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BACKGROUND OF THE INVENTION
Polycarbonate lenses of the type used in eyeglasses, camera lenses, optical instruments, eyeglass shields, goggles and other protective gear, cannot be dyed at temperatures of 212° F. or less, because of the high second order transition temperature (T g ) (250°-260° F.) of the polycarbonate. Aqueous dyeing under pressure at 265°-270° F. for 60-90 minutes is needed to obtain good coloration. However, this long heat treatment is costly and slow, and drastically reduces the impact resistance of the polycarbonate article. During the long heat treatment, the molding-related physical arrangements undergo changes which cause the loss of impact resistance. High impact resistance is a necessary requirement for all plastic lenses, and it is a special requirement for the military.
Thus, an object of this invention is to develop a rapid solvent dyeing process with uniform dye uptake without reducing the high impact resistance or changing the haze factor of dyed polycarbonate lenses.
Polycarbonate lenses are produced by placing liquid polycarbonate monomer (undyed) and an initiator, usually an organic peroxide, e.g., isopropyl peroxide, in a mold. After polymerization is completed, the lenses are polished and cleaned. Normally, lenses are dyed by adding organic dye to the monomer and initiator blend. These dyes must be compatible with both the monomer and initiator. This process requires a significant investment for dyes and an inventory of colored lenses to provide a full range of products.
Polycarbonate articles including lenses which contain tint or dye are required for optical and nonoptical uses, such as safety glasses and sunglasses, and for industrial and military applications such as helmets with protective face shields.
DESCRIPTION OF THE INVENTION
The present invention provides a dyeing process effective for dyeing polycarbonate lenses to obtain high retention of impact resistance, uniform dyeing, high UV stability (clarity) of the thus-colored lenses, no change in haze of the lens, and high productivity.
The effects of time and temperature of treatment on polycarbonate lens dyeing are shown below in Table III. Based on those tests, a dyeing process was developed to provide the advantages mentioned above. An outline of this process is as follows:
Polycarbonate lenses are dyed in a solution consisting of 0.1 to 1% of selected organic dye (see below) in white mineral oil. The oil is a naphthenic hydrocarbon, NF/USP pharmaceutical grade, and is referred to herein as "white mineral oil". Dyeing is preferably conducted for 3 to 4 minutes at 268°-270° F.
Annealing is performed at about 80°-85° F. for 3-4 minutes. Excess solvent and dye are then scoured off as described below, and the lenses are then dried at room to warm air temperature. A hard siloxane can then be applied as a coating to improve the lenses' scratch resistance. To avoid dye oxidation, oxygen-free gas, e.g., nitrogen, should be used above the dye and scouring baths; this is required if the dye solution is to be re-used.
The following nonionic, organic dyes have been found suitable for the process:
Crude Nonionic Dyes
Disperse Yellow 3
Disperse Orange 30
Disperse Red 55:1
Disperse Blue 56
Solvent Nonionic Dyes
Solvent Yellow 93
Solvent Orange 60
Solvent Red 52
Solvent Blue 59
Solvent 1:2 Premetalized Dyes
Solvent Yellow 83:1
Solvent Orange 54
Solvent Red 22
The process of this invention can be carried out at temperatures and times between 250° F. for 4 minutes and 380° F. for 30 seconds depending upon the dyeing media employed. Preferably, however, the process is carried out between 270° F. for 3 minutes and 290° F. for 2 minutes. The annealing time can vary between 2 and 4 minutes.
The process of the invention is conducted in the following manner: molded but otherwise untinted lenses are tinted or dyed by immersing the lens in a high-boiling solvent (specified in detail below) containing a tinctorial amount of at least one dye. The dyeing medium is maintained in a sealed container under an inert gas, nitrogen being convenient, to prevent dye oxidization. Dyeing is carried out at temperatures in the range of 250° F. to 380° F., preferably about 270° F. to 290° F. for 5 seconds up to 5 minutes depending on the depth of shade required. Temperature and time are inversely related, i.e., lower temperatures require longer exposure to the dyeing medium.
Next, the lens is given an after dyeing heat treatment or annealing, again in a nitrogen environment, to prevent dye oxidation. After annealing, any non-diffused dye and/or high boiling solvent remaining on the lens are removed in a solvent rinse or scour, for instance, in a fluorinated hydrocarbon scouring medium (e.g. Freon 113) optionally containing a small quantity of a solvent-soluble detergent. Three separate scourings of 15 to 30 seconds each with the fluorinated hydrocarbon scouring medium at slightly above room temperature (80° F. to 85° F.) are preferred. The dyed lens is then dried in warm air. Protective coatings or other finishes may be applied as required.
The process of this invention is described with emphasis on a lens, shield or other optically-related configuration; however, it will be understood that other forms of three-dimensional shaped articles made of polycarbonate may be similarly treated.
The total light transmittance of the dyed lenses varies with the depth of dyeing which, in turn, is a function of the materials and conditions employed. Approximately 20% to 25% light transmittance of the dyed lenses is preferable, e.g., for sunglasses. The process yields uniformly dyed lenses or articles with no visible change in haze (clarity) as compared with untreated lenses.
Suitable high-boiling organic media for the process of this invention are selected from those organic liquids having a boiling point above the operational temperature of the dyeing medium, compatible with the polycarbonate article to be dyed and in which the dye is soluble. Several types of solvents for dyeing and scouring media were screened to obtain optimum materials for processing as shown in Tables I and II, below.
TABLE 1__________________________________________________________________________Properties of Candidate Media for Dyeing Polycarbonate Lenses Boiling Viscosity at Point 75° F. 270° F. Cost UV Depth of Dyeing at.sup.(e)Solvent °F. cps cps $/lb stability.sup.(d) 270° F. 300° F. 350° F.__________________________________________________________________________Diethylene glycol 470 80 15 0.40 3-4 Low Med. HighDow Corning200 Fluid.sup.(a) 380 500 180 2.80 3-4 Low Med. High510 Fluid 410 400 160 4.50 3-4 Low Med. High210H Fluid 800 180 45 9.50 5 Low High --710 Fluid 650 250 80 18.50 3-4 Low High --550 Fluid 480 500 180 8.90 5 Low Med. HighPolysulfolane 520 solid 30-50 1.70 2-3 Low Med. HighTEHM.sup.(b) 650 400 15-30 2.80 3-4 Low High --White Mineral 600 20-30 1-2 0.68 5 High -- --Oil.sup.(c)__________________________________________________________________________ .sup.(a) Silicone fluid. .sup.(b) Tris(2ethylhexyltrimellitate). .sup.(c) Naphthenic hydrocarbon NF/USP pharmaceutical white mineral oil. .sup.(d) UV stability in AATCC Test 16E, using 60 hours of continuous xenon arc exposure. A rating of 5 is best, and indicates absence of a color break. .sup.(e) The test for depth of dyeing was conducted in a 0.5% solution of Solvent Blue 59 for 2 minutes at the specified temperatures.
TABLE II______________________________________Properties of Candidate Media for ScouringDyed Polycarbonate Lenses Effect on Solubility Poly- of White Solubility carbonate Mineral of Organic Lens Oil Dyes Surface______________________________________Dimethyl sulfoxylate Medium High SevereDimethylformamide Medium High SevereMethylethyl ketone Medium Medium SevereMethylethyl acetate Medium Medium SeverePerchloroethylene High Medium SevereTrichloroethylene High Medium Severe1,1,1-Trichloroethane High Medium SlightMethylene chloride Medium Medium SevereFluorinated High Low/ Nonehydrocarbon (Freon 113) Medium*______________________________________ *Solubility of dyes can be increased by addition of cationic detergent soluble in fluorinated hydrocarbon.
As shown by Table I, the dyeing media tested (with the exception of white mineral oil) provided a low depth of dyeing at 270° F., but demonstrated improved dyeing depths at higher temperatures. Impact resistance was least affected at lower treatment temperatures as shown by Table II. Thus, the preferred dyeing medium is white mineral oil, not only for the favorable depth of dyeing at lower temperatures, but also for the ultraviolet stability of the resulting product. An acceptable scouring medium will solubilize and remove the high boiling medium and solubilize the organic dye (at least to a reasonable extent while not extracting a significant portion of the dye diffused into the lens) while the polycarbonate lens surface should not be adversely affected. Fluorinated hydrocarbons are the preferred scouring agents for use in association with white mineral oil as the dyeing medium, as shown in Table II.
The invention will now be explained with reference to the following example in which all parts and percents are by weight unless otherwise indicated.
EXAMPLE
A series of 14 separate dye uptake studies were made in a 0.5% solution of Solvent Blue 59 in white mineral oil for two minutes under the times and temperatures specified, as shown in Table III.
Table III__________________________________________________________________________Effect of Treating Conditions on Polycarbonate Lens DyeingTest for Dye Uptake: Conducted in a 0.5% solution of Solvent Blue 59 inWhite MineralOil for 2 minutes at the specified temperatures.Dyeing AnnealingExperiment Conditions Time at 80° F. Dye UV* Impact**No. Temp. °F. Time Min. Min. Uptake Stability Resistance__________________________________________________________________________1 260 1 2 None -- High2 260 2 2 Low 1 High3 260 4 2 Low 2 High4 270 1 2 Medium 2-3 Med./High5 270 2 2 Med./High 4-5 Med./High6 270 3 2 High 5 Med./High7 270 4 2 High 5 Med./High8 270 3 2 High 5 Med./High9 270 3 3 High 5 High10 270 3 4 High 5 High11 280 2 4 High 5 Low12 300 2 4 High 5 Low13 325 2 4 High 5 Low14 350 2 4 High 5 Low__________________________________________________________________________ *UV stability in AATCC TEST 16E, using 60 hours of continuous Xenon arc exposure. A rating of 5 is best, and indicates absence of a color break. **Qualitative judgment of cracking after dropping a 10 lb. weight from a height of one foot on lens specimens.
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Polycarbonate articles, especially eyeglass and optical lenses, are dyed in a dye solvent having a boiling point of at least 350° F. in which a dye is dissolved. The article to be dyed is retained in the solution maintained at 200° F. or more until sufficient dye has penetrated the polycarbonate, then removed, rinsed and dried. The dyeing operation does not unduly detract from impact resistance and the dyed product exhibits excellent ultraviolet light stability.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a planer apparatus and, in particular, to a depth stop mechanism and other accessories for a planer.
[0003] 2. Description of the Invention Background
[0004] Over the years, in response to consumer demand, thickness and finishing planers, i.e. planers for reducing the thickness of a piece of wood or similar materials while providing a smooth and flat finish, have been decreasing in size. Such portable planers balance the need to provide the required power to produce a smooth finish with the need to conserve space and decrease weight for portability.
[0005] The popularity of portable planers among professionals and woodworking enthusiasts has spurred the introduction of new features designed to increase versatility, precision and convenience. For example, U.S. patent application Ser. No. 09/782,453 to Garcia et al., assigned to the assignee of the present invention, discloses a portable planer having a compact two-speed gear mechanism that is actuated to drive the infeed and outfeed rollers of the planer selectively at a high or low speed.
[0006] U.S. Pat. No. 6,089,287 to Welsh et al. discloses a planer with a depth stop adjustment mechanism that allows an operator to select a minimum workpiece depth from one or more predetermined depths, but does not allow selection of any depth within the full range of travel of the cutterhead of the planer.
[0007] Also current depth stop arrangements are located between the cutterhead and the workpiece support table and can place undesirable torque on the cutterhead if the cutterhead is inadvertently lowered beyond the point wherein the depth stop engages the table or other support structure. Such torque can result in damage to the apparatus for positioning the cutterhead.
[0008] Additional accessories such as dust collector chutes, depth scales and workpiece level indicators need to be designed for ease of manufacturing, installation and cost-effectiveness.
[0009] There remains, therefore, a need for a planer that includes features that overcome the limitations, shortcomings and disadvantages of other planers without compromising their advantages.
SUMMARY OF THE INVENTION
[0010] The invention meets the identified needs, as well as other needs, as will be more fully understood following a review of this specification and drawings.
[0011] One embodiment of the invention includes a planer a base, a first and second support members attached to the base and supporting a cutterhead for selective travel toward and away from the base, a top frame attached to at least the first support member and a depth stop mechanism attached to the top frame for selectively preventing travel toward the base beyond a pre-selected distance from the base.
[0012] The depth stop mechanism may also include a depth stop member, such as a nut, rotatably supported on a portion of the first support member adjacent to an abutment surface thereof and slidably supported in the top frame. The depth stop mechanism may also include an adjustment assembly, such as a sleeve, in the top frame, for selectively adjusting a position of the depth stop member on the support member relative to the abutment surface.
[0013] Another embodiment of the invention includes a planer having a base, a top frame connected to the base, a cutterhead movably supported relative to the base to define an adjustable opening therebetween for selective travel in a first direction toward the base and a second opposite direction, and a depth stop mechanism attached to the top frame and not extending into the adjustable opening. The depth stop mechanism selectively prevents travel of the cutterhead in the first direction beyond a pre-selected distance from the base.
[0014] In another embodiment the planer may include a retractable measuring device, such as a tape, attached to the top frame of the planer. The retractable tape may have a first end retractably affixed to the top frame and a second end affixed to the cutterhead. The retractable measuring device has a scale thereon and may include a transparent member covering a portion of the scale, and a scale indicator. The scale indicator shows the height of the cutterhead from the base on the scale through the transparent member.
[0015] In another embodiment the planer includes a cutterhead, a motor operating the cutterhead, a power switch for the motor, and an infeed table pivotable between an operating position and an upright storage position that switches off the power to the motor. The planer includes a side frame with a first aperture thereon. The infeed table has a second aperture aligned with the first aperture so that the apertures may receive a locking device when the infeed table is in the storage position.
[0016] Another embodiment of the planer may also include a workpiece level indicator assembly mounted on the cutterhead. The workpiece level indicator assembly includes a workpiece level indicator plate that has a bottom face parallel to the base and a front ledge, and is movable between an engaged position and a disengaged position. When the cutterhead is lowered such that the bottom face of the indicator contacts the workpiece, the level indicator moves to the disengaged position. The workpiece level indicator assembly may also include a cover plate covering an inscription on the workpiece level indicator in the disengaged position and exposing the inscription in the engaged position.
[0017] The planer may also include a dust removal assembly that includes a manifold removably attachable to the cutterhead over the cutting member, a dust deflector directing airflow to the manifold, and a dust chute communicating with the manifold. The dust chute has a side opening for connection to a vacuum hose and has also a channel that is releasably connected to the carriage assembly through posts that are received in corresponding slots on the cutterhead.
[0018] One feature of an embodiment of the present invention is to provide a depth stop mechanism that is not located between the cutterhead and the workpiece support table.
[0019] It is a feature of at least one embodiment of the invention to provide a compact depth stop mechanism for a full range of travel of the cutterhead of a planer or other similar machine.
[0020] Another feature of the invention is to provide efficient, effective and easily installable accessories for a portable planer and other similar machines.
[0021] It is also feature of at least one embodiment of the invention to provide an inexpensive and readily adaptable depth measuring device and a convenient workpiece level indicator, either of which that can be used with or without a depth stop mechanism for a planer or other similar machine.
[0022] It is yet another feature of at least one embodiment of the invention to provide a locking mechanism for storing a portable planer in a safe position with the cutting member and power switch inaccessible to unauthorized persons.
[0023] It is also a feature of at least one embodiment of the invention to provide a dust removal assembly that is readily attached to and detached from a portable planer.
[0024] Other features and advantages of the invention will become apparent from the detailed description of the preferred embodiments and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is an isometric view of an embodiment of planer according to the invention;
[0026] FIG. 2 is an isometric view of the planer of FIG. 1 with a portion of the support structure removed;
[0027] FIG. 3 is a sectional view of the planer of FIG. 1 with a part of the support structure for the planer removed to show an embodiment of the depth stop mechanism of the invention;
[0028] FIG. 4 is a sectional view of the depth stop mechanism of FIG. 3 in an engaged position;
[0029] FIG. 5 is a sectional view of the depth stop mechanism of FIG. 3 in a disengaged position;
[0030] FIG. 6 is an exploded view of an embodiment of a sleeve of the depth stop mechanism of FIG. 3 ;
[0031] FIG. 7 is a partial isometric view of an embodiment of the top end of the sleeve of FIG. 6 ;
[0032] FIG. 8 is a partial isometric view of an embodiment of a knob attached to the sleeve of FIG. 6 ;
[0033] FIG. 9 is an exploded assembly view of an embodiment of the knob, retainer ring and retainer shaft for the depth stop mechanism of FIG. 3 ;
[0034] FIG. 10 is a diagram illustrating the height traveled by the depth stop nut for a corresponding height traveled by the cutterhead for the depth stop mechanism of FIG. 3 ;
[0035] FIG. 11 is a partial isometric view of an embodiment of a depth-measuring device of the invention;
[0036] FIG. 12 ( a ) is a partial isometric view of an embodiment of a workpiece level indicator assembly in the engaged position;
[0037] FIG. 12 ( b ) is an isometric view of the workpiece level indicator of FIG. 12 ( a );
[0038] FIG. 12 ( c ) is an isometric view of the workpiece level indicator of FIG. 12 ( b ) in the disengaged position;
[0039] FIG. 12 ( d ) is an isometric view a spring connected to the workpiece level indicator of FIG. 12 ( a );
[0040] FIG. 13 ( a ) is an isometric view of an embodiment of a locking device for a planer in the storage position;
[0041] FIG. 13 ( b ) is a magnified view of the locking device of FIG. 13 ( a );
[0042] FIG. 14 is a partial isometric view of an embodiment of a dust removal assembly of the invention;
[0043] FIG. 15 is a detail of the dust removal assembly of FIG. 13 ( a ) showing only the end posts of the dust channel in the guiding slots;
[0044] FIG. 16 is an isometric view of the dust chute and dust channel of FIG. 14 ; and
[0045] FIG. 17 is a sectional view of the dust removal assembly of FIG. 14 assembled on a carriage assembly of a planer.
DETAILED DESCRIPTION OF THE INVENTION
[0046] Referring now to the drawings for the purpose of illustrating the invention and not for the purpose of limiting the same, it is to be understood that standard components or features that are within the purview of an artisan of ordinary skill and do not contribute to the understanding of the various embodiments of the invention are omitted from the drawings to enhance clarity, even when such features may otherwise be necessary for the operation of a machine, such as a planer, embodying the invention. In addition, it will be appreciated that the characterizations of various components described herein as moving, for example, upwardly or downwardly, or being vertical or horizontal, are relative characterizations only based upon the particular position or orientation of a given component for a particular application.
[0047] FIG. 1 is an isometric view of a portable planer 100 according to one embodiment of the invention. The planer 100 includes a support structure, generally designated as 112 , which includes a top frame 104 , a base 103 for supporting a workpiece 114 , columns 107 connecting the top frame 104 and the base 103 , an infeed table 108 for supporting the workpiece 114 as it enters the planer 100 , and an outfeed table 110 for supporting the workpiece 114 as it exits the planer 100 . Side housings 106 cover portions of the planer 100 .
[0048] The planer 100 also includes a cutterhead or carriage assembly 102 , as shown in FIGS. 2 and 3 , in which part of the support structure 112 has been removed. The cutterhead 102 is mounted on a first support member also referred to as a spindle or elevating screw 118 and a second support member or spindle 119 . The first spindle 118 defines an axis of rotation designated as A-A. The height of the cutterhead 102 from the base 103 can be adjusted by rotating a crank handle 116 , which imparts rotational motion to the second spindle 119 . An adjustable opening 143 is thereby defined between the cutterhead 102 and the base 103 .
[0049] The first spindle 118 is linked to the second spindle 119 by a chain 122 and sprockets 123 or other means of transmitting rotational motion, so that the rotation of the second spindle 119 results in rotation of the first spindle 118 . See FIG. 3 . The first spindle 118 and the second spindle 119 may be engaged respectively with a first carriage nut 124 and second carriage nut 125 , so that the cutterhead 102 may be moved up and down on the spindles 118 and 119 while remaining parallel to the base 103 . The first carriage nut 124 and the second carriage nut 125 may be separate components inserted into the cutterhead 102 or they may comprise appropriate threaded surfaces that are integral to the cutterhead 102 .
[0050] The typical travel distance of the cutterhead 102 relative to the base 103 of a portable planer 100 , may be of the order of several inches. One planer, such as the model Delta 22-560 planer manufactured by Delta International Machinery Corp. of Jackson, Tenn., the assignee of this invention, for example, has a 6 inches travel.
[0051] In one embodiment, the planer includes an embodiment of a depth stop mechanism 128 . See FIG. 4 . The depth stop mechanism 128 permits an operator to select a minimum thickness dimension desired for a workpiece 114 and, by a simple operation, engage the depth stop mechanism 128 to stop the cutterhead 102 when the cutterhead 102 reaches a predetermined height from the base 103 corresponding to the desired minimum thickness dimension (t min ) for the workpiece 102 . The predetermined height can essentially be any height along the travel path of the cutterhead 102 from the base 103 to the top frame 104 .
[0052] As shown in FIG. 4 , the depth stop mechanism 128 includes a knob 130 and an adjustment assembly generally designated as 131 . In this embodiment, the adjustment assembly includes as sleeve 132 that has a top end 133 and a bottom end 134 . The top end 133 may be an integral part of the sleeve 132 or it may be formed from a separate component such as a bushing attached to the sleeve 132 . The sleeve 132 receives an upper portion 138 of the first spindle 118 and may slide along or rotate about the first spindle 118 . A retainer shaft 140 within the sleeve 132 connects the upper portion 138 of the first spindle 118 to the knob 130 and is secured by a knob fastener 142 , such as, for example, a retaining screw or retainer slot and ring. The first spindle 118 includes a first threaded portion 136 and a second threaded portion 137 . The pitch p 1 of the first threaded portion 136 is smaller than the pitch p 2 of the second threaded portion 137 , i.e. the number of threads per inch n 1 of the first threaded portion 136 is greater than the number of threads per inch n 2 of the second threaded portion 137 , for reasons that will become apparent herein below.
[0053] The depth stop mechanism 128 of this embodiment further includes a depth stop member 144 , such as a depth stop nut, which is threadedly engaged with the first threaded portion 136 of the first spindle 118 , such that when the depth stop nut 144 rotates clockwise or counterclockwise with respect to the first spindle 118 , the depth stop nut 144 moves down or up the first threaded portion 136 of the first spindle 118 . The depth stop nut 144 may be, for example, a hex nut having a six-sided lateral surface. An abutment surface 146 , also referred to herein as a spindle shoulder, may be formed at the junction of the first threaded portion 136 to the second threaded portion 137 by the difference of the diameters of the first threaded portion 136 to the second threaded portion 137 of the first spindle 118 . See FIG. 5 . Those of ordinary skill in the art will appreciate that when the depth stop nut 144 contacts the abutment surface 146 , the depth stop nut 144 will be prevented from moving further downward on the first threaded portion 136 . The abutment surface 146 may also be defined by an appropriate washer, nut or other similar means. Another washer 145 or abutment surface on the first threaded portion of the first spindle 118 prevents further upward motion of the nut 144 that may interfere with the function of the retainer shaft 140 .
[0054] One embodiment of the sleeve 132 is shown in exploded view in FIG. 6 . In this embodiment, the top end 133 of the sleeve 132 is partially received within a bore 152 in the top frame 104 . See FIG. 7 . In this embodiment, a portion of the exterior circumference of the top end 133 of the sleeve 132 is non-circular in shape and includes a hexagonally-shaped surface 148 that defines six corners 149 . The exterior of the top end 133 is sized to be received in the bore 152 . As can be seen in FIG. 7 , the bore 152 has a surface 150 that defines a plurality of notches 153 for selectively receiving the corners 149 of the top end 133 therein. In the embodiment shown in FIG. 7 , the bore 152 has a surface 150 with twenty four sides 150 and twenty four notches of which twelve outer notches 153 define twelve positions about axis A-A in which the sleeve may be retained. As will be further explained below, when the top end 133 is received within the bore 152 such that the corners 149 are received in corresponding notches 153 , the top end 133 and ultimately the sleeve 132 is prevented from being rotatable about axis A-A.
[0055] The top end 133 may further include a plurality of ramps 154 having corresponding slots 156 , and an annular plate 157 for receiving the top end of the retainer shaft 140 . The knob 130 is then fastened to the retainer shaft by a fastener 142 , such as, for example, the retaining screw 142 shown in FIG. 8 or the retaining ring 158 and retaining slot 159 at the top of retainer shaft 140 , as shown in FIG. 9 .
[0056] In this embodiment, the knob 130 includes a plurality of posts 160 that correspond in number and are sized to fit into the slots 156 of the top end 133 . In the embodiment shown in FIGS. 6, 7 and 9 , there are three ramps 154 , three slots 156 and three posts 160 . A compression spring 162 is coiled around the retainer shaft 140 between the bottom surface of the annular plate 157 and a shoulder 163 in the retainer shaft 140 , and is biased to push the sleeve 132 upwardly, i.e. toward the knob 130 . See FIG. 5 .
[0057] The inner surface of the sleeve 132 includes two diametrically opposed flat portions 164 , which are sized to contact and hold respective sides of the depth stop nut 144 , so that when the sleeve 132 rotates about the first spindle 118 , the depth stop nut also rotates about the first spindle 118 , causing it to move up or down the first threaded portion 136 of the first spindle 118 .
[0058] The depth stop mechanism 128 is selectively moveable between an engaged position, shown in FIG. 4 , and a disengaged position, shown in FIG. 5 . In the engaged position, the corners 149 of the top end 133 of the sleeve 132 are received within the corresponding notches 153 in the bore 152 , which serves to prevent the sleeve 132 from either sliding or rotating about the first spindle 118 . The sleeve 132 is retained in the engaged position by depressing and rotating the knob 130 so that the posts 160 ride up the ramps 154 and are received into the slots 156 thereby also compressing the spring 162 . In this position, the depth stop nut 144 cannot rotate, but it will slidably move up or down within the sleeve 132 by the rotation of the first spindle 118 .
[0059] In the “disengaged” position, illustrated in FIG. 5 , the sleeve 132 may freely rotate and slide relative to the first spindle 118 . The sleeve 132 can be rotated with the knob 130 in the unlocked position and the spring 160 extended. In this position, when the knob 130 is rotated, the sleeve 132 rotates, consequently rotating the depth stop nut 144 and causing it to move up or down on the first spindle 118 .
[0060] As is often the case, a workpiece may have to be passed through the planer several times in order to attain the final desired thickness. Those of ordinary skill in the art will appreciate that after the workpiece 114 has passed through the planer 100 , the cutterhead 102 is positioned closer to the base 103 and the workpiece 114 is again passed through the planer 100 . This activity is repeated until the workpiece 114 is planed to a desired thickness. As will be discussed below, the depth stop mechanism 128 of the present invention permits the user to quickly and accurately establish a stop which prevents the cutterhead 102 from inadvertently being adjusted beyond a point which would result in the workpiece 114 being planed to a lesser than desired thickness.
[0061] This embodiment of the depth stop mechanism 128 operates as follows. The knob 130 is rotated counterclockwise to release it from the locked position causing the posts 160 to slide from the slots 156 down the ramps 154 with the spring 162 pushing the sleeve 132 up in the disengaged position and moving the hexagonal surface 148 out of the twenty-four sided surface 150 of the bore 152 . Starting at the disengaged position, the cutterhead is moved to a desired height from the base 103 by operating the crank handle 116 , which causes the second spindle 119 to rotate. The second spindle 119 has a threaded portion 166 , which has the same pitch p 2 as the second threaded portion 137 of the first spindle 118 . As the chain 122 and sprocket 123 transmit the rotational motion of the second spindle 119 to the first spindle 118 , the common pitch p 2 keeps the cutterhead 102 level, i.e. parallel to the base 103 .
[0062] After the cutterhead 102 has reached the height corresponding to the minimum thickness t min desired for the finished workpiece 114 , the knob 130 is rotated clockwise, causing the sleeve 132 , and therefore the depth stop nut 144 , to also rotate clockwise. As a result, the depth stop nut 144 moves down the first threaded portion 136 of the spindle until it contacts the abutment surface 144 . At this position, the knob 130 is depressed and rotated clockwise locking the sleeve 132 within the bore 152 thereby bringing the depth stop mechanism 128 in the engaged position. See FIG. 4 .
[0063] The cutterhead 102 is thereafter moved away from the base 103 by operation of the crank handle 116 to an initial height “h” from the base 103 that will allow for an unfinished/thicker workpiece to be initially inserted. The height “h” is equal to h c plus t min , where h c is the distance of the cutterhead 102 from the minimum desired distance t min from the base 103 , as shown in FIG. 10 . While the cutterhead 102 is raised to the initial height h, the rotation of the first spindle 118 causes the depth stop nut 144 to advance a distance h n away from the abutment surface 146 . When the cutterhead 102 is gradually lowered to plane the workpiece 114 in successive passes, the depth stop nut 144 will also be advanced downward and eventually contact the abutment surface 146 having traveled a distance h n while the cutterhead 102 has traveled a distance h c . The abutment surface 146 prevents the depth stop nut 144 from moving further downward and resists further rotation of the crank handle 116 , and therefore prevents reduction of the thickness of the workpiece 114 beyond the predetermined minimum thickness t min . By an appropriate choice of the pitch ratio p 1 /p 2 , the distance h n traveled by depth stop nut 144 is only a fraction of the distance h c traveled by the cutterhead 102 :
( p 1 /p 2 )=( n 2 /n 1 )=( h n /h c ).
[0064] For example, if the first threaded portion 136 has 40 threads per inch, or 1/40 pitch, and the second threaded portion 137 has 16 threads per inch or 1/16 pitch, then the depth stop nut 144 will travel only 40% (i.e. 16/40) of the distance traveled by the cutterhead 102 . Accordingly, the cutterhead 103 can be set at any height from the base within its full range of motion, for example 6.5 inches, provided that the depth stop mechanism 128 is constructed such that the distance between the washer 145 and the abutment surface 146 is only 2.6 inches (40% of 6.5), with the pitch ratio chosen for this example. Therefore, the depth stop mechanism 128 is very compact and can be added as a feature of a portable planer 100 without increasing the overall dimensions of the planer, because the depth stop mechanism 128 can be accommodated within the original size of the planer 100 .
[0065] As can be seen in FIG. 11 , another embodiment of the planer 100 may also include a depth measuring device 168 that displays the distance of the cutterhead 102 from the base 103 as the cutterhead 102 is adjusted in height. The depth measuring device 168 includes a commercially available retractable measuring device 170 , such as a tape, of the type that retracts to wind up on a tape roll 174 inside a housing 176 . The retractable tape 170 has a first end 171 and a second end 172 . The first end 171 of the retractable tape 170 is attached to the cutterhead 102 by common mechanical fasteners, such as rivets or screws, and the second end 172 is attached to the tape roll 174 . The housing 176 is attached to the top frame 104 of the planer. The retractable tape 170 has a portion with a scale 178 thereon. A viewing window 179 covers a portion of the scale 178 and is attached to the top frame 104 of the planer. The scale is calibrated to show the current height of the cutterhead 102 from the base 103 at a cursor line or other scale indicator 180 on the clear window 179 . The depth measuring device 168 is an inexpensive and easy to install accessory for a planer 100 and may be advantageously used in conjunction with the depth stop mechanism 128 to measure at a glance the height of the cutterhead 102 from the base 103 for setting the desirable minimum thickness t min for planing a workpiece 114 .
[0066] Another embodiment of the present invention may comprise a planer 100 that has a workpiece level indicator assembly 181 shown in FIGS. 12 ( a )- 12 ( d ). The workpiece level indicator assembly 181 includes a workpiece level indicator plate 182 that is mounted preferably on the front surface 184 of the cutterhead 102 , such that it can slide between an engaged position shown in FIG. 12 ( a ) and a disengaged position shown in FIG. 12 ( c ). The mounting means may be, for example, two slots 194 each having a left indentation 195 and fasteners 196 sized to extend through the slots 194 to be threadedly received in corresponding threaded holes in the cutterhead. The workpiece level indicator plate 182 has a bottom face 186 parallel to the base 103 and a front ledge 188 .
[0067] A spring 190 , illustrated in FIG. 12 ( d ) mounted on the front side 184 of the cutterhead 103 biases the workpiece level indicator plate 182 to the right and such that the fasteners 196 are received in their respective indentation 195 . This position is the engaged position. As can be seen in FIG. 12 ( b ), when the level indicator plate 182 is in the engaged position, the bottom face 186 extends below the lower surface of the cutterhead 102 . When the cutterhead 102 is lowered onto the workpiece, the bottom face 186 of the level indicator plate 182 contacts the workpiece causing the plate 182 to slide upward against the biasing force of the spring 190 . A cover plate 192 may also be mounted on the front side 184 of the cutterhead 103 with fasteners 196 such that it may cover an inscription on the indicator in the disengaged position, such as the word “ENGAGED” and exposing the inscription in the engaged position.
[0068] Yet another embodiment of the planer 100 may include a locking mechanism 198 , which allows the infeed table 108 to pivot between an extended position during operation and an upright storage position in which the planer 100 is switched off and the cutting blade is inaccessible for safety reasons, as shown in FIGS. 1 , and 13 ( a ) and ( b ). The locking mechanism 198 includes an aperture 199 on the side frame 106 of the planer 100 and an aperture 200 on the infeed table 108 . The apertures 199 and 200 are aligned such that a locking device 201 , such as, for example, an ordinary padlock or other safety lock, may be inserted through the aperture 199 of the side frame 106 and the aperture 200 of the infeed table 108 to secure and lock the infeed table 108 in the upright position. In the upright and locked position, the infeed table 108 pushes against and switches off the power switch 203 (shown in FIG. 1 ) of the planer 100 .
[0069] The planer 100 may also include a dust removal assembly 206 , as shown in FIGS. 14-17 . The dust removal assembly 206 is positioned on the outfeed side 208 of the carriage assembly 102 and includes a manifold 210 having a manifold deck 211 . The manifold 210 is removably attached to the carriage assembly 102 by means of, for example, a pair of thumb screws 212 (only one is shown) through the manifold deck 211 . The dust removal assembly 206 also includes a dust deflector 214 , which is attached to the carriage assembly 102 with any suitable fasteners toward the infeed side 209 and deflects airflow and dust or shavings under the manifold deck 211 .
[0070] The dust removal assembly 206 also includes a dust chute 216 that communicates with the manifold 210 through a dust channel 218 , which is releasably connected to the carriage assembly 102 . The dust channel 218 may be attached to the dust chute 216 with fasteners 224 , or by welding, and may be an integral part of the dust chute 216 . The dust channel 218 has two end posts 220 , which are attached, for example, by spot welds, and are sized to slide into corresponding guiding slots 222 on the carriage assembly 102 . The guiding slots 222 help slide the dust channel 218 and dust chute 216 easily onto the carriage assembly 102 . The manifold 210 is then placed on the carriage assembly 102 and the thumbscrews 212 are inserted and tightened over the manifold deck 211 . The dust chute 216 has a side opening 226 , to which a vacuum hose may be attached for dust removal. The side opening 226 directs dust to one side of the planer 100 . The portion of the dust channel 218 that connects to the carriage assembly is symmetrically shaped. Thus, the dust channel 218 may be connected to the carriage assembly 102 in either a first position, with the side opening 226 directed to a right side of the planer 100 , or a second position, with the side opening 226 directed to a left side of the planer 100 .
[0071] The depth stop mechanism 128 , the depth measuring device 168 , the workpiece level indicator assembly 181 , the locking mechanism 198 and the dust removal assembly 206 have all been described for a portable planer, but they can readily be used with a standard planer or other machine that includes a rotary cutting member 105 mounted on a carriage assembly 102 , such as a combination planer/molder, planer/sander, etc.
[0072] Whereas particular embodiments of the invention have been described herein for the purpose of illustrating the invention and not for the purpose of limiting the same, it will be appreciated by those of ordinary skill in the art that numerous variations of the details, materials and arrangement of parts may be made within the principle and scope of the invention without departing from the invention as described in the appended claims.
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A planer having a base, a first support member attached to the base and supporting a cutterhead for selective travel in a first direction toward the base and a second opposite direction, a top frame attached to the first support member and a depth stop mechanism attached to the top frame for selectively preventing travel of the cutterhead in the first direction beyond a pre-selected distance from the base. A depth measuring device including a retractable tape may be attached to the cutterhead. A workpiece level indicator plate movable between an engaged position and a disengaged position may be attached to the planer to indicate contact with a workpiece. A locking mechanism for locking a pivotable infeed table of a planer in the upright position for storage, and thereby switching off power to the planer is also disclosed. The planer may include a readily attachable and detachable dust removal assembly.
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GOVERNMENT RIGHTS
This invention was made with United States Government support under Contract No. DE-AC04-76DP00789 awarded by the U.S. Department of Energy. The Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
The present invention relates generally to the field of surface passivation of micromechanical structures formed on semiconductor, ceramic, oxide or metal substrates. More particularly, the present invention relates to a technique for preventing the undesirable adhesion of micromechanical structures to one another or to a substrate due to static friction (i.e. stiction).
Many micromechanical structures manufactured today rely upon semiconductor etching techniques. The same techniques utilized in the electronics industry to develop integrated circuits also permit manufacturers to create a wide variety of miniaturized mechanical devices, including sensors such as accelerometers, microphones, analytical chemical systems, flow sensors, combustion sensors, and bolometers. Other micromachined devices developed by traditional semiconductor manufacturing techniques include actuators used as weapon surety devices and valves employed in flow control systems.
Manufacture of micromechanical structures using typical semiconductor processing technology involves the patterning and deposition of structural layers of polycrystalline silicon (polysilicon), metal or silicon nitride on a semiconductor substrate. Sacrificial layers of silicon dioxide, polymer or metal can also be deposited and patterned on the semiconductor wafer, allowing for the formation of composite micromechanical structures. These sacrificial layers can be subsequently dissolved during an etching process, leaving the structural layers and the supporting substrate intact. The remaining micromechanical structures can rotate or translate, depending upon the design and intent of the original structural pattern.
Unfortunately, the chemistries designed to release adjacent structural parts by dissolving the sacrificial layers can also cause unwanted adhesion between released adjacent structural parts or between such structural parts and the supporting substrate. The undesired adhesion or stiction that results from the use of such wet release chemistries poses a serious barrier to the manufacturing of effective micromechanical structures. When micromechanical structures touch, their extremely flat surfaces, small scales, mechanical flexibility, and the tendency for direct chemical bonding between contacting surfaces make it difficult to separate these micromechanical structures. When the micromechanical structures stick, the resulting micromechanical device is no longer functional.
Various methods have been developed for the chemical passivation of semiconductor device surfaces. One method that has been developed for the passivation of micromechanical device surfaces is described in U.S. Pat. No. 5,318,928 to Gegenwart et al. The method of Gegenwart et al. calls for introducing an inert gas into a tank where a high frequency energy source is applied to internal electrodes for the ignition of a plasma within the tank. The micromechanical device surfaces are cleaned by sputtering away impurities from the surface by means of plasma particles striking the surface. Such a method is necessarily expensive due to the use of plasma enhanced depositions on the micromechanical devices, unlike the present invention which involves a simple and inexpensive wet chemical treatment process, which also avoids the harmful effects to humans and animals associated with plasma etching.
Other methods for semiconductor surface passivation include those shown in U.S. Pat No. 4,910,840 and U.S. Pat. No. 4,908,805 to Sprenkels et al. The Sprenkels et al. patents provide for an electrical passivation method that is unlike the chemical surface passivation method disclosed in the present invention.
Still other methods use less effective or more expensive passivation techniques such as supercritical carbon dioxide drying or foregoing the use of a non-stick release mechanism. Foregoing the use of non-stick release mechanisms in particular results in often severe yield problems. Carbon dioxide drying, in particular, involves the high pressure, super critical transition of carbon dioxide from a liquid to a gas phase. In such circumstances, costly and dangerous high pressure vessels and cryogenic liquids must be utilized to complete the passivation of a semiconductor surface.
The present method of preventing micromechanical devices from adhering to another object offers many advantages over existing technologies. One advantage of the present invention is that cumbersome and potentially hazardous plasma devices are not required, thereby reducing the passivation method to a simple, yet unique and inexpensive, wet chemical passivation method. The present invention provides a method which enhances throughput, safety and economy over existing technologies.
SUMMARY OF THE INVENTION
A method for preventing micromechanical structures from adhering to another object. The present invention comprises a wet chemical treatment process in combination with conventional integrated circuit processing techniques. Initially, unreleased micromechanical structures, along with the substrate upon which the micromechanical structures are located are immersed in an etching agent so that the micromechanical structures can be released from one another and/or from the substrate by any supporting sacrificial layers. Subsequently, the substrate and micromechanical structures are rinsed with deionized water, thereby removing the etching agent along with any dissolved sacrificial layer material. The water can then be displaced by immersing the substrate and any micromechanical structures in alcohol. The alcohol can then be displaced by immersing the substrate and the micromechanical structures in an organic solvent, and adding hexamethyldisilazane ("HMDS") to the solvent.
Further scope of applicability of the present invention will become apparent from the detailed description of the invention provided hereinafter. It should be understood, however, that the detailed description of the invention and the specific example presented, while indicating an embodiment of the present invention, is provided for illustration purposes only because various changes and modifications within the spirit and scope of the invention will become apparent to those of ordinary skill in the art from the detailed description of the invention and claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
The manner in which the above recited features and advantages of the present invention are attained are illustrated in the appended drawings.
FIG. 1 depicts the method steps of the present invention.
FIG. 2 depicts the formation of undesirable strong bonds between structural layers.
FIG. 3 depicts a treatment for preventing the formation of undesirable strong bonds between structural layers.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a method for preventing the undesirable adhesion of micromechanical structures to one another or to a substrate. The method of the present invention can be accomplished by immersing released micromechanical structures and the associated substrate on which the micromechanical structures were formed, into a liquid selected from a class of liquids that have the property of reacting chemically with the surfaces of the micromechanical structures and their associated substrate so as to form a layer of a surface-attached inert chemical functional group. One such inert chemical functional group is the trimethylsilyl group. Such inert chemical functional groups do not form strong chemical bonds with like functional groups upon simple direct contact.
Hexamethyldisilazane is an example of a liquid selected from an inert chemical functional group. When hexamethyldisilazane is applied to a substrate and micromechanical structures, a thin film forms, approximately one molecular monolayer in thickness, which terminates in methyl groups that point away from the surfaces of the substrate and micromechanical structures. Methyl groups do not bond well to other methyl groups nor to other chemical and surface functional sites. When the surfaces of two separate micromechanical structures are coated with a monolayer that terminates in methyl groups and are subsequently placed together, the micromechanical structures will not stick to one another under ordinary ambient conditions.
A first embodiment of the present invention is shown in FIG. 1. In a first step 10, unreleased micromechanical structures formed on a substrate are etched with a hydrofluoric acid based etchant so as to release the micromechanical structures. In a second step 20, the micromechanical structures and the substrate are rinsed with deionized water. In a third step 30, the deionized water is displaced with a water-miscible alcohol. In a fourth step 40, the alcohol is displaced with an organic solvent. The organic solvent is compatible with a liquid derived from an inert chemical functional group such as the trimethylsilyl group. In a fifth step 50, a liquid derived from an inert chemical functional group such as the trimethylsilyl group is added to the organic solvent to form a solution which forms a layer on the surface of the micromechanical structures so as to passivates the surface of the micromechanical structures and their associated substrate. A sixth step 60 includes drying of the substrate and the micromechanical structures. The method according to the present invention, however, is not limited to this particular sequence of steps.
The method disclosed in the present invention can apply to micromechanical structures derived from polysilicon or silicon nitride and which further include sacrificial elements. Such sacrificial elements can be oxide sacrificial elements. Given a substrate with these micromechanical structures, a release can be accomplished by etching the sacrificial oxide elements and associated sacrificial layers with an appropriate etchant such as hydrofluoric acid, hydrofluoric acid buffered with ammonium fluoride, a diluted hydrofluoric acid solution, or mixtures of hydrofluoric acid and other acids such as hydrochloric acid. A dihydroxy alcohol such as ethylene glycol can also be added to this etch.
Upon completion of this initial release step, the substrate and structural elements can be rinsed thoroughly with deionized water. A hydrophilic surface can then be formed by rinsing the substrate and the micromechanical structural elements with a diluted aqueous ammonia solution. The reaction of the diluted aqueous ammonia solution with the substrate forms the hydrophilic surface. After the formation of the hydrophilic surface, a secondary rinse of the substrate and structural elements can be performed with deionized water. The deionized water can be subsequently displaced with a water-miscible alcohol such as isopropanol, ethanol or methanol.
The alcohol can then be displaced with an organic solvent such as acetone that is compatible with trimethylsilyl. The organic solvent can be a mixture of toluene, heptane, octane, trichloroethylene or other solvents compatible with hexamethyldisilazane and also miscible with the selected alcohol. Hexamethyldisilazane is then be added to the aforementioned solvent to passivate the surface of the substrate and the structural elements that comprise a micromechanical device. The addition of hexamethyldisilazane to the solvent can result in the generation of ammonia gas which assists in the overall release process. The gas pressure of the ammonia gas also serves to push the structures apart and away from the substrate. Adding hexamethyldisilazane serves to completely displace the organic solvent and prepare the substrate and micromechanical surfaces for drying. Drying can be accomplished by utilizing any of a number of drying techniques such as air drying of the substrate and micromechanical structures in a sterile clean environment or using a convection oven or a hotplate. The process of coating all surfaces with a layer of firmly chemically bound trimethylsilyl groups begins when the hexamethyldisilazane is first added to displace the organic solvent and can continue up until the completion of the drying process wherein the remaining hexamethyldisilazane is removed from the substrate and any mechanical parts.
FIG. 2 and FIG. 3 depict a second embodiment of the present invention in which several chemical reactions serve to release micromechanical structures from an associated substrate. Generally, when micromechanical structures are released in hydrofluoric acid and then rinsed in H 2 O, the micromechanical structures stick together when the H 2 O dries due to bonding of oxide or nitride to polysilicon, other oxides, nitrides or other silicon based structures. Micromechanical structural surfaces 90 include an Si 3 N 4 layer 100, an SiO x N y layer 110, a hydroxide layer 102, a SiO x layer 104 and a polysilicon layer 106. H 2 O is removed from micromechanical structural surfaces 90 by drying. Removal of H 2 O modifies the micromechanical structural surfaces 90 to form micromechanical structural surfaces 92, which now include a layer of strong covalent bonds 112. To avoid the formation of a layer of strong covalent bonds 112, the micromechanical structural surfaces 90 should instead be treated with hexamethyldisilazane as shown in FIG. 3. A reaction of hexamethyldisilazane with micromechanical structural surfaces 90 forms layers 96 which now include a non-bonded layer 118.
Although the present invention has been shown and described with respect to one embodiment, various changes and other modifications which are obvious to persons skilled in the art to which the invention pertains are deemed to lie within the spirit and scope of the invention.
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A method for preventing micromechanical structures from adhering to another object includes the step of immersing a micromechanical structure and its associated substrate in a chemical species that does not stick to itself. The method can be employed during the manufacture of micromechanical structures to prevent micromechanical parts from sticking or adhering to one another and their associated substrate surface.
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BACKGROUND OF THE INVENTION
The present invention relates to the field of instrumented assemblies of the kind for control or operating wheels used, for example, to steer motor vehicles, handling vehicles or civil engineering works vehicles or any other type of vehicle or machine requiring a steering wheel.
In the conventional way, a control wheel is connected to a shaft, for example a steering column shaft, which, depending on the type of steering used, either directly turns the steering mechanism in the case of mechanical steering, actuates hydraulic pressure distributors in the case of hydraulic steering or, finally, in the case of electric steering, actuates the encoderring of a sensor delivering a signal to the electric control motor, various combinations of these types being possible.
In the case of purely electrical steering, which is increasingly commonly in use on handling vehicles such as fork lift trucks. A system detecting the rotation of the wheel, which may or may not be incorporated into the bearings, delivers, via a cable, a signal representative of the turning of the wheel to the device for steering the wheels of the vehicle. As the wheel is mounted on its support by one or more antifriction bearings and is not connected to mechanical torque-transmitting systems, the wheel can be turned with an extremely low resistive torque. Often added to this is a wheel-braking system intended to generate therein a resistive torque so as to encourage precision and driveability in the driving of the vehicle. A device of this type is described, for example, in document DE-A-195 10 717.
This device does, however, exhibit certain disadvantages among which we shall take note first of all of the relatively great axial bulk and the relatively high cost which are due to the presence of two antifriction bearings in the continuation of which is arranged a braking system employing a coil spring which presses a conical friction piece into a cup which also has a conical friction surface. The frictional torque developed by such a device is relatively low and the wear is high because of the small friction surfaces. Furthermore, the braking system alters the operating play in the bearings.
Document FR-A-2 782 970 discloses a control wheel mounted on an instrumented antifriction bearing and to which is added a braking system, the rotating part of which is supported by the rotating inner ring of the antifriction bearing and rubs against the end wall of a housing. However, in this type of device, the antifriction bearing is not mounted on a shaft and the diametral bulk of the bearing and of the device is great.
The invention proposes to overcome the disadvantages of the devices of the prior art.
SUMMARY OF THE INVENTION
The invention proposes an economical and radially unbulky device.
The braked antifriction bearing device, according to one aspect of the invention, is of the kind intended for a control wheel. The device comprises an outer part and an inner part, one being rotating and the other non-rotating, a row of rolling elements which are arranged between said rotating and non-rotating parts. Said device further comprises a means of detecting rotation parameters and a means of braking the rotating part. The braking means comprises a plurality of disks kept in frictional contact by at least one axially elastic element. This yields a radially compact device which is simple to manufacture and the braking characteristics of which are easily adjustable. The disks may form an axial stack.
As a preference, the braking means comprises at least one disk secured axially to the non-rotating part and at least one disk secured angularly to the rotating part.
As a preference, the braking means comprises at least one elastic washer which serves to ensure mutual contact with axial preload between the friction surfaces of the disks.
In one embodiment, at least one of the disks of the braking means is angularly connected to the corresponding part which supports it by means of a lug projecting into a slot.
In one embodiment, the braking means is in the form of an annular cartridge the two axial ends of which comprise a lateral element of L-shaped cross section.
In one embodiment, the braking means is arranged radially between the outer and inner parts and is arranged axially, at least in part, in the axial continuation of the rolling elements and near the latter.
In one embodiment, the bearing device comprises two rings, one secured to the rotating part and the other secured to the non-rotating part and between which the rolling elements are arranged.
In one embodiment, the means of detecting rotation parameters comprises a sensor secured to the non-rotating ring and an encoder secured to the rotating ring.
In one embodiment, the sensor comprises a connection output passing through the non-rotating part.
In one embodiment, the non-rotating part comprises a tubular portion and a radial portion which is provided with means of attaching the device to a support.
In one embodiment, the rotating part comprises a tubular portion and a radial portion which is provided with means of attaching a wheel to the device.
This braked bearing device can be fitted and mounted easily at numerous possible locations on a vehicle or on a machine, for example on a dashboard, via the housing which acts as a support. Just a few screws are needed to fix the device by means of the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood and other advantages will become apparent from reading the detailed description of a few embodiments taken by way of entirely nonlimiting examples and illustrated by the appended drawings, in which:
FIG. 1 is a view in axial section of a bearing device; and
FIG. 2 is a view in section on II—II of FIG. 1 of the bearing device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As can be seen in the figures, the antifriction bearing device comprises an outer element 1 of annular shape, with an L-shaped half section, with a tubular portion 2 and a radial portion 3 extending at one end of the tubular portion outward. The radial portion 3 is provided with a plurality of fixing holes 4 able to take screws with a view to fixing to a fixed structure, not depicted. The tubular portion 2 is provided with two notches forming slots 5 extending from the free end of said tubular portion 2 and situated opposite the radial portion 3 . The slots 5 are of rectangular shape, their length being aligned with the axis referenced 6 on which the outer element 1 is centered. The outer element 1 may be made of pressed or bent sheet metal. A cap 7 , for example made of synthetic material, with the shape of a disk, closes the free end of the tubular portion 2 at which the slots 5 open, being push-fitted into its bore.
The antifriction bearing device also comprises an inner element 8 , also centered on the axis 6 , of annular shape and U-shaped section, exhibiting a tubular portion 9 one end of which is closed off by a radial portion 10 . A plurality of holes 11 are provided through the tubular portion 10 to take screws, not depicted, for example intended for fixing an operating wheel, also not depicted. The inner element 8 may also be made of pressed sheet metal. Arranged between the outer 1 and inner 8 elements is a row of rolling elements 12 which are held by a cage 13 .
In the alternative form illustrated in the figures, the rolling elements 12 are arranged between outer 14 and inner 15 rings. However, provision could be made for the rolling elements to be in direct contact with the outer 1 and inner 8 elements via raceways formed on said outer and inner elements.
The outer ring 14 is push-fitted into the bore 2 a of the tubular portion 2 of the outer element 1 and is provided with a raceway 16 for the rolling elements 12 . The inner ring 15 is push-fitted onto the outer surface 9 a of the tubular portion 9 of the inner element 8 and is provided with a raceway 17 for the rolling elements 12 . The outer ring 14 is also provided with two symmetric grooves 18 and 19 formed on its bore, one on each side of the raceway 16 . Fixed into the groove 18 is a sealing member 20 which rubs against a bearing surface of the inner ring 15 . Fixed into the groove 19 is a sensor unit referenced 21 in its entirety.
In the example illustrated, the sensor unit 21 comprises two detection elements 22 , 23 , arranged diametrically opposed and each embedded in a synthetic material forming a central part 24 of the sensor unit 21 . The sensor unit 21 is fixed on the front face of the outer ring 14 by means of a fixing support 25 inserted between the ring 14 and the sensor unit 21 , both on the radial parts and on the circumferential parts and a free end of which is bent into the groove 19 .
A cylindrical annular portion 24 a is inserted partially into the bore of the non-rotating ring 14 more or less in the region of the groove 19 so that the detection elements 22 , 23 can be arranged partly between the two rings 14 and 15 . An external protective plate 26 is also fixed to the outside of the sensor unit 21 by crimping performed by folding the other free end 25 a of the support 25 onto the periphery of the external protective plate 26 .
The sensor unit 21 further comprises two wire terminals 27 and 28 , which are associated respectively with the detection elements 22 and 23 and formed by an outgrowth of the synthetic material of the central part 24 for fixing the end of a cable 29 , 30 by means of which a signal emitted can be passed onto an electric signal processing and operating unit, not depicted in the figures. The wire terminals 27 , 28 of the sensor unit 21 each project through a slot 5 of the tubular portion 2 of the outer element 1 , being in contact with the end walls of said slots 5 .
The two detection elements 22 , 23 each collaborate with a single encoder ring 31 mounted facing the sensor unit 21 on the external cylindrical surface of the rotating ring 15 , so as to be driven in rotation by the latter.
The encoder ring 31 is mounted by means of a support 32 which is housed in part between the rings 14 and 15 . The support 31 , of annular shape with T-shaped cross section, is push-fitted onto the outer cylindrical surface of the rotating ring 15 and butts against a frontal surface thereof. A portion of the encoder ring 31 thus lies between the rings 14 and 15 and a portion projects outward. Most of the exterior cylindrical surface of the encoder ring 31 lies facing the two detection elements 22 , 23 , with a small gap.
An antifriction bearing is thus formed by the rolling elements 12 and the rings 14 and 15 . One or more sealing gaskets, one or more encoders, one or more sensors, etc. may be added to this antifriction bearing.
A braking member 33 is also arranged between the exterior surface 9 a of the tubular portion 9 of the inner element 8 and the bore 2 a of the tubular portion 2 of the outer element 1 . The braking member 33 is arranged in the axial continuation of the antifriction bearing equipped with its system for detecting the rotation parameters and is situated axially between the free end of the tubular portion 9 of the inner element 8 and the plate 26 protecting the sensor unit 21 . More generally, the braking member 33 is bounded axially by the cap 7 , because provision could be made for it to project axially beyond the free end of the tubular portion 9 toward said cap 7 .
The braking member 33 comprises a rotating part 33 a formed of two elements 34 , 35 of similar form and each comprising a tubular axial portion 34 a, 35 a and a radial portion 34 b, 35 b in the form of a disk. The free ends of the tubular portions 34 a, 35 a are mounted in contact with one another so that the elements 34 and 35 form a rotating part 33 a with a U-shaped cross section push-fitted onto the exterior surface 9 a of the tubular portion 9 .
The non-rotating part 33 b of the braking member 33 comprises two metal disks 36 and 37 arranged axially between the radial portions 34 b and 35 b of the rotating part 33 a. Arranged between the disks 36 and 37 is an axially elastic washer 38 . A friction lining or disk 39 is inserted axially between the disk 36 and the disk-shaped radial portion 34 b. This friction lining or disk is made of a material with a high coefficient of friction with respect to the fixed disks 36 and the radial portion 34 b. In the case of a lining, it is preferably bonded to the disk 36 and rubs against the radial portion 34 b. The same is true for the friction lining 40 , the disk 37 and the radial portion 35 b.
The disks 36 and 37 each comprise two lugs 41 , 42 projecting radially outward, diametrally opposed and arranged each one in a slot 5 of the tubular portion 2 of the outer element 1 .
In operation, the disks 36 and 37 are angularly secured to the outer element 1 because of the presence of the lugs 41 , 42 which thus prevents any angular displacement with respect to the slots 5 . The disks 36 , 37 are therefore fixed while the lateral elements 34 , 35 can turn. The frictional contact between the fixed disks and the rotating elements by way of the friction linings or disks 39 , 40 therefore creates a resistive torque.
The elastic washer 38 permanently maintains an axial force tending to force the disks 36 and 37 apart and thus ensure that the friction linings or disks 39 and 40 rub on the corresponding surfaces of the radial portions 34 b and 35 b of the rotating part 33 a of the braking member 33 .
The braking means is thus in the form of a compact cartridge arranged radially between the fixed outer element 1 and the rotating inner element 8 , in the axial continuation of and in close proximity to the instrumented antifriction bearing.
The structure of such a braking means has numerous advantages. First of all, it is very compact. Further, its modular design makes the frictional torque easy to alter simply by altering the number of disks, the number or type of elastic preloading washers, it being possible for this to be performed without any significant variation in the axial bulk of the cartridge, given the thinness of the components.
The braking means can, in a small bulk, generate a high frictional torque because of the number and magnitude of the surfaces in frictional contact.
The structure of the braking cartridge allows the preload to be preset easily by construction or by assembly, and therefore allows the braking torque to be calibrated.
All that is required is to determine the value of the gap needed between the two radial portions 34 b and 35 b, according to the desired preload.
This gap value is obtained easily when the two elements 34 and 35 are mounted on the inner element 8 . All that is required is for the extent to which these two elements are push-fitted together to be adjusted, or alternatively for the length of the tubular parts 34 a and 35 a to be predefined so that the desired gap is obtained when the free ends of the two tubular portions come into contact with one another.
This braking torque will remain particularly stable over time during operation because of the very little wear due to the large friction surfaces. The fact that the axial forces exerted on the wheel fixed to the inner element 8 do not in any way alter the braking torque is another advantage of the invention.
Finally, such a braking cartridge device has absolutely no influence on the antifriction bearings and is not likely to alter the clearance or preload thereof.
The various functions, particularly the bearing function afforded by the rolling elements 12 , the function of detecting rotation parameters afforded by the sensor unit 21 and the function of braking afforded by the braking member 33 are performed by means arranged in an annular space bounded radially between the tubular portion 2 of the outer element 1 and the tubular portion 9 of the inner element 8 and bounded axially between the radial portion 34 a of the element 34 of the braking member 33 and the frontal surface of the rings 14 and 15 opposite the sensor unit 21 .
The various elements can be mounted by push-fitting the antifriction bearing and the braking member 33 onto the inner element 8 then by bringing the outer element 1 from right to left in FIG. 1 , causing the outer ring 14 to be push-fitted into the bore 2 a, causing the wire terminals 27 and 28 to be pass into the slots 5 and causing the lugs 41 and 42 also to pass into the same slots 5 . The cap 7 is then fixed onto the outer element 1 .
It will be noted that the slots 5 , of which in an alternative form there may be a number different than 2 , allow both the passage of the cables 28 and 29 and the angular securing of the non-rotating part 33 b of the braking member 33 and of the outer element 1 . The various elements are all of simple shape. The antifriction bearing may be of standard and therefore very economical type. The braking member can be manufactured from sheet metal parts which are also very economical.
In place of the wire terminals 27 and 28 , it would be possible to imagine a connector originating directly from the sensor unit 21 . The elastic washer 38 constantly maintains an axial force which tends to move the disks 36 and 37 apart, increasing the friction of the friction linings or disks 39 and 40 on the corresponding surfaces of the rotating part 33 a of the braking member 33 .
Of course, it is possible to imagine reversing the arrangement of the braking member, with the friction linings and disks secured to the elements 34 and 35 , or alternatively reversing by swapping the rotating part and the non-rotating part. It would even be possible to imagine a rotating outer element 1 and an non-rotating inner element 8 . If the diameter of the inner element is small, it can be made from a solid piece, of the cylindrical rod type, of a metallic or synthetic material. In the latter instance, said inner element could be produced as one piece with other parts.
This braked antifriction bearing is particularly simple and economical to produce. It is perfectly modular and it is possible, in the same bulk, simply by changing the elastic washer 38 , to obtain a higher or lower braking torque. It is also possible to alter the material of the disks or of the friction linings to alter the resulting frictional torque.
It is also possible very easily to adapt the number of disks or preload washers to alter the braking torque without that considerably altering the axial bulk of the device. The resistive torque generated by the braking device can be high for a small bulk. This torque is perfectly calibrated by design and is particularly stable over time because the small amount of wear of the member of the elements has very little influence on the resistive torque. The entire braked antifriction bearing is in the form of a cartridge which is very unlikely to lose parts and which appropriately protects the most delicate elements.
In the examples illustrated, the sensor unit 21 is located between the rolling elements 12 and the braking member 33 . It is of course conceivable, without departing from the scope of the invention, to design a device in which the sensor unit is arranged on one side of the row of rolling elements 12 and the braking member is arranged axially on the other side of said row. In this case, the braking member 33 is no longer axially adjacent to the sensor unit as in FIG. 1 , but is axially adjacent to the rolling elements 12 .
Of course it would be possible to provide a cartridge in which the device for detecting rotation parameters was not mounted on the bearing rings but beside them, for example in direct contact with the outer 1 and inner 8 elements. Provision could be made for just one single detection element and one single wire terminal to be used.
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A locked antifriction bearing, for control wheel, includes an outer part and an inner part, one being rotating and the other non-rotating through at least a row of rolling elements arranged between said rotating and non-rotating parts, the device further comprising elements for detecting rotation parameters and elements for braking the rotating part. The braking elements comprise an axial stack of discs maintained in frictional contact through at least a disc angularly secured to the non-rotating part and at least a disc integral with the rotating part. The braking elements comprise at least an elastic washer for providing axially prestressed mutual contact of the friction surfaces of the discs.
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This is a continuation of U.S. application Ser. No. 07/766,949, filed Sep. 30, 1991, abandoned.
The present invention relates to an automatic transmission and, more particularly, to what is known as a "multi-step" or "multi-speed" automatic transmission.
BACKGROUND OF THE INVENTION
A multi-step transmission typically has a planetary gearset which changes a path in which engine torque is transmitted by various combinations of friction coupling elements so as to place the automatic transmission in, for instance, four forward gears and a reverse gear. Such an automatic transmission is well known from, for instance, Japanese Unexamined Utility Model Publication No. 62-100,357.
In an automatic transmission which has an increased number of shiftable gear ratios, for example five forward gear ratios, it is necessary to arrange a plurality of friction coupling elements in the automatic transmission differently from the manner in which the elements of a four forward gear ratio automatic transmission are arranged. From a manufacturing aspect, friction coupling elements of automatic transmissions should be compatible with automatic transmissions having different numbers of shiftable gear ratios. However, although automatic transmissions having different numbers of gear ratios have some friction coupling elements which are commonly useable, these common friction elements are not always identical in arrangement.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the invention to provide an automatic transmission having a plurality of forward gear ratios which can be provided by simply adding a gear ratio extension means to an automatic transmission having a smaller number of forward gear ratios.
The above object of the present invention is accomplished by providing an automatic transmission equipped with a torque convertor for an automobile engine which has first and second multi-transmission means mounted on first and second juxtaposed transmission shafts, respectively, and operationally coupled by counter gear means for transmitting engine torque from the first to the second multi-transmission means. The automatic transmission comprises extension means detachably coupled to the first multi-speed transmission means for changing a transmission path of engine output of the first multi-speed transmission. The number of shiftable gear ratios is made larger when the extension means is attached than it is when the extension means is detached.
Because the number of shiftable gear ratios is changed by installing or removing the extension means, at least most of the essential structural elements of the automatic transmission having a lower number of forward gear ratios are available for use in the automatic transmission having a higher number of forward gear ratios.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the present invention will be apparent to those skilled in the art from the following description of preferred embodiments when considered in conjunction with the drawings, wherein similar reference numerals have been used to designate the same or similar elements throughout the drawings, and in which:
FIG. 1 is a skeleton view illustrating a four forward speed automatic transmission in accordance with a preferred embodiment of the present invention;
FIG. 2 is a table showing combinations of activated friction coupling elements for four forward gears and a reverse gear;
FIG. 3 is a skeleton view illustrating a five forward speed automatic transmission in accordance with a preferred embodiment of the present invention;
FIG. 4 is a table showing combinations of activated friction coupling elements for five forward gears and a reverse gear;
FIG. 5 is a cross-sectional view illustrating portions of the four and five speed automatic transmissions shown in FIGS. 1 and 3 in which details of a rear portion of the four forward speed automatic transmission are shown in an upper half section and details of a rear portion of the five forward speed automatic transmission are shown in a lower half section;
FIG. 6 is a skeleton view illustrating a four forward speed automatic transmission in accordance with another preferred embodiment of the present invention;
FIG. 7 is a skeleton view illustrating a five forward speed automatic transmission in accordance with the other preferred embodiment of the present invention; and
FIG. 8 is a cross-sectional view illustrating portions of the four and five speed automatic transmissions shown in FIGS. 6 and 7 in which details of a rear portion of the four forward speed automatic transmission are shown in a lower half section and details of a rear portion of the five forward speed automatic transmission are shown in an upper half section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in detail and, in particular, to FIG. 1, a four forward speed automatic transmission AT4 in accordance with a preferred embodiment of the present invention is shown. The automatic transmission has two parallel shafts, such as a first shaft 2, integral with an output shaft 3 of a torque convertor 1, and a second shaft 4 in parallel with the first shaft 2. The torque convertor 1 comprises a pump 1a fastened to an engine output shaft 5, a turbine 1b fastened to the torque convertor output shaft 3 and a stator 1c. The pump 1a and turbine 1b are placed face to face with a slight clearance therebetween. The stator 1c is inserted between the pump 1a and turbine 1b. A lockup unit, such as a lockup clutch 6, is disposed between the convertor output shaft 3 and the engine output shaft 5 so as to mechanically lock the pump 1a and turbine 1b together when activated. A pressurized oil supply pump 7 is connected to the pump 1a of the torque convertor 1. The second shaft 4 is connected to a portion of a transmission casing 17 through a one-way clutch OWC1 at its front end and is coupled to and uncoupled from a portion of the transmission casing 17 through a clutch B1 at its rear end.
The automatic transmission AT4 comprises a first multi-speed transmission 13, such as a three speed gear transmission, including front and rear planetary gearsets 10 and 11 mounted on the first shaft 2, and a second multi-speed transmission 16, such as a two speed gear transmission, including a planetary gearset 15 mounted on the second shaft 4. The planetary gearsets 10, 11 and 15 themselves are well known in structure and operation. The front planetary gearset 10 has a sun gear 10a which is coupled to and uncoupled from the first shaft 2 by means of a clutch K2, and is coupled to and uncoupled from a portion of a transmission casing 17 by means of a brake B2 or by means of a brake B4 through a one-way clutch OWC2. The front planetary gearset 10 further has a planetary gear 10b having a front carrier 18 which is coupled to and uncoupled from a portion of the transmission casing 17 through a one-way clutch OWC3 or a brake B3.
The rear planetary gearset 11 has a sun gear 11a which can be coupled to the first shaft 2 by means of a clutch K3. The rear planetary gearset 11 further has a planetary gear 11b having a front carrier 19 which is connected to a ring gear 10c of the front planetary gearset 10, a ring gear 11c connected to a front carrier 18 of the planetary gear 10b of the front planetary gearset 10, and a rear carrier 20 operationally coupled to the second multi-speed transmission 16 mounted on the second shaft 4 through a pair of counter gears 21. The planetary gearset 15 of the second multi-speed gear transmission 16 has a ring gear 15a which is coupled to the counter gears 21 and is coupled to and uncoupled from the second shaft 4 by means of a brake K1. The planetary gearset 15 further has a sun gear 15c, which is fixedly connected to a portion of the casing 17, and a planetary gear 15b having a carrier 23 which is connected to an output gear 24. Parts shaded in FIG. 1 are pistons of various friction coupling elements, such as clutches and brakes.
The engine output is transmitted from the first shaft 2 to the second shaft 4 through the first and second multi-speed transmissions 13 and 16 coupled to each other by the counter gears 21. The automatic transmission AT4 is placed into various speed gears, such as first, second, third, fourth and reverse gears. In each speed gear, the friction coupling elements, namely, the clutches K1-K3, the brakes B1-B4, and the one-way clutches OWC1-OCW3 are selectively coupled and uncoupled as is shown in FIG. 2. In FIG. 2, the respective friction elements are coupled in speed gears indicated by circles, and the respective brakes are coupled in speed gears indicated by circles in parentheses in which engine braking is necessary. As is shown in FIG. 2, in the forward fourth speed gear (4th), the first to third clutches K1-K3 and the brake B4 are coupled, so as to directly connect the planetary gear 11b of the rear planetary gearset 11 of the first multi-speed transmission 13 to the first shaft 2, thereby providing a gear ratio of 1 (one).
Referring to FIG. 3, a five forward speed automatic transmission AT5 in accordance with another preferred embodiment of the present invention is shown. This transmission AT5, in addition to the whole structure of the four forward speed automatic transmission AT4 shown in FIG. 1, includes a gear unit X for a fifth speed gear detachably mounted to the rear end of the first multi-speed transmission 13 remote from the torque convertor 1. The fifth speed gear unit X comprises clutches K4 and K5 and a one-way clutch OWC4. The clutch K4 and one-way clutch OWC4 connects and disconnects the first shaft 2 from the sun gear 11a of the rear planetary gearset 11 of the first multi-speed transmission 13. The clutch K5 connects and disconnects the first shaft 2 from the rear carrier 28 of the planetary gear 10b of the front planetary gearset 10 of the first multi-speed transmission 13.
The automatic transmission AT5 is placed into the first to fifth and reverse gears. In each speed gear, the friction coupling elements, namely, the clutches K1-K5, the brakes B1-B4 and the one-way clutches OWC1-OCW4, are selectively coupled and uncoupled as is shown in FIG. 4. The respective friction elements are coupled in speed gears indicated by circles, and the respective brakes are coupled in speed gears marked by circles in parentheses where engine braking is necessary. As is apparent from FIG. 4, the clutch K4 of the automatic transmission AT5 has the same function as the clutch K3 of the automatic transmission AT4. Also, the clutch K3 of the automatic transmission AT5 serves as a clutch effecting engine braking. In the forward fifth speed gear (5th), in addition to elements coupled in the coupling condition in the fourth speed gear, in which a gear ratio is 1 (one), the brake B4 is coupled so as to transmit the engine output to the ring gear 10c of the front planetary gearset 10 of the first multi-speed transmission 13 from the planetary gear 10b.
The four forward speed automatic transmission AT4 shown in FIG. 1 is used, as it is, as part of the five forward speed automatic transmission AT5 shown in FIG. 3. In order to clarify the compatibility of the four forward speed automatic transmission AT4, reference should be made to FIG. 5, which shows, as an upper half section, details of a rear portion of the four forward speed automatic transmission AT4 and, as a lower half section, details of a rear portion of the five forward speed automatic transmission AT5.
In the four forward speed automatic transmission AT4, the clutch K3 has a clutch ring K3a, spline-coupled to a hollow shaft 25 disposed coaxially with the first shaft 2 and coupled to the sun gear 11a of the rear planetary gearset 11 through the hollow shaft 25, and a friction element K3b having an outer periphery which is supported by a generally cylindrical ring member 26 fixedly mounted on the first shaft 2. The clutch K3 further has a hydraulic pressure chamber K3d, in communication with a hydraulic pressure line 27, formed between the generally cylindrical ring member 26 and a piston K3c, forced by a return spring K3e toward the clutch K3. Mounted between the first shaft 2 and the hollow shaft 25 is a hollow shaft 28 connected to the ring gear 11a of the rear planetary gearset 11.
The five forward speed automatic transmission AT5 with the fifth speed gear unit X has a piston K3c' having a cylindrical extension, of a clutch K3' disposed within a cylindrical member 30 mounted on the first shaft 2' so as to form a hydraulic pressure chamber K3d' between the piston K3c' and the cylindrical member 30. Within the cylindrical extension of the piston K3c', there is disposed a cylindrical member 31 with a friction ring element K3b' installed therein. The friction ring element K3b' is spline-coupled by a spline ring member K3a' to the hollow shaft 25 through cylindrical ring members 32 and 33, mounted on the hollow shaft 25, and is connected to the ring gear 11a of the rear planetary gearset 11.
The clutch K4 comprises a friction ring member K4b and a cylindrical piston K4c, both installed in the cylindrical member 31, so as to form a hydraulic pressure chamber K4d between the friction ring member K4b and piston K4c. The friction ring member K4b is connected, by a spline ring member K4a, to the ring gear 11a of the rear planetary gearset 11 through the one-way clutch OWC4 mounted on the cylindrical ring member 33 on the hollow shaft 25. The clutch K5 comprises a friction ring member K5b, installed within the cylindrical member 31, and a piston K5c, disposed within the cylindrical piston K4c, so as to form a hydraulic pressure chamber K5d between the friction ring member K5b and piston K5c. The friction ring member K5b is connected, by a spline ring member K5a, to the rear carrier 28 of the planetary gear 10b of the front planetary gearset 10 through a cylindrical spline ring member 35. The cylindrical spline ring member is connected to the hollow shaft 25.
As is clearly understood from the above, in order to convert the four forward speed automatic transmission AT4 to the five forward speed automatic transmission AT5, it is enough to attach the clutches K4 and K5 to the counter gears 21 on one end remote from the torque convertor 1 after replacing the clutch K3 with the one-way clutch OWC4. The first shaft 2 and the rear carrier 28 of the planetary gear 10b of the front planetary gearset 10 extend rearward sufficiently greatly to mount thereon the clutches K4 and K5. All parts, other than first shaft 2 and the rear carrier 28 of the four forward speed automatic transmission AT4, are available for use in the five forward speed automatic transmission AT5.
Referring to FIGS. 6 to 8, a four forward speed automatic transmission AT4' and a five forward speed automatic transmission AT5' in accordance with another preferred embodiment of the present invention are shown. Almost all of the essential parts are compatibly used in this embodiment. Because the four forward speed automatic transmission AT4' is almost the same in structure and arrangement as the four forward speed automatic transmission AT4, the following description will be directed primarily to differences between the four forward speed automatic transmission AT4' and the four forward speed automatic transmission AT4. As is shown in FIG. 6, the four forward speed automatic transmission AT4' includes first and second multi-speed transmissions 13' and 16'. In the first multi-speed transmission 13' a one-way clutch OWC2' is disposed axially in front of a clutch K2'. A brake B2' rather than the brake B2 of the previous embodiment shown in FIG. 1 to 5 is disposed in the same axial position as the clutch K2'. A front carrier 18' of a front planetary gearset 10' is connected to a front carrier 19' of a rear planetary gearset 11' through a connecting member 50' on which a count gear 21' is mounted A ring gear 10c' of the front planetary gearset 10' is connected to a sun gear 11a' of the rear planetary gearset 11' through a connecting member 28'. A brake B3' is located in front of a one-way clutch OWC3'. A clutch K3" is connected to a sun gear 11a' of the rear planetary gearset 11' through a connecting member 51'.
In the second multi-speed transmission 16' a brake B1' is disposed outside a clutch K1' and a one-way clutch OWC1' is disposed rearward of the clutch K1'.
Because the five forward speed automatic transmission AT5' is also almost the same in structure and arrangement as the five forward speed automatic transmission AT5, the following description will be directed primarily to differences between the five forward speed automatic transmission AT5' and the five forward speed automatic transmission AT5. As is shown in FIG. 7, the five forward speed automatic transmission AT5' is provided with a fifth speed gear unit X' attached to the multi-speed transmission 13' mounted on the first shaft 2"' at one end remote from the torque convertor 1. The fifth speed gear unit X' has two clutches K4' and K5' and a one-way clutch OWC4'. The clutch K5' and the one-way clutch OWC4' are connected to the sun gear 11a' of the rear planetary gearset 11'.
In order to describe the compatibility between the fourth and fifth forward speed automatic transmissions AT4' and AT5', reference is made to FIG. 8, which shows, as a lower half section, details of a rear portion of the four forward speed automatic transmission AT4' and, as an upper half section, details of a rear portion of the five forward speed automatic transmission AT5'.
In the four forward speed automatic transmission AT4', the clutch K3" has a clutch ring K3a", spline-coupled to a hollow shaft 51' disposed coaxially with the first shaft 2" and coupled to the sun gear 11a' of the rear planetary gearset 11' through the hollow shaft 51' and a friction element K3b". The outer periphery of the friction element K3b" is supported by a generally cylindrical ring member 26' fixedly mounted on the first shaft 2". The clutch K3" further has a hydraulic pressure chamber K3d", in communication with a hydraulic pressure line 27', formed between the generally cylindrical ring member 26' and a piston K3c". The piston K3c" is forced by a return spring K3e" toward the clutch K3".
The five forward speed automatic transmission AT5' with the fifth speed gear unit X' has a clutch K3"' connected to a cylindrical member 53' formed integrally with the ring gear 11c' of the rear planetary gearset 11' through a spline K3a"'. A cylindrical member 54', within which a friction ring element K3b"' is installed, is connected to the shaft 2"' through a cylindrical member 55'. A piston K3c' and a cylindrical member 56' behind the cylindrical member 55' are adjacent to each other so as to form a hydraulic pressure chamber K3d"' therebetween. A return spring K3e"' is disposed between the piston K3c"' and the cylindrical member 55'.
The clutch K4' is connected by a spline K4a' to a cylindrical member 59', which is fastened to a cylindrical hollow shaft 60' formed integrally with a sun gear 11a' of the rear planetary gearset 11' through a one-way clutch OWC4'. A friction ring member K4b' is disposed within the cylindrical member 55'. The cylindrical member 55' and a piston K4c', disposed in front of the cylindrical member 55', form therebetween a hydraulic pressure chamber K4d'.
A clutch K5' is connected by a spline K5a' to the cylindrical hollow shaft 60' formed integrally with a sun gear 11a' of the rear planetary gearset 11' and has a friction ring member K5b' installed within the cylindrical member 55'. The clutch K5' further has a piston K5c' disposed in front of the piston K4c' of the piston K4' so as to form a hydraulic pressure chamber K5d'. A return spring K5e' is disposed in front of the piston K5c' for biasing both the clutches K4' and K5'. The transmission casing 17 is integrally formed, at its mid-portion, with a partition wall 17a which extends radially inward between the counter gear 21 and the rear planetary gearset 11' and holds a thrust bearing 17b. The partition wall 17a with the thrust bearing 17b makes the automatic transmission very rigid in both the radial and axial directions.
As is clear from the above, in order to change the four forward speed automatic transmission AT4' into the five forward speed automatic transmission AT5' it is enough to attach the clutches K4' and K5' and the one-way clutch OWC4', as friction elements of the fifth speed gear unit X', after replacing the clutch K3" with another. In this case, although it is necessary to extend the hollow shaft 51' of the four forward speed automatic transmission AT4', as the shaft 60', with which the sun gear 11a' of the rear planetary gearset 11', is integrally formed therewith almost all of the parts, other than first shaft 2 and hollow shaft 51', of the four forward speed automatic transmission AT4' are available to the five forward speed automatic transmission AT5' for use.
It is to be understood that although the present invention has been described with respect to preferred embodiments thereof, various other embodiments and variants which fall within the scope and spirit of the invention may be apparent to those skilled in the art. Such other embodiments and variants are intended to be covered by the following claims.
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An automatic transmission includes first and second multi-step or speed transmissions mounted in parallel with each other with respect to a transmission shaft. The multi-step or speed transmissions are operationally coupled by a counter gear for transmitting engine torque from the first multi-step or speed transmission to the second multi-transmission. An extension unit having friction clutch elements is detachably coupled to the first multi-step or speed transmission for changing a transmission path of the engine torque through it. The number of shiftable gear ratios of the automatic transmission, therefore, can be increased.
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This is a division of application Ser. No. 450,773, filed Mar. 13, 1974 now U.S. Pat. No. 3,986,903.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to semiconductor devices and more specifically to MOS field effect transistors.
2. Prior Art
MOSFET devices are well known in the prior art and are described in many patents and publications. One such source of prior art practice is a book "MOS Integrated Circuits" (1972) edited by William M. Penney and Lillian Lau.
The structure of a MOSFET device, as disclosed by the prior art, includes a monocrystalline semiconductor region (e.g., substrate wafer) with a pair of closely spaced regions on the surface, opposite in conductivity type as compared with the substrate, called the source and the drain. A gate electrode, made either of an appropriate material, such as, a metal, or a semiconductor material, removed from the wafer by a layer of insulating material such as silicon oxide or nitride or a combination thereof which insulating material covers the area between the source and the drain. Various maskings, oxidation steps and metalizations are used in the process of forming the device elements and making contact with them. The impedance existing between the source and drain elements is controlled by the potential applied to the gate element.
Certain difficulties have been noted in the prior art devices which have been eliminated by the present invention. For example, in prior art devices "junction spiking" is a very common defect. This defect comes about because of the preferential etching which occurs along the 100 plane in a monocrystalline silicon wafer (hereinafter referred to as "100 plane silicon"). The 100 plane silicon is often used in n-channel MOS devices although 111 plane silicon may be employed. (In 111 plane silicon the preferential etching tends to occur in a lateral plane.) The preferential etching defect results from the processing temperatures commonly used after metalization (e.g., aluminum), which enables material from the substrate (e.g., silicon) to diffuse from the contact area of the substrate into the metalization and conversely the metalization flows to fill the voids in the substrate (e.g., contact areas of substrate). Thus, the substrate material dissolves in the metalization. Further, the metalization (e.g., aluminum) often dissolves the substrate material (e.g., silicon) in a preferential manner that produces metal penetration much further into the substrate than would be the case if the dissolution of the substrate and the subsequent penetration by the metalization were isotropic (radiating equally in all directions). If the metalization penetrates through the junction it often results in a short of the junction. This phenomena is known in the industry as junction spiking. As will be described later, preferential etching does not tend to occur in the invented device. In addition, the junctions can be preferentially deepened in the vicinity of the contacts. Both of these improvements result in a device that is much less prone to junction spiking.
An important use of MOS devices is for dynamic memory purposes. In this application, information may be stored in the cell for a short period of time due to the effect of minority carrier lifetime in the source and drain elements and associated effective capacitance. In prior art devices the storage time available is often quite short and very sensitive to the presence of certain impurities in the semiconductor material. Because of the greatly increased minority carrier lifetime of a cell employing the invention, the yields of parts with an acceptable storage time can be significantly increased. Alternatively, it is possible to maintain the present yields and produce parts having a substantially longer refresh cycle. Thus, when circuits employing the invention are in use, it is possible that such circuits will employ a much smaller percentage of available system time to restore and maintain the stored information. In substance, a dynamic cell is, without structural addition or the addition of components, made to approach the performance of a static cell which generally requires many more components. This result is attained with a number of other advantages incident thereto. For example, it is possible in an n-channel MOS device to deepen the junctions in the vicinity of the contacts to the source and drain without making the source and drain equally deep at portions directly adjacent the gate. Thus, low gate to drain capacitance may be obtained enabling high-speed performance while permitting simple metalization. Also, the metal cracking problem is simultaneously provided for and greater flexibility and tolerance are enabled in the metalization.
SUMMARY OF THE INVENTION
The present invention is described herein, by way of example, as a silicon gate MOSFET, however, the invented method is applicable to various forms of field effect devices such as, for example, metal gate MOS, silicon gate MOS, FAMOS devices, MNOS devices, charge coupled devices, bucket brigade devices, or silicon on sapphire or other insulator devices. All such devices and similar devices shall be within the term "field effect devices."
The processing of a MOSFET device in accordance with the present invention proceeds along conventional lines up to the metalization of contacts onto the source, drain and gate elements. After preparation for metalization, including masking, etc., but prior to metalizing, a heavy doping of phosphorous or arsenic or other material is made onto the surface of the wafer, resulting in a heavily doped n++ region in both the source and drain. This step is followed by an etchant dip to remove any oxides formed on the surfaces where electrical contact will be made to the device and then metalization is accomplished as disclosed by the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a substrate on which the invented MOS device is fabricated.
FIG. 2 is the substrate of FIG. 1 after a layer of silicon dioxide has been added thereon.
FIG. 3 is a cross-sectional view of the device after removing the oxide coating from an area of the substrate and regrowing a thinner oxide layer.
FIG. 4 is the device of FIG. 3 after deposition of a silicon layer.
FIG. 5 is a cross-sectional view of the device after the silicon gate has been formed.
FIG. 5A is a perspective view of a portion of the device at the stage of FIG. 5.
FIG. 6 is a cross-sectional view of the device after formation of the source and drain.
FIG. 7 shows the addition of layer of silicon oxide to the device as shown in FIG. 6.
FIG. 8 is a cross-sectional view of the device after having a portion of the silicon oxide layer removed over the source and drain.
FIG. 9 is a cross-sectional view of the device of FIG. 8 after a diffusion of phosphorous.
FIG. 10 is a cross-sectional view of a completed MOSFET made in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with one embodiment of the invention, a substrate or region of p-type monocrystalline silicon (e.g., with 100 plane orientation) is used to form an n channel MOS field effect transistor. The substrate may be a thick, mechanically substantial wafer or may be a thin layer of p-type silicon deposited on some other form of base. For example, one type of construction which could be used is the so-called silicon on sapphire configuration which consists simply of a thin layer of silicon deposited on a sapphire wafer. The substrate, whether it be mechanically independent or merely a layer on another base is indicated in FIG. 1 by numeral 10. While only one device is shown being fabricated on the substrate, common practice is to use a single substrate wafer for a large number of devices (e.g., 100 or more chips each containing 1000 or more MOSFETS).
By way of an example but not as a limitation, the invention will be described as it applies to a fairly common n-channel Si gate process. The first step of the process is the growing of a thick layer of silicon oxide 11 (e.g., S/O 2 ) on the top surface of the substrate 10 as shown in FIG. 2. The thickness of the layer is typically one micron thick. Alternatively, this layer may be chemically deposited. Next, the area which is to be the site of the invented MOS device is etched, using conventional photo fabrication techniques, to remove a portion of the oxide layer 11 or the site of the invented device may be left substantially non-oxide covered by the presence of a suitable oxidation barrier (silicon nitride) during the growth of the thick oxide. (For example, see Electronics, Dec. 21, 1971, pp. 43-48.) A thin layer of silicon dioxide 12, typically 1000 angstroms thick, is then regrown or deposited in the etched area. The device at this stage of fabrication is shown in FIG. 3.
A layer 13 of polycrystalline silicon is then deposited over the entire surface of the wafer as shown in FIG. 4. Portions of this layer 13 and layer 12 are then removed, again by standard prior art techniques, leaving only strips of polycrystalline silicon which are to become either the gate element of the device (layer 13) or interconnects. The layer 13 is seen to be separated from the substrate 10 by a thin insulating layer of silicon dioxide 12. (It should be noted that an opening in the thin oxide may be appropriate prior to forming layer 13 whereupon the layer 13 may then also be employed as a contact and an interconnect in accordance with U.S. Pat. No. 3,699,646 assigned to the assignee of the subject invention.)
Next, source 14 and drain 15 are formed and the gate is doped with a type impurity (e.g., phosphorous, arsenic, antimony, etc.), as is done in the prior art. Subsequently, the entire wafer surface is covered with a coating of silicon dioxide 16 by vapor deposition. (These steps are illustrated in FIGS. 6 and 7.) Openings are then etched through oxide coating 16 to uncover a portion of the souce 14 and drain 15. It should be understood that while reference has been frequently made above to diffusion, ion implantation may be employed in combination with diffusion or alone to obtain a desired impurity profile. This is true throughout the application where reference is made to diffusion.
The process to this point has been disclosed in the prior art and has been in common use for some time and consequently, the description has not been greatly detailed. There are numerous alternatives to arriving at the same general partially completed device shown in FIG. 8 with various steps rearranged and/or other steps or materials added or deleted.
The next steps in the process would normally involve the forming of a metalization layer. In the subject invention, prior to metalization and after formation of the source and drain (or other region), the surface is subjected to a heavy diffusion of an n-type impurity which causes regions 17 and 18 of n++ conductivity type silicon to be formed in the substrate (e.g., solid solubility at over 1000° C). Preferably, phosphorus is employed as the impurity or dopant. The phosphorous diffusion is preferably made heavy enough and at a temperature to cause rounding of the corners on layer 16 of silicon oxide. This corner rounding makes possible smaller than standard sized metal interconnects, thereby saving space. It should be noted that an earlier glass forming step may be employed to assist in rounding the corner. This aspect of the process is disclosed in Great Britain Pat. No. 1,326,947 assigned to the assignee of the subject application. It should be noted that in one form of the invention the additional diffusion or impurity addition is employed with a prior diffusion or impurity addition wherein in both instances the impurity employed is phosphorous. It is possible and desirable in some devices to employ arsenic or antimony as an impurity in connection with the first diffusion or impurity addition and phosphorous in connection with the second impurity addition to the source and drain region. Since arsenic and antimony are much slower diffusants than phosphorous, this will result in a shallow junction in the region most closely adjacent the gate and a substantially deeper junction in the portion of the source and drain removed from the gate and in the proximity of the contact metalization. Thus, the gate to drain capacitance is maintained at a relatively low value providing high speed performance while all of the advantages of the invention are attained.
Following the extra diffusion the wafer is then dipped in an etchant which thins layer 16 somewhat and removes any oxides formed during the phosphorus diffusion. After the etchant dip, the device is completed by formation of contacts 19 and 20 on the surface of the wafer, which may provide a means for connecting the device to an external circuit, to other devices on the same substrate, or to another layer of interconnect.
The very high surface concentration of phosphorous has been found to have some unique, important and surprising results. The silicon at the surface appears to be strained by the diffusion to such an extent that there is no longer preferential etching in the "100" direction and consequently "spiking" of the source and drain junctions is substantially reduced. In addition, the source and drain are driven deeper so that any spikes, if such did exist, would not be as apt to penetrate the junctions. The nature of the source and drain are also changed to enable an alloying cycle of a less critical nature and/or to permit pure aluminum to be used rather than an aluminum silicon alloy for metalization.
Another important result of the invented device is that the bulk lifetime of minority carriers is greatly increased so that when being used as a part of a dynamic memory device, the refresh rate can be substantially reduced. In one experiment refresh rates for prior art devices were in the order of 10 microseconds to a millisecond whereas, with the invented device, a refresh rate of 0.5 seconds to 2 seconds was noted. This dramatic result which was not contemplated is apparently attained by the placing of a gettering material (heavily n++ phosphorous doped material) in contact with the substrate and in such close proximity to the junction of the device. It should be noted that all of the advantages of the present invention are accomplished without an additional masking step. This is particularly important since the addition of masking steps commonly decreases the yields and densities attainable.
The present invention has been described as a conventional n channel MOS device, but it will be clear to those skilled in the art that the same principles can be applied to other devices with advantage. For example, it is contemplated within the spirit of the invention that charge coupled devices or stepless MOS devices can be constructed in accordance with the present invention. While in the presently preferred embodiment of the invention, the n++ diffusion is of phosphorous, it has been found that in some devices arsenic could also be used with similar advantages.
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An n channel MOSFET transistor which includes doping of previously formed source and drain elements with a heavy diffusion of phosphorous or arsenic creating n++ regions in the source and drain. The extra diffusion step is preferably accomplished just prior to contact metalization.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to process optimization. More particularly the present invention relates to a system to reduce water loss and overflow loss in a paper mill by recycling water back into the system, and using the entire overflow.
2. Description of Related Art
In present-day paper mills, an abundance of fresh water is needed for the paper making process, including, among other things, washing requirements and paper stock preparation. After these uses, these waters are passed mainly to mix with fibrous circulation waters. Any excess amount of circulation water is disposed of as waste water. The net amount of fresh water that is needed for a paper machine is of an order of about 10 cubic meters per ton of paper produced. Thus, from a paper mill, an abundance of warm waste water is obtained, which must be cleaned and filtered before disposal.
Therefore, what is needed is a system that may efficiently and effectively recycle water in a paper mill, reducing waste water and the need for fresh water.
SUMMARY OF THE INVENTION
The subject matter of this application may involve, in some cases, interrelated products, alternative solutions to a particular problem, and/or a plurality of different uses of a single system or article.
In one aspect, a method of conserving fluid in a paper machine system, such as a Fourdrinier machine system, is provided. The method eliminates overflow from a wire pit, and recycles excess water, minimizing waste. The method may begin with collecting a fluid drained from a paper stock on a wire mesh in a seal water tank. A quantity of this collected fluid may then be drained. The flow of the drained fluid is separated into two distinct flows, preferably through a splitting of piping through which the fluid travels. The first flow is directed to a wire pit of the paper machine system, the second flow is recycled to various processes requiring clean water in the paper machine system. Control of the first and second flows is determined largely based on a fluid level in the wire pit. A fluid level sensor is positioned to measure fluid level in the wire pit. This fluid level sensor is in electronic communication with a computer, and provides an output signal to the computer based on the fluid level measured. The computer is configured to adjust the fluid flow from the seal water tank to the wire pit to maintain the fluid level therein at a desired level. Adjustment may be performed by the computer adjusting one or a plurality of valves along the flows, and/or by adjusting a pump to control fluid flow rate. The balance of the fluid from the seal water tank passes to the second flow and is recycled. As such, the system efficiently recycles clean fluid through the system. Further, the need for processing waste water is eliminated because the system does not dispose of excess fluid.
In another aspect, a system of conserving fluid in a paper machine system is provided. This system prevents overflow from a wire pit to conserve and recycle fluid within the system. A wire mesh of the paper machine has a quantity of paper stock disposed on its top surface, and a quantity of fluid is allowed to drain from the paper stock, through the mesh to a seal water tank. This fluid may drain naturally by gravity, or may be urged out using a vacuum system. Fluid draining to the seal water tank is relatively distant from a head box where the paper stock is initially disposed on the wire mesh. As such, fluid draining from the stock is substantially clean, and contains almost no paper fibers. A piping is connected to the seal water tank, and drains the fluid from the tank. This piping splits into a first flow section and a second flow section. The first flow section directing fluid to a wire pit, the second flow section directing fluid to a clear water tank to be recycled into the paper machine system. A computer controller is configured to control fluid flows within the system. A fluid level sensor is positioned and configured to measure a level of fluid within the wire pit, and is in electronic communication with the computer controller. A valve is positioned along the piping, and may be positioned at any portion, for example, close to the seal water tank drain before the piping splits, on the first flow section, or on the second flow section. The valve is configured to control a fluid flow within the piping, and comprises an actuator in communication with the computer controller. This communication may be electronic, or pneumatic, or a combination of the two. The fluid level sensor is configured to send a first signal to the computer controller based on the fluid level measured. Based on the signal received, the computer controller is configured to send a second signal to the valve based on the first signal. In one embodiment, the valve may comprise an actuator which may receive the second signal and adjust the valve accordingly to increase or decrease flow through the valve. In a further embodiment, a plurality of valves and/or pumps may be positioned along the piping. The computer controller may be further configured to control one or multiple of these valves and/or pumps based on the signal received from the fluid level sensor.
In yet another aspect, a method of installing a system of conserving fluid on an existing paper machine system, such as a Fourdrinier machine, is provided. The method may be carried out on an existing machine system with minimal downtime of the system. Traditionally, a piping connects a seal water tank and a wire pit, with fluid flowing unimpeded from the seal water tank to the wire pit. The method begins with installing a quantity of new piping is to direct a portion of fluid flow in the existing piping to a clear water tank. The clear water tank acting as a storage area for fluid to be recycled into the system such as for stock preparation, shower systems, and the like. A valve is installed along either the existing piping or the new piping, the valve being configured to control a fluid flow through it. A fluid level sensor must be installed on the wire pit, to measure a fluid level therein. A computer controller may be installed, in communication with the fluid level sensor and the valve. The computer controller being configured to receive a first signal from the fluid level sensor, and to output a second signal to the valve based on the first signal. The valve is then configured to automatically adjust fluid flow through it based on the second signal. This automatic adjustment of the valve may be affected by, for example, an actuator. By controlling fluid level within the wire pit, the wire pit overflow can be eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 provides a process view of a prior art paper machine system.
FIG. 2 provides a process view of the present invention.
DETAILED DESCRIPTION
The detailed description set forth below in connection with the appended drawings is intended as a description of presently preferred embodiments of the invention and does not represent the only forms in which the present invention may be constructed and/or utilized. The description sets forth the functions and the sequence of steps for constructing and operating the invention in connection with the illustrated embodiments.
The present invention utilizes a system and method that may be installed in existing paper machines. The present invention eliminates wire pit overflow, controls wire pit level, and allows relatively clean seal pit water to be recycled throughout the system for various uses.
An example of a prior art paper mill wet end is shown in FIG. 1 . In the prior art, paper stock exits the head box 10 and onto a wire 11 . Along the wire, fluid drains from the solid fibrous content of the paper stock. Fluid 111 draining from a region close to the head box 10 contains a relatively high concentration of fibers, as well as chemicals, dyes and other contaminants. This fluid 111 drains to a wire pit 14 . Fluid 211 from the wire pit 14 may overflow into a white water chest 15 . The white water chest 15 fluid 211 may then be recycled for stock preparation 110 . Excess fluid 211 in the white water chest is sent via 114 to a treatment (Save All) system 16 . Through the treatment system 16 a substantial amount of fluid must be processed and sent to a sewer system, leading to wasted energy and fluid. This fluid could be recycled and reused, resulting in reduced cost and reduced waste.
Fluid 212 draining from a region further from the head box is pulled from a dryer stock and drains to a seal pit 13 . This fluid may be drained by gravity, or may be urged from the stock using a vacuum system 12 . This fluid 212 has a substantially lower concentration of fiber than fluid 111 draining from a region close to the head box.
Fluid from the seal pit drains freely via path 113 to the wire pit 14 , causing the wire pit 14 to overflow. As discussed above, the overflow fluid 211 is transferred to a white water chest 15 for recycling and processing.
By contrast, as shown in FIG. 2 , the present invention prevents overflow from the wire pit 14 , which contains cloudy white water, to the white water chest 15 of FIG. 1 , eliminating the need for the white water chest 15 (of FIG. 1 ) entirely. Thereby eliminating the fluid flow path 211 of FIG. 1 . Accordingly this clean seal pit 13 fluid 212 of FIG. 1 may be used for numerous uses in the plant aside from stock preparation in the head box. As shown in FIG. 2 , seal pit 13 fluid of the present invention is used differently than the prior art.
FIG. 2 provides a process view of the present invention. Similarly to FIG. 1 , a stock exits the head box 10 and is received on the wire 11 . In a region close to the head box 10 fluid 111 drains from the wire 11 to a wire pit 14 . Fluid 111 draining into the wire pit 14 may be recycled back to the head box 10 via path 210 . In one embodiment, a fan pump 21 may be used to pump the fluid 111 along path 210 to the head box 10 . Fluid 111 has a high concentration of fibers and other contaminants and is referred to herein as cloudy white water. In a region further from the head box, gravity, flat boxes or vacuum systems 12 serve to extract fluid 212 from the stock, which drains to the seal water tank 13 . This fluid 212 has a substantially lower concentration of fiber and contaminants than the cloudy white water 111 . Because of the low concentration, the fluid 212 is relatively pure and is referred to herein as clean water 212 .
The clean water 212 from the seal water tank 13 may be drained from the tank along path 214 . In one embodiment a pump 29 may aid in draining fluid 212 from the seal water tank 13 . Further, a check valve 30 may prevent a backflow of fluid into the seal water tank. This path may then be split into two flows: 214 a and 214 b . Flow 214 a may be recycled to the wire pit 14 to maintain fluid level therein. Flow 214 b travels to a clear water tank 22 . Fluid from the clear water tank 22 may exit the tank via 200 for use in stock prep, for shower water, and for other plant uses that require clean water 212 .
Clean water 212 flow 214 from the seal water tank may be separated into flows 214 a and 214 b in any manner capable of separating flows in a controlled manner. In one embodiment, a three way valve (not shown) may be utilized to control flow separation from path 214 to 214 a and 214 b . In another embodiment, a valve 26 along path 214 a may control flows along both 214 a and 214 b . In yet another embodiment, a valve 27 along path 214 b may control flows along both 214 a and 214 b . In still another embodiment, two valves 26 and 27 may be used to control flow, 214 a being controlled by valve 26 , and 214 b being controlled by valve 27 .
A computer controller 25 may be utilized to control fluid flow along path 214 , 214 a to the wire pit 14 and/or 214 b to the clear water tank 22 . The computer controller may receive an input 215 from a fluid meter 24 which measures the level of fluid in the wire pit 14 . Based on this input, the computer controller 25 may adjust flow valves 26 and/or 27 via electronic or pneumatic communication along paths 216 and 217 . The computer controller 25 may also adjust pump 29 in other embodiments via electronic or pneumatic communication along path 219 . In further embodiments, a liquid level meter 28 may communicate with the computer controller via electronic or pneumatic path 218 . Based on this communication, the computer controller may adjust pump 29 via electronic or pneumatic path 219 .
While several variations of the present invention have been illustrated by way of example in preferred or particular embodiments, it is apparent that further embodiments could be developed within the spirit and scope of the present invention, or the inventive concept thereof. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention, and are inclusive, but not limited to the following appended claims as set forth.
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A method and system for reducing waste water from a paper machine system. The system involves splitting a flow output from a seal water tank. With a portion of the flow output being used to maintain a fluid level within a wire pit, and the balance being recycled to the system as substantially clean water.
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BACKGROUND OF THE INVENTION
This invention relates to parking garages for automobiles and similar vehicles. More particularly, the invention relates to a multistory parking garage of such simple construction that it can be quickly assembled at a minimum expenditure of labor and money, and which occupies only a small area of ground.
With the growing commercialization of available land, especially in urban areas, and the attendant increase in land costs, the use of large areas of such land for parking automobiles is an uneconomical operation from the standpoint of monetary return, and yet the aforementioned commercialization has created an increasing demand for parking space. It is obvious, therefore, that a more economically desirable result can only be achieved through the use of multistory parking garages.
In the past there have been numerous designs of multistory parking garages. One such design is disclosed in U.S. Pat. No. 3,330,083 of E. Jaulmes, which discloses a multistory garage having first and second central portals which define a loading elevator shaft and third and fourth portals which define the outer limits of parking cells extending outward from two sides of the central shaft area. Each cell constitutes a floor pan for holding a vehicle, and all of such floor pans, each defining a parking cell, are suspended from suspension cables running from the top of the structure to the bottom thereof. Such a structure is, in some respects, more complex, especially in the use of cables, than is necessary for most uses. In addition, the risk of a cable failure is always present, and the failure of just one cable could be catastrophic, since large numbers of cells are held in place by such cable. In addition, the structure has numerous cells side-by-side on each level, necessitating the use of an elevator either moveable in a lateral direction or large enough to bring a vehicle in line with any given storage cell.
In U.S. Pat. No. 1,815,429 of J. L. Canady there is shown a parking garage having inner upright numbers forming an aisle for a vertically and horizontally moveable elevator, and outer uprights defining the outer ends of the parking stalls. Joists running between the inner and outer members support the pans which in turn support the vehicles, each pan supporting a single vehicle. Again, the parking cells extend outward from only two sides of the elevator shaft, since the elevator has to move horizontally to deliver vehicles to individual cells.
One multistory garage that does not use a horizontally moveable elevator and, as a consequence, has parking cells extending radially outward from the elevator shaft is shown in German patent No. 1,129,274 of Kann et al. This garage, while compressing the total area in which cars are stored by means of the radially extending parking cells, nevertheless relies on a complicated turntable elevator to bring each vehicle in line with a cell.
A multistory garage structure using conveyor belts to move the cars transversely from the elevator to the parking cell is shown in French patent No. 1,585,920. Such a structure is quite complicated and comparatively expensive.
In all of the foregoing designs, the elevator must be moveable in more than one direction, i.e., a direction other than the vertical, in order to place the vehicles in line with the parking cells, or, in the case of the French design, conveyor belts must be used between elevator and cell to accomplish the same end.
SUMMARY OF THE INVENTION
The present invention, through its unique and simple structure, eliminates most of the disadvantages characterizing prior art devices, and makes most efficient and economical use of the area available.
In one preferred embodiment of the invention, four steel box columns are arranged in a square configuration defining a central core which, in turn, defines an elevator shaft. Eight box columns are positioned in pairs to define four planes, each parallel to a plane of the square defined by the first four columns. Each pair of columns defines the outer ends of the parking cells, and they are joined to respective ones of the inner columns by a plurality of joists angled slightly upward from the outer columns to the inner columns. The joists define the floors or stories of the garage. Each pair of outer columns is joined by a plurality of steel beams, each beam being joined to the columns at points slightly above the juncture of each joist with the outer column. Each steel beam defines the outer end of a parking cell and, in addition to providing structural strength, acts as a barrier to any vehicles in the cell. Extending between the joists, each pair of which defines the sides of a cell are steel cables which function as supports for the floor of the cell. The floor itself is made of stamped or pressed steel forming a plurality of ridges running from front to back, and also defining guide means for the wheels of the vehicles. In addition to being supported by the cables, each floor is welded or otherwise attached to both the inner and outer columns. Each floor is designed with a pair of tracks, and it is one feature of the invention that each cell can contain two vehicles, parked facing in opposite directions so that the drivers' side of both vehicles is on the inside and reachable by an attendant from a walkway formed in the floor between the two vehicle tracks.
An elevator is located in the central core or shaft, and guide means on the elevator keeps it centered as it is raised or lowered. The floor of the elevator contains a first pair of vehicle tracks and a second pair at right angles thereto, so that vehicles can enter the elevator from any of the four sides of the square core. The elevator, which can carry two vehicles at a time, is adapted to travel only in the vertical direction, all of the parking cells being accessible to the elevator with only vertical movement thereof.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the multilevel parking garage of the present invention;
FIG. 2 is a plan view of the garage of FIG. 1;
FIG. 3 is a plan view of a vehicle parking cell as used in the garage of FIG. 1;
FIG. 4 is an elevation view of a portion of the parking cell of FIG. 3;
FIG. 5 is a perspective view of the elevator for use in the garage of FIG. 1;
FIGS. 5A and 5B depict certain details of the elevator of FIG. 5;
FIG. 6 is a view of a portion of the floor of the elevator of FIG. 4; and
FIG. 7A and 7B are partial views of a variation of the structure of the garage of FIG. 1.
DETAILED DESCRIPTION
In FIG. 1 there is depicted a multistory parking garage 11 embodying the principles and features of the present invention. While the garage of FIG. 1 is shown as having only three parking levels, it is to be understood that the unique design permits several more parking levels, e.g., six, eight, or ten, depending upon the demand for parking in the particular locale. FIG. 2, which will be discussed concurrently with FIG. 1, shows a plan view of the structure of FIG. 1. The garage 11 comprises four inner pillars or columns 12, 13, 14, 16 formed of, for example, 10 in.×10 in.×1 in. structural steel box column. As can be seen in FIG. 2, the columns 12, 13, 14, 16 define a square inner core space 17 which, as will be discussed hereinafter, functions as an elevator shaft. First, second, third, and fourth pairs of box columns 18-18, 19-19, 21-21, and 22-22 are located remote from columns 12, 13, 14, and 16 and, as can be seen in FIG. 2, each pair of such columns defines an imaginary plane parallel to a corresponding side of the square formed by columns 12, 13, 14, and 16 thus producing a cruciform shape. The column pairs 18-18, 19-19, 21-21, and 22-22 are each located approximately twenty feet or slightly more from the inner columns. This distance is dictated by the maximum vehicle length to be encountered. At the present time the maximum for a standard passenger vehicle is slightly over nineteen feet, hence a minimum parking cell length would be twenty feet. This will be discussed more fully hereinafter. The columns thus far discussed are free standing, and at their lower ends are sunk into concrete, as illustrated in FIG. 1.
For simplicity, the remainder of the description of FIG. 1, as relates to the structure of the arms of the cruciform, will be limited to one such arm or bay, it being understood that the remaining three bays are identical. Each of the columns 18, 18 is joined as by welding to its corresponding inner column by a plurality of structural steel beams or joists 23-23, 24-24, and 26-26. The beams may be, for example, 6 in.×4 in.×3/4 in. C-channel steel. Beams 23, 23 are located approximately ten feet from the ground, while the vertical spacing between beams 23 and 24, and 24 and 26, may be between five and six feet. Although it is not readily discernible from the drawings, each of the beams 23, 24 and 26 slopes slightly downward from the inner columns 12, 13 to the outer columns 18, 18.
Supported by the beams 23-23, 24-24, and 26-26 are floor pans 27, 28, and 29 respectively, which will be discussed in detail hereinafter in connection with FIGS. 3 and 4. The floor pans are the supports for the parked vehicles, and each pan with its supporting structure defines a parking cell. Extending between columns 18, 18 and attached thereto, as by welding, are barriers 31, 32, and 33, each barrier being located slightly above (at approximately automobile bumper height) its corresponding floor pan. Barriers 31, 32, and 33 perform the dual function of containing the vehicles and adding strength and rigidity to the ovrall structure. These barriers may be made, for example, from 6 in.×4 in.×3/4 in. C-channel steel. The inner surface of the barriers may be covered with cushioning material to protect the vehicles. Strung between the inner columns 12, 13 and the outer columns 18, 18 are cables 34, 36, and 37 whose primary function is to protect any personnel who may be in one of the parking cells.
As can be seen in FIG. 1, inner columns 12, 13, 14, and 16 extend above outer columns 18-18, 19-19, 21-21, and 22-22. At the top of columns 12, 13, 14, and 16 is a machinery cell 38 which contains the necessary motors and machinery, shown schematically as 39, for raising and lowering an elevator 41 by means of elevator suspension means 42, shown schematically as a cable. In addition, if elevator counter weights are required they may be strung down the outside of the structure in any suitable manner, not shown.
In FIGS. 1 and 2, it can be seen that the garage can be approached from four directions. It can also be seen that the actual structure occupies very little area on the ground, taking up the space that would normally be occupied by approximately sixteen standard size vehicles.
FIG. 3 is a plan view of a typical storage or parking cell, while FIG. 4 is an elevation view of the floor 27 of FIG. 3. As can be seen in FIG. 3, floor 27 is supported at its inner and outer ends by suitable structural support members 43 and 44, which may take the form of L-shaped angle "iron", made of structural steel of approximately 4 in.×6 in.×3/4 in., and welded to columns 12 and 13 and to columns 18, 18 respectively. The floor pan 27 is welded or riveted or otherwise firmly attached to the members 43 and 44. Floor pan 27 is also supported by means of wire rope or cable members 46 and 47 which are attached to members 23,23 by suitable attaching means 48, 49 respectively, shown in the figure as eye bolts. Members 46 and 47 may be of any suitable cable size sufficient to support the weight of two vehicles. Approximately 3/4 in. stranded cable or wire rope may be used, for example.
Referring now to both FIGS. 3 and 4, the floor pan 27 is built up from several component parts. Pan 27 consists of four wheel guides 51, 52, 53, and 54, which may be rolled or stamped from, for example, 5 mm thick high strength low carbon steel. Each wheel guide comprises a pair of flanges 56, 57 joined by a corrugated portion 58, and the innermost flanges of each pair of wheel guides (51, 52 and 53, 54) are jointed as by welding by a corrugated member 59 which may be, for example, of 2 mm thick high strength low carbon steel, welded to the flanges. Since member 59 is not a load bearing member, the strength requirements on it are not so great. The corrugated portion 58 has, as can be seen in FIG. 4, variable corrugation widths. Wider corrugations are on the inner portion of the guide where normally smaller car wheels will track and narrower corrugations are on the outer portion of the guide where the wheels of larger cars will track. The corrugations run the entire length of the floor pan, and the width variations in conjunction with the flanges 56, 57 insure straight line tracking of the vehicle wheels. It is necessary that flanges 56, 57 be high enough to prevent the vehicle wheels from riding up over them. A height of approximately 6 in. is adequate for this purpose.
The corrugated web 59 functions as both a strength member and an oil drip catcher, and, since the floor pan is angled slightly downward, any fluid dripping will flow to the outer end of the pan where it can be collected by a suitable channel member 61 of any suitable material. The drippings thus collected may be drained off by any suitable means, not shown.
The two innermost guides 52, 53 are joined by a web 62 of metal grating approximately 2 to 3 mm thick which is welded or otherwise joined to the two innermost flanges 56, 57. Web 62 may be formed of expanded steel mesh, and must be of sufficient load bearing capability to support one or two parking attendants. The structure of the floor pan, as just described, is strong and relatively light weight. The use of corrugations increases the strength to weight ratio, and the various components of the floor may be pre-fabricated and assembled at the garage building site.
In FIGS. 5, 5A, and 5B there is depicted the structure of the elevator cage and, in particular, the floor thereof. Elevator 41 comprises four corner posts 66, 67, 68, 69 defining a square and formed of, for example, 6 in.×6 in.×1/2 in. L-shaped angle "iron" made of structural steel. Each post is oriented so that the angle opens outward, as shown. Posts 66 and 67 are joined as by welding at the bottom by a length of angle iron (steel) 71, posts 67 and 68 by a length 72, posts 68 and 69 by a length 73, and posts 69 and 66 by a length 74. Lengths 71, 72, 73, and 74 also function as support members for the elevator floor. In a like manner, posts 66 and 67 are joined at the top by members 76, posts 67 and 68 by member 77, posts 68 and 69 by members 78, and posts 69 and 66 by member 79. The net result is a rigid and extremely strong elevator cage. The cage is further strengthened at the top by bracing members 81 and 82, formed, for example, by structural I-beams, and welded or otherwise joined at the four corners of the cage. At the corner of the X thus formed, the members 81 and 82 are joined, as by welding, and the junction is further strengthened by plate 83 which is firmly affixed to the junction. Attached to plate 83 is a member 84 to which the elevator cable 42 is attached. It is to be understood that the means of connecting cable 42 to the elevator is in accordance with best practices, and member 84 is merely a representation of such connecting means. Likewise, cable 42 is such a representation, inasmuch as sound practice may dictate the use of several cables, for example.
As can be seen in FIG. 5, each of posts 66, 67, 68 and 69 has a slot in each arm of the L at the upper end 86, 87, and a slot in each arm of the L 88, 89 toward the lower end. Extending through said slots 86, 87, 88, 89 are guide wheels 91, 92, 93, 94 mounted on axles affixed to the back sides of each arm of the L as best seen in FIG. 5A. The guide wheels are adapted to ride against columns 12, 13, 14, and 16 to hold the elevator 41 in relatively fixed lateral relationship to the columns while permitting vertical movement of the elevator. The wheels may be rubber-tired and, if desired, spring loaded to obviate possible jamming that could occur with rigidly fixed wheels. Members 81 and 82 are notched at their outer ends, as shown, to provide clearance for the columns 12, 13, 14, and 16 so that elevator 41 can move freely up and down.
The floor of elevator 41 is designed to rest upon and be affixed to members 71, 72, 73, and 74. The floor comprises first and second pairs 102, 102 and 103, 103 of walled or flanged tire guides. The floor further comprises third and fourth pairs 104, 104 and 106, 106 of walled or flanged tire guides oriented at right angles to the first and second pairs of guides. The tire guides may be built up from one inch C-channel steel, for example, and cut and welded to the other tire guides at their intersections. The flanges are also cut at the intersections, thereby creating a plurality of walled open spaces 107, 107, 108, 108, and 109, 109. To avoid possible damage to vehicle tires, the corners of the walls of the open spaces are rounded, as shown. Open spaces 108, 108 have mounted on and affixed to the walls thereof expanded steel grating members 111, 111 for supporting the parking attendants, as does the central open space 107, as shown. Centrally located on each side of the elevator floor, and mounted within the central space 109 are shock absorbers, 112, 112 for cushioning the elevator as it reaches ground level. Shock absorbers 112, 112 may take any of a number of forms, such as oiled filled piston and cylinder, or heavy duty springs.
To facilitate ingress and egress of vehicles to and from the elevator, the ends of the tire guides 102, 103, 104, and 106 are flared and sloped downward, as best seen in FIG. 5B, which is a cross section along the line B--B of FIG. 5, and in FIG. 6. The flaring of the flanges insures proper centering within the tire guides of the vehicles as it is driven onto the elevator, and the sloping eliminates bumps and insures a smooth transition between the ground and the elevator, as well as between the elevator and each parking cell.
In the operation of the garage, vehicles may approach the elevator from any one of four directions, as best seen in FIG. 2. The elevator holds two cars at a time, which are driven onto it from opposite directions, thus insuring that the driver's side is to the inside of the elevator. Thus at no time do the attendants enter or leave the vehicles from the outer sides of the elevator. In like manner, when the elevator reaches the desired storage cell, one vehicle is driven forward into the cell, while the other is backed into the cell, thus assuring that both attendants enter and leave the vehicles from the central grid 62 of the cell. The unique design of the elevator and the parking cells makes this possible, and guarantees the safety of the attendants.
In FIGS. 7A and 7B there is shown a variation of the columnar arrangement of the garage which permits vehicles to make sharper turns in entering the garage, thus saving ground space. The arrangement of FIGS. 7A and 7B comprises columnar members 121 and 122 spaced from the inner columns, only column 12 being shown, a distance about two-thirds of the length of a parking cell. Members 121 and 122 support structural beam members 123, 124 which may be, for example, heavy duty, i.e., 12 inch, I-beam members welded together and to the inner columns. Members 123, 124 define the first parking level designated by floor pan 27.
Extending vertically upward from members 123 and 124 are vertical members 127 and 128, which may be, for example, 6 inch I-beams. Members 127 and 128 form the outer supports for each of the parking cells. Between members 127 and 128 are a plurality of spaced vertical members 129, 131, 132 and 133 which also function as supports. In addition, members 129, 131, 132 and 133 also function as stops for the vehicles in the parking cells. To this end, their inner surfaces may be covered with a cushioning material.
It can be seen that the variation shown in FIGS. 7A and 7B occupies less ground space and permits sharper turns than the arrangement of FIG. 1.
It is readily apparent from the foregoing that the invention comprises a simple, economical parking garage utilizing a minimum of space and which may be quickly erected utilizing standard, readily available materials. While the foregoing illustrative embodiments of the invention represented preferred forms thereof, various modifications and changes may occur to persons skilled in the art without departure from the spirit and scope of the invention.
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A multistory parking garage has a central core defined by four vertical columns, and a plurality of pairs of columns, each pair defining a plane parallel to the plane defined by pairs of vertical columns, defined bays containing vertically spaced parking cells, each cell adapted to hold two vehicles. An elevator is contrained to move only vertically within the central core, is enterable from any of four directions, and is capable of carrying two vehicles at a time, preferably in a nose to tail orientation.
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FIELD OF THE INVENTION
This invention relates to lab-on-a-chip (LOC) and microfluidics technology. It has been developed to provide fully integrated microfluidic systems (e.g. LOC devices), as well as microfluidic devices which do not rely solely on soft lithographic fabrication processes.
CO-PENDING APPLICATIONS
The following applications have been filed by the Applicant simultaneously with the present application:
LOC001US LOC002US LOC003US LOC004US LOC005US LOC006US LOC007US LOC008US LOC009US LOC011US LOC012US LOC013US
The disclosures of these co-pending applications are incorporated herein by reference. The above applications have been identified by their filing docket number, which will be substituted with the corresponding application number, once assigned.
CROSS REFERENCES
The following patents or patent applications filed by the applicant or assignee of the present invention are hereby incorporated by cross-reference.
7,344,226
7,328,976
11/685,084
11/685,086
11/685,090
11/740,925
11/763,444
11/763,443
11,946,840
11,961,712
12/017,771
11/763,440
11/763,442
MMJ003US
MMJ004US
BACKGROUND OF THE INVENTION
“Lab-on-a-chip” (LOC) is a term describing devices of only a few square millimeters or centimeters, which are able to perform a myriad of tasks normally associated with a standard laboratory. LOC devices comprise microfluidic channels, which and are capable of handling very small fluid volumes in the nanoliter or picoliter range. The applicability of LOC devices for chemical and biological analysis has fuelled research in this field, especially if LOC devices can be fabricated cheaply enough to provide disposable biological analysis tools. For example, one of the goals of LOC technology is to provide real-time DNA detection devices, which can be used once and then disposed of.
Fabrication of LOC devices evolved from standard MEMS technology, whereby well-established photolithographic techniques are used for fabricating devices on silicon wafers. Fluidic control is crucial for most LOC devices. Accordingly, LOC devices typically comprise an array of individually controllable microfluidics devices, such as valves and pumps. Although LOC devices originally evolved from silicon-based MEMS technology, more recently there has been general shift towards soft lithography, which employs elastomeric materials. Elastomers are far more suitable than silicon for forming effective valve seals. Thus, polydimethylsiloxane (PDMS) has now become the material of choice for fabricating microfluidics devices in LOC chips. A PDMS microfluidics platform is typically fabricated using soft lithography and then mounted on a glass substrate.
One of the most common types of valve employed in LOC devices is the ‘Quake’ valve, as described in U.S. Pat. No. 7,258,774, the contents of which is incorporated herein by reference. The ‘Quake’ valve uses fluidic pressure (e.g. pneumatic pressure or hydraulic pressure) in a control channel to collapse a PDMS wall of an adjacent fluid flow channel, in the manner of a conventional pneumatic pinch valve. Referring briefly to FIGS. 1A-C , the Quake valve comprises a fluid flow channel 1 and control channel 2 , which extends transversely across the fluid flow channel 1 . A membrane 3 separates the channels 1 and 2 . The channels 1 and 2 are defined in a flexible elastomeric substrate, such as PDMS, using soft lithography so as to provide a microfluidic structure 4 . The microfluidic structure 4 is bonded to a planar substrate 5 , such as a glass slide.
As shown in FIG. 1B , the fluid flow channel 1 is “open”. In FIG. 1C , pressurization of the control channel 2 (either by gas or liquid introduced therein by an external pump) causes the membrane 3 to deflect downwards, thereby pinching the fluid flow channel 1 and controlling a flow of fluid through the channel 1 . Accordingly, by varying the pressure in control channel 2 , a linearly actuable valving system is provided such that fluid flow channel 1 can be opened or closed by moving membrane 3 as desired. (For illustration purposes only, the fluid flow channel 1 in FIG. 1C is shown in a “mostly closed” position, rather than a “fully closed” position).
A plurality of Quake valves may cooperate to provide a peristaltic pump. Hence, the ‘Quake’ valving system has been used to create thousands of valves and pumps in one LOC device. As foreshadowed above, the number of potential chemical and biological applications of such devices is vast, ranging from fuel cells to DNA sequencers.
However, current microfluidics devices, such as those described in U.S. Pat. No. 7,258,774, suffer from a number of problems. In particular, these prior art microfluidics devices must be plugged into external control systems, air/vacuum systems and/or pumping systems in order to function. Whilst the microfluidics platform formed by soft lithography may be small and cheap to manufacture, the external support systems required to drive the microfluidics devices means that the resulting μTAS device is relatively expensive and much larger than the actual microfluidics platform. Hence, current technology is still unable to provide fully integrated, disposable LOC or μTAS devices. It would be desirable to provide a fully integrated LOC device, which does not require a plethora of external support systems to drive the device.
SUMMARY OF THE INVENTION
In a first aspect the present invention provides a peristaltic microfluidic pump comprising:
a pumping chamber positioned between an inlet and an outlet; a plurality of moveable fingers positioned in a wall of said pumping chamber, said fingers being arranged in a row along said wall; and a plurality of thermal bend actuators, each actuator being associated with a respective finger such that actuation of said thermal bend actuator causes movement of said respective finger into said pumping chamber,
wherein said pump is configured to provide a peristaltic pumping action in said pumping chamber via movement of said fingers.
Optionally, the pumping chamber is elongate, and said fingers are arranged in a row along a longitudinal wall of said pumping chamber.
Optionally, each finger extends transversely across said chamber.
Optionally, said fingers are arranged in opposed pairs of fingers, each finger in an opposed pair pointing towards a central longitudinal axis of said pumping chamber.
Optionally, each finger comprises said thermal bend actuator.
Optionally, said pumping chamber comprises a roof spaced apart from a substrate, and sidewalls extending between said roof and a floor defined by said substrate.
Optionally, said fingers are positioned in said roof.
Optionally, each thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, an extent of each finger is defined by said passive beam.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to control circuitry for controlling each actuator.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys.
Optionally, said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
Optionally, said substrate comprises control circuitry for controlling each actuator.
Optionally, said substrate is a silicon substrate having said control circuitry contained in at least one CMOS layer thereof.
Optionally, said wall is covered with a polymeric layer, said polymeric layer providing a mechanical seal between each finger and said wall.
Optionally, said polymeric layer is comprised of polydimethylsiloxane (PDMS).
Optionally, said inlet is defined in said substrate.
In a further aspect there is provided a microfluidic system comprising the microfluidic pump comprising:
a pumping chamber positioned between an inlet and an outlet; a plurality of moveable fingers positioned in a wall of said pumping chamber, said fingers being arranged in a row along said wall; and a plurality of thermal bend actuators, each actuator being associated with a respective finger such that actuation of said thermal bend actuator causes movement of said respective finger into said pumping chamber,
wherein said pump is configured to provide a peristaltic pumping action in said pumping chamber via movement of said fingers.
In another aspect there is provided a microfluidic system comprising the microfluidic pump comprising:
a pumping chamber positioned between an inlet and an outlet; a plurality of moveable fingers positioned in a wall of said pumping chamber, said fingers being arranged in a row along said wall; and a plurality of thermal bend actuators, each actuator being associated with a respective finger such that actuation of said thermal bend actuator causes movement of said respective finger into said pumping chamber,
wherein said pump is configured to provide a peristaltic pumping action in said pumping chamber via movement of said fingers,
which is a LOC device or a Micro Total Analysis System.
In a second aspect the present invention provides a MEMS integrated circuit comprising one or more peristaltic microfluidic pumps and control circuitry for said one or more pumps, each pump comprising:
a pumping chamber positioned between an inlet and an outlet; a plurality of moveable fingers positioned in a wall of said pumping chamber, said fingers being arranged in a row along said wall; and a plurality of thermal bend actuators, each actuator being associated with a respective finger such that actuation of said thermal bend actuator causes movement of said respective finger into said pumping chamber,
wherein said control circuitry controls actuation of said plurality of actuators, and said control circuitry is configured to provide a peristaltic pumping action in each pumping chamber via peristaltic movement of said fingers.
Optionally, the pumping chamber is elongate, and said fingers are arranged in a row along a longitudinal wall of said pumping chamber.
Optionally, each finger extends transversely across said chamber.
Optionally, said fingers are arranged in opposed pairs of fingers, each finger in an opposed pair pointing towards a central longitudinal axis of said pumping chamber.
Optionally, each finger comprises said thermal bend actuator.
Optionally, said pumping chamber comprises a roof spaced apart from a substrate, and sidewalls extending between said roof and a floor defined by said substrate.
Optionally, said fingers are positioned in said roof.
Optionally, each thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, an extent of each finger is defined by said passive beam.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to said control circuitry.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys.
Optionally, said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
Optionally, said substrate is a silicon substrate having said control circuitry contained in at least one CMOS layer thereof.
Optionally, said wall is covered with a polymeric layer, said polymeric layer providing a mechanical seal between each finger and said wall.
Optionally, said polymeric layer is comprised of polydimethylsiloxane (PDMS).
Optionally, said polymeric layer defines an exterior surface of said MEMS integrated circuit.
Optionally, said outlet is defined in said exterior surface.
Optionally, said inlet is defined in said substrate.
In another aspect there is provided a microfluidic system comprising the MEMS integrated circuit comprising one or more peristaltic microfluidic pumps and control circuitry for said one or more pumps, each pump comprising:
a pumping chamber positioned between an inlet and an outlet; a plurality of moveable fingers positioned in a wall of said pumping chamber, said fingers being arranged in a row along said wall; and a plurality of thermal bend actuators, each actuator being associated with a respective finger such that actuation of said thermal bend actuator causes movement of said respective finger into said pumping chamber,
wherein said control circuitry controls actuation of said plurality of actuators, and said control circuitry is configured to provide a peristaltic pumping action in each pumping chamber via peristaltic movement of said fingers.
In a third aspect the present invention provides a mechanically-actuated microfluidic valve comprising:
an inlet port; an outlet port; a thermal bend actuator; and a valve closure member cooperating with said actuator, such that actuation of said thermal bend actuator causes movement of said closure member, thereby regulating a flow of fluid from said inlet port to said outlet port.
Optionally, said thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to control circuitry for controlling said actuator.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys.
Optionally, said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
Optionally, at least said actuator is defined in a MEMS layer of a silicon substrate.
Optionally, said substrate comprises control circuitry for controlling said actuator, said control circuitry being contained in at least one CMOS layer of said substrate.
Optionally, said inlet port and said outlet port are defined in a MEMS layer of a silicon substrate.
Optionally, said inlet port and said outlet port are defined in polymeric microfluidics platform.
Optionally, said closure member is comprised of a compliant material for sealing engagement with a sealing surface of said valve.
Optionally, said closure member is comprised of an elastomer.
Optionally, said closure member is comprised of polydimethylsiloxane (PDMS).
Optionally, said closure member is fused or bonded to said thermal bend actuator.
Optionally, said actuation causes open or closing of said valve.
Optionally, said actuation causes partial opening or partial closing of said valve.
In a fourth aspect the present invention provides a microfluidic system comprising a MEMS integrated circuit bonded to a polymeric microfluidics platform, said system comprising one or more microfluidic devices, wherein at least one of said microfluidic devices comprises a MEMS actuator positioned in a MEMS layer of said integrated circuit.
Optionally, said microfluidic devices are selected from the group comprising: microfluidic valves and microfluidic pumps.
Optionally, all of said microfluidic devices comprise a MEMS actuator positioned in said MEMS layer.
Optionally, said MEMS layer further comprises a microheater for heating a fluid in a microfluidic channel.
Optionally, said MEMS integrated circuit comprises a silicon substrate and said MEMS layer is formed on said substrate.
Optionally, said MEMS layer is covered with a polymeric layer.
Optionally, said polymeric layer defines a bonding surface of said MEMS integrated circuit.
Optionally, said polymeric layer is comprised of photopatternable PDMS.
Optionally, said microfluidics platform comprises a polymeric body having one or more microfluidic channels defined therein.
Optionally, said polymeric body is comprised of PDMS.
Optionally, at least one of said microfluidic channels is in fluid communication with said at least one microfluidic device.
Optionally, said MEMS integrated circuit comprises control circuitry for controlling said actuator, said control circuitry being contained in at least one CMOS layer of said substrate.
Optionally, said MEMS actuator is a thermal bend actuator.
Optionally, said thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to control circuitry for controlling said actuator.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys.
Optionally, said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
In a further aspect there is provided a microfluidic system comprising a MEMS integrated circuit bonded to a polymeric microfluidics platform, said system comprising one or more microfluidic devices, wherein at least one of said microfluidic devices comprises a MEMS actuator positioned in a MEMS layer of said integrated circuit, which is a LOC device or a Micro Total Analysis System (μTAS).
In a fifth aspect the present invention provides a microfluidic system comprising an integrated circuit having a bonding surface bonded to a polymeric microfluidics platform, said microfluidic system comprising one or more microfluidics devices controlled by control circuitry in said integrated circuit,
wherein at least one of said microfluidic devices comprises a MEMS actuator positioned in a MEMS layer of said integrated circuit, said MEMS layer being covered with a polymeric layer which defines said bonding surface of said integrated circuit.
Optionally, said microfluidic devices are selected from the group comprising: microfluidic valves and microfluidic pumps.
Optionally, said microfluidic devices are positioned in any one of:
said integrated circuit; said microfluidics platform; and an interface between said integrated circuit and said microfluidics platform.
Optionally, said integrated circuit comprises a silicon substrate having at least one CMOS layer, and said control circuitry is contained in said at least one CMOS layer.
Optionally, said integrated circuit comprises a silicon substrate and said MEMS layer is formed on said substrate.
Optionally, said polymeric layer is comprised of photopatternable PDMS.
Optionally, said microfluidics platform comprises a polymeric body having one or more microfluidic channels defined therein.
Optionally, said polymeric body is comprised of PDMS.
Optionally, at least one of said microfluidic channels is in fluid communication with at least one said microfluidic devices.
Optionally, said MEMS actuator is a thermal bend actuator.
Optionally, said thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to said control circuitry for controlling said actuator.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys.
Optionally, said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
Optionally, said integrated circuit is in fluidic communication and/or mechanical communication with said polymeric microfluidics platform.
In another aspect there is provided a microfluidic system comprising an integrated circuit having a bonding surface bonded to a polymeric microfluidics platform, said microfluidic system comprising one or more microfluidics devices controlled by control circuitry in said integrated circuit,
wherein at least one of said microfluidic devices comprises a MEMS actuator positioned in a MEMS layer of said integrated circuit, said MEMS layer being covered with a polymeric layer which defines said bonding surface of said integrated circuit, which is a LOC device or a Micro Total Analysis System (μTAS).
In a sixth aspect the present invention provides a microfluidic system comprising a MEMS integrated circuit, said MEMS integrated circuit comprising:
a silicon substrate having one or more microfluidic channels defined therein; at least one layer of control circuitry for controlling one or more microfluidic devices; a MEMS layer comprising said one or more microfluidic devices; and a polymeric layer covering said MEMS layer,
wherein at least part of said polymeric layer provides a seal for at least one of said microfluidic devices.
Optionally, said MEMS integrated circuit contains all the microfluidic devices and control circuitry required for operation of said microfluidic system.
Optionally, said microfluidic devices are selected from the group comprising: microfluidic valves and microfluidic pumps.
Optionally, said control circuitry is contained in at least one CMOS layer.
Optionally, said polymeric layer is comprised of photopatternable PDMS.
Optionally, said polymeric layer defines an exterior surface of said MEMS integrated circuit.
Optionally, MEMS integrated circuit is mounted on a passive substrate via said polymeric layer.
Optionally, said at least one microfluidic device comprises a MEMS actuator.
Optionally, said MEMS actuator is a thermal bend actuator.
Optionally, said thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to said control circuitry for controlling said actuator.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys.
Optionally, said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
Optionally, said microfluidic device is a microfluidic valve comprising a sealing surface positioned between an inlet port and an outlet ports, and wherein said at least part of said polymeric layer is configured for sealing engagement with said sealing surface.
Optionally, said sealing engagement regulates fluid flow from said inlet port to said outlet port.
Optionally, said microfluidic device is a microfluidic peristaltic pump comprising:
a pumping chamber positioned between an inlet and an outlet; and a plurality of moveable fingers positioned in a wall of said pumping chamber, said fingers being arranged in a row along said wall and configured to provide a peristaltic pumping action via movement of said fingers,
wherein said at least part of said polymeric layer provides a mechanical seal between each moveable finger and said wall.
In a further aspect there is provided a microfluidic system comprising a MEMS integrated circuit, said MEMS integrated circuit comprising:
a silicon substrate having one or more microfluidic channels defined therein; at least one layer of control circuitry for controlling one or more microfluidic devices; a MEMS layer comprising said one or more microfluidic devices; and a polymeric layer covering said MEMS layer,
wherein at least part of said polymeric layer provides a seal for at least one of said microfluidic devices,
which is a LOC device Micro Total Analysis System (μTAS).
In a seventh aspect the present invention provides a microfluidic valve comprising:
an inlet port; an outlet port; a weir positioned between said inlet and outlet ports, said weir having a sealing surface; a diaphragm membrane for sealing engagement with said sealing surface; and at least one thermal bend actuator for moving said diaphragm membrane between a closed position in which said membrane is sealingly engaged with said sealing surface and an open position in which said membrane is disengaged from said sealing surface.
Optionally, in said open position, a connecting channel is defined between said diaphragm membrane and said sealing surface, said connecting channel providing fluidic communication between said inlet and outlet ports.
Optionally, said open position includes a fully open position and a partially open position.
Optionally, said diaphragm membrane is fused or bonded to at least one moveable finger, said actuator causing movement of said finger.
Optionally, said at least one finger comprises said thermal bend actuator.
Optionally, the microfluidic valve according to the present invention comprising a pair of opposed fingers, each of said fingers pointing towards said weir, wherein said diaphragm membrane bridges between said opposed fingers.
Optionally, said valve is formed on a substrate, said diaphragm membrane and said fingers being spaced apart from said substrate, and said weir extending from said substrate towards said diaphragm membrane.
Optionally, said weir is positioned centrally between said opposed fingers.
Optionally, each of said fingers comprises a respective thermal bend actuator.
Optionally, each thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, an extent of each finger is defined by said passive beam.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to control circuitry for controlling each actuator.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys.
Optionally, said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
Optionally, said substrate comprises control circuitry for controlling said at least one actuator.
Optionally, said substrate is a silicon substrate having said control circuitry contained in at least one CMOS layer thereof.
Optionally, said diaphragm membrane is defined by at least part of a polymeric layer.
Optionally, said polymeric layer is comprised of polydimethylsiloxane (PDMS).
Optionally, a plurality of the microfluidic valves according to the present invention are arranged in series for use in peristaltic pump.
In an eighth aspect the present invention provides a MEMS integrated circuit comprising one or more microfluidic diaphragm valves and control circuitry for said one or more valves, each valve comprising:
an inlet port; an outlet port; a weir positioned between said inlet and outlet ports, said weir having a sealing surface; a diaphragm membrane for sealing engagement with said sealing surface; and at least one thermal bend actuator for moving said diaphragm membrane between a closed position in which said membrane is sealingly engaged with said sealing surface and an open position in which said membrane is disengaged from said sealing surface,
wherein said control circuitry is configured to control actuation of said at least one actuator so as to control opening and closing of said valve.
Optionally, in said open position, a connecting channel is defined between said diaphragm membrane and said sealing surface, said connecting channel providing fluidic communication between said inlet and outlet ports.
Optionally, said open position includes a fully open position and a partially open position, a degree of opening being controlled by said control circuitry.
Optionally, said diaphragm membrane is fused or bonded to at least one moveable finger, said actuator causing movement of said finger.
Optionally, said at least one finger comprises said thermal bend actuator.
Optionally, the MEMS integrated circuit according to the present invention comprising a pair of opposed fingers, each of said fingers pointing towards said weir, wherein said diaphragm membrane bridges between said opposed fingers.
Optionally, said valve is formed on a substrate, said diaphragm membrane and said fingers being spaced apart from said substrate, and said weir extending from said substrate towards said diaphragm membrane.
Optionally, said weir is positioned centrally between said opposed fingers.
Optionally, each of said fingers comprises a respective thermal bend actuator.
Optionally, each thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, an extent of each finger is defined by said passive beam.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to control circuitry for controlling each actuator.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys.
Optionally, said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
Optionally, said substrate is a silicon substrate having said control circuitry contained in at least one CMOS layer thereof.
Optionally, said diaphragm membrane is defined by at least part of a polymeric layer.
Optionally, said polymeric layer is comprised of polydimethylsiloxane (PDMS).
Optionally, said polymeric layer defines an exterior surface of said MEMS integrated circuit.
Optionally, a plurality of said valves are arranged in series and said control circuitry is configured to control actuation of each actuator so as to provide a peristaltic pumping action.
In a ninth aspect the present invention provides a microfluidic pinch valve comprising:
a microfluidic channel defined in a compliant body; a valve sleeve defined by a section of said microfluidic channel, said valve sleeve having a membrane wall defining at least part of an outer surface of said body; a compression member for pinching said membrane wall against an opposed wall of said valve sleeve; and a thermal bend actuator for moving said compression member between a closed position in which said membrane wall is sealingly pinched against said opposed wall, and an open position in which said membrane wall is disengaged from said opposed wall.
Optionally, said open position includes a fully open position and a partially open position.
Optionally, a moveable finger is engaged with said compression member, said finger being configured to urge said compression member between said open and closed positions via movement of said actuator.
Optionally, said compression member is sandwiched between said finger and said membrane wall.
Optionally, said compression member protrudes from said membrane wall.
Optionally, said compression member is biased towards said closed position when said thermal bend actuator is in a quiescent state.
Optionally, a MEMS integrated circuit is bonded to said outer surface of said body, said moveable finger being contained in a MEMS layer of said integrated circuit.
Optionally, said MEMS integrated circuit comprises a bonding surface defined by a polymeric layer, said bonding surface being bonded to said outer surface of said body.
Optionally, said polymeric layer covers said MEMS layer.
Optionally, said polymeric layer and/or said compliant body are comprised of PDMS.
Optionally, actuation of said actuator causes said finger to move away from said body, thereby opening said valve; and
deactuation of said actuator causes said finger to move towards said body, thereby closing said valve.
Optionally, said moveable finger comprises said thermal bend actuator.
Optionally, said thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, an extent of said finger is defined by said passive beam.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to control circuitry for controlling each actuator.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys; and said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
Optionally, said MEMS integrated circuit comprises a silicon substrate having control circuitry contained in at least one CMOS layer.
Optionally, there is provided a microfluidic system comprising the microfluidic valve according to the present invention.
Optionally, the microfluidic system according to the present invention comprising a plurality of said valves arranged in series.
In a tenth aspect the present invention provides a microfluidic system comprising:
(A) a microfluidics platform comprising:
a compliant body having a microfluidic channel defined therein; a valve sleeve defined by a section of said microfluidic channel, said valve sleeve having a membrane wall defining at least part of an outer surface of said body; and a compression member for pinching said membrane wall against an opposed wall of said valve sleeve; and
(B) a MEMS integrated circuit bonded to said outer surface of said body, said MEMS integrated circuit comprising:
a moveable finger engaged with said compression member, said finger being configured to urge said compression member between a closed position in which said membrane wall is sealingly pinched against said opposed wall, and an open position in which said membrane wall is disengaged from said opposed wall; a thermal bend actuator associated with said finger, said actuator configured for controlling movement of said finger; and control circuitry for controlling actuation of said actuator so as to control opening and closing of said valve sleeve.
Optionally, said open position includes a fully open position and a partially open position.
Optionally, said compression member is sandwiched between said finger and said membrane wall.
Optionally, said compression member protrudes from said membrane wall.
Optionally, said compression member is part of said membrane wall.
Optionally, said compression member is biased towards said closed position when said thermal bend actuator is in a quiescent state.
Optionally, said MEMS integrated circuit comprises a bonding surface defined by a polymeric layer, said bonding surface being bonded to said outer surface of said body.
Optionally, said polymeric layer covers a MEMS layer containing said moveable finger.
Optionally, said polymeric layer and/or said compliant body are comprised of PDMS.
Optionally, actuation of said actuator causes said finger to move away from said body, thereby opening said valve sleeve; and
deactuation of said actuator causes said finger to move towards said body, thereby closing said valve sleeve.
Optionally, said moveable finger comprises said thermal bend actuator.
Optionally, said thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, an extent of said finger is defined by said passive beam.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to said control circuitry.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys.
Optionally, said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
Optionally, said MEMS integrated circuit comprises a silicon substrate having said control circuitry contained in at least one CMOS layer.
In an eleventh aspect the present invention provides a microfluidic system comprising:
(A) a microfluidics platform comprising:
a compliant body having a microfluidic channel defined therein; an elongate chamber defined by a section of said microfluidic channel, said chamber having a membrane wall defining at least part of an outer surface of said body; and a plurality of compression members spaced apart along said membrane wall, each compression member being configured for pinching a respective part of said membrane wall against an opposed wall of said chamber; and
(B) a MEMS integrated circuit bonded to said outer surface of said body, said MEMS integrated circuit comprising:
a plurality of moveable fingers, each finger engaged with a respective compression member, each finger being configured to urge said respective compression member between a closed position in which said respective part of said membrane wall is sealingly pinched against said opposed wall, and an open position in which said respective part of said membrane wall is disengaged from said opposed wall; a plurality of thermal bend actuators, each associated with a respective finger for controlling movement of said respective finger, and control circuitry for controlling actuation of said actuators.
Optionally, said control circuitry is configured to provide one or more of:
(i) a peristaltic pumping action in said chamber via peristaltic movement of said fingers; (ii) a mixing action in said chamber via movement of said fingers; (iii) a concerted valving action in said chamber.
Optionally, said mixing action generates a turbulent flow of fluid through said chamber.
Optionally, said concerted valving action concertedly moves all said compression members into either an open position or a closed position.
Optionally, said control circuitry is configured to provide interchangeably two or more of said peristaltic pumping action, said mixing action and said concerted valving action.
Optionally, each compression member is sandwiched between its respective finger and said membrane wall.
Optionally, each compression member protrudes from said membrane wall.
Optionally, each compression member is part of said membrane wall.
Optionally, each compression member is biased towards said closed position when said thermal bend actuator is in a quiescent state.
Optionally, said MEMS integrated circuit comprises a bonding surface defined by a polymeric layer, said bonding surface being bonded to said outer surface of said body.
Optionally, said polymeric layer covers a MEMS layer containing said moveable finger.
Optionally, said polymeric layer and/or said compliant body are comprised of PDMS.
Optionally, actuation of each actuator causes its respective finger to move away from said body, thereby disengaging a respective part of said membrane wall from said opposed wall; and
deactuation of each actuator causes said respective finger to move towards said body, thereby sealingly pinching a respective part of said membrane wall against said opposed wall.
Optionally, each moveable finger comprises said thermal bend actuator.
Optionally, each thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, an extent of each finger is defined by said passive beam.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to said control circuitry.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys; and said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
Optionally, said MEMS integrated circuit comprises a silicon substrate having said control circuitry contained in at least one CMOS layer.
In a twelfth aspect the present invention provides a microfluidic system comprising a MEMS integrated circuit bonded to a microfluidics platform, said microfluidics platform comprising a polymeric body having at least one microfluidic channel defined therein, and said MEMS integrated circuit comprising at least one thermal bend actuator, wherein said microfluidic system is configured such that movement of said at least one actuator causes closure of said channel.
Optionally, said at least one thermal bend actuator is associated with a respective moveable finger such that actuation of said thermal bend actuator causes movement of said respective finger.
Optionally, said finger is engaged with a wall of said microfluidic channel.
Optionally a microfluidic system according to the present invention which is configured such that movement of said finger towards said microfluidics platform causes closure of said channel by pinching said wall against an opposed wall.
Optionally, said movement is provided by deactuation of said thermal bend actuator.
Optionally a microfluidic system according to the present invention comprising a plurality of moveable fingers configured as a linear peristaltic pump.
Optionally, said pump is in fluidic communication with a control channel defined in said polymeric body, said control channel cooperating with said microfluidic channel such that pressurizing said control channel with a control fluid causes pinching closure of said microfluidic channel.
Optionally, said control fluid is a gas providing pneumatic control, or a liquid providing hydraulic control.
Optionally, said at least one thermal bend actuator is positioned in a MEMS layer of said MEMS integrated circuit.
Optionally, said MEMS integrated circuit comprises a silicon substrate and said MEMS layer is formed on said substrate.
Optionally, said MEMS integrated circuit comprises control circuitry for controlling said at least one thermal bend actuator, said control circuitry being contained in at least one CMOS layer of said substrate.
Optionally, said MEMS layer is covered with a polymeric layer.
Optionally, said polymeric layer defines a bonding surface of said MEMS integrated circuit.
Optionally, said polymeric layer is comprised of photopatternable PDMS.
Optionally, said polymeric body is comprised of PDMS.
Optionally, said thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, said active beam is fused to said passive beam.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to control circuitry for controlling said actuator.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys; and said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
Optionally, a microfluidic system according the present invention which is a LOC device or a Micro Total Analysis System (μTAS).
In a thirteenth aspect the present invention provides a microfluidic system comprising a pneumatic or an hydraulic pinch valve, said pinch valve comprising:
a microfluidic channel defined in a compliant body; an inflatable control channel cooperating with a valve section of said microfluidic channel such that pneumatic or hydraulic pressurization of said control channel causes inflation of said control channel and pinching closure of said valve section,
wherein said microfluidic system comprises an on-chip MEMS pump in fluidic communication with said control channel for pressurizing said control channel.
Optionally, said valve section comprises resiliently collapsible walls.
Optionally, a wall of said control channel is engaged with a wall of said valve section.
Optionally, shutting off said pump releases a pressure in said control channel, thereby opening said valve section.
Optionally, the microfluidic system according to the present invention comprises on-chip control circuitry for controlling said pump, and thereby controlling closure of said valve section.
Optionally, the microfluidic system according to the present invention comprises a MEMS integrated circuit bonded to a microfluidics platform, said microfluidics platform comprising a polymeric body having said microfluidic channel and said control channel defined therein, and said MEMS integrated circuit comprising said MEMS pump.
Optionally, said MEMS pump comprises a plurality of moveable fingers configured as a linear peristaltic pump, each of said fingers being associated with a respective thermal bend actuator for moving a respective finger.
