felted onto an apertured and pleatable scrim which can be made of metal, and having a permeability lower than a permeability of the scrim. A membrane of lower-permeability material, such as an E-PTFE membrane, covers the support felt on the outer side of the bag. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to the field of livestock loading equipment, and more particularly, but not by way of limitation, to a retrofittable loading chute which converts a dock loading livestock trailer to a livestock trailer capable of loading livestock from the ground while retaining the capability of loading livestock from a dock.
[0003] 2. Discussion
[0004] Double-deck livestock trailers, commonly referred to as “pot load trailers” or “cattle pots,” have an internal ramp located at the rear of the trailer so livestock (most frequently cattle) can be moved from the lower floor to the upper floor. The pot load trailers are normally towed by a tractor using a kingpin connection. Most pot load trailers are dock loading trailers, i.e., they are designed for loading livestock by means of an entry ramp from a dock or an elevated chute. A typical entry height for a dock loading trailer is 40 inches. As used herein, the term “entry height” refers to the height of the entry ramp above the surface on which the trailer rests.
[0005] Many single-deck livestock trailers, also normally towed by a tractor using a kingpin connection, are suitable for dock loading only. The livestock are loaded into the single-deck livestock trailer from an elevated dock which may or may not match the entry height of the single-deck livestock trailer. Many single-deck livestock trailers accommodate ground loading by incorporating a drop-down box on the rear of the trailer. The addition of a drop-down box achieves an entry height of 14-16 inches. Because the box tends to drag over curbs and other ground-based obstacles, the box cannot be longer than about eight feet. For the overall length to remain under the 53-foot legal limit, the trailer must have a maximum length of 45 feet. In the alternative, a shorter box with a steeper internal ramp can be added to the trailer, but the shorter box results in a steeper internal ramp which creates livestock loading problems.
[0006] Another option for ground loading applications involves stock trailers designed to be towed by pickup trucks. The livestock (most frequently cattle) are loaded by means of an entry ramp directly from the ground into the trailer. A typical entry height for a ground loading stock trailer is 14 inches. Ground loading stock trailers cannot be used to load from a dock or portable loading chute.
[0007] Stockyards normally have “truck days” when primarily big trucks unload cattle at a dock. A livestock trailer limited to dock loading cannot unload to ground, so cattle haulers must frequently wait in line until a dock is available.
[0008] Similarly, stockyards normally have limited facilities for unloading livestock from ground loading stock trailers. A stock trailer which requires a ground loading facility cannot unload at a dock, and cattle haulers must wait in line until a ground loading facility is available.
[0009] Single-mode livestock trailers face a similar problem when picking up livestock from farms and ranches. A dock loading livestock trailer requires an elevated, or “dockload” chute, and a ground loading livestock trailer can load livestock only from the ground.
[0010] Most states limit the length of a trailer for use on non-interstate highways. Older pot load trailers of 46, 48, and 50 feet, and made of heavy gauge steel, are widely available for purchase at a fraction of the cost of a pickup truck to tow a ground loading livestock trailer. While the pot load trailers are capable of hauling a large number of cattle, pot load trailers are normally limited to loading livestock by a single mode, either ground load or dock load.
[0011] The applicant's livestock loading chute solves the problems of single-mode loading by providing a livestock loading chute which converts a dock loading livestock to a ground loading livestock trailer while retaining the trailer's ability to load livestock from a dock. When applicant's livestock loading chute is attached to a dock loading trailer, an unaided individual can switch from a dock loading configuration to a ground loading configuration—or from a ground loading configuration to a dock loading configuration—in about 30 seconds.
SUMMARY OF THE INVENTION
[0012] The livestock loading chute of present invention is suitable for attachment to the rear frame of any dock loading livestock trailer to permit either dock loading or ground loading of livestock. The livestock loading chute includes an upper chute section, attached to the rear frame of the trailer, and a lower chute section, which is supported by the upper chute section. The upper chute section, which is attached to the rear frame of the trailer in alignment with the trailer's roll-up door, contains an upper chute section ramp adjustable between a horizontal position (for dock loading) and an inclined position (for ground loading). The lower chute section is hinged to the upper chute section so the lower chute section swings around a rear corner of the upper chute section between a storage position, wherein the lower chute section is secured to the rear of the trailer alongside the upper chute section, and a ground loading position, wherein the lower chute section is aligned with the upper chute section. The lower chute section contains a lower chute section loading ramp which mates with the upper chute section ramp, when the upper chute section ramp is adjusted to the inclined position, to form a generally continuous ramp having an entry height of about 12 inches.
[0013] An object of the present invention is to provide a sturdy livestock loading chute which enables a livestock trailer to load and unload livestock either from a dock or from the ground.
[0014] Another object of the present invention is to provide a livestock loading chute for either ground loading or dock loading wherein the livestock loading chute can be manufactured as an integral part of a livestock trailer.
[0015] Yet another object of the present invention is to provide a livestock loading chute which permits an unaided individual to adjust the livestock loading chute between a ground loading position and a storage position for transport in about 30 seconds.
[0016] Yet another object of the present invention is to provide a livestock loading chute which enables a livestock trailer to load and unload livestock either from a dock or from the ground wherein the livestock loading chute is suitable for either steel or aluminum livestock trailers.
[0017] Yet another object of the present invention is to provide a livestock loading chute which enables a livestock trailer to load and unload livestock either from a dock or from the ground wherein the livestock loading chute can be retrofitted to an existing livestock trailer.
[0018] Yet another object of the present invention is to provide a livestock loading chute which enables a livestock trailer to load and unload livestock either from a dock or from the ground wherein the livestock loading chute adds no more than 3 additional feet to the length of the livestock trailer.
[0019] Other objects, features, and advantages of the present invention will become clear from the following description of the preferred embodiment when read in conjunction with the accompanying drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 shows the livestock loading chute of the present invention wherein the livestock loading chute is deployed in a ground loading position.
[0021] FIG. 2 is another view of the livestock loading chute shown of the present invention wherein the livestock loading chute is deployed in the ground loading position.
[0022] FIG. 3 is still another view of the livestock loading chute of the present invention wherein the livestock loading chute is deployed in the ground loading position.
[0023] FIG. 4 shows the livestock loading chute of the present invention wherein the lower chute section is in an intermediate position between the ground loading position shown in FIGS. 1-3 and a transport position shown in FIGS. 6, 7 , and 10 .
[0024] FIG. 5 is a the livestock loading chute of the present invention wherein the lower chute section is in an intermediate position between the ground loading position shown in FIGS. 1-3 and a transport position shown in FIGS. 6, 7 , and 10 .
[0025] FIG. 6 shows the livestock loading chute of the present invention wherein the lower chute section is in a transport position.
[0026] FIG. 7 is another view of the livestock loading chute of the present invention wherein the lower chute section is in a transport position.
[0027] FIG. 8 is an enlarged view, partially cut away, of the upper chute section of the present invention.
[0028] FIG. 9 is another enlarged view, partially cut away, of the upper chute section of the present invention.
[0029] FIG. 10 is an enlarged view, partially cut away, of the lower chute section of the livestock loading chute of the present invention.
[0030] FIG. 11 is side view of the upper chute section of the present invention, partially cut away to show the upper chute section adjustable ramp.
[0031] FIGS. 12-14 show apparatus for attaching applicant's livestock loading chute to the rear frame of a livestock trailer.
[0032] FIGS. 15-17 show another apparatus for attaching applicant's livestock loading chute invention to the rear frame of a livestock trailer.
[0033] FIGS. 18-20 show still other apparatus for attaching applicant's livestock loading chute invention to the rear frame of a livestock trailer.
DETAILED DESCRIPTION OF THE INVENTION
[0034] In the following description of the of the present invention, like numerals and characters designate like elements throughout the figures of the drawings.
[0035] Referring generally to the drawings and more particularly to FIGS. 1-3 , a livestock loading chute 50 is shown in a ground loading position. An upper chute section 54 is welded to the rear trailer frame F of a potload livestock trailer T. A lower chute section 52 is aligned with the upper chute section 52 and secured to the upper chute section 52 by a boomer 56 . It will be understood by one skilled in the art that a boomer is a device commonly utilized to secure cargo during shipment.