Optionally, each finger comprises a respective thermal bend actuator.
Optionally, said MEMS pump is positioned in a MEMS layer of said MEMS integrated circuit.
Optionally, said MEMS integrated circuit comprises a silicon substrate and said MEMS layer is formed on said substrate.
Optionally, said MEMS integrated circuit comprises control circuitry for controlling said thermal bend actuators, said control circuitry being contained in at least one CMOS layer of said substrate.
Optionally, said MEMS layer is covered with a polymeric layer.
Optionally, said polymeric layer defines a bonding surface of said MEMS integrated circuit.
Optionally, said polymeric layer is comprised of photopatternable PDMS.
Optionally, said compliant body is comprised of PDMS.
Optionally, each thermal bend actuator comprises:
an active beam comprised of a thermoelastic material; and a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator.
Optionally, said active beam is fused to said passive beam.
Optionally, said passive beam defines an extent of each finger.
Optionally, said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to control circuitry for controlling said actuator.
Optionally, said thermoelastic material is selected from the group comprising: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys; and said passive beam is comprised of a material selected from the group comprising: silicon oxide, silicon nitride and silicon oxynitride.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:
FIGS. 1A-C show a prior art valving system;
FIG. 2 shows a partially-fabricated thermal bend-actuated inkjet nozzle assembly;
FIG. 3 is a cutaway perspective of a completed inkjet nozzle assembly;
FIG. 4 is a perspective of a MEMS microfluidic pump with a polymeric sealing layer removed to reveal MEMS devices;
FIG. 5 is a cutaway perspective of the pump shown in FIG. 4 which includes the polymeric sealing layer;
FIG. 6 is a plan view of an alternative MEMS microfluidic pump;
FIG. 7 shows schematically a microfluidics platform and a MEMS integrated circuit prior to bonding;
FIG. 8 shows schematically an integrated LOC device comprising a bonded microfluidics platform and MEMS integrated circuit;
FIG. 9 shows schematically a microfluidic pinch valve fabricated by bonding a microfluidics platform with a MEMS integrated circuit;
FIG. 10 shows the microfluidic pinch valve of FIG. 9 in an open position;
FIG. 11 shows a multifunctional device comprising a plurality of microfluidic pinch valves, as shown in FIG. 10 , arranged in series;
FIG. 12 shows a microfluidic diaphragm valve in an open position; and
FIG. 13 shows the microfluidic diaphragm valve of FIG. 12 in a closed position.
DETAILED DESCRIPTION OF THE INVENTION
For the avoidance of doubt, the term “microfluidics”, as used herein, has its usual meaning in the art. Typically microfluidic systems or structures are constructed on a micron scale and comprise at least one microfluidic channel having a width of less than about 1000 microns. The microfluidic channels usually have a width in the range of 1-800 microns, 1-500 microns, 1-300 microns 2-250 microns, 3-150 microns or 5 to 100 microns. Microfluidic systems and devices are typically capable of handling fluidic quantities of less than about 1000 nanoliters, less than 100 nanoliters, less than 10 nanoliters, less than 1 nanoliter, less than 100 picoliters or less than 10 picoliters.
As used herein, the term “microfluidic system” refers to a single, integrated unit which is usually in the form of a ‘chip’ (in the sense that it has similar dimensions to a typical microchip). A microfluidic ‘chip’ typically has width and/or length dimensions of less than about 5 cm, less than about 4 cm, less than about 3 cm, less than about 2 cm, or less than about 1 cm. The chip typically has a thickness of less than about 5 mm, less than about 2 mm or less than about 1 mm. The chip may be mounted on a passive substrate, such as a glass slide, to provide it with structural rigidity and robustness.
A microfluidic system typically comprises one or more microfluidic channels and one or more microfluidic devices (e.g. micropumps, microvalves etc). Moreover, the microfluidic systems described herein typically contain all the requisite support systems (e.g. control circuitry) for driving microfluidic devices in the system.
As used herein, the term “microfluidics platform” refers to a platform of, for example, microfluidic channels, microfluidic chambers and/or microfluidic devices, which traditionally requires external support systems for operation (e.g. off-chip pumps, off-chip control circuitry etc.). Microfluidics platforms typically have a polymeric body formed by soft lithography. As will become apparent, a microfluidics platform may form part of a bonded microfluidic system according to the present invention. Bonded microfluidic systems according to the present invention generally comprise an integrated circuit bonded to a microfluidics platform via an interfacial bond. Typically, a bonded microfluidic system has fluidic communication and/or mechanical communication between the integrated circuit and the microfluidics platform
“Lab-on-a-Chip” or LOC devices are examples of microfluidic systems. Generally, LOC is a term used to indicate the scaling of single or multiple laboratory processes down to chip-format. A LOC device typically comprises a plurality of microfluidic channels, microfluidic chambers and microfluidic devices (e.g. micropumps, microvalves etc.)
A “Micro Total Analysis System” (μTAS) is an example of a LOC device specifically configured to perform a sequence of lab processes which enable chemical or biological analysis.
Any of the microfluidic systems according to the present invention may be a LOC device or a μTAS. The person skilled in the art will be capable of designing specific architectures for LOC devices (or, indeed, any microfluidic system) tailored to a particular application, utilizing the present teaching. Some typical applications of microfluidic systems are enzymatic analysis (e.g. glucose and lactate assays), DNA analysis (e.g. polymerase chain reaction and high-throughput sequencing), proteomics, disease diagnosis, analysis of air/water samples for toxins/pathogens, fuel cells, micromixers etc. The number of traditional laboratory operations that may be performed in a LOC device is virtually limitless, and the present invention is not limited to any particular application of microfluidics technology.
Thermal Bend Actuation in Inkjet Nozzle Assemblies
Hitherto, the present Applicant has described a plethora of thermal bend-actuated inkjet nozzle assemblies suitable for forming pagewidth printheads. Some elements of these inkjet nozzles are relevant to the microfluidic systems and devices described and claimed herein. Accordingly, a brief description of an inkjet nozzle assembly now follows.
Typically, inkjet nozzle assemblies are constructed on a surface of a CMOS silicon substrate. The CMOS layer of the substrate provides all the necessary logic and drive circuitry (i.e. “control circuitry”) for actuating each nozzle of the printhead.
FIGS. 2 and 3 show one such nozzle assembly 100 at two different stages of fabrication, as described in the Applicant's earlier U.S. application Ser. No. 11/763,440 filed on Jun. 15, 2007, the contents of which is incorporated herein by reference.
FIG. 1 shows the nozzle assembly partially formed so as to illustrate the features of bend actuator. Thus, referring to FIG. 1 , there is shown the nozzle assembly 100 formed on a CMOS silicon substrate 102 . A nozzle chamber is defined by a roof 104 spaced apart from the substrate 102 and sidewalls 106 extending from the roof to the substrate 102 . The roof 104 is comprised of a moving portion 108 and a stationary portion 110 with a gap 109 defined therebetween. A nozzle opening 112 is defined in the moving portion 108 for ejection of ink.
The moving portion 108 comprises a thermal bend actuator having a pair of cantilever beams in the form of an upper active beam 114 fused to a lower passive beam 116 . The lower passive beam 116 defines the extent of the moving portion 108 of the roof. The upper active beam 114 comprises a pair of arms 114 A and 114 B which extend longitudinally from respective electrode contacts 118 A and 118 B. The arms 114 A and 114 B are connected at their distal ends by a connecting member 115 . The connecting member 115 comprises a titanium conductive pad 117 , which facilitates electrical conduction around this join region. Hence, the active beam 114 defines a bent or tortuous conduction path between the electrode contacts 118 A and 118 B.
The electrode contacts 118 A and 118 B are positioned adjacent each other at one end of the nozzle assembly and are connected via respective connector posts 119 to a metal CMOS layer 120 of the substrate 102 . The CMOS layer 120 contains the requisite drive circuitry for actuation of the bend actuator.
The passive beam 116 is typically comprised of any electrically/thermally-insulating material, such as silicon dioxide, silicon nitride etc. The thermoelastic active beam 114 may be comprised of any suitable thermoelastic material, such as titanium nitride, titanium aluminium nitride and aluminium alloys. As explained in the Applicant's copending U.S. application Ser. No. 11/607,976 filed on 4 Dec. 2006, vanadium-aluminium alloys are a preferred material, because they combine the advantageous properties of high thermal expansion, low density and high Young's modulus.
Referring to FIG. 3 , there is shown a completed nozzle assembly at a subsequent stage of fabrication. The nozzle assembly 100 of FIG. 2 has a nozzle chamber 122 and an ink inlet 124 for supply of ink to the nozzle chamber. In addition, the entire roof is covered with a layer of polydimethylsiloxane (PDMS). The PDMS layer 126 has a multitude of functions, including: protection of the bend actuator, hydrophobizing the roof 104 and providing a mechanical seal for the gap 109 . The PDMS layer 126 has a sufficiently low Young's modulus to allow actuation and ejection of ink through the nozzle opening 112 .
A more detailed description of the PDMS layer 126 , including its functions and fabrication, can be found in, for example, U.S. application Ser. No. 11/946,840 filed on Nov. 29, 2007 (the contents of which are herein incorporated by reference).
When it is required to eject a droplet of ink from the nozzle chamber 122 , a current flows through the active beam 114 between the electrode contacts 118 . The active beam 114 is rapidly heated by the current and expands relative to the passive beam 116 , thereby causing the moving portion 108 to bend downwards towards the substrate 102 relative to the stationary portion 110 . This movement, in turn, causes ejection of ink from the nozzle opening 112 by a rapid increase of pressure inside the nozzle chamber 122 . When current stops flowing, the moving portion 108 is allowed to return to its quiescent position, shown in FIGS. 2 and 3 , which sucks ink from the inlet 124 into the nozzle chamber 122 , in readiness for the next ejection.
From the foregoing, it will be appreciated that the PDMS layer 126 significantly improves operation of the nozzle assembly 100 . As described in U.S. application Ser. No. 11/946,840, the formation of the PDMS layer 126 is made possible through the integration of spin-on photopatternable PDMS with a MEMS fabrication process. The Applicant has developed a versatile MEMS fabrication process utilizing photopatternable PDMS, which may be modified for use in a plethora of applications. Microfluidics devices and systems utilizing PDMS are described hereinbelow.
Microfluidic Pump
FIGS. 4 and 5 show a linear peristaltic pump 200 , comprising a row of MEMS devices, each of which is similar in construction to the thermal bend-actuated inkjet nozzle assembly 100 described above. FIG. 4 shows the pump 200 in perspective view with an upper PDMS layer removed to reveal details of each MEMS device.
The linear peristaltic pump 200 is formed on a surface of a CMOS silicon substrate 202 . A pumping chamber 203 is defined by a roof 204 spaced apart from the substrate 202 and sidewalls 206 extending from the roof to the substrate 202 . The roof 204 and sidewalls 206 are typically comprised of silicon oxide or silicon nitride and are constructed using a fabrication process analogous to the process described in U.S. application Ser. No. 11/763,440.
The pumping chamber 203 takes the form of an elongate channel extending longitudinally between a pump inlet 208 and a pump outlet 210 . As shown in FIG. 4 , the pump inlet 208 is defined in a floor 212 of the pumping chamber 203 and a fluid is fed to the pump inlet 108 via a pump inlet channel 214 defined through the silicon substrate. The pump outlet 210 is defined in the roof 204 of the pumping chamber 203 , at an opposite end to the pump inlet 108 . This arrangement of pump inlet 208 and pump outlet 210 is specifically configured for providing fully integrated LOC devices as described below. However, it will be appreciated that in its broadest form, the peristaltic pump 200 may have any suitable arrangement of pump inlet and outlet, provided that peristaltic pumping fingers are positioned therebetween.
FIG. 4 , having the upper PDMS layer removed, shows three peristaltic pumping fingers 220 arranged in a row and spaced apart along the longitudinal extent of the pumping chamber 203 . By analogy with the inkjet nozzle assembly 100 described above, each finger 220 is moveable into the pumping chamber 203 by thermal bend actuation. Thus, each finger 220 comprises a MEMS thermal bend actuator in the form of an active beam 222 cooperating with a passive beam 224 . Typically, the active beam 222 is fused to the passive beam 224 , and the passive beam 224 defines the extent of each moving finger 220 .
The passive beam 224 is usually formed of the same material as the roof 204 , and the finger 220 is separated from the roof by a perimeter gap 226 , which is defined by an etch process during MEMS fabrication.
The active beam 222 defines a bent current path extending between a pair of electrode contacts 228 . In keeping with the inkjet nozzle assembly 100 , the active beam 222 comprises a pair of arms 229 extending from respective electrode contacts 228 . The arms 229 are connected at their distal ends by a connecting member 230 .
Each finger 220 extends transversely across the roof 204 of the longitudinal channel defined by the pumping chamber 203 . Hence, it will be appreciated that by controlling movement of each finger 220 , a peristaltic pumping action may be imparted on a fluid contained in the pumping chamber 203 . The skilled person will be aware of linear peristaltic pumps employing a similar pumping action, as described in, for example, U.S. Pat. No. 4,909,710, the contents of which are herein incorporated by reference.
Control of each finger actuation is provided by a CMOS layer 240 in the silicon substrate 202 , shown in FIG. 5 . FIG. 5 is a perspective of the pump 200 including an upper polymeric sealing layer 242 of PDMS. The pump 200 is cutaway through one of the fingers 220 to reveal part of a metal CMOS layer 240 . The CMOS layer 240 connects with each electrode contact 228 via a connector post 244 , which extends from the CMOS layer, through the sidewalls 206 , and meets with the electrode contact. The CMOS layer 240 contains all the necessary control and drive circuitry for actuating each finger 220 . Hence, a chip comprising the pump 200 contains all the requisite control and drive circuitry for actuating the pump, without the need for any external off-chip control. On-chip control is one of the advantages of the pump 200 according to the present invention.
Moreover, in contrast with peristaltic pumps built from an array of ‘Quake’ valves (as described in U.S. Pat. No. 7,258,774), the pump 200 does not require any control fluid (e.g. air) to drive the peristaltic action. Whereas ‘Quake’ valves (and thereby ‘Quake’ pumps) are reliant on fluid in a control channel, which must be supplied externally, the mechanically-actuated pump 200 is fully self-contained and does not require any external input, except, of course, for the actual fluid which is to be pumped.
Referring again to FIG. 5 , the polymeric sealing layer 242 (typically PDMS) is deposited onto the roof 204 , and the pump outlet 210 defined therethrough, using fabrication techniques analogous to those described in U.S. application Ser. No. 11/763,440. Of course, the polymeric layer 242 has sufficiently low Young's modulus to enable movement of each finger 220 during actuation. The polymeric layer 242 principally provides a mechanical seal for the perimeter gap 226 around each finger 220 , but also provides a protective layer for each thermal bend actuator.
Furthermore, PDMS provides an ideal bonding surface for bonding a MEMS integrated circuit comprising the microfluidic pump 200 to a conventional microfluidics platform formed by soft lithography. Integration of a MEMS integrated circuit with a conventional LOC platform is a particularly advantageous feature of the present invention and will be described in more detail below.
Alternative Microfluidic Pump
Of course, the pump 200 may take many different forms. For example, the number and orientation of the fingers 220 may be modified to optimize the peristaltic pumping action. Turning now to FIG. 6 , there is shown in plan view an alternative linear peristaltic pump 250 employing the same operational principles as the pump 200 described above. In FIG. 6 , the upper polymeric layer 242 has been removed to reveal the individual fingers 220 and the pumping chamber 203 . In the interests of clarity, like reference numerals have been used to describe like features in FIG. 6 .
Thus, the pump 250 comprises a pumping chamber 203 in the form of a longitudinal channel. Pairs of opposed fingers 220 are positioned in the roof of the chamber 203 , and a plurality of finger pairs extend longitudinally in row along the chamber. Each finger 220 in a pair points towards a central longitudinal axis of the chamber 203 so as to maximize the peristaltic pumping action by simultaneous actuation of both fingers in a pair. During pumping, opposed pairs of fingers may be actuated (e.g. sequentially) to provide the peristaltic pumping action. Of course, any sequence of actuations may be employed to optimize pumping, as described in, for example, U.S. Pat. No. 4,909,710. In some pumping cycles, more than one finger pair may be actuated simultaneously, or some finger pairs may be partially actuated. The skilled person will readily be able to conceive of optimal peristaltic pumping cycles, within the ambit of the present invention, utilizing the pump 250 .
Still referring to FIG. 6 , the fingers 220 are positioned between a pump inlet 208 and a pump outlet 210 . An outlet channel 252 between the pump outlet 210 and the fingers 220 comprises a valve system 254 . The valve system 254 comprises a channel circuit 256 , which is configured to minimize backflow of fluid from the outlet 210 towards the inlet 208 . Thus, the valve system 254 further optimizes the efficiency of the pump 250 . Although a very simple valve system 254 is shown in FIG. 6 , it will appreciated that any check valve may be used to improve the efficiency of a one-way pump according to the present invention.
Of course, pumps according to the present invention may be made reversible, simply by altering the sequence of finger actuations via the on-chip CMOS.
Fully Integrated LOC Device Comprising MEMS Micropumps
As foreshadowed above, a PDMS polymeric layer 242 provides an ideal bonding surface for bonding MEMS integrated circuits to conventional microfluidic platforms formed by soft lithography. This enables integration of CMOS control circuitry with microfluidic devices in a fully integrated LOC device. Therefore, a significant advantage is achieved by obviating the need for external off-chip control systems and pumping systems, which are usually required in conventional LOC devices.
Interfacial bonding between a conventional PDMS microfluidics platform and a PDMS-coated MEMS integrated circuit is achieved using conventional techniques known from multilayer PDMS soft lithography. Such techniques will be well known to a person skilled person in the art of soft lithography. Typically, each PDMS surface is exposed to an oxygen plasma and the two surfaces bonded together by applying pressure.
FIG. 7 shows how a simple integrated LOC device according to the present invention may be fabricated using a conventional PDMS bonding technique. A MEMS integrated circuit (or chip) 290 comprises a silicon substrate 202 , a CMOS layer 240 and MEMS layer 260 . The MEMS layer 260 comprises MEMS microfluidic pumps 200 . In the schematic integrated circuit 290 , two MEMS microfluidic pumps 200 A and 200 B are shown, each comprising a plurality of thermal bend-actuated fingers 220 for providing a peristaltic pumping action. Of course, in practice, each MEMS integrated circuit 290 may comprise many hundreds or thousands of MEMS devices, including the pumps 200 .
The MEMS layer 260 is covered with the PDMS layer 242 , which defines an external bonding surface 243 of the integrated circuit 290 .
A conventional microfluidics platform 295 is comprises of a body 280 of PDMS in which is defined a plurality of microfluidic channels, chambers and/or microfluidic devices. In the schematic microfluidics platform 295 shown in FIG. 7 , there is shown a ‘Quake’ valve 282 comprising a fluidic channel 284 cooperating with a control channel 286 . An arbitrary reaction chamber 288 is also defined in the PDMS body 280 . It will be appreciated that any three-dimensional microfluidics platform 295 may be formed by conventional soft lithographic techniques, as known in the art.
The body 280 of the microfluidics platform 295 has a bonding surface 281 , in which is defined a control fluid inlet 283 and a fluid channel inlet 285 . The control fluid inlet 283 and fluid channel inlet 285 are in fluid communication with their respective control channel 286 and fluid channel 284 . The control fluid inlet 283 and fluid channel inlet 285 of the microfluidics platform 295 are positioned to align with pump outlets 274 and 276 defined in the PDMS layer 242 of the MEMS integrated circuit 290 .
The two bonding surfaces 243 and 281 are bonded together by exposing each surface to an oxygen plasma and then applying pressure. The resultant bonded assembly, in the form of an integrated LOC device 300 , is shown in FIG. 8 .
In the integrated LOC device 300 , the pumps 200 controlled by the CMOS layer 240 of the integrated circuit 290 pump fluid into microfluidic channels 286 and 284 of the PDMS microfluidics platform. The pumps 200 may pump either control fluid (for driving valves in the PDMS platform 295 ) or actual sample fluids used by the device (e.g. fluids for analysis). Accordingly, the CMOS control circuitry can be used to provide full control over operation of the integrated LOC device 300 .
A simple example will now be described to illustrate how the LOC device 300 may be operated in practice. A control fluid enters a first inlet 270 and is pumped, using the microfluidic pump 200 A, into the control channel 286 of the microfluidics platform 286 . The control channel 286 becomes pressurized with the control fluid. As described above in connection with FIGS. 1A-C , the control channel 286 overlays and cooperates with part of the fluid channel 284 to form the valve 282 . When the control channel 286 is pressurized with the control fluid, a wall of the fluid channel 284 is collapsed, which closes the valve 282 . Accordingly, a section of the fluid channel 284 downstream of the chamber 288 is closed by the valve 282 , thereby fluidically isolating a device outlet 287 from the chamber 288 .
With the valve 282 closed, a sample fluid entering a second inlet 272 is pumped, using microfluidic pump 200 B, into the chamber 288 via the fluid channel 284 . Further fluids (e.g. reagents) may be also be pumped into the chamber 288 via further fluid channels (not shown). Once all fluids have been pumped into the chamber 288 and sufficient time has elapsed, the valve 282 may be opened by shutting off the pump 200 A, and allowing fluid to flow through the downstream section of the fluid channel 284 towards the device outlet 287 .
This simple example illustrates how the integrated LOC device 300 can provide full control over LOC operations via the CMOS circuitry and MEMS micropumps 200 . It is a particular advantage of the LOC device 300 that external, off-chip pumps and/or control systems are not required. The control fluid may be either air (providing pneumatic control of the valve 282 ) or a liquid (providing hydraulic control of the valve 282 ).
Although the example provided herein is very simple, the skilled person will appreciate that the present invention may be used to provide control of a complex LOC device having a complex, labyrinthine array of valves, pumps and channels.
A notable advantage of the present invention is that it fully complements existing LOC technology based on soft lithographic fabrication of microfluidics platforms. Complex microfluidics platforms have already been fabricated using soft lithography. These conventional platforms would require only minor modifications in order to be integrated into the CMOS-controllable LOC devices provided by the present invention.
Microfluidic Valves
As foreshadowed above, silicon-based MEMS technology has inherent limitations in the microfluidics and LOC fields. Microfluidic valves are usually essential in LOC devices and hard, inflexible materials such as silicon are unable to provide the sealing engagement required in a valve. Indeed, this limitation was the primary reason that microfluidics moved away from silicon-based MEMS lithography into soft lithography, based on compliant polymers, such as PDMS.
Hitherto, the present Applicant has demonstrated how PDMS can be integrated into a conventional silicon-based MEMS fabrication process. It will be described how this same technology enables effective microfluidic valves to be created using conventional silicon-based MEMS technology. Moreover, such valves do not require external fluidic supplies or control systems, in contrast with the ‘Quake’ valves described above. Two types of valve are described below, although the skilled person will be able to conceive of many other variants by integrating PDMS into a silicon-based MEMS fabrication process. In each case, engagement of a PDMS surface with another surface (e.g. silicon surface, silicon oxide surface, PDMS surface etc.) provides the sealing engagement necessary for a valving action. Furthermore, each valve takes the form of a mechanically-actuated valve, where engagement of opposed surfaces is driven by actuation or deactuation of a thermal bend actuator, which is itself controlled by on-chip CMOS.
Valve Providing Closure in a Polymeric Microfluidics Channel
Referring to FIG. 9 , there is shown a microfluidics pinch valve 310 resulting from bonding of a polymeric microfluidics platform 312 and a MEMS integrated circuit 314 having a surface layer of PDMS 316 . The PDMS layer 316 defines a first bonding surface 313 of the MEMS integrated circuit 314 .
The MEMS integrated circuit 314 comprises an actuation finger 318 constructed on a CMOS silicon substrate 315 . The actuation finger 318 may be identical in design to one of the fingers 220 described above in connection with FIGS. 4 and 5 . Thus, although the actuator finger 318 is shown only schematically in FIG. 9 , it can be assumed that it contains all features, including the thermal bend actuator, described above in relation to the fingers 220 .
The microfluidics platform 312 is formed by standard soft lithography and comprises a polymeric body (e.g. PDMS body) 320 , in which is defined a microfluidics channel 322 . The channel 322 includes a sleeve portion 324 , which passes adjacent a second bonding surface 325 of the microfluidics platform 312 . The sleeve portion 324 is separated from the second bonding surface 325 by a layer of PDMS which defines an exterior wall 326 of the sleeve portion. The exterior wall 326 comprises a compression member 328 , which protrudes from the exterior wall and extends away from the second bonding surface 325 .
As can be seen from FIG. 9 , when the two bonding surfaces 313 and 325 are bonded together, the compression member 328 is aligned with the actuation finger 318 . By virtue of projecting from the exterior wall 326 , the compressions member 328 abuts against the first bonding surface 313 during the bonding process, and is consequently compressed against an interior wall 330 of the sleeve portion 324 . Hence, the sleeve portion 324 is pinched closed by the bonding process.
In the assembled LOC device 350 shown in FIG. 9 , the valve 310 is closed when the actuation finger 318 is in its quiescent state, and no fluid can pass through the sleeve portion 324 . Referring now to FIG. 10 , the finger actuator 318 is actuated and bends downwards, thereby pulling the compression member 318 with it towards the silicon substrate 315 . This actuation urges the exterior wall 326 away from the interior wall 330 and, hence, the valve 310 is opened so as to allow fluid to pass through the sleeve portion 324 .
It is an advantage of the valve 310 that it is biased to be closed when the finger actuator 318 is in its quiescent state. This means that a LOC device comprising the valve 310 will not be power hungry. A further advantage is that it is possible to regulate opening of the valve by modulating an actuation power supplied to the finger actuator 318 . Partial valve closures may be readily achieved using this mechanically-actuated pinch valve.
Self-evidently, a plurality of valves 310 may be arranged in series to provide a microfluidic device 340 , as shown in FIG. 11 . The device 340 may be configured to provide a peristaltic pumping action.
Alternatively, the device 340 may simply provide a more effective valving action via concerted actuation of each finger actuator 318 .
The device 340 can also be configured to create a turbulent flow, which is useful for mixing fluids. Typically, fluids flowing on a microscale are difficult to mix due to laminar flow. Accordingly, the device 340 may be used as a “micromixer”. It will be appreciated that optimal mixing actions may be different from peristaltic pumping actions. It is advantage of the present invention that the device 340 may be used interchangeably as either a valve, a micromixer or peristaltic pump. The CMOS control circuitry may be configured to provide either a valving action, a mixing action or a pumping action in the device 340 , simply by altering an actuation sequence for the finger actuators 318 .
Alternatively, when used as a pump, the device 340 may be ‘tuned’ to the individual characteristics of a particular fluid. For example, more viscous liquids may require a different (e.g. slower) peristaltic pumping cycle to less viscous liquids. It is an advantage of the present invention that the CMOS control circuitry, individually controlling each finger actuator 318 , may be configured accordingly so as to ‘tune’ the pump to the characteristics of particular fluid. The control achievable by the on-chip CMOS circuitry would not be possible using traditional LOC technology.
Valve Providing Closure in a Silicon Microfluidics Channel
Referring to FIGS. 12 and 13 , there is shown a microfluidics diaphragm-type valve 350 formed on a CMOS silicon substrate 351 . The valve 350 is entirely self-contained in a MEMS integrated circuit 360 . Thus, the valve 350 potentially obviates the need for bonding the MEMS integrated circuit 360 to a microfluidics platform altogether, since the MEMS integrated circuit can contain all the control circuitry, microchannels, valves and pumps required to create a complete LOC device or μTAS. The valve 350 paves the way for LOC devices constructed entirely using silicon-based MEMS technology, as opposed to soft lithography, which has now become standard in the art.
Alternatively, the MEMS integrated circuit 360 may still be bonded to a microfluidics platform, as described above. It will be appreciated that microchannels in a microfluidics platform may be connected to fluid outlets (not shown) in the MEMS integrated circuit 360 to create a LOC device.
Turning now to FIGS. 12 and 13 , the valve 350 comprises a pair of opposed first and second actuation fingers 352 and 353 , which both point towards a central saddle or weir 354 having a sealing face 355 . The weir 354 is essentially a block of silicon oxide, which may be defined at the same time as sidewalls 357 of the valve 350 are defined during MEMS fabrication. It will be appreciated that each finger 352 and 353 is similar in design to the fingers 220 described above.
The weir 354 divides the valve 350 into an inlet port 356 and an outlet port 358 . A layer of PDMS 359 bridges between the first and second actuation fingers 352 and 353 to form a roof 362 , which acts as a diaphragm membrane for the valve 350 .
As shown in FIG. 12 , the inlet port 356 fluidically communicates with the outlet port 358 via a connecting channel 361 , which is defined between the sealing face 355 of the weir 354 and the roof 362 . In FIG. 13 , each of the fingers 352 and 353 is actuated and bends downwards towards the silicon substrate 351 . This bending of the fingers 352 and 353 , in turn, pulls the roof 362 into sealing engagement with the sealing face 355 of the weir 354 . This sealing engagement between the roof 362 and the sealing face 355 prevents any fluid flowing from the inlet port 356 to the outlet port 358 (and vice versa). Hence, the valve 350 is closed as shown in FIG. 13 .
Subsequent deactuation of the fingers 352 and 353 releases the roof 362 from sealing engagement with the sealing face 355 as the fingers return to their quiescent state shown in FIG. 12 .
Hence, a highly effective diaphragm valve 350 is provided, which makes use of a PDMS covering to provide a sealing diaphragm membrane for the valve. By using PDMS in this way, an effective valve can be made for microfluidic channels defined in rigid materials, such as a silicon-based MEMS integrated circuit. It will be appreciated that such a valve may be used in a variety of microfluidic systems, such as LOC devices.
It will, of course, be appreciated that the present invention has been described purely by way of example and that modifications of detail may be made within the scope of the invention, which is defined by the accompanying claims.
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A microfluidic system. The system comprises: (A) a microfluidics platform comprising: a compliant body having a microfluidic channel defined therein; a valve sleeve defined by a section of the microfluidic channel, the valve sleeve having a membrane wall defining part of an outer surface of the body; and a compression member for pinching the membrane wall against an opposed wall of the valve sleeve; and (B) a MEMS integrated circuit bonded to the outer surface of the body, the MEMS integrated circuit comprising: a moveable finger engaged with the compression member, the finger being configured to urge the compression member between a closed position in which the membrane wall is sealingly pinched against the opposed wall, and an open position in which the membrane wall is disengaged from the opposed wall; a thermal bend actuator associated with the finger, the actuator configured for controlling movement of the finger; and control circuitry for controlling actuation of the actuator so as to control opening and closing of the valve sleeve.
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TECHNICAL FIELD
The present invention relates generally to an apparatus for removing water from the surface of a vehicle in a vehicle wash system. More particularly, the present invention relates to an apparatus for removing water from the surface of a vehicle that yields increased drying capabilities as well as improved longevity of the apparatus.
BACKGROUND INFORMATION
Assemblies for blowing liquids from a vehicle surface are well known. An exemplary assembly includes a support plenum for distributing air and a nozzle system, including a nozzle for directing air toward the top surface of a vehicle. Assemblies of these types are well known and have been utilized in the art for many years.
Many such assemblies for blowing liquids (drying) include an air delivery conduit interconnecting the plenum and the nozzle system for delivering air from the plenum to the nozzle system and then to the vehicle exterior. Some assemblies allow the nozzle system to move in an adjustment direction toward and away from the plenum between various-operating positions. Further, other assemblies cause the nozzle to rotate to different directions as the vehicle moves thereby. However, these systems all suffer from operational disadvantages and provide only limited drying capabilities.
Additionally, the nozzles of most drying systems are constructed of a solid hard material such that if a vehicle or other structure contacts them it can cause significant damage. For example, if a vehicle contacts a nozzle of these existing drying systems it can cause damage to the vehicle. Moreover, it can also cause damage to the nozzle or the drying system itself, which would be extremely costly to replace or repair.
It is therefore a need to overcome these disadvantages and provide an improved drying system.
SUMMARY OF THE INVENTION
It is therefore an advantage of the present invention to provide an improved drying system that has a nozzle that can be extended or retracted.
It is another advantage of the present invention is to provide an improved drying system that has a nozzle that extends and retracts to the height of a vehicle passing therebeneath to direct the air stream close to the exterior surface of the vehicle.
It is still another advantage of the present invention to provide an improved drying system that has an extendable and retractable nozzle that is constructed of a pliable material such that it can move or yield if contacted by a vehicle to minimize damage to both the vehicle and the nozzle.
It is yet another advantage of the present invention to provide an improved drying system that keeps air directed closer to a vehicle surface to more effectively blow water off the vehicle exterior.
It is a further advantage of the present invention to provide an improved drying system that increases the length of relative laminar air flow to increase drying efficiency.
In accordance with the above and the other advantages of the present invention, an improved drying system is provided. The system includes a plurality of drying elements, namely at least one forward drying element and a pair of rear drying elements. The system also includes a plurality of sensors that generally map the exterior surface contour of a vehicle passing beneath the drying system. Each of the drying elements includes a nozzle having a first nozzle portion and a second nozzle portion. The first nozzle portion of each drying element is moveable with respect to the second nozzle portion. The second nozzle portion extends and retracts based on feedback from the sensors which detect vehicle height, to provide a high force substantially laminar air flow to the exterior surface of the vehicle to blow water off the exterior and dry the vehicle. The nozzle portions are constructed of a soft pliable material to minimize damage to it or a vehicle in the event of contact between the nozzle and the vehicle.
These and other features and advantages of this invention will become more apparent to those skilled in the art from the detailed description of a preferred embodiment. The drawings that accompany the detailed description are described below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a drying system in accordance with a preferred embodiment of the present invention;
FIG. 2 is a side view a drying apparatus with a nozzle of one dryer of the drying system in an extended position in accordance with a preferred embodiment of the present invention;
FIG. 3 is a side view of a drying apparatus with a nozzle of one dryer of the drying system in a retracted position in accordance with a preferred embodiment of the present invention;
FIG. 4 is a schematic illustration of a drying system with a vehicle passing therethrough in a first position in accordance with a preferred embodiment of the present invention;
FIG. 5 is a schematic illustration of a drying system with a vehicle passing therethrough in a second position in accordance with a preferred embodiment of the present invention;
FIG. 6 is a schematic illustration of a drying system with a vehicle passing therethrough in a third position in accordance with a preferred embodiment of the present invention;
FIG. 7 is a schematic illustration of a drying system with a vehicle passing therethrough in a fourth position in accordance with a preferred embodiment of the present invention;
FIG. 8 is a schematic illustration of a drying system with a vehicle passing therethrough in a fifth position in accordance with a preferred embodiment of the present invention; and
FIG. 9 is a schematic illustration of a drying system with a vehicle in contact with nozzle in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION
Referring to the Figures, a vehicle washing system in accordance with the present invention is illustrated and generally designated by reference number 10 . The vehicle washing system includes a vehicle treatment apparatus. In the embodiments shown and described, the vehicle treatment apparatus is a dryer or drying device that is utilized to blow water off of a vehicle exterior as part of the vehicle washing process. It will be understood by one of ordinary skill in the art that air is emitted from the vehicle treatment apparatus to blow water off the vehicle exterior. In accordance with a preferred embodiment, high pressure air is emitted from the device. Additionally, the air can be heated when emitted or may instead be ambient air. The vehicle treatment apparatus is illustrated as disposed above the vehicle to emit air to the upper surface of the vehicle. However, it will be understood that the vehicle treatment apparatus could be oriented to primarily contact other portions of the vehicle.
As shown in FIG. 1 , the vehicle washing system 10 includes a frame 12 upon which various vehicle treatment apparatus are disposed. The vehicle treatment apparatus act on a vehicle 5 as it passes within or through the frame 12 to accomplish the various steps of the vehicle wash process. One of the vehicle treatment apparatus disposed on the frame 12 is a drying system 14 . In accordance with the preferred embodiment, the drying system 14 blows water off the exterior surface of a vehicle as it passes thereby. The preferred drying system 14 is coupled to the frame 12 such that it is disposed above the upper surface of the vehicle. The drying system 14 preferably includes three individual drying units 16 , 18 , 20 , which operate together to perform the drying process, as discussed in more detail below. It will be appreciated, however, that the drying system 14 can include more or less drying units as required.
Each of the drying units 16 , 18 , 20 have the same configuration and thus the structure of only one is described in detail herein. Specifically, the drying unit 16 has a blower 22 , which includes a blower housing 24 and a fan or impeller 26 disposed therein. The fan 26 rotates to draw air into the blower housing 24 and then forces it at a high velocity out of a housing exit 28 . The blower 24 is in communication with a power source to effectuate rotation of the fan 26 , as is well known in the art. Further, the blower 24 is actuated by a control system that is part of the vehicle wash system such that it is turned on and off as required. Additionally, the blower 22 can be in communication with a heater or other heating device to heat the air such that warm or heated air exists the blower housing 24 through the housing exit 28 .
A nozzle portion 30 is secured to the blower housing 24 such that its upper end 32 is disposed around the housing exit 28 . This configuration ensures that air emitted through the housing exit 28 enters the nozzle portion 30 . As shown, the nozzle portion 30 preferably has an upper nozzle portion 34 and a lower nozzle portion 36 . The upper nozzle portion 34 has a top end 38 that is secured around the housing exit 28 . In accordance with one embodiment, the upper nozzle portion 34 has a slight conical shape such that a bottom end 40 of the upper nozzle portion 34 has a smaller diameter than the top end 38 of the upper nozzle portion 34 . The lower nozzle portion 36 has a top end 42 and a bottom end 44 . The top end 42 of the lower nozzle portion 36 has a larger diameter than the bottom end 40 of the upper nozzle portion 34 , such that the lower nozzle portion 36 surrounds the upper nozzle portion 34 . The lower nozzle portion 36 also preferably has a slight conical shape. Alternatively, each of the nozzle portions 34 , 36 can be cylindrical in shape or can have a variety of other shapes. The lower nozzle portion 36 preferably has a larger diameter than the upper nozzle portion 34 .
As shown, the lower nozzle portion 36 is coupled to the blower housing 24 by a cylinder 50 , such as a pneumatic cylinder. This connection allows the lower nozzle portion 36 to be raised and lowered with respect to a vehicle during the drying process, as discussed in detail below. FIG. 2 illustrates the lower nozzle portion 36 in a fully extended position such that the bottom end 44 is disposed relatively closer to the exterior surface of the vehicle such that the emitted air is more properly directed to the vehicle exterior and contacts that area at an increased force. In this position, the top end 42 of the lower nozzle portion 36 encompasses the bottom end 44 of the upper nozzle portion 34 to ensure that the air is directed out the bottom end 44 of the lower nozzle portion 36 . FIG. 3 illustrates the lower nozzle portion 36 in a fully retracted position such that the bottom end 40 is raised up with respect to a vehicle to accommodate a higher vehicle exterior surface. In this position, the upper nozzle portion 34 and the lower nozzle portion 36 are in telescopic engagement with the lower nozzle portion 36 to surround the entirety of the upper nozzle portion 34 when it is retracted.
The retraction and extension of the lower nozzle portion 36 is accomplished by the cylinder 50 , which is in communication with the control system to raise and lower it as directed. In the preferred embodiment, the lower nozzle portion 36 only includes two positions, namely a fully retracted position and a fully extended position. However, it will be understood that the control system can be configured to allow the cylinder 50 to position the lower nozzle portion 36 at a variety of different heights and positions with respect to the vehicle exterior, as needed, i.e. partially lowered or retracted.
FIGS. 4 through 8 illustrate the operation of the drying system 14 of the present invention as incorporated into a vehicle wash system 10 for drying a vehicle passing therethrough. The present drying system 14 can be incorporated into any known vehicle wash system, including tunnel car washes or roll-over car washes. After a vehicle has passed through the rinse and wash portions of the vehicle wash process, it encounters the drying system 14 as it travels along the conveyer. In accordance with the present invention, the drying system 14 , includes three drying units 16 , 18 , 20 . The drying unit 16 is positioned forward (will encounter the vehicle first) while the drying units 18 , 20 are disposed rearwardly of the drying unit 16 . The drying unit 16 is positioned on the frame 12 such that it is intended to overlie the center of the vehicle so that air emitted therefrom generally contacts the center of the vehicle as well as portions on either side thereof. The drying units 18 , 20 are disposed outwardly (away from the center of the vehicle) of the drying unit 16 and are intended to overlie the sides of the vehicle and emit air to the side portions of the upper surface of the vehicle as well as the side portions of the vehicle. Thus, in operation, the forward drying unit 16 blows high speed air onto the exterior surface of the vehicle to blow off any water that is located in the middle of the vehicle as well as the areas a couple feet on either side of the vehicle center to leave a dry section. The rear drying units 18 , 20 then blow off the remaining water located on the exterior surface closer to the sides off of the vehicle as well as any water located on the sides of the vehicle.
The drying system 14 also includes a plurality of sensors located on either side of the frame 12 through which the vehicle passes. As shown, the preferred embodiment preferably includes three sets of sensors 52 , 54 , 56 located on the frame 12 . The sensors are preferably photo eyes. However, other suitable types of sensors, such as Sonar sensors, may instead be utilized. Each set of sensors 52 , 54 , 56 preferably include a pair of sensors with each sensor positioned on opposite sides of the frame 12 from one another with each sensor set spaced apart from another along the length of the frame. Each sensor set 52 , 54 , 56 is intended to determine whether or not clear visual contact exists between the sensors of each set. The control system is in communication with the sensor sets 52 , 54 , 56 to monitor this condition throughout the vehicle drying process. In the event, the line of sight is broken or interrupted between the sensors of any set 52 , 54 , 56 , i.e. a vehicle passes therebetween, this condition is also sensed by the control system. The sets of sensors 52 , 54 , 56 are preferably located forwardly of the individual drying units 16 , 18 , 20 to properly control their operation.
In accordance with the preferred embodiment, the lower nozzle portions 36 of each of the drying units 16 , 18 , 20 is in the normal extended position. As the vehicle enters the drying system 14 as shown in FIG. 4 , the hood of the vehicle is positioned beneath the first sensor set 52 and thus the line of sight between the individual sensors is not interrupted. Thus, all three drying units 16 , 18 , 20 remain in the extended position and are closer to the exterior surface of the vehicle to provide increased drying efficiency. This extended nozzle position delivers focused relatively laminar air to the exterior surface of the vehicle and better drying as a higher force of air is provided to the desired area. This is compared to other drying systems where the nozzles are located further from the exterior surface of the vehicle and thus the air emitted therefrom expands and becomes turbulent and does not encounter the vehicle with the same force as the dryer of the disclosed drying system 14 and thus provides decreased drying capabilities. It will also be understood that some vehicles have higher hood heights and thus will break the communication between the sensors of the first, second, and third sets of sensors, thereby causing the lower nozzle portions 36 to be retracted when the vehicle is in this position shown in FIG. 4 . The forward drying unit 16 is positioned to blow water off the middle portion of the vehicle (with reference to the direction of travel) while the rear drying units 18 , 20 blow the water of the side portions of the vehicle.
As shown in FIG. 5 , as the vehicle continues forward through the drying system 14 , the increased height of the car will break the line of sight between the first set of sensors 52 . As the vehicle continues to travel, it will break the line of sight between the second set of sensors 54 . When the line of sight to both sensor sets is broken, the control system will send a signal to the cylinder 50 associated with the forward drying unit 16 to cause it to raise the lower nozzle portion 36 . The lower nozzle portion 36 of the forward drying unit 16 is thus raised to blow water off the windshield. In this position, the lower nozzle portion 36 of the rear drying units 18 , are still in the lowered positions to blow water off the side areas of the hood.
Next, as shown in FIG. 6 , as the vehicle breaks the line of sight with the third set of sensors 56 , such that all three sets of sensors have interrupted the line of sight, the rear drying units 18 , 20 are retracted by their respective cylinders 50 based on signals received from the control system. In this position, the drying units each can blow water off the roof of the vehicle. The drying unit 16 remains in the retracted position even if the first sensor set 52 line of sight is reestablished.
As the vehicle continues its motion forwardly, and its height decreases, the line of sight of both the first set of sensors 52 and the second set of sensors 54 is reestablished, as shown in FIG. 7 . In this position, the forward drying unit 16 is lowered to the extended position to blow air off the rear window and back of the vehicle. The rear drying units 18 , 20 remain in the retracted position.
As shown in FIG. 8 , as the vehicle progresses, and the second set of sensors 54 and the third set of sensors 56 have unblocked line of sight, the rear drying units 18 , 20 are also lowered. In accordance with the present invention, two adjacent sets of sensors must have visible line of sight for a drying unit to be lowered to the extended position. It will also be understood that more or less sensor sets may be utilized and that a variety of other control methods for raising and lowering the nozzles can be utilized. The drying units remain in the extended position until the next vehicle approaches the drying system 14 and then the same process is repeated.
Referring now to FIG. 9 , a vehicle is illustrated as contacting the nozzle portion 30 of a drying unit. In a preferred embodiment, the nozzle portion 30 is constructed of a fabric material that is relatively compliant or soft. The material is preferably non-absorbent. This relatively soft material allows the nozzle portion to bend, collapse or move if contacted by a portion of a vehicle or other object. This prevents damage to either the nozzle or the vehicle. After the vehicle or other object contacts the nozzle portion 30 , it returns to its normal position, either on its own or when air is forced therethrough. It will be appreciated that a variety of other flexible materials can be utilized that allow the nozzle portion 30 to bend or move away to prevent damage to the nozzle structure of the vehicle. In fact, the nozzle structure can be positioned to travel along an upper surface of the vehicle and due to its flexible composition will not cause any damage.
The foregoing invention has been described in accordance with the relevant legal standards, thus the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and do come within the scope of the invention. Accordingly, the scope of legal protection afforded this invention can only be determined by studying the following claims.
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A dryer nozzle for a drying unit in a vehicle wash system includes a nozzle portion for emitting high velocity air to an exterior surface of a vehicle passing thereunder. The nozzle portion has an inner nozzle section and an outer nozzle section. The inner nozzle section and the outer nozzle section being configured such that they can be positioned one inside the other during operation. At least one of the inner nozzle section or the outer nozzle section can be extended and retracted as directed towards or away from the surface of the vehicle.
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The present invention relates to a lighting fixture and in particular to a lighting fixture for a fluorescent lamp which is suspended from or mounted on a ceiling above an area to be illuminated.
BACKGROUND OF THE INVENTION
There are typically two types of light sources, those that emanate from a single point source like incandescent globes, and those that emanate from linear sources such as fluorescent tubes.
Linear type light sources generally provide a broader area of illumination than do point sources of equal intensity and numerous luminaires or fixtures using linear type light sources have come into existence, especially those that house fluorescent tubes. Typically these are mounted in ceilings although wall mounted luminaires have also come into existence. The fixture mounted on the ceiling includes a housing having two ends, in between which is suspended a fluorescent tube. Since one of the difficulties experienced in such an arrangement is that there is a high glare factor, that is, the light emanating directly from the tube is bright compared to the surroundings, most such fixtures simply alter the direct light by diffusion through a lens or by diffuse reflection. Whilst this overcomes the problems of glare, a high percentage of the total light is lost, with the efficiencies of some of the luminaires being below 50%.
Some luminaires propose reflecting the light above the tube towards the ceiling. This arrangement does provide indirect ceiling light but is still relatively inefficient and results in uneven downward light illumination.
Other luminaires include curved or angled inner surfaces that spread the light more broadly generally upwardly but the distribution of light is still limited by the rectangular perimeter of the housing. Yet others cause the light to be distributed at generally low angles to the ceiling that also does not provide a even distribution of light.
Accordingly, the applicant is not aware of any luminaire that is highly efficient, and maintains a broad area of illumination generally below the luminaire.
It is an object of the present invention to propose a luminaire that overcomes at least some of the abovementioned problem or provides a useful alternative to luninaires currently known.
It is a further object of the present invention to propose a luminaire that maximises efficiency and provides good glare control.
SUMMARY OF THE INVENTION
Therefore in one form of the invention there is proposed a luminaire optical system for an indirect light source including:
a tubular lamp having a longitudinal axis; a first reflector assembly extending generally parallel to and spaced above said lamp, said first reflector assembly including a pair of first reflectors joined to form a first apex; a second reflector assembly extending generally parallel to and spaced below said lamp, said second reflector assembly including a pair of second reflectors joined to form a second apex, each of said second reflectors including two arc segments joined at a middle apex; and wherein said first apex, said second apex and lamp longitudinal axis are axially aligned along a first plane.
In a further form of the invention there is proposed a luminaire optical system for an indirect light source including:
a tubular lamp having a longitudinal axis; a first reflector assembly extending generally parallel to and spaced above said lamp, said first reflector assembly including a pair of first reflectors joined to form a first apex; a second reflector assembly extending generally parallel to and spaced below said lamp, said second reflector assembly including a pair of second reflectors joined to form a second apex wherein said first apex, said second apex and lamp longitudinal axis are axially aligned in a first plane; and each of said second reflectors including a second distal edge on opposed sides of said second apex, each of said second distal edges and said lamp longitudinal axis defining planes intersecting said first plane at substantially 90 degrees on either side of said first plane.
In preference said first plane is substantially vertical.
In preference said first reflectors are symmetrical about said first apex.
In preference said second reflectors are symmetrical about said second apex.
Preferably each of said first reflectors includes a first distal edge on opposed sides of said first apex, each of said first distal edges and said lamp longitudinal axis defining planes intersecting said first plane at substantially 70 degrees on either side of said first plane.
Preferably each of said second reflectors includes a second distal edge on opposed sides of said second apex, each of said second distal edges and said lamp longitudinal axis defining planes intersecting said first plane at substantially 90 degrees on either side of said first plane.
In preference each of said second reflectors includes two arc segments joined at a middle apex.
In preference said middle apex and said lamp longitudinal axis of each of said second reflectors define a plane intersecting said first plane at substantially 45 degrees on either side of said first plane.
Preferably said luminaire optical system includes a housing adapted to hold said lamp, first reflector assembly and second reflector assembly in fixed relationship thereto.
Preferably said housing is adapted to suspend from a ceiling.
Preferably said second reflectors include translucent areas.
Preferably said second reflectors include perforated areas.
Preferably said tubular lamp is a tube having a diameter of ⅝ inches (equivalent to approximately 1.5875 cm).
Preferably said first reflector assembly first apex is positioned some 1 and ¾ inches (equivalent to approximately 4.445 cm) from said tube longitudinal axis.
Preferably said second reflector assembly second apex is positioned some 1 and ⅛ inches (equivalent to approximately 2.8575 cm) from said tube longitudinal axis.
In preference said first reflector assembly has a footprint substantially greater than said second reflector assembly.
In preference the reflection angle of said first reflectors is some 70 degrees from vertical at the first apex and some 125 degrees from vertical at said first distal edge.
In preference the reflection angle of said second reflectors is some 117.5 degrees from vertical at the second apex and some 11.25 degrees at said second distal edge.
In preference said middle apex is generally in the range of some 3–40 degrees.
Although the above description related to a linear light source it is to be understood that the present invention could equally well be applied to a point light source. In such an arrangement the bottom and top reflectors would instead of being of a linear configuration be of a circular configuration.
Furthermore it is to be understood that in the case of a linear source that the housing need not have two ends whose purpose is to provide the support of the tube, but that the housing simply be able to support the tube above an area to be illuminated. It may therefore be that a suitable design may even include a one-end support.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings,
FIG. 1 is a perspective schematic view of a luminaire embodying the present invention;
FIG. 2 is an exploded perspective view of the luminaire of FIG. 1 ;
FIG. 3 is a cross-sectional view of the luminaire of FIG. 1 ; and
FIG. 4 is a cross-sectional view as in FIG. 3 but illustrating the reflection of individual light rays.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts.
Referring now to the drawings and in particular to FIGS. 1 to 3 , there is shown simplified schematic views of a lighting fixture or luminaire 10 including a tube 12 a first reflector assembly 14 and a second reflector assembly 16 . Sides 18 and 20 located on opposite ends of the luminaire are used to keep the structure integral and to, for example, suspend the luminare from the ceiling.
The first reflector assembly 14 is positioned above the tube 12 and includes two parabolic reflectors 22 and 24 joined at first apex 26 , the first apex 26 positioned generally directly above the longitudinal axis 28 of the tube 12 .
The second reflector assembly 16 is positioned directly below the tube 12 and includes two reflectors 30 and 32 joined at a second apex 34 , the second apex 34 positioned generally directly below the longitudinal axis 28 of tube 12 .
It will now be readily apparent to the reader that the first apex 26 , longitudinal axis 28 and second apex 34 all lie on a first plane, the plane being generally vertical when one is considering a luminaire that is mounted to or hung from a ceiling. Although not shown it is to be understood that the luminaire is generally mounted to the ceiling by appropriate fixing means and includes the necessary electrical components including power supply and ballast.
Typically the reflector assemblies are symmetrical. However, when the luminare may be applied to an atypical situation, such as being mounted proximate a wall, where one is desirous of maintaining efficiency in one direction only and gently illuminating a wall in the other, the assemblies may in fact not be symmetrical but will be modified to accommodate the particular situation.
The footprint of the first reflector assembly 14 is substantially greater than the second reflector assembly 16 so that light that is produced by the tube 12 is reflected pre-dominantly downwards.
Both the first apex 26 and the second apex 34 ensure that emitted light from the tube 12 is substantially reflected outwardly from the luminaire 10 or at least towards one of the reflecting surface assemblies rather than being reflected back into the tube 12 where it would be lost thus reducing the total illumination efficiency of the luminaire. Thus, it is the relative geometry of the luminarie that will achieve this result with each configuration having a unique solution, but each configuration having at the very least a first refector assembly with a larger footprint than the second and each assembly having an apex that lies directly below or above the tube. One particular configuration will be discussed shortly.
Those skilled in the art will appreciate that this size differential results in a larger percentage of light being reflected generally downwardly whether reflected straight from the tube 12 or whether it is a primary or secondary reflection after light has first been reflected from reflector assembly 14 . The skilled addressed will now also appreciate that to minimise total light intensity loss one wants to minimise total reflections that a light ray may undergo prior to propagating generally downwardly out of the luminarie. The use of the first and second reflector assemblies means that with the right geometrical shape of the reflectors the substantial percentage of light goes through not more than two such reflections. Theoretically it may even be possible that all of the light goes through no more than two reflections, much depending on the accuracy of the manufacturing process.
This is further aided by each of the reflecting surfaces 30 and 32 of the second reflector assembly 16 being composed of two arc segments, surface 30 comprising segments 30 a and 30 b and surface 32 comprising segments 32 a and 32 b . The segments 30 a and 30 b join in a middle apex 36 , segments 32 a and 32 b join in middle apex 38 . The middle apex changes the angle of reflection quite markedly by a figure approaching some 50 degrees.
The distal edges 40 and 42 of the first reflectors 22 and 24 respectively of the first reflector assembly extend substantially horizontally above the tube 12 so that the distal edges and said tube longitudinal axis define planes intersecting said vertical plane at substantially 70 degrees on either side of the vertical plane.
The distal edges 44 and 46 of the second reflectors 30 and 32 respectively of the second reflector assembly extend below the tube 12 so that the distal edges and said tube longitudinal axis define planes intersecting said vertical plane at substantially 90 degrees on either side of the vertical plane. This ensures that there is no direct downwards light from the tube that would result in glare.
The apex is positioned at 45 degrees to the tube, that is, the middle apex and lamp longitudinal axis define a plane intersecting said vertical plane at substantially 45 degrees on either side of the vertical plane.
When referring to FIG. 4 , the reader can now appreciate that the particular geometric configuration of the reflector assemblies leads to very little, if any, of the reflected light passing back through the tube thus increasing the efficiency of the luminaire.
In the particular case when one is using a T 5 type tube the following table provides approximate geometrical estimates of the surface angles at various angles form the vertical plane. This assumes that the first reflection assembly is some 1 and ¾ inches above the tube centre whilst the bottom reflector is some 1 and ⅛ inch below.
Top reflector
Reflector surface angle from
Angle from lamp
vertical
0°
70°
25°
0°
50°
115°
70°
125°
It is to be understood that the curvature in between the angles above is of a smooth transitional type with no sudden angle changes. Accordingly in most instances the curvature would vary in the range of some 0.5° to 1° with every degree change in the angle from the tube.
Bottom reflector
Reflector surface angle from
Angle from lamp
vertical
0°
117.5°
5°
112.5°
20°
105°
25°
100°
30°
97.5°
45°
Apex angle around 30°–35°
50°
51.25°
90°
11.25°
In the case where the tube is of a different diameter, or where one wishes for a different light distribution, the sizes, distances, and curvature of the reflectors may be changed to accommodate the situation.
In cases where there may be a need for greater direct downward illumination, one may include apertures or slits in the bottom reflector where some radiated light projected downwardly is not reflected through any surface. A reflector may include a mixture of circular apertures and longitudinal slits distributed in a pattern through the reflector.
Those skilled in the art will now appreciate that use of reflectors symmetrically disposed below and above the tube wherein the top reflector is of a greater cross-sectional size than the bottom one and where the curvature of the two reflectors is relatively chosen results in a luminaire with a greater light efficiency than hitherto known.
The reflectors are typically coated with a reflecting surface having a high efficiency of reflection and that acts as a mirrored surface. However those skilled in the art will appreciate that the surfaces of the reflectors may include different coatings and/or filters that may not only control the reflection percentages but also change its characteristic. The reflecting surface may also include individual micro specular reflectors whose orientation may vary slightly to achieve a more homogenous distribution of light.
One can now appreciate that the present invention teaches the use of upper and lower reflectors with high reflectivity and specular reflective surfaces that are designed to interdependent geometry that maximises efficiency by minimising light loss and the number of reflections required to exit the fixture while providing good glare control by covering the tube form view.
The lower reflector is generally perforated to avoid contrast at the reflector edge and to provide a good light output profile. The concept is adapted to any diameter tube and to general or specific purpose fixture as well as other types of light source.
As discussed above it is to be understood that the present invention can be applied to a point light source. In such an arrangement, the reflectors assume a circular symmetry instead of the linear symmetry as discussed above.
Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but embraces all equivalent devices and apparatus.
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A luminaire optical system ( 10 ) for an indirect light source including a tubular lamp ( 12 ) having a longitudinal axis ( 22 ), a first reflector assembly ( 14 ) extending parallel to and radially spaced directly above said lamp and a second reflector assembly ( 16 ) parallel to and radially spaced from said lamp directly below the lamp. Each of the assemblies includes symmetrical reflectors ( 22; 24; 30; 32 ) joining in an apex ( 26; 34 ) directly below and above the lamp. The bottom reflector ( 16 ) further may include two segments ( 30 a; 30 b; 32 a; 32 b ) on each reflecting surface, the segments marking a sharp change in reflecting angle. Most such luminaires will typically also include perforations to maintain useful light profiles. The luminaire according to the present configuration increases the lighting efficiency by minimising any reflections passing back into the tube and ensuring an even spread of light throughout an area being illuminated.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method of manufacturing a multilayer plasterboard in which a core layer of the board has a different density from the outer layers, and to an apparatus therefor.
2. Description of Related Art
The manufacture of a multilayer gypsum plasterboard is disclosed in U.S. Pat. No. 2,940,505. This document discloses the application of thin layers of gypsum plaster slurry to two paper liners. A core layer of gypsum plaster slurry is applied to the first slurry coated liner, and the second slurry coated liner is brought onto the exposed surface of the core. A very satisfactory bond between the liners and the plaster is said to result, even without the use of starch or other adhesive. The apparatus disclosed in U.S. Pat. No. 2,940,505 includes three slurry mixers, supplying gypsum slurry to the two paper liners and the core respectively. In practice, this necessitates complex control systems to ensure synchronicity between the mixes and to ensure that each mixer supplies slurry at the correct rate. The capital and running costs of such an arrangement are high compared to a conventional plasterboard manufacturing line with only one mixer.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method for making a multilayer set cementitious product comprising the steps of:
(a) dispersing particulate cementitious material in a liquid medium under conditions of relatively high shear to form a first slurry;
(b) blending a first portion of the first slurry with foam under conditions of relatively low shear to form a second, foamed, slurry;
(c) depositing a first layer of one of a second portion of the first slurry and the second slurry on a support; and
(d) depositing a second layer of the other of the second portion of the first slurry and the second slurry on the surface of the first layer.
In preferred embodiments, the first layer is of the first slurry.
Preferably, a third layer of the same slurry as the first layer is deposited on the second layer. Also preferably, the first and third layers are deposited on facing sheets.
Preferably, the foam is formed prior to blending with the initial dispersion. Preferred foams are formed by incorporating air into a liquid medium.
Additives or other ingredients of the second slurry may be added at any stage, but preferably in step (b), in which the foam is mixed with the first slurry of the particulate material.
The invention also provides an apparatus for making a multilayer set cementitious product which comprises: at least one rotary mixer element operative in a first mixing zone and adapted to develop relatively high shear to produce a first slurry of the particulate material, the first zone having inlets for the particulate material and a liquid medium; and at least one rotary mixer element operative in a second mixing zone of relatively low shear in direct communication with the first mixing zone, the second mixing zone being provided with an inlet for a foam component and an outlet for the second, foamed, slurry of particulate material, and the first zone having a second outlet for the first slurry.
If a preformed foam is employed, the inlet to the second zone is an inlet for the preformed foam. Inlets may additionally be provided for additives or other ingredients, usually solid, of the slurries.
A preferred embodiment of this invention comprises: a first mixing chamber containing a first mixing rotor adapted to be driven at a relatively high speed and having inlets for the particulate material and for a liquid (such as water) and first and second outlets for the resulting first slurry; a second mixing chamber containing a second mixing rotor adapted to be driven at a lower speed than the first mixing rotor and having inlets for the first slurry of the particulate material and for a foam component and an outlet for the second, foamed, slurry, the first outlet of the first mixing chamber being disposed to deliver the first slurry directly into the corresponding inlet of the second mixing chamber.
The relatively high shear in the first mixing zone or chamber is preferably developed by rotating the mixing rotor in the first mixing zone at a peripheral speed of 10-50 m/s. Where the second mixing rotor is provided in the second mixing zone it is preferably rotated at a peripheral speed in the range of 0.1 to 10 m/s. Preferably the shear rate in the first zone is at least 5 times as in the second zone and may be 30 times more as great. It is preferred that the inlets for the particulate material and the liquid in the first mixing zone should be at smaller radial distances from the rotational axis of the mixing rotor than the outlet for the first slurry. Similarly it is preferred that the inlets for the first slurry and the foam in the second mixing zone should be radially less distant from the axis of rotation of the mixing rotor than the outlet for the aerated slurry. In both cases, this means that the input is in a relatively low energy region of the mixer and the output from a relatively high energy region.
The preferred apparatus according to the invention further comprises: a support for slurry; a first slurry application station adjacent the support and in communication with one of the first outlets from the first zone or chamber and the outlet from the second zone or chamber, the first station comprising a slurry outlet and a spreader for spreading slurry on the support; and a second station adjacent the support and in communication with the other of the outlets, the second station comprising a slurry outlet and a spreader for spreading slurry on the support. Preferably, a third station is in communication with the same zone or chamber as the first station. In a preferred embodiment, the first and third stations are in communication with the first outlet from the first zone or chamber, so that the outer layers of the finished plasterboard are unfoamed.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 shows diagrammatically a preferred apparatus according to the invention;
FIG. 2 shows a section through a board made by the invention; and
FIG. 3 shows a section through a preferred mixer according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The apparatus shown diagrammatically in FIG. 1 comprises a two-stage mixer 10, including a first, high shear, mixing chamber 12 and a second, low, shear, mixing chamber 14, each having a rotor 16, 16' respectively, for mixing the contents. Water and stucco are supplied continuously to the first chamber 12 through inlets 18, 20. The water and stucco are subjected to high shear mixing conditions by rotor 16. Some of the resulting slurry passes directly from the first chamber 12 to the second, low shear, chamber 14. A preformed foam is also supplied to the second chamber through an inlet 22. The foam is blended with the slurry under conditions of low shear to produce a foamed slurry.
The slurry from the first chamber 12 which does not pass directly into the second chamber leaves the first chamber through outlet 24, and is pumped by pumps 26, 26' to first 28 and third 30 slurry deposition stations. At the first station, the slurry is deposited and spread by air knives on a liner paper 32 carried on a continuous belt 34, the return run of which is shown in FIG. 1. In an alternative embodiment, spreading is achieved with rollers, rather than air knives. The upper run of the belt 34 travels in the direction shown by the arrow in FIG. 1. Similarly, at the third station 30, the slurry is deposited and spread on a second liner paper 36. Thus, layers 38, 40 of the unfoamed slurry on liner paper are formed. In order to assist adhesion of the slurry to the liner papers, starch may be added to the slurry through an inlet 42 immediately upstream of the pumps 26, 26'.
The foamed slurry formed in the second chamber 14 leaves the second chamber through an outlet 44 which leads the foamed slurry to a second slurry deposition station 46, which is a conventional slurry outlet.
The continuous belt 34 carries the first liner paper 32 with the first layer 38 of slurry thereon from the first station 28 to the second station 46. At the second station, foamed slurry is deposited and spread on the layer 38 of unfoamed slurry to form a foamed slurry layer 48. The second liner paper 36 carrying the layer 40 of unfoamed slurry is passed over two rollers 50, 50' each of which turns the paper through 90° to reverse the liner paper so that the unfoamed slurry layer 40 is below the liner paper rather than above it, as it was formed. As the liner paper 36 passes around the second roller 50', the slurry layer 40 comes into contact with the foamed slurry layer 48 on the belt 34. In an alternative embodiment, the unfoamed slurry is deposited on the vertical run of the second liner paper 36 between the two rollers 50, 50'.
The plaster is then set and dried in a conventional manner, to provide a gypsum board 52 as shown in FIG. 2 having a lightweight foamed core 48' between more dense unfoamed layers 38', 40', faced on both sides with liner paper 32, 36. By using the method and apparatus of the invention, the outer layers 38', 40' may be as much as 50% or more dense than a conventional plasterboard. These layers are typically at least 0.5 mm in thickness and are preferably 1 mm thick and the foamed core is typically 10 mm thick.
FIG. 3 shows a preferred mixer 10. As shown, it comprises a first mixing chamber 12 formed from a top wall plate 110, a bottom wall plate 112 and a cylindrical side wall 114. For cleanliness of operation these are preferably made of stainless steel although other materials may be used. A disc shaped mixing rotor 16, preferably also of stainless steel, is mounted on a rotatable shaft 116 which is supported by bearings 118 and passes in a liquid-tight manner through the bottom wall 112. The top of the shaft and the central area of the rotor are covered by a conical deflector 120.
An inlet 20 for stucco is provided in the top wall 110, preferably in a central or axial position. A further inlet 18 for water is also provided in the top wall, approximately midway between the stucco inlet 20 and the outer periphery of the mixing chamber 12. A first outlet 122 for the slurry formed in the first mixing chamber is provided in the bottom wall 112, preferably in the outermost region thereof, and in the vicinity of the side wall 114. A second outlet 24 is provided diametrically opposite to the first outlet.
Top scrapers 124 are mounted radially on the top of each rotor, being supported at the outer edge of the rotor and extending inwards to the edge of the stucco inlet 20. Bottom scrapers 126 are mounted radially on the under surface of the rotor 16. The scrapers are adjusted to give minimal clearance with the respective walls.
The surface of the rotor can be provided with pegs or teeth, for example around the periphery, but this has not been found necessary in the case of preparing slurries of gypsum plaster.
The apparatus shown in the drawings includes a second mixing chamber 14 which similarly includes top 128 and bottom 130 walls and a cylindrical side wall 132. The top wall 128 may be formed from the same plate as the bottom wall 112 of the first mixing chamber 10.
A second mixing rotor 16' is mounted on a shaft 134 in similar manner to the rotor in the first mixing chamber 12 and may likewise be provided with top and bottom scrapers 136, 138. The top scraper 136 may conveniently extend continuously across the top of the chamber because there is no central inlet for particulate material in the second chamber 14. The rotor has a similar clearance with the side wall 132 and the scrapers similar clearances with the top 128 and bottom 130 wall respectively, as in the first mixing chamber.
The first outlet 122 from the first chamber constitutes the inlet to the second chamber for the unfoamed slurry, and the top wall 128 is also formed with an inlet 22 for previously formed aqueous foam. An outlet 44 for the foamed slurry is provided in the outer region of the bottom wall 130 in close proximity to the side wall 132.
In operation, plaster or stucco is supplied continuously through the inlet 20 and water through the inlet 18. These meet on the upper surface of the rotor element 16, where they are mixed and passed between the rotor and the side wall 114. Some of the resulting slurry passes through the first outlet 122 into the second chamber 14, falling on the upper surface of the rotor 16', where it meets preformed foam entering through the inlet 22. The slurry and the foam are mixed together under lower shear conditions than those prevailing in the first mixing chamber 12, whereby uniform distribution of the incorporated air is achieved with minimal separation of air into significant voids.
The proportion of unfoamed slurry leaving the first mixing chamber 12 by the first outlet 24 to go directly to a slurry application station without foaming will depend, upon the relative thickness of the foamed and unfoamed layers in the finished plasterboard and on the degree of foaming to which the foamed slurry is subject. Typically, about 25% by volume of the contents of the first mixing chamber 12 will leave by the first outlet 24 and will not be foamed.
When, as is commonly the case, additives and other ingredients are employed, for example, lightweight aggregate, reinforcing fiber, setting accelerator and starch, there may be added at either stage through specially provided inlets. If an additive is required in both the foamed and the unfoamed slurry, it is preferably added to the first chamber 12. If it is required only in the unfoamed slurry, it can be added to the unfoamed slurry after it has left the first chamber, and if it is required only in the foamed slurry it can be added to the second chamber 14.
Surprisingly, it has been found advantageous to have the second mixing chamber 14 of smaller capacity than the first mixing chamber 12, despite the increased volume (due to the addition of foam) of the contents of the second chamber compared to those of the first chamber. The residence time in the second stage is thus kept very short, so that the total residence time in the complete mixer will be comparable with that in a single stage mixer of the prior art.
The portion of the unfoamed slurry formed in the first chamber 12 which does not pass into the second chamber 14 passes out of the second outlet 24 to the pumps 26, 26' (FIG. 1) and thence to the first 28 and third 30 deposition stations. The foamed slurry formed in the second chamber 14 leaves that chamber through the outlet 44 therefrom and passes to the second deposition station 46. As previously described, a first layer 38 of unfoamed slurry is deposited and spread on a first liner paper 32 on the continuous belt 34 at the first station 28, and a second layer of foamed slurry is deposited and spread on the first layer 38 at the second station 46. Unfoamed slurry is also spread at the third station 30 on a second liner paper 36 to form a third layer 40. The second liner paper 36 is then reversed, and the third layer 40 is brought onto the second layer 48 to form the three-layered product shown in FIG. 2.
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The apparatus includes a two-stage mixer formed within a single housing and including a first high shear mixer and a second low shear mixer. Plaster slurry is formed in the first mixer. A partition is laid on a first fixing sheet, a portion laid on a second fixing sheet, and the remainder discharged to the second mixer. In the second mixer, foam is added and the formed slurry is laid on the unformed slurry on the first fixing sheet. The unformed slurry in the second fixing sheen is brought to the formed slurry to join the product.
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BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention pertains to the field of mechanical locking devices, particularly of the type wherein a rod is axially translatable through a lock housing and having one or more coil springs normally gripping the rod and locking the same to the housing, the rod being releasable by unwinding the coil spring.
2. STATE OF THE PRIOR ART
Considerable inventive activity has been directed towards developing and improving linear friction lock mechanisms. These devices are characterized b one or more coil springs coaxial to the rod. One end of the coil spring is fixed in relation to the lock housing while the opposite end is engaged to a bushing rotatable about the rod. In a normal state the coil spring has an inner diameter somewhat smaller than the rod diameter and thus firmly grips the rod in a friction lock to prevent relative movement of the rod through the housing. A release lever is actuatable, manually or otherwise, for turning the rotatable bushing to momentarily unwinding the coil spring to increase its inside diameter and free the rod for axial translation through the housing. When the release lever is released the coil spring returns to its normal, rod gripping state. An example of a single coil spring friction lock is shown in commonly owned U.S. Pat. No. 4,411,339 issued to Porter on Oct. 25, 1983. Friction locks have found widespread application in adjustable vehicle seat installations. For example, the driver's seat in an automobile is mounted for sliding movement towards and away from the steering wheel on a pair of mounting rails and the seat is normally locked to one of the rails by means of such a friction lock mechanism. When adjustment of the seat is desired, the occupant of the seat manually actuates the release lever, moves the seat to the new desired position and releases the lock lever to secure the seat in the new position.
It has been found that while such locks are generally capable of reliable performance, under certain circumstances the rod may creep through the housing even while being gripped by the locking coil spring. This may happen for example, under conditions of severe vibration or other circumstances where a high axial load is repeatedly applied to the rod. This occurs in single coil locks because there is an inherent degree of asymmetry in the gripping action of the spring which is unwound only at one end. Efforts have been made to overcome this difficulty by providing dual spring lock mechanisms such as disclosed in commonly owned U.S. Pat. No. 4,577,730 issued to Porter on Mar. 25, 1986.
Nevertheless, a continuing need exists for improved linear friction lock mechanisms having positive rod locking characteristics under severe vibration or intermittent load conditions. In particular, there is a need for simple, relatively compact single coil spring friction locks featuring positive fail-safe redundant locking for securing the rod against creep through the coil spring and also to hold the rod in the event of structural failure of the coil spring. Such a redundant lock should be of simple and economical construction, and of uncomplicated operation.
SUMMARY OF THE INVENTION
This invention addresses the aforementioned need by providing a linear friction lock mechanism of the type having a rod axially translatable through a lock housing, at least one locking coil spring axially fixed to the housing and having an inner coil diameter such that the coil spring normally grips the rod against such axial movement, and a lock release mechanism actuatable for unwinding the locking coil spring thereby to free the rod for movement through the housing. This linear lock is improved by providing a backup latch element mounted to the housing for movement towards or away from interlocking engagement with the rod. The backup latch is spring loaded towards interlocking engagement with the rod and normally holds the rod against axial movement through the lock housing.
In a first embodiment of the invention a backup release arrangement is connected between the backup latch and the coil spring release mechanism so that actuation of the coil spring release mechanism simultaneously operates to disengage the backup latch, thus freeing the rod for axial movement through the lock housing. Conversely, when the coil spring release lever is released to allow the coil spring to wind and again grip the rod, the backup latch mechanism is also thereby returned to a rod engaging condition in which the spring and the backup latch cooperate to secure the rod in place relative to the lock housing.
Specifically, the locking spring is held between a fixed nonrotatable bushing and a sleeve rotatable for unwinding the locking coil and releasing its friction grip on the rod. The rotatable sleeve is provided with a cam element which operates through a cam follower arrangement to disengage the backup latch upon rotation of this sleeve, such that both the locking coil and backup latch can be released by actuation of a single lock release lever.
The cam follower arrangement includes a backup release lever pivoted to the lock housing with a cam follower edge spring biased into camming engagement with the cam element and a free end acting to disengage the backup latch upon rotation of the rotatable sleeve. A single bias spring having two end tangs may be arranged to bias both the backup latch and the backup release lever. The lock housing is advantageously formed of two opposite halves held together by welding to a pair of fixed bushings through which slides the rod.
In a second embodiment of the invention the aforedescribed camming arrangement is replaced by a single lever fixed externally to the housing on a spindle which is mounted for rotation to the lock housing transversely to the rod. The end of the spindle is normally provided with a suitable handle by means of which the spindle is turned by an operator in order to release the lock from its normally locked condition. The lever is provided with a finger extending parallel to the spindle axis through a window in the lock housing and into engagement with the backup latch element. A generally diametrically opposite portion of the release lever is movable into engagement with a coil spring release lever fixed to the rotatable sleeve. The relative arrangement is such that upon rotation of the spindle from its normal to a release position the finger on the release lever first moves the backup latch away from engagement with the rod and maintains the release latch in disengaged condition. Upon further rotation of the spindle an arm generally diametrically opposite to the finger on the main release lever engages against the coil spring release lever to move the spring release lever from its normally locked to a coil unwinding position whereupon the rod is completely freed from both the coil spring and backup latch for axial movement through the lock housing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section of the improved lock of this invention shown in its normal redundantly locked condition;
FIG. 2 is a longitudinal section as in FIG. 1 showing the lock in fully released condition and the rod shown displaced axially to the left of its FIG. 1 position;
FIG. 3 is a longitudinal perspective view of the lock seen along arrows 3--3 in FIG. 1;
FIG. 4 is a longitudinal view with the lock housing partly broken away to expose the backup latch and main release lever arrangement shown in normal redundantly locked condition;
FIG. 5 is a view as in FIG. 4 with the backup latch in released condition and the main release lever just prior to engaging the coil spring release lever;
FIG. 6 is an axial section of the lock taken along line 6--6 in FIG. 4;
FIG. 7 is a partial longitudinal view with the housing partly broken away taken along arrows 7--7 in FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the drawings, FIG. 1 shows a first embodiment of the improved mechanical lock 10. A clam-shell type lock housing 12 consists of two opposite halves 12' only one of which is seen in FIG. 1 and are seen joined together in FIG. 3. A rod 16 is slidable through two fixed, nonrotatable bushings 14 disposed between and spot welded to the two housing halves 12' so as to secure and hold together the housing halves. For mounting purposes, a first mounting hole 17 is provided in the rod 16 and a second mounting hole 21 is provided in each of the two halves of the lock housing 12. The rod 16 is axially movable through the housing 12 and both fixed bushings 14. A first mounting hole 17 is provided in the rod 16 and a second mounting hole 21 is provided in each of the two halves of the lock housing 12. The rod 16 has an end 18 serrated by a number of parallel circumferential V-grooves 19 between which are defined circumferential teeth 20. A locking coil spring 22 is wound about the rod 16 and has a normal inner diameter slightly smaller than the diameter of the rod 16 such that the spring 22 normally grips the rod 16 in tight frictional engagement. Most of the spring 22 is contained within tubular rotatable sleeve 28 which is rotatable about the rod 16 within the lock housing 12. The spring 22 terminates at each end in radial tangs 24. One tang 24 is visible in the drawings and is captive within a radial slot 26 in one fixed bushing 14. The opposite end of the spring 22 lies within the hollow cylindrical rotatable sleeve 28 and also terminates in an end tang at that end which is likewise radially engaged to the rotatable sleeve 28 in a conventional manner. The locking coil spring 22 can be unwound by turning the rotatable sleeve 28 in response to force applied to lock release lever 30 so as to increase the spring inner diameter and release its grip on the rod 16 which then becomes free to move axially through bushings 14, rotatable sleeve 28 and the housing 12.
A backup latch pawl 32 is pivoted on a shaft 34 supported between the two housing halves 12. The latch 32 is movable between a rod engaging condition shown in FIG. 1 and a disengaged condition seen in FIG. 2. The pawl 32 has a pair of pawl teeth 32a configured to mate with the V-grooves 19 in rod 16. In a normal, locked condition of the device, the latch pawl is biased by tang 40 of bias spring 36 into interlocking engagement with rod 16 by engagement of the pawl teeth 32a with the rod grooves 19 as shown in FIG. 1. A pawl release lever 46 is pivoted on shaft 48 and is held under the urging of tang 44 of the single bias spring 36 with cam follower edge 54 against a camming lobe 52 formed on the exterior surface of the tubular bushing 28. In a normal locked condition of the device 10 as shown in FIG. 1, the cam lobe 52 presents a minimum diameter portion towards the cam follower edge 54 allowing the backup latch pawl 32 to engage and interlock with the rod 16 under the urging of tang 40 of the same bias spring 36. In this normal locked condition of the device 10, both the locking coil spring 22 and backup latch 32 cooperate in holding the rod 16 against axial movement through the housing 12.
As the rotatable sleeve 28 is turned by actuation of the lever 30 in the direction of arrow R in FIG. 3, the radial dimension of the cam lobe 52 bearing against the cam follower edge 54 of the pawl release lever 46 gradually increases, pushing the pawl release lever 46 counter-clockwise about pivot 48 as indicated by arrow P in FIG. 2 such that its free end 50 acts against the end 42 of the latch 32, turning the latch clockwise about pivot 34 as indicated by arrow Q and lifting the latch teeth 32a away from the grooves 19 to disengage the backup latch 32. Upon further rotation of the sleeve 28 the locking coil 22 is unwound by rotation of the sleeve 28, so that rod 16 is freed for axial movement through housing 12 and remains in such free state as the lock release lever 30 is held in the rod releasing position shown in FIGS. 2 and 3 against the tendency of the locking spring 22 to return to its normal state of reduced diameter.
A second embodiment of this invention is shown in FIGS. 4 through 7 in which the lock 100 is similar to the lock 10 of FIGS. 1-3 in that it incorporates a rod 16 axially movable through a lock housing 12 assembled from two opposite halves 12'0 best seen in FIG. 6. The rod 16 moves through two fixed nonrotatable bushings 14, only one of which is visible in FIG. 4, the other being hidden under the unbroken portion of the housing 12. A locking coil spring 22 is wound on the rod 16 axially between the two bushings 14 and normally tightly grips the rod 16 so as to hold it against axial translation through the housing and bushings. The coil 22 ends in two opposite tangs, one of which is engaged to the visible fixed bushing 14, the opposite tang being secured to rotatable tubular sleeve 28 to which is fixed a radially projecting coil release lever 30. Upon rotation of the hollow cyindrical rotatable sleeve 28, the spring 22 is unwound at one end and its inner diameter enlarged so as to release its grip on rod 16, freeing the latter for relative axial movement.
Elements common to both locks 100 and 10 are designated by like numerals in the drawings. The lock of FIG. 4 is shown with an expansion spring 102 compressed between the housing 12 and the end 15 of the rod 16. The spring 102 drives the rod 16 to maximum extension from the lock housing upon release of the lock mechanism. Provision of such an extension spring is optional depending on the particular application of the lock mechanism and a similar extension spring arrangement may be provided in the lock 10 of FIGS. 1-3.
The lock 100 is provided with a redundant locking mechanism which includes a backup locking latch 132 pivotable on transverse shaft 134 between a locking position wherein latch teeth 136 are in mating engagement with V-grooves 19 defined between circumferential teeth 20 in the rod 16 near the rod end 18 as in FIG. 1 and a released position where the latch teeth 136 are spaced from the rod 16 as in FIG. 2. The latch 132 is normally spring driven into locking engagement with the serrated end of the rod 16 in the condition shown in FIG. 1.
A spindle 160 is mounted for rotation to the housing 12 transversely to the rod 18 and has a free outer end 162 on which will normally be mounted a lock release handle or knob of appropriate size for easy operation. Mounted transversely on the spindle 160 is a main release lever 164 as best understood by reference to FIGS. 6 and 7. The lever 164 is rotatable with the release spindle 160 and the lever includes a latch release finger 166 projecting through a window into the lock housing between the rod 16 and the free radially outer end of the backup latch 132. Upon clockwise rotation of the spindle 160 as suggested in FIG. 5, the end of the finger 166 makes contact against the edge 168 of backup latch, pivoting the same counterclockwise away from engagement with the serrations on the rod 16. Upon further rotation of the spindle 160, the elongated arm 170 of the lever makes contact with the free end of the coil release lever 30 and moves the lever 30 to its coil releasing position, the levers 164 and 30 moving in circular paths which lie in mutually perpendicular planes. The finger 166 maintains the backup latch 132 disengaged from the rod 16 throughout the additional arc of spindle rotation necessary to actuate the coil release lever 30. The main release lever 164 is constructed so as to first disengage the backup latch 132 following a relatively small angle of rotation and before releasing the locking coil 22 so as to avoid transmitting the axial loading of spring 102 or other load on the rod 16 onto the backup latch 132 prior to disengagement.
While particular embodiments of the invention have been shown and illustrated by way of example and for purposes of clarity, it must be understood that many changes, substitutions and modifications to these embodiments will become apparent to those possessed of ordinary skill in the art without thereby departing from the scope of this invention which is defined only by the following claims.
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A linear friction lock mechanism of the type having a rod axially translatable through a lock housing, at least one locking coil spring axially fixed to the housing and having an inner coil diameter such that the coil spring normally grips the rod against such axial movement, and a lock release mechanism actuatable for unwinding the locking coil spring thereby to free the rod for movement through the housing. This linear lock is improved by providing a backup latch element mounted to the housing and spring loaded towards interlocking engagement with the rod redundantly holds the rod against axial movement through the lock housing independently of the locking coil spring to eliminate creeping of the rod through the spring. Manual and remote cable release mechanisms are optional.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 12/946,645, filed on Nov. 15, 2010, the entirety of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The invention generally relates to devices for deploying an intraocular shunt within an eye.
[0004] 2. Description of the Related Art
[0005] Glaucoma is a disease of the eye that affects millions of people. Glaucoma is associated with an increase in intraocular pressure resulting either from a failure of a drainage system of an eye to adequately remove aqueous humor from an anterior chamber of the eye or overproduction of aqueous humor by a ciliary body in the eye. Build-up of aqueous humor and resulting intraocular pressure may result in irreversible damage to the optic nerve and the retina, which may lead to irreversible retinal damage and blindness.
[0006] Glaucoma may be treated by surgical intervention that involves placing a shunt in the eye to result in production of fluid flow pathways between the anterior chamber and various structures of the eye involved in aqueous humor drainage (e.g., Schlemm's canal, the sclera, or the subconjunctival space). Such fluid flow pathways allow for aqueous humor to exit the anterior chamber. Generally, the surgical intervention to implant the shunt involves inserting into the eye a deployment device that holds an intraocular shunt, and deploying the shunt within the eye. A deployment device holding the shunt enters the eye through a cornea (ab interno approach), and is advanced across the anterior chamber. The deployment device is advanced through the sclera until a distal portion of the device is in proximity to a drainage structure of the eye. The shunt is then deployed from the deployment device, producing a conduit between the anterior chamber and various structures of the eye involved in aqueous humor drainage (e.g., Schlemm's canal, the sclera, or the subconjunctival space). See for example, Prywes (U.S. Pat. No. 6,007,511).
[0007] A problem associated with such surgical interventions is ensuring that placement of the shunt does not change during deployment of the shunt from the deployment device. Deployment devices that are used to place the shunt in the eye generally rely on multiple moving components in order to deploy the shunt. Movement of the components of the deployment device shifts the position of the deployment device within the eye during the deployment process, and thus shifts the position of the shunt as it is being deployed. Such movement leads to improper placement of the shunt within the eye.
SUMMARY
[0008] The invention generally relates to deployment devices that are designed to minimize movement of the device during deployment of an intraocular shunt from the device, thereby ensuring proper placement of the shunt within the eye.
[0009] In certain aspects, deployment devices of the invention include a housing, a deployment mechanism at least partially disposed within the housing, and a hollow shaft coupled to the deployment mechanism, in which the shaft is configured to hold an intraocular shunt. With such devices, rotation of the deployment mechanism results in deployment of the shunt. Such rotational movement is translated into axial movement for deploying the shunt from the device. By utilizing rotational movement for the deployment mechanism, axial movement of the deployment device is minimized, ensuring proper placement of the shunt within the eye.
[0010] Other aspects of the invention provide devices for deploying an intraocular shunt including a housing, a deployment mechanism at least partially disposed within the housing, in which the deployment mechanism includes a two stage system, and a hollow shaft coupled to the deployment mechanism, in which the shaft is configured to hold an intraocular shunt.
[0011] Another aspect of the invention includes devices for deploying an intraocular shunt including a housing, a deployment mechanism at least partially disposed within the housing, and a hollow shaft coupled inside the housing to the deployment mechanism, wherein the shaft is configured to hold an intraocular shunt, in which the device includes an insertion configuration and a deployment configuration and the deployment configuration includes a proximal portion of the shaft being at least partially retracted to within the housing. In certain embodiments, the insertion configuration includes a distal portion of the shaft being disposed within the housing and a proximal portion of the shaft extending beyond the housing.
[0012] In certain embodiments, the shaft is configured to at least partially retract to within the housing. However, it will be appreciated that the shaft may fully retract to within the housing. In certain embodiments, the device further includes the intraocular shunt. The shunt may be completely disposed within the hollow shaft of the device. Alternatively, the shunt is partially disposed within the hollow shaft of the device.
[0013] The deployment mechanism may include a two stage system. In such embodiments, the first stage is a pusher component and the second stage is a retraction component. In this embodiment, rotation of the deployment mechanism sequentially engages the pusher component and then the retraction component. The pusher component pushes the shunt to partially deploy the shunt from within the shaft, and the retraction component retracts the shaft from around the shunt, thereby deploying the shunt. In certain embodiments, the deployment mechanism may additionally include at least one member that limits axial movement of the shaft.
[0014] The hollow shaft of the deployment device may include a beveled distal end. An exemplary hollow shaft is a needle. Devices of the invention may be completely automated, partially automated, or completely manual. Devices of the invention may be connected to larger robotic systems or may be used as stand-alone handheld deployment devices. In particular embodiments, the device is a handheld device.
[0015] Devices of the invention may include an indicator that provides feedback to an operator as to the state of the deployment mechanism. The indicator may be any type of indicator known in the art, for example a visual indicator, an audio indicator, or a tactile indicator. In certain embodiments, the indicator is a visual indicator.
[0016] Aspects of the invention also include methods for deploying an intraocular shunt within an eye. These methods involve using devices described herein to deploy an intraocular shunt from the device within the eye. Generally, deploying the shunt results in a flow path from an anterior chamber of the eye to an area of lower pressure. Exemplary areas of lower pressure include intra-Tenon's space, the subconjunctival space, the episcleral vein, the suprachoroidal space, and Schlemm's canal. In certain embodiments, the area of lower pressure is the subarachnoid space.
[0017] Any of a variety of methods known in the art may be used to insert devices of the invention into an eye. In certain embodiments, devices of the invention may be inserted into the eye using an ab externo approach (entering through the conjunctiva) or an ab interno approach (entering through the cornea).
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic showing an embodiment of a shunt deployment device according to the invention.
[0019] FIG. 2 shows an exploded view of the device shown in FIG. 1 .
[0020] FIGS. 3A-3D are schematics showing different enlarged views of the deployment mechanism of the deployment device.
[0021] FIGS. 4A-4C are schematics showing interaction of the deployment mechanism with a portion of the housing of the deployment device.
[0022] FIG. 5 shows a cross sectional view of the deployment mechanism of the deployment device.
[0023] FIGS. 6A-6B show schematics of the deployment mechanism in a pre-deployment configuration.
[0024] FIG. 6C shows an enlarged view of the distal portion of the deployment device of FIG. 6A . This figure shows an intraocular shunt loaded within a hollow shaft of the deployment device.
[0025] FIGS. 7A-7B show schematics of the deployment mechanism at the end of the first stage of deployment of the shunt from the deployment device.
[0026] FIG. 7C shows an enlarged view of the distal portion of the deployment device of FIG. 7A . This figure shows an intraocular shunt partially deployed from within a hollow shaft of the deployment device.
[0027] FIG. 8A shows a schematic of the deployment device after deployment of the shunt from the device.
[0028] FIG. 8B show a schematic of the deployment mechanism at the end of the second stage of deployment of the shunt from the deployment device.
[0029] FIG. 8C shows an enlarged view of the distal portion of the deployment device after retraction of the shaft with the pusher abutting the shunt.
[0030] FIG. 8D shows an enlarged view of the distal portion of the deployment device after deployment of the shunt.
[0031] FIGS. 9A-9B show an intraocular shunt deployed within the eye. A proximal portion of the shunt resides in the anterior chamber and a distal portion of the shunt resides within the intra-Tenon's space. A middle portion of the shunt resides in the sclera.
[0032] FIG. 10 depicts a schematic of an exemplary intraocular shunt.
DETAILED DESCRIPTION
[0033] Reference is now made to FIG. 1 , which shows an embodiment of a shunt deployment device 100 according to the invention. While FIG. 1 shows a handheld manually operated shunt deployment device, it will be appreciated that devices of the invention may be coupled with robotic systems and may be completely or partially automated. As shown in FIG. 1 , deployment device 100 includes a generally cylindrical body or housing 101 ; however, the body shape of housing 101 could be other than cylindrical. Housing 101 may have an ergonomical shape, allowing for comfortable grasping by an operator. Housing 101 is shown with optional grooves 102 to allow for easier gripping by a surgeon.
[0034] Housing 101 is shown having a larger proximal portion that tapers to a distal portion. The distal portion includes a hollow sleeve 105 . The hollow sleeve 105 is configured for insertion into an eye and to extend into an anterior chamber of an eye. The hollow sleeve is visible within an anterior chamber of an eye. The sleeve 105 provides a visual preview for an operator as to placement of the proximal portion of the shunt within the anterior chamber of an eye. Additionally, the sleeve 105 provides a visual reference point that may be used by an operator to hold device 100 steady during the shunt deployment process, thereby assuring optimal longitudinal placement of the shunt within the eye.
[0035] The sleeve 105 may include an edge 131 at a distal end that provides resistance feedback to an operator upon insertion of the deployment device 100 within an eye of a person. Upon advancement of the device 100 across an anterior chamber of the eye, the hollow sleeve 105 will eventually contact the sclera 134 , providing resistance feedback to an operator that no further advancement of the device 100 is necessary. The edge 131 of the sleeve 105 prevents the shaft 104 from accidentally being pushed too far through the sclera. A temporary guard 108 is configured to fit around sleeve 105 and extend beyond an end of sleeve 105 . The guard is used during shipping of the device and protects an operator from a distal end of a hollow shaft 104 that extends beyond the end of the sleeve 105 . The guard is removed prior to use of the device.
[0036] Housing 101 is open at its proximal end, such that a portion of a deployment mechanism 103 may extend from the proximal end of the housing 101 . A distal end of housing 101 is also open such that at least a portion of a hollow shaft 104 may extend through and beyond the distal end of the housing 101 . Housing 101 further includes a slot 106 through which an operator, such as a surgeon, using the device 100 may view an indicator 107 on the deployment mechanism 103 .
[0037] Housing 101 may be made of any material that is suitable for use in medical devices. For example, housing 101 may be made of a lightweight aluminum or a biocompatible plastic material. Examples of such suitable plastic materials include polycarbonate and other polymeric resins such as DELRIN and ULTEM. In certain embodiments, housing 101 is made of a material that may be autoclaved, and thus allow for housing 101 to be re-usable. Alternatively, device 100 may be sold as a one-time-use device, and thus the material of the housing does not need to be a material that is autoclavable.
[0038] Housing 101 may be made of multiple components that connect together to form the housing. FIG. 2 shows an exploded view of deployment device 100 . In this figure, housing 101 , is shown having three components 101 a, 101 b, and 101 c. The components are designed to screw together to form housing 101 . FIG. 2 also shows deployment mechanism 103 . The housing 101 is designed such that deployment mechanism 103 fits within assembled housing 101 . Housing 101 is designed such that components of deployment mechanism 103 are movable within housing 101 .
[0039] FIGS. 3A-3D show different enlarged views of the deployment mechanism 103 . Deployment mechanism 103 may be made of any material that is suitable for use in medical devices. For example, deployment mechanism 103 may be made of a lightweight aluminum or or a biocompatible plastic material. Examples of such suitable plastic materials include polycarbonate and other polymeric resins such as DELRIN and ULTEM. In certain embodiments, deployment mechanism 103 is made of a material that may be autoclaved, and thus allow for deployment mechanism 103 to be re-usable. Alternatively, device 100 may be sold as a one-time-use device, and thus the material of the deployment mechanism does not need to be a material that is autoclavable.
[0040] Deployment mechanism 103 includes a proximal portion 109 and a distal portion 110 . The deployment mechanism 103 is configured such that proximal portion 109 is movable within distal portion 110 . More particularly, proximal portion 109 is capable of partially retracting to within distal portion 110 .
[0041] In this embodiment, the proximal portion 109 is shown to taper to a connection with a hollow shaft 104 . This embodiment is illustrated such that the connection between the hollow shaft 104 and the proximal portion 109 of the deployment mechanism 103 occurs inside the housing 101 . In other embodiments, the connection between hollow shaft 104 and the proximal portion 109 of the deployment mechanism 103 may occur outside of the housing 101 . Hollow shaft 104 may be removable from the proximal portion 109 of the deployment mechanism 103 . Alternatively, the hollow shaft 104 may be permanently coupled to the proximal portion 109 of the deployment mechanism 103 .
[0042] Generally, hollow shaft 104 is configured to hold an intraocular shunt 115 . An exemplary intraocular shunt 115 is shown in FIG. 11 . Other exemplary intraocular shunts are shown in Yu et al. (U.S. Patent Application No. 2008/0108933). Generally, in one embodiment, intraocular shunts are of a cylindrical shape and have an outside cylindrical wall and a hollow interior. The shunt may have an inner diameter of approximately 50 μm to approximately 250 μm, an outside diameter of approximately 190 μm to approximately 300 μtm, and a length of approximately 0.5 mm to about 20 mm. Thus, hollow shaft 104 is configured to at least hold a shunt of such shape and such dimensions. However, hollow shaft 104 may be configured to hold shunts of different shapes and different dimensions than those described above, and the invention encompasses a shaft 104 that may be configured to hold any shaped or dimensioned intraocular shunt. In particular embodiments, the shaft has an inner diameter of approximately 200 μm to approximately 400 μm.
[0043] The shaft 104 may be any length. A usable length of the shaft may be anywhere from about 5 mm to about 40 mm, and is 15 mm in certain embodiments. In certain embodiments, the shaft is straight. In other embodiments, shaft is of a shape other than straight, for example a shaft having a bend along its length or a shaft having an arcuate portion. Exemplary shaped shafts are shown for example in Yu et al. (U.S. Patent Application No. 2008/0108933).
[0044] In particular embodiments, the shaft includes a bend at a distal portion of the shaft. In other embodiments, a distal end of the shaft 104 is beveled or is sharpened to a point to assist in piercing the sclera and advancing the distal end of the shaft 104 through the sclera. In particular embodiments, the distal end of the shaft 104 has a double bevel. The double bevel provides an angle at the distal end of the shaft 104 such that upon entry of the shaft into intra-Tenon's space, the distal end of shaft 104 will by parallel with Tenon's capsule and will thus not pierce Tenon's capsule and enter the subconjunctival space. This ensures proper deployment of the shunt such that a distal end of the shunt 115 is deployed within the intra-Tenon's space, rather than deployment of the distal end of the shunt 115 within the subconjunctival space. Changing the angle of the bevel allows for placement of shunt 115 within other areas of lower pressure than the anterior chamber, such as the subconjunctival space. It will be understood that implanting into intra-Tenon's space merely one embodiment of where shunt 115 may be placed within the eye, and that devices of the invention are not limited to placing shunts within intra-Tenon's space and may be used to place shunts into many other areas of the eye, such as Schlemm' s canal, the subconjunctival space, the episcleral vein, or the suprachoroidal space.
[0045] The shaft 104 may hold the shunt at least partially within the hollow interior of the shaft 104 . In other embodiments, the shunt is held completely within the hollow interior of the shaft 104 . Alternatively, the hollow shaft may hold the shunt on an outer surface of the shaft 104 . In particular embodiments, the shunt is held within the hollow interior of the shaft 104 . In certain embodiments, the hollow shaft is a needle having a hollow interior. Needles that are configured to hold an intraocular shunt are commercially available from Terumo Medical Corp. (Elkington, Md.).
[0046] A distal portion of the deployment mechanism includes optional grooves 116 to allow for easier gripping by an operator for easier rotation of the deployment mechanism, which will be discussed in more detail below. The distal portion 110 of the deployment mechanism also includes at least one indicator that provides feedback to an operator as to the state of the deployment mechanism. The indicator may be any type of indicator known in the art, for example, a visual indicator, an audio indicator, or a tactile indicator. FIG. 3 shows a deployment mechanism having two indicators, a ready indicator 111 and a deployed indicator 119 . Ready indicator 111 provides feedback to an operator that the deployment mechanism is in a configuration for deployment of an intraocular shunt from the deployment device 100 . The indicator 111 is shown in this embodiment as a green oval having a triangle within the oval. Deployed indicator 119 provides feedback to the operator that the deployment mechanism has been fully engaged and has deployed the shunt from the deployment device 100 . The deployed indicator 119 is shown in this embodiment as a yellow oval having a black square within the oval. The indicators are located on the deployment mechanism such that when assembled, the indicators 111 and 119 may be seen through slot 106 in housing 101 .
[0047] The distal portion 110 includes a stationary portion 110 b and a rotating portion 110 a. The distal portion 110 includes a channel 112 that runs part of the length of stationary portion 110 b and the entire length of rotating portion 110 a. The channel 112 is configured to interact with a protrusion 117 on an interior portion of housing component 101 a ( FIGS. 4A and 4B ). During assembly, the protrusion 117 on housing component 101 a is aligned with channel 112 on the stationary portion 110 b and rotating portion 110 a of the deployment mechanism 103 . The distal portion 110 of deployment mechanism 103 is slid within housing component 101 a until the protrusion 117 sits within stationary portion 110 b ( FIG. 4C ). Assembled, the protrusion 117 interacts with the stationary portion 110 b of the deployment mechanism 103 and prevents rotation of stationary portion 110 b. In this configuration, rotating portion 110 a is free to rotate within housing component 101 a.
[0048] Referring back to FIG. 3 , the rotating portion 110 a of distal portion 110 of deployment mechanism 103 also includes channels 113 a, 113 b, and 113 c. Channel 113 a includes a first portion 113 a 1 that is straight and runs perpendicular to the length of the rotating portion 110 a, and a second portion 113 a 2 that runs diagonally along the length of rotating portion 110 a, downwardly toward a distal end of the deployment mechanism 103 . Channel 113 b includes a first portion 113 b 1 that runs diagonally along the length of the rotating portion 110 a , upwardly toward a proximal end of the deployment mechanism 103 , and a second portion that is straight and runs perpendicular to the length of the rotating portion 110 a. The point at which first portion 113 a 1 transitions to second portion 113 a 2 along channel 113 a, is the same as the point at which first portion 113 b 1 transitions to second portion 113 b 2 along channel 113 b. Channel 113 c is straight and runs perpendicular to the length of the rotating portion 110 a . Within each of channels 113 a, 113 b, and 113 c, sit members 114 a, 114 b, and 114 c respectively. Members 114 a, 114 b, and 114 c are movable within channels 113 a, 113 b, and 113 c. Members 114 a, 114 b, and 114 c also act as stoppers that limit movement of rotating portion 110 a, which thereby limits axial movement of the shaft 104 .
[0049] FIG. 5 shows a cross-sectional view of deployment mechanism 103 . Member 114 a is connected to the proximal portion 109 of the deployment mechanism 103 . Movement of member 114 a results in retraction of the proximal portion 109 of the deployment mechanism 103 to within the distal portion 110 of the deployment mechanism 103 . Member 114 b is connected to a pusher component 118 . The pusher component 118 extends through the proximal portion 109 of the deployment mechanism 103 and extends into a portion of hollow shaft 104 . The pusher component is involved in deployment of a shunt from the hollow shaft 104 . An exemplary pusher component is a plunger. Movement of member 114 b engages pusher 118 and results in pusher 118 advancing within hollow shaft 104 .
[0050] Reference is now made to FIGS. 6A-8D , which accompany the following discussion regarding deployment of a shunt 115 from deployment device 100 . FIG. 6A shows deployment device 100 is a pre-deployment configuration. In this configuration, shunt 115 is loaded within hollow shaft 104 ( FIG. 6C ). As shown in FIG. 6C , shunt 115 is only partially within shaft 104 , such that a portion of the shunt is exposed. However, the shunt 115 does not extend beyond the end of the shaft 104 . In other embodiments, the shunt 115 is completely disposed within hollow shaft 104 . The shunt 115 is loaded into hollow shaft 104 such that the shunt abuts pusher component 118 within hollow shaft 104 . A distal end of shaft 104 is beveled to assist in piercing tissue of the eye.
[0051] Additionally, in the pre-deployment configuration, a portion of the shaft 104 extends beyond the sleeve 105 ( FIG. 6C ). The deployment mechanism is configured such that member 114 a abuts a proximal end of the first portion 113 a 1 of channel 113 a, and member 114 b abut a proximal end of the first portion 113 b 1 of channel 113 b ( FIG. 6B ). In this configuration, the ready indicator 111 is visible through slot 106 of the housing 101 , providing feedback to an operator that the deployment mechanism is in a configuration for deployment of an intraocular shunt from the deployment device 100 ( FIG. 6A ). In this configuration, the device 100 is ready for insertion into an eye (insertion configuration or pre-deployment configuration). Methods for inserting and implanting shunts are discussed in further detail below.
[0052] Once the device has been inserted into the eye and advanced to a location to where the shunt will be deployed, the shunt 115 may be deployed from the device 100 . The deployment mechanism 103 is a two-stage system. The first stage is engagement of the pusher component 118 and the second stage is retraction of the proximal portion 109 to within the distal portion 110 of the deployment mechanism 103 . Rotation of the rotating portion 110 a of the distal portion 110 of the deployment mechanism 103 sequentially engages the pusher component and then the retraction component.
[0053] In the first stage of shunt deployment, the pusher component is engaged and the pusher partially deploys the shunt from the deployment device. During the first stage, rotating portion 110 a of the distal portion 110 of the deployment mechanism 103 is rotated, resulting in movement of members 114 a and 114 b along first portions 113 a 1 and 113 b 1 in channels 113 a and 113 b. Since the first portion 113 a 1 of channel 113 a is straight and runs perpendicular to the length of the rotating portion 110 a, rotation of rotating portion 110 a does not cause axial movement of member 114 a. Without axial movement of member 114 a, there is no retraction of the proximal portion 109 to within the distal portion 110 of the deployment mechanism 103 . Since the first portion 113 b 1 of channel 113 b runs diagonally along the length of the rotating portion 110 a, upwardly toward a proximal end of the deployment mechanism 103 , rotation of rotating portion 110 a causes axial movement of member 114 b toward a proximal end of the device. Axial movement of member 114 b toward a proximal end of the device results in forward advancement of the pusher component 118 within the hollow shaft 104 . Such movement of pusher component 118 results in partially deployment of the shunt 115 from the shaft 104 .
[0054] FIGS. 7A-7C show schematics of the deployment mechanism at the end of the first stage of deployment of the shunt from the deployment device. As is shown FIG. 7A , members 114 a and 114 b have finished traversing along first portions 113 a 1 and 113 b 1 of channels 113 a and 113 b. Additionally, pusher component 118 has advanced within hollow shaft 104 ( FIG. 7B ), and shunt 115 has been partially deployed from the hollow shaft 104 ( FIG. 7C ). As is shown in these figures, a portion of the shunt 115 extends beyond an end of the shaft 104 .
[0055] In the second stage of shunt deployment, the retraction component is engaged and the proximal portion of the deployment mechanism is retracted to within the distal portion of the deployment mechanism, thereby completing deployment of the shunt from the deployment device. During the second stage, rotating portion 110 a of the distal portion 110 of the deployment mechanism 103 is further rotated, resulting in movement of members 114 a and 114 b along second portions 113 a 2 and 113 b 2 in channels 113 a and 113 b. Since the second portion 113 b 2 of channel 113 b is straight and runs perpendicular to the length of the rotating portion 110 a, rotation of rotating portion 110 a does not cause axial movement of member 114 b. Without axial movement of member 114 b, there is no further advancement of pusher 118 . Since the second portion 113 a 2 of channel 113 a runs diagonally along the length of the rotating portion 110 a, downwardly toward a distal end of the deployment mechanism 103 , rotation of rotating portion 110 a causes axial movement of member 114 a toward a distal end of the device. Axial movement of member 114 a toward a distal end of the device results in retraction of the proximal portion 109 to within the distal portion 110 of the deployment mechanism 103 . Retraction of the proximal portion 109 , results in retraction of the hollow shaft 104 . Since the shunt 115 abuts the pusher component 118 , the shunt remains stationary at the hollow shaft 104 retracts from around the shunt 115 ( FIG. 8C ). The shaft 104 retracts almost completely to within the sleeve 105 . During both stages of the deployment process, the sleeve 105 remains stationary and in a fixed position.
[0056] FIG. 8A shows a schematic of the device 100 after deployment of the shunt 115 from the device 100 . FIG. 8B shows a schematic of the deployment mechanism at the end of the second stage of deployment of the shunt from the deployment device. As is shown in FIG. 8B , members 114 a and 114 b have finished traversing along second portions 113 a 1 and 113 b 1 of channels 113 a and 113 b. Additionally, proximal portion 109 has retracted to within distal portion 110 , thus resulting in retraction of the hollow shaft 104 to within the sleeve 105 . FIG. 8D shows an enlarged view of the distal portion of the deployment device after deployment of the shunt. This figure shows that the hollow shaft 104 is not fully retracted to within the sleeve 105 of the deployment device 100 . However, in certain embodiments, the shaft 104 may completely retract to within the sleeve 105 .
[0057] Referring to FIG. 8A , in the post-deployment configuration, the deployed indicator 119 is visible through slot 106 of the housing 101 , providing feedback to the operator that the deployment mechanism has been fully engaged and that the shunt 115 has been deployed from the deployment device 100 .
[0058] Any of a variety of methods known in the art may be used to insert devices of the invention into an eye. In certain embodiments, devices of the invention may be inserted into the eye using an ab externo approach (entering through the conjunctiva) or an ab interno approach (entering through the cornea).
[0059] In certain embodiments, devices of the invention are inserted into the eye using an ab interno approach. Ab interno approaches for implanting an intraocular shunt are shown for example in Yu et al. (U.S. Pat. No. 6,544,249 and U.S. Patent Application No. 2008/0108933) and Prywes (U.S. Pat. No. 6,007,511), the content of each of which is incorporated by reference herein in its entirety.
[0060] Devices of the invention may be inserted into the eye to deploy shunts that create fluid drainage passageways from the anterior chamber of the eye to various drainage structures of the eye. Exemplary drainage structures include Schlemm's canal, the subconjunctival space, the episcleral vein, the suprachoroidal space, or the intra-Tenon's space. In certain embodiments, fluid is drained to the subarachnoid space.
[0061] In particular embodiments, devices of the invention are inserted into the eye to deploy shunts that create fluid drainage passageways from the anterior chamber to the intra-Tenon's space. Within an eye, there is a membrane known as the conjunctiva, and the region below the conjunctiva is known as the subconjunctival space. Within the subconjunctival space is a membrane known as Tenon's capsule. Below Tenon's capsule there are Tenon's adhesions that connect the Tenon's capsule to the sclera. The space between Tenon's capsule and the sclera where the Tenon's adhesions connect the Tenon's capsule to the sclera is known as the intra-Tenon's space.
[0062] FIGS. 9A-9B show an intraocular shunt placed into the eye using devices of the invention such that the shunt forms a passage for fluid drainage from the anterior chamber to the intra-Tenon's space. To place the shunt within the eye, a surgical intervention to implant the shunt is performed that involves inserting into the eye 202 a deployment device 200 that holds an intraocular shunt 201 , and deploying at least a portion of the shunt 201 within intra-Tenon's space 208 , within the subconjunctival space 209 and below the conjunctiva 210 . In certain embodiments, a hollow shaft 206 of a deployment device 200 holding the shunt 201 enters the eye 202 through the cornea 203 (ab interno approach). The shaft 206 is advanced across the anterior chamber 204 (as depicted by the broken line) in what is referred to as a transpupil implant insertion. The shaft 206 is advanced through the sclera 205 until a distal portion of the shaft 206 is in proximity to Tenon's capsule 207 .
[0063] Once a distal portion of the hollow shaft 206 is within the intra-Tenon's space 208 , the shunt 201 is then deployed from the shaft 206 of the deployment device 200 , producing a conduit between the anterior chamber 204 and the intra-Tenon's space 208 to allow aqueous humor to drain from the anterior chamber 204 (see FIGS. 9A and 9B ).
Combinations of Embodiments
[0064] As will be appreciated by one skilled in the art, individual features of the invention may be used separately or in any combination. Particularly, it is contemplated that one or more features of the individually described above embodiments may be combined into a single shunt.
Incorporation by Reference
[0065] References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made throughout this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes.
Equivalents
[0066] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting on the invention described herein.
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An intraocular shunt deployment device can release an intraocular shunt into an eye using a deployment mechanism that coordinates action between a pusher component, a shaft component, and a housing of the device. The deployment mechanism causes axial movement of the components in response to a rotational input force.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a national phase application based on PCT/EP2002/014773, filed Dec. 27, 2002, the content of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a water-resistant telecommunication cable, in particular an optical fibre cable, comprising a solid and compact element, in particular a buffer tube, housing a loose transmitting element.
The present invention also relates to a method for maintaining loose the transmitting element of the cable of the invention upon the extrusion thereof and to the use of a water-soluble polymer material, comprising a vinyl alcohol/vinyl acetate (referred to hereinbelow as VA-VAc copolymer and generally identified in the art as PVA), for the preparation of the solid and compact element in order to maintain loose the transmitting element upon extrusion of the cable.
2. Description of the Related Art
In extruding polyvinyl alcohol (PVA) several problems have been generally encountered. It is known that the melting point of PVA is higher than its decomposition temperature and that the risk of cross-linking is high. The extrudability of PVA has hitherto been sought to be improved, e.g., by the addition of plasticizers, commonly a polyhydric alcohol and lubricants such as stearic acid; the result being however of limited utility because the use of PVA requires to work within a very narrow temperature range. Also the fugitive nature of the plasticizer could generate a tendency to stick thereby interfering with a smooth extrusion. The kind and amount of the plasticizer are also important to get a composition neither too tacky in use and nor too soft for the manufacturing process.
U.S. Pat. No. 3,607,812 discloses a method of manufacturing a PVA film insoluble in water at a temperature below 40° C., by adding 5–13 parts by weight of a polyhydric alcohol plasticizer such as glycerine, triethylene glycol, triethylol propane, to 87–95 parts by weight of a fully hydrolysed PVA; the film is useful for making hospital bags or the packaging material of detergents and agricultural chemicals.
U.S. Pat. No. 3,997,489 discloses a PVA composition of improved melt flow characteristics, the PVA having a degree of polymerisation of about 500–2,000 and a degree of hydrolysis of at least about 88%; the composition comprises 0–20% of a plasticizer, about 0.5–5% of a wax and about 0.5–5% of an ethylene polymer, all amounts being based upon the weight of the PVA-plasticizer blend. The optional presence of a plasticizer is said to enhance the improvement of the melt flow characteristics.
GB 2,340,835 discloses an extrudable PVA composition comprising a blend of partially and fully hydrolysed PVAs, a lubricant such as a fatty acid amide and, optionally, up to 20 wt % of a plasticizer such as glycerine, ethylene glycol, etc. The composition is said to be suitably extruded on current unmodified extrusion lines without processing problems such as thermal degradation and high temperature cross-linking.
U.S. Pat. Nos. 4,323,492 and 4,542,178 disclose a tack-free granular PVA composition, and a process for the manufacture thereof, capable of being processed thermoplastically. The composition comprises a 10–30 wt % of a plasticizer, f.i. glycerol, polyethylene glycol, trimethylol propane, an amount of water insufficient to dissolve the PVA granules, and 2–12 wt % of a fine particle high molecular weight organic compound, f.i. starch, cellulose, casein, amounts being referred to the unplasticized PVA granules.
U.S. Pat. No. 4,611,019 discloses a melt extrudable composition consisting essentially of a mixture of a PVA homopolymer, having a degree of hydrolysis greater than 95% and a molecular weight range which spans the solution viscosity range of 2 to 30 cP at 4% concentration in water at 20° C., and 7–15 wt % of a plasticizer such as aromatic sulphonamides, polyols, etc., and 0.5–4.5 wt % of a polyamide, amounts being based on the PVA. The composition can be extruded and is particularly useful, as a film, for protecting oxygen sensitive products.
EP-A-0635545 discloses a melt extrudable PVA composition, especially useful for injection moulding of articles, in particular personal care articles which are flushable and biodegradable. The composition consists essentially of a blend of partially (30–50%) and fully hydrolysed (50–70%) PVAs, a solid (1–10%) and a liquid (8–20%) plasticizer, the amount of the plasticizers being referred to PVA. The PVA blend is said to be used because only fully hydrolysed PVA would give the moulded articles an excessive brittleness which would be offset by using an excess of plasticizer which, in its turn, would lead to lower water resistance; on the other hand, using an all partially hydrolysed PVA composition would result to be too tacky in use and too soft for the manufacturing process. Preferred plasticizers are polyhydric alcohols, the preferred solid ones being sorbitol, mannitol, pentaerythritol or dipentaerythritol and the preferred liquid ones being glycerol, ethylene glycol and polyethylene glycol. Further, an exudation of the liquid plasticizer on the surface of the article, and upon ageing, especially with fully hydrolysed PVA, is noted at greater than 10 wt % solid plasticizer and low levels of liquid plasticizer.
In order to prevent a PVA powder from originating coarse lumps of a degraded and partially cross-linked material upon extrusion, U.S. Pat. No. 4,469,837 discloses a thermoplastic extrudable PVA composition comprising a dry mixture of PVA, preferably having a hydrolysis degree greater than 70% and a degree of polymerisation of 500–2500, with one or more solid monomeric polyhydroxylated alcohol which, as such or in mutual admixture, exhibit the main melting point peak ranging from 160° to 230° C., such as pentaerythritol, bipentaerythritol and trimethylolethane, preferably in an amount of 10–50 parts per 100 parts of the PVA. The addition of small percentages of other liquid alcohols, such as glycerols or glycols, is further contemplated so to maintain the melting point of the polyhydroxylated alcohol(s) within the above mentioned temperature range.
EP-A-0860471 discloses a three stages process for the preparation of a mouldable and extrudable solid thermoplastic composition comprising partially or totally hydrolysed PVA, 1–10 parts of one or more solid plasticizers, 5 to 30 parts of a liquid mixture containing one or more hydroxylated organic compound, water and at least a salt of an alkaline or alkaline earth metal, 15–30 parts of a solid mixture containing solid polyhydroxylated alcohols, glycols and glycolic ethers, liquid alkanolamines, mineral or organic acids, hydrated inorganic salts stabilizers, other compatible polymers and/or copolymers having low molecular weight and possible mineral charges. The resulting composition is reported to show a good plasticization of the PVA in the transformation equipments and a good workability constancy in time and results to be transformable in manufactures provided with good flexibility. The composition obtained by the disclosed process is useful for the production of granulates, flat or tubular films, moulded articles of manufacture, plates or films coextruded with polyolefins, polyvinyl chloride, polystyrene or polyamides.
WO00/21098 discloses a water-resistant cable, particularly an optical fibre cable, comprising a longitudinal cavity extending along the length of the cable, at least one optical fibre housed inside the cavity and a solid and compact element associated with the cavity, said element being made of a water-soluble material which, upon contact with water, dissolves itself, at least partially, and forms a viscous solution capable of stopping the longitudinal flow of water along such element. Solid and compact elements of this kind allow to avoid the use, or at least substantially reduce the amount, of conventional water-blocking means, such as grease-like material, water-swellable powders and the like. Said solid and compact element is, particularly, a buffer tube, preferably made of a VA-VAc copolymer having a hydrolysis degree of from about 50% to 95%, preferably from 70% to about 90%. This copolymer, in the presence of relative humidity percentages of less than 75–80%, does not show any phenomena of surface stickiness caused by the partial absorption of water. The use of conventional plasticizers, in an amount of at least 5% of the total weight of the polymer material composition, is further disclosed.
The addition of plasticizers to the polymer material, generally in an amount of about 1% to about 30% of the weight of the latter, is well known, in the field, in order to improve the processability and final flexibility of the material; it is further known that the plasticizers are also capable of increasing the ability of the water-soluble polymer material to absorb water.
EP01130960 discloses a water-resistant telecommunication cable, particularly an optical fibre cable comprising an elongated element housing at least one transmitting element comprising a water-soluble polymer composition which comprises a VA-VAc copolymer having a hydrolysis degree of from about 60% to about 95%, a plasticizer, and a hydrolysis stabiliser comprising a chelant. The presence of the stabiliser allows to reduce the increase of the hydrolysis degree of the VA-VAc copolymer upon ageing, thus maintaining the desired water-blocking properties of the VA-VAc copolymer. Further, there is disclosed the addition of a plasticizer such as glycerol, sorbitol, trimethylolpropane, low molecular weight polyglycol, such as polyethylene glycol (e.g. di- or tri-ethyleneglycol), pentaerythritol, neopentylglycol, triethanolamine or oxyethylated phosphoric esters, preferably in an amount of from about 5% to about 30% by weight with respect to the weight of VA-VAc copolymer.
The Applicant has now observed that while buffer tubes, as disclosed in WO00/21098, comprising a partially hydrolysed VA-VAc copolymer allow to avoid the use, or at least substantially reduce the amount, of conventional water-blocking means and that while adding a stabiliser, as disclosed in EP01130960, allows to reduce the increase of the hydrolysis degree of the VA-VAc copolymer upon ageing, thus maintaining the desired water-blocking properties of the VA-VAc copolymer, a stickiness of said copolymer is experienced during the estrusion process generating an interference with the transmitting element, f.i. optical fibres, put inside the solid and compact element, such as a buffer tube, of the cable.
Particularly, the Applicant noted that the water-soluble VA-VAc based polymer material resulted to be sticky during its extrusion, regardless of the presence of a stabiliser and a plasticizer and of the fact that the water-soluble polymer material is extruded alone or in combination with the water-insoluble polymer materials commonly used for the outer layer of a solid and compact element, such as a the buffer tube, of a transmission cable.
The Applicant observed that, during the extrusion of, f.i., a buffer tube for an optical fibre cable, the stickiness of the water-soluble polymer material, due to the prevailing of the viscous component of the melt, generates a negative interaction with the surface of the optical fibres, this being detectable both co-extruding different polymer materials, which is industrially preferred, and even singly extruding them, although the problem is less evident in the latter case.
In fact, in both cases, the Applicant experienced that sticking phenomena affect the quality of the resulting transmission cable regardless of possible adjusting the common industrial extrusion process by, f.i. slowing the production.
The Applicant has also noted that, extruding the PVA composition disclosed in U.S. Pat. No. 3,997,489, the polyethylene waxes separate from PVA, due to their mutually different polarity, thus slowing the interaction with the water possibly penetrated in the cable and actually making this composition useless as a water-blocking mean aid in a water-resistant communication cable. The same shortcoming has been also experienced by the Applicant with the composition disclosed in GB 2,340,835 where the fatty acid amine separates upon extrusion from PVA, because—once again—of their different polarity.
The Applicant has also observed that using release agents such as oils or powders on, f.i., optical fibres to prevent the above described stickiness, results to be unsuitable to guarantee a regular extrusion process, also because it is cumbersome to uniformly distribute the release agent on the fibres; besides, oils and/or powders move along the optical fibres distributing themselves irregularly this, especially with powders, possibly bringing to a mechanical interference between the tube and fibres.
Further, the solid and compact element, f.i. a buffer tube, housing the transmission element, f.i. an optical fibre, has to be dimensionally stable and regular in order to avoid any interference of the optical fibres with the polymer material comprised in the solid and compact element, during the extrusion step.
The fibers and the plastic material tube enclosing them, proceed for a certain length along the extrusion line, independently from one another. The dimensional stability of the molten state of the water-soluble polymer material and the stickiness phenomena to optical fibres can be observed between the extrusion head and the final collection reel.
When the stickiness phenomena occur, the water-soluble polymer material and optical fibres proceed together and during the coooling step the shrinkage of the water-soluble polymer material cause the macrobending of the optical fibres.
The macrobending gives rise to attenuation phenomena of the transmitted signal, on account of either irregularly distributed pressures on the surface of the transmission element or excessive ringing of the transmission element, both of which being drawbacks which can result in attenuation phenomena of the transmitted signal, even under conditions which would otherwise not be harmful to the functioning of the cable.
Specifically, the stickiness of the water-soluble VA-VAc based polymer material results in potentially damaging the transmission element and, at the same time, does not guarantee the desired and needed stability and regularity upon its extrusion, this further potentially giving rise to attenuation phenomena of the transmitted signal.
SUMMARY OF THE INVENTION
The Applicant has now found that a cable, which has no elements of fluid or pulverulent type for blocking the flow of water i.e. housing a loose transmitting element, shows no stickiness of the water-soluble polymer material comprised therein upon extrusion, such material being extruded either alone or in combination with the water-insoluble polymer materials commonly used for the outer layers of a transmission cable without adjusting or slowing the current extrusion techniques; the cable elements resulting to be dimensionally stable and regular so that no attenuation phenomena of the transmitted signal result to be detectable.
According to a first aspect, the present invention relates to a water-resistant telecommunication cable comprising a longitudinal cavity extending along the length of the cable and a solid and compact element housing at least one transmitting element, wherein the solid and compact element is associated with the cavity and comprises a water-soluble polymer material comprising:
a vinyl alcohol/vinyl acetate copolymer having a hydrolysis degree of about 60% to about 95% and a polymerisation degree higher than about 1,800; at least a first solid plasticizer, having a melting point between 50° and 110° C., and a second solid plasticizer, having a melting point equal or higher than 140° C., in an amount of about 10–30 and 1–10 parts by weight per hundred parts by weight of the copolymer, respectively;
the water-soluble polymer material showing:
a complex modulus (G*) equal or higher than 2.5.10 6 MPa; a ratio of the viscous modulus to the elastic modulus (tan δ) equal or lower than 2.30; a glass transition temperature (Tg) of about 20° to about 35° C.
The solid and compact element comprises, preferably, about 30% by weight or more, particularly about 50% by weight or more, most preferably about 75% by weight or more of the water-soluble polymer material.
The solid and compact element is, preferably, a structural element of the cable and, specifically, a tubular element comprising at least one sheath, made of the water-soluble polymer material, the longitudinal cavity being defined by the inner volume of the tubular element.
Preferably, the tubular element is a single sheath completely made of the water-soluble polymer material or, alternatively, it can be a double layer sheath, the inner layer being made of the water-soluble polymer material and the outer layer being made of a water-insoluble polymer material.
According to a preferred embodiment, the solid and compact element of the cable of the invention is a buffer tube and the transmitting element is an optical fibre.
In another embodiment of the invention, the tubular element is a three-layer sheath, the inner and the outer layers being made of the water-soluble polymer material and the intermediate layer being made of a water-insoluble polymer material.
The vinyl alcohol/vinyl acetate copolymer is, preferably, in an amount of from about 50% to about 95%, particularly from about 60% to about 85% of the total weight of the water-soluble polymer material; the copolymer preferably has a hydrolysis degree of from about 70% to about 92% and a polymerisation degree of about 2,500–3,700, most preferably of about 3,000–3,500.
In the present description, the expression “vinyl alcohol/vinyl acetate copolymer” is meant to comprise modified polyvinyl alcohol including, yet not limited to, the following polymers obtained:
a) by partial etherification of a polyvinyl alcohol (for example by epoxidation by introducing groups such as —(CH 2 CH 2 —O—) n —H into the PVA homopolymer chain;
b) by partial esterification of alcohol groups (similarly, a suitable polyester homopolymer can be hydrolysed in order to introduce hydroxyl functions therein);
or
c) by block copolymerization thus obtaining, for example, poly(vinyl alcohol-co-polyoxyethylene) from vinyl acetate, polyoxymethylene monomethyl ether and using a diisocyanate or a diepoxide as chain extender.
The VA-VAc copolymer is generally obtained by hydrolysis of polyvinylacetate, by which the acetate groups of the polymer are converted to hydroxy groups. More specifically, the reaction is typically an alcoholysis of polyvinylacetate with a metal (typically sodium) hydroxide as catalyst. The VA-VAc copolymer resulting from the alkaline alcoholysis has mainly a block structure, where blocks formed by sequences of vinyl-acetate groups of formula —CH 2 —CH(OCOCH 3 )— are alternated to blocks formed by sequences of vinyl-alcohol groups of formula —CH 2 —CH(OH)—.
For the purposes of the present invention, a VA-VAc copolymer, which can be obtained by partial hydrolysis of the acetate groups of a polyvinyl acetate (PVAc) homopolymer, is particularly preferred.
As regards the degree of hydrolysis of the copolymer, the Applicant has observed that, for a zero degree of hydrolysis (i.e. for polyvinyl acetate homopolymer), the solubility in water is very modest, equal to about 0.01 g/liter at 20° C.
As the degree of hydrolysis increases, the hydrophilic properties of the material increase, along with its solubility, to about 300 g/l for a degree of hydrolysis of about 88%. However, applicant has noticed that a further increase in the degree of hydrolysis results into a corresponding decrease in the solubility of the material in water. In point of fact, in the case of complete hydrolysis of the acetate groups, the polyvinyl alcohol homopolymer obtained has an extremely low solubility (1.43 g/liter at 20° C.), even though the material is still highly hydrophilic.
For the purposes of the present invention, the VA-VAc copolymer suitable for the cable of the invention shows a degree of hydrolysis which is incomplete, so as to ensure good solubility of this polymer in water, and which is sufficiently high, such that the copolymer hydrophilic properties are sufficient to ensure an adequate degree of interaction with water.
The VA-VAc copolymer described in EP01130960 is suitable for the purposes of the present invention; accordingly, as far as such VA-VAc copolymer is concerned, said application is herein incorporated as a reference.
Examples of commercially available VA-VAc copolymers showing the desired properties are those sold under the trade name Mowiol® (Kuraray), Gohsenol® (Nippon Gohsei), Elvanol® (Du Pont).
Preferably, the first and the second plasticizers are in an amount of about 12–25 and 3–7 parts by weight per hundred parts by weight of the copolymer, respectively.
The preferred plasticizers for realising the cable of the invention are polyhydric alcohols; particularly, the first plasticizer is selected from sorbitol, trimethylolpropane, di-trimethylolpropane, methylpropyl propanediol, and mixtures thereof whereas the second plasticizer is selected from mannitol, pentaerythritol, dipentaerythritol, trimethylolethane, and mixtures thereof.
More preferably, the first plasticizer is trimethylolpropane or di-trimethylolpropane and the second is pentaerythritol or dipentaerythritol; in particular, the first and the second plasticizer are in an amount of about 20 and about 5 parts by weight per hundred parts by weight of said copolymer, respectively.
Further, the above defined water-soluble polymer material comprises a third plasticizer, liquid at room temperature, in an amount of about 0.5–10 parts by weight per hundred parts by weight of the copolymer.
The third plasticizer is, preferably, a polyhydric alcohol; the preferred third plasticizer being selected from glycerol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, trimethylolpropane ethoxylates, pentaerythritol ethoxylates, and mixtures thereof.
Preferably, the third plasticizer is in an amount of 2–7, particularly 5, parts by weight per hundred parts by weight of said copolymer. The most preferred third plasticizer is diethylene glycol or triethylene glycol.
The following table shows the melting points of the preferred first and second plasticizers suitable for the cable of the invention.
PLASTICIZER
m.p. (° C.)
sorbitol
100
trimethylolpropane
60
di-trimethylolpropane
109
methylpropyl propanediol
60
mannitol
167
pentaerythritol
255
dipentaerythritol
215
trimethylolethane
200
The Applicant has also found that the VA-VAc copolymer comprised in the solid and compact element of the cable of the invention can be protected against the ageing effects caused by hydrolysis phenomena, by adding an effective amount of a hydrolysis stabiliser compound.
In fact, according to another preferred embodiment, the above defined polymer material further comprises a hydrolysis stabilizer compound comprising a chelant group comprising two hydrogen atoms bonded to two respective heteroatoms selected from nitrogen, oxygen and sulfur, said two hydrogen atoms having a distance between each other of from 4.2×10 −10 m to 5.8×10 −10 m, preferably of from 4.5×10 −10 m to 5.5×10 −10 m, said stabilizer compound being present in an amount of at least 0.75 mmoles per 100 g of the VA-VAc copolymer.
The hydrolysis stabiliser described in EP01130960 is suitable for the purposes of the present invention; accordingly, as far as such stabiliser is concerned, said application is herein incorporated as a reference; the most preferred stabiliser is N,N′-esan-1,6-diylbis[3,5-di-ter-butyl-4-hydroxyphenyl)propionamide].
The presence of the stabiliser allows to reduce the increase of the hydrolysis degree of the VA-VAc copolymer upon ageing, thus maintaining the desired water-blocking properties of the VA-VAC copolymer.
The viscoelastic properties of the above defined water-soluble polymer material were measured by oscillatory techniques, applying a stress or strain thereto and working in the so-called “region Of linear strain response”.
The water-soluble polymer material was characterised by measuring the phase lag between the applied shear stress and measured shear strain and deriving which component is dominant.
Hooke's law correlates the strain to the stress via a material costant: the modulus; in the oscillation tests, the stress and strain are constantly changing and any number of instantaneous values can be used to obtain the instantaneous value of the viscoelastic or complex modulus G* according to the following formula:
G*=G′+iG″
wherein
G′ is the elastic modulus, a measure of the elastic storage of energy since the strain is recoverable in an elastic solid, also known as the storage modulus;
G″ is the viscous modulus, a measure of the viscous dissipation of energy through permanent deformation in flow, also known as the loss modulus; and
i is the imaginary unit of complex numbers.
G′ and G″ are also related to the phase angle (delta) by the following formula:
tan δ= G″/G′
wherein G′ and G″ are as above defined.
The Applicant observed that there is an excellent correlation between the complex modulus G*, measured at a frequency of 100 Hz and a temperature of 200° C., and the extrudability properties of the water-soluble polymer material above defined in terms of dimensional stability and regularity.
The extrudability properties of the material, in terms of dimensional stability and regularity, were found and considered to be acceptable when G* is equal or higher than 2.5 10 6 MPa, preferably between 3.0 10 6 and 4.0 10 6 MPa; the rheological test method was considered to be predictive of said properties because when G* is lower than 2.5 10 6 MPa, the material molten shape does not show the consistency needed to guarantee said properties for the solid and compact element of the cable of the invention.
The Applicant further noted that tan δ well describes the stickiness effects observed during the extrusion test.
Stickiness is due to the material being more viscous and wetting the surface of the other material with which it comes into contact. The degree of stickiness can be expressed by the ratio of G″ to G′, determined by an oscillation frequency sweep test at 10 −2 Hz.
The stickiness properties between the melt shape of the solid and compact element and the transmission element of the cable of the invention were found and considered to be acceptable when tan δ is equal or lower than 2.3, preferably between 0.5 and 2.0. Higher tan δs are therefore an index of the stickiness of the water-soluble polymer material and result in potentially damaging the transmission element and, at the same time, do not guarantee the desired and needed stability and regularity thereof upon extrusion, this further potentially giving rise to attenuation phenomena of the transmitted signal, on account of either irregularly distributed pressures on the surface of the transmission element or excessive ringing of the transmission element, both of which being drawbacks which can result in attenuation phenomena of the transmitted signal, even under conditions which would otherwise not be harmful to the functioning of the cable.
The Applicant used the glass transition temperature Tg, measured according to Differential Scanning Calorimetry (DSC), to evaluate the interaction between the VA-VAc copolymer and the plasticizers.
The Tg of the water-soluble polymer material of the cable of the invention was found and considered to be acceptable when close to room temperature, specifically in the range of 20°–35° C., preferably of 25–30° C., because the material has to be neither soft nor brittle in order to be easily handled during the different steps of the making of the cable of the invention.
In fact, if Tg is lower than about 20° C., the material results too soft and, due to the water absorbed by the cable produced with such a material upon ageing, its surface becomes sticky. If, on the other hand, Tg is higher than about 35° C., the material results too brittle, which may cause microfractures damaging the transmitting element of the cable possibly produced with such material.
According to a second aspect, the invention also relates to a method for maintaining loose a transmitting element of a water-resistant telecommunication cable, upon the extrusion thereof, comprising a longitudinal cavity extending along the length of the cable and a solid and compact element housing the transmitting element which comprises preparing the solid and compact element using a water-soluble polymer material comprising:
a vinyl alcohol/vinyl acetate copolymer having a hydrolysis degree of about 60% to about 95% and a polymerisation degree higher than about 1,800; at least a first solid plasticizer, having a melting point between 50° and 110° C., and a second solid plasticizer, having a melting point equal or higher than 140° C., in an amount of about 10–30 and 1–10 parts by weight per hundred parts by weight of the copolymer, respectively;
the water-soluble polymer material showing:
a complex modulus (G*) equal or higher than 2.5 10 6 MPa; a ratio of the viscous modulus to the elastic modulus (tan δ) equal or lower than 2.30; a glass transition temperature (Tg) of about 20° to about 35° C.
According to another aspect, the cable of the invention also relates to the use of a water-soluble polymer material comprising:
a vinyl alcohol/vinyl acetate copolymer having a hydrolysis degree of about 60% to about 95% and a polymerisation degree higher than about 1,800; at least a first solid plasticizer, having a melting point between 50 and 110° C., and a second solid plasticizer, having a melting point equal or higher than 140° C., in an amount of about 10–30 and 1–10 parts by weight per hundred parts by weight of the copolymer, respectively;
the water-soluble polymer material showing:
a complex modulus (G*) equal or higher than 2.5 10 6 MPa; a ratio of the viscous modulus to the elastic modulus (tan δ) equal or lower than 2.30; a glass transition temperature (Tg) of about 20° to about 35° C.;
for the preparation of a solid and compact element of a water-resistant telecommunication cable comprising a longitudinal cavity extending along the length of the cable and the solid and compact element housing a transmitting element for maintaining loose the latter upon extrusion of the cable.
The Applicant observed that the polymer material comprised in the cable of the invention has a consistency of the fuse which allows to maintain the desired extruded shape during the cooling step. Further, the above defined polymer material has the ability to hinder and avoid the penetration of water both as a vapour and a liquid and allows at the same time to regularly carry out its extrusion without noting any interference of the transmission element with the polymer material therefore guaranteeing the absence of any shift from the desired dimension and any possible interruption of the extrusion due to the breaking of the solid and compact element.
The cable of the invention allows to use small plasticizer amounts, this further avoiding any exudation of the plasticizers in time.
The water-soluble polymer material comprised in the cable of the invention is capable of quickly stopping the longitudinal flow of water along said solid and compact element such as buffer tubes. Solid and compact elements of this kind allow to avoid the use, or at least substantially reduce the amount, of conventional water-blocking means, both inert and active, such as grease-like material, water-swellable powders and the like, which is highly desirable when tubular elements containing loosely arranged optical fibres are realised.
Further, the cable of the invention is not subject to microbending phenomena as, adversely it happens when water-swellable powders are in direct contact with the transmission element, this presenting appreciable risks of increasing the attenuation of the transmitted signal, even independently of the presence of moisture.
Still further, the cable of the invention allows to avoid inserting any additional element (such as powders, tapes, foils etc.) into the cable structure, thus omitting the introduction of any additional steps into the cable manufacturing process, as well as any possible cumbersome operations while connecting the cable ends and/or repairing damaged portions of the cable.
For the purposes of the present invention, the expression “solid and compact element” is intended to refer to an element consisting of a material, or a mixture of materials, which, at the working temperatures of the cable (and in the near absence of water), is not fluid, fibrous or pulverulent, and has mechanical properties, such as elastic modulus, breaking load, elongation at break and the like, which are similar to those of conventional polymer materials employed to make the structural elements of the cable, such as, for example, cores, sheaths or tubular elements containing optical fibres. The term “conventional materials” is referred in the present description to those material typically employed in the art for manufacturing the above structural elements and comprise within its meaning, although not being limited to, polymer materials such as polyolefins, for example polyethylene (high, medium and low density PE), polypropylene (PP) or ethylene-propylene copolymers (PEP), polybutylene terephthalate (PBT), polyvinylchloride (PVC) or polyamides (PA).
The solid and compact element comprised in the cable of the invention can comprise more than about 75% of the water-soluble polymer material above defined, this meaning that this solid element can be mainly made of such water-soluble polymer material, with the optional addition of other minor components such as, for example, fillers, plasticizers, pigments, dyes, processing agents, biocides or stabilisers, present in an amount of less than about 25% by weight, preferably less than about 10%.
In the present description, the expressions “water-blocking material” or “water-blocking properties” are intended to refer typically to a material capable of blocking the longitudinal propagation of water inside the cable within a predetermined length of this cable. Preferably, this length is less than or equal to 10 meters.
The expression “water-soluble polymer material” is intended to mean that the water-blocking material used in a cable according to the present invention is capable of at least partially dissolving on contact with water, creating an aqueous solution with a predetermined viscosity value. In particular, the viscosity of the solution which forms upon contact with water will be such that it hinders the flow of said solution in the cable. Preferably, this solution has a viscosity such that it essentially blocks a flow of water which has penetrated into a cavity, within a distance of less than about ten meters from the point of ingress of said water.
For the purpose of the present invention, the term “transmitting element” includes within its meaning any element capable of transmitting a signal, particularly optical fibres, including individual optical fibres, ribbons or bundles of optical fibres, either as such or protected by a polymeric sheath. Non limiting examples of optical fibres are, for example, single-mode fibres, multi-mode fibres, dispersion-shifted (DS) fibres, non-zero dispersion (NZD) fibres, or fibres with a large effective area and the like, depending on the application requirements of the cable. They are generally fibres with an outside diameter of between 230 and 270 μm.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention will result from the following detailed description with reference to the attached drawings, wherein:
FIG. 1 is a schematic cross section of an example of an optical fibre cable according to the invention, of the type containing a tubular element with a central support;
FIG. 2 is a cross section of a tubular element of a cable according to the invention, with a two-layer coating containing optical fibres;
FIG. 3 is the same cross section of the tubular element as FIG. 2 , after the ingress of water;
DETAILED DESCRIPTION OF THE INVENTION
A cable of the so-called tubular element type, in particular of the loose tube type, as represented in FIG. 1 , has, in the radially innermost position, a supporting element comprising a reinforcing element, typically made of glass resin ( 5 ), coated with a layer ( 6 ) of polymer, up to a given diameter.
The cable has one or more tubular elements or tubes ( 7 ), wound around the supporting element ( 5 ) and around its coating layer ( 6 ), inside which are located the optical fibres ( 3 ) arranged individually, or assembled in bundles, ribbons, mini-tubes (i.e. a micro-sheath surrounding a bundle of optical fibres) and the like.
The number of tubular elements present (which may also be arranged on several layers) and the dimensions of these tubular elements depend on the intended capacity of the cable, as well as on the conditions of use of this cable.
For example, cables are envisaged with only one tubular element (in which case the central element ( 5 ) and its coating ( 6 ) is not present), and cables are envisaged with six, eight or more tubular elements, wound in one or more layers (for example up to 24 tubular elements bundled on two layers).
The tubular elements ( 7 ) are in turn held together in a containing layer ( 8 ) made, for example, by wrapping, and are preferably combined with a reinforcing element ( 9 ), for example a layer of Kevlar® fibres or of glass yarn, the size of which depends on the mechanical strength requirements of the cable.
Two sheath-dividing filaments ( 10 ), arranged longitudinally with respect to the cable, can be included within the reinforcing layer ( 9 ).
Lastly, the cable comprises a protective outer sheath ( 11 ), typically made of polyethylene. In relation to specific requirements, further protective layers can also be present, for example of metal layers, either inside or outside the structure described.
According to one illustrative embodiment of the present invention, in a cable with the structure described above, the tubular elements ( 7 ) can be made with a double-layer wall, in which the inner layer ( 7 b ) is made of the above defined water-soluble polymer material with water-blocking properties and the outer layer ( 7 a ) is made of a conventional material such as polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PE) or ethylene-propylene copolymer (PEP).
FIG. 2 shows a tubular element ( 7 ) with a two-layer wall (produced, for example, by co-extrusion), the outermost of which ( 7 a ) being made from a conventional polymer material (e.g. PE, PP, PEP or PBT) while the innermost ( 7 b ) being made from the water-soluble polymer material. The space inside the tube, not occupied by the optical fibres, is typically empty.
One or more optical fibres ( 3 ) are arranged inside the tubular element, typically loosely, separate or assembled in the form of fibre ribbons, mini-tubes or the like.
The material forming the inner layer ( 7 b ) of the tubular element is a solid extrudable material with mechanical properties more or less similar to those of the outer layer ( 7 a ), such that, preferably, the thickness of the entire tubular element is not dissimilar to the typical thickness of a tubular element with a single conventional layer.
Typically, for example, a tubular element with an outside diameter of 3 mm can have a wall with a total thickness of about 0.6–0.7 mm, divided in almost equal parts between the inner water-soluble layer ( 7 b ) and the outer conventional layer ( 7 a ).
In the case of accidental ingress of water, the water-soluble polymer material of the inner layer ( 7 b ) of the two-layer tubular element dissolves at least partly in the penetrating water, starting from the original position (represented by the dashed line in the figure), as shown in FIG. 3 , forming a viscous solution ( 4 ) which moves between the fibres, thus filling the free spaces (generally of irregular outline), independently of their shape, until the entire free cross section of the tubular element has been occluded.
The aqueous solution thus formed has a viscosity which is sufficiently high to hinder the subsequent propagation of water along the cable, until this propagation is blocked within a few meters from the point of ingress of the water.
In this way, without introducing additional materials into the tubular element, such as powders, blocking fluids and the like, which would involve, inter alia, a substantial increase in the weight of the cable, blockage of the propagation of water which has accidentally penetrated into the cable is obtained.
Where appropriate, one can envisage to make an outer layer of the tubular elements ( 7 ) with the water-soluble polymer material, or alternatively the entire tubular element can be made of such material.
If desired, the containing layer ( 8 ), can be made (entirely or partly) by wrapping with a compact tape of solid, water-soluble polymer material, or alternatively with an extruded layer of the same material.
The presence of layers of solid, water-soluble polymer material in the layers ( 6 ) and ( 8 ) and the size of said solid, water-soluble polymer material present in these layers are determined by the free cross sections present [for example the star-shaped areas ( 8 a )] and by the requirements for blocking the flow of water in the cable in more or less narrow spaces.
The Applicant has observed that, in a cable according to the present invention, as the viscosity of the solution formed from the water-soluble polymer material upon contact with water increases, it is possible to increase the dimensions of the cavity within which the blocking of water must take place and/or reduce the time taken to block this flow of water.
The Applicant has moreover observed that the water-soluble polymer material to make a cable according to the present invention forms upon contact with water, an aqueous solution which substantially increases its viscosity over time, until a gel is produced which further contributes to maintaining the water-blocking condition over time.
The Applicant has observed that in order to obtain the desired solubility, it is preferable for the water-soluble polymer material not to be crosslinked, so that the various macromolecules are relatively independent from one another, to allow the water to dissolve sufficient amounts of the polymer material.
Among the solid, water-soluble polymer materials which can be used in a cable according to the present invention, the preferred ones are those which, up to relatively high relative humidity (R.H.) values, typically about 75–80%, absorb only modest amounts of water, typically less than about 25% by weight of the amount which can be absorbed by the material under saturation conditions (R.H.=100%).
This property of the material is particularly advantageous since, as the optical fibres are relatively insensitive to the presence of water vapour up to relative humidity values of less than about 75–80%, below these values it is advantageous for the water-soluble polymer material to be more or less unchanged.
The fact that the material is virtually insensitive at these relatively low relative humidity values allows a better processability and fewer problems of storage of the finished product, since it is not necessary to protect it against ambient humidity, which is generally less than 75%.
In addition, by virtue of this property, the material remains almost entirely available to block water in the event of an ingress of liquid water or an increase in the relative humidity beyond the critical threshold, without any part of this material having needlessly interacted with the water in the vapour state below the critical threshold for the relative humidity, or even needlessly undergoing swelling so as to result in any undesired squeezing of the transmission elements.
The Applicant has moreover observed that, among the water-soluble polymer materials which can be used in a cable according to the present invention, it is particularly advantageous to use materials which, when placed in a housing which contains optical fibres, give this housing hygrostatic properties. The reason for this is that when the environment outside the cable structure in which the transmission elements are housed (for example a tubular element of plastic material) exceeds the relative humidity critical threshold (75–80%), a material according to the present invention placed inside the cable structure in an adequate amount is capable of maintaining, around the transmission elements, relative humidity values which are lower than the critical values.
The presence, inside the cable structure, of further elements made essentially of the water-soluble polymer material of the invention, such as, for example, interstitial tapes or filaments, can further increase the time to reach the relative humidity critical threshold.
In order to evaluate a water-soluble polymer material which can be used in a cable according to the present invention, the Applicant has developed the following tests.
A first test consists in producing, by extrusion, a tubular element with an outside diameter of 2.6 mm, with a double layer of material and containing 12 optical fibres having a diameter of 250 μm, consisting in an outer layer of polyethylene about 0.25 mm thick and an inner layer of water-soluble polymer material about 0.25 mm thick.
A conventional co-extrusion line for manufacturing a buffer tube containing 12 optical fibres comprises twelve reels from which the optical fibres are taken and sent to a common extruder head through which the water-soluble polymer material is extruded around them forming a tube. The tube is then sent to a cooling device and from there to a stretching device and then to a final collection reel. Optionally, the extrusion line can comprise an additional pulley arranged between the stretching element and the extruder.
The fibres and the polymer material buffer tube enclosing them, proceed for a certain length along the extrusion line each independently from the others. The dimensional stability of the molten state of the water-soluble polymer material and the stickiness phenomena can be observed between the extrusion head and the final collection reel.
According to a second test, plates of the above defined water-soluble polymer material (having a diameter of about 25 mm and being 0.5 mm thick) are moulded at 200° C. and put between two parallel plates of a rotational rheometer for the Theological characterization to determine G* and tan δ at different shear rates.
To determine the region of linear strain response, an amplitude sweep test has to be run at a fixed frequency close to the phenomena investigated (10 −2 Hz) and slowly increasing the applied stress (stress range: 0.1–5000 Pa; delay time: 2 sec), verifying that the measured viscoelasticity values remain constant.
G* and tan δ are then measured by a frequency sweep at a constant stress (100 Pa) from 10 −3 to 10 2 Hz (delay time: 1 sec) at 200° C.