[0036] Still referring to FIGS. 1-3 , vertical frame members 58 , 60 , 62 , 64 cooperate with horizontal frame members 66 , 68 , 70 , 72 , 74 , 76 , 78 , 80 (horizontal frame member 80 is not shown) to form an upper chute section frame 82 . The upper chute section frame 82 is reinforced by diagonal braces 84 , 86 , 88 , 90 and by horizontal braces 92 , 94 . Diagonal rods 96 extend between vertical frame members 58 , 62 and between vertical frame members 60 , 64 to prevent livestock from leaving the upper chute section 52 during the loading process. Upper chute section sides 98 on each side of the upper chute section 52 extend from the horizontal braces 92 , 94 upwardly to the diagonal braces 84 , 88 , respectively.
[0037] Still referring to FIGS. 1-3 , vertical frame members 100 , 102 , 104 , 106 cooperate with horizontal frame members 108 , 110 , 112 , 114 , 116 , 118 and also with diagonal frame member 120 , 122 to form a lower chute section frame 124 . The lower chute section frame 124 is reinforced by diagonal braces 126 , 128 , 130 , 132 . Lower chute section sides 134 extend between vertical frame members 100 , 102 and between vertical frame members 104 , 106 to prevent livestock from leaving the lower chute section 54 during the loading process. Lower chute section sides 134 on each side of the lower chute section 54 extend from the diagonal frame members 120 , 122 upwardly to the diagonal braces 126 , 130 , respectively.
[0038] Still referring to FIGS. 1-3 , a lower chute section ramp 136 is formed by diamond plate 138 (sometimes also known as tread plate) attached to lower chute ramp horizontal frame members 116 , 118 (See FIG. 4 ). Transverse rods 140 welded to the diamond plate 138 serve as traction cleats for livestock. A rubber bumper 142 is attached to the lower chute horizontal frame member 116 by fasteners (not shown) deployed in throughways 144 . The rubber bumper 142 protects the livestock from injury. The rubber bumper 142 also provides a cushion between the lower chute section 54 and the back B of the livestock trailer T when the lower chute section 54 is deployed in the transport position (See FIGS. 7 and 10 ).
[0039] Referring now to FIG. 1 , a ramp adjustment lever 146 is stored in a ramp adjustment lever holder 148 for use in conjunction with a ramp jack 150 (See FIG. 2 ).
[0040] Referring now to FIG. 2 , an upper chute section adjustable ramp 152 is formed by diamond plate 154 and transverse rods 156 . The transverse rods 156 , which are welded to the diamond plate 154 , provide increased traction for livestock. A rubber bumper 158 is attached to an upper chute section ramp support (not shown) by fasteners (not shown) deployed in throughways 160 . As shown in FIG. 2 , the lower chute section ramp 136 and the upper chute section adjustable ramp 152 cooperate to form a continuous ramp to support livestock as the livestock move from the ground, upwardly across the lower chute section ramp 136 , upwardly across the upper chute section adjustable ramp 152 , and into the livestock trailer T.
[0041] Still referring to FIG. 2 , D-rings 162 provide attachment points for securing the lower chute section 54 to corral gates or dock gates during the loading/unloading process.
[0042] Referring now to FIG. 3 , the lower chute section 54 is attached to and supported by the upper chute section 52 by an upper hinge assembly 164 and a lower hinge assembly 166 . In the presently preferred embodiment, each hinge assembly consists of two 5-inch by 18-inch plates and three 6-inch pipe sections. One plate of the upper hinge assembly 164 is attached to the lower chute section vertical frame member 106 . The other plate of the upper hinge assembly 164 is attached to the upper chute section vertical frame member 64 so the 6-inch pipe sections are in vertical alignment. The lower hinge assembly 166 is similarly attached to the lower chute section vertical frame member 106 and the upper chute section vertical frame member 64 .
[0043] Still referring to FIG. 3 , shown therein are electrical wires 168 , 170 . The electrical wires 168 , 170 provide power to brake lights and tail lights which are required in all states of the United States and in most foreign countries (See FIGS. 4, 6 , 7 , and 8 ).
[0044] In FIG. 3 , the trailer T is supported by its wheels on a surface S. The rubber bumper 142 attached to the lower chute section ramp 136 is a distance A above the plane of the surface S. The distance A, representing the distance livestock must step up when entering the lower chute section ramp 136 , is the entry height. In the presently preferred embodiment, the entry height A is about twelve inches.
[0045] Still referring to FIG. 3 , a plate 172 is attached to the lower end 174 of the upper chute section vertical frame member 60 . The plate 172 mates with and supports the lower end 176 of the lower chute section vertical frame member 104 when the lower chute section 54 is deployed in the transport position (See FIGS. 6-7 ).
[0046] Referring now to FIGS. 4-5 , the livestock loading chute of the present invention is shown in an intermediate position between the ground loading position shown in FIGS. 1-3 and the transport position shown in FIGS. 6, 7 , and 10 . The upper chute section adjustable ramp 152 is shown in the same position as in FIGS. 1-3 , i.e., in a position for ground loading of livestock. Lights 200 provide brake lights and tail lights when the trailer T is traveling with the lower chute section 54 in the transport position.
[0047] Referring now to FIG. 5 , the lower chute section 54 swings on hinge assemblies 164 , 166 along B. A chain 202 attached to the rear portion 204 of the trailer T is used to secure the lower chute section 54 in the transport position.
[0048] Referring now to FIGS. 6-10 , the livestock loading chute 50 of the present invention is shown in the transport position, i.e., in a position wherein the lower chute section 54 is secured to the trailer for travel on highways.
[0049] Referring now to FIG. 7 , the boomer 56 is used to secure the lower chute section 54 to the rear of the truck T when the lower chute section 54 is in the transport position.
[0050] Referring now to FIG. 8 , an enlarged view of the upper chute section 52 , partially cut away, shows the upper chute section adjustable ramp 152 in a horizontal dock loading position for loading livestock from a dock. The ramp adjustment lever 146 is engaging the ramp jack 150 . Two chains 206 attached to the upper chute section adjustable ramp 152 terminate in hooks 208 . The hooks 208 are received by slots 210 in the sides 98 of the upper chute section 52 to support the upper chute section adjustable ramp 152 in the horizontal position.
[0051] Referring now to FIG. 9 , an enlarged view of a portion of the upper chute section frame 82 shows the ramp adjustment lever 146 in the ramp adjustment lever holder 148 . An upper chute section ramp pivot rod 212 provides a pivot for the upper chute section adjustable ramp 152 (See FIG. 11 ). A chain 214 us used in conjunction with the boomer 56 to secure the lower chute section 54 to the upper chute section 52 .
[0052] Referring now to FIG. 10 , an enlarged view of the lower chute section 54 , partially cut away, shows the boomer 56 attached to the chain 202 to secure the lower chute section 54 to the rear of the trailer T in the transport position. The chain 202 is attached to a threaded eye-bolt 203 having an eye portion 205 and a threaded portion 207 . The eye portion 205 of the threaded eye-bolt 203 is secured to the frame F of the livestock trailer T. An appropriate link in the chain 202 is placed over the threaded portion 207 of the eye-bolt 203 and held in place by a nut 209 .
[0053] Referring now to FIG. 11 , the upper chute section adjustable ramp 152 pivots on the upper chute section adjustable ramp pivot rod 212 . The rubber bumper 142 moves along C as the upper chute section adjustable ramp moves between a ground loading position, indicated in solid lines, and a dock loading position, indicated in phantom lines.
[0054] It will be understood by one skilled in the art that the livestock loading chute 50 of the present invention can be attached to the rear frame of a livestock trailer in a variety of ways. For the purposes of FIGS. 1-11 , the livestock loading chute 50 is welded to the rear frame of the livestock trailer T. It will be further understood by one skilled in the art that the livestock loading chute 50 of the present invention can be constructed from steel, aluminum, stainless steel, or any convenient material compatible with the rear frame of the livestock trailer T.
[0055] Referring now to FIGS. 12-14 , four female receivers 216 welded to the rear frame F of the livestock trailer T receive mating male inserts 218 attached to the vertical frame members 58 , 60 of the upper chute section frame 82 . Latching pins 220 (See FIG. 14 ) extend through mating bores 222 , 224 in the female receivers 216 and the mating male inserts 218 , respectively to secure the livestock loading chute 50 to the rear frame F of the livestock trailer T.
[0056] Referring now to FIGS. 15-17 , four hinge assemblies are used to attach the livestock loading chute 50 to the rear frame F of the livestock trailer T. Each hinge assembly includes a female receiver hinge plate 226 , a male hinge plate 228 , and a hinge pin 230 . An L-shaped member 232 is welded to the center member of the rear frame F of the trailer T, and the two female receiver hinge plates 226 located near the center of the rear of the livestock trailer T are attached to the L-shaped member.
[0057] Referring now to FIGS. 18-20 , the vertical frame members 58 , 60 include four bores 234 (two bores 234 in each vertical frame member). Four sleeves 236 are welded to the rear frame F of the livestock trailer T in alignment with the four bores 234 . A threaded bolt 238 is inserted simultaneously through each of the bores 234 and each of the sleeves 236 . A washer 240 is placed on the threaded end of the threaded bolt 238 adjacent the sleeve 236 . A nut 242 is tightened on the threaded bolt 238 to secure the livestock loading chute to the rear frame F of the livestock trailer T.
[0058] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. | A livestock loading chute is suitable for attachment to the rear frame of any dock loading livestock trailer to permit either dock loading or ground loading of livestock. The livestock loading chute includes an upper chute section, attached to the rear frame of the trailer, and a lower chute section, which is supported by the upper chute section. The upper chute section, which is aligned with the trailer's roll-up door, contains an upper chute section ramp adjustable between a horizontal position for dock loading and an inclined position for use in conjunction with the lower chute section for ground loading. | 1 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to safety screens to prevent workers from falling from edges of building-construction precipices that include stair wells, elevator shafts, windows, balconies and from other high edges and openings in buildings under construction and with scaffolding used in performing exterior work thereon.
[0002] Safety barriers and nets to prevent workers from falling into stair wells, into elevator shafts, out of windows and from other high portions of buildings under construction or scaffolding are known. None are known, however to have opening-height closure, restraint reliability and cost-effectiveness in a manner taught by this invention.
[0003] Examples of most-closely related known but different restraints against accidental falling from construction precipices are described in the following patent documents:
U.S. Pat. No. Inventor Issue Date 6,068,085 Denny, et al. May 30, 2000 6,182,790 Denny, et al. Feb. 06, 2001 5,582,266 Rexroad, et al. Dec. 10, 1996 4,815,562 Denny, et al. Mar. 28, 1989 4,875,549 Denny, et al. Oct. 24, 1989 3,480,069 Handwerker Nov. 25, 1969 3,805,816 Nolte Apr. 23, 1974 4,986,389 Halligan, Sr., et al. Jan. 22, 1991
[0004] Currently at building precipices, two-by-four boards nailed about forty-two inches high is the most common prevention against accidental falling into stair wells, into elevator shafts, out of windows and from other high portions of buildings under construction. Other known restraints against falling, such as described in the above prior art have not been adopted for effective use in the construction industry. An urgent need remains for effective building-precipice fall protection.
SUMMARY OF THE INVENTION
[0005] Objects of patentable novelty and utility taught by this invention, therefore, are to provide a construction safety screen which:
[0006] closes entire worker-area openings and precipices of construction buildings and scaffolding as appropriate to prevent accidental falling therefrom;
[0007] allows working ventilation and visibility;
[0008] can be put in place for temporary use and removed quickly and conveniently;
[0009] can be stored and reused;
[0010] can be customized for construction-precipice features;
[0011] is readily visible;
[0012] can be positioned inwardly from, in line with or outside of edges of building precipices;
[0013] can be tilted outwardly and upwardly to catch individuals who fall from work on or near outsides of buildings;
[0014] is reliable, sturdy and long-lasting; and
[0015] is cost-effective.
[0016] This invention accomplishes these and other objectives with a construction safety screen having structural capacity to screen predetermined portions of or entire worker-area openings and other precipices of under-construction buildings and scaffolding against individuals accidentally falling therefrom. The construction safety screen includes a fastening border, building-structure fasteners, netting apertures, visibility coloring, size adaptors and buckles, base rods, net struts, framework and guys. The net can be rolled up for light-weight shipping or storage and unrolled easily and conveniently for use and reuse.
[0017] The above and other objects, features and advantages of the present invention should become even more readily apparent to those skilled in the art upon a reading of the following detailed description in conjunction with the drawings wherein there is shown and described illustrative embodiments of the invention.
BRIEF DESCRIPTION OF DRAWINGS
[0018] This invention is described by appended claims in relation to description of a preferred embodiment with reference to the following drawings which are explained briefly as follows:
[0019] [0019]FIG. 1 is a partially cutaway front elevation view of a multi-story apartment building under construction with the construction safety screen positioned at edges of precipices that include stairways, and balconies;
[0020] [0020]FIG. 2 is a partially cutaway enlarged view of the construction safety screen positioned in place in a building aperture;
[0021] [0021]FIG. 3 is a side view of a straight hook bolt for hanging the construction safety screen to a top of a precipice framework;
[0022] [0022]FIG. 4 is a side view of a centered hook bolt for hanging the construction safety screen to the top of the precipice framework;
[0023] [0023]FIG. 5 is a side view of an eye bolt for anchoring the construction safety screen to a bottom of the precipice framework;
[0024] [0024]FIG. 6 is a partially cutaway side view of a fastener socket for screwing the hook bolt and the eye bolt into and out from construction framework that can include concrete, wooden and other bio-materials;
[0025] [0025]FIG. 7 is a bottom view of the FIG. 6 illustration;
[0026] [0026]FIG. 8 is a partially cutaway front elevation view of a plurality of the construction safety screens covering a long precipice and attached end-to-end;
[0027] [0027]FIG. 9 is a fragmentary view of a double-ring buckle on a fastening border as an optional buckle for adjusting length of a fastening line to the eye bolt;
[0028] [0028]FIG. 10 is a partially cutaway side view of the double-ring buckle with the attachment line attached to the eye bolt;
[0029] [0029]FIG. 11 is a fragmentary side view of the fastening border with a strap orifice for optional use of a predetermined standard belt buckle for attaching the eye bolt to the attachment line;
[0030] [0030]FIG. 12 is a partially cutaway side view of the fastening border with the strap orifice for optional use of the standard belt buckle for attaching the eye bolt to the attachment line;
[0031] [0031]FIG. 13 is a fragmentary view of a potion of the fastening border having a buckle with optional quick disconnection shown from a top;
[0032] [0032]FIG. 14 is a section view of the FIG. 13 quick disconnection shown through section line 13 - 13 of FIG. 13;
[0033] [0033]FIG. 15 is a fragmentary top view of the fastening border with the quick-disconnection;
[0034] [0034]FIG. 16 is a side view of the eye bolt positioned to receive a section of a quick-disconnect line on which a quick disconnection is positioned;
[0035] [0035]FIG. 17 is a partially cutaway side view of the quick-disconnect line on which a quick disconnection is positioned;
[0036] [0036]FIG. 18 is a front view of the eye bolt positioned to receive the quick-disconnect line;
[0037] [0037]FIG. 19 is a top view of the quick-disconnect line;
[0038] [0038]FIG. 20 is a partially cutaway side view of the eye bolt to which the quick-disconnect line is connected and with the quick-disconnect line connected to the fastening border with a quick disconnection on the fastening border;
[0039] [0039]FIG. 21 is a fragmentary side view of a precipice that is a building aperture having a precipice top to which the hook bolt is attached and an precipice bottom to which the eye bolt is attached with the construction safety screen attached to them;
[0040] [0040]FIG. 22 is the fragmentary side view of the building aperture with a building-structure fastener that includes a base rod having an edge end proximate a precipice edge, an anchor end anchored to a precipice floor and a guy intermediate a frame top and the anchor end of the base rod;
[0041] [0041]FIG. 23 is an attachment-side view of the FIG. 22 illustration;
[0042] [0042]FIG. 24 is a partially cutaway side view of a precipice edge not having a precipice top or precipice side and with the base rod extended outwardly over the precipice edge;
[0043] [0043]FIG. 25 is a partially cutaway side view of the precipice edge of the FIG. 24 illustration with the construction safety screen slanted from the base rod as fall protection of individuals doing outside finish work and other work at or near outside edges of buildings under construction;
[0044] [0044]FIG. 26 is a front elevation view of another embodiment of the safety screen with reinforcement straps and snap ring fasteners; and
[0045] [0045]FIG. 27 is a front elevation view of the safety screen with snap ring fasteners being used on a scaffold.
DESCRIPTION OF PREFERRED EMBODIMENT
[0046] Listed numerically below with reference to the drawings are terms used to describe features of this invention. These terms and numbers assigned to them designate the same features throughout this description.