According to a third test, the glass transition temperature Tg is measured according to Differential Scanning Calorimetry (DSC). Operating with a Perkin Elmer DSC, Series 7, a sample of about 20 mg, in a first step, is heated to erase the thermal history thereof and, in a second step, the Tg is measured at a heating rate of 20° C./min.
The above defined water-soluble polymer material can be used in several different ways in the various components which form the structure of the cable of the invention, so as to optimise the water-blocking effect.
It is possible, f.i., to make optical cables such as mini-tube cable, wherein two or more optical fibres are contained in a microsheath (about 0.07–0.15 mm thick) which can advantageously be formed from the water-soluble polymer material according to the invention, a number of such mini-tubes being in turn housed into a larger diameter buffer tube.
It is particularly advantageous to make an optical fibre cable housing said water-soluble polymer material, such that the dissolution of the latter brings it into contact with the optical fibres, thus blocking the flow of water along the cavity in which these fibres are housed. The viscous solution formed following the accidental ingress of water into the cable fills the interstitial spaces, thus blocking the flow, avoiding the fibres to experience any significant mechanical stresses. This allows the cable, following accidental ingress of water, to nevertheless remain functional without experiencing any particular drawbacks in terms of attenuation of the signal, thereby allowing its repair to be carried out at a later time.
The manufacturing of the various elements mentioned above, made of or incorporating the water-soluble polymer material above defined, can be carried out according to the known techniques, preferably by extrusion.
The following examples illustrate the invention without limiting it.
EXAMPLE 1
Preparation of the Water-soluble Polymer Material
Table 1 herebelow reports the detailed composition for any of the water-soluble polymer materials exemplified hereinafter, which were prepared feeding the blend of the VA-VAc copolymer with the plasticizers using a gravimetric feeder into a 40 mm co-rotating twin-screw extruder 35L/D, possibly injecting, where appropriate, the liquid plasticizer, at the following operating conditions: screw speed 150 rpm, production rate 30 kg/h, melt temperature at the extruder exit 200° C. The strands were air cooled and granulated into pellets.
TABLE 1
VA-VAc
POL.
COPOLYMER
Polym.
MAT.
TRADENAME
degree
DEG (other)
TMP
PENTA
1
Mowiol 26/88
3,300
—
20
5
2
Mowiol 26/88
3,300
(2 di-PENTA)
—
—
(30 di-TMP)
3
Mowiol 26/88
3,300
(12 di-TMP)
—
10
4
Mowiol 26/88
3,300
(15 di-TMP)
15
10
5*
Mowiol 8/88
1,400
—
9
3
6*
Mowiol 15/79
1,900
(6 GLY)
—
12
7*
Mowiol 26/88
3,300
(10 PEG)
—
15
8
Mowiol 26/88
3,300
1
15
5
9
Mowiol 26/88
3,300
5
15
5
10
Mowiol 26/88
3,300
7
15
5
11*
Mowiol 26/88
3,300
5
5
15
12
Mowiol 26/88
3,300
3
15
5
13
Mowiol 26/88
3,300
5
15
1
14
Mowiol 26/88
3,300
5
15
3
15
Mowiol 26/88
3,300
5
14
5
16
Mowiol 26/88
3,300
4
13
4
17
Mowiol 26/88
3,300
6
17
5
DEG = diethylene glycol;
TMP = trimethylol propane;
di-TMP = di-trimethylol propane;
PENTA = pentaerythritol;
di-PENTA = di-pentaerythritol;
GLY = glycerine;
PEG = polyethylene glycol;
the plasticizer amounts are expressed as parts per hundred parts of the VA-VAc polymer;
*= comparative
EXAMPLE 2
Evaluation of the Melt Consistency
Plates, having a diameter of about 25 mm and being 0.5 mm thick, of the pellets of the water-soluble polymer materials 1 – 10 , prepared according to example 1, were moulded at 200° C. and put between two parallel plates of a rotational rheometer for the rheological characterization to determine G* and tan δ at different shear rate.
All the tests were carried out on a Bohlin Cvo 120 stress control rheometer at a temperature of 200° C.
To determine the region of linear strain response, an amplitude sweep test was run applying a stress range of 0.1 to 5000 Pa (delay time: 2 sec) at 10 −2 Hz (geometry PP25; gap 500 μm), slowly increasing the applied stress and verifying that the measured viscoelasticity values remain constant.
G* and tan δ were then measured by a frequency sweep at a constant stress (100 Pa) from 10 −3 to 10 2 Hz (delay time: 1 sec) at 200° C.
The melt consistency of the extruded fuse was evaluated by the measure of the complex modulus G* at a frequency of 10 2 Hz; the data obtained are reported in Table 2.
TABLE 2
Polymer material
G* (MPa)
1
3.5 10 6
2
3.3 10 6
3
3.6 10 6
4
2.5 10 6
5*
2.1 10 6
6*
2.4 10 6
7*
3.5 10 6
8
3.3 10 6
9
3.3 10 6
10
3.3 10 6
*- comparative
Although the polymer material 7 showed an excellent stability of the fuse, it came out indeed to be sticky as it resulted by detecting its tan δ (data shown in the table 3 herebelow).
EXAMPLE 3
Evaluation of the Interference of the Optical Fibres with the Buffer Tube
The interference between the optical fibres and the buffer tube surface during the extrusion thereof was evaluated by measuring the tan δ, at a frequency of 10 −2 Hz, of the polymer materials 1 – 11 ; the data obtained are reported in the following table.
TABLE 3
Polymer material
tanδ
1
1.81
2
2.22
3
1.67
4
2.30
5*
2.40
6*
2.46
7*
2.40
8
1.90
9
1.96
10
1.99
11*
2.40
*- comparative
Further, a double layer tubular element (outer diameter 2.6 mm) containing 12 optical fibres having a diameter of 250 μm, was produced, by extrusion, for each of the water-soluble polymer materials shown in Table 3, the outer layer being of polyethylene and the inner layer being of the selected water-soluble polymer material, both layers being about 0.25 mm thick.
The tubular elements made with the polymer materials 1 – 4 and 8 – 10 did not show any stickiness, adversely to the elements comprising the polymer materials 5 – 7 and 11 , coherently with the tan δ data illustrated in table 3 above, this showing evidently the meaningfulness of tan δ to evaluate the visco-elastic characteristics of the water-soluble polymer material comprised in the solid and compact element of the cable of the invention.
EXAMPLE 4
The glass transition temperature Tg was measured on the pellets of the polymer materials 1 – 10 and 12 – 17 , prepared as described in example 1, according to Differential Scanning Calorimetry (DSC).
Operating with a Perkin Elmer DSC, Series 7, a sample of about 20 mg, in a first step, was heated to erase the thermal history thereof and, in a second step, the Tg was measured at a heating rate of 20° C./min, as shown in the following table.
TABLE 4
Polymer material
Tg (° C.)
1
33
2
27
3
35
4
21
5*
34
6*
30
7*
31
8
35
9
27
10
21
12
25
13
36
14
27
15
28
16
34
17
20
*- comparative
The polymer materials 5 – 7 did neither show brittleness nor softness although they resulted to be sticky as illustrated in the example 2 hereabove.
On the basis of above data, it can be noted that only the polymer materials as above defined to be suitable for the cable of the invention came out to be able to guarantee an excellent dimensional stability as well as the absence of any interaction of the VA-VAc copolymer with the plasticizers and, at the same time, no stickiness upon extrusion.
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A water-resistant telecommunication cable is disclosed comprising a solid and compact element surrounding at least one optical transmitting element, wherein the element is made from a vinyl alcohol/vinyl acetate copolymer having a hydrolysis degree of about 60% to about 95% and a polymerization degree higher than about 2,500; at least a first solid plasticizer having a melting point between 50° and 110° C., and a second solid plasticizer having a melting point equal or higher than 140° C., in an amount of about 10–30 and 1–10 parts by weight per hundred parts by weight of the copolymer, respectively; the water-soluble polymer material showing: a complex modulus (G*) equal to or higher than 2.5 10 6 Mpa; a ratio of the viscous modulus to the elastic modulus (tan δ) equal to or lower than 2.30; and a glass transition temperature (Tg) of about 20° to about 35° C.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to control of earth working implements, such as road graders, and in particular, to improvements in hydraulic control systems therefore.
2. Prior Art
Hydraulic control systems for road graders have long been known and used extensively. Usually of course these are double acting hydraulic cylinders with one positioned on each side of the road grader frame, that in turn control the depth, and also the angle or slope of the circle frame that supports the common earth working blade. Hydraulic cylinders are difficult to control for finish work, in particular when automatic depth controls are being utilized, any changes in depth usually results in some change in the slope of the earth working blade as well, thereby minimizing the preciseness of operation of the unit.
SUMMARY OF THE INVENTION
The present invention relates to improvements in hydraulic control systems for use with hydraulic cylinder controlled earth working implements particularly designed to be selectively operable so that both of the hydraulic cylinders normally used for controlling the depth of an earth working blade will be moved precisely the same amount so as to not disturb the slope of the cut during depth changes. The improvements in the hydraulic circuitry herein include flow integrators, which are commonly used elements that combine two separate flows into one and are designed such that without precise ratios between the two flows, one of the flows will be restricted in respect to the other until the ratio equals.
When the system is set to operate in a normal manner, the flow integrators are bypassed, and thus the angle of the blade can be changed in the usual manner, and once the selector is set, when the depth of the blade is changed the blade will be moved parallel to its original setting in that both of the cylinders will move the same amount.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a typical hydraulically controlled road grader showing an earth working blade with hydraulic cylinders attached thereto for raising and lowering; and
FIG. 2 is a schematic representation of a hydraulic circuit embodying the improved features for control of an earth working blade.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A road grader illustrated part schematically at 10 is of the usual design having a frame 11, and front wheels 12, and rear propelling wheels 13. An operator control platform illustrated generally at 14 is used for operating controls 15 for the various functions of the grader. A power unit can be mounted in the housing 16 at the rear of the frame.
An earth working blade assembly indicated generally at 22 includes the blade member 23 that is used for working the surface of the ground indicated at 17, and the blade 23 is attached to upright supports 24 which are in turn attached to a circle frame 25 that is rotatably mounted about an upright axis to a circle frame support 26. The circle frame support 26 in turn is attached to a drawbar 27. The drawbar 27 is coupled to the upright member 28 of the frame at the forward end thereof through a drawbar leveling attachment indicated generally at 19. The drawbar leveling attachment is fully disclosed in my U.S. Pat. No. 3,856,089, Issued Dec. 24, 1974 and includes a ball joint assembly 31, that mounts a first portion of the drawbar and a pivot connection 32, between the first short portion of the drawbar and the main portion of the drawbar. A control cylinder 33 controls the angular relationship between the two drawbar portions to permit leveling the circle frame. That is, the plane of the circle frame 25 is maintained exactly horizontal or parallel to the desired cutting plane of the earth surface 17. The controls for the cylinder 33 and the mode of operation are fully disclosed in my U.S. Pat. No. 3,856,089. When the plane of the circle frame is maintained parallel to the desired cutting plane, rotation of the earth working blade 23 about its upright axis when the circle frame is rotated will not disturb the angle of cut of the earth working blade as fully explained in that patent.
The present invention finds particular use in connection with automatic level control of earth working blades, and thus the device for leveling the circle frame which is important for automatic operation is also disclosed herein.
The circle frame 25 is raised and lowered by a pair of double acting hydraulic cylinders 40A and 40B, one being the left side cylinder and one being the right side cylinder. These cylinders are mounted in suitable brackets 41 to the frame 11 of the earth working machine, and the cylinders have longitudinally extendable and retractable rods 42 which are mounted through suitable connections 43 to a cross bar attached to the rear of the drawbar 27. The cylinders are operable under fluid pressure to raise and lower the rear of the drawbar and thus the circle frame 40A or 40B are actuated.
The circle frame also can be moved from side to side by a suitable control cylinder which is illustrated only schematically at 36.
The individual cylinders 40A and 40B are controlled by separate control valves, as shown schematically in FIG. 2. For example, the right lift cylinder 40A is controlled through a four way valve 50 that is connected through a pilot operated check valve 51 and a selector valve 56, as will be more fully explained, to the respective base and rod ends of the cylinder.
The left lift cylinder 40B is controlled by a four way valve 53 that provides pressure through a pair of lines 55A and 55B and through a pilot operated check valve 54 to the respective ends of the cylinder by providing pressure and return through the respective lines 55A and 55B.
When the selector valve is in its normal position there is no fluid interconnection between the two cylinders 40A and 40B and thus the cylinders can be individually raised and lowered by operating the respective valves 50 or 53. This is the normal operation to the unit, and permits changing of the incline of the circle frame and earth working blade 23 as well as the depth. The circle frame pivots about the ball joint at the front of the frame, and with the leveling mechanism 29 installed, the circle frame 25 can be kept substantially parallel to the desired cutting plane.
When the grader is used with an automatic leveling control, generally the valves 50 and 53 would be solenoid operated, and will respond to a level sensor, or to a string line sensor in the conventional manner to keep the blade at a preset depth or cutting angle. Usually when this is done, one of the cylinders will be used for a depth control, that is operating a single cylinder will raise one side of the blade, and then the automatic control will bring the blade back to the desired level by operating the other cylinder. However, in automatic leveling control, and even in manual leveling control it has been found that the changing of the depth setting generally results in lack of precise control between the movements of the two cylinders so that the blade will change in transverse angle or incline. In order to prevent errors in the blade incline from occurring, the present invention has been advanced.
Selector valve 56 is connected by lines 57A and 57B to the check valve 51, and the selector valve has a control handle 58 that controls the spool in the valve so that in one position the lines 57A and 57B will be connected directly to lines 59A and 59B, and then as shown, through T connectors, to the rod and base ends of the cylinder 40A. In this normal position of the selector valve 56 the unit will operate in a normal manner, that is, any operation of the lift valve 50 will merely result in changing the setting of cylinder 40A and operation of the valve 53 will result in changing the setting of cylinder 40B.
The selector 56 has a pair of lines 60 and 61, respectively, connected to, and when control handle 58 is moved to the second position from the selector valve 56, the lines 60 and 61 will be connected to the lines 57A and 57B, respectively. The lines 60 and 61 are blocked by valve 56 with valve 56 in its normal position. Line 60 is connected to the output port of a flow integrator valve 62 which is shown schematically. The flow integrator valve has a pair of inlet lines 63 and 64. The line 63 is connected through a T connection to line 59A and thus directly to the rod end of the cylinder 40A, and the line 64 is connected through a T connection to a line leading to the rod end of the cylinder 40B. The flow integrator valve such as valve 62 are well known, and a flow integrator valve which will operate satisfactorily in this application is one made by Brand Hydraulics, Inc., Omaha, Nebraska, their Model B-300 or Model F1300. The valve is described in their bulletin relating to this model. Briefly, a flow integrator valve is made so that it will combine two streams into one, and does it at a fixed ratio. In the form shown, the flow integrator valve is selected so that each of the input streams or flows coming through lines 63 and 64 to the valve must be equal or an internal spool will shift to insure equality in the flow.
A second flow integrator valve 65 has an integrated output port connected to line 61, and the input ports of the flow integrator valve 65 are connected to lines 66 and 67, respectively, which are connected in turn to the base ends of the cylinders 40A and 40B respectively. When a flow of fluid under pressure is provided through line 60, for example, the single normal output port of the flow integrator valve 62, check valves on the interior of the flow integrator open so that such reverse flow from line 60 will be supplied in parallel to lines 63 and 64 through the internal check valves. However, assuming that selector valve 56 is in its non-normal position so lines 57A and 60 are connected and lines 57B and 61 are also connected, and further assuming that valve 50 has been actuated in a manner to provide pressure through line 52B and check valve 51, and a flow return passage through line 52A, then fluid under pressure will be provided through line 57B to line 61, and this fluid under pressure will be provided through the internal check valves of integrator valve 65 through lines 66 and 67 to the base ends of cylinder 40A and 40B, tending to lower the circle frame and cutting blade. Check valve 54, which is a pilot operated check valve will prevent reverse flow back to valve 53 inasmuch as no pilot pressure is supplied to the input of the check valve.
However, return flow then must come from the rod ends of both cylinders through lines 63 and 64 to the inputs of the flow integrator valve 62. The flows from the two lines must be exactly equal or the flow integrator will adjust to restrict the largest flow to insure that the flows become equal. The combined flows will be discharged through lines 60, 57A and 52A. The exhaust flows from both cylinders thus have to be equal, meaning that the cylinders will have to move an equal amount. The blade control is therefore precise.
Operating the valve 50 in opposite direction will cause retraction of the cylinders by supplying fluid under pressure to line 60 with the return flows from the base ends of the cylinders will be kept precisely equal by the integrator valve 65. The depth of the blade can be changed by operating valve 50, but only if both of the cylinders controlling the depth of the blade change exactly the same amount, which will insure that the slope of the blade will not change.
The left lift cylinder valve 53 is not normally operated when the selector valve is in its position to activate the flow integrator. However, valve 53 may be used to adjust the slope of the blade without damaging the system even when the selector valve is connecting lines 60 and 61 in the circuit.
Thus, by using flow integrators which integrate flow from the exhaust side of the cylinders, and a selector valve to permit selective operation of these flow integrators, precise slope and depth control of the grader blade can be achieved during automatic operation or manual operation for insuring that once a slope has been established it will be maintained if the depth is changed.
The selector valve can be Model DS75 made by Gresen Manufacturing Company, Minneapolis, Minn. The check valves 51 and 54 are pilot operated check valves of conventional design presently on hydraulically operated road grader equipment made by Caterpillar Tractor Co. of Peoria, Ill.
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A hydraulic control system for use for precise control of the height of the earth working blade on road graders, and in particular for use in combination with road graders that are automatically controlled. The control system is selectively operable, and when engaged will permit only simultaneous movement of the two cylinders used for controlling the depth of the earth working blade.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 10/158,615, now U.S. Pat. No. 6,881,386, filed May 30, 2002.
GOVERNMENT SUPPORT
This invention was made with government support under Grant Nos. DE-AC03-99EE50565 and DE-FG04-95AL88002, awarded by the Department of Energy. The United States Government has certain rights in the invention.
FIELD OF THE INVENTION
The present invention relates to a method and apparatus for a plasma fuel converter and more particularly to a low current plasmatron fuel converter having enlarged volume discharges.
BACKGROUND OF THE INVENTION
Plasmatron fuel converters reform hydrocarbons to generate a hydrogen rich gas through the use of plasma discharges. (See, for example, U.S. Pat. Nos. 6,322,757 and 5,887,554, the teachings of which are incorporated herein by reference). Two general types of plasma discharge regimes can be distinguished by their electrical characteristics and their modes of operation. A non-arcing discharge regime operates at high voltage and low currents, while an arc discharge regime operates at low voltage and high currents. (For a general treatise, see J. Reece Roth, Industrial Plasma Engineering, Vol. 1 and 2 , Institute of Physics: Bristol, UK, 1995).
Thermal arc plasmatrons have received particular attention in the prior art. (See, for example, U.S. Pat. Nos. 5,425,332 and 5,437,250, the teachings of which are incorporated herein by reference). These thermal arc plasmatrons operate at low voltage and high current and, therefore, have relatively inefficient electrical power to chemical power conversion ratios. Better electrical power to chemical power conversion ratios, as well as lower current resulting in lower electrode erosion, can be obtained through the use of non-arcing discharge plasmatrons. However, non-arcing discharges are usually operable at sub-atmospheric pressure, typically less than about 20 Torr. When pressure is increased, the non-arcing discharge rapidly transitions to an arc discharge. Low pressure gas glow discharges and apparatus for their production are known. (See, for example, U.S. Pat. Nos. 2,787,730; 3,018,409; 3,035,205; 3,423,562; 4,830,492; 4,963,792; and 4,967,118, the teachings of which are incorporated herein by reference). However, the effective volumetric flow rates through these low pressure devices are limited.
It is desirable to have a plasma converter that produces discharges in the non-arcing regime in a substantially continuous manner with a substantially enlarged effective discharge volume.
SUMMARY OF THE INVENTION
A novel apparatus and method is disclosed for a plasmatron fuel converter (“plasmatron”) that efficiently uses electrical energy to produce hydrogen rich gas. The volume and shape of the plasma discharge is controlled by a fluid flow established in a plasma discharge volume. A plasmatron according to this invention produces a substantially large effective plasma discharge volume allowing for substantially greater volumetric efficiency in the initiation of chemical reactions within a volume of bulk fluid reactant flowing through the plasmatron.
In one aspect, the invention is a plasmatron fuel converter comprising a first electrode and a second electrode separated from the first electrode by an electrical insulator and disposed to create a gap with respect to the first electrode so as to form a discharge volume adapted to receive a fuel/air mixture. A power supply is connected to the first and second electrodes and adapted to provide voltage and current sufficient to generate a plasma discharge within the discharge volume. Fluid flow is established in the discharge volume so as to stretch and deform the plasma discharge.
BRIEF DESCRIPTION OF THE DRAWING
The invention is described with reference to the several figures of the drawing, in which:
FIG. 1 is a cross-sectional view of a low current, low power plasmatron fuel converter according to one embodiment of the invention;
FIG. 2 is a cross-sectional view of a plasmatron fuel converter illustrating a combined flow of a fuel/air mixture and plasma shaping air;
FIG. 3 is a cross-sectional view of a plasmatron fuel converter with a turbulizer according to one embodiment of the invention;
FIG. 4 is a cross-sectional view of a plasmatron fuel converter showing the use of hot recirculated hydrogen rich gas according to one embodiment of the invention; and
FIG. 5 is a cross-sectional view of a plasmatron fuel converter with a heat exchanger according to one embodiment of the invention; and
FIGS. 6A-6C are cross-sectional views of multiple electrode configurations according to multiple embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Robust, large volume plasma discharges are needed for fast start-up of low current, low power plasmatron fuel converters (“plasmatrons”) and for efficient operation after start-up. Efficient operation requires both the efficient use of electrical energy to promote chemical reactions in a given discharge volume and volumetric efficiency in the percentage of chemical conversion achieved in the volume of bulk reactant fluid. Such efficient operation has been achieved by the present invention through the use of a plasmatron having a special configuration which utilizes a low current plasma discharge that is continually stretched and extinguished by flowing gas and is then quasi-instantly and randomly reestablished elsewhere in the discharge volume. Importantly, the chemical effects of the active species flux in the region of the bulk fluid local to an extinguished discharge typically persist for a much greater period than the cycle period of an individual plasma discharge. This continual and rapid displacement of the discharge from one path in the discharge region to another covers both a relatively large area perpendicular to the flow of injected reactant fluids and a significant distance along the flow. Rapid establishment, extinction and reestablishment of the plasma discharges, combined with initiation of persistent chemical reactions by the flux of active species generated by the discharge, result in a quasi-continuous plasma discharge. The quasi-continuous plasma discharge effectively fills the discharge volume and initiates chemical reactions throughout that volume.
The efficiency of the plasmatron in use of electrical energy to promote hydrogen producing reactions is determined, in part, by the ratio of the period of operation in the non-arcing discharge regime to the total period of plasma discharge during an average cycle of operation. Thus, the plasmatron of this invention can operate in a substantially continuous manner in the non-arc discharge regime.
One preferred embodiment of the invention is as a fast starting, low current, low power enlarged volume plasmatron. One application involves partial oxidation of hydrocarbon fuels to produce hydrogen rich fuels for use in internal combustion systems such as gasoline or diesel engines and their associated exhaust systems. Such plasmatrons may be selected for operation between stoichiometric partial oxidation and full combustion depending on conditions and applications. During full combustion, the output of the plasmatron is a hot gas that is no longer hydrogen-rich. Operation in full combustion is generally only maintained for brief periods. Power for operation of the plasmatron will preferably be provided by components of the internal combustion system.
Referring now to the figures of the drawing, the figures constitute a part of this specification and illustrate exemplary embodiments of the invention. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.
FIG. 1 is a cross-sectional view of one embodiment for a low current, low power plasmatron 10 . In a preferred embodiment, fuel 12 and oxidant (e.g. air) 14 are supplied to the plasmatron 10 to form a fuel-air mixture 16 . Alternatively, the reactive mixture 16 supplied to the plasmatron 10 may comprise only atomized fuel (without oxidant). In a preferred embodiment that maximizes volume and minimizes electrode wear, the plasmatron is comprised of a top cylindrical electrode 20 and a bottom cylindrical electrode 24 separated by an electrical insulator 22 . This cylindrical geometry minimizes average current density and associated erosion on the surface of both electrodes 20 , 24 . Inadvertent or excessive operation in the arc discharge regime, and its associated wear on the surface of the electrodes 20 , 24 , may be minimized by including a current limiting feature in a high voltage power supply 18 attached to the electrodes 20 , 24 . The electrodes 20 , 24 are axially aligned with the longitudinal axis of the plasmatron 10 allowing for a gap in between them to form a plasma discharge volume 26 . An additional fluid flow (e.g. air or a fuel/air mixture) 19 is introduced into the plasma discharge volume 26 with a tangential component to produce a flow that stretches, deforms and moves poloidally the discharge. This plasma shaping air (or air/fuel) 19 may be established by one or more apertures (or channels) 28 between the top and bottom electrodes. These apertures may be designed to provide a vorticity to the plasma shaping air as it flows through the plasma discharge volume 26 .
In one embodiment, the flow of the fuel/air mixture 16 and the flow of the plasma shaping air 19 are perpendicular to one another. Establishing the flows in this manner through the discharge volume maximizes the effective volume of the bulk fuel/air mixture 16 and plasma shaping air 19 that interact with the volume of active species from the plasma discharges. These active species are within each plasma discharge and within the regions of the bulk fuel/air mixture 16 local to each plasma discharge. This geometry can provide continual initiation of the partial oxidation reactions at all sub-volumes of plasma discharge volume 26 radial to the axis of the flow of the fuel/air mixture 16 . The relatively long paths of plasma discharges along the main direction of flow ensures adequate reaction initiation at multiple radial and axial positions, thus assuring efficient ignition. Where conditions, such as low oxygen/fuel ratios, limit the persistence and propagation of partial oxidation reactions (i.e. limited or quenched “flame” or “ignition” propagation), reaction initiation at multiple radial and axial positions along the axis of flow ensures reaction initiation in the fuel/air mixture 16 throughout the plasma discharge volume 26 .
In a preferred embodiment, the liquid fuel 12 is atomized and introduced from the center of the top electrode 20 . Fuel atomization can be achieved by appropriate nozzle 21 design, with or without air assist. When operating with liquid hydrocarbons, fuel deposition and condensation on the inner surfaces of electrodes 20 , 24 may be reduced by employing the nozzle 21 to produce a narrow jet of fuel droplets. Spray angles between 15 and 30 degrees have been shown to be sufficient.
The plasma discharge is established by supplying high voltage (300 V to 60 kV) (and resulting current in the range of approximately 10 milliamperes to 2 amperes) in the discharge volume 26 between electrodes 20 , 24 . The plasma shaping air 19 is injected from a side aperture 28 in such a way as to create shear and displacement stresses that deform and displace the volume of the plasma discharge (and plasma sheath, if any) and mix the fuel/air mixture 16 with the plasma discharge. The stresses stretch and deform the discharge, thus affecting the electrical and thermal characteristics of the plasma. If stretched beyond a critical length, the plasma's electrical field becomes unsustainable. Whether in thermodynamic equilibrium or non-equilibrium, the low current non-arcing discharge is eventually elongated to the point of extinction due to current limitation, voltage limitation or geometric plasma instability.
The plasma discharge is reestablished almost instantaneously along a different pathway between two random points on the electrodes 20 , 24 . The plasma discharge is generally restablished in a time of less than 100 nanoseconds. Depending on the selections of various operational parameters of the plasmatron, this process occurs naturally at a high frequency of plasma discharge initiation and extinction and provides quasi-uniform plasma discharge throughout the entire volume of the discharge region. The frequency of plasma discharge initiation and extinction is here termed ‘cycle frequency’. Natural cycle frequency for a plasmatron fuel converter of the illustrated preferred embodiment will typically be on the order of several kHz (1-10 kHz). Since the chemical reactions initiated by each individual discharge persist and propagate in the region of the bulk fuel/air mixture 16 local to the discharge for a significant time after the extinction of the discharge, the effect of the quasi-uniform, ‘volumetric’ plasma discharge is to produce a volumetric initiation (‘volumetric ignition’) of chemical reactions throughout the bulk fuel/air mixture 16 .
Generally, the plasmatron will provide average power to the plasma in range of between 10 and 1000 watts. The electrical power consumption is generally between 0.3 % to 10 % of the thermal power content of the hydrogen rich gas produced by the plasmatron.
The cycle frequency necessary to provide a quasi-uniform plasma discharge can be provided by the selection of various electrical and fluid dynamic characteristics of the plasmatron as described above. Generally, the power supply frequency will be adjusted in the range of 100 Hz to 2 MHz. By controlling the electrical and thermodynamic parameters of the plasma, the operation of this plasmatron fuel converter can be selected for high energy conversion efficiency and for selectivity in the chemical processes initiated by the volumetric ignition. In the preferred embodiment of the invention, such selectivity is for the production of hydrogen gas from hydrocarbon fuel.
The combination of volumetric ignition and high turbulence of the fuel/air stream is a very important feature of fast start fuel reforming. The enlarged volumetric discharge maximizes plasma and fuel/air mixture 16 contact and ensures initiation of the reaction throughout this mixture. By careful selection of the operating parameters of the air 14 and the fuel 12 , and with the turbulence provided by the plasma and the fluid flow, the conditions for optimal chemical reactions are achieved. The air-fuel ratio, and thus the oxygen—carbon (O/C) ratio, can be varied from as low as an O/C ratio=1 for stoichiometric partial oxidation to as high as an O/C ratios=2 for liquid hydrocarbon fuels with a composition of (CH 2 ) n , and preferably the O/C ratio will be in the range of 1.0 to 1.2.The volumetric ignition feature of the present application is very useful in achieving high volumetric efficiencies and high electrical efficiencies under conditions of reduced chemical reaction persistence and/or propagation. Such conditions occur in very fuel rich environments characteristic of partial oxidation reformation of hydrocarbon fuel, where chemical initiation at any individual site in the discharge volume is difficult to initiate and maintain because of very slow “flame” propagation speed.
Following quasi-uniform volumetric ignition in the discharge region, an ignited fuel/air stream 29 is introduced into a reactor 30 having a reaction extension cylinder or region 32 . The reactor 30 includes a steel tube 34 with inner thermal insulation 36 and outer thermal insulation 38 . The reactor 30 may have a catalytic structure 40 at the bottom. The preferable catalytic structure 40 is a ceramic or metallic honeycomb support coated with rare metals (e.g. Pt, Pd). The honeycomb configuration has a low thermal mass which facilitates fast start.
In a preferred embodiment, the reaction extension region 32 provides a gap between the exit of the bottom electrode 24 and the catalytic structure 40 . This gap is necessary for fuel droplets vaporization and production of a homogenous mixture ready for reforming on the catalyst surface, and to control temperature of the catalyst. The length of the reaction extension region gap should be greater than 1 cm, and preferably greater than 10 cm. In order to achieve higher productivity of output hydrogen rich gas 50 , it is possible to inject additional fuel/air mixture 16 into the reaction extension region 32 .
FIG. 2 is a cross-sectional view of an embodiment of the plasmatron. fuel converter 10 showing the addition of a fuel/air mixture by injection into the plasma discharge volume between electrodes 20 , 24 . In this variant of the invention, all fuel is vaporized and then introduced as a fuel/air vapor mixture 16 into the discharge region 26 through the side opening 28 between the electrodes 20 , 24 . This embodiment could also be used for gaseous hydrocarbon fuels reformation. Thus, the injection of the fuel/air mixture 16 can provide the reactive mixture while also shaping the plasma discharge.
FIG. 3 is a cross-sectional view of an embodiment of the plasmatron fuel converter 10 showing the use of a turbulizer 42 to shorten start-up time and increase the heat and mass transfer capacity of the reactor 30 . The turbulizer 42 deflects the hot, ignited fuel/air stream 29 coming from the bottom electrode 24 to the cold walls of the reactor 30 . By heating the cold walls with the ignited fuel/air stream 29 , the temperature gradient across the reactor is decreased resulting in increased efficiency and a faster start-up time. Also, the turbulizer's 42 hot surface helps to vaporize any remaining liquid fuel droplets in the ignited fuel/air stream 29 . In a preferred embodiment, the turbulizer 42 is made of steel.
FIG. 4 is a cross-sectional view of an embodiment of the plasmatron fuel converter 10 in which, to further decrease the start up time, part of the hot hydrogen rich gas 50 reformate output from the plasmatron is recirculated back into the plasmatron 10 , potentially premixed with the plasma shaping air 19 . In other embodiments, the recirculated hydrogen rich gas output may be mixed with the fuel/air mixture. Hydrogen rich gas 50 recirculation increases the ease of the reforming operation, due to the much greater volumetric ignition rate (‘flame speed’) of the hydrogen. In this configuration, the equilibrium of the reformate is not changed, but the kinetics of the partial oxidation reaction could be dramatically increased. The hot recirculated hydrogen rich gas 50 can also help in quickly raising the temperature needed for start-up.
FIG. 5 is a cross-sectional view of an embodiment of the plasmatron fuel converter 10 wherein following the fast start period, the energy consumption could be decreased by using a heat exchanger 44 to preheat the plasma shaping air 19 . In other embodiments, the heat exchanger may be used to preheat the air 14 , the fuel 12 , and the fuel/air mixture 16 . The heat exchanger 44 allows for decreasing the temperature of the hydrogen rich gas 50 injected into an engine's inlet manifold. Also by preheating air 14 in the counter flow heat exchanger 44 it is possible to decrease power of plasmatron necessary to reform the fuel 12 at a given fuel flow rate. Alternatively at a constant level of plasmatron power the heat exchanger 44 makes it possible to reform a higher flow rate of fuel 12 .
It is recognized that selection of various geometries of electrode configurations and various geometries of introducing fuel and air into the plasma discharge volume will provide various conversion efficiencies and chemical selectivity. Without limitation, embodiments of alternative electrode configurations include: two parallel ring electrodes with a gap disposed between; two parallel rod electrodes with a gap disposed between; and a first cylindrical electrode co-axially disposed in a second cylindrical electrode which has a cylindrical inner bore of greater diameter than the outer diameter of the first electrode.
FIGS. 6A-6C are cross-sectional views of multiple electrode configurations according to multiple embodiments of the invention. FIG. 6A illustrates the use of ring electrodes 60 and 62 positioned in a vertical configuration. Fuel or fuel/oxidant mixture 16 is injected from nozzle 21 through the top ring electrode 60 and into the plasma discharge volume 26 defined by top and bottom ring electrodes 60 and 62 where the electrodes supply a voltage to generate the plasma discharge. The electrodes 60 and 62 are electrically separated by insulator 22 . Plasma shaping air 19 is injected from one or more apertures 28 which may be located at multiple circumferential positions.
FIG. 6B illustrates a rod-to-rod electrode configuration in which the rod electrodes 64 and 66 are positioned in a horizontal configuration. The operation of the system is generally similar to that of other embodiments in that a fuel/air mixture 16 is injected from a nozzle 21 into the plasma discharge volume 26 . The electrodes supply voltage to generate the plasma discharge that is shaped by plasma shaping air 19 injected from one or more injection apertures 28 .
FIG. 6C illustrates a dual co-axial cylinder configuration in which the inner cylindrical (or conic shaped) electrode 68 has an smaller diameter than the outer cylindrical electrode 70 . In the case of liquid hydrocarbons, it is necessary to configure the nozzle 21 to deliver a hollow spray of fuel or fuel/air mixture 16 into the plasma discharge volume 26 between the electrodes 68 and 70 to prevent deposition and coagulation of the fuel/air mixture droplets on the electrodes. The electrodes supply voltage to generate the plasma discharge that is shaped by plasma shaping air 19 injected from one or more injection apertures 28 .
Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.
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A novel apparatus and method is disclosed for a plasmatron fuel converter (“plasmatron”) that efficiently uses electrical energy to produce hydrogen rich gas. The volume and shape of the plasma discharge is controlled by a fluid flow established in a plasma discharge volume. A plasmatron according to this invention produces a substantially large effective plasma discharge volume allowing for substantially greater volumetric efficiency in the initiation of chemical reactions within a volume of bulk fluid reactant flowing through the plasmatron.
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This is a continuation of application Ser. No. 07/048,566 filed 5-11-87, now abandoned.
BACKGROUND
1. Field of The Invention
The present invention relates to the field of water fountains and, more specifically, to a water fountain incorporating colored flames as a means of illumination.
2. Prior Art
Water fountains have long been treasured for their decorative and entertaining qualities. Fountains range in size and complexity from small fountains with single streams of water, to large outdoor fountains incorporating sophisticated light displays. Such large fountains are typically installed in hotels, shopping malls, museums and parks. A whole new art form has developed in which the movement of water in a fountain is choreographed to music. Often electric lights are used for illumination, making nighttime performances of such fountains particularly impressive. By using multiple, differently colored lights, a particularly entertaining interplay between water, light and music can be rested.
In addition to electric lights, gas burners have also been used to illuminate water fountains. While the resulting interplay of fire and water has added a new dimension to water fountain displays, heretofore water fountain flame illumination systems have been able to produce flames of only a single color.
The present invention, however, produces flames for the illumination of water fountain displays, the color of which can be changed at will. By adding the versatility of color to flame illuminated water fountain displays, the present invention makes possible even more attractive and entertaining water fountain displays than were possible with the prior art.
SUMMARY OF THE INVENTION
The invention consists of apparatus and a method for producing colored flames for the illumination of water fountain displays. The invention comprises a main burner nozzle attached to a fuel supply and mounted in proximity with one or more of the water nozzles of a water fountain display. A pilot burner and a glow plug or spark discharge igniter are located adjacent to the main burner nozzle, as are a number of flame colorant nozzles. To produce a colored flame, a stream of colorant, preferably consisting of a concentrated solution of metallic salts, is forced under pressure through a colorant nozzle. As the atomized stream of colorant impinges on the main burner flame, the metallic salts are ionized, producing a colored flame. The invention also includes a flame sensor located adjacent to the pilot and main burners. During the operation of the fountain, the flame sensor detects the presence or absence of a flame and is used as a safety device to insure that the flow of fuel to the burners is cut off if the pilot and main burner flames suddenly die. A central control panel oversees the operation of the colored flame system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the main burner assembly illustrating the arrangement of the various elements of the invention.
FIG. 2 is a sectional view of the main burner assembly.
FIG. 3 is a schematic view illustrating the interconnections of fuel lines, colorant lines and electrical control lines between the major components of the invention.
DETAILED DESCRIPTION OF THE INVENTION
A colored flame illumination system for water fountain displays is disclosed. In the following description, for purposes of explanation, numerous details are set forth, such as specific materials, arrangements and proportions in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the invention may be practiced without these specific details. In other instances, well-known electrical and piping system components, such as UV sensors, check valves and solenoid valves, have not been described in detail in order not to obscure the present invention unnecessarily. In the following discussion, the same numbers are used to designate like elements throughout the drawings.
The invention comprises three main components: a burner assembly; a colorant reservoir assembly; and a control unit.
FIGS. 1 and 2 are illustrations of the burner assembly. The major structual elements of the burner assembly are burner cup 21, a main fuel line comprised by pipe segments 22 and 38, for supplying a fuel such as gas and colorant nozzle mounting block 30. The burner cup is mounted such that its open side faces vertically upwards, and it is generally located adjacent to one or more water nozzles 20 of a water fountain. The burner cup may be situated above the water level of the fountain, or may be recessed in a well or pipe such that it is flush or slightly below the surface of the surrounding water. Pipe segment 22 protrudes vertically through the bottom of the burner cup, generally in a central location. The open top of the pipe segment 22 is provided with a wire mesh atomizing screen 25 that assists in the atomization of colorants prior to their impinging on the main burner flame 36. The colorant nozzle mounting block 30 is located adjacent to and below the burner cup. Nozzle mounting block 30 contains a central hole 35, threaded at each end to accept the pipe segments 22 and 38 of the main fuel line. The bottom side of the nozzle mounting block also contains threaded holes for accepting the top threaded ends of the colorant lines 33. Colorant nozzles 34 project into centra1 hole 35. Internal passages 31 are provided to allow colorant to pass from each colorant line 33 to its corresponding nozzle 34. In the preferred embodiment, passages 31 are formed by drilling a first hole 81 vertically upward from the bottom of block 30, and a second hole 82 radially inward from the side of block 30, such that the second hole 82 intersects both the first hole 81 and the central hole 35 of mounting block 30. A colorant nozzle 34 is mounted in the end of a hollow cylindrical insert 83 that is slid into the second hole. The insert has a hole 84 through its side located in a position corresponding to the first vertical hole 81 in the mounting block. After the insert and the nozzle have been inserted into the mounting block, a plug 32 is used to seal off the outside end of the second hole 82, and a colorant line 33 is threaded into the bottom end of the first hole 81. Nozzle mounting block 30 comprises a nozzle 34, internal passage 31 and colorant line 33 for each colorant used. In the preferred embodiment, the number of colorants is four. Nozzle mounting block 30 may also contain passages for the various pipes and wires leading to the burner cup, or those pipes and lines may pass around the outside of the block.
Burner cup 21 is also fitted with a drain 37 and an ignition means for lighting the main burner flame. In the preferred embodiment, this ignition means comprises a pilot burner 26 attached to pilot fuel line 24, together with a glow plug 27. The glow plug is used to ignite the pilot flame 39, and the pilot flame in turn lights the main flame 36. Burner cup 21 may also include an optical flame sensor 23. Sensor 23 is typically a UV light sensor. It senses when the pilot or the main burner is lit and is used as part of a safety mechanism that prevents the flow of fuel to the main or pilot burners when the main and pilot flames have been extinguished.
Turning now to FIG. 3, this Figure is a schematic showing the layout of the various components of the invention. In addition to the burner assembly 40, the main elements of the invention are a control unit 41, and a colorant reservoir assembly indicated generally by number 67. The colorant reservoir assembly 67 consists of tanks or other vessels for holding a quantity of each colorant, indicated by numbers 42 through 45, together with a pump and valve assembly, 46 through 49, for each colorant. Colorant lines 52 through 55 connect each colorant reservoir with its corresponding colorant nozzle contained in burner assembly 40. The main fuel line 56 and the pilot fuel line 57 connect the main burner and the pilot burner located in the main burner assembly 40 with fuel supply line 66. Fuel control valves 50 and 51 are inserted in the main fuel line and the pilot fuel line between the main burner assembly and fuel supply line 66. Main fuel control valve 51 and pilot fuel control valve 50 are connected to control unit 41 by means of electrical control lines 61 and 60, respectively. Electrical control line 28 connects control unit 41 with the flame sensor 23, and electrical control line 29 connects the control unit with the glow plug 27.
Fuel control valves 51 and 50 are electrically operated solenoid valves, or any other electrically, hydraulically, or pneumatically operated valves. Pump and valve assemblies 46 through 49 are devices or combinations of devices that, upon command by the control unit, are capable of delivering colorant from the colorant reservoirs to the colorant nozzles under pressure. In the preferred embodiment, the colorants consist of concentrated metallic salt solutions that must be delivered to the colorant nozzle at a pressure between 60 and 100 PSI. Such pressures are necessary to insure that the liquid colorant is atomized finely enough by passage through the colorant nozzles such that the metallic salts in solution are ionized when they contact the burner flame. In the preferred embodiment, pump and valve assemblies 46 through 49 comprise conventional pneumatically operated pinch valves mounted in series with inlet and outlet check valves. A pinch valve consists basically of a flexible hose surrounded by a collar or envelope into which pressurized air can be introduced. When air is introduced in the envelope, the tube is pinched, and any liquid contained in the tube is squeezed out. The inlet and outlet check valves insure that the liquid flows in one direction only.
Control unit 41 is connected to several operator controls. These may include an emergency stop button 71, a start up switch 72, a safety switch 73, a dead man switch 74, and a color control 70. In the preferred embodiment, control unit 41 comprises a microprocessor that is programmed to control various modes of operation of the flame burner system. The first such mode of operation is the pilot ignition sequence. Engaging the start up switch 72 initiates the ignition sequence. During the ignition sequence, the control unit first activates the glow plug 27 for about 30 seconds to allow it to reach a temperature sufficient to ignite the pilot burner 26. After 30 seconds, the control unit opens pilot control valve 50 for 10 seconds. If, at the end of the 10 seconds, the flame sensor 25 senses that the pilot flame 39 has been lit, the control unit 41 signals main fuel control valve 51 to open. The main burner flame 36 is then ignited by the pilot flame 39.
If, at the end of 10 seconds the flame sensor 25 does not see a pilot flame, the ignition sequence is repeated. If after a second 10 second period, the pilot flame still remains unlit, control unit 41 shuts down the system. Once this shutdown occurs, the flame system can only be restarted upon the manual resetting of safety switch 73
Once the main flame 36 is lit, colorant can be added in response to inputs from the colorant control 70.
Each colorant produces a differently colored flame. In the preferred embodiment, the colors produced are blue, green, orange and red. If, for example, colorant control 70 indicates that a red flame is desired, the control unit 41 first checks to see whether the main burner flame 36 is lit and, if it is, sends a signal to the pump and valve assembly for the red colorant. It will be recalled that in the preferred embodiment this pump and valve assembly comprises a pinch valve and two check valves. This signal from the control unit 41 opens a solenoid valve controlling the introduction of pressurized air into the pinch valve. The pressurized air causes the volume of fluid contained within the tube of the pinch valve to be pumped up and out of the red colorant nozzle causing the flame to turn red. If an additional amount of red colorant is desired, control unit 41 sends a second signal to the pinch valve, causing the pressurized air to be released. The cycle can then begin again.
In addition to shutting down the system when the pilot valve refuses to light for two consecutive ignition sequences, the control unit 41 will shut down the system, thereby shutting off the flow of fuel to the main and pilot burners, if the emergency switch 71 is pushed or a dead man switch 74 is released. The safety of the operation of the color flame system is thereby assured.
Accordingly, a system for using colored flames to illuminate water fountains has been disclosed. The invention allows the creation of aesthetically pleasing and entertaining water and light show displays that was not possible in the prior art. Although specific details are described herein, it will be understood that various changes can be made in the materials, details, arrangements and proportions of the various elements of the present invention without departing from the scope of the invention. For example, although this specification refers mainly to liquid colorants, gaseous colorants may also be used. In addition, the specific arrangement of the pilot and main burners, the colorant nozzles and the flame sensor may be varied. The location of the burner assembly with respect to water nozzles of the fountain may also be changed. Any number of colorant nozzles may be used, and more than one burner may be incorporated in a single burner cup. Other variations will be apparent to those skilled in the art.
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The invention consists of a colored flame system for illuminating water fountains. A burner assembly, comprising a main burner, a pilot burner, an igniter, a flame sensor and multiple colorant nozzles is located adjacent to one or more water nozzles of the fountain. A control unit oversees operation of the system. Upon commands from an operator, the control unit causes the pilot and main burners to light and injects the desired colorants into the main burner flame. The colorants are concentrated solutions of metallic salts. The flame sensor acts as a safety device insuring that gas and colorants are emitted only when the pilot and main burners are lit. 7
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FIELD OF THE INVENTION
The field of the invention is control systems for hydraulically operated downhole tools and more particularly sliding sleeve valves that operate in multiple positions including fully open and closed.
BACKGROUND OF THE INVENTION
Flow during production is regulated by a valve called a choke. The typical design for a choke comprises a body having a series of lateral ports and a sliding sleeve that has a matching port layout. A hydraulic system is used to move the insert sleeve in opposed directions. The hydraulic system also controlled the movement of the insert sleeve broadly in two different ways, both of which will be described in detail below.
In the J-slot design cycles of pressure application and removal made a pin follow a j-slot. A lug also on the movable member with the pin followed the pattern defined by the j-slot and with each cycle of application and removal of pressure the lug would encounter a different fixed travel stop that would define a different amount of percentage open for the valve. In one known design of the HCM-A choke offered by Baker Hughes Incorporated the j-slot allows the insert sleeve to go from a diffused position where it is not totally closed to various open positions with the j-slot pattern having two open passages to allow the lug an extra travel distance so that the valve could go to the fully open or fully closed positions.
In a modification to this valve the hydraulic control system was designed to move the insert sleeve a fixed amount for each pressure up cycle. Removal of the pressure in the second part of each cycle would simply leave the insert sleeve where it was and the next application of pressure would incrementally move the insert sleeve by an amount related to the displaced volume of a piston. Any time the pressure was applied to another control line the insert sleeve would go to the fully closed position.
The details of both these designs and their shortcomings that lead to the development of the present invention will now be described.
Referring to FIGS. 1 and 2 , a valve housing 10 has control lines 12 and 14 that extend to opposite sides of piston 16 . Piston 16 is connected to insert sleeve 18 for tandem movement. Insert sleeve 18 has a hole pattern 20 that moves up and down into and out of alignment with openings 22 in the housing 10 . Seals 24 and 26 straddle ports 22 so that when openings 20 are not between seals 24 and 26 the valve is fully closed. On the other hand when the ports 20 are between seals 24 and 26 , as shown in FIG. 1 , then the valve is in the diffused position where some flow is possible between ports 20 and 22 through diffuser 28 . Alternating pressure application between lines 12 and 14 forces relative movement of pin 30 in the j-slot pattern 32 . A series of stair step travel stops 34 define how much more open the valve gets in each pressure cycle. The other half of each cycle has the lug 36 landing on the same spot 38 to define the diffused position shown in FIG. 1 . In each pressure cycle, the lug 36 lands on a different step 34 to represent another opening increment. After a predetermined number of cycles the lug 36 can go to landing 40 for a fully closed position where the openings 20 are no longer between seals 24 and 26 . In the very next cycle it can go to fully open when lug 36 is allowed to keep traveling by slot 41 until it hits stop 42 .
This design does not allow the valve to always be closed with a single command. The design also usually requires multiple commands to reopen the valve after closure to a desired position. This mode of operation can result in additional wear on the ports 20 and 22 . In some instances, operators wanted the ability to step the valve to different opening percentages but to also have the ability to snap it closed without having it go through any steps. The design in FIGS. 1 and 2 couldn't do this. What it could do is shown in FIG. 3 . In each cycle it could open incrementally more and go to a diffused position where flow through it was fairly close to nothing. As a result a spike pattern of percent open was created and no provisions existed for a rapid close by skipping any part of the sequence illustrated in the j-slot of FIG. 2 .
FIG. 4 represents a modification of the original design in FIGS. 1 and 2 that works on the principle of using a predetermined displaced volume to get a predetermined movement of an insert sleeve. Rather than going to almost closed in each cycle the insert sleeve just stays in position until the next cycle bumps it a finite amount proportional to the displaced hydraulic fluid volume. Another feature of this system is that it can be taken to closed immediately by applying pressure on one of the control lines.
The design in- FIG. 4 includes the following components: Line 44 supplies opening pressure to the mechanism and is connected to lines 48 and 46 . Line 48 supplies pressure to piston 50 . Line 46 supplies pressure to plunger 76 which is connected to piston 74 , lines 68 , 66 and 90 furnish pressure from the control mechanism to the valve 62 to cause the valve to open. Line 92 furnishes pressure to the valve to cause it to close. Piston 50 is used to move the valve from the fully closed position to the diffused position (such as is shown in FIG. 1 ). Piston 74 is used to move the valve sequentially to different opening positions. Spring 84 causes piston 74 to move to the left when pressure is bled off of line 44 . The surface 86 of plunger 76 allows fluid to bypass plunger 76 during its movement to the left.
The operation of this control system will now be described. Initial application of pressure to line 44 will transmit through line 48 causing Piston 50 to move to the right until it stops and seals at face 94 . This causes fluid in chamber 64 to move through lines 66 and 90 causing valve 62 to move from the closed position to the diffused position. Continued application of pressure to line 44 , which is also communicating through Line 46 with plunger 76 , will now cause plunger 86 and piston 74 to move to the right compressing spring 84 and causing fluid in chamber 70 to move through lines 68 and 90 moving valve 62 from the diffused position to the first open position. At this point, elimination of pressure in line 44 will allow spring 84 to move piston 74 and plunger 76 to the left. The design of plunger 76 includes the surface 86 which allows fluid from lines 44 and 46 to bypass plunger 76 during this leftward movement. Piston 50 does not move and stays in contact with face 94 . A second application of pressure to line 44 will communicate trough line 46 to plunger 76 causing it to again move to the right which induces fluid to flow from chamber 70 , through lines 68 and 90 to valve 62 , moving valve 62 from opening position number 1 to opening position number 2 . This elimination and application of pressure to line 44 will cause the valve 62 to consecutively move to opening positions 3 , 4 , 5 , etc.
Any time the above opening sequence is interrupted by elimination of pressure from line 44 combined with application of pressure to line 92 , full closure of the valve 62 is achieved. During this closure, fluid is exhausted from valve 62 through line 90 to lines 68 and 66 . The exhaust flow in line 68 , along with aid of spring 84 , cause piston 74 and plunger 76 to move fully to the left. The exhaust flow in line 66 will cause the piston 50 to mover fully to the left. Continued exhaust flow from valve 62 is through lines 90 and 66 to chamber 64 and then through check valves 54 and 52 to lines 48 and 44 which enables the exhaust flow to be vented to surface. Now the valve 62 is fully closed. Valve 62 can now be re-opened as described above by application of pressure to line 44 . However, note that in order to return valve 62 to the previous open position (that is occupied before closure) may require multiple pressure applications to line 44 . Note also that any gas present in chambers 70 and 64 may affect the ability of piston 74 and plunger 76 to move valve 62 accurately to the next open position.
The present invention presents a control system for a hydraulic control valve, for example, that allows incremental opening in steps by cycling pressure to an opening chamber. Removing pressure to the opening chamber sends the system into a neutral position. Applying pressure to a closing chamber closes the valve by moving the insert sleeve to the closed position. Reapplying pressure after closure on the opening side returns the valve to the position it was in before it was closed. On the other hand, cycling pressure on the closing chamber can allow the valve to be subsequently reopened at any smaller percentage opening than it was in before it was closed. To open the valve to an open percentage that is higher than open position it was in when it was closed, pressure cycles are applied to the opening line. A split j-slot is employed to cycle the valve incrementally toward greater percentage openings on one half of the j-slot while on the separate j-slot the cycling allows the valve to be positioned to subsequently open at a desired percentage opening while staying closed as the cycling takes place. The cycling at either of the separate j-slots allows a travel stop for the insert sleeve to be repositioned. In essence the j-slot cycling creates relative rotation in either direction to extend or retract a travel stop for the insert sleeve. Pressure applied to the opening chamber always urges the insert sleeve to move toward the movable travel stop. Pressure applied to the closing chamber always urges the insert sleeve toward its fully closed position away from the movable travel stop. These and other features of the present invention will be more readily apparent from a review of the description of the preferred embodiment and the associated drawings that appear below with the understanding that the claims set out the full literal and equivalent scope of the invention.
SUMMARY OF THE INVENTION
A hydraulic control system can be used on a downhole choke and has the feature of moving a travel stop for a sliding sleeve using discrete j-slot mechanisms for selectively moving the stop in either one of two opposed directions. The valve can be incrementally opened further with pressure cycling on an opening chamber. The valve can be immediately put to the closed position with pressure on a closing chamber. After closing, the valve can assume its former open position or other selected less open positions by reconfiguring the travel stop while the valve stays in the closed position In order to achieve a higher open percent after closing, one or more pressure cycles must be applied to the open chamber after the valve is reopened to the position it was in before it was closed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a section view of a known choke valve in the diffused position;
FIG. 2 is the valve of FIG. 1 showing the j-slot portion of it rolled open;
FIG. 3 shows the progression of percentage open per pressure cycle on the valve of FIG. 1 ;
FIG. 4 is a schematic representation of a different known control system for the valve of FIG. 1 which works on the principle of displacement of a predetermined fluid volume;
FIG. 5 is the progression of percentage opening with each cycle for the valve of FIG. 1 using the control system of FIG. 4 ;
FIG. 6 is a section view of the control system of the present invention in a neutral position;
FIG. 7 is a view along section lines 7 - 7 of FIG. 6 ;
FIG. 8 is a view along section lines 8 - 8 of FIG. 6 ;
FIG. 9 is a section view of the control system in a neutral position with the valve closed;
FIG. 10 is the view of FIG. 9 during an opening cycle;
FIG. 11 is the view of FIG. 10 showing the completion of an opening cycle;
FIG. 12 is the view of FIG. 11 showing the closed position;
FIG. 13 is a layout of the opening j-slot showing pin movement on the piston and how it moves the j-slot; and
FIG. 14 shows how the pin of FIG. 13 is spring loaded to laterally deflect to allow it to exit from the j-slot without moving the j-slot.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
For continuity, FIG. 6 shows the insert sleeve 18 , for the valve in FIG. 1 . The present invention is focused on the control system and one application is on a valve with a basic structure as shown in FIG. 1 although uses on other downhole tools are envisioned. There are two control lines 100 and 102 that extend from the surface. Line 100 branches into lines 104 and 106 and line 102 branches into lines 108 and 110 . Line 104 goes into opening port 112 in body 114 . Line 108 goes to closing port 116 in body 114 . A piston 118 defines opening chamber 120 and closing chamber 122 between itself and body 114 with the aid of seals 124 , 126 and 128 . Piston 118 has a key 130 that rides in track 132 in the body 114 to limit the movement of piston 118 to longitudinal only without relative rotation. Piston 118 supports upper j-slot pin 134 and lower j-slot pin 136 . Pin 134 can selectively enter and exit j-slot assembly 138 on travel stop 142 for rotation of travel stop 142 in a manner so as to do up thread 144 to bring top end 146 closer to surface 148 which forms part of the body 114 . This is done by cycling pin 134 in and out of the j-slot 138 as will be described below. Similarly, pin 138 can engage j-slot assembly 140 that is on the travel stop 142 as is j-slot assembly 138 . Cycling pin 136 in and out of j-slot assembly 140 undoes thread 144 and brings end 146 away from surface 148 . Spring 150 urges piston 118 to the right extracting pin 134 out of j-slot 138 and spring 152 urges piston 118 to the left extracting pin 136 out of j-slot 140 .
Referring to FIGS. 13 and 14 and using pin 134 as an example, FIG. 13 indicates that pin 134 can translate in tandem with piston 118 in opposed directions 154 . As the piston 118 moves up to compress spring 150 , pin 134 moves into position 156 . From that point on any further translation along travel stop 142 by pin 134 will turn stop 142 in direction 158 as pin 134 rides on ramp 160 of the now rotating travel stop 142 . When pin 134 gets to position 162 the piston 118 cannot move to further compress spring 150 . At that point applied pressure that drives the piston 118 in that direction is removed and spring 150 reverses the motion of piston 118 but still along a longitudinal path 154 . Again, piston 118 is keyed at 130 to body 114 and cannot rotate. As a result, pin 134 under the force of spring 150 rides down surface 164 to position 166 . As spring 150 continues to push on piston 118 , the pin 134 is forced to move transversely to the movement of piston 118 in direction 168 and against the bias of spring 170 . This movement allows the pin 134 to ride down ramp 174 to location 172 without rotating the travel stop in a direction opposite to 158 . Resisting this tendency of the travel stop to move opposite direction 158 as pin 134 moves from position 166 to 172 is the pitch and friction forces in thread 144 . Once clear of the j-slot assembly 138 by moving from position 172 to 176 under bias on piston 118 from spring 150 , spring 170 now can relocate pin 134 to the FIG. 14 position and that puts pin 134 in position 178 ready to repeat the cycle just described and incrementally rotate travel stop 142 toward shoulder 146 and in turn allow the insert sleeve 18 to move higher for the next open increment of valve. This process can be repeated from a valve closed position through as many increments as the j-slot assembly 138 has for opening the valve to the full open position. Once full open is obtained the piston 118 has to be cycled in the opposite direction so that pin 136 will move selectively in and out of j-slot 140 to rotate it in direction 180 so as to bring end 146 away from surface 148 . The pin 136 is spring loaded so that it can interact with j-slot assembly 140 in the manner described above for pin 134 interacting with j-slot 138 but the movement of the travel stop 142 is in direction 180 rather than 158 . It should be noted that although pins 134 and 136 are described as being spring loaded, the same result can be obtained by putting j-slots 138 and 140 on spring loaded sleeves that go over the travel stop 142 while fixedly connecting pins 134 and 136 to piston 118 .
It should further be noted that applying pressure in line 100 puts pressure in line 106 that urges the insert sleeve 18 toward travel stop 142 . At the same time, pressure also goes to line 104 and into chamber 120 to move piston 118 and pin 134 into selective engagement with j-slot assembly 138 . With each application of pressure in line 100 insert sleeve hits the travel stop 142 and pin 134 rotates travel stop 142 along thread 144 to bring end 146 higher or closer to surface 148 . With each removal of pressure from line 100 pin 134 is pushed out of j-slot 138 by the action of spring 150 . Removal of pressure from line 100 does not shift insert sleeve 18 . As pressure cycles in line 100 are repeated the valve opens incrementally but holds it previous position in each pressure release portion of every cycle. The opening increments are preferably identical but they don't have to be. Differing opening increments can be achieved by changing the slope lengths or/and angle of inclination in the j-slot assembly 138 .
When pressure cycles are applied to line 102 , the pressure in line 110 causes the insert sleeve 18 to go closed. Repeated application and removal of pressure to line 102 will not move insert sleeve away from its closed position. What such cycles through line 108 will do is to cycle pin 136 in and out of j-slot assembly 140 to turn it in direction 180 and to undo thread 144 to bring travel stop 142 away from surface 148 . In this manner, the valve can be positioned to where it was before it was closed initially with pressure in line 102 so that the next time after an initial pressure cycle in line 102 a subsequent pressure cycle in line 100 will open the valve to exactly the same percentage opening it was in when it was previously closed. As another option, with the valve having been closed in any given position by applying pressure to line 102 , the valve can be manipulated without opening it by pressure cycles in line 102 so that when a pressure cycle is then applied to line 100 the valve can first open to a position different than it was in when it was initially made to close with the first pressure cycle in line 102 . In another mode of operation, after the valve is closed with a pressure cycle in line 102 it can then be made to open the next lower increment by adding one cycle to line 102 followed by a cycle in line 100 . Going to the next more open increment from closing with a cycle in line 102 is accomplished by first cycling once in line 100 to get the valve to open to the same position that it was in before it closed and then adding as many cycles in line 100 as needed to further open the valve. It should be noted that once the valve is cycled to fully open with pressure cycles in line 100 that it can't continue to be cycled in line 100 to smaller opening positions of the valve. This is because the travel stop 142 is translated by rotating it on thread 144 . When travel stop 142 is in its closest position to surface 148 representing the full open position of insert sleeve 18 pushed up against stop 142 by pressure in line 106 , that sleeve 142 has to now be rotated in direction 180 by pressure cycles in line 108 to move the travel stop 142 in as many desired increments to the new position needed for the valve to be in when it is made to open with a pressure cycle in line 100 .
FIG. 9 shows the parts in position with no pressure applied to lines 100 and 102 and springs 150 and 152 keeping pins 134 and 136 on piston 118 respectively out of j-slots 138 and 140 . In FIG. 10 pressure has been applied to line 100 to engage pin 134 with j-slot 138 while compressing return spring 150 . In FIG. 11 , the pressure is removed from line 100 and a neutral position for both pins 134 and 136 out of their respective j-slots is assumed with spring 150 now relaxed. Finally in FIG. 12 pressure is applied to line 102 causing pin 136 to engage j-slot 140 to turn travel stop 142 in direction 180 .
The present invention provides for a movable travel stop that allows incremental opening of the valve by sequentially shifting a travel stop while using hydraulic pressure to cycle the insert sleeve 18 against it. Cycling in sequence from fully closed to fully open can be accomplished in a series of pressure cycles delivered through line 100 . At any time applying pressure to line 102 will force the valve to close. If the very next pressure cycle is in line 100 then the valve will resume the open position it had before it was closed. If the next pressure cycle or cycles after the initial cycle in line 102 is one or more additional cycles in line 102 , then the valve will not open but each cycle will bring the travel stop 142 further from surface 148 so that the next time pressure is cycled to line 100 will result in the valve opening but to a position that is not as open as it was when it was closed initially. The pins 134 and 136 that drive their respective j-slots 138 and 140 are preferably spring loaded so that they can exit their respective j-slots without driving their respective j-slots in a direction opposite to the respective intended drive direction.
While the travel stop 142 is shown to be adjusted using a thread 144 a j-slot can also be used to shift its position as piston 118 moves back and forth. While the control system is shown for use in the preferred embodiment for use with a choke it can be used with other downhole tools that operate by a series of discrete movements to accomplish a task downhole.
It is to be understood that this disclosure is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended other than as described in the appended claims.
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A hydraulic control system can be used on a downhole choke and has the feature of moving a travel stop for a sliding sleeve using discrete j-slot mechanisms for selectively moving the stop in either one of two opposed directions. The valve can be incrementally opened further with pressure cycling on an opening chamber. The valve can be immediately put to the closed position with pressure on a closing chamber. After closing, the valve can assume its former open position or other selected less open positions by reconfiguring the travel stop while the valve stays in the closed position In order to achieve a higher open percent after closing, one or more pressure cycles must be applied to the open chamber after the valve is reopened to the position it was in before it was closed.
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BACKGROUND OF THE INVENTION
This invention relates generally to interlocked multiple-member composite structures and more particularly to the field of art of various shaped articles of bar shape each formed by mechanically joining at least an outer member and an inner member into a unitized structure. Examples of such structures are: screw seats or washers and seal rings of parts of mechanical apparatuses and devices; tubular structures such as steel pipe piles for architectural foundations; and column-form structural materials having cross-sections of shapes such as a circle, angle, and H-section.
More specifically, the invention concerns composite bar structures of interlocked multiple members, each bar structure comprising, for example, an aluminum alloy tubular outer member and a column-shaped inner member or core of a metal such as steel, the outer and inner members being joined mechanically at their mating interface in an interlocking manner to produce an integral bar structure. A method of producing the bar structures comprises forcibly stratifying the tubular outer member relative to the inner member which has been provided on its surface in its longitudinal and circumferential directions with a large number of projections formed integrally thereon by a process such as rolling, whereby the projections on the inner member engage interlockingly with corresponding recesses thus formed in the inner wall surface of the outer member to form a unitary bar structure.
The outer and inner members can be thus joined by a plastic deformation method such as passing the tubular outer member, with the inner member positioned therein in a telescope state, through a die by drawing or extruding, thereby to cause a shrinkage of its diameter or causing the inner member to undergo an expansion of its diameter.
As is known, spring means for functions such as absorption of vibrations and oscillations are widely used in various machines and apparatuses. For retaining these spring means, spring seats or retainers are used Also, screw or bolt seats such as washers are used for preventing loosening of the screws or bolts. Similarly, seal rings and the like are widely used. In the field of civil engineering and architecture, foundation piles are required for constructing buildings and like structures on weak ground In order to ensure ample strength and durability of such pilings, particularly with respect to corrosion resistance over a long period of time, so-called steel pipe piles and the like are used.
These items of hardware and construction materials are frequently liable to become defective by deformation due to impact, vibration, or thermal behavior with the passage of time. In order to avoid variations with time of the functional capacities of these materials, there is an increasing trend toward the use of multiple-member composite bar structures fabricated by joining unitarily outer and inner members of different materials respectively suitable for their characteristics such as mechanical strength and corrosion resistance. These outer and inner members have heretofore been joined by methods such as explosion pressure bonding and shrinkage fitting.
However, by these known methods of joining, the joining between the outer and inner members at their interface is a metallurgical bonding or a smooth pressure joining. As a consequence, in the case of repeated thermal action over a long time or the application of a great load, slippage may occur between the outer and inner members in the longitudinal or circumferential directions, whereby the structure can no longer perform as originally designed Furthermore, a large number of process steps are required in the production of these known structures, and the control and management of these steps are considerably complicated. As a result, the production cost of these known structures becomes high.
SUMMARY OF THE INVENTION
It is an object of this invention to overcome the above described problems encountered in the prior art with regard to composite bar structures for articles such as screw seats and washers, spring retaining seats, and steel tube piles, and to the production thereof by providing improved bar structures of interlocked multiple members. The improved bar structures can be produced at low production cost, including low labor cost, and the respective characteristics of the multiple members are fully and advantageously utilized. The original performance and functional capacity of each bar structure are preserved unchanged with the passage of time, and by providing a method of producing these bar.
According to this invention, there is provided a composite bar structure comprising at least an outer member and an inner member, these members extending parallelly in the longitudinal direction of the structure and being joined together mechanically at an interface therebetween by the interlocking of a plurality of projections formed integrally on one member in the longitudinal and circumferential directions with respective recesses formed in the other member at the interface over the entire expanse thereof. In a particular form of the composite bar structure, each of the projections has at its distal end an overhanging head which interlockingly fits into a corresponding recess in the other member, whereby an anchor bond is obtained between the joined members.
Such composite bar structure composed of at least outer and inner members extending parallelly in the longitudinal direction of the structure and joined together mechanically at an interface therebetween is produced by a method that comprises forming a plurality of projections or, alternatively, recesses on the surface of the inner member in the longitudinal and circumferential directions thereof integrally therewith, preparing the outer member in a tubular shape to readily encompass the inner member, relatively positioning the members to place the inner member within the outer member in a telescoped state, and applying on the outer member a constrictive compressive force to cause the same to undergo plastic deformation and reduction in diameter, thereby to cause interlocking engagement of the projections or recesses with respective recesses or projections, whereby the members are joined tightly to form the integral composite bar structure.
The nature, utility, and further features of this invention will become more clearly understood from the following detailed description with respect to preferred embodiments of the invention when read in conjunction with the accompanying drawings, briefly described below.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a cross section of one example of the composite bar structure according to this invention;
FIGS. 2 and 3 are longitudinal sections respectively taken along the planes indicated by lines 2--2 and 3--3 in FIG. 1;
FIG. 4 is a cross section of another example of the composite bar structure of the invention;
FIG. 5 is a longitudinal section of the structure shown in FIG. 4;
FIGS. 6 and 7 are perspective views respectively showing examples of practical forms of the composite bar structure;
FIGS. 8 through 15 are cross sections respectively showing other examples of the composite bar structure of the invention;
FIG. 16 is a side view indicating a process of rolling an inner member with flat dies to form projects on the surface thereof;
FIG. 17 is a plan view orthogonal to FIG. 16 with one die removed;
FIG. 18 is a side view indicating a process of rolling with flat dies an inner member to have overhang parts on its projections;
FIG. 19 is a plan view orthogonal to FIG. 18;
FIG. 20 is a longitudinal section taken along the plane indicated by line 20--20 in FIG. 18;
FIG. 21 is an end view of an inner member which has been rolled to form projections;
FIGS. 22 and 23 are longitudinal sections respectively taken along the planes indicated by lines 22--22 and 23--23 in FIG. 21;
FIG. 24 is a side view indicating a process of producing by rolling projections with overhangs on an inner member;
FIG. 25 is a plan view orthogonal to FIG. 24;
FIG. 26 is a longitudinal section taken along the plane indicated by line 26--26 in FIG. 24;
FIG. 27 is a longitudinal section of an inner member to be inserted into an outer member;
FIG. 28 is a partial perspective view of the same inner member;
FIG. 29 is a cross section of the same inner member;
FIG. 30 is a longitudinal section showing an outer member to fit around the inner member in a telescoped state;
FIG. 31 is a cross section of the same outer member;
FIG. 32 is a longitudinal section indicating the manner in which the outer member shown in FIG. 30 is caused by its being drawn through a die to undergo plastic deformation and contraction of diameter relative to the inner member shown in FIGS. 27, 28, and 29;
FIG. 33 is a cross section of the composite bar section which has been fabricated as a unitary structure by the process indicated in FIG. 32;
FIG. 34 is a longitudinal section of an inner member having projections with overhanging heads formed at their tips;
FIG. 35 is a longitudinal section of an outer member to fit around the inner member shown in FIG. 34; and
FIG. 36 is a longitudinal section indicating the manner in which the outer member shown in FIG. 35 is caused by its being drawn through a die to undergo plastic deformation and contraction of its diameter relative to the inner member shown in FIG. 34.
DETAILED DESCRIPTION OF THE INVENTION
The composite bar structure 1 of interlocked double members as shown in FIGS. 1, 2, and 3 constitutes a basic embodiment of this invention and can be used for parts such as various rotor shafts of machines and other devices. This structure 1 comprises a tubular outer member 2 made of an aluminum alloy and a steel inner member or core 3 interlocked therewith. These two members 2 and 3 are mechanically and integrally joined by the tight engagement of a large number of pin-like projections 5 formed integrally with and radiating from the entire cylindrical surface of the core 3 in a plurality of recesses 4 formed in the inner wall surface of the outer member 2.
Therefore, when this bar structure 1- of interlocked double members is used as a shaft or spindle, it possesses high resistance with respect to oscillations and vibrations in its axial and circumferential directions during operation. Thus there is no possibility of slippage, shearing, deformation, or other adverse consequences.
In a modification of the above described example as illustrated in FIGS. 4 and 5, the projections 5a, projecting radially outward from the entire cylindrical surface of the core 3 respectively have Tee-shaped heads at their outer ends, which form overhanging parts that bite deeply into the inner parts of the outer member 2. By this interlocking mode, the resulting integral structure 11 has a high resistance relative to slippage, shearing and deformation in the radial direction arising from causes such as thermal expansion at the time of temperature variations.
The example shown in FIG. 6 illustrates a mode of practice of the invention wherein either of the bar structures 1 and 11 described above is cut into pieces 12 of specific short cylinder or ring shape having a bore 31 to serve as screw seats or washers. In the example shown in FIG. 7, the combination of the outer and inner members 13, 32 is reversed, the inner member being made of an aluminum alloy. This structure is suitable for use as a seal ring in machine parts.
FIG. 8 illustrates an example wherein the bar structure 14 is in the shape of a column of square cross section. This bar structure 14 comprises an aluminum alloy outer member 2a of tubular shape of a square cross section and an inner member or core 3a of square column shape interlockingly and coaxially fitted in the outer member 2a. These two members 2a and 3a are tightly and unitarily joined together by the mechanical interlocking of a large number of projections 5 of the core 3a and respective recesses 4 in the outer member 2a similarly as in the above described examples. Thus, relative slippage, shearing or deformation between these two members is prevented.
In another mode of practice of the invention as illustrated in FIG. 9, the bar structure 15 has the cross section of an angle member in which both the outer member 2a and the inner core 3a have L-shaped cross sections. Similarly as in the preceding examples, these outer and inner members 2a and 3a are tightly and integrally joined together by the mechanical interlocking of projections 5 of the core 3a with respective recesses 4 in the outer member 2a.
In still another mode of practice as shown in FIG. 10, the bar structure 16 is in the form of an H-beam comprising an outer member 2a and a core 3a mechanically joined by the interlocking of projections 5 similarly as in the preceding examples. In a further mode of practice as shown in FIG. 11, the bar structure 16a comprises an aluminum outer member 2a of flower-shaped outer contour in cross section and a steel core 3a of circular cross section, which are interlockingly joined as in the preceding examples. These bar structures described above and shown in FIGS. 8 to 11 are suitable for various uses such as structural materials for architectural construction and foundation piles.
FIGS. 12 and 13 illustrate applications of this invention to tubular bar structures 17 and 18 respectively of circular and square outer contours in cross section with longitudinally extending hollow interiors of respective circular and square cross sections. These structures also comprise outer members 2b and inner members or cores 3b, which are integrally joined similarly as in the preceding examples.
Further examples of application of the invention are shown in FIGS. 14 and 15. The outer members 2b of these bar structures 19 and 20 have circular outer contours in cross section. The core 3b of the bar structure 19 has a triangular cross section, while the core of the bar structure 20 comprises two spaced-apart and parallel inner members 3c, each of rectangular cross section. In each of these bar structures 19 and 20, the outer member and the core are integrally joined as in the preceding examples.
The bar structures of interlocked double members of the above described construction are produced as described below with reference to FIGS. 16 to 36.
First, as shown in FIGS. 16 to 20, a cylindrical inner or core member 3 of circular cross section is rolled between planar rolling dies 23 and 24 having on their working surfaces longitudinal grooves 21 and transverse grooves 22 formed with a slight inclination, thereby to form pin-shaped projections 5, in a helical pattern on the cylindrical surface of the core member 3.
A core member 3 formed in the above described manner has grooves 25 formed between the projections 5 as shown in FIGS. 21 and 22. Then, by imparting a pressing and upsetting action to the tips of all projections 5 of the core 3 by means of flat dies 23a and 23a with smooth working surfaces as shown in FIGS. 24 and 25, a core member 31 having projections 51 with T-shape overhanging heads at their tips can be produced by rolling. The inner core 3 or 31 can also be produced by an extruding process or a die drawing process.
The inner core 3 or 31 fabricated in the above described manners is then mechanically joined to a tubular outer member 2 to form a unitary bar structure as described below.
A tubular outer member 2 as shown in FIGS. 30 and 31 of an inner diameter greater by a specific allowance than the outer diameter, including the projections 5, of the core 3 as shown in FIGS. 27, 28, and 29 is prepared. Then, as shown in FIGS. 32 and 33, this outer member 2 and the inner core 3 are placed in a relatively superposed or telescoped state, and, by means of a suitable die device such as squeeze rollers, the outer member 2 is pressed inward from the outside to be pressed against the outer surface of the core 3, thereby to undergo plastic deformation and contraction of diameter. As a consequence, the projections 5 of the core 3 are thrust in by a biting action into the inner wall surface of the outer member 2 as shown in FIG. 33, whereby the two parts are interlockingly joined into an integral bar structure 1 as shown in FIGS. 1, 2, and 3.
In the case of an inner core 31 formed to have projections 51 with overhanging head parts at their tips, this core 31 and an outer member 2 of an inner diameter greater by a specific allowance than the outer overall diameter of the projections 51 as shown in FIGS. 34 and 35 are placed in a mutually superposed state. Then, as shown in FIG. 36, one end of the outer member 2 is clamped by a clamper 61 and drawn in the direction of the arrow to cause the outer member 2 to pass through a stationary die 62 and thus undergo plastic deformation to be constricted in diameter, thereby imparting a squeezing action relative to the core 31. As a consequence, the projections 51 are forced to bite into the inner surface of the outer member 2, whereby the two members 2 and 31 are mechanically joined into a unitary bar structure as shown in FIGS. 4 and 5.
The above described process can be applied to produce bar structures of various kinds some of which are shown in FIGS. 8 to 15. While the invention has been described above with respect to examples of bar structures each comprising two members joined integrally together, it will be evident that the principle of the invention is applicable equally to bar structures comprising more than two members. Furthermore, prior to the process step of mechanically forcing the outer member to contract in diameter against the inner or core member, a suitable industrial adhesive or an anticorrosive composition for preventing electrolytic (galvanic) corrosion can be applied to the respective surfaces of the two members to be interlockingly engaged along the interface therebetween.
Because of the construction of the bar structure of this invention, wherein an outer member and a core member have been joined in an interlocking manner to form a unitary structure as described hereinabove, the bar structure is suitable for a wide range of applications such as screw and bolt washers, seal rings, and steel pipe piles for construction work. An advantageous feature of the bar structure of the invention is that it has strong resistance to deformation such as relative slippage between the outer and inner members in the circumferential direction or the longitudinal direction due to vibrations, oscillations, or thermal action during use. Thus the original performance and functional capacity of the bar structure can be preserved indefinitely with the passage of time. A still further advantage afforded by this invention is that the process as described above of producing the bar structures requires less process time (man-hours) than known processes such as explosive forming or explosion pressure fitting and shrinkage fitting. Moreover, the process can be carried out at lower cost to produce a stronger joint between the outer and inner members.
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A composite bar structure is composed of at least outer and inner members extending parallelly in the longitudinal direction of the structure and joined mechanically at an interface therebetween in an interlocked. The structure is fabricated by forming a plurality of projections on the inner member over the entire interface, preparing the outer member in a tubular shape to readily encompass the inner member, relatively positioning the members to place the inner member within the outer member in telescoped state, and applying a constrictive compression force on the outer member so that it undergoes plastic deformation and reduction in diameter, whereby the projections bite into the inner surface of the outer member. The members are thus joined tightly to form the integral composite bar structure.
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BACKGROUND OF THE INVENTION
As a result of the energy crisis, considerable attention has been lately directed to the utilization of solar heat collectors. Predominantly the apparatus that is used is mounted on the roof of a dwelling or building and very little attention has been given to the utilization of heat exchangers installed on vertical building walls, and more particularly doors or other movable openings into a building.
In the prior art the principal attention that has been given to the utilization of solar heat collectors, particularly of the air exchange type, has been collectors that mount on roofs of buildings. Examples of this type of apparatus are seen in the Koizumi et al patent U.S. Pat. No. 4,108,155. In utilizing solar collectors in walls, the only prior art known is seen in U.S. Pat. Nos. 4,068,652 and 4,050,443, and in French Pat. No. 2,303,250. The prior art, however, is singularly lacking in a solar collector heat exchanger which is adapted to be used in movable openings through the walls of a building.
SUMMARY OF THE INVENTION
A solar collector for a removable panel or door in a building is provided which consists essentially of an outer flat metallic sheet, preferably formed from a heat conductive material, such as copper or aluminum, and whose outer surface is blackened for heat absorption purposes. This flat metallic sheet is secured to a vertical panel, such as a door, over an area which has been hollowed-out to form a cell. The cell has communication with the interior of the building by upper and lower openings therein and the cell may be provided with baffles therein in order to slow down the flow of air therein and create a mild turbulence. In order to provide the proper efficiency to the heat exchange or panel, a heat trap formed of transparent material will transmit the solar radiation is supported in spaced relationship to the heat exchanger plate.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the panel constructed in accordance with the invention installed on a movable opening in the side wall of the building;
FIG. 2 is a central sectional view through the movable opening shown in FIG. 1;
FIG. 3 is a rear view of the panel;
FIG. 4 is a central sectional view of a modified form of the invention;
FIG. 5 is a sectional view of a panel of a door that may be made from metallic material that is complete;
FIG. 6 is a rear elevational view showing baffles that may be used with any of the preceding embodiments.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1 there is shown a portion 10 of a building through which a framework 12 is fitted and into which there is illustrated a door, generally designated 13, that is hinged to the framework in a manner well known to those skilled in the art. As seen in FIG. 2, the door may comprise a solid door and through the solid door there is cut an upper opening 15 and a lower opening 16. On the front face 14 of the door, there is fastened a frame 18 that includes a bottom, side and top sections and to the frame there is affixed a metallic plate 20 which may be further secured to the frame 18 by molding 22. Over the molding there may extend and be fastened thereto a heat trap 24 made of any transparent or semi-transparent material such as glass, fiberglass or the like that is sealed to the molding 22. The outer facing surface of the plate 20 is blackened to impart heat absorbing properties thereto, any conventional blackening material being suitable such as the various coatings that are available. The openings 15 and 16 are preferably covered with louvers 25 and 26 seen best in FIG. 3, and it will be apparent therefore that there is formed between the front face 14 of the door and the metallic plate 20 a cell which is herein designated by the reference numeral 28.
Referring to FIG. 4 of the drawings, a modified version of the solar heat collecting apparatus is disclosed in which the door 13' has been specially constructed with a recess or cell 28', there being upper and lower openings 15' and 16' that lead into the cell. The door 13' can be made of a variety of materials including metal and to the front surface 14' thereof, there is suitably affixed a metallic plate 20' which seals the cell 28'. In order to provide a suitable heat trap, this type of door configuration may be provided more effectively with the usual storm door generally designated 30 which has transparent or glass panels 31, 32 therein that allow the transmission of solar energy. The storm door may be fitted over the frame 12' into which the door is set in usual fashion, sealing to the framework and by the utilization of gasketing at the bottom or sill portion will be substantially air sealed to the sill. In this fashion solar energy can pass through the panels 31 and 32 and impinge upon the plate 20'.
Referring now to FIGS. 5 and 6 of the drawings, there is shown a still further modification of an arrangement where a specially constructed door 13" is provided with a built-in cell 28" which is made by recessing out a substantial portion of the door, and in like fashion to the previous embodiment a metallic plate 20" is suitably set into the door to be substantially flush therewith and in sealing engagement so as to close off the cell 28". In order to provide suitable heat trap, a framework 18" extends about and over the entire plate 20" area and affixed to the framework is a heat trap made of transparent or semi-transparent material that is designated 24". In this particular arrangement a number of air deflecting devices in the form of baffles such as are designated 40, 41, 42 and 43 have been provided, their arrangement being somewhat oblique to the general longitudinal extent of the door panel. As seen better in FIG. 6, these members are arranged so that as air rises from the bottom of the panel to the top of the panel it is forced to follow a turbulent or tortuous path. The door 13" is also fitted with a lower opening 16" and an upper opening 15" and over the opening 16" there is fitted an electric fan 45 which will force air into the cell area 28", there being a register 25" fitted over the opening 15".
The operation of the device will be readily apparent from the brief description above, it being understood that the panel should generally face in a southerly direction so that solar rays will be directed onto the heat trap 24 and thence on to the metallic plate 20 where the ultraviolet rays are and other solar energy is absorbed by the black coating over the metallic panel 20. Cold air will be naturally drawn into the opening 16, either naturally or by the fan 45, and will pass upwardly through the cell 28 where it is heated and then will be discharged through the opening 15 at the top of the panel. It will be further apparent that there is an advantage to a vertical panel or door type installation which has a normal vertical attitude in view of the fact that a chimney effect takes place where air will naturally flow in through the lower opening 16 and out the upper opening 15.
In some instances, the combination of the FIG. 2 arrangement with a glass door 30 will enhance the operation as a further insulating area is provided between the door 30 and the heat trap 24.
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A vertically-oriented solar collecting apparatus primarily for installation in the wall of a building is disclosed in which the panel has a heat collecting plate spaced therefrom and covering an open cell formed in the panel which has lower and upper openings communicating therewith. The cell may be provided with deflecting devices to create turbulence within the cell and the panel has a cover thereover capable of passing the sun's heating rays and forming a heat trap.
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BACKGROUND OF THE INVENTION
The invention relates to a hoisting hook assembly comprising a block with a hoisting element which consists of a shaft with attaching parts for the load ropes, which shaft is capable of rotation about a vertical axis and is supported in the block. Such an object is known in several variations and is used for hoisting large and medium large objects.
Very heavy and large-sized loads such as drilling platforms or their parts have as a rule a rectangular form. It is then usual to work with four load ropes, which ropes are fastened near the four angular points. Sometimes eight load ropes with attaching parts are used on the two long sides. Each rope ends in a loop or sling, and in the case of four ropes being used, around each of the four hooks of the hoisting element one of the slings is tied.
It is evident that the distribution of the load over the four load ropes depends entirely on the correct lengths of the four ropes. If the four taut ropes do not meet in one point, the load will, theoretically, be carried by two diagonally opposite load ropes. The elastic elongation of the ropes provides a very limited adaptation, but the latter is unreliable and, moreover, cannot be truly verified. Therefore, it is possible that that two load ropes might substantially carry the whole load. The strength and hence also the thickness of the load ropes should therefore be chosen carefully, which in the case of the very heavy loads referred to above leads to great difficulties.
SUMMARY OF THE INVENTION
The invention refers to a hoisting hook assembly aiming at obtaining a good and reliable distribution of the load with four or more load ropes.
A further object of the invention relates to the possibility of checking visually the degree of inequality of the individual rope loads in a simple way. According to the invention the shaft of the hoisting element is provided with at least two anchor-like devices capable of swinging about a central axis lying in a plane which is perpendicular to the shaft, the free ends of the anchor-like devices forming attaching parts. These features permit an additional degree of freedom, enabling the load distribution aimed at to be realized, in consequence of which it will as a rule suffice to reduce the dimensions of the load ropes to 1.2 times the nominal load calculated instead of twice, as is the case with the four-arm hoisting hook.
The invention enables more than two anchor-like devices (for instance three) to be pivotally connected to the shaft of the hoisting element in the case of hoisting a triangular or hexagonal object. Since most loads are formed by rectangular objects, the hoisting hook assembly according to the invention is preferably so constructed that the shaft of the hoisting element is provided with a central carrying element to which two swinging anchor-like devices are connected by way of mutually parallel hinge pins.
The invention further refers to a method for hoisting a load with the help of more than three load ropes, using a hoisting hook assembly indicated above. According to this method when picking up the load, one checks the angular position of the shafts of the anchor-like devices with respect to the direction of the corresponding load ropes, and one does not proceed to hoisting before the included angles are approximately equal. Consequently, this affords a visual check, which can further be facilitated if in the hoisting hook assembly according to the invention a bar is fixed at the bottom of each swinging anchor-like device in line with its axis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view, showing an embodiment with two swinging anchor-like devices, each with two hooks that can receive a loop or sling;
FIG. 2 is partially a view and partially the cross-section of the hoisting element in FIG. 1 according to the line II--II in that figure;
FIG. 3 is a view, similar to that of FIG. 1, of an embodiment comprising swinging anchor-like devices which receive the middle part of a continuous load rope;
FIG. 4 is partially a view and partially the cross-section of the hoisting element in FIG. 3 according to the line III-IV in that figure;
FIGS. 5 and 6 represent diagrammatically the top view and the side view of the arrangement of the load ropes and the forces involved;
FIG. 7 shows on an enlarged scale the middle part of FIG. 5, a possible small deviation from the ideal situation being represented exaggeratedly;
FIG. 8 is a variant of the hoisting element from FIG. 3, enabling hoisting processes with eight ropes by using four continuous ropes.
DETAILED DESCRIPTION
As shown in FIGS. 1 and 3, the hoisting hook assembly consists of a block 1 provided with a hoisting element 2 made up of a shaft 3 and attaching parts 4, for the load ropes 5. Shaft 3 is in the usual manner rotatable round a vertical axis supported in block 1. Further, the shaft is capable of turning slightly around a horizontal axis owing to the shaft being mounted in hinged piece 6 provided with two lateral pins 7. Block 1 is furthermore provided with two rope pulleys 8 and 9 accommodating the hoisting cable 10. Thus far the hoisting hook assembly largely corresponds to the prior art situation.
Whereas in a well-known hoisting hook assembly the attaching parts 4 for the ropes 5 are permanently fixed to shaft 3 of the hoisting element 2 and form one whole with it, the shaft of the hoisting element according to the invention is provided with at least two anchor-like devices 11 that are capable of swinging around a center line lying in a plane perpendicular to shaft 3. The free ends of these devices form the attaching parts 4 for the load ropes 5. To this end, shaft 3 of the hoisting element 2 is provided with a central carrying element 12 to which the two swinging devices 11 are connected by means of two interparallel hinged shafts 13.
In the embodiment according to FIGS. 1 and 2 each anchor-like device 11 consists of a shaft 14 having two hooks 15 for the sling 16 of a load rope 5. Each device 11 is rotatable round the centre line of its shaft 14. To this end, the shaft 14 of each device 11 is fixed to a head 18 by means of screw thread 17, the head 18 being hinged to hoisting element 2. Between the shaft 14 and the head 18 means of limiting to less than 90° the rotation of each shaft round its center line are present. Such means may, for instance, consist of a lateral pin-shaped projection 26 of the shaft 14, which projection may operate together with two stops 27 on the head 18.
There are a few remarkable points of difference between the hoisting hook assembly according to FIGS. 1 and 2 on the one hand and the embodiment according to FIGS. 3 and 4 on the other. One instance is that in the latter embodiment each attaching part 4 of a swinging anchor-like device 11 is designed as a doubly curved sliding saddle 19 in which a continuous load rope can slide. Another point of difference of the embodiment according to the FIGS. 3 and 4 with respect to the embodiment according to the FIGS. 1 and 2 is that in the latter design the shaft 3 of the hoisting element 2 is provided at its upper end, with screw thread in the usual manner, and onto this a nut 20 is screwed which rests on a rolling bearing 21. In the embodiment according to FIGS. 3 and 4 on the other hand, the central carrying element 12 is no longer whole with the shaft 3, but is an individual element provided with a hole with internal screw thread. The shaft 3 of the hoisting element 2 is designed as a bolt whose screw thread works together with the thread inside the carrying element. The head 22 of the bolt rests on the rolling bearing 21. This separation of the shaft 3 with respect to the central carrying element 12 enables the shaft to be designed as a bolt, which makes possible the manufacture from a high-alloy forged steel. This enables the diameter of the shaft 3 to be made smaller, which may produce a reduction of weight. As a consequence of this smaller thickness of the shaft 3 a smaller rolling bearing 21 can be applied, which brings about a saving of cost.
For hoisting with eight load ropes the embodiment according to the FIG. 8 is used. In it, each anchor-like device is provided with two hinged sliding saddles 19, the hinge pins 23 crossing the hinge shafts 13 perpendicularly. In each saddle 19 a continuous load rope is used. Each of the four "double" load ropes 5 then acts as attached individual ropes. The continuous rope 5 is capable of sliding through the saddle 19 as soon as the ratio of the forces in both parts of the rope exceeds the familiar ratio , where μ represents the friction coefficient and α the bearing arc length in radials. In actual practice this value will lie between 1.4 and 1.6. Consequently a large difference between the rope forces will automatically equalize in a great measure.
It is observed that the various types of swinging anchor-like devices 11 maybe screwed into the heads 18 so that the anchor like devices may be combined as desired. Thus a swinging anchor-like device with hooks may be used (FIG. 2) in combination with a swinging device, with sliding saddle (FIG. 4). Further it may be remarked that with reference to the system of forces to be discussed later with the help of FIGS. 5-7, the hinge pins 23 from the embodiment according to FIG. 8 are to be considered equivalent to the part of each sling 16 of FIG. 2, resting on the acting surface of the hook 15.
The operation of the hoisting hook assembly according to the invention is represented idealized in the FIGS. 5 and 6. In these Figures it is assumed that the center lines of two ropes attached to one anchor-like device intersect in the axis of the shaft of the device. In FIG. 5 the right hand ropes are exactly equal in length the left-hand ones differing a little in length. The hoisting hook assembly now rotates about its vertical axis until the resultant of the load-rope forces passes through the axis of the central carrying element 12. The ratio of the rope forces is now visible from the direction of the shaft 14 with respect to the load ropes 5. This is evident from the parallelogram of forces in FIG. 5. If there is a sliding saddle 19 instead of a double hook 15, then the continuous rope 5 will continue to slide until the ratio of forces equals e.sup.μα .
FIG. 7 represents the situation of the middle part of FIG. 5 on an enlarged scale, and shows in an exaggerated manner the direction of the forces when the center lines of the ropes 5 meet outside the axis of the shaft 14. The resultant of the rope forces then exerts a relatively small bending moment on the shaft of the anchor-like device and the hinge shafts 13. In addition, the shafts 14 will rotate about their axes until the center lines of the ropes attached to an anchor-like device lie in one plane. Finally, the line of intersection of the two rope planes passes through the point of intersection of the center lines of the two shafts 14. From a comparison between FIGS. 5 and 7 it appears that the actual situation (represented in FIG. 7 exaggeratedly) of the distribution of forces can be somewhat more unfavorable than the idealized situation of FIG. 5. It is noticed that in the situation of FIG. 5 the rotatability of the shafts 14 of the swinging anchor-like devices 11 with respect to the heads 18 is not necessary. Consequently, in cases in which the center lines of the ropes meet in the center lines of the shafts 14, this rotatability can be dispensed with.
In the FIGS. 5 and 6 the load is represented as a rectangular element 24. Further, in FIG. 7 a rod 25 is also shown which is also shown in FIG. 2. The center line of this rod is a continuation of the center line of the shaft 14 of the swinging anchor-like device 11. The presence of this rod facilitates the visual verification of the measure of inequality of the individual rope loads. It should be remembered that in the case of hoisting very heavy loads such as drilling platforms and the like, cranes with very large dimensions are concerned, in consequence of which the hoisting hook assembly may be situated at a considerable distance of the verifying person. The presence of the rod 25 now makes it possible, in the case of an unfavorable ratio of the rope forces, to take action in good time and perform the required correction of the length of the rope.
An important practical advantage of the invention is that the hoisting hook assembly can be mounted in a simple way in any existing conventional hoisting block. This makes possible a replacement of the conventional hoisting hook by the hoisting hook assembly according to the invention with comparatively little loss of time at little cost.
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A hoisting hook for at least four ropes comprising a block, a shaft rotatably supported in said block and a plurality of anchor-like devices rotatably supported in said shaft, so that sufficient degrees of freedom are created for the ropes to divide the hoisting load equally over the ropes.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 12/427,318 entitled “SHORT RANGE EFFICIENT WIRELESS POWER TRANSFER,” filed Apr. 21, 2009, which claims benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/046,757, filed Apr. 21, 2008, the entire contents of which are herewith incorporated by reference.
[0002] Applicant's previous applications and provisional applications, including, but not limited to, U.S. patent application Ser. No. 12/018,069, filed Jan. 22, 2008, entitled “Wireless Apparatus and Methods”, the entire contents of the disclosure of which is herewith incorporated by reference, describe wireless transfer of power between a transmitter and receiver.
FIELD
[0003] The described technology generally relates to wireless charging, and more specifically to short range efficient wireless power transfer.
BACKGROUND
[0004] The transmit and receiving antennas are preferably resonant antennas, which are substantially resonant, e.g., within 10% of resonance, 15% of resonance, or 20% of resonance. The antenna may be of a small size to allow it to fit into a mobile, handheld device where the available space for the antenna may be limited. An embodiment describes a high efficiency antenna for the specific characteristics and environment for the power being transmitted and received.
[0005] One embodiment uses an efficient power transfer between two antennas by storing energy in the near field of the transmitting antenna, rather than sending the energy into free space in the form of a travelling electromagnetic wave. This embodiment increases the quality factor (Q) of the antennas. This can reduce radiation resistance (R r ) and loss resistance (R l ).
[0006] The inventors noticed that many of the solutions raised by this system include power delivery at a distance, for example power delivery over inches or feet from a power transmitter to a receiver. The techniques disclosed in our co-pending applications allow delivery of power at reasonable efficiencies, for example between 3 and 5 feet, for example, and efficiencies from 5 to 40%.
SUMMARY
[0007] However, it was noticed that many users and/or manufacturers would actually prefer higher power-delivery efficiencies, and are willing to accept this power delivery at short distances. For example, many would prefer a power delivery solution which was over 90% efficient, even if that power delivery solution was less convenient to use. The inventors noticed that the resonant which have been used for delivery of power at a distance, could actually be used to produce very high efficiencies when used in a close contact situation.
[0008] An aspect describes a magnetically coupled resonance system, that includes a first pad surface against that accepts devices to be provided with power. The device uses the magnetically coupled resonance to provide power at a first efficiency of power transfer to devices on the pad surface. Power is provided at a second efficiency of power transfer, lower than the first efficiency, to other devices that are not on the first surface, e.g., devices that are remote from the pad by e.g., less than 12 inches or less than 3 feet.
[0009] The devices and pad can each use magnetically resonant circuits with antennas formed of an inductor formed by a coil, and a separate capacitor, tuned to an appropriate frequency.
[0010] The present application discloses use of these techniques to form a wireless desktop. The wireless desktop can be used to charge personal electronic devices such as communications terminals, cellular phones, or computer based peripheral devices these charged devices are either or both of powered or recharged, without wires, using a wireless energy transfer technique.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a wireless desktop with wireless powered items.
[0012] FIG. 2 shows an equivalent circuit.
[0013] FIGS. 3A-3F show single receivers on pads with and without foldouts.
[0014] FIG. 4 shows efficiencies for the single receivers.
[0015] FIGS. 5A-5D show pads with multiple receivers.
[0016] FIG. 6 shows transfer efficiencies for the multiple receivers.
[0017] FIG. 7 shows coplanar field coupling using parasitic.
[0018] FIG. 8 shows a desktop parasitic.
DETAILED DESCRIPTION
[0019] An embodiment uses coupled magnetic resonance using magnetic field antennas. Embodiments may operate at any frequency, but two embodiments may operate either at LF (e.g. 135 kHz) or at HF (e.g. 13.56 MHz), but at short distances. One embodiment uses a loop coil in series with a capacitor as the antenna. In one embodiment, the receiver part (e.g., the portable device) is intended to be placed directly on the pad. In this embodiment, there is a relatively small, fixed distance between the transmitter and receiver. That fixed distance, for example, may be set by the thickness of the material of the pad and the material of the housing. This may be less than a centimeter or less than 10 mm, between the coils forming the transmitter and receiver. The distance will be constant, so the item is always the same distance from the antenna when pressed against the pad.
[0020] That fixed distance is dependent on the geometry of the pad and the geometry of the charged item. In the embodiment, the antenna can be tuned to have a maximum response at that constant distance. This tuning, as well as other tuning operations described in this specification, can be calculated and then optimized by trial and error, for example.
[0021] However, unlike other close-charging systems, this system can also charge items which are located at a distance, e.g., inches or feet from the antenna. The antenna is less efficient when charging at a distance, but will still provides power at that distance. That allows charging of items that are not directly placed on the charging pad—unlike pure inductive systems which provide in essence no charge at all other than at the very specific fixed distance and/or orientation.
[0022] This produces certain advantages, including the ability to use less precision in the placement of the device on the charging pad. Even if the device is placed off the pad, it will still receive charging at a lower level from proximity. The lower level charge can be, for example, between 0.05 watts and 0.25 watts, for example, even when the device is not precisely placed on the pad.
[0023] To utilize desktop space efficiently and to reduce desktop wiring, the antenna of the power transmitter/power base may be incorporated into a host device that normally exists on a desktop. Embodiments describe that host device as including either a PC monitor or a lamp, but can be any other item, such as a printer, scanner, fax machine, telephone, router, or the like.
[0024] The transmitter unit may be powered directly from the 110/230 VAC supply already existing in this host device, thus not requiring an extra power cord or power connection.
[0025] In one embodiment, as shown in FIG. 1 , the transmit antenna is embedded in the pedestal 104 of a PC monitor screen 100 or in the pedestal 112 of a desk lamp 110 . The pedestals may be disk-shaped, to house a circular wire loop antenna generating a symmetric magnetic field. This field is mostly vertically polarized at any position on the desk, in the plane of the antenna loop. This embodiment favors coplanar orientation of antenna loops integrated in wireless-power-enabled devices; that is, the best power-transfer will be obtained when a loop coil in the receiving device is oriented in a substantially parallel plane to a loop coil in the transmitting device. The surface of the charging base may be substantially parallel with the coil, so that the coplanar relationship can be maintained. FIG. 7 illustrates how the coplanar operation can extend to all the items on the desktop.
[0026] This coplanar orientation can be used, for example, for wire loop antennas integrated into keyboards, mouse devices, and into many other electronic devices such as mobile phones, MP3 players, PDAs, etc. if placed in the usual manner. This may, however, be used in other applications.
[0027] In another embodiment, there may be more than one power base on a desktop as shown in FIG. 1 . Power is supplied from the base that is closest to the receiving device or from multiple different sources.
[0028] Each power base may also provide an area to place devices directly on the wire loop antenna, resulting in strongest coupling, thus enabling high power transfer at high efficiency. This close proximity coupling is attained by providing a surface 105 , for example, adjacent the charging coil. In this embodiment, more than one device may be placed on such a charging pad surface 105 . This has the other advantage of allowing a larger coil for the transmitting, which also provides improved efficiency.
[0029] Low power devices with long battery autonomy, such as a keyboard or a computer mouse, may be placed in the proximity or vicinity of a power base to charge by proximity coupling. Available power and transfer efficiency for these devices will be lower than for the fixed distance coupling. However, these devices may be constantly charged, and intermittently used. Hence, these devices do not require continuous charging. In one embodiment, the amount of charging may be reduced when other devices are additionally placed on the charging pad, because the multiple devices may more heavily load the system than a single device.
[0030] Magnetic field strength in the vicinity of a power base will preferably be below safety critical levels. The power base may additionally provide a function to automatically reduce magnetic field strength if a person is approaching. This function may use infrared or microwave person detection 108 . This can be a proximity detector, e.g., one that can be activated by user proximity.
[0031] A first embodiment actuates the proximity detector manually. Persons that feel uncomfortable in presence of magnetic fields can turn on the function. This function will can also cause devices in the vicinity to stop receiving power during the time when persons are in proximity. This may use, for example, an IR detector to detect the presence of persons.
[0032] Another embodiment may always have the proximity detector active and automatically turn off the function when
[0033] Other devices such as cordless phones, digicams, etc. may be placed on a charging station. This allows the wireless power receiver and its antenna to be made an integral part of the recharging station. A charging station may provide more area and/or space to integrate an efficient power receiver other than the portable device itself. For example, this may use electrical contacts, or by using a wireless technique or a wireless parasitic antenna, as described herein. The charging station itself may be configured and used as a power relay or a parasitic antenna that improves coupling between the transmitter and the portable devices which receive the charge.
[0034] In an embodiment, shown in FIG. 1 , there may be a number of different electrically operated devices on a user's “desktop”, which may be items used by a user for work every day. One such item is a monitor 100 for a PC. This operates off power provided by a 110 V connection 102 which plugs into the AC outlet. The 110 V connection 100 provides power for both the operation of the monitor, and also provides the power for the wireless surface 104 that is integrated into the base of the monitor. The charging pad may use the techniques that are described in detail herein.
[0035] Wireless proximity charging may be enabled in the area 105 , which forms a flat surface on the base. According to this embodiment, the wireless proximity charging may be specifically tuned for short distance connections, although it may also operate properly over longer distance connections. Surface 105 may be sized such that devices such as cell phones and PDAs such as 107 may be rested on the surface. While charging is optimized for the area 105 , charging is still carried out in other areas.
[0036] In this embodiment, there is also another charging base as part of a desk lamp 110 . This forms a charging base 112 with an area 113 thereon. As in the 104 charging base, the charging is optimized for carrying out up close proximity charging of items such as 114 using magnetically coupled resonance. It may also charge items that are distant from the charging base.
[0037] In addition to charging items such as 114 on the charging base, either or both of the items produces magnetically resonant output power that is coupled to remote devices that are enabled for wireless charging. These remote devices, for example, may include a magnetically resonant antenna therein that is resonant to the same frequency of the transmission. In an embodiment, this may be at 13.56 MHz or at 135 Khz, or at any other frequency.
[0038] The charged devices can include a digital camera 121 , a wireless mouse 122 , and a wireless keyboard 123 . Each of these devices, for example, can include a battery therein, which is charged by the operation of the device.
[0039] An important feature is that an up close charge can be carried out at high efficiency, or a distance charge can be carried out lower efficiency.
[0040] FIG. 2 shows an equivalent circuit of the power transmission system, and illustrates how the efficiency can be calculated. A power source 200 portion includes a power source 205 , for example the AC socket. The power source 205 has an equivalent loss resistance 210 . The loss resistance 210 models the resistance and power conversion losses. Alternatively, the power source can include some parts of the conversion electronics, for example in the case that the power from the power source is changed to some other frequency or some other power value.
[0041] The power source 205 is connected across terminals 215 , to antenna part 220 . Antenna includes an inductor 230 and series capacitance 235 . The LC constant of the inductor and capacitance is tuned to be substantially at the frequency of the source 205 . The antenna also has shows a loss resistance value 235 , which is a parasitic value that represents the transmit antenna losses, including internal losses, external losses, and radiation losses.
[0042] A magnetic field 250 is created in the vicinity of the antenna 230 . This is coupled to the antenna 240 of the receiver. As in the antenna 230 , the antenna 240 includes an inductor 242 capacitor 244 . The inductor and capacitor form a circuit that is resonant with the received frequency that is received.
[0043] Receive antenna losses are shown by the series resistance 246 . The input power P r is connected via the terminals 248 to a load 260 . The load 260 also includes receive power losses 262 shown as a series resistance, which can be modeled as losses in the system.
[0044] These losses can include the power conversion losses as well as series resistance losses.
[0045] Another system can attempt to obtain maximum efficiency in various different scenarios. For example, in one scenario, the transmit antenna can be tuned by changing the capacitance to obtain resonance at the operating frequency in the presence of an unloaded receiver. In an unloaded receiver scenario, the resistance of the load is infinite. Loaded receivers change this resistance. Receiver measurements can also be carried out, by tuning the receiving antenna to change the capacitance etc. in the presence of an unloaded transmitter or in the case of multiple transmitters.
[0046] The different values can be measured. Capacitance value adjustments can be available, for example, for unloaded, moderately loaded (e.g, a single load) or highly loaded systems. Different capacitance values can be dynamically switched to create the highest efficiency value, and to operate with that value.
[0047] FIGS. 3A-3F show different scenarios of charging. FIG. 3A shows a conventional PDA 300 on a large charging pad 305 . In the embodiment, this may be a low-frequency charging pad which may have a 26 cm diameter. Another embodiment may use a PDA 310 which includes a foldout antenna portion 315 . The foldout antenna portion 315 may include a loop antenna that can be folded away from the body of the device to improve the coupling efficiency.
[0048] FIG. 3C shows a small pad embodiment, where the pad 320 is substantially the same size as the PDA 300 . In this embodiment, the pad may be 6×9 cm. FIG. 3B shows how this pad might be used with a foldout embodiment, where the flap 315 fits directly over the pad 320 . A medium pad is shown in FIGS. 3E and 3F . In this embodiment, the medium pad 330 includes the PDA 300 thereon, or a foldout PDA 310 with its foldout flat. The medium pad may be 18 cm in diameter in this embodiment.
[0049] The efficiency results for these devices are shown in FIG. 4 , which shows how the different size devices can be located on the different size pads. Five of the six situations have efficiencies which are greater than 80%. Even the lowest efficiency, created by a large pad with an integrated receiver in the phone, had a transfer efficiency of 50%.
[0050] Another embodiment shown in FIGS. 5A-5D may use multiple receivers all on the same pad. Since the pads, especially the large and medium pads, have sizes that are large enough to physically hold multiple different phones, multiple different devices can be placed all on the pad.
[0051] FIGS. 5A-5D illustrates these different embodiments. In FIG. 5A , the pad 305 includes three PDA phones/devices thereon, shown as 400 , 402 and 404 ; however, the pad may include more or fewer devices.
[0052] In the FIG. 5B embodiment, the devices have foldout antennas, with the devices 510 , 512 and 514 each representing a PDA on the pad, along with its foldout flat against the pad and away from the body of the phone.
[0053] FIG. 5C shows the medium pad 330 with two phones thereon, 400 , 402 , while FIG. 5B shows this same pad with two foldouts thereon 510 , 512 .
[0054] FIG. 6 shows the measured efficiency of this system, with again most of the efficiencies being greater than 80%.
[0055] The efficiency of the system la can be calculated as the input power across the terminals 215 divided by receive power across the terminals 248
[0056] or η a =P r /P t .
[0057] Another embodiment shown in FIG. 8 forms a power relay as a parasitic antenna that improves coupling between energy source and energy sink. The energy source is formed of a resonant antenna 810 , which may be a resonant capacitor and inductor. A parasitic antenna 800 , which may also be resonant at the same frequency, may be used. This parasitic antenna may be expanded to cover a large portion of the desktop area 820 as shown. Such a parasitic loop may either be mounted beneath the desk, or built into the desktop surface, or put on the desk's surface e.g. as a flat structure, such as a desk mat. The parasitic device can be excited by a single and small active power base, and can be used to dramatically improve performance and efficiency of wireless desktop powering and charging in that area.
[0058] Inductive excitation from a small power base may however be a convenient solution since it does not require integration of any part. This becomes particularly true when the parasitic antenna is invisibly integrated into the desktop. FIG. 8 illustrates a large parasitic loop thereby improving the coupling between power base and receiver devices. The parasitic loop can cover an entire desk surface, providing a hot zone throughout that desk surface. The parasitic antenna, in this embodiment, provides passive repeating of power to the entire desktop area.
[0059] The same kind of antenna, in another embodiment, may also be driven directly from a transmitter unit.
[0060] The general structure and techniques, and more specific embodiments which can be used to effect different ways of carrying out the more general goals are described herein.
[0061] Although only a few embodiments have been disclosed in detail above, other embodiments are possible and the inventors intend these to be encompassed within this specification. The specification describes specific examples to accomplish a more general goal that may be accomplished in another way. This disclosure is intended to be exemplary, and the claims are intended to cover any modification or alternative which might be predictable to a person having ordinary skill in the art.
[0062] Also, the inventors intend that only those claims which use the words “means for” are intended to be interpreted under 35 USC 112, sixth paragraph. Moreover, no limitations from the specification are intended to be read into any claims, unless those limitations are expressly included in the claims.
[0063] Where a specific numerical value is mentioned herein, it should be considered that the value may be increased or decreased by 20%, while still staying within the teachings of the present application, unless some different range is specifically mentioned. Where a specified logical sense is used, the opposite logical sense is also intended to be encompassed.
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Method and system for wireless power transmission are disclosed. In one aspect, the system includes a charging base positioned on a desktop component and configured to be positioned on a desktop. The system also includes a transmitter located in the charging base and including a transmit coil wound about a plane, the transmitter being configured to wirelessly transfer power, via a wireless field, from the transmit coil to a first receiver. The system further includes a power relay configured to be positioned on the desktop and configured to relay power received from the transmitter to at least one peripheral device different from the first receiver when the peripheral device is positioned on the desktop.
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RELATED APPLICATIONS
[0001] This application is a Continuation application of, and claims the benefit under 35 U.S.C. §120 of, application Ser. No. 10/430,183 filed on May 6, 2003 entitled METHOD AND SYSTEM FOR AN ONLINE TALENT BUSINESS, which in turn is a Continuation application of application Ser. No. 09/481,671 (now U.S. Pat. No. 6,578,008) filed on Jan. 12, 2000 entitled METHOD AND SYSTEM FOR AN ONLINE TALENT BUSINESS, and all of whose entire disclosures are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The invention relates generally to online business methods, and more specifically to a method for implementing an online record business whereby large numbers of unknown artists can have their music made available to the public and wherein the public votes on which artists they like and whereby the online record business enters into recording contracts based on the public voting.
BACKGROUND OF THE INVENTION
[0003] Music is one of the most popular forms of entertainment in the world, but it is also a big business. According to the Recording Industry Association of America, domestic sales of recorded music were $13.7 billion in 1998, or more than one-third of world-wide revenue.
[0004] Of the $13.7 billion in revenue, “rock” remained the dominant genre, with 25.7% of the market in 1998. The next most popular category was “country,” with 14.1%. Rhythm and blues (“R&B”) came in next at 12.8%, with “pop” and “rap” coming in at 10.0% and 9.7%, respectively. As can be seen, these five categories of music are responsible for over 72% of all sales, and it is these genres to which the present application is directed. Moreover, the buyers of these categories of music are also the most Internet-aware.
[0005] The compact disc (CD) became the dominant format for recorded music in 1992, the year in which its market share (in terms of dollars, not units) barely exceeded that of cassettes (46.5% vs. 43.6%). However, in terms of dollars, CDs now outsell cassettes by a 5-to-1 margin. The shift to this new format did not take place overnight, but it did take place. It is Applicants' belief that the same transformation from CDs to a purely digital format is inevitable.
[0006] The sale of prerecorded music is mostly of interest to the younger consumer, and over 73% of revenue is derived from buyers aged 10-39. The importance of this is the fact that, except for the 18.1% market share attributed to buyers 45 and older, the next greatest demographic segment is buyers aged 15-19, with 15.8% of the market; and it is this category of buyer that is among the most Internet-aware.
[0007] In 1998, 85.2% of music sales took place in retail stores, with record clubs having a distant 9% share of the market. By contrast, the Internet was in distant last place at only 1.1%. Given that the market for domestic music is almost $14 billion, each one-percent of additional market share translates into $140 million in sale, assuming no growth in the market as a whole.
[0008] The music industry has not changed very much during the last few decades. Record companies typically require artists to sign exclusive contracts, and in exchange, the record labels develop, distribute, and promote the music. Additionally, the major record labels (as well as several “independent” labels) control, to a great extent, the type and quantity of recorded music that consumers can buy.
[0009] This existing system limits artists and consumers in the following ways:
[0010] Few artists can sell enough music to cover the high distribution and promotion costs. These costs include producing CDs and tapes, inventory and retail chain management as well as television, print and radio promotions and public relations efforts.
[0011] The majority of artists can only reach limited audiences due to finite shelf space at retailers and limited air time on radio and television stations, thus limiting the choices available to consumers.
[0012] There is very little communication and exchange of information between artists and consumers. For example, artists do not readily know who is buying their music or how to contact them, and consumers often do not have an opportunity to interact directly with their favorite artists.
[0013] Because of these limitations, the number of artists served by the existing music distribution system is small compared to the universe of musicians with commercial aspirations. According to a recent Gallup poll, over 25% of the U.S. population over the age of twelve, or 53 million people, are active music-makers. In addition, according to the National Association of Music Merchants, approximately 62% of U.S. households contain an amateur musician. These musicians represent a broad spectrum of artists including hobbyists, amateurs, semi-professional and professional musicians.
[0014] The World-Wide Web is also emerging as an important source of music, dramatically altering the way consumers discover, listen to and purchase music. According to Jupiter Communications, domestic sales of recorded music over the Internet are projected to grow from approximately $327 million in 1999 to $2.6 billion in 2002. The Web offers music fans major advantages over traditional media, such as unprecedented interactivity and access to new and archived music content on demand. Since music initially appeared on the Web, the number and types of music Web sites have expanded to include content, e-commerce and downloadable music sites. As a result, both consumers and artists have embraced the Web as an attractive medium for exploring and distributing music content. Forrester Research estimates that approximately 50 million individuals will be capable of downloading and playing digital music by the end of 1999. In addition, a number of artists, such as Public Enemy, Green Day, Hole and Todd Rundgren, either sell CDs directly through their Web sites or allow visitors to purchase and download digital music.
[0015] In recent years, consumers have increasingly used their computers to play music. Dataquest estimates that in 1998, 30% of U.S. households had multimedia PCs with a sound card, speakers and either a CD-ROM or DVD-ROM drive. Consumers can now play CDs on their computers with the ease and fidelity formerly associated only with stereo systems.
[0016] However, music files can be very large. For example, a three-minute song can occupy more than thirty megabytes of storage. Storing and transferring audio files can be expensive and slow. To address this problem, compression formats have been developed. One of the first widely accepted standards for the compression of music was “mp3”, adopted by the Moving Picture Experts Group (MPEG). There are also competitive formats that may receive more widespread industry and consumer acceptance. These formats have different and additional features including SDMI (Secure Digital Music Initiative) and proprietary audio formats from companies like Microsoft Corporation and AT&T Corp. The mp3 standard offers at least 10:1 compression and audio integrity at near-CD quality. Mp3 playback is currently available on most operating environments including Microsoft Windows 95, Windows 98, Windows NT and MacOS, most major versions of UNIX and many other operating environments.
[0017] Capitalizing on the growing popularity of mp3, Diamond Multimedia Systems, Inc. introduced the Rio, the first commercially available mp3 portable player, in November 1998. Over 250,000 units have been sold to date. Several other manufacturers, including Creative Labs, Thompson Multimedia's RCA division, LG Electronics and Samsung, have recently released or announced plans to sell portable mp3 players.
[0018] The development of compression formats like mp3 has made it practical to transmit music over the Internet. However, until recently there have been few legitimate sources of downloadable music on the Internet.
[0019] The distribution method of recorded music has changed very little over time. Until recently, a typical arrangement required solid relationships between recording companies and distributors. It is believed that eventually, recording companies may distribute digitally their music directly to the consumer.
[0020] The following discussion relates to currently-available online promotion and distribution of music and music-related products.
[0021] Traditional music industries companies, including BMG Entertainment, a unit of Bertelsmann AG; EMI Group plc; Sony Corporation; Time Warner, Inc. and Universal Music Group, a unit of the Seagram Company Ltd. have recently entered in the online commercial community and are currently backing the SDMI security format.
[0022] Examples of providers of online music content are Emusic.com Inc. (formerly GoodNoise Corporation), Launch Media, Inc., Mp3.com, Musicmaker.com, and Tunes.com. Some of these companies offer artist services.
[0023] Examples of companies offering mp3 or other audio compression formats are AT&T Corp., IBM Corporation, Liquid Audio, Inc., Microsoft Corporation and RealNetworks, Inc. Some of these companies also offer customers the ability to download music from their web sites.
[0024] Examples of online music retailers are Amazon.com, Inc. and CDNow Inc., as well as online “portals” such as American Online, Inc., Excite, Inc., Infoseek Corporation, Lycos, Inc. and Yahoo, Inc.
[0025] In particular, Amazon.com has announced its launch of a digital-download area on its Web site, allowing free song downloads. In addition, America Online recently announced its acquisition of two Internet music companies, Spinner Networks, Inc. and Nullsoft, Inc. and stated its intent to offer downloadable music in leading formats.
[0026] Other companies have agreed to work together to offer music over the Internet. For example, in May 1999, Microsoft Corporation and Sony Corporation announced an agreement to pursue a number of cooperative activities. Sony has announced that it will make its music content downloadable from the Internet using Microsoft's multi-media software. In addition, Universal Music Group and BMG Entertainment have announced a joint venture to form an online music store, and Musicmaker.com recently announced that it signed an exclusive 5-year licensing agreement for EMI's music catalogue for custom compilation CDs.
[0027] U.S. Pat. No. 5,237,157 (Kaplan) discloses a user interactive multi-media based point-of-preview system. In particular, this system comprises a kiosk station at which a user can preview music available on CDs at a retail store.
[0028] U.S. Pat. No. 5,963,916 (Kaplan) discloses a system for online user interactive multimedia based point-of-preview. An improvement to U.S. Pat. No. 5,237,157 (Kaplan), this system basically integrates a network web site as the source of prerecorded products.
[0029] U.S. Pat. No. 5,629,867 (Goldman) discloses a digital radio broadcast station which includes a single online digital database having stored therein a plurality of at least several hundred different selections of music to be played and broadcast by the radio station.
[0030] In view of all of the above, there remains a need for an online record business that provides talent recruitment world-wide, from any artist that wishes to participate. Furthermore, there remains a need for an online record business that presents these artitsts' works for review by the consuming public and then obtains feedback from the consuming public on which artists the consuming public prefers. Finally, there remains a need for an online record business that awards recording contracts to participating artists based on the consuming public feedback.
OBJECTS OF THE INVENTION
[0031] Accordingly, it is the general object of this invention to provide an apparatus which improves upon and overcomes the disadvantages of the prior art.
[0032] It is another object of this invention to provide a method and system for implementing an online record business.
[0033] It is still another object of this invention to provide a method and system for implementing an online record business that provides for talent recruitment from artists world-wide.
[0034] It is still another object of this invention to provide a method and system for implementing an online record business that permits any artist to participate in the world-wide talent recruitment.
[0035] It is still another object of this invention to provide a method and system for accelerating and streamlining the process through which the record industry recruits new talent.
[0036] It is still yet a further object of this invention to provide for decreased talent acquisition costs, decreased marketing costs and decreased production costs.
[0037] It is still yet another object of this invention to provide a method and system for implementing an online record business that provides for retrieving and analyzing music-listening consumer feedback.
[0038] It is still yet another object of this invention to provide an interactive investment simulation game.
[0039] It is even a further object of this invention to provide a method and system for implementing an online record business that awards recording contracts based on the feedback from the music-listening consumer feedback.
[0040] It is even yet a further object of this invention to provide a virtual record label.
[0041] It is still yet another object of this invention to provide a method and system that offers participating artists the opportunity to upload and promote their music through their own Web page.
[0042] It still yet another object of this invention to provide a method and system for participating recording artists to reap the benefits of a multi-million dollar marketing campaign without spending any additional money of their own.
[0043] It is still yet another object of this invention to provide a method for providing one of the largest collections of music available online.
[0044] It is still yet another object of this invention to provide a method for browsing the large collection of music using multiple genre and geographical search classifications.
[0045] It is still yet another object of this invention to provide a method and system for providing an interactive music-based game for obtaining consuming public feedback.
[0046] It is still yet another object of this invention to provide a method and system for purchasing music in a cost and time efficient manner.
[0047] It is still yet another object of this invention to provide a method and system for building brand awareness through a combination of online and off-line advertising and promotional activities.
[0048] It is even yet a further object of this invention to provide a method and system for identifying international artists to add to the talent pool.
[0049] It is even yet another object of this invention to provide a method and system for multiple language content, multilevel geographical indexing, global reach and rankings.
SUMMARY OF THE INVENTION
[0050] These and other objects of the instant invention are achieved by providing a method for recruiting artists (e.g., musicians, models, authors, etc.) world-wide having artistic works (e.g., music, appearance, story scripts, etc.) for engaging artists in contracts. The method comprises the steps of: (a) receiving artistic works via global computer networks (e.g., the Internet) in order to recruit artists; (b) evaluating the received artistic works; and (c) engaging an artist, whose work has been received, in a contract.
DESCRIPTION OF THE DRAWINGS
[0051] Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
[0052] [0052]FIG. 1 is a block diagram of a method of an online business that recruits artistic talent world-wide using the Internet and also which utilizes consumer feedback to determine which artists are preferred by the consuming public;
[0053] [0053]FIG. 2 is a is a block diagram of a method of an online record business that recruits artistic talent world-wide using the Internet and also which utilizes consumer feedback to determine which artists are preferred by the consuming public;
[0054] [0054]FIG. 3A is a block diagram of the main functions available to the user of the web site provided by the online record business;
[0055] [0055]FIG. 3B is a functional diagram of the online record business;
[0056] [0056]FIG. 4 is a block diagram of a system that depicts an implementation of the method for the online record business;
[0057] [0057]FIG. 5 is a display screen view of the home page web site for the online record business;
[0058] [0058]FIG. 6 is a display screen view of an exemplary unsigned artist profile available at the web site of the online record business; and
[0059] [0059]FIG. 7 is a pop-up toolbar for the interactive investment simulation game.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0060] Referring now in detail to the various figures of the drawing wherein like reference characters refer to like parts, there is shown at 10 in FIG. 1, a block diagram of a method of an online business 11 that recruits artistic talent 12 world-wide using the Internet and that also utilizes consumer feedback to determine which artists are preferred by the consuming public 13 so that a contract can be awarded from a contracting entity 14 to the preferred artists. The online business 11 basically comprises a web site 15 and the support entity 16 that runs the online business 11 and operates the web site 15 . Artists from around the world, can upload representations of their respective works, as well as personal information, to the web site 15 . The online business 11 then organizes the artist information and artistic works via artist profiles (to be discussed in detail later) that are available to the consuming public 13 at the web site 15 . The consuming public can then review any artist and his/her respective artistic works. In addition, the consuming public can provide input (e.g., where the online business 11 is an online record label, the consuming public can “rate an artist's band” or post a message about the artist/band) via the artist profile (see FIG. 6).
[0061] Furthermore, to obtain consuming public 13 feedback regarding those artists preferred by the consuming public 13 , an interactive investment simulation game 30 (as will be discussed in detail later) is available via the web site. In particular, all of the unsigned artists/artistic works are pre-selected by talent representatives of the online business (e.g., in the record business, the online record business uses artist and repetoire (A&R) representatives; see FIG. 3B; similarly, in the modeling business or story-scripting business analogous pre-selecting personnel are used) to determine their eligibility for the interactive simulation game 30 . Those artists considered eligible to participate in the interactive investment simulation game 30 can be “voted on” by the consuming public 13 through virtual stock bought and sold by the consuming public 13 , as will be discussed in detail later. Based on those artist(s) preferred by the consuming public, the online business 11 then awards those artists contracts and implements the contracts.
[0062] It should be understood that the method 10 set forth above has applications in many types of businesses, such as the record business, the modeling business, the story-scripting business, etc. When applied to the record business (as will be discussed in detail below), the support entity 16 is a record label and the artists/work 12 are musicians that want to promote their music/video; when applied to the modeling industry, the support entity 16 may be an online modeling agency seeking models to promote their clients' products or operation/services and the models send pertinent information (e.g., images, photographs, etc.) to the modeling agency 16 for consideration; when applied to the story scripting business, the support entity 16 may be a publisher or movie production company seeking a story line for a new book or movie. One of the key features of the method 10 is that it provides an artist, anywhere in the world, with the ability to have his/her talent presented to the consuming public for their consideration, thereby avoiding the current hurdles of not being able to even “get a foot in the door.” Another key feature of the method 10 is that it lets the consuming public 13 decide who should be promoted to the next stage, i.e., contract, of bringing a new work of art to the world, thereby avoiding the support agency 16 always making that determination for the consuming public 13 . For example, in the record industry, the record labels alone make the decision of which artists will be promoted.
[0063] [0063]FIG. 2 depicts the method 10 implemented in the record business and is hereinafter referred to as the method 20 . In particular, the method 20 comprises an online record business 21 that operates, supports and maintains a web site 25 . As also shown in FIG. 2, the Online record business 21 is known as “OnlineRecordBiz.com” and supports the web site 25 having that URL (uniform resource locator). Unsigned recording artists 22 , from around the world, interface with the online record business 21 via the Internet by uploading their music and personal information to the web site 25 . By providing this interface, the online record business 21 greatly assists the unsigned artists 22 by avoiding all of the “hype” (at great expense and time to the artists 22 ) that normally would need to be created before a record label would even “give 'em a chance”. In addition, the consuming public 13 can then access the web site 25 and review the various unsigned artists' music/information and listen to the artists' music. Following the pre-selecting of all of these unsigned artists by A&R representatives, the consuming public 13 can then “vote” (as will be discussed in detail later) on which artists' 22 music they prefer via the interactive investment simulation game 30 . Since record labels are in the business to make money, the online record business 21 will award recording contracts to those unsigned artists 22 that are most preferred by the consuming public 13 . Thus, the consuming public 13 drives the awarding of recording contracts, rather than the record label driving the awarding of recording contracts.
[0064] It should also be understood that the term “artist” when used with regard to the online record business means an artist as an individual or artist as a band.
[0065] [0065]FIG. 3A depicts a block diagram of the main functions available to the user of the OnlineRecordBiz.com web site 25 . Through this web site 25 , OnlineRecordBiz.com finds the best new artists from around the world, determines new artists' success potential before signing, markets its artists, and distribute its artists' music and merchandise. This method 20 provides for decreased talent acquisition costs, decreased marketing costs, and decreased production costs. In particular, users of the web site 25 can utilize the extensive unsigned artist database 28 which includes pictures, profiles and mp3 files. The users can also utilize an interactive investment simulation game 30 , a community center 32 with bulletin boards, chat rooms and e-mail. The users can also utilize an online store 34 for music and merchandise distribution.
[0066] The unsigned artist database (also referred to as the “unsigned artist talent pool”) 28 comprises an extensive database of unsigned recording artists 28 developed through both online and offline marketing techniques. Each artist is presented with the opportunity to create and maintain his/her own no-cost web page on the OnlineRecordBiz.com web site 25 , known as artist profiles (see FIG. 6). Within their profiles, the artists share their relevant information, photographic images, at least one song, and one music video (if available). In particular, artists upload a photographic image, a text-based profile, up to three mp3 files and one video file. This is accomplished in a “do-it-yourself” fashion similar to the method used by GeoCities in permitting users to create their own pages. Furthermore, OnlineRecordBiz.com employs experienced talent scouts (i.e., the A&R representatives) to track the recording artists that join its talent pool. Talent scouts have access to daily, detailed statistics regarding each unsigned artist profile, including how many users traffic the profile, how many songs were listened to and downloaded, as well as access to interactive opinion polls and newsgroups contained within the artist profile. Those top artists are then invited to join the interactive investment simulation game 30 through which OnlineRecordBiz.com determines the actual appeal of the unsigned artist.
[0067] The interactive investment simulation game 30 is the key tool in evaluating the actual demand of the unsigned artists. Through the interactive investment simulation game 30 , users virtually buy and sell stock in the more than 50 unsigned artists with imaginary money. Every few days, OnlineRecordBiz.com adds more unsigned artists to the interactive investment simulation game 30 . Prices of the imaginary stocks are driven by the actual supply and demand as dictated by the traders. The top traders for each month or quarter receive various prizes such as T-shirts, CD's, cash and even a new car. In addition, the web site 25 includes a feedback section so that web site visitors can post their comments about the recording artist. Users who participate in the interactive investment simulation game 30 compete against thousands of other users daily in order to earn a variety of prizes. Moreover, through participation in the game, users actually take part in determining the next interactive investment simulation game 30 signed artist. The combination of the enjoyment and fun of the game with the power of the experience creates an exciting opportunity to OnlineRecordBiz.com users.
[0068] As mentioned previously, OnlineRecordBiz.com also uses A&R (Artist and Repertoire) representatives to watch the results of the interactive investment simulation game 30 to determine which unsigned recording artists have received the most favorable reception by the public. The artists that excel in the game 30 (i.e., the highest stock price) are traditionally scouted by the A&R representatives. If decided appropriate, those artists are then offered a recording contract with OnlineRecordBiz.com.
[0069] Once a particular artist warrants a OnlineRecordBiz.com contract (as reflected by the investment simulation game 30 ) OnlineRecordBiz.com actually signs the artist to a recording contract, utilizing several new media and traditional music industry marketing strategies to market its artists. For example, when OnlineRecordBiz.com signs a new artist to a recording contract, the company's site, the OnlineRecordBiz.com web site 25 , features a 15 to 30 second animated introduction to introduce the new artist (e.g., see www.3dfx.com for a similar experience). The introduction contains information on the artist, graphics, and the artist's actual music as the user enjoys an exciting and unique experience. Furthermore, OnlineRecordBiz.com provides an individual web site for each of its signed artists. The site includes profile information, concert information, discographies, online videos, and other relevant information. After OnlineRecordBiz.com signs a particular artist, users receive a direct e-mail containing the signed artist's profile information, an attached digital download, an instant play hyperlink and a compact disc order form. In order to provide links to the new artist's web site, OnlineRecordBiz.com purchases banner advertisements on appropriate web sites to attract more potential users of the web site 25 . In addition, OnlineRecordBiz.com uses television promotions, radio promotions, record store promotions and music videos to generate as much interest as possible in artists signed by OnlineRecordBiz.com. Furthermore, through the online store 34 , OnlineRecordBiz.com offers users the opportunity to purchase signed artists' music, and merchandise directly through its site.
[0070] In addition to the unsigned artist talent database 28 and the interactive investment simulation game 30 , OnlineRecordBiz.com offers services designed to instill a sense of community in the web site 25 . Among these are e-mail accounts, chat rooms, bulletin boards, and interactive games. The web site 25 permits fans to contact artists directly via e-mail and to communicate with one another through message boards and chat. In addition, artists can use their artist profile to communicate directly with their fans, advising them of concerts and new releases and developing a fan email list.
[0071] The result of the method 20 is fourfold. First, it accelerates and streamlines the process through which the record industry recruits new talent. Second, the power to choose which recording artists become commercially popular resides in the hands of the consumer. As opposed to music being “pushed” through the channel by today's entertainment companies, music is “pulled” through by consumers who decide what they want to hear through the method 20 . Third, consumers have more music from more recording artists from which they can choose. Fourth, the industry experiences major “disintermediation,” i.e., that dependence on a middle-man between suppliers and buyers (i.e., a retailer) is greatly reduced or eliminated. In order to better understand the value of the method 20 , consider a brief examination of each of the four aforementioned results:
[0072] With regard to talent recruitment, by using the World Wide Web as its headquarters, OnlineRecordBiz.com essentially has a talent scout wherever there is a connection to the Internet, be it in North America, Asia, Europe or anywhere in the world. Therefore, OnlineRecordBiz.com has access to the best new talent from around the world before any other traditional music company.
[0073] With regard to consumer feedback, while traditional music companies rely solely upon their executives to predict those artists that will achieve commercial success, OnlineRecordBiz.com lets the music buying public decide. OnlineRecordBiz.com only signs those artists that have proven to be popular by the music-buying public. In doing so, OnlineRecordBiz.com greatly reduces the inefficiency currently plaguing the traditional music industry.
[0074] With regard to the consumers' music choice, via the expanding collection of artists in the unsigned artist database 28 , the consuming public is provided with one of the largest databases of musical content available on the Internet. Consumers can listen to real-time or streaming audio or download thousands of songs posted on the web site 25 by artists to their personal computers free of charge, twenty-four hours a day. The music collection spans dozens of categorized genres, including pop, rock, classical, country, alternative, children's, easy listening, electronic, hip hop, rap, blues, jazz, international. Those music categories are searchable by genre, artists or location.
[0075] With regard to industry “disintermediation,” once OnlineRecordBiz.com signs a particular artist to a recording contract, the company then makes that signed artist's music available for purchase in all reasonable formats, including digital, compact disk, and cassette tape, directly within the company web site 25 . Considering that consumers (potential music buyers) already traffic the OnlineRecordBiz.com web site 25 , it makes sense for the consumer to purchase the signed artist's music directly through the OnlineRecordBiz.com web site 25 and not a traditional third party retailer. As consumer acceptance of the new digital distribution systems pick up, OnlineRecordBiz.com completely eliminates the need for a distributor and retailer, greatly increasing the revenue of OnlineRecordBiz.com as well as its artist.
[0076] [0076]FIG. 4 is a diagram of a system 120 that depicts an implementation of the method 20 for the online record business. In general, the system uses servers, networks, computer terminals and other conventional systems, subsystems and components that are known in the art which are necessary for Internet communication.
[0077] In particular, the system comprises a plurality of consuming public and unsigned artist terminals 122 for interaction with the Internet 124 . OnlineRecordBiz.com's web site 25 , as will be discussed in detail, is available via the Internet 124 . The web site 25 communicates with, and maintains, a plurality of relational databases, namely, an artist database 126 , a music database 128 , an e-commerce database 130 and an end-user database 132 . These databases are used to enhance the user experience at the web site 25 and to provide OnlineRecordBiz.com with valuable information for marketing and sales activities. Content databases 134 make content available for download, CD purchase, web site ranking and cataloging and are updated as artists and users interact with the web site 25 . Statistics databases 136 maintain traffic and site analysis information including the number of times that web pages were viewed, download counts and artist/song rankings. The end-user database 132 and e-commerce database 130 , which are firewalled for protection, contain customer information and transaction histories.
[0078] As mentioned previously, each participating artist has his/her artist profile 138 within the OnlineRecordBiz.com web site 25 as supported by, among other things, the artist database 126 and the music database 128 . It should be understood that the artist database 126 and the music database 128 encompass the unsigned artist database 28 mentioned earlier.
[0079] Finally, other links 140 (e.g., ticketing agencies) are also available via the Internet 124 as part of the system 120 .
[0080] The technology infrastructure is based on architecture designed to be secure, reliable and expandable. Software used in the system 120 is a combination of proprietary applications, third party database software, and open operating systems that support acquisition of content, management of that content, publication of the web site 25 , downloads of music and media files, registration and tracking of users, reporting of information for both internal and external use.
[0081] The infrastructure is designed to allow each component to be independently scaled, usually by purchasing additional readily-available hardware and software components, to meet or exceed future capacity requirements.
[0082] All servers, networks and systems are monitored on a continuous basis. Numerous levels of firewall systems are implemented to protect the databases, electronic commerce servers, customer information and music archive. Backups of all databases, data and media files are performed on a daily basis. Data back-up takes are archived at a remote location on a weekly basis.
[0083] The OnlineRecordBiz.com web site 25 can support new technology formats and standards, including a variety of leading audio compression formats. Music in offered in both the mp3 and RealAudio formats, as well as in the still popular CD format.
[0084] The web site 25 incorporates the latest technologies, featuring the use of Macromedia's Flash 4 and Shockwave to make the web site 25 one of the most exciting and creative destinations on the web. Moreover, the site offers four to five languages other than English.
[0085] The OnlineRecordBiz.com web site 25 is discussed in further detail below. It should be understood that although record industry terminology and symbology are shown in FIGS. 5 - 7 , it is within the broadest scope of this application to include other industry/business terminology and symbology, e.g., the modeling industry and story-scripting business, in each of those figures; thus, as a result, FIGS. 5 - 7 are exemplary only in that other industries/businesses may modify the language and icons of FIGS. 5 - 7 to meet their respective terminologies and symbologies.
[0086] As mentioned previously, a 15-second powerful introduction greets the user to the OnlineRecordBiz.com web site 25 , introducing the company through a powerful flash presentation incorporating text, graphics, and music (see www.balthaser.com for a similar experience). Upon completion of the introduction, the OnlineRecordBiz.com home page (FIG. 5) is loaded along with the Investment Game Toolbar pop-up window (FIG. 7). The home page (FIG. 5) links the user to five optional sections: (1) the OnlineRecordBiz.com Talent Pool, (2) Top Artists, (3) the OnlineRecordBiz.com Brand Store, (4) OnlineRecordBiz.com Artists (4) the Investment Game Overview, and (5) the OnlineRecordBiz.com Community Center (OnlineRecordBiz.com Lounge). Each option is presented through an image map showing partial graphics of each individual station compiled into one circular graphic (see www.millerbrewing.com as a reference). A navigation bar is displayed along the top window margin of the OnlineRecordBiz.com home page. The user can find links to the several important OnlineRecordBiz.com sections and services. Among those sections included on the toolbar are: Login/Register, Talent Pool, Top Artists, Store, OnlineRecordBiz.com Artists, Game Overview, Community, DJ, Prizes, and Leaders. A real time ticker showing the updated artist price quotes of that particular user's portfolio sits along the bottom margin of the OnlineRecordBiz.com home page. The ticker resembles those tickers found on non-fantasy investment sites. The user can click on a particular ticker symbol to view a description of the artist.
[0087] The OnlineRecordBiz.com Talent Pool: The talent pool is the unsigned artist section of the OnlineRecordBiz.com site. As mentioned earlier, users can view profiles 138 (FIG. 6) of artists contained within the extensive pool of unsigned artists that appear on the OnlineRecordBiz.com web site 25 . Each profile 138 contains important information about the artist. In the upper left corner of the profile window is a picture of the artist. To the right and below the picture is the artist's name, songs available for sampling and download, a brief description, and other relevant information. Below the artist's description is an interactive weekly survey (e.g. generating opinion polls), a link to that artist's individual newsgroup (e.g., for disseminating information about the artists and the consuming public input), and a button allowing users to “join this band's e-mail list” (e.g., using e-mail listserves).
[0088] Top Artist Stocks: The music artist stocks offered section of the site links the user to a list of all of those artists available for ranking on the Investment Game (music artists that can be traded in the game) and their current stock price. The artists are categorized into nine categories: (1) hip hop, (2) R&B, (3) jazz, (4) classical, (5) new age, (6) pop, (7) alternative, (8) rock/pop, and (9) country. Each band name listed is linked to that artist's profile.
[0089] The OnlineRecordBiz.com Records Store: In the OnlineRecordBiz.com Records store users can purchase OnlineRecordBiz.com music and brand-name merchandise. Among the merchandise offered is OnlineRecordBiz.com signed artists' downloadable digital and deliverable CD and cassette tape music, OnlineRecordBiz.com T-shirts, Polo shirts, hats, sweatshirts, mugs, distinctive shot glasses, books, lighters, can openers, pitchers, mouse pads, and others.
[0090] OnlineRecordBiz.com Signed Artists: In the OnlineRecordBiz.com Signed Artist sections users find information on the signed OnlineRecordBiz.com artists. Each artist has his/her own web site within the OnlineRecordBiz.com web site 25 that features information on the artist, including profile information, concert information, discographies, online videos, and other relevant information. As more artists are signed, this section grows to be an invaluable marketing tool for OnlineRecordBiz.com.
[0091] The Game Overview: The Game Overview is the “how to play” section of the OnlineRecordBiz.com web site 25 . The interactive teaching instrument educates the user through a logical progression of flowing page interactions, as well as contains specific links to other help sections. One example of a similar instructional resource can be found at Miller Brewing Company's web site at www.millerbrewing.com/a_lite_section/index.asp (see Pilsner Beer Story) and the Esignal web site at www.esignal.com/flash_demo.htm.
[0092] The OnlineRecordBiz.com Community Center (The OnlineRecordBiz.com Lounge): The OnlineRecordBiz.com Community Center offers many of those options found on a standard music community web site such as Billboard Online and Rolling Stone Online. Among those options are live concerts, chat sessions, daily news, newsgroups, and email. In addition to those common features, OnlineRecordBiz.com offers the OnlineRecordBiz.com leader board, OnlineRecordBiz.com postcards, OnlineRecordBiz.com member web pages, and OnlineRecordBiz.com interactive games.
[0093] The OnlineRecordBiz.com Power Toolbar (FIG. 7) is an individual pop-up window that acts as OnlineRecordBiz.com Record's consumer feedback portion of the web site 25 . Within this section, all artists involved in the interactive investment simulation game 30 are listed along with the user's buy/sell tools and other necessary features.
[0094] At the top of the window is the OnlineRecordBiz.com game logo. Below the OnlineRecordBiz.com logo is a scrollable ranking of the artists in the OnlineRecordBiz.com game. Each name contains a hyperlink to each artist's profile 138 . The top five artists are visible at window launch, but all others can be reached through the scrollbar.
[0095] Below the OnlineRecordBiz.com artist list is the user's investment toolbar. With the toolbar, the user can utilize three features: (1) enter a quick search of a particular artist's name or ticker symbol, (2) buy or sell a particular quantity of shares, and (3) see his/her current revenue and portfolio. Each individual feature links to a new window. The quick search feature links to a full description of the particular searched artist. The buying and selling tools link to a confirmation screen that finalizes the trade. When the user clicks on the portfolio link, he/she can view his/her current artist stocks, balance, and other relevant information. Below the portfolio is a description of each prize the user can win if he/she attains a certain amount of money. Below the OnlineRecordBiz.com Investment Toolbar the user can download a desktop version of the Investment Challenge and link back to the OnlineRecordBiz.com home page (FIG. 5).
[0096] Without further elaboration, the foregoing will so fully illustrate my invention that others may, by applying current or future knowledge, readily adopt the same for use under various conditions of service.
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A method for recruiting artists whereby a talent business can streamline the talent discovery process. In particular, the talent business receives and evaluates submissions of artistic works over global computer networks and engages an artist, whose works have been received, in a contract. This talent business is exemplified by a record business but may encompass any talent business, such as in the modeling or script writing industries.
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FIELD OF THE INVENTION
The present invention relates generally to methods and apparatuses for circular weaving of tubular fabrics, and more particularly to a new circular weaving method and apparatus for weaving characters, letters and other indicia in a tubular fabric.
BACKGROUND OF THE INVENTION
In weaving flat fabrics, it is fairly common to weave initials or other characters into the fabric. While it is fairly common to weave letters, initials or other designs into a flat fabric, such is not the case for tubular fabrics. Instead, the design is usually stenciled onto the tubular fabric or mechanically printed with an offset printer after it has been woven. However, there are numerous drawbacks to using stenciled designs on tubular fabrics.
One drawback is that stenciling requires additional manufacturing steps which would not otherwise be required. Once the tubular fabric is woven, it must be pressed flat so that the design can be applied. After pressing the tubular fabric, it is stenciled and the ink is given time to dry. These additional manufacturing steps increase the costs of the tubular fabric.
Another drawback associated with stenciled designs on tubular fabrics is that the design may wear off the fabric. For example, tubular fabrics are frequently used as fire hoses or irrigation lines. In these types of applications, the hose or line may be dragged over the ground causing the stenciled design to be worn off.
Accordingly, there is a genuine need for an alternative method of applying designs to tubular fabrics.
SUMMARY AND OBJECTS OF THE INVENTION
The present invention provides a method and apparatus for weaving tubular fabrics with predetermined woven designs. A warp yarn selector is incorporated into a circular loom for manipulating the warp yarns to produce the predetermined design. The circular loom includes a circular comb having a plurality of warp guide slots for guiding the radially extending warp yarns. A shed forming means forms a shed in the warp yarns. The shed is formed by dividing the warp yarns into two sheets and raising or lowering one sheet with respect to the other. A shuttle travels in a circular path inside the comb of the loom and inserts a weft yarn into the shed. When the shed changes, the weft yarn becomes interleaved with the warp yarns to form the tubular fabric.
To make a tubular fabric bearing a woven design, selected warp yarns (referred to herein as the base warp yarns) are paired with an indicia forming warp yarn. The indicia forming warp yarn is of a different color than the base warp yarn and is used to produce the design in the tubular fabric. A warp yarn selector is incorporated into the circular loom to select one warp yarn from each pair of warp yarns to be woven into the tubular fabric. The warp yarn selector includes means for floating the non-selected warp yarn along the inside of the tubular fabric. The non-selected warp yarn is not woven into the fabric, but strings along on the inside of the tubular fabric until it is once again selected to be woven into the tubular fabric.
The warp yarn selector is mounted to the comb or reed of the circular loom and the warp yarn pairs extend through the selector. A catch means is provided for each pair of warp yarns. The non-selected warp yarn is engaged by the catch means and is lifted above the shuttle so that the non-selected warp yarn is not woven into the tubular fabric. In the embodiment described, the catch means comprises an elongated selector rod having first and second catches formed on opposite sides of the rod. A shielding means is provided for shielding the catch of the selected warp yarn while exposing the catch for the non-selected warp yarn. The shielding means comprises a shield rod disposed closely adjacent to the selector rod and having a diameter at least as great as the selector rod. The shielding rod includes first and second cut-outs and is moveable between a raised position and a lowered position. In the lowered position, a first cut-out aligns with a first catch in the selector rod. The other catch is shielded by the shielding rod. In a raised position, the second catch is exposed by the second cut-out in the shielding rod while the first catch is shielded. An electrical actuator is used for moving the shielding rod between the raised and lowered positions. The electrical actuator is controlled by a programmable controller which gets its instructions from a computer.
Based on the foregoing, it is a primary object of the present invention to provide a method and apparatus for weaving tubular fabrics having woven designs in the tubular fabric.
Another object of the present invention is to provide a warp yarn selector for a circular loom for selectively manipulating warp yarns to produce a predetermined woven design in a tubular fabric.
Another object of the present invention is to provide a warp yarn selector which can be incorporated into existing looms without modification to the looms.
Yet, another object of the present invention is to provide a warp yarn selector which is relatively simple in construction and easy to install and use.
A further object of the present invention is to provide a woven fire hose having a woven indicia such as a trademark, symbol or design incorporated therein.
Another object of the present invention is to provide a relatively simple method of weaving indicia such as trademark or symbol into a tubular woven fabric.
Still a further object of the present invention is to provide a method of weaving indicia into a tubular woven fabric that exclusively utilizes warp yarns to form the woven indicia.
A further object of the present invention resides in the provision of a method and apparatus for weaving indicia into a woven tubular product wherein the apparatus is susceptible to being automatically controlled.
Another object of present invention resides in the provision of a system for weaving indicia into a woven tubular fabric that is capable of executing various designs and is also designed in such a manner that the system has the capability of changing from one design to another design during a weaving process.
Still a further object of the present invention resides in the provision of a method for weaving indicia into a tubular woven fabric wherein there is provided special indicia yarns that are selectively woven into the tubular fabric to create and give rise to the indicia and wherein those same indicia yarns are floated to the inside of the tubular fabric along areas where there is to be no indicia.
Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational schematic view of a circular loom with portions broken away to better illustrate the same and wherein the base warp yarn and indicia forming warp yarn selector of the present invention is incorporated into the loom.
FIG. 2 is a side elevational view of a portion of the circular loom particularly illustrating the shed forming means of the loom.
FIG. 3 is a side elevational view of the warp yarn selector of the present invention.
FIG. 4 is a front elevational view of the warp yarn selector of the present invention with the rod that forms the guide slot being removed to better illustrate the structure of the selector.
FIG. 5 is a schematic plan view of a portion of a circular loom having a plurality of individual warp yarn selectors mounted thereto.
FIG. 6 is a schematic cross sectional view of a woven tubular fabric showing how certain base warp yarns and indicia forming warp yarns are selected to form a woven indicia within the surface of a tubular product such as a fire hose.
FIG. 7 is a illustration of a fire hose having a woven indicia according to the present invention incorporated therein.
FIG. 8 is a schematic illustration of a computer and programmable controller for controlling the warp yarn selector of the present invention.
FIG. 9 is a digital illustration of a programmed matrix for forming the letter "A."
FIG. 10 is a schematic flow chart showing the basic steps involved in controlling the warp yarn selector to cause a selected indicia to be formed within a circular product or fabric.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and particularly to FIGS. 1-4, a circular loom incorporating a warp yarn selector is shown therein and indicated generally by the numeral 10. The loom 10 includes a frame 12 which supports a circular reed 14. Circular reed 14 is stationary and includes a plurality of circumferentially spaced reed pins 28 defining a plurality of warp slots 30. Reed pins 28 are fixed at the lower end to a ring or cylinder 26 which is mounted to frame 12. A top ring 32 is secured to the upper end of the reed pins 28. A shuttle track ring 34 is secured on top of the reed 14.
The reed 14 directs radially-extending warp yarns to the point where a weft yarn is inserted to form a tubular fabric. The weft yarn is inserted by means of a shuttle which travels in a circular path inside the reed 14. The shuttle is supported by a shuttle carrier 16 that is rotatably mounted within the circular comb or reed 14. The shuttle carrier 16 is fastened to a housing 38 by screws 40. The housing 38 is rotatably mounted by bearings on a stationary main drum 44. A weaving cone 48 is supported by a collar 46 at the top of the main drum 44.
The shuttle carrier 16 is driven by an electric motor and first power transmission assembly 52. Power transmission assembly 52 includes a drive gear 56 which meshes with a ring gear 58 secured to the turntable housing 38. A second power transmission means 60 including a gear 62 is driven by the ring gear 58. The second power transmission means 60 drives the take up means 24 synchronously with the shuttle carrier 16 to take up the tubular fabric as it is being woven.
A warp supply means is provided for supplying warp yarns to the loom 10. Warp yarns for weaving the tubular fabric are stored on a creel (not shown) which is disposed below the circular loom 10. The warp yarns extend upwardly through perforated plates in the floors and around a tensioning roll 62. The warp yarns then pass over tensioning rods 64 and extend radially through respective slots 30 in the circular reed 14.
As previously indicated, the tubular fabric is formed by interleaving a circumferentially extending weft yarn with the warp yarns. To interleave the weft yarn, the warp yarns must be divided into two sheets which can then be separated so that the weft yarn can be inserted.
The warp yarns are separated into two sheets by a shed-forming means 20. Shed-forming means 20 comprises a pair of shedding wheels 66 which are rotatably mounted on the shuttle carrier 16. The shedding wheels 66 are disposed at an angle relative to the reed 14. Each shedding wheel 66 includes a series of radially projecting teeth 68 which engage the reed pins. Due to the engagement of the teeth 58 with the reed pins, the shedding wheel 58 rotates at a speed which corresponds directly to the speed of the shuttle carrier 16. As the shedding wheels 66 rotates, every other warp yarn will be caught in the notch 70 formed in the outer end of the tooth 58. The alternate warp yarn will fall into the slot 72 formed between the teeth 68 of the sheeding wheel 66. The warp yarns received by the radially projecting teeth 58 of the shedding wheel 66 will be raised for form the top sheet of the weaving shed. The warp yarns falling into the slot 72 between the teeth 68 of the shedding wheel 66 will form the bottom sheet of the weaving shed.
Shedding wheels 66 are disposed approximately 180° appart on the turntable 16. The warp yarns are threaded through the comb 14 such that the shedding wheels raise and lower opposite groups of warp yarns. Thus, the passing of each shedding wheel 66 will change the shed. That is, the warp yarns in the top and bottom sheets during the passing of the first shedding wheel 66 will switch positions during the passing of the second shedding wheel 66. Since there are two shedding wheels 66, the weaving shed will change twice during each complete revolution of the turntable.
Shedding wheels 66 are mounted to the shuttle carrier 16 directly in front of the shuttle 80. Shedding wheels 66 form a preliminary shed which must be further opened to allow the passing of the shuttle 80 through the weaving shed. A shed opener 90 extends from the front end of the shuttle 80 for opening the shed. The shed opener 90 includes upper and lower guide rails 92 and 94 which meet at a point 96. Point 96 of the shed opener 90 is positioned such that the warp yarns caught by the arms of the shedding wheel 66 pass over the upper guide rail 92, while the warp yarns in the slots 72 of the shedding wheel 66 pass under the lower guide rail 94. The upper and lower guide rails 92 and 94 taper outwardly as they extend towards the shuttle to spread the warp yarns apart to open the shed as the shuttle 80 passes through. As the shuttle 80 moves through the weaving shed, the weft yarn is unwound from the spool 88 and is transferred by the circular motion of the shuttle 80 to the edge of the tubular fabric. After the shuttle 80 passes through the shed, the shed changes so that the weft yarn is interleaved into the tubular fabric. The tubular fabric so formed is taken up by the take-up means 24. The woven tubular fabric passes around an idle roller 104 and is wound through a series of take up rollers 106 as shown in FIG. 1.
The structure and function of the loom 10 just described is conventional and well known to those skilled in the art and therefore a detailed discussion of the loom per se is not necessary. Circular looms substantially as described are made by Mandals Reberbane Christisian & Co. A/S and sold under the trade name "Hosemaker." Since the structure and function of the circular loom is well known to those skilled in the art, further explanation of the loom is omitted.
In the past, circular looms have been used for weaving tubular fabric and any indicia would be stenciled or painted onto the outer surface. This limitation is overcome in the present invention by incorporating a warp yarn selector into the circular loom for weaving indicia directly into the woven tubular fabric. A yarn selector 100 is used in connection with a new method for weaving tubular fabrics to produce tubular fabrics bearing woven indicia or designs. The process involves pairing the base warp yarns in a selected portion of the tubular fabric with an indicia forming warp yarn of a different color. On each pass of the shuttle 80, selector 100 exclusively selects one and only one warp yarn from each pair to interleave with the weft yarn. The unselected warp yarn is allowed to float along the inside of the tubular fabric and is not interleaved with the weft yarn. FIG. 6 shows a cross-section of a tubular fabric produced according to the present invention. As can be clearly seen in the drawings, only one warp yarn from each pair of warp yarns is interleaved with the weft yarn. For purposes of reference, the warp yarns comprise two types, the base warp yarns (BWY) and the indicia forming yarns (IWY). The weft yarns are referred to by WY. By selecting which one of the warp yarns, IWY or BWY, is interleaved with the weft yarn at a given location on the tubular fabric, characters or other indicia can be woven into the fabric.
Referring now to FIGS. 3-7, the selector 100 for selecting the warp yarn to be woven into the tubular fabric is shown. Selector 100 includes a frame comprising an upper mounting plate 102, a lower mounting plate 104, and a plurality of guide rods 106 extending between the upper and lower mounting plates 102 and 104. A positioning pin 122 extends from the back edge of the upper mounting plate 102 for positioning the selector 100 on the reed 14. The positioning pin 122 fits between the reed pins 28 of the reed 14 to align the selector 100 relative to the reed 14.
In the embodiment shown, five guide rods are laterally spaced along the front and back edges of the mounting plates 102 and 104. The guide rods 106 define four warp guide slots 108. Thus, the selector 100 of the present invention can handle four pairs of warp yarns. The number of warp yarns handled by the selector 100 is not a material part of the invention and the selector 100 can be easily modified to handle a larger or smaller number of warp yarns. It is appreciated that individual selectors 100 can be placed side-by-side on the loom 10 as shown in FIG. 7 to accommodate a large quantity of warp yarns.
A support plate 110 is supported in spaced relation to the upper mounting plate 102 by a support block 112. A conventional bolt and nut fastener 114 secures the support plate 110 and support block 112 to the upper mounting plates 102. A pair of securing screws 116 are threadably engaged with corresponding screw holes 118 along the front end of the support plate 110. The function of the securing screws 116 is to secure the selector 100 to the reed 14. The selector's entire frame assembly is mounted to the reed 14 of the circular loom 10. Mounting plates 102 and 104 fit between the top and bottom rings of the reed 14 respectively. The securing screws 116 are then tightened against the top ring 32. The positioning pin 122 fits between the guide pins 28 of the reed 14 to position the selector 100.
A selector mechanism 124 is mounted within the selector frame assembly 120. Selector mechanism 124 includes four shielding rods 126 and four selector rods 128. Each shielding rod 126 is paired with one selector rod 128, and each pair of rods is disposed along the centerline of one of the warp guide slots 108. The selector rods 128 are stationary and have their ends fixed to the upper mounting plate 102 and lower mounting plate 104 respectively. The shielding rods 126, on the other hand, slide freely up and down within guide holes 132 formed in the upper and lower mounting plates 102 and 104. The lower end of the shielding rods 126 extend below the lower mounting plate 104. A spring 140 is inserted over the lower end of the shielding rods 126 and is retained by a retaining ring 142. Biasing spring 140 biases the shielding rods 126 to the lower position. The upper end of the shielding rods 126 are secured to a connecting block 134. Two shielding rods 126 are connected to each connecting block 134 so that two adjacent shielding rods 126 move up and down together. The connecting blocks 134 are connected to an actuator rod 138 which is actuated by a solenoid 136. When the solenoid 136 is turned on, the shielding rods 126 are lifted by the actuator rod 138. The shielding rods 126, under the influence of springs 140, return to the lower position when the solenoid 136 is turned off.
The shielding rods 126, in combination with the selector rods 128, select one warp yarn from each pair to be interleaved with the weft yarn WY. Each selector rod 128 is formed with first and second catches 128a and 128b which are disposed on opposite sides of the selector rod 128. Each shielding rod 126 includes cut outs 126a and 126b disposed on opposite sides of the shielding rod 126. When the shielding rod is in the lower position, cut-out 126a exposes the catch 128a on the associated selector rod. Conversely, when the shielding rod 126 is in a raised position, catch 128b on the selector rod 128 is exposed by the cut out 126b. Only one catch 128a or 128b will be exposed at a time so that only one yarn from each pair is woven into the fabric.
In operation, four pairs of warp yarns are threaded through the guide slots 108 of the selector 100. The warp yarns of each pair are extended around opposite sides of the rods 126 and 128. For example, the base warp yarn BWY may pass on the right side of the shielding rod 126 and selector rods 128 while the indicia-forming yarn IWY passes around the left side. The warp yarns are then threaded through the loom in the usual manner.
As the loom operates, the warp yarns move up and down within the warp guides slots 108 of the selector 100 as the weaving shed alternates. When the shielding rod 126 is in the lower most position, the indicia-forming warp yarns IWY will be caught in the catch 128a of the selector rod 128. The opposite catch 128b will be shielded by the shielding rod 126. Thus, the primary warp yarn or base warp yarn BWY will continue to move up and down in the usual manner and will be woven into the tubular fabric. The indicia-forming warp yarn IWY, which is held in the catch 128a, is lifted to a height so that it will always pass over the top of the shuttle 80. As long as the indicia-forming yarn IWY is held, it will not be interleaved with the weft yarn. Instead, the indicia-forming yarn IWY will float along the inside of the tubular fabric (See FIG. 6).
When the shielding rod is in a raised position (See the right hand half of the selector 100 in FIG. 3), the indicia-forming yarn IWY will be woven into the tubular fabric while the base warp yarn BWY is floated along the inside of the tubular fabric. The base warp yarn BWY will get caught in the catch 128b of the selector rod 128. Catch 128a will be shielded by the shielded rod allowing the indicia-forming warp yarn IWY to freely move up and down in the warp guide slots 108. Thus, the indicia-forming warp yarn IWY is interleaved with the weft yarn WY into the tubular fabric, and the base warp yarn BWY is floated (i.e. not woven) on the inside of the tubular fabric.
Control of the selector 100 is accomplished by means of a programmable logic controller 150 which turns the solenoids 136 on or off according to a predetermined pattern. The pattern is generated by a personal computer 152 and then stored as an array in the programmable logic controller's memory. FIG. 9 illustrates an array which might be used to weave the letter "A" into the tubular fabric. The array contains a series of binary digits. The horizontal rows of the array represent each pass of the shuttle. The vertical columns represent one solenoid 136 which controls two warp yarn pairs. The rows and columns are designated by reference numerals. A "0" stored at a particular coordinate position means that the corresponding solenoid 136 is turned off for a particular pass of the shuttle. A "1" means that the solenoid 136 is turned on. For example, in FIG. 9, "0" is stored at row 12, column 05. Thus, on the 12th pass of the shuttle 80, the solenoid 136 controlling two corresponding warp yarn pairs will be turned "off". A " 1" is stored at row 12, column 04 which will cause the corresponding solenoid 136 to be turned "on" during the 12th pass of the shuttle.
To sense the passing of the shuttle 80, a detector 154 is mounted under loom 10 near a pointer on gear 58 to sense shuttle 80 passing selector 100. When the shuttle 80 passes, an electrical signal is sent to the programmable controller 150. As shown in FIG. 10, the programmable controller 150 stays in a wait state until the passing of the shuttle 80 is detected. When the shuttle 80 is detected, the programmable controller 150 looks up to the proper settings for each solenoid 136 which is stored in the programmable controller's memory and then resets all of the solenoids 136. The count is then incremented by one and the programmable controller 150 returns to a wait state until the next pass of the shuttle 80.
Therefore, the present method and apparatus utilizes special indicia forming warp yarns to create a woven name, design or symbol within a woven tubular fabric. Specifically along an elongated warp yarn segment strip, the indicia forming warp yarns are selectively woven and floated (unwoven) to form the selected woven indicia in the tubular fabric. See, for example, FIG. 7 where the mark "Angus" has been woven into the woven fabric of a fire hose. Note that the "Angus" indicia formed on the fire hose is actually formed by the indicia forming warp yarns IWY which are of a different color than the base warp yarns BWY which effectively form that background for the indicia. It should be noted that in the approach illustrated in this disclosure that the respective weft yarns are tightly tucked such that their exposure from the outside of the tubular fabric is minimum. In any event, the weft yarns can be colored the same color as the base warp yarns so as to cooperate with the base warp yarns to form the contrast against which the formed indicia lies. Referring back to FIG. 7 and the illustration of the "Angus" indicia, note that the two construction lines 200 and 202 define the indicia warp yarn segment which essentially comprises that elongated segment of the tubular fabric consisting of both the base and indicia forming warp yarns that cooperate to form the woven indicia.
As already discussed, for each warp increment in the indicia warp yarn segment, the present process envisions feeding a pair of warp yarns into the loom, one warp yarn being a base warp yarn while the other is an indicia forming warp yarn. The selector 100 in response to the program controller and is controlled so as to weave the indicia forming warp yarns into selective positions on the tubular fabric and always while a certain indicia forming warp yarn is being woven, its mated base yarn is being floated or unwoven along the inside of the tubular fabric adjacent the formed indicia forming warp yarns. Likewise, when the base warp yarns are being woven in the indicia forming warp segment, defined between lines 200 and 202 of FIG. 7, the mating indicia forming yarns are likewise being floated or non-woven along the adjacent inside area of the woven fabric. This is particularly illustrated in FIG. 6 where it is seen that across the indicia forming warp segment that both base warp yarns and indicia forming yarns are interwoven with the weft yarns WY. Adjacent the woven base warp yarns and indicia forming warp yarns, one finds floating or non-woven yarns which differ from the warp yarns actually woven.
As already discussed, to select a particular warp yarn, that is a base warp yarn or an indicia forming warp yarn, the selector 100 effectively catches the non-selected warp yarn and holds it at an elevation sufficient to assure that it will not be pulled in the alternating shed forming process. This effectively assures that the non-selected warp yarn will not be interwoven with the weft yarn, and consequently, the non-selected warp yarns will be pulled into the loom and effectively floated or non-woven with the tubular fabric.
It is appreciated that all types of names, designs and symbols can be interwoven into a fire hose or any other tubular fabric according to the present invention. In addition, the basic process disclosed is compatible with computer technology and standard control systems that enable a predetermined design to be effectively stored into a computer and form the basis for automatically controlling the selector 100 to produce a desired design.
The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
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A method and apparatus for weaving an indicia such as a trademark, symbol or design into a tubular fabric. About a selected warp yarn segment of the tubular fabric, for each warp yarn increment, two warp yarns are actually directed into the loom, one warp yarn being a base yarn while the other warp yarn is an indicia forming yarn. The loom is provided with a warp yarn selector that for each pair of base and indicia forming yarns, it selects one and only one of the pair to be interwoven with a weft yarn. The non-selected yarn is essentially positioned such that it is not woven with the weft yarn and runs in a floating or unwoven fashion along the inside wall of the tubular fabric being woven. To provide a selected indicia interwoven in the tubular fabric, the selector is controlled in such a fashion that it causes indicia forming yarns to be woven in areas calling for the indicia background and base warp yarns to be woven in areas that call for the base yarn as a background. As noted, in all cases the non-selected warp yarn of the pair will be floated to run along the inside wall of the tubular fabric.
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BACKGROUND OF THE INVENTION
This invention relates generally to cooking apparatus and particularly to a cooking apparatus having an improved conveyor and heating system.
Restaurants of the type referred to as "fast food" as well as "full service" restaurants commonly use cooking apparatus which utilize a heating chamber in the form of a tunnel. Food to be cooked is conveyed through the heating chamber by an endless conveyor and overhead radiant heating is used in the cooking process. Examples of such apparatus are disclosed in U.S. Pat. No. 4,008,996 of Harold D. Wells; U.S. Pat. No. 4,245,613 of Harold D. Wells et al and U.S. Pat. No. 4,366,177 of Harold D. Wells et al.
One of the primary problems associated with the prior art apparatus is that of high energy consumption because of significant heat loss. Heat Loss results from several factors including the use of an endless conveyor having upper and lower spans which are continuously moving from the apparatus into the relatively cool ambient air. Another problem associated with the cooking process itself is that, unlike manual cooking, conveyor cooking in which a relatively enclosed tunnel is used does not readily permit the food product to be shuffled or shifted on the conveyor by use of a spatula. Further, linear movement through a conventional apparatus, without the use of fans to assist in moving the stratified air does not provide the desirable air agitation which enchances the cooking process.
The present invention solves these and other problems in a manner not disclosed in the known prior art.
SUMMARY OF THE INVENTION
This cooking apparatus provides a heating chamber and conveyor combination which minimizes heat loss, and optimizes even heat distribution resulting in significant energy savings of up to fifty percent (50%) as compared with conventional cooking apparatus.
In addition, the apparatus facilitates the cooking process by providing an intermittently moving conveyor surface having vertical as well as horizontal movement which tends to shuffle the product and move the air within the apparatus and distribute heat by convection as well as radiation and conduction.
This cooking apparatus includes a longitudinally extending housing assembly having a heating chamber with an upper portion, a lower portion, opposed side portions, a first end portion defining an entrance opening and a second end portion defining an exit opening; a heater assembly having an upper heater means housed in the upper portion of the heating chamber, and a control means for the heater means; and a longitudinally extending conveyor assembly including a plurality of first elongate rails and a plurality of second elongate rails disposed in side-by-side alternating relation with said first rails, each of said rails having a product carrying upper surface, said rails being disposed below the upper heater means, said conveyor assembly also including means for moving the common second rail surface in orbital relation relative to the common first rail surface.
In one aspect of this invention the first rails have a flat upper surface disposed in a common, substantially horizontal plane and the second rails have a flat upper surface disposed in a common movable substantially horizontal plane to move the product intermittently through the heating chamber while shuffling the product relative to the carrying surface.
It is another aspect of this invention to provide a heater assembly having a lower heater means housed in the lower portion of the heating chamber below the upper surface of the rails and to provide both upper and lower heater means with convex reflectors to improve heating distribution.
Yet another aspect of this invention is to provide that the moving means for the conveyor rails include transversely extending shafts disposed at the entrance end and the exit end of the housing, each of said shafts including eccentric portions carrying associated second rails to facilitate smooth movement of the product through the heating chamber.
Still another aspect of this invention is to provide the heater means with independent controls to provide zones of heating within the heating chamber.
Another aspect of this invention is to provide vestibule portions at each end of the heating chamber to retain heat within the chamber.
Yet another aspect of the invention is to provide at least one end of each rail with a longitudinally captive end support to permit expansion and contraction of the rails under temperature differential within the heating chamber yet provide that the rails can be readily lifted and pulled from the heating chamber to facilitate cleaning.
It is yet another aspect of this invention to provide channel-shaped first and second rails which include transverse perforations to reduce the conductive area and thereby reduce heat loss from the chamber.
Still another aspect of the invention is to provide outwardly extending rails having side spacers to facilitate transverse alignment of the rails and upwardly extending stops to prevent over-run of the product.
It is still another aspect of this invention to provide a method of depositing a product between first and second adjacent support surfaces, cyclically moving one of said support surfaces relative to the other support surface to separate the product intermittently from the other support surface and applying heat to the product continuously said movement providing heat distribution by convection to the underside of the product as well as the upper side of the product.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of the cooking apparatus carried on a mobile stand;
FIG. 2 is a plan view thereof;
FIG. 3 is an end view taken at the exit end of the conveyor;
FIG. 4 is an enlarged fragmentary elevational view of the apparatus taken at the entrance end of the conveyor;
FIG. 5 is an enlarged fragmentary elevational view of the apparatus taken at the exit end of the conveyor;
FIG. 6 is a fragmentary plan view taken on line 6--6 of FIG. 4;
FIG. 7 is a fragmentary view taken on line 7--7 of FIG. 5;
FIG. 8 is an enlarged cross sectional view taken on line 8--8 of FIG. 2;
FIG. 9 is an enlarged view illustrating the eccentric shaft and the stationary and movable rails;
FIG. 10 is an enlarged view illustrating the movable conveyor rails in a first position in which the movable rails are coplanar with the stationary rails;
FIG. 11 is a similar view to FIG. 10 illustrating the movable rails in a second, raised position;
FIG. 12 is a similar view to FIG. 10 illustrating the movable rails in a third position in which the movable rails are coplanar but longitudinally shifted relative to the stationary rails;
FIG. 13 is a similar view to FIG. 10 illustrating the movable rails in a fourth lowered position;
FIG. 14 is a schematic rendering of the heater arrangement;
FIG. 15 is a schematic rendering of the control circuitry of the heater elements and drive motor;
FIG. 16 is a schematic rendering of the temperature control unit;
FIG. 17 is a schematic rendering of the control panel;
FIG. 18 is a schematic rendering of the drive transmission, and
FIG. 19 is a fragmentary perspective view of the rails illustrating conductive-inhibiting perforations, alignment spacers and end stops.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now by reference numerals to the drawings and first to FIGS. 1, 2 and 3 it will be understood that the cooking apparatus generally indicated by numeral 10 is preferably carried by a mobile stand 12 and consists essentially of a longitudinally extending housing assembly 14, including a heating chamber 16 and end portions 18 and 20, and a conveyor assembly 22 consisting essentially of alternating rails 24 and 26 which cooperate to provide an article moving deck for moving a product such as trays 28 which move into the apparatus by way of an entrance opening 30 and exit by way of an exit opening 32.
The heating chamber 16 which, in the embodiment shown, is formed from sheet steel paneling, includes an upper portion 34, a lower portion 36, opposed side portions 38 and 40 and opposed end portions provided by vestibule members 42 and 44 which define the entrance opening 30 and the exit opening 32 respectively. In the embodiment shown the heating chamber near side 38 is provided with access doors 46 which permit products to be deposited onto the conveyor assembly 22 between its ends. The housing end portion 20 includes a control panel 21 as will be described.
The details of the cooking apparatus 10 will now be described with reference to FIGS. 4 through 12 and first with respect to FIGS. 4 through 8.
The heating chamber 16 is defined by upper panel 50, lower panel 52, side panels 54 and 56, a generally inverted U-shaped entrance end panel 58 and a similar exit end panel 60. In addition, the heating chamber 16 includes inner side panels 62 and 64 and a lower intermediate panel 66.
The upper portion 34 of the heating chamber 16 provides a housing for a tier of infra-red, tubular sheath radiant heater elements 70 disposed in opposed pairs three in number in the preferred embodiment. The heater elements 70 include outer legs 72 which are attached to the inner walls 62 and 64. An opposed pair of generally convex reflector plates 76 are disposed above the heater elements 70, said reflector plates being carried by an intermediate I-beam 78 welded, or otherwise attached, to the upper panel 50 and an elongate angle member 80 welded, or otherwise attached, to the inner side panel 64. The inner end and outer portions of the reflector plates 76 are provided with depending lugs 82 and 84 respectively which are attached thereto, as by welding, and which are longitudinally slotted to receive the inner ends of the radiant heater elements 70 and permit expansion thereof.
The lower portion of the heating chamber 16 includes a lower tier of radiant heater elements 71 which are similar to heater elements 70 of the upper tier and are provided with identical convex reflector plates 76 which are attached at their ends to support members 78 and 80, said support member 78 being attached to the lower intermediate panel 66. The upper and lower heater elements 70 and 71 provide a controlled heater assembly which will be discussed in greater detail.
The entrance and exit vestibules 42 and 44 disposed at opposite ends of the heating chamber provide short tunnel-like members which are attached to end panels 58 and 60 respectively and provide extended pasageways into and out of the heating chamber 16. The vestibules 42 and 44 tend to confine radiant heat to the useful working area within the heating chamber to stratify and reduce convection air losses at the open ends and make baffling or reduction of the passageway openings unnecessary.
The conveyor assembly rails 24 and 26 are disposed in alternating relation as clearly shown in FIG. 8. Both sets of rails extend outwardly of the heating chamber 16 to facilitate emplacement and removal respectively of the trays 28 or raw, unplated product such as pizza (not shown) before entry into the cooking chamber 16 and after exit of said trays from said chamber. The conveyor assembly rails 24 and 26 are disposed in alternating relation and both sets of rails extend outwardly of the heating chamber to provide platform areas to facilitate emplacement and removal respectively of products such as cooking trays 28 before entry into the heating chamber 16 and after exit from said chamber.
Rails 24 remain stationary during the conveying process and are horizontally aligned in coplanar relation. The rails 24 are supported at each end by transverse struts 90 notched to provide spaced tooth-like support members 92 at their upper end which receive the inverted channel-shaped rails 24 in clearance relation so that the rails can be readily removed for cleaning by simply lifting upwardly. The rails 24 are held in place longitudinally, at one end only, as by a pair of stop elements 93 on each side of supports 92, which permits free longitudinal movement of the rails due to heat expansion and contraction with the heating chamber 16.
Rails 26 also of inverted channel-shaped configuration are movable during the conveying process, as will be discussed below in greater detail, and are horizontally aligned in coplanar relation so that the upper surface thereof orbits relative to the upper surface of adjacent rails 24. The rails 26 are supported at each end by opposed transverse shafts 94 and 96 each of which includes ends 97 mounted for rotation between walls 64 and an elongate eccentric cylindrical portion 98. As best shown in FIGS. 4 and 5 the shafts 94 and 96 are rotated in the same direction by a drive system which includes a longitudinally extending shaft 100 rotated by the shaft 101 of a variable speed motor M through the medium of transmission assembly generally indicated by 104. The motor and transmission assembly are housed in the housing end portion 20. In the embodiment shown the motor M is a variable speed 0-90 volts D.C. induction motor, as shown in the circuit diagram FIG. 15 provided with a speed control SC.
The shaft 100 is supported by bearing brackets 102 attached to the heating chamber inside panel 64 and said shaft includes spaced bevel gears 108 and 110 attached thereto and engaging associated bevel gears 112 and 114 at the end of the transverse shafts 94 and 96 respectively.
The transmission 104 is mounted between support plates 116 and includes a motor shaft drive pulley 118 which is connected to the longitudinal drive shaft pulley 128 through the medium of pulleys 120, 122, 124 and 126 and associated belts 119, 123, and 127 as shown in FIG. 15.
The mounting of the rails 24 and 26 is best shown by reference to FIGS. 9-13. At one end, rails 26 are provided with a saddle block 130 of teflon or other suitable bearing material having an arcuate surface 132 with a radius substantially equal to the radius of the shaft eccentric 98. In the embodiment shown, the bearing surface 132 is generally semi-circular so that the saddle block is held by the eccentric 98 in captive relation to preclude longitudinal movement between the rails 26 and the eccentric 98 of shaft 94 while permitting relative longitudinal and vertical movement between the rails 26 and the rotational center of the shafts. At the other end, the rails 26 are provided with a block 134 having a flat bearing surface 136 of teflon or the like which is carried by the shaft 94. This arrangement of parts also permits the rails 26 to be readily removed by simply lifting upwardly from the saddle block end and pulling outwardly from the heating chamber 16. In addition, the provision of a saddle block connection at one end only permits free longitudinal movement of the rails due to heat expansion and contraction in the area within the heating chamber 16.
As shown in FIGS. 9 and 19 alignment of the movable rails 26 relative to the stationary rails 24 is facilitated by the provision of snap-fit, grooved spacer inserts 138 of nylon, or the like, in openings 139 provided in the depending legs of said rails at each end of the rails away from the heated portions. In order to provide stop members to prevent the product from leaving the rails, selected spacers 138 a at each side of the exit end of the conveyor assembly can be provided which extend upwardly above the plane of the rails as shown in FIG. 19. If desired openings 139 can be elongated to prevent rotation of said stop members. As also shown in FIG. 19 both rails 24 and 26 are perforated on their upper surface and sides with a plurality of openings 150 which are located at each end of the rails in the vicinity of the entrance and exit opening 30 and 32 and also at a location about one-third of the length of the heating chamber 16 measured from the entrance end thereof to separate the heating zones. These openings reduce the area of the cross section at least 50% and act to reduce heat loss by conduction from the portion of the rails disposed inside the heating chamber 16 as well as between said heating chamber and the portion of the rails disposed outside of the heating chamber.
The operation of the conveyor assembly and particularly the relative movement of the rails 24 and 26 is best understood by reference to FIGS. 9 through 13. It will be understood that the transverse shafts 94 and 96 are identical in that each shaft eccentric 98 provides a cam moving the horizontal upper surface 142 of rails 26 in orbital motion relative to the horizontal upper surface 140 of adjacent rails 24. The effect of this camming action is illustrated by considering coordinate movement of corresponding points on the rails 24 and 26 as the eccentric 98 rotates through four quandrants.
For explanatory purposes the fixed center of rotation of the shafts 94 and 96 is indicated by point A and the rotation of the surface of the eccentric indicated by point B. The rail 24 is stationary and for convenience the entrance and corner of said rail is chosen as reference point C while the corresponding corner of the movable rail 26 is chosen as point D.
Initially, as shown in FIG. 10, the rails surfaces 140 and 142 are coplanar and the points C and D are coincident. After movement of point B through one quandrant, as shown in FIG. 11, surface 142 is disposed above surface 140 as illustrated by the position of point D relative to fixed reference point C. After movement of point B through two quandrants, as shown in FIG. 12, surface 142 is again coplanar to surface 140 but there has been a forward shift of the surfaces as illustrated by the position of point D relative to reference point C. After movement of point B through three quandrants, as shown in FIG. 13, surface 142 is disposed below surface 140 as illustrated by the position of point D relative to reference point C. After movement of point B through four quandrants rails 24 and 26 are again coplanar and points C and D are again coincident as shown in FIG. 9 which completes one revolution of the shafts 94 and 96. Thus, as the shafts 94 and 96 move through one cycle or revolution, a product is moved intermittently through a distance equal to the difference between the diameter of the eccentric and the diameter of the ends 97 of shafts 94 and 96. In the case of a differential of one-quarter inch, the longitudinal movement is also one-quarter inch while the upward and downward displacements are an eighth of one inch respectively. The result of this is that the product is lifted and moved forwardly these amounts each cycle or revolution of the shafts.
The heater assembly control system is best understood by reference to FIGS. 14-17 which illustrate the heater arrangement and the circuitry in schematic form. In the embodiment shown, see FIG. 14, each row of upper heater elements 70a, 70b, 70c, and 70d, 70e, 70f, is disposed above a lower row of heaters 71a, 71b, 71c, and 71d, 71e, 71f respectively. The right hand rows of heaters 70a, 70b, 70c, and 71a, 71b, 71c on one side of the longitudinal axis of the heating chamber 16 are controlled independently of the left hand row of heaters 70d, 70e, 70f, and 71d, 71e, 71f, on the other side of the longitudinal axis. FIG. 14 illustrates, by broken lines, the cooperative arrangement of the heater elements.
It has been determined that it is an advantage to have higher temperature heaters at the entrance end of the heating chamber and for this reason, as shown in FIG. 14 and FIG. 15, the right hand row upper heater 70c (3300w) and lower heater 71c (1975w) at the entrance end are connected and controlled by contactor C1; the upper heater 70a (1975w) at the exit end and the intermediate upper heater 70b (1975w) are controlled by contactor C2 and the lower heater 71 (1450w) at the exit end and the intermediate lower heater 71b (1450w) are controlled by contactor C3. Similarly, the left hand row upper heater 70f (3300w) and lower heater 71f (1975w) at the entrance end are connected and controlled by contactor C4; the upper heater 70d (1975w) at the exit end and the intermediate heater 70e (1975w) are controlled by contactor C6 and the lower heater 71d (1450w) at the exit end and the intermediate lower heater 71e (1450w) are controlled by contactor C6.
As shown in FIGS. 15 and 16 the heater contactors C1-C6 are energized by corresponding temperature control and power switching units indicated by TC1-TC6. Such units are exemplified by Model 35AA-2600-1100 single pole units as manufactured by Watlow of Winona, Minn. As will be readily understood, each contactor for example C1 is connected to a corresponding temperature control such as TC1 which permits independent temperature setting of the heaters 70c and 71c. As will also be readily understood this arrangement permits considerably versatility in apparatus temperature control.
It is thought that the structural features and functional advantages of this cooking apparatus have become fully apparent from the foregoing description of parts but for completeness of disclosure the operation of the apparatus will be briefly described.
The speed of the conveyor assembly 22 and the temperature adjustment of the heater elements 70 and 71 are adjusted to suit the particular product to be cooked. When this adjustment has been made the product is either placed directly onto the upper surface of the conveyor rails 24 and 26 (in the case of pizza for example) or are placed in trays (in the case of buns) and the trays are then placed on the rails.
The product, for example trays 28, are placed on the outwardly extending portion of the conveyor. It will be understood that the length of this outwardly extending portion can be increased or decreased by the simple expedient of using longer or shorter rails since, unlike conventional conveyors, the length of the conveyor deck is not dependent on the center-to-center distance between the transverse shafts 94 and 96.
Rotation of the shafts 94 and 96, which carry the rails 26, results in orbital movement of the rails 26 relative to the rails 24 with the result that the articles are lifted by the rails 26 from the rails 24, moved forwardly and again lowered and deposited onto the rails 24. The rails 26 continue downward and rearward movement to return to their original postion in the course of one cyclical revolution of the shafts 94 and 96. In the preferred embodiment the center of rotation of the shafts 94 and 96 is one-eighth inch (1/8") from the center of the shaft eccentric portion 98 which results in a high position of the article one-eighth inch above the upper surface 140 of rails 24 and intermittent incremental forward movement of the product a distance of one-quarter inch.
Radiant heat from the upper tier of heater elements 70 is directed downwardly onto the upper surface of the rails 24 and 26 and consequently on the upper surface of the cooking products, the radiant heat being directed downwardly by virtue of the reflector plates 76. The reflector plates 76 are generally convex with the results that the heat tends to move outwardly rather than to be concentrated in the center of the heating chamber, resulting in a more even distribution of heat. The lower convex reflector 76 directs radiant heat from the lower tier of heater elements 71 upwardly onto the underside of the rails 24 and 26 and therefore reaches the cooking product indirectly by passing through the upper portions of the rails. As with the upper heaters 70, the convex shape also causes heated air to converge outwardly thereby providing convection heating as well as radiant heating.
It is well known that, in the conventional cooking of products such as pizza, it is necessary to move the product constantly by using a spatula to raise and redeposit the product to prevent sticking to the hot cooking surface. This particular procedure undoubtedly assists the cooking process by allowing air agitation underneath the cooking product and in the case of radiant, and also griddle heating, prevents a cold spot from developing under the product. It is believed that a similar advantageous process takes place automatically with the conveyor assembly 22 in which, unlike a conventional belt conveyor for example, cold spots are not permitted to develop and, to the contrary, the relative movement of the rails keeps the air agitated and provides heat distribution to all of the outer surface of the product by up and down motion of the product, as illustrated in FIG. 9 as well as transporting the product forwardly.
Further, moving the product consistently to new heated areas enchances the conduction heating process while balancing uniformity of the cooking. Thus, the cooking system promotes the benefits of all three heat transfer methods to the article, namely, infrared radiation, convection and conduction. Moreover, the orbital motion of the conveyor rail surface provided by rails 26 moves the article through the heating chamber in a manner that increases the velocity of the heated air onto the article so that it is unnecessary to use fans to provide convective air movement, the transportation speed being such that the product is moved through a four feet long heating chamber in a time period of between 21/2 minutes-19 minutes depending on the product and the temperature setting.
The upper and lower heater elements 70 and 71 are temperature controlled so that the heat applied during the initial cooking stage as the product enters the heating chamber is greater than that during the remaining stage. This also results in energy savings.
The provision of entrance and exit vestibule portions 42, of the heating chamber 16 results in less heat loss and the fact that the conveyor deck as a whole is virtually stationary means that, unlike a conventional endless belt conveyor, the heated deck does not circulate from a hot apparatus area to a cold ambient area which results in further energy savings. Further, the provision of openings 150 prevents conduction of heat out of the heating chamber 16 between the inner heated zone and the outer cooler zone, and between different heating zones within the chamber. Thus the initial heating stage can be maintained at 700° F. while the second stage can be maintained at 400° F. with a substantially clear temperature differential existing between the zones.
Essentially, the cooking method outlined above provides that a product can be deposited between two adjacent support surfaces, one of which is cyclically moved relative to the other by camming so that the product is intermittently separated from one of the support surfaces and is shifted in position to facilitate the cooking process by breaking tension between the product surface and the cooking surface.
In view of the above it will be seen that various aspects and features of the invention are achieved and other advantageous results attained. While preferred embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made therein without departing from the invention in its broader aspects.
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This cooking apparatus includes a housing assembly providing a heating chamber having an entrance and an exit, and a conveyor assembly extending through the heating chamber and having end portions extending outwardly of the heating chamber. The heating chamber includes vestibule portions at each end and heater elements within the chamber provide zone-controlled heating. The conveyor assembly includes stationary rails defining a coplanar product-receiving surface alternating with moving rails defining a coplanar product-receiving surface having orbitral motion relative to the stationary surface to lift the product, transport it forwardly and deposit it so that the product moves intermittently through the heating chamber. The relative motion of the rails is provided by rotatable transverse shafts having eccentric portions supporting bearings provided at each end of the movable rails and both sets of rails are restrained from longitudinal movement at one end and are liftably removable from their supports to facilitate cleaning. The rails are perforated lengthwise to inhibit heat loss by conduction and include spacers to facilitate alignment and carry stop members to limit longitudinal movement of the product.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser. No. 13/587,962 filed Aug. 17, 2012 and now issued as U.S. Pat. No. ______, which is a continuation of U.S. application Ser. No. 11/712,249 filed Feb. 28, 2007 and now issued as U.S. Pat. No. 8,272,008, with both application incorporated herein by reference in their entireties.
BACKGROUND
[0002] Exemplary embodiments generally relate to communications, to interactive video, and to television and, more generally, to selection of multiple sources for audio inputs.
[0003] Alternate audio content is desirable. When a user receives audio-visual content (such as a movie, for example), the user may not be satisfied with the audio portion of that content. The audio portion may contain offensive language, undesirable dialog, or an unknown language. A common situation involves televised sporting events. When televised football and baseball are watched, some people prefer to listen to different announcers for the play-by-play action. For whatever reasons, then, a user may prefer to receive and experience an alternate audio source that provides a different language track, sanitized dialog, and/or alternate commentary. What is needed, then, are methods, systems, and products that search and retrieve alternate audio sources for video signals.
SUMMARY
[0004] Exemplary embodiments provide methods, systems, and products for searching, retrieving, and synchronizing alternate audio sources. Exemplary embodiments identify alternate audio content that may be separately available from video content. When a user receives and watches a movie, for example, exemplary embodiments permit the user to seek out and retrieve alternate audio content from the Internet, from an AM/FM radio broadcast, or from any other source. When the video content is received, the video content may self-identify one or more alternate audio sources that correspond to the video content. The video content, for example, may be tagged or embedded with websites, server addresses, frequencies, or other information that describe the alternate audio sources. Exemplary embodiments may even automatically query database servers (such as GOOGLE® and YAHOO®) for alternate audio sources that correspond to the video content. Once the user selects an alternate audio source, exemplary embodiments may then synchronize the video content and the separately-available alternate audio content. Because the video content and the alternate audio content may be received as separate streams of data, either of the streams may lead or lag. Exemplary embodiments, then, may also synchronize the separately-received streams of data to ensure a pleasing entertainment experience.
[0005] Exemplary embodiments include a method for retrieving an audio signal. A video signal is received that comprises a content identifier and an alternate audio tag. In response to the alternate audio tag, a query is sent for an alternate audio source that corresponds to the content identifier. This query may be automatically generated and sent, or the query may be specifically requested by the viewer. A query result is received that identifies an audio signal that corresponds to the content identifier and that is separately received from the video signal.
[0006] More exemplary embodiments include a system for retrieving an audio signal. A video signal is received that comprises a content identifier and an alternate audio tag. In response to the alternate audio tag, a query is sent for an alternate audio source that corresponds to the content identifier. A query result is received that identifies an audio signal that corresponds to the content identifier and that is separately received from the video signal.
[0007] Other exemplary embodiments describe a computer program product for retrieving an audio signal. The computer program product has processor-readable instructions for receiving a video signal that comprises a content identifier and an alternate audio tag. In response to the alternate audio tag, a query is sent for an alternate audio source that corresponds to the content identifier. A query result is received that identifies an audio signal that corresponds to the content identifier and that is separately received from the video signal.
[0008] Other systems, methods, and/or computer program products according to the exemplary embodiments will be or become apparent to one with ordinary skill in the art upon review of the following drawings and detailed description. It is intended that all such additional systems, methods, and/or computer program products be included within this description, be within the scope of the claims, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] These and other features, aspects, and advantages of the exemplary embodiments are better understood when the following Detailed Description is read with reference to the accompanying drawings, wherein:
[0010] FIG. 1 is a schematic illustrating an operating environment in which exemplary embodiments may be implemented;
[0011] FIG. 2 is a schematic illustrating a process for retrieving alternate audio sources, according to more exemplary embodiments;
[0012] FIG. 3 is a schematic further illustrating a process for retrieving alternate audio, according to more exemplary embodiments;
[0013] FIG. 4 is a schematic illustrating additional queries for alternate audio sources, according to more exemplary embodiments;
[0014] FIG. 5 is a schematic illustrating a user interface for retrieving alternate audio sources, according to more exemplary embodiments;
[0015] FIGS. 6 and 7 are schematics illustrating synchronization of signals, according to more exemplary embodiments;
[0016] FIG. 8 is a schematic illustrating an electronic device, according to more exemplary embodiments;
[0017] FIGS. 9-14 are schematics illustrating additional operating environments in which exemplary embodiments may be implemented; and
[0018] FIG. 15 is a flowchart illustrating a method of retrieving audio signals, according to more exemplary embodiments.
DETAILED DESCRIPTION
[0019] The exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings. The exemplary embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete and will fully convey the exemplary embodiments to those of ordinary skill in the art. Moreover, all statements herein reciting embodiments, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure).
[0020] Thus, for example, it will be appreciated by those of ordinary skill in the art that the diagrams, schematics, illustrations, and the like represent conceptual views or processes illustrating the exemplary embodiments. The functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing associated software. Those of ordinary skill in the art further understand that the exemplary hardware, software, processes, methods, and/or operating systems described herein are for illustrative purposes and, thus, are not intended to be limited to any particular named manufacturer.
[0021] As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms “includes,” “comprises,” “including,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. Furthermore, “connected” or “coupled” as used herein may include wirelessly connected or coupled. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0022] It will also be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first device could be termed a second device, and, similarly, a second device could be termed a first device without departing from the teachings of the disclosure.
[0023] FIG. 1 is a schematic illustrating an environment in which exemplary embodiments may be implemented. A user's electronic device 20 receives a video signal 22 from a communications network 24 . The video signal 22 may be a movie, sporting event, or any other content. The video signal 22 may originate, or be received from, any source, such as a video server 26 . The video signal 22 may have any formatting, and the video signal 22 may be unicast, multicast, or broadcast to the electronic device 20 . The video signal 22 may also originate from a local source, such as a DVD player, a digital or analog recorder, local memory, or other local source that may be accessible without the communications network 24 . Although the electronic device 20 is generically shown, the electronic device 20 , as will be later explained, may be a computer, a radio, a set-top receiver, a personal digital assistant (PDA), a cordless/cellular/IP phone, digital music player, or any other processor-controlled device.
[0024] The video signal 22 may include an alternate audio tag 28 . According to exemplary embodiments, the alternate audio tag 28 may be any information that identifies alternate audio sources for the video signal 22 . The video signal 22 may include, or be received with, audio content or portions (such as an audio track to a movie). The user, however, may wish to experience an alternate audio source that is not sent with the video signal 22 . The alternate audio source, for example, may be a different language track, sanitized dialog, an AM or FM radio broadcast, and/or alternate commentary. These alternate audio sources, in general, may be any audio signal that is separately received from the video signal 22 . As FIG. 1 illustrates, the video signal 22 , and/or alternate audio tag 28 , may include a video content identifier 30 . The video content identifier 30 may be any identification number, title, code, or other data that uniquely describes the content associated with the video signal 22 . The alternate audio tag 28 may be embedded within the video signal 22 (or otherwise associated with the video signal 22 ) to alert or notify users of these alternate audio sources.
[0025] The user's electronic device 20 receives the video signal 22 . The user's electronic device 20 also receives the alternate audio tag 28 and/or the video content identifier 30 . The user's electronic device 20 comprises a processor 32 (e.g., “μP”), application specific integrated circuit (ASIC), or other similar device that may execute an alternate audio application 34 stored in memory 36 . According to exemplary embodiments, the alternate audio application 34 comprises processor-executable instructions that may inspect the video signal 22 for the alternate audio tag 28 or otherwise identify the associated alternate audio tag 28 . The presence of the alternate audio tag 28 notifies the alternate audio application 34 that alternate audio sources may exist for the video signal 22 . When the alternate audio tag 28 is detected, the alternate audio application 34 may alert the user that alternate audio sources may exist for the video signal 22 . The alternate audio application 34 , for example, may cause the visual and/or audible presentation of a prompt 38 on a display device 40 . The prompt 38 notifies the user that alternate audio sources may exist. When the user wishes to retrieve an alternate audio source, the user may affirmatively select a control 42 , thus authorizing the alternate audio application 34 to query for the alternate audio sources.
[0026] FIG. 2 is a schematic illustrating a process for retrieving alternate audio sources, according to more exemplary embodiments. When the user wishes to retrieve an alternate audio source, the user affirmatively responds to the prompt (shown as reference numeral 38 in FIG. 1 ). The alternate audio application 34 may call or invoke a search application 50 to issue or send a query for any alternate audio sources associated with the video content identifier (Step 52 ). The query may communicate (via the communications network 24 illustrated in FIG. 1 ) to a database server 54 (such as a YAHOO® or GOOGLE® server). The query may additionally or alternatively communicate to other devices in the vicinity of the user's electronic device 20 . The query, for example, may be sent via an infrared, BLUETOOTH®, WI-FI®, or other coupling to other devices within the user's social network.
[0027] A response is then received (Step 56 ). The response includes a query result that may include or describe a listing 58 of one or more alternate audio sources that may correspond to the video signal 22 . The listing 58 , for example, may describe one or more websites or network addresses that provide an alternate, simulcast or archived audio signal to accompany the video signal 22 . The listing 58 may describe one or more radio stations that broadcast an alternate audio signal (such as alternate announcers for a sporting event). The listing 58 may include real-time or archived podcasts from a member of an audience. The listing 58 may also include alternate audio sources obtainable from members of the user's social network.
[0028] The listing 58 is presented to the user (Step 60 ). The search application 50 and/or the alternate audio application 34 may cause the listing 58 to be displayed on the display device (illustrated as reference numeral 40 in FIG. 1 ). The user may then select an alternate audio source from the listing 58 , and that selection is received (Step 62 ). According to exemplary embodiments, the alternate audio application 34 causes an audio query to be sent for the selected alternate audio source (Step 64 ). The audio query communicates (via the communications network 24 illustrated in FIG. 1 ) to a communications address associated with a source of the selected alternate audio source. The audio query, for example, may communicate to an audio server. An audio signal is then received at the user's electronic device 20 (Step 66 ). If the alternate audio source is a terrestrial AM or FM radio station signal, then the user's electronic device 20 may be tuned to the corresponding frequency (as later paragraphs will explain).
[0029] The user's electronic device 20 then processes signals. The user's electronic device 20 thus receives the video signal (illustrated as reference numeral 22 in FIG. 1 ) and also receives the separate, audio signal. The video signal and the audio signal may thus be separately received as separate streams of data. The user's electronic device 20 then processes the video signal and the audio signal for visual and audible presentation (Step 68 ).
[0030] Exemplary embodiments may be applied regardless of networking environment. The communications network 24 may be a cable network operating in the radio-frequency domain and/or the Internet Protocol (IP) domain. The communications network 24 , however, may also include a distributed computing network, such as the Internet (sometimes alternatively known as the “World Wide Web”), an intranet, a local-area network (LAN), and/or a wide-area network (WAN). The communications network 24 may include coaxial cables, copper wires, fiber optic lines, and/or hybrid-coaxial lines. The communications network 24 may even include wireless portions utilizing any portion of the electromagnetic spectrum, any modulation technique, and/or any signaling standard (such as the I.E.E.E. 802 family of standards, GSM/CDMA/TDMA or any cellular standard, and/or the ISM band). The concepts described herein may be applied to any wireless/wireline communications network, regardless of physical componentry, physical configuration, or communications standard(s).
[0031] FIG. 3 is a schematic further illustrating a process for retrieving alternate audio, according to more exemplary embodiments. Here, when the video signal (illustrated as reference numeral 22 in FIG. 1 ) is received (Step 80 ), the video signal may also identify the alternate audio sources. That is, when the alternate audio tag 28 is received, the listing 58 of one or more alternate audio sources may also be embedded or encoded within the video signal and/or the alternate audio tag 28 . Alternatively, the listing 58 may be separately retrieved via a database query using the video content identifier 30 . A content provider of the video signal, for example, may configure the video signal to self-identify the alternate audio sources. The video signal may include information that identifies a website or server address that provides an alternate language track or a different dialog. The content provider may identify radio stations providing different announcers for a football game, political convention, or background music. Again, whatever the alternate audio sources, the listing 58 may be embedded or encoded within the video signal and/or the alternate audio tag 28 .
[0032] The user's electronic device 20 receives the alternate audio tag 28 . The presence of the alternate audio tag 28 again notifies the alternate audio application 34 that alternate audio sources may exist for the video signal. The alternate audio application 34 may visually and/or audibly present the listing 58 already received from the video signal (Step 82 ). The user may select an alternate audio source from the listing 58 , and the alternate audio application 34 receives that selection (Step 84 ). The alternate audio application 34 sends the audio query to the source of the selected alternate audio source (e.g., an audio server 86 ) (Step 88 ). The audio server 86 sends the separate audio signal (Step 90 ). The user's electronic device 20 thus receives the video signal and also receives the separate, audio signal. The user's electronic device 20 then processes the video signal and the audio signal for visual and audible presentation (Step 92 ).
[0033] FIG. 4 is a schematic illustrating additional queries for alternate audio sources, according to more exemplary embodiments. Because FIG. 4 is similar to FIGS. 2 and 3 , FIG. 4 is only briefly described. When the video signal is received (Step 100 ), the video signal may also include the alternate audio tag and the listing of alternate audio sources. The listing of alternate audio sources is presented to the user (Step 102 ). Here, even though the content provider may embed or provide the listing of alternate audio sources, the user may still wish to query for other alternate audio sources. The alternate audio sources identified in the listing, for example, may not appeal to the user. The user may, instead, wish to conduct a search for additional alternate audio sources not identified in the listing. The alternate audio application 34 , then, may prompt to search for alternate audio sources, despite the listing (Step 104 ). When the user affirmatively responds to the prompt, the alternate audio application 34 is authorized to query for additional alternate audio sources. The alternate audio application 34 calls or invokes the search application 50 and sends the query for any alternate audio sources associated with the video content identifier (Step 106 ). A response to the query is received (Step 108 ), and the query result describes more alternate audio sources that may correspond to the same video content identifier.
[0034] The alternate audio sources are then presented (Step 110 ). The user may select any alternate audio source from the listing or from the query result. The user's selection is received (Step 112 ) and the audio query is sent to the source (e.g., the audio server 86 ) (Step 114 ). The separate audio signal is received (Step 116 ) and processed along with the video signal (Step 118 ).
[0035] FIG. 5 is a schematic illustrating a user interface for retrieving alternate audio sources, according to more exemplary embodiments. According to exemplary embodiments, the alternate audio application 34 causes the processor 32 to graphically present a user interface 130 on the display device 40 . When the video signal 22 includes the listing 58 , the user interface 130 may present the listing 58 to the user. The user is thus informed of alternate audio sources embedded or encoded within the video signal 22 . The user, however, may wish to search for additional alternate audio sources not identified in the listing 58 . The user interface 130 , then, may include the control 42 to search for additional audio sources. When the user selects the control 42 , the alternate audio application 34 may invoke the search application (illustrated as reference numeral 50 in FIGS. 2-4 ) and query for alternate audio sources associated with the video content identifier 30 . When the search results are received, the user interface 130 may visually present those additional audio sources 134 . The user may then select a desired alternate audio source from the alternate audio sources provided by the listing 58 and/or from the additional alternate audio sources found by invoking the search application 50 . The desired alternate audio source is retrieved and processed.
[0036] FIG. 6 is a schematic illustrating synchronization of signals, according to more exemplary embodiments. Now that the user has selected an alternate audio source, the user's electronic device 20 may receive the video signal 22 and the separate audio signal 140 . The video signal 22 may communicate from the video server 26 via the communications network 24 . According to exemplary embodiments, the separate audio signal 140 communicates from a separate source, such as the audio server 86 . The video signal 22 and/or the audio signal 140 may be unicast, multicast, or broadcast to the electronic device 20 . The video signal 22 and the audio signal 140 may thus be separately received as separate streams of data.
[0037] The audio signal 140 and the video signal 22 may need synchronization. When the audio signal 140 and the video signal 22 correspond to the same content, propagation delays in the communications network 24 may cause the video signal 22 and/or the audio signal 140 to lead or lag. The video signal 22 , for example, may contain more bits or information than the audio signal 140 , so the video signal 22 may propagate more slowly through the communications network 24 . Whatever the causes, though, the audio signal 140 and the video signal 22 may be unsynchronized. When the audio signal 140 and the video signal 22 correspond to the same content, then the audio portion of the content may be out-of-synchronization with the video portion. The electronic device 20 , then, may synchronize the audio signal 140 and the video signal 22 to help ensure the content is enjoyed as intended.
[0038] A synchronizer 142 may be invoked. The synchronizer 142 may be a component of the electronic device 20 that causes synchronization of the audio signal 140 and the video signal 22 . As later paragraphs will explain, the synchronizer 142 may be circuitry, programming, or both. The synchronizer 142 , for example, may compare time stamps and/or markers. As FIG. 6 illustrates, the video signal 22 may include one or more video time stamps 144 . The video time stamps 144 mark or measure an amount of time from a reference point or time. The video time stamps 144 , for example, may signify an offset time from the start of a file, program, or the video signal 22 . Some or all frames in the video signal 22 may have corresponding time stamps that measure when a frame occurs with reference to the start of the file, program, or the video signal 22 .
[0039] The electronic device 20 may also receive audio time stamps 146 . When the audio signal 140 is received, the audio time stamps 146 may be encoded within the audio signal 140 . The audio time stamps 146 mark or measure an amount of time from a reference point or time. The audio time stamps 146 may signify an offset time from the start of a file, program, or the audio signal 140 . The audio time stamps 146 mark or measure when portions of the audio signal 140 occur with reference to the start of the file, program, or the audio signal 140 .
[0040] The synchronizer 142 may compare the audio time stamps 146 to the video time stamps 144 . When a currently-received audio time stamp 148 exceeds a currently-received video time stamp 150 , then the synchronizer 142 may delay the audio signal 140 . The synchronizer 142 may subtract the currently-received video time stamp 150 from the currently-received audio time stamp 148 . That difference is compared to a threshold time 152 . The threshold time 152 is any configurable time at which timing lag (or lead) in the video signal 22 is unacceptable. When the difference between the currently-received audio time stamp 148 and the currently-received video time stamp 150 equals and/or exceeds the threshold time 152 , then the synchronizer 142 may delay the audio signal 140 . The synchronizer 142 may even compare the absolute value of the difference to the threshold time 152 . The synchronizer 142 continues to compare the successively-received audio time stamps 146 to the successively-received video time stamps 144 until the difference is within the threshold time 152 . The synchronizer 142 then releases a delayed audio signal 154 for subsequent processing. The delayed audio signal 154 , for example, may be processed by processing circuitry 156 for audible presentation. The video signal 22 may also be processed by the processing circuitry 156 for visual presentation. Because the audio signal 140 has been delayed, though, exemplary embodiments synchronize the delayed audio signal 154 and the video signal 22 to help ensure the content is enjoyed.
[0041] The synchronizer 142 may additionally or alternatively utilize markers. The video signal 22 and/or the audio signal 140 may include or be associated with markers. These markers may or may not be based on time stamps. These markers represent and/or identify an event within the video signal 22 and/or the audio signal 140 . A marker, for example, may identify a scene, a transition, a beginning of a new segment, and/or some other occurrence in the video signal 22 and/or the audio signal 140 . For example, a marker may identify a kick-off of a football game, a transition from one scene to another in a movie, or some other occurrence. The synchronizer 142 may compare the video signal 22 and/or the audio signal 140 for similar markers. When a lead condition is detected, the leading signal may be delayed for synchronization.
[0042] Some aspects of synchronization are known, so this disclosure will not greatly explain the known details. If the reader desires more details, the reader is invited to consult the following sources, all incorporated herein by reference in their entirety: U.S. Pat. No. 4,313,135 to Cooper; U.S. Pat. No. 4,839,733 to Karamon, et al.; U.S. Pat. No. 5,055,939 to Karamon, et al.; U.S. Pat. No. 5,202,761 to Cooper; U.S. Pat. No. 5,387,943 to Silver; U.S. Pat. No. 5,440,351 to Ichino; U.S. Pat. No. 5,577,042 to McGraw, Sr., et al.; U.S. Pat. No. 5,917,557 to Toyoda; U.S. Pat. No. 6,263,505 to Walker, et al.; U.S. Pat. No. 6,502,142 to Rapaich; U.S. Pat. No. 6,630,963 to Billmaier; U.S. Pat. No. 6,710,815 to Billmaier; U.S. Patent Application Publication 2002/0101442 to Costanzo, et al.; U.S. Patent Application Publication 2003/0086015 to Korhonen, et al.; U.S. Patent Application Publication 2004/0117825 to Watkins; and U.S. Patent Application Publication 2005/0027715 to Casey, et al.
[0043] FIG. 7 is a schematic illustrating a delay of the video signal 22 , according to more exemplary embodiments. Here, for whatever reason, the video signal 22 may lead the audio signal 140 . That is, when the audio signal 140 lags the video signal 22 , exemplary embodiments may delay the video signal 22 . The synchronizer 142 may again compare the audio time stamps 146 to the video time stamps 144 . When the currently-received video time stamp 150 exceeds the currently-received audio time stamp 148 , then the synchronizer 142 may delay the video signal 22 . The synchronizer 142 may subtract the currently-received audio time stamp 148 from the currently-received video time stamp 150 and compare that difference to the threshold time 152 . When the difference equals and/or exceeds the threshold time 152 , then the synchronizer 142 may delay the video signal 22 . The synchronizer 142 continues to compare the successively-received video time stamps 144 to the successively-received audio time stamps 146 until the difference is within the threshold time 152 . The synchronizer 142 then releases a delayed video signal 160 for subsequent processing. The processing circuitry 156 processes the audio signal 140 and/or the delayed video signal 160 for audible/visual presentation. The audio signal 140 and the delayed video signal 160 are thus synchronized to help ensure the content is enjoyed.
[0044] FIG. 8 is a schematic further illustrating the electronic device 20 , according to more exemplary embodiments. Here the synchronizer 142 comprises the processor 32 , and the processor 32 executes a synchronization application 170 . The synchronization application 170 is illustrated as a module or sub-component of the alternate audio application 34 . The synchronization application 170 , however, may be a separate application that stores in the memory 36 and cooperates with the alternate audio application 34 . The synchronization application 170 may even be remotely stored and accessed at some location within the communications network (illustrated as reference numeral 24 in FIG. 1 ). Regardless, the synchronization application 170 comprises processor-executable instructions that determine when synchronization is needed between the received audio signal 140 and the received video signal 22 , according to exemplary embodiments. When synchronization is needed, the synchronization application 170 synchronizes the video signal 22 and the separately-received audio signal 140 .
[0045] The synchronization application 170 may first determine when synchronization is desired. When the audio signal 140 and the video signal 22 correspond to the same content, synchronization may be desired. If, however, the audio signal 140 and the video signal 22 are unrelated, then perhaps synchronization is unnecessary. The synchronization application 170 , then, may inspect for content identifiers. As FIG. 8 illustrates, when the audio signal 140 is received, the audio signal 140 may include an audio content identifier 172 . The audio content identifier 172 may be any information that describes the audio signal 140 . The audio content identifier 172 , for example, may be any identification number, title, code, or other alphanumeric string that uniquely describes the audio signal 140 . Likewise, when the video signal 22 is received, the synchronization application 170 may inspect the video signal 22 for the video content identifier 30 . The video content identifier 30 may be any identification number, title, code, information, or alphanumeric string that uniquely describes the video signal 22 .
[0046] The synchronization application 170 may then compare the audio content identifier 172 to the video content identifier 30 . If the audio content identifier 172 matches the video content identifier 30 , then the audio signal 140 and the video signal 22 likely correspond to the same content. If even some portion of the audio content identifier 172 matches the video content identifier 30 (or vice versa), then the audio signal 140 and the video signal 22 may still correspond to the same content. The synchronization application 170 may thus confirm that the audio signal 140 and the video signal 22 should be synchronized. If the synchronization application 170 observes no similarity, or an insubstantial amount of similarity, in the audio content identifier 172 and the video content identifier 30 , then synchronization application 170 may decline to synchronize. Regardless, a user may configure the synchronization application 170 to start, or to stop, synchronization as needed, despite dissimilar content identifiers.
[0047] Once synchronization is determined to be needed and/or desired, the synchronization application 170 may ensure the content remains pleasing and enjoyable. The synchronization application 170 reads, extracts, or otherwise obtains the audio time stamps 146 and the video time stamps 144 and makes a comparison. Whenever a lead or a lag condition is detected, the synchronization application 170 may instruct the processor 32 to divert the leading signal to a buffer memory 174 . The buffer memory 174 may store the leading signal in a first in, first out (FIFO) fashion. As the leading signal accumulates in the buffer memory 174 , the leading signal is delayed in comparison to a lagging signal 176 . A delayed signal 178 may then be retrieved from the buffer memory 174 and processed by the processing circuitry 156 . So, regardless of whether the video signal 22 or the audio signal 140 leads, the buffer memory 174 may cause a delay, thus synchronizing the audio and video portions.
[0048] FIG. 8 also illustrates user-configuration of the threshold time 152 , according to more exemplary embodiments. Because the threshold time 152 is configurable, the threshold time 152 may be specified by a user of the electronic device 20 , according to exemplary embodiments. The user interface 130 , for example, may permit changing or entering the threshold time 152 . The user interface 130 allows the user to alter the threshold time 152 and, thus, manually set or establish any delay caused by the synchronizer 142 . The user interface 130 , for example, may have a data field 180 into which the user enters the threshold time 152 . The threshold time 152 may be expressed in any measurement and/or in any increment of time, from zero delay to seconds, minutes, or even hours of delay. The user interface 130 may additionally or alternatively include a first timing control 182 for increasing the threshold time 152 . A second timing control 184 may be used to decrease the threshold time 152 . The user interface 130 may additionally or alternatively include a graphical or physical rotary knob, slider, button, or any other means of changing the threshold time 152 .
[0049] The threshold time 152 may be specified by a content provider. A provider of the video signal 22 , for example, may include threshold information 186 within the video signal 22 . The threshold information 186 is then used to define, derive, or specify the threshold time 152 . The threshold information 186 , for example, may be embedded or encoded within the video signal 22 . When the video signal 22 is received, exemplary embodiments may then obtain, read, and/or extract the threshold information 186 . The provider of the video signal 22 may thus specify the threshold time 152 and determine how much asynchronism is tolerable between the video signal 22 and the corresponding (but separately received) audio signal 140 . A content provider, for example, may encode 500 millisecond as the threshold information 186 within the video signal 22 . When a lead or lag condition exceeds 500 milliseconds, then the synchronization application 170 instructs the processor 32 to delay the audio signal 140 , the video signal 22 , or both. Similarly, the threshold information 186 may be embedded or encoded within, or modulated onto, the audio signal 140 , and the synchronization application 170 causes a delay when needed. If the audio signal 140 and the video signal 22 both include the threshold information 186 , then the synchronization application 170 may have authority to choose one or the other. When the audio signal 140 specifies a first threshold information, while the video signal 22 specifies another, second threshold information, then the synchronization application 170 may choose the smaller value to minimize asynchronous conditions.
[0050] FIG. 9 is a schematic illustrating another operating environment in which exemplary embodiments may be implemented. The electronic device 20 again receives the video signal 22 and the separate audio signal 140 . Here, however, the video signal 22 and/or the audio signal 140 are terrestrially broadcast at some frequency of any portion of the electromagnetic spectrum. The audio signal 140 , for example, may be wirelessly broadcast from an antenna coupled to the communications network 24 . The audio signal 140 may be wirelessly transmitted using any signaling standard (such as the I.E.E.E. 802 family of standards, GSM/CDMA/TDMA or any cellular standard, WI-FI®), and/or the ISM band). The video signal 22 , too, may be received via wireless or wired communication. Regardless, the video signal 22 and the audio signal 140 may be separately received as separate streams of data.
[0051] According to exemplary embodiments, the electronic device 20 includes at least one wireless receiver. A wireless video receiver 200 , for example, couples to an antenna 202 and wirelessly receives the video signal 22 at some frequency of any portion of the electromagnetic spectrum. A wireless audio receiver 204 may couple to another antenna 206 and wirelessly receives the audio signal 140 at some frequency of any portion of the electromagnetic spectrum. If the audio signal 140 and/or the video signal 22 is/are modulated, the electronic device 20 may include one or more demodulators 208 . If analog or digital conversion is needed, the electronic device 20 may include an A/D or D/A converter 210 . If synchronization is needed, the synchronizer 142 delays the leading video signal 22 and/or the audio signal 140 . Analog and/or digital broadcasting techniques and circuitry are well known, so no further discussion is made. If, however, the reader desires a further explanation, the reader is invited to consult the following sources, with each incorporated herein by reference in its entirety: F ERRILL L OSEE , RF S YSTEMS , C OMPONENTS, AND C IRCUITS H ANDBOOK (1997); L EENAERTS ET AL ., C IRCUIT D ESIGN FOR RF T RANSCEIVERS (2001); J OE C ARR , RF C OMPONENTS AND C IRCUITS (2002); W OLFGANG H OEG AND T HOMAS L AUTERBACH , D IGITAL A UDIO B ROADCASTING (2003); and A NNA R UDIAKOVA AND V LADIMIR K RIZHANOVSKI , ADVANCED D ESIGN T ECHNIQUES FOR RF P OWER A MPLIFIERS (2006).
[0052] Exemplary embodiments, as earlier explained, may determine whether synchronization is desired. For example, the audio content identifier 172 is compared to the video content identifier 30 . If a partial or full match is found, then a determination may be made that the audio signal 140 and the separately-received video signal 22 likely correspond to the same content. Exemplary embodiments thus confirm that the audio signal 140 and the video signal 22 should be synchronized.
[0053] Once synchronization is desired, exemplary embodiments may compare time stamps. The audio time stamps 146 are compared to the video time stamps 144 , as explained above. Whenever a lead or a lag condition is detected, exemplary embodiments implement a delay in the audio signal 140 , the video signal 22 , or both. When, for example, the audio signal 140 is digital, exemplary embodiments may divert the audio signal 140 to the buffer memory (shown as reference numeral 174 in FIG. 8 ). As the digital audio signal 140 accumulates in the buffer memory, the audio signal 140 is delayed in comparison to the video signal 22 . The video signal 22 , alternatively or additionally, may similarly be stored in the buffer memory when the video content leads the audio content. Exemplary embodiments then release the buffered audio signal 140 and/or video signal 22 when synchronization is achieved.
[0054] FIG. 10 is a schematic illustrating yet another operating environment in which exemplary embodiments may be implemented. Here the electronic device 20 is illustrated as a television or set-top receiver 220 that receives the video signal 22 and the separate audio signal 140 . The video signal may be broadcast along a wireline, cable, and/or satellite portion of the communications network 24 , while the audio signal 140 is separately and wirelessly received at an RF receiver 222 as a terrestrial broadcast. While the television or set-top receiver 220 may receive the audio signal 140 at any frequency of any portion of the electromagnetic spectrum, here the audio signal 140 is wirelessly received at the radio-frequency portion of the spectrum. The audio signal 140 may or may not be modulated onto a carrier signal 224 . The audio signal 140 , for example, may be amplitude modulated or frequency modulated (e.g., AM or FM) onto the carrier signal 224 . The audio signal 140 may additionally or alternatively be broadcast from a satellite using any frequency of any portion of the electromagnetic spectrum, and the satellite broadcast may or may not be modulated onto the carrier signal 224 . Here, then, the electronic device 20 may be an AM-FM real time television-capable device with broadband capability to wirelessly receive television signals and/or RF audio signals. Regardless, the electronic device 20 may also receive time stamps and content identifiers. The electronic device 20 may receive the video time stamps 144 and the video content identifier 30 encoded within the video signal 22 . The electronic device 20 may also receive the audio time stamps 146 and the audio content identifier 172 . The audio time stamps 146 and the audio content identifier 172 may be encoded within the audio signal 140 and, if desired, modulated onto the carrier signal 224 .
[0055] Exemplary embodiments may then proceed as discussed above. The demodulator 208 may demodulate the audio signal 140 , the audio time stamps 146 , and/or the audio content identifier 172 , from the carrier signal 224 . Exemplary embodiments may compare the audio content identifier 172 to the video content identifier 30 . If a partial or full match is found, then the audio signal 140 and the separately-received video signal 22 may correspond to the same content and may be synchronized. The audio time stamps 146 may be compared to the video time stamps 144 , as explained above. When a lead or a lag condition is detected, exemplary embodiments may implement a delay in the audio signal 140 , the video signal 22 , or both to synchronize the audio signal 140 and the separately-received video signal 22 .
[0056] FIG. 11 is a schematic illustrating still another operating environment in which exemplary embodiments may be implemented. Here the video signal 22 is received, processed, and presented by a television or computer 240 , while the audio signal 140 is separately received by an AM/FM radio 242 . The AM/FM radio 242 includes the RF receiver 222 that wirelessly receives the audio signal 140 as a terrestrial broadcast. The user, for example, may be watching a football game on the television or computer 240 , yet the user prefers to listen to play-by-play action from radio announcers. Unfortunately, though, the separately-received audio signal 140 may lead the video signal 22 by several seconds. The radio announcer's commentary, then, is out-of-synchronization with the television video signal 22 .
[0057] Exemplary embodiments, then, may delay the audio signal 140 . The user interface 130 may be used to establish an amount of delay introduced by the synchronizer 142 . The user interface 130 , for example, may be graphical (as illustrated and explained with reference to FIGS. 1 , 5 , and 8 ), or the user interface 130 may be a physical knob, slider, or other means for adjusting delay. When the user notices that the audio signal 140 leads the video signal 22 , the user may adjust the user interface 130 to introduce a delay into the leading audio signal 140 . The user refines the delay until the audio signal 140 is synchronized to the video signal 22 .
[0058] FIG. 12 is a schematic illustrating another operating environment in which exemplary embodiments may be implemented. Here the user has multiple electronic devices 20 operating in the user's residence, business, building, or other premise. Some of the electronic devices 20 may receive analog signals and some of the electronic devices 20 may receive digital signals. Some of the electronic devices 20 may receive audio signals and some of the electronic devises 20 may receive video signals. When all the electronic devices 20 receive signals that correspond to the same content, the user may need to synchronize one or more of the electronic devices 20 . When, for example, all the electronic devices 20 receive the same football game, any leading or lagging audio/video signal may be annoying. Exemplary embodiments, then, allow the user to individually synchronize any of the electronic devices 20 for an enjoyable entertainment experience.
[0059] As FIG. 12 illustrates, exemplary embodiments may operate in one or more of the electronic devices 20 . An instance of the alternate audio application 34 , for example, may operate in a computer 260 . The computer 260 may receive the video signal 22 and the separate audio signal 140 from the communications network 24 . Another instance of the alternate audio application 34 may operate in a set-top receiver 262 that also receives the video signal 22 and the separate audio signal 140 from the communications network 24 . Yet another instance of the alternate audio application 34 may operate in an analog television 264 that receives a terrestrially-broadcast analog version 266 of the video signal 22 . Another instance of the alternate audio application 34 may operate in a digital television 268 that receives a terrestrially-broadcast standard definition or high-definition digital version 270 of the video signal 22 . More instances of the alternate audio application 34 may even operate in a wireless phone 272 and an AM/FM radio 274 .
[0060] Exemplary embodiments permit synchronization of all these electronic devices 20 . When all the electronic devices 20 receive signals that correspond to the same content, some of the electronic devices 20 may lead or lag, thus producing an unpleasant entertainment experience. Exemplary embodiments, however, allow the user to delay the audio and/or video signals received at any of the electronic devices 20 . The user may thus synchronize audio and video outputs to ensure the content remains pleasing.
[0061] FIG. 13 is a block diagram further illustrating the electronic device 20 , according to even more exemplary embodiments. When either the audio signal 140 or the video signal 22 lags, here the synchronizer 142 may divert a leading signal 300 to a first delay circuit 302 . The first delay circuit 302 may comprise clocked and/or unclocked circuits or components. If clocked, a reference or clock signal 304 may be received at the first delay circuit 302 . The leading signal 300 propagates through the first delay circuit 302 . As the leading signal 300 propagates, delays may be introduced by the first delay circuit 302 . The amount of delay may be determined according to the complexity and/or the number of components within the first delay circuit 302 . When a delayed signal 306 emerges from the first delay circuit 302 , the delayed signal 306 may be synchronized with a lagging signal 308 . The delayed signal 306 may then be diverted through, or “peeled off” by, a first gate circuit 310 and sent to the processing circuitry 156 for audible presentation.
[0062] More delay may be needed. The first delay circuit 302 may introduce a predetermined amount of delay. Suppose, for example, that the first circuit introduces twenty milliseconds (20 msec.) of delay in the audio signal 140 . If twenty milliseconds of delay does not satisfy the threshold time 152 , then more delay may be needed. The first gate circuit 310 , then, may feed, or cascade, the delayed signal 306 to a second delay circuit 312 . The second delay circuit 312 introduces additional delay, depending on its complexity and/or number of components. If this additional delay is sufficient, then a second gate circuit 314 diverts an additionally delayed signal 316 to the processing circuitry 156 . If more delay is again needed, the second gate circuit 314 may feed or cascade the additionally delayed signal 316 back to the first delay circuit 302 for additional delay. According to exemplary embodiments, the leading signal 300 , then, may cascade or race through the first delay circuit 302 and through the second delay circuit 312 until synchronization is achieved.
[0063] FIG. 14 depicts other possible operating environments for additional aspects of the exemplary embodiments. FIG. 14 illustrates that the alternate audio application 34 and/or the synchronizer 142 may alternatively or additionally operate within various other devices 400 . FIG. 14 , for example, illustrates that the alternate audio application 34 and/or the synchronizer 142 may entirely or partially operate within a personal/digital video recorder (PVR/DVR) 402 , personal digital assistant (PDA) 404 , a Global Positioning System (GPS) device 406 , an interactive television 408 , an Internet Protocol (IP) phone 410 , a pager 412 , or any computer system and/or communications device utilizing a digital processor and/or digital signal processor (DP/DSP) 414 . The device 400 may also include watches, radios, vehicle electronics, clocks, printers, gateways, and other apparatuses and systems. Because the architecture and operating principles of the various devices 400 are well known, the hardware and software componentry of the various devices 400 are not further shown and described. If, however, the reader desires more details, the reader is invited to consult the following sources, all incorporated herein by reference in their entirety: A NDREW T ANENBAUM , C OMPUTER N ETWORKS (4 th edition 2003); W ILLIAM S TALLINGS , C OMPUTER O RGANIZATION AND A RCHITECTURE : D ESIGNING FOR P ERFORMANCE (7 th Ed., 2005); and D AVID A. PATTERSON & J OHN L. H ENNESSY , C OMPUTER O RGANIZATION AND D ESIGN : T HE H ARDWARE /S OFTWARE I NTERFACE (3 rd . Edition 2004); L AWRENCE H ARTE et al., GSM S UPERPHONES (1999); S IEGMUND R EDL et al., GSM AND P ERSONAL C OMMUNICATIONS H ANDBOOK (1998); and J OACHIM T ISAL , GSM C ELLULAR R ADIO T ELEPHONY (1997); the GSM Standard 2.17, formally known Subscriber Identity Modules, Functional Characteristics (GSM 02.17 V3.2.0 (1995-01))”; the GSM Standard 11.11, formally known as Specification of the Subscriber Identity Module—Mobile Equipment ( Subscriber Identity Module—ME ) interface (GSM 11.11 V5.3.0 (1996-07))”; M ICHEAL R OBIN & M ICHEL P OULIN , D IGITAL T ELEVISION F UNDAMENTALS (2000); J ERRY W HITAKER AND B LAIR B ENSON , V IDEO AND T ELEVISION E NGINEERING (2003); J ERRY W HITAKER , DTV H ANDBOOK (2001); J ERRY W HITAKER , DTV: T HE R EVOLUTION IN E LECTRONIC I MAGING (1998); and E DWARD M. S CHWALB, I TV H ANDBOOK : T ECHNOLOGIES AND S TANDARDS (2004).
[0064] FIG. 15 is a flowchart illustrating a method of retrieving audio signals, according to more exemplary embodiments. A video signal is received (Block 500 ). The video signal may comprise the alternate audio tag 28 , the video content identifier 30 , the video time stamps 144 , the threshold information 186 , and/or the listing 58 of alternate audio sources that correspond to the video signal. In response to the alternate audio tag 28 , a query is sent for an alternate audio source that corresponds to the video content identifier (Block 502 ). A query result is received that identifies an audio signal that corresponds to the video content identifier and that is separately received from the video signal (Block 504 ). A selection is received that selects an alternate audio source from the listing and/or from the query result (Block 506 ). Another query is sent for the alternate audio source (Block 508 ), and a separate audio signal is received (Block 510 ). The separate audio signal may comprise the audio content identifier 172 , the audio time stamps 146 , and the threshold information 186 . The audio time stamps are compared to the video time stamps (Block 512 ). When an audio time stamp exceeds a corresponding video time stamp by a threshold time, then the audio signal is delayed until the audio time stamps are within the threshold time of the video time stamps (Block 514 ). When a video time stamp exceeds a corresponding audio time stamp by the threshold time, then the video signal is delayed until the video time stamps are within the threshold time of the audio time stamps (Block 516 ).
[0065] Exemplary embodiments may be physically embodied on or in a computer-readable medium. This computer-readable medium may include CD-ROM, DVD, tape, cassette, floppy disk, memory card, and large-capacity disk (such as IOMEGA®, ZIP®, JAZZ®, and other large-capacity memory products (IOMEGA®, ZIP®, and JAZZ® are registered trademarks of Iomega Corporation, 1821 W. Iomega Way, Roy, Utah 84067, www.iomega.com). This computer-readable medium, or media, could be distributed to end-subscribers, licensees, and assignees. These types of computer-readable media, and other types not mention here but considered within the scope of the exemplary embodiments. A computer program product comprises processor-executable instructions for synchronizing audio and video content.
[0066] While the exemplary embodiments have been described with respect to various features, aspects, and embodiments, those skilled and unskilled in the art will recognize the exemplary embodiments are not so limited. Other variations, modifications, and alternative embodiments may be made without departing from the spirit and scope of the exemplary embodiments.
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Audio and video signals are synchronized for pleasing presentation of content. As content is streamed to a device, an audio portion may lag or lead a video portion. Spoken words, for example, are out of synch with the lip movements. Video time stamps are synchronized to audio time stamps to ensure streaming content is pleasing.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of architectural subceilings for commercial, industrial, and residential buildings. More particularly, it relates to suspended open subceiling configurations having a grid pattern of intersecting open-ended runner beam sections and open-ended cross beam sections formed of sheet material.
In addition to the usual subceiling requirements of producibility, cost effectiveness, appearance and safety, the particular field addressed by this invention requires that the component parts of the subceiling be prefabricated ready for easy assembly and installation at the final site without requiring high skill levels or special tools. The completed subceiling must present a finished appearance, free of light leaks at joints and intersections, and all fastening hardware such as rivets or screws must be completely concealed from a viewer anywhere in the room below.
2. The Prior Art
Intersection structures heretofore known for joining runner beams and cross beams in a suspended subceiling have largely addressed the field of support rails for panels, where at least a major portion of the structure, being concealed by the panels, could be designed functionally with little concern for aesthetic appearance. Consequently, even those approaches which could be adapted structurally to an open grid beam subceiling configuration pose formidable problems in attempting to meet the standards of aesthetic appearance demanded in the particular field addressed by this invention.
An additional requirement is that, because subceilings of this type often stand free in a room without abutting the walls, the perimeter and corner intersections must present a finished appearance. Existing intersection joining systems would leave an unacceptable unfinished appearance due to gaps and unconcealed fastening structure or else would require additional trim parts to be installed around the perimeter.
A further requirement is that the intersection structure must be light in weight to minimize the total loading stress on the supporting structure. Consequently, metal castings or other such heavy configurations used in the structural fields are unsatisfactory.
Known subceiling systems which require complete prefabrication of the entire subceiling offsite are impractical for all but very small rooms. Prefabricating and shipping full length runner beams is also unsatisfactory. However, known subceiling systems in which both the runner beams and the cross beams may be installed in short sections fail to satisfy one or more of the above requirements.
An increasing demand for suspended subceilings in the architectural style of an open grid framework of intersecting beams has created a heretofore unfulfilled need for an intersection structure which fully satisfies the abovementioned requirements.
SUMMARY OF THE INVENTION
The present invention overcomes the shortcomings of existing beam intersection methods and structures, and fully satisfies all of the requirements cited by providing a lightweight intersection spacer assembly onto which open ends of runner beam sections and cross beam sections may be assembled to form a suspended subceiling.
Outwardly facing protrusions on all four sides of the spacer fit into the open ends of the beam sections, which are secured to a top plate on the spacer by fasteners inserted on the top side of the beams where by fasteners are concealed from normal view. The top plate is attached to a rod or wire grid suspension element for suspending the subceiling from structure above.
When the spacers are used at the corners and perimeter of the subceiling, they present a finished appearance requiring no further trim treatment even in installations where the perimeter of the subceiling stops short of the walls.
The lower edge of the open ends of the runner beam sections may be provided with tabs to be inserted thru slots near the bottom of the spacer and bent upward to stiffen the beams temporarily during installation while they are being suspended in place.
A cap snaps onto a skirt at the bottom of each spacer to conceal the bent-over tab ends. The cap presents a finished appearance without further treatment. However, as a styling option, a removeable decorative panel may be placed in a recessed area provided at the bottom of each cap.
According to a feature of the invention, the intersection spacer comprises two identical core body halves joined together along vertical seams. The core body parts may be made of molded plastic, while the top plate is advantageously made of metal.
In the completed subceiling, the weight of the beams is carried by the suspended top plates with virtually no stress applied to the core body.
Other features and advantages of the invention will become apparent from the description of the preferred embodiment which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary underside oblique perspective view of a completed subceiling constructed with intersection spacers according to the invention;
FIG. 2 is an oblique isometric exploded view of an intersection spacer according to the invention; and
FIG. 3 is a fragmentary oblique isometric view showing two sections of a runner beam joined together by an intersection spacer according to the invention, and including an exploded view of a cross beam section and a bottom cap according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
By way of disclosing a preferred embodiment of the invention, and not by way of limitation, FIG. 1 shows a completed and installed subceiling. The subceiling includes in its general organization a number of spaced, parallel runner beams 10, spaced, parallel cross beams 11, intersection spacers 12 disposed at the intersections between beams, and suspension elements 13 which may be wires or rods and which are secured at their lower ends to the intersection spacers 12 and at their upper ends to suitable structure above.
Each runner beam 10 is made up of a colinear run of similar runner beam sections 15. In like manner, each cross beam is made up of a colinear run of cross beam sections 16. These beams sections are each hollow and formed of folded sheet metal. The intersection spacers 12 are variously located at intersections of one runner beam section 15 with one cross beam section as at 17, two runner beam sections with one cross beam section as at 18, one runner beam section with two cross beam sections as at 19, and two runner beam sections with two cross beam sections as at 20. About the outer perimeter of the subceiling, the intersection spacers exhibit outwardly facing protrusions 21 having the appearance of short extensions of the beams. Bottom caps 22 with decorative panels 23 are visible at the undersides of the intersection spacers 12.
FIG. 2 shows the arrangement and assembly of the intersection spacers 12. Identical half-shells 30, when assembled together, form a core body, which in turn, when assembled together with a top plate 31 will become an intersection spacer 12.
Each half-shell has a pair of boss-supported upwardly extending pins 32 at the top end, a row of small seam-alignment pins 34 and a larger boss-supported bottom-alignment pin 35 on one mating edge, a corresponding row of seam-alignment holes 36 and a boss-enclosed bottom-alignment hole 37 on the other mating edge.
The half-shells 30 are each shaped to have inverted vertical corner edges 40 forming a rectangular protrusion 21 and two rectangular half protrusions 42. These are provided with a protrusion floor 43. At the bottom of the the protrusion floor depending at the bottom of the half-shell is a skirt 45. Formed through the skirt are slotted openings 46.
Top plate 31 has a perimeter outline corresponding to the generally square cross section of the core body as assembled from the half-shells 30, including four rectangular side extensions 50, each of which has a pair of holes 51. Near the four inverted corners are four holes 52 corresponding to the lcoations of pins 32. At the center is a grommet 53 having a threaded bore for attachment to a suspension element 13.
After the two half-shells 30 are assembled together by inserting pins 34 and 35 of one into holes 36 and 37 of the other with a solvent type adhesive applied for bonding the halves together to form a core body, top plate 31 is positioned on top of the core body by inserting pins 32 through holes 52. the completed intersection spacer thus formed presents four outwardly extending rectangular protrusions, each shaped and sized to fit, along with a corresponding top plate extension, into an open end of a hollow beam section.
FIG. 3 shows an assembled intersection spacer 12 comprising a core body 55 and a top plate 31 attached to open ends of runner beam sections 15 which are typically two inches by four inches formed from sheet metal with a gap along the top side. Each runner beam section end 56 fits over a protrusion 21 and top plate extension 50, and is attached to the top plate by a pair of blind rivets 57 or sheet metal screws inserted through a pair of holes provided on the top side of the beam end and a pair of holes 51 in each top plate side extension.
The runner beam section ends 56 are fabricated with a pair of tab extensions 60 at their bottom sides. These tabs, after assembly, protrude through the slotted openings 46 shown in FIG. 2. The protruding protions of the tabs may be bent upward to provide bottom fastening for additional runner beam stiffness during assembly and initial suspension of the runner beams during installation.
It may be seen in FIG. 3 that the cross beam sections fit over the protrusions 21 formed by the adjoining half protrusions 42. Also, it may be see that the core body 55 exhibits seams disposed in a vertical plane bisecting the core body through the centers of two opposite sides.
In installation, typically the runner beams are assembled from runner beam sections joined by intersection spacers prior to attachment of cross beam sections, as shown in FIG. 3. The intersection spacers are suspended in place by suspension elements attached to the threaded grommets in the top plates. Levelling of the beams may be accomplished such as by threaded suspension element adjustments of known art.
It should be noted that the ends of cross beam sections 16 are cut off in a single plane since it does not require tabs as at 60 on the runner beam section ends. Fastening of the cross beam sections is accomplished with a pair of blind rivets or sheet metal screws inserted through holes 62 in the runner beam end 63 and through a pair of holes 51 in top plate 31 in the same manner as with the runner beam sections 15.
Assembling one cross beam section end 63 to the intersection spacer along with two runner beam sections ends 56 forms a three-way intersection for use at the perimeter of a subceiling. The unattached protrusion 21 remains exposed as a finish trim feature at the subceiling perimeter, with the seam 58 being rendered unnoticable by virtue of accurate mating of the two half-shell parts accomplished by the seam alignment pins 34 of one half-shell engaging holes 36 of the other half-shell, in conjunction with the aforementioned adhesive bonding at the mating surfaces.
Shown at the bottom of FIG. 3 is bottom cap 22 which is square with an upwardly extending perimeter lip 66 on the inside of which are two oppositely disposed detents 66. Corresponding protrusions 67 are provided on the outside of the core body bottom skirt 45 as shown in FIG. 2. To finish the bottom of the intersection spacer, bottom cap 22 is pushed upwards and snapped over the core body bottom skirt where it is held in place by detent action of recesses 66 engaging corresponding detent protrusions 67.
The bottom side of bottom cap 22 is provided with a square recess for retaining an optional decorative panel 23 which may be finished in a color or texture chosen for special decorative effect. The panel may be held in place by a suitable adhesive, and may be replaced for redecorating purposes.
This invention is susceptible of variations in dimensions, proportions, shapes, and materials, and may be implemented in various alternative embodiments by those skilled in the art without departing from the scope of the claims which follow.
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An intersection spacer is disclosed for use in a subceiling structure of a grid of open-ended runner beams and intersecting open-ended cross beams, the intersection spacer being generally square in horizontal cross section with inverted vertical corner edges forming four outwardly directed protrusions adapted to engage within the beam ends. A top plate on the spacer bears the weight of the ceiling. A bottom cap on the spacer carries a decorative panel. The spacer may be made of two identical mating halves. A method of assembling a subceiling with such intersection spacers is also disclosed.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a method for making multi-layered shingles, and to roofing shingles made thereby. The shingles are uniquely thickened to enhance the appearance of a roof.
[0003] 2. Description of the Prior Art
[0004] There have been many approaches by the roofing industry to the task of covering a roof deck with shingles which are both protective and aesthetically pleasing. Whatever their appearance, suitable shingles have been made sufficiently durable and weatherproof for prolonged protection of the roof. The shingles' visual appeal has been attained in various ways, such as by providing particular butt edge contours and surface treatments which function to simulate more traditional, and in most cases more expensive, forms of roof coverings, including thatch, wooden shakes, slates, and even tiles of various forms.
[0005] Simulation of such more traditional roof coverings is afforded by asphalt shingles of the laminated type. These shingles provide depth or its appearance on the roof, thus more or less giving the look of the wood or other natural appearing shingles. U.S. Pat. No. 3,921,358 provides an example of such composite shingles. After describing the futile attempts in the past to achieve the irregular, bulky, butt edge profile and surface contour characteristic of wood roofing shingles, this patent presents an improved composite shingle comprising a rectangular sheet having a headlap portion and a butt portion. The butt portion is divided into a series of spaced apart tabs and a strip is secured to the sheet in a position underlying the tabs and filling the spaces therebetween. While the resultant bilaminate structure suggests somewhat the substantial and imposing architectural appearance of the more expensive roofing materials, such as wood shingles, the structure still diverges considerably in appearance from them.
[0006] For many years roofing manufacturers have offered a variety of two-layered shingles of the type disclosed in U.S. Pat. No 3,921,358 in the attempt to present a thicker and more attractive appearance. A structure markedly different from these prior art bilaminate shingles is shown in U.S. Pat. No. 4,869,942. This structure, which has an exposed butt portion three layers in depth, with tabs two layers in depth, and an additional strip under the cut-outs, gives the shingle an appearance that goes well beyond the bilaminates in simulating wood and tile shingles.
[0007] Although the asphalt composite shingles have significant cost, service life and non-flammability advantages over wood shingles, the latter type are still seen by many to be a much more desirable roofing material for aesthetic purposes. A key reason for wood shingles' continuing aesthetic appeal stems from their greater thickness relative to the composite shingles, in spite of the many efforts in the past to simulate this thickness. Accordingly, it would be most beneficial to find ways to enhance the appearance of depth in the composite shingles without sacrificing these shingles' advantageous features.
OBJECT OF THE INVENTION
[0008] It is therefore an object of the invention to provide an asphalt shingle that simulates very closely the thickness of wood or other traditional roof coverings, and also possesses those attributes desired in roof coverings, including waterproofness, durability and fire-resistance.
[0009] It is a further object of the invention to enhance the appearance of a laminated shingle through the use of multiple layers of the butt portion of the shingle.
[0010] It is yet another object of the invention to provide a simple, efficient and economical manufacturing process for the continuous production of a laminated shingle from a single indefinitely long roofing sheet.
SUMMARY OF THE INVENTION
[0011] The foregoing and other objects of the invention have been achieved by a roof shingle which is multi-layered for enhancement of the shingle's visual appeal and thickness. The composite shingle comprises a headlap portion and a butt portion having three or more layers. The headlap portion may also be multi-layered, comprising two or more layers. The butt portion is divided into a series of spaced apart tabs. The spacing between the tabs significantly exceeds that of the slots which have been formed over the years in the manufacture of multi-layered shingles, such as those disclosed in U.S. Pat. Nos. 5,209,802 and 5,426,902. Such narrow openings, which are typically less than one inch, e.g., about ¼ to ⅝ inch, do not provide the openly spaced and particularly deep wells of a roof surfaced by the shingles of the present invention. The spacing between the tabs of the inventive shingles is greater than 1 inch, preferably greater than 2 inches.
[0012] The multi-layered shingle is of the laminated type. The butt portion of this shingle composite is made of at least three laminae, and may have four, five or more laminae. The laminae are preferably constructed of felted material comprising organic or inorganic fibers or a mixture of both. The fibers are usually held together with a binder and are coated, saturated, or otherwise impregnated with an asphaltic bituminous material. The laminae lie one above another in the composite, and are exposed to view as a bulky composite when the shingle is installed on a roof. Inherent in this laminated construction is an appreciable difference in surface elevation between the top surface of the tabs of one shingle and the top surface of the tabs of the underlying shingle(s). The perception of depth is greatly magnified when the array of shingles on the roof is viewed. The viewer's eye will naturally go from the deep wells formed by the adjoining tabs of one shingle to those of the next upper or lower shingle(s) and so forth over the roof.
[0013] A preferred laminate manifesting the inventive shingle's unique structure, incomparable to any of the prior art, comprises an asphalt shingle having a headlap portion and a butt portion which extends from the lower boundary of the headlap portion to the butt edge of the shingle and comprises a series of composite tabs which are separated by spaces, each extending from the side edge of one composite tab to that of the next adjacent composite tab, and each of which comprises at least three layers. The type of laminated shingle consisting of a single overlay member and a single underlay tab is well-known and illustrated, for example, in U.S. Pat. Nos. 3,998,685 and 5,052,162.
[0014] In accordance with the process of the invention, one or more fibrous sheets, which are to be made into the shingles, are treated with a cementitious waterproofing composition, such as asphalt or other bituminous material. The treatment includes surfacing the sheet or sheets; with sufficient waterproofing material to which is adhered granules such as crushed rock, slate or other surfacing material. While the entire outer face of the shingle, i.e. the face which is uppermost when the shingle lies on a roof, is desirably covered over its full extent with granular matter, the portion of the outer face which is important for colorful effects is that portion which is exposed to view when the shingles are laid together in overlapping courses on a roof. Accordingly, the sheet portions which ultimately become these exposed portions are profitably surfaced with colorful granules so as to provide areas of distinctive coloration, and lower cost, less decorative granular material is employed to surface the sheet portions which are to become the covered or hidden areas of the final assemblage.
[0015] The process is advantageously carried out continuously with the sheet(s) being transported along a production line for sequential processing. The continuous process is especially useful in the production of laminated shingles from a single elongate sheet. In the process, the top surface of the sheet is coated with asphalt and a coating of granules is applied to this surface. At least two narrow elongate sheets or strips are cut from the total elongate sheet to yield a main sheet and the narrow portions cut therefrom. The narrow elongate sheets are desirably cut from the main sheet in one step, although the cuts may be made in more than one step. The narrow sheets are positioned one above another and below the main sheet. A laminate of the main and narrow sheets is formed.
[0016] Desirably, each narrow sheet is coextensive with the other or others, and the narrow sheets are positioned so that the side edges of each one are in the same vertical plane as the respective side edges of the other(s) lying above and/or below. The first narrow sheet moved directly below the main sheet is centered on the longitudinal line which will become the central line of the multi-layered portion of the total composite sheet before cutting of this total sheet. Each succeeding narrow sheet is centered on the narrow one above it. After centering, each cut-off sheet is adhered to the sheet above it to form a composite. Each cut-off sheet may or may not be inverted before adhesion. In the formation of an advantageous embodiment, the last adhered sheet is inverted. When the bottom sheet is thus inverted, the final multi-layered tab portion of the resultant roofing shingle has exposed granules on both its top and bottom. The eventual shingle's butt edge is thickened by the multiple layers and their protruding granules, leading to an assembly of the shingles on a roof which has the aesthetically attractive, bulky look of a roof of wood or tile shingles.
[0017] A longitudinal cut is made along the centerline of and within the side boundaries of the multi-layered portion of the totally laminated composite sheet advancing along the production line so as to form two complementary sheets, each individually having multi-layered tabs separated by cut-out portions along the thus cut longitudinal edge. The cut defines a substantially zigzag or “dragons' teeth” configuration comprising a series of interdigitated tabs on each complementary sheet. This side-edge arrangement is of the type described in U.S. Pat. No. 5,052,162. Each resulting composite sheet is cut transversely into shingles of preselected lengths. The zigzag cut desirably forms a series of tabs which differ from one another in each individual shingle so as to create a wooden shake simulation. The final shingle may thus be made from a single sheet, e.g., glass mat, by a process which converts this sheet into a plurality of shingles having multi-layered tabs, each layer being made of a portion of the original sheet. This multi-level roofing shingle is more visually appealing than previous bi-level shingles because of its thicker butt edge. This look of thickness is especially manifest when the shingles are arrayed in rows on a roof and the shingles of each row act like levers lifting the butt edges of the row above and so forth over the entire roof.
[0018] An important aspect of the present invention is that it permits laminated shingles having multi-layered tabs, such as those of three layers, to be manufactured continuously and expeditiously from a single sheet(s) of an indefinite length. Each of the steps involved in the formation of the final roofing shingles can be carried out on the base roofing material (e.g., glass fiber mat) as the material advances continuously along the production line in the form of an elongate sheet and strips cut therefrom. The continuously performed steps comprise waterproofing the sheet, coating it with mineral granules, cutting it along its length into elongate strips, laminating these strips together to form a composite multi-level strip, and finally cutting the composite laminated strip into the individual roofing shingles. The granules may be applied before or after the sheet is cut into elongate strips, as described, for example, in U.S. Pat. No. 4,869,942, and may be applied to only a portion of the main sheet or narrow strips. A different coloration may be applied to the main sheet and strips.
[0019] In a preferred embodiment of the invention, trilaminated shingles are continuously produced from a single elongate sheet which is waterproofed and coated over its top surface with mineral granules before being cut into elongate strips. Two first straight cuts divide the sheet into three elongate rectangular strips, one much wider than the other two. Advantageously, one of the straight cuts is made near one of the side edges of the original elongate sheet, and the other straight cut is made near the original sheet's opposite side edge. One of the two narrow strips is shifted, without being inverted, to a position underneath the wide strip and the two strips are laminated together. Prior to lamination, the upper strip's undersurface which is to be bonded is advantageously coated with an adhesive material. Additionally, in another embodiment, the lower strip is turned upside down before lamination so that the laminate of the two strips has the granules of the top strip facing upwardly and the granules of the bottom strip facing downwardly. The second narrow strip is shifted underneath and laminated to the bi-level portion formed in the first lamination. Preferably, the undersurface of the bi-level portion is coated with an adhesive and the second narrow strip is turned upside down before lamination so that the total composite will have granules on both the top and bottom of the three-layered, laminated section.
[0020] A third cut is made (i) alternately across and generally along the centerline of the tri-level section (i.e., multi-layered portion) formed by the two previous laminations and (ii) within the longitudinal side boundaries of this section. This central cut, which divides the sheet into two elongate parts, is made to form a repeating pattern of interdigitating triply thick tabs so that upon separation each part has a long straight edge along one side which is one layer in thickness and alternating triply layered tabs and cut-out portions along the other side. Each of the narrow strips, which were positioned to underlie the uppermost wider strip, is desirably cut to be wide enough to completely cover the underside of the wider strip's tabs, but not so wide as to extend much toward the long straight edge of the wider strip. The width is desirably sufficient to adequately support the overlying shingle portion and to contribute to ease of production in the continuous manufacturing process. The two elongate laminated sheets are finally cut into suitable lengths for shingles and packaged. This final cutting may be accomplished conveniently just about when the third longitudinal cut is made or thereafter.
[0021] The continuous process thus provides a unique shingle structure having alternating tabs, three layers in depth and cut-outs therebetween. Like conventional bilaminates, this structure comprises a rectangular sheet having headlaps and butt portions. When these prior art and inventive laminated shingles are installed in successive offset courses in separate arrangements on a roof, their butt edge portions are exposed to view. Because the inventive trilaminated shingle's butt portion is three layers in depth, with the tabs and cut-outs three layers deep, the shingle presents, through this unusual enlargement of the butt portion, a bulky appearance that very closely approaches that presented by wood and tile shingles.
DESCRIPTION OF THE DRAWINGS
[0022] The invention will now be described with reference to the accompanying drawings in which:
[0023] [0023]FIGS. 1 and 3 are schematic elevational views of one form of apparatus whereby laminated shingles may be manufactured according to this invention;
[0024] [0024]FIG. 2 is a top plan view of a sheet of fibrous material partially coated with granules in accordance with the invention;
[0025] [0025]FIG. 4 is a perspective view of the top and two bottom sheets laminated together;
[0026] [0026]FIG. 5 is a perspective view of the novel roofing shingle of the invention; and
[0027] [0027]FIG. 6 is a perspective view of an assembly of the shingles of the invention as applied on a roof.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Referring now to the drawings and more specifically to FIGS. 1 and 3 thereof, there is shown diagrammatically an overall process for forming multi-layered roofing shingles according to the instant invention. A rectangular sheet or web 10 of an indefinite length is unwound from a roll (not shown) and fed along the production line. Sheet 10 is preferably a mat of glass fibers but may also be fabricated from organic felt or other types of base material. The glass mat is generally about 38 to 48 inches in width, although other widths can be chosen without departing from the scope of the invention. The sheet generally weighs from about 1.35 to 3.00 lbs/100 ft. 2
[0029] After sheet 10 is fed over a series of loopers 11 - 14 and between a pair of tension rollers 15 and 16 for uniform tensioning, it is then passed to a station for the application of filled asphalt coating. Discharge pipe 17 supplies a layer of the asphalt coating 18 to the upper surface of sheet 10 just before the nip of rotating rolls 19 and 20 . Reservoir 21 is placed below the coating area to capture runover asphalt from the operation for application to the sheet by back coating roll 20 immersed in the asphalt of reservoir 21 . Nip rolls 19 and 20 coact to apply the appropriate weight of asphalt coating to the sheet, with the nip of the rolls providing pressure to ensure that the asphalt has impregnated the sheet properly. Heating units 22 keep the coating asphalt at the proper temperature for application.
[0030] Downstream of roll 20 is another back coating roll 23 , which is also immersed in reservoir 21 for pickup of liquid asphalt and deposition on the back surface of sheet 10 . Sheet 10 may be coated by both rolls, as shown in FIG. 1, or it may be subjected to a single treatment by one or the other of the rolls. Excess asphalt is advantageously wiped from the surface of the back coating roll(s) by a doctor knife(s) 24 or the like, installed on either or both sides of the back coating roll(s) to ensure uniform application and avoid excesses of the asphalt. Downstream of the back coating application there is a doctor blade or knife 25 or the like which removes excess coating from the back or under surface of sheet 10 . Sheet 10 is further acted upon by a smoothing roll 26 and a carrier roll 27 , which rolls are generally heated.
[0031] Stabilized asphalt coating 18 suitably has a softening point as measured by ASTM D36 of from about 195° to 260° F., more preferably from about 215° to 235° F., and is usually applied in an amount from about 50 to 70 pounds, more preferably from about 55 to 65 pounds, per 100 square feet of sheet 10 . The coating is advantageously maintained at about 380° to 450° F. before application to the sheet.
[0032] After the coating step and while the coating material is still hot, soft and tacky, coated sheet 10 passes beneath surfacing apparatus 28 from which decorative granules are deposited on the upper surface of the sheet. Apparatus 28 includes a series of bins filled with mineral granules and positioned above the longitudinally moving sheet. This known type of roofing machinery is equipped for selectively depositing the mineral granules contained in the bins onto the adhesive upper surface of sheet 10 . Apparatus 28 is outfitted with enough bins to hold each collection of granules to be applied to the sheet in the formation of the overall color pattern being developed on the sheet.
[0033] In the mineral granule treatment schematically shown in FIG. 2, sheet 10 is moving longitudinally under apparatus 28 in the direction of the arrow. The granule deposition can be understood with reference to the lines extending longitudinally and transversely over the surface of sheet section 29 , as shown in FIG. 2. The three solid lines running longitudinally between the two side edges of the sheet correspond to the cuts to be subsequently made in the formation of the component laminae of the shingle, as set forth below. It is seen that there will be two straight cuts and one zigzagged cut. The cutting pattern of FIG. 2 is merely one of many such patterns which could be used to produce the component laminae. The two dashed lines extending lengthwise to either side of the zigzagged line do not correspond to eventual cuts but, in conjunction with the other four straight and parallel lines extending lengthwise, including the side edges, demarcate five zones which are designated zones A-E. As indicated in FIG. 2, the widths of the zones across sheet 10 are as follows: zones A and E-7″; zones B and D-5″; and zone C-14″. These five zones extend over the entire length of sheet 10 . The overall width of sheet 10 as well as the number and widths of the zones can vary depending on factors such as the capacity of the apparatus and the number and size of the shingles being produced per unit length of the sheet.
[0034] The granule discharges which are applied onto the five zones of section 29 are made from the above-mentioned bins of apparatus 28 . The bins are contained in two applicator compartments, a so-called blend box 30 and spill box 31 . In progressing along the production line, sheet 10 first passes under applicator box 30 which deposits granules onto zone C, and then under applicator 31 , which deposits granules onto all of the zones. As shown in FIG. 2, the far right side of section 29 of sheet 10 has passed under both applicator boxes 30 and 31 and thus has granules covering all of the zones, while the left-hand side, having passed under only applicator box 30 , has the granules covering only zone C. As sheet 10 progresses further along the production line, the uncovered zones of section 29 will, of course, become covered by granules discharged from applicator box 31 .
[0035] In a preferred embodiment of the invention, the roof's exposed layers from zone C are in the form of an effectively random series of differently colored portions. To form this random pattern in zone C, applicator (blend) box 30 is equipped with a group of bins, each of which contains variously colored granules for application to zone C. The contents of each bin advantageously consist of blends of the colored granules. The deposition of blends is found to protect against the surface flaws encounterable with the use of singly colored granules. There must be a sufficient number of these bins to produce a random look on the covered roof surface. Suitably, there are at least four such bins each holding different color blends of mineral granules. Applicator box 30 of FIG. 1 has four such bins from which the blends of the contained mineral granules are selectively dropped onto the upper surface of sheet 10 as it passes beneath these bins. The average of the colored granules found in these four bins is contained in a bin of applicator box 31 for the follow-up treatment of zone C described below. This average or composite of all the colored granules not only adds an aesthetically pleasing color variation but also permits the utilization of the inevitable accumulation of the spilled granules from the other bins.
[0036] The selective dropping of mineral granules from the bins of applicator box 30 results in deposited bands of mineral granules (so-called “color drops”) on zone C. The first four such bands of FIG. 2, which are designated C 1 through C 4 , are bordered by dotted lines L extending across zone C. The deposition from applicator box 30 is interrupted at various randomly located places along zone C, yielding spaces designated S, which are uncovered by granules.
[0037] After its passage under applicator box 30 , sheet 10 next passes under applicator (spill) box 31 , which is divided into a number of bins supplied with granular material and equipped for the simultaneous application of the granules across sheet 10 to complete the coverage of zones A to E. One of these bins continuously delivers to zone C a blend of colored granules which represent the average of the granules deposited from the four bins of applicator box 30 . The spaces designated S of zone C become covered with this average blend. Additionally, granules of this blend fill in any spots left uncovered in bands C 1 to C 4 after the surfacing by applicator box 30 .
[0038] Applicator boxes 30 and 31 thus together provide on zone C a series of color drops or bands C 1 through C 4 and S, each band having a variable length and a color which contrasts with the color of the mineral granules in the bands adjacent thereto in the completely granule-covered sheet. In the embodiment illustrated in FIG. 2, each of the color drops onto each of zones C 1 , C 2 , C 3 and C 4 (bounded by a pair of dotted lines) is about 11 inches lengthwise along sheet 10 . Applicator boxes 30 and 31 are operated to alternate the color drops from the five mineral granule bins in an effectively random fashion. The term “effectively random fashion” is used since the machinery is constructed to set up a pattern of alternating color drops which for the FIG. 2 embodiment is repeated only after 36 such color drops. This 36 drop cycle results in a pattern of such color drops which, for practical purposes in the final roof covering of the invention, is undetectable visually from an entirely random, nonrepeating pattern.
[0039] As shown in FIG. 2, the first six designated color blends or bands from the five granule-containing bins of applicator boxes 30 and 31 discharging onto sheet 10 are C 1 , S, C 2 , S, C 3 and C 4 in order from right to left. Color drop S, which constitutes the average color blend which would result from a combination of the colored granules of drops C 1 , C 2 , C 3 and C 4 , is applied twice from its bin in this group of six drops. As sheet 10 advances, applicator boxes 30 and 31 apply this same group of six color blends, viz. C 1 to C 4 and S (deposited twice), as a set over and over to zone C but with the sequence of the six drops changed from each set to the next. After the application of six differently ordered sets or a total of thirty-six color drops, the cycle of these six sets is repeated on and on over the entire length of sheet 10 . The result of this coloring process is an effectively random, nonrepeating color pattern on the shingles' overlying laminae derived from zone C.
[0040] Applicator box 31 is further equipped with one or more bins for application, simultaneously with the application of the continuous layers of granules to zone C of continuous layers of granules to zones A, B, D and E. As will hereinafter be understood, the material of the latter four zones form portions which are not visible in the completely constructed and installed shingles of the invention. Accordingly, the granules deposited on these four zones suitably are low cost materials.
[0041] As illustrated in FIG. 1, after the stream of granules is discharged from applicator box 31 onto sheet 10 , the sheet goes around a slate drum 32 which functions to embed the granular material in the top asphalt coating. In the continued passage of the surfaced sheet 10 , excess granules fall off from the sheet into applicator box 31 from which they are reapplied onto the sheet. The back of the sheet then comes under hopper 33 containing fine back-surfacing material, such as talc, mica dust, fine grit, sand or other composition capable of rendering the back of the sheet non-cementitious. The material from hopper 33 is uniformly distributed over the back of the sheet by means of a distributing roll 34 . The coated roof sheet at this point generally weighs from about 80-100 lbs/100 ft. 2
[0042] Sheet 10 next passes through a cooling section 35 which may simply involve a water spray or a series of cooling rolls 36 around which sheet 10 is looped. At the finish looper station 37 , the sheet is fed over a series of rolls 38 which control its speed as it advances to the slitting station (see FIG. 3). After embedment of the granular material on sheet 10 by slate drum 32 and prior to slitting of the sheet, adhesive strips (not shown) are desirably applied to the front or back of the sheet. In the final roof covering, this adhesive material acts as a self-sealing means for attaching the shingles in one horizontal course to those in the next upper or lower course. At this interval during shingle production, release tape (also not shown) should be affixed to those sheet portions which in the finished and packaged shingles will come in contact with the above-mentioned adhesive strips of adjacent shingles. Sticking in the package is thereby prevented.
[0043] As shown at the right-hand side of FIG. 3, the cooled sheet is pulled by rolls 40 and 41 and divided lengthwise at a slitting station 39 , utilizing two cutters, into three portions, a wide sheet 10 a and two narrow sheets 10 b and 10 d. The cutting may be accomplished by any suitable means, such as by cutting wheels. More than two cutting wheels could be utilized for the production of shingles having four or more layered tabs. Advantageously, the original 38 inch wide sheet of the preferred embodiment of FIG. 2 is cut along the lines separating zones A and E from the remainder of sheet 10 or more specifically from zones B through D. Accordingly, for this embodiment, slitting station 39 cuts sheet 10 into a sheet 10 a (zones B through D) which is 24 inches wide and two sheets 10 b (zone A) and 10 d (zone E) which are each 7 inches wide. At this point both the main sheet 10 a and the narrow strips 10 b and 10 d have granules embedded on their upper surfaces.
[0044] Sheets 10 a and 10 b are pulled and guided along by conventional rollers 42 - 44 . The wide sheet 10 a is fed over a back coater 45 which comprises a tray 46 containing adhesive, such as asphalt, and a drum 47 , whose lower surface rotates in the adhesive-containing tray 46 . Drum 47 applies adhesive from the tray to the back side of zone C of the wide sheet 10 a to form an adhesive coating zone about the width of the narrow strip 10 b (zone A) or 10 d (zone E), e.g., about 7 inches wide, to receive strip 10 b. The adhesive may be applied as a continuous layer or as strips.
[0045] Strip 10 b passes up over a guide bar 48 and then across to another guide bar 49 . In its passage from guide bar 48 to guide bar 49 , strip 10 b is shifted underneath strip 10 a so that the centerline of the narrower strip is below and coincident with the centerline of zone C of the wider strip. With their centerlines so aligned and their granule-covered surfaces both facing upwardly, the two strips are brought into contact and strip 10 b is pressed against the adhesive-coated underside of main strip 10 a by laminating rolls 50 to form a composite 10 c of the two strips. In a further embodiment of the invention, strip 10 b is twisted in its passage from guide bar 48 to guide bar 49 so that its bottom without granules faces upwardly for bonding to the back side of strip 10 a. This results in the formation of a laminated composite of the two strips having one layer of granules surfacing the composite's upper surface and another layer of granules surfacing the lower surface of strip 10 b.
[0046] Trilaminate 10 e of the invention is formed by essentially repeating the process carried out in forming bilaminate 10 c, as shown in FIG. 3. The wide sheet composite 10 c is fed over a back coater 45 ′ comprising an adhesive-containing tray 46 ′ and a drum 47 ′. Drum 47 ′ applies the adhesive, e.g., asphalt, to the downwardly facing, backside surface of strip 10 b (original zone A) which constitutes the lower surface of the laminated portion of sheet 10 c.
[0047] Strip 10 d passes up over a guide bar 48 ′ and then across to another guide bar 49 ′. In its passage from guide bar 48 ′ to guide bar 49 ′, strip 10 d is twisted so that it is turned upside down (180°) and its back without granules faces upwardly for bonding to the laminated portion of the backside of strip 10 c. Strip 10 d is then shifted underneath strip 10 c so that the centerline of the narrower strip is below and coincident with the centerline of the wider strip 10 c. With their centerlines so aligned, the two strips are brought into contact and the asphalt coated underside of strip 10 c is pressed against the top side (originally bottom side) of narrow strip 10 d by laminating rolls 50 ′ to form a composite 10 e of the two strips having one layer of granules surfacing the composite's upper surface and another layer of granules surfacing the lower surface of strip 10 d. By instead again carrying out the embodiment involving not twisting the lower laminae, a trilaminate will result with granules on the composite's upper surface and the upper surface of each lower layer.
[0048] As shown in FIG. 3, laminated combination 10 e is fed into a cutting station 51 which is equipped to make one lengthwise cut along this laminate. The cutter suitably comprises a lower cutting wheel and an upper anvil roll. The path of the lengthwise cut is illustrated in FIG. 4. While it is not illustrated in FIG. 4, cutting station 51 also profitably makes transverse cuts in laminate 10 e to form the individual inventive shingles, one of which is shown in FIG. 5. In FIG. 4, the centerlines of strips 10 b and 10 d are shown aligned with the centerline of main sheet 10 a and the lengthwise cut performed at cutting station 51 is shown as an angularly offset line forming tabs 52 and 52 ′. The cut separates the laminated sheet 10 e into two lengthwise parts 10 f and 10 g, which comprise two complementary, interlocking-tab strips, each of which is cut transversely of its length into shingles of the desired length by transverse cutters or any other suitable cutting mechanism. An appropriate length F for each shingle is 40 inches, as shown in FIG. 2 for two portions of sheet section 29 . In a preferred embodiment, all shingles cut from strip 10 f have the same shape and all those cut from strip 10 g have the same shape, and the average surface area of all the shingles cut from strip 10 f is the same or approximately the same as that of all the shingles cut from strip 10 g.
[0049] With reference to zones A to E of sheet 10 shown in FIG. 2, it is seen that the topmost layers of strips 10 f and 10 g are derived from zones B, C and D, and the underlying layers are derived from zones A and E. Each of strips 10 f and 10 g has tabs which are three layers thick because of the previous laminations of zones A and E underneath the central portion of zones B, C and D. Advantageously, strips 10 f and 10 g are each 12 inches wide or greater. The resulting shingles are conveyed for packaging to stations 53 and 53 ′.
[0050] [0050]FIG. 5 shows a perspective view of a final shingle 54 with an upper main sheet 55 having granules 56 on top and two strips 57 , 57 ′ adhered along the angularly shaped edge thereof. Strip 57 ′ has exposed granules on its side facing downwardly. As shown in FIG. 5, 54 comprises a headlap portion 58 , which is approximately rectangular in shape, and a butt portion 59 , which is divided into the series of spaced-apart tabs 52 which are integral with and extend from the headlap portion 58 . A lower longitudinal section of headlap 58 is seen to form part of the top layer of the tri-level portion of shingle 54 . The tabs 52 are spaced apart from each other at a distance which will ensure that a considerable portion of an underlying tab(s) will be viewable when an array of the shingles is installed on a roof. The spacing between the tabs may vary and is preferably greater than two inches and more preferably is greater than 2½ inches, such as from about 3 to 7 inches. The tabs 52 may be of equal and/or unequal widths and each width typically is in the same range as that of the spaces therebetween. The tabs may have various shapes.
[0051] [0051]FIG. 6 illustrates a roof covered with a plurality of successive offset courses of laminated shingles 54 . The triply thick marginal edge of the butt portion of each shingle of a given course abuts the likewise triply thick marginal edge of the adjacent shingle of that course. Furthermore, as illustrated in FIG. 6, the shingles of a course 60 are offset from the shingles of an immediately subjacent course 61 by a first longitudinal distance and the shingles of course 61 are, in turn, offset from the shingles of the next immediately subjacent course 62 by a second longitudinal distance, the first and second longitudinal distances desirably being unequal to each other. The longitudinal distances may be equal and/or unequal over the entire surface of the roof.
[0052] The respective courses of shingles of the FIG. 5 embodiment may be offset from each other at any distance less than the length of a shingle and such distance may be varied at random without adversely affecting the appearance of the ultimate roof covering. Contrarily, the arrangement of the inventive shingles on a roof produces an appealingly variegated look with strikingly deep wells throughout the extent of the roof. As is evident in FIG. 6, a view of the exposed lower edges of the butt portions of shingles of one course in conjunction with the directly lower exposed butt edges of the shingles of a successive course reveals thicknesses which are three times (see 63 ) and six times (see 64 ) greater than the thickness of the granule-covered sheet material from which the shingles are made.
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A multi-layered shingle adapted to be positioned with other similar shingles in an overlapping arrangement on a roof to yield a simulated wooden shake roof covering comprising a headlap portion and a butt portion. The butt portion comprises a series of multi-layered tabs. All the tabs have the same number of layers and each multi-layered tab (a) is separated from the next adjacent multi-layered tab or tabs by a space or spaces, respectively, and (b) comprises an uppermost layer and at least two layers underlying the uppermost layer. Each underlying layer is laminated to the layer above it to form a multi-layered laminated composite. The laminated composite is integral with the headlap portion and the top surface of the uppermost layer of each tab is coplanar with the top surface of the headlap portion. The invention also includes an apparatus and a process for the continuous manufacture of the shingles of the invention.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of Japan application serial no. 2011-259029, filed on Nov. 28, 2011, and 2012-089083, filed on Apr. 10, 2012. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.
TECHNICAL FIELD
[0002] The invention relates to a liquid crystal composition containing a polymerizable compound that is polymerized, for example, by light or heat. The invention also relates to a liquid crystal display device in which the liquid crystal composition is sealed between substrates, and the polymerizable compound contained in the liquid crystal composition is polymerized while adjusting a voltage applied to a liquid crystal layer to immobilize alignment of liquid crystals.
[0003] As the technical field of the invention, the invention relates to a liquid crystal composition mainly suitable for use in an active matrix (AM) device and so forth, and an AM device and so forth including the composition. More specifically, the invention relates to a liquid crystal composition having a negative dielectric anisotropy, and a device and so forth that include the composition and have a mode such as an in-plane switching (IPS) mode, a fringe field switching (FFS) mode, a vertical alignment (VA) mode or a polymer sustained alignment (PSA) mode. The VA mode includes a multi-domain vertical alignment (MVA) mode and a patterned vertical alignment (PVA) mode.
BACKGROUND ART
[0004] In a liquid crystal display device, a classification based on an operating mode for liquid crystals includes a phase change (PC) mode, a twisted nematic (TN) mode, a super twisted nematic (STN) mode, an electrically controlled birefringence (ECB) mode, an optically compensated bend (OCB) mode, an in-plane switching (IPS) mode, a fringe field switching (FFS) mode, a vertical alignment (VA) mode and a polymer sustained alignment (PSA) mode. A classification based on a driving mode in the device includes a passive matrix (PM) and an active matrix (AM). The PM is classified into static, multiplex and so forth, and the AM is classified into a thin film transistor (TFT), a metal insulator metal (MIM) and so forth. The TFT is further classified into amorphous silicon and polycrystal silicon. The latter is classified into a high temperature type and a low temperature type according to a production process. A classification based on a light source includes a reflective type utilizing natural light, a transmissive type utilizing backlight and a transflective type utilizing both the natural light and the backlight.
[0005] The devices include a liquid crystal composition having suitable characteristics. The liquid crystal composition has a nematic phase. General characteristics of the composition should be improved to obtain an AM device having good general characteristics. Table 1 below summarizes a relationship of the general characteristics between two aspects. The general characteristics of the composition will be further explained based on a commercially available AM device. A temperature range of the nematic phase relates to a temperature range in which the device can be used. A preferred maximum temperature of the nematic phase is approximately 70° C. or higher and a preferred minimum temperature of the nematic phase is approximately −10° C. or lower. Viscosity of the composition relates to a response time in the device. A short response time is preferred for displaying moving images on the device. Accordingly, a small viscosity in the composition is preferred. A small viscosity at a low temperature is further preferred.
[0000]
TABLE 1
General Characteristics of Composition and AM Device
General Characteristics
No.
of Composition
General Characteristics of AM Device
1
Wide temperature range
Wide usable temperature range
of a nematic phase
2
Small viscosity 1)
Short response time
3
Suitable optical
Large contrast ratio
anisotropy
4
Large positive or
Low threshold voltage and
negative dielectric
small electric power consumption
anisotropy
Large contrast ratio
5
Large specific resistance
Large voltage holding ratio and
large contrast ratio
6
High stability to
Long service life
ultraviolet light
and heat
1) A liquid crystal composition can be injected into a liquid crystal cell in a shorter period of time.
[0006] An optical anisotropy of the composition relates to a contrast ratio in the device. A product (Δn×d) of the optical anisotropy (Δn) of the composition and a cell gap (d) in the device is designed so as to maximize the contrast ratio. A suitable value of the product depends on a type of operating mode. The suitable value is in the range of approximately 0.30 micrometer to approximately 0.40 micrometer in a device having the VA mode or the PSA mode, and in the range of approximately 0.20 micrometer to approximately 0.30 micrometer in a device having the IPS mode. In the above case, a composition having a large optical anisotropy is preferred for a device having a small cell gap. A large absolute value of dielectric anisotropy in the composition contributes to a low threshold voltage, a small electric power consumption and a large contrast ratio in the device. Accordingly, the large absolute value of dielectric anisotropy is preferred. A large specific resistance in the composition contributes to a large voltage holding ratio and a large contrast ratio in the device. Accordingly, a composition having a large specific resistance at room temperature and also at a high temperature in an initial stage is preferred. A composition having a large specific resistance at room temperature and also at a high temperature even after the device has been used for a long period of time is preferred. Stability of the composition to ultraviolet light and heat relates to a service life of the liquid crystal display device. In the case where the stability is high, the device has a long service life. Such characteristics are preferred for an AM device used in a liquid crystal projector, a liquid crystal television and so forth.
[0007] A composition having a positive dielectric anisotropy is used in an AM device having the TN mode. On the other hand, a composition having a negative dielectric anisotropy is used in an AM device having the VA mode. A composition having a positive or negative dielectric anisotropy is used in an AM device having the IPS mode and the FFS mode. A composition having a positive or negative dielectric anisotropy is used in an AM device having the PSA mode. Examples of the liquid crystal composition having the negative dielectric anisotropy are disclosed in Patent literatures No. 1 to No. 6 as described below and so forth.
CITATION LIST
Patent Literature
[0000]
Patent literature No. 1: JP 2003-307720 A.
Patent literature No. 2: JP 2004-131704 A.
Patent literature No. 3: JP 2006-133619 A.
Patent literature No. 4: EP 1889894A.
Patent literature No. 5: JP 2010-537010 A.
Patent literature No. 6: JP 2010-537256 A.
[0014] A desirable AM device has characteristics such as a wide temperature range in which a device can be used, a short response time, a large contrast ratio, a low threshold voltage, a large voltage holding ratio and a long service life. A shorter response time even by one millisecond is desirable. Thus, desirable characteristics of a composition include a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, a small viscosity, a suitable optical anisotropy, a large positive or negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat.
[0015] In a display having a PSA mode, a small amount (approximately 0.3% by weight to approximately 1% by weight, for example) of a polymerizable compound (RM) is added to a liquid crystal composition. After introduction into a liquid crystal display cell, only the polymerizable compound is polymerized ordinarily under irradiation with ultraviolet light in a state in which a voltage is applied between electrodes to form a polymer structure within the device. As the RM, a polymerizable mesogenic or liquid crystal compound is known to be particularly suitable as a monomer to be added to the liquid crystal composition.
SUMMARY OF INVENTION
[0016] The inventors of the invention have diligently continued to conduct research for solving the problem, as a result, have found that a specific liquid crystal composition satisfies desirable characteristics and a liquid crystal display device including the composition exhibits an excellent performance, and thus have completed the invention based on the finding.
[0017] The invention concerns a liquid crystal composition containing at least one compound selected from the group of compounds represented by formula (1) as a first component and at least one compound selected from the group of compounds represented by formula (2) as a second component:
[0000]
[0000] Wherein, for example, P 1 and P 2 are independently a group selected from groups represented by formula (P-1) to formula (P-6);
[0000]
[0018] The invention also concerns a polymer sustained alignment liquid crystal display device, comprising two substrates including an electrode layer on at least one of the substrates, and arranging the liquid crystal composition between the two substrates.
[0019] The invention further concerns a method for manufacturing a liquid crystal display device, wherein a specific liquid crystal display device is manufactured by polymerizing a polymerizable compound by subjecting a specific liquid crystal compound arranged between two substrates to irradiation with light under a voltage application state.
[0020] The invention still further concerns use of the liquid crystal composition in the liquid crystal display device.
TECHNICAL PROBLEM
[0021] In general, the polymerizable mesogenic or liquid crystal compound described above has a high capability for aligning liquid crystal molecules. On the other hand, the compound has a poor solubility in a liquid crystal composition, and cannot be added in a large amount. The solubility in the liquid crystal composition is improved by introducing a flexible bonding group such as alkylene or ester between ring structures. However, rigidity of molecules are weakened to decrease capability for aligning the liquid crystal molecules, and also to decrease a pretilt angle as an inclination of liquid crystal alignment. Moreover, a polymerizable compound into which two flexible bonding groups are introduced is poorly suitable for use in a display having a PSA mode because a rate of image sticking is large or the like.
[0022] One of the aims of the invention is to provide a liquid crystal composition satisfying at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat. Another aim is to provide a liquid crystal composition having a suitable balance regarding at least two of the characteristics. A further aim is to provide a liquid crystal display device including such a composition. A still further aim is to provide a composition having a suitable optical anisotropy to be a small optical anisotropy or a large optical anisotropy, a large negative dielectric anisotropy and a high stability to ultraviolet light and so forth, and is to provide an AM device having a short response time, a large pretilt angle, a small rate of image sticking, a small residual monomer concentration, a large voltage holding ratio, a large contrast ratio, a long service life and so forth by constructing a polymer structure in a liquid crystal layer.
SOLUTION TO PROBLEM
[0023] The invention concerns a liquid crystal composition containing at least one compound selected from the group of compounds represented by formula (1) as a first component and at least one compound selected from the group of compounds represented by formula (2) as a second component, and a liquid crystal display device including the composition:
[0000]
[0000] wherein P 1 and P 2 are independently a group selected from groups represented by formula (P-1) to formula (P-6);
[0000]
[0000] R 1 and R 2 are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons; ring A and ring B are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl or pyrimidine-2,5-diyl, and in the groups, at least one of hydrogen may be replaced by halogen or alkyl having 1 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by halogen; ring C and ring E are independently 1,4-cyclohexylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene or 3-fluoro-1,4-phenylene; ring D is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Sp is alkylene having 1 to 6 carbons, and in the alkylene, at least one of —CH 2 — may be replaced by —O—, —OCO—, —COO— or —CH═CH—; Z 1 , Z 2 and Z 3 are independently a single bond, ethylene, methyleneoxy or carbonyloxy; k is 0, 1, 2 or 3; m is 1, 2 or 3; and n is 0 or 1, and a sum of m and n is 3 or less.
[0024] The inventors of the invention have focused attention on a skeletal structure of a polymerizable compound for use in a liquid crystal display device to which a PSA technology is applied, and have found out that solubility in a liquid crystal composition or a pretilt angle is improved to effectively develop a PSA effect and to enhance capability for aligning liquid crystal molecules by introducing into one of the skeletal structures a bonding group such as alkylene, and a group in which —CH 2 — in the alkylene is replaced by —O— or —CH═CH—, introducing a nonidentical reaction group thereinto or introducing a substituent into a ring structure.
[0025] In particular, the invention is significantly effective in improving performance of a VA liquid crystal display device to which the PSA technology is applied. The VA device using the PSA technology is a liquid crystal display apparatus having two substrates including transparent electrodes and alignment control films for aligning the liquid crystal molecules to be manufactured through a process for arranging between the substrates a liquid crystal composition containing the polymerizable compound, and polymerizing the polymerizable compound while applying a voltage between opposing transparent electrodes of the substrates.
[0026] According to the invention, a liquid crystal material in which an alignment state during voltage application is memorized in a polymeric component can be arranged between the substrates to memorize an inclination direction of sealed liquid crystal molecules and to shorten a response time, and thus a degree of image sticking can be improved.
[0027] In particular, use of the polymerizable compound of the invention allows a wide correspondence to a process for manufacturing a cell, and thus a high-definition liquid crystal display device can be manufactured.
ADVANTAGEOUS EFFECTS OF INVENTION
[0028] An advantage of the invention is a high stability of a polymer of a polymerizable mesogenic compound or liquid crystal compound to ultraviolet light or heat. Another advantage of the invention is a liquid crystal composition satisfying at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat. One aspect of the invention is a liquid crystal composition having a suitable balance regarding at least two of the characteristics. Another aspect is a liquid crystal display device including such a composition. A further aspect is a polymerizable compound having a high stability to ultraviolet light or heat, a composition having a suitable optical anisotropy, a large negative dielectric anisotropy, a high stability to ultraviolet light and so forth, and an AM device having a short response time, a suitable pretilt angle, a small rate of image sticking, a large voltage holding ratio, a large contrast ratio, a long service life and so forth.
DESCRIPTION OF EMBODIMENTS
[0029] Usage of terms herein is as described below. A liquid crystal composition or a liquid crystal display device of the invention may be abbreviated as “composition” or “device,” respectively. The liquid crystal display device is a generic term for a liquid crystal display panel and a liquid crystal display module. “Liquid crystal compound” means a compound having a liquid crystal phase such as a nematic phase or a smectic phase, or a compound having no liquid crystal phase but being useful as a component of the composition. Such a useful compound has a six-membered ring such as 1,4-cyclohexylene and 1,4-phenylene, and a rod-like molecular structure. An optically active compound and a polymerizable compound may occasionally be added to the composition. Even in the case where the compounds are liquid crystalline, the compounds are classified as an additive herein. At least one compound selected from the group of compounds represented by formula (1) may be abbreviated as “compound (1).” “Compound (1)” means one compound or two or more compounds represented by formula (1). A same rule also applies to any other compound represented by any other formula. At least one group selected from groups represented by formula (P-1) may be abbreviated as “group (P-1).” A same rule also applies to any other group represented by any other formula. “At least one” described prior to “replaced” indicates an arbitrary selection of not only positions but also numbers.
[0030] A higher limit of a temperature range of the nematic phase may be abbreviated as “maximum temperature.” A lower limit of the temperature range of the nematic phase may be abbreviated as “minimum temperature.” An expression “having a large specific resistance” means that the composition has a large specific resistance at room temperature and also at a temperature close to the maximum temperature of the nematic phase in an initial stage, and that the composition has a large specific resistance at room temperature and also at a temperature close to the maximum temperature of the nematic phase even after the device has been used for a long period of time. An expression “having a large voltage holding ratio” means that the device has a large voltage holding ratio at room temperature and also at a temperature close to the maximum temperature of the nematic phase in an initial stage, and that the device has a large voltage holding ratio at room temperature and also at a temperature close to the maximum temperature of the nematic phase even after the device has been used for a long period of time. When characteristics such as an optical anisotropy are explained, values obtained according to the measuring methods described in Examples will be used. A first component includes one compound or two or more compounds. “Ratio of the first component” is expressed in terms of a weight ratio (part by weight) of the first component based on 100 parts by weight of a liquid crystal composition excluding the first component and a polymerizable compound other than the first component. “Ratio of a second component” is expressed in terms of weight percent (% by weight) of the second component based on the weight of the liquid crystal composition excluding the first component and the polymerizable compound other than the first component. “Ratio of a third component” is expressed in a manner similar to “ratio of the second component.” A ratio of the additive mixed with the composition is expressed in terms of weight percent (% by weight) or weight parts per million (ppm) based on the total weight of the liquid crystal composition. “Ratio of the polymerizable compound other than the first component” is expressed in terms of a weight ratio (part by weight) of the polymerizable compound other than the first component based on 100 parts by weight of the liquid crystal composition excluding the first component and the polymerizable compound other than the first component.
[0031] A symbol R 1 is used for a plurality of compounds in chemical formulas of component compounds. In two of arbitrary compounds among the plurality of compounds, a group to be selected by R 1 may be identical or different. In one case, for example, R 1 of compound (2) is ethyl and R 1 of compound (2-1) is ethyl. In another case, R 1 of compound (2) is ethyl and R 1 of compound (2-1) is propyl. A same rule also applies to a symbol R 2 , X 1 , Y 1 or the like.
[0032] The invention includes the items described below. Item 1. A liquid crystal composition containing at least one compound selected from the group of compounds represented by formula (1) as a first component and at least one compound selected from the group of compounds represented by formula (2) as a second component:
[0000]
[0000] wherein P 1 and P 2 are independently a group selected from groups represented by formula (P-1) to formula (P-6);
[0000]
[0000] R 1 and R 2 are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons; ring A and ring B are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl or pyrimidine-2,5-diyl, and in the groups, at least one of hydrogen may be replaced by halogen or alkyl having 1 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by halogen; ring C and ring E are independently 1,4-cyclohexylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene or 3-fluoro-1,4-phenylene; ring D is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Sp is alkylene having 1 to 6 carbons, and in the alkylene, at least one of —CH 2 — may be replaced by —O—, —OCO—, —COO— or —CH═CH—; Z 1 , Z 2 and Z 3 are independently a single bond, ethylene, methyleneoxy or carbonyloxy; k is 0, 1, 2 or 3; m is 1, 2 or 3; and n is 0 or 1, and a sum of m and n is 3 or less.
[0033] Item 2. The liquid crystal composition according to item 1, wherein the first component is at least one compound selected from the group of compounds represented by formula (1-1) to formula (1-8):
[0000]
[0000] wherein Y 1 to Y 12 are independently hydrogen, halogen, alkyl having 1 to 12 carbons or trifluoromethyl; and X 1 and X 2 are independently hydrogen or methyl.
[0034] Item 3. The liquid crystal composition according to item 1, wherein the first component is at least one compound selected from the group of compounds represented by formula (1-1) to formula (1-8) according to item 2, and Y 1 to Y 12 are hydrogen.
[0035] Item 4. The liquid crystal composition according to item 1, wherein the first component is at least one compound selected from the group of compounds represented by formula (1-1) to formula (1-8) according to item 2, in formula (1-1) to formula (1-7), at least one of Y 1 to Y 8 is fluorine or trifluoromethyl, and in formula (1-8), at least one of Y 1 to Y 12 is fluorine or trifluoromethyl.
[0036] Item 5. The liquid crystal composition according to any one of items 1 to 4, wherein the first component is at least one compound selected from the group of compounds represented by formula (1-1) according to item 2.
[0037] Item 6. The liquid crystal composition according to any one of items 1 to 4, wherein the first component is at least one compound selected from the group of compounds represented by formula (1-2) according to item 2.
[0038] Item 7. The liquid crystal composition according to any one of items 1 to 6, wherein the first component comprises at least two or more compounds selected from the group of compounds represented by formula (1) according to item 1.
[0039] Item 8. The liquid crystal composition according to anyone of items 1 to 7, wherein the first component is at least one compound selected from the group of compounds represented by formula (1) according to item 1, and further contains a polymerizable compound other than the compounds represented by formula (1) according to item 1.
[0040] Item 9. The liquid crystal composition according to any one of items 1 to 8, wherein the second component is at least one compound selected from the group of compounds represented by formula (2-1) to formula (2-19):
[0000]
[0000] wherein R 1 and R 2 are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons.
[0041] Item 10. The liquid crystal composition according to item 1, wherein the second component is at least one compound selected from the group of compounds represented by formula (2-3) according to item 9.
[0042] Item 11. The liquid crystal composition according to item 1, wherein the second component is at least one compound selected from the group of compounds represented by formula (2-5) according to item 9.
[0043] Item 12. The liquid crystal composition according to item 1, wherein the second component is at least one compound selected from the group of compounds represented by formula (2-7) according to item 9.
[0044] Item 13. The liquid crystal composition according to item 1, wherein the second component is at least one compound selected from the group of compounds represented by formula (2-13) according to item 9.
[0045] Item 14. The liquid crystal composition according to any one of items 1 to 13, further containing at least one compound selected from the group of compounds represented by formula (3) as a third component:
[0000]
[0000] wherein R 3 and R 4 are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which at least one of hydrogen is replaced by fluorine; ring F, ring G and ring I are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 3-fluoro-1,4-phenylene; Z 4 and Z 5 are independently a single bond, ethylene, methyleneoxy or carbonyloxy; and p is 0, 1 or 2.
[0046] Item 15. The liquid crystal composition according to item 14, wherein the third component is at least one compound selected from the group of compounds represented by formula (3-1) to formula (3-13):
[0000]
[0000] wherein R 3 and R 4 are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which at least one of hydrogen is replaced by fluorine.
[0047] Item 16. The liquid crystal composition according to item 14, wherein the third component is at least one compound selected from the group of compounds represented by formula (3-1) according to item 15.
[0048] Item 17. The liquid crystal composition according to item 14, wherein the third component is at least one compound selected from the group of compounds represented by formula (3-7) according to item 15.
[0049] Item 18. The liquid crystal composition according to any one of items 14 to 17, wherein a ratio of the second component is in the range of 10% by weight to 80% by weight, and a ratio of the third component is in the range of 20% by weight to 90% by weight, based on the weight of a liquid crystal composition excluding the first component and a polymerizable compound other than the first component, and a ratio of the first component and the polymerizable compound other than the first component is in the range of 0.03 part by weight to 10 parts by weight based on 100 parts by weight of the liquid crystal composition excluding the first component and the polymerizable compound other than the first component.
[0050] Item 19. The liquid crystal composition according to any one of items 1 to 18, further containing a polymerization initiator.
[0051] Item 20. The liquid crystal composition according to any one of items 1 to 19, further containing a polymerization inhibitor.
[0052] Item 21. The liquid crystal composition according to any one of items 1 to 20, wherein a maximum temperature of a nematic phase is 70° C. or higher, an optical anisotropy (25° C.) at a wavelength of 589 nanometers is 0.08 or more, and a dielectric anisotropy (25° C.) at a frequency of 1 kHz is −2 or less.
[0053] Item 22. A polymer sustained alignment (PSA) liquid crystal display device, comprising two substrates including an electrode layer on at least one of the substrates, and arranging between the two substrates a liquid crystal material containing a compound in which a polymerizable compound in the liquid crystal composition according to any one of items 1 to 21 is polymerized.
[0054] Item 23. The liquid crystal display device according to item 22, wherein an operating mode in the liquid crystal display device is a TN mode, a VA mode, an OCB mode, an IPS mode or a FFS mode, and a driving mode in the liquid crystal display device is an active matrix mode.
[0055] Item 24. A method for manufacturing a liquid crystal display device, wherein the liquid crystal display device according to item 22 is manufactured by polymerizing the polymerizable compound by subjecting the liquid crystal compound according to any one of items 1 to 21 as arranged between two substrates to irradiation with light under a voltage application state.
[0056] Item 25. Use of the liquid crystal composition according to any one of items 1 to 21 in a liquid crystal display device.
[0057] The invention also includes the following items: (1) the composition, further containing the optically active compound; (2) the composition, further containing the additive such as an antioxidant, an ultraviolet light absorber or an antifoaming agent; (3) an AM device including the composition; (4) a device including the composition, and having a TN, an ECB, an OCB, an IPS, a FFS, a VA or a PSA mode; (5) a transmissive device including the composition; (6) use of the composition as the composition having the nematic phase; and (7) use as an optically active composition by adding the optically active compound to the composition.
[0058] The composition of the invention will be explained in the following order. First, a constitution of the component compounds in the composition will be explained. Second, main characteristics of the component compounds and main effects of the compounds on the composition will be explained. Third, a combination of components in the composition, a preferred ratio of the components and the basis thereof will be explained. Fourth, a preferred embodiment of the component compounds will be explained. Fifth, specific examples of the component compounds will be shown. Sixth, the additive that may be mixed with the composition will be explained. Seventh, methods for synthesizing the component compounds will be explained. Last, an application of the composition will be explained.
[0059] First, the constitution of the component compounds in the composition will be explained. The composition of the invention is classified into composition A and composition B. Composition A may further contain any other liquid crystal compound, the additive and an impurity, in addition to the liquid crystal compound selected from compound (1), compound (2) and compound (3). “Any other liquid crystal compound” means a liquid crystal compound different from compound (1), compound (2) and compound (3). Such a compound is mixed with the composition for the purpose of further adjusting the characteristics. Of any other liquid crystal compounds, a ratio of a cyano compound is preferably as small as possible in view of stability to heat or ultraviolet light. A further preferred ratio of the cyano compound is 0% by weight. The additive includes the optically active compound, the antioxidant, the ultraviolet light absorber, a dye, the antifoaming agent and the polymerization initiator. The impurity includes a compound mixed in a process such as preparation of the component compounds. Even in the case where the compound is liquid crystalline, the compound is classified as the impurity herein.
[0060] Composition B consists essentially of compound (1), compound (2) and compound (3). A term “essentially” means that the composition may also contain the additive and the impurity, but does not contain any liquid crystal compound different from the compounds. Composition B has a smaller number of components than composition A has. Composition B is preferred to composition A in view of cost reduction. Composition A is preferred to composition B in view of possibility of further adjusting physical properties by mixing any other liquid crystal compound.
[0061] Second, the main characteristics of the component compounds and the main effects of the compounds on the characteristics of the composition will be explained. The main characteristics of the component compounds are summarized in Table 2 on the basis of advantageous effects of the invention. In Table 2, a symbol L stands for “large” or “high,” a symbol M stands for “medium,” and a symbol S stands for “small” or “low.” The symbols L, M and S represent a classification based on a qualitative comparison among the component compounds, and 0 (zero) means “a value is close to zero.”
[0000]
TABLE 2
Characteristics of Compounds
Compounds
Compound (2)
Compound (3)
Maximum temperature
S to L
S to L
Viscosity
M to L
S to M
Optical anisotropy
M to L
S to L
Dielectric anisotropy
M to L 1)
0
Specific resistance
L
L
1) A value of dielectric anisotropy is negative, and the symbol shows magnitude of an absolute value.
[0062] Upon mixing the component compounds with the composition, the main effects of the component compounds on the characteristics of the composition are as described below. Compound (2) increases the absolute value of dielectric anisotropy, and decreases the minimum temperature. Compound (3) decreases the viscosity, or increases the maximum temperature and decreases the minimum temperature.
[0063] Third, the combination of components in the composition, the preferred ratio of the components and the basis thereof will be explained. The combination of the components in the composition includes a combination of the first component and the second component, and a combination of the first component, the second component and the third component.
[0064] A preferred ratio of the first compound is approximately 0.05 part by weight or more for aligning liquid crystal molecules, and approximately 10 parts by weight or less for avoiding a poor display, based on 100 parts by weight of the liquid crystal composition excluding the first component. A further preferred ratio is in the range of approximately 0.1 part by weight to approximately 2 parts by weight.
[0065] A preferred ratio of the second component is approximately 10% by weight or more for increasing the absolute value of dielectric anisotropy, and approximately 80% by weight or less for decreasing the minimum temperature, based on the liquid crystal composition excluding the first component. A further preferred ratio is in the range of approximately 15% by weight to approximately 70% by weight. A particularly preferred ratio is in the range of approximately 20% by weight to approximately 60% by weight.
[0066] A preferred ratio of the third component is approximately 20% by weight or more for decreasing the viscosity or increasing the maximum temperature, and approximately 90% or less for increasing the absolute value of dielectric anisotropy, based on the liquid crystal composition excluding the first component. A further preferred ratio is in the range of approximately 30% by weight to approximately 80% by weight. A particularly preferred ratio is in the range of approximately 40% by weight to approximately 70% by weight.
[0067] Fourth, the preferred embodiment of the component compounds will be explained.