1. Construction safety screen 2. Building under construction 3. Stairwell 4. Balcony 5. See-through aperture 6. Netting material 7. Fastening border 8. Precipice top 9. Precipice bottom 10. Precipice sides 11. Attachment line 12. Eye bolt 13. Hook bolt 14. Centered Hook bolt 15. Fastener socket 16. Fastener bay 17. Socket-wrench connection 18. Double-ring buckles 19. Flat-strap buckles 20. Strap orifice 21. Quick-disconnect line 22. Quick disconnection 23. Quick-disconnection eyes 24. Double-point ratchets 25. Ratchet hooks 26. Outward-tension member 27. Closure inclines 28. Base rod 29. Precipice floor 30. Edge end 31. Anchor end 32. Precipice edge 33. Floor-anchor position 34. Net strut 35. Frame bottom 36. Frame top 37. Guy 38. Hinge 39. Adjustable fastening strap 40. Net border generally 41. Box stitching 42. Adjustable buckle 43. Swivel snap ring 44. Netting 45. Horizontal reinforcement straps 46. Vertical reinforcement strap 47. Intermediate section of horizontal reinforcement strap 48. Bottom border 49. Top border 50. Side border 51. Scaffold staging ends 52. Straps 53. Snap rings 54. Netting 55. Border
[0047] Referring to FIGS. 1 - 2 , a construction safety screen 1 is sized and shaped to screen a portion of a precipice of a building 2 under construction, the precipice including a stairwell 3 and a balcony 4 . The construction safety screen 1 includes see-through apertures 5 that preferably are two-to-six-inches square to screen against passage of a human body and surrounded by netting material 6 having strength to support weight of the human body predeterminedly to prevent individuals from falling from the precipice.
[0048] The construction safety screen 1 includes a fastening border 7 for fastening it to building-structure fasteners that are attached detachably to predetermined building structure which can include a precipice top 8 , a precipice bottom 9 and precipice sides 10 that can be building-aperture walls and optionally structural members thereat. Attachment lines 11 having adjustable length are extended intermediate an eye bolt 12 and the fastening border 7 at the precipice bottom 9 and at the precipice sides 10 . A hook bolt 13 is used to hang the construction safety screen 1 from the precipice top 8 .
[0049] Referring to FIGS. 1 - 7 , the eye bolt 12 and the hook bolt 13 can be structured designedly for sizes and shapes of attachment lines 11 and for centering with a centered hook bolt 14 .
[0050] For screwing the eye bolt 12 , the hook bolt 13 and the centered hook bolt 14 in and out of hard building material that can include concrete, a fastener socket 15 , shown in FIGS. 6 - 7 , is provided with a fastener bay 16 having a laterally long portion to receive eye portions of the eye bolt 12 and a shorter but deeper portion to receive hook portions of the hook bolt 13 and the centered hook bolt 14 . A socket-wrench connection 17 can be sized and shaped to receive a wrench socket and a socket-wrench handle that are not shown. The centered hook bolt 14 is provided for concentric wrenching and thread-fastening.
[0051] Concrete of building precipices can be set with the eye bolt 12 , the hook bolt 13 and/or the centered hook bolt 14 therein or with bays to receive them. Optionally, the concrete can be drilled with a concrete bit on a motorized drill.
[0052] As shown in FIG. 8, a plurality of the construction safety screens 1 can be joined end-to-end with attachment lines 11 that are buckled together, attached to the precipice top 8 with the hook bolts 13 or centered hook bolts 14 and attached to the precipice bottom 9 with the attachment lines 11 and the eye bolts 12 .
[0053] Referring to FIGS. 2, 8 and 9 - 12 , the attachment lines 11 can have length-adjustment attachment intermediate the eye bolt 12 and the fastening border 7 with double-ring buckles 18 that are attached to the fastening border 7 . Optionally as shown in FIGS. 11 - 12 , standard flat-strap buckles 19 can be used in combination with a strap orifice 20 in the fastening border 7 . A first end of the attachment line 11 is attached to the eye bolt 12 and a second end is attached to the fastening border 7 .
[0054] Preferably, the construction safety screen 1 has visibility coloration that includes yellow for the netting material 6 , orange for the fastening border 7 , pink for the attachment lines 11 , blue for the buckles 18 and blue for the building-structure fasteners 12 , 13 , 14 and 28 .
[0055] Referring to FIGS. 13 - 20 , convenient and fast connection to and disconnection from the eye bolts 12 can be provided with quick-disconnect lines 21 . The quick-disconnect lines 21 have first line ends attached to the building-structure fastener, which includes the eye bolt 12 , with a quick disconnection 22 on the quick-disconnect line 21 . A second end of the quick-disconnect line 21 is attached to the fastening border 7 with a quick disconnection 22 on the fastening border 7 .
[0056] The quick disconnection 22 can include a spring-hook projection that spring-hooks into quick-disconnection eyes 23 that are suitably bordered apertures spaced apart along the quick-disconnect lines 21 . The quick disconnection 22 includes double-point ratchets 24 that are juxtaposed with ratchet hooks 25 oppositely disposed and extended resiliently from the first line end of the quick-disconnect line 21 and from the fastening border 7 respectively to which they are attached. The double-point ratchets 24 are forced inwardly towards each other against spring force of preferably an outward-tension member 26 by insertion into the quick-disconnection eyes 23 which slide against closure inclines 27 . The quick disconnections 22 are removed by finger-squeezing the double-point ratchets 24 together and pushing them out from the quick-disconnection eyes 23 .
[0057] This allows fast, convenient and secure connection and disconnection that cannot be disconnected or loosened accidently.
[0058] Referring to FIGS. 21 - 23 , optionally to attachment of the eye bolt 12 and the centered hook bolt 14 to edge portions of the building precipice depicted in FIG. 21, the building-structure fasteners can include a base rod 28 that rests on a precipice floor 29 as depicted in FIGS. 22 - 23 . The base rod 28 includes an edge end 30 and an anchor end 31 . The edge end 30 is positioned selectively proximate a precipice edge 32 and the anchor end 31 is positioned inwardly from the precipice edge 32 at proximate a floor-anchor position 33 where it is anchored preferably but not necessarily with the eye bolt 12 . One or more net struts 34 are extended vertically upward from the edge end 30 of the base rod 28 . A frame bottom 35 is extended horizontally from proximate a bottom of the net strut 34 . A frame top 36 is extended horizontally from proximate a top of the net strut 34 .
[0059] The fastening border 7 has a bottom edge that is attached to the frame bottom 35 and a top edge that is attached to the frame top 36 . A guy 37 , which can be a flexible line or a rigid member, is positioned intermediate a top end of the net strut 34 and the anchor end 31 of base rod 28 to brace the net strut 34 , the construction safety screen 1 and framework to which it is attached from falling outwardly.
[0060] The net strut 34 can be attached to the base rod 28 with a hinge 38 for ease of reuse and storage.
[0061] A plurality of the base rods 28 and the net struts 34 can be employed for wide building precipices.
[0062] The edge end 30 of the base rod 28 can be positioned as close to or on either side of the precipice edge 32 . This allows screening building precipices that do not have any structure or adequate structure at sides and tops to which the construction safety screen 1 can be anchored or attached directly. With the base rod 28 extended over the precipice edge 32 , the net struts 34 can be oriented or tilted to position the construction safety screen 1 for catching individuals who fall from outsides of buildings when doing final or other outside work. This also allows walling of entire sides or side portions of buildings for protection against falling during outside or near-precipice work on buildings.
[0063] Referring to FIGS. 24 - 25 , the base rod 28 can be extended over precipice edges 32 which have only the precipice floor 29 for suitable attachment. Additionally with this embodiment, the construction safety screen 1 can be slanted as fall protection of individuals doing outside finish work at or near outside edges of buildings under construction. The guy 37 can support the frame top 36 and the net strut 34 in a select orientation with protective positioning at particularly dangerous building precipices.
[0064] [0064]FIG. 26 shows a safety screen wherein the fastening straps 39 are all adjustable. The safety screen is made of netting 44 surrounded by a net border 40 to which the adjustable fastening straps 39 are attached on all four sides, approximately every two feet, using a very strong box stitching 41 . All straps 39 are adjustable by suing a common adjustment buckle 42 .
[0065] Stitched to the end of all straps is a swivel snap ring 43 which makes the safety screen attachable and detachable by both sides. The snap ring 43 also connects each section of screen to other screens and allows the screen to cover different size openings.