[0068] R 1 and R 2 are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons. Preferred R 1 or R 2 is alkyl having 1 to 12 carbons for increasing the stability to ultraviolet light or heat, and alkoxy having 1 to 12 carbons for decreasing the viscosity.
[0069] R 3 and R 4 are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which at least one of hydrogen is replaced by fluorine. Preferred R 3 or R 4 is alkenyl having 2 to 12 carbons for decreasing the viscosity, and alkyl having 1 to 12 carbons for increasing the stability to ultraviolet light, or for increasing the stability to heat.
[0070] Preferred alkyl is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl. Further preferred alkyl is ethyl, propyl, butyl, pentyl or heptyl for decreasing the viscosity.
[0071] Preferred alkoxy is methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy or heptyloxy. Further preferred alkoxy is methoxy or ethoxy for decreasing the viscosity.
[0072] Preferred alkenyl is vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl or 5-hexenyl. Further preferred alkenyl is vinyl, 1-propenyl, 3-butenyl or 3-pentenyl for decreasing the viscosity. A preferred configuration of —CH═CH— in the alkenyl depends on a position of a double bond. Trans is preferred in the alkenyl such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl and 3-hexenyl for decreasing the viscosity, for instance. C is preferred in the alkenyl such as 2-butenyl, 2-pentenyl and 2-hexenyl. In the alkenyl, straight-chain alkenyl is preferred to branched-chain alkenyl.
[0073] Preferred examples of alkenyl in which at least one of hydrogen is replaced by fluorine include 2,2-difluorovinyl, 3,3-difluoro-2-propenyl, 4,4-difluoro-3-butenyl, 5,5-difluoro-4-pentenyl and 6,6-difluoro-5-hexenyl. Further preferred examples include 2,2-difluorovinyl and 4,4-difluoro-3-butenyl for decreasing the viscosity.
[0074] Alkyl does not include cyclic alkyl. Alkoxy does not include cyclic alkoxy. Alkenyl does not include cyclic alkenyl. With regard to a configuration of 1,4-cyclohexylene, trans is preferred to cis for increasing the maximum temperature.
[0075] Sp is alkylene having 1 to 6 carbons, and in the alkylene, at least one of —CH 2 — may be replaced by —O—, —OCO—, —COO— or —CH═CH—. Preferred Sp is alkylene having 1 to 6 carbons for increasing the stability to ultraviolet light or heat, and alkylene in which —CH 2 — is replaced by —CH═CH— for increasing solubility in the liquid crystal composition. With regard to a configuration of —CH═CH—, cis may be and trans may be.
[0076] P 1 and P 2 are independently a group selected from groups represented by formula (P-1) to formula (P-6):
[0000]
[0077] Preferred P 1 or P 2 is group (P-1) and group (P-2) for increasing reactivity or shortening a response time, group (P-5) for increasing the solubility in the liquid crystal composition, and group (P-3) and group (P-4) for increasing the stability to ultraviolet light or heat.
[0078] Ring A and ring B are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl and pyrimidine-2,5-diyl, and in the rings, at least one of hydrogen may be replaced by halogen or alkyl having 1 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by halogen, and two of arbitrary ring A when k is 2 or 3 may be identical or different. Preferred ring A or ring B is 1,4-phenylene in which at least one of hydrogen may be replaced by halogen or alkyl having 1 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by halogen for shortening a response time. Further preferred ring A or ring B is 1,4-phenylene. Ring C and ring E are independently 1,4-cyclohexylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene or 3-fluoro-1,4-phenylene, and two of arbitrary ring C when m is 2 or 3 may be identical or different. Preferred ring C or ring E is 1,4-cyclohexylene for decreasing the viscosity, tetrahydropyran-2,5-diyl for increasing the absolute value of dielectric anisotropy, and 1,4-phenylene for increasing the optical anisotropy. Tetrahydropyran-2,5-diyl includes:
[0000]
[0079] Ring D is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl. Preferred ring D is 2,3-difluoro-1,4-phenylene for decreasing the viscosity, 2-chloro-3-fluoro-1,4-phenylene for decreasing the optical anisotropy, and 7,8-difluorochroman-2,6-diyl for increasing the absolute value of dielectric anisotropy.
[0080] Ring F, ring G and ring I are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 3-fluoro-1,4-phenylene, and two of arbitrary ring F when p is 2 may be identical or different. Preferred ring F, ring G or ring I is 1,4-cyclohexylene for decreasing the viscosity or increasing the maximum temperature, and 1,4-phenylene for decreasing the minimum temperature.
[0081] Z 1 , Z 2 and Z 3 are independently a single bond, ethylene, methyleneoxy or carbonyloxy, two of arbitrary Z 1 when k is 2 or 3 may be identical or different, and two of arbitrary Z 2 when m is 2 or 3 may be identical or different. Preferred Z 1 is a single bond for increasing the reactivity, and ethylene for increasing the solubility in the liquid crystal composition. Preferred Z 2 or Z 3 is a single bond for decreasing the viscosity, ethylene for decreasing the minimum temperature, and methyleneoxy for increasing the absolute value of dielectric anisotropy.
[0082] Z 4 and Z 5 are independently a single bond, ethylene, methyleneoxy or carbonyloxy, and two of Z 4 when p is 2 may be identical or different. Preferred Z 4 or Z 5 is a single bond for decreasing the viscosity, ethylene for decreasing the minimum temperature, and carbonyloxy for increasing the maximum temperature.
[0083] Y 1 to Y 12 are independently hydrogen, halogen, alkyl having 1 to 12 carbons or trifluoromethyl. Preferred Y 1 to Y 12 are hydrogen for increasing the reactivity, and halogen or trifluoromethyl for increasing the solubility in the liquid crystal composition.
[0084] X 1 and X 2 are independently hydrogen or methyl. Preferred X 1 or X 2 is methyl for increasing the reactivity, and hydrogen for increasing the stability to ultraviolet light.
[0085] Then, k is 0, 1, 2 or 3. Preferred k is 1 for increasing the reactivity. Moreover, m is 1, 2 or 3. Preferred m is 1 for decreasing the viscosity, and 2 or 3 for increasing the maximum temperature.
[0086] Further, n is 0 or 1. Preferred n is 0 for decreasing the viscosity, and 1 for decreasing the minimum temperature.
[0087] Furthermore, p is 0, 1 or 2. Preferred p is 0 for decreasing the viscosity, and 1 or 2 for increasing the maximum temperature.
[0088] Fifth, the specific examples of the component compounds will be shown. In the preferred compounds described below, R 5 and R 8 are straight-chain alkyl having 1 to 12 carbons, straight-chain alkoxy having 1 to 12 carbons or straight-chain alkenyl having 2 to 12 carbons. R 6 is straight-chain alkyl having 1 to 12 carbons or straight-chain alkoxy having 1 to 12 carbons. R 7 is straight-chain alkyl having 1 to 12 carbons or straight-chain alkenyl having 2 to 12 carbons. Y 4 is hydrogen, halogen, alkyl having 1 to 12 carbons or trifluoromethyl. X 1 and X 2 are hydrogen or methyl.
[0089] Preferred compound (1) includes compound (1-1-1) to compound (1-8-1). Further preferred compound (1) includes compound (1-1-1) to compound (1-5-1) and compound (1-8-1). Particularly preferred compound (1) includes compound (1-1-1) and compound (1-2-1). Preferred compound (2) includes compound (2-1-1) to compound (2-19-1). Further preferred compound (2) includes compound (2-1-1) to compound (2-10-1), and compound (2-12-1) to compound (2-15-1). Particularly preferred compound (2) includes compound (2-1-1) to compound (2-8-1), compound (2-13-1) and compound (2-15-1). Preferred compound (3) includes compound (3-1-1) to compound (3-13-1). Further preferred compound (3) includes compound (3-1-1) to compound (3-7-1), and compound (3-9-1) to compound (3-13-1). Particularly preferred compound (3) includes compound (3-1-1), compound (3-3-1), compound (3-7-1) and compound (3-13-1).
[0000]
[0090] Sixth, the additive that may be mixed with the composition will be explained. Such an additive includes the optically active compound, the antioxidant, the ultraviolet light absorber, the dye, the antifoaming agent, the polymerization initiator and the polymerization inhibitor. The optically active compound is mixed with the composition for the purpose of inducing a helical structure in liquid crystals to give a twist angle. Examples of such a compound include compound (4-1) to compound (4-5). A preferred ratio of the optically active compound is approximately 5% by weight or less. A further preferred ratio is in the range of approximately 0.01% by weight to approximately 2% by weight.
[0000]
[0091] The antioxidant is mixed with the composition for the purpose of preventing a decrease in the specific resistance caused by heating in air, or maintaining a large voltage holding ratio at room temperature and also at a temperature close to the maximum temperature of the nematic phase even after the device has been used for a long period of time.
[0000]
[0092] Preferred examples of the antioxidant include compound (5) where w is an integer from 1 to 9. In compound (5), preferred w is 1, 3, 5, 7 or 9. Further preferred w is 1 or 7. Compound (5) where w is 1 is effective in preventing a decrease in the specific resistance caused by heating in air because the compound (5) has a large volatility. Compound (5) where w is 7 is effective in maintaining a large voltage holding ratio at room temperature and also at a temperature close to the maximum temperature of the nematic phase even after the device has been used for a long period of time because the compound (5) has a small volatility. A preferred ratio of the antioxidant is approximately 50 ppm or more for achieving the effect thereof, and approximately 600 ppm or less for avoiding a decrease in the maximum temperature or avoiding an increase in the minimum temperature. A further preferred ratio is in the range of approximately 100 ppm to approximately 300 ppm.
[0093] Preferred examples of the ultraviolet light absorber include a benzophenone derivative, a benzoate derivative and a triazole derivative. A light stabilizer such as an amine having steric hindrance is also preferred. A preferred ratio of the ultraviolet light absorber or the stabilizer is approximately 50 ppm or more for achieving the effect thereof, and approximately 10,000 ppm or less for avoiding a decrease in the maximum temperature or avoiding an increase in the minimum temperature. A further preferred ratio is in the range of approximately 100 ppm to approximately 10,000 ppm.
[0094] A dichroic dye such as an azo dye or an anthraquinone dye is mixed with the composition to be adapted for a device having a guest host (GH) mode. A preferred ratio of the dye is in the range of approximately 0.01% by weight to approximately 10% by weight.
[0095] The antifoaming agent such as dimethyl silicone oil or methyl phenyl silicone oil is mixed with the composition for preventing foam formation. A preferred ratio of the antifoaming agent is approximately 1 ppm or more for achieving the effect thereof, and approximately 1,000 ppm or less for avoiding a poor display. A further preferred ratio is in the range of approximately 1 ppm to approximately 500 ppm.
[0096] The liquid crystal composition of the invention is suitable for use in the device having the polymer sustained alignment (PSA) mode because the composition contains the polymerizable compound. The composition may further contain a polymerizable compound other than compound (1). Preferred examples of the polymerizable compound include a compound having a polymerizable group, such as an acrylate, a methacrylate, a vinyl compound, a vinyloxy compound, a propenyl ether, an epoxy compound (oxirane, oxetane) and a vinyl ketone. Particularly preferred examples include an acrylate or methacrylate derivative. A preferred ratio of the polymerizable compound is approximately 0.03 part by weight or more for achieving the effect thereof, and approximately 10 parts by weight or less for avoiding a poor display, based on 100 parts by weight of the liquid crystal composition. A further preferred ratio is in the range of approximately 0.1 part by weight to approximately 2 parts by weight. A preferred ratio of compound (1) in the polymerizable compound is approximately 10% by weight or more. A further preferred ratio is approximately 30% by weight or more. The polymerizable compound is preferably polymerized by irradiation with ultraviolet light or the like in the presence of a suitable initiator such as a photopolymerization initiator. Suitable conditions for polymerization, suitable types of the initiator and suitable amounts thereof are known to those skilled in the art and are described in literatures. For example, Irgacure 651 (registered trademark; BASF), Irgacure 184 (registered trademark; BASF) or Darocure 1173 (registered trademark; BASF), each being a photoinitiator, is suitable for radical polymerization. A preferred ratio of the photopolymerization initiator is in the range of approximately 0.1% by weight to approximately 5% by weight, and a further preferred ratio is in the range of approximately 1% by weight to approximately 3% by weight, based on the polymerizable compound. A polymerized compound may be arranged through a process of arranging the liquid crystal composition containing the polymerizable compound between two substrates in the liquid crystal display device and polymerizing the polymerizable compound while applying a voltage between opposing electrode layers on the substrates, or a liquid crystal composition containing a preliminarily polymerized compound may be arranged between the two substrates in the liquid crystal display device.
[0097] Examples of the polymerizable compound that may be further contained, other than compound (1), include compound (6-1) to compound (6-9). The solubility in the composition can be increased and the reactivity can be enhanced by adding compound (1) in the polymerizable compound.
[0000]
[0000] wherein R 9 , R 10 , R 11 and R 12 are independently acryloyl or methacryloyl, and R 13 and R 14 are independently hydrogen, halogen or alkyl having 1 to 10 carbons; Z 6 and Z 7 are simultaneously a single bond or alkylene having 1 to 12 carbons, and in the alkylene, at least one of —CH 2 — may be replaced by —O—; Z 8 and Z 9 are independently a single bond or alkylene having 1 to 12 carbons, and in the alkylene, at least one of —CH 2 — may be replaced by —O—; and q, r and s are independently 0, 1 or 2.
[0098] Seventh, the methods for synthesizing the component compounds will be explained. The component compounds can be prepared by suitably combining known techniques of synthetic organic chemistry as described in Organic Syntheses (John Wiley & Sons, Inc.), Organic Reactions (John Wiley & Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press) and New Experimental Chemistry Course (Shin Jikken Kagaku Koza in Japanese) (Maruzen Co., Ltd.) or the like.
[0099] The compounds can be prepared according to known methods. Examples of synthetic methods will be shown. Compound (2-1-1) and compound (2-5-1) are prepared by the method described in JP H2-503441 A (1990). Compound (3-1-1) and compound (3-5-1) are prepared by the method described in JP S59-176221 A (1984). The antioxidant is commercially available. A compound represented by formula (5) where w is 1 is available from Sigma-Aldrich Corporation. Compound (5) where w is 7 and so forth are prepared according to the method described in U.S. Pat. No. 3,660,505 B.
[0100] Any compounds whose synthetic methods are not described above can be prepared according to the methods described in books such as Organic Syntheses (John Wiley & Sons, Inc.), Organic Reactions (John Wiley & Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press) and New Experimental Chemistry Course (Shin Jikken Kagaku Koza in Japanese) (Maruzen Co., Ltd.). The composition is prepared according to publicly known methods using the thus obtained compounds. For example, the component compounds are mixed and dissolved in each other by heating.
[0101] Last, the application of the composition will be explained. Most of the compositions have a minimum temperature of approximately −10° C. or lower, a maximum temperature of approximately 70° C. or higher and an optical anisotropy in the range of approximately 0.07 to approximately 0.20. The device including the composition has a large voltage holding ratio. The composition is suitable for use in the AM device. The composition is particularly suitable for use in a transmissive AM device. A composition having an optical anisotropy in the range of approximately 0.08 to approximately 0.25 may be prepared by controlling the ratio of the component compounds or by mixing any other liquid crystal compound. The composition can be used as the composition having the nematic phase, and as the optically active composition by adding the optically active compound.
[0102] The composition can be used in the AM device. The composition can also be used in a PM device. The composition can be used in an AM device and a PM device both having a mode such as PC, TN, STN, ECB, OCB, IPS, VA or PSA. Use for in the AM device having the PSA mode is particularly preferred. The devices may be of a reflective type, a transmissive type or a transflective type. Use for in the transmissive device is preferred. The composition can also be used in an amorphous silicon-TFT device or a polycrystal silicon-TFT device. The composition can also be used in a nematic curvilinear aligned phase (NCAP) device prepared by microencapsulating the composition, and in a polymer dispersed (PD) device in which a three-dimensional network polymer is formed in the composition.
[0103] The liquid crystal display device of the invention is characterized by comprising two substrates including the electrode layer on at least one of the substrates, and arranging between the two substrates the liquid crystal composition of the invention or the liquid crystal composition containing the compound in which the polymerizable compound of the invention is polymerized. For example, the liquid crystal display device comprises two glass substrates referred to as an array substrate and a color filter substrate, and a thin film transistor (TFT), pixels, a coloring layer and so forth are formed on each of the glass substrates. An aluminosilicate glass or aluminoborosilicate glass is used for each of the glass substrates, for example. For the electrode layer, Indium-Tin Oxide and Indium-Zinc Oxide are generally used.
[0104] It will be apparent to those skilled in the art that various modifications and variations can be made in the invention and specific examples provided herein without departing from the spirit or scope of the invention. Thus, it is intended that the invention covers the modifications and variations of this invention that come within the scope of any claims and their equivalents.
[0105] The following examples are for illustrative purposes only and are not intended, nor should they be interpreted to, limit the scope of the invention.
EXAMPLES
[0106] In the following, the invention will be explained in detail byway of Examples, but the invention is not limited by the Examples.
[0107] A compound obtained by synthesis was identified by means of proton nuclear magnetic resonance spectroscopy ( 1 H-NMR), high performance liquid chromatography (HPLC), ultraviolet/visible spectroscopy (UV/Vis) and so forth. A melting point of the compound was determined by differential scanning calorimetry (DSC). First, each analytical method will be explained.
[0108] 1 H-NMR Analysis: As a measuring apparatus, DRX-500 (made by Bruker BioSpin Corporation) was used. A sample prepared in Examples and so forth was dissolved in a deuterated solvent such as CDCl 3 in which the sample was soluble, and measurement was carried out under the conditions of room temperature, 500 MHz, 24 times of accumulation and so forth. In the explanation of nuclear magnetic resonance spectra obtained, s, d, t, q and m stand for a singlet, a doublet, a triplet, a quartet, and a multiplet, respectively. Moreover, tetramethylsilane (TMS) was used as an internal standard for a zero point of chemical shifts (δ).
[0109] HPLC Analysis: As a measuring apparatus, Prominence (LC-20AD; SPD-20A) made by Shimadzu Corporation was used. Asa column, YMC-Pack ODS-A (length 150 mm, bore 4.6 mm, particle diameter 5 μm) made by YMC Co. Ltd. was used. As an effluent, acetonitrile/water (volume ratio: 80/20) was used, and a flow rate was adjusted to 1 mL/min. As a detector, an UV detector, a RI detector and a CORONA detector or the like was suitably used. When the UV detector was used, a detection wavelength was set at 254 nanometers.
[0110] A sample was dissolved in acetonitrile to prepare a solution of 0.1% by weight, and 1 microliter of the solution obtained was introduced into a sample injector.
[0111] As a recorder, C-R7Aplus made by Shimadzu Corporation was used. The chromatogram obtained shows a retention time of a peak and a value of each peak area corresponding to each component compound.
[0112] A ratio of peak areas in the chromatogram obtained from HPLC corresponds to a ratio of component compounds. In general, the weight percent of each component compound in an analytical sample is not completely identical with the percentage of each peak area in the analytical sample. When the columns described above are used in the invention, however, the weight percent of each component compound in the analytical sample corresponds substantially to the percentage of each peak area in the analytical sample because a correction coefficient is essentially 1 (one). The reason is that no significant difference exists among the correction coefficients of components in the liquid crystal compound. In order to more accurately determine a composition ratio of the liquid crystal compounds in the liquid crystal composition by the chromatogram, an internal standard method by the chromatogram is applied. Each component (test-component) of the liquid crystal compounds and a liquid crystal compound as a standard (standard reference material) as weighed accurately in a fixed amount are simultaneously analyzed by means of HPLC, and relative intensity of a ratio of a peak area of the test-component to a peak area of the standard reference material is calculated in advance. When corrected using the relative intensity of the peak area of each component to the peak area of the standard reference material, the composition ratio of the liquid crystal compounds in the liquid crystal composition can be more accurately determined from the chromatogram.
[0113] UV/Vis Analysis:
[0114] As a measuring apparatus, PharmaSpec UV-1700 made by Shimadzu Corporation was used. A detection wavelength was set to 190 nanometers to 700 nanometers.
[0115] A sample was dissolved in acetonitrile and prepared to be a 0.01 mmol/L solution, the solution was put in a quartz cell (optical path length 1 cm), and measurement was carried out.
[0116] DSC Measurement:
[0117] A sample was heated and then cooled at a rate of 3° C. per minute using a differential scanning calorimeter, DSC-7 System or Diamond DSC System, made by PerkinElmer, Inc. A starting point (on set) of an endothermic peak or an exothermic peak caused by a phase change of the sample was determined by extrapolation, and thus a melting point was determined.
Example 1
Comparison of Solubility in Liquid Crystal Composition 1
[0118] As a comparison, 1 part by weight of polymerizable compound (R-1) was added to 100 parts by weight of liquid crystal composition A, and dissolution was attempted at 25° C., but crystals remained in the liquid crystal composition and the compound did not wholly dissolved.
[0119] When 1 part by weight of polymerizable compound (1-1-1-1) of the invention was added to 100 parts by weight of liquid crystal composition A, and dissolution was attempted at 25° C., a whole amount of compound (1-1-1-1) was dissolved. The comparison shows that the compound of the invention is more easily dissolved in the liquid crystal composition. The results are shown in Table 3. In expressions in Table 3, “good” indicates no finding of crystals, and “bad” indicates finding of crystals. Components and ratios of liquid crystal composition A were as described below.
[0000]
[0000]
TABLE 3
Comparision of Solubility in Liquid Crystal Composition
Solubility
(2 days, room
Formula No.
Structural Formula
temperature)
Comparative Example (R-1)
Bad
(1-1-1-1)
Good
[0120] In order to evaluate characteristics of a composition and a compound to be contained in the composition, the composition and the compound were made a measurement object. When the measurement object was the composition, the composition was measured as a sample as is, and values obtained were described. When the measurement object was the compound, a sample for measurement was prepared by mixing the compound (15% by weight) with mother liquid crystals (85% by weight). Values of characteristics of the compound were calculated using values obtained by measurement, according to an extrapolation method: (extrapolated value)={(measured value of a sample for measurement)−0.85×(measured value of mother liquid crystals)}/0.15. When a smectic phase (or crystals) precipitated at the above ratio at 25° C., a ratio of the compound to the mother liquid crystals was changed step by step in the order of (10% by weight:90% by weight), (5% by weight:95% by weight) and (1% by weight:99% by weight). Values of a maximum temperature, an optical anisotropy, viscosity and a dielectric anisotropy with regard to the compound were determined according to the extrapolation method.
[0121] Components of the mother liquid crystals and ratios thereof were as described below.
[0000]
[0122] The characteristics were measured according to the methods described below. Most of the methods are applied as described in the Standard of Japan Electronics and Information Technology Industries Association, hereafter abbreviated as JEITA) discussed and established as the Standard of JEITA (JEITA ED-2521B), or as modified thereon.
[0123] Maximum Temperature of a Nematic Phase (NI; ° C.):
[0124] A sample was placed on a hot plate in a melting point apparatus equipped with a polarizing microscope and was heated at a rate of 1° C. per minute. Temperature when a part of the sample began to change from a nematic phase to an isotropic liquid was measured. A higher limit of a temperature range of the nematic phase may be abbreviated as “maximum temperature.”
[0125] Minimum Temperature of a Nematic Phase (T c ; ° C.):
[0126] A sample having a nematic phase was put in glass vials and kept in freezers at temperatures of 0° C., −10° C., −20° C., −30° C. and −40° C. for 10 days, and then liquid crystal phases were observed. For example, when the sample maintained the nematic phase at −20° C. and changed to crystals or a smectic phase at −30° C., T c was expressed as T c <−20° C. A lower limit of the temperature range of the nematic phase may be abbreviated as “minimum temperature.”
[0127] Viscosity (Bulk Viscosity; η; Measured at 20° C.; mPa·s):
[0128] A cone-plate (E type) rotational viscometer was used for measurement.
[0129] Optical Anisotropy (Refractive Index Anisotropy; Δn; Measured at 25° C.):
[0130] Measurement was carried out by means of an Abbe refractometer with a polarizing plate mounted on an ocular, using light at a wavelength of 589 nanometers. A surface of a main prism was rubbed in one direction, and then a sample was added dropwise onto the main prism. A refractive index (n∥) was measured when the direction of polarized light was parallel to the direction of rubbing. A refractive index (n⊥) was measured when the direction of polarized light was perpendicular to the direction of rubbing. A value of optical anisotropy was calculated from an equation: Δn=n∥−n⊥.
[0131] Dielectric Anisotropy (Δ∈; Measured at 25° C.):
[0132] A value of dielectric anisotropy was calculated from an equation: Δ∈=∈∥−∈⊥. A dielectric constant (∈∥ and ∈⊥) was measured as described below.
[0133] (1) Measurement of dielectric constant (∈∥): An ethanol (20 mL) solution of octadecyl triethoxysilane (0.16 mL) was applied to a well-washed glass substrate. After rotating the glass substrate with a spinner, the glass substrate was heated at 150° C. for 1 hour. A sample was put in a VA device in which a distance (cell gap) between two glass substrates was 4 micrometers, and the device was sealed with an ultraviolet-curable adhesive. Sine waves (0.5 V, 1 kHz) were applied to the device, and after 2 seconds, a dielectric constant (∈∥) in the major axis direction of liquid crystal molecules was measured.
[0134] (2) Measurement of dielectric constant (∈⊥): A polyimide solution was applied to a well-washed glass substrate. After calcining the glass substrate, rubbing treatment was applied to the alignment film obtained. A sample was put in a TN device in which a distance (cell gap) between two glass substrates was 9 micrometers and a twist angle was 80 degrees. Sine waves (0.5 V, 1 kHz) were applied to the device, and after 2 seconds, a dielectric constant (∈⊥) in the minor axis direction of the liquid crystal molecules was measured.
[0135] Threshold Voltage (Vth; Measured at 25° C.; V):
[0136] An LCD-5100 luminance meter made by Otsuka Electronics Co., Ltd. was used for measurement. Alight source was a halogen lamp. A sample was put in a normally black mode VA device in which a distance (cell gap) between two glass substrates was 4 micrometers and a rubbing direction was anti-parallel, and the device was sealed with an ultraviolet-curable adhesive. A voltage (60 Hz, rectangular waves) to be applied to the device was stepwise increased from 0 V to 20 V at an increment of 0.02 V. On the occasion, the device was irradiated with light from a direction perpendicular to the device, and the amount of light transmitting the device was measured. A voltage-transmittance curve was prepared, in which the maximum amount of light corresponds to 100% transmittance and the minimum amount of light corresponds to 0% transmittance. A threshold voltage is voltage at 10% transmittance.
[0137] Voltage Holding Ratio (VHR-1; Measured at 25° C.; %):
[0138] A TN device used for measurement had a polyimide alignment film, and a distance (cell gap) between two glass substrates was 5 micrometers. A sample was put in the device, and then the device was sealed with an ultraviolet-curable adhesive. A pulse voltage (60 microseconds at 5 V) was applied to the TN device and the device was charged. A decaying voltage was measured for 16.7 milliseconds with a high-speed voltmeter, and area A between a voltage curve and a horizontal axis in a unit cycle was determined. Area B is an area without decay. A voltage holding ratio is a percentage of area A to area B.
[0139] Voltage Holding Ratio (VHR-2; Measured at 80° C.; %):
[0140] A TN device used for measurement had a polyimide alignment film, and a distance (cell gap) between two glass substrates was 5 micrometers. A sample was put in the device, and then the device was sealed with an ultraviolet-curable adhesive. A pulse voltage (60 microseconds at 5 V) was applied to the TN device and the device was charged. A decaying voltage was measured for 16.7 milliseconds with a high-speed voltmeter, and area A between a voltage curve and a horizontal axis in a unit cycle was determined. Area B is an area without decay. A voltage holding ratio is a percentage of area A to area B.
[0141] Voltage Holding Ratio (VHR-3; Measured at 25° C.; %):
[0142] Stability to ultraviolet light was evaluated by measuring a voltage holding ratio after a device was irradiated with ultraviolet light. A TN device used for measurement had a polyimide alignment film and a cell gap was 5 micrometers. A sample was injected into the device, and then the device was irradiated with light for 20 minutes. A light source was an ultra high-pressure mercury lamp USH-500D (made by Ushio, Inc.), and a distance between the device and the light source was 20 centimeters. In measuring VHR-3, a decaying voltage was measured for 16.7 milliseconds. A composition having a large VHR-3 has a large stability to ultraviolet light. A value of VHR-3 is preferably 90% or more, further preferably, 95% or more.
[0143] Voltage Holding Ratio (VHR-4; Measured at 25° C.; %):
[0144] A TN device into which a sample was injected was heated in a constant-temperature bath at 80° C. for 500 hours, and then stability to heat was evaluated by measuring a voltage holding ratio. In measuring VHR-4, a decaying voltage was measured for 16.7 milliseconds. A composition having a large VHR-4 has a large stability to heat.
[0145] Response Time (τ; Measured at 25° C.; ms):
[0146] An LCD-5100 luminance meter made by Otsuka Electronics Co., Ltd. was used for measurement. A light source was a halogen lamp. A low-pass filter was set at 5 kHz. A sample was put in a normally black mode PVA device in which a distance (cell gap) between two glass substrates was 3.2 micrometers and a rubbing direction was anti-parallel, and the device was sealed with an ultraviolet-curable adhesive. The device was irradiated with ultraviolet light of 25 mW/cm 2 (EXECURE4000-D lamp made by HOYA CANDEO OPTRONICS CORPORATION) for 400 seconds while applying a voltage of 15 V to the device. Rectangular waves (60 Hz, 10 V, 0.5 second) were applied to the device. On the occasion, the device was irradiated with light from a direction perpendicular to the device, and the amount of light transmitting the device was measured. The maximum amount of light corresponds to 100% transmittance, and the minimum amount of light corresponds to 0% transmittance. A response time is a period of time required for a change from 0% transmittance to 90% transmittance (rise time; millisecond).
[0147] Specific Resistance (ρ; Measured at 25° C.; ΩCm):
[0148] Into a vessel equipped with electrodes, 1.0 milliliter of a sample was injected. A DC voltage (10 V) was applied to the vessel, and a DC current after 10 seconds was measured. A specific resistance was calculated from the following equation: (specific resistance)={(voltage)×(electric capacity of a vessel)}/{(DC current)×(dielectric constant of vacuum)}.
[0149] Gas Chromatographic Analysis:
[0150] GC-14B Gas Chromatograph made by Shimadzu Corporation was used for measurement. A carrier gas was helium (2 mL per minute). A sample injector and a detector (FID) were set to 280° C. and 300° C., respectively. A capillary column DB-1 (length 30 m, bore 0.32 mm, film thickness 0.25 μm; dimethylpolysiloxane as a stationary phase, non-polar) made by Agilent Technologies, Inc. was used for separation of component compounds. After the column was kept at 200° C. for 2 minutes, the column was heated to 280° C. at a rate of 5° C. per minute. A sample was prepared in an acetone solution (0.1% by weight), and then 1 microliter of the solution was injected into the sample injector. A recorder was C-R5A Chromatopac made by Shimadzu Corporation or the equivalent thereof. The resulting gas chromatogram showed a retention time of a peak and a peak area corresponding to each of the component compounds.
[0151] As a solvent for diluting the sample, chloroform, hexane and so forth may also be used. The following capillary columns may also be used for separating the component compounds: HP-1 (length 30 m, bore 0.32 mm, film thickness 0.25 μm) made by Agilent Technologies, Inc., Rtx-1 (length 30 m, bore 0.32 mm, film thickness 0.25 μm) made by Restek Corporation and BP-1 (length 30 m, bore 0.32 mm, film thickness 0.25 μm) made by SGE International Pty. Ltd. A capillary column CBP1-M50-025 (length 50 m, bore 0.25 mm, film thickness 0.25 μm) made by Shimadzu Corporation may also be used for the purpose of avoiding an overlap of peaks of the compounds.
[0152] A ratio of liquid crystal compounds contained in the composition may be calculated by the method as described below. The liquid crystal compounds can be detected by means of a gas chromatograph. A ratio of peak areas in a gas chromatogram corresponds to a ratio (in the number of moles) of the liquid crystal compounds. When the capillary columns described above were used, a correction coefficient of each of the liquid crystal compounds may be regarded as 1 (one). Accordingly, a ratio (% by weight) of the liquid crystal compounds was calculated from the ratio of the peak areas.
[0153] The compounds in Comparative Examples and Examples were described using symbols according to definitions in Table 4 below. In Table 4, a configuration of 1,4-cyclohexylene is trans. A parenthesized number next to a symbolized compound in the Examples corresponds to the number of the compound. A symbol (−) means any other liquid crystal compound. A ratio (percentage) of the liquid crystal compounds is expressed in terms of weight percent (% by weight) based on the weight of the liquid crystal composition excluding the first composition. The liquid crystal composition further includes an impurity in addition thereto. Last, values of characteristics of the composition were summarized.
[0000]
TABLE 4
Method for Description of Compounds using Symbols
—R—(A 1 )—Z 1 —. . . . .—Z n —(A n )—R′
1) Left-terminal Group R—
Symbol
C n H 2n+1 —
n-
C n H 2n+1 O—
nO—
C m H 2m+1 OC n H 2n —
mOn—
CH 2 ═CH—
V—
C n H 2n+1 —CH═CH—
nV—
CH 2 ═CH—C n H 2n —
Vn—
C m H 2m+1 —CH═CH—C n H 2n —
mVn—
CF 2 ═CH—
VFF—
CF 2 ═CH—C n H 2n —
VFFn—
CH 2 ═CHCOO—
AC—
CH 2 ═C(CH 3 )COO—
MAC—
CH 2 ═CHOCOO—
VCA
CH 2 ═CHCH 2 OCOO—
ACA—
2) Right-terminal Group —
Symbol
—C n H 2n+1
-n
—OC n H 2n+1
—On
—CH═CH 2
—V
—CH═CH—C n H 2n+1
—Vn
—C n H 2n —CH═CH 2
-nV
—CH═CF 2
—VFF
—COOCH 3
—EMe
—OCOCH═CH 2
—AC
—OCOC(CH 3 )═CH 2
—MAC
3) Bonding Group —Zn—
Symbol
—C 2 H 4 —
2
—COO—
E
—CH═CH—
V
—CH═CH—O—
VO
—CF 2 O—
X
—CH 2 O—
1O
—O—
O
4) Ring Structure —An—
Symbol
H
Dh
dh
B
B(F)
B(2F)
B(2F,3F)
B(2F,3F,6Me)
B(2F,3CL)
B(Me)
B(CF3)
Cro(7F,8F)
5) Examples of Description
Example 1 MAC—VO—BB—MAC
Example 2 ACA—BB—AC
Example 3 3-HHB-1
Example 4 MAC—BB—MAC
Comparative Example M1
[0154] The composition is a liquid crystal composition having a negative dielectric anisotropy without containing a first component of the invention. Components and characteristics of the composition were as described below.
[0000]
V-HB(2F,3F)-O2
(2-1-1)
15%
V-HB(2F,3F)-O4
(2-1-1)
10%
2-HBB(2F,3F)-O2
(2-8-1)
4%
3-HBB(2F,3F)-O2
(2-8-1)
10%
5-HBB(2F,3F)-O2
(2-8-1)
10%
2-HHB(2F,3CL)-O2
(2-9-1)
2%
3-HHB(2F,3CL)-O2
(2-9-1)
3%
4-HHB(2F,3CL)-O2
(2-9-1)
3%
5-HHB(2F,3CL)-O2
(2-9-1)
3%
2-HH-3
(3-1-1)
27%
3-HB-O2
(3-2-1)
2%
3-HHB-1
(3-5-1)
3%
3-HHB-3
(3-5-1)
5%
3-HHB-O1
(3-5-1)
3%
[0155] NI=73.8° C.; Tc<−20° C.; Δn=0.092; Δ∈=−3.1; Vth=2.11 V; τ=8.0 ms; VHR-1=99.1%; VHR-2=98.0%; VHR-3=98.0%.
Example M1
[0156]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
15%
V-HB(2F,3F)-O4
(2-1-1)
10%
2-HBB(2F,3F)-O2
(2-8-1)
4%
3-HBB(2F,3F)-O2
(2-8-1)
10%
5-HBB(2F,3F)-O2
(2-8-1)
10%
2-HHB(2F,3CL)-O2
(2-9-1)
2%
3-HHB(2F,3CL)-O2
(2-9-1)
3%
4-HHB(2F,3CL)-O2
(2-9-1)
3%
5-HHB(2F,3CL)-O2
(2-9-1)
3%
2-HH-3
(3-1-1)
27%
3-HB-O2
(3-2-1)
2%
3-HHB-1
(3-5-1)
3%
3-HHB-3
(3-5-1)
5%
3-HHB-O1
(3-5-1)
3%
[0157] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-1-1-1) as a first component of the invention was added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
[0158] Characteristics of the composition were as described below.
[0159] NI=74.3° C.; Tc<−20° C.; Δn=0.095; Δ∈=−3.1; Vth=2.13 V; VHR-1=99.2%; VHR-2=98.2%; VHR-3=98.3%.
Method for Preparation of a Liquid Crystal Display Device
[0160] An aligning agent was coated onto two glass substrates with ITO electrodes by means of a spinner, and a film was formed. After the coating, heating and drying were carried out at 80° C. for approximately 10 minutes, and heat treatment was carried out at 180° C. for 60 minutes, and thus an alignment film was formed. A gap material was sprayed onto one glass substrate, a peripheral was sealed with an epoxy adhesive for the other substrate with leaving an inlet of liquid crystals, and the substrates were laminated by internally placing a plane on which the alignment film was formed. A sample of Example M1 as a liquid crystal composition described herein was injected into the device in vacuum, the inlet was sealed with a photo-curing agent, and the photo-curing agent was irradiated with ultraviolet light, and thus cured. Subsequently, heat treatment was carried out at 110° C. for 30 minutes, and thus a liquid crystal display device was prepared. The device was irradiated with ultraviolet light of 25 mW/cm 2 for 400 seconds (EXECURE4000-D type made by HOYA CANDEO OPTRONICS, Inc.; mercury-xenon lamp) while applying a voltage of 15 V to the device, and thus a liquid crystal display device was finally prepared.
[0161] A response time of the liquid crystal device was as described below: τ=4.3 ms.
Example M2
[0162]
[0000]
3-H2B(2F,3F)-O2
(2-2-1)
17%
5-H2B(2F,3F)-O2
(2-2-1)
16%
3-HHB(2F,3F)-O2
(2-5-1)
7%
3-HBB(2F,3F)-O2
(2-8-1)
5%
4-HBB(2F,3F)-O2
(2-8-1)
6%
5-HBB(2F,3F)-O2
(2-8-1)
10%
2-HH-3
(3-1-1)
20%
3-HH-4
(3-1-1)
4%
5-HB-O2
(3-2-1)
4%
3-HHB-1
(3-5-1)
4%
5-HBB(F)B-2
(3-13-1)
7%
[0163] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-1-1-1) as a first component of the invention was added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
[0164] Characteristics of the composition obtained were as described below.
[0165] NI=76.8° C.; Tc<−20° C.; Δn=0.099; Δ∈=−3.1; Vth=2.36 V; VHR-1=99.1%; VHR-2=98.5%; VHR-3=98.6%.
[0166] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.6 ms.
Example M3
[0167]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
11%
3-H2B(2F,3F)-O2
(2-2-1)
15%
5-H2B(2F,3F)-O2
(2-2-1)
5%
3-BB(2F,3F)-O2
(2-3-1)
5%
3-H1OB(2F,3F)-O2
(2-4-1)
5%
3-HH2B(2F,3F)-O2
(2-6-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
5%
4-HBB(2F,3F)-O2
(2-8-1)
6%
5-HBB(2F,3F)-O2
(2-8-1)
6%
3-HH-4
(3-1-1)
10%
1-BB-3
(3-3-1)
4%
3-HHB-1
(3-5-1)
4%
3-HHB-3
(3-5-1)
5%
3-HHB-O1
(3-5-1)
3%
5-HBB(F)B-2
(3-13-1)
6%
5-HBB(F)B-3
(3-13-1)
5%
[0168] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-1-1-1) as a first component of the invention was added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
[0169] Characteristics of the composition obtained were as described below.
[0170] NI=85.3° C.; Tc<−20° C.; Δn=0.122; Δ∈=−3.8; Vth=2.15 V; VHR-1=99.2%; VHR-2=98.7%; VHR-3=98.6%.
[0171] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=5.3 ms.
Example M4
[0172]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
10%
V-HB(2F,3F)-O4
(2-1-1)
10%
3-H1OB(2F,3F)-O2
(2-4-1)
6%
3-HBB(2F,3F)-O2
(2-8-1)
10%
5-HBB(2F,3F)-O2
(2-8-1)
8%
3-dhHB(2F,3F)-O2
(2-14-1)
3%
3-HH1OCro(7F,8F)-5
(2-19-1)
5%
2-HH-5
(3-1-1)
8%
3-HH-4
(3-1-1)
14%
5-HB-O2
(3-2-1)
8%
3-HHB-1
(3-5-1)
3%
3-HHB-O1
(3-5-1)
2%
5-HBB-2
(3-6-1)
4%
3-HHEBH-3
(3-10-1)
2%
3-HHEBH-5
(3-10-1)
2%
3-HBBH-5
(3-11-1)
3%
5-HBB(F)B-2
(3-13-1)
2%
[0173] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-1-1-1) as a first component of the invention was added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
[0174] Characteristics of the composition obtained were as described below.
[0175] NI=89.9° C.; Tc<−20° C.; Δn=0.100; Δ∈=−3.0; Vth=2.30 V; VHR-1=99.2%; VHR-2=98.6%; VHR-3=98.8%.
[0176] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=5.3 ms.
Example M5
[0177]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
10%
3-H2B(2F,3F)-O2
(2-2-1)
13%
5-H2B(2F,3F)-O2
(2-2-1)
12%
5-BB(2F,3F)-O2
(2-3-1)
5%
5-H1OB(2F,3F)-O2
(2-4-1)
5%
5-HH1OB(2F,3F)-O2
(2-7-1)
6%
5-HBB(2F,3F)-O2
(2-8-1)
9%
3-HHB(2F,3CL)-O2
(2-9-1)
4%
3-HH-4
(3-1-1)
2%
5-HH-V
(3-1-1)
5%
3-HHEH-3
(3-4-1)
2%
3-HHEH-5
(3-4-1)
2%
4-HHEH-3
(3-4-1)
2%
4-HHEH-5
(3-4-1)
2%
3-HHB-1
(3-5-1)
4%
3-HHB-3
(3-5-1)
7%
3-HHB-O1
(3-5-1)
4%
3-HHEBH-3
(3-10-1)
3%
3-HHEBH-5
(3-10-1)
3%
[0178] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-2-1-1) as a first component of the invention was added.
[0000]
MAC-V-BB-MAC
(1-2-1-1)
[0179] Characteristics of the composition obtained were as described below.
[0180] NI=89.5° C.; Tc<−20° C.; Δn=0.095; Δ∈=−4.3; Vth=2.05 V; VHR-1=99.1%; VHR-2=98.2%; VHR-3=98.6%.
[0181] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=5.5 ms.
Example M6
[0182]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
11%
3-H2B(2F,3F)-O2
(2-2-1)
5%
3-HH1OB(2F,3F)-O2
(2-7-1)
5%
4-HBB(2F,3F)-O2
(2-8-1)
4%
5-HBB(2F,3F)-O2
(2-8-1)
7%
3-HDhB(2F,3F)-O2
(2-13-1)
5%
3-dhBB(2F,3F)-O2
(2-15-1)
6%
3-HH1OCro(7F,8F)-5
(2-19-1)
8%
2-HH-3
(3-1-1)
17%
3-HH-5
(3-1-1)
4%
5-HB-O2
(3-2-1)
6%
1-BB-3
(3-3-1)
5%
3-HHB-1
(3-5-1)
5%
3-HHB-3
(3-5-1)
6%
3-HHB-O1
(3-5-1)
3%
3-B(F)BB-2
(3-8-1)
3%
[0183] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-6-1-1) as a first component of the invention was added.
[0000]
MAC-2O-BB(CF3)-MAC
(1-6-1-1)
[0184] Characteristics of the composition obtained were as described below.
[0185] NI=84.5° C.; Tc<−20° C.; Δn=0.103; Δ∈=−3.1; Vth=2.22 V; VHR-1=99.3%; VHR-2=98.5%; VHR-3=98.5%.
[0186] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.5 ms.
Example M7
[0187]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
10%
3-H2B(2F,3F)-O2
(2-2-1)
5%
3-BB(2F,3F)-O2
(2-3-1)
5%
3-H1OB(2F,3F)-O2
(2-4-1)
6%
3-HBB(2F,3F)-O2
(2-8-1)
6%
3-HHB(2F,3CL)-O2
(2-9-1)
3%
3-DhHB(2F,3F)-O2
(2-12-1)
3%
3-HDhB(2F,3F)-O2
(2-13-1)
3%
3-HH1OCro(7F,8F)-5
(2-19-1)
5%
2-HH-3
(3-1-1)
19%
5-HB-O2
(3-2-1)
5%
V2-BB-1
(3-3-1)
3%
3-HHB-1
(3-5-1)
4%
3-HHB-3
(3-5-1)
7%
3-HHB-O1
(3-5-1)
4%
2-BB(F)B-3
(3-7-1)
4%
3-HB(F)BH-3
(3-12-1)
3%
5-HBB(F)B-2
(3-13-1)
5%
[0188] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-5-1-1) as a first component of the invention was added.
[0000]
ACA-BB-AC
(1-5-1-1)
[0189] Characteristics of the composition obtained were as described below.
[0190] NI=83.3° C.; Tc<−20° C.; Δn=0.111; Δ∈=−2.6; Vth=2.32 V; VHR-1=99.1%; VHR-2=98.5%; VHR-3=98.5%.
[0191] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.1 ms.
Example M8
[0192]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
14%
5-H2B(2F,3F)-O2
(2-2-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
10%
4-HBB(2F,3F)-O2
(2-8-1)
4%
5-HBB(2F,3F)-O2
(2-8-1)
5%
3-HH1OCro(7F,8F)-5
(2-19-1)
7%
2-HH-3
(3-1-1)
23%
3-HH-O1
(3-1-1)
5%
3-HH-V
(3-1-1)
3%
4-HHEH-3
(3-4-1)
3%
4-HHEH-5
(3-4-1)
3%
3-HHB-1
(3-5-1)
6%
3-HHB-3
(3-5-1)
6%
3-HHB-O1
(3-5-1)
3%
2-BB(F)B-5
(3-7-1)
3%
[0193] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-5-1-2) as a first component of the invention was added.
[0000]
ACA-BB-MAC
(1-5-1-2)
[0194] Characteristics of the composition obtained were as described below.
[0195] NI=83.2° C.; Tc<−20° C.; Δn=0.093; Δ∈=−2.6; Vth=2.25 V; VHR-1=99.3%; VHR-2=98.7%; VHR-3=98.6%.
[0196] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.1 ms.
Example M9
[0197]
[0000]
3-H2B(2F,3F)-O2
(2-2-1)
15%
5-H2B(2F,3F)-O2
(2-2-1)
15%
2-HBB(2F,3F)-O2
(2-8-1)
3%
3-HBB(2F,3F)-O2
(2-8-1)
9%
5-HBB(2F,3F)-O2
(2-8-1)
9%
3-HHB(2F,3CL)-O2
(2-9-1)
5%
2-HH-5
(3-1-1)
4%
3-HH-4
(3-1-1)
15%
3-HH-V1
(3-1-1)
4%
3-HB-O2
(3-2-1)
12%
3-HHB-3
(3-5-1)
6%
3-HB(F)HH-2
(3-9-1)
3%
[0198] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-1-1-1) as a first component of the invention was added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
[0199] Characteristics of the composition obtained were as described below.
[0200] NI=75.2° C.; Tc<−20° C.; Δn=0.096; Δ∈=−2.7; Vth=2.41 V; VHR-1=99.2%; VHR-2=98.5%; VHR-3=98.5%.
[0201] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.5 ms.
Example M10
[0202]
[0000]
3-H2B(2F,3F)-O2
(2-2-1)
17%
5-H2B(2F,3F)-O2
(2-2-1)
17%
3-HH1OB(2F,3F)-O2
(2-7-1)
5%
3-HHB(2F,3CL)-O2
(2-9-1)
4%
4-HHB(2F,3CL)-O2
(2-9-1)
3%
5-HHB(2F,3CL)-O2
(2-9-1)
3%
3-HBB(2F,3CL)-O2
(2-10-1)
8%
2-BB(2F,3F)B-3
(2-11-1)
4%
3-HH-V
(3-1-1)
27%
V-HHB-1
(3-5-1)
7%
2-BB(F)B-3
(3-7-1)
2%
3-HHEBH-3
(3-10-1)
3%
[0203] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-2-1-1) as a first component of the invention was added.
[0000]
MAC-V-BB-MAC
(1-2-1-1)
[0204] Characteristics of the composition obtained were as described below.
[0205] NI=71.9° C.; Tc<−20° C.; Δn=0.093; Δ∈=−2.8; Vth=2.33 V; VHR-1=99.2%; VHR-2=98.6%; VHR-3=98.6%.
[0206] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=3.8 ms.
Example M11
[0207]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
15%
V-HB(2F,3F)-O4
(2-1-1)
7%
3-HBB(2F,3F)-O2
(2-8-1)
3%
V-HBB(2F,3F)-O2
(2-8-1)
10%
V2-HBB(2F,3F)-O2
(2-8-1)
10%
3-HH1OCro(7F,8F)-5
(2-19-1)
8%
2-HH-3
(3-1-1)
29%
3-HHB-1
(3-5-1)
6%
3-HHB-3
(3-5-1)
6%
3-HHB-O1
(3-5-1)
6%
[0208] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-1-1-1) as a first component of the invention was added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
[0209] Characteristics of the composition obtained were as described below.
[0210] NI=80.9° C.; Tc<−20° C.; Δn=0.094; Δ∈=−3.1; Vth=2.26 V; VHR-1=99.3%; VHR-2=98.5%; VHR-3=98.6%.
[0211] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.7 ms.
Example M12
[0212]
[0000]
5-BB(2F,3F)-O2
(2-3-1)
7%
5-H1OB(2F,3F)-O2
(2-4-1)
10%
4-HH1OB(2F,3F)-O2
(2-7-1)
5%
5-HH1OB(2F,3F)-O2
(2-7-1)
5%
5-HBB(2F,3CL)-O2
(2-10-1)
6%
2-BB(2F,3F)B-3
(2-11-1)
3%
3-DhHB(2F,3F)-O2
(2-12-1)
6%
3-HDhB(2F,3F)-O2
(2-13-1)
7%
3-HH-V
(3-1-1)
30%
3-HH-V1
(3-1-1)
6%
3-HHB-1
(3-5-1)
4%
3-HHB-O1
(3-5-1)
4%
3-B(F)BB-2
(3-8-1)
3%
1O1-HBBH-5
(—)
4%
[0213] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-1-1-1) as a first component of the invention was added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
[0214] Characteristics of the composition obtained were as described below.
[0215] NI=90.8° C.; Tc<−20° C.; Δn=0.099; Δ∈=−2.6; VHR-1=99.1%; VHR-2=98.1%; VHR-3=98.3%.
[0216] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.1 ms.
Example M13
[0217]
[0000]
3-H2B(2F,3F)-O2
(2-2-1)
12%
3-HH2B(2F,3F)-O2
(2-6-1)
5%
2-HBB(2F,3F)-O2
(2-8-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
7%
5-HBB(2F,3F)-O2
(2-8-1)
4%
3-HH2B(2F,3F,6Me)-O2
(2-16-1)
5%
3-HH1OB(2F,3F,6Me)-O2
(2-17-1)
6%
3-HH1OCro(7F,8F)-5
(2-19-1)
4%
4-HH-V
(3-1-1)
15%
5-HH-V
(3-1-1)
23%
3-HH-V1
(3-1-1)
6%
V-HHB-1
(3-5-1)
5%
V2-HHB-1
(3-5-1)
3%
[0218] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-1-1-1) as a first component of the invention was added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
[0219] Characteristics of the composition obtained were as described below.
[0220] NI=88.5° C.; Tc<−20° C.; Δn=0.092; Δ∈=−2.9; VHR-1=99.4%; VHR-2=98.5%; VHR-3=98.7%.
[0221] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.7 ms.
Example M14
[0222]
[0000]
3-HB(2F,3F)-O2
(2-1-1)
8%
3-HHB(2F,3F)-O2
(2-5-1)
10%
3-HBB(2F,3F)-O2
(2-8-1)
7%
5-HBB(2F,3F)-O2
(2-8-1)
5%
3-dhBB(2F,3F)-O2
(2-15-1)
6%
3-HH1OB(2F,3F,6Me)-O2
(2-17-1)
6%
3-H1OCro(7F,8F)-5
(2-18-1)
5%
3-HH-V
(3-1-1)
40%
1-HH-2V1
(3-1-1)
6%
3-HHEBH-3
(3-10-1)
4%
3-HHEBH-4
(3-10-1)
3%
[0223] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-2-1-1) as a first component of the invention was added.
[0000]
MAC-V-BB-MAC
(1-2-1-1)
[0224] Characteristics of the composition obtained were as described below.
[0225] NI=84.7° C.; Tc<−20° C.; Δn=0.090; Δ∈=−3.1; VHR-1=99.1%; VHR-2=98.6%; VHR-3=98.6%.
[0226] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.0 ms.
Example M15
[0227]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
12%
V-HB(2F,3F)-O4
(2-1-1)
5%
3-H2B(2F,3F)-O2
(2-2-1)
15%
3-BB(2F,3F)-O2
(2-3-1)
4%
3-HBB(2F,3F)-O2
(2-8-1)
7%
4-HBB(2F,3F)-O2
(2-8-1)
6%
5-HBB(2F,3F)-O2
(2-8-1)
6%
2-BB(2F,3F)B-4
(2-11-1)
3%
2-HH-5
(3-1-1)
5%
3-HH-4
(3-1-1)
14%
3-HHB-1
(3-5-1)
4%
3-HHB-3
(3-5-1)
5%
3-HHB-O1
(3-5-1)
3%
5-HBB(F)B-2
(3-13-1)
6%
1O1-HBBH-5
(—)
5%
[0228] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-2-1-1) as a first component of the invention was added.
[0000]
MAC-V-BB-MAC
(1-2-1-1)
[0229] Characteristics of the composition obtained were as described below.
[0230] NI=88.7° C.; Tc<−20° C.; Δn=0.115; Δ∈=−3.3; VHR-1=99.2%; VHR-2=98.5%; VHR-3=98.6%.
[0231] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.9 ms.
Example M16
[0232]
[0000]
3-HB(2F,3F)-O2
(2-1-1)
5%
3-H2B(2F,3F)-O2
(2-2-1)
19%
5-H2B(2F,3F)-O2
(2-2-1)
5%
3-HHB(2F,3F)-O2
(2-5-1)
8%
5-HHB(2F,3F)-O2
(2-5-1)
7%
3-HBB(2F,3F)-O2
(2-8-1)
10%
4-HBB(2F,3F)-O2
(2-8-1)
5%
3-HDhB(2F,3F)-O2
(2-13-1)
5%
2-HH-3
(3-1-1)
20%
3-HH-4
(3-1-1)
7%
3-HHB-1
(3-5-1)
4%
V-HHB-1
(3-5-1)
3%
5-B(F)BB-2
(3-8-1)
2%
[0233] To 100 parts by weight of the composition, 0.15 part by weight of compound (1-1-1-1) as a first component of the invention, and 0.15 part by weight of polymerizable compound (6-1-1) that is not the first component of the invention were added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
MAC-BB-MAC
(6-1-1)
[0234] Characteristics of the composition obtained were as described below.
[0235] NI=78.8° C.; Tc<−20° C.; Δn=0.090; Δ∈=−3.5; VHR-1=99.1%; VHR-2=98.3%; VHR-3=98.4%.
[0236] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.2 ms.
Example M17
[0237]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
5%
3-H2B(2F,3F)-O2
(2-2-1)
10%
5-H2B(2F,3F)-O2
(2-2-1)
10%
3-HHB(2F,3F)-O2
(2-5-1)
8%
5-HHB(2F,3F)-O2
(2-5-1)
6%
3-HH1OB(2F,3F)-O2
(2-7-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
10%
4-HBB(2F,3F)-O2
(2-8-1)
5%
3-HDhB(2F,3F)-O2
(2-13-1)
5%
2-HH-3
(3-1-1)
20%
3-HH-4
(3-1-1)
7%
3-HHB-1
(3-5-1)
4%
3-HHB-3
(3-5-1)
3%
5-B(F)BB-2
(3-8-1)
2%
[0238] To 100 parts by weight of the composition, 0.15 part by weight of compound (1-1-1-1) as a first component of the invention, and 0.15 part by weight of polymerizable compound (6-1-2) that is not the first component of the invention were added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
MAC-B(2F)B-MAC
(6-1-2)
[0239] Characteristics of the composition obtained were as described below.
[0240] NI=83.7° C.; Tc<−20° C.; Δn=0.090; Δ∈=−3.6; VHR-1=99.2%; VHR-2=98.3%; VHR-3=98.6%.
[0241] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.4 ms.
Example M18
[0242]
[0000]
3-H2B(2F,3F)-O2
(2-2-1)
19%
5-H2B(2F,3F)-O2
(2-2-1)
10%
3-HHB(2F,3F)-O2
(2-5-1)
8%
5-HHB(2F,3F)-O2
(2-5-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
10%
4-HBB(2F,3F)-O2
(2-8-1)
5%
3-dhBB(2F,3F)-O2
(2-15-1)
5%
2-HH-3
(3-1-1)
20%
2-HH-5
(3-1-1)
5%
3-HHB-1
(3-5-1)
5%
3-HHB-3
(3-5-1)
3%
5-B(F)BB-2
(3-8-1)
5%
[0243] To 100 parts by weight of the composition, 0.15 part by weight of compound (1-1-1-1) and 0.15 part by weight of compound (1-1-1-2) both as a first component of the invention were added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
MAC-VO-BB-AC
(1-1-1-2)
[0244] Characteristics of the composition obtained were as described below.
[0245] NI=81.1° C.; Tc<−20° C.; Δn=0.100; Δ∈=−3.4; VHR-1=99.2%; VHR-2=98.5%; VHR-3=98.6%.
[0246] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.4 ms.
Example M19
[0247]
[0000]
3-H2B(2F,3F)-O2
(2-2-1)
10%
5-H2B(2F,3F)-O2
(2-2-1)
10%
3-BB(2F,3F)-O2
(2-3-1)
5%
3-HHB(2F,3F)-O2
(2-5-1)
8%
5-HHB(2F,3F)-O2
(2-5-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
10%
2-BB(2F,3F)B-3
(2-11-1)
5%
3-HDhB(2F,3F)-O2
(2-13-1)
5%
2-HH-3
(3-1-1)
20%
3-HH-4
(3-1-1)
7%
3-HH-V1
(3-1-1)
3%
3-HHB-1
(3-5-1)
4%
3-HHB-3
(3-5-1)
3%
5-B(F)BB-2
(3-8-1)
5%
[0248] To 100 parts by weight of the composition, 0.1 part by weight of compound (1-1-1-1) and 0.1% by weight of compound (1-1-1-2) both as a first component of the invention, and 0.1 part by weight of polymerizable compound (6-1-2) that is not the first component of the invention were added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
MAC-VO-BB-AC
(1-1-1-2)
MAC-B(2F)B-MAC
(6-1-2)
[0249] Characteristics of the composition obtained were as described below.
[0250] NI=79.0° C.; Tc<−20° C.; Δn=0.101; Δ∈=−3.0; VHR-1=99.4%; VHR-2=98.7%; VHR-3=98.8%.
[0251] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=3.9 ms.
Example M20
[0252]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
5%
3-H2B(2F,3F)-O2
(2-2-1)
10%
3-BB(2F,3F)-O2
(2-3-1)
5%
3-HHB(2F,3F)-O2
(2-5-1)
8%
5-HHB(2F,3F)-O2
(2-5-1)
6%
3-HH1OB(2F,3F)-O2
(2-7-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
10%
5-HBB(2F,3F)-O2
(2-8-1)
5%
3-HHB(2F,3CL)-O2
(2-9-1)
3%
3-HDhB(2F,3F)-O2
(2-13-1)
5%
2-HH-3
(3-1-1)
22%
3-HH-4
(3-1-1)
7%
3-HHB-1
(3-5-1)
4%
2-BB(F)B-5
(3-7-1)
3%
5-B(F)BB-3
(3-8-1)
2%
[0253] To 100 parts by weight of the composition, 0.1 part by weight of compound (1-1) and 0.1 part by weight of compound (1-1-1-2) both as a first component of the invention, and 0.1 part by weight of compound (6-1-2) that is not the first component of the invention were added.
[0000]
MAC-VO-BB(F)-MAC
(1-1)
MAC-VO-BB-AC
(1-1-1-2)
MAC-B(2F)B-MAC
(6-1-2)
[0254] Characteristics of the composition obtained were as described below.
[0255] NI=86.1° C.; Tc<−20° C.; Δn=0.098; Δ∈=−3.6; VHR-1=99.2%; VHR-2=98.4%; VHR-3=98.7%.
[0256] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=3.9 ms.
Example M21
[0257]
[0000]
3-H2B(2F,3F)-O2
(2-2-1)
19%
5-BB(2F,3F)-O2
(2-3-1)
5%
3-HHB(2F,3F)-O2
(2-5-1)
8%
5-HHB(2F,3F)-O2
(2-5-1)
7%
3-HBB(2F,3F)-O2
(2-8-1)
5%
5-HBB(2F,3F)-O2
(2-8-1)
5%
2-BB(2F,3F)B-3
(2-11-1)
5%
5-dhBB(2F,3F)-O2
(2-15-1)
5%
2-HH-3
(3-1-1)
22%
3-HH-5
(3-1-1)
3%
3-HH-O1
(3-1-1)
3%
3-HHB-1
(3-5-1)
5%
3-HHB-O1
(3-5-1)
3%
2-B(F)BB-5
(3-8-1)
5%
[0258] To 100 parts by weight of the composition, 0.1 part by weight of compound (1-1) and 0.1 part by weight of compound (1-8-1-1) both as a first component of the invention, and 0.1 part by weight of compound (6-1-2) that is not the first component of the invention were added.
[0000]
MAC-VO-BB(F)-MAC
(1-1)
MAC-VO-BB(F)B-MAC
(1-8-1-1)
MAC-B(2F)B-MAC
(6-1-2)
[0259] Characteristics of the composition obtained were as described below.
[0260] NI=81.7° C.; Tc<−20° C.; Δn=0.104; Δ∈=−3.1; VHR-1=99.3%; VHR-2=98.5%; VHR-3=98.7%.
[0261] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.3 ms.
Example M22
[0262]
[0000]
V-HB(2F,3F)-O2
(2-2-1)
5%
3-H2B(2F,3F)-O2
(2-2-1)
13%
5-BB(2F,3F)-O2
(2-3-1)
5%
3-HHB(2F,3F)-O2
(2-5-1)
8%
5-HHB(2F,3F)-O2
(2-5-1)
6%
2-HH1OB(2F,3F)-O2
(2-7-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
10%
5-HBB(2F,3F)-O2
(2-8-1)
5%
2-HDhB(2F,3F)-O2
(2-13-1)
5%
2-HH-3
(3-1-1)
22%
3-HH-4
(3-1-1)
7%
3-HHB-1
(3-5-1)
4%
2-BB(F)B-5
(3-7-1)
3%
5-B(F)BB-3
(3-8-1)
2%
[0263] To 100 parts by weight of the composition, 0.3 part by weight of compound (1-1-1-3) as a first component of the invention was added.
[0000]
AC-VO-BB-MAC
(1-1-1-3)
[0264] Characteristics of the composition obtained were as described below.
[0265] NI=80.0° C.; Tc<−20° C.; Δn=0.096; Δ∈=−3.6; VHR-1=99.0%; VHR-2=98.1%; VHR-3=98.5%.
[0266] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.6 ms.
Example M23
[0267]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
5%
3-H2B(2F,3F)-O2
(2-2-1)
10%
3-BB(2F,3F)-O2
(2-3-1)
5%
3-HHB(2F,3F)-O2
(2-5-1)
8%
5-HHB(2F,3F)-O2
(2-5-1)
6%
2-HH1OB(2F,3F)-O2
(2-7-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
10%
2-BB(2F,3F)B-4
(2-11-1)
8%
3-HDhB(2F,3F)-O2
(2-13-1)
5%
2-HH-3
(3-1-1)
20%
3-HH-4
(3-1-1)
9%
3-HHB-1
(3-5-1)
4%
2-BB(F)B-5
(3-7-1)
3%
5-B(F)BB-3
(3-8-1)
2%
[0268] To 100 parts, by weight of the composition, 0.285 part by weight of compound (1-1-1-1) and 0.015 part by weight of compound (1-1-1-4) both as a first component of the invention were added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
AC-VO-BB-AC
(1-1-1-4)
[0269] Characteristics of the composition obtained were as described below.
[0270] NI=81.7° C.; Tc<−20° C.; Δn=0.106; Δ∈=−3.3; VHR-1=99.3%; VHR-2=98.7%; VHR-3=98.9%.
[0271] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.4 ms.
Example M24
[0272]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
5%
3-H2B(2F,3F)-O2
(2-2-1)
10%
3-BB(2F,3F)-O2
(2-3-1)
5%
3-HHB(2F,3F)-O2
(2-5-1)
8%
5-HHB(2F,3F)-O2
(2-5-1)
6%
3-HH1OB(2F,3F)-O2
(2-7-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
10%
3-HHB(2F,3CL)-O2
(2-9-1)
2%
3-HDhB(2F,3F)-O2
(2-13-1)
4%
3-dhBB(2F,3F)-O2
(2-15-1)
5%
2-HH-3
(3-1-1)
22%
5-HB-3
(3-2-1)
7%
3-HHB-1
(3-5-1)
8%
2-BB(F)B-3
(3-7-1)
3%
[0273] To 100 parts by weight of the composition, 0.1 part by weight of compound (1-1), 0.1 part by weight of compound (1-1-1-4) and 0.1 part by weight of compound (1-8-1-2) all as a first component of the invention were added.
MAC-VO-BB(CF3)-MAC (1-1) AC-VO-BB-AC (1-1-1-4) MAC-VO-BB(2F)B-MAC (1-8-1-2)
[0277] Characteristics of the composition obtained were as described below.
[0278] NI=81.7° C.; Tc<−20° C.; Δn=0.098; Δ∈=−3.5; VHR-1=99.1%; VHR-2=98.5%; VHR-3=98.1%.
[0279] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.5 ms.
Example M25
[0000]
3-HB (2F,3F)-O(2-1-1) 5%
5-H 2 B(2F,3F)-O2 (2-2-1) 10%
3-BB(2F,3F)-O2 (2-3-1) 5%
3-HHB(2F,3F)-O2 (2-5-1) 8%
5-HHB(2F,3F)-O2 (2-5-1) 6%
3-HH1OB(2F,3F)-O2 (2-7-1) 5%
3-HBB(2F,3F)-O2 (2-8-1) 7%
3-HHB(2F,3CL)-O2 (2-9-1) 3%
3-HDhB(2F,3F)-O2 (2-13-1) 5%
2-HH-3 (3-1-1) 22%
3-HH-4 (3-1-1) 7%
1-BB-3 (3-3-1) 5%
3-HHB-1 (3-5-1) 4%
5-B(F)BB-3 (3-8-1) 5%
5-HBB(F)B-2 (3-13-1) 3%
[0295] To 100 parts by weight of the composition, 0.05 part by weight of compound (1-1-1-4) and 0.2 part by weight of compound (1-8-1-3) both as a first component of the invention, and 0.15 part by weight of compound (6-1-2) that is not the first component of the invention were added.
AC-VO-BB-AC (1-1-1-4) MAC-VO-B(2F)BB-MAC (1-8-1-3) MAC-B(2F)B-MAC (6-1-2)
[0299] Characteristics of the composition obtained were as described below.
[0300] NI=82.8° C.; Tc<−20° C.; Δn=0.099; Δ∈=−3.1; VHR-1=99.1%; VHR-2=98.0%; VHR-3=98.5%.
[0301] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.2 ms.
Example M26
[0302]
[0000]
V-HB(2F,3F)-O2
(2-1-1)
5%
3-H2B(2F,3F)-O2
(2-2-1)
10%
5-BB(2F,3F)-O4
(2-3-1)
5%
3-HHB(2F,3F)-O2
(2-5-1)
8%
5-HHB(2F,3F)-O2
(2-5-1)
6%
5-HH1OB(2F,3F)-O2
(2-7-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
10%
5-HDhB(2F,3F)-O2
(2-13-1)
5%
2-HH-3
(3-1-1)
18%
2-HH-5
(3-1-1)
7%
3-HB-O2
(3-2-1)
7%
3-HHB-3
(3-5-1)
5%
3-B(F)BB-2
(3-8-1)
4%
5-HBB(F)B-3
(3-13-1)
5%
[0303] To 100 parts by weight of the composition, 0.1 part by weight of compound (1-1-1-1), 0.1 part by weight of compound (1-3-1-1) and 0.1 part by weight of compound (1-8-1-2) all as a first component of the invention were added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
MAC-1V-BB-MAC
(1-3-1-1)
MAC-VO-BB(2F)B-MAC
(1-8-1-2)
[0304] Characteristics of the composition obtained were as described below.
[0305] NI=88.0° C.; Tc<−20° C.; Δn=0.103; Δ∈=−3.3; VHR-1=99.3%; VHR-2=98.5%; VHR-3=98.9%.
[0306] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.5 ms.
Example M27
[0307]
[0000]
5-HB(2F,3F)-O2
(2-1-1)
5%
3-H2B(2F,3F)-O4
(2-2-1)
10%
3-BB(2F,3F)-O2
(2-3-1)
5%
3-HHB(2F,3F)-O2
(2-5-1)
9%
5-HHB(2F,3F)-O2
(2-5-1)
8%
2-HH1OB(2F,3F)-O2
(2-7-1)
5%
5-HBB(2F,3F)-O2
(2-8-1)
5%
2-BB(2F,3F)B-4
(2-11-1)
10%
2-HDhB(2F,3F)-O2
(2-13-1)
5%
2-HH-3
(3-1-1)
22%
3-HH-4
(3-1-1)
7%
3-HHB-1
(3-5-1)
4%
5-B(F)BB-3
(3-8-1)
5%
[0308] To 100 parts by weight of the composition, 0.1 part by weight of compound (1-1-1-1), 0.15 part by weight of compound (1-1-1-3) and 0.1 part by weight of compound (1-8-1-3) all as a first component of the invention were added.
[0000]
MAC-VO-BB-MAC
(1-1-1-1)
AC-VO-BB-MAC
(1-1-1-3)
MAC-VO-B(2F)BB-MAC
(1-8-1-3)
[0309] Characteristics of the composition obtained were as described below.
[0310] NI=80.7° C.; Tc<−20° C.; Δn=0.104; Δ∈=−3.3; VHR-1=99.3%; VHR-2=98.4%; VHR-3=98.5%.
[0311] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.5 ms.
Example M28
[0312]
[0000]
V-HB(2F,3F)-O3
(2-1-1)
5%
3-H2B(2F,3F)-O2
(2-2-1)
10%
3-BB(2F,3F)-O2
(2-3-1)
5%
5-HHB(2F,3F)-O2
(2-5-1)
8%
3-HH1OB(2F,3F)-O2
(2-7-1)
5%
3-HBB(2F,3F)-O2
(2-8-1)
10%
3-HHB(2F,3CL)-O2
(2-9-1)
3%
5-BB(2F,3F)B-2
(2-11-1)
10%
3-HDhB(2F,3F)-O2
(2-13-1)
5%
2-HH-3
(3-1-1)
20%
3-HH-4
(3-1-1)
7%
5-HB-3
(3-2-1)
3%
3-HHB-1
(3-5-1)
3%
2-BB(F)B-5
(3-7-1)
3%
5-HBB(F)B-2
(3-13-1)
3%
[0313] To 100 parts by weight of the composition, 0.1 part by weight of compound (1-1-1-4), 0.1 part by weight of compound (1-8-1-2) and 0.1 part by weight of compound (1-8-1-3) all as a first component of the invention were added.
[0000]
AC-VO-BB-AC
(1-1-1-4)
MAC-VO-BB(2F)B-MAC
(1-8-1-2)
MAC-VO-B(2F)BB-MAC
(1-8-1-3)
[0314] Characteristics of the composition obtained were as described below.
[0315] NI=81.6° C.; Tc<−20° C.; Δn=0.109; Δ∈=−3.2; VHR-1=99.2%; VHR-2=98.7%; VHR-3=98.9%.
[0316] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.5 ms.
Example M29
[0317]
[0000]
3-HB(2F,3F)-O2
(2-1-1)
5%
3-H2B(2F,3F)-O4
(2-2-1)
8%
2-BB(2F,3F)-O2
(2-3-1)
5%
3-HHB(2F,3F)-O2
(2-5-1)
8%
5-HHB(2F,3F)-O2
(2-5-1)
6%
3-HH1OB(2F,3F)-O2
(2-7-1)
5%
5-HBB(2F,3F)-O2
(2-8-1)
5%
3-HDhB(2F,3F)-O2
(2-13-1)
8%
5-dhBB(2F,3F)-O2
(2-15-1)
5%
2-HH-3
(3-1-1)
20%
3-HH-4
(3-1-1)
8%
1-BB-3
(3-3-1)
5%
3-HHB-1
(3-5-1)
4%
5-B(F)BB-2
(3-8-1)
5%
5-HBB(F)B-3
(3-13-1)
3%
[0318] To 100 parts by weight of the composition, 0.1 part by weight of compound (1-1-1-3) and 0.1 part by weight of compound (1-8-1-2) both as a first component of the invention, and 0.1 part by weight of compound (6-1-2) that is not the first component of the invention were added.
[0000]
AC-VO-BB-MAC
(1-1-1-3)
MAC-VO-BB(2F)B-MAC
(1-8-1-2)
MAC-B(2F)B-MAC
(6-1-2)
[0319] Characteristics of the composition obtained were as described below.
[0320] NI=84.1° C.; Tc<−20° C.; Δn=0.100; Δ∈=−3.2; VHR-1=99.2%; VHR-2=98.4%; VHR-3=98.7%.
[0321] A response time of the liquid crystal display device prepared according to the method described in Example M1 was as described below: τ=4.3 ms.
[0322] The compositions according to Examples M1 to M29 have a shorter response time in comparison with the composition according to Comparative Example M1. Thus, the liquid crystal composition according to the invention is so much superior in characteristics to the liquid crystal composition shown in Comparative Example M1.
[0323] Although the invention has been described and illustrated with a certain degree of particularity, it is understood that the disclosure has been made only by way of example, and that numerous changes in the conditions and order of steps can be resorted to by those skilled in the art without departing from the spirit and scope of the invention.
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To provide a highly reactive polymerizable compound having a high solubility in a liquid crystal compound; a liquid crystal composition satisfying at least one characteristic such as a high maximum temperature of a nematic phase, a low minimum temperature thereof, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy and specific resistance, a high stability to ultraviolet light and heat, and having a suitable balance regarding at least two characteristics; a PSA device having a short response time, a large pretilt angle, a small residual monomer concentration, a large voltage holding ratio and contrast ratio and a long life; a polymerizable compound into which one bonding group or nonidentical reaction group is introduced by constructing a polymer structure having a high polymerization degree in a PSA device manufacturing process to obtain a stable display, a liquid crystal composition containing thereof, and a liquid crystal device including thereof.
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BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates to an arrangement for producing package spools used as feeding packages for twisting onto which two yarns are wound side by side, having drafting units for two slivers, having air nozzles for strengthening the slivers to form yarn components, and having yarn guides for the guiding-together of the yarn components to form a double yarn. A withdrawal device is provided for withdrawing the double yarn which has a wind-up device for winding the double yarn onto a package spool. A control apparatus is also Provided for interrupting the operation, with sliver detectors connected arranged in front of the drafting units and with at least one yarn detector connected arranged behind the air nozzles.
Arrangements of the initially mentioned type are known (DE-A 36 34 464--corresponding U.S. application Ser. No. 105,813, filed Oct. 8, 1987, now U.S. Pat. No. 4,790,130 and DE-A 38 00 810). If one or both slivers to be fed should break in these arrangements, this sliver breakage must be eliminated first, for example, by connecting with a newly fed sliver, before a piecing operation can be carried out.
It is also known to monitor the individual yarn components with respect to thick and thin points and to clean these out before the yarn components are guided together to form a double yarn. After the cleaning-out, a new piecing must also be carried out.
In the case of ring spinning machines, it is known (DE-A 23 39 654) to equip an automatic piecing apparatus with a device at the outlet of the drafting unit which determines whether roving is supplied at the spinning point at which a yarn breakage is to be eliminated. If no roving is present, no piecing operation is initiated. Since the emerging of roving, which is not spun into a yarn, from the drafting unit is also an indication of a yarn breakage, this signal is at the same time used as a piecing signal, i.e., as the signal which triggers the start of the operation of the piecing device.
An object of the invention is to develop an arrangement of the initially mentioned type so that it is suitable for an automatic device and so that an automatic piecing carriage can be called to the respective arrangement, as required.
This object is achieved in that the control apparatus is equipped with devices for generating a piecing signal, the piecing signal being generated after the yarn detector or detectors has/have responded or, if a sliver detector has responded, after the defect signal of the sliver detector is extinguished.
By means of this construction, it is taken into account that a piecing cannot be carried out if one or both slivers moving into the drafting units is or are broken. In this case, a piecing device does not become operative at the respective arrangement as long as the sliver breakage is not eliminated and the defect signal of the sliver detector is not extinguished. It is only when a successful piecing operation is possible that the automatic piecing carriage receives a corresponding signal so that it becomes operative.
As a rule, there will only be a sliver breakage when the sliver which is taken from a can for example, is used up. In order to draw the attention of the operator or of an automatic can changing device with an automatic sliver piecing device to this defect, it is provided in a further development of preferred embodiments of the invention that the control apparatus is equipped with devices for generating a signal which indicates a sliver defect.
In a further development of preferred embodiments of the invention, it is provided that the control apparatus is equipped with devices for the switching-on of the drafting unit which can be switched on for a given time period after the extinguishing of a signal of a sliver detector indicating a sliver defect, and that the control apparatus is connected with devices for the simultaneous activating of suction devices assigned to the outlet of the drafting units. As a result, it is ensured that the part of the sliver to which the new sliver was pieced and which represents a thick point, in most cases, is not used for producing a yarn component. The reason is that there is the risk that this thick point may result in a yarn defect which would be detected by a corresponding yarn detector and would lead to a switching-off of the corresponding spinning arrangement for the cleaning-out of this yarn defect. In this case, the piecing operation would have to be repeated within a very short time at the same spinning arrangement. However, this cannot happen before the piecing carriage, when carrying out its monitoring travel, passes by again at the respective arrangement. In the case of a large machine, this may result in a disadvantageously long stoppage time.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic top view of a spinning machine utilizing the present invention; and
FIG. 2 is a schematic view of an individual spinning unit of the machine of FIG. 1, constructed according to a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The spinning arrangement contains two drafting units 1, 2, which are combined into a double aggregate. Slivers 3, 4 enter into the drafting units 1, 2 and are drawn to a desired yarn count in the drafting units. The drawn yarn components 5, 6, which leave the drafting units 1, 2, enter into pneumatic false-twisting devices 7, 8. In these pneumatic false-twisting devices 7, 8, they are prestrengthened in a known manner to such an extent that they can be temporarily wound up for a later operation.
The two prestrengthened yarn components 9, 10 which leave the false-twisting devices 7, 8, are combined to a double yarn 12 by means of yarn guides 11. The double yarn 12 is withdrawn by means of a withdrawal device 13 and then moves in the direction of the arrow (C) to a wind-up device 14 by which the double yarn 12 is wound up side by side onto a package spool 57.
The slivers 3, 4 are fed from cans 15, 16 which are placed on the rearward side of the machine. The drafting units 1, 2, the false-twisting device 7, 8, the withdrawal device 13 and the wind-up device 14, on the other hand, are located on the front side of the machine.
In the shown embodiment, the drafting units 1, 2 are constructed as so-called three-cylinder drafting units. They each have three top rollers 20, 22; 24, 26; 28, 30 to which the bottom rollers 19, 21; 23, 25; 27, 29 are assigned. The top rollers 20, 22; 24, 26; 28, 30 are each held in a common bearing arm 34 by means of common shafts 31, 32, 33. For the opening of the drafting units 1, 2, this bearing arm 34 can be swivelled around a holding rd 35 extending in the longitudinal direction of the machine. The bottom rollers 19, 21; 23, 25; 27, 29 are constructed as cylinders which extend through in the longitudinal direction of the machine and are driven at the machine end. As indicated in the drawing, apron drafting units are provided in the main drafting zone.
Instead of the shown drafting units 1, 2, a drafting unit aggregate may be provided according to another contemplated embodiment in which the adjacent drafting units, corresponding to drafting units 1, 2, consist of shaft sections which can be stopped individually.
The pneumatic false-twisting devices 7, 8 each contain two air nozzles 38, 39; 42, 43 arranged behind one another which are connected to a compressed-air source by means of pipes 40, 41, 44, 45. The respectively first air nozzles 38, 42 are constructed as so-called intake nozzles, while the air nozzles 39, 43 which follow are constructed as false-twisting nozzles. By means of these pneumatic false-twisting devices 7, 8, a false twist is generated in the yarn components 5, 6, which extends to the drafting units 1, 2 and which disappears when leaving the false-twisting nozzles 39, 43. However, fiber ends at the surface remain wound around the fiber core consisting essentially of parallel fibers and provide the yarn components 5, 6 with a certain strength.
The yarn guides 11 consist of rod-shaped yarn guides 48, 49 and additional yarn guides 50, 51 which guide the two yarn components 9, 10 together, in which case they define the remaining narrow distance of the yarn components 5, 6 in the double yarn 12.
The withdrawal device 13 consists of a driven bottom cylinder 52 extending through in the longitudinal direction of the machine and of a pressure roller 53.
Of the wind-up device 14, only one wind-up roller 56 is shown which extends through in the longitudinal direction of the machine and is driven at the machine end, the spool package 57 resting on this wind-up roller 56 during the wind-up operation. Devices for holding the spool package 57 are also part of the wind-up device 14. The wind-up device 14 also has a cross-winding device 58 which is only outlined in the drawing.
Sliver detectors 17, 18 are arranged in front of the drafting units 1, 2 which monitor the presence of the slivers 3, 4. Yarn detectors 46, 47 are arranged directly behind the false-twisting devices 7, 8. Another yarn detector 54 is arranged behind the withdrawal device 13 and monitors the double yarn 12 with respect to unacceptable thick points or thin points. A yarn intake nozzle 55 is also arranged in front of the wind-up device 14.
The sliver detectors 17, 18 as well as the yarn detectors 46, 47 and 54 are connected to a control apparatus, as shown by dash-dotted lines. This control apparatus 59 is connected with a device which is not shown, such as a pneumatic or hydraulic press, by means of which the bearing arm 34 of the drafting units 1, 2 can be lifted; i.e., by means of which the operation of the drafting units 1, 2 can be interrupted. As also shown by a dash-dotted line, the control apparatus 59 is connected with a yarn suction device 55, i.e., with a valve assigned to this suction device. As shown by means of another dash-dotted line, the control apparatus 59 is also connected with the wind-up device 14, i.e., with an actuating element, such as also a pneumatic or hydraulic press by means of which the package spool 57 can be lifted off for interrupting the wind-up operation of the wind-up roller 56.
This interrupting of the operation of the arrangement takes place as soon as the sliver detectors 17, 18 or the yarn detectors 46, 47 report a breakage, or the yarn detector 54 reports an unacceptable quality defect. Subsequently, a piecing operation takes place by means of an automatic piecing carriage which is not shown, which travels along the front side of the spinning machine and which, in each case, can be applied to an individual spinning arrangement for the carrying-out of a piecing operation.
The control apparatus 59 is connected with a signal generator 60 at which a piecing signal is set if the piecing carriage is to stop at the corresponding spinning arrangement. This piecing signal is set if one of the yarn detectors 46, 47 or 54 is addressed and subsequently a piecing operation is required. However, since the same piecing carriage cannot check the sliver supply from the cans 15, 16 on the rearward side of the machine, it is provided that, when one or both sliver(s) 3, 4 break(s), which is indicated by the sliver detectors 17, 18, a corresponding signal is set by the control apparatus 59 which indicates the sliver breakage, such as an additional signal 61 in the form of a button or the like, which can be moved out, at the signal generator 60. This signal indicates to the piecing carriage that, despite the stoppage, it must not carry out any piecing operation. It is only after the sliver breakage is eliminated, for example, by the making-available of new cans 15, 16 and by connecting the slivers 3, 4 with the start of the newly supplied slivers, for example, by splicing, that the signal indicating the sliver breakage is reset. It is only then that the piecing signal becomes operative so that the piecing carriage starts its operation.
Also if the new sliver is connected with the end of the old sliver by means of splicing, as a rule, a thick point cannot be avoided which, under certain circumstances, may result in such a defect that the yarn detector 54 will response. In order to prevent that this thick point enters the wound-up double yarn at all, it is provided in a further development of the invention that, after the resetting of the "sliver breakage" signal, the control apparatus 59, by way of the pertaining actuating device, shuts down the drafting units 1, 2 for a given time period and, at the same time, activates the suction nozzles 36, 37 located at the outlet of the drafting units 1, 2. In this case, it may be provided that these suction devices 36, 37 are applied only during a yarn breakage. The fiber material which, during this time period, moves through the drafting unit 1, 2, is therefore sucked off and removed without entering into the double yarn.
Although the present invention has been described and illustrated in detail, it is to be 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 are to be limited only by the terms of the appended claims.
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An arrangement for producing spool packages serving as feeding packages for twisting, having a control apparatus for interrupting the operation. Sliver detectors arranged in front of drafting units are connected to the control apparatus. At least one yarn detector is connected which is arranged behind air nozzles. It is provided that the control apparatus is equipped with devices for generating a piecing signal, the piecing signal being generated after the yarn detector or detectors has/have responded or, if a sliver detector has responded, after the defect signal of the sliver detector is extinguished.
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RELATED APPLICATIONS
[0001] This application claims priority to Eurasian Patent Application No. 201100963, filed Jul. 18, 2011, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to the area of X-ray technology, namely to the digital detectors of X-ray image and is intended for X-ray image enhancement. More specifically the present invention is designed for stitching and linearization of gain characteristics of independent sensors of multisensor detectors.
BACKGROUND OF THE INVENTION
[0003] At present the application of digital multisensor detectors in medicine, astronomy and the other areas is continuously extended [Howell S. B. Handbook of CCD Astronomy. Cambridge University Press, 2000; Gino M. Noise, Noise, Noise; S. I. Miroshnichenko, A. A. Nevgasimyj Theory and technique of multisensor digital X - ray receivers. Biotechnosphere, No. Apr. 10, 2010; B. Yane Digital processing of images, M., Technosphera, 2007].
[0004] The image in multisensor detectors can be formed by several CCD or CMOS sensors. Each sensor of multisensor detector, in its turn, can consist of smaller sensors with their own signal conversion path. Gain characteristics of each sensor of such detector, that determine output values of signal intensity of the formed image will differ due to technologic and other reasons. The discrepancy of gain characteristics result in common inhomogeneity of response (inhomogeneity of output image) of detector, in occurrence of discontinuous changes (so called stitches) at the joints of sensors in the resulting digital image. Therefore, in actual practice, when using multisensory detectors, the task arises to stitch the gain characteristics of sensors, constituting the same detector. For the purpose of image acquisition, homogeneous in response and without any stitches at the sensor joints, the procedure of calibration shall be applied which could stitch all the characteristics to the set one. In addition to combining, in order to perform calibration of the flat field, the task of gain characteristics linearization shall be settled.
[0005] There are several approaches to settle the task of stitching characteristics. In case of sensors linear responses the standard approach is so called two-point calibration. The methods of stitching and linearization of their characteristics at highly nonlinear characteristics of CMOS-sensors are known. For example, the method of stitching and linearization pixel by pixel of CMOS sensors characteristics is described in the source [ Rad-icon Imaging Corp. AN 08: Polynomial Gain Correction for RadEye Sensors, www.rad-icon.com/pdf/Radicon AN08.pdf)], wherein:
[0006] Using the source of light field with equal distribution of intensity along the detector field-of-view (FOV), two calibration images are received at two levels of input signal, the first level of input signal being selected twice as little as the next one;
[0007] Parameters of quadratic dependence simulating the sensor response are determined and using the calibration images received the correction function is set up which linearizes and stitches pixel characteristics of CMOS-sensor.
[0008] The other method of stitching and linearization of CMOS-sensors pixels is described in the source [Liji C., Jorg P. A Practical Non - linear Gain Correction Method for High - resolution CMOS Imaging Detectors ], wherein:
[0009] Three calibration images at three various levels of output signal are received using light field with equal distribution of intensity along the detector field-of-view;
[0010] The responses of sensor pixels are simulated by piecewise quadratic plain dependence of three segments;
[0011] Parameters of model dependence are determined and using the calibration images received the correction function is set up which linearizes and stitches pixel characteristics of CMOS-sensor.
[0012] The nearest to the inventive engineering solution is the method described in the source [ Kodak. Multiple Output Sensors Seams Correction. Application Note, 2009], wherein the sensor-by-sensor linearization and stitching of the detector characteristics is performed.
[0013] Within this method:
[0014] The series of N calibration images is received at increasing values of radiation intensity using the light field source with equal distribution of intensity along the detector field-of-view;
[0015] The sensor responses are measured by way of LUT functions describing dependence of output signal on the values of the input signal,
[0016] The measured sensor responses are linearized and stitched to the one response arbitrarily selected among these linearized responses.
[0017] In all the methods of linearization and stitching of gain characteristics listed above, including the method [ Kodak. Multiple Output Sensors Seams Correction. Application Note, 2009], the light field source is used with equal distribution of intensity along the detector filed-of-view. However, in some cases it is inconvenient or essentially impossible to use such source. The inconvenience is connected with difficulty of its generation. The impossibility to use light field source with equal distribution of intensity along the detector filed-of-view can be caused, for example, by designer's availability of detector with already integrated scintillation screen converting X-ray radiation to light. In the latter instance, only non-planar X-ray field turns out to be available to stitch and linearize gain characteristics of sensors of multisensory detector causing non-equal distribution of intensity along the detector filed-of-view (non-equal irradiance (light) illumination).
[0018] The present invention object is the development of method of stitching and linearization of detector gain characteristics under the conditions of non-equal irradiance.
SUMMARY OF THE INVENTION
[0019] The technical result of the alleged invention is to present method of stitching and linearization of multisensory detectors gain characteristics under the conditions of non-equal irradiance (the use of radiation source with equal distribution of intensity along the detector field-of-view is not required).
[0020] The technical result in the method of stitching and linearization of multisensory detectors gain characteristics consisting in obtaining series of N calibration images with equal distribution of intensity along the detector filed-of-view at increasing values of radiation intensity, measuring sensor responses by way of Look-Up Tables (LUTs) functions describing dependence of output signal on the values of the input signal, linearization and stitching of measured sensor responses to the one response arbitrarily selected among these linearized responses, IS ACHIEVED BY accumulation along joints of adjacent sensors of M values of their responses at the received detector calibration images by way of moving average calculation, obtaining for each pair of adjacent sensors the assembly of M×N LUT transformation functions which perform direct conversion of boundary values of adjacent sensors signal; the obtained LUT conversion functions interpolate for the whole dynamic range of detector output signal intensity, obtaining assembly of M stitching LUT functions of the adjacent sensors; it is further averaged obtaining for each sensor the LUT function of stitching its response to the response of the adjacent sensor; the response of any sensor is selected as the reference one and the LUT functions of stitching of sensors responses to the reference sensor response are modified successively, obtaining LUT functions of stitching of sensors responses to the reference sensor response, at that each stitching LUT function for the current sensor is set up taking into account the LUT function of stitching of the previous sensor; the linearization LUT function is calculated which performs linearization of reference sensor response and the stitching LUT functions are modified successively using the determined linearization function obtaining resulting LUT functions of stitching of detector sensors responses to the linearized response of the selected reference sensor.
[0021] It is possible to perform the invention in such a way that instead of accumulation of M values of sensors responses using method of calculation of moving average along the sensors joints, the moving localized linear approximation of signal by plane with extrapolation of its M values outside the sensor is used allowing to decrease the influence of gradient of input X-ray (light) field at the joints of replaceable sensors. The other possible variant is to perform stitching and linearization of gain characteristics of sensors of detector being irradiated by the input light field with non-equal intensity.
[0022] At least one sensor can be divided into parts and the intra-sensor stitching can be performed first followed by inter-sensor stitching of characteristics.
[0023] The main distinctive aspect of the present invention lies in the fact that the stitching and the linearization of multisensory detectors characteristics does not require to use the radiation source with equal distribution of intensity along the detector filed-of-view.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The inventive engineering solution, the possibility of its technical realization and the achievement of the technical result is illustrated by FIGS. 1-6 .
[0025] FIG. 1 shows a device for X-ray imaging.
[0026] FIG. 2 shows general scheme of sensor responses evaluation used in the present invention to stitch them.
[0027] FIG. 3 shows the schematic diagram of stitching and linearization of sensor characteristics of detector consisting of two adjacent sensors only.
[0028] FIG. 4 shows LUT functions graphs of conversion of gain characteristics stitching and linearization.
[0029] FIG. 5 shows initial X-ray image 5000×4000 pixels in size obtained using detector consisting of 24 sensors.
[0030] FIG. 6 illustrates effectiveness of the technique of stitching and linearization of gain characteristics for detector consisting of 24 sensors proposed in the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] The acquisition of X-ray images is performed, for example, using the device shown in FIG. 1 . It consists of X-ray tube 1 which emits X-ray beam 2 . The X-ray beam 2 is received by detector 3 . The detector 3 includes scintillation screen (not drawn) and the matrix array camera (not drawn). The scintillation screen is optically connected with the surface of the active matrix array camera. The matrix array camera (not drawn) consists of at least one sensor. It can consist of any finite number of sensors, for instance, of two.
[0032] The X-ray beam 2 falls on detector 3 , the scintillation screen converts it into visible light which is in its turn converted into digital form by the detector sensors. The stated form represents digital image consisting of several parts which number corresponds to the number of sensors in detector. FIG. 2 shows schematically the digital image 4 formed by detector 3 , consisting of two adjacent sensors 5 and 6 .
[0033] In accordance with the inventive method the series of N calibration images is made first. The calibration images are performed with equal distribution of intensity along the detector filed-of-view without absorbing objects. The images are generated at increasing values of radiation intensity with random step by intensity from zero exposure (the read-out image) up to occurrence of saturation signal from detector sensors. Since the radiation field is in general non-planar, the sensors of detector 3 achieve saturation unequally. To decrease noise influence at the following stage of sensors response evaluation several images are obtained for each value of intensity being averaged afterwards. Simultaneously with obtaining series of images the values of radiation intensity are measured by dosimeter (not drawn) at the arbitrarily chosen place of detector 3 , disposing it, for example, above the detector 3 or alongside of it.
[0034] Then the M values of sensor responses are accumulated using method of calculation of moving average by means of small-size evaluation unit of signal 7 , for instance, 30××30 pixels, along joints of adjacent sensors. The evaluation unit of signal 7 in position 8 corresponds to sensor response 5 under number 1 , position 9 ( FIG. 2 ) of evaluation unit of signal 7 corresponds to the sensor response 5 under number M . Likewise for sensor 6 the position 10 of evaluation unit of signal 7 corresponds to the first response of sensor 6 , and the position 11 of evaluation unit of signal 7 corresponds to the response of sensor 6 under number M . For signal evaluation the sample average is used or, in order to increase noise tolerance,—the median. FIG. 3 shows graphs of functions where 12 —response of sensor 5 in one of the M positions of evaluation unit of signal 7 at joint of adjacent sensors 5 and 6 , 13 —responses of sensor 6 in one of the M positions of evaluation unit of signal 7 , 14 —the desirable common linear response of the neighboring sensors 5 and 6 . At the horizontal axis of graph ( FIG. 3 ) the measured values of intensity are shown (in relative units, for instance, in doses (D), standardized to the maximum intensity value), at the vertical axis—the calculated value of signal intensity (I) at the selected signal evaluation area.
[0035] The main idea of accumulation of sensor responses value along their boundaries consists in the use of the fact that near the sensors joints, the radiation intensity is virtually the same with the input X-ray (light) field smoothly changing along the area of detector 3 , that is why the values of responses of corrected sensors 5 and 6 have similar values at the joints. To realize the idea on the basis of received M values of signal responses of sensors for N calibration images, the assembly of M×N LUT conversion functions is received, which perform direct conversion of boundary values of one of adjacent sensors signal into the boundary values of signal the other sensor. For example, each output signal intensity of sensor 6 , calculated at its boundary in the calibration image is associated with the value of boundary intensity of sensor 5 .
[0036] These LUT conversion functions interpolate for the whole dynamic range of detector output signal intensity, obtaining assembly of M LUT functions of stitching.
[0037] The assembly of M LUT of stitching is averaged for the purpose of the following decrease of error in signal evaluation caused by noise presence at the calibration images.
[0038] In such a manner for each sensor the LUT of stitching its response to the response of the adjacent sensor is received. For this purpose the response of any of the detector sensors (for example, the response of sensor 5 in FIG. 2 ) is selected hereinafter referred to as the reference, and the stitching LUTs are modified successively, from the reference one to the other sensors to the effect that the stitching of gain characteristics of sensors to the gain characteristic of the reference sensor 5 to be performed.
[0039] As a result, such stitching LUTs are received by calibration images, which provide stitching of gain characteristics of sensors of multisensory detector.
[0040] In addition to the stitching of gain characteristics of sensors 5 and 6 , the calibration of flat field is performed, the gain characteristic of reference sensor 5 is linearized and is converted into gain characteristic of sensor 6 to the linearized gain characteristic of the reference sensor 5 . That is, the LUT of linearization is calculated which performs linearization of reference sensor response. Then, the LUTs of stitching are successively modified by means of determined linearization function receiving the resulting LUTs of stitching of responses of sensor 6 of the detector to the linearized response of the selected reference sensor 5 .
[0041] FIG. 4 shows the graph of stitching LUTs 15 of sensor 5 response to the linear response 14 FIG. 3 , 16 —graph of stitching LUT of the response of sensor 6 to the linear response 14 FIG. 3 , at the horizontal axis ( FIG. 4 ) the input intensity signal (I) is set, at the vertical axis the output intensity T(I) is depicted.
[0042] The described scheme of stitching and linearization of gain characteristics proposes that the response of each separate sensor is determined, first of all, by one characteristic. Various combinations of stitching and linearization of multisensory detectors gain characteristics are possible. If the sensor characteristic has various nonlinearity within separate sensor, the scheme of stitching and linearization described here allows for a possibility to divide sensor into parts and to perform first intra-sensor stitching followed by inter-sensor stitching of characteristics. In order to decrease the gradient influence at the sensors joints, especially when using input field with the big gradient, the method of moving localized linear approximation of signal by plane with extrapolation of its M values outside the sensor is used, instead of accumulation of M values of sensor responses by method of calculation of moving average along the sensors joints at the received calibration images.
[0043] The result of application of inventive method is shown in FIG. 5-6 . FIG. 5 depicts the shot with size 5000×4000 pixels, consisting of 24 sensors, where 17 —image of dosimeter, 18 and 19 —images received from the two neighboring sensors of detector 3 . FIG. 5 illustrates differences in response of sensors, consisting, in particular, in the availability of joints between the images 18 and 19 received from the adjacent sensors. FIG. 6 shows the example of application of the method of stitching and linearization of sensors gain characteristics stated in this invention: the responses of sensors became the same and linear, the boundaries between the sensors are imperceptible.
BEST MODE OF PRACTICING THE INVENTION
[0044] The following embodiment of the inventive method is possible. First the series of N calibration images with equal distribution of intensity along the detector filed-of-view ( FIG. 2 ) is received. The images are generated at increasing values of radiation intensity D j , j= 1,N with random step by intensity from zero exposure (the read out image) up to saturation of signal from detector sensors. The radiation intensity is measured by dosimeter located at the random place at the detector surface. To decrease the noise influence, several images are received and averaged for each intensity value.
[0045] Then using evaluation unit of signal 7 , M values of adjacent sensors responses are accumulated along the joints of the adjacent sensors at the obtained calibration images of detector by method of calculation of moving average. For the sake of simplicity the situation will be considered when the detector consists of two sensors only ( FIG. 2 ). The signal evaluation in this case shall be performed by the following formulas:
[0000] R i,j 1 =median(S 1 (x±Δ, y±Δ)), R i,j 2 =median(S 2 (x±Δ, y±Δ)), where R i,j 1 —the evaluation array of signal of the first sensor S 1 , R i,j 2 —the evaluation array of signal of the second array S 2 , Δ—radius of evaluation unit of signal, i= 1,M —number of signal evaluations at the joint of sensors, j= 1,N —overall number of calibration images, (x, y)—center coordinates of evaluation unit of signal. When using the smooth X-ray field, the radiation intensity near the joint is virtually the same, therefore using the sensors with the same gain characteristics the following approximate equation shall be performed
[0000] R i,j 1 ≈R i,j 2 . (1)
[0046] The arrangement of LUT conversion is performed in the proposed invention based on the use of approximate equation (1).
[0047] To that effect:
[0048] 1. The assembly of M×N LUT conversion functions of the following view T i =(R i,j 2 ,R i,j 1 ), i= 1,M is received for the adjacent sensors pair.
[0049] 2. The LUT conversion T i are interpolated within the whole dynamic range I (for instance, I=[0,2 16 −1]) of detector, the stitching LUT functions of sensors {tilde over (T)} i =interpolate(T i )={tilde over (T)} i (k), k ε I are received.
[0050] 3. The LUT stitching are averaged, i.e. one LUT function of stitching T of response of sensor 6 to sensor 5 is received
[0000]
T
(
k
)
=
average
i
=
1
,
M
_
(
T
~
i
)
,
k
∈
I
.
(
2
)
[0051] When averaging by formula (2) the averaging by assembly of functions is used set at the same value grid of the dependent argument (input brightness k ε I). This T stitching LUT function represents the desirable LUT which stitches distinguishing gain characteristics of sensors 5 and 6 to one (to the characteristic of the reference sensor 5 ) ( FIG. 2 ).
[0052] Afterwards to perform linearization procedure of the sensors gain characteristics the response of any sensor is selected, for example, let us assume that it is the response R M,j 2 of sensor 6 , and the determined LUT conversion function is applied to it
[0053] {tilde over (R)} M,j 2 =T(R M,j 2 ).
[0054] 1. Considering response {tilde over (R)} M,j 2 (D j ) as a function of the measured radiation intensity D j , j= 1,N (of dose), the decline parameter α of the desirable linear characteristic of detector sensors is found by the following formula [ Kodak. Multiple Output Sensors Seams Correction. Application Note, 2009]:
[0000]
∑
j
=
1
N
(
1
-
aD
j
R
~
M
,
j
2
)
→
min
a
.
[0055] 2. The LUT function for linearization is set up, linearizing sensor 6 with its interpolation for the whole dynamic range of detector
[0056] T lin =({tilde over (R)} M,j 2 ,αD j ),
[0057] {tilde over (T)} lin =interpolate(T lin )={tilde over (T)} lin (k), k ε I
[0058] 3. The resulting stitching LUT of sensors 5 and 6 responses are found therefore by the formulas
[0059] T(k)hd 1 ={tilde over (T)} lin (k), T 2 (k)={tilde over (T)} lin (T(k)), k ε I (sensor 5 was not changed).
[0060] The scheme of successive stitching and linearization of sensors gain characteristics outlined herein can be easily extended to the case of more than two sensors in detector.
REFERENCES
[0061] 1. Howell S. B. Handbook of CCD Astronomy. Cambridge University Press, 2000.
[0062] 2. Kodak. Multiple Output Sensors Seams Correction. Application Note, 2009. (www.kodak.com/global/plugins/acrobat/en/business/ISS/supportdocs/MultipleOutputSensor sSeamsCorrection.pdf).
[0063] 3. Rad-icon Imaging Corp. AN08: Polynomial Gain Correction for RadEye Sensors (www.rad-icon.com/pdf/Radicon AN08.pdf).
[0064] 4. Liji C., Jorg P. A Practical Non-linear Gain Correction Method for High-resolution CMOS Imaging Detectors. (https://www.hoertech.hausdeshoerensoldenburg.de/dgmp2008/abstract/Cao.pdf&rct=j&q=Liji Practical Non-linear Gain Correction Method for High-resolution pdf).
[0065] 5. Gino M. Noise, Noise, Noise. (http://www.astrophys-assist.com/educate/noise/noise.htm)
[0066] 6. S. I. Miroshnichenko, A. A. Nevgasimyj Theory and technique of multisensory digital X-ray receivers. Biotechnosphera, No. Apr. 10, 2010.
[0067] 7. B. Jähne Digital Image Processing, M., Technosphera, 2007, p 583.
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Digital detectors of X-ray image intended for stitching and linearization of gain characteristics of independent sensors of multisensor detectors are disclosed. The technical result is the development of methodology of stitching and linearization of multisensor detectors gain characteristics under the conditions of non equal irradiance (the use of radiation source with flat X-ray (light) field is not required). The method is based on calculation of LUT functions for conversion of output signals intensity of detector sensors. As a result of application of the stated conversion LUT functions the sensors gain characteristics are received which are the same and linear within the precision of measurements. Calculation of stitching LUT functions employs the availability of non-equal X-ray (light) field slowly changing along the area of detector. The responses of any two adjacent sensors with the same gain characteristics shall have similar values near the joint of these sensors.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an extreme level circuit, i.e., a circuit for detecting an extreme level (maximum or minimum value) of a plurality of input signals.
2. Description of the Related Art
EP-A-0,430,707 corresponding to U.S. Pat. No. 5,159,211 describes such an extreme level circuit for detecting an extreme level of two input signals. Starting from a well-known circuit comprising a pair of differential transistors with interconnected emitters from which the output extreme level can be taken, an improvement is presented to prevent distortions from occurring. This improvement comprises a pair of bias generating circuits which are crossconnected to the collectors of the differential transistors. This cross-connection makes it very difficult to expand the circuit to a circuit suitable for determining the extreme level of more than two input signals.
SUMMARY OF THE INVENTION
It is, inter alia, an object of the invention to provide an extreme level circuit which also prevents distortions from occurring but which can easily be expanded to a circuit suitable for determining the extreme level of more than two input signals. To this end, one aspect of the invention provides an extreme level circuit for determining an extreme level of a plurality of input levels, the extreme level circuit comprising a plurality of independent parallel branches with intercoupled output terminals from which the extreme level can be taken, each branch having an input terminal for receiving a respective one of the input levels, and including a separate distortion compensation circuit which is independent of the distortion compensation circuits of the other parallel branches.
The extreme level circuit for determining an extreme level of a plurality of input levels in accordance with the present invention includes a plurality of independent parallel branches with intercoupled output terminals from which the extreme level (maximum or minimum) can be taken. Each branch has an input terminal for receiving a respective one of the input levels, and includes a separate distortion compensation circuit which is independent of the distortion compensation circuits of the other parallel branches. It is thus easily possible to add further independent parallel branches in order to be able to calculate the extreme value of as many input values as is desired.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 shows a first embodiment of an extreme level circuit in accordance with the present invention; and
FIG. 2 shows a second embodiment of an extreme level circuit in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, input signals INA, INB and INC are applied to the base terminals of NPN transistors T4, T5 and T6, respectively. The emitters of the transistors T4, T5 and T6 are interconnected, connected to ground thru a current source J3 which pulls a current I, and connected to an output terminal which delivers the maximum value of the input signals INA, INB and INC. The collectors of the transistors T4, T5 and T6 are connected to a positive supply line thru respective PMOSFETs M2, M3 and M4, which FETs form a current mirror with an input FET M1 whose gate and drain are connected to ground thru a current source J2 which pulls a current I/3. Further, the emitters of the transistors T4, T5 and T6 are connected to the positive supply line thru respective PMOSFETs M5, M6 and M7, whose respective gate terminals are connected to the collectors of the transistors T4, T5 and T6, respectively.
In this circuit, the maximum current thru the transistors T4, T5 and T6 is limited by the current sources M2, M3 and M4. Hence, the current thru the transistors T4, T5 and T6 will not exceed I/3. Suppose that the base of transistor T5 receives the largest of the three input signals INA, INB and INC. In this case, the current thru transistor T5 will be I/3, while the currents thru the transistors T4 and T6 will be lower, determined by their respective base-emitter voltages Vbe(T4)=INA-(INB-Vbe(T5)) and Vbe(T6)=INC-(INB-Vbe(T5)). Consequently, the series-FETs M2 and M4 will go into saturation, so that the gate-source voltages of the corresponding parallel-FETs M5 and M7 will be so low that these parallel-FETs M5 and M7 are switched off. The parallel-FET M6 will convey a current which is given by the current I thru the current source J3 minus the current I/3 thru the transistor T5 and minus the collector currents of the transistors T4 and T6.
As a result of the constant collector current thru the transistor T4, T5, T6 which (from time to time) receives the largest of the three input signals INA, INB, INC, its δVbe will be small, so that no significant amplitude distortion will be shown.
For M2, M3 and M4, MOS (PMOS) transistors were chosen, because if the current thru the NPN transistors is lower than the current source feeding its collector, the current source pulls the collector node to the supply voltage. With PNP transistors instead of MOSFETs, this would lead to big substrate currents when the current source saturates, and the PNPs would only slowly come out of saturation which would make the circuit less suitable for high frequencies. In principle, also FETs could be used for the transistors T4, T5 and T6, but bipolar transistors can more easily be matched. For M5, M6 and M7, MOS transistors are chosen because the gate-source capacitance of a MOS transistor is smaller than the corresponding base-emitter capacitance of corresponding bipolar PNP transistors which are thus less suitable for high frequencies.
In FIG. 2, two parallel branches of another maximum detection circuit are shown; extension to any desired number of parallel branches is easily possible. Input signal levels IN1, IN2 are applied to base terminals of NPN transistors N1 and N3, respectively, whose collectors are connected to a positive supply line and whose emitters are connected to ground thru respective current sources I1, I2, and connected to respective base terminals of NPN transistors N2, N4. Emitters of the transistors N2, N4 are connected to an output supplying the maximum value MAX of the input signals. Collectors of the transistors N2, N4 are connected to their respective base terminals thru respective PNP current mirrors P1, P2 and P3, P4.
This circuit thus comprises in each branch two base-emitter junctions in series (N1, N2 and N3, N4). If the current thru the transistor N2 (N4) increases, the additional current is mirrored by the current mirror P1, P2 (P3, P4) so that the current thru the transistor NI (N3) decreases, as the sum of the current to the emitter of the transistor N1 (N3) and the current to the transistor P2 (P4) is constant due to the constant current source I1 (I2). Consequently, a current increase thru the transistor N2 (N4) is compensated by an identical current decrease thru the transistor N1 (N3), and as a result, a Vbe modification of the transistor N2 (N4) is compensated by an identical Vbe modification of the transistor N1 (N3). Any distortions caused by these Vbe modifications as set out in detail in EP-A-0,430,707 are thus automatically compensated for.
It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The embodiments of FIGS. 1, 2 show maximum detection circuits; minimum detection circuits can easily be obtained therefrom by interchanging NPN and PNP transistors etcetera. Alternatively, a minimum can be calculated by taking the inverted maximum of inverted input signals, which causes no additional components in a balanced environment in which at several stages both an output and an inverted output and both an input and an inverted input are available. The circuit of FIG. 2 provides the advantage that it can be build in pure bipolar manufacturing processes. The extreme level circuits according to the present invention can very advantageously be used in luminance transient improvement circuits.
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An extreme level circuit for determining an extreme level of a plurality of input levels includes a plurality of independent parallel branches (T4+M2+M5, T5+M3+M6) with intercoupled output terminals (MAX) from which the extreme level can be taken. Each branch has an input terminal (INA, INB) for receiving a respective one of the input levels, and includes a separate distortion compensation circuit (M2+M5, M3+M6) which is independent of the distortion compensation circuits of the other parallel branches.
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TECHNICAL FIELD
[0001] Various exemplary embodiments disclosed herein relate generally to controlling usage of a subscriber in telecommunications networks.
BACKGROUND
[0002] As the demand increases for varying types of applications within mobile telecommunications networks, service providers must constantly upgrade their systems in order to reliably provide this expanded functionality. What was once a system designed simply for voice communication has grown into an all-purpose network access point, providing access to a myriad of applications including text messaging, multimedia streaming, and general Internet access. In order to support such applications, providers have built new networks on top of their existing voice networks, leading to a less-than-elegant solution. As seen in second and third generation networks, voice services must be carried over dedicated voice channels and directed toward a circuit-switched core, while other service communications are transmitted according to the Internet Protocol (IP) and directed toward a different, packet-switched core. This led to unique problems regarding application provision, metering and charging, and quality of experience (QoE) assurance.
[0003] In an effort to simplify the dual core approach of the second and third generations, the 3rd Generation Partnership Project (3GPP) has recommended a new network scheme it terms “Long Term Evolution” (LTE). In an LTE network, all communications are carried over an IP channel from user equipment (UE) to an all-IP core called the Evolved Packet Core (EPC). The EPC then provides gateway access to other networks while ensuring an acceptable QoE and charging a subscriber for their particular network activity.
[0004] The 3GPP generally describes the components of the EPC and their interactions with each other in a number of technical specifications, including the following components: Policy and Charging Rules Function (PCRF); Policy and Charging Enforcement Function (PCEF); and Bearer Binding and Event Reporting Function (BBERF) of the EPC. These specifications further provide some guidance as to how these elements interact in order to provide reliable data services and charge subscribers for use thereof.
[0005] Within these communication networks, metering may be used to measure usage of the communication network by subscribers. When a prepaid subscriber reaches their usage limit, the telecommunication network must provide a way for the subscriber to continue, for example, a call when they run out of credit.
SUMMARY
[0006] A brief summary of various exemplary embodiments is presented below. Some simplifications and omissions may be made in the following summary, which is intended to highlight and introduce some aspects of the various exemplary embodiments, but not to limit the scope of the invention. Detailed descriptions of a preferred exemplary embodiment adequate to allow those of ordinary skill in the art to make and use the inventive concepts will follow in later sections.
[0007] Various exemplary embodiments relate to a method performed by a policy and charging rules node (PCRN), the method including: receiving an event trigger and a Charging-Rule-Report AVP with Final-Unit-Indication AVP that contains restriction filter rule(s) associated with the original set of policy and charging control (PCC) rules from a policy and charging enforcement node (PCEN) indicating that a subscriber is out of credit; producing a second set of PCC rules to implement the restriction filter to handle the out of credit status of the subscriber; installing the second set of PCC rules; receiving an indication that the subscriber has received a reallocation of credit; and uninstalling the second set of PCC rules after receiving an indication that the subscriber has completed the reallocation of credit operation.
[0008] Various exemplary embodiments relate to a policy and charging rules node (PCRN), including: a network interface configured to: receive an event trigger and a Charging-Rule-Report AVP with Final-Unit-Indication AVP that contains restriction filter rule(s) associated with the original set of policy and charging control (PCC) rules from a policy and charging enforcement node (PCEN) indicating that a subscriber is out of credit; and receive an indication that the subscriber has received a reallocation of credit; a PCC rules engine configured to: produce a second set of PCC rules to implement the restriction filter to handle the out of credit status of the subscriber; install a second set of PCC rules to handle the out of credit status of the subscriber; and uninstall the second set of PCC rules after receiving an indication that the subscriber has completed the reallocation of credit operation.
[0009] Various exemplary embodiments relate to a non-transitory machine-readable storage medium encoded with instructions for execution by a policy and charging rules node (PORN), the medium including: instructions for receiving an event trigger and a Charging-Rule-Report AVP with Final-Unit-Indication AVP that contains restriction filter rule(s) that is associated with the original set of policy and charging control (PCC) rules from a policy and charging enforcement node (PCEN) indicating that a subscriber is out of credit; instructions for producing a second set of PCC rules to implement the restriction filter to handle the out of credit status of the subscriber; instructions for installing the second set of PCC rules; instructions for receiving an indication that the subscriber has received a reallocation of credit; and instructions for uninstalling the second set of PCC rules after receiving an indication that the subscriber has completed the reallocation of credit operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In order to better understand various exemplary embodiments, reference is made to the accompanying drawings, wherein:
[0011] FIG. 1 illustrates an exemplary subscriber network for providing various data services;
[0012] FIG. 2 illustrates an embodiment for the exchange of messages between a PCEN and PCRN in response to receiving an OUT_OF_CREDIT event; and
[0013] FIG. 3 illustrates a flow diagram illustrating a method of handling of an OUT_OF_CREDIT event.
[0014] To facilitate understanding, identical reference numerals have been used to designate elements having substantially the same or similar structure and/or substantially the same or similar function.
DETAILED DESCRIPTION
[0015] FIG. 1 illustrates an exemplary subscriber network 100 for providing various data services. Exemplary subscriber network 100 may be telecommunications network or other network for providing access to various services. Exemplary subscriber network 100 may include user equipment 110 , base station 120 , evolved packet core (EPC) 130 , packet data network 140 , application function (AF) 150 , and online charging system (OCS) 160 .
[0016] User equipment 110 may be a device that communicates with packet data network 140 for providing the end-user with a data service. Such data service may include, for example, voice communication, text messaging, multimedia streaming, and Internet access. More specifically, in various exemplary embodiments, user equipment 110 is a personal or laptop computer, wireless email device, cell phone, tablet, television set-top box, or any other device capable of communicating with other devices via EPC 130 .
[0017] Base station 120 may be a device that enables communication between user equipment 110 and EPC 130 . For example, base station 120 may be a base transceiver station such as an evolved nodeB (eNodeB) as defined by 3GPP standards. Thus, base station 120 may be a device that communicates with user equipment 110 via a first medium, such as radio waves, and communicates with EPC 130 via a second medium, such as Ethernet cable. Base station 120 may be in direct communication with EPC 130 or may communicate via a number of intermediate nodes (not shown). In various embodiments, multiple base stations (not shown) may be present to provide mobility to user equipment 110 . Note that in various alternative embodiments, user equipment 110 may communicate directly with EPC 130 . In such embodiments, base station 120 may not be present.
[0018] Evolved packet core (EPC) 130 may be a device or network of devices that provides user equipment 110 with gateway access to packet data network 140 . EPC 130 may further charge a subscriber for use of provided data services and ensure that particular quality of experience (QoE) standards are met. Thus, EPC 130 may be implemented, at least in part, according to various 3GPP standards. Accordingly, EPC 130 may include a serving gateway (SGW) 132 , a packet data network gateway (PGW) 134 , a policy and charging rules node (PCRN) 136 , and a subscription profile repository (SPR) 138 .
[0019] Serving gateway (SGW) 132 may be a device that provides gateway access to the EPC 130 . SGW 132 may be the first device within the EPC 130 that receives packets sent by user equipment 110 . SGW 132 may forward such packets toward PGW 134 . SGW 132 may perform a number of functions such as, for example, managing mobility of user equipment 110 between multiple base stations (not shown) and enforcing particular quality of service (QoS) characteristics for each flow being served. In various implementations, such as those implementing the Proxy Mobile IP standard, SGW 132 may include a Bearer Binding and Event Reporting Function (BBERF). In various exemplary embodiments, EPC 130 may include multiple SGWs (not shown) and each SGW may communicate with multiple base stations (not shown).
[0020] Packet data network gateway (PGW) 134 may be a device that provides gateway access to packet data network 140 . PGW 134 may be the final device within the EPC 130 that receives packets sent by user equipment 110 toward packet data network 140 via SGW 132 . PGW 134 may include a policy and charging enforcement function (PCEF) that enforces policy and charging control (PCC) rules for each service data flow (SDF). Therefore, PGW 134 may be a policy and charging enforcement node (PCEN). PGW 134 may include a number of additional features such as, for example, packet filtering, deep packet inspection, and subscriber charging support. PGW 134 may also be responsible for requesting resource allocation for unknown application services.
[0021] Policy and charging rules node (PCRN) 136 may be a device or group of devices that receives requests for application services, generates PCC rules, and provides PCC rules to the PGW 134 and/or other PCENs (not shown). PCRN 136 may be in communication with AF 150 via an Rx interface. As described in further detail below with respect to AF 150 , PCRN 136 may receive an application request in the form of an Authentication and Authorization Request (AAR) from AF 150 . Upon receipt of AAR 160 , PCRN 136 may generate at least one new PCC rule for fulfilling the application request.
[0022] PCRN 136 may also be in communication with SGW 132 and PGW 134 via a Gxx and a Gx interface, respectively. PCRN 136 may receive an application request in the form of a credit control request (CCR) (not shown) from SGW 132 or PGW 134 . As with AAR, upon receipt of a CCR, PCRN may generate at least one new PCC rule for fulfilling the application request 170 . In various embodiments, AAR and the CCR may represent two independent application requests to be processed separately, while in other embodiments, AAR and the CCR may carry information regarding a single application request and PCRN 136 may create at least one PCC rule based on the combination of AAR and the CCR. In various embodiments, PCRN 136 may be capable of handling both single-message and paired-message application requests.
[0023] Upon creating a new PCC rule or upon request by the PGW 134 , PCRN 136 may provide a PCC rule to PGW 134 via the Gx interface. In various embodiments, such as those implementing the PMIP standard for example, PCRN 136 may also generate QoS rules. Upon creating a new QoS rule or upon request by the SGW 132 , PCRN 136 may provide a QoS rule to SGW 132 via the Gxx interface. These QoS rules may be applied based upon usage information received from the OCS 160 . When the OCS 160 indicates that certain usage thresholds have been reached, the PCRF 105 may change the QoS related to a subscriber and apply updated QoS rules to the PCEF 125 .
[0024] The PCRN 136 may include network interfaces for communication with other network node, a PCC rule engine, and PCC rule storage. For example, the PCRN 136 may receive an OUT_OF_CREDIT trigger event via the network interface, and pass that event to the PCC rule engine for processing. The PCC rule engine may make decisions regarding existing rules and to create new rules based upon the trigger event. Any new rules or changes to rules may be noted in the PCC rule storage.
[0025] Subscription profile repository (SPR) 138 may be a device that stores information related to subscribers to the subscriber network 100 . Thus, SPR 138 may include a machine-readable storage medium such as read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and/or similar storage media. SPR 138 may be a component of PCRN 136 or may constitute an independent node within EPC 130 . Data stored by SPR 138 may include an identifier of each subscriber and indications of subscription information for each subscriber such as bandwidth limits, charging parameters, and subscriber priority.
[0026] Packet data network 140 may be any network for providing data communications between user equipment 110 and other devices connected to packet data network 140 , such as AF 150 . Packet data network 140 may further provide, for example, phone and/or Internet service to various user devices in communication with packet data network 140 .
[0027] Application function (AF) 150 may be a device that provides a known application service to user equipment 110 . Thus, AF 150 may be a server or other device that provides, for example, a video streaming or voice communication service to user equipment 110 . AF 150 may further be in communication with the PCRN 136 of the EPC 130 via an Rx interface. When AF 150 is to begin providing known application service to user equipment 110 , AF 150 may generate an application request message, such as an authentication and authorization request (AAR) 160 according to the Diameter protocol, to notify the PCRN 136 that resources should be allocated for the application service. This application request message may include information such as an identification of the subscriber using the application service, an IP address of the subscriber, an APN for an associated IP-CAN session, and/or an identification of the particular service data flows that must be established in order to provide the requested service. AF 150 may communicate such an application request to the PCRN 136 via the Rx interface.
[0028] OCS 160 may be used to track pre-paid usage of subscribers. For pre-paid usage charging occurs in real-time, where the service cost is deducted from the subscriber balance while the service is in operation. The OCS 160 may receive usage information from the PGW 134 . Further the OCS 160 may install monitoring keys in the PGW 134 to monitor certain types of subscriber usage. The OCS 160 receives information related to usage limits associated with the subscriber. Further, the OCS 160 may receive threshold information based upon various desired usage thresholds. When a threshold is reached certain policies may become applicable. The OCS 160 may also communicate with the PCRN 136 via the Sy interface. The OCS 160 may send usage information to the PCRN 136 . The OCS 160 may send indications when various thresholds have been exceeded such as for example an OUT_OF CREDIT event to the PGW 134 , and the PGW 134 may then send an OUT_OF_CREDIT event trigger to the PCRN 136 .
[0029] Typically a pre-paid subscriber of the subscriber network 100 may have a metering limit that defines a limit on the amount of resources that the subscriber may use. For example, a subscriber may have purchased 100 minutes. Other usage, for example, data usage may be metered as well.
[0030] For example, when a pre-paid subscriber places a call, they may be informed by a voice message that indicates how many remaining call minutes that the subscriber has. Alternatively, such a voice reminder may only occur when the remaining minutes of the pre-paid subscriber is less than a threshold amount. If during a call, the pre-paid subscriber runs out of minutes, the network may restrict the subscriber's access to the network. Because the PCRN 136 makes rule decisions, the PCRN 136 may receive an OUT_OF_CREDIT event trigger when the pre-paid subscriber has exceeded their usage limit. Along, with the OUT_OF_CREDIT event trigger, the PCRN 136 may also receive a Charging-Rule-Report containing restriction filter(s). The PCRN 136 may then use the restriction filter(s) to create rules to achieve a desired response to the OUT_OF_CREDIT event trigger.
[0031] FIG. 2 illustrates an embodiment for the exchange of messages between a PCEN and PCRN in response to receiving an OUT_OF_CREDIT event. First, PCEN 134 sends an OUT_OF_CREDIT trigger event 205 to the PCRN 136 . In this example, the OUT_OF_CREDIT trigger event may be associated with PCC rule 1 which now may have a status of TEMPORARILY INACTIVE as reported by Charging-Rule-Report AVP. Within the Charging-Rule-Report AVP, a final unit indication (FUI) may contain a final unit action (FUA) that has a value of, for example, RESTRICT_ACCESS and a restriction filter rule. As a result, a restriction filter rule may be associated with the FUA of RESTRICT_ACCESS. Also, when the PCEN 134 determines that the subscriber is OUT_OF_CREDIT, the PCEN 134 may set the rule-status of PCC rule 1 to TEMPORARILY INACTIVE.
[0032] Next, the PCRN 136 may create a second PCC rule, PCC rule 2 , and the status of that rule may be set to ACTIVE 210 . The action indicated by PCC rule 2 may be based upon the value of the FUA received with the OUT_OF_CREDIT trigger event. Because FUI included a FUA of RESTRICT_ACCESS and a restriction filter rule, the PCC rule 2 may be used to implement the restriction filter rule. Then the PCRN 136 may send a message to the PCEN 134 to install PCC rule 2 215 .
[0033] Once the pre-paid subscriber has purchased more minutes, the PCEN 134 may receive a notification. As a result, the PCEN 134 may set the rule status of PCC rule 1 to ACTIVE. Next, the PCEN 134 may then send a REALLOCATION_OF_CREDIT trigger event 220 to the PCRN 136 . Upon the receipt of the REALLOCATION_OF_CREDIT event trigger, the PCRN 136 may remove PCC rule 2 225 . Next, the PCRN 136 may send a message to the PCEN 134 to uninstall PCC rule 2 from the PCEF 230 .
[0034] Accordingly, when an OUT_OF_CREDIT event trigger occurs for a pre-paid subscriber, the PCRN 136 may use a second PCC rule in order to carry out a desired action as specified by the FUA, for example RESTRICT_ACCESS.
[0035] FIG. 3 illustrates a flow diagram illustrating a method of handling of an OUT_OF_CREDIT event. The method 300 begins at step 305 . Next, the PCRN 136 may receive and OUT_OF_CREDIT event trigger and a restriction filter rule 310 .
[0036] Then the PCRN 136 may create a second PCC rule 315 . The second PCC rule may implement restriction filter rule received with the OUT_OF_CREDIT event trigger. The PCRN 136 may then install the second PCC rule 320 in the PCEN 134 .
[0037] Next, the PCRN 136 may receive a REALLOCATION_OF_CREDIT event trigger 325 . In response, the PCRN 136 may uninstall the second PCC rule 330 . The method 300 may then end at 335 .
[0038] While the above method was described as being carried out by a PCRN 136 , other hardware elements that may implement the PCRF may be used to carry out the method as well.
[0039] When reference is made to PCC rule 1 and PCC rule 2 , PCC rule 1 and PCC rule 2 may also encompass sets of rules.
[0040] It should be apparent from the foregoing description that various exemplary embodiments of the invention may be implemented in hardware and/or firmware. Furthermore, various exemplary embodiments may be implemented as instructions stored on a machine-readable storage medium, which may be read and executed by at least one processor to perform the operations described in detail herein. A machine-readable storage medium may include any mechanism for storing information in a form readable by a machine, such as a personal or laptop computer, a server, or other computing device. Thus, a tangible and non-transitory machine-readable storage medium may include read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and similar storage media.
[0041] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative circuitry embodying the principles of the invention. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in machine readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.
[0042] Although the various exemplary embodiments have been described in detail with particular reference to certain exemplary aspects thereof, it should be understood that the invention is capable of other embodiments and its details are capable of modifications in various obvious respects. As is readily apparent to those skilled in the art, variations and modifications can be effected while remaining within the spirit and scope of the invention. Accordingly, the foregoing disclosure, description, and figures are for illustrative purposes only and do not in any way limit the invention, which is defined only by the claims.
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Various exemplary embodiments relate to a method performed by a policy and charging rules node (PCRN), the method including: receiving an event trigger and a restriction filter rule associated with a first set of policy and charging control (PCC) rules from a policy and charging enforcement node (PCEN) indicating that a subscriber is out of credit; producing a second set of PCC rules to implement the restriction filter to handle the out of credit status of the subscriber; installing the second set of PCC rules; receiving an indication that the subscriber has received a reallocation of credit; and uninstalling the second set of PCC rules after receiving an indication that the subscriber has completed the reallocation of credit operation.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to a system, apparatus and method for controlling and/or expelling water from basements or other subterranean rooms. More particularly, the invention relates to a water drainage device that includes a plurality of flow channels to allow water to bypass a clogged area of a flow channel. The invention further relates to a method of water control utilizing such apparatus, wherein the apparatus is installed in a subterranean room to receive and redirect water.
[0002] The use of conduit systems, and structures to control water leakage in basements has long been known. The following patents describes such various conduit systems and structures.
[0003] U.S. Pat. No. 3,990,469, titled Basement drainage structure, to Ralston, teaches a plurality of elongated drainage members connected in end to end fashion. The drainage members are located about the periphery of a basement floor, upon the floor and adjacent the basement walls. Each drainage member has a base and a wall connected to the base and spaced apart from the basement wall. A sealant member connects the bases to the basement floor. A drain channel is attached to one drainage member, whereby water collected by the drainage members is directed to an area drain in the basement. A flush assembly is attached to a drainage member half-way about the periphery of the basement floor from the drain channel.
[0004] U.S. Pat. No. 4,590,722 titled Unique improved drainage system for basements, to Bevelacqua, teaches a drainage apparatus for basements includes a conventional block or poured concrete wall supported by a footer having an excavation at its inner side extending to the same level as the lower part of the footer, with an aperture and drain tile positioned in the excavation and extending the length thereof. A cover plate means extends from the drain pipe over to the wall for end support on an inner ledge means on the block wall, whereby a floor section can be laid over the cover plate and drain tile to blend into the remainder of the basement floor.
[0005] U.S. Pat. No. 4,757,651 titled Wall system, to Crites, teaches a wall system for use on a vertical wall, such as a basement wall, is disclosed. A drain conduit is positioned adjacent the wall footer and a collection member is mounted along the bottom of the wall. A plurality of connector conduits extend between the collection member and the drain conduit. In one embodiment a vertical support column is mounted adjacent the wall.
[0006] U.S. Pat. No. 4,869,032, titled Apparatus and method for waterproofing basements, to Geske, teaches a drainage control apparatus for basements having a poured concrete floor. The drainage system includes a plurality of drainage structures in an end-to-end abutting relationship. Each drainage structure has a vertical leg and a horizontal leg, with the vertical leg being positioned proximate to the vertical side wall of the basement and the horizontal leg resting upon the top of the foundation footing. The vertical leg includes a plurality of outwardly protruding embossments proximate the bottom end of the vertical leg. The vertical leg also includes an outwardly projecting, longitudinal spacer lip proximate the upper end of the vertical leg. Both the embossments and spacer lip touch the vertical basement side wall to maintain a gap between the vertical leg and the vertical side wall. The horizontal leg of the drainage structure includes a plurality of channels to direct water into a drain pipe.
[0007] U.S. Pat. No. 5,784,838, titled Drain for draining water from a basement floor, to Philips, teaches a basement wall drain unit that extends around the periphery of a basement next to the wall for draining away any potentially damaging moisture. The drain fits securely to a foundation wall before a concrete floor is poured in a basement. The drain further has a removable cap. The cap being removed after the concrete floor has been poured and hardened. The cap is for preventing wet concrete from filling the drain during installation of the basement floor or the like. Another feature of the invention is to provide a device and method that have spaced apart drainage holes in a channel for draining water from the basement area to a location under the basement floor.
[0008] U.S. Pat. No. 6,405,508, titled Method for repairing and draining leaking cracks in basement walls, to Janesky. teaches a method for repairing and concealing a crack in the interior surface of a basement wall, and for draining water admitted through the crack into a drain at the base of the wall. The method involves the steps of covering the crack, along the length thereof and down to the drain, with a thin, narrow strip of a water-absorbing, water-wicking fabric such as a layer of plastic foam or woven cotton. Thereafter, a thin barrier layer of an elastomeric caulk composition is spread thereover and beyond the edges thereof onto the surface of the basement wall to channel the flow of water from the wall crack, through the layer of wicking fabric, and down into the drain.
[0009] U.S. Pat. No. 6,672,016, titled Wall and sub-floor water drain barrier panel for basement water-control systems, to Janesky, titled a sub-floor, perimeter, L-shaped water drainage panel for new construction basements having walls and supporting footings for receiving and draining water running down the walls and/or water entering at the wall/footing interface. The plastic drainage panel is molded with a plurality of spaced frustroconical wells on vertical and horizontal sections thereof, to engage the wall and footing, and space the panels therefrom and to be filled with wet concrete composition, when the floor is poured, to support the wall and footing against the basement floor and prevent relative movement therebetween.
[0010] Each of the patents discussed above, are incorporated herein by reference for all purposes. Generally, most of these systems include a channel which receives water from the foundation walls and directs the water along its length and into a commercial pump to pass out of the basement. Variations and improvements have been introduced, such as having attachments means to more securely hold the system in place or having apertures to receive water at various lengths along the conduit rather than at a single location. All involve the same basic concept—a system with a way to direct water into the system, move it along its length and direct the water to a pump where it will be directed out of the basement.
[0011] As water seeps into the basement, it brings with it sediment and other particulates. Over time, these various particulates can build up within the channel and eventually impede the flow of water through the channel. Once blockage occurs, water may then seep into the basement.
SUMMARY OF THE INVENTION
[0012] The system of the present invention is designed to alleviate the problems associated with sediment/particulates clogging the flow of water through the conduit. The present drainage conduit has two channels rather than just one as found in existing systems. The present invention has a part of its design, a filtering material that serves to filter out sediments/particulates preventing any such sediments/particulates from entering the second flow channel. Additionally, the system utilizes apertures positioned along the length of the side wall of the first conduit to receive water at various locations. If blocking occurs at one area of the conduit preventing further inflow of water at that position, water can enter at any of the unclogged apertures.
[0013] This dual channel system provides a filtered second flow channel to receive water when the first flow channel is blocked at some points along its length. The system allows the water to rise into the second flow channel and bypass the blocked area and move back down into the first flow channel. By filtering the water, ensures that particulates are filtered from the water and thus do not prevent movement in the second flow channel.
[0014] In one aspect of the invention there is a basement drain comprising a frame and a filter element. The frame has a first flow channel, and a second flow channel. The first flow channel is positioned generally above the second flow channel. The first channel has an open end along its length. The frame is preferably formed from a flat sheet of flexible plastic. The frame, however, may be made of other useful materials, such as certain metals, such as aluminum. Based on the disclosure herein, the use of other materials would become readily apparent to one skilled in the art.
[0015] The filter element has a frame and a filter material disposed about said frame, the filter element disposed within the first channel. The filter element may have any size or shape such that it provides filter of sediments or other debris, thereby allowing the flow of water within the filter element. In a sense, the filter element provides a filter flow channel, or multiple flow channels depending on the construction of the filter element. The filter element is adapted to provide filtering into the first flow channel. It is contemplated that to increase the filter capacity, that a second filter element may be contained within the second flow channel.
[0016] In one embodiment, the frame is formed from six walls. A first flow channel is formed by the second wall connected to the third wall, and the sixth wall connected to the third wall. A second flow channel is formed by the third wall connected to the fourth wall, the fourth wall connected to the fifth wall, the fifth wall connected to the sixth wall, the sixth wall connected to the third wall. Preferably, the fifth wall has a plurality of openings to allow water to enter the second flow channel. The sixth wall forms a floor of the first channel and forms a ceiling of the second channel. The first wall has a free end along the length of the first wall. The first wall may have a plurality of wall spacers along its length to space the free end from the wall so that water dripping down the basement wall will be directed to one side of the first wall.
[0017] In one aspect of the invention, the first wall, third wall, and fifth wall are substantially perpendicular to the second wall, fourth wall, and sixth wall. Also, the second wall, fourth wall, and the sixth wall each have a substantially similar width.
[0018] In one aspect of the invention, the first wall is flexibly connected to said second wall. The second wall is flexibly connected to said third wall. The third wall is flexibly connected to the fourth wall. The fourth wall is flexibly connected to said fifth wall. The fifth wall is flexibly connected to sixth wall. In this particular embodiment of the invention, a single sheet of rigid flexible plastic, or other suitable material may be cut out from a roll of stock plastic, and then the particular walls created by forming longitudinal creases in the plastic.
[0019] In this embodiment, there would be a total of five longitudinal creases, one crease between each wall. Forming the basement drain this way allows, a low cost method of producing the frame of the water drainage device. After, the drain template is cut from the plastic, it can be easily stacked in a flat manner without taking up much space. When ready for installation, the frame can be folded into a proper configuration.
[0020] In one aspect of the invention, the sixth wall has a one or more connectors extending along a free end of the sixth wall. The connectors are adapted to connect to openings disposed about the third wall. Preferably, the connectors are tab-shaped. When folding the frame, the tabs are then inserted into the openings. Various shapes may be utilized to connect the sixth wall to the third wall.
[0021] A method according to the invention relates to the control and drainage of water which enters the walls and which must be drained away from the walls and out of the basement to the exterior. Typically, such a drainage method is accomplished by directing water through gaps between the floor and walls.
[0022] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
[0024] FIG. 1 is a schematic perspective view showing the present invention;
[0025] FIG. 2 is a detail perspective of a water drainage device for the water drainage device shown in FIG. 1 ;
[0026] FIG. 3 is a side view of a frame of the water drainage device of FIG. 2 , according to the present invention;
[0027] FIG. 4 is a perspective view of the frame in FIG. 3 in an open condition;
[0028] FIG. 5 is a perspective view of a filter element of the water drainage device of FIG. 2 , according to the present invention; and
[0029] FIG. 6 is a bottom view of a filter element of the water drainage device of FIG. 2 , according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Each of FIGS. 1-6 show various aspects of the system, apparatus and method according to the present invention. FIG. 1 depicts the water drainage device 10 , wherein the water drainage device is installed in a subterranean room, such as a basement. FIGS. 2-6 depict in further detail the water drainage device.
[0031] Typically a subterranean room includes a foundation wall that is built on a footer and a floor that abuts the foundation wall. The wall illustrated is a block wall 26 but the system may be successfully implemented with other types of walls, such as, for example, concrete or limestone walls. Frequently, water builds up within the walls and can leak through the walls into the subterranean room. Building codes normally require that subterranean rooms be constructed to drain water from within a basement wall and redirect it out of the room. This may be achieved in a number of ways, including the use of drain and tile. The foundation wall may have a vapor barrier in the form of a membrane material or coating applied to further inhibit the flow of water into the basement and on to the basement floor 30 .
[0032] A concrete block wall 26 is constructed with the use of concrete blocks which are hollow and are positioned vertically on top of each other aligning the hollow centers. As water enters into the concrete wall, the water flows through the hollow centers of the blocks and exits the wall from apertures 36 in blocks that are placed at intervals along the concrete wall. The water drainage device 10 is designed to receive this water, as more fully explained below, and direct the water along the device via water flow channels 19 , 22 and toward a sump where the water is directed out of the basement.
[0033] The water drainage device 10 is designed to rest on the footer of the wall 24 and is placed adjacent to the inner surface of the foundation wall 26 and extends around the periphery of the room. In the exemplary embodiment of FIG. 2 , the water drainage device 10 is set within a recess formed in the foundation.
[0034] The water drainage device 10 includes a frame 16 and a filter element 20 . The frame has a first flow channel 19 , and a second flow channel 22 . The first flow channel 19 is positioned generally above the second flow channel 22 . The first channel has an open end along its length.
[0035] The frame is preferably formed from a flat sheet of flexible plastic, such as high density polyethylene. The frame 16 , however, may be made of other useful materials, such as certain metals, such as aluminum. The apparatus is preferably a two-piece construction, including a frame or jacket, and a divider in the form of a filter element.
[0036] The filter element may be purchased or fabricated. Prefabricated filter frames with filter material suitable for the present invention, may be purchased from American Wick Drain Corporation, which sells the Akwadrain™ Highway Edge Drain, or from JDR Enterprises, Inc. which sells the JDRain™ line of drains.
[0037] As used in the Figures the following references numerals refer to various aspects of the water drainage device:
10 water drainage device 16 frame of the water drainage device 19 first flow channel 20 filter element 22 second flow channel 40 first wall 42 second wall 44 third wall 46 fourth wall 48 fifth wall 50 sixth wall 52 openings 54 openings in third wall 56 wall spacers 58 connecting tabs 60 filter frame 62 filter material
[0055] Turning now to FIGS. 2-4 , the frame 16 has a plurality of interconnecting walls. The frame 16 may be generally rectangular in cross-section, or may be an alternative configuration. In one embodiment, the frame 16 is formed by six walls 40 , 42 , 44 , 46 , 48 , 50 . A first flow channel 19 is formed by the second wall 42 connected to the third wall 44 , and the sixth wall 50 connected to the third wall 44 . The first flow channel 19 has an opening along its length. A second flow channel 22 is formed by the third wall 44 connected to the fourth wall 46 , the fourth wall 46 connected to the fifth wall 48 , the fifth wall 48 connected to the sixth wall 50 , the sixth wall 50 connected to the third wall 44 . Preferably, the fifth wall 48 has a plurality of openings 52 to allow water to enter the second flow channel 22 . The fourth wall 46 forms a floor of the first channel 19 and forms a ceiling of the second channel 22 . The first wall has a free end along the length of the first wall.
[0056] As shown in FIG. 3 , the frame 16 of the water drainage device 10 has tabs on the free end of the sixth wall 50 for interconnected with openings 54 in the third wall 44 .
[0057] The first 40 , third 44 and fifth 48 walls are generally perpendicular to the second 42 , fourth 46 , and sixth 50 walls. When the water drainage device is implement the first wall 40 will extend past the surface of the basement floor. The second wall 42 will disposed above the sixth wall 50 which will be disposed above the fourth wall 46 . The first wall 40 may have a plurality of wall spacers 56 to space the free end of the first wall from the basement wall.
[0058] The second flow channel 22 is preferably rectangular and is disposed at a lower portion of the frame 16 . The first wall 40 may have a plurality of wall spacers 56 to space the free end of the first wall from the basement wall.
[0059] The frame 16 is further provided with a plurality of receiving apertures or openings 54 . The apertures 54 are formed substantially about the third wall 44 and corresponding tabs 58 are situated on the free end of the sixth wall 50 . As illustrated in FIG. 3 , the apertures 54 are spaced apart at longitudinal intervals.
[0060] The frame 16 is further provided with a plurality of apertures 52 . The apertures are formed substantially in the fifth and sixth walls. As is best illustrated in FIG. 3 , the apertures 52 are spaced apart at longitudinal intervals. In one embodiment, the apertures 52 are generally elongated and rectangular. As will become apparent, the generally lower portions of the apertures 52 (formed in the fifth wall 48 ) function to direct water external of the frame 16 into the lower flow channel 22 . As will be described below, the upper or generally horizontal portion of the apertures 52 (formed in the sixth wall 50 ) allows for fluid communication between the lower flow channel 22 and the upper flow channel 19 .
[0061] FIG. 3 also illustrates the sixth wall 50 being connected to the third wall 44 . Specifically, the sixth wall is provided with tabs 58 that mate with matching tab holes 54 provided in the third wall 44 . Accordingly, in this preferred embodiment, the sixth wall separates the lower flow channel 22 from an upper flow channel 19 compartment (as is shown in FIG. 2 ).
[0062] Turning now to FIGS. 5 and 6 , the filter element 20 has a frame 60 and a filter material 62 disposed about said filter frame 60 . In a preferred embodiment, the filter element 20 is disposed within the first channel 19 . The filter element 20 may have any size or shape such that it provides filter of sediments or other debris, thereby allowing the flow of water within the filter element 20 . In a sense, the filter element 20 provides a filter flow channel, or multiple flow channels depending on the construction of the filter element. The filter element 20 is adapted to provide filtering into the first flow channel. It is contemplated that to increase the filter capacity, that a second filter element may be contained within the second flow channel 22 .
[0063] The water drainage device 10 preferably includes a filter element 20 situated in the first flow channel 19 compartment. In the preferred embodiment, the filter element 20 is comprised of a sheet of plastic comprising a frame 60 that is shaped with a plurality of cones spaced on the upper surface of the element and has a covering of foam filter material 62 . The configuration of the foam on the filter element 20 creates spaces between the cones and provides the spacing for the flow of water (which would be filtered).
[0064] Various lengths of the water drainage device may be used for installation. A separate corner section may also be fabricated which for installation in the corner of a wall. The corner section allows for coupling of the straight sections of the water drainage device.
[0065] It will become apparent to one skilled in the art upon viewing the figures and reading the accompanying description that the filter frame 60 may take on a variety of suitable functional configurations. Each of these variations and/or configurations are within the scope of the invention. For example, in one embodiment, the walls of the frame 60 may define substantially each of the first and second flow channels, and, as necessary, further additional flow channels. In another embodiment, the supporting wall is replaced by other means for supporting the filtering element 20 . In this embodiment, the bottom of the filter element provides the only separation between the first and second flow channels. As a further example, the filter element 20 may be defined by a rigid filter material only.
[0066] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein. Without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
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The invention relates to a system, apparatus and method for controlling and/or expelling water from basements or other subterranean rooms. More particularly, the invention relates to a water drainage device that includes a multiple flow channels to allow water to bypass a clogged area of a flow channel. Preferably, one the flow channels is filtered to impede the build of particulate matter and sediment in the channel.
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This application is a continuation of U.S. application Ser. No. 14/819,385 filed Aug. 5, 2015; now U.S. Pat. No. 9,486,476 issued Nov. 8, 2016; the entired contents of which are incorporated by reference herein. This application also claims the priority benefit under 35 U.S.C. section 119 of U.S. Provisional Patent Application Nos. 62/033,416 entitled “Fast Acting Joint Relief Formulations” filed on Aug. 5, 2014; and 62/033,565 entitled “Fast Acting Joint Relief Formulations” filed Aug. 5, 2014, which are in their entirety herein incorporated by reference.
FIELD OF INVENTION
This invention relates to methods and compositions for the prevention and treatment of osteoarthritis in a mammal. More particularly, the present invention relates to compositions and methods for reducing inflammation and pain associated with acute inflammation of body parts, particularly joints, due to injury or due to arthritic conditions or other disease conditions.
The present invention relates generally to compositions and methods for treating joints. This invention also relates to a mixture of natural ingredients for the treatment of bone or joint inflammation. The instant invention is also generally related to chemical formulations and methods for administration of a natural chemical formulation to mammals and, more particularly, is related to natural chemical formulations directed towards reducing muscle and joint soreness and methods of administration thereof. The present invention also relates to pharmaceutical preparations for the treatment of degenerative afflictions of the joints.
The present invention is generally further directed to compositions useful for the treatment and/or prevention of damage to diarthrodial (synovial) joints and, in particular traumatic synovitis, inflammation of the synovial membrane, and damage to the articular cartilage of the joint. Specifically, the invention relates to compositions specially formulated for oral administration in the treatment and/or prevention of traumatic synovitis and damage to articular cartilage, e.g., for post surgical joint lavage or treatment and/or prevention of inflammatory arthritis, osteoarthritis (OA) and/or degenerative joint disease (DJD).
The instant invention also relates generally to the treatment of cartilage disorders, including stimulation of cartilage repair and treatment of degenerative cartilagenous disorders. The present invention also concerns compositions and methods of treating arthritis, repairing of articular joint surfaces and relief of symptoms associated with arthritis.
This invention also relates to compositions having natural components. More particularly, this invention relates to a natural composition capable of reducing inflammation in bones and joints. The present invention further relates to methods of using such natural compositions to reduce inflammation.
The instant invention also relates to a method for treating diseases characterized by connective tissue destruction and, more specifically, to a method for treating articular diseases, characterized by destruction of collagen which is a major constituent of connective tissues. The present invention further relates to therapeutic compositions for the repair of connective tissue in mammals and, in particular to “nutraceutical” compositions capable of promoting chondroprotection, the repair and replacement of mammalian connective tissue.