[0066] Horizontal reinforcement straps 45 are stitched to the border 40 and a vertical reinforcement strap 46 . The intermediate section of the horizontal reinforcement strap 47 between the border 40 and the vertical reinforcement strap 46 is not attached to the netting 44 , so in the case that the bottom border 48 of the safety screen was not properly fastened or fastened at all and a worker fell horizontal reinforcement straps 45 will serve as a grab line. These reinforcement straps 45 also create the protection needed if the netting 44 itself was cut or torn. The reinforcement straps are located at the heights required to be in compliance with OSHA regulations. Even if the safety screen is not fastened at the bottom border 48 or at the top border 49 , so long as the screen is fastened at the side borders 50 , it is safe, strong and in compliance. This added feature also gives the worker the ability to detach the top border 44 of the safety screen and let the netting 44 fold over when the completion of upper portion of the work area has occurred and still be in compliance with current regulations.
[0067] The safety screen also may be fastened to steel beans without penetrating the steel. This is possible by attaching longer adjustable straps to the borders which then may be wrapped around the steel beams and attached by the snap rings 43 to a D-ring (not shown) attached to the border 40 . Such a design may be necessary for steel erected structures where penetrations are prohibited, such as nuclear power plants.
[0068] Other features, such as zipper fasteners or snap-on plastic covers may also be used, particularly to provide protection in cold climates.
[0069] The safety screen system of the present invention also provides vertical fall prevention in common construction scaffolding. As illustrated in FIG. 27, the safety screen may be installed at the end 51 of staging levels, attached by straps 52 and snap rings 53 operable by the border 54 surrounding the netting 55 . The safety screen may also be attached to the end of outrigger work areas at each scaffold level by suing the same strap and snap ring fastening system. This same type of netting will also be installed inside the walk-thru area of the staging attached to the center supports of the scaffolding which provides fall prevention from a worker's feet to head along the entire working area. At the top level of scaffolding the safety screen may also be installed to provide a debris barrier as well as a brightly colored safety system which will quickly alert workers to an un-safe working area.
[0070] This product may also be installed in different sections of the scaffolding to provide easy access to scaffolding stairways and ladders and prevent falls while climbing and descending to the work areas. In addition, the safety screen also provide areas to attach signs to the netting 55 , such as “Scaffold Ladder,” “Stairway,” “Caution-Men Working Above” and so forth.
[0071] A new and useful construction safety screen having been described, all such foreseeable modifications, adaptations, substitutions of equivalents, mathematical possibilities of combinations of parts, pluralities of parts, applications and forms thereof as described by the following claims and not precluded by prior art are included in this invention. | A construction safety screen ( 1 ) has structural capacity to wall predetermined portions of or entire worker-area precipices which include apertures and edges of under-construction buildings and scaffolding against accidental falling. Included are a fastening border ( 7 ), fasteners ( 12, 13, 14, 28, 43 ), netting apertures ( 5 ), netting material ( 6 ), visibility coloring and size adaptors. It can be rolled up for light-weight shipping or storage and unrolled easily and conveniently for use and reuse. | 4 |
BACKGROUND OF THE INVENTION
1. The Field of The Invention
This invention relates to means for distributing hot gas on a moving sheet of paper.
2. State of the Art
In most paper products it is desirable to automatically control the cross machine moisture content using a steam shower or steam distributor. Most paper machines have continuous moisture scanners which read the sheet moisture content across the machine as the paper is manufactured. The information from this continuous measurement can be fed into a controlling computer and the steam flow in the steam distributor can be automatically controlled according to this information.
One type of steam distributor is taught in U.S. Pat. No. 4,253,247. The patent teaches a multi-chambered steam hood with means of steam distribution to each chamber provided by a steam distributor. Steam flows from the steam distributor through ports into a nozzle and into each chamber. The steam flow is controlled by raising or lowering a control plug.
According to the patent the plug has a piston ring located around its periphery. It is believed that a piston ring in such a location would substantially prevent any flow of steam into the chamber when the plug is in the closed position. This could lead to cooling of parts of the chamber and condensation of steam to liquid water therein. The liquid water could drop from the chamber onto the paper thereby producing local discoloration called streaking.
OBJECT OF THE INVENTION
An object of the present invention is to provide a steam distribution system with valve means to prevent condensation of steam and streaking of the paper.
Further objects and advantages of the invention can be ascertained by reference to the specification and drawings which are provided by way of example and not in limitation of the invention, which is defined by the claims and equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a paper making machine including a steam distributor;
FIG. 2 is an isometric illustration of a present embodiment;
FIG. 3 is a cross sectional illustration of a present embodiment;
FIG. 4 is another cross sectional illustration of the present embodiment.
FIG. 5 is a cross sectional view of FIG. 4 taken along line 5--5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
There is shown in FIG. 1 a paper making machine 10 including a hot gas distributor 12. In practice steam is normally used; however in some applications other hot gases could be substituted. Herein the word steam will be used to mean steam or such other hot gas. The machine shown is of the Fourdrinier type and includes a pulp box 14 feeding pulp mixture 16 to a web-like conveyor 18 on which the liquid is drawn from the pulp to leave a paper web 20, which travels partially dried under the distributor 20 and over vacuum box 22, a press section 26, further dryers (not shown) and a known moisture measuring device (not shown) which measures the moisture content across the sheet. The distributor is adjusted manually or automatically to reduce the moisture variations in the cross direction.
As shown in FIG. 2 the steam distributor 12 includes a hood 38 having end plates 30 at each end, each supported by a pair of legs 32 carried by feet 34 mounted on the conveyor frame (not shown) outside the path of the conveyor. A pipe 36 is supported by the end plates 30. A steam pipe 40 supplies a hot gas, in the present instance, steam from a suitable source to the pipe 36. The hood 38 includes outer shell 42, an inner shell 44 and insulation 46 which together form side walls 47 and 49. Transverse partitions 48 divide the hood into a plurality of chambers or compartments 50 spanning the entire width of the web 20. Tubes 52, individual to the compartments having ports 51 each supplies steam to its compartment in accordance with the setting of a pneumatic valve 56 individual to that chamber and controlled by the moisture profile measuring device or manually. The steam travels through the pipe 36, through ports 51 into the tubular nozzles 52, through the nozzles into the chambers 50, through slotted, arcuate diffusing plates 60, through the web 20 and a supporting screen or vacuum box cover 62 forming the top of a vacuum box 22. The diffusion plates may be drilled plates of different patterns. The plates may be omitted to leave an open bottom chamber.
Turning to FIG. 3, the sidewalls 47 and 49 of the chamber 50 are spaced apart from paper web 20 so that spaces 70 and 72 are formed therebetween. In practice, we have found it desirable to space the sidewalls 47 and 49 about four inches above the paper web 20. Hinges 74 and 76 are mounted along the bottoms of side walls 47 and 49 and plates 78 and 80 are affixed one to each hinge. The plates are of sufficient height to extend from the hinges to about three quarter inch above the paper web 20.
FIG. 4 shows the valve 56 in cross section. The valve 56 includes a bellows member 82 including a cap 84 with a part 86 formed therein to permit connection to a source of fluid, not shown, for actuating the bellows. The bellows 82 also includes a base member 88 which is affixed to the upper part of hood 38 by support members 90. A plunger 92 is disposed inside the base 88, and a flexible diaphragm 93 is coupled between the edges of the cap 82 and base 88 to contain the working fluid in cavity 94. The plunger 92 is affixed to the diaphragm 93 so that when the cavity 94 is filled with working fluid, the plunger 92 is forced downward. A rod 96 is coupled to the plunger 92 and extends downward therefrom. The rod 96 is constructed and arranged to move slidably in a first brushing 99 and a second brushing 100. The second bushing 100 is coupled to the upper end of the nozzle 52, and the nozzle is set in a retainer member 102 which is welded to the pipe 36. The pipe 36 has a port 104 to permit the nozzle to extend therethrough, and the nozzle 52 has a groove 106 in its upper end which is compatible with a snap ring 108 to hold the nozzle 52 in place.
The rod 96 has a conical end 109 which is welded to a plate 110, and the plate in turn is connected to a hollow, cylindrical sleeve 112. The sleeve 112 has an outside diameter which is about 0.004 inch less than the inside diameter of the nozzle 52, and the sides of the sleeve 112 are substantially smooth and without a groove or any seal member or the like. The nozzle 52 includes two ports 114, one of which is shown in FIG. 4, and the sleeve 112 is located so that when it is in its uppermost or maximum closed position some steam can flow through the ports 114 and downward through the space between the sleeve and the nozzle 52 and through the interior of the sleeve. Of course, the flow of steam is significantly restricted because the port 114 is substantially blocked by the nozzle 52. When the sleeve 112 moves downward, the ports 114 are exposed thus permitting a controllable flow of steam to enter the nozzle 52 and flow primarily through the interior of the sleeve 112.