The present invention is also directed to formulations, and methods using such formulations, that when administered to an animal, arrest the inflammatory response in affected tissues and facilitate repair and maintenance of damaged tissues in the joints of vertebrates.
Considering the complexity of symptoms related to different kinds of arthritis and inflammatory disease, there is still a need for compositions which include analgesic and anti-inflammatory components, as well as components to protect against the abrasion of connective tissue and to support its production. Considering different side effects of current treatments, also a need for compositions remains to avoid side effects like dyspepsia, ulcer and gastrointestinal bleeding and designed for both, short-term and long-term treatment.
BACKGROUND OF THE INVENTION
In healthy conditions, articular cartilage forms a smooth surface between articulating bone ends to reduce the friction caused by movement. This friction is further reduced by the synovial fluid. Articular cartilage consists of chondrocytes and two major macro-molecules; i.e., collagen and proteoglycans, which are synthesized by and deposited around the chondrocytes. The chondrocytes also synthesize the synovial fluid which bathes the articular cartilage.
The structural integrity of the articular cartilage is the foundation of optimal functioning of the skeletal joints in the hip, shoulders, elbows, hocks and stifles. Impaired function of skeletal joints will dramatically reduce mobility such as rising from sitting position or climbing and descending stairs. To maintain the structural integrity and the proper functioning of the articular cartilage, the chondrocytes constantly synthesize collagen and proteoglycans, the major components of the articular cartilage, as well as the friction-reducing synovial fluid. This constant synthesis of the macro-molecules and synovial fluid provides the articular cartilage with the repairing mechanism for most of the wearing caused by friction between the bone ends. However, it also leads to the constant demand for the supply of precursors, or building blocks, for the macromolecules and synovial fluid. Lack of this precursors will lead to defects in the structure and function of the skeletal joints. This deficiency occurs often when activity levels are very high, or cartilage tissue has been traumatized.
Degradation of the structures in articular cartilage is a typical characteristic of all diseases resulting in chronic destruction of the joint structures. Examples of such disorders are rheumatoid arthritis, psoriatic arthritis, and osteoarthrosis. Also, acute inflammation of a joint is often accompanied by destruction of the cartilage, although in most cases this will not develop into the chronically destructive disease. It is not known which factors are crucial for the acutely inflamed joint to either proceed to healing or develop into the chronic process. Examples of diseases involving acute joint inflammation are yersinia arthritis, pyrophosphate arthritis, gout arthritis (arthritis urica), septic arthritis and various forms of arthritis of traumatic etiology. Among other factors potentially conducive to the destruction of articular cartilage may be mentioned, for instance, treatment with cortisone; this has been known for a long time to accelerate the degenerative process in osteoarthrosis.
An adequate supply of metabolic precursors or building blocks is thus paramount to replacement and repair of the constituents of skeletal joints, connective tissue and synovial fluid. Proteoglycans (or mucopolysaccharides) form the ground substance of cartilage, bone and joint fluid. Proteoglycans are comprised of proteins linked to glycosaminoglycans (GAGS). The building block GAG subunit of the proteoglycan in cartilage and bone is chondroitin sulfate. Chondroitin sulfate A is present in cornea and cartilage. Chondroitin sulfate B (G-heparin) is found in tendon, aorta, skin and heart valves. Chondroitin C is found in cartilage, tendon and umbilical cord and similar tissues. The building block GAG subunit of the proteoglycan in joint fluid is hyaluronic acid. Intercellular solutions of hyaluronic acid are viscous and thus assist in lubrication of the joints of body skeleton. Hyaluronic acid is synthesized from the metabolic precursor, glucosamine. The availability of glucosamine in cartilage tissue can be rate-limiting to the enzymatic step leading to the production of proteoglycans. Exogenous glucosamine serves to drive the biosynthetic pathway forward past the rate-limiting blockage point. Glucosamine serves as a substrate for a kinase enzyme which yields glucosamine-6-phosphate, the rate-limiting precursor in proteoglycan synthesis.
Recently, studies have reported the suppression of autoimmune disorders such as rheumatoid arthritis upon ingestion of cartilage fibers derived from chickens and sharks. The therapy, termed oral tolerization, is not fully understood but it is theorized that a mechanism in the digestive tract disarms immune cells that would otherwise assault food molecules as foreign intruders to the body, akin to foreign substances that enter the blood stream by means other than the gastrointestinal tract. Apparently, the immune-disarming effect occurs not only in the gut, but also in the vulnerable tissues.
Also, it is well known that articular cartilage is composed of about 70% of water, chondrocytes and a cartilage matrix. The major components constituting the articular matrix are collagen and proteoglycan; the proteoglycan having good water retention characteristics is contained in the network of collagen having a reticulated structure. The articular matrix is rich in viscoelasticity and has an important role in reducing the stimulus and load imposed on the cartilage in order to maintain the normal morphology and function of the articular cartilage.
Osteoarthritis and rheumatoid arthritis are representative of the diseases accompanied by the destruction of the cartilage matrix. It is thought that the destruction of the matrix in these diseases is triggered by mechanical stresses with aging in the case of osteoarthritis and by excess proliferation of the surface layer cells of the synovial membrane, pannus formation and inflammatory cell infiltration in the case of rheumatoid arthritis, and both phenomena are caused through the induction of proteases. Since the degradation of articular cartilage is progressed in the extracellular region at a neutral pH, it is said that a matrix metalloprotease (hereinafter referred to as “MMP” or “MMPs” when used as the general term) whose optimal pH is in the neutral range plays a leading role in the degradation.
Numerous disclosures describe therapy of damaged tissues by introduction of precursors in the metabolic pathway leading to biosynthesis of the macromolecules of connective tissues. For example, in U.S. Pat. No. 3,697,652 (Rovati et al.), N-acetylglucosamine is used to treat degenerative afflictions of the joints. In U.S. Pat. No. 3,683,076 (Rovati et al.), glucosamine salts are described as pharmaceutically useful for treatment of osteoarthritis and rheumatoid arthritis. U.S. Pat. No. 4,647,453 (Meisner) and U.S. Pat. No. 4,772,591 (Meisner) disclose the use of glucosamine salts for treatment of degenerative inflammatory disease and as a means of accelerating wound healing. In U.S. Pat. No. 4,801,619 (Lindblad), a hyaluronic acid preparation is claimed to be effective for treatment of steroid arthropathy and progressive cartilage degeneration caused by proteoglycan degradation. A combination of glucosamine, chondroitin and manganese is claimed in U.S. Pat. No. 5,364,845 (Henderson) as a means of protecting and repair of connective tissue. None of these prior investigators, however, disclose a composition having metabolic precursors, herbal phytochemicals and palatability agents that work synergistically to prevent and treat joint and connective tissue disorders.
No medical cure exists for osteoarthritis. The progressive degeneration of the joint due to osteoarthritis is irreversible. Present therapies are directed to palliative medical therapies to reduce inflammation and pain and surgical therapies to reconstruct an affected joint or, in severe cases, to replace the joint with an artificial, prosthetic joint.
A need exists for an effective palliative medication for the treatment of osteoarthritis and other joint diseases which is both safe and effective when used for both short-term and long-term therapy and which can be administered orally.
SUMMARY OF THE INVENTION
The invention provides a composition for the treatment of arthritis, joint stiffness, joint mobility and joint pain in vertebrates, comprising: effective amounts of a source of boswellic acid and effective amounts of Angelica root extract.
The present invention relates to prophylaxis and therapy of joint disorders in vertebrates accomplished by oral administration of a combination of natural physiological compounds and herbal phytochemicals. Arthritic disorders, including rheumatism, osteoarthritis, dysplasia, lupus, bursitis and gout, are all characterized by inflammation and pain in joints, muscles and related connective tissues. Most of the forms are progressive. The present inventors disclose for the first time herein a beneficial effect of the natural physiological compounds and herbal phytochemicals for treatment of joint disorders in vertebrates.
The present invention is directed to a composition capable of eliminating or diminishing inflammation and in accelerating the tissue repair process. Even though prior investigators used anti-inflammatory substances, their compositions did not provide a complete array of necessary repair and maintenance precursor building blocks along with anti-inflammatory substances. Furthermore, the anti-inflammatory substances utilized by prior investigators are not comprised of natural herbal phytochemicals. In fact, it is known that some substances which exhibit anti-inflammatory responses, such as glucosamine, do not exert general activity. Instead, the response may be mediator specific. Thus, one aspect of the present invention relates to the provision of multiple anti-inflammatory herbal phytochemicals that have more general reactivity and, hence, are more efficacious in a broader population.
The present invention provides a method for treating or preventing osteoarthritis, joint effusion, joint inflammation and pain, synovitis, lameness, post operative arthroscopic surgery, deterioration of proper joint function, the reduction or inhibition of metabolic activity of chondrocytes, the activity of enzymes that degrade cartilage, the reduction or inhibition of the production of hyaluronic acid, said method comprising orally administering to a mammalian species a therapeutically effective amount of natural physiological compounds and herbal phytochemicals.
The invention is also directed to a Chondroprotective/Restorative composition comprising natural physiological compounds and herbal phytochemicals and optionally a pharmaceutically acceptable carrier.
DETAILED DESCRIPTION OF INVENTION
The invention provides a composition comprising effective amounts of Boswellia Serrata , effective amounts of freeze dried green lipped mussle, effective amounts of white willow bark extract containing salicin, effective amounts of glucosamine and salts thereof, effective amounts of chondroitin and salts thereof and effective amounts of omega 3 fatty acids.
The invention also provides a composition comprising effective amounts of Boswellia Serrata , effective amounts of freeze dried green lipped mussle, effective amounts of white willow bark extract containing salicin, effective amounts of glucosamine and salts thereof, effective amounts of angelica root extracts and effective amounts of omega 3 fatty acids.
The invention further provides a composition containing 100-1000 mgs of Boswellia serrata , 250-1000 mgs of freeze dried green lipped mussel, 35-500 mgs of white willow bark containing 15% by weight salicin, 100-450 mgs of glucosamine sulfate potassium, 5-20 mgs of angelica root extracts 4:1, 10-40 mgs of omega 3 fatty acids and inert pharmaceutical excipients.
Without wishing to be limiting, the Boswellia gum, gel, resin or extract or dried extract may be derived from the leaves, plant or roots of Boswellia serrata or other species of Boswellia , such as Boswellia sacra or Boswellia carterii . In a preferred embodiment, the composition comprises about 10% to 99% boswellic acids (e.g. as measured by UV-VIS spectrometry analysis, HPLC diode array or the like).
In an embodiment, the Boswellia gum, gel, resin or extract or dried extract is derived from the leaves, plant or roots of Boswellia serrata , or other species of Boswellia such as Boswellia sacra , Boswellia carterii , and contains between about 10% and 99% boswellic acids, for example but not limited to about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 99% or any value therein between. The amount of boswellic acids may also be defined by a range of any two of the values listed above or any value therein between, and can be measured, for instance, by UV-VIS spectrometry analysis, HPLC diode array or other non-limiting method. More preferably the Boswellia gum, gel, resin or extract contains between about 50% to 79% boswellic acids.
By way of non-limiting example, boswellia serrata is a source of boswellic acid, which may provide relief from pain and inflammation. Other sources of boswellic acid may include for example, extracts of: Boswellia bhau - dajiana, Boswellia frereana, Boswellia papyrifera, Sudanese Boswellia sacra , and Boswellia carterii, Commiphora incisa, Commiphora myrrha, Commiphora abyssinica, Commiphora erthraea, Commiphora molmol , and Bursera microphylla , may be used as a substitute for or in conjunction with boswellia serrata.
The preferred mussel extract used in the present invention is an extract or freeze dried powder of the New-Zealand green-lipped mussel ( Perna canaliculus ) and contains substances having a beneficial anti-inflammatory effect. The preparation of the Mussel extract is described in the New Zealand patent application No. 328489, which relates to an anti-inflammatory composition including a freeze-dried substance containing proteins. The product containing the substance extracted from green-lipped mussel possesses chondroprotective, gastro protective and anti-inflammatory activity and is beneficial to sufferers of many of the arthritic disorders. A typical composition is a green-lipped mussel extract containing by weight 0.65-3.21% of moisture, 0.67-10.54% of lipids, 52.13-55.6% of carbohydrates and 11.7-14.9% of ash. This is a very suitable extract for the present invention. A suitable green lipped mussel powder is sold as Biolane in the market place.
The willow bark or salicis cortex of the invention consists of the bark of the young, 2-3-year-old branches harvested during early spring of Salix alba L, S. purp[upsilon]res L, S. fragilis L. and other comparable Salix species (Salicaceae), as well as their preparations in effective dosage. The bark contains at least 2 percent total salicin derivates, calculated as salicin and related to dried herb. Antipyretic, analgesic and antiphlogistic effects are described for the willow bark. Administration of Willow Bark leads to positive effects in non-human animals suffering from arthritis. Positive effects are recognized in the symptoms that accompany this disease, i.e. fever, rheumatic ailments and headaches. For Willow Bark the same is true as for the other substances characterized herein, namely that much better results are obtained after the administration of a combination of products rather than by applying only one component. A preferred willow bark component contains 15% salicin.
The pharmaceutically effective salts of glucosamine used in the invention are selected from the group consisting of glucosamine chloride, glucosamine bromide, glucosamine iodide and glucosamine sulfate. Similarly, with chondroitin the same type of salts are usable i.e., chondroitin chloride, chondroitin bromide, chondroitin sulfate and chondroitin iodide.
The Angelica root powder of the invention may be derived from Angelica archangelica, Angelica sinensis, Angelica sylvestris, Angelica officinalis, archangel, European angelica, garden Angelica, Angelica acutiloba, Angelica pubescens. Angelica root is preferred, but other parts of the plants can be used as well. Angelica contains a wide and complex variety of different constituents, of a defined and undefined nature. Preferred bioactive compounds are flavinoids, flavones and coumarins, preferably, osthole or 7-methoxy-8-(3-methylpent-2-enyl)coumarin, and alpha-angelicalactone. Other coumarins, include, e.g., meranzin hydrate, nodakentin, marmesinin, columbianadin, columbianetin, bergapten, heramandiol, 6-alkylcoumarins, angelol-type coumarins, byak-angelicin, ferulin, oxypeucedanin, umbelliprenin, imperatorin, neobyakangelicin, prenylcourmarins, glabralactone, anpubesol, angelical, angelin, furanocourmins, and derivatives thereof. Other bioactive agents include, e.g., linoleic acid, osthenol, falcarindiol, numerous flavinoids and flavones, 11(S), 16(R)-dihydroxyoctadeca-9Z, 17-diene-12,14-diyn-1-yl-acetate, xanthotoxin, umbelliferone, ferulic acid, magnesium, and derivatives thereof.
Angelica possesses a number of pharmacological activities, including, but not limited to smooth muscle relaxant activity, phosphodiesterase inhibition, calcium antagonist activity, cycloxygenase and 5-lipoxygenase inhibition, etc. Coumarins, and osthole in particular, have been identified to display activities such as, inhibition of platelet aggregation, inhibition of smooth muscle contraction, smooth muscle relaxation inhibition of calcium flux, cyclic nucleotide (such as cGMP and cAMP) phosphodiesterase inhibition, increase in cAMP and cGMP levels, anti-proliferative, anti-inflammatory, enhancement of the increase of cAMP and cGMP induced by forskolin, vasorelaxation, neurotransmitter receptor binding, such as GABA, 5HT-1A, D-2, and D-1 receptors. Alpha-angelicalactone also possesses various activities, including, e.g., calcium antagonism. Ferulic acid, another component of Angelica root also has been shown to scavenge oxygen free radicals and increase intracellular cAMP and cGMP. Preferred activities of Angelica are cyclic nucleotide phosphodiesterase inhibition, calcium antagonism, oxygen free radical scavenging, smooth muscle modulation, as either vasorelaxant or vasodilatory.
In making the compositions of the invention, the active materials will usually be mixed with a carrier, or diluted by a carrier, or enclosed within a carrier which may be in the form of a capsule, sachet, paper or other container. When the carrier serves as a diluent, it may be solid, semi-solid or liquid material which acts as a vehicle, excipient or medium for the active ingredient. Thus, the compositions can be in the form of tablets, pills, powders, lozenges, sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups, aerosols (as a solid or in a liquid medium), ointments containing for example up to 10% by weight of the active compound, soft and hard gelatin capsules, suppositories, sterile injectable solutions and sterile packaged powders.
Some examples of suitable carriers, excipients, and diluents include lactose, dextrose, sucrose, sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates, tragacanth, gelatin, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrup, methylcelluse, methyl and propylhydroxybenzoates, talc, magnesium stearate and mineral oil. The formulations can additionally include lubricating agents wetting agents, emulsifying and suspending agents, preserving agents, sweetening agents or flavoring agents. The compositions may be formulated so as to provide rapid, sustained or delayed release of the active ingredient after administration to the patient by employing procedures well-know in the art.
Further orally administrable compositions include hard capsules consisting of gelatine, and also soft, sealed capsules consisting of gelatine and a plasticizer, such as glycerol or sorbitol. The hard capsules may contain the active ingredients in the form of granules, for example in admixture with fillers, such as lactose, binders, such as starches, and/or glidants, such as talc or magnesium stearate, and where appropriate stabilizers. In soft capsules, the active ingredients are preferably dissolved or suspended in suitable liquids, such as fatty oils, paraffin oil, or liquid polyethylene glycols, and stabilizers may likewise be added. Amongst other forms, capsules, which can be both easily, chewed and also swallowed whole, are preferred.
The compositions of the invention can be prepared in a known manner, e.g. for example by means of conventional mixing, granulating, coating, dissolving or lyophilizing methods. Veterinary compositions for oral administration can be obtained, for example, by combining the active ingredients with solid carriers, granulating a resulting mixture where appropriate, and processing the mixture or granules, if desired or necessary, to form tablets or tablet cores following the addition of suitable excipients.
The active ingredients of the invention are used in these compositions in standardized solid form and preferably together with—at least—one of the adjuvants conventionally employed in the art of formulation, such as extenders, e.g. solvents or solid carriers, or surface-active compounds (surfactants). For usage in non-human animals, such as domestic animals, livestock, and pets of course only physiologically acceptable adjuvants are used.
One further embodiment of the present invention is a unique formulation that combines effective amounts of Boswellia Serrata , effective amounts of freeze dried green lipped mussle, effective amounts of white willow bark extract containing salicin, effective amounts of glucosamine and salts thereof, effective amounts of chondroitin and slats thereof and effective amounts of omega 3 fatty acids for direct oral administration.
In another preferred embodiment, a dosage for the composition for oral treatment of the present invention may consist of one or more capsules or tablets for mammal oral consumption. The dosage ranges defined herein before are meant per 1 Kg bodyweight per day. This dosage may be administered in a single daily dosage form in which all components are present. Alternatively, the nutritional supplement compositions for the present invention may be administered more than once, preferably twice, per day. The number of daily administrations will depend upon the needs of the mammal recipient. Different connective tissue disorders and injuries may require different amounts of the compositions of the present invention. In those regards, several dosages may be administered depending on the particular needs of the mammal.
This is the only product available which combines the above substances which are important for joint relief, cartilage metabolism and production of synovial fluid. Conditions in which embodiments of the present invention would be beneficial:
1) Osteoarthritis
2) Joint effusion
3) Joint inflammation and pain
4) Post operative arthroscopic surgery
5) Restoring proper joint function
6) Promote metabolic activity of chondrocytes (cartilage producing cells)
7) Inhibit enzymes that degrade cartilage
8) Stimulate the production of Hyaluronic acid.
The product of the invention provides clinical responses in about 3 to 10 days.
The present invention is illustrated by the following Examples, but should not be construed to be limited thereto. In the Examples, “part” and “%” are all part by weight or % by weight unless specified otherwise.
EXAMPLE 1
COMPONENTS
AMOUNT mg
Boswellia Serrata 65%
167.50
Biolane Green Lipped Mussel
250.00
White Willow Bark Extract 15% Salic
200.00
MEG 3 18/12 EPA/DHA Powder
10.00
Glucosamine Sulfate Potassium
150.00
Chondroitin Sulfate Sodium 85%
55.00
Silica-Sipernat
1
Magnesium stearate
0.5
The above composition is filled into a hard gelatin capsule.
EXAMPLE 2
COMPONENTS
AMOUNT mg
Boswellia Serrata 65%
177.50
Biolane Green Lipped Mussel
225.00
White Willow Bark Extract 15% Salic
250.00
MEG 3 18/12 EPA/DHA Powder
15.00
Glucosamine Sulfate Potassium
175.00
Chondroitin Sulfate Sodium 85%
75.00
Silica-Sipernat
1
Magnesium stearate
0.5
The above composition is filled into a hard gelatin capsule.
EXAMPLE 3
COMPONENTS AMOUNT mg Boswellia Serrata 65% 177.50 Biolane Green Lipped Mussel 225.00 White Willow Bark Extract 15% Salic 250.00 MEG 3 18/12 EPA/DHA Powder 15.00 Glucosamine Sulfate Potassium 175.00 Chondroitin Sulfate Sodium 85% 75.00 Silica-Sipernat 1 Magnesium stearate 0.5
The above composition is filled into a hard gelatin capsule.
EXAMPLE 4
COMPONENTS AMOUNT mg Boswellia Serrata 65% 166.50 Biolane Green Lipped Mussel 175.00 White Willow Bark Extract 15% Salic 38.50 MEG 3 18/12 EPA/DHA Powder 50.00 Glucosamine Sulfate Potassium 50.00 Angelica Root Extract 4:1 10.00 Calcium Carbonate 36% granular 4.0 Sipemat-Silica 1.0
The above composition is filled into a hard gelatin capsule.
EXAMPLE 5
COMPONENTS AMOUNT mg Boswellia Serrata 65% 175.50 Biolane Green Lipped Mussel 200.00 White Willow Bark Extract 15% Salic 45.50 MEG 3 18/12 EPA/DHA Powder 75.00 Glucosamine Sulfate Potassium 65.00 Angelica Root Extract 4:1 12.00 Calcium Carbonate 36% granular 4.0 Sipemat-Silica 1.0
The above composition is filled into a hard gelatin capsule.
EXAMPLE 6
COMPONENTS AMOUNT mg Boswellia Serrata 65% 175.50 Angelica Root Extract 4:1 12.00 Calcium Carbonate 36% granular 4.0 Sipemat-Silica 1.0
The above composition is filled into a hard gelatin capsule.
EXAMPLE 7
Study of Anti-Inflammatory Activity in a Model of Formalin-Induced Arthritis in Rats
The model of arthritis in animals is caused by injection of 0.1 ml of 2% formalin solution into the cavity of the knee joint. After 24 hrs a model of acute arthritis is obtained, which is suitable for studying the anti-inflammatory and anaesthetizing action of the preparations. Butadion and diclofenac are used as control preparations. The present agent (3 doses of Example 6) are dissolved in corn oil and administered according to the following regimen: 3 days prior to inflammation one time per day intraperitoneally (by a probe) and on the 4th day 4 hours prior to the injection of formalin. The treatment is conducted over a period of 7 days by administering the investigated preparation one time per day. The evaluation of the results of treatment is conducted on the 4th and 8th day. Anti-inflammatory activity was estimated using the parameters of volume, pain sensitivity and inflammation temperature of the extremity. The total activity index is calculated (total percentages of decrease in size of the affected extremity for 7 days) and the therapeutic index (ratio of the total activity index of the preparation to the total activity index of the group with formalin).
With respect to the anaesthetizing and febrifugal activity the present agent exceeded the effect of butadion at all doses and it is practically not inferior to the effect of diclofenac at a dose of 250 mg/kg.
In the model of formalin arthritis, the talocrural joints of rats and gastric mucosa are also investigated. Histological sections included the zone of the joint with adjacent parts of bone tissue, surrounding soft tissues which are intimately connected to the joint including the adjacent derma, and in a series of observations also epidermis.
During the macroscopic inspection of the joints of the control group rats (formalin-induced arthritis without treatment) an enlargement of the joint and smoothening of its outlines is observed. At the incision periarticular tissues is edematic. A small quantity of unclear liquid occurs in the cavity of the joint. And the articulate surfaces of the cartilages are smooth. During the microscopic examination of the knee joint plethora and edema of periarticular tissues are observed, as well as changes in the synovial membrane, in the fibers of which the plethora, edema and lymphoid infiltration of areolar tissue of fibres are noted.
The joints of rats treated with the present agent do not show any pronounced macroscopic changes. Histologically, the synovial membrane, which lines the surface of the joint, consisted of less differentiated cells of connective tissue with round or oval nuclei. Plethoras or lymphoid infiltrations are not observed.
During the dissection of the experimental rats, the size and the shape of stomach and intestine did not show changes. The mucous membrane of the stomach body is bright, smooth and light pink. The lumen of the small intestine over the whole length was uniform. The mucous membrane of the small intestine is bright, smooth and light pink.
During the histological study of stomach and small intestine no destructive or inflammatory changes in the mucous membranes is noted. The epithelium of the mucous membrane of the small intestine do not show changes either.
All patents, patent applications and publications cited in this application including all cited references in those patents, applications and publications, are hereby incorporated by reference in their entirety for all purposes to the same extent as if each individual patent, patent application or publication were so individually denoted.
While the many embodiments of the invention have been disclosed above and include presently preferred embodiments, many other embodiments and variations are possible within the scope of the present disclosure and in the appended claims that follow. Accordingly, the details of the preferred embodiments and examples provided are not to be construed as limiting.
It is to be understood that the terms used herein are merely descriptive rather than limiting and that various changes, numerous equivalents may be made without departing from the spirit or scope of the claimed invention.
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The instant invention provides a method and composition for treating or preventing osteoarthritis, joint effusion, joint inflammation and pain, synovitis, lameness, post operative arthroscopic surgery, deterioration of proper joint function including joint mobility, the reduction or inhibition of metabolic activity of chondrocytes, the activity of enzymes that degrade cartilage, said method comprising administering effective amounts of Boswellia Serrata , effective amounts of freeze dried green lipped mussle, effective amounts of white willow bark extract containing salicin, effective amounts of angelica root, effective amounts of glucosamine and salts thereof, effective amounts of chondroitin and salts thereof and effective amounts of omega 3 fatty acids.
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The present invention relates to a power supply unit including a blocking oscillator for utilization with a television receiver provided with ultrasonic remote control, and more particularly to a television receiver the operating conditions of which are normal operation, a stand-by operation, and the turned-off condition, and a power supply unit therefor that includes an isolating transformer.
In recent times television receivers have frequently been provided with ultrasonic remote control devices for the purpose of offering easier control. As more and more television receivers are utilized in combination with additional equipment, it becomes increasingly necessary to connect the receivers only indirectly to the electric power mains (house wiring). In a known advantageous solution of this problem, a power supply unit includes an isolating transformer which is wired up with a blocking oscillator in the primary circuit. The blocking oscillator is supplied with a d-c voltage which is obtained by rectification of the supply voltage. Compared to the isolating transformers which are directly mains-operated, these so-called switch-mode power supply units have the advantage that they can be made in considerably smaller size, as they are operated at a significantly higher frequency, and the further advantage that they require less expensive means for rectification.
It is necessary to supply television receivers equipped with ultrasonic remote control with the possibility for a stand-by operation in which only the ultransonic receiver is supplied with power and, in some cases, also the heating current for the picture tube. Usually a separate power supply unit is provided for the ultrasonic receiver and the heating of the picture tube, a unit that includes an isolating transformer of its own, the primary winding of which is directly mains-fed. Upon transition from normal operation to stand-by operation, the power supply unit of the blocking osciallator is switched off, so that the television receiver receives only the relatively small quantity of energy required for the ultrasonic receiver and, in some cases, also for the heating of the picture tube.
Because of the required second isolating transformer, this known circuit has the disadvantages that it requires both greater space and greater expenditure.
It is the object of the present invention to develop a simplified power supply unit which does not have the above-mentioned disadvantages.
SUMMARY OF THE INVENTION
Briefly, the television receiver and the ultrasonic receiver are connected to the same isolating transformer; means for the switching from normal operation to stand-by operation and vice versa are placed in the secondary circuit of the isolating transformer, and means are arranged in the primary circuits of the isolating transformer for reducing the amount of energy made available for stand-by operation purposes.
The main advantages of the present invention are that no separate isolating transformer is required for supplying the current during the stand-by operation, and that, during the stand-by operation, it is nevertheless only the power required for this operation which is consumed.
An advantageous embodiment of the present invention obtains reduction of the energy quantum transmitted through the power supply during stand-by by reduction of the pulse width of the pulses generated by the blocking oscillator.
Another advantageous embodiment of the present invention utilizes measurement in the primary circuit of the isolating transformer of variation in load occurring in the secondary circuit as a control variable for determining the pulse width.
A further advantageous embodiment of the present invention obtains the control variable for the pulse width across a measuring resistor interposed in the connection of the emitter of the switching transistor of the blocking oscillator to the chassis.
Still another advantageous embodiment of the present invention provides that the voltage drop across the measuring resistor controls a controllable resistor.
The advantageous embodiments described above offer highly simple and advantageous possibilities for measuring the variation in load upon switching between normal and stand-by operation, as well as for the consequent control of the energy transmitted via the isolating transformer.
The possibility of a simple and inexpensive switching between normal and stand-by operation is achieved by effecting the switching between normal and stand-by operation by means of switching on or switching off, respectively, the low voltage supply of the line scan oscillator, and, especially, by a first switching transistor which short-circuits the base bias of a second switching transistor at the collector of which a direct current supply voltage is present and at the emitter of which a stabilized low voltage exists, when a positive signal is supplied from the operating control of the television receiver or from the remote control receiver to the base of the first switching transistor.
The circuit arrangements just mentioned offer the advantage that they may simultaneously be utilized as a protective circuit. This is achieved by a switching-off device for the low voltage which can also be triggered at any time by a signal built up by overcurrent in the picture tube.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is further described by way of illustrative example by reference to the annexed drawings in which:
FIG. 1 is a circuit diagram, partly in block form, of an embodiment of the invention;
FIG. 2 is a circuit diagram of one form of means for interrupting the power to the picture circuits in the stand-by condition in connection with the circuit of FIG. 1, and
FIG. 3 is a circuit diagram of one way of controlling the pulse width of the blocking oscillator 4 in response to the switching circuit 8 in the circuit of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An on-off power switch 2 of the television receiver is connected to the supply terminals 1, providing a primary operating control for the receiver. Consquently, the supply voltage is also present at the output of the operating control 2 when the television receiver is turned on thereby, and arrives at a rectifying stage 3 comprising means for rectifying and smoothing the supply current as well as for suppressing interference. A d-c voltage, feeding a blocking oscillator stage 4, is present at the output of the recifying stage 3. The main part of the blocking oscillator 4, symbolically represented in FIG. 1 by a fragmentary circuit diagram, is a switching transistor 5, in the load circuit of which the primary winding of an isolating tranformer 6 is placed. A measuring resistor 7 is connected between the emitter of the switching transistor 5 and the chassis, across which measuring resistor a voltage is taken and applied to a load-dependent control circuit 8. The voltage taken at the measuring resistor 7 is fed via a resistor 9 to the base of a transistor 10 which serves as a controllable load for the blocking oscillator 4. A resistor 11 and a capacitor 12, each of which is connected to chassis with its other terminal, are also connected to the base of the transistor 10. The emitter of transistor 10 is connected to chassis, while the collector of the transistor 10 is connected back to the blocking oscillator stage 4.
In the secondary circuit of the isolating transformer 6, a d-c voltage supply stage or power conversion circuit 13 is placed, substantially consisting of a rectifying circuit 14, which, in the example shown, is provided with six outputs at which the voltages U 1 to U 5 can be taken off with respect to the sixth output connected to the chassis. At the terminal U 3, there is, in addition, a branch feeding both the collector-to-emitter path of the transistor 15 and also, through a resistor 16, the collector-to-emitter path of the transistor 15a. The emitter of the transistor 15a is directly connected to the base of transistor 15. The emitter of the transistor 15 is connected to chassis via a series connection of a resistor 17, a potentiometer 18, and a further resistor 19. The tap of the potentiometer 18 is connected to the base of a further transistor 20. The transistor 20 is connected to chassis by means of its emitter via a Zener diode 21, the collector of the transistor 20 controlling the base of the transistor 15a. The emitter of the transistor 20 is connected to the emitter of the transistor 15 via a resistor 22. A terminal for tapping off the voltage U 3' is connected to the emitter of the transistor 15.
The base of the transistor 15a is connected to a switching stage 23 responsive to a remote control ultrasonic receiver by a conductor leading to the collector of a switching transistor 24 which is connected to chassis via its emitter. The base of the switching transistor 24 is connected to an input terminal 28 leading into the television receiver via two resistors 25, 26 and a capacitor 27 connected in series, that input terminal 28 passing on switching signals from the receiver to the switching transistor 24, as will be explained in more detail below.
The cathode of a diode 29, which is connected to chassis via its anode, is connected to the junction point of the resistor 26 and the capacitor 27. The junction point of the two resistors 25, 26 is connected to chassis via a capacitor 30. The base of the switching transistor 24 is connected to chassis via a resistor 31. Furthermore, that base electrode is also connected to a terminal 32 to which an electrical switching signal is applied which is either built up in response to an ultrasonic signal received by the remote control receiver 32' or is supplied from an operating control of the television receiver. At the terminal 32, the switching transistor 24 receives the signal containing the information whether the television receiver is to work in the normal operating condition, i.e. to receive and process the sound and video signals, or in the stand-by condition in which it is substantially only the ultrasonic receiver that is supplied with current.
When a positive signal arrives at the base of the switching transistor 24, the latter becomes conductive, and causes chassis potential to be present at the base of transistor 15a. The transistor 15 is thereby blocked, and there is no longer any voltage at the terminal U 3'. Since the voltage U 3' serves as an operating voltage for the line and picture scan oscillator, the deflecting stages of the receiver cannot work and no high voltage and other related supply voltages are generated at the line circuit transformer. In consequence, by means illustrated diagrammatically in FIG. 2, the electric circuits connected to the terminals U 1 to U 3 are interrupted. The voltages U 4 and U 5 serve for supplying the ultrasonic receiver, i.e. they are required for the stand-by operation.
In case no counteracting means should be provided for, the variation in load would cause a voltage rise in the secondary circuit of the isolating transformer 6, which effect is, of course, not desired. Therefore, a measuring resistor is connected in the primary circuit in the emitter line of the switching transistor 5 of the blocking oscillator 6, the variation in load in the secondary circuit appearing at the measuring resistor 7 as a current variation. The current change thus produced, causes a variation in the base bias of the transistor 10, the capacitor 12 having an integrating effect to avoid undesired effects due to interference pulses and abrupt load fluctuations.
The change of the working point of the transistor 10 causes a change in the pulse width in the blocking oscillator stage 4, as more fully shown in FIG. 3, so that the energy quantum transmitted via the isolating transformer 6 is such that the required voltages are present in the secondary circuit. It should also be mentioned that the load-dependent switch 8 and the circuit of FIG. 3 are represented only by way of illustration and that many circuit arrangements may be devised by straight-forward application of known principles for controlling the pulse width.
The circuit connected between the terminal 28 and the base of the switching transistor 24 serves as a part of a protective circuit for the picture tube. Any overcurrent is measured at the low-end resistor 31 of the high-voltage cascade in conventional techinque. The voltage thus produced is fed to the base of the switching transistor 24, and causes the television receiver to be switched over to stand-by operation, so that no damage can be done to the picture tube. Thus, the device performing the switching between normal operation and stand-by operation is advantageously and simultaneously utilized as a protective circuit. The circuit 23, as shown, provides for stabilizing the potential at the base of transistor 24 and for integrating such possibly occurring overload peaks as are not intended to triggering the protective circuit.
Using the circuit diagram according to FIG. 3 it is possible in a simple manner to control the pulse width of the blocking oscillator 4 in response to the switching circuit 8.
According to the circuit diagram of FIG. 2 the terminal U1 is connected to a line scan oscillator circuit 40, the terminal U2 to a picture scan oscillator circuit 41 and the terminal U3 to a circuit 42 for a sound output stage. The circuits 40, 41, 42 get their operating voltage from the terminal U3'. If the operating voltage U3' is zero, the circuits 40, 41, 42 are interrupted. In this case the voltages at the terminals U1, U2, U3 remain.
The described circuit of this invention for controlling the voltage in the secondary circuit of the isolating transformer 6 offers the advantage that it is exclusively arranged in the primary circuit, and, therefore, permits an uncomplicated design which is easy to realize. To control the pulse width by measuring the load fluctuations at the low-end resistor of the switching transistor 5, represents a very useful means for control since, thereby the transmitted energy can effectively and easily be controlled.
The blocking oscillator stage 4 shown in detail in FIG. 3 incorporates an externally triggered blocking oscillator arranged to be triggered through an oscillator operating preferably at the line scanning frequency, which is to say its wave form is not particularly critical and it should be provided with means to keep it in step with the line scanning frequency, as is known to be desirable. The transistors 51 and 52 of the triggered output stage of the blocking oscillator circuit could be regarded as constituting a differential amplifier the inputs of which are defined by the base connections of the respective transistors 51 and 52. The input voltage applied to the base connection of transistor 52 is the Zener voltage of the Zener diode 53, thus a constant reference voltage. The operating voltage for the transistors 51 and 52 and for the Zener diode 53 is obtained from the supply voltage U B , which is to say from the rectifier 3. The diode 67 protects the transistor 52, for example at the time of the apparatus being switched on, against damage from an excessively high emitter-base blocking voltage. The capacitor 65 prevents undesired oscillation of the circuit of transistors 51 and 52, which could give rise to undesired disturbances.
At the base of the transistor 51, there is present as input voltage for the circuit a composite voltage that is the sum of three voltages. These are, first, the line scan frequency trigger voltage coupled through the capacitor 63; second, a bias voltage dependent upon the loading of the blocking oscillator stage resulting from the load on the secondary of the transformer 6, but detected by the voltage across the resistor 7 and actually controlled by the load-sensitive control circuit 8, and, third, a regulating voltage applied at the terminal 71 of the resistor 70, which regulating voltage is proportional to the voltage of the secondary winding of the transformer 6 and can accordingly be provided by one or another of the output circuits of the rectifier 14 of FIG. 1 or by a separate winding of the transformer 6 and a separate rectifier element connected in circuit therewith. This regulating voltage and the control voltage provided by the control circuit 8 are applied to the resistor 61 which completes the circuit for both of these bias voltages and their combined effect constitutes the bias voltage for the transistor 51 which determines its working point.
The circuit of the transistors 51 and 52 operates as an overdriven differential amplifier. When the trigger voltage exceeds the threshold determined by the base voltage of the transistor 51, the circuit produces an approximately rectangular output voltage pulse of constant amplitude. Since the trigger voltage is recurrent, the result is a periodic succession of rectangular output voltage pulses, but the duration or pulse width of these pulses depends upon the loading and the output voltage of the stage. The output voltage of the circuit constituted by the transistors 51 and 52 comes from the emitter connection of the transistor 52 and is furnished to the switching transistor 5, preferably through a driver stage 54, such as a transformer or another transistor stage for better matching of the circuit impedances. Of course, the collector circuit of the transistor 5 includes the primary winding of the transformer 6 of FIG. 1.
The described power supply unit thus represents a well functioning component subject to but a small number of potential sources of error, due to the simple design, and permits considerable reduction of costs in comparison with circuits and equipment heretofore known.
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A single isolation transformer supplies both the remote control receiver and the television receiver. A pulse generator such as a blocking oscillator which energizes the primary winding of the isolation transformer has its pulse width controlled in response to the loading of the circuit of the secondary winding of the isolation transformer, as measured by the voltage across a resistor in the circuit of a primary winding. This measuring resistor is interposed between the emitter of the switching transistor of the blocking oscillator and the receiver chassis. A transistor switching circuit for cutting off the low voltage supply to the scanning circuit oscillators of the television receiver is responsive to the output of the remote control receiver, to a signal from an operating control of the television receiver, and to an indication of overcurrent in the picture tube, independently.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a process for enhanced oil recovery from subterranean liquid hydrocarbon or oil wells which usually have undergone primary liquid hydrocarbon (oil) removal and are pressure depleted. In particular the present invention relates to the injection of highly compressed cooled exhaust gas from an internal combustion engine into an injection well in a gas bearing strata so as to be directed downwardly to solubilize and drive the liquid hydrocarbons from an oil bearing strata to a separate production well. Also the present invention relates to the recycling of the exhaust gas removed from the production well with the oil into the injection well.
(2) Description of Related Art
A general discussion of enhanced oil recovery (EOR) is set forth in Kirk-Othmer Edition 17 168-174 (1982). The goal of EOR is to extract oil which is trapped in the sedimentary rock of the subterranean reservoir. The rock can be sandstone or carbonates, such as dolomite. Commonly, gases are used as a solvent and/or as a driving fluid. Carbon dioxide is usually used as the oil miscible, driving gas and nitrogen is an immiscible driving gas.
Prior art literature in enhanced recovery is as follows: Stoesppelwerth, George P., Oil & Gas Journal, 68-69 (Apr. 26, 1993); Shelton, Jack L., et al., Journal of Petroleum Technology, 890-896 (1973); Bardon, C. P., et al., Society of Petroleum Engineers, U.S. Department of Energy, SPE/DOE 14943, 247-253 (1986); Palmer, F. S., et al., Society of Petroleum Engineers (SPE 15497), (1986); Monger, T. G., et al., SPE Reservoir Engineering, 1168-1176 (1988); Haines, H. K., et al., International Technical Meeting, Paper #CIM/SPE (1990); Johnson, H. R., et al., SPE/DOE 20269, pages 933-939 (1990); Monger, T. G., et al., SPE Reservoir Engineering, 25-32 (1991).
Patents which are related are U.S. Pat. No. 3,295,601 to Santourian; U.S. Pat. No. 3,411,583 to Holm et al; U.S. Pat. No. 3,547,199 to Fronina et al; U.S. Pat. No. 3,841,406 to Burnett; U.S. Pat. No. 3,995,693 to Cornelius; U.S. Pat. No. 4,465,136 to Troutman; U.S. Pat. No. 4,509,596 to Emery; U.S. Pat. No. 4,656,249 to Pebdani et al; U.S. Pat. No. 5,381,863 to Weaner; U.S. Pat. No. 5,402,847 to Wilson et al; U.S. Pat. No. 5,065,821 to Hang et al; U.S. Pat. No. 5,413,177 to Horn; U.S. Pat. No. 5,725,054 to Shays et al; and U.S. Pat. No. 5,663,121 to Moody.
The prior art has described the use of exhaust gases from internal combustion engines for increasing hydrocarbon production. Illustrative is a system described by Stoesppelwerth in Oil/Gas Journal, April 1993 and an Internet listing by Energy, Inc. of Tulsa, Okla. In the latter case, a single well is used and a primary purpose is to unplug the openings in the production well. U.S. Pat. No. 4,465,136 to Troutman describes the use of exhaust gas with water flooding around the injection production well. The gas pressure in the reservoir is cycled between about 150-300 pounds/m 2 , which is relatively low, and is referred to as “huff'n-puff”. U.S. Pat. No. 5,381,863 to Wehner the carbon dioxide is initially immiscible in the oil at low pressures during injection and miscible at high pressures during extraction from the well.
U.S. Pat. No. 5,065,821 to Huana et al describes lateral drilling for gas injection. There is no use of any plugs in the wells and the well openings for injection and extraction are at the same level. U.S. Pat. No. 5,725,054 to Shayeai et al descries a method using steps of carbon dioxide injection separate from nitrogen injection.
There is a need for a more reliable method for the production of oil from pressure depleted reservoirs.
OBJECTS
It is therefore an object of the present invention to provide an improved method for enhanced oil recovery from a subterranean well. In particular, the present invention relates to a method which is relatively economical and reliable. Further, it is an object of the present invention to provide a method which is environmentally sound. These and other objects will become increasingly apparent by reference to the following description and the drawings.
SUMMARY OF THE INVENTION
The present invention relates to a method for enhanced recovery of hydrocarbons containing oil from a subterranean hydrocarbon bearing strata comprising the steps of:
(a) providing an exhaust gas from an internal combustion engine, which gas is compressed by a compressor connected to the engine motor, wherein the gas consists essentially of nitrogen and carbon dioxide;
(b) injecting the exhaust gas from the compressor into an injection well and from the injection well into a gas bearing strata which is above the hydrocarbon bearing strata, without injection of the exhaust gas directly into the hydrocarbon bearing strata from the injection well which increases pressure in the oil bearing strata; and
(c) recovering the hydrocarbons and the exhaust gas from a production well in the hydrocarbon bearing strata.
Further the present invention relates to an oil producing well system for enhanced recovery of hydrocarbons including oil from a subterranean bearing strata which comprises:
(a) an injection well for injecting a compressed exhaust gas from an internal combustion engine, which is connected to a compressor for the exhaust gas, into a gas bearing strata which is above the hydrocarbon bearing strata, without injection of the exhaust gas directly into the hydrocarbon bearing strata from injection well;
(b) a production well in spaced relationship to the injection well and extending into the hydrocarbon bearing strata for recovering the exhaust gas and hydrocarbons from the hydrocarbon bearing strata; and
(c) a separation facility above the production well for separating the hydrocarbons from the exhaust gas.
DESCRIPTION OF DRAWINGS
FIGS. 1 to 4 are front partial cross-sectional views of wells 100 , 200 , 300 and 400 for liquid hydrocarbon production. FIG. 1A and 1B are cross-sections along lines 1 A— 1 A and 1 B— 1 B of FIG. 1, respectively.
FIG. 5 is a schematic view of the unit 10 which generates the internal combustion engine exhaust.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention provides a method and system for the enhancement of oil recovery from mature, pressure depleted, subterranean formations via re-pressurization utilizing a gas stream mixture of nitrogen and carbon dioxide produced by an internal combustion engine. The exhaust gas is preferably has reduced acid and corrosion properties by the addition of neutralizing agents and cooled.
The recovery of the oil is from the subterranean formation containing oil, gas and/or water, penetrated by vertical or angled production and injection well bores, through reservoir repressurization. The subterranean formation is initially depleted of its natural pressure drive. Exhaust gases are preferably produced on-site by a mobile internal combustion engine(s), usually fueled by either diesel fuel or propane.
The method comprises the steps of injecting via the injector well bore a stream of an inert gas mixture produced by said internal combustion engines and with the reduced acid and corrosion characteristics prior to the injection. The inert gas is a mixture of nitrogen and carbon dioxide and contains trace amounts of other associated gases; carbon monoxide, hydrogen, oxygen, argon, hydrocarbons and other similar gases. The temperature of the gas at the well head is preferably between about 80° and 150° F. The gas is injected via a compressor into the injection well bore (s) in an amount and under pressures sufficient to establish either miscible, near-miscibility or immiscible conditions.
The injection well alone or with the production well is shut-in for a period of time to allow for reservoir stabilization, produced during the re-pressurization phase or produced immediately upon the completion of the injection phase. The oil is removed through the production well.
Gases produced through production well bore(s) are re-injected into subterranean formation via compressor and the injection well bore until such time as deemed uneconomical by the operator. Additional makeup gas may be used during the course of operation to maintain a desired bottom hole pressure.
FIGS. 1 to 4 show various types of well systems 100 , 200 , 300 or 400 which can be used. Referring to FIG. 1, a strata 500 which has reduced production is injected with the gas from the unit 10 through injection well 101 in a casing 102 . The well 101 is closed with cap 101 A. The injection well 101 leads to the gas section 501 of a strata 500 above the oil section 502 . The casing 102 leads to the bottom of the well, usually just above the water level below the strata 500 . Adjacent to the injection well 101 in the casing 102 is a production well 103 which leads to the oil production section 502 below the gas section 501 . In Michigan, the strata 500 is comprised of dolomite and limestone. The casing 102 is provided with retrievable packings 104 and 105 which are on either side of the gas section 501 . A lateral well 106 for injection the gas into the gas section 501 is provided from the casing 102 above the packing 105 and below the packing 104 . An oil production lateral well 107 is provided below the packing 105 . The well is provided with a cement top 108 (about 500 feet above the strata 500 ). An outer casing 109 shields the ground water and generally extends in Michigan down below the fresh water table. A secondary inner casing 110 extends down to adjacent the formation at the level of the cement top 108 . The annulus 113 between the casing 102 and wells 101 and 103 is optimally filled with fluid to prevent corrosion of the wells 101 and 103 . The production well 103 is connected to a production facility 111 which processes the oil and recycles the exhaust gas extracted through a recycling compressor 112 into the injection well 101 .
In operation the unit 10 generates gas which is injected via well 101 and lateral well 106 into the gas section 501 . This causes pressure in the oil section 502 forcing the oil into production well 103 which is collected in production facility 111 . The gas to the compressor 112 from the facility 111 is recycled into the injection well 101 . The result is better production of oil from the well. The unit 10 may have been returned to a lessor prior to production of the oil, thus reducing the cost of producing the oil.
FIG. 2 is similar to FIG. 1 except that an injection well 201 and production wells 203 are spaced a significant distance from the injection well 201 . Injection well 201 is provided in the casing 202 which can extend only to above the oil section 502 . Packings 204 and 205 are provided in the casing 202 above and between an opening from the well 201 A. A lateral injection well 206 is provided from the casing 202 . The outer casing 209 and inner casing 210 around casing 202 are provided as in FIG. 1 . Well caps 201 A and 203 A are provided to close the wells 201 and 203 . Around the injection well 201 and casing 202 are provided production wells 203 . These cement wells 203 include the packings 205 A and 205 B in the oil section 502 in casing 202 A. Production wells 203 are provided in casings 202 A. A cement cap 208 is provided as in FIG. 1 as are inner and outer casings 209 A and 210 A.
In operation gas from the unit 10 is injected through a lateral well 206 into the gas section 501 . The oil is forced out the production well 203 . The oil is collected in facility 211 and the gas is recompressed by compressor 212 for reintroduction into the injection well 201 .
The wells 301 and 303 in FIG. 3 are identical to FIG. 2 except there are no lateral wells 206 and 207 and instead openings 306 and 307 are included. Included are the following common parts: 301 —injection well; 301 A—well cap; 302 —casing; 303 —production well; 303 A—well cap; 304 —packing; 305 —packing; 308 —cement top; 309 —casing; 309 A—outer casing; 310 —inner casing; 310 A—outer casing; 311 —facility; and 312 —compressor.
This construction is not preferred since there is lower oil production without the lateral wells 206 and 207 .
FIG. 4 schematically represents the most preferred embodiment of the present invention. FIG. 4 shows an injection well 401 in gas section 501 and a production well 403 in the oil bearing strata 502 . The arrows show the direction of fluid flow. The gas generation unit 10 produces the gas which is injected at well cap 401 A. The tank 11 preferably contains propane to fuel the generation unit 10 . The production well 403 is below the gas injection well 401 and lateral drilling is used so that the injected gas is dispensed in the gas section 501 and the oil is collected in the oil section 502 . In any event, the wells 401 and 402 can have multiple openings along the horizontal sections. The oil is removed at well cap 403 A to a separator 416 wherein some exhaust gas is removed and sent to the recycle compressor 412 for injection into well cap 401 A. A heater 413 is used to separate gas, oil and water. Gas is also sent to the compressor 412 . Oil is sent to tank 414 and water to tank 415 .
The separator 416 is standard in the oil industry and is also available from NATCO (Houston, Tex.). The heater 413 is also available from NATCO, for instance. The oil tank 414 is also available from NATCO. The recycle compressor is available from Gas Compressor Services (Traverse City, Mich.) on lease. Preferred is model #JGR/2 from Ariel Compressors (Mount Vernon, Ohio). The gas generation unit 10 is also available on lease from Northland Energy Corporation, Houston, Tex. and is mounted on a wheeled flatbed for over-the-road hauling. The specifications of two available units are shown in Table 1.
TABLE 1
Large Unit
Standard Unit
Configuration
Configuration
Unit Size
Two Tri Axle Trailers,
One 11.5′ by 50′
10′ by 53, each
skid unit
Fuel Trailer
35,000 litres
35,000 litres
Capacity
Discharge
2000 p.s.i. (13,800
1,400 psi (9,600
Pressure
kPa)
kPa)
Flow Rate
2000 s.c.f.m. (57
1,425 s.c.f.m. (41
m 3 /min.)
m 3 /min.)
First Stage
Frick Screw
Fuller-Kovako
Compressor
Rotary vane
compressor 1
Reciprocating
Ariel 2 Four Stage
Gardner Denver 3 WB
Compressor
14, 4 stage, Radial
(Booster)
reciprocating
compressor
Engine (First
Caterpillar 4 3412
Cummins 5 G.T.A. 12
Stage)
(propane)
(propane)
Engine (Booster)
Caterpillar 3412
Cummins G.T.A. 28
(propane)
(propane)
Gen Set Capacity
(2) 80 kVa Continuous
100 kVa Continuous
480 Volt 3 Phase
Oxygen Content of
0.02% or less
0.02% or less
Gas
Oxygen Monitoring
Teledyne 6 Continuous
Teledyne (Model 326
System
Read Out
RA)
Corrosion Rate
Less than 2.0
Less than 2.0
pounds/ft 2 per yr.
pounds/ft 2 per yr.
1 SCS-Screw Compression Systems Catoosa, OK
2 Ariel Compressors Mt. Vernon, OH
3 Gardner Denver Quincy, IL
4 Caterpillar Peoria, IL
5 Cummins Columbus, IN
6 Teledyne Brown Engineering Hunt Valley, MD
As shown in FIG. 5, the gas generation unit 10 of FIGS. 1 to 4 includes a fuel (propane) in a tank 11 which is provided to a motor 12 which produces the exhaust in a conduit 20 A. A catalytic converter 13 from the conduit 20 A leads to a conduit 20 B. A cooler body 14 leads to conduit 20 C. A corrosion inhibitor injector unit 15 leads to conduit 20 D, compressor heads 16 A and 16 B of compressor 16 . A shaft 17 from the motor 12 drives the compressor 16 . The outlet through conduit 20 E from the compressor 16 is fed into the well of FIGS. 1 to 4 . A unit of this type is shown in U.S. Pat. No. 5,663,121 to Moody.
As shown in FIGS. 1 to 4 , the tank 11 provides gas to the gas generation unit 10 and to the recycle compressor 112 , 212 , 312 or 412 . The gas generation unit 10 is only on line during the injection to reduce the cost of the project.
The following is a list of vendors and their related services:
(1) Nitrogen-CO/2 Gas Generation Unit: Northland Energy Corporation, 1115 Goodnight Trail, Houston, Tex. 77060-1112;
(2) Packers: Baker Hughes, Inc. (Houston, Tex.);
(3) Cement/Tools: Halliburton Energy Services (Houston, Tex.);
(4) Weatherford International (Houston, Tex.);
(5) Corrosion Inhibitor: M-1 Drilling Fluids (ConQuor 404; phosphate ester salt (Houston, Tex.);
(6) Corrosion Inhibitor: Magnesia, (use as a weight 10% by volume) Martin Marietta (Hunt Valley, M.d.).
It will be appreciated that over time additional gas can be added through the injection well to maintain the desired pressure. This can be done with the recycle compressor. Also corrosion inhibitors can be added to the injection and/or production well over time to prevent corrosion in the injection well.
It is intended that the foregoing description be only illustrative of the present invention and that the present invention be limited only by the hereinafter appended claims.
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A method and system for tertiary or enhanced oil recovery from a subterranean liquid hydrocarbon or oil wells is described. The method uses packers ( 104, 105, 204, 205, 304, 305, 305 A, 305 B) or angled wells ( 401 ) in order to force the gas down into the oil bearing strata ( 502 ) from a gas containing strata ( 501 ). The result is increased production of oil since the gas is forced downward over a large horizontal area between the gas containing strata and oil bearing strata.
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BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to non-volatile memory, and more particularly, to a non-volatile memory that utilizes extra devices to accelerate transient state transitions, and disables extra load units to maintain the sensitivity of operating margins when reading data.
2. Description of the Prior Art
The growth of the so-called information age has led to the storage of mass quantities of information in digital form. Memory storage devices are thus an important topic of research and develop. Flash memory has become prevalent, allowing the access of data at speeds comparable to those of other forms of electronic memory, while storing digital data in a non-volatile manner without requiring any moving parts. Flash memory has thus become one of the most important types of non-volatile storage devices.
Please refer to FIG. 1, which is a circuit diagram of a prior art flash memory 10 . The flash memory 10 is biased by DC current V dd , and has a plurality of memory units 11 A and 11 B, two on-load isolating units 12 A and 12 B, a sensor unit SA 1 , two p-type MOS transistors Ta 1 and Ta 3 for load units, and a p-type MOS Ta 7 for reference units. In memory units 11 A and 11 B, MOS transistors Ma 1 and Ma 2 have floating gates to store data. The gates of MOS transistors Ma 1 , Ma 2 , TA 1 and TA 2 are controlled by the controlling voltage V ma1 , V ma2 , V d1 and V d2 respectively to determine whether the MOS is on or off. The MOS transistor TA 1 of the memory unit 11 A is also electrically connected to one end of the MOS transistor Ma 1 ; the other end serves as a data end, and is electrically connected with on-load isolating at the node Na 5 . Similarly, an end of MOS transistor TA 2 of the memory 11 B is electrically connected with the node Na 5 , and serves as a data end of the memory unit 11 B. On-load isolating units 12 A and 12 B utilize inverters Iva 1 , Iva 2 and p-type MOS transistors Ta 5 , Ta 6 , respectively. The p-type MOS transistors serve as a loading unit, connecting to provide negative feedback, of which the source electrode is connected to the node Na 1 with the load unit 12 A, and the drain electrode is grounded. The source electrode of the MOS transistor Ta 3 , serving as a third end, connects with the on-load isolating unit 12 B at the node Na 3 , and its drain electrode is grounded. The sensor unit SA 1 is a differential sensing amplifier, comprising a first comparing end N 1 a and a second comparing end N 2 a, which are connected respectively to the nodes Na 1 and Na 3 ; the sensor unit SA 1 compares the first comparing end N 1 a to the second comparing end N 2 a, and then generate a data signal V rp1 . The MOS transistor Ta 7 with a floating gate electrode serves as a reference unit, of which its gate electrode is controlled by the controlling-voltage V ca ; one of the other two electrodes is connected to the power V dd , and the other is connected to the node Na 6 with the on-load isolating unit 12 B.
The principle of operation for storing data into flash memory is to store each bit to one of the memory units that contains transistors with floating gates. Programming a bit into a memory unit, represented by a binary “0” or a binary “1” is performed by injecting differing amounts of electric charge. The floating-gate electrode is injected with a different amount of electric charge, which changes the threshold voltage. Even when under the same condition of voltage bias, the different amount of electric charge in the floating-gate results in a different conductance of the MOS transistor, and thus different amounts of data current. Accordingly, it is possible to read out the data stored in the floating-gates of all the memory units. As shown in the FIG. 1, when the memory 10 is to read the binary data stored in the memory unit 11 A, the memory 10 controls the controlling-voltage V ma1 to bias and turn on the MOS transistor Ma 1 from the gate electrode, and the MOS transistor Ma 1 then generates a data current If 1 . The memory 10 also turns on the MOS transistor TA 1 by a high-voltage level V d1 , so that the data current I f1 can flow through the MOS transistor TA 1 via the node Na 5 . Of course, the MOS transistor TA 2 of the memory unit 11 B is turned off by the controlling-voltage V d2 , which prevents the memory 11 B from outputting data current I f1 to the node Na 5 , and thus prevents interfere when reading the data from the memory unit 11 A. The on-load insolating unit 12 A transmits data current I f1 to the node Na 1 , and injects the current I f1 into the MOS transistor Ta 1 , which is the load unit. With the MOS transistor Ta 1 current-biased by this data current I f1 , the MOS transistor Ta 1 establishes a corresponding voltage at the node Na 1 . When the MOS transistor Ta 1 is turned on, the controlling-voltage V ca turns on the MOS transistor Ta 7 , which also serves as a reference unit, making the MOS transistor Ta 7 generate a reference current I r1 , and injecting the current I r1 into the MOS transistor Ta 3 . Serving as the load unit, after the MOS transistor Ta 3 is biased with this reference current I r1 , the MOS transistor Ta 3 generates a corresponding voltage at the node Na 3 . The sensor unit SA 1 compares the voltage at Na 1 with the voltage at Na 3 through the first comparing end N 1 a and the second comparing end N 2 a, and generate a corresponding data signal V rp1 , which reads out the data in the memory unit 11 A.
The process of reading data is further illustrated in FIG. 2 . Please refer to FIG. 2 and FIG. 3 . FIG. 2 is a graph of voltage versus time at first comparing end N 1 a and the second comparing end N 2 a when the memory 10 is in process of reading data; the X-axis represents time, and the Y-axis represents the voltage; the curves V(N 1 a)H and V (N 1 a)L represent voltage at the first comparing end N 1 a varying with time, whereas the curve V(N 2 a) represents the voltage at the second comparing end N 2 a. Before the timing point ta 0 , the memory 10 has not yet read the data, and the first and the second comparing ends, N 1 a and N 2 a, are charged to high-voltage levels. When the time reaches ta 0 , the MOS transistors Ma 1 and Ta 7 generate current, and pull down the voltages of the first comparing end Na 1 and the second comparing end Na 2 . As mentioned above, differing amounts of electric charge stored in the floating gate of the MOS transistor Ma 1 in the memory unit 11 A results in a different data current I f1 . When the data current I f1 is greater (indicating a lower threshold voltage), the voltage of the first comparing end N 1 a will have the shape of V(N 1 a)H, and eventually falls to a higher steady-state voltage V aH ; on the other hand, when the data current I f2 is smaller, the voltage of the first comparing end N 1 a will follow curve V(N 1 a)L, and eventually falls to a lower steady-state voltage V aL . Similarly, the voltage of the second comparing end N 2 a falls to a steady-state voltage V aR . During the interval between ta 0 and ta 2 , the inverters Iva 1 and Iva 2 in the on-load isolating units 12 A and 12 B respectively and adequately bias the MOS transistors Ta 5 and Ta 6 , which lightens the load-effect occurring at the nodes Na 1 and Na 3 to accelerate the speed at which a steady-state is reached. When the voltages of the two comparing-ends N 1 a, N 2 a have reached their respective steady-state voltages, the sensor-unit SA 1 determines what data is stored in the memory 11 A by detecting the voltage difference between the two comparing ends N 1 a, n 2 a. When the voltage of the first comparing end N 1 a is greater than that of the second comparing end N 2 a, the electric charge stored in the MOS transistor Ma 1 corresponds to a greater data current. The sensor unit SA 1 thus decides if the data stored in the memory unit 11 A is a binary “0” or a binary “1”, and accordingly generates a data signal V rp1 .
It's common to utilize many memory units in an ordinary flash memory, and connect them to the node Na 1 through relatively long metal paths. A large capacitance is consequently formed at the node Na 1 . Decreasing the voltage of the node Na 1 to a steady state merely by way of the data current of a memory unit is quite slow. One drawback of the prior art memory 10 is that the process of reading data is easily affected by transient states, or discharging. As shown in FIG. 2, if the sensor unit SA 1 incorrectly compares the voltages at the timing-point ta 1 , regardless of the data current flowing out of the memory unit 11 A is great or small, the sensor unit SA 1 will erroneously decide that data is stored in the memory unit 11 A, since the voltage of the first comparing end N 1 a is definitely greater than that of the second comparing end N 2 a.
Please refer to FIG. 3, which is circuit diagram of a prior art memory 20 . For the sake of convenience, item numbers marked in FIG. 3 that are the same as those in the FIG. 1 correspond to devices or nodes having the same functionality. The most obvious difference between the memory 20 and the memory 10 is that the memory 20 utilizes an additional equalizing unit 24 . Between the first comparing end N 1 a and the second comparing end N 2 a of the memory 20 there is a p-type MOS transistor Tta, an n-type MOS transistor Ttb and an inverter Ivb 3 . The p-type MOS transistor Tta and the n-type MOS transistor Ttb form a transmission gate, where V eq0 controls the transmission gate with the inverter Ivb 3 . When the transmission gate is on, the nodes Na 1 and Na 3 are shorted, otherwise, they are opened.
Please refer to FIG. 4A, which is a graph of voltage versus time between the first comparing end N 1 a and the second comparing end N 2 a when the memory 20 is reading data. The X-axis of FIG. 4A is time, and the Y-axis is voltage. The curves V (N 1 a)L and V(N 1 a)H show how differing data currents result in different voltages at the first comparing end N 1 a. The curve V(N 2 b) illustrates the voltage of the second comparing end N 2 a. Continuing with the example depicted in FIG. 2, it is also assumed that the memory unit 11 A of the memory 20 provides a data current I f1 . Differing from the memory unit 10 , however, is that at the timing point ta 0 , when the memory 20 controls the memory unit 11 A to generate the data current I f1 and the MOS transistor Ta 7 to generate the data current I r1 , the memory 20 also controls the voltage Veq 0 to turn on the transmission gate in the equalizing unit 24 to short the nodes Na 1 and Na 3 . Therefore, the voltages of the first and the second comparing ends N 1 a and N 2 a are equal, and their voltages changing at the same rate. As shown in FIG. 2, the curves V(N 1 b)H, V(N 1 b)L and V(N 2 b) overlap between the timing points ta 0 and tb 1 . When the timing point tb 1 is reached, the controlling voltage Veq 0 changes to turn off the transmission gate, and the nodes Na 1 and Na 3 are no longer shorted through the equalizing unit 24 ; their reach their respective steady state values. At the time point tb 2 , the sensor unit SA 1 determines the data stored in the memory unit 11 A by the voltage difference between the first and the second comparing end N 1 a and N 2 a. In short, the memory 20 causes the voltages of the first and the second comparing ends N 1 a and N 2 a to be the same by controlling the equalizing unit 24 . This prevents the memory unit 20 from incorrectly determining the data during the transient states.
The sensor unit SA 1 of memory 20 determines the data stored in the memory unit 11 A according to the steady-state-voltages of V aH , V aL and the reference voltage V aR (please refer to FIG. 2 and FIG. 4 A). As the differences between these voltages is greater, the SA 1 is able to determine and read the data more clearly, and the margin for reading the data is increased as well. The steady-state-voltages V aH and V aL are affected by the following factors: inconsistencies in the semiconductor manufacturing process that makes memory units that are not perfectly identical, noise interference when a read operation is in process, and changes to electrical characteristics because of repeated programming and erasing. If these factor are taken into consideration in advance to increase the operating margin by enlarging the voltage difference between V aH , V aL and V aR , then even when the above factors occur and result in voltage-drifting between V aH and V aL during operation of the memory, the memory is still able to correctly read the data. Since the steady-state-voltages V aH and V aL are established by the data current injecting into the MOS transistor Ta 1 (as shown in FIG. 1 and FIG. 3 ), it is possible to change the characteristics of the MOS transistor TA 1 when designing the memory so as to enlarge the voltage difference between V aH and V aL . Generally speaking, if the MOS transistor Ta 1 has a smaller aspect ratio (W/L ratio) under the condition of a fixed data current, then the voltage difference between V aH and V aL will be larger. Please refer to FIG. 4B, which is a graph of current versus voltage between the currents of source and drain electrodes and the voltage across the MOS transistor Ta 1 . If MOS transistor Ta 1 has a smaller aspect ratio, its current-voltage curve is as shown by IV 1 ; if MOS transistor Ta 1 has a larger aspect ratio, its current-voltage curvature is as shown in IV 2 . As mentioned above, the supplied current will be different if the data stored in the memory unit is different. The two currents I f1 (H) and I f1 (L) shown in FIG. 4B illustrate that the memory unit can provide two current levels, and when they are injected into the MOS transistor Ta 1 , they establish two levels of steady-state-voltages V aH and V aL . As shown in the curve IV 1 , if the aspect ratio of the MOS transistor Ta 1 is smaller, the voltage difference DV 1 between the two corresponding steady-state-voltages is larger, as well as the operating margin. On the other hand, as the curve IV 2 illustrates, when the aspect ratio of MOS transistor Ta 1 is lower, the operating margin DV 2 is narrower.
However, it is known in the prior art that decreasing the aspect ratio of the MOS transistor Ta 1 also decreases the current-driving ability the MOS transistor. The period of transient states is thus lengthened. Consequently, the period from when the memory unit begins to supply data current and pulls down the voltage of the first comparing end, to the voltage reaching steady state and thus able to be read data, is increased. This decreases the efficiency data accessing. The prior art memory units 10 and 20 are all undermined by their inability to give consideration to both the operating margins and the reading speed.
SUMMARY OF INVENTION
It is therefore a primary objective of the claimed invention to provide a memory using a two-stage sensing amplifier with an additional load unit to increase the operating margin while maintain a good reading speed, enabling the memory in the claimed invention to read data both quickly and correctly.
In the prior art, to read data in the memory unit, it is required to first establish a voltage by injecting the data current generated from the memory unit into the load unit, and then the sensor unit determines the data condition according to the voltages. In the claimed invention, an enabled and a disabled load unit are added.
During the transient state of reading data from the memory unit, the load unit is enabled to enhance the current-driving ability and decrease the period of the transient state. When the transient state is finished, the load unit is disabled and a smaller aspect ratio load unit is instead used for establishing a final steady-state-voltage to achieve a better operating margin for the claimed invention.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic diagram of a first prior art circuitry.
FIG. 2 is a graph of voltage versus time when the memory of FIG. 1 is reading data.
FIG. 3 is a schematic diagram of a second prior art circuit.
FIG. 4A is a graph of voltage versus time when the memory of FIG. 3 is reading data.
FIG. 4B is a graph of the relationship between the voltage and current of a load unit in FIG. 3 .
FIG. 5 is a schematic diagram of a memory circuit of the present invention.
FIG. 6 is a graph of voltage versus time when the memory showed of FIG. 5 is reading data.
FIG. 7 is a circuit schematic diagram of a sensor unit for an operation in the present invention memory circuit.
FIG. 8 is a circuit schematic diagram of a memory for an operation in the present invention.
DETAILED DESCRIPTION
Please refer to FIG. 5, which is a circuit schematic diagram of a memory 30 in according to the present invention. The memory 30 is DC biased by a voltage V dd , and utilizes a plurality of memory units 31 A and 31 B, on-load isolation units 32 A and 32 B, a MOS transistor Ml as a first load unit, a second load unit 36 A, a sensor unit SA, an equalizing unit 34 , a MOS transistor M 3 as a third load unit, a fourth load unit 36 B and a MOS transistor as a reference unit M 7 . The memory units 31 A and 31 B respectively store data into the MOS transistors Mm 1 and Mm 2 with floating gates.
The MOS transistors MA 1 and MA 2 control data accessing to the memory unit 31 A and 31 B, respectively. The gates of the MOS transistors Mm 1 and Mm 2 are controlled by the voltage biases Vm 1 and Vm 2 , respectively. The gates of the MOS transistors MA 1 and MA 2 are controlled by the voltage biases V A1 and V A2 , respectively. In the memory unit 31 A, the three electrodes of the MOS transistor MA 1 , besides the gate electrode, are connected respectively to the MOS transistor Mm 1 or the outputting data current end of the memory unit 31 A and connected to the node N 5 through the node Nd 1 and the on-load isolating unit 32 A. Similarly, one of the electrodes of the MOS transistor MA 2 connects to the MOS transistor Mm 2 and the other connects to the output end of the memory unit 31 B and the node N 5 through the node Nd 2 . The on-load isolating units 32 A and 32 B respectively control the gate electrodes of the MOS transistor M 5 and M 6 by inverters Iv 1 and Iv 2 . The gate of the MOS transistor M 7 , which serves as the reference unit, is controlled by the controlling voltage V c , and one of the electrodes is connected to the power V dd , and the other serves as a reference end, connecting to the on-load isolating unit 32 B at the node N 6 , to output the reference current I r generated by the MOS transistor M 7 . The sensor unit SA is itself a differential sensor amplifier, having a first comparing end N 1 A and a second comparing unit N 2 c to generate a data signal V r according to the voltage difference between the two comparing ends. The equalizing unit 34 forms a transmission gate with two MOS transistors Mta and Mtb, and controls the transmission gate by a controlling voltage V eq and an inverter Iv 3 . When the transmission gate is on, it shorts the node N 1 to the node N 3 . On the other hand, when the transmission gate in the equalizing unit is off, the node N 1 and the node N 3 are not shorted. The MOS transistor M 1 serves as a first load unit, is diode-connected with two ends, with one of them connected to the sensor unit at the node N 11 and the other connected to ground G. Based on a similar implementation, the MOS transistor M 3 serves as the third load unit, is connected to the sensor unit SA at the node of N 3 on one side, and is grounded on the other side.
The main difference between the present invention and the prior art is that in addition to the first and the third load units in the present invention, a second load unit 36 A and a fourth load unit 36 B are utilized in this invention. The second load unit 36 A comprises MOS transistors Msa and M 2 . The MOS transistor Msa is a switching transistor, and the controlling voltage V eq controls its gate electrode as well. The other two electrodes are connected to the MOS transistor Msa and to the sensor unit SA at the node of N 2 . The MOS transistor M 2 is diode-connected to be a load unit, and its source electrode is connected to the MOS transistor Msa. The fourth load unit 36 B utilizes MOS transistors Msb and M 4 . The MOS transistor Msb serves as a switching transistor, with its gate electrode controlled by the controlling voltage V eq , and the other ends connected to the diode-connected MOS transistor M 4 and to the sensor unit SA at the node N 4 . The MOS transistor M 4 is also a load unit, with its source electrode connected to the MOS transistor Msb. When the switch transistor Msa in the second load unit 36 A is turned on by the controlling voltage V eq , current is injected into the load transistor M 2 through the MOS transistor Msa, and the MOS M 2 establishes a voltage at the node N 2 . The second load unit 36 A is then enabled. If the controlling voltage V eq turns off the switch transistor, the second load unit 36 A is disabled and the node N 2 isn't used for receiving current, and the node N 2 shows a high-impedance characteristic. The operations of the fourth load unit 36 B are similarly decided.
As in the prior art memory, the memory 30 stores electric charge corresponding to digital data in the floating gate. Under the same biases, a data current is different according to the different quantity of electric charge stored in the floating gate. According to the voltage that the data current has established on the load units, the sensor unit SA can read out the data stored in the memory unit. For example, when the memory 30 is about to read the data stored in the memory unit 31 A, the memory 30 turns on the MOS transistors Mm 1 and MA 1 in the memory unit 31 A by the controlling voltages Vm 1 and VA 1 , respectively. The MOS transistor Mm 1 generates a data current I f according to the quantity of electric charge stored in the floating gate, and the current I f is injected into the node N 5 through the turned-on transistor MA 1 . Meanwhile, the memory 30 turns off the MOS transistor MA 2 in the memory unit 31 B by way of the controlling voltage V A2 , so as to prevent interference while accesses the memory unit 31 A.
Please refer to FIG. 6 and FIG. 5 . FIG. 6 is a graph of voltage versus time for the first comparing end N 1 c and the second comparing end N 2 c when a read operation is in process. The X-axis represents the time domain, and the Y-axis represents voltage. The curves V(N 1 c)H and V(N 1 c)L represent the voltage of the first comparing end, and the curve V(N 2 c) represents the voltage of the second comparing end. Before the time point t 0 , when the read process has not yet begun, the first and second comparing ends N 1 c and N 2 c are charged to a high voltage level. At time t 0 , the memory unit 31 A begins to provide a data current I f , and the controlling voltage V c turns on the MOS transistor M 7 to provide a reference current I r . At the same time, the controlling voltage V eq turns on the transmission gate of the equalizing unit 34 , and thus shorts the node N 1 and N 3 . The MOS transistors Msa and Msb are also controlled by the controlling voltage V eq , and so are turned on to enable the second and the fourth on-load isolating units 36 A and 38 B. The controlling current flows into the load transistors M 2 and M 1 , through the load units 32 A and 32 B, and through the nodes N 1 and N 2 L. This is equivalent to adding discharging paths to accelerate the speed of lowering the voltages of the first and the second comparing ends N 1 c and N 2 c to a steady state, and the time region T 1 from time point t 0 to time point t 1 in FIG. 6 illustrates this condition. In the time region T 1 , the inverters Iv 1 and Iv 2 of the on-load isolating units 32 A and 32 B change the biases of the transistors M 5 and M 6 , which increases the equivalent impedances between the source and the drain electrodes of the two transistors MS, M 6 , and accelerates the transient state condition. At time point t 1 , the controlling voltage V eq changes to turn off the transmission gate of the equalizing unit 34 , and the switch transistors Msa and Msb of the second and the fourth load units are simultaneously turned off to disable the two load units 36 A, 36 B. The data current I f is thus no longer injected into the second load unit 36 A, but instead injects into the MOS transistor M 1 in the first load unit and establishes a steady-state-voltage V H or V L according to the level of the data current I f . Similarly, the reference current I r is stopped from injecting into the fourth load unit 36 B, and instead only injects into the MOS transistor M 3 in the third load unit to establish a steady-state-reference-voltage V R . At the time point t 2 , the sensor unit SA determines the data stored into the memory unit 31 A according to the voltage difference between the first comparing end N 1 c and the second comparing end N 2 c and generates a corresponding data signal V r .
To sum up, the purpose of this invention is to provide two load units 36 A and 36 B during the transient state when reading data, and to thus shrink the time needed for transient state transitions. At the time when the steady-state is almost reached, the second and the fourth load units 36 A and 38 B are disabled, which then establishes a steady-state-voltage at the first comparing end N 1 c by way of the original load unit transistor M 1 . In operation, the MOS transistor M 1 of this invention is a low aspect ratio transistor, and the load unit M 2 is a higher aspect ratio transistor. Within the time region T 1 , the transistor m 2 provides a lower impedance discharging path (compared to the transistor M 1 ), and in combination with the discharging path provided by the transistor M 1 , makes the voltage of the first comparing end N 1 c decrease rapidly, and so reduces the period required for the transient state. At time point t 1 , time region T 2 is entered in which the second load unit 36 A is disabled so as to no longer drain current, and the. steady-state-voltage VH or V L is completely established by way of the transistor M 1 according to the data current I f . As discussed above, a transistor with a lower aspect ratio generates a larger range for the steady-state-voltage, which enlarges the operating margin. Therefore, the present invention has the advantages of both accelerating the read process, and providing better operating margins. If the load transistor M 2 for the memory 30 of the present invention is the same as the load transistor Ta 1 of the prior art memory 20 , and similarly if the memory units and on-load isolating circuits are the same, then the curve V(N 1 b)L in FIG. 6 represents one of the voltage versus time curves of the first comparing end N 1 b of the memory 20 . It is clear that the transient state period in the present invention is shorter, and that the operating margin is significantly increased.
Please refer to FIG. 7, which is a circuit schematic diagram of a sensor unit SA in the memory 30 for a read operation in the present invention. In this operation, MOS transistors Q 1 and Q 2 are taken as a differential output pair, MOS transistors Q 3 and Q 4 are dynamic loads, and the MOS transistor Q 5 is a current source for bias, controlled by the controlling voltage V i .
Please refer to FIG. 8, which is a circuit schematic diagram of a memory 40 of a read operation in the present invention. Memory 40 utilizes memory units 41 A and 41 B, on-load isolating units 42 A and 42 B, an equalizing unit. 44 , a sensor unit SAb, MOS transistor QL 1 and QL 3 as a first and a third load unit, respectively; a second unit 46 A; a fourth unit 46 B, and a MOS transistor QL 7 as a reference unit. The controlling voltage Veq 2 controls the equalizing unit 44 and the second load unit 46 A and the fourth load unit 46 B. The main difference between the memory 30 and the memory 40 is that the memory 30 takes memory units as current sources and load units as current sinks. The memory 40 takes memory units as current sinks and load units as current sources. When the memory 40 is in the process of reading data, the memory 40 discharges the two ends of the sensor unit SAb to a low-voltage-level and charges them by the load units to a high-voltage-level. During the transient state that occurs while charging, the equalizing unit conducts so as to short the two comparing ends, and enables the second and the fourth load units to provide a low-impedance-path and so shrink the period of the transient state. Finally, the second and the fourth load units are disabled, since the equalizing unit 44 is switched off, and the load units transistors QL 1 and QL 3 instead establish the steady-state-voltage, allowing the sensor unit SAb to determine the data stored in the memory unit and output a corresponding data signal V r . The advantages of the memory 40 are identical to those indicated in the memory 30 . The spirit of the invention can be utilized in other types of non-volatile memory, or MOS devices with ONO gate electrodes. That is, all the transistors mentioned above can be other types of non-volatile memory, rather than simply transistors with floating gate electrodes. In addition, the p-type load transistors M 1 to M 4 can be n-type and diode-connected transistors; equally, the n-type transistors QL 1 and QL 3 in FIG. 8 and the load transistors of the load units 46 A and 46 B can be converted to p-type and diode-connected MOS devices, as shown in FIG. 5 .
In the prior art memory, only one load unit is implemented to provide a discharging path, preventing the prior art from simultaneously giving consideration to both reading speed and operating margins. In contrast, the memory of the present invention dynamically enables extra load units to speed up the discharging process. When a transient state is near completion, the extra load units are disabled and a lower aspect ratio transistor takes over to serve as the load unit to achieve the steady-state-voltage. A better operating margin is thereby achieved.
Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
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A non-volatile memory unit includes memory units for providing a data current corresponding to stored data; a first load unit having a first end; a second load unit having a second end; and a sensing unit. The first load unit and the second load unit can receive current input to build voltages respectively at the first end and the second end. When the memory unit provides the data current, the second load unit is enabled such that the data current inputs into the first load unit and the second load unit; then the second load is disabled after a predetermined time such that the data current inputs into the first load unit only, and the sensing unit generates a data signal for data-acquisition according to a voltage difference between the voltage at the first end and a reference voltage.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of priority of the prior International Patent Application No. PCT/JP2007/000174, filed on Mar. 6, 2007, the entire contents of which are incorporated herein by reference.
FIELD
[0002] The embodiments discussed herein are related to a 90° phase shifter for local oscillator signals used in a radio circuit.
BACKGROUND
[0003] In recent years, wireless system services such as mobile phones, wireless LAN, etc. have employed higher frequency bands, and have employed multilevel modulation or multiplexing methods using reduced spacing between carrier waves in order to increase their communication capacity. This type of wireless system often use quadrature modems, and local oscillator signals thereof are required to be of a high phase accuracy in order to secure an acceptable communications quality.
[0004] FIGS. 1A and 1B illustrate phase shifters used in commonly used radio transceivers.
[0005] FIG. 1A illustrates a quadrature demodulator used in a receiver. FIG. 1B illustrates a quadrature modulator used in a transmitter. In FIG. 1B , a received signal is amplified by a receiving amplifier 10 , and is branched so as to be input into mixers 11 - 1 and 11 - 2 in the quadrature demodulator. An oscillator 15 generates a local oscillator signal, and the generated local oscillator signal is input into a phase shifter 14 . In the phase shifter 14 , a 0° signal, which is not phase-shifted, and a 90°-phase-shifted signal, which is phase-shifted by 90 degrees, are generated from the local oscillator signal so as to be input into the mixers 11 - 1 and 11 - 2 , respectively. The received signal that is down-converted by the mixer 11 - 1 for receiving 0° signals is changed into an I-signal. The I-signal is passed through a low-pass filter 12 - 1 and an amplifier 13 - 1 so as to be changed into a demodulated baseband signal. Meanwhile, the received signal that is down-converted by the mixer 11 - 2 for receiving 90° signals is changed into a Q-signal, and is passed through a low-pass filter 12 - 2 and an amplifier 13 - 2 so as to be changed into a demodulated baseband signal.
[0006] Also in FIG. 1B , an oscillator 16 generates local oscillator signals, and a phase shifter 17 generates a 0° signal and a 90° signal to be input into mixers 20 - 1 and 20 - 2 , respectively. The modulated baseband signal that is an I-signal is passed through an amplifier 18 - 1 and a low-pass filter 19 - 1 to be input into the mixer 20 - 1 to be up-converted, and is input into a transmitting amplifier 21 . The modulated baseband signal that is a Q-signal is passed through an amplifier 18 - 2 and a low-pass filter 19 - 2 to be input into the mixer 20 - 2 to be up-converted, and is input into the transmitting amplifier 21 . The transmitting amplifier 21 amplifies a signal obtained by synthesizing the signals that are results of the up-conversions of the I-signal and the Q-signal, and treats the resultant signal as a transmission signal.
[0007] A 0° signal and a 90° signal are generated from a local oscillation signal of a quadrature modem by using, for example, a 90° phase shifter of a dividing type. However, phase shifts caused by element processes or production variations have to be adjusted for quadrature demodulators to meet the requirement of high phase accuracy, and a 90° phase shifter needs a function of performing this adjustment.
[0008] FIGS. 2A and 2B illustrate operations of a 90° phase shifter of a dividing type.
[0009] Differential signals, i.e., a 0° signal and a 180° signal, are input to obtain a desired frequency signal with the phases being shifted by 90 degrees. Operation at the rising edge of a frequency signal two times higher, i.e., a signal with a phase shifted by 180 degrees, can produce a phase difference of 90 degrees.
[0010] As illustrated in FIG. 2A , differential signals made of a 0° signal and a 180° signal of a frequency of 2 f are used as input signals. The DC components are eliminated by a condenser. DC voltage sources 26 and 27 newly give DC components to the signals. Thereafter, the signals are input into a divider-type-90° phase shifter 25 , and differential signals with phases at 0 degree and 90 degrees are obtained as output signals of frequency f.
[0011] FIG. 2B illustrates operations of a divider-type-90° phase shifter. A 0° signal and a 180° signal each having a frequency of 2 f are used as input signals. The divider-type-90° phase shifter 25 varies the signal values of the two input signals only at the rising edges of the signals so that a 0° output signal having a frequency f is obtained from a 0° input signal, and a 90° phase output signal having a frequency f is obtained from a 180° input signal.
[0012] FIGS. 3 and 4 illustrate an example of the circuit of a 90° phase shifter and its detailed configuration.
[0013] In FIG. 3 , a 0° signal that was input is input into the inverted clock terminal of D latch ( 1 ) and the clock terminal of D latch ( 2 ). A 180° signal that was input is input into the clock terminal of D latch ( 1 ) and the inverted clock terminal of D latch ( 2 ). A normal output of D latch ( 1 ) is a 90° signal of the output signal, and it is input into the normal input terminal of D latch ( 2 ). An inverted output of D latch ( 1 ) is input into the inverted input terminal of D latch ( 2 ). A normal output of D latch ( 2 ) is a 0° signal of the output signal, and it is input into the inverted terminal of D latch ( 1 ). An inverted output of D latch ( 2 ) is input into the normal terminal of D latch ( 1 ).
[0014] Operations on a 0° input signal are explained. D latch ( 1 ) reads input (D) at the falling edge of (A) to output it to (B). This (B) becomes an output 90° signal. D latch ( 2 ) reads input (B) at the rising edge of (A), and outputs it to (C). This (C) becomes an output 0° signal. Accordingly, the signal value of the output 90° signal is varied at the timing of the rising edge of the input 0° signal, and the signal value of the input 0° signal is varied at the timing of the rising edge of the input 0° signal.
[0015] For the determination of the clock inputs and the inverted clock inputs in D latches ( 1 ) and ( 2 ), threshold values are set in the latches so that the individual latches input and output signals when the input clock signal exceeds the threshold value.
[0016] FIG. 4 is a timing chart for explaining the operation of the 90° phase shifter illustrated in FIG. 3 .
[0017] Signal (B) is a signal output from D latch ( 1 ) that has read signal (D) at the rising edge of signal (A). Signal (C) is a signal output from D latch ( 2 ) that has read signal (B) at the rising edge of signal (A). Accordingly, the output 0° signal becomes signal (C), and the output 90° signal becomes signal (B).
[0018] FIG. 5 illustrates a conventional method of adjusting a phase in a divider-type-90° phase shifter.
[0019] The timing of the rising edge of a signal is adjusted by changing the DC voltage of the input signal so that the phase difference of an output signal is adjusted. The chart denoted by ( 1 ) in FIG. 5 represents a case of a 0° signal in which a signal is input with a lower DC voltage than the threshold voltage of the phase shifter in order to delay the timing of the point where the waveform of the input signal and the threshold value intersect. Thereby, the timing of the 0° signal can be delayed. The chart denoted by ( 2 ) in FIG. 5 illustrates a case of a 90° phase signal in which a signal is input with a higher DC voltage than the threshold voltage of the phase shifter in order to advance the timing of the point where the waveform of the input signal and the threshold value intersect. Thereby, the timing of the 90° phase signal can be advanced. Thus, the rising and falling edges are formed at the timings where the waveform of the input signal and the threshold value intersect, and accordingly, the phase difference can be reduced by implementing charts ( 1 ) and ( 2 ) in FIG. 5 at the same time in order to delay the timing of the 0° signal and advance the timing of the 90° signal. The procedures opposite to the above can increase the phase difference between the signals.
[0020] However, the range and steps of adjusting DC voltages are limited due to shifts in threshold values in phase shifters caused by element processes or production variations, or due to changes in waveforms of input signals caused by variations in speeds of transistors in the input signal circuits, and the like, and this may prevent the obtainment of a desirable phase adjustment range.
[0021] FIG. 6 illustrates a problem in a conventional technique.
[0022] As indicated by ( 1 ) in FIG. 6 , in the technique of Patent Document 1, the adjustment range of DC voltages tend to be concentrated in the upper or lower side with respect to the threshold value of the phase shifter when there is a difference between the threshold voltage of the phase shifter and the DC voltage of an input signal due to the element processes or production variations, and consequently a situation occurs where the timing of the rising edge of output signals can be adjusted to be delayed to a large extent while the timing can be adjusted to be advanced only to a small extent, or vice versa. When a timing adjustment has to be made to a large extent in the direction in which an adjustment is only allowed to a small extent, the phase difference of the input signal cannot be adjusted sufficiently, which is problematic. Also, when the rising edge of the waveform of the input signal is steep as in FIG. 6 , even a great change to the DC voltage of the input signal can cause only a narrow timing range of adjustment because of the steepness. Also, when a timing range of adjustment is narrow, a situation occurs where the phase difference of the output signal cannot be adjusted to the required level.
Patent Document 1:
[0023] Japanese Laid-open Patent Publication No. 58-56522
SUMMARY
[0024] A phase shifter of the present invention includes: phase shifting unit operating at a timing at which a clock signal becomes equal to or greater than a threshold value and outputting periodic signals having phases shifted by 90 degrees from each other; DC voltage setting unit for setting a voltage value of a DC component of the clock signal input into the phase shifting unit; and clock signal slope varying unit varying a slope of a rising edge of the clock signal.
[0025] The object and advantages of the invention will be realized and attained by means of the elements and combinations articularly pointed out in the claims.
[0026] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed
BRIEF DESCRIPTION OF DRAWINGS
[0027] FIG. 1A illustrates a phase shifter used in a conventional wireless transceiver;
[0028] FIG. 1B also illustrates a phase shifter used in a conventional wireless transceiver;
[0029] FIG. 2A illustrates operations of a dividing-type-90° phase shifter;
[0030] FIG. 2B also illustrates operations of a dividing-type-90° phase shifter;
[0031] FIG. 3 is a first view illustrating an example of the circuit of a 90° phase shifter;
[0032] FIG. 4 is a second view illustrating an example of the circuit of the 90° phase shifter;
[0033] FIG. 5 illustrates a conventional method of shifting phases in a dividing-type-90° phase shifter;
[0034] FIG. 6 illustrates a problem in a conventional technique;
[0035] FIG. 7A illustrates operations of an embodiment of the present invention (1);
[0036] FIG. 7B illustrates operations of an embodiment of the present invention (1);
[0037] FIG. 7C illustrates operations of an embodiment of the present invention (1);
[0038] FIG. 8A illustrates operations of an embodiment of the present invention (2);
[0039] FIG. 8B illustrates operations of an embodiment of the present invention (2);
[0040] FIG. 9 illustrates operations of an embodiment of the present invention (3);
[0041] FIG. 10 illustrates operations of an embodiment of the present invention (4);
[0042] FIG. 11 illustrates an example of the second configuration of moderating rising edges of input signals;
[0043] FIG. 12 illustrates an example of the third configuration of moderating rising edges of input signals; and
[0044] FIG. 13 illustrates an example of the fourth configuration of moderating rising edges of input signals.
DESCRIPTION OF EMBODIMENTS
[0045] FIGS. 7A through 10 illustrate operations in embodiments of the present invention.
[0046] Moderating the rising edge of the waveform of a signal input into the phase shifter as illustrated in FIG. 7 enables the changing of the timing of rising without changing the DC voltage. The more moderate the rising edge is, the more the phase changes with respect to changes in voltage so as to widen the range over which phases can be varied, and the more the scale of adjustment steps can be varied.
[0047] FIG. 7A illustrates a case where the DC voltage of the input signal is higher than the threshold voltage of the phase shifter and by moderating the rising of the waveform of the input signal, the rising timing of the output signal can be advanced to a greater extent. FIG. 7B illustrates a case where the DC voltage of the input signal is lower than the threshold voltage of the phase shifter and by moderating the rising of the waveform of the input signal, the rising timing of the output signal can be delayed to a greater extent. As illustrated in the enlarged view of FIG. 7C , the rising edge and the falling edge of the output signal are formed at timings at which the input signal waveform and the threshold voltage of the phase shifter intersect, and accordingly the more moderate the rising edge of the input signal waveform is, the wider the ranges are for adjusting the rising and falling timings of the output signal.
[0048] The situations illustrated in FIGS. 7A through 7C can be realized by providing a variable low-pass filter (LPF) for the input of the phase shifter and adjusting the time constant (cutoff frequency) of the low-pass filter so that a required timing adjustment range can be obtained as illustrated in FIG. 8A . Low-pass filters 30 and 31 are provided in stages earlier than condensers for cutting direct currents for both input 0° signals and input 180° signals. These Low-pass filters 30 and 31 have a same configuration. A plurality of capacitors C 1 through C 3 are connected, via switches, to each of the low-pass filters 30 and 31 so that the time constants of the low-pass filters are adjusted by operating the switches as necessary. The capacitors in the Low-pass filters 30 and 31 that are denoted by like symbols are configured to have like capacitances. FIG. 8B illustrates the waveforms of the signals input into the divider-type-90° phase shifter of the 0° signal side. The rising edges of the input signal waveforms become more moderate with increasing capacitances of the capacitors in the low-pass filters. Thereby, the range over which phases can be varied can be widened as illustrated in FIG. 7 .
[0049] FIGS. 9 and 10 illustrate examples of setting phase adjustment amounts in phase shifters.
[0050] FIG. 9 illustrates an example of a phase adjustment amount in a phase shifter where the phase difference between the 0° signal (I-signal) and the 90° signal (Q-signal) output from the phase shifter is 70 degrees when the DC voltage of signal input into the phase shifter is 0. In a default state, capacitor C 1 is connected to the low-pass filter and a case when a capacitor is not connected and a case when capacitor C 2 with a larger capacitance than that of C 1 can be connected are illustrated. The phase difference between the I-signal and the Q-signal should be 90 degrees, although it is actually 70 degrees, and this requires the adjustment of the phase of the output signal of the phase shifter. However, in the case illustrated in FIG. 9 , capacitor C 1 is connected by default, and even when the DC voltage of the input signal is changed to the maximum, the adjustment amount of the phase shifter does not reach 90 degrees. When there is no capacitor, the rising edge of the input signal becomes steep so as to narrow the adjustment range. When capacitor C 2 is connected to the low-pass filter, the adjustment range is made wider and the adjustment amount of the phase shifter reaches 90 degrees. As described above, in the present embodiment, the characteristic of the low-pass filter is changed in order to moderate the rising edge of the waveform of the signal input into the phase shifter, and accordingly a sufficient phase adjustment amount can be obtained even when the required phase adjustment amount cannot be obtained in the default state.
[0051] FIG. 10 illustrates a case where the phase difference between the I-signal and the Q-signal is 90 degrees when the DC voltage of the signal input into the phase shifter is 0. The low-pass filter in this example can have three configurations, i.e., a configuration without capacitors, a configuration with capacitor C 1 connected to itself, and a configuration with capacitor C 2 having a larger capacitance than capacitor C 1 . By default, the low-pass filter includes capacitor C 1 connected to itself. In the case of FIG. 10 , the adjustment amount of the phase shifter has reached 90 degrees when the DC voltage is 0, and thus a large phase adjustment is not needed. Rather, a fine adjustment is desired. The use of capacitor C 2 in a low-pass filter widens the adjustment range; however, the changing ratio of the phase shifter adjustment amount in units of changes in DC voltage increases, which prevents a fine adjustment. When a capacitor is not connected to a low-pass filter, the adjustment range remains narrow; however, the changing ratio of the phase shifter adjustment amount in units of changes in DC voltage is decreased as indicated by the decrease in the slope of the phase shifter adjustment amount in the graph of FIG. 10 . Accordingly, the changing ratio of the phase shifter adjustment amount in units of changes in DC voltage is decreased, and thus a fine adjustment of phases can be performed.
[0052] FIG. 11 illustrates a second example of a configuration for moderating rising edges of input signals.
[0053] As illustrated in FIG. 11 , a differential amplifier is provided in a stage earlier than the phase shifter to increase/decrease load resistance, and thereby a mirror effect can vary the capacitance to achieve the effect of a low-pass filter. It is now assumed that resistance R 1 is selected as a load resistance, the capacitance based on a mirror effect is obtained by C=Cgd×(1+gm×R 1 ) where gm represents the mutual conductance of the transistor, and Cgd represents the parasitic capacitance between the drain and the gate of the transistor. When the resistance value is R 2 or R 3 , R 2 or R 3 is used in place of R 1 in the above equation. The cutoff frequency of the low-pass filter obtained by this configuration is expressed by 1/(Ri×C) where C is obtained by the first equation, and Ri represents the input resistance value to the transistor. Increased resistance increases the mirror capacitance, and the rising edge of the phase shifter input waveform is moderated by a low-pass filter effect. In this configuration, a circuit including a transistor and a resistor achieves a low-pass filter effect, and accordingly when this circuit is implemented in a LSI configuration, the circuit can be smaller than a configuration using plural capacitors so as to achieve the variability of capacitance, although this causes the circuit configuration to become complicated to some extent.
[0054] FIG. 12 illustrates the third example of a configuration of moderating the rising edges of input signals.
[0055] A cascode differential amplifier is provided in a stage earlier than the phase shifter to increase/decrease the mutual conductance of the grounded-gate amplifier connected to the drain of the input transistor so that a mirror effect can vary the capacitance to achieve the effect of a low-pass filter. Transistors gm, gm 1 , gm 2 , and gm 3 represent transistors with mutual conductances gm, gm 1 , gm 2 , and gm 3 , respectively. The symbol Cgd represents a parasitic capacitance between the drain and the gate of the transistor. A cascode differential amplifier using a transistor whose gm is gm 1 has a capacitance of C=Cgd×(1+gm/gm 1 ). The cutoff frequency of the low-pass filter is obtained by 1/(Ri×C), where Ri represents an input resistance. Also in this case, the cascode differential amplifier does not include a capacitor when the circuit is configured in an LSI configuration. Thereby, the circuit can be smaller.
[0056] FIG. 13 illustrates the fourth example of a configuration of moderating the rising edges of input signals.
[0057] The integrated circuit utilizes its wiring capacity to achieve the effect of a low-pass filter. The wider and closer to the bottom the wires are, the larger the wiring capacity can be. As illustrated in FIG. 13 , a metal wire 35 is provided as a lower-layer wire close to the GND layer of the LSI including plural layers. Further, the width of the wire is broad so that it has the greatest capacity. A metal wire 36 is provided as a lower-layer wire; however, the width thereof is narrower than that of the metal wire 35 , and thus the capacity of the metal wire 36 is smaller than that of the metal wire 35 . A metal wire 37 is provided as an upper-layer wire, and the width thereof is not wide, and accordingly the capacity thereof is the smallest. The metal wire 35 is the most effective, the metal wire 36 is the second most effective, and the metal wire 37 is the third most effective in moderating the rising edges of signals.
[0058] All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiment(s) of the present invention has (have) been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.
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A phase shifter includes a phase shifting unit for operating at a timing at which a clock signal becomes equal to or greater than a threshold value and outputting periodic signals having phases shifted by 90 degrees from each other; a DC voltage setting unit for setting a voltage value of a DC component of the clock signal input into the phase shifting means; and a clock signal slope varying unit for varying a slope of a rising edge of the clock signal.
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RELATED APPLICATION
This is a continuation-in-part of my application Ser. No. 565,987, filed Dec. 27, 1983, and to be abandoned.
BACKGROUND
1. Field of the Invention
This invention relates generally to microprocessor-operated sound-generating ornaments, novelties and toys, particularly to such items powered by photoelectric cells.
2. Prior Art
Ornaments, novelties, toys and games with digital-logic integrated circuits that excite acoustic speakers are now commonplace. Well-known to electronic technicians and computer programmers are various techniques for causing such circuits to develop a controlled series of electrical oscillations that correspond to musical tunes, or even to more elaborate sounds such as simulated speech. Such oscillations are directed to conventional acoustic speakers, or for small inexpensive applications are directed to ceramic drivers attached to thin metal discs ("benders") which rather reedily convert the electrical oscillations into acoustic vibrations.
With the development of ever-smaller and ever-less-expensive microprocessors, such music or voice simulators have been used in formats that are more and more disposable--as well as tiny. For example, there are now on the market greeting cards that play one or more tunes when opened. All such applications of course require tiny batteries in conjunction with the microprocessors and acoustic converters, and of course become inoperative when the batteries run down.
Also well known are photoelectric cells, commonly termed "solar cells," which generate electricity whenever adequate light impinges upon them. Such cells are now used to develop electrical power for a great variety of purposes. For instance, they are now in general use in commercial public-utility power grids. They are used also to power many different kinds of remote equipment--such as environmental monitoring equipment, complete with digital circuits to preliminarily process the monitoring information and with radio transmitters to report the preliminarily processed information to a base station.
To the best of my knowledge these two areas of modern development have not previously been combined.
SUMMARY OF THE DISCLOSURE
Preferred embodiments of my invention are ornaments and novelties which emit music or other sounds when exposed to light. Each such ornament or novelty includes a body that may be decorative and preferably that is compatible with some distinct theme. For example the body may be in the form of a bird, a butterfly, a flower, a person, or a recognizable article such as a San Francisco cablecar, the Eiffel tower, or an airplane.
Also part of each ornament or novelty, according to certain preferred embodiments of my invention, is a three-element working module sealed in a watertight can.
The three elements are (1) a solid-state digital electronic circuit, programmed to generate a series of electronic oscillations corresponding to a tune or other series of sounds, (2) a small speaker connected to receive the electronic oscillations from the circuit and to emit the corresponding tune or other sounds, and (3) a solar cell connected to power the circuit when exposed to light.
The decorative body, the detailed programming of the circuit, and the particular tune or other sounds are advantageously coordinated in theme. For example, the body may have the shape of a bird, and the circuit may be programmed to emit certain sounds only as the light level increases through a particular range of values. The sounds may be sounds customarily associated with the morning--such as bird-like twitterings, or recognizable melodies such as "Oh What a Beautiful Morning" or "Mockingbird Hill." Such an ornament may be placed in a window or outside in a garden, and will provide the preprogrammed morning sounds only as the sun rises.
Similarly the ornament body may have the shape of a trumpet, and the circuit may be programmed to play "taps" or some other evening song, or to imitate the chirping of crickets, only as the light level decreases through a particular range of values. Thus the ornament will emit these characteristic evening sounds only as the sun sets.
The ornament body may be given a shape thematically related to midday, and the circuit programmed to play a midday song or to emit other midday sounds only when the light level remains generally constant for an extended period. Thus the ornament or novelty may play "Whistle While You Work" only when the sun is near the zenith.
An ornament that has a somewhat neutral shape (such as a bird) may be programmed to perform all of the functions already described, at different times of the day. Alternatively, a much simpler embodiment of the invention may simply emit sounds (such as bird sounds in a garden) constantly whenever there is enough light to operate the circuit and speaker.
On another tack, such articles may be given commercial or political themes and used as promotional novelties. A restaurant chain could give away (or sell at around cost) novelties in the shape of some cartoon character used in the restaurant's television advertising. Near midday (or as the sun sets, for a dinner house) the cartoon-character novelty article could play the restaurant's advertising theme song--and even emit words, such as "It's time for lunch- Come to McDonald's-" The potential for such items extends to airlines, banks, retail stores, political campaigns, and so forth.
Ornaments may also be provided with thematically coordinated bodies and tunes for particular kinds of events, such as birthday parties. Such ornaments may be attached to decorations or food at such special events--particularly when the events are to be held outdoors. As will be apparent, however, some of the benefits of the invention accrue even when the resulting ornaments and novelties are used indoors under artificial lighting--provided that the light level is sufficiently high. In particular, such ornaments may be reused many times for events having similar or related themes, without the need for either power leads or battery replacement.
The working module may also be made with a user-programmable memory (a so-called R. A. M.), and made and sold with a mating input device for easy entering of a particular tune, but without a particular thematic body. Such a module may be made to accept programming for a particular tune by professional caterers or by any musically oriented people preparing for a party or other special event; and may be embedded in a variety of bodies made from papier mache, clay, foodstuffs, etc.--specially shaped for the occasion. Once again, such a module is reusable, with virtually an unlimited life.
Generally the sound level from such devices is relatively low, and consequently is audible only to people who are quite close by. The sound is therefore not so intrusive as to constitute an annoyance, but only a pleasant addition to the surrounds. I have found that when tastefully done, the overall effect produced by such novelties and ornaments is actually quite charming.
The detailed description below, and the drawings, will clarify the principles and advantages of my invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general sketch--broken away to show the module clearly--of one preferred embodiment, to be hung on a cord in a window or from a tree.
FIG. 2 is a similar sketch of another preferred embodiment, to be staked into the ground as in a garden.
FIG. 3 is a generalized cross-sectional elevation of a module usable with either embodiment, or with others.
FIG. 4 is an electrical schematic diagram show interconnections between the elements of the FIG. 3 module.
FIG. 5 is a schematic of a preferred embodiment that shuts off the speaker in inadequate light, and amplitude modulates it otherwise.
FIG. 6 is a perspective view of an embodiment with an adjustable shield to control the light at the solar cell.
FIG. 7 is an elevation of another embodiment, incorporating the FIG. 6 module.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows an ornament generally having the shape of the body 12 of a creature--perhaps a garden creature such as a snail or a bird--with a working module 21 embedded in the body 12. The ornament also has a hook 14, by which it is attached to a suspending thread or cord 15.
The body is drawn partially broken away as at 13 to show the generally right-circular-cylindrical shape of the working module 21, which has on the visible planar end face a solar cell or an array of solar cells 22. The cylindrical surface 24 of the module 21 is simply a structural member which holds the various pieces of the module together and seals them against the environment.
FIG. 2 shows a generally simlar ornament having the shape of a body 112 of a different creature, with a working module 121 similarly embedded in the body 112 and a support member 115. The support 115 may be connected to a pedestal (not illustrated) or may be sharpened at its lower end for insertion as a stake into a relatively soft medium.
The soft medium, into which the support or stake 115 if so sharpened may be pushed, can be soil in the garden. Myriad other uses, however, are contemplated.
For instance, the support 115 may be inserted into a wedding cake for use at a reception--with the body 112 in the form of a bride and groom, and the working module 121 playing a wedding song. Alternatively the support 115 may be inserted into other foods (melons, bread, casseroles, meatloaf, etc.) or into decorative articles at a picnic or other party--and the body 112 may be suitably configured for the event, and the working module 121 programmed to play a suitably selected festive tune.
As previously mentioned, such uses may be "manufactured into" the ornament complete with body theme, or may be left to the imagination and creativity of purchaser-users by providing the working module in programmable form without a body.
FIG. 3 shows the structure of the working module 21 of FIG. 1 (or 121 of FIG. 2). In this cross-sectional elevation through a diameter of the cylindrical working module 21, the solar cell or cells 22 are seen to form one end wall of the cylinder, while the acoustic surface forming the other wall is provided by a metal or ceramic disc 33, to which is internally mounted a piezoelectric or other suitable driver 32.
In the middle of this sandwich is a printed-circuit board 28 carrying various electronic components 25. Prominent among these is a microprocessor and read-only memory (R. O. M.) 26. Interconnecting wires 27 provide power from the solar cell 22 to the circuit elements 25; and like wires 31 provide controlled electrical pulse trains from the circuit elements 25 to excite the acoustic driver 32.
This assemblage is held together and sealed against the environment by a cylindrical can 24, which may be provided with a pair of ridges 29 or a single groove for retention of the printed-circuit board 28--suitable arrangements being made for one-time insertion of the board 28 between the ridges 29 or into the groove.
FIG. 4 shows further that the solar cell 22 provides power via leads 27 and 41 to the microprocessor and R. O. M. 26, and via leads 27 and 43 to a buffer or power amplifier 44 (which may be incorporated into the microprocessor and R. O. M. 26). The internally time-structured series of electrical oscillations produced by the microprocessor and R. O. M. 26 passes by leads 42 to the power amplifier 44, whence lower-impedance oscillations of the same time structure pass to the acoustic driver 32.
As previously mentioned the microprocessor and R. O. M. 26 may be replaced by a microprocessor and R. A. M., so that the working module 21 can be made to play various tunes entered by users. For this purpose there should advantageously also be provided a suitable umbilicus (not illustrated) from the microprocessor to an electrical connector at the outside of the working module 21. Such an umbilical connection is preferably used for communication from a mating console with suitable keyboard for entering desired tones, or tones with associated durations.
Advantageous for certain applications previously mentioned, but not necessary to all embodiments of my invention, is the analog-to-digital converter 46, which receives power along leads 27 and 45 from the solar cell 22, and which produces a digital indication of the solar-cell power output at each time. This digital signal is impressed upon the voltage-level bus 47 for use by the microprocessor 26 in any of a variety of ways. More specifically, this signal is usable by the microprocessor 26 to determine whether the light level at the solar cell 22 is within a particular range of values, and/or whether it is increasing or decreasing--over selected intervals such as one to fifteen minutes.
In this way the operation of the microprocessor may be inhibited by the logic programmed within the microprocessor itself when the behavior of the incident light does not satisfy particular criteria. As described earlier, such criteria as well as the tune or other sounds to be emitted are advantageously coordinated with the theme represented by the shape of the body (if any) of the ornament.
In testing prototypes of my invention I have found somewhat surprisingly that there is a range of light levels in which the solar cell generates adequate voltage for operation of the electronic circuit and the speaker to produce some sounds, but not for proper operation of the circuit and speaker to produce the preestablished, intended sounds. The result of operation in this range is to produce rather unpleasant, erratic sounds--more specifically, a grossly distorted verson of the intended sounds.
It appears that this behavior is due to erratic or inconsistent operation of the oscillator in the circuit. Apparently the oscillator may skip pulses, or produce pulses of reduced amplitude which are not picked up by the next downstream stages. It seems that there are consequently gaps in the sequence of notes, or notes of incorrect duration, or both. While I am not certain of the precise mechanisms by which the sounds are grossly distorted, I have found a way to prevent this undesirable result.
My solution is to suppress operation of the speaker when the voltage from the solar cell is not positively adequate for proper operation of the electronic circuit. FIG. 5 shows such an arrangement. The microprocessor, amplifier, and R. O. M. discussed earlier are within the block 126 labelled "microprocessor & amplifier." The acoustic driver is identified as a "bender" 132, and solar cell or cells here appear as a "solar panel" 122.
Voltage on the output leads 127 of the solar panel 122 is filtered by the capacitor C1, in combination with the internal impedance of the solar panel 122. The result is a somewhat more stable supply voltage at the input leads 141 to the microprocessor & amplifier 126. This added stability is particularly helpful for purposes of the "suppressing means" circuit which will now be described.
The voltage at the power leads 141 is tapped off as at 163 and through two series diodes D1 and D2 to the control lead 164 at the base of the transistor Q1. The threshold voltage required by the diodes D1 and D2 in effect is subtracted from the supply voltage at 163, in constructing the voltage on the control lead 164. This threshold voltage has been selected as slightly larger than the voltage required by the microprocessor & amplifier block 126 for entirely correct operation--that is to say, with no erratic operation such as skipping of pulses.
Until the supply voltage exceeds the threshold voltage required by the two diodes D1 and D2, no current is available at the base of the transistor Q1 to switch on the transistor. Since the transistor Q1 is in series with the "bender" 132, the bender is shut off until the microprocessor & amplifier 126 are fully up and running.
A resistor R1 is attached between the power return lead as at 161 and the transistor base as at 162. This resistor holds down the voltage on the base to achieve a positive, definite, stable crossover of the turn-on characteristic of the transistor.
Once the turn-on point has been passed, the transistor conducts generally proportionally to the excess of the supply voltage over the diode threshold voltage. Thus the volume of sound increases generally with the supply voltage, and hence with the light level at the solar cell.
The capacitor C1 may be a 22-microfarad, 6-volt unit. The resistor R1 may be a 10-kilohm resistor. The transistor Q1 and the diodes D1 and D2 may be of the types commonly available under the commercial component designators 4123 and 1N914 respectively.
It is desirable to be able to switch the music off without removing the novelty item entirely from its decorative position, and it is also desirable to be able to adjust the volume of the sound. It would be generally prohibitive, however, to provide an electrical switch. It would be even more problematical to provide an electrical volume control. Both switching and electrical volume controls could also introduce problems in maintaining the working module watertight, which is important for many potential outdoor and other applications of the invention.
I have found, however, that on-off switching can be obtained without an electrical switch, by adding a movable cover that can be positioned to shield the solar panel from incident light, and that can be positioned to expose the panel. The cover can pivot into position, or as shown in FIG. 6 it can slide into position. Appearing in FIG. 6 is a working module with a rectangular case 224, and solar panel 222 in a broad face of the case 224.
Affixed to or integral with that broad face is a retaining extension 252, shaped to form two opposed flanges 253 and under each flange 253 a slot 254. A shallow rectangular cover 251 slides under the retaining flanges 253 and within the slots 254. The cover 251 is narrow enough, in the direction parallel to the sliding motion, that it can be positioned to entirely expose the solar panel 222 without extending past the edge of the case 224. The cover 251 is wide enough, in that same direction, that it can be positioned to entirely cover the solar panel 222.
When in the latter position the cover 251 shuts off the power to the circuit and speaker, and thus effectually shuts off the music or other sounds. When positioned to expose the solar panel 222, the cover 251 allows power to flow to the circuit and speaker, if there is sufficient light to energize the solar panel.
Furthermore, if the working module is equipped with a "suppressing means" circuit such as illustrated in FIG. 5, the cover 251 will interact with that circuit to provide a volume control for the music or other sounds. When the cover 251 is positioned to provide enough light to properly operate the microprocessor & simplify 126 (FIG. 5), the transistor Q1 will be conductive and will allow the bender 132 to operate. As long as that condition is maintained, adjustments of the cover will control the degree of conduction of the transistor Q1 and hence the volume of the sound produced by the bender 132.
FIG. 7 shows another embodiment of my invention which may incorporate a working module such as that of FIG. 6. The FIG. 7 embodiment is an essentially two-dimensional open framework 281 cast in plastic, ceramic, or metal. Between the shaped members 281 of the framework are complementarily shaped open spaces 282. The shapes defined by the members 281 of the framework and the open spaces 282 are made to resemble familiar objects such as butterflies 271, a sun 272, and haze or a hazy horizon 273.
Mounted in the bottom of this framework 281 is the working module 224, with its solar panel 222. The cover 251 is mounted to slide, as in FIG. 6, below retaining flanges 253. Here the cover 251 is shown in a position which exposes one part 222 of the solar panel--and covers another part 222' of the solar panel so as to reduce the sound level as previously explained.
It is to be understood that all of the foregoing detailed descriptions are by way of example only, and not to be taken as limiting the scope of the invention--which is expressed only in the appended claims.
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These small, inexpensive ornaments and novelties emit music and other sounds (such as simulated voice) when exposed to light, and can be placed out-of-doors in a garden. Being light-powered, they can operate for an essentially indefinite time, even though unattended.
Each such ornament or novelty consists of a thematically configured body and a three-element working module sealed in a watertight can. It has no input keyboard or other terminal, and no display panel or other electronic or visual data output, except the audio output.
Elements are (1) a circuit, preprogrammed to produce electronic oscillations corresponding to a tune or other sounds preestablished at manufacture, (2) a speaker receiving the oscillations and emitting the sounds, and (3) a solar panel powering the circuit. The speaker shuts off if light is inadequate for completely correct operation, and otherwise is amplitude modulated by the light level.
The decorative body, the detailed programming of the circuit, and the particular tune or other sounds are coordinated in theme.
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FIELD OF THE INVENTION
The present invention relates to a cemented carbide material which exhibits a gradient in binder concentration. In particular, the material exhibits a relatively low binder concentration near surface regions and nominal concentrations at the interior of the material. The invention also relates to methods of producing the above.
BACKGROUND OF THE INVENTION
Various constructions and techniques will be described below. However, nothing described herein should be construed as an admission of prior art. To the contrary, Applicants expressly preserve the right to demonstrate, where appropriate, that anything described herein does not qualify as prior art under the applicable statutory provisions.
Cemented Carbide inserts and articles have been commercially available for use as cutting tools, wear parts and dies for many years. Typical cemented carbides are comprised of metal carbides, normally WC, often with the addition of carbides of other metals such as Ti, Ta, Nb, V, Zr, etc., and a metallic binder comprising Co, Ni, Fe or combination thereof. Various combinations of binders and metal carbides are mixed together in a body to produce the desired characteristics of hardness, toughness, and chemical and abrasion resistance. Cemented WC parts incorporating a binder in nominal concentrations between about 2 and 30 weight %, and cubic carbides such as TiC, TaC, NbC, VC and ZrC, and combinations thereof in concentrations up to about 30% by weight of the total weight have the requisite characteristics for most applications useful to the automobile and other industries. The parts formed from such cemented carbides are often coated with one or more refractory layers to impart desired characteristics which may be lacking in the substrate material or to otherwise improve performance of the finished article. Known coatings include Al 2 O 3 , ZrO 2 , Y 2 O 3 , AlN, cBN, as well as nitrides and carbonitrides of Groups IVA and VA, and combinations thereof.
Parts combining various amounts of metal carbides and binders, as well as different carbide phases, have been developed in attempts to optimize performance. U.S. Pat. Nos. 4,743,515 and 5,856,626 from Fischer et al. attempted to improve the strength of cobalt cemented carbide by creating a two-layered body utilizing eta-phase. Eta-phase is understood in the industry to mean compositions of tungsten, cobalt and carbon, such as M 6 C and M 12 C, where M=tungsten and cobalt, for example W 3 CoC. However it is known in the art that eta-phase forms brittle grains around WC crystals, providing sites for crack initiation and propagation. The presence of eta-phase results in a marked reduction in strength of the resulting article. Fischer et al. disclose parts having an inner layer comprised of WC, Co and eta-phase, with an outer layer which was eta-phase-free. In the substrates described by Fischer et al., the cobalt concentration in the eta-phase-free outer layer varies with depth from about 10-90% of the nominal value at the surface, to at least 120% of nominal, and then drops sharply in the inner eta-phase containing layer. The method for achieving the two layers requires sintering powders having substochiometric quantities of carbon at high temperature to generate eta-phase and then transforming the outer layer of eta-phase via high temperature carburization.
U.S. Pat. No. 5,453,241 by Akerman et al. seeks to improve the toughness of products produced per Fischer et al. by establishing a method of high temperature carburization followed by rapid cooling. All of the foregoing patents share the drawback of containing eta-phase, which is brittle and acts as a source for fracture initiation and propagation. Furthermore, the use of temperatures greater than 1400° C. for post sintering heat treatments has the drawback of loss of geometric features, warpage, and a reduction in hardness, due to excessive grain growth. Another drawback of this prior art is the presence of porosities in the substrate which are detrimental to the performance of the finished article.
Modifications can also be carried out by increasing the concentration of the binder phase in the near surface regions of the part. This binder phase enrichment improves certain properties of the part, such as toughness, but has the drawback of leaving residual binder at the surface, which interferes with later coating of the part. U.S. Pat. Nos. 5,560,839; 5,660,881; 5,618,625; and 5,713,133 detail the removal of the binder from the surface by etching, grinding, and other means followed by coating of the article with diamond. A drawback to these methods is increased porosity in the body and damage to the WC grains at the surface. U.S. Pat. No. 5,380,408 by Svensson details a method of removing cobalt from the surface of a part having a cobalt enriched surface region by chemical etching without removal of cobalt channels between the hard material grains. Removal of only the surface cobalt is asserted to improve coating adherence without creating undesirable porosity in the part.
Another drawback of the cobalt enriched surface region in the cemented carbide is a resulting decrease in hardness and chemical wear resistance, particularly when machining super alloys, such as titanium and its alloys. This lack of hardness leads to accelerated tool wear, even when coatings are applied to the part. Alternative materials such as eta-phase containing cemented carbides, discussed above, and selected cemented carbides consisting of WC with very small amounts of cobalt and ceramics, are thought to lack sufficient toughness to withstand forces associated with repeated use of tools, wear parts and dies. It is therefore desirable to produce a cemented carbide part having a combination of hardness and toughness, which overcomes the drawbacks of the prior art.
SUMMARY OF THE INVENTION
It has been demonstrated in the present invention that a body which is eta-phase-free, and exhibits a binder concentration which gradually increases from concentrations at or near zero in the surface regions of the article to higher concentrations, not exceeding nominal concentration levels, in the interior of the part provides a desirable combination of hardness and toughness.
According to a first aspect, the present invention provides a hard, wear resistant article of manufacture comprising a cemented carbide substrate, substantially free of eta-phase, comprising tungsten carbide and 2-30 weight % binder selected from the group consisting of Co, Ni, Fe, and combinations thereof, wherein binder concentration increases from approximately zero at the substrate surface to nominal at a selected distance interior to the surface and does not exceed nominal.
According to another aspect, the present invention provides an article of manufacture comprising an eta-phase-free cemented carbide body, composed of well defined metal carbide grains and a binder wherein said binder concentration varies within the part according to a binder concentration gradient decreasing from nominal concentrations in the interior of the part to less than 1% at the part surface.
According to a further aspect, the present invention provides a method of making a hard, wear resistant article comprising the steps of: a) heat treating a green or pre-sintered article to produce a fully sintered product; b) removing binder from surface regions of a cemented carbide article to a selected depth within said article by immersion in a chemical etching solution; c) heating the etched article in a vacuum between 1225 and 1275° C.; and d) further heating the article in a carburizing atmosphere between 1300 and 1350° C. for a time sufficient to diffuse binder from interior regions of the article into said surface regions.
According to yet another aspect, the present invention provides a method of making a hard wear resistant article comprising the steps of: a) removing binder from surface regions of a cemented carbide article to a selected depth within said article; b) heating the article in a vacuum to between 1200 and 1250° C.; and c) introducing an atmosphere comprising carbon monoxide and further heating the article to between 1300 and 1350° C. and holding at that temperature in the carbon monoxide atmosphere for a period of time sufficient to diffuse binder from interior regions of the article into said surface regions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot of the cobalt concentration versus the depth beneath the surface for a 6 weight % Co part according to one embodiment of the present invention.
FIG. 2 is a plot of cobalt concentration versus depth beneath the surface for different embodiments of the present invention based on different depths of etch and an identical heat treatment.
FIG. 3 is a plot depicting the depth at which the cobalt concentration returns to nominal after heat treatment of an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to articles comprising an eta-phase-free cemented carbide part having well defined metal carbide grains and a binder concentration between 0 and 1 weight %, preferably 0 weight %, at the surface of the part. In the inner regions of the part, binder concentration is equal to the nominal concentration for the selected cemented carbide grade. Therebetween, a concentration gradient is present wherein the concentration of the binder decreases from nominal in the interior of the part to at or near zero at the substrate surface. Concentration of the binder in the near surface region is controlled to form this gradient of decreasing binder concentration moving from the interior of the part to the outer surface of the substrate. The decreasing binder concentration of the present invention extends over a selected distance, which is controlled by processing parameters, for example duration of each step, concentration of the etching solutions, temperature, and the nominal binder concentration. Control of these parameters and their affects can be readily ascertained based from the methods described herein by one of ordinary skill in the art. Selected distances over which the gradient extends range from approximately 25-500 microns, preferably 100-250 microns.
Binders may be selected from any of Co, Ni, Fe or combinations thereof, wherein Co comprises a minimum weight percent of 50% of the binder. In a preferred embodiment, the binder is cobalt, with inevitable impurities. Nominal binder concentration may be selected to achieve various properties in the part, but generally ranges from 3-20 weight %, preferably 5-12 weight %. Cemented WC parts of the invention may incorporate cubic carbides such as TiC, TaC, NbC, VC, HfC, Cr 2 C 3 and ZrC, and combinations thereof in concentrations up to about 30 weight % of the total weight.
In a first embodiment of the invention, the substrate is a cobalt cemented tungsten carbide material having a nominal binder concentration of 6 weight %. The binder concentration in the interior of the part is nominal and decreases to less than nominal along a gradient to the near surface regions of the part, preferably the near surface regions are from 5-10 microns beneath the surface. The concentration gradient begins at approximately 100-250 microns below the surface, with the binder concentration gradually decreasing until it reaches a minimum at the near surface region, as illustrated in FIGS. 1 and 2 .
In a second preferred embodiment, having a nominal binder concentration of 6 weight %, the gradient begins at 400 microns below the surface and reaches a minimum at the near surface region, as illustrated in FIG. 3 .
The surface has a porosity of less than 1 volume %. Preferably maximum porosity is less than 0.5 volume %, most preferably ranging from 0.4 to 0.1 volume %. In the most preferred embodiment, the porosity is less than 0.2 volume %. The part also exhibits substantially no distortion, which would contribute to malformation or warpage of the finished article.
The present method of producing articles with an eta-phase-free, binder gradient includes removing binder from the sintered part surface and near surface regions over a selected distance into the interior of the part and subsequent heat treating to cause migration of binder from the interior of the article into the binder depleted region. The result of this process is a controlled change in concentration of binder without spikes in concentration of binder to greater than nominal in the substrate. While greater than nominal concentrations of binder are considered beneficial in prior art, it is believed that low concentration gradually increasing to nominal, without regions of high binder concentration, provide a more cohesive substrate and better predictability in performance of the article of the present invention.
Optionally, the articles may also be ground, subjected to a carbon correction or other processing provided that such processing does not interfere with the effectiveness of the described binder removal and heat-treating process.
Binder removal according to the present invention is generally accomplished through chemical etching. See, for example, U.S. Pat. No. 5,560,839 which details a variety of chemical systems for etching cobalt binder, the content of which is incorporated here by reference in its entirety. While any of the afore-referenced chemical systems may be used to etch the binder phase, the preferred embodiment makes use of a ferric chloride solution to chemically etch the binder from the substrate to a selected depth. Those skilled in the art will recognize that the depth of etching of the binder will depend upon the molality of the ferric chloride solution, the temperature, the reaction time, and the composition of the part (i.e. nominal cobalt content, binder chemistry and carbide grain size) so that some reaction experimentation is expected prior to industrial application to define optimum process parameters. Preferred concentrations of ferric chloride aqueous solutions for use in the present invention range from 0.005 M to 1.0 M, but other concentrations known in the art may be used. An approximately 20 micron depth of etch may be achieved by immersing the selected article in 0.005 M ferric chloride for a period of approximately 2 hours; doubling the immersion time yields an approximately 37 micron depth of etch.
Those skilled in the art will recognize that the preferred depth of binder removal is dependant upon the end use to which the cemented carbide part will be put, and the ranges given herein are not to be construed as limiting, but rather as merely illustrative of use for a cutting tool insert. Alternately, binder may be removed via other methods known in the art that are not incompatible with the remainder of the process.
The apparatus used in the heat-treating process of the present invention comprises an enclosed vessel and a retort of steel or other suitable material. The reaction vessel is provided with an inlet and an outlet whereby the gaseous atmosphere for heat-treating enters the vessel through the inlet, flow through a reaction zone containing the part and exits through an outlet. Typically the vessel includes a premix area such as a chamber, where the gases utilized are premixed at a temperature lower than the heat-treating temperature. This premix area can be internal or external to the vessel or the reaction zone. In one embodiment uniformly mixed gases exiting the premix chamber flow into the inlet and continue into the reaction zone. The apparatus is equipped with furnace controls for process parameter regulation, such as monitoring and adjusting processing time, the vessel's temperature and pressure, the temperature and pressure of the premix area, flow rate and partial pressures of gasses at selected points within the apparatus. Preferably, as is typical of manufacturing level furnaces, the furnace controls can be set at selected process parameters utilizing a personal computer or other computer interface with the operator. To maintain repeatability from batch to batch, in the most preferred embodiment, the process parameters are computer controlled.
The articles, cutting tools or inserts to be heated are positioned in the reaction zone by conventional means, such as tables, trays or other fixtures known in the art. The reaction vessel includes heating elements typically in the form of graphite. The reaction vessel is loaded with articles, cutting tools or inserts and may be flushed with a suitable inert gas such as nitrogen, argon, or the like. Typically, the vessel is vacuum evacuated and the temperature ramped up to within the range of 900-1300° C. and the carburizing gas is introduced. The temperature may be increased to not more than 1350° C., preferably 1300-1330° C., or maintained and the inserts held at this temperature for a sufficient time to cause diffusion of binder from the interior of the article into the etched portion, without causing deleterious warpage of the article or migration of the binder onto the surface of the article. In a preferred embodiment of the invention, carbon monoxide comprises the atmosphere in the reaction vessel during the heating step. The pressure during the heating step can be atmospheric pressure or less. Suitable pressures are within the knowledge of one of ordinary skill in the art based upon the composition and size of the carbide article and can be readily determined.
The present invention will become even clearer upon consideration of the following examples, which are intended to be illustrative of the present invention, and not limiting.
EXAMPLE 1
Step 1: Groups of sintered cemented carbide inserts containing <0.5 weight % cubic carbides and 6 weight % cobalt, were treated with freshly prepared 0.05 M ferric chloride solutions for periods of 2 and 4 hours respectively. Upon examination, the cobalt binder in the inserts was found to have been etched away to depths of 20±1 microns and 37±2 microns respectively. A second set of cemented carbide inserts containing <1 weight % cubic carbides and 12.3 weight % cobalt was top and bottom ground and then etched to depths of 21±1 micron and 34±2 microns using freshly prepared 0.05 M ferric chloride solutions for periods of 4.5 and 9 hours respectively.
Step 2: Inserts selected from each group prepared in Step 1 were heated in a furnace to approximately 1100° C. for 100 minutes in a vacuum. A second batch of the selected inserts was heated in a furnace to approximately 1250° C. for 100 minutes in a vacuum. The heat-treated inserts were then cross-sectioned, polished and examined at a magnification of 1000× on an optical microscope. No differences between the etched and the etched/heat treated inserts were observed.
EXAMPLE 2
Inserts prepared according to Example 1, Step 1, were heated in a furnace to approximately 1300° C. for 100 minutes in a vacuum. The heat-treated inserts were examined as in Example 1, step 2. Partial filling of voids in the substrate and some reduction in the cobalt content just below the etched region was observed.
EXAMPLE 3
Inserts prepared according to Example 1, Step 1, were heated in a furnace to approximately 1350° C. for 100 minutes in 1 torr argon. The resulting inserts had cobalt on the periphery and the edges were distorted.
EXAMPLE 4
Step 1: Group A sintered cemented carbide inserts containing <0.5 weight % cubic carbides and 6 weight % cobalt were etched to depths of 20±1 microns using freshly prepared 0.05 M ferric chloride solutions for 2 hours, and Group B sintered cemented carbide inserts containing <1 weight % cubic carbide and 12.3 weight % cobalt, were etched to depths of 21±1 microns using freshly prepared 0.05 M ferric chloride solutions for 4.5 hours.
Step 2: Group A and B were heat treated in 10 torr carbon monoxide. The gas was introduced at 1250° C., the temperature was ramped up to 1325° C. and held for 100 minutes. The resulting inserts were uniformly light gray in color. Losses in mass ranged from 0.01% to 0.02% and decreases in magnetic saturation levels (Ms) ranged from 0.28% to 0.37%. Surfaces of the inserts were examined optically at 1000×; well-defined WC grains were visualized and a lack of surface Co or distortion was noted. The heat-treated inserts were also examined as in Example 1, Step 2.
Cemented carbide articles which have been made according to the present invention may also be subjected to coating with monolayer or multilayer coatings.
It is intended that the specification and examples be considered as exemplary only. Other embodiments of the invention, within the scope and spirit of the aforementioned claims will be apparent to those of skill in the art from practice of the invention disclosed herein and consideration of this specification. All documents referred to herein are hereby incorporated by reference, in their entirety.
While the present invention has been described by reference to the above-mentioned embodiments, certain modifications and variations will be evident to those of ordinary skill in the art. Therefore, the present invention is limited only by the scope and spirit of the appended claims.
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An eta-phase-free cemented carbide insert with improved surface hardness and wear resistance containing WC, and possibly cubic phases of a carbide and/or carbonitride, in a binder phase of Co, Ni, Fe or a combination thereof, with a binder phase gradient in the surface and near surface regions, is disclosed. The nominal binder phase content in the insert is 3-20 weight %. The surface, and near surface cobalt content is 50-100% of the binder phase content of the inner portion of the insert. The insert is formed by standard sintering practices, followed by the chemical removal of the binder phase from the surface and near surface regions of the insert. The insert is then heat treated at a temperature of 1300-1350° C. in a carburizing atmosphere, for a time of 5-400 minutes to cause diffusion of the binder phase from the interior into the binder depleted surface regions.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application 60/747,106, filed May 12, 2006; U.S. Provisional Patent Application 60/821,764, filed Aug. 8, 2006; and U.S. Provisional Patent Application 60/863,810, filed Nov. 1, 2006; and U.S. Provisional Patent Application 60/867,401, filed Nov. 28, 2006. All of these related applications are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to memory devices, and specifically to methods and devices for reducing errors in data storage and readout.
BACKGROUND OF THE INVENTION
[0003] Several types of memory devices, such as Flash memories and Dynamic Random Access Memory (DRAM), use arrays of analog memory cells for storing data. Flash memory devices are described, for example, by Bez et al., in “Introduction to Flash Memory,” Proceedings of the IEEE 91:4 (April, 2003), pages 489-502, which is incorporated herein by reference. In such memory devices, each analog memory cell typically comprises a transistor, which holds a certain amount of electric charge that represents the information stored in the cell. The electric charge written into a particular cell influences the “threshold voltage” of the cell, i.e., the voltage that needs to be applied to the cell so that the cell will conduct current.
[0004] Some memory devices, commonly referred to as Single-Level Cell (SLC) devices, store a single bit of information in each memory cell. Typically, the range of possible threshold voltages of the cell is divided into two regions. A voltage value falling in one of the regions represents a “0” bit value, and a voltage belonging to the second region represents “1”. Higher-density devices, often referred to as Multi-Level Cell (MLC) devices, store more than one bit per memory cell. In multi-level cells, the range of threshold voltages is divided into more than two regions, with each region representing more than one bit.
[0005] Multi-level Flash cells and devices are described, for example, by Eitan et al., in “Multilevel Flash Cells and their Trade-Offs,” Proceedings of the 1996 IEEE International Electron Devices Meeting ( IEDM ) (New York, N.Y.), pages 169-172, which is incorporated herein by reference. The paper compares several kinds of multilevel Flash cells, such as common ground, DINOR, AND, NOR and NAND cells. Other types of analog memory cells that are known in the art include Nitride Read Only Memory (NROM), Ferroelectric RAM (FRAM), Magnetic RAM (MRAM) and Phase change RAM (PRAM, also referred to as Phase Change Memory—PCM).
[0006] In some applications, the data stored in the memory device is encoded using an Error Correcting Code (ECC). For example, Rodney and Sayano describe a number of on-chip coding techniques for the protection of Random Access Memory (RAM) devices, which use multi-level storage cells, in “On-Chip ECC for Multi-Level Random Access Memories,” Proceedings of the 1989 IEEE/CAM Information Theory Workshop (Jun. 25-29, 1989, Ithaca, N.Y.), which is incorporated herein by reference. As another example, U.S. Pat. No. 6,212,654, whose disclosure is incorporated herein by reference, describes methods for storing data in an analog memory device using coded modulation techniques. Other ECC schemes for multilevel memory devices are described in U.S. Pat. Nos. 6,469,931 and 7,023,735, whose disclosures are incorporated herein by reference.
[0007] The threshold voltage values read from analog memory cells are sometimes distorted. The distortion may be due to various causes, such as electrical field coupling from neighboring memory cells, disturb noise caused by operations on other cells in the array, and threshold voltage drift caused by device aging. Some common distortion mechanisms are described in the article by Bez et al., cited above.
[0008] U.S. Pat. No. 5,867,429, whose disclosure is incorporated herein by reference, describes a method for compensating for electric field coupling between floating gates of a high-density Flash Electrically Erasable Programmable Read Only Memory (EEPROM) cell array. A reading of a cell is compensated by first reading the states of all cells that are field-coupled with the cell being read. A number related to either the floating gate voltage or the state of each coupled cell is then multiplied by the coupling ratio between the cells. The breakpoint levels between states for each of the cells are adjusted by an amount that compensates for the voltage coupled from adjacent cells.
SUMMARY OF THE INVENTION
[0009] Embodiments of the present invention provide a method for storing data in an array of analog memory cells. The method includes defining a constellation of voltage levels to be used in storing the data in the analog memory cells, and writing a part of the data to a first analog memory cell in the array by applying to the analog memory cell a first voltage level selected from the constellation. After writing the part of the data to the first analog memory cell, a second voltage level that does not belong to the constellation is read from the first analog memory cell. A modification to be made in writing to one or more of the analog memory cells in the array is determined responsively to the second voltage level. Data are written to the one or more of the analog memory cells subject to the modification.
[0010] In some embodiments, determining the modification includes selecting one or more third voltage levels to be written respectively to one or more of the analog memory cells, and writing to the one or more of the analog memory cells includes writing the one or more third voltage levels to the one or more of the analog memory cells.
[0011] In a disclosed embodiment, selecting the one or more third voltage levels includes determining a voltage correction to be applied to the first analog memory cell, and writing the one or more third voltage levels includes adding charge to the first analog memory cell so as to apply the voltage correction. Typically, defining the constellation includes defining a matrix of codewords to represent the data, each codeword corresponding to a set of the voltage levels in the constellation that are to be written to a corresponding set of the analog memory cells, and determining the voltage correction includes finding a distance between the set of the voltage levels, including the second voltage level, read from the corresponding set of the analog memory cells and one of the codewords in the matrix, and choosing the voltage correction so as to reduce the distance.
[0012] Writing the part of the data may include choosing a first codeword in the matrix to be written to the corresponding set of the analog memory cells, and finding the distance may include determining a first distance between the set of the voltage levels and the first codeword and a second distance between the set of the voltage levels and a second codeword in proximity to the first codeword, whereupon choosing the voltage correction includes computing the voltage correction so as to reduce a ratio of the first distance to the second distance.
[0013] Alternatively, the method may include, when the distance exceeds a maximal distance criterion, rewriting the part of the data to the first analog memory cell.
[0014] In another embodiment, selecting the one or more third voltage levels includes selecting a third voltage level from the constellation to be written to a second analog memory cell. Typically, selecting the third voltage level includes choosing the third voltage level responsively to both the first voltage level and the second voltage level, while applying feedback coding so as to write multiple successive voltage levels representing the data to a succession of the analog memory cells.
[0015] Applying the feedback coding may include choosing the first voltage level responsively to a probability density function (PDF), which relates the data to the voltage levels that are to be used in storing the data in the analog memory cells, and choosing the third voltage level may include updating the PDF responsively to the first and second voltage levels, and choosing the third voltage level responsively to the updated PDF. When the constellation includes 2 M voltage levels in each of the analog memory cells, wherein M>1, and choosing the third voltage level may include partitioning the PDF into 2 M sub-intervals corresponding to the 2 M voltage levels, selecting one of the sub-intervals responsively to a value of the data, and choosing the third voltage level that corresponds to the selected one of the sub-intervals.
[0016] Additionally or alternatively, writing the part of the data may include writing respective first voltage levels to a first group of the memory cells in a first row in the array, wherein the second analog memory cell belongs to a second group of the memory cells in a second row of the array, to which the one or more third voltage levels are written after writing to the memory cells in the first row, and wherein each of the memory cells is located in a respective column, and selecting the third voltage level includes determining a respective third voltage level to write to each of the memory cells in the second group responsively to the second voltage level read from one of the first group of the memory cells in the same respective column.
[0017] Further additionally or alternatively, writing the part of the data may include simultaneously writing respective first voltage levels to a first group of the memory cells in a first row in the array, wherein the first and second analog memory cells are chosen from among the memory cells in the group responsively to an ordering of the voltage levels to be written to the memory cells.
[0018] In some embodiments, the constellation has a first voltage resolution, and reading the second voltage level includes determining the second voltage level with a second voltage resolution that is finer than the first voltage resolution.
[0019] Typically, the memory cells are selected from a set of memory cell types consisting of Flash memory cells, Dynamic Random Access Memory (DRAM) cells, Phase Change Memory (PCM) cells, Nitride Read-Only Memory (NROM) cells, and Magnetic Random Access Memory (MRAM) cells.
[0020] In a disclosed embodiment, the constellation of the voltage levels includes at least four voltage levels per cell.
[0021] In some embodiments, the constellation is modified responsively to the second voltage level. In one embodiment, modifying the constellation includes increasing at least one of the voltage levels to be used in storing the data.
[0022] In other embodiments, the modification includes changing a number of error correction bits that are to be added to a word of the data.
[0023] There is also provided, in accordance with an embodiment of the present invention, apparatus for storing data, including:
[0024] a read/write unit, which is coupled to an array of analog memory cells so as to write a part of the data to a first analog memory cell in the array by applying to the analog memory cell a first voltage level selected from a predefined constellation of voltage levels, and which is configured to read from the first analog memory cell, after writing the part of the data thereto, a second voltage level that does not belong to the constellation; and
[0025] a signal processing unit, which is configured to determine, responsively to the second voltage level, a modification to be made in writing to one or more of the analog memory cells in the array, and to instruct the read/write unit to write to the one or more of the analog memory cells subject to the modification.
[0026] The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken together with the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a block diagram that schematically illustrates a memory system, in accordance with an embodiment of the present invention;
[0028] FIG. 2 is a schematic circuit diagram that illustrates a memory cell array, in accordance with an embodiment of the present invention;
[0029] FIG. 3 is a schematic plot of voltage distribution in an array of multi-level memory cells, in accordance with an embodiment of the present invention;
[0030] FIG. 4 is a schematic plot of constellation points and voltage values used in programming a memory device with encoded data, in accordance with an embodiment of the present invention;
[0031] FIG. 5 is a flow chart that schematically illustrates a method for programming a memory device, in accordance with an embodiment of the present invention; and
[0032] FIG. 6 is a flow chart that schematically illustrates a method for programming a memory device, in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
Overview
[0033] Some analog memory devices use a process of “program and verify” (P&V) in writing information to the memory cells. In a typical P&V process, a cell is programmed by applying a sequence of voltage pulses, whose voltage level increases from pulse to pulse. The programmed voltage level is read (“verified”) after each pulse, and the iterations continue until the desired level is reached. P&V processes are described, for example, by Jung et al., in “A 117 mm 2 3.3V Only 128 Mb Multilevel NAND Flash Memory for Mass Storage Applications,” IEEE Journal of Solid State Circuits 11:31 (November, 1996), pages 1575-1583, and by Takeuchi et al., in “A Multipage Cell Architecture for High-Speed Programming Multilevel NAND Flash Memories,” IEEE Journal of Solid - State Circuits 33:8 (August,), pages 1228-1238, which are both incorporated herein by reference.
[0034] The embodiments of the present invention that are described hereinbelow improve upon the conventional program-and-verify model by measuring the voltages of analog memory cells against a set of levels that are different from the constellation of levels that correspond to the data values that may be written to the cells. Typically, although not necessarily, the set of levels used in measuring the cell voltages has finer resolution, i.e., is more tightly spaced, than the set of levels in the write constellation. The measured voltage levels may then be used, for example, in providing fine correction to the amount of charge already stored in the cells, or in a feedback coding scheme for determining the voltage levels to be used in writing to subsequent cells in the array.
[0035] These fine correction and measurement schemes increase the accuracy of programming the memory and thus reduce the likelihood of data error at readout. Such schemes may thus be used in enhancing memory reliability or, alternatively or additionally, in achieving increased storage density and/or lifetime.
System Description
[0036] FIG. 1 is a block diagram that schematically illustrates a memory system 20 , in accordance with an embodiment of the present invention. System 20 can be used in various host systems and devices, such as in computing devices, cellular phones or other communication terminals, removable memory modules (such as “disk-on-key” devices), digital cameras, music and other media players and/or any other system or device in which data is stored and retrieved. In a typical application, memory system 20 interacts with a memory controller 22 , i.e., accepts data for storage from the memory controller and outputs data that are stored in memory to the memory controller when requested.
[0037] System 20 comprises a memory device 24 , which stores data in a memory cell array 28 . The memory array comprises multiple analog memory cells 32 . In the context of the present patent application and in the claims, the term “analog memory cell” is used to describe any memory cell that holds a continuous, analog value of a physical parameter, such as an electrical voltage or charge. Array 28 may comprise analog memory cells of any kind, such as, for example, NAND or NOR Flash cells, or PCM, NROM, FRAM, MRAM or DRAM cells. The charge levels stored in the cells and/or the analog voltages written into and read out of the cells are referred to herein collectively as analog values.
[0038] Data for storage in memory device 24 are provided to the device and cached in data buffers 36 . The data are then converted to analog voltages and written into memory cells 32 using a reading/writing (R/W) unit 40 , whose functionality is described in greater detail below. When reading data out of array 28 , unit 40 converts the electric charge, and thus the analog voltages, of memory cells 32 , into digital samples. The samples are cached in buffers 36 . The samples produced by unit 40 are referred to as soft samples. The operation and timing of memory device 24 are managed by control logic 48 .
[0039] Storage and retrieval of data in and out of memory device 24 are performed by a Memory Signal Processor (MSP) 52 . MSP 52 intermediates between memory device 24 and memory controller 22 or other host. As will be shown in detail hereinbelow, MSP 52 applies novel methods in determining the analog values that are to be written to memory array 28 in order to improve the reliability and storage density of the data.
[0040] MSP 52 comprises an encoder/decoder 64 , which typically encodes the data to be written to device 24 using an error correcting code (ECC), and decodes the ECC when reading data out of device 24 . A signal processing unit 60 processes the data that are written into and retrieved from device 24 . In particular, as data are programmed into cells 32 , unit 60 receives digital samples that are indicative of the measured voltage levels of the cells, and then determines further voltage levels to be written (to the same cells and/or other cells) on this basis. Techniques that may be used by unit 60 for this purpose are described in detail hereinbelow with reference to FIGS. 4-6 . Alternatively or additionally, these techniques may be implemented, mutatis mutandis, in the circuitry of memory device 24 , and specifically in R/W unit 40 .
[0041] MSP 52 comprises a data buffer 72 , which is used by unit 60 for storing data and for interfacing with memory device 24 . MSP 52 also comprises an Input/Output (I/O) buffer 56 , which forms an interface between the MSP and the host. A memory management unit 76 manages the operation and timing of MSP 52 . Signal processing unit 60 and management unit 76 may be implemented in hardware. Alternatively, unit 60 and/or unit 76 may comprise microprocessors that run suitable software, or a combination of hardware and software elements. Further alternatively, memory controller 22 or even a host processor may be configured to carry out some or all of the functions of the signal processing and management units that are described hereinbelow, as well as other functions of MSP 52 .
[0042] The configuration of FIG. 1 is an exemplary system configuration, which is shown purely for the sake of conceptual clarity. Any other suitable configuration can also be used. Elements that are not necessary for understanding the principles of the present invention, such as various interfaces, addressing circuits, timing and sequencing circuits, data scrambling circuits and debugging circuits, have been omitted from the figure for clarity.
[0043] In the exemplary system configuration shown in FIG. 1 , memory device 24 and MSP 52 are implemented as two separate Integrated Circuits (ICs). In alternative embodiments, however, the memory device and MSP may be integrated in a single IC or System on Chip (SoC). In some implementations, a single MSP 52 may be connected to multiple memory devices 24 . Additional architectural and functional aspects of system 20 and other possible embodiments of the present invention are described in greater detail in U.S. Provisional Patent Application 60/867,399 and in a PCT patent application entitled, “Combined Distortion Estimation and Error Correction Coding for Memory Devices,” filed on even date, both of which are incorporated herein by reference.
[0044] In a typical writing operation, data to be written into memory device 24 are accepted from the host and cached in I/O buffer 56 . Encoder/decoder 64 encodes the data, and the encoded data are transferred, via data buffers 72 , to memory device 24 . In device 24 the data are temporarily stored in buffers 36 . R/W unit 40 converts the data to analog voltage values and writes the data (as analog voltage values) into the appropriate cells 32 of array 28 . After writing the analog voltage values to a cell or group of cells, R/W unit 40 reads the analog voltage values from the cell(s) and converts the voltages to soft digital samples. The samples are cached in buffers 36 and transferred to buffers 72 of MSP 52 . Signal processing unit 60 processes the data samples, using methods that are described hereinbelow, in order to determine data values to be written subsequently by R/W unit.
[0045] When data are to be read out of system 20 to controller 22 , R/W unit 40 reads the analog voltage values from the appropriate cells and converts these voltage values to digital samples in buffers 36 . Blocks of data are transferred from buffers 72 to unit 60 , and encoder/decoder 64 decodes the ECC of these blocks. Encoder/decoder 64 may use distortion estimation provided by unit 60 to improve the performance of the ECC decoding process (as described in the above-mentioned PCT patent application). The decoded data are transferred via I/O buffer 56 to the memory controller or host.
Memory Array Structure and Programming
[0046] FIG. 2 is a diagram that schematically illustrates memory cell array 28 , in accordance with an embodiment of the present invention. Although cells 32 in FIG. 2 represent Flash memory cells, which are connected in a particular array configuration, the principles of the present invention are applicable to other types of memory cells and other array configurations, as well. Some exemplary cell types and array configurations that may be used in this context are described in the references cited in the Background section above.
[0047] Memory cells 32 of array 28 are arranged in a grid having multiple rows and columns. Each cell 32 comprises a floating-gate Metal-Oxide Semiconductor (MOS) transistor. A certain amount of electrical charge (electrons or holes) can be stored in a particular cell by applying appropriate voltage levels to the transistor gate, source and drain. The value stored in the cell can be read by measuring the threshold voltage of the cell, which is defined as the minimal voltage that must be applied to the gate of the transistor in order to cause the transistor to conduct. The read threshold voltage is indicative of the charge stored in the cell.
[0048] In the exemplary configuration of FIG. 2 , the gates of the transistors in each row are connected by word lines 80 . The sources of the transistors in each column are connected by bit lines 84 . In some embodiments, such as in some NOR cell devices, the sources are connected to the bit lines directly. In alternative embodiments, such as in some NAND cell devices, the bit lines are connected to strings of floating-gate cells.
[0049] Typically, R/W unit 40 reads the threshold voltage of a particular cell 32 by applying varying voltage levels to its gate (i.e., to the word line to which the cell is connected) and checking whether the drain current of the cell exceeds a certain threshold (i.e., whether the transistor conducts). Unit 40 usually applies a sequence of different voltage values to the word line to which the cell is connected, and determines the lowest gate voltage value for which the drain current exceeds the threshold. Unit 40 then outputs a digital sample to data buffers 36 corresponding to this gate voltage, thus indicating the voltage level of the cell. Typically, unit 40 reads an entire row of cells, also referred to as a page, simultaneously. Alternatively, unit 40 may read cells individually.
[0050] In some embodiments, unit 40 measures the drain current by pre-charging the bit line of the cell to a certain voltage level. Once the gate voltage is set to the desired value, the drain current causes the bit line voltage to discharge through the cell. Unit 40 measures the bit line voltage several microseconds after the gate voltage is applied, and compares the bit line voltage to the threshold. In some embodiments, each bit line 84 is connected to a respective sense amplifier (not shown in the figures), which compares the bit line voltage to the threshold using a comparator.
[0051] The above method of voltage reading is described solely by way of example. Alternatively, R/W unit 40 may use any other suitable method for reading the threshold voltages of cells 32 . For example, unit 40 may comprise one or more Analog to Digital Converters (not shown in the figures), which convert the bit line voltages to digital samples.
[0052] In some embodiments, entire pages (rows) are written and read in parallel. Typically, adjacent pages are written in succession, one after another. In alternative embodiments, cells are written sequentially across each row and may likewise be read sequentially.
[0053] FIG. 3 is a schematic plot showing voltage distributions in memory cell array 28 , in accordance with an embodiment of the present invention. FIG. 3 demonstrates inaccuracy that can occur in writing values to the memory cell array. In the example of FIG. 3 , each cell 32 stores two bits of information using a constellation of four nominal threshold voltage levels. In order to store two data bits in a memory cell, R/W unit 40 writes one of the four nominal voltage levels into the cell. In the present example, voltage level 90 A corresponds to “11” bit values. Voltage levels 90 B . . . 90 D correspond to “01”, “00” and “10” bit values, respectively.
[0054] Although the R/W unit writes a particular nominal voltage level, the actual threshold voltage level of the cell usually deviates from the nominal level, because of distortion mechanisms and other nonuniformities. Curves 92 A . . . 92 D show an exemplary voltage distribution created during the initial program stage of a program-and-verify procedure. Curve 92 A shows the distribution of voltages in the cells that store “11” bit values. Curves 92 B, 92 C and 92 D show the voltage distribution in the cells that store “01”, “00” and “10” bit values, respectively.
[0055] For purposes of verification, a different set of voltage levels is used—in this case a set of levels with finer resolution than the constellation of write voltages represented by levels 90 A . . . 90 D. The total range of threshold voltages is divided in this example into sixteen intervals 96 by defining fifteen read thresholds 94 . Thus, R/W unit 40 reads the threshold voltage levels of the memory cells using four-bit conversion, depending on the decision interval in which the threshold level read from the cell falls. MSP 52 uses this readout in determining voltages to be written to array 28 subsequently, as described in detail hereinbelow. The particular read thresholds and intervals shown in FIG. 3 were chosen solely by way of example. The R/W unit may alternatively use different read thresholds, at different voltages and at higher or lower resolution (bits/sample), depending on performance requirements.
Correcting Cell Voltage Values
[0056] FIG. 4 is a schematic plot of a matrix of constellation points 150 and corresponding voltage values used in programming memory device 24 with encoded data, in accordance with an embodiment of the present invention. Each constellation point 150 represents a legal codeword. As explained above, encoder/decoder 64 encodes input data words that are to be written to memory array 28 in multi-bit codewords, which are then stored over groups of cells 32 . The size of the group of cells depends on the length of the codeword, and may typically extend over an entire page of the array. In this example, however, for the sake of simplicity, it is assumed that three bits of input data are encoded at rate ¾ and are thus stored as a four-bit codeword in two cells. The two bits stored in each cell are represented by respective voltage levels V 1 and V 2 , which may be set to values A, B, C and D. Points 150 in the codeword constellation represent the eight pairs of voltage values that may legally correspond to input data words. More generally, if each codeword in a given coding scheme is to be stored over a group of m cells, then the constellation of legal voltage values could be represented as a matrix of points in an m-dimensional space.
[0057] As explained above, the actual voltage values read from cells 32 in array 28 typically spread over a range of values around the nominal values represented by constellation points 150 . Thus, in the example shown in FIG. 4 , a pair of cells, represented by the respective voltage levels V 1 and V 2 , were programmed with an intent to write the voltages represented by a target constellation point 150 a . Because of distortion mechanisms and programming inaccuracies, however, the actual voltages of the cells, represented by an initial point 152 , may deviate on one or both axes from the nominal values of target constellation point 150 a . As a result, when the voltage values are subsequently read out and decoded, the codeword may be erroneously identified as corresponding to another nearby constellation point 150 b (particularly if distortion mechanisms in device 24 cause a subsequent shift in the voltage values that are read out).
[0058] In order to reduce the effect of this sort of error, R/W unit 40 reads out the voltage levels V 1 and V 2 in the verify stage with resolution that is finer than the nominal resolution of the constellation, as illustrated by thresholds 94 and intervals 96 in FIG. 3 . Signal processing unit 60 (or alternatively, the R/W unit itself) determines a voltage addition ΔV that may be applied to one or more of the cells so as to bring the voltage levels to a corrected point 154 that is closer to target constellation point 150 a , without approaching any of the other constellation points. An exemplary method for this purpose is described below with reference to FIG. 5 . This correction mechanism reduces the likelihood of error upon readout. It can thus be used to enhance the reliability of system 20 or, alternatively or additionally, to permit the storage of data in the system with greater density.
[0059] FIG. 5 is a flow chart that schematically illustrates a method for programming memory device 24 , in accordance with an embodiment of the present invention. Initially, as explained above, R/W unit 40 programs a block of cells 32 , such as a page, in array 28 with the nominal voltage levels of the constellation point corresponding to the bits of a codeword generated by MSP 52 , at a program step 160 . The R/W unit then reads out the voltage levels of the cells in the block that it has programmed, at a verification step 162 . As noted above, the readout is performed using a different set of voltage levels from the nominal write levels used at step 160 . Typically, the readout is performed with finer resolution, using thresholds 94 ( FIG. 3 ), for example. The R/W unit passes the voltage levels that it has read out, in the form of digital sample values, to signal processing unit 60 .
[0060] The signal processing unit finds the location of initial point 152 corresponding to this set of voltage readout values in the m-dimensional constellation space, and calculates the distance of the initial point from the target constellation point, at a distance computation step 164 . Any suitable distance measure, such as the Euclidean (sum of squares) distance, may be used at this step. The signal processing unit may also find the distances from the initial point to other nearby constellation points. Referring to the example shown in FIG. 4 , the signal processing unit will find the distances from point 152 to points 150 a and 150 b , and possibly to other nearby constellation points.
[0061] Signal processing unit 60 compares the distance from the initial point to target point 150 a with the distances to other constellation points, at a distance checking step 166 . For example, the signal processing unit may find the ratio of these distances. If the ratio is smaller than a predefined threshold, for example, less than ½, then the signal processing unit may conclude that the present codeword has been written correctly, and may proceed to the next block of cells. Alternatively or additionally, another threshold may be defined such that if the distance from the initial point to target 150 a is smaller than then threshold, then the signal processing unit concludes that the present codeword has been written correctly, without reference to the ratio.
[0062] If the ratio is too large, however, the signal processing unit checks whether it is possible to improve the ratio by correcting the voltage in one or more of the cells in the present block, at a correction checking step 168 . Typically, the signal processing unit determines whether, by adding charge to one or more of the cells, it will be possible to decrease the ratio, i.e. to bring the set of cell voltages closer to the target constellation point without reducing substantially the distances to other constellation points. In the example shown in FIG. 4 , adding charge corresponding to voltage ΔV to one of the cells will bring the voltage levels from initial point 152 to corrected point 154 , which is near target point 150 a and farther from point 150 b . The signal processing unit instructs R/W unit 40 to apply the appropriate voltage to the cell or cells in question, at a charge addition step 170 . The new charge level may optionally be verified, and the process then moves on to the next codeword.
[0063] Alternatively, signal processing unit 60 may conclude at step 168 that it is not possible to correct the initial point written at step 160 . The reason may be that the initial point is too far from the target point to be effectively corrected by addition of charge to the cells, or that attempting to correct the voltage will bring the point too close to an incorrect constellation point, or that charge must be removed from one or more of the cells (which is not possible without erasure of the cells). In this case, the signal processing unit may instruct R/W unit 40 to rewrite the entire block. Optionally, the codeword may be revised before writing to contain a greater number of bits, by adding parity bits, for example (or the number of data bits encoded by the codeword may be reduced), thereby effectively spacing constellation points 150 farther apart in the constellation space. Increasing the size of the codeword in this manner effectively reduces the information capacity of the block in question. Methods for adapting information storage to the achievable capacity of memory cells in an array are described further, for example, in a PCT patent application entitled “Memory Device with Adaptive Capacity,” filed on even date, which is assigned to the assignee of the present patent application and whose disclosure is incorporated herein by reference.
[0064] The R/W unit then returns to verify the rewritten block at step 162 , and the process of verification and possible correction is repeated, as described above. If the signal processing unit returns to step 168 and again finds the point written at step 172 to be too far from the target point, it may mark the current block in array 28 as a bad block, and then proceed to rewrite the current codeword to another block in the array.
[0065] The addition of charge to target cells at step 170 is useful when the cell voltage is found at step 164 to be lower than that of the target point. Alternatively, in some cases, such as when the measured cell voltage is above that of the target point, MSP 52 may decide to modify the constellation, typically by increasing the voltage levels of the constellation. (A drawback of this approach is that the use of higher programming voltages may cause a high level of wear to the memory cells.) The MSP may add to the data an indication that the constellation levels have been increased, by setting a flag, for example.
[0066] Although the method of FIG. 5 is described above in the context of correcting cell voltages at the time of programming, the principle of this method may be applied at long periods (even years) after programming, in order to combat distortions due to aging and leakage current.
Reducing Programming Errors Using Feedback
[0067] FIG. 6 is a flow chart that schematically illustrates a method for programming device 24 , in accordance with another embodiment of the present invention. This method uses feedback coding, in which signal processing unit 60 applies the values of voltage written to preceding cells in determining the voltage to be written to the current cell. The basic principles of feedback coding in communication systems are described, for example, by Horstein, in “On the Design of Signals for Sequential and Nonsequential Detection Systems with Feedback,” IEEE Transactions on Information Theory IT-12:4 (October, 1966), pages 448-455, which is incorporated herein by reference.
[0068] The method of FIG. 6 is initiated when signal processing unit 60 receives a data word (or a sequence of multiple words) to be written to array 28 , at a data reception step 180 . In Flash memories, as noted above, each word may correspond to an entire page (row) of cells 32 , and the voltage values corresponding to the bits of the word may be written to all the cells in the page simultaneously. Furthermore, these voltage values may correspond to two or more bits per cell. For purposes of simplicity in the present explanation, however, it will first be assumed that the cell voltages are written to the array sequentially, cell by cell, and that the voltages represent a single bit per cell. Extensions of the principles of this method to multiple bits per cell and to simultaneous programming of multiple cells are described further hereinbelow.
[0069] For the sake of the feedback coding scheme, the sequence of bits that is to be written to a sequential group of cells is represented as a “floating point” number x, wherein 0≦x<1. In other words, the information bits to be stored in the array are the bits in the binary 2's complement representation of x, normalized to the range 0≦x<1, starting from the most significant bit (MSB) and moving sequentially to the right. Signal processing unit 60 determines the voltage value to be written to each cell by applying a probability distribution function (PDF) to the bits in x, at a voltage computation step 182 . For purposes of computing the PDF in the simplified method that follows, array 28 is assumed to behave as a binary symmetric channel (BSC), meaning that each bit is written correctly to a cell in the array with probability 1−p, or incorrectly with error probability p. Before writing the first bit, the PDF is uniform over the interval [0,1). Alternatively, the method may be adapted to use other representations of error probability and PDF, such as a Gaussian representation.
[0070] In the first iteration through step 182 , using the initial PDF, signal processing unit 60 instructs R/W unit 40 to write the voltage value corresponding to “1” to the first cell in the block in question if x>0.5 and “0” otherwise. The R/W unit writes this value to the first cell, at a writing step 184 . It then reads out the voltage value that is actually recorded in the cell, at a reading step 186 . As noted above, the R/W unit typically reads out the voltage value with higher resolution than the binary constellation of write levels.
[0071] The signal processing unit updates the PDF based on the voltage value read from the cell, at a PDF update step 188 . After the first iteration through step 188 , the PDF will be piecewise-constant with two levels, according whether the voltage read from the cell was above or below the nominal threshold voltage between the “1” and “0” voltage values. For example, if the voltage read from the cell corresponds to “1”, the signal processing unit will set the PDF to equal 2(1−p) for 0.5<x<1 and 2p for 0<x<0.5. (In contrast to the method of FIG. 5 , the signal processing unit does not attempt to adjust the voltage of the first cell, even if the voltage corresponds to an incorrect bit value, but rather proceeds to program the subsequent cells. The feedback coding scheme implemented by the present method will inherently compensate for these errors while permitting the amount of information actually stored in array 28 to approach the theoretical storage capacity.)
[0072] At the next iteration through step 182 , to determine the voltage value to be written to the next cell, signal processing unit 60 calculates the median point of the PDF (i.e., the point m for which the probability that x<m is 0.5), in accordance with the latest update of the PDF at step 188 . The signal processing unit instructs R/W unit 40 to write a voltage value corresponding to “1” to the next cell if x is larger than the median, and “0” otherwise. The voltage values that are chosen for writing to the cells are thus based both on the values of data bits that are to be stored in the memory and on the values of the voltages that are actually written to the memory.
[0073] After programming and reading the appropriate voltage value at steps 184 and 186 , the signal processing unit again updates the PDF at step 188 . At this iteration, the signal processing unit divides the PDF into three intervals, by splitting either the lower interval (0<x<0.5) or the upper interval (0.5<x<1) at the median point found at step 182 . It then multiplies the PDF in either the interval above the median or the interval below the median by (1−p), depending on whether the voltage read out of the current cell corresponds to “1” or “0”, and multiplies the PDF by p in the other interval. The resulting PDF is then normalized (multiplied by a constant) so that its integral from 0 to 1 will be 1. The PDF will now be piecewise-constant with three levels.
[0074] This process continues iteratively, wherein at each pass through step 182 , signal processing unit 60 outputs the voltage value corresponding to “1” if x is larger than the current median of the PDF, and “0” otherwise. Over many iterations, the PDF gradually takes the shape of an impulse response at x. The amplitude of the impulse, relative to the baseline PDF (corresponding to other data words), is indicative of the probability of error when the data are read out of array 28 . When the probability falls below a predetermined threshold, the iteration terminates.
[0075] Errors in writing data to array 28 (i.e., discrepancies between the voltage values read at step 186 and those written at step 184 ) will delay the buildup of the impulse, but the impulse will eventually build up as long as there are no errors in readout at step 186 . It can be shown that under these conditions, this feedback-based coding scheme causes information to be stored in array 28 at a density approaching the theoretical capacity, and also attains the theoretical limit for coding delay. In practice, this method may be combined with other techniques for correcting read errors that may occur in readout of data from array 28 .
[0076] The method described above may be generalized for use in multi-level memory cells, which store M bits per cell. In this case, each cell has 2 M possible input and output levels, with a probability P(i,j) that a level i that is output by signal processing unit 60 will be written to a memory cell as level j. Instead of calculating the median of the PDF at step 182 , the signal processing unit finds the 2 M-1 points that partition the interval [0,1) into 2 M equiprobable sub-intervals. For each successive cell, the signal processing unit then instructs R/W unit 40 to write the voltage value corresponding to the interval that contains x. The signal processing unit builds up the PDF at step 188 in the same manner, as a piecewise-constant function (but with more sub-intervals than for the binary case).
[0077] Although the method described above depends on sequential coding and writing of bits to successive cells, it may be adapted for use in devices, such as Flash memories, in which R/W unit 40 writes data to a group of cells, such as a page (i.e., a row), simultaneously. For this purpose, MSP 52 may code a sequence of words of data that are to be written to successive pages. Since each word is to be written to a corresponding page, it contains one respective symbol to be written to each cell in the page, i.e., one symbol per column. The MSP extracts the symbols in each column of the sequence of words and arranges these symbols in succession so as to define a respective number x for that column, which is then used in determining the values to be written to cells 32 on the corresponding bit line 84 . In other words, the symbols in the first column are extracted and arranged in order to define a first word, which is written to the cells on the first bit line, and so forth. The signal processing unit then determines and updates the respective PDF for each bit line of array 28 , and uses this specific PDF in determining the voltage value to be written on the corresponding bit line in each page that it sends to R/W unit 40 .
[0078] It is not necessary that all the symbols that are to go into a respective number x for purposes of feedback coding be known in advance. Rather, the signal processing unit may begin the coding process of FIG. 6 with only one or a few initial symbols, which define the most significant bits of x. As new symbols arrive, the signal processing unit refines the value of x accordingly, so that refinement of the PDF proceeds in parallel with refinement of the number that is stored.
[0079] As another alternative, MSP 52 may take advantage of the way in which many Flash memories write data to cells 32 on a common word line 80 in order to perform feedback coding of data within each page. As noted above, in the course of writing a given page, R/W unit 40 applies pulses of gradually increasing voltage on the corresponding word line. When the voltage reaches the level to which a given cell in that page is to be charged, the R/W unit switches the corresponding bit line to stop the charging of that cell. Thus, writing to different cells in the same page will be completed at different times, depending on the respective voltage values that are to be written to the cells. In order to code the values, the signal processing unit arranges them in order of increasing value, which will typically differ from the order of the corresponding cells in the page. The method described above may then be applied, mutatis mutandis.
[0080] Alternatively or additionally, feedback techniques may be applied in determining the number of ECC (parity) bits to be used in encoding data. For example, after data have been written to a first group of memory cells, and R/W unit 40 has read out the voltage values from these memory cells, MSP 52 may process these voltage values in order to decide how many ECC parity bits are required to ensure the reliability of the programmed data. ECC encoder 64 than calculates these parity bits for subsequent data, and in the resultant codewords are written to a second group of memory cells. Techniques of this sort for adaptive capacity adjustment are described further in the above-mentioned PCT patent application entitled “Memory Device with Adaptive Capacity.”
[0081] Although the embodiments described above relate, for the sake of clarity, to the specific device architecture and features shown in FIGS. 1 and 2 , the principles of the present invention may similarly be applied in memory devices of other types, including not only solid-state memories, but also disk memories. Furthermore, although these embodiments relate primarily to prevention of errors that may occur in the stages of programming a memory device, the methods described above may be used advantageously in conjunction with other techniques for enhancing reliability and capacity of memory devices based on distortion estimation and correction of errors that may occur at other stages of programming and readout.
[0082] It will thus be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.
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A method for storing data in an array ( 28 ) of analog memory cells ( 32 ) includes defining a constellation of voltage levels ( 90 A, 90 B, 90 C, 90 D) to be used in storing the data. A part of the data is written to a first analog memory cell in the array by applying to the analog memory cell a first voltage level selected from the constellation. After writing the part of the data to the first analog memory cell, a second voltage level that does not belong to the constellation is read from the first analog memory cell. A modification to be made in writing to one or more of the analog memory cells in the array is determined responsively to the second voltage level, and data are written to the one or more of the analog memory cells subject to the modification.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. application for patent, Ser. No. 543,690, filed Oct. 20, 1983, now U.S. Pat. No. 4,590,777.
TECHNICAL FIELD
This invention relates to locks and to piston or pin type locks in particular.
BACKGROUND ART
The piston lock has wide application both as a primary locking device and as an actuator for another, primary locking apparatus. Some examples of their use as actuators in more complex structures appear in U.S. Pat. No. 4,590,777.
Piston locks, also called pin locks, are often packaged in barrel form. A cylindrical rotor is disposed in a cylindrical cavity in a larger diameter housing cylinder. The axis of the larger cylinder and its cavity are parallel but usually are spaced. One or more pairs of pistons are contained in a like number of aligned bores which extend normal to the housing and rotor axis and into both housing and rotor. Insertion of a proper key into a key slot of the rotor forces the pin to positions in which the parting plane of the pins of a pair occurs at the plane between the housing and rotor. In that condition the rotor is free to rotate in the housing and accomplish its locking and unlocking function. The pins of the housing are spring biased in the direction of the key slot. In past designs they have been free to fall out or spring out on removal of the rotor from the housing. Ordinarily that is not a problem. The cylinder need be removed from the housing only for servicing and to "change the lock" by interchanging or replacing pins to require a different key. However when it is a problem it can be a difficult one. It is not uncommon even for locksmiths to lose control of the pins and springs and once loose it takes skill and perseverence to replace them.
SUMMARY OF THE INVENTION
One object of the invention is to provide improved piston locks.
Another object is to provide a piston lock structure in which the pistons or pin and springs will not fall or spring from their bores on disassembly of the lock rotor from the lock housing.
A further object is to provide a novel arrangement for retaining the rotor in its housing when the key is inserted and the pins are in their unlocked position.
Another object is to provide the novel pin and rotor retention arrangement in a form which is applicable to padlocks and other types as well as to barrel locks.
These and other objects and advantages of the invention are realized in part by the provision of pins and pin bores having stepped diameters or other dimensional arrangements such that the springs and pins cannot fall or spring out of their bores on removal of the rotor from the housing and by provision of a multilevel or multidiameter rotor, or rotor cavity, to serve as a stop by which one or more pins may be used unless otherwise defeated to prevent disassembly of the rotor and housing when the lock is open.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a view in central cross section of a barrel lock in which the invention is embodied;
FIG. 2 is an enlarged isometric view of one of the pistons employed in the lock of FIG. 1;
FIG. 3 is an enlarged fragment of what is shown in FIG. 1;
FIG. 4 is a cross section view of an alternative form of barrel lock;
FIG. 5 is an isometric view of the rotor of the lock of FIG. 4;
FIG. 6 is a cross sectional view taken on line 6--6 of FIG. 4;
FIG. 7 is a cross sectional view of a padlock in which the invention is embodied;
FIG. 8 is a bottom view of the padlock of FIG. 7; and
FIG. 9 is an isometric view of an L-shaped tool which is representative of tools useful in the invention.
DESCRIPTION OF PREFERRED EMBODIMENT
A piston lock is one in which two elements having opposing surfaces touching, or in close proximity, are each formed with a number of bores which open to its surface. Each bore contains a piston or pin which is free to reciprocate in the bore. The bores of one member are aligned with the bores of the other in the closed condition of the lock such that the pins of one extend partly into the bores of the other. Some of the pins being disposed partly in one member and partly in the other, the two members are foreclosed from relative movement in either of the two dimensions in which displacement of one would move the bores out of alignment. If the pins are moved to positions in the bore such that the interface between the pins of one member with the pins of the other member lies between the opposing surfaces or at least such that no portion of a pin of one element lies within a bore of the other element, relative movement in one or both of those two dimensions is possible. In practice such relative movement is limited to one dimension and displacement in that dimension is defined as being unlocked.
A common form of such a lock is shown in FIG. 1 and in FIG. 4. They are often called barrel locks. A relatively large diameter cylinder called a housing is formed with a through bore on an axis parallel to but spaced from the axis of the housing. Another cylinder called a rotor is disposed in the bore of the housing, its axis substantially coincident with the axis of the bore. The outer diameter of the rotor is almost equal, in preferred form, to the inside diameter of the housing at the bore. A key inserted in a slot in the rotor lifts rotor pins to force the ends of housing pins to the surface of the rotor. The rotor is then free to rotate about its axis in the housing. The rotor is fixed or coupled to some kind of keeper and latch arrangement which is locked and unlocked by such rotation of the rotor. To prevent longitudinal separation of the rotor and housing they are formed with some kind of retaining means.
In practice the pins of the housing are biased toward and into the bores of the rotor by a resilient element. It is almost universal to use coiled springs to apply the biasing force. The key forces the rotor pins to "lift" the housing pins against the springs. The elements that oppose longitudinal separtion of the rotor and housing when the pins are in unlocked condition are less standard. It is preferred that they be internal because in many applications making them inaccessible enhances security.
One advantage of the piston lock is that the lock can be "changed" to require a different key. The pins of the rotor differ from one another in length. The key is made so that the width of the key and the length of the rotor pins is such that each pin is forced to the unlocked condition when the key is in place. To render one key inoperative it is required only to replace with pins of different length by substitution or interchange. To do that requires separation of the rotor and housing by moving the pins to unlocked position and by removing or disabling the means by which the rotor is ordinarily retained in the housing. If the springs and pins are permitted to fall out of their bores replacement is almost always a difficult task. In general the task is sufficiently difficult to require a locksmith and special tools. The design of the pin, bias spring and pin bores is such as to make them inaccessible to those who would attempt to violate the lock. In the case of relatively inexpensive locks it is often preferred to replace rather than to try to reassemble the device.
It is the spring biased pins of the housing that are more difficult to retain. Gravity may be utilized to keep the pins of the rotor in place in their respective bores but the bias springs necessarily exert more than gravitational force on the housing pins so gravity is not helpful in retaining springs and housing pins. In the lock 10 of FIG. 1 the pins of the housing 12 cannot fall out on removal of the rotor 14 because both those pins and the bores in which they are lodged have increased diameter at their upper ends away from the cavity in which the rotor is disposed. Pin or piston 16 is shown enlarged in FIGS. 2 and 3. Its upper portion 18 has a larger diameter than does the lower portion 20. The upper portion of the bore 22 in which the pin is contained has a diameter only slightly larger than the upper portion of the pin and the lower portion of the bore has a diameter only slightly larger than the lower part 20 of the pin. Bore 22 and the other bores of housing 12 extend through the upper part of the housing from an outer opening at the top 24 of the housing to an inner opening into the cylindrical bore in which the rotor is contained.
There are seven housing pins in respectively associated ones of seven housing pin bores in this design. All seven bores are closed near their upper ends by a common retainer strip 26 which is inserted in a longitudinal slot 28 best shown in FIG. 2. A bias spring is trapped between the strip 26 and the housing pin in each of the seven bores. The spring in bore 22 is numbered 30. The bias springs urge their respective housing pins downwardly and in each case the lower, smaller diameter end of the housing pin is longer than the lower, smaller diameter portion of the bore in which it is disposed. In locked condition the bores of the rotor are aligned with those of the housing. In the absence of the key 32 the housing pins extend down into respectively associated bores in the rotor.
Each of the rotor bores contains a rotor pin which is lifted upon the insertion of a key that "fits" the lock. The sum of the width of the key at the point of engagement with any pin and the length of that pin is enough to raise the associated housing pin to clear the rotor but not enough to permit entry of the rotor pin into the housing. In FIG. 1 the rotor pin 34 has been lifted just enough by key 32 so that the juncture of pins 16 and 34 occurs at the plane of separation of the rotor 14 and the housing 12. All of the pins are arranged in FIG. 1 so that no rotor pin extends into the housing and so that no housing pin extends into the rotor. The rotor is free to rotate in the housing and the key serves as the lever or handle for applying the rotational force. In an actual application rotation of the rotor is made to actuate another mechanism that results in a locking or unlocking action.
A C-ring or spring 36 is disposed in an annular groove formed in the outer wall of the rotor. It extends beyond the rotor wall behind the housing so the rotor cannot be withdrawn from the housing to the right. In some circumstances it is not acceptable that the means for preventing separation of the rotor from the housing be so easily accessible. Also, in some cases a means is required for preventing removal of the rotor from either the front or the rear of the housing. The task is then to make that means inaccessible while providing a convenient means for removal of the rotor without loss of the pins when it is desired to "change" the lock. That has been done in the embodiment shown in FIGS. 4, 5 and 6.
Instead of a C-spring like spring 36, one of the pins is used to retain the rotor in the housing. Operation of the lock by rotation of the rotor in the housing requires only that the separation between rotor and housing pins occur in the plane or space which separates the rotor and housing. Axial separation of the rotor from the housing requires only that no part of the rotor be larger in diameter than the cylindrical cavity of the housing in the direction in which the rotor is to be removed. Those conditions are met in a uniform diameter design such as the one depicted in FIG. 1. They can also be met in a design in which the diameters of one or both rotor and cavity are stepped or tapered. They can also be met in a design in which the diameter of the rotor is decreased, or the diameter of the cavity is decreased over part of its length. That has been done in the lock 50 of FIGS. 4, 5 and 6. A circumferentially directed groove 52 has been milled in the surface of the rotor 54.
The rotor 54 is disposed in a cylindrical cavity in the housing 56. The key 58 is in the lock and it has lifted the six rotor pistons or pins such that those pins have lifted the housing pins against the bias of their respective bias springs. In the case of each pair of rotor and housing pins the parting line between pins is such that the rotor pin does not extend into the bore of the housing and the housing pin does not extend into the rotor bore. In the case of five of the pairs that parting line occurs at the surface of the housing cavity but in the first pin pair from the right in FIG. 4 the housing pin 60 extends down into the rotor groove 52. It bears against the rotor pin 62 at the level of the bottom of groove 52. That can also be seen in FIG. 6. Spring 63 is trapped between the retainer strip 66 and the pin 60. In the absence of key 58 the spring would force the pin 60 down so its lower end was lodged in the bore of the rotor. The rotor pin would be drawn down by gravity or be forced away by pin 60. Thus in the absence of a proper key pin 60 would contribute to locking like any of the other housing pins. In the locking and unlocking functions it is like any any other pin except, as will be apparent on inspection of FIG. 6, it serves to limit rotation of the rotor to the arc over which groove 52 extends. If it is desirable in a given application that rotation be limited to a different angular degree the arc would be made to extend to that degree. If the groove extended entirely around the rotor the rotor could be rotated completely around. However, even in unlocked condition the pin 60 is in the groove 52. It retains the rotor against axial displacement in the housing. Unlike the C-spring 36 of FIG. 1 it is not accessible at the exterior of the unit.
Before the rotor can be removed from the housing for servicing or lock change, the pin 60 must be lifted to clear groove 52. To that end another groove is formed in the surface of the rotor as best shown in FIG. 5. Groove 64 extends longitudinally from the front end of the rotor at least to the groove 52. It could extend from the rear instead or could extend the full length of the rotor. All that is required is an arrangement for lifting the pin with some kind of tool, such as the small Allen wrench 66 shown in FIG. 9. The groove 64 must intersect with the groove 52 and, of course, it must not intersect the bores in which the rotor pins are contained. Only when the lock has been opened can the rotor be rotated to align the groove 64 with pin 60 and only then can the pin be lifted by a tool which is inserted in groove 64.
The tapered flat 68 at the rear of the rotor serves as a cam to facilitate reinsertion of the rotor into the housing. It aids by lifting the housing pins during insertion. Also, it will be apparent that the groove 52 may be positioned and sized to cooperate with any other pair of pins or with more than one pin pair. In this design the flat 68 is formed on a separate locking element 70 which is connected by two pins to the end of the rotor 54. The pins extend parallel to the rotor axis into bores in the rotor one on each side of the key slot. One pin 72 is visible in FIG. 4. Element 70 is rotatable with the rotor but is not removable with it. It is retained by a retainer spring 74 which is disposed in matching grooves in the outer wall of the element and the inner wall of body 56.
FIGS. 7 and 8 illustrate how the invention can be applied to a padlock. The bail 76 of the padlock 78 is J-shaped. The longer arm 82 is slideably and rotatably disposed in bore 83 of padlock 84. The bail is retained in the locked closed condition by two metal balls 86 and 88 which fit into respectively associated depressions in arms 82 and 90 of the bail. The balls are held in those depressions to prevent withdrawal of the bail by a cam 90 at the upper end of a locking element 92 which is almost a duplicate of element 70 of FIGS. 4 and 5 and which rotates with rotor 94. The cam is formed by milling flats on opposite sides of the end of the element. When the rotor is rotated 90 degrees the balls are free to move inwardly against the flats to release the bail. That part of the construction is conventional. The rotor is like the rotor 54 of FIG. 5 except that instead of being six pins long it is only four pins long in this embodiment. Pins and springs and a retainer strip like those that are disposed in bores and slots in the housing of FIGS. 4 and 6, are part of a separate assembly 96 in the padlock. The assembly is disposed as a unit in a recess milled out of the body of the lock.
In obedience to the rules, the best mode now known for practicing the invention has been shown in the accompanying drawing and described in the specification above. However, it is to be understood that other embodiments and variations of the invention are possible and that the invention is to be limited by what is defined in the appended claims rather than by what has been shown.
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A piston type lock employs stepped diameter pistons or pins and bores to prevent fallout of pins on disassembly and also multilevel surfaces at the lock rotor and housing interface such that one or more of the pins serve to retain the rotor in the housing in the unlocked condition of the lock.
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REFERENCE TO CROSS-RELATED APPLICATIONS
This application claims priority to provisional application No. 60/538,624, filed on Jan. 23, 2004.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to hatch systems for use on tanks, and more particularly, to remotely operated hatch systems for tanks and bulk carriers, such as those carried by trucks and trains.
2. Background Information
Commercial tanks, also commonly known as “tankers” and “bulk carriers”, are widely used for transporting both liquid and dry goods. Tanks are configured with hatches to open and close an opening in the top of the tank, to access to the interior of the tank. Opening or closing the hatch often requires an operator to climb on top of the tank to manually release securing or locking mechanisms that keep the hatch closed. The operator then must lift or otherwise move the hatch cover to open the hatch. This operation can be hazardous to the operator, because a fall from the typical height of the top of the tank may cause injury, and because the contents of many such tanks often include vapors or gases which may be toxic or unpleasant. Inclement weather and moisture or ice on the top of the tank can increase the danger associated with climbing up on the tank and operating the hatch securing mechanism.
Since some types of goods transported by tank are transported under pressure, some tanks have opening closures that must withstand a pressure differential between internal and external pressures. For example, some tanks are used for the storage or transportation of granular or powder form dry bulk goods such as flour, salt, cement, lime, and cereal grains. These dry bulk goods are pneumatically transferred into the tank from a storage facility, via a pneumatic transfer system. Pneumatic transfer systems do not work properly unless the closure on the access port of the tank can maintain a pressure differential between the interior pressure of the tank and exterior pressure on the tank.
Automated hatch opening and closing systems have been devised in the prior art to allow remote operation of a hatch. Some of these systems can be retrofit on existing manually-operated hatches. Many preexisting automated hatch systems suffer from a number of disadvantages. One known disadvantage of these prior art hatch systems is that these systems are prone to leak when pressurized. Another known disadvantage to these systems is that significant modification is required to retrofit the preexisting tanks, which can be costly and time consuming to retrofit. Another known disadvantage of the prior art systems is that they may be complicated to install and somewhat expensive to purchase. A further known disadvantage of the prior art systems is that they may open the hatch vertically, thus potentially obstructing tank-filling equipment.
BRIEF SUMMARY OF THE INVENTION
The invention includes hatch systems for use on tanks and bulk carriers. One embodiment built in accord with the invention is a remotely operated hatch system for tanks and bulk carriers, such as those carried by trucks and trains.
The invented hatch system may comprise an upper frame and a lower frame that are joined by a hinge assembly. The lower frame is coupled to a collar of an opening of the tank and the hatch is coupled to the upper frame. The hinge assembly allows the upper frame to pivot the hatch between an open and closed position relative to the opening of the tank. The frame may also include at least one catch that is intended to receive an edge of the frame, when the hatch is closed.
A plurality of spring members on the upper frame are configured to urge the hatch upward and away from the tank opening. This provides a space between the opening of the tank and the hatch, so that the hatch may be swung away from the opening and thus not obstruct equipment used to fill the tank. An inflatable bladder may be positioned between the upper frame and the hatch. Inflating the bladder overcomes the spring pressure and urges the hatch into tight contact with the opening of the tank. The hatch system also includes a remote control means for inflating the bladder and for rotating the hatch between the open and closed positions.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, in which:
FIG. 1 is a side view of an embodiment of a remotely activated tank hatch system of the invention in closed position;
FIG. 1A is a side view of an embodiment of the invention where helical springs are visible;
FIG. 2 is a side view of an embodiment of the invention in closed position and further showing a remote control panel of the invention;
FIG. 3 is a side view of an embodiment of the invention in a partially open position;
FIG. 4 is a side view of an embodiment of the invention in a fully open position and showing the panel of the invention;
FIG. 5 is a perspective view of an embodiment of a hinge assembly of the invention;
FIG. 6 is a perspective view of an embodiment of a hinge assembly of the invention;
FIG. 7 is a perspective view of an embodiment of a pivot mechanism of the hinge assembly of the invention;
FIG. 8 is a detail view of an example of a lower frame of the invention;
FIG. 9 is a side view of an embodiment of a catch of the invention
FIG. 10 is a top perspective view of an embodiment of an upper frame of the remotely activated tank hatch system of the present invention; and
FIG. 11 is a perspective view of an alternative embodiment of an inflatable member of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention includes hatch systems for use on tanks. One embodiment built in accord with the invention is a remotely operated hatch system for tanks and bulk carriers, such as those carried by trucks and trains.
Reference will now be made in detail to a presently preferred example embodiment of the invention as illustrated in the accompanying drawings. The invented hatch system shown in FIGS. 1-10 is provided as an example only, and although the examples given include many specifics, they are illustrative of only a few possible embodiments of the invention. Other embodiments and modifications will no doubt occur to those skilled in the art. The examples given should only be interpreted as illustrations of some of the preferred embodiments of the invention, and the full scope of the invention is comprehended to include alternate designs which may not be specifically disclosed herein.
Referring to the drawing Figures, there is shown generally at 10 , an embodiment of a remotely activated tank hatch system of the present invention. The hatch system 10 is shown coupled to a collar 12 defining a tank opening 14 of a tank 16 . It is to be understood that the tank 16 may comprise any commercial tank or bulk carrier, such as those carried by trucks and trains, for example.
Referring to FIG. 1 through FIG. 4 , FIG. 8 , and FIG. 10 of the drawings, the invented hatch system 10 may include an upper frame, shown generally at 18 , and a lower frame, shown generally at 20 , that are coupled by a hinge assembly 22 . The lower frame 20 is coupled to the collar 12 and a hatch 24 is coupled to the upper frame 18 , for enclosing the opening 14 .
Referring to FIG. 3 , FIG. 4 , FIG. 8 , and FIG. 10 , the lower frame 20 may include an arcuate, U-channel member 26 . The channel member 26 may have a lower edge 28 and an upper edge 30 . A plurality of support members 32 may be spatially positioned along the channel member 26 for strengthening it. The lower edge 28 of the channel member 26 may be configured to extend about the periphery of the collar 12 and is coupled thereto.
Referring particularly to FIG. 1 and FIG. 8 , in the embodiment shown, the collar 12 is configured tabs 34 that are spatially positioned about its periphery. The lower edge 28 of the channel member 26 may be configured with pairs of vertically extending flanges 36 . Adjacent flanges 36 are positioned to extend over each side of a tab 34 . A hole 38 (not clearly seen) may bored though each tab 34 and a corresponding opening 40 may also be formed in adjacent flanges 36 . The tabs 34 are positioned between adjacent flanges 36 until the hole 38 in the tab 34 is aligned with the openings 40 in the flanges 36 . A pin 42 may then be inserted through the opening 40 in one of the flanges 36 , then through the hole 38 in the tab 34 , and through the opening 40 in the remaining flange 36 , to detachably couple the channel member 26 to the collar 12 . The lower frame 20 may be fabricated using methods and materials well known in the art.
Referring to the drawing Figures, the upper frame 18 of the hatch system 10 is provided for retaining the hatch 24 . The upper frame 18 may include a hatch support plate 44 that is coupled to the hatch 24 and affixed to the hinge assembly 22 . The upper frame 18 may also include support members 46 that are affixed to both the support plate 44 and hinge assembly 22 . The support plate 44 is preferably annular and may have a diameter similar to, or slightly greater than, the diameter of the hatch 24 .
A plurality of pins 48 are provided to couple the hatch 24 to the support plate 44 . The pins 46 may be affixed to the hatch 24 adjacent to its rim (not shown). The pins 46 extend approximately vertically upward from the hatch 24 , through holes 50 in the support plate 44 , and above a top side 52 of the support plate 44 .
Compressible retaining members 54 are provided for lifting the hatch 24 toward a bottom side 56 of the support plate 44 . In the embodiment shown, each compressible member 54 comprises a helical spring 58 fit over a pin 48 and a stop 60 that is affixed to the pin 48 adjacent to its end 62 . The spring 58 is compressed between the stop 60 and the top side 52 of the support plate 44 . The force exerted by compression of the springs 58 tends to lift the hatch 24 toward the bottom side 56 of the support plate 44 . A cover 64 may be fit over each compressible retaining member 54 for protection from the elements.
Returning to FIG. 1 , an inflatable bladder 66 is coupled to the bottom side 56 of the support plate 44 between the hatch 24 and the plate 44 . The bladder 66 may be doughnut shaped and may be fabricated using suitable expandable and resilient materials, such as rubber for example. The bladder 66 may be inflated to overcome the spring force of the helical springs 58 and will tend to force the hatch 24 downwardly from the bottom side 56 of the support plate 44 . This downward force is used to obtain a positive seal between the hatch 24 and the collar 12 of the tank 16 .
Referring to FIG. 1 through FIG. 3 , and FIG. 9 (best seen in FIG. 9 ), the invented hatch system 10 is provided with one or more catches 68 that inhibit the hatch 24 from moving relative to the opening 14 of the tank 16 . The catch 68 may be any suitable configuration that inhibits the hatch 24 from moving relative to the opening 14 and that interlocks the upper and lower frames 18 , 20 to allow pressure to be applied by the hatch 24 and opening 14 , in order to assure a positive seal between the hatch 24 and collar 12 . The catch 68 may also reduce stresses applied to the hinge assembly 22 .
In the embodiment shown, the catch 68 may comprise one or more generally “C” shaped members that are configured to extend about a portion of the lower frame 20 . For example, a catch 68 may comprise a pair of adjacent “C” shaped members 70 that are affixed to each other using know means, such as welding.
Each catch 68 may have an end 72 affixed to the support plate 44 , then extend and is generally perpendicular to the plate 44 and down towards the lower frame 20 . The catch 68 may also have a lip 74 that is configured to overlap a portion of the lower frame 20 . The lip 74 of the catch 68 may be configured to overlap a lower edge 76 of the flanges 36 .
When the inflatable bladder 66 is inflated, expansion of the bladder 66 tends to force the hatch 24 away from the opening. The lip 74 of the catch 68 may contact the lower edge 76 of the flanges 36 and the channel member's upper edge 30 may contact the top side 52 of the support plate 44 , thus interlocking the upper and lower frames 18 , 20 . This may prevent the hatch 24 from moving, thereby trapping the hatch 24 between the tank opening 14 and the upper frame 18 . This allows pressure to be applied by the hatch 24 and to the tank opening 14 in order to assure a positive seal of the hatch 24 and collar 12 . It is to be understood that one or more catches 68 may alternatively be affixed to the lower frame 20 to provide the functionalities of the catches 68 described herein.
Referring to FIG. 5 through FIG. 7 , the hinge assembly 22 may include a hinge 78 coupling the upper frame 18 to the lower frame 20 , to allow the upper frame 18 to rotate the hatch 24 between an open and closed position relative to the tank's opening 14 . The hinge assembly 22 may include a means for inflating and deflating the bladder 66 , and a means for rotating the upper frame 18 .
In the embodiment shown, the hinge assembly 22 includes a pneumatic piston 80 that is coupled to the upper frame 18 for opening and closing the hatch 24 . A rod 82 of the piston 80 may be pivotably coupled to the hinge 78 and a body of the piston 80 may be affixed to the U-channel 26 of the lower frame 20 . Air lines 86 may be coupled to the piston 80 for actuation thereof. The rod 82 of the piston 80 may be extended when the hatch 24 is in the closed position and may be retracted to open the hatch 24 .
An air hose 88 may be coupled to the bladder 66 , via the support plate 44 , at one end 90 and may be coupled to an air source (not shown) at the other end. The air hose 88 provides a gas conduit for inflation and deflation of the bladder 66 . The air lines 86 may be coupled to the piston 80 and the air hose 88 coupled to the support plate 44 using pneumatic fittings known in the art.
Referring to the drawings and particularly to FIG. 2 and FIG. 4 , an embodiment of a remote control panel 92 is shown for remotely actuating the invented tank hatch system 10 . The control panel 92 is typically positioned at a distance from the hatch 24 , such as near the ground where an operator could easily access the controls of the panel 92 . The remote control panel 92 typically may include controls for actuating the piston 80 to open and close the hatch 24 and for inflating and deflating the bladder 66 . The remote control panel 92 may be configured however desired, such that it provides the features of operation of the hatch system 10 discussed herein.
In use, an operator actuates the piston 80 for rotating the upper frame 18 to the open position. The tank 16 may then be filed without obstruction of the opening 14 by the hatch 24 . Once the tank 16 is filled, the operator can then actuate the piston 80 to extend its rod 82 to rotate the upper frame 18 to the closed position. The bladder 66 may then be inflated to force the hatch 24 downward, to form a positive seal between the hatch 24 and opening 14 .
When it is desired to open the hatch 24 , the bladder 66 is first deflated. Once the bladder 66 is deflated, the compressible members 54 lift the hatch 24 away from the tank opening 14 at the top of the collar 12 . The upper frame 18 , and thus hatch 24 , may then be rotated away from the opening 14 .
FIG. 11 shows an alternative embodiment 10 A of the invented hatch system. In the alternative embodiment 10 A, the upper frame 18 includes a plurality of support members 26 A that extend from the support plate 44 and meet at a center hub 102 . A generally spherical bladder 66 A is coupled to the hub 102 and to a center portion 104 of the hatch 24 . Inflation and deflation of the spherical bladder 66 A is controlled by the remote control 92 as previously discussed.
Further, in the alternative embodiment 10 A, one or more catches 106 may be coupled to the lower frame 20 . A lip 108 the catch 106 may overlap the support plate 44 to limit movement of the upper frame 18 , to form a positive seal between the hatch 24 and opening 14 , as discussed above.
The above described configuration is provided as an example. The important functionality includes the ability to lift the hatch from the tank opening, then later the ability to press the hatch downward tightly against the tank opening. Therefore, other apparatus configurations that provide this functionality may be useable in the invention.
Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.
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A remotely activated tank hatch system includes an upper frame and a lower frame joined by a hinge assembly. The lower frame is coupled to a collar of an opening of a tank and a hatch is coupled to the upper frame. The hinge assembly allows the upper frame to pivot the hatch between an open and closed position. The lower frame includes at least one catch to receive an edge of the hatch, when the hatch is closed. Spring members on the upper frame urge the hatch toward the upper frame so that the hatch may be swung away from the opening. Inflating a rubber bladder positioned between the upper frame and hatch overcomes the spring pressure and urges the hatch into tight contact with the collar. The hatch system includes a remote control for inflating the bladder and opening and closing the hatch.
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RELATED APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 11/278,788, filed Apr. 5, 2006, which is a continuation under 37 C.F.R. 1.53(b) of U.S. patent application Ser. No. 09/547,249 filed Apr. 11, 2000, now U.S. Pat. No. 7,032,756, issued Apr. 25, 2006, which applications are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to containers, and more specifically, to plastic containers. The containers described herein may be applied to any use, but they are particularly useful for storing paint, varnish, stain and the like. The containers of the invention will be described in connection with the use of storing paint with the understanding that the container has other usages, such as storing food or other contents.
[0003] Paint is conventionally stored and sold in metal cans which have an upper edge with a groove in which an annular edge of a metal cover is secured by a press fit. The cover is typically removed by prying an edge of the cover upwardly out of engagement with the can edge so that the stored paint can be used. The cover is usually pried upwardly with a screwdriver or other pointed device. The cover can be resecured onto the can by press fit, typically by striking the lid with a solid object, such as a hammer. Because the paint frequently fills the groove of the can, striking the lid with a hammer oftentimes causes the paint to spray outwards. Further, any paint that remains in the groove prevents a tight securing of the cover.
[0004] Paint has generally been stored in round metal containers because the density and weight of paint has been too great for polymeric-based containers to contain and because of a reactivity of the paint with polymeric containers. Round-shaped cans have been used to store paint because it has been difficult to fabricate metal containers with symmetries that are not round.
[0005] Notwithstanding the widespread use of round metal cans as containers for paint, the use of those cans has been expensive and wasteful with respect to storage and transport. For example, round metal cans cannot be positioned efficiently. Further, round metal cans add significant weight to the paint product. Round metal cans are typically difficult to open and close, and round metal cans are difficult to carry. Round metal cans are also easily be dented. Moreover, problems are associated with reclosing the round metal can after use since paint has most likely filled the channel groove portion of the can which receives the standard lid, resulting in spray, spillage and disrupted resealing.
[0006] Efforts have been made to utilize paint containers manufactured from materials other than paint. For example, plastic paint containers are reported in U.S. Pat. Nos. 3,938,686; 4,453,647; 4,530,442; 4,548,332; 4,619,373; 4,655,363; 5,303,839; and 5,975,346. However, a need still exists for a paint container that can be easily and efficiently transported, stored, positioned, opened, closed and carried by hand. In securing the cover in position, it is important that the cover is both securely attached and readily removed when desired. Further, the container should be designed not only to store the paint, but also to prevent undesired escape of the paint, to prevent the ingress of dust, moisture or other materials into the container, to allow opening without special tools and to allow tight resealing.
SUMMARY OF THE INVENTION
[0007] One embodiment of the present invention includes a polymeric container. The polymeric container comprises a main body. The main body includes a neck portion, a bottom portion and a handle portion. The bottom portion defines a lug. One other embodiment further includes a lid positionable over the neck. The lid defines indentations capable of receiving lugs from another polymeric container. In another embodiment, the main body defines an indentation capable of receiving one or more lugs.
[0008] Another embodiment includes a method for stacking containers. The method comprises providing a first container comprising a main body with a bottom portion. The bottom portion defines one or more lugs. A second container is also provided. The second container comprises a main body that defines an indentation and a bottom portion. The bottom portion defines one or more lugs. The first container is stacked on the second container so that the lug of the first container is seated within the indentation of the second container.
[0009] One other embodiment of the present invention includes a method for stacking containers. The method comprises providing a first container with a main body that includes a bottom portion. The bottom portion defines one or more lugs. The method also comprises providing a second container and a lid positioned on the container. The lid defines an indentation. The first container is stacked on the second container so that the lug of the first container is seated within the indentation on the lid.
DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view of one embodiment of the container of the present invention.
[0011] FIG. 2 is a top plan view of a plurality of the containers positioned for transport or storage.
[0012] FIG. 3 is a top plan view of one embodiment of the container of the present invention.
[0013] FIG. 4 is a top plan view of one embodiment of the container with an indentation for lug receipt in a lid applied to the container.
[0014] FIG. 5 a is a top plan view of another embodiment of the bottom portion of the container of the present invention with an annular lug in a main body of the container.
[0015] FIG. 5 b is a top plan view of one other embodiment of the bottom portion of the container of the present invention with a plurality of discrete lugs in the main body of the container.
[0016] FIG. 5 c is a top plan view of another embodiment of the bottom portion of the container of the present invention with a single centrally positioned lug.
[0017] FIG. 6 a is a tp plan view of a top portion of one embodiment of the container of the present invention wherein the main body defines an annular indentation.
[0018] FIG. 6 b is a top plan view of a top portion of one embodiment of the container of the present invention wherein the main body defines a plurality of discrete indentations.
[0019] FIG. 6 c is a top plan view of one embodiment of a container and lid of the present invention wherein an indentation is defined by the lid.
DETAILED DESCRIPTION
[0020] One embodiment of the container of the present invention, illustrated generally at 10 in FIG. 1 , includes a main body 12 with a generally parallelpiped shape and a lid 14 attachable to the main body 12 at a neck 24 . The main body 12 comprises the neck 24 , a handle 16 , and a bottom portion 18 with an annular lug 20 and a central indentation 22 . Although the container depicted represents a paint volume content of approximately one gallon, the container is readily manufactured in different sizes. The container of the present invention is not limited to any one volume or dimension.
[0021] The container of the present invention includes a number of features that render the container more easily and efficiently stored and transported than conventional containers, such as round metal paint containers. One of these features is the symmetry of the main body. The main body of the container of the present invention is a parallelpiped that permits the container to be transported with a minimum of free space. Straight sidewalls of adjacent containers are alignable with each other, as is shown at 3 in FIG. 2 . The container of the present invention also includes a number of features that render the container more easily and efficiently opened and closed than conventional containers.
[0022] The container of the present invention 10 includes a unitary handle 16 that forms indentations for fingers 26 that enable a user to more easily carry the container 10 . One embodiment of the container 10 includes an annular lug 20 that permits more stable stacking of the container 10 . In particular, the lug 20 is insertable in an annular groove 28 defined within one embodiment of the lid 14 .
[0023] The shape of the lug 20 can be varied for other container embodiments. For example, the lug may be a continuous annular lug, such as is shown at 20 in FIG. 5 a or may be a discrete lug such as is shown at 50 in FIG. 5 b . The lug may also be a single lug 52 positioned in a central region of the bottom of the container, as shown in FIG. 5 c . Although four lugs are shown, in FIG. 5 b , it is understood that more or fewer lugs are suitable for use. The lugs 20 , 50 , and 52 have shapes ranging from rectangular to ovoid.
[0024] The shape of the groove 28 defined is of a shape that permits the stacking of the containers and that permits receipt of the lug 20 . This shape is an annular shape for receipt of annular lug 20 as shown at 60 in FIG. 6 a . The groove 60 is defined by the container main body. The shape of the groove or indentation is discrete, as shown at 62 in FIG. 6 b , for receipt of discrete lugs 50 . The discrete indentations 62 are also positioned within the main body of the container. In one other embodiment shown in FIG. 6 c , the indentation 64 is in a lid 62 . The indentation receives the lug 52 .
[0025] The unitary handle 16 also creates a modular shape for the container 10 that renders the container more efficient to store. The handle 16 may be hollow or solid. The handle 16 is, for some embodiments, integral with the main body.
[0026] One lid embodiment is illustrated generally at 14 in FIG. 3 . The lid 14 comprises two turning mechanisms, a central mechanism 32 and indentations 34 . The central mechanism comprises a unitary band 36 that allows the lid 14 to be moved in clockwise and a counter clockwise directions. The band 36 has an elevation that permits fingers of a user to be placed below the band 36 to turn the lid 14 . The band forms indentations 40 for fingers that enable the user to more easily carry, open and close the container. The indentations 34 are positioned and sized to enable a user to grasp the lid 14 and to turn the lid 14 clockwise and counter clockwise. The lid 14 of the present invention is configured to enable individuals with “stiff” fingers to use and to turn with relative ease. The lid 14 is sealed to the container 12 by an o-ring 38 . The lid 14 defines threading 42 , and the neck 24 defines threading 44 , so that the threadings 42 and 44 are capable of interacting to attach the lid 14 to the main body 12 .
[0027] The container of the present invention is fabricated from a polymeric material such as polypropylene with methods well known to the art worker. The handle is for some embodiments filled and for other embodiments hollow.
[0028] For some embodiments, the container is lined with a material such as a heat sealable thermoplastic or laminate which acts to contain a material such as paint and, along with the o-ring seal, to prevent air oxidation. Suitable liner materials include polyester, polyvinylidene chloride, polyethylene and the like. Other suitable liner materials include cellulosics, polycarbonates, polypropylene, polyester or metallized plastic sheet material. One liner material is a plastic laminate that includes nylon, polyvinylidene chloride, polyethylene and a 0.003 to 0.001 inch aluminum foil. The aluminum foil is sandwiched between layers of the plastic material.
[0029] In one embodiment, an aluminum foil barrier is laminated to an outer polymeric shell by a thermosealing polycoat. The polycoat thermally bonds the foil to the polymeric material. One polycoat comprises a polyethylene extrusion that is coated to the polymeric shell.
[0030] The container of the present invention is usable for storing and transporting a material such as paint. The shape of the container permits space-efficient transport. The shape of the container as well as the ergonomic features of the lid and handle render the container easy and safe for an individual to carry.
[0031] While preferred embodiments of the invention are described herein, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the present invention that do not depart from the spirit and scope of the present invention. All such modifications and variations are intended to be included within the scope of the invention, as defined by the following claims.
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The present invention relates to containers, and more specifically, to plastic containers. The containers described herein may be applied to any use, but they are particularly useful for storing paint.
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BACKGROUND OF THE INVENTION
[0001] The invention relates generally to food and food preparation, and more particularly to a seasoning for cooking and a method of producing the seasoning.
[0002] Seasoning is a substance necessary for flavoring food, which is frequently used in large amounts when cooking dishes. Especially for Chinese dishes, a special and strong demand is growing for the seasoning due to the requirements of the special preparation methods and traditional cooking techniques.
[0003] With a long history, Chinese food has become a food of cultural heritage, which is enjoyed by people all over the world, and therefore widely used and disseminated. Thus, there is a worldwide need for the Chinese seasoning. Among various seasonings, spice is a seasoning that imparts typical savors such as aroma, pungent flavor, numbness, spicy flavor, bitterness, sweetness, and the like to the food, and is commonly made of spice plants.
[0004] Common, commercially available composite spicy seasonings include curry powder, five spices powder, Thirteen Spices, optimum spice, seasoning for making stuffing, and stewing seasoning. However, disadvantages of these common seasonings include the following: they lack a standard formula; they are generally made by conventional mixing and crushing; there is no principle basis for the prescription; side effects are unclear; the flavoring effect, which is provided by these common seasonings, is often unable to sufficiently reach desired requirements, and may be unable to meet the increasing requirements for dish tastes and even for a function of health care.
SUMMARY OF THE INVENTION
[0005] Accordingly, the invention provides a seasoning for cooking and a method of producing the seasoning. The seasoning, which comprises 31 varieties of spices, is produced by stir-frying fructus anisi stellati and fructus tsaoko, respectively, and then mixing the obtained stir-fried fructus anisi stellati and fructus tsaoko with the remaining 29 varieties of spices, and finally crushing the mixture.
[0006] By applying the principle for compounding properties and tastes in traditional Chinese medicine, and performing treatments for detoxifying the fructus anisi stellati and eliminating odors of the fructus tsaoko, a seasoning is produced that has a unique flavor, and decreased side effects caused by the fructus anisi stellati contained in traditional seasonings and thus has better food safety.
DETAILED DESCRIPTION OF EMBODIMENTS
[0007] The invention provides a seasoning for cooking with a unique flavor which is produced by simple techniques with a scientific prescription, by using the raw materials derived from natural herbs and applying a principle for compounding properties and tastes in traditional Chinese medicine, in order to satisfy the increasing demand for the seasoning quality.
[0008] The seasoning according to the invention comprises spices as follows: fructus schisandrae chinensis 4-6% by weight, fructus lycii 2-4% by weight, lemon 0.5-1.5% by weight, white pepper 3-5% by weight, arillus longan 2-4% by weight, radix angelicae dahuricae 1.5-2.5% by weight, fructus foeniculi 2-4% by weight, rhizoma curcumae longae 2-4% by weight, coriander 0.5-1.5% by weight, semen trigonellae 2-4% by weight, pericarpium citri reticulatae 3-5% by weight, fructus piperis longi 1.5-2.5% by weight, cortex acanthopanacis 4-6% by weight, radix saussureae lappae 2-4% by weight, rhizoma chuanxiong 1.5-2.5% by weight, semen alpiniae katsumadai 2-4% by weight, galanga resurrectionlily rhizome 3-5% by weight, bay leaf 1.5-2.5% by weight, rhizoma alpiniae officinarum 4-6% by weight, fructus tsaoko 1.5-2.5% by weight, bulbus lilii 4-6% by weight, thyme 2-4% by weight, semen sojae praeparatum 1.5-2.5% by weight, flos caryophylli 2-4% by weight, myristica fragrans houftuyn 2-4% by weight, rhizoma zingiberis 4-6% by weight, fructus anisi stellati 0.5-1.5% by weight, cortex cinnamomi 2-4% by weight, fructus amomi 3-5% by weight, brassica alba boiss 2-4% by weight, pericarpium zanthoxyli 2-4% by weight, provided that, after a final product is prepared using the raw materials in the above blending weight ranges, the sum of all components is 100% by weight.
[0009] The seasoning according to the invention is preferably produced as follows:
the fructus anisi stellati is slightly stir-fried in a hot wok with gentle heat for about 10 minutes to 20 minutes, and then taken out and cooled to room temperature and reserved; the fructus tsaoko is put into the wok and stir-fried with high heat, and then removed from the wok when it appears dark brown and foaming and starts giving off an aroma, and then sieved to remove ash and cooled to room temperature and reserved; the remaining 29 kinds of spices are then selected, washed, and dried to have a water content of 4 wt. % to 6 wt. %, and then the stir-fried fructus anisi stellati and the stir-fried fructus tsaoko are added thereto; the obtained mixture is uniformly mixed by physical stirring and crushed into 120 mesh to 150 mesh fine powders; and the fine powders are preferably packaged in the form of 50 g per pack and then irradiated by Co-60 (cobalt-60) for 24 hours to 48 hours.
[0011] The fructus anisi stellati in the seasoning of the invention is a spice commonly used in the traditional seasoning, but since the component of safrole contained in the fructus anisi stellati can result in poisoning when excessively ingested, producing side effects such as dizziness, nausea, limb weakness, numbness and so on, there exists a problem of food safety when using the fructus anisi stellati. By performing the treatment for detoxifying the fructus anisi stellati, specifically, slightly stir-frying the fructus anisi stellati in a hot wok with gentle heat for about 10 to 20 minutes, the seasoning of the invention has no toxicity even though containing the normally toxic fructus anisi stellati, and thus can be used safely.
[0012] In addition, the fructus tsaoko has odors when used without being stir-fried. Accordingly, by processing the fructus tsaoko, specifically, stir-frying it with high heat until it appears dark brown and foaming and starts giving off aroma, its odors can be removed.
[0013] By making up the seasoning of the invention based on the principle for the prescription in traditional Chinese medicine, and performing the treatments for detoxifying the fructus anisi stellati and eliminating odors of the fructus tsaoko during the production process, the seasoning of the invention does not only have such a unique flavor as to make food tastes delicious and rich, but also has decreased side effects and thus can be used safely.
EXAMPLE
[0014] The invention will be further described by an example.
[0015] The components in the formula of the Example are as follows: fructus schisandrae chinensis 50 g, fructus lycii 30 g, lemon 10 g, white pepper 40 g, arillus longan 30 g, radix angelicae dahuricae 20 g, fructus foeniculi 30 g, rhizoma curcumae longae 30 g, coriander 10 g, semen trigonellae 30 g, pericarpium citri reticulatae 40 g, fructus piperis longi 20 g, cortex acanthopanacis 50 g, radix saussureae lappae 30 g, rhizoma chuanxiong 20 g, semen alpiniae katsumadai 30 g, galanga resurrectionlily rhizome 40 g, bay leaf 20 g, rhizoma alpiniae officinarum 50 g, fructus tsaoko 20 g, bulbus lilii 50 g, thyme 30 g, semen sojae praeparatum 20 g, flos caryophylli 30 g, myristica fragrans houttuyn 30 g, rhizoma zingiberis 50 g, fructus anisi stellati 10 g, cortex cinnamomi 30 g, fructus amomi 40 g, brassica alba boiss 30 g, pericarpium zanthoxyli 30 g.
[0016] The producing method in the Example is as follows:
[0017] the fructus anisi stellati (10 g) is slightly stir-fried in a hot wok with gentle heat for 10 minutes, and then taken out and cooled to room temperature and reserved; the fructus tsaoko (20 g) is put into the wok and stir-fried with high heat, and then taken out when it appears dark brown and foaming and starts giving off aroma, and after that, it is sieved for ash removal and cooled to room temperature and reserved; the remaining 29 varieties of spices (970 g in total) are selected, washed, and dried respectively, and then the stir-fried fructus anisi stellati and the stir-fried fructus tsaoko are added thereto; the obtained mixture is uniformly mixed by physical stirring and crushed into 120-mesh fine powder; and the thus-crushed fine powders are packaged in the form of 50 g per pack with 20 packets obtained in total, and then sent to the final product storage after being irradiated by Co-60 for 24 hours.
[0018] The seasoning of the invention can be used in various foods, for example, various meat dishes and vegetable dishes which are cooked by frying, stir-frying, stewing, pickling in soy sauce and salting, stuffing of flavor snacks, soups, pickles, hot pot soup bases, hot pot flavorings, hot pot seasonings as well as various wheaten foods, and moreover the addition amount thereof can be appropriately determined depending on the taste of the consumer.
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A seasoning for cooking and a method of producing the seasoning. The seasoning comprises 31 varieties of spices, and a method of producing the seasoning includes stir-frying fructus anisi stellati and fructus tsaoko, respectively, and then mixing the obtained stir-fried fructus anisi stellati and stir-fried fructus tsaoko with the remaining 29 varieties of spices, and finally crushing the mixture. The seasoning of the invention has the characteristics of unique flavor, low toxic side effects, and safe edibility.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to bushings, which are extensively used in a variety of assemblies within automobiles, particularly in suspension systems. More specifically, the present invention relates to a sectioned composite bushing having directionally variable dampening properties. In addition, the inventive bushing is characterized by inner and outer cylindrical collars bridged by circumferentially arranged elastomeric sections. The inventive bushing attenuates vibration and noise transmitted through metal structures.
[0003] 2. Description of the Background Art
[0004] In today's automotive industry, extensive time and effort has been expended to reduce vibration, and vibration and friction-induced noise in vehicles, while improving ride comfort and vehicle handling. Technologically refined vibration isolators and resilient bushings have been developed to achieve better vibration isolation and noise control, and are commonly employed between interrelated structural components. A number of bushings are known in which a resilient annular cylinder is fitted between two coaxial sleeves. The resilient annular portion of the bushing permits components of a suspension system that are connected to the inner sleeve and the outer sleeve, respectively, to move toward and away from each other in the radial direction with respect to the bushing axis, while the elastomeric portion dampens the initial harshness of the motion.
[0005] Preferably, the elastomeric member is designed to permit a large deflection in the radial direction, so that the elastomeric material can absorb large loads or shocks, without damaging the surrounding components. However, deflection of the bushing in the axial direction is undesirable, because such deflection causes axial spreading and consequent misalignment of the suspension system components. Axial deflection also has adverse effects upon the bushing, since it tends to weaken the mechanical bond between the compressed elastomeric member and the respective inner and outer sleeves.
[0006] Typically, this type of known bushing includes at least two concentric rigid cylindrical collars (sleeves) with an annular elastic member interposed between them. The inner sleeve is securely connected to one structural component, while the outer sleeve is secured to another structural component. Generally, the sleeves are formed of metal, while the annular elastic member is of a flexible, resilient material such as rubber. In the automotive industry, such resilient bushings are incorporated in frames and others parts to dampen the dynamic vibration of metal structures. They are also utilized to generate high noise impedance in what might otherwise be an all-metal path for the transmission of structure-borne sounds in a metal structure.
[0007] A few illustrative examples of previously known resilient composite bushings are described in U.S. Patents issued to Hadano et al., Johnson et al., Tsuiki et al., and Hein.
[0008] In U.S. Pat. No. 6,747,631, Hadano et al. discloses a cylindrical stabilizer bushing with a main body elastic rubber member. The rubber elastic member has a radially layered structure comprising an inner rubber layer having with high sliding properties and an outer rubber layer integrally laminated on the outer surface of the inner layer rubber. This construction allows vulcanized bonding of the inner sliding rubber portion to the outer, main body rubber portion, even if the sliding rubber portion material is injected when the vulcanization of the main body rubber portion is almost complete.
[0009] In U.S. Pat. No. 6,419,230, Johnson et al. reveal a suspension bushing with a sleeve. The sleeve member includes an inner surface and a cavity. A core member is disposed inside the cavity. In addition, two elastomeric members are also disposed inside the cavity. The first elastomeric member is positioned adjacent to the core, while the second elastomeric member is interposed between the first elastomeric member and the inner surface. The first elastomeric member has a modulus that is greater than that of the second elastomeric member, so that one of the elastomeric members absorbs low frequency vibration, while the other elastomeric member absorbs high frequency vibration. As seen in the previous reference, an outer elastomeric member is concentrically surrounding an inner elastomeric member.
[0010] Tsuiki et al., in U.S. Pat. No. 5,984,283, disclose a stabilizer bushing for use as component of a vehicle suspension system. The subject bushing is provided with a vibration damping main body. This main body comprises a resilient, thick-walled cylindrical body, formed of rubber, which defines a stabilizer bushing. The resilient body is obtained by inserting a rubber cylindrical inner body into a rubber cylindrical outer body. The outer body acts as a main part of the resilient rubber body. The inner surface of the inner rubber body has high sliding characteristics, and acts as a slide surface that is adapted to hold a stabilizer bar.
[0011] In the U.S. Patent to Hein (U.S. Pat. No. 5,224,790), a bushing assembly with axial restraint properties is disclosed. The bushing assembly of Hein includes an outer sleeve encircling an inner sleeve that contacts a stabilizer bar. The outer sleeve is formed of a more flexible material than the inner sleeve. The nesting sleeves are designed to restrain axial movement, while allowing ease of rotational movement. The outer sleeve engages and at least partially surrounds an inner sleeve. The inner sleeve is designed to surround and engage a metal stabilizer bar. The engagement of the stabilizer bar by the inner sleeve is designed to inhibit relative axial movement between the stabilizer bar relative and the inner sleeve. The inner diameter of the inner sleeve includes a high-friction surface, such as knurling, or even an adhesive engagement of the inner sleeve to the stabilizer bar.
[0012] Primarily, the known background art, including the references cited herein, use concentrically disposed and radially stacked concentric layers of elastomeric material to provide composite bushings. Although the reference patents teach combining rubber materials of differing resiliency to offer an improved bushing, which results in improved vehicle comfort and handling, they achieve this goal by providing concentric layering of elastomeric components in a radial direction. However, when the composite is formed in this configuration and is placed under a radial load, one layer of rubber with a particular resiliency transfers its unique physical attributes to radially adjacent layer(s) of a different resiliency.
[0013] Hence, the bushings disclosed in the references are unable to derive the benefits from the attributes of one particular layer having a specific resiliency, because of the interdependence with the other radially disposed layer(s) having a different resiliency. Since each of the bushings described above uses a structure composed of elastic materials of differing elasticities radially disposed in concentric layers, the dampening effect they provide is a result of the combined elasticities of the layers. Controlling the resulting damping effect can be difficult.
[0014] A composite bushing is needed that optimally uses a plurality of elastic elements of differing elasticities, disposed in such a manner that the physical characteristics of one elastic element can be experienced substantially independently of the influence of adjacent elastic elements. A composite bushing is needed wherein the resiliency is directionally dependent, such that the bushing provides a plurality of elasticities, wherein a specific resiliency is associated with a specific direction of applied load. A composite bushing is needed that, when used to attenuate vibration and transmitted noise in an automotive assembly, provides improved vehicle handling and ride comfort.
SUMMARY OF THE INVENTION
[0015] In accordance with an illustrative embodiment of the present invention, a composite bushing is provided having an elastomeric annulus which is radially sectioned, to provide plural wedge-shaped elastic members. Selected individual elastic members have a specific resiliency which varies from other elastic members. The wedge-shaped members cooperate to provide an annulus having circumferentially varying resiliency. As a result, the inventive bushing provides a variable resistance to deflection, which depends upon the direction of the applied load.
[0016] More specifically, illustrative embodiment of the present invention provides a radially sectioned bushing in which the resiliency in a first radial direction differs significantly from the resiliency in a second radial direction, where the second radial direction is at an angle to the first radial direction. The resulting bushing configuration, when used to attenuate vibration and transmitted noise in an automotive assembly, provides improved vehicle handling and ride comfort.
[0017] The inventive composite bushing, according to the first embodiment hereof, is an assembly including two co-axial outer and inner sleeve members. The outer and inner sleeve members are separated in the radial direction to define an annular space therebetween. A resilient composite elastomeric annulus is positioned within the annular space. The annulus is radially sectioned so as to include a plurality of wedge-shaped portions. The wedge-shaped portions are circumferentially contiguous, and arranged to form an elastomeric ring to substantially fill the space between the outer and inner sleeve members. Individual wedge portions are provided having specific resiliency and assembled with other wedge portions, of which at least one wedge portion is formed having a different resiliency.
[0018] In a particular embodiment of the instant invention, a composite cylindrical annulus comprising four wedge portions is provided, wherein adjacent wedge portions are of different resiliency and are disposed in abutting relation with their respective centers disposed at a 90 ° angle to one another. In this embodiment, wedge portions which are diametrically opposed are formed of the same elastomeric material, and thus possess the same resistance to deflection. Thus, a first pair of wedge portions, having a first resiliency, are disposed on opposed sides of the inner sleeve member, and a second pair of wedge portions, having a second resiliency, are also disposed on opposed sides of the inner sleeve member so as to lie between and separate the individual wedge portions of the first pair of wedge portions.
[0019] In the particular embodiment described herein, a first pair of the two pairs of opposed elastomeric wedge portions is bonded to both the inner surface of the outer sleeve and the outer surface of the inner sleeve, so as to form a bushing body. Each wedge portion of the remaining pair of wedge portions is attached at one end to an elastomeric disk of suitable thickness so as to form a bushing insert.
[0020] In assembling the described bushing, the bushing insert is slidably inserted into the vacant space remaining between the outer and inner sleeves of the bushing body to form a closed end composite annulus. The bushing insert may be bonded to the bushing body, if desired, using a suitable adhesive.
[0021] Optionally, the elastic disk of the bushing insert may be configured to fit inside of the outer sleeve, and after the bushing insert is fully inserted in the bushing body, the end of the outer sleeve may be crimped or swaged inwardly, in order to retain the bushing insert in the bushing body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is perspective view of a composite bushing according to a first illustrative embodiment of the invention, having an elastomeric annulus which is radially sectioned to provide wedge-shaped elastic members of differing resiliency to provide a bushing having circumferentially varying elastic properties.
[0023] FIG. 2 is a cross sectional view of the inventive bushing of FIG. 1 as seen across line 2 - 2 in FIG. 1 , showing the sectioned elastomeric annulus disposed between an inner sleeve and and outer sleeve.
[0024] FIG. 3 is partial cross sectional view of one end of the inventive bushing as seen across line 3 - 3 in FIG. 2 , showing the elastomeric disc which closes this end of the bushing.
[0025] FIG. 4 is an exploded perspective view of the inventive bushing showing the bushing insert separated from the bushing body.
[0026] FIG. 5 is a partial cross sectional view, similar to FIG. 3 , of one end of a second embodiment of the inventive bushing as seen across line 3 - 3 in FIG. 2 , showing the elastomeric disc having a central reinforcing metal washer therein; and
[0027] FIG. 6 is partial cross sectional view of one end of a third embodiment of the inventive bushing as seen across line 3 - 3 in FIG. 2 , showing an elastomeric disc configured to fit inside the outer sleeve, and showing the end of the outer sleeve swaged to retain the bushing insert therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] A number of selected illustrative embodiments of the present invention will be described, with reference to the drawings.
[0029] In each of FIGS. 1 through 4 , according to instant invention; there is shown an embodiment of a radially segmented composite elastomeric bushing 10 characterized by directionally dependent resistances to deflection. Further embodiments are illustrated in FIGS. 5 and 6 .
[0030] More specifically, in the first illustrative embodiment of FIGS. 1-4 , the present invention provides a composite bushing 10 , in which the spring rate, or resistance to deflection in a first radial direction appreciably differs from the spring rate or resistance to deflection in a second radial direction that is at an angle to the first radial direction, to improve vehicle handling and ride comfort.
[0031] The inventive composite bushing 10 includes a rigid, axially elongated hollow cylindrical outer sleeve 16 , and a rigid, axially elongated hollow cylindrical inner sleeve 18 disposed concentrically within the outer sleeve 16 . The outer sleeve 16 and the inner sleeve 18 are radially separated and spaced apart from each other, to define an annular space 17 therebetween ( FIG. 4 ). The sleeves 16 , 18 are preferably formed from metal, such as iron, steel, or any suitable high-strength alloy.
[0032] An elongated composite elastomeric annulus 30 is provided within the annular space 17 between the cylindrical surfaces of the inner sleeve 18 and the outer sleeve 16 . The elastomeric annulus 30 is interposed between the outer sleeve 16 and inner sleeve 18 so as to substantially fill the annular space 17 .
[0033] The annulus 30 includes an open end portion 42 , and a closed end portion 44 ( FIG. 4 ). The annulus 30 is radially segmented into a plurality of elongated elastomeric wedge portions 31 , 32 , 33 , 34 , which are generally wedge-shaped in cross section, and which are substantially circumferentially contiguous to each other within the annular space.
[0034] Individual wedge portions 31 , 32 , 33 , 34 , are provided in pairs 35 , 36 such that each wedge portion within a wedge portion pair 35 , 36 has the same resiliency. However, the resiliency of the wedges 32 , 34 in a first wedge portion pair 35 is different than the resiliency of the wedges 31 , 33 in a second wedge portion pair 36 . Each wedge portion within a wedge portion pair 35 , 36 is disposed about the longitudinal axis L of the bushing such that it is aligned with, and on opposed sides of the inner sleeve 18 from its pair mate. Thus, the diametrically opposed wedge portions within a pair 35 or 36 are formed of the same elastomeric material, and thus possess the same resistance to deflection. However, adjacent abutting wedge portions such as 31 and 32 , for example, are formed from different materials.
[0035] Further, the bushing 10 provides a resistance to deflection corresponding to the resiliency of the wedge portion pair in a direction corresponding to central plane of symmetry of the wedge portion pair.
[0036] Plural wedge portion pairs 35 , 36 are provided, each pair having a specific, unique resiliency. The plural wedge portion pairs 35 , 36 are assembled so as to be substantially contiguous with the adjacent wedge portion pairs, to form a circumferentially continuous annular body 30 having radial directionally dependent deflection resistance.
[0037] In the particular embodiment of the instant invention illustrated in FIGS. 1-4 , the composite annulus 30 is made up of two wedge portion pairs 35 , 36 , or having a total of four wedge portions 31 , 32 , 33 , 34 . However, it is within the scope of this invention to provide a composite annulus 30 having three or more wedge portion pairs. In this particular embodiment, the first wedge portion pair 35 has a first resiliency or hardness, and the second wedge portion pair 36 has a second resiliency which is different from the first resiliency. The first wedge portion pair 35 has a central plane of symmetry disposed at a 90° angle in relation to a central plane of symmetry of the second wedge portion pair 36 .
[0038] Thus, in the embodiment of FIGS. 1-4 , a first pair 35 of wedge portions 32 , 34 , having a first resiliency, are disposed on opposed sides of the inner sleeve 18 , and a second pair 36 of wedge portions 31 , 33 , having a second resiliency, are also disposed on opposed sides of the inner sleeve 18 , but are positioned so as to lie between the individual wedge portions 32 , 34 of the first pair of wedge portions 35 . This configuration results in bushing 10 which, in use, provides two different elastic responses oriented at 90 degrees to each other.
[0039] Material selection is used to determine the resiliency of a wedge portion pair 35 , 36 . For the purpose of illustrating this embodiment of the invention, the two elastomeric materials used in the instant invention are referred to as high-tan-delta and low-tan-delta materials, respectively, to reflect differing elasticities therein. The high-tan-delta elastomer wedge portions are employed to achieve improved ride comfort, while the low-tan-delta elastomer wedge portions are provided to offer an ease in handling with a smoother maneuvering of the vehicle.
[0040] However, it is within the scope of this invention to form the bushings having wedge portions formed of materials having alternative elasticities, or alternatively, to form the bushings having wedge portions formed of elastomeric materials other than rubber.
[0041] The inventive bushing is assembled by inserting a bushing insert 50 into a bushing body 52 ( FIG. 4 ).
[0042] The bushing body 52 is formed as follows: A first pair of wedge portions, such as first wedge portion pair 35 , of the two provided pairs of wedge portions 35 , 36 , is formed by injecting uncured elastomeric material between the sleeves 16 , 18 using suitable dividers to limit distribution of the material, and this uncured material is cured in place between the inner and outer sleeves.
[0043] It will therefore be understood that each wedge 32 , 34 of the first wedge portion pair 35 is bonded to the sleeves 16 , 18 during vulcanization or curing of the material, to form the bushing body 52 as a substantially integral composite member.
[0044] Specifically, for each wedge 32 , 34 of the first wedge portion pair 35 , a wedge portion inner surface 37 is bonded to the outer surface 26 of the inner sleeve 18 during curing of the wedge, and the wedge portion outer surface 39 is bonded to the inner surface 24 of the outer sleeve 16 during curing of the wedge.
[0045] Each wedge 32 , 34 of the first wedge portion pair 35 has a central plane of symmetry which is aligned with a first axis T 1 , with the respective wedges disposed on opposite sides of the inner sleeve 18 . The resulting structure is a bushing body 52 , in which two elastomeric wedges 32 , 34 are adhesively secured between the inner sleeve 18 and the outer sleeve 16 , and in which vacant openings exist between the opposed wedges.
[0046] Alternatively, the wedges 32 , 34 of the first portion pair 35 may be formed and cured separately from the sleeves 16 , 18 , and then may be subsequently post-bonded to the sleeves, using a suitable adhesive.
[0047] The bushing insert 50 is formed by securing the remaining, or second, wedge portion pair 36 to one side of a hollow elastomeric disc 22 . The insert 50 may be molded as a single, integral one-piece member out of a selected elastomer, including the disc 22 and the wedges 32 .
[0048] In the first embodiment hereof, the disc 22 has an outer diameter sized to conform to the outer diameter of the outer sleeve 16 , and includes a central opening 28 aligned with and sized to conform to the inner diameter of the inner sleeve 18 . The bushing insert 50 may be formed by bonding one end 44 of each wedge portion 31 , 33 of the second wedge portion pair 36 to one side of the disc 22 , such that the wedge portion outer surface 40 lies adjacent the outer periphery of the disc 22 , and the wedge portion inner surface 38 lies adjacent to the central opening 28 of the disc 22 . Further, each wedge 31 , 33 of the second wedge portion pair 36 has a common plane of symmetry which is aligned with a second axis T 2 , so that the wedges are situated on opposite sides of the central opening 28 . It will be noted that the second axis T 2 is substantially transverse to the first axis T 1 .
[0049] The bushing insert 50 and the bushing body 52 are assembled by positioning the respective components such that the first axis T 1 is oriented at an angle of 90° to the second axis T 2 . The bushing insert 50 is then slidably inserted into the bushing body 52 , such that wedges 31 , 33 of the second wedge portion pair 36 , respectively reside within the vacancies in the bushing body 32 . When fully inserted, the disc 22 abuts one end 14 of the outer sleeve 16 to provide a closed end. At the opposing end 12 of the outer sleeve, the terminal ends 42 of the wedges 32 are not covered, and extend to lie substantially flush with terminal end 42 . If desired, a suitable adhesive may be used to affix the bushing insert 50 and the bushing body 52 , to maintain the assembled configuration of the bushing 10 .
[0050] A second embodiment of a bushing 110 according to the present invention is illustrated in FIG. 5 , in which the disk 22 is replaced with a reinforced disk 122 . The bushing 110 in this second embodiment is a modified version of the bushing 10 as previously described. In will be understood that unless features of the bushing 110 are specifically described as being different from the bushing 10 , they are the same as those features previously described.
[0051] The bushing 110 includes inner and outer sleeves 118 , 116 , respectively, having opposed wedge portions 132 , 134 therein and forming part of an elastomeric annulus 130 .
[0052] The reinforced disc 122 shown in FIG. 5 is substantially similar to the disk 22 according to the first embodiment, except that it is provided with a centrally located reinforcing metal washer 125 cast in place therein and surrounding the central opening 128 , to strengthen and reinforce the bushing insert 150 .
[0053] A third embodiment of a bushing 210 according to the present invention is illustrated in FIG. 6 . The bushing 210 in this third embodiment is a modified version of the bushing 10 of FIGS. 1-4 as previously described. In will be understood that unless features of the bushing 210 are specifically described as being different from the bushing 10 , they are the same as those features previously described.
[0054] The bushing 210 includes inner and outer sleeves 218 , 216 , respectively, having opposed wedge portions 232 , 234 therein and forming part of an elastomeric annulus 230 .
[0055] In the embodiment shown in FIG. 6 , an alternative structure for the first end 214 of the outer sleeve 216 is provided, in which the disc 222 may be dimensioned to fit inside of the outer sleeve 216 , and the outer sleeve 216 may be made long enough to extend beyond the inner sleeve 218 and to cover the outer peripheral side edge of the disc 222 . In this configuration, the outer sleeve 216 may have the terminal end portion 215 thereof swaged or crimped in place about the outside peripheral side edge of the disc 222 , to retain the bushing insert 250 inside of the bushing body 252 .
[0056] Although the presently contemplated embodiment of a circumferentially sectioned composite bushing has been described herein, the foregoing description is intended to illustrate, rather than to limit the invention. Those skilled in the art will recognize that various substitutions and modifications can be made, without departing from the invention. For example, other connecting members besides the disc 22 could be used to interconnect the wedge portions 31 , 33 of the bushing insert 50 , or thin partitions could be placed between adjacent wedge portions to create a separation therebetween. All such modifications, which are within the scope of the appended claims, are intended to be within the scope and spirit of the present invention.
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A composite bushing including an outer sleeve coaxially surrounding an inner sleeve, and including an elastomeric body extending between the outer sleeve and the inner sleeve. The elastomeric body is provided with circumferentially alternating wedge sections having different physical characteristics, so as to provide a bushing having directional differences in resistance to deflection. The resiliency in a first radial direction appreciably differs from the resiliency in a second radial direction, where the second radial direction is at an angle to the first radial direction. The resulting bushing configuration can be used to attenuate vibration and noise in a vehicle, and thereby contribute to improved vehicle handling and ride comfort.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S. Provisional Application No. 61/406,532, filed Oct. 25, 2010, which is pending at filing of the present application, and which is incorporated by reference in its entirety herein.
BACKGROUND
[0002] 1. Field
[0003] Embodiments of the present invention generally relate to systems and methods for drainage of door, window and other fenestration systems, and more specifically relate to accessible adjustable height drainage systems configured for draining water or other liquid intrusion in to building structure openings, access routes, or fenestration products such as one or more doors, sliding doors, hinged doors, rotational door, revolving doors, jambs, windows, window sills, and other types of openings in a building or wall.
[0004] 2. Description of the Related Art
[0005] Various door, window and fenestration systems have long been a desirable option for providing access to residences, businesses and other structures as they can provide an opening for entry and exit. However, with environmental conditions, water, rain, snow, sprinklers, flooding, puddles or other liquids can also enter from the exterior to the interior of a structure through these systems, potentially causing cosmetic or structural damage to flooring, rugs, carpets, paneling, furniture, and other items inside the structure. Some drainage systems are fixed or non-adjustable, and some require removal of the door or window for accessibility for service, adjustment or cleaning purposes.
[0006] Some door, window or fenestration systems are difficult to seal. Some door systems include some type of weather stripping or a brush along a border or edge to form a seal with the floor, wall, and/or ceiling surface. However, in order to effectively seal, some types of weather stripping or brushes slide along the floor or other surface while the door system is being opened or closed. Accordingly, the weather stripping can wear rather quickly until it loses effectiveness at forming a seal. If the unit is adjusted downward in order to close the gap too much, the added friction will not allow the panel to slide freely. Many attempts to just add brushes to reduce the friction will allow water and air infiltration. Thus, many of these systems do not easily compensate for infiltration of non-desired liquids in to the interior of a structure.
SUMMARY
[0007] Several embodiments of the present invention relate to drainage systems for reduction or elimination of liquid infiltration in to a structure though an access point in or out of buildings or structures, such as commercial or residential homes, or other structures with doors or windows. In some embodiments, the drainage system is adjustable. In some embodiments, the drainage system is vertically adjustable to controllably place the height of the drainage system above, below or flush with one or more surrounding floor or fenestration portal surfaces. In some embodiments, the drainage system is readily accessible for service without removing or disassembling the door or window.
[0008] In various embodiments, the drainage system can be used with any door or window or other opening in a wall for any type of structure, such as a door, sliding door, hinged door, revolving door, rotating door, pet door, window or other portal structure. Although some embodiments will be described in the context of use on a sliding door system, some embodiments of the drainage system can be used on any type of door, window, or panel.
[0009] In various embodiments, a drainage system is configured to redirect water or other liquids or fluids from accumulation on or near a door or other structural entry point. In various embodiments, the drainage system includes a channel to collect liquid and redirect or drain the liquid to the exterior or to a drainage system, such as a sewer or rain gutter or other system for removing the liquid from the structure. In one embodiment, the drainage system includes an adjustable dimension component for vertically, horizontally, or otherwise moveably adjusting a drainage system component, such as a cap, to a position with respect to the surrounding floor, wall, or other structural feature. In various embodiments, the drainage system is accessible for service. In various embodiments the service is cleaning, adjusting, adjusting the height, or other action in relation to the drainage system.
[0010] In one embodiment, a door drainage system includes a base, an adjustable height cover and two or more adjustable members configured to controllably position the adjustable height cover. The base includes a channel configured for redirecting a liquid away from a door. The adjustable height cover is removably positionable on the base. In one embodiment, the adjustable height cover is configured to be readily removable from the base for service without removing or disassembling the door. In one embodiment, the adjustable member base is connected to the base. In one embodiment, the adjustable member is linearly positionable with respect to the adjustable member base. In various embodiments, the two or more adjustable members are configured to controllably position the adjustable height cover to be flush with, higher than, or recessed below an adjacent structural surface. In one embodiment, at least one adjustable member includes an elongate threaded member configured for controlled vertical positioning of the adjustable height cover. In one embodiment, the adjustable height cover includes a plurality of apertures configured to redirect flow of a liquid through the drainage system. In one embodiment, the body includes a first wall, a second wall and a base at least partially surrounding the channel. In one embodiment, the body includes a U-shaped extrusion. In one embodiment, the door drainage system also includes a filter configured to fit in the channel. In one embodiment, the drainage system also includes one or more exit ports in the base in fluid connection with one or more drainage ports configured to direct the liquid away from the base. In one embodiment, the drainage system also includes a valve for adjustable fluid control. In one embodiment, a valve is disposed on one or more drainage ports. In one embodiment, the drainage system also includes one or more sliding doors disposed on a track disposed in an exterior position with respect to the base.
[0011] 1. In one embodiment, a door drainage system includes a base, an adjustable height cover, an adjustable member base, two or more adjustable members, and one or more exit ports. The base includes a channel configured for redirecting a liquid away from a door. The adjustable height cover is removably positionable on the base, with the adjustable height cover including a plurality of apertures configured to redirect flow of a liquid through the drainage system. The adjustable member base is connected to the base, and the adjustable member is linearly positionable with respect to the adjustable member base. The two or more adjustable members are configured to controllably position the adjustable height cover to be flush with, higher than, or recessed below an adjacent structural surface. The one or more exit ports in the base is in fluid connection with one or more drainage ports configured to direct the liquid away from the base. The adjustable height cover is configured to be readily removable from the base for service without removing or disassembling the door. In one embodiment, at least one adjustable member includes an elongate threaded member configured for controlled vertical positioning of the adjustable height cover. In one embodiment, the drainage system includes a filter configured to fit in the channel. In one embodiment, the drainage system includes a valve for adjustable fluid control.
[0012] In one embodiment, a fenestration product drainage system includes a base, an adjustable height cover, and an adjustable member. The base includes a channel configured for redirecting a liquid away from a fenestration product. The adjustable height cover is removably positionable on the base. The adjustable member is configured to controllably position the adjustable height cover. In one embodiment, the adjustable height cover is configured to be readily removable from the base for service without removing or disassembling the fenestration product. In one embodiment, the fenestration product is a door. In one embodiment, the fenestration product is a window. In one embodiment, the adjustable member includes an elongate threaded member configured for controlled vertical positioning of the adjustable height cover. In one embodiment, the fenestration product includes one or more exit ports in the base in fluid connection with one or more drainage ports configured to direct the liquid away from the base. In one embodiment, the fenestration product includes a valve for adjustable fluid control. In one embodiment, the fenestration product includes a filter configured to fit in said channel.
[0013] The details of various embodiments are set forth in the accompanying drawings and the description herein. Other features and advantages will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and other aspects of embodiments of the present invention will now be described in detail with reference to the following drawings.
[0015] FIG. 1 is a schematic front partial cross sectional view of a drainage system according to an embodiment of the present invention;
[0016] FIG. 2 is a schematic front partial cross sectional view of a flush configuration drainage system according to an embodiment of the present invention;
[0017] FIG. 3 is a schematic front partial cross sectional view of an elevated configuration drainage system according to an embodiment of the present invention;
[0018] FIG. 4 is a schematic front partial cross sectional view of a recessed configuration drainage system according to an embodiment of the present invention;
[0019] FIG. 5 is a schematic front partial cross sectional view of a sliding door configuration drainage system according to an embodiment of the present invention;
[0020] FIG. 6 is a schematic front partial cross sectional view of a multiple sliding door drainage system according to an embodiment of the present invention;
[0021] FIG. 7 is a schematic front partial cross sectional view of a drainage system according to an embodiment of the present invention;
[0022] FIG. 8 is a schematic front partial cross sectional view of a compact height configuration of a drainage system according to an embodiment of the present invention;
[0023] FIG. 9 is a schematic front partial cross sectional view of the drainage system according to FIG. 7 with an adjustable height cover removed;
[0024] FIG. 10 is a schematic side view of the drainage system according to FIG. 7 ;
[0025] FIG. 11 is a schematic isometric view of the drainage system according to FIG. 7 with an adjustable height cover removed;
[0026] FIG. 12 is a schematic elevated isometric view of the drainage system according to FIG. 7 with an adjustable height cover removed;
[0027] FIG. 13 is a schematic elevated isometric view of the drainage system according to FIG. 7 ;
[0028] FIG. 14 is a schematic side isometric view of the drainage system according to FIG. 7 ;
[0029] FIG. 15 is a schematic side isometric view of the drainage system according to FIG. 7 with an adjustable height cover removed;
[0030] FIG. 16 is a schematic side isometric view of the drainage system according to FIG. 7 with an adjustable height cover removed;
[0031] FIG. 17 is a schematic isometric view of a cover according to an embodiment of the present invention;
[0032] FIG. 18 is a schematic side view of a cover according to FIG. 17 .
[0033] Like reference symbols in the various drawings indicate like elements. Throughout the figures, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components or portions of the illustrated embodiments. Moreover, while embodiments of the subject invention will now be described in detail with reference to the figures, it is done so in connection with the illustrative embodiments. It is intended that changes and modifications can be made to the described embodiments without departing from the true scope and spirit of the subject invention as defined by the appended claims.
DETAILED DESCRIPTION
[0034] Several embodiments of the present invention relate to drainage systems for access points to architectural building structures, such as commercial or residential homes, buildings, or other structures with doors or windows. In various embodiments, the drainage system can be used with any door or window or other opening in a wall for any type of structure, such as a door, sliding door, hinged door, rotatable door, revolving door, pet door, or window. Although some embodiments will be described in the context of use on a sliding door system, some embodiments of the drainage system can be used on any type of door, window, or panel. In various embodiments, the drainage system can be configured to be flush with, higher than, or recessed below a floor or jamb surface. In some embodiments, the drainage system is located inside, outside, or anywhere on the floor between interior to exterior jamb edges. In various embodiments, the drainage system can be configured to act as a stop on the interior or exterior of any door, window, or other fenestration product. In one embodiment, the drain system is configured to prevent liquid or moisture from entering the interior of a structure beyond an interior jamb line.
[0035] FIG. 1 illustrates one embodiment of the invention in which a drainage system 200 is configured to reduce or eliminate liquid infiltration in to a structure through a fenestration product 10 . In various embodiments, the fenestration product is a door, window, or other moveable closure device configured for providing access in to or out of a structure, building or wall. In various embodiments, the drainage system 200 comprises a body 210 and a cover 280 . In one embodiment, the body 210 is a U-shaped extrusion with a first wall 220 , a second wall 230 and a base 240 partially or completely surrounding a channel 215 . In one embodiment, the first wall 220 comprises a first wall channel surface 222 facing the channel 215 and a first wall floor surface 224 facing a floor 6 , 7 or a direction laterally outside of the body 210 . In one embodiment, the second wall 230 comprises a second wall channel surface 232 facing the channel 215 and a second wall floor surface 234 facing a floor 6 , 7 or a direction laterally outside of the body 210 . In one embodiment, the first wall 220 has a first wall height 226 (see FIGS. 7 and 8 ). In one embodiment, the second wall 230 has a second wall height 236 . In various embodiments, the first wall height 226 is the same or similar to the second wall height 236 , the first wall height 226 is greater than the second wall height 236 , or the first wall height 226 is less than the second wall height 236 . In various embodiments, the first wall height 226 and/or the second wall height 236 is less than 1 inch, 1 inch, 1.125 inches, 1.1875, 1.25 inches, 1.375 inches, 1.5 inches, 1.625 inches, 1.75 inches, 1.875 inches, 2 inches, 2.125 inches, 2.1875, 2.25 inches, 2.375 inches, 2.5 inches, 2.625 inches, 2.75 inches, 2.875 inches, 3 inches, 3.125 inches, 3.1875, 3.25 inches, 3.375 inches, 3.5 inches, 3.625 inches, 3.75 inches, 3.875 inches, 4 inches, or any dimension or range of dimensions between 0.5 inches and 1 foot or more.
[0036] In one embodiment, the first wall 220 is on an interior 120 side and the second wall 230 is on an exterior 122 side of the drainage system 200 with respect to a fenestration product 10 . In one embodiment, the first wall 220 is on an exterior 122 side and the second wall 230 is on an interior 120 side of the drainage system 200 with respect to a fenestration product 10 .
[0037] In one embodiment, the base 240 includes a base channel surface 245 facing the channel 215 . In various embodiments, the base channel surface 245 is sloped, slanted, angled, or configured to direct a liquid from the channel 215 to one, two, three, four, or more exit ports 250 . In various embodiments, the second wall 230 includes one, two, three, four, or more exit ports 250 . In various embodiments, the first wall 220 includes one, two, three, four, or more exit ports 250 . In various embodiments, the base channel surface 245 includes one, two, three, four, or more exit ports 250 .
[0038] In one embodiment, the exit port 250 is in fluid connection with one or more drainage ports 254 . In one embodiment, the drainage port 254 includes a drainage port lumen 256 configured to direct a liquid away from the channel 215 of the base 210 . In various embodiments, the drainage port 254 is directed toward the exterior 122 of the structure, the interior of the structure 120 , a sewer, a gutter, a rain gutter, piping, tubing, or other devices for diverting a fluid away from a structure.
[0039] In various embodiments, a valve 258 may be placed in or along the fluid drainage route. In one embodiment, one or more valves 258 are positioned to control the rate and/or direction of fluid (gas, liquid, etc.) flow. In one embodiment, one or more valves 258 is positioned in or along one or more exit ports 250 . In one embodiment, as shown in FIGS. 11 and 14 , one or more valves 258 is positioned in or along one or more drainage ports 254 . In one embodiment, one or more valves 258 is positioned in or along one or more drainage port lumens 256 . In one embodiment, one or more valves 258 is positioned in or along a structure, interior structure, exterior structure, drain, sewer, a gutter, a rain gutter, piping, tubing, or other devices for diverting a fluid away from a structure. In some embodiments, one or more valves 258 is readily accessible for service or actuation without removing or disassembling the door or window. In various embodiments, the valve 258 can be accessed through removal of the cover 280 . In various embodiments, a valve 258 can be directly or indirectly controlled through manual manipulation, electronic control, remote control, and other techniques. In one embodiment, a valve 258 can be altered or actuated to account for potential severe weather conditions, such as a storm, flooding, rain, high winds or other conditions. In various embodiments, a valve 258 can open, close, partially obstruct, and/or redirect flow within the drainage system 200 . In some embodiments, fluid flow moves in a direction from high to low pressure, and can use pressure or head to control fluid flow. In various embodiments, one or more actuators, handles, levers, pedals, switches, pistons, diaphragms, hydraulics, pneumatics, solenoids, motors, and/or materials can be used to respond to pressure, temperature, humidity or other measurable conditions. In various embodiments, a valve 258 may be a ball valve, butterfly valve, disc valve, check valve, one-way valve, two-way valve, choke valve, diaphragm valve, gate valve, globe valve, knife valve, needle valve, pinch valve, piston valve, plug valve, poppet valve, spool valve, thermal expansion valve, pressure relief valve, active valve, passive valve, or any other type of valve. In various embodiments, a valve 258 can connects to the drainage system 200 mechanically, chemically, magnetically, in threaded engagement, snap locked together, adhered, bonded, or with other connecting devices or methods.
[0040] In various embodiments, any components of a drainage system 200 can be manufactured from stainless steel, aluminum, metal, plastic, wood, hard wood or other materials and can be extruded, machines, cast, and/or completed with multiple finishes to accommodate specific needs of a customer whether for harsh weather conditions or more aesthetically pleasing to their tastes. In various embodiments, the drainage port 254 is rigid, flexible, malleable, bendable, PVC, copper, tubing, and can be circular, rectangular, square, or any other shape in cross section. In various embodiments, the drainage port 254 has a length in the range of 1-12 inches, 1-5 feet or more, the width of a door assembly, the width of a window assembly, the width of a jamb, configured to connect to a secondary drainage system, or other lengths. In one embodiment, the drainage port 254 is connectable to the base 210 with an exit port interface 252 . In various embodiments, the exit port interface 252 connects the drainage port 254 to the base 210 mechanically, chemically, magnetically, in threaded engagement, snap locked together, adhered, bonded, or with other connecting devices or methods.
[0041] In various embodiments, the body 210 can optionally include one, two, three, four or more flanges 270 . In various embodiments, the flanges 270 can structurally connect the body 210 to a fenestration product 10 or objects related to the fenestration product 10 , an interior floor 6 , an exterior floor 7 , a track 8 , channel, extrusion, or other structure. In various embodiments, the drainage system 200 is optionally configured to fit with or connect to a fenestration system, a door system, a window system, a track system, a cross member, flooring, interior flooring, exterior flooring, a shim, shim space, caulk, caulk line, seal, sill pan, flashing, insulation, stone, concrete, wood, foundation, framing, drywall, expansion joints, or other structures.
[0042] In one embodiment, a cover 280 is an adjustable cover. In one embodiment, the cover 280 is height-adjustable. In one embodiment, the cover 280 includes a cover top surface 283 . In one embodiment, the cover 280 includes a cover top surface 283 , a cover first wall 284 and a cover second wall 286 . In one embodiment, the cover 280 is a U-shaped cap. In one embodiment, the cover 280 has a cover width 281 and a cover height 282 and a cover length 287 (see FIG. 18 ). In various embodiments, the cover 280 can be configured with a cover width 281 and a cover height 282 and a cover length 287 to fit on top of a base 210 , inside a base 210 , around a base 210 , outside a base, have corresponding dimensions as a base 210 , have a dimension that is greater than a corresponding base 210 dimension, have a dimension that is less than a corresponding base 210 dimension, have a dimension that is the same as or similar to a corresponding base 210 dimension, or other dimensions. In various embodiments, the cover length 287 is 1 foot or less, 1-5 feet, 5-10 feet, 10 feet or more, or any range of sizes. In various embodiments, a drainage system 200 is straight, curved, arced, segmented, angular, or otherwise shaped to meet fenestration product 10 dimensions.
[0043] In one embodiment, the cover 280 includes one or more apertures 288 . In various embodiments, the cover 280 includes one, two, three, four, five or more, ten or more, twenty or more, fifty or more, a plurality, or multiple apertures 288 configured to redirect fluid from the cover 280 through the channel 215 of the body 210 to one or more drainage ports 254 . In various embodiments, the apertures 288 can be located on the cover top surface 283 , the cover first wall 284 and/or the cover second wall 286 . In one embodiment the cover has a cover width 281 (see FIGS. 7 and 8 ). In one embodiment the cover has a cover height 282 (see FIGS. 7 and 8 ). In one embodiment the distance of the top of the cover 280 to the top of a body wall 220 , 230 is a cover-to-body-wall height 292 (see FIGS. 7 and 8 ). In various embodiments, the cover-to-body-wall height 292 is less than 1 inch, 0.125 inches, 0.1875, 0.25 inches, 0.375 inches, 0.5 inches, 0.625 inches, 0.75 inches, 0.875 inches, 1.0 inches, 1.25 inches, 1.5 inches, 2 inches, or any dimension or range of dimensions between 0.125 inches and 3 inches or more. FIGS. 17-18 illustrate a cover 280 according to an embodiment of the present invention.
[0044] In various embodiments, the one or more apertures 288 is a slot, opening, hole, weep hole, a punch hole, a filter, or otherwise configured to redirect flow of a liquid away from a fenestration product 10 . In various embodiments, the one or more apertures 288 can have a circular, oval, rounded, rectilinear, square, rectangular, slanted, patterned or other shape. In one embodiment, the apertures 288 are configured to prevent the passage of insects or debris from clogging the drainage system 200 . In one embodiment, the cover 280 is configured to be readily accessible for servicing without removing or disassembling the fenestration product 10 .
[0045] In one embodiment, the drainage system 200 includes one or more adjustable members 260 configured to be movable with respect to an adjustable member base 262 to adjust a dimension or a position of the cover 280 . In one embodiment, the one or more adjustable members 260 are configured to alter, modify, adjust, move, or align a cover 280 . In one embodiment, an adjustable member 260 is configured to change the cover-to-body-wall height 292 . In various embodiments, the adjustable member 260 is a screw, bolt, nut, spring, lever, mechanism, solenoid, ratchet, gear, shim, elongate member, threaded member, or other device configured to be controllably altered to change and/or maintain the position of an adjustable cover 280 . In various embodiments, the adjustable member base 262 is a threaded hole, nut, screw, bolt, spring, lever, mechanism, solenoid, ratchet, gear, shim, elongate member, threaded member, or other device configured to be controllably change and/or maintain the position of the adjustable member 260 . In one embodiment, the adjustable member 260 is configured to be readily accessible for servicing without removing or disassembling the fenestration product 10 . In one embodiment, the adjustable member base 262 is configured to be readily accessible for servicing without removing or disassembling the fenestration product 10 .
[0046] In one embodiment, the first wall channel surface 222 includes one, two, three, four, or more adjustable member interfaces 264 . In one embodiment, an adjustable member interface 264 extends along a body length 213 of body 210 (see FIG. 14 ). In various embodiments, an adjustable member interface 264 is configured to connect the base 210 to an adjustable member 260 and/or an adjustable member base 262 through unitary construction, separate movable parts, welding, bonding, attaching, adhering, permanently attaching, temporarily attaching or some other type of interface. In one embodiment, the drainage system 200 is configured to conceal, contain, and/or route wires, connectors, cables, optical cables, lights, sensors, alarms or other apparatus in proximity to a fenestration product 10 .
[0047] As illustrated in FIGS. 2-6 , in accordance with various embodiments of drainage systems 200 , one or more drainage systems 200 includes can be used with one or more fenestration products 10 .
[0048] FIG. 2 illustrates a flush configuration drainage system 200 according to an embodiment of the present invention in which a cover 280 is configured to be substantially flush with an interior floor surface 6 , an exterior floor surface 7 , or both. In one embodiment, the cover 280 is an adjustable cover 280 set to a height to allow a fenestration product 10 to open or close inward and/or outward, in an interior 120 direction, an exterior 122 direction, and/or a direction parallel or substantially parallel to the body length 213 of the drainage system 200 .
[0049] FIG. 3 illustrates an elevated configuration drainage system 200 according to an embodiment of the present invention in which a cover 280 is configured to be elevated above an interior floor surface 6 , an exterior floor surface 7 , or both. In one embodiment, the cover 280 and/or body 210 of the drainage system 200 is configured to act as a stop to a fenestration product 10 , preventing motion in the direction impacting or abutting the drainage system 200 .
[0050] FIG. 4 illustrates a recessed configuration drainage system 200 according to an embodiment of the present invention in which a cover 280 is configured to be recessed below an interior floor surface 6 , an exterior floor surface 7 , or both. In one embodiment, the cover 280 is an adjustable cover 280 set to a height to allow a fenestration product 10 to open or close inward and/or outward, in an interior 120 direction, an exterior 122 direction, and/or a direction parallel or substantially parallel to the body length 213 of the drainage system 200 .
[0051] FIG. 5 illustrates a sliding door configuration drainage system 200 according to an embodiment of the present invention configured to operate with a sliding door. FIG. 6 illustrates a multiple sliding door drainage system 200 according to an embodiment of the present invention whereby the present invention configured to operate with multiple sliding doors. In various embodiments, any number of embodiments of one or more fenestration products 10 can be used to form a sliding door panel system 11 . In various embodiments, additional door panels can be denoted with a prime symbol, such as a first door panel 15 , a second door panel 15 ′, a third door panel 15 ″, etc. In various embodiments of sliding door systems, two or more sliding door panels 15 can be arranged, typically sliding on parallel tracks, to form a “multislide” door system that can span an opening. The individual door panels 15 of a multislide door system can include one or more transparent or translucent windowpanes 20 to provide access to a panoramic view or light even when the door system is closed. In some embodiments, some or all of the door panels of multislide systems can be retracted into a pocket of a door jamb in an adjacent wall, such that when the door system is open, an indoor/outdoor building space is created. In one embodiment, the fenestration product 10 is configured to open and close between an interior 120 and an exterior 122 . In one embodiment, the interior 120 is the inside of a building, house, room, or structure. In one embodiment, the exterior 122 is the outside of a building, house, room, or structure. In various embodiments, although the term interior 120 or exterior 122 is used, the names are being used in reference to a side of embodiments of the fenestration product 10 and can simply refer to a side of a wall or side of the fenestration product 10 whether one side is in or out of a structure or wall. In various embodiments the interior 120 and/or exterior 122 can be any combination of inside, outside, both inside or both outside of a structure, wall, etc. In various embodiments, a door panel 15 can comprise vertical stiles 12 , 14 and horizontal rails 16 , 18 . The stiles and rails can comprise a rigid material such as a wood, metal, plastic or polymer, composite, or other suitable material construction. In some embodiments, the stiles 12 , 14 and the rails 16 , 18 comprise a hardwood. In some embodiments, the stiles 12 , 14 and the rails 16 , 18 comprise aluminum. In some embodiments, the stiles 12 , 14 and the rails 16 , 18 comprise a wood reinforced with at least a metallic strip. Where the stiles 12 , 14 and the rails 16 , 18 are comprised of a metal, in some embodiments, they can be formed by extrusion. In various embodiments, any combination of materials can be used.
[0052] In one embodiment, a sliding door panel system 11 includes one, two or more door panels 15 , 15 ′ slideably disposed on one or more lower tracks 8 , 8 ′. In one embodiment, each door panel 15 is slideably disposed on a track segment 8 . It is contemplated that multiple door panels 15 , 15 ′ can be arranged (for example, including two, three, four, five, six, or more door panels 15 ) to form various sliding door systems. The sliding door panel system 11 can be configured to be slideably mounted to a jamb or door frame 1 having a header 2 and an upper track 4 (not illustrated here). In one embodiment, the door panels 15 can run on parallel tracks 4 , 4 ′, 8 , 8 ′. In one embodiment, one or more door panels 15 can be stored in a pocket 3 (not illustrated here) to the side of the door frame 1 or an upper track 4 (not illustrated here) or a lower track 8 . For example, in some embodiments, the door panel 15 can include one or more upper roller mechanisms 30 configured to ride in the upper track 4 to guide the door panel 15 along the upper track 4 (not illustrated). In one embodiment, the door panel 15 has adjustable rollers. In one embodiment, the door panel 15 has weather stripping. In one embodiment, both adjustable rollers and weather stripping are used together, and as the rollers are adjusted the weather stripping may or may not come into contact with the threshold or the ground.
[0053] In one embodiment, the door panel 15 can be configured to be slideably disposed on a lower track 8 . In various embodiments, the lower track 8 can be recessed below a floor surface 6 , even with a floor surface 6 , or raised above a floor surface 6 . In the one embodiment, the door panel 15 can further be configured to be slideably disposed on a lower track 8 recessed into a floor surface 6 . For example, in some embodiments, the door panel 15 can include one or more lower roller mechanisms 32 configured to ride on the lower track 8 . In some embodiments, the door panel 15 can be configured to run on a lower track 8 that is not recessed.
[0054] In several embodiments, the drainage systems described herein are particularly suitable for the sliding doors described in PCT/US2009/047540, filed on Jun. 16, 2009. This application incorporates the disclosure of U.S. application Ser. No. 12/999,433, filed Dec. 16, 2010 as a national phase application from PCT/US2009/047540 filed in English on Jun. 16, 2009, which claims the benefit of priority to U.S. Provisional Application No. 61/073,320, filed Jun. 17, 2008, and which is incorporated by reference in its entirety herein. In several embodiments, the drainage systems described herein are particularly suitable for the sliding doors described in PCT/US2008/050928, filed on Jan. 11, 2008. This application incorporates the disclosure of U.S. application Ser. No. 12/522,909, filed Jul. 10, 2009 as a national phase application from PCT/US2008/050928 filed in English on Jan. 11, 2008, which claims the benefit of priority to U.S. Provisional Application No. 60/880,255, filed Jan. 12, 2007, and which is incorporated by reference in its entirety herein.
[0055] FIG. 7 illustrates a drainage system 200 according to an embodiment of the present invention in accord with the embodiments of a drainage system 200 disclosed herein with respect to FIGS. 1-6 . As illustrated in FIG. 7 , the embodiment is shown at a location in which an adjustable member 260 is not visible. In one embodiment, a drainage system 200 is configured to fit within or between the interior jamb line of a wall and the fenestration product 10 . In one embodiment, an adjustable height cover 280 is configured with a cover width 281 that is less than the body width 212 to fit inside or between the walls 220 , 230 of the body 210 . In one embodiment, not illustrated here, an adjustable height cover 280 is configured with a cover width 281 that is greater than the body width 212 to fit over and around the body 210 . In various embodiments, the cover width 281 is less than 1 inch, 0.125 inches, 0.1875, 0.25 inches, 0.375 inches, 0.5 inches, 0.625 inches, 0.75 inches, 0.875 inches, 1.0 inches, 1.25 inches, 1.5 inches, 2 inches, or any dimension or range of dimensions between 0.125 inches and 1 foot or more. In various embodiments, the body width 212 is less than 1 inch, 0.125 inches, 0.1875, 0.25 inches, 0.375 inches, 0.5 inches, 0.625 inches, 0.75 inches, 0.875 inches, 1.0 inches, 1.25 inches, 1.5 inches, 2 inches, or any dimension or range of dimensions between 0.125 inches and 1 foot or more.
[0056] In various embodiments, the cover-to-body-wall height 292 is configured to be controllably adjustable or variable. As illustrated in FIGS. 7 and 8 , the first wall height 226 , second wall height 236 , cover height 282 , and cover-to-body-wall height 292 can be varied or produced in various fixed dimensions to meet any of the various configurations shown at least in FIGS. 2-6 or other configurations. FIG. 8 illustrates a compact height configuration of a drainage system 200 according to an embodiment of the present invention, wherein the body 210 is relatively shorter than the body 210 shown in the embodiment illustrated at FIG. 7 .
[0057] In optional embodiments, a cover 280 can comprise a filter 290 , 290 ′, 290 ″. In various embodiments, the filter 290 is a mesh, screen, matrix, fabric, sponge, porous medium or other material configured to fit outside, inside or within one or more apertures 288 . In various embodiments, the filter 290 is configured to prevent the passage of insects or debris from clogging the drainage system 200 . In one embodiment, the filter 290 is configured to be removable for cleaning or replacement from the drainage system 200 . In one embodiment, the filter 290 is roughly two-dimensional structure configured to extend across one or more or all apertures 288 . In one embodiment, the filter 290 is three-dimensional structure configured to fit within the cover 280 . In one embodiment, the filter 290 is three-dimensional structure configured to fit within the channel 215 of a body 210 . In one embodiment, the filter 290 is configured to be readily accessible for servicing without removing or disassembling the fenestration product 10 .
[0058] FIG. 9 illustrates the drainage system 200 according to FIG. 7 with an adjustable height cover 280 removed. In various embodiments, the adjustable height cover 280 can be configured to be disposable and maneuverable or adjustable with one, two or more adjustable members 260 . In one embodiment, a single adjustable member 260 is configured to adjust the height of the adjustable height cover 280 . In one embodiment, a two, three, four, or more adjustable members 260 are distributed along a length or a cover 280 are configured to adjust the height of the adjustable height cover 280 . In one embodiment, a first end adjustable member 260 and second end adjustable member 260 are configured to adjust the height, tilt, slant, slope, and/or position of the adjustable height cover 280 . In various embodiments, two or more adjustment members 260 can be distributed evenly or asymmetrically at any distance apart. In various embodiments, the distance between adjustment members 260 can vary depending on the length of the cover 280 , the body length 213 , interior floor surface 6 considerations, exterior floor surface 7 considerations, or other distances, including, but not limited to 6 inches, 12 inches, 18 inches, 24 inches, or anywhere in the range of 1 inch to six feet. In one embodiment, any adjustment member 260 can be set to the same or different height as adjacent or other adjustment members 260 in an attempt to flatten, tilt, slant, and/or configure a position of a cover 280 . FIGS. 10-16 illustrate the drainage system 200 according to FIG. 7 either with or without an adjustable height cover 280 shown.
[0059] It will be understood by those of skill in the art that numerous and various modifications can be made without departing from the spirit of the present invention. Therefore, it should be clearly understood that the forms of the present invention are illustrative only and are not intended to limit the scope of the present invention. Although a few embodiments have been described in detail above, other modifications are possible. For example, although several of the embodiments described herein discuss drainage systems used with linear movement of door panels along tracks that can be parallel or linear, it is also contemplated that drainage systems can be used with door panels, track, and related movement can be accomplished with rounded doors and or tracks, curves and/or arcs, or other shapes as well. Other embodiments may be within the scope of the following claims. It will be understood that the foregoing is only illustrative of the principles of the invention, and that various modifications, alterations, and combinations can be made by those skilled in the art without departing from the scope and spirit of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.
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A drainage system is configured for draining water or other liquid intrusion in to building structure openings, access routes, including fenestration, door or window products. Embodiments include adjustable height drainage systems that are vertically adjustable to controllably place the height of the drainage system above, below or flush with one or more surrounding floor or fenestration portal surfaces. One or more adjustable members controllably move and position the cover with respect to the drainage system body. Drainage systems are readily accessible for service and/or adjustment of the drainage system without removal or disassembly of a fenestration product.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Application No. 61/699,972 filed Sep. 12, 2012, herein incorporated by reference.
BACKGROUND
[0002] Disclosed herein is a device for exercising the human body, and the legs in particular.
[0003] Recently, it has become more widely understood that seated and inactive persons, such as aircraft passengers, may be prone to deep vein thrombosis (DVT), occurring in the main over longer journey times and affecting the legs in particular. Normally, movement of the calf muscles helps to pump blood from the legs to the heart. However, if the legs are rested or inactive for extended periods, such as in the case of long haul air travel, there is a risk of blood clots forming in the legs, although these may be dispersed through exercise that activate the calf muscles to increase the flow of blood. While seated, this can be best achieved by rocking the foot at the ankle, which, primarily, generates movement in the calf muscle group.
[0004] Certain exercise devices for the legs are produced that may be operated while seated for the relief of DVT. However, these devices need setting up and may not always fully exercise the calf muscles due to imprecise action through not being operated correctly. The present invention sets out to provide improvements in these respects.
BRIEF SUMMARY
[0005] The present inventor has realized that a simple and highly effective exercise device may be provided in the form of a rigid body comprising a foot-contacting surface and a floor-contacting surface which are configured so that rolling the floor-contacting surface over a floor surface will cause the foot-contacting surface to rise above the floor surface. Surprisingly, the action of lifting the foot causes the calf muscles to contract in a way which helps to pump blood through the veins in the leg. Repeated operation of the device in a rocking, oscillating or rolling motion causes a repeated contraction and relaxing of the calf muscles and can help resist the formation of clots and deep vein thrombosis.
[0006] Accordingly, the present invention provides an exercise device comprising a solid body having a first surface for contacting the instep of the foot of a user and a second surface for contacting a floor surface, wherein the first and second surfaces are configured so that rolling the second surface over a floor surface causes at least a part of the first surface to rise with respect to the floor surface.
[0007] In a first aspect, the first and second surfaces are textured to improve grip, the texturing extending up to a distance of at least 1 cm from at least one of the ends of the device in an axial direction of the device. This is found to give both good grip with respect to a floor surface and also comfort for a user when handling. Preferably, the texturing extends up to a distance of at least 1 cm from both of the ends of the device in an axial direction of the device
[0008] In a second aspect, the length of the device in an axial direction is at least 12.5 cm. This is found to give a good directional stability of the device during rolling.
[0009] In a third aspect, the device is in the form of a hollow body, comprising a movable, hinged closure at at least one end.
[0010] According to the present invention, an oblong length of material is shaped to act as a support and fulcrum for the foot while seated. The oscillator is located under the instep, just forward of the ankle, so that it can be rocked, or oscillated, backwards and forwards by the foot which, primarily, requires the effort of the calf muscles, thus increasing blood flow in the leg concerned.
[0011] Preferably, the second surface is a smoothly curving surface or a surface defined by a plurality of small stepped surface segments whose edges lie on a smooth curve. Suitably, if the surface comprises small surface segments, each surface segment is no wider than 2 cm, preferably no wider than 1.5 cm and preferably no wider than 0.8 cm. Preferably, the first surface is also curved, being defined by a smooth curve or a series of stepped surface segments in a similar way to the second curved surface. Suitably, the first and second surfaces define a closed body.
[0012] The necessary rising action may be achieved if the first and second surfaces together define a body which, when seen in cross section, is generally non-circular. The body may be elliptical, ovoid, oblong or polygonal with a rounded edges or even an irregular non-circular figure.
[0013] All of these figures have the advantage that, when they are pushed, pulled, rocked, oscillated or rolled across a floor surface, using the foot, a rising action is generated in the foot, causing the calf muscles to contract.
[0014] The first and second curved surfaces may have substantially the same form so that the device can be used with either surface in contact with the floor or with the foot.
[0015] The device may comprise a section of a cylinder or prism whose cross section has the shape described above. Alternatively, it may be a section of a conoid, a pair of conoids meeting at their bases, or a cylindroid, having outwardly bowed side walls in a manner of a barrel, or inwardly bowed side walls.
[0016] The body may even be in a form of a distorted ball.
[0017] The body may be formed of any suitable material, for example, metal, synthetic material such as thermoplastic or composite material, wood, paper, papier maché or any other suitable material. A suitable material is polystyrene. The device may be formed by any suitable technique, such as molding. It may be formed as a solid body or it may comprise a hollow body.
[0018] Where the body is in form of a hollow body, it may be open at at least one end, so that items may be stored inside the body. Removable closure elements may be provided for at least one end of the body.
[0019] The body may be symmetrical about at least one and preferably two planes of symmetry, suitably, the planes of symmetry intersect one another at right angles.
[0020] Where the device comprises a symmetrical body, it can be placed any way round or anyway up and will still function.
[0021] The shape of the body may be further defined by defining the shape of the cross section of a foot-contacting zone of the device. In the foot contacting zone, a cross section, extending between a foot contacting portion and ground contacting portion will have a greatest dimension and a least dimension. For example, if the shape were elliptical, these would be the distance along the minor axis and the distance along the major axis.
[0022] Suitably, the greatest dimension is in the range 50-150 mm more preferably 50-100 mm. Preferably, the least dimension is in the range 20-100 mm, more preferably 25-60 mm. Suitably, the ratio between the least and the greatest dimension is in the range 1.0:1.05 to 1.0:2.0, preferably 1.0:1.15 to 1.0:2.0 more preferably 1.0:1.2 to 1.0:1.9, most preferably around 1.0:1.5 to 1.0:1.8.
[0023] The first and second surfaces may be textured to improve grip. For example, they may be roughened, matt, ridged, stepped or grooved to improve contact and friction.
[0024] Where the shape comprises an ellipse or at least approximates to an ellipse, the shape may be defined with reference to a plane dissecting a circular section cylinder at an angle. The angle between the plane and a plane which is perpendicular to the axis of the cylinder is referred to. In this case, the shape of the foot-contacting portion is suitably defined by a 20-60° ellipse or ellipsoid, preferably a 35-40° ellipse or ellipsoid.
[0025] If the difference between the greatest and least dimension is not sufficiently large, an insufficient lifting action is obtained. Suitably, a lift in the range 10-25 mm is obtained when rolling the device over a distance of about 5 cm.
[0026] If, however, the difference between the greatest dimension and the least dimension is too much, the device becomes difficult to operate. Further, if the difference is too small, the object will tend to approximate too much to a smooth cylinder and may roll around floor in an uncontrolled fashion, providing a hazard to other people.
[0027] The body may comprise at least two parts which fit together for use. The parts may define between them a space for enclosing objects. The shape must be constructed in a way, known to the person skilled in the art, so that it can bear the weight of at least the leg of a fully grown adult.
[0028] Alternatively, the body may comprise two geometrically similar parts, one of which is slidably mounted in the other, so that the device may be opened like a telescope.
[0029] The present invention further provides a method of exercising the foot, comprising placing an exercise device according to the invention between the instep of the foot and a floor surface and rocking, oscillating or rolling the foot and the device backward and forwards.
[0030] It is a particular advantage of the present invention that it may be used while the user is in a seated position. For example, it may be used by a passenger in an aircraft or other vehicle while at their seat, allowing for use with minimal interference. It employs a natural foot action. The device may be used substantially silently, as it does not require hinges or other moving parts. The device may be prepared for use simply by placing it on the ground, making it easy to operate.
[0031] Preferably, the device is formed of material, thickness and size which allow its weight way to be small. Preferably, the weight is in the range 50-250 gms more preferably 100-150 gms.
[0032] An optional feature of the invention may include a timer device for setting off a warning, for example a flashing light, buzzer or other device for alerting a user that it is time to exercise.
[0033] The lifting motion imparted to the leg may be taken up by movement of the foot or movement of the whole leg, according to the preference of the user.
[0034] In either case, the calf muscles will be contracted, with the accompanying beneficial effect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] By way of example, a specific embodiment of the invention, referred to in the description as an oscillator, will now be described with reference to the accompanying drawings in which:
[0036] FIG. 1 shows in perspective, the general configuration of the oscillator.
[0037] FIG. 2 shows in perspective, the oscillator in position under the in step.
[0038] FIGS. 3A , B illustrate in end view, the alternating positions of the oscillator.
[0039] FIG. 4 illustrates the top and underside details of the oscillator.
[0040] FIG. 5 shows the oscillator in two parts.
DETAILED DESCRIPTION
[0041] Referring to FIG. 1 , an oblong, oval-shaped oscillator 7 , which may be of solid or hollow construction, is designed to function under and across the instep of the foot while supporting the full weight of the leg and foot on its upper surface, as indicated by the arrows, and with the underside being in contact with the floor at 8 . The oscillator and foot may then be rocked backwards and forwards on the spot by applying alternate pressure with the ball of the foot and heel, with shoes on or off. The oscillator 7 is symmetrical in design so that either surface may provide the floor-contacting surface or the foot-contacting surface. First and second surfaces are textured to improve grip, the texturing extending up to a distance of at least 1 cm from both ends of the device in an axial direction of the device. The length of the device in an axial direction is at least 12.5 cm. This is found to give a good directional stability of the device during rolling. The device is suitably in the form of a hollow body, comprising a movable, hinged closure at at least one end.
[0042] According to FIG. 2 , the oscillator 7 is shown in position with the leg near vertical and arrows indicating the rocking motion of the foot.
[0043] Referring to FIGS. 3A and 3B , the central principle employed in the oscillator is that the dual cam effect of the rocking ellipsoid, reacting with the floor, lifts either the front or back of the foot as it is progressively rotated so that the following occurs. FIG. 3A shows the oscillator rocked forwards by pressure on the ball of the foot so that the rear lobe of the ellipse has risen, giving an increase in height shown at C which is lifting the heel and increasing the angle of the foot to the horizontal plane so as to fully flex the calf muscles. FIG. 3B shows the oscillator rocked backwards by downward pressure of the heel which is lifting the front of the foot and also increasing its angle to the horizontal plane so as to fully flex the calf muscles in reverse. The “pumping” effect of the calf muscles can thus be controlled and varied depending on the degree of effort applied to the rocking action, affecting the angle of the foot.
[0044] The oscillator may also have an asymmetrical, or egg-shaped, outer profile which provides a variation in lift characteristics, if required.
[0045] According to FIG. 4 , the plan view of the upper and lower surfaces of the oscillator shows lateral ridges 9 which improve grip and control slippage at the foot and floor interfaces when in use. If the oscillator is of hollow construction, end cap(s) 10 may be removable to access items that may be kept within.
[0046] Referring to FIG. 5 , the oscillator may be constructed of two separate halves with the horizontal join surfaces shown at 11 . The oscillator may function as a single unit if the halves are joined together, or it may be separated to provide two units that may be used with the flat surfaces uppermost in contact with the feet.
[0047] The oscillator 7 shown in FIGS. 1 and 5 of the drawings comprises an elliptical sectioned prism.
[0048] When seen in cross section, the width along the major axis is 57 mm and the depth along the minor axis is 33 mm, corresponding to a 36° ellipse.
[0049] The prism section is preferably of length of 106 mm. The device is formed of thermoplastic material and weighs 120 gms.
[0050] In order to determine the effectiveness of the device according to FIG. 1 for increasing blood flow and for resisting DVT, live tests were carried out at a leading Medical Center.
[0051] Ten healthy subjects of both sexes were individually tested at half hourly intervals to evaluate how using the device of FIG. 1 affected blood flow in the legs. A standard economy class aircraft seat was provided in which each subject remained for the duration of the test. A sensor was attached to each leg to monitor venous outflow Vo in the femoral region. The left leg (LT) was kept static as a control throughout the test while the right (RT) foot and leg were exercised. The object being to determine blood flow differential in the legs as a result of right leg activity alone, thus indicating blood flow improvement directly attributable to the exercise device of FIG. 1 .
[0052] The subjects were seated and totally inactive for the initial two hours so that the fall off in venous outflow could be monitored in both legs. Thereafter, at half hourly intervals, the right foot was exercised for one minute duration using the device of FIG. 1 and the Vo readings were taken 15 minutes after cessation of exercise. Exercise was conducted every 30 minutes for one minute only.
[0053] The following results were obtained.
[0054] After two hours, venous outflow from the unexercised left leg was reduced by 43.5%. In contrast, venous outflow, in the right leg, 15 minutes after exercise was ceased had only reduced by 19.57%. Further, venous capacitance was measured. The venous capacitance of the left leg after two hours had increased by 34.66% whereas it had only increased by 30.1% in the right leg.
[0055] It can be seen that there is 55% improvement in blood flow produced by just one minute of exercise. This value compares directly with blood flow improvements obtained by normal walking action for the same time in a similar test environment.
[0056] The present invention has been described above by way of example only. Modification can be made within the spirit of the invention which extends to equivalents of the features described. The invention also consists in any individual features described or implicit herein or shown or implicit in the drawings or any combination of any such features or any generalization of any such features or combination.
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The present invention provides an exercise device comprising a rigid solid body or a rigid hollow body having a first surface for contacting the instep of the foot of a user and a second surface for contacting a floor surface, wherein the first and second surfaces are configured so that rolling the second surface over a floor surface causes at least a part of the first surface to rise with respect to the floor surface.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to provisional U.S. Patent Application Ser. No. 60/363,424, filed Mar. 11, 2002, and Ser. No. 09/974,578, filed Oct. 9, 2001 which are expressly incorporated by reference for all purposes.
FIELD OF THE INVENTION
[0002] The present invention pertains to the field of distributed active transformers. More specifically, the invention relates to distributed active transformers that include features that provide additional control over operational parameters.
BACKGROUND OF THE INVENTION
[0003] A distributed active transformer includes a primary winding that uses active devices to control the current direction and magnitude on the winding. For example, U.S. patent application Ser. No. 09/974,578, filed Oct. 9, 2001, describes distributed active transformers that can comprise at least two push/pull amplifiers designed to amplify an RF input signal. The distributed active transformer can be operated where a first amplifier causes current to flow on the primary winding in a first direction, and where a second amplifier causes current to flow on the primary in a second direction. In this manner, an alternating current is induced on the secondary winding.
SUMMARY OF THE INVENTION
[0004] In accordance with the present invention, a distributed active transformer is provided that overcomes known problems with existing transformers.
[0005] In particular, a distributed active transformer is provided that allows sections of the distributed active transformer to be independently controlled.
[0006] In accordance with an exemplary embodiment of the present invention, a distributed active transformer is provided. The distributed active transformer includes a primary winding having two or more sets of push/pull amplifiers, where each set of push/pull amplifiers is used to create an alternating current on a section of the primary winding. A secondary winding is disposed adjacent to the primary winding, such that the alternating current on the primary induces alternating current on the secondary. The primary winding and the secondary winding can be disposed on a semiconductor substrate.
[0007] The present invention provides many important technical advantages. One important technical advantage of the present invention is a distributed active transformer that allows sections of the distributed active transformer to be independently controlled, so as to adjust the operating parameters of the distributed active transformer.
[0008] Those skilled in the art will appreciate the advantages and superior features of the invention together with other important aspects thereof on reading the detailed description that follows in conjunction with the drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] FIG. 1 is a diagram of a distributed active transformer in accordance with an exemplary embodiment of the present invention;
[0010] FIG. 2 is a diagram of a distributed active transformer with two primary windings in accordance with an exemplary embodiment of the present invention;
[0011] FIGS. 3 and 3A are diagrams of a distributed active transformer with first and second primary windings and compensating capacitors in accordance with an exemplary embodiment of the present invention;
[0012] FIG. 4 is a diagram of a distributed active transformer with first and second primary windings and compensating capacitors in accordance with another exemplary embodiment of the present invention;
[0013] FIG. 5 is a diagram of a distributed active transformer with impedance transformation ratio correction and resonance frequency selection in accordance with an exemplary embodiment of the present invention;
[0014] FIG. 6 is a diagram of a distributed active transformer with switched-in capacitors that are in parallel with amplifiers in accordance with an exemplary embodiment of the present invention;
[0015] FIG. 7 is a diagram of a distributed active transformer with a low noise amplifier in accordance with an exemplary embodiment of the present invention; and
[0016] FIG. 8 is a diagram of a distributed active transformer with a low noise amplifier in accordance with another exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] In the description that follows like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawing figures are not necessarily to scale and certain features may be shown in somewhat generalized or schematic form in the interest of clarity and conciseness.
[0018] FIGS. 1 AND 1A are diagrams of distributed active transformer 100 in accordance with an exemplary embodiment of the present invention. Distributed active transformer 100 allows the number of primary sections in the primary winding of a distributed active transformer to be reconfigured.
[0019] Distributed active transformer 100 includes primary winding sections 102 A, 102 B, 102 C, and 102 D, and secondary winding 104 . Each primary winding section has an associated push/pull amplifier pair that includes amplifiers 106 A and 108 A for primary winding section 102 A, amplifiers 106 B and 108 B for primary winding section 102 B, amplifiers 106 C and 108 C for primary winding section 102 C, and amplifiers 106 D and 108 D for primary winding section 102 D. The amplifiers can be implemented using bipolar junction transistors (BJTs), metal oxide semiconductor field-effect transistors (MOSFETs), hetero-junction bipolar transistors (HBTs), metal-semiconductor field effect transistors (MESFETs), lateral double-diffused metal oxide semiconductor transistors (LDMOSs), complementary MOS transistors (CMOS), or other suitable devices. Amplifier 106 A drives current to the positive terminal of primary winding section 102 A, whereas amplifier 108 A drives current from the negative terminal of primary winding section 102 A. The polarities of the amplifiers can be alternated to reverse the direction of current flow. A drain voltage V dd (not explicitly shown) may alternatively be provided at a midway point, corner, or at other suitable locations on each primary winding section to provide the current source or other suitable configurations can be used to create time-varying current on the primary winding sections using the push/pull amplifier pairs. A similar configuration is used for primary winding sections 102 B, 102 C, and 102 D.
[0020] Each push/pull amplifier pair of each primary winding section can be controlled so that the current flowing on the primary winding section alternates in direction and magnitude in a manner that creates a magnetic field that induces an electromotive force (EMF) on secondary winding 104 . The EMF causes current to flow in secondary winding 104 , based on the impedance of that winding and any associated circuit. The current through the push/pull amplifier pairs can be controlled so as to adjust both the current and the voltage induced in this manner on secondary winding 104 .
[0021] Switches 110 A, 110 B, 110 C, and 110 D can be implemented as transistors, micro-electromechanical devices (MEMS), or other suitable devices, and are connected to a one amplifier out of each set of two adjacent push/pull amplifier pairs, such that the two adjacent push/pull amplifiers can be bypassed and a new push/pull amplifier pair can be created. As used herein, “connect” and its cognate terms such as “connects” or “connected” can refer to a connection through a conductor, a semiconducting material, or other suitable connections. In one exemplary embodiment, amplifiers 106 A and 108 B are connected to switch 110 A, such that the amplifiers can be bypassed by closing switch 110 A. In this embodiment, amplifiers 106 B and 108 A would then form the push/pull amplifier pair for primary winding sections 102 A and 102 B. Likewise, a similar configuration can be provided for switches 110 B, 110 C and 110 D. In this regard, it should be noted that the set of push/pull amplifiers that the switches are connected to is different from the set of push/pull amplifiers that service each primary winding section. Nevertheless, each switch can operate to bypass one amplifier from a first push/pull amplifier pair and a second amplifier from a second push/pull amplifier pair so as to result in the remaining amplifiers from those two push/pull amplifier pairs operating as a push/pull amplifier pair on a combined primary winding section.
[0022] For example, if switch 110 A is closed, the power level generated by distributed active transformer 100 is less than the power level that is generated for distributed active transformer 100 with all switches open. The current magnitude through secondary winding 104 will be determined by the sum of the electromotive forces induced on the secondary by each primary winding section, which equals the change in flux linkages over time (dΦ/dt) which is determined by the mutual inductance of the primary and the secondary and the change in the current of the secondary (M*dI/dt.)
[0023] When a push-pull configuration is used with no V dd points, closing a single switch 110 results in an increased impedance for each remaining push/pull amplifier pair that drives current through the two connected primary winding sections. This configuration decreases the output power by increasing the impedance seen by the remaining amplifiers. Alternately, the winding sections can be capacitively coupled, such that the impedance seen by each amplifier remains the same, but where power is controlled by turning off or switching out amplifier sections. In either configuration, turning off amplifiers results in a decrease in output power and can be used to lower the overall power dissipation of the amplifier.
[0024] When a push-pull configuration is used that includes V dd points, with a single switch 110 closed, one quarter of the primary winding section will not be carrying any current, as no current will flow between the V dd points of the two connected primary winding sections.
[0025] In the described configurations, closing one switch can decrease the flux linkages between the primary and secondary windings, such that the open loop voltage on the secondary will be decreased to fraction of the maximum open loop voltage that could be realized with all switches 110 A through 110 D open. Likewise, with two and three switches 110 closed, the open loop voltage will drop more. Thus, distributed active transformer 100 can operate in four different modes of operation—a maximum power mode with all switches 110 A through 110 D open, a medium-high power mode, with any one of switches 110 A through 110 D closed, a medium-low power mode with any two of switches 110 A through 110 D closed, and a low power mode with any three of switches 110 A through 110 D closed. The power levels will be a function of whether the impedance seen by each amplifier is constant or varies as a function of the switches that are closed, as well as other factors.
[0026] In addition to providing different power modes of operation with switches 110 A through 110 D, the biasing current required for each of the bypassed amplifiers can also be decreased, such that the bias current requirements for distributed active transformer 100 can also be controlled. For example, with all switches 110 A through 110 D open, the bias current required for each of amplifiers 106 A and 108 A through 106 D and 108 D can be at a maximum. If switch 110 A is closed, then the bias current required for amplifiers 106 A and 108 B can decrease. In this manner, bias current requirements for distributed active transformer 100 can be controlled through the use of switches 110 A through 110 D, where suitable. Likewise, the bias current for a given power level can be optimized by determining the power level range for a given switch setting, and using the range that provides the lowest bias current for the expected range of operation. For example, if the expected power levels for the operating range of an application would fall within either the power level range for operation of distributed active transformer 100 with either two of switches 110 closed or three of switches 110 closed, then operation of distributed active transformer 100 with three of switches 110 closed would satisfy the power requirements for the operating range while minimizing the bias current required to support operation.
[0027] FIG. 1A shows an exemplary configuration of switches 120 A and 120 B, which can be used to connect or disconnect amplifiers 108 A and 106 D, respectively, from distributed active transformer 100 while allowing 102 A and 102 D to be independently coupled or decoupled. The exemplary configuration of switches 120 A and 120 B can be implemented at each connection between each primary winding section, secondary winding sections (if such sections are used), or in other suitable locations. Switches 120 A and 120 B thus provide additional flexibility for the configuration of distributed active transformer 100 .
[0028] In operation, distributed active transformer 100 allows the power capability and biasing current requirements to be controlled through the operation of switches 110 A through 110 D. In this manner, additional control of the power output and power consumption of a distributed active transformer is provided.
[0029] FIG. 2 is a diagram of distributed active transformer 200 with two primary windings in accordance with an exemplary embodiment of the present invention. Additional primary and secondary windings can likewise be provided for additional power conversion control, either internal or external to the secondary winding.
[0030] Distributed active transformer 200 includes first primary winding sections 202 A, 202 B, 202 C, and 202 D, and second primary winding 212 . Secondary winding 204 is disposed between the first primary winding sections 202 A through 202 D and second primary winding 212 . For the first primary winding sections, push/pull amplifiers 206 A and 208 A are associated with primary winding section 202 A, push/pull amplifiers 206 B and 208 B are associated with primary winding section 202 B, push/pull amplifiers 206 C and 208 C are associated with primary winding section 202 C, and push/pull amplifiers 206 D and 208 D are associated with primary winding section 202 D. Likewise, push/pull amplifiers 210 A and 210 B are associated with second primary winding 212 , although a single driver amplifier can alternatively be used where suitable. The secondary winding has an output 214 .
[0031] Distributed active transformer 200 can operate with primary winding sections 102 A through 102 D active and second primary winding 212 inactive. In this mode, distributed active transformer 200 can provide higher power but with increased bias current requirements. Likewise, distributed active transformer 200 can operate with primary winding sections 102 A through 102 D inactive and with second primary winding 212 active. In this exemplary embodiment, the power delivered to output 214 can be lower than the power delivered to output 214 when first primary winding sections 202 A through 202 D are activated, but the bias current required can be lower than the bias required with primary winding sections 202 A through 202 D active.
[0032] In another exemplary embodiment, the spacing between second primary winding 212 and secondary winding 204 can be increased, so as to decrease the magnetic coupling between the primary and secondary windings. The power loss in second primary winding 212 when it is not being used can thus be decreased, as well as the voltage breakdown requirements of push/pull amplifiers 210 A and 210 B. Additional primary windings can likewise be provided, depending on the power levels required and the available space.
[0033] In operation, distributed active transformer 200 can be operated in a first mode for high power with high bias current requirements by activation of primary winding sections 202 A through 202 D, and in a second mode with lower power and bias current requirements by activation of second primary winding 212 . Use of a first primary winding and a second primary winding allows the power output and bias current requirements for a distributed active transformer to be adjusted as needed by switching between primaries.
[0034] FIGS. 3 AND 3A are diagrams of distributed active transformer 300 A with first and second primary windings and compensating capacitors in accordance with an exemplary embodiment of the present invention. Distributed active transformer 300 A allows the power loss caused by circulating currents in an unused primary winding to be mitigated through the use of a switched series capacitance, as well as decreasing the breakdown voltage imposed on the associated primary winding amplifiers.
[0035] Distributed active transformer 300 A includes primary winding sections 302 A through 302 D with associated push/pull amplifier pairs 306 A and 308 A through 306 D and 308 D, respectively, and secondary winding 304 with output 312 . Likewise, second primary winding 310 includes push/pull amplifiers 314 A and 314 B, which can be connected using switch 316 through capacitor 318 . When capacitor 318 is connected in parallel with second primary winding 310 through switch 316 , an LC resonant circuit can be formed with secondary winding 304 . When second primary winding 310 is not in use, switch 316 can be opened to take second primary winding 310 out of resonance with secondary winding 304 and decrease losses due to circulating currents, as well as to decrease the peak voltage imposed on push/pull amplifiers 314 A and 314 B when they are inactive. In general, capacitors can be switched into and out of windings in other suitable configurations, to take the windings in and out of resonance with other windings.
[0036] As shown in FIG. 3A , a suitable configuration of switches and capacitors can be used in lieu of a single switch 316 and capacitor 318 , where each switch-capacitor pair can be controlled separately, thus allowing the resonance frequency of the secondary loop to be adjusted. In one exemplary embodiment, this combination can be used to adjust the center frequency of a power amplifier so as to achieve a flat gain and efficiency response across multiple frequency bands or channels, to account for manufacturing process variations, to account for temperature variations, or for other suitable purposes.
[0037] FIG. 4 is a diagram of distributed active transformer 300 B with first and second primary windings and compensating capacitors in accordance with an exemplary embodiment of the present invention. Distributed active transformer 300 B allows the power loss caused by circulating currents in an unused primary winding to be mitigated through the use of switched capacitors, as well as decreasing the breakdown voltage imposed on the associated primary winding amplifiers.
[0038] Distributed active transformer 300 B includes primary winding sections 302 A through 302 D with associated push/pull amplifier pairs 306 A and 308 A through 306 D and 308 D, respectively, with secondary winding 304 and output 312 . Likewise, second primary winding 310 includes push/pull amplifiers 314 A and 314 B, which can be connected using switches 316 through capacitors 318 . When capacitors 318 are connected to second primary winding 310 through switches 316 , an LC resonant circuit is created with secondary winding 304 . When second primary winding 310 is not in use, switches 316 can be opened to take second primary winding 310 out of resonance with secondary winding 304 and decrease losses due to circulating currents, as well as to decrease the peak voltage imposed on push/pull amplifiers 314 A and 314 B when they are inactive.
[0039] FIG. 5 is a diagram of distributed active transformer 400 with impedance transformation ratio correction and resonance frequency selection in accordance with an exemplary embodiment of the present invention. Distributed active transformer 400 includes primary winding sections 402 A through 402 D with associated push/pull amplifiers 406 A and 408 A through 406 D and 408 D, respectively. Switches 418 A through 418 D are connected in series with capacitors 416 A through 416 D, respectively. Output 410 of secondary winding 404 includes switch 414 and capacitor 412 for impedance transformation ratio control. Alternatively, switch 414 and capacitor 412 can be omitted, such as where it is desirable only to allow the resonance frequency of distributed active transformer 400 to be controlled. Likewise, a suitable configuration of switches and capacitors can be used in lieu of a single switch 414 and capacitor 412 , where each switch-capacitor pair can be controlled separately, thus allowing the resonance frequency of the secondary loop to be adjusted.
[0040] In this exemplary embodiment, the power operation mode of distributed active transformer 400 can be controlled, such as by closing one or more of switches 418 A through 418 D, so as to insert capacitors 416 A through 416 D in series with primary winding sections 402 A through 402 D. In this manner, a series LC circuit is created to compensate for leakage inductance between the primary winding sections 402 A through 402 D and secondary winding 404 . Thus, by placing one or more of capacitors 416 A through 416 D in series with primary winding sections 402 A though 402 D, the maximum output power is decreased, but the bias current required to achieve a gain level is also decreased. Alternatively, if capacitor 412 is placed in parallel across the load by closing switch 414 to compensate for this leakage inductance, then the impedance transformation ratio is increased, which increases the maximum output power but which also increases the bias current requirements.