In operation fluid is controllably introduced into the cavity 94 thus causing the sleeve 112 to move downward a controllable distance against the force of the spring 98. Thus, the rate of flow of steam through the nozzle 52 is controlled. When the sleeve 112 is in its maximum closed, i.e. uppermost position, the upper edge of the sleeve 112 is above the upper edges of the ports 114. However, a slight flow of steam is still permitted which thus keeps the nozzles 52 and other parts of the hood 38 warm thereby reducing or eliminating condensation.
It should be understood that the sleeve 112 can be closed at its top. In this case the maximum open position of the sleeve 112 would be completely above the ports 114, so that filling the cavity 94 with fluid would close the ports 114, and releasing fluid from the cavity 94 would open the ports.
Steam is introduced into the hood 38 and vacuum is applied to the vacuum box 22 so that the pressure in the hood is near ambient. In this case the plates 78 and 80 are vertical as indicated by plate 78 in FIG. 3 so that no substantial quantity of steam escapes to the atmosphere and no substantial quantities of ambient air enters the hood. However, if through operator error or mechanical failure steam is not introduced through pipe 36 while vacuum is applied to the box 64, ambient air is drawn into the hood as indicated by the arrows, and the plate is opened by the air flow as shown by plate 80. Thus the vacuum does not exert downward force on the hood 38. It should be understood that the downward force on the hood 38 could be extreme, if not for the present invention. For example, for a hood 60 inches in width and 300 inches in length 90,000 pounds of force would be exerted by a vacuum of five pounds per square inch, which is not uncommon.
In some applications it could be necessary to have only one plate 78 or 80 rather than both plates. In such a case sidewall 47 or 49 would extend downward to near the paper mat 20. However, in practice I have found it generally desirable to utilize two plates which will move slightly to accommodate high spots in the paper mat thus insuring that the mat will not build up against a sidewall. | The specification discloses a steam distributor having a chamber to contain steam on one side of a paper web and a vacuum box on the opposite side of the paper web. The distributor has a feeding system for controlling the rate at which hot gas is applied to the paper. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of PPA Ser. No. 61/107,429, filed Oct. 22, 2008 by the present inventors, which is incorporated by reference.
FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
SEQUENCE LISTING OR PROGRAM
[0003] Not Applicable
BACKGROUND
[0004] 1. Field of Invention
[0005] This invention pertains to a device for monitoring the health status of a patient and, more specifically to a mechanism for rapidly applying such a monitoring device to a wearer's extremity, and for improving and stabilizing subsequent monitoring device measurements from external disturbances.
[0006] 2. Prior Art
[0007] Subsequent to a mass casualty incident (MCI), when there are more patients than can be instantaneously cared for, it is important to triage the patients. Triage is the utilitarian process of putting the patients into an order based on priority, so that available medical resources are allocated in as sensible a fashion as possible; proverbially, to do “the greatest good for the greatest number”. Most triage systems make use of blood pressure measurements, specifically, systolic blood pressure. For instance, the Revised Trauma Score, the Pre-hospital Index, the Triage Index, and the CRAMS scale (Circulation, Respiration, Abdomen, Motor, Speech) all involve systolic blood pressure data in a formula that yields a “severity score” for the patient, which quantifies the severity of the patient's condition after a traumatic event, as suggested, for example, by Kennedy, et al., Triage: techniques and applications in decision making, 28(2), Ann Emerg Med, (1996), pp. 136-44.
[0008] Also, while triage is important as an initial response to a mass casualty event, it is also essential that patients be continually re-assessed, because the rapid initial triage is imperfect at identification of major problems, and therefore, it is essential that those patients who, initially, do not appear to have severe injuries are monitored and re-evaluated as best as possible, though in practice, first responders will have many competing demands for their attention. It would be ideal to have the means to re-perform triage screening and scoring continually, through time, to identify patients with life-threatening conditions that were not initially appreciated.
[0009] One challenge of triage is that there is simply no suitable solution for measurement of SBP for situations such as those subsequent to an MCI. The familiar oscillometric blood pressure (BP) cuff is problematic to use in uncontrolled environments. U.S. Pat. No. 7,014,611 to Geddes et al. (2006) shows a noninvasive oscillometric blood pressure monitor. The familiar BP cuff must be wrapped around a patient's arm, and in many cases, neatly wrapped around itself so that it can be held in place by Velcro or Velcro-like fasteners. For the proper use of a conventional BP cuff, it is also important that the cuff is wrapped so that its inflatable bladder overlies the patient's brachial artery. If the cuff is wrapped with any physical irregularity, the BP cuff may not be well fastened by the Velcro, or the BP cuff may make erroneous measurements during inflation. Properly wrapping the cuff may take some care in normal clinical circumstances, and there is ample evidence that clinicians often do not use proper technique even for routine doctor visits, such as was reported by Jones, et al., Measuring blood pressure accurately: new and persistent challenges, 289(8), JAMA, (2003), pp. 1027-1030.
[0010] Considering that poor measurement technique involving BP cuffs is a challenge in a doctor's office appointment, it is undeniably a major challenge in the chaotic environment after an MCI, such as a train crash. In such circumstances it is very difficult to properly wrap the cuff, especially when patients may be uncooperative (due to panic, unconsciousness or severe pain), when patients may be wearing bulky clothing encumbering their upper arms, or when patients may be obese. As well, standard BP cuffs involve careful measurements of pulsations at given cuff pressures, and this technique is vulnerable to measurement errors caused by patient movement. Asking a patient to hold still in the chaotic aftermath of a MCI is also a challenge. What would be ideal is to have reliable, accurate blood pressure data, specifically SBP as well as other vital signs, available for mass casualty patients via a new tool or method that (a) could be quickly and easily applied by first responders without much effort; (b) require minimal patient cooperation; and (c) provide the means to continually reassess SBP with minimal risk of the device becoming dislodged or improperly positioned.
[0011] To date, no pre-existing device offers a solution to the problem of rapid reliable BP measurement for MCI triage and subsequent continual, reliable monitoring. The Vasotrac, described by U.S. Pat. No. 5,450,852 to Archibald, et al. (1995) is a blood pressure monitoring device that clamps around the wrist of a patient. The blood pressure measuring mechanism involves a small gelatinous bulb that is pressed to the skin overlying the radial artery, and then the device uses a basic variation of the well-known oscillometric technique to measure arterial blood pressure. The Vasotrac is correctly positioned by means of a wrist guard that fits against the the ulnar eminence, and thus aligns a small gelatinous bulb in a typical location of the radial artery. However, the device is prone to misalignment, because if the bulb is not overlying the radial artery, the measurement is erroneous. The device requires careful initial positioning and then delicate closing by an attentive, trained user, making it impractical to use in emergent care.
[0012] U.S. Pat. No. 5,490,523 to Isaacson, et al. (1996) shows a finger clip pulse oximeter. A pulse oximeter's fingertip probe uses a clamp-like design to allow for ease of placement on the end of a finger. However, this design is mechanically unstable in its attachment to the subject, because the device has a tendency to slip off the end of a naturally tapered fingertip in the setting of any forceful hand movement, as may be experienced in challenging environments. Moreover, in the fingertip, there is no means to measure arterial blood pressure, a previously noted critically important parameter for optimal MCI triage, since the blood vessels of the nailbed are arteriolar or smaller (not arterial).
[0013] The use of a ring-type device for the finger base has been described by the research group of the inventors. Two examples of such devices are U.S. Pat. No. 5,964,701 to Asada et al. (1999) and Shaltis, et al., Novel Design for a Wearable, Rapidly Deployable, Triage Sensor, Proceedings from the 27 th Annual International Conference of the IEEE - EMBS, (2006), pp 3567-3570. However, the former Asada ring does not have a mechanical design that is appropriate for deployment a chaotic MCI setting: placing a closed ring on individual subjects' fingers would be infeasible given the range of finger base sizes and knuckles blocking the rings' application, and possibility of minimally-cooperative patient because of pain, etc.
[0014] Regarding the latter ring-type device, described by Shaltis, et al., this prior art is a single-piece, horseshoe-shaped device. This single-piece design has two non-obvious limitations. First, the single-piece design is not able to accommodate a wide range of finger types and sizes. For example, a single-piece sensor will not firmly attach to both a full-grown adult and then to a small child. The second non-obvious limitation is that this design employs the well-known oscillometric method for blood pressure measurement. However, as noted above, oscillometry is suboptimal for MCI triage and continual monitoring because it is prone to measurement error unless the patients holds very still during the measurement, which is an unlikely human response after an MCI. An innovative mechanical design that is easy to attach on a wide range of patients, without careful placement, while enabling a more robust method of measuring blood pressure, would advance the prior art.
[0015] It has been previously noted that systolic blood pressure (SBP) can be determined by assaying for the loss of measureable pulsations distal to a cuff that is being inflated; the threshold cuff pressure that causes the loss of distal pulsations is close to SBP. Such implementations are taught, for example, by Talke, Measurement of systolic blood pressure using pulse oximetry during helicopter flight, 19, Crit Care Med, (1991), pp. 934-937, Talke, et al., Does measurement of systolic blood pressure with a pulse oximeter correlate with conventional methods?, 6, J Clin Monit, (1990), pp. 5-9, and McCluskey, et al., Out - of - hospital use of a pulse oximeter to determine systolic blood pressures, 11, Prehospital Disaster Med, (1996), pp. 105-107. However, these citations involve standard hospital instrumentation, i.e., a blood pressure cuff on the upper arm and a pulse oximetry probe on the finger. There is no mention that a compact, rapidly attached device that provides both controlled pressure application and pulsation measurement could be developed. Moreover, there is no suggestion that this technique, in conjunction with a compact, rapidly attached device, would enable rapid deployment of a blood pressure monitor in challenging, uncontrolled environments in which casualties' blood pressure must be assessed and continually re-measured.
SUMMARY
[0016] {The Invention Summary will comport with the claims as filed.}
DRAWINGS—FIGURES
[0017] In the drawings, closely related figures have the same number but different alphabetic suffixes.
[0018] FIG. 1 is an isometric view of the clip assembly constructed in accordance with the invention;
[0019] FIG. 2A is a front view of the clip assembly from the view of looking down the length of the patient's finger;
[0020] FIG. 2B is a front view of the clip assembly when opened prior to placement on the patient's finger;
[0021] FIG. 3 is a side view of the clip assembly showing the exposed sensor components and conditioning boards that are contained within the housing. This figure also shows the torsion spring used for elastically loading the clip;
[0022] FIG. 4 is a top view of the clip assembly showing exposed sensor components and a conditioning board; and
[0023] FIG. 5 is a personal point of view perspective looking down at the clip assembly as it is worn by a patient.
[0024] FIG. 6 is an isometric view of the lever with a removable attachment for resizing the structural clip of the sensor.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 is an isometric view of the clip assembly 11 taken from a view that is angled slightly relative to the length of a patient's finger in accordance with the invention. The top of the clip 14 covers a hollow top sensor housing 15 which contains signal conditioning electronics and a user interface. The structural clip 12 half of the assembly can be opened ( FIG. 2B ) by pinching together the top housing contour 21 , which is fixed, and the lever 20 at the lever contour 13 . The structural clip 12 rotates about a central guiding rod 29 and returns to a closed position, as pictured, due to a force applied by the arm of a torsion spring 19 on the lever 20 . The stationary half of the clip assembly 11 is hollowed and contains both a detector array 17 and an emitter array 18 in this embodiment. The sensor arrays 17 and 18 and their associated electronics are shielded by an inner sensor cover 16 . The inner sensor cover 16 also serves as a surface which presses directly against the finger of the patient. The clip assembly is made of a durable plastic such as ABS or could be made of an alternative durable material such as a light-weight metal. The sensors in this design are optical sensors but could consist of an alternative sensor modality capable of measuring either a volume or a pressure.
[0026] FIG. 2A is a front view of the ring in a closed configuration. In this configuration, the clip assembly 11 and the structural clip 12 are in contact with each other and form a closed ring. Note that a flat inner wall 22 would be positioned along the side of the finger and creates a uniform surface for performing measurements. Note also that the bottom of the clip assembly 11 contains a contoured end 24 which helps prevent pinching of the skin of the patient's finger when the ring closes.
[0027] FIG. 2B is a front view of the ring in a partially opened configuration. In this configuration, the lever 20 has been moved in centrally toward the top sensor housing 15 . The inward movement of the lever 20 leads to a resized ring opening 23 at the bottom of the ring and provides for easy attachment to a wide range of finger sizes.
[0028] FIG. 3 is a side view of the ring with both the structural clip 12 and the inner sensor cover 16 removed. In this view we see the torsion spring 28 which applies a force to the lever (not shown) to keep the ring normally closed. The torsion spring 28 is kept in position by being placed about a guiding rod 29 running through the underside of the top sensor housing 15 . The removed inner sensor cover 16 exposes the inside of the clip housing, making visible the detector array 17 and an accompanying detector conditioning board 25 positioned along the length of the flat inner wall 22 . At the bottom of the ring the emitter array 18 and an accompanying emitter board 27 are also visible. In the present embodiment, the conditioning boards 25 and 27 are connected to a signal processing board (not shown) located within the top sensor housing 15 .
[0029] FIG. 4 is a top view of the ring with the clip top piece 14 removed. The view looks into the hollowed out portion of the top sensor housing 15 where a signal processing board 30 is situated. This board is connected to the conditioning boards (not shown) contained within the clip assembly 11 . Note how the top housing contour 21 serves as a stationary surface for pinching on the clip assembly 11 side of the ring while a similar contoured surface on the opposite side of the top sensor housing 15 provides an open space where the lever 20 can fit when the ring is opened.
[0030] FIG. 5 is a personal point of view perspective looking down at the clip assembly as it is worn by a patient. Here, we clearly see the clip top piece 14 aligned along the length of the finger. The lever 20 and associated lever grip contour 13 are clearly visible on the ring finger side of the device. Note how these components are not in the way of the neighboring finger and would be easily accessible to a care provider during deployment. Opposite to the lever grip contour 13 , we see the top housing contour 21 . The top housing contour 21 serves as an additional location for a care provider to squeeze when opening the clip assembly. Within the top sensor housing 15 , we see the guiding rod 29 around which both the torsion spring (not pictured) and the structural clip 12 pivot. Note how the structural clip 12 half of the assembly consists of a thin and smooth design to maximize patient comfort between the fingers. Opposite to the structural clip 12 is the clip assembly half of the ring. Again, this is the portion of the design that contains the detector array (not pictured) and the emitter array (not pictured).
[0031] FIG. 6 is an isometric view of the lever with a removable attachment for resizing the structural clip of the sensor. The lever 20 is attached to a removable structural clip 31 . The removable structural clip allows the curvature and shape of the sensor unit assembly to be changed to accommodate a wide range of patients when used in the field.
Operation
[0032] In its preferred embodiment, the device is applied to the bare finger of a trauma casualty. The device displays a clear visual indicator, located in the clip top piece 14 , that its battery charges are sufficient for prolonged field use, indicating to a medical responder which individual units are ready for field use. A medical responder pinches the levers 20 and 21 of the device (one lever 21 is actually the side of the top sensor housing 15 ), which opens the clip portions of the device 11 and 12 , as shown in FIG. 2A and FIG. 2B . These levers 20 and 21 are contoured 13 and covered in a high-friction surface, to make them easy to grip by medical responders, even in demanding environments, e.g., rain. The height of the top sensor housing 15 is enough for the responders to pinch, but minimal enough that the top sensor housing 15 does not protrude in an obtrusive way when worn by a casualty. In an alternative embodiment, the clip portions of the device 11 and 12 each possess a joint, and when the medical responder pinches the levers 20 and 21 , the clip portions 11 and 12 open, but also, there is articulation at each joint so that the distal elements of each clip flares open. In other words, the entire clip mechanism opens up due to rotation both at the guiding rod 29 , but also due to rotation in the joints along each clip portion 11 and 12 . When the medical responder releases the levers 20 and 21 , the device closes with two points of rotation for each clip portion 11 and 12 , and so the device firmly encloses the base of the subject's finger with reduced risk of pinching skin.
[0033] In the preferred embodiment, the device is placed around the thumb, pointer finger, or pinky finger of the casualty. The device has two contoured halves 11 and 12 , matching the contour of a typical human finger. The bulkier of the two halves 11 contains all the sensor elements 17 and 18 and electronics 25 and 26 . This bulkier half 11 is clearly labeled, to communicate to the responder that it should ideally face externally, facing open space and away from any fingers, so that it will be more comfortable to wear for the casualty. The structural half 12 is very thin, a structural component without any other functionality. Because it is so thin, it can comfortably be worn between two fingers, e.g., pinky and ring finger or pointer finger and long finger. When the medical responder releases the levers 20 and 21 , the spring-loaded clips 19 close and the device holds securely about the base of the finger, as shown in FIG. 5 . As the two halves close, they overlap in a tapered manner, and both have rounded edges 24 , so that the device completely encircles the finger without pinching the skin of the casualty. In one alternative embodiment, the two halves do not overlap, which also avoids pinching the skin of the casualty.
[0034] In another alternative embodiment, the devices are held open by some mechanical means, but when the mechanism is tripped, i.e. a button is depressed, the restraint is removed and the spring-loaded jaws automatically close around a finger. In another alternative embodiment, there is a simple mechanism to activate the sensing electronics, such as a button inside the band of the ring that is depressed when the sensor fits onto a finger, so that its batteries are not consumed prior to deployment. In one alternative embodiment, there is a simple locking mechanism, such as a latch, so that, once the jaws close around a finger, the locking mechanism holds the jaws closed. In alternative embodiments, the locking mechanism can either be automatic or alternatively, set and unset by the medical responder. In alternative embodiments, the device may have the means to be re-sized, to fit on larger and smaller (e.g. pediatric) digits. For instance, there may be the means to change the angle of the jaws at the pivot. Alternatively, there may be the means to adjust the curvature of one or both of the sensor halves 11 and 12 , or to replace one of the sensor halves using a removable structural clip, such as is illustrated in 31 .
[0035] Once the sensor is fit to the finger of a casualty, the spring-loaded pivot 12 , 19 , 20 holds the sensor in place. The compliant material within the ring ensures a snug fit, and that the device remains comfortable, too. In an alternative embodiment, there are small grooves within the interior surface, which establishes channels for sweat and water to drain. The top sensor housing 15 and the lever 20 restrict the rotation of the ring around the finger, so that the sensor elements 17 and 18 cannot become grossly misaligned with the digital artery at the base of the finger. The emitter array 18 illuminates the base of the finger, and a detector array 17 records the reflected optical signal. The device automatically identifies the optimal photodetector for measuring the PPG, automatically optimizes the signal, and begins measuring the continuous PPG signal, from which heart rate, oxygen saturation, and respiratory rate are computed. The threshold pressure above which the pulsatile PPG signal is lost is taken as the systolic blood pressure (SBP), which is measured on a continual basis. In an alternative embodiment, SBP is taken as a function of this threshold pressure. This SBP functionality requires using information from a motion sensor, to ensure that SBP is measured only when the patient's hand is in a known, stable orientation, e.g., horizontal; and to account for SBP measurements when the hand's orientation changes, e.g. pointing down or pointing up, which can alter the SBP that is measured in the hand. This same position sensing functionality may be applied to other physiologic measurements.
[0036] The pressure necessary for occluding the pulsatile PPG signal is provided by at least one of the following, the spring loading of the device's hinge, elasticity in the structural components of the ring, or physical action by the responder. The torsion spring 28 may be joined with or even replaced by a small motor that can be used to automatically close the clip portions 11 and 12 of the ring to apply pressure to the trauma casualty's extremity.
[0037] The device measures one or more physiologic signals, and processes them within the top sensor housing 15 . The device wirelessly transmits numeric vital signs every few seconds. The wireless transmissions from each deployed device may be received and monitored by a mobile computing unit, such as a phone or other portable computing device, or by a stationary base station. In alternative embodiments, the device may transmit full waveform data, or it may merely transmit a sparse summary priority status for triage purposes, e.g., “red”, “green”, “yellow”, or “black”, which is generated by automated processing of the physiologic data with a triage algorithm. In an alternative embodiment, the device emits a unique signal to help remote caregivers locate the individual casualty, who may be in need of urgent medical therapy. For instance, a remote medical responder may notice that the casualty condition has gone from “yellow” (urgent) to “red” (emergent), and may want to identify that casualty from amongst a large number of monitored casualties. Through wireless electronic communication, the medical responders may be able to initiate a homing signal that is either electromechanical or acoustic in nature. In an alternative embodiment, the acoustic speaker is also able to transmit verbal instructions to the casualty, sent from the medical responders by wireless electronic communication.
[0038] The device transmits data related to the status of the sensor, including a rating of the reliability of its physiologic measurements (e.g., if the waveform data appear physiologic or noisy) and related to its battery status. The device is able to automatically determine, and transmit, whether or not the device is applied to a finger. In the preferred embodiment, this is determined by a pressure sensor within the band of the ring 11 . In an alternative embodiment, alternative sensor modalities are employed, including the inner-ring photodetectors, which can detect the presence or absence of ambient light, as well as thermocouples both on the inner-ring and the exterior housing. In the alternative embodiment, an algorithm utilizes all the available sensor data to determine when the ring is attached to a finger. In an alternative embodiment, the algorithm uses the presence or absence of inner-ring temperature only when the ambient temperature, measured by the exterior housing thermocouple, is well below physiologic ranges of human body temperature.
[0039] In an alternative embodiment, the device is networked to a monitoring station that is observed by medical responders. In the alternative embodiment, the sensor data are processed, and all the aforementioned data are displayed, specifically, any measurements made directly by the sensor; any indices related to the quality of the measurements; and lastly, any overall assessment of the casualty that results from automated data processing of a ring sensor's data, which may include, but is not limited to: severity color-coding (e.g., red, green, etc.); severity scoring (e.g., the revised triage score, or a novel severity score); numerical triage priorities; and specific casualty conditions (e.g., major hemorrhage).
[0040] In an alternative embodiment, the device is altered so that it is large enough to fit over the wrist or ankle or other location on the extremity of a casualty, while preserving all the other aforementioned functionality.
[0041] From the description above, a number of advantages of some embodiments of our rapidly deployable sensor design become evident:
[0042] (a) A care provider is able to use a simple, familiar, and relatively effortless pinching motion to rapidly attach the proposed device to a patient's extremity, minimizing the time required to begin assessment of a trauma casualty and establish the means to automatically monitor the casualty through time.
[0043] (b) The device completely encircles the circumference of the patient's extremity, so that it is securely and comfortably attached, while applying a suitably uniform loading about the instrumented segment of the extremity.
[0044] (c) Using a plurality of rigid components attached by one or more hinges provides a means to adjust the angle of the rigid components so that the device can conform to a wide range of finger shapes and sizes.
[0045] (d) Employing an unconventional method to measure SBP, rather than employing conventional Oscillometry, provides the means to assess SBP without the unrealistic expectation that supervised or unsupervised MCI casualties would be willing to remain voluntarily motionless during the time it takes to make an Oscillometric BP measurement. Together with heart rate and respiratory rate, SBP is an essential metric of circulatory function in trauma patients, and a standard input to a plurality of well-known triage methods and triage scoring systems (The photoplethysmographic sensors offer the means to measure and monitor HR and RR).
[0046] (e) The encircling design of the sensor will permit accurate patient monitoring in a wide range of device orientations, making it easier to deploy rapidly.
CONCLUSION, RAMIFICATIONS, AND SCOPE
[0047] Accordingly the reader will see that the rapidly deployable sensors of the various embodiments can be attached quickly, securely, and comfortably, to obtain vital signs from a patient in emergent monitoring scenarios, and demonstrates a design that can provide robust measurements of vital signs including systolic blood pressure even in the aftermath of an MCI, where consistent cooperation of the casualties is unlikely. While the above description contains many specificities, these should not be construed as limitations on the scope of any embodiment, but as exemplifications of the presently preferred embodiments thereof. Many other ramifications and variations are possible within the teachings of the various embodiments. For example, the device may have other shapes, such as a round, square, or triangular top; the hinge mechanism may be made of a different compliant mechanism, such as a flexible polymer or have a bi-stable, uni-body design; a compliant material may be added to the inside surface of the device to provide additional comfort for the patient and shield the sensors from environmental disturbances, etc.
[0048] Thus the scope of the invention should be determined by the appended claims and their legal equivalents, and not by the examples given. | A new clip-type ring design for a rapidly-deployable triage sensor is described. The triage sensor is capable of measuring one or more parameters related to a patient's current health state. The device consists of two contoured halves which are designed to wrap around a finger like a ring. At least one of the halves is at least spring-loaded or motorized and is capable of opening or closing to allow for quick attachment to a wide range of finger shapes and sizes. The spring-loaded halves serve as both a means of securing the device to the patient as well as make it possible to measure patient health parameters such as systolic blood pressure, that are standard inputs to conventional triage methodologies. As data are acquired, the ring is able to transmit pertinent information wirelessly to medical responders for evaluation and decision making purposes. | 0 |
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