[0041] In addition, the resonant frequency of distributed active transformer 400 can be adjusted for a particular frequency of operation by switching in capacitors 416 A through 416 D. In this manner, the efficiency and power output by distributed active transformer 400 can be optimized for a desired frequency of operation by configuring it for resonance at that frequency. Thus, depending on the sizes of the capacitors, distributed active transformer 400 can be operated in a first mode either with or without switch 414 and capacitor 412 to change the impedance transformation ratio by compensating for winding leakage inductance, in a second mode without switch 414 and capacitor 412 to change the resonant frequency of distributed active transformer 400 , or in both modes simultaneously. Likewise, a suitable configuration of switches and capacitors can be used in lieu of switches 418 and capacitors 416 , where each switch-capacitor pair can be controlled separately, thus allowing the resonance frequency of the primary loop to be adjusted.
[0042] FIG. 6 is a diagram of distributed active transformer 500 with switched-in capacitors that are in parallel with amplifiers 506 A and 508 A through 506 D and 508 D, in accordance with an exemplary embodiment of the present invention. Distributed active transformer 500 includes primary windings sections 502 A through 502 D with associated push/pull amplifiers 506 A and 508 A through 506 D and 508 D, respectively. Switch pairs 518 A through 518 D are connected in series with capacitor pairs 516 A through 516 D, respectively. Output 510 of secondary winding 504 includes switch 514 and capacitor 512 for impedance transformation ratio control. Alternatively, switch 514 and capacitor 512 can be omitted, such as where it is desirable to allow the resonance frequency of distributed active transformer 500 to be controlled.
[0043] In this exemplary embodiment, the power operation mode of distributed active transformer 500 can be controlled, such as by closing one or more of switch pairs 518 A through 518 D, so as to insert capacitor pairs 516 A through 516 D in series with primary winding sections 502 A through 502 D. In this manner, a series LC circuit is provided to compensate for leakage inductance between the primary winding sections 502 A through 502 D and secondary winding 504 . Thus, by placing one or more of capacitor pairs 516 A through 516 D in series with primary winding sections 502 A though 502 D, the maximum output power is decreased, but the bias current required to achieve a gain level is also reduced. Alternatively, if capacitor 512 is placed in parallel across the load by closing switch 514 to compensate for this leakage inductance, then the impedance transformation ratio is increased, which increases the maximum output power but which also increases the bias current requirements.
[0044] In addition, the resonant frequency of distributed active transformer 500 can be adjusted for a particular frequency of operation by switching in capacitor pairs 516 A through 516 D. In this manner, the efficiency and power output of distributed active transformer 500 can be optimized for a desired frequency of operation by placing it in resonance for that frequency. Thus, depending on the sizes of the capacitors, distributed active transformer 500 can be operated in a first mode either with or without switch 514 and capacitor 512 to change the impedance transformation ratio by compensating for winding leakage inductance, in a second mode without switch 514 and capacitor 512 to change the resonant frequency of distributed active transformer 500 , or in both modes simultaneously.
[0045] FIG. 7 is a diagram of distributed active transformer 600 integrated with a low noise amplifier in accordance with an exemplary embodiment of the present invention.
[0046] In addition to the primary and secondary windings and associated push/pull amplifiers previously described, distributed active transformer 600 includes a low noise amplifier 614 and associated switch 612 . When switch 612 is closed, as shown, a transmitted signal can be provided by modulating the input through push/pull amplifiers 606 A and 608 A through 606 D and 608 D. When switch 612 is opened and push/pull amplifier pairs 606 A and 608 A through 606 D and 608 D are not operated, a received signal can be fed through an inductor coil formed by the secondary winding of distributed active transformer 600 , and low noise amplifier 614 can be used to process the signal. In this manner, integration of low noise amplifier 614 with switch 612 through a single-ended output of distributed active transformer 600 allows a receiver/transmitter architecture to be implemented. In one exemplary embodiment, distributed active transformer 600 can be used in place of a transmit switch in a transceiver, or for other suitable applications.
[0047] FIG. 8 is a diagram of distributed active transformer 700 with a low noise amplifier in accordance with another exemplary embodiment of the present invention. Although a low noise amplifier is shown, any suitable device can be used, including but not limited to a mixer, a transceiver, a filter, and a digital to analog converter.
[0048] In addition to the primary and secondary winding structures and associated push/pull amplifiers previously described, distributed active transformer 700 includes a split secondary winding 704 with switches 710 A and 710 B connected to low noise amplifier 712 . Distributed active transformer 700 can be operated in a first transmit mode with switches 710 A and 710 B closed, as shown, and in a second receive mode with switches 710 A and 710 B open. When switches 710 A and 710 B are open, low noise amplifier 712 can be used to amplify a signal received at input 714 . When switches 710 A and 710 B are closed, primary winding sections 702 A through 702 D of distributed active transformer 700 can be driven by push/pull amplifiers 706 A and 708 A through 706 D and 708 D, respectively, so that an input signal can be amplified and provided for transmission at input 714 .
[0049] Although exemplary embodiments of the system and method of the present invention has been described in detail herein, those skilled in the art will also recognize that various substitutions and modifications can be made to the systems and methods without departing from the scope and spirit of the appended claims.
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Reconfigurable distributed active transformers are provided. The exemplary embodiments provided allow changing of the effective number and configuration of the primary and secondary windings, where the distributed active transformer structures can be reconfigured dynamically to control the output power levels, allow operation at multiple frequency bands, maintain a high performance across multiple channels, and sustain desired characteristics across process, temperature and other environmental variations. Integration of the distributed active transformer power amplifiers and a low noise amplifier on a semiconductor substrate can also be provided.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to write operations performed by a client computing station in a client/server computing system while the server or network is inoperative. More particularly, the present invention relates to management of log files maintained in the client by reducing the number of entries placed in the log file during a period of server or network unavailability.
2. Description of Related Art
In a client/server computing system operating over a network, file system architectures are employed in which the server stores all files created at the client in the computing system. In such a computing system, when an application program, operating on the client, needs to write data to a file, the file data is transferred over the network to the server for storage in the file maintained by the server. If the client is equipped with a local disk cache, the data is also optionally written to the local disk cache of the client. Under normal operating conditions, such a computing system can operate smoothly.
However, when the server becomes inoperative (i.e., crashes) or if the network connection between the server and the client becomes inoperative, then the client is unable to transfer new file data over the network to the server for storage therein as would normally be done. This period of server unavailability is also referred to as disconnected operations.
In order to make the client/server computing system more fault-tolerant, it is desirable to enable the user of an application program running on the client to be able to modify or write data to a file even during unavailability of the server.
During the period of server unavailability, a log file can be created and maintained in the client for collecting a list of operations performed by the client during the period of unavailability of the server. The log file generally includes the type of operation performed and the data associated with the operation, along with an identification of the file upon which the operation was performed. Once the server again becomes available, the client utilizes the log file to "replay" or "roll" the operations performed during the unavailability of the server, thereby attempting to insure the consistency between the server's version of the file and the client's version of the file.
Client operations involving file modifications (i.e., writing data to a file) during the unavailability of the server are of particular importance. Conventional log file techniques generally utilize a linear logging technique wherein all write file operations are sequentially entered into a single log file.
The linear logging technique has the disadvantage that the size of the log file can become quite large during extended periods of server unavailability, since each write operation performed to a file is separately entered in the log file. For instance, if a user running an application on the client modifies the same file 1,000 times during a period of server unavailability, the conventional linear logging technique would create 1,000 separate entries in the log file. A large log file is disadvantageous because during periods of server unavailability, the client's memory/storage space can become an extremely scarce resource, since the server is generally designed to have substantially greater file storage abilities than the client. If the growing size of the log file exceeds the client's memory/storage capabilities, then it is possible that the client could no longer process and store new data being provided by the user to the application program running on the client. Hence, operations on the client would have to be suspended under this scenario until the server again becomes available.
Furthermore, each entry placed into the log file requires processing time by the client. Where the client utilizes a disk cache for persistent storage, each write of data to the log file is associated with a period of disk processing time. Therefore, it is advantageous to minimize the number of entries placed in the log file to improve the performance of the client.
It is also important that the relative ordering of the file modifications listed in the log file is preserved. For example, if during disconnected operations, a file A was modified by the user at the client after a file B was modified, it is important that this relative order of file modifications is preserved. In some client/server computing systems, the server will maintain a modification time for each file, and update this modification time whenever the server modifies the file by writing data to the file. This modification time is utilized by many conventional software programs, such as the "makefile" compilation utility, to track the state of a file.
Therefore, the client should, during the "rolling" or replaying of the log file after the server has again become available, transfer the modified file data to the server in an order which accurately reflects the relative order in which the files were modified by the user on the client during disconnected operations.
SUMMARY OF THE INVENTION
In accordance with the present invention, the above problems have been solved by a method for reducing the number of entries placed in a log file during disconnected client write operations. A write file table is created for tracking the file name and a sequence number of entries placed in the log file during disconnected operations. A count is maintained of the sequence number of a present write operation, and the log file is encoded with entries identifying the file name and the sequence number of the present write operation. A first condition is detected wherein if the present write operation operates on the same file as a prior write operation, only the write file table entry is updated with the latest sequence number corresponding to the present write operation. Hence, no additional entry for the present file is created in the log file.
Upon reconnection of the client to the server, the write operations performed by the client during disconnected operations are replayed in the proper sequential order by transferring the file data over the network to the server for storage therein. A deferred write list is created for temporarily storing operations which should not be replayed in order to preserve the correct sequence of disconnected operations. For any entry from the log file being processed, if the sequence number of the entry from the log file does not match the sequence number of entry in the write file table, then the entry should be placed in the deferred write list for replaying at a later time.
The above computer implemented steps in another implementation of the invention are provided as an article of manufacture, i.e., a computer storage medium containing a computer program of instructions for performing the above described steps.
In a machine implementation of the invention, an apparatus for efficiently replaying the entries placed in a log file during disconnected client write operations has an encoding module and a decoding module. The encoding module places entries in the log file and in a write file table for tracking the state of the log file. The encoding module logs in the log file only writes associated for different files. Upon reconnection of the client to the server, the decoding module replays the events in the correct chronological order by transferring the file data modified during the period of disconnection in the order dictated by the write file table. The decoding module replays the write operations by accessing the log file and the write file table. The decoding module places entries in a deferred write list for temporary storage and subsequent replaying at the appropriate moment.
The great utility of the present invention is that the number of entries in the log file maintained by the client during disconnected operations are substantially reduced, thereby reducing the amount of memory/storage space consumed by the log file during the period of server unavailability. In this manner, the present invention permits an efficient storage of file data created by the user at a client workstation while the server is unavailable.
Still another utility of the present invention is that the number of entries written to the log file are reduced, thereby reducing the amount of client processing associated with these log file write operations.
Still another utility of the present invention is that the relative order of files modified during server unavailability is preserved in the client's "replay" or "rolling" of the log file after the server has become available.
Still another utility of the present invention is that the present invention can be incorporated into an existing client/server computing system without modification to either the server file system implementation or the client-to-server file system protocol.
The foregoing and other features, utilities, and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 illustrates a distributed processing computer system with a server and multiple clients connected in a communications network to perform the logical operations of the invention.
FIG. 2 is a block diagram of the preferred embodiment of the present invention.
FIG. 3A is an illustrative example of a sequence of three events which occur on the client during a period of server unavailability.
FIG. 3B illustrates a log file utilized in the preferred embodiment of the present invention.
FIG. 3C illustrates a write file table utilized by the preferred embodiment of the present invention.
FIG. 4A through FIG. 4B illustrate the logical operations performed by the client during a period of server unavailability to write an entry into the log file 50 using the write file table 56 of FIG. 3C.
FIG. 5 illustrates a deferred write list utilized in the preferred embodiment of the present invention.
FIG. 6A through FIG. 6B illustrate the logical operations performed by the client, after the server has again become available, to "replay" or "roll" the contents of the log file to the server.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The embodiments of the invention described herein are implemented as logical operations in a computing system. The logical operations of the present invention are implemented (1) as a sequence of computer implemented steps running on the computing system and (2) as interconnected machine modules within the computing system. The implementation is a matter of choice dependent on the performance requirements of the computing system implementing the invention. Accordingly, the logical operations making up the embodiments of the invention described herein are referred to variously as operations, steps, or modules.
The operating environment, in which the present invention is used, encompasses a standalone computing system as well as the general distributed computing system. In the distributed computing system, general purpose computers, workstations, or personal computers are connected in a client-server arrangement via communication links of various types, wherein programs and data, many in the form of objects, are made available by various members of the system.
Some of the elements of a standalone computer or a general purpose workstation computer are shown in FIG. 1. In accordance with the invention, users at remote workstations in a network, such as client processors 35, communicate through the network to a computer server 20. Server 20 includes processor 21 having an input/output section 22, a central processing unit 23, and a memory section 24. The input/output section 22 is optionally connected to a keyboard 25, a display or monitor 26, and a disk storage unit 29. The input/output unit 22 includes a communications adaptor (not shown) for communicating on the network 46 to the remote client stations 35.
Application programs 45 operate on client station 35 which may access or modify files maintained by server 20. The computer program products to effectuate the apparatus and methods of the present invention may reside in the memory section 24, or on the disk storage unit 29 or similar storage media (not shown), or reside on storage mediums used by clients 35. Examples of computing systems that may be used as either a server 20 or a client 35 include the SPARC 1 ™ systems offered by Sun Microsystems™, Incorporated, personal computers offered by IBM Corporation and by other manufacturers of IBM compatible personal computers and systems running the UNIX 2 , OS/2 3 , HP-UX, AIX 3 , DOS etc. operating systems.
As shown in FIGS. 1-2, client 35 and server 20 communicate over network 46 which provides client 35 with access to the files maintained on disk 29 of the server. Conversely, client 35 also transfers file data over network 46 for files maintained on the server.
The client generally creates file data in response to a request by an application program 45 (FIG. 1), running on the client 35, to store or write data associated with a file. If server 20 is unavailable either because the network connection 46 is inoperative, server 20 has crashed, or otherwise, then the client 35 cannot transfer the file data to the server. As will be explained, the present invention permits the client to transfer file data to the server, despite the unavailability of the server, by the efficient use of a log file, a write file table, and a deferred write list.
FIG. 2 illustrates the preferred embodiment of the present invention. Client 35 has a write file table 56, a deferred write list 58, a log file 50, and file data 52. File data block 52 represents the various files maintained in the client, and each file is assumed to have an identifier such as a file name. For example, if files A, B, and C exist on the client 35, then these files would be contained in file data block 52.
As previously described, when client 35 writes or modifies file data 52, the client 35 normally transmits this data over network 46 to server 20 to be stored as file data 54 by server 20. The server stores this file data 54 in disk 29 (FIG. 1).
However, if server 20 or network 46 become inoperative, then client 35 utilizes log file 50 to log entries of data written into file data 52. In accordance with the preferred embodiment of the present invention, client 35 creates and maintains a write file table 56 and a deferred write list 58 for optimizing the entries stored in log file 50 during a period of server unavailability.
Client 35 also has an encoding module 55 and a decoding module 57. During disconnected operations, encoding module 55 places entries of operations performed by the client into log file 50 and write file table 56. Decoding module 57 "replays" or "rolls" the contents of log file 50 by systematically cross-referencing the entries in log file 50 and write file table 56, thereby transferring file data 52 from the client to the server after the server has again become available.
FIG. 3A illustrates a sample of events which will be useful in explaining the operations of the preferred embodiment of the invention. Assuming that the server has become unavailable for communications with the client 35, at point 60 in time, the client writes data to file A. Then, at point 62, the client writes data to file B. At point 64, the client again writes data to file A. This example illustrates two important items with regards to the advantages of the present invention. First, since file A was modified both at event 60 and 64, a conventional linear or sequential log file technique would create separate entries for each of these events and store them separately in the log file. Secondly, since event 64 occurs after event 62, the modification time of file A should be greater than the modification time of file B. As previously explained, it is important that this relationship is maintained upon the completion of the operations which transfer data for files A and B to server 20.
FIG. 3B illustrates the log file 50 utilized by the preferred embodiment of the present invention. Log file 50 has three columns comprised of a record number column 70, a file name column 72, and a sequence number column 74. As will be explained below in greater detail, log file 50 is created during the period of server unavailability, and is deleted after its contents have been used to transfer file data 52 over network 36 to server 20 upon the server becoming available again.
FIG. 3C illustrates the write file table 56 of the preferred embodiment of the present invention. Write file table 76 is used to reduce the number of entries made in log file 50, and also tracks the final state of log file 50. Write file table 56 has three columns including file name column 72, sequence number 76, and a flag 78 indicating whether or not the file has been written as an entry in log file 50.
Write file table 56 is created during normal operations and will contain an initialized entry for each file which is written to by the client during connected operations. For instance, FIG. 3C illustrates a file name C which, having been accessed by the client 35 during normal operations, has an initialized entry in write file table 56. If the client has a disk cache, the write file table 56 will have an entry for each file placed in the client's cache. The entries for files A and B in write file 50, as illustrated in FIG. 3B, will be explained below.
FIGS. 4A-4B illustrate the logical operations performed by the encoding module 55 (FIG. 2) of the preferred embodiment of the present invention while the server is unavailable. The operations illustrated in FIGS. 4A-4B, occur in response to each singular event depicted in FIG. 3A on a per event basis.
Operation 80 initially determines if there is file data 52 (FIG. 2) to be written by client 35. If there is no file data to write, the program exits. If operation 80 determines that there is file data to be written, then operation 82 determines if the client is disconnected (i.e., there is a condition of server unavailability). If the client is not disconnected from server 20 (FIG. 2), then operation 84 writes the file data to the server over network 46, as previously explained. If client 35 is provided with a local cache, then operation 86 writes the file data to the local cache.
In accordance with the present invention, when operation 82 determines that the client is disconnected from the server, operation 88 determines if log file 50 (FIG. 2) already exists. If not, then operation 90 creates a log file containing the components already described in relation to FIG. 3B.
The encoding module 55 maintains a sequence number variable for tracking the state of the disconnected write operations. Operation 92 initializes the sequence number variable to zero after the log file has been created by operation 90. Control is then passed to operation 94. If operation 88 determined that a log file already exists, then control is also passed to operation 94.
At operation 94, the sequence number is incremented for use in the write file table, explained below.
As explained above, the write file table 56 will contain an initialized entry for each file accessed (i.e., placed in the client cache) during normal operations. These initialized entries have a zero in the sequence number column 76 (FIG. 3C) and a zero in the written flag column 78 (FIG. 3C).
Referring to FIG. 4B, during disconnected operations, decision operation 96 determines if the current file to be written in the client has previously been written by the client. Decision operation 96 is performed by examining flag 78 contained in write file table 56 corresponding to the present file referenced by file name 72.
If operation 96 determines that the present file has not been written during disconnected operations, then operation 102 makes a new entry of this file in log file 50. The new entry reflects that data was written to a particular file (identified by file name 72) and the sequence number reflecting the current sequence number stored by client 35. Operation 104 then writes the current value of the sequence number to column 76 of write file table 56. Operation 106 then sets the flag 78 in write file table 56 to reflect the fact that the present file has been entered in log file 50. Write file table 56 now has the present state of the particular file reference in the log file 50. At operation 100, the file data is written to the local disk cache or other storage mechanism in the client.
If operation 96 has determined that the present file has already been written by the client during disconnected operation, then, according to the present invention, no new entries in log file 50 are made for the event. Instead, write file table 56 is appropriately modified to reflect the file data written to the present file.
Operation 98 locates the entry corresponding to the present file in the write file table 56, and the present value of the sequence number, maintained by the encoding module in the client, is written to the sequence number column 76 of write file table 56 (the old sequence number in column 76 is overwritten). After operation 98, operation 100 writes file data 52 to the local disk cache or other persistent storage in the client.
The write file table now has the current state of the log file reflecting events that occurred during disconnected operations. As will be described below, the replay operations or log rolling operations of the present invention will utilize both write file table 56 and log file 50 to accurately recreate the sequence of events which occurred during disconnected operations.
The operations of the present invention will be explained using the scenario described in FIG. 3A using FIGS. 3A and 3B, wherein during disconnected operations, the client must write file data to a file A, then must write different file data to file B, and finally must write different file data to file A.
Assuming that the sequence number maintained by the encoding module has a present value of 1, then beginning at operation 96 and in response to events 1 at point 60 in FIG. 3A, operation 96 would determine that File A has not yet been written because the written flag of write file table 56 would contain a zero corresponding to file name A (not shown). Operation 102 would append an entry in log file 50 for file name A, using a sequence number of 1. Operations 104 and 106 would then overwrite the value of the sequence number contained in the table (changing the sequence number from an initialized zero to the present value of the sequence number 1), and set the written flag to 1. Operation 100 would then write the file data for file A into the local cache or other file storage medium in the client.
In response to event 2 occurring at point 62 (FIG. 3A), operation 94 would increment the current sequence number to a value of 2, and operations 96, 102-106, and 100, would operate in the same manner as with event 1 as previously described, except that the sequence number used now has the value of 2.
Assuming event 3 occurs at point 64 (FIG. 3A) wherein new file data is written again to file A, then after incrementing the sequence number to 3 at operation 94, operation 96 detects that file A has already been written in the log file by examining the written flag 78 in the write file table 56 (the flag is set to 1). Hence, operation 96 passes control to operation 98 which overwrites the sequence number in the sequence column 76 with the present value of the sequence number (i.e., 3) for file name A, as shown in FIG. 3C. No additional entries are made in log file 50 for this event. Operation 100 then writes the new data into file A in the client's local disk cache or other media.
As this example illustrates, the number of entries in log file 50 were reduced where the events occurring in the client included a write operation to the same file occurring at different times.
FIGS. 5, and 6A-6B are used by the decoding module 57 of the preferred embodiment of the present invention after the server has again become available. The client's primary goal after reconnection with the server involves the transfer of the most recent data for each file over the network to the server so that the server can write this data to its storage devices.
Deferred write list 58 is used by the decoding module to ensure that the relative sequence of file modifications which occurred on the client during disconnected operations is preserved during the replay or rolling of events stored in the log file and write file table. In general, for a given file having an entry in log file 50, the sequence number for an entry in the log file, obtained from column 74 (FIG. 3B), is compared to the sequence number of a corresponding entry in the write file table, obtained from column 76 (FIG. 3C). If these sequence numbers match, then the file data for that file is transferred from the client to the server for storage therein. If these sequence numbers do not match, replaying this entry at the present time would be premature. The decoding module therefore places this entry in the deferred write list so that the file data referenced by this entry can be transferred to the server at a time which would properly preserve the order of events.
FIG. 5 illustrates the components of deferred write list 58. Column 72 of deferred write list 58 reflects the file name of the particular entry in list 58, while sequence number 110 reflects the sequence number derived from column 76 of write file table 56. Record pointer column 112 reflects the record number column 70 from log file 50.
The decoding module maintains two variables in the replay of events. A record pointer variable (RECORD -- PTR) is read from the record number column 70 of the log file, and the current sequence number (CURRENT -- SEQ#) is read from the log file for comparison to the sequence number contained in the write file table.
Referring to FIGS. 6A-6B, the logical operations of the decoding module are illustrated. Operation 120 detects reconnection of the client to the server. Operation 122 sets the RECORD -- PTR (not shown) to the first record 70 contained in log file 50. Operation 124 initializes the current sequence number to zero.
Operation 126 creates a deferred write list 58 in the client, explained above. Operation 128 determines if there are any records in log file 50 to process. If there are no remaining records to be processed, operation 130 checks the contents of the deferred write list 58 for processing of any remaining items contained therein. If there are no entries in the deferred write list, the program terminates. If there is an entry in the deferred write list, control passes to operation 138, described below.
If operation 128 determines that there are records to process, then operation 132 reads the next record indexed by the record pointer of the log file. Operation 134 sets the current sequence number maintained by the decoding module of the client to the sequence number of the present entry of the log file record.
Operation 136 determines if it is time to process a deferred write contained in list 58. If the write deferred write list 58 is empty, then control passes to operation 146. If list 58 has an entry, then operation 136 compares the current sequence number, obtained by operation 134, to the sequence number in column 110 of the front entry of the deferred write list 58. If the current sequence number is greater than or equal to the sequence number of the front entry of the deferred write list, then it is time to process this deferred write entry contained in list 58. Operation 138 removes this front entry from the deferred write list for processing. Operation 140 reads the corresponding record contained in the front entry, while operation 142 gets the file name from the record. Operation 144 then copies the file, referenced by the record, from the client to the server for storage therein. The front entry can then be removed from the deferred write list.
If operation 136 determines that there are no deferred write entries for processing at this time, then operation 146 increments the record pointer to the next record in the log file. Operation 148 locates the row in write file table 56 corresponding to the file name of the particular entry being processed. Operation 150 determines if the present entry of the log file should be written to the deferred write list 58. Operation 150 makes this determination by comparing the current sequence number to the sequence number of the write file table 56. If these sequence numbers match, then the current entry being processed need not be added to deferred write list 58, and control is passed to operation 142 and 144, described above.
If, however, the sequence numbers compared by operation 150 do not match, then operation 152 adds a new entry to the end of the deferred write list. The new entry includes the sequence number of the entry, copied from sequence number column 76 of the write file table 56, the file name of the entry, and a record pointer of the entry, copied from column 70 of log file 50.
Both operations 152 and 144 pass control back to operation 128 for subsequent processing of any entries contained in either the write file table or the deferred write list.
The operations of the present invention will be described with reference to FIG. 5, and 6A-6B using the example of FIG. 3B-3C, wherein during disconnected operations, the client wrote file data to a file A, then different file data to file B, and finally different file data to file A.
Beginning with operation 132, the first record in log file 50 (FIG. 3B) is read. Operation 134 sets the current sequence number to 1, the sequence number of the current record from the log file. Since this is the first record, operation 136 determines that there can be no records in the deferred write list, thereby passing control to operation 146 which increments the record pointer to the second record in the log file for the next iteration.
Operation 148 locates the entry in write file table 56 corresponding to the file name of the present record (i.e., file name A). Operation 150 then compares the current sequence number (i.e., 1) to the sequence number corresponding to file A in the write file table (i.e., 3). Because these sequence numbers do not match, operation 150 passes control to operation 152 wherein a new entry is made in the deferred write list for file name A having a sequence number of 3, as shown in FIG. 5. Control is then returned to operation 128.
Upon the second iteration of the logical operations, operation 132 reads the next record in log file 50 (i.e., file B with sequence No. 2). Operation 134 sets the current sequence number to the value of 2, and operation 136 compares the current sequence number (i.e., 2) to the sequence number contained in column 110 of the deferred write list (i.e., 3). Because the current sequence number (i.e., 2) is less than the sequence number in column 110 (i.e., 3), it is not yet time to process the entry contained in the deferred write list. Therefore, control is passed to operation 146, then to operation 148 which reads the write file table entries corresponding to file name B. Operation 150 then compares the current sequence number (i.e., 2) to the sequence number in column 76 of write file table 56 corresponding to file name B (i.e., 2). Since these sequence numbers match, operation 142 and 144 copy the file data for file B from the client to the server.
Control is then passed to operation 128 for another iteration. Operation 132 reads the third record in the log file, and operation 134 sets the current sequence number to a value of 3. Operation 136 compares the current sequence number (i.e., 3) to the sequence number in column 110 of deferred write list 58, and since these numbers are equal, control is passed to operation 138 which removes this entry from the deferred write list so that the file data referenced by this entry can be transferred to the server.
As illustrated by this example, the file data for file B was transferred to the server before the file data for file A. Hence, from the server's perspective, file B was modified earlier than file A. This accurately reflects the order of file modifications which occurred while the server was disconnected. Therefore, the present invention preserves the relative order of file modifications during disconnected operations.
Using the methods and apparatus of the preferred embodiment of the present invention, the size of the log file will be governed by the number of files accessed during disconnected operations. Conventional sequential logging techniques have log file sizes which are proportional to the number of write operations performed on the client during disconnected operations, which can grow quite large for multiple write operations on a single file. Hence, a substantial reduction in the log file size can be achieved by the use of the present invention.
After the operations of FIG. 6A-6B are completed and the file data has been successfully transferred to the server, the decoding module can perform various housekeeping functions such as deleting the deferred write list 58, deleting the log file 50, and re-initializing columns 76 and 78 of the write file table 56. Hence, efficient operations in the client are archived.
Depending on the hardware components of the client workstation 35, log file 50, write file table 56, and deferred write list 58 can be maintained by client 50 in memory or in persistent storage such as a disk drive (not shown). A disk drive provides the benefit of greater data reliability in the event of fluctuations in the power provided to the client workstation.
While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various other changes in the form and details may be made therein without departing from the spirit and scope of the invention. For instance, the preferred embodiment has described write file table 56 and deferred write list 58 as components maintained separately from log file 50 (FIG. 2). It will be understood that the components of table 56 and list 58 could be incorporated into log file 50 to form a single file. The particular implementation and maintenance of log file 50, write file table 56, and deferred write list 58, is a matter of choice of the particular system developer.
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In a client/server computing system, a method and apparatus for efficiently storing entries in a log file during disconnected client operations. An encoder utilizes a log file and a write file table for logging the write operations performed by the client during disconnected operations. The logging method employed by the encoding module logs in the log file only writes associated for different files. The encoding module tracks the status of the entries in the log file with a write file table containing the most recent sequence number associated with a file entry of the log file. Upon reconnection of the client to the server, a decoding module replays the events in the correct chronological order by transferring the file data modified during the period of disconnection in the order dictated by the write file table. A deferred write list is accessed by the decoding module for temporary storage any write operations whose replay should be delayed to preserve the relative order of events.
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FIELD OF THE INVENTION
[0001] The invention relates to flavorings. In particular, the invention relates to extruded flavors that are capable of retaining their particle shape and integrity when exposed to high temperature and humid environments.
DESCRIPTION OF THE PRIOR ART
[0002] The present invention pertains to the use of certain materials and methods of applying these materials to improve the physical properties of edible solid particles exposed to high humidity conditions. At highest risk are particles that have a high surface area, contain amorphous sugars or carbohydrates or other ingredients that tend to absorb moisture from the environment, and are processed or held in such a way that exposes the particles for an extended period of time to a humid environment without adequate moisture protection. Such particles include flavor encapsulates, dry mixes, spices, and seasonings, flavored tea, powdered soft drinks, confectionery, pharmaceuticals, dietary supplements, among others.
[0003] Adding anti-caking or flow agents to pharmaceutical preparations to improve flow properties in the event that these products absorb moisture from the environment is known. U.S. Pat. No. 2,555,463 describes normally hygroscopic Na pantothenate which is converted into a dry, stable, non-hygroscopic, granulated product by mixing it intimately with 2-60% by weight of methylcellulose or an alkali metal salt of carboxymethylcellulose.
[0004] In certain cases, the protection provided by these flow agents is insufficient to meet the needs of the specific application based on above-mentioned limitations or other product-specific needs. In the case of flavored tea bags, several factors make it necessary to have robust flavor granules that can withstand the deleterious effects of moisture uptake. Tea leaves or herbal tea blends contain moisture that can be readily absorbed by the flavor granules that in turn can cause flavor granules to become sticky and cause bag spotting or tearing. Secondly, the processes involved in mixing flavor granules with tea and dispensing into tea bags could expose both tea and flavor granules to the atmosphere sufficient to adversely affect the filling process and shut down operations or cause bag spotting if the environment is hot and humid. Thirdly, packaged tea bags must be stable for at least 2 years under ambient conditions which could entail storage at high humidity. Lastly, is the unavoidable use of certain flavors that by their nature contain materials that promote plasticization of the matrix materials that make up the flavor granule. Of the various factors enumerated, the last is considered one of the major causes of potential product failure because plasticizing materials often greatly accelerate moisture uptake. The common practice of coating or blending the flavor granules with traditional flow agents is often not sufficient to prevent the flavor granules from becoming sticky or is not compatible with the requirement that the flow agent does not affect the properties of the tea upon reconstitution, i.e., maintaining solution clarity and flavor neutrality.
[0005] It has been found that it is possible to minimize or eliminate the adverse effect of plasticizing flavor actives or other matrix materials on moisture uptake by incorporating certain functional ingredients to the flavor granule matrix prior to melt encapsulation via extrusion or other similar processes to produce non-hygroscopic particles. Moreover, it has also been possible to overcome the plasticizing effect of flavor solvents such as triacetin and propylene glycol. Thirdly, a synergistic effect was discovered between inclusion of these functional ingredients into the extrusion matrix and with specific flow agents that are applied externally or post-extrusion. The effect may be seen not only in the decreased level of moisture that is absorbed by the flavor granule from the environment, but also in the ability of the flavor granules to remain relatively hard, discrete, and intact in spite of the moisture absorbed by the granule.
SUMMARY OF THE INVENTION
[0006] An object of the present invention is to provide a method of forming a free flowing granule flavor composition comprising mixing in any order the following ingredients a flavor, a carrier, and a functional ingredient selected from the group consisting of distilled monoglycerides, mono- and diglycerides, sodium carboxymethylcellulose, hydroxypropylcellulose, methylcellulose, hydroxypropyl methylcellulose, ethylcellulose, silicon dioxide; extruding the ingredients at a temperature sufficient to form a melt which on cooling solidifies and can be reduced in particle size by milling to form a free flowing granule material and optionally blending the extruded ingredients with silicon dioxide, calcium stearate, and magnesium stearate and providing free flowing granule flavors.
[0007] It is a further embodiment of the invention to provide flavor granules having a particle size distribution such that at least 60%, more preferably 80% of the particles pass through about US 20 ASTM mesh sieve (herein referred to as a US 20 mesh sieve) after exposure to a humid environment.
[0008] An additional embodiment of the present invention is directed to a flavored tea bag. According to this aspect of the invention, a conventional tea bag comprising a porous bag and a preselected amount of cut tea leaves further includes an amount of the free flowing flavor granules of the invention sufficient to impart a brewed portion of tea the flavor of the free flowing flavor granules.
DETAILED DESCRIPTION OF THE INVENTION
[0009] Suitable conventional flavoring materials include saturated fatty acids, unsaturated fatty acids and amino acids; alcohols, including primary and secondary alcohols; esters; carbonyl compounds including ketones and aldehydes; lactones; other cyclic organic materials including benzene derivatives, acyclic compounds, heterocyclics such as furans, pyridines, pyrazines and the like; sulfur-containing compounds including thiols, sulfides, disulfides and the like; proteins; lipids, carbohydrates; so-called flavor potentiators such as monosodium glutamate, magnesium glutamate, calcium glutamate, guanylates and inosinates; natural flavoring materials such as cocoa, vanilla and caramel; essential oils and extracts such as anise oil, clove oil and the like and artificial flavoring materials such as vanillin, ethyl vanillin and the like.
[0010] Specific preferred flavor adjuvants include, but are not limited to, the following: anise oil; ethyl-2-methyl butyrate; vanillin; cis-3-heptenol; cis-3-hexenol; trans-2-heptenal; butyl valerate; 2,3-diethyl pyrazine; methyl cyclo-pentenolone; benzaldehyde; valerian oil; 3,4-dimeth-oxyphenol; amyl acetate; amyl cinnamate; γ-butyryl lactone; furfural; trimethyl pyrazine; phenyl acetic acid; isovaleraldehyde; ethyl maltol; ethyl vanillin; ethyl valerate; ethyl butyrate; cocoa extract; coffee extract; peppermint oil; spearmint oil; clove oil; anethol; cardamom oil; wintergreen oil; cinnamic aldehyde; ethyl-2-methyl valerate; γ-hexenyl lactone; 2,4-decadienal; 2,4-heptadienal; methyl thiazole alcohol (4-methyl-5-β-hydroxyethyl thiazole); 2-methyl butanethiol; 4-mercapto-2-butanone; 3-mercapto-2-pentanone; 1-mercapto-2-propane; benzaldehyde; furfural; furfuryl alcohol; 2-mercapto propionic acid; alkyl pyrazine; methyl pyrazine; 2-ethyl-3-methyl pyrazine; tetramethyl pyrazine; polysulfides; dipropyl disulfide; methyl benzyl disulfide; alkyl thiophene; 2,3-dimethyl thiophene; 5-methyl furfural; acetyl furan; 2,4-decadienal; guiacol; phenyl acetaldehyde; β-decalactone; d-limonene; acetoin; amyl acetate; maltol; ethyl butyrate; levulinic acid; piperonal; ethyl acetate; n-octanal; n-pentanal; n-hexanal; diacetyl; monosodium glutamate; monopotassium glutamate; sulfur-containing amino acids, e.g., cysteine; hydrolyzed vegetable protein; 2-methylfuran-3-thiol; 2-methyldihydrofuran-3-thiol; 2,5-dimethylfuran-3-thiol; hydrolyzed fish protein; tetramethyl pyrazine; propylpropenyl disulfide; propylpropenyl trisulfide; diallyl disulfide; diallyl trisulfide; dipropenyl disulfide; dipropenyl trisulfide; 4-methyl-2-[(methylthio)-ethyl]-1,3-dithiolane; 4,5-dimethyl-2-(methylthiomethyl)-1,3-dithiolane; and 4-methyl-2-(methylthiomethyl)-1,3-dithiolane. These and other flavor ingredients are provided in U.S. Pat. Nos. 6,110,520 and 6,333,180 hereby incorporated by reference.
[0011] The level of flavor employed in the dry particle of the invention varies from about 0.1 to about 30 weight percent, preferably from about 5 to about 20 and most preferably from about 10 to about 15 weight percent.
[0012] When flavors are employed the level of flavor particles of the invention will vary depending on many factors including other ingredients, their relative amounts and the effect that is desired. Those with skill in the art will incorporate suitable materials in the invention when the product incorporating the present invention is intended for human or animal consumption.
[0013] The amount of the functional ingredient(s) ranges from about 1% to about 10% by weight, more preferably from about 0.5 to about 2% by weight. Suitable functional ingredients include distilled monoglycerides, mono- and diglycerides, sodium carboxymethylcellulose, hydroxypropylcellulose, methylcellulose, hydroxypropyl methylcellulose, ethylcellulose, silicon dioxide, calcium stearate, magnesium stearate, mixtures thereof and the like.
[0014] The preferred materials for inclusion in the matrix prior to extrusion are distilled monoglycerides, mono- and diglycerides, sodium carboxymethylcellulose, and hydroxypropylcellulose. It should be noted that these ingredients are not known in the art to impart this effect on flavor materials encapsulated in a sugar or carbohydrate matrix prepared by melt encapsulation. Typical known uses for cellulosic polymers are as thickeners, film-formers, and suspending aids. Mono- and diglycerides are used as emulsifiers. The mechanism of action of the present invention is not completely understood at this time and most likely the way these ingredients provide moisture resistance to the flavor granules differ depending on compound class. One theory is that the cellulosic polymers preferentially bind the absorbed water from the environment thereby making the water less available for binding to or dissolution of the sugars and other hygroscopic materials in the matrix. The high molecular weight of these polymers and their film-forming properties may further enhance this effect.
[0015] Microcrystalline cellulose or powdered cellulose is commonly used as flow aids, such as in shredded or grated cheese. Surprisingly, in this case the microcrystalline cellulose did not produce free flowing flavor granules as compared to the use of sodium carboxymethylcellulose and distilled monoglycerides.
[0016] Distilled monoglycerides and mono- and diglycerides are commonly used emulsifiers in food products. Emulsifiers enable oil-soluble materials to be dispersed or suspended in highly polar or water-soluble matrices. They have a low HLB value (hydrophilic/lipophilic balance), hence, are readily dissolved in oil-soluble materials. They are also known to complex with starch to retard staling of bakery products. Any combination of above properties may render flavor granules to be less hygroscopic by modifying the macro and chemical environment surrounding the hygroscopic materials in such a way that water binding is reduced.
[0017] In one embodiment a flow agent, such as silicon dioxide, calcium stearate, and magnesium stearate are applied externally as a coating. The amount of flow agent employed according to the present invention is from about 1 to about 2% by weight. One type of silicon dioxide is Aerosil 200 manufactured by Degussa Corporation (Parsippany, N.J.) through a high temperature hydrolysis process. The flow agent may be applied as a direct coating to the flavor granule or as a secondary coating after applying a coating of triglycerides, glycerol triacetate, or other edible but water-insoluble fluids to the flavor granules.
[0018] Carrier materials such as, but not limited to, sugar, maltodextrin, dextrose and silicon dioxide and flavors are blended together in a mixer. This blend is introduced into a twin-screw extruder. There are different temperature and mixing/shear zones within the extruder that are designed to either feed, mix/emulsify, and/or heat transforming the blend into a viscous melt. The product inside the extruder is heated to a temperature sufficient to melt the sugar or carbohydrate in the matrix, typically up to about 120 to about 180° C.
[0019] The flavor particles prepared in accordance with the present invention preferably have a particle size distribution such that from about 60% to about 80% of the particles pass through about a US 20 mesh sieve after exposure to a humid environment. According to the present invention a humid environment is understood to exist when temperatures are above about 20° C. and above about 50% relative humidity, more preferably at about 30° C. and about 60% relative humidity.
[0020] The free flowing flavor granules may also be combined with tea leaves. This mixture may be used to fill tea bags, which may be made of porous materials such as paper, cellulose and mixtures thereof and provide flavored tea bags wherein the free flowing flavor granules do not stick to the tea bags and not produce any visible spots on the tea bags. In one embodiment the ratio of the amount of the free flowing flavor granules to the amount of cut tea leaves is about 1:10.
[0021] The following are provided as specific embodiments of the present invention. Other modifications of this invention will be readily apparent to those skilled in the art. Such modifications are understood to be within the scope of this invention. As used herein all percentages are weight percent unless otherwise noted, ppm is understood to mean parts per million; mm is understood to be millimeters, ml is understood to be milliliters, Bp is understood to be boiling point. IFF as used in the examples is understood to mean International Flavors & Fragrances Inc., New York, N.Y., USA.
[0022] In order to demonstrate the invention, the following examples were conducted. All U.S. patent and patent applications referenced herein are hereby incorporated by reference as if set forth in their entirety. The following disclosures are provided to exemplify the present invention.
[0023] Unless noted to the contrary all weights are weight percent. Upon review of the foregoing, numerous adaptations, modifications and alterations will occur to the reviewer. These adaptations, modifications, and alterations will all be within the spirit of the invention. Accordingly, reference should be made to the appended claims in order to ascertain the scope of the present invention.
[0024] All formulations are expressed as percentage by weight. Observations after 24 hours were based on subjecting the sample to the moisture resistance test to determine the hygroscopic property of the particles, wherein a 2-gram sample is weighed into an aluminum dish and kept in a humidity chamber set to conditions of 30° C. and 60% relative humidity. The terms moisture resistance test and hygroscopicity testing are used interchangeably in the following examples. Samples were also tested to determine the percentage of material that would pass through a US 20 mesh sieve after storage at above condition. For this test, a 5-gram sample is weighed into an aluminum dish and kept in a humidity chamber set to conditions of 30° C. and 60% relative humidity. After a 24 hour period, each sample was removed and placed on a US 20 mesh sieve with a bottom pan. This system was then placed in a Ro-Tap® unit (W. S. Tyler) for 1 minute. All samples tested originally have a particle size range of −20/+60 US mesh or 0.25 to 0.84 mm. The amount of material passing through the US 20 mesh sieve is a direct measure of the moisture resistance of the formulation. Particles that pass through a 20 mesh sieve have a particle size of about less than 0.84 mm or 840 microns.
EXAMPLE 1
[0025] The following formulations were processed via extrusion:
1 2 3 4 Ingredients Sugar 35.2 35.2 37.4 41.2 Maltodextrin 39.2 38.2 40.4 41.2 Dextrose 10.1 10.1 10.7 10.1 Silicon Dioxide 3.5 4.5 4.5 2.5 Lecithin 2.0 2.0 2.0 0 Orange Flavor 10.0 0 0 0 Raspberry Flavor 0 10.0 0 0 Lemon Flavor 0 0 5.0 0 Pomegranate Flavor 0 0 0 5.0 24 Hr Observations % Moisture 4.50% 5.50% 4.10% 6.75% Pick-Up Appearance free- free- mostly free- caked Comments flowing flowing flowing; together particles particles slightly clumpy % Through 20 98.85% 97.92% 98.08% 0.00% US mesh (Extruder zone temperatures, ° C.: Z1 = 0, Z2 = 0, Z3 = 120, Z4 = 180, Z5 = 180, Z6 = 170, Z7 = 150, Z8 = 120, Die Block = 125). After extrusion, the products were blended with 2% silicon dioxide.
[0026] From this example, it is seen that flavor granules absorb different levels of moisture. The amount of moisture absorbed is not always a clear indication of the tendency of the granule to become sticky. The same is true for flavor type. Although both Orange 1 and Lemon 3 are citrus type flavors, Orange 1 absorbs 4.50% moisture and still remains free-flowing, while Lemon 3 absorbs less moisture but the particles tend to clump together.
EXAMPLE 2
[0027] The following formulations were processed via extrusion:
4 5 6 7 8 9 Ingredients Sugar 41.2 40.2 40.2 40.2 40.6 38.8 Maltodextrin 41.2 40.2 40.2 40.2 41.6 40.6 Dextrose 10.1 10.1 10.1 10.1 11.6 11.2 Silicon Dioxide 2.5 2.5 2.5 2.5 1.8 2.7 Lecithin 0 0 0 0 0.7 1.0 Pomegranate 5.0 5.0 5.0 5.0 0 0 Flavor Microcrystalline 0 2.0 0 0 0 0 Cellulose Sodium Carboxy- 0 0 2.0 0 0 0 methylcellulose Distilled 0 0 0 2.0 0 0 Monoglycerides Apple Flavor 0 0 0 0 3.7 3.7 Triglycerides 0 0 0 0 0 2.0 24 Hr Observations % Moisture Pick- 7.95% 7.67% 7.09% 7.26% 7.42% 6.92% Up Appearance Caked caked free- free- caked free- Comments together; together; flowing; flowing; flowing; losing particle slightly slightly slightly particle identity clumpy clumpy clumpy identity remains % Through 20 US 0.00% 8.52% 85.23% 97.56% 7.81% 58.96% mesh (Extruder zone temperatures, ° C.: Z1 = 0, Z2 = 0, Z3 = 120, Z4 = 180, Z5 = 180, Z6 = 170, Z7 = 150, Z8 = 120, Die Block = 125). After extrusion, the products were blended with 2% silicon dioxide.
[0028] From this example, it is seen that the addition of such functional ingredients helps to reduce the level of moisture flavor granules absorb. More importantly, their addition also helps the flavor granules to retain particle integrity even after absorbing some moisture. From this example, it is seen that microcrystalline cellulose (Pomegranate 5) is not as effective as sodium carboxymethylcellulose (Pomegranate 6) or distilled monoglycerides (Pomegranate 7) in retaining particle integrity.
EXAMPLE 3
[0029] The presence of a functional ingredient and a silicon dioxide coating works in synergy to help reduce moisture absorption and retain the particle integrity of the encapsulate. Pomegranate 4 and Pomegranate 6 from Example 2 were tested with and without a 2% silicon dioxide coating at 30° C. and 60% relative humidity.
6 Hr 4 (no 4 6 (no 6 Observations coating) (w/coating) coating) (w/coating) % Moisture 5.79% 6.58% 5.20% 5.52% Pick-Up Appearance paste; no Caked paste; slight free- Comments particle particle flowing identity identity % Through 20 0% 0% 0% 99% US mesh
[0030] In both cases, the presence of a silicon dioxide coating helped to improve the appearance of the flavor granules after being subjected to such harsh conditions. The presence of the functional ingredient in Pomegranate 6 also helped to improve the hygroscopic tendencies of the granule. The best result is seen with Pomegranate 6 (w/coating) where the presence of sodium carboxymethylcellulose and the silicon dioxide coating work in synergy to keep the particles free-flowing.
EXAMPLE 4
[0031] The following formulation was processed via extrusion:
4 6 10 11 12 13 14 Ingredients Sugar 41.2 40.2 41.7 40.7 34.5 33.7 36.7 Maltodextrin 41.2 40.2 41.7 40.7 39.5 38.7 40.6 Dextrose 10.1 10.1 10.1 10.1 9.9 9.7 10.1 Silicon Dioxide 2.5 2.5 2.0 2.0 4.0 4.0 3.0 Lecithin 0 0 1.0 1.0 2.0 2.0 2.0 Pomegranate 5.0 5.0 0 0 0 0 0 Flavor Sodium Carboxy- 0 2.0 0 2.0 0 2.0 2.0 methylcellulose Pineapple Flavor 0 0 3.6 3.6 0 0 0 Honey Flavor 0 0 0 0 10.0 10.0 0 Passion Fruit 0 0 0 0 0 0 5.6 Flavor 24 Hr Observations % Moisture Pick- 7.95% 7.09% 8.26% 6.03% 6.90% 4.51% 6.24% Up Appearance caked free- caked free- caked, hard, free- Comments together; flowing; flowing gummy very flowing losing slightly particles clumpy particle clumpy particles identity % Through 20 US 0.00% 85.23% 7.72% 92.84% 0.00% 69.60% 99.06% mesh (Extruder zone temperatures, ° C.: Z1 = 0, Z2 = 0, Z3 = 120, Z4 = 180, Z5 = 180, Z6 = 170, Z7 = 150, Z8 = 120, Die Block = 125). After extrusion, the products were blended with 2% silicon dioxide.
[0032] From this example, it can be seen that the addition of a functional ingredient, such as sodium carboxymethylcellulose, greatly reduces the hygroscopic tendencies of amorphous flavor granules regardless of the flavor used.
EXAMPLE 5
[0033] Passion Fruit 14 from Example 4 was incorporated into tea leaves at 10% by weight. This mixture was filled into tea bags, placed in the overwrap, and put into paperboard tea boxes. These boxes were then subjected to conditions of 30° C. and 60% relative humidity. After 10 days, the tea bags were evaluated. The tea bags did not stick to the overwrap and there were no visible spots.
EXAMPLE 6
[0034] The following formulation was processed via extrusion:
Ingredients 15 Sugar 41.1 Maltodextrin 42.1 Dextrose 11.8 Silicon Dioxide 1.5 Blueberry Flavor 3.5 (Extruder zone temperatures, ° C.: Z1 = 0, Z2 = 0, Z3 = 120, Z4 = 180, Z5 = 180, Z6 = 170, Z7 = 150, Z8 = 120, Die Block = 125)
EXAMPLE 7
[0035] Product from Example 6 was blended with 2% silicon dioxide prior to hygroscopicity testing. This product was then placed in an aluminum dish and subjected to conditions of 30° C. and 60% relative humidity. Within 24 hours it had absorbed approximately 8.53% moisture and had formed a paste.
EXAMPLE 8
[0036] Product from Example 6 was first thoroughly mixed with 5% medium chain triglycerides and then blended with 2% silicon dioxide prior to hygroscopicity testing. This product was then placed in an aluminum dish and subjected to conditions of 30° C. and 60% relative humidity. Within 24 hours it had absorbed approx. 7.72% moisture. Although the product appeared to be caked at first glance, it broke apart to be free-flowing/clumpy particles with a small shake of the pan.
EXAMPLE 9
[0037] Product from Example 6 was first thoroughly mixed with 5% glycerol triacetate and then blended with 2% silicon dioxide prior to hygroscopicity testing. This product was then placed in an aluminum dish and subjected to conditions of 30° C. and 60% relative humidity. Within 24 hours it had absorbed approx. 6.07% moisture and remained as free-flowing, slightly clumpy particles.
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The invention relates to flavorings. In particular, the invention relates to extruded flavors that are capable of retaining their particle shape and integrity when exposed to high temperature and humid environments.
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BACKGROUND OF THE INVENTION
This invention relates generally to a fishing line release mechanism for use with side planers or outriggers, and more particularly to a fishing line release mechanism of simple construction which is easy to use and readily adjustable.
In certain methods of fishing, it is desirable to locate a trolling line away from the fishing boat either to provide room for additional lines or to keep the bait or lure from following directly in the path of the boat. To provide for such remote location, outriggers, downriggers or side planers (skiis) extend from the side of the boat. The trolling line, or lines, are coupled to the outriggers, downriggers or tow lines of the side planers by release mechanisms which secure the trolling line during fishing and release a trolling line when a fish is hooked. Prior release mechanisms range from spring loaded clamps, which are difficult to adjust for varying fishing conditions, to complex and expensive releases such as shown in U.S. Pat. No. 3,800,458 issued Apr. 2, 1974 in the name of Swanby for example.
SUMMARY OF THE INVENTION
This invention is directed to a simple, readily adjustable, mechanism for releasably connecting a fishing line to a member such as an outrigger, downrigger or side planer tow line. The release mechanism includes a body selectively secured to such member. A pair of elements, at least one of which is resilient, is associated with the body. The elements are adjustably urged into intimate contact. A fishing line, receivably held between the elements, is released by exertion of a preselected tension on such line when a fish is hooked.
The invention, and its objects and advantages, will become more apparent in the detailed description of the preferred embodiment presented below.
BRIEF DESCRIPTION OF THE DRAWINGS
In the detailed description of the preferred embodiment of the invention, reference is made to the accompanying drawings, in which:
FIG. 1 is a schematic view of fishing boat employing the side planer method of fishing;
FIG. 2 is a view, in perspective, of the fishing line release mechanism according to this invention secured to a tow line; and
FIG. 3 is an exploded view, in perspective and on an enlarged scale, of the fishing line release mechanism of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawings, an examplary method of fishing in which fishing line release mechanisms can be employed is schematically depicted in FIG. 1. In this method, referred to as side planer fishing, a fishing boat 10, traveling in the direction indicated by arrow A, has outboard side planers 12 coupled thereto by tow lines 14. The forward motion of the boat through the water maintains the spacing of the side planers to the boat with the tow lines taught. A plurality of fishing lines 16 are then respectively secured to the tow lines 14 by release mechanisms 18 according to this invention. The lines 16 are thus positioned outwardly from the boat 10 so as to extend away from the sides of the boat. Of course, the release mechanisms 18 are suitable for any other fishing method where remote release of the fishing line is desirable.
The release mechanism 18, as best shown in FIGS. 2 and 3, includes a body 20, a support member 26, and a fishing line receiver assembly 28. The body 20 is formed of an elongated substantially rigid wire, for example. The body 20 has a large loop 22 formed in one end and a substantially smaller loop 24 formed in the opposite end. The loop 22 has a sharply bent portion 22a at the end thereof. The portion 22a is engageable with an intermediate portion of the body 20 to hold the loop in a closed position (shown in solid lines in FIGS. 2 and 3). Due to the limited resilience of the wire, the portion 22a is movable to an open position (shown in broken lines in FIG. 3) to enable the loop 22 to be readily slipped over a tow line 14 and then closed to secure the mechanism 18 to the tow line.
The support member 26 has a screw threaded portion 26a, upon which the fishing line receiver assembly 28 is mounted, and a hand engageable portion 26b. The receiver assembly 28 includes a pair of substantial disk-shaped elements 30, 32, formed for example of resilient open cell dense foam material. The elements 30, 32 have openings 30a, 32a, along their respective longitudinal axes of a diameter less than the diameter of the threaded portion 26a of the support member 26. Because of the relationship of the respective diameters of the openings to the diameter of the threaded portion, the elements 30, 32 are relatively securely held on the threaded portion 26a when such portion is inserted through the openings coincident with the longitudinal axes of such elements. A pair of pressure pads or washers 34, 36 are located on the threaded portion 26a outboard of the elements 30, 32. The washers 34, 36 have respective openings 34a, 36a of a diameter greater than the diameter of the threaded portion. Accordingly, the washers are free to move axially along the threaded portion 26a while being supported by such portion.
The smaller loop 24 of the body 20 defines an opening 24a (see FIG. 3) of sufficient diameter to accept the threaded portion 26a. On assembly, the threaded portion 26a passes through the loop 24 which is located between washer 34 and element 30. A clinch nut 38 is mounted on the threaded portion 26a outboard of washer 36. Thus, when the hand engageable portion 26b of the support member 26 is rotated, the washers 34, 36 are urged together between the clinch nut 38 and a flange 26c on the portion 26b. That is, rotation of the threaded portion 26a by the hand engageable portion 26b moves the clinch nut 38 along the axis of the portion 26a. The clinch nut, in turn, causes translational movement of the washer 36 toward the washer 34 abutting the flange 26c to compress the elements 30, 32. Due to the resilience of elements 30, 32, adjustment of such portion 26b readily sets the thrust loading on the elements 30, 32 by compression of the elements between the washers.
Element 30 may be of a lesser diameter than element 32 and desirably has a notch 30b formed in its peripheral surface. Such notch, and the relationship of diameters of the elements, facilitates insertion of a fishing line 16 between elements 30, 32. Of course any other arrangement for facilitating insertion of the fishing line (e.g. chamferring one or both of the facing surfaces of the elements 30, 32) is suitable for use with the mechanism 18 of the invention. In operation, a loop 16a is hand formed in a fishing line 16 and such loop is readily inserted between the elements 30, 32 of the release mechanism 18. The hand engageable portion 26b is conveniently rotated to set the desired thrust loading on the elements such that the line 16 is retained between the elements until a preselected tension is applied to the line by a fish being hooked. Such preselected tension is of course dependent upon the type of fish being sought and the conditions under which fishing is taking place (e.g. speed of boat, current, depth of lure).
Portion 22a of loop 22 is then opened, the loop 22 is placed over a tow line 14, and portion 22a is closed to secure the release mechanism 18 to the tow line. The release mechanism is then fed out a desired distance from the boat along the tow line where it remains until the fishing line is released when a fish is hooked. In a similar manner, additional fishing lines 16 in respective release mechanisms 18 may be secured to the tow lines 14. Placement of the release mechanism 18 on the line 14 as shown in FIG. 2 locates the portion 22a such that snagging of fishing lines 16 in adjacent release mechanism is substantially prevented. Of course the loop 22 retains the release mechanism 18 on the tow line after the fishing line is released so that it can be readily recovered for reuse. Moreover, the use of the loop 22 to secure the release mechanism to the tow line 14, enables the mechanism to be oriented by tension in the fishing line 16 so that the fishing line lies in the plane of intimate contact between the elements 30 and 32. Such orientation makes the setting of the preselected tension easier, in that the adjusted thrust loading need not have to compensate for a variable component of the tension perpendicular to the plane between the elements caused by the fishing line moving laterally with respect to the release mechanism.
The invention has been described in detail with particular reference to a preferred embodiment thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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A simple, readily adjustable, mechanism for releasably connecting a fishing line to a member such as an outrigger, downrigger or side planer tow line. The release mechanism includes a body selectively secured to such member. A pair of elements, at least one of which is resilient, is associated with the body. The elements are adjustably urged into intimate contact. A fishing line, receivably held between the elements, is released by exertion of a preselected tension on such line when a fish is hooked.
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IDENTIFICATION OF RELATED PATENT APPLICATIONS
This application is related to four other concurrently filed copending patent applications, namely U.S. patent application Ser. No. 10/192,225, entitled “Snow Plow Having an In-Line Frame Design and Method of Making the Same,” U.S. patent application Ser. No. 10/192,224, entitled “Cushion Stop and Method for Absorbing Bidirectional Impact of Snow Plow Blade Tripping,” now U.S. Pat. No. 6,618.965, U.S. patent application Ser. No. 10/192,577, entitled “Spring Bracket Design and Method for Snow Plow Blade Trip Mechanism,” U.S. patent application Ser. No. 10/192,230, entitled “Back Blade Wearstrip for Efficient Backward Operation of Snow Plows and Method for Facilitating the Same,” all assigned to the assignee of the present patent application, which four patent applications are hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates generally to snow plows for use with light and medium duty trucks, and more particularly to an improved snow plow with a hitch mounting mechanism and method which enables the snow plow to be easily and quickly mounted to and detached from a truck.
Once the exclusive domain of municipality-operated heavy trucks, snow plows have been used with light and medium duty trucks for decades. As would be expected in any area of technology which has been developed for that period of time, snow plows for light and medium duty trucks have undergone tremendous improvement in a wide variety of ways over time, evolving to increase both the usefulness of the snow plows as well as to enhance the ease of using them. The business of manufacturing snow plows for light and medium duty trucks has been highly competitive, with manufacturers of competing snow plows differentiating themselves based on the features and enhanced technology that they design into their products. Two types of features that are particularly important are the ease of installation (and removal) and features bringing an enhanced level of performance in plowing snow.
In the past several years one of the most important of these features has been the ease of installation of a snow plow. While the first snow plows were bolted onto supports which were typically welded onto the frame of a truck at the front end thereof, it will be appreciated by those skilled in the art that such an installation mechanism makes the installation both difficult and time consuming. Since snow plows for light and medium duty trucks weigh hundreds of pounds and are somewhat unwieldy, merely getting the snow plow into the proper position for installation can be a problem. In addition, bolting the snow plow onto the supports can also be difficult to accomplish. Even when it is straightforward, it is time consuming and awkward, particularly when done during the winter when the weather is cold.
Thus, it is apparent that one of the most important improvements which can be made to the design of a snow plow is the inclusion of a mechanism for mounting the snow plow on a truck which improves the snow plow installation process. A number of attempts at designing such mechanisms have been made, but they have all been of a less than optimal design. One problem is that many such hitch mechanisms require such a precise degree of accuracy in the interconnection of the snow plow-mounted hardware and the truck-mounted hardware that they are difficult and time consuming to install.
Another problem is that some previously known hitch mechanisms are unduly complex, both in construction and in operation, which means that they are both expensive to manufacture and difficult to operate. Still another problem with some existing hitch mechanisms is that they provide a less than secure and robust connection between the snow plow and the truck. Yet another problem with them is that many of them have mechanisms which are bulky, reducing the ground clearance between the bottom of the hitch mechanisms and the ground significantly.
It is accordingly the primary objective of the present invention that it provide an improved hitch mounting mechanism and method of operating the same which allows the snow plow to be both connected to and disconnected from a truck easily and simply, without requiring tools. It is a related objective of the snow plow hitch mounting mechanism of the present invention that it require no physical effort to connect or disconnect the snow plow from the truck. It is another related objective of the snow plow hitch mounting mechanism of the present invention that the process of connecting or disconnecting the snow plow to or from the truck is so simple and easy to use that it can be done by a single person without requiring assistance.
It is a further objective of the snow plow hitch mounting mechanism of the present invention that it be mechanically simple both in construction and in operation. It is a still further objective of the snow plow hitch mounting mechanism of the present invention that it provide a robust connection between the snow plow and the truck. It is yet a further objective of the snow plow hitch mounting mechanism of the present invention that it be of a construction which provides a high ground clearance between the bottom of the hitching mechanism and the ground, thereby not presenting a problem even when plowing on hilly or uneven terrain.
The snow plow hitch mounting mechanism of the present invention must also be of construction which is both durable and long lasting, and it should also require little or no maintenance to be provided by the user throughout its operating lifetime. In order to enhance the market appeal of the snow plow hitch mounting mechanism of the present invention, it should also be of inexpensive construction to thereby afford it the broadest possible market. Finally, it is also an objective that all of the aforesaid advantages and objectives of the snow plow hitch mounting mechanism of the present invention be achieved without incurring any substantial relative disadvantage.
SUMMARY OF THE INVENTION
The disadvantages and limitations of the background art discussed above are overcome by the present invention. With this invention, a snow plow hitch mounting mechanism with four points of attachment between a snow plow-mounted hitching apparatus and a hitch frame nose piece mounted at the front of a truck under the bumper as is conventional is provided. Two of the four points of attachment are located on each of the left and right sides of the hitching mechanism, with upper and lower points of attachment being used on each side. One of the points of attachment on each side is made by engaging the snow plow-mounted hitching apparatus with the hitch frame nose piece, and the other attachment point on each side is engaged by using a releasable retaining mechanism.
In the preferred embodiment, the lower points of attachment are made by engaging the snow plow-mounted hitching apparatus with the hitch frame nose piece, with the upper points of attachment being engaged by using the releasable retaining mechanism. The hitch frame nose piece has a pair of spaced-apart hitch brackets mounted on each side thereof, with each of the hitch brackets having a rectangular notch located in the front side thereof. Located in the bottom of each of the rectangular notches is a slot, and located above the notch in each of the hitch brackets is an aperture. All of the notches in the hitch brackets are aligned laterally with each other, and all of the apertures in the hitch brackets are also aligned laterally with each other.
The snow plow-mounted portion of the hitching mechanism is based upon a plow A-frame which has a pair of pins mounted at the rear side thereof. The pins extend laterally, and one pin is mounted at each side of the plow A-frame. These pins are mounted to the plow A-frame such that both ends of the pins are free, and it is these ends of the pins which are received in the rectangular notches in the hitch brackets, where they will rest in the slots located in the hitch brackets. Mounted on these pins for pivoting movement are the two mounting supports for a lift bar, and the ends of the pins protrude from these mounting supports for the lift bar. A portion of the mounting supports will also be engaged by the pairs of hitch brackets.
The lift bar is actuated by a mechanical linkage which is driven by a hydraulic cylinder which will cause it to pivot between a first forward position and a second rearward position. Located on each of the mounting supports above the location of the pins are apertures, which, when the lift bar is in the second rearward position, will be aligned with the apertures in the hitching plates. When the apertures in the mounting supports are so aligned with the apertures in the hitching plates, a pin may be placed into the apertures on each side of the snow plow and the hitch frame nose piece to retain the snow plow in the hitch frame nose piece. Following installation of the snow plow onto the hitch frame nose piece, the hydraulic cylinder and the mechanical linkage will operate to raise and lower the plow blade.
In the preferred embodiment, the snow plow also includes a stand which supports the rear of the snow plow when it is not mounted on a truck. In this embodiment, the mechanical linkage also serves to operate this stand. When the snow plow is not connected to the truck, actuating the hydraulic cylinder which drives the mechanical linkage causes the stand to begin to raise, which in turn causes the rear end of the snow plow to lower, since the base of the stand is still resting on the ground. This allows the pins located at the rear of the snow plow to be brought to a height at which they may be engaged by the hitch frame nose piece.
The truck may then be driven forward so that these pins are engaged by the hitch frame nose piece 300 (they enter the rectangular notches in the hitch brackets). Once the pins are so engaged by the hitch frame nose piece, further actuation of the hydraulic cylinder causes the stand to continue to raise and the rear end of the snow plow to lower, allowing the pins to drop into the slots in the bottom of the rectangular notches in the hitch brackets. Still further actuation of the hydraulic cylinder will lift the stand off of the ground, at which point it may be pivoted out of the way.
Simultaneously, actuation of the hydraulic cylinder also causes the lift bar to pivot toward its second position, at which point the apertures in the mounting supports of the lift bar will be aligned with the apertures in the hitching plates of the hitch frame nose piece. At this point, pins may be inserted from each side of the snow plow and the hitch frame nose piece into the aligned apertures, thereby retaining the snow plow in position on the truck. Further operation of the hydraulic cylinder which drives the mechanical linkage with the snow plow mounted onto the truck will serve to raise and lower the snow plow blade, which is mounted at the front of the snow plow.
It may therefore be seen that the present invention teaches an improved hitch mounting mechanism and method of operating the same which allows the snow plow to be both connected to and disconnected from a truck easily and simply, without requiring tools. The snow plow hitch mounting mechanism of the present invention requires no physical effort to connect or disconnect the snow plow from the truck. The process of connecting or disconnecting the snow plow to or from the truck with the hitch mounting mechanism of the present invention is so simple and easy to use that it can be done by a single person without requiring assistance.
The snow plow hitch mounting mechanism of the present invention is mechanically simple, both in construction and in operation. The snow plow hitch mounting mechanism of the present invention provides a robust connection between the snow plow and the truck. The snow plow hitch mounting mechanism of the present invention is of a construction which provides a high ground clearance between the bottom of the hitching mechanism and the ground, thereby not presenting a problem even when plowing on hilly or uneven terrain.
The snow plow hitch mounting mechanism of the present invention is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The snow plow hitch mounting mechanism of the present invention is also of inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives are achieved by the snow plow hitch mounting mechanism of the present invention without incurring any substantial relative disadvantage.
DESCRIPTION OF THE DRAWINGS
These and other advantages of the present invention are best understood with reference to the drawings, in which:
FIG. 1 is a perspective view of a plow A-frame;
FIG. 2 is a partial cross-sectional view of the plow A-frame illustrated in FIG. 1 ;
FIG. 3 is a perspective view of a plow swing frame which will be pivotally mounted on the front end of the plow A-frame illustrated in FIGS. 1 and 2 and which will support a plow blade therefrom;
FIG. 4 is a cross-sectional view of the plow swing frame illustrated in FIG. 3 ;
FIG. 5 is a bottom plan view of the plow swing frame illustrated in FIGS. 3 and 4 ;
FIG. 6 is a perspective view of a pivoting lift bar which will be pivotally mounted at the rear end of the plow A-frame illustrated in FIGS. 1 and 2 ;
FIG. 7 is a perspective view of a hitch frame nose piece which will be mounted on a truck under the front bumper thereof;
FIG. 8 is a perspective view of a bellcrank which is used to operate the pivoting lift bar illustrated in FIG. 6 ;
FIG. 9 is a perspective view of a lift link which connects the bellcrank illustrated in FIG. 8 to the pivoting lift bar illustrated in FIG. 6 ;
FIG. 10 is a cutaway view of the various components of the snow plow frame assembled together, showing the hydraulic cylinder used to pivot the lift bar;
FIG. 11 is a perspective view of a plow blade from the rear side which will be mounted onto the plow swing frame illustrated in FIGS. 3 through 5 ;
FIG. 12 is an exploded view of the plow blade illustrated in FIG. 11 , showing the assembly of a moldboard made of man-made material onto the plow blade frame;
FIG. 13 is a partial cross-sectional view of the top of the plow blade illustrated in FIG. 11 , showing how the top of the moldboard is retained by the plow blade frame;
FIG. 14 is a partial cross-sectional view of the bottom of the plow blade illustrated in FIG. 11 , showing how the bottom of the moldboard is retained by the plow blade frame and the plow cutting edge;
FIG. 15 is a partial cross-sectional view of a side edge of the plow blade illustrated in FIG. 11 , showing how the side of the moldboard is retained by the plow blade frame;
FIG. 16 is a partial perspective view of the rear of the plow blade illustrated in FIG. 11 , showing the installation of a wear strip onto the rear of the plow blade;
FIG. 17 is an exploded, partial cross-sectional view showing the assembly of the plow swing frame illustrated in FIGS. 3 through 5 onto the plow A-frame illustrated in FIGS. 1 and 2 ;
FIG. 18 is a partial cross-sectional view showing the plow swing frame and the plow A-frame illustrated in FIG. 17 assembled together;
FIG. 19 is a perspective view of a blade stop cushion;
FIG. 20 is a cross-sectional view from the side showing the installation of the blade stop cushion illustrated in FIG. 19 onto the plow swing frame, with the plow blade in its normal position as stopped by the blade stop cushion;
FIG. 21 is a cross-sectional view of the components illustrated in FIG. 20 , from the top side thereof;
FIG. 22 is a cross-sectional view from the side similar to the view of FIG. 20 , but with the plow blade in a rotated position as stopped by the blade stop cushion;
FIG. 23 is a perspective view of portions of the plow blade and the plow swing frame, showing the spring mounts on one side of the plow blade and the plow swing frame, and also showing two springs in phantom lines;
FIG. 24 is a partial rear plan view of the plow blade, the plow swing frame, and the spring mounts illustrated in FIG. 23 ;
FIG. 25 is a perspective view of an alternate embodiment similar to the view shown in FIG. 23 , but with a single spring mount on one side of the plow blade and the plow swing frame, and also showing a spring in phantom lines;
FIG. 26 is a partial rear plan view of plow blade, the plow swing frame, and the spring mount illustrated in FIG. 25 ;
FIG. 27 is a cross-sectional view from the side of the assembled plow blade and the plow swing frame, showing the plow blade in its normal position;
FIG. 28 is a cross-sectional view from the side of the assembled plow blade and the plow swing frame, showing the plow blade in its rotated position;
FIG. 29 is a perspective view of the assembled snow plow of the present invention;
FIG. 30 is a top view of the assembled snow plow illustrated in FIG. 29 ;
FIG. 31 is a partial view from the top showing the hitch mounting mechanism on one side of the snow plow illustrated in FIGS. 29 and 30 prior to installation;
FIG. 32 is a partial view from the top showing the components illustrated in FIG. 31 in a mounted position;
FIG. 33 is a partial cross-sectional view from the front showing the components illustrated in FIGS. 28 and 29 in a mounted position with the retaining pin inserted;
FIG. 34 is a side view of the snow plow illustrated in FIGS. 29 and 30 as the hitch frame nose piece is brought into engagement with a mounting pin on the pivoting lift bar;
FIG. 35 is a schematic depiction of the engagement of the mounting pin with a slot in the hitch frame nose piece;
FIG. 36 is a side view similar to that of FIG. 34 , with the pivoting lift bar beginning to pivot to bring the mounting pin into engagement with the slot in the hitch frame nose piece;
FIG. 37 is a side view similar to that of FIGS. 34 and 36 , with the pivoting lift bar pivoted to bring the mounting holes in the pivoting lift bar into alignment with the mounting holes in the hitch frame nose piece; and
FIG. 38 is a perspective view of an alternate embodiment snow plow having blade shoes mounted thereupon.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention is illustrated in a series of figures, of which the FIGS. 1 through 9 and 11 are components of the snow plow which embodies the present invention. FIGS. 10 , 12 through 24 , and 27 through 29 illustrate the assembly of the snow plow embodying the present invention, and FIGS. 30 through 37 illustrate the manner in which the snow plow is attached to the hitch. Finally, FIGS. 25 , 26 , and 38 illustrate two alternate embodiments. The snow plow of the present invention includes five novel aspects: a novel frame design which has a lower profile and an enhanced linear strength which is attained by that design; a novel hitch quick connect, quick release design; a novel plow blade trip spring placement; a novel plow blade stop design which uses replaceable cushion stop blocks to absorb the impact of plow blade movement between extreme positions; and a novel back blade wearstrip which allows the plow blade to be used to plow backward as well as forward.
The first of these five novel aspects of the snow plow of the present invention resides in the innovative design of its two-piece frame. Referring first to FIGS. 1 and 2 , the first of these two pieces, a plow A-frame 50 , is illustrated. The plow A-frame 50 as illustrated in FIG. 2 has its front end shown at the left of FIG. 2 and its rear end shown at the right of FIG. 2 , and is symmetric around an axis running from the front to the rear thereof. The plow A-frame 50 tapers from a narrower width at the front thereof to a wider width at the rear thereof.
The basic shape of the plow A-frame 50 is formed by a top plate 52 and a bottom plate 54 , which are essentially parallel and are spaced apart from each other. The configurations of the top plate 52 and the bottom plate 54 as viewed from the top (or from the bottom) resemble a portion of the capital letter “A,” with the portions of the sides of the “A” above the crossbar of the “A” being absent. There is a large aperture extending through each of the top plate 52 and the bottom plate 54 above the crossbar of the “A,” which apertures resemble an isosceles trapezoid. The top plate 52 and the bottom plate 54 are preferably made of steel plate.
Mounted between the sides of the top plate 52 and the bottom plate 54 at the location of the crossbar of the “A” and extending rearwardly so as to resemble abbreviated legs of the “A” below the crossbar are two lugs 56 and 58 made of flat bar stock. The lugs 56 and 58 are also preferably made of steel, and are welded onto the sides of the top plate 52 and the bottom plate 54 . The portion of the lug 56 which extends rearwardly from the top plate 52 and the bottom plate 54 has an aperture 60 extending therethrough, and the portion of the lug 58 which extends rearwardly from the top plate 52 and the bottom plate 54 has an aperture 62 extending therethrough.
Portions of three sides of the top plate 52 are bent downwardly at a ninety degree angle to extend to the top of the bottom plate 54 . Only one of these sides, a left side 64 , is visible in FIGS. 1 and 2 . The left side 64 of the top plate 52 extends from just in front of the lug 58 , and extends approximately two-thirds of the way toward the front end of the plow A-frame 50 . A right side of the top plate 52 (which is the mirror image of the left side 64 of the top plate 52 ) and a rear side of the top plate 52 extending between the lugs 56 and 58 are also bent downwardly at ninety degree angles to extend to the top of the bottom plate 54 . These three sides are all welded to the bottom plate 54 to create a box-like structure. A rectangular plate 66 is located just in front of the isosceles trapezoid-shaped apertures in the top plate 52 and the bottom plate 54 , and extends between the sides of the top plate 52 and the bottom plate 54 . The rectangular plate 66 is also preferably made of steel, and all four sides of the rectangular plate 66 are welded onto the top plate 52 (including the left side 64 and right side thereof) and the bottom plate 54 to provide the fourth side of the box-like structure.
Extending from the sides of the lugs 56 and 58 are U-shaped swing cylinder mounts 76 and 78 , respectively. The swing cylinder mounts 76 and 78 are also preferably made of steel, and are welded onto the lugs 56 and 58 , respectively, with the legs of the U's of the swing cylinder mounts 76 and 78 being located on the top and the bottom of the plow A-frame 50 . An aperture 80 is located in each leg of the U in the swing cylinder mount 76 , and an aperture 82 is similarly located in each leg of the U in the swing cylinder mount 78 .
Located between the rear of the top plate 52 at the location of the crossbar of the “A” and the rear of the bottom plate 54 at the location of the crossbar of the “A” are two lift cylinder mounts 84 and 86 . The cylinder mounts 84 and 86 are parallel both to each other and to the plane which divides the plow A-frame 50 into left and right sides thereof. The cylinder mounts 84 and 86 each extend from slots 88 and 90 , respectively, located in the crossbar of the “A” of the top plate 52 and slots 92 and 94 , respectively, located in the crossbar of the “A” of the bottom plate 54 . The cylinder mounts 84 and 86 are also preferably made of steel, and their ends are welded into the slots 88 and 90 , respectively, in the top plate 52 and the slots 92 and 94 , respectively, in the bottom plate 54 . The cylinder mounts 84 and 86 each have an aperture 96 or 98 , respectively, located therein which apertures 96 and 98 are coaxial.
Located at the top of the aperture in the “A” in the plow A-frame 50 are two parallel, spaced-apart, pivot mount plates 100 and 102 . The pivot mount plates 100 and 102 are also preferably made of steel, and are welded onto the rectangular plate 66 , the portion of the top plate 52 adjacent thereto, and the portion of the bottom plate 54 adjacent thereto. The pivot mount plates 100 and 102 are mounted on opposite sides of the centerline of the plow A-frame 50 , and extend rearwardly and upwardly from the rectangular plate 66 , and are beneath a portion of the bottom plate 54 . Located near the rearmost and uppermost ends of the pivot mount plates 100 and 102 are apertures 104 and 106 , respectively, which are coaxial.
Mounted near the front of the plow A-frame 50 are two hollow cylindrical swing frame pivots 108 and 110 . The swing frame pivots 108 and 110 are centrally mounted near the front end of the plow A-frame 50 in apertures 112 and 114 , respectively, which are located in the top plate 52 and the bottom plate 54 , respectively. The swing frame pivots 108 and 110 are also preferably made of steel, and are welded into the apertures 112 and 114 , respectively. The swing frame pivots 108 and 110 are coaxial and are orthogonal to the top plate 52 and the bottom plate 54 .
Located on the inside of each of the legs of the “A” of the plow A-frame 50 near to the top of the “A” are two support sides 116 and 118 . The support sides 116 and 118 extend perhaps one-fourth of the way from the top of the opening of the “A” toward the crossbar of the “A.” The ends of the support sides 116 and 118 oriented closest to the crossbar of the “A” extend between the top side of the top plate 52 and the bottom side of the bottom plate 54 , and the support sides 116 and 118 increase in height above the top plate 52 and below the bottom plate 54 as the support sides 116 and 118 extend towards the front of the plow A-frame 50 . The support sides 116 and 118 are preferably made of steel, and are welded to the top plate 52 , the bottom plate 54 , and the rectangular plate 66 .
Four U-shaped ribs 120 , 122 , 124 , and 126 extend between the support sides 116 and 118 and the swing frame pivots 108 and 110 . The bases of the “U” of each of the U-shaped ribs 120 , 122 , 124 , and 126 are much wider than the legs of the “U” are tall. The U-shaped ribs 120 and 122 are mounted on top of the top plate 52 , and the bases of the “U's” of the U-shaped ribs 120 and 122 are located close adjacent the right and left sides, respectively, of the top plate 52 . The U-shaped rib 124 and 126 are mounted on the bottom of the bottom plate 54 , and the bases of the “U's” of the U-shaped ribs 124 and 126 are located close adjacent the right and left sides, respectively, of the bottom plate 54 . In the preferred embodiment, the U-shaped rib 120 , the support side 116 , and the U-shaped rib 124 are manufactured as a single component, and likewise the U-shaped rib 122 , the support side 118 , and the U-shaped rib 126 are also manufactured as a single component.
One leg of the U-shaped rib 120 extends between the base of the “U” and the support side 116 , and the other leg of the U-shaped rib 120 extends between the base of the “U” and the swing frame pivot 108 . One leg of the U-shaped rib 122 extends between the base of the “U” and the support side 118 , and the other leg of the U-shaped rib 122 extends between the base of the “U” and the swing frame pivot 108 . One leg of the U-shaped rib 124 extends between the base of the “U” and the support side 116 , and the other leg of the U-shaped rib 124 extends between the base of the “U” and the swing frame pivot 110 . One leg of the U-shaped rib 126 extends between the base of the “U” and the support side 118 , and the other leg of the U-shaped rib 126 extends between the base of the “U” and the swing frame pivot 110 .
The U-shaped ribs 120 , 122 , 124 , and 126 are preferably made of steel, and the U-shaped ribs 120 and 122 are welded onto the top plate 52 , while the U-shaped ribs 124 and 126 are welded onto the bottom of the bottom plate 54 . As mentioned above, the U-shaped ribs 120 and 124 may be made integrally with the support side 116 , while the U-shaped rib 122 and 126 may be made integrally with the support side 118 . The swing frame pivots 108 and 110 define an axis upon which a swing frame which will be described below in conjunction with FIGS. 3 through 5 will be mounted, and the area between the top plate 52 and the bottom plate 54 and in front of the rectangular plate 66 is the area in which the swing frame will be mounted.
Referring next to FIGS. 3 through 5 , a swing frame 140 is illustrated which will be mounted as described above on the plow A-frame 50 (illustrated in FIGS. 1 and 2 ). The swing frame 140 is based upon a rectangular swing frame tube 142 having a hollow cylindrical pivot 144 extending through the thinner cross section thereof at the midpoint of the length of the rectangular swing frame tube 142 . The rectangular swing frame tube 142 has an aperture 146 located in the top side thereof and another aperture 148 located in the bottom side thereof. The apertures are closer to the rear side of the rectangular swing frame tube 142 than they are to the front side thereof. Both the rectangular swing frame tube 142 and the pivot 144 are preferably made of steel, and the pivot 144 is welded to the rectangular swing frame tube 142 . The pivot 144 extends slightly above and below the top and bottom, respectively, of the rectangular swing frame tube 142 .
A guide plate 150 extends from the rear of the rectangular swing frame tube 142 . The guide plate 150 is shaped like an isosceles trapezoid with a low triangle mounted on the top thereof, with the base of the isosceles trapezoid mounted onto the rectangular swing frame tube 142 . The width of the guide plate 150 is perhaps half of the length of the rectangular swing frame tube 142 , and the guide plate 150 is centrally mounted both as to the length of the rectangular swing frame tube 142 and as to its height as well. The guide plate 150 is preferably also steel, and is welded onto the rectangular swing frame tube 142 .
Mounted on the rear edge of the guide plate 150 is a guide/stop bar 152 which is made of a segment of flat stock which is wider than the height of the rectangular swing frame tube 142 . The guide/stop bar 152 is bent to conform to the guide plate 150 , and its ends contact the rear side of the rectangular swing frame tube 142 . The guide plate 150 and the guide/stop bar 152 together form a T-shaped configuration in cross-section, as best shown in FIG. 4 . The guide/stop bar 152 thus extends both slightly above and slightly below the rectangular swing frame tube 142 , as is also best shown in FIG. 4 . The guide/stop bar 152 is preferably made of steel, and is welded onto the guide plate 150 , with the ends of the guide/stop bar 152 being welded onto the rear of the rectangular swing frame tube 142 . When the swing frame 140 is mounted onto the plow A-frame 50 (illustrated in FIGS. 1 and 2 ), the guide/stop bar 152 will contact the rectangular plate 66 when the swing frame 140 is rotated between its extreme positions, with the guide/stop bar 152 thus acting to prevent rotation of the swing frame 140 in either direction beyond these positions.
Four triangular swing cylinder mounting plates 154 , 156 , 158 , and 160 are mounted onto the rectangular swing frame tube 142 at positions approximately halfway between the center and the ends of the rectangular swing frame tube 142 , and project rearwardly. The swing cylinder mounting plates 154 and 156 are mounted on the top of the rectangular swing frame tube 142 near the rear edge thereof and the right and left sides thereof, respectively. The swing cylinder mounting plates 158 and 160 are mounted on the bottom of the rectangular swing frame tube 142 near the rear edge thereof and the right and left sides thereof, respectively. The swing cylinder mounting plates 154 , 156 , 158 , and 160 are preferably made of steel, and are welded onto the rectangular swing frame tube 142 .
The swing cylinder mounting plates 154 , 156 , 158 , and 160 each have a slot 162 , 164 , 166 , or 168 , respectively, cut therein to receive an end of the guide/stop bar 152 . The ends of the guide/stop bar 152 fit into these slots 162 , 164 , 166 , or 168 and are welded therein. Located in each of the swing cylinder mounting plates 154 , 156 , 158 , and 160 near the rearmost corner thereof is an aperture 170 , 172 , 174 , or 176 , respectively. The apertures 170 and 174 are coaxial, and the apertures 172 and 176 are coaxial.
Four blade pivot mounts 178 , 180 , 182 , and 184 are mounted on the rectangular swing frame tube 142 in spaced-apart pairs located at each end thereof. The blade pivot mounts 178 , 180 , 182 , and 184 have rectangular apertures 186 , 188 , 190 , and 192 , respectively, extending therethrough to receive therein the rectangular swing frame tube 142 . The blade pivot mount 178 is mounted at the end of the rectangular swing frame tube 142 which will be on the right when the swing frame 140 is mounted on the plow A-frame 50 (illustrated in FIGS. 1 and 2 ), and the blade pivot mount 180 is spaced away from the blade pivot mount 178 on the rectangular swing frame tube 142 .
Similarly, the blade pivot mount 184 is mounted at the end of the rectangular swing frame tube 142 which will be on the left when the swing frame 140 is mounted on the plow A-frame 50 , and the blade pivot mount 182 is spaced away from the blade pivot mount 184 on the rectangular swing frame tube 142 . The spacing between the blade pivot mount 178 and the blade pivot mount 180 , and between the blade pivot mount 182 and the blade pivot mount 184 is sufficient to admit cushion stops which will be discussed below in conjunction with FIG. 19 . The blade pivot mounts 178 , 180 , 182 , and 184 are preferably also made of steel, and are welded onto the rectangular swing frame tube 142 .
It should be noted that the blade pivot mounts 178 , 180 , 182 , and 184 are identical in construction, with each extending forwardly in front of the rectangular swing frame tube 142 (as best shown in FIG. 4 ) and rearwardly and upwardly behind the rectangular swing frame tube 142 . Located near the front of the blade pivot mounts 178 , 180 , 182 , and 184 are apertures 194 , 196 , 198 , and 200 , respectively, which will be used to pivotally mount the snow plow blade (illustrated below in FIG. 11 ). The apertures 194 , 196 , 198 , and 200 are coaxial. Located in the blade pivot mounts 178 , 180 , 182 , and 184 intermediate the apertures 194 , 196 , 198 , and 200 , respectively, and the front of the rectangular swing frame tube 142 are apertures 202 , 204 , 206 , and 208 , respectively, which will be used to retain cushion stops which will be discussed below in conjunction with FIG. 19 . The pairs of apertures 202 and 204 , and 206 and 208 are coaxial.
As mentioned above, each of the blade pivot mounts 178 , 180 , 182 , and 184 also extends rearwardly of the rectangular swing frame tube 142 , resembling the profile of a vertical tail fin of a plane as best shown in FIG. 4 . Mounted to each pair of each pair of the blade pivot mounts 178 and 180 , and 182 and 184 , are two trip spring brackets 210 and 212 . The trip spring brackets 210 and 212 are preferably also made of steel, are generally oval in configuration, and are mounted with the wider sides being oriented between the left and right sides of the swing frame 140 . The trip spring bracket 210 is welded onto the blade pivot mounts 178 and 180 , and the trip spring bracket 212 is welded onto the blade pivot mounts 182 and 184 . The trip spring bracket 210 has apertures 214 and 216 disposed near opposite ends thereof, and similarly the trip spring bracket 212 has apertures 218 and 220 disposed near opposite ends thereof.
Completing the swing frame 140 are two additional components which are used both to act as a stop for rotational movement of the plow blade (which will be discussed below in conjunction with FIG. 11 ) as well as to help define an enclosure for the cushion stops (which will be discussed below in conjunction with FIG. 18 ). A stop 222 is mounted at the top of, intermediate, and at the bottom of the blade pivot mounts 178 and 180 . The stop 222 extends rearwardly from a point above the apertures 202 and 204 , drops down in front of the rectangular swing frame tube 142 , and extends rearwardly below the rectangular swing frame tube 142 to a point halfway between the front edge of the rectangular swing frame tube 142 and the pivot 144 .
Similarly, a stop 224 is mounted at the top of, intermediate, and at the bottom of the blade pivot mounts 182 and 184 . The stop 224 extends rearwardly from a point above the apertures 206 and 208 , drops down in front of the rectangular swing frame tube 142 , and extends rearwardly below the rectangular swing frame tube 142 to a point halfway between the front edge of the rectangular swing frame tube 142 and the pivot 144 . The stops 222 and 224 are both preferably also made of steel, and are welded to the blade pivot mount pairs 178 and 180 , and 182 and 184 , respectively.
Referring next to FIG. 6 , a lift bar 230 is illustrated which forms part of the hitch mechanism of the snow plow. The lift bar 230 has two lift bar support members 232 and 234 , which are located on the right and left sides, respectively, of the lift bar 230 . Each of the lift bar support members 232 and 234 has a configuration consisting of three segments: rear mounting supports 236 and 238 , respectively, which extend upward vertically; central support arms 240 and 242 , respectively, which extend forwardly and upwardly from the top of the rear mounting supports 236 and 238 , respectively; and front light bar supports 244 and 246 , respectively, which extend upwardly from the forwardmost and upwardmost ends of the central support arms 240 and 242 , respectively. The lift bar support members 232 and 234 are preferably made of steel plate.
Extending inwardly from the rear sides of rear mounting supports 236 and 238 are segments of angled stock 248 and 250 , respectively. It should be noted that the angle defined by each of the segments of angled stock 248 and 250 is less than ninety degrees, as, for example, approximately seventy degrees. The reason for this angle will become apparent below in conjunction with the discussion of FIGS. 31 and 32 . The angled stock segments 248 and 250 are also preferably made of steel, and are welded onto rear mounting supports 236 and 238 , respectively, so that the rear mounting supports 236 and 238 and the angled stock segments 248 and 250 together form vertically-oriented channels which are essentially U-shaped. Referring for the moment to FIG. 1 in addition to FIG. 6 , the space between the rear mounting support 236 and the angled stock segment 248 of the lift bar 230 is designed to admit the lug 56 of the plow A-frame 50 with space between the lug 56 and the inside of the angled stock segment 248 , and similarly the space between the angled stock segment 250 , and the rear mounting support 238 of the lift bar 230 is designed to admit the lug 58 of the plow A-frame 50 with space between the lug 58 and the inside of the angled stock segment 250 .
Referring again solely to FIG. 6 , a rectangular reinforcing segment 252 (preferably also made of steel) is located at the bottom of the U-shaped channel formed by the rear mounting support 236 and the angled stock segment 248 , and is welded to the bottoms of the rear mounting support 236 and the angled stock segment 248 . Similarly, a rectangular reinforcing segment 254 (preferably also made of steel) is located at the bottom of the U-shaped channel formed by the rear mounting support 238 and the angled stock segment 250 , and is welded to the bottoms of the rear mounting support 238 and the angled stock segment 250 .
Not illustrated in the figures but used to reinforce the construction of the lift bar 230 are two additional rectangular reinforcing segments which are respectively located above the reinforcing segments 252 and 254 . On the right side of the lift bar 230 , the first of these additional reinforcing segments (preferably also made of steel) is located near the top of the U-shaped channel formed by the rear mounting support 236 and the angled stock segment 248 , and is welded to the tops of the rear mounting support 236 and the angled stock segment 248 . Similarly, the other of these reinforcing segments (preferably also made of steel) is located at near the top of the U-shaped channel formed by the rear mounting support 238 and the angled stock segment 250 , and is welded to the tops of the rear mounting support 238 and the angled stock segment 250 .
Extending between the lift bar support members 232 and 234 are a larger diameter hollow round upper pin support tube 256 and a smaller diameter round light bar brace 258 . The upper pin support tube 256 and the light bar brace 258 are both also preferably made of steel. One end of the upper pin support tube 256 extends through an aperture 260 located in an intermediate position in the central support arm 240 of the lift bar support member 232 , and the other end of the upper pin support tube 256 extends through an aperture 262 located in an intermediate position in the central support arm 242 of the lift bar support member 234 . The ends of the upper pin support tube 256 are welded onto the central support arms 240 and 242 . One end of the light bar brace 258 is welded onto the lift bar support member 232 at the intersection of the central support arm 240 and the light bar support 244 , and the other end of the light bar brace 258 is welded onto the lift bar support member 234 at the intersection of the central support arm 242 and the light bar support 246 .
Two upper pin hanger plates 264 and 266 are mounted on the upper pin support tube 256 in spaced-apart fashion near the middle of the upper pin support tube 256 . The upper pin hanger plates 264 and 266 have apertures 268 and 270 , respectively, extending therethrough near one end thereof, and the upper pin support tube 256 extends through these apertures 268 and 270 . The upper pin hanger plates 264 and 266 are both also preferably made of steel, and are welded onto the upper pin support tube 256 in a manner whereby they are projecting forwardly. A tubular upper pin 272 extends through apertures 274 and 276 in the upper pin hanger plates 264 and 266 , respectively, near the other end thereof. The upper pin 272 is also preferably made of steel, and is welded onto the upper pin hanger plates 264 and 266 .
Located in the rear mounting support 236 , the angled stock segment 248 , the angled stock segment 250 , and the rear mounting support 238 near the bottoms thereof are apertures 278 , 280 , 282 , and 284 , respectively, which are aligned with each other and which together define a pivot axis about which the lift bar 230 will pivot when it is mounted onto the plow A-frame 50 (Illustrated in FIG. 1 ). Located in the rear mounting support 236 , the angled stock segment 248 , the angled stock segment 250 , and the rear mounting support 238 nearer the tops thereof than the bottoms thereof are apertures 286 , 288 , 290 (not shown in FIG. 6 ), and 292 , which are aligned with each other.
The apertures 286 and 288 define a first location into which a retaining pin (not shown in FIG. 6 ) will be placed to mount the snow plow of the present invention onto a truck, and the apertures 290 and 292 define a second location into which another retaining pin (not shown in FIG. 6 ) will be placed to mount the snow plow of the present invention onto the truck. Located in the light bar support 244 are three apertures 294 , and located in the light bar support 246 are three apertures 296 . The apertures 294 and 296 will be used to mount a light bar (not illustrated in FIG. 6 ) onto the lift bar 230 .
Referring now to FIG. 7 , a hitch frame nose piece 300 which will be mounted onto a truck under the front bumper (not illustrated in FIG. 7 ) thereof is illustrated. The hitch frame nose piece 300 has a square hitch frame tube 302 which is horizontally oriented. Four hitch brackets 304 , 306 , 308 , and 310 are mounted on the square hitch frame tube 302 in spaced-apart pairs located nearer the ends of the square hitch frame tube 302 than the center thereof. The hitch brackets 304 , 306 , 308 , and 310 have square apertures 312 , 314 , 316 , and 318 , respectively, extending therethrough to receive therein the square hitch frame tube 302 . Both the square hitch frame tube 302 and the hitch brackets 304 , 306 , 308 , and 310 are preferably made of steel, and the hitch brackets 304 , 306 , 308 , and 310 are welded onto the square hitch frame tube 302 .
Referring for the moment to FIG. 6 in addition to FIG. 7 , the space between the hitch bracket 304 and the hitch bracket 306 of the hitch frame nose piece 300 is designed to admit the rear mounting support 236 and the angled stock segment 248 of the lift bar 230 , and similarly the space between the hitch bracket 308 and the hitch bracket 310 of the hitch frame nose piece 300 is designed to admit the angled stock segment 250 and the rear mounting support 238 of the lift bar 230 . The hitch brackets 304 , 306 , 308 , and 310 have rectangular notches 320 , 322 , 324 , and 326 , respectively, cut into the front sides thereof.
Located in the hitch brackets 304 , 306 , 308 , and 310 in the bottoms of the rectangular notches 320 , 322 , 324 , and 326 , respectively, are slots 328 , 330 , 332 , and 334 , respectively. The slots 328 , 330 , 332 , and 334 have rounded bottoms, and are axially aligned. Also located in the hitch brackets 304 , 306 , 308 , and 310 above the tops of the rectangular notches 320 , 322 , 324 , and 326 , respectively, are apertures 336 , 338 , 340 , and 342 , respectively. The apertures 336 , 338 , 340 , and 342 are also axially aligned.
Unlike the hitch brackets 306 and 308 which are flat, the hitch brackets 304 and 310 have their forward-most portions flanged outwardly to act as guides to direct the lift bar 230 (illustrated in FIG. 6 ) into engagement with the hitch frame nose piece 300 . Thus, the portions of the hitch brackets 304 and 310 at the front of the rectangular notches 320 and 326 , respectively, extend outwardly, both on the top of the rectangular notches 320 and 326 and on the bottom of the rectangular notches 320 and 326 . It should be noted that, if desired, the hitch brackets 304 and 310 may also be flat. The ramifications of having them flat instead of flanged will eliminate the utility of the right and left sides of the lift bar 230 .
The respective ends of the square hitch frame tube 302 are mounted onto mounting plates 344 and 346 . The mounting plates 344 and 346 are also preferably made of steel, and the ends of the square hitch frame tube 302 are welded onto the mounting plates 344 and 346 . Located in the mounting plates 344 and 346 are a plurality of apertures 348 and 350 , respectively, which will be used to mount the hitch frame nose piece 300 onto the frame of a truck (not shown in FIG. 7 ) using mounting brackets (not shown in FIG. 7 ) in a manner which is conventional.
Referring next to FIG. 8 , a bellcrank 360 is illustrated. The bellcrank 360 has parallel, spaced apart triangular pivot plates 362 and 364 . One of the sides of the triangle is shorter than the other two in each of the pivot plates 362 and 364 . A gusset plate 366 is mounted between the pivot plates 362 and 364 with one side thereof near the shortest side of the triangle to support the pivot plates 362 and 364 in their spaced-apart configuration. In the preferred embodiment, both the pivot plates 362 and 364 and the gusset plate 366 are made of steel, and are welded together.
The pivot plates 362 and 364 have apertures 370 and 372 , respectively, located therein near a first corner of the triangle which will be used to mount the bellcrank 360 for pivotal movement from the apertures 104 and 106 of the pivot mount plates 100 and 102 , respectively (illustrated in FIG. 1 ). The pivot plates 362 and 364 have apertures 374 and 376 , respectively, located therein near a second corner of the triangle which will be connected via the element to be discussed in FIG. 9 below to drive the upper pin 272 of the lift bar 230 (illustrated in FIG. 6 ). The pivot plates 362 and 364 have apertures 378 and 380 , respectively, located therein near the third corner of the triangle will be connected to a hydraulic cylinder (not shown in FIG. 9 ). The short side of the triangle is between the first and third corners of the triangle. The side of the gusset plate 366 adjacent this short side will act as a lift stop to limit pivotal movement of the gusset plate 366 when this side of the gusset plate 366 contacts the pivot mount plates 100 and 102 (illustrated in FIG. 1 ).
Referring now to FIG. 9 , a lift link 390 is illustrated. The lift link 390 has parallel, spaced apart arms 392 and 394 . A gusset plate 396 is mounted between the arms 392 and 394 in their spaced-apart configuration. The side of the gusset plate 396 which is oriented toward one end of the arms 392 and 394 has a notch 398 cut therein. In the preferred embodiment, both the arms 392 and 394 and the gusset plate 396 are made of steel, and are welded together. The one end of the arms 392 and 394 have apertures 400 and 402 , respectively, located therein, and the other ends of arms 392 and 394 have apertures 404 and 406 , respectively, located therein.
Referring next to FIG. 10 , the linkage used to attach the snow plow of the present invention to the hitch frame nose piece 300 is illustrated. The components which are linked together are the plow A-frame 50 , the lift bar 230 , the bellcrank 360 , and the lift link 390 . Accordingly, reference may also be had to FIGS. 1 , 6 , 8 , and 9 as well as to FIGS. 31 and 32 in the following description of the interconnection of these components. The lift bar 230 is pivotally mounted on the plow A-frame 50 using two pins 408 and 410 (the pin 410 is not shown in FIG. 10 ) which are each of a length longer than distance between the opposite-facing sides of the pairs of the hitch brackets 304 and 306 , or 308 and 310 (illustrated in FIG. 7 ). The pins 408 and 410 are preferably made of steel.
In the preferred embodiment, a hollow cylindrical collar 409 (shown in FIGS. 31 and 32 ) having a setscrew 411 (also shown in FIGS. 31 and 32 ) is used with the pin 410 as a spacer. A similar collar which a setscrew (not shown in the drawings) is used with the pin 408 as a spacer. The collar 409 will be located intermediate the lug 58 on the plow A-frame 50 and the angled stock segment 250 on the lift bar 230 . The setscrew 411 on the collar 409 may be used to lock the collar 409 in place on the pin 410 . The other collar will be located intermediate the lug 56 on the plow A-frame 50 and the angled stock segment 248 on the lift bar 230 , with a setscrew in that collar being used to lock that collar in place on the pin 408 .
The pin 408 will thus extend sequentially through the aperture 278 in the rear mounting support 236 of the lift bar 230 , the aperture 60 in the lug 56 of the plow A-frame 50 , the collar, and the aperture 280 in the rear mounting support 238 of the lift bar 230 . The pin 408 will be retained in place by the setscrew on the collar, which will contact the pin 408 when it is screwed into the collar. Approximately equal lengths of the pin 408 extend outwardly beyond the rear mounting support 236 and the angled stock segment 248 at each end of the pin 408 . Alternately, the pin 408 may be welded in place on the rear mounting support 236 and the angled stock segment 248 of the lift bar 230 , or C-clips (not shown herein) could be installed in annular groves (not shown herein) in the pin 408 at locations which correspond to the ends of the collar.
The pin 410 will thus extend sequentially through the aperture 282 in the angled stock segment 250 of the lift bar 230 , the collar 409 , the aperture 62 in the lug 58 of the plow A-frame 50 , and the aperture 284 in the rear mounting support 238 of the lift bar 230 . The pin 410 will be retained in place by the setscrew 411 on the collar 409 , which will contact the pin 410 when it is screwed into the collar 409 . Equal lengths of the pin 410 extend outwardly beyond the angled stock segment 250 and the rear mounting support 238 at each end of the pin 410 . Alternately, the pin 410 may be welded in place on the angled stock segment 250 and the rear mounting support 238 of the lift bar 230 , or C-clips (not shown herein) could be installed in annular groves (not shown herein) in the pin 410 at locations which correspond to the ends of the collar 409 .
It will thus be appreciated by those skilled in the art that the lift bar 230 is pivotally mounted onto the plow A-frame 50 using the pins 408 and 410 . When the snow plow of the present invention is mounted onto a vehicle using the hitch frame nose piece 300 , the ends of the pins 408 and 410 will be received in the pairs of slots 328 and 330 , and 332 and 334 in the hitch frame nose piece 300 (illustrated in FIG. 7 ). Thus, the pins 408 and 410 function both to pivotally mount the lift bar 230 onto the plow A-frame 50 , and to help to mount the snow plow onto the hitch frame nose piece 300 .
The bellcrank 360 is pivotally mounted on the plow A-frame 50 using two bolts 412 and two nuts 414 . The pivot plates 362 and 364 of the bellcrank 360 will fit outside of the pivot mount plates 100 and 102 , respectively. One of the bolts 412 will extend through the aperture 104 in the pivot mount plate 100 of the plow A-frame 50 and the aperture 370 in the pivot plate 362 of the bellcrank 360 , and one of the nuts 414 will be mounted on that bolt 412 to retain it in place. The other one of the bolts 412 will extend through the aperture 106 in the pivot mount plate 102 of the plow A-frame 50 and the aperture 372 in the pivot plate 364 of the bellcrank 360 , and the other one of the nuts 414 will be mounted on that bolt 412 to retain it in place.
The bolts 412 allow the bellcrank 360 to pivot on the plow A-frame 50 . In the preferred embodiment, a spacer and two washers (not shown) may be used with each of the bolts 412 , the spacer going through the apertures in the parts being pivotally joined and being longer than the combined thickness of the apertures in the parts, and a washer being located on either end of the spacer to facilitate free rotation of parts, here movement of the bellcrank 360 with reference to the plow A-frame 50 . It will be understood by those skilled in the art that a spacer and two washers will preferably be used at other points of relative movement between two elements of linkage of the snow plow described herein, although the spacer and two washers will not be specifically mentioned in conjunction with each of these pivoting connections made between two elements using a bolt. In addition, it will be understood by those skilled in the art that a pin retained by a cotter pin (not shown herein) could be used instead of a bolt and nut in many of the applications for a fastener used in the linkage discussed herein.
A hydraulic cylinder 416 is mounted at one end to the cylinder mounts 84 and 86 of the plow A-frame 50 using a bolt 418 which extends through the aperture 96 in the cylinder mount 84 and the aperture 98 in the cylinder mount 86 , with a nut 420 being used to retain the bolt 418 in place. The other end of the hydraulic cylinder 416 drives the third corner of the triangular pivot plates 362 and 364 of the bellcrank 360 , with a bolt 422 extending between the aperture 378 in the pivot plate 362 of the bellcrank 360 and the aperture 380 in the pivot plate 364 of the bellcrank 360 . A nut 424 is used to retain the bolt 422 in place. The bolts 418 and 422 allow the hydraulic cylinder 416 to move as it drives the bellcrank 360 . Spacers (not shown herein) may be used on each side of the other end of the hydraulic cylinder 416 on the insides of the pivot plates 362 and 364 to center the hydraulic cylinder 416 .
The lift link 390 is used to connect the bellcrank 360 to pivot the lift bar 230 . A bolt 426 is used to connect the lift link 390 to the lift bar 230 , with the bolt 426 extending sequentially through the aperture 404 in the arm 392 of the lift link 390 , the upper pin 272 from the end extending through the upper pin hanger plate 264 to the end extending through the upper pin hanger plate 266 of the lift bar 230 , and the aperture 406 in the arm 394 of the lift link 390 . A nut 428 is used to retain the bolt 426 in place. The bolt 426 allows the lift link 390 to pivot on the lift bar 230 , and a spacer and two washers may also be used as mentioned hereinabove.
The second corner of the triangle formed by the pivot plates 362 and 364 of the bellcrank 360 drives the ends of the arms 392 and 394 of the lift link 390 which are not connected to the lift bar 230 . Two bolts 430 are used to connect the bellcrank 360 to the lift link 390 , with one of the bolts 430 also being used to mount a stand 432 . The stand 432 is described in U.S. Pat. No. 5,894,688, to Struck et al., which patent is assigned to the assignee of the inventions described herein. U.S. Pat. No. 5,894,688 is hereby incorporated herein by reference.
One bolt 430 (not shown) extends through the aperture 400 in the arm 392 of the lift link 390 and the aperture 374 of the pivot plate 362 of the bellcrank 360 , with a nut 434 being used to retain the first bolt 430 in place, and a spacer and two washers may also be used as mentioned hereinabove. The other bolt 430 extends sequentially through an aperture (not shown) in the upper portion of the stand 432 , the aperture 376 of the pivot plate 364 of the bellcrank 360 , and the aperture 402 in the arm 394 of the lift link 390 , with a nut 434 being used to retain the second bolt 430 in place. The second bolt 430 allows the lift link 390 to pivot on the bellcrank 360 , and a spacer and two washers may again be used as mentioned hereinabove. A removable pin (not shown) extending through an aperture near the top of the stand 432 and apertures located in the lift link 390 is used to link the stand 432 with the lift link 390 .
The hydraulic cylinder 416 is shown in FIG. 10 nearly in its fully retracted position. When the hydraulic cylinder 416 is fully extended, it will be appreciated by those skilled in the art that the lift bar 230 will rotate counterclockwise from the position in which it is shown in FIG. 10 , and the stand 432 will be lowered to engage the ground (not shown) and thereby tend to lift the rear end of the plow A-frame 50 upwardly. It will also be appreciated that once the pins 408 and 410 are in engagement with the slots 328 , 330 , 332 , and 334 in the hitch brackets 304 , 306 , 308 and 310 , respectively, of the hitch frame nose piece 300 , the hydraulic cylinder 416 may be used to align the apertures 286 , 288 , 290 , and 292 on the lift bar 230 with the apertures 336 , 338 , 340 , and 342 , respectively, in the hitch brackets 304 , 306 , 308 , and 310 , respectively, of the hitch frame nose piece 300 .
Turning next to FIGS. 11 through 16 , a plow blade 440 and various aspects thereof are illustrated. The plow blade 440 has a frame which may be fundamentally thought of as a horizontal top plow frame member 442 , a bottom plow frame member 444 , and a plurality of vertical ribs 446 , 448 , 450 452 , 454 , 456 , and 458 extending between the top plow frame member 442 and the bottom plow frame member 444 . The top plow frame member 442 is made of a triangular tube as best shown in FIG. 13 . The bottom plow frame member 444 is made of a three sided channel resembling a wide, inverted “U” with the tops of the legs of the “U” angling outwardly as best shown in FIG. 14 .
The right side rib 446 is located on the right side of the plow blade 440 , and the left side rib 458 is located on the left side of the plow blade 440 . The ribs 448 , 450 , 452 , 454 , and 456 are located at evenly spaced intervals intermediate the right side rib 446 and the left side rib 458 . Note that all of the ribs 446 , 448 , 450 452 , 454 , 456 , and 458 have an arcuate shape when viewed from the side. The ribs 448 , 450 , 452 , 454 , and 456 all extend between the back side of the top plow frame member 442 and the top side of the bottom plow frame member 444 , while the right side rib 446 and the left side rib 458 are mounted on the ends of the top plow frame member 442 and the bottom plow frame member 444 , thereby overlying them as best shown in FIGS. 11 through 14 . The top plow frame member 442 , the bottom plow frame member 444 , and the ribs 446 , 448 , 450 452 , 454 , 456 , and 458 are all preferably made of steel, and are welded together.
Located in front of the ribs 450 and 454 are curved reinforcing plates 460 and 462 which serve to strengthen the ribs 450 and 454 , which will be used to mount the plow blade 440 to the swing frame 140 (shown in FIGS. 3 through 5 ). The rib 450 has a mounting aperture 464 which extends therethrough and which is located near to the bottom end of the rib 450 . Similarly, the rib 454 has a mounting aperture 466 which extends therethrough and which is located near to the bottom end of the rib 454 . The curved reinforcing plates 460 and 462 are welded to the ribs 450 and 454 , respectively, and to the top plow frame member 442 and the bottom plow frame member 444 .
Four arcuate torsional stiffeners 468 , 470 , 472 , and 474 are used to provide stiffness to the configuration of the plow blade 440 . The torsional stiffener 468 extends from the bottom of the rib 448 to a position near the top of the right side rib 446 . The torsional stiffener 470 extends from the bottom of the rib 450 to a position near the top of the rib 448 . The torsional stiffener 472 extends from the bottom of the rib 454 to a position near the top of the rib 456 . The torsional stiffener 474 extends from the bottom of the rib 456 to a position near the top of the left side rib 458 . The torsional stiffeners 468 , 470 , 472 , and 474 are also preferably made of steel, and are welded to other components in the plow blade 440 .
Located on the left side of the right side rib 446 and on the right side of the left side rib 458 are curved support plates 476 and 478 , respectively. The curved support plates 476 and 478 are recessed back from the front edges of the right side rib 446 and the left side rib 458 , respectively, as best shown in FIG. 15 for the curved support plate 478 . The curved support plates 476 and 478 are preferably also made of steel, and are welded to other components in the plow blade 440 . The frontmost portions of the top plow frame member 442 , the curved support plate 476 , the rib 448 , the curved reinforcing plate 460 , the rib 452 , the curved reinforcing plate 462 , the rib 456 , and the curved support plate 478 together define a curved support surface which will support a moldboard 480 thereupon. The right side rib 446 and the left side rib 458 extend slightly forward of the top plow frame member 442 , the bottom plow frame member 444 , and the ribs 448 , 450 , 452 , 454 , and 456 , to thereby prevent the moldboard 480 from moving laterally. The moldboard 480 may be made of a man-made material such as polycarbonate, which may be clear, or other man-made materials such as ultra-high molecular weight (UHMW) polyethylene, or steel.
Extending across the front side of the top plow frame member 442 is a moldboard retainer strip 482 (best shown in FIG. 13 ), into which the top edge of the moldboard 480 fits and is retained. The moldboard retainer strip 482 is bent slightly toward the top plow frame member 442 , which ensures that the top edge of the moldboard 480 fits snugly therein. Thus, it will be appreciated that the top, right, and left sides of the moldboard 480 are retained in position on the plow blade 440 . The front of the bottom plow frame member 444 extends forwardly with respect to the curved moldboard support surface defined by the frontmost portions of the top plow frame member 442 , the curved support plate 476 , the rib 448 , the curved reinforcing plate 460 , the rib 452 , the curved reinforcing plate 462 , the rib 456 , and the curved support plate 478 . The bottom edge of the moldboard 480 comes just to the top of the bottom plow frame member 444 , as best shown in FIG. 14 .
The front of the bottom plow frame member 444 has a plurality of tapped apertures 484 located therein across the entire width thereof. A wearstrip 486 which is approximately the same width as the bottom plow frame member 444 has a matching plurality of apertures 488 located therein. The wearstrip 486 is preferably made of a high carbon steel such as AISI 1080 high carbon steel. The wearstrip 486 is bolted onto the bottom plow frame member 444 with a plurality of bolts 490 . Alternately, if the apertures 484 are not tapped, bolts and nuts could be used to mount the wearstrip 486 onto the bottom plow frame member 444 . Optionally, the apertures 488 in the wearstrip 486 may be countersunk to recess the heads of the bolts 490 to the level of surface of the wearstrip 486 . The front of the bottom plow frame member 444 is arranged and configured such that the wearstrip 486 will be mounted with its bottom edge angled forwardly with respect to the ground at angle of between approximately zero and forty-five degrees, with between approximately fifteen and thirty degrees being preferred, and an angle of approximately twenty-five degrees being most preferred.
The wearstrip 486 retains the bottom of the moldboard 480 in place, and it will at once be appreciated that the moldboard 480 may be replaced by merely removing the wearstrip 486 , making the replacement substantially easier than in earlier snow plow blade designs. When the wearstrip 486 is bolted to the bottom plow frame member 444 , it will be appreciated by those skilled in the art that it extends well below the bottom of the bottom plow frame member 444 , so that as it is worn down, the bottom plow frame member 444 will not be damaged by contact with the ground.
Mounted on the back of the ribs 450 and 454 , respectively, are two trip spring brackets 492 and 494 . The trip spring brackets 492 and 494 are mounted approximately three-quarters of the way up the ribs 450 and 454 , and are bent at a ninety degree angle, the bends being on an axis parallel to the lateral axis of the plow blade 440 . The portions of the trip spring brackets 492 and 494 facing forward have notches 496 and 498 , respectively, cut into them from the forwardmost edges thereof to the bends therein. The rear edges of the ribs 450 and 454 fit into the notches 496 and 498 , respectively, and the portions of the spring brackets 492 and 494 facing rearwardly fit against the ribs 450 and 454 , respectively. The spring brackets 492 and 494 are also preferably made of steel, and are welded onto the ribs 450 and 454 , respectively. The rear-facing portion of the trip spring bracket 492 has two apertures 500 and 502 located therein on which lie on opposite sides of the rib 450 , and the rear-facing portion of the trip spring bracket 494 has two apertures 504 and 506 located therein on which lie on opposite sides of the rib 454 .
Located on the right side of the plow blade 440 in the right side rib 446 near the top thereof are two apertures 512 . Similarly, located on the left side of the plow blade 440 in the left side rib 458 near the top thereof are two apertures 514 . The apertures 512 and 514 serve to allow a marker bar or the like (not shown in FIGS. 11 through 13 ) to be attached to the plow blade 440 .
Located at the rear of the plow blade 440 at the bottom thereof is a back blade wearstrip 516 , which is mounted onto the bottom plow frame member 444 and extends substantially across the width of the plow blade 440 . The back blade wearstrip 516 has a plurality of apertures 518 therein, and the bottom plow frame member 444 has matching tapped apertures 520 located in the rear-facing side thereof. Bolts 522 are used in the back blade wearstrip 516 to mount it onto the bottom plow frame member 444 . Alternatively, if the apertures 520 are not tapped, bolts and nuts could be used to mount the back blade wearstrip 516 onto the bottom plow frame member 444 . Optionally, the apertures 518 in the back blade wearstrip 516 may be countersunk to recess the heads of the bolts 522 to the level of surface of the back blade wearstrip 516 .
The back blade wearstrip 516 is permanently mounted at an optimum angle with respect to the ground which is defined by the angle of the rear side of the bottom plow frame member 444 . The rear of the bottom plow frame member 444 is arranged and configured such that the back blade wearstrip 516 will be mounted with its bottom edge angled rearwardly with respect to the ground at angle of between approximately zero and forty-five degrees, with between approximately fifteen and thirty degrees being preferred, and an angle of approximately twenty-five degrees being most preferred. In the preferred embodiment, the wearstrip 486 and the back blade wearstrip 516 will be mounted at the same angles, but with the wearstrip 486 being angled forwardly and the back blade wearstrip 516 being angled rearwardly.
In the preferred embodiment, the back blade wearstrip 516 is made of an UHMW polyethylene material which is used instead of steel to decrease the weight of the plow blade 440 . Alternately, the back blade wearstrip 516 could be made of rubber, urethane, steel, aluminum, or any other suitable material. Also, if desired, the back blade wearstrip 516 can be manufactured as multiple identical narrower segments if desired.
Turning next to FIGS. 17 and 18 , and making reference also to FIGS. 1 and 3 through 5 , the installation of the swing frame 140 onto the plow A-frame 50 is illustrated. The rectangular swing frame tube 142 of the swing frame 140 is inserted between the top plate 52 and the bottom plate 54 of the plow A-frame 50 , with the pivot 144 of the swing frame 140 being brought into alignment intermediate the swing frame pivot 108 and the swing frame pivot 110 of the plow A-frame 50 . A pivot pin 524 having a threaded distal end 526 is inserted sequentially through the swing frame pivot 108 in the plow A-frame 50 , the pivot 144 in the swing frame 140 , and the swing frame pivot 110 in the plow A-frame 50 , and is retained in place by a locking nut 528 . Washers (not shown herein) may also be used if desired.
Thus, the swing frame 140 is pivotally mounted on the plow A-frame 50 , and it will be appreciated by those skilled in the art that the movement of the swing frame 140 is limited by the guide/stop bar 152 on the swing frame 140 which interacts with the rectangular plate 66 on the plow A-frame 50 to limit movement to approximately thirty degrees either to the right or to the left. The swing frame 140 will be pivoted by two hydraulic cylinders, the installation of which will be described later in conjunction with FIG. 30 .
It will be appreciated by those skilled in the art that the design of the plow A-frame 50 and the swing frame 140 represents a substantial improvement over past snow plow frame designs since their centerlines are in the same horizontal plane. Thus, rather than having the swing frame 140 being located on top of the plow A-frame 50 , the swing frame 140 is located in the same plane as is the plow A-frame 50 . In the preferred embodiment, the apertures 60 and 62 in the lugs 56 and 58 , respectively, as well as the pins 408 and 410 , are also in the same horizontal plane.
Moving now to FIG. 19 , a cushion block 530 is illustrated which will be used to absorb the impact of the plow blade 440 (shown in FIG. 11 ) as it moves between its limits. Such movement of the plow blade 440 is caused by the plow blade 440 striking an object, and is designed to prevent damage to the snow plow by allowing the plow blade 440 to “trip,” that is, for the bottom of the plow blade 440 to move rearwardly and the top of the plow blade 440 to simultaneously move forward, resulting in a rotation of the plow blade 440 around a horizontal axis. Such a rotation is inhibited by springs, which act as a shock absorbing mechanism, and which return the plow blade 440 to a normal or “trip return” position. The springs are quite strong, since they must prevent the plow blade 440 from rotating when it is plowing snow, and the metal-to-metal impacts of both a blade trip and a blade trip return can be substantial. The cushion block 530 is designed to cushion the impacts on both the blade trip and the blade trip return.
The cushion block 530 is brick-shaped with a corner cut off to create a beveled face 532 , and will be mounted with the beveled face 532 of the cushion block 530 facing both forwardly and downwardly. Above the beveled face 532 of the cushion block 530 and facing forwardly when the cushion block 530 is mounted is a front face 534 . Extending laterally through the cushion block 530 at a central location is an aperture 536 , which will be used to mount the cushion block 530 on the swing frame 140 (shown in FIGS. 3 through 5 ). A cushion block 530 will be mounted between each pair of the blade pivot mounts 178 and 180 , and 182 and 184 . The apertures 202 and 204 in the blade pivot mounts 178 and 180 , respectively, will align with the aperture 536 in one cushion block 530 , and the apertures 206 and 208 in the blade pivot mounts 182 and 184 , respectively, will align with the aperture 536 in the other cushion block 530 .
Turning next to FIGS. 20 through 22 , and referring also to FIGS. 3 , 11 , and 19 , the installation of both the cushion blocks 530 and the plow blade 440 onto the swing frame 140 is illustrated. One of the cushion blocks 530 is shown installed between the blade pivot mounts 182 and 184 , with a bolt 538 extending sequentially through the aperture 208 in the blade pivot mount 184 , the aperture 536 in the cushion block 530 , and the aperture 206 in the blade pivot mount 182 , and with a nut 540 being used to retain the bolt 538 in place. The top and the rearwardly facing side of the cushion block 530 are retained in position by the stop 222 in the swing frame 140 . The other cushion block 530 would be similarly mounted between the blade pivot mounts 178 and 180 . Alternately, silicone adhesive (or any other suitable type of adhesive) may be used instead of bolts to retain the cushion blocks 530 in place. Another alternate retaining mechanism would be to have the cushion blocks 530 fit in place with an interference fit.
The plow blade 440 will pivot around an axis defined by the mounting apertures 464 and 466 located in the ribs 450 and 454 , respectively, and is mounted onto the swing frame 140 using two pins 542 . One of the pins 542 extends sequentially through the aperture 200 in the blade pivot mount 184 , the mounting aperture 466 in the rib 454 , and the aperture 198 in the blade pivot mount 182 . The other one of the pins 542 extends sequentially through the aperture 196 in the blade pivot mount 180 , the mounting aperture 464 in the rib 450 , and the aperture 194 in the blade pivot mount 180 . Retaining pins 544 are installed into diametrically extending apertures located in the distal ends of each of the pins 542 , and retain the pins 542 in place, thereby pivotally mounting the plow blade 440 on the swing frame 140 .
The plow blade 440 thus may pivot between the trip return position shown in FIG. 20 and the tripped position shown in FIG. 22 . It will be appreciated by those skilled in the art that when the plow blade 440 hits an object on the ground sufficiently hard, it will be driven to the tripped position shown in FIG. 22 , at which time the portion of the rib 454 and also the portion of the rib 450 (which is not shown in FIG. 22 ) below the pins 542 will contact the beveled faces 532 of the cushion blocks 530 , which will absorb the impact. Similarly, when the plow blade 440 is driven back into the trip return position shown in FIG. 20 , the portion of the rib 454 and also the portion of the rib 450 (which is not shown in FIG. 22 ) above the pins 542 will contact the front face 534 of the cushion blocks 530 , which will absorb the impact. In the preferred embodiment, the cushion blocks 530 are made of polyurethane, such as, for example, Quazi formulated methylenebisdiphenyl diisocyanate (MDI) polyester-based 93 durometer (Shore A scale) polyurethane, available commercially from Kryptonics, Inc. under the trademark Kaptane 93 black.
Referring now to FIGS. 23 and 24 , portions of the left side of the swing frame 140 and the plow blade 440 are illustrated in the blade trip return position. In the principal design described herein and shown in the drawings, four trip springs 550 , 552 , 554 , and 556 (the first two of which are not shown in FIG. 23 or 24 ) will be used to bias the plow blade 440 into the trip return position, and to resist movement of the plow blade 440 into the tripped position. Two trip springs 550 and 552 , or 554 and 556 will be located on each side of the swing frame 140 and the plow blade 440 . The trip springs 554 and 556 are shown in phantom lines in FIG. 23 , with the trip spring 554 being connected between the aperture 218 of the trip spring bracket 212 and the aperture 504 of the trip spring bracket 494 , and the trip spring 556 being connected between the aperture 220 of the trip spring bracket 212 and the aperture 506 of the trip spring bracket 494 .
It will at once be appreciated by those skilled in the art that the trip springs 554 and 556 are located immediately on either side of the pivoting connection between the plow blade 440 and the swing frame 140 . The trip springs 554 and 556 exert a force in a plane which is parallel to the plane of rotation defined by the pivoting connection between the plow blade 440 and the swing frame 140 . Thus, the trip springs 554 and 556 do not pull in a direction which is even in part at an angle to the plane of rotation. This represents a major advantage over previously known snow plow trip spring mounting designs, which without exception are located at an angle to the plane of rotation defined by the pivoting connection between the plow blade and the swing frame of such previously known snow plows. The design of the snow plow described herein utilizes all of the trip spring force for the blade trip operation, and thus provides more consistent blade trip operation as well as eliminating lateral trip spring force being exerted on the frame of the plow blade 440 .
Turning next to FIGS. 25 and 26 , an alternate embodiment is illustrated in which two trip springs are used to bias the plow blade 440 into the trip return position, and to resist movement of the plow blade 440 into the tripped position. One trip spring will be located on each side of the swing frame 140 and the plow blade 440 (the trip spring 560 on the left side of the swing frame 140 and the plow blade 440 is illustrated in the blade trip return position in FIG. 25 ). In the alternate embodiment illustrated in FIGS. 25 and 26 , the design of the trip spring brackets which are mounted on the back of the ribs 450 and 454 differs from the design of the trip spring brackets 210 and 212 (shown in FIGS. 3 through 5 ). A strip spring bracket 562 having a single aperture 564 located therein is mounted on the blade pivot mounts 182 and 184 . The trip spring bracket 562 is also preferably made of steel, and is welded onto the blade pivot mounts 182 and 184 with the aperture 564 being located between the blade pivot mounts 182 and 184 . An identical spring trip bracket (not shown) would also be used on the right side of the swing frame 140 .
In the alternate embodiment illustrated in FIGS. 25 and 26 , the design of the trip spring brackets which are mounted on the back of the ribs 450 and 454 also differs from the design of the trip spring brackets 492 and 494 (shown in FIGS. 11 and 12 ). A trip spring bracket 566 is mounted approximately three-quarters of the way up the rib 454 , and is bent at a ninety degree angle, the bend being on an axis parallel to the lateral axis of the plow blade 440 . The portion of the trip spring bracket 566 facing forward has a notch 568 cut into it from the forwardmost edge thereof to the bend therein. The rear edge of the rib 454 fits into the notch 568 , and the portion of the spring bracket 566 facing rearwardly fits against the rib 454 . The rear-facing portion of the trip spring bracket 566 has an aperture 570 located therein which lies in the same plane as the rib 454 . The spring bracket 566 is also preferably made of steel, and is welded onto the rib 454 . An identical spring trip bracket (not shown) would also be used on the right side of the plow blade 440 .
It will be appreciated by those skilled in the art that the trip spring 560 is located, and exerts a force, in the plane of rotation defined by the pivoting connection between the plow blade 440 and the swing frame 140 . Thus, the trip spring 560 does not pull in a direction which is even in part at an angle to the plane of rotation (unlike previously known snow plow trip spring mounting designs). The alternate embodiment design of the snow plow of FIGS. 25 and 26 utilizes all of the trip spring force for the blade trip operation and provides more consistent blade trip operation as well as eliminating lateral trip spring force being exerted on the frame of the plow blade 440 .
Referring next to FIGS. 27 and 28 , the movement of the plow blade 440 between the trip return position shown in FIG. 27 and the fully tripped position shown in FIG. 28 is illustrated. From these figures (and also by looking at the orientation of the trip springs 550 , 552 , 554 , and 556 in the top plan view of FIG. 30 ), it will be appreciated that the trip springs 550 , 552 , 554 , and 556 (which are already under tension even in the trip return position) are all further stretched as the plow blade 440 moves from the trip return position to the tripped position, and thus serve to return the plow blade 440 to the trip return position when the force which caused the plow blade 440 to be tripped is removed.
Turning next to FIGS. 29 and 30 , the assembly of several additional components is illustrated. First, all four of the trip springs 550 , 552 , 554 , and 556 are illustrated as mounted onto the swing frame 140 and the plow blade 440 . In addition, right and left light support towers 572 and 574 , respectively, are mounted on the light bar supports 244 and 246 , respectively, of the lift bar 230 , and a light support bar 576 is mounted on the top ends of the right and left light support towers 572 and 574 . Lights (not shown herein) would be mounted on the light support bar 576 , in a manner well known to one skilled in the art.
In addition, right and left swing cylinders 578 and 580 , respectively, are mounted between the plow A-frame 50 and the swing frame 140 . The right swing cylinder 578 extends between the swing cylinder mount 76 on the plow A-frame 50 (where it is secured with a pin 582 ) and the swing cylinder mounting plates 154 and 158 on the swing frame 140 (where it is secured with a pin 584 ), and the left swing cylinder 580 extends between the swing cylinder mount 78 on the plow A-frame 50 (where it is secured with a pin 586 ) and the swing cylinder mounting plates 156 and 160 on the swing frame 140 (where it is secured with a pin 588 ). It will be understood that the pins 582 , 584 , 586 , and 588 are all retained in place with cotter pins (not shown) as is well known to those skilled in the art.
Also not shown or discussed herein is the hydraulic system to operate the snow plow, the construction and operation of which is also well known to those skilled in the art. The right and left swing cylinders 578 and 580 are used to pivot the swing frame 140 and the plow blade 440 on the plow A-frame 50 . The hydraulic cylinder 416 (shown in FIG. 10 ) is used to operate the stand 432 (also shown in FIG. 10 ) prior to the snow plow being mounted onto a truck, to facilitate the mounting of the snow plow onto the truck (as will become apparent below in conjunction with the discussion of FIGS. 31 through 37 ), and to raise and lower the plow A-frame 50 , the swing frame 140 , and the plow blade 440 after the snow plow has been mounted onto the truck. The hydraulic system for the snow plow may be mounted on the plow A-frame 50 at the front thereof, and if so mounted would have a hydraulic system cover 590 mounted thereupon to protect it, as shown in phantom lines.
Referring now to FIGS. 31 through 37 , the operation of the mounting system used to mount the snow plow on the hitch frame nose piece 300 is shown. Referring first to FIGS. 31 through 33 , in conjunction with FIGS. 1 , 6 , 7 , and 10 , the mechanism used to connect the snow plow to the hitch frame nose piece 300 is shown. In the discussion herein, all references are to the left side of the snow plow and the hitch frame nose piece 300 , but those skilled in the art will understand that the principles thereof are equally applicable to the right side of the snow plow and the hitch frame nose piece 300 .
The snow plow is mounted onto the hitch frame nose piece 300 with the plow standing on the stand 432 (shown in FIG. 10 ). In this position, the pin 410 which extends laterally at the rear of the snow plow on the left side will be at a height such than when the truck having the hitch frame nose piece 300 mounted thereon moves forward, the pin 410 will fit into the rectangular notches 324 and 326 at the front of the hitch brackets 308 and 310 , respectively. The pin 410 is brought fully into the rectangular notches 324 and 326 by moving the truck forward. It will be noted that the flange at the front of the hitch bracket 310 as well as the approximately seventy degree bend in the angled stock segment 250 will assist in guiding the rear mounting support 238 and the angled stock segment 250 of the lift bar 230 into position intermediate the hitch bracket 308 and 310 .
A this point, the hydraulic cylinder 416 (shown in FIG. 10 ) is actuated to begin to retract it to raise the stand 432 (also shown in FIG. 10 ), causing the pin 410 to drop into the slots 332 and 334 in the hitch brackets 308 and 310 , respectively. By continuing to actuate the hydraulic cylinder 416 to retract it, the lift bar 230 is pivoted to bring the apertures 290 and 292 in the angled stock segment 250 and the rear mounting support 238 , respectively, of the lift bar 230 into alignment with the apertures 340 and 342 in the hitch brackets 308 and 310 , respectively, of the hitch frame nose piece 300 . At this point, a retaining pin 592 having a handle 594 may be inserted sequentially through the aperture 342 in the hitch bracket 310 , the aperture 292 in the rear mounting support 238 , the aperture 290 in the angled stock segment 250 , and the aperture 340 in the hitch bracket 308 . The retaining pin 592 has an aperture 596 extending through near the distal end thereof, and a retaining spring pin 598 is used to retain the retaining pin 592 in place.
Referring next to FIGS. 34 through 37 , the installation of the snow plow onto the hitch frame nose piece 300 mounted on a truck 600 (shown in phantom lines in FIG. 37 ) is illustrated. In FIG. 34 , the snow plow is shown in its stored position, supported on the stand 432 . In this position, the hydraulic cylinder 416 is in its fully extended position, and the rear end of the snow plow is raised. In this position, the pin 408 (not shown in FIGS. 34 through 37 ) at the right rear of the snow plow will be received by the rectangular notches 320 and 322 (not shown in FIGS. 34 through 37 ) at the front of the hitch brackets 304 and 306 (not shown in FIGS. 34 through 37 ), respectively, at the right side of the hitch frame nose piece 300 . Similarly, the pin 410 at the left rear of the snow plow will be received by the rectangular notches 324 (not shown in FIGS. 34 through 37 ) and 326 at the front of the hitch brackets 308 (not shown in FIGS. 34 through 37 ) and 310 , respectively, at the left side of the hitch frame nose piece 300 . The truck 600 may be driven forward to fully engage the pins 408 and 410 with the hitch frame nose piece 300 as shown in FIG. 34 .
Next, as shown in FIG. 36 , as the hydraulic cylinder 416 begins to retract, the plow A-frame 50 will lower at the rear end thereof as the stand 432 begins to move upwardly relative to the plow A-frame 50 . This causes the pin 408 (not shown in FIGS. 34 through 37 ) to drop into the slots 328 and 330 (not shown in FIG. 36 ) in the hitch brackets 304 and 306 (not shown in FIG. 36 ), respectively, at the right side of the hitch frame nose piece 300 . Similarly, the pin 410 drops into the slots 332 (not shown in FIG. 36 ) and 334 in the hitch brackets 308 (not shown in FIG. 36 ) and 310 , respectively, at the left side of the hitch frame nose piece 300 . This initial retraction of the hydraulic cylinder 416 also causes the lift bar 230 to begin to rotate clockwise as viewed from the left side of the snow plow, as is evident from the movement of the right light support towers 572 and 576 and the light support bar 576 .
As shown in FIG. 37 , as the hydraulic cylinder 416 continues to retract, the lift bar 230 rotates clockwise until the light support towers 572 and 576 are oriented nearly vertically. As this further rotation occurs, the pin 408 (not shown in FIG. 37 ) remains in the slots 328 and 330 in the hitch brackets 304 and 306 , respectively (none of which are shown in FIG. 37 ). Similarly, the pin 410 remains in the slots 332 (not shown in FIG. 37 ) and 334 in the hitch brackets 308 (not shown in FIG. 37 ) and 310 , respectively. On the right side of the lift bar 230 and the hitch frame nose piece 300 (best shown in FIGS. 6 and 7 ), the apertures 286 and 288 in the rear mounting support 236 and the angled stock segment 248 , respectively, of the lift bar 230 move into engagement with the apertures 336 and 338 in the hitch brackets 304 and 306 , respectively, of the hitch frame nose piece 300 . Likewise, on the left side of the lift bar 230 and the hitch frame nose piece 300 (portions of which are also best shown in FIGS. 6 and 7 , respectively), the apertures 290 and 292 in the angled stock segment 250 and the rear mounting support 238 , respectively, of the lift bar 230 move into alignment with the apertures 340 and 342 in the hitch brackets and 310 , respectively, of the hitch frame nose piece 300 .
At this point, one of the retaining pins 592 is inserted sequentially through the aperture 336 in the hitch bracket 304 , the aperture 286 in the rear mounting support 236 , the aperture 288 in the angled stock segment 248 , and the aperture 338 in the hitch bracket 306 (all of which are best shown in FIGS. 6 and 7 ). The other one of the retaining pins 592 is inserted sequentially through the aperture 342 in the hitch bracket 310 , the aperture 292 in the rear mounting support 238 , the aperture 290 in the angled stock segment 250 , and the aperture 340 in the hitch bracket 308 (many of which are also best shown in FIGS. 6 and 7 ). The retaining spring pins 598 are then inserted into the apertures 596 near the distal ends of the retaining pins 592 to retain the retaining pins 592 in place. At this point, the stand 432 may also be moved to a stowed position by disconnecting it from the lift link 390 (by removal of the pin (not shown)) and rotating it to the stowed position as is taught in U.S. Pat. No. 5,894,688, which was incorporated by reference above.
Also shown in FIG. 37 is a marker bar 602 , one of which may be mounted on each side of the plow blade 440 at the top thereof using the apertures 512 and 514 (not shown in FIG. 37 ) on the right and left sides of the plow blade 440 , respectively, using bolts 604 and nuts (not shown herein). The marker bars 602 are used to allow the driver of the truck 600 to see where the front of the plow blade 440 is at any given time (since the driver may not be able to see the plow blade 440 over the hood of the truck 600 from the cab of the truck 600 ).
Referring finally to FIG. 38 , a snow plow having an alternate embodiment is illustrated in which shoes 610 and 612 are installed on the plow blade 440 . The shoes 610 and 612 are designed to ride in sliding contact with the surface to be plowed, and are particular useful on gravel or during the spring when the ground may not be fully frozen. The shoes 610 and 612 are mounted to the plow blade 440 using shoe mounts 614 and 616 , respectively. The shoe mount 614 is mounted on the bottom plow frame member 444 near the right side thereof, and the shoe mount 616 is mounted on the bottom plow frame member 444 near the left side thereof. The shoe mounts 614 and 616 are preferably made of steel and are welded onto the bottom plow frame member 444 .
The shoes 610 and 612 are mounted on posts 618 and 620 , respectively, which posts 618 and 620 are received by the shoe mounts 614 and 616 , respectively. The shoes 610 and 612 are adjusted using a combination of washers and tubular spacers, which are placed on the posts 618 and 620 either below or above the shoe mounts 614 and 616 to adjust the height of the shoes 610 and 612 . The position of the shoes 610 and 612 relative to the plow blade 440 may be adjusted to adjust the height of the plow blade 440 relative to the surface to be plowed. This allows the degree to which the wearstrip 486 scrapes the surface to be plowed to be controlled. Retaining pins 622 and 624 are used on the posts 618 and 620 , respectively, to retain them in the shoe mounts 614 and 616 .
The shoes 610 and 612 are typically made out of cast iron. It should be noted that although the back blade wearstrip 516 is not shown in the embodiment illustrated in FIG. 38 , it can in fact be used with the shoes 610 and 612 , so long as the shoe mounts 614 and 616 extend sufficiently back to clear the back blade wearstrip 516 . The shoes 610 and 612 have feet which are adapted to ride in sliding contact with the surface to be plowed. The position of the feet relative to the plow blade may be adjusted to adjust the height of the plow blade relative to the surface to be plowed. In this way, the degree to which the blade edge scrapes the surface to be plowed may be controlled.
It may therefore be appreciated from the above detailed description of the preferred embodiment of the present invention that it teaches an improved hitch mounting mechanism and method of operating the same which allows the snow plow to be both connected to and disconnected from a truck easily and simply, without requiring tools. The snow plow hitch mounting mechanism of the present invention requires no physical effort to connect or disconnect the snow plow from the truck. The process of connecting or disconnecting the snow plow to or from the truck with the hitch mounting mechanism of the present invention is so simple and easy to use that it can be done by a single person without requiring assistance.
The snow plow hitch mounting mechanism of the present invention is mechanically simple, both in construction and in operation. The snow plow hitch mounting mechanism of the present invention provides a robust connection between the snow plow and the truck. The snow plow hitch mounting mechanism of the present invention is of a construction which provides a high ground clearance between the bottom of the hitching mechanism and the ground, thereby not presenting a problem even when plowing on hilly or uneven terrain.
The snow plow hitch mounting mechanism of the present invention is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The snow plow hitch mounting mechanism of the present invention is also of inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives are achieved by the snow plow hitch mounting mechanism of the present invention without incurring any substantial relative disadvantage.
Although an exemplary embodiment of the snow plow hitch mounting mechanism of the present invention has been shown and described with reference to particular embodiments and applications thereof, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described herein may be made, none of which depart from the spirit or scope of the present invention. All such changes, modifications, and alterations should therefore be seen as being within the scope of the present invention.
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An improved snow plow for use with light and medium duty trucks is disclosed which has a hitch mounting mechanism and method that enables the snow plow to be easily and quickly mounted to and detached from a truck without requiring tools. The snow plow hitch mounting mechanism has four points of attachment between a snow plow-mounted hitching apparatus and a hitch frame mounted at the front of a truck, two points of attachment being at each side. The lower points of attachment are made by initially engaging the snow plow-mounted hitching apparatus with the hitch frame, with the upper points of attachment being engaged by using a releasable retaining mechanism.
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This is a division of application Ser. No. 320,595, filed Nov. 12, 1983, now U.S. Pat. No. 4,393,524.
BACKGROUND OF THE INVENTION
Marine sanitary devices in particular and waste disposal system in general have been proceeding through an evolutionary process for a number of years. The Environmental Protection Agency (EPA) has issued various specifications regarding requirements for processing liquid and solid human waste as set forth in 33 CFR 159. Sewage or waste disposal basically requires that under certain circumstances, substantially all of the solid waste be removed from any liquid discharged from a vessel. In many instances recirculation of the fluid, for example water, is desirable.
Separation of solid waste and collection can be accomplished in a variety of different well known manners. The difficulty resides in storage and disposal. Clearly improvements in this area are necessary particularly when stringent EPA sanitary regulations are taken into consideration and criteria such as size, cost and efficiency of operation are kept in mind.
SUMMARY OF THE INVENTION
With the above background in mind, it is among the primary objectives of the present invention to provide a system for processing liquid and solid human waste in a manner consistent with the stringent requirements of the United States EPA. The system includes a self-contained unit including a removable disposable filter media cassette designed to achieve "white glove" servicing of the system. The system is compact and the cassette can be interconnected with a toilet bowl and packaged beneath the toilet bowl in a compact arrangement which is particularly useful in confined areas such as found in marine use.
It is also an objective to utilize low cost filtration materials to achieve minimum cost per flush of the system. Also, the system is energy efficient and only a small amount of electrical power is required for use. Furthermore, the system requires no chemical additions for sanitizing purposes.
A unique two stage filtration process is incorporated in the cassette with initial phase separation that satisfies United States EPA requirements for suspended solids.
More particularly, the basic objective of the system is achieved with the use of a filter cassette which is removable and disposable and acts in cooperation with a toilet bowl. The cassette is designed to roll a filter material about a spindle or take up roll assembly. Solid waste material is rolled up into the take up roll. Two stage filtration can be accomplished by first screening out or projecting out with the aid of a flapper design the majority of the solid waste ingredient. A second stage or solids removal is achieved with a filter media such as an unwoven plastic fabric. The two stage filter material method employs one roll of screen and one roll of filter media positioned adjacent to one another and adapted to be rolled together onto the take up roll. The first stage of separation through the screen material removes approximately 97% of the solids from the fluid. The majority of the remaining 3% of the solids is collected by the second stage filter in the form of the filter media. When the filter is fully rolled up it can be replaced by removing the filter cassette and replaced by a new one. The filter cassette can then be disposed in a simple and clean manner.
A still further objective of the invention is to provide a unique take up roll including a triangular configuration which facilitates directing the larger portion of the solid waste on the filter material with the material wrapping around the roll for collection and storage.
Also among the objectives of the present invention is to provide increased storage capacity for solid material in the unique filter cassette design. Conventional disposal filter devices usually are fully loaded when they have collected solids in a quantity of approximately 1 to 5% of the total volume of the device. In the present invention, the two stage filter concept permits separation of very large quantities of solid material from the fluid which is then conveyorized into storage. The screen material and finer filter media are both wrapped around the take up roll because screen material provides additional traction for moving the solid material onto the roll. As the solid material is entering the area of the take up roll there is a tendency for it to compress or extrude through the coarse screen material. The fine filter media is immediately behind the coarse filtering screen material and stops or prevents the possibility of extrusion. By the time the filter cassette is totally used up, approximately 40 to 50% of its volume has filled with waste plus the filter material. Conventional disposable filter devices would have to be 10 to 20 times lager to do the same job.
It is an objective of the invention to provide a toilet bowl as part of this system for receiving human waste and to contain fluid for dilution of the waste, transporting of the waste material from the bowl into the filter cassette, and also to assist in rinsing or cleaning the bowl. It is contemplated that appropriate electro magnetic flush valve controls can be used to maintain the fluid in the bowl until such time as the operator commands the dumping of the bowl contents and a subsequent refilling of the bowl with clean recycled fluid.
The unique filter cassette has two prime functions, first to separate both the coarse and fine solid particles from the fluid and second to store the solids in a compact manner for subsequent disposal.
A further objective is to provide a system incorporating a fluid pump to transport fluid from the interior of the system to fill the toilet bowl after a flush, to transport fluid from the filter cassette beneath the filter material and place it on top of the filter material to provide recirculation, and to transport fluid from the interior of the system when it is in excess. The excess fluid is transported out through the exterior of the unit to a location determined by an effluent pipe.
Appropriate valving structure is provided to facilitate control, storage and direction of the fluid in the sequence set forth above.
Also incorporated in the system is a decoloring cell, for example a carbon canister, for the purpose of removing color from the recirculated system fluid as well as providing fine filtration. The decoloring is achieved by activated carbon adsorption. The fine filtration is achieved through the "deep bed effect" of the carbon particles.
A further objective is to provide a system incorporating an electrolytic cell for conversion of the chlorides normally found in human urine into chlorine compounds which in turn are capable of sanitizing and deodorizing the recirculated fluid.
Also contemplated as part of the system is a coloring cell located in the toilet bowl flush circuit and provided to function in the conversion of the slightly yellow tinted cloudy fluid into a masked blue solution to improve its aesthetic appearance in the bowl.
Also, an appropriate arrangement of electronic controls are provided to separately flush, filter and recirculate fluid containing only liquid waste; flush, filter and recirculate fluid containing solid waste while collecting and storing the solid waste in a unique filter cassette, store the filtered fluid for recirculation and reuse, dispose of excess fluid in the system when desired, and collect and store solid waste while filtering the fluid therefrom and collecting the fluid for recirculation and reuse, and indicate when a filter cassette is advanced and when it is in condition for replacement.
Suitable controls are also provided to facilitate replacement of the filter cassette and carbon canister without dismantling or substantially affecting the remainder of the system. The replacement can be accomplished in a quick efficient and clean manner.
The present system is capable of being utilized in marine environments, camping sites, construction locations, mobile vehicles, and other similar places where self-contained waste disposal systems are applicable.
In summary, a self-contained sewage waste disposal system is provided. The system includes a housing structure and a toilet bowl adapted to receive human waste and fluid for diluting the waste, transporting the waste and rinsing the bowl in the housing. A removable filter cassette is in the housing in communication with the toilet bowl. Means is provided for flushing the bowl and dumping the contents into the filter cassette and for subsequent refilling of the bowl. Filter means in the cassette is provided for separating the coarse and fine particles of solid material from the fluid received from the bowl. Storage means is in the cassette to store the solid material in a compact manner for subsequent disposal upon removal of the cassette. Pump means including interconnected conduits in the housing is provided to transport fluid from the interior of the system to fill the bowl after a flush, to transport filtered fluid from the filter cassette to a position for recirculation, and to transport excess fluid from the interior of the housing to the exterior thereof. Means is in the housing and positioned to sanitize and deodorize the recirculated fluid. Control means is provided to pass the fluid through the system to facilitate the collection and disposal of sewage waste within the system in a predetermined sequence.
With the above objectives among others in mind, reference is made to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In The Drawings
FIG. 1 is a perspective view of the self-contained sewerage waste disposal system of the present invention;
FIG. 2 is a sectional front view thereof;
FIG. 3 is a sectional side view thereof taken along the plane of line 3--3 of FIG. 2;
FIG. 4 is a schematic drawing of the electrical circuitry employed in the invention;
FIG. 5 is a block diagram of the sequence of operations of the system of the invention;
FIG. 6 is an end plan view of a valve assembly for controlling fluid flow in the system of the invention;
FIG. 7 is a sectional view thereof taken along the plane of line 7--7 of FIG. 6;
FIG. 8 is a sectional view thereof taken along the plane of line 8--8 of FIG. 7;
FIG. 9 is a plan view of the other end of the valve assembly employed for fluid flow in the system of the invention;
FIG. 10 is an enlarged sectional view of the filter cassette used in the system of the invention; and
FIG. 11 is a sectional view thereof taken along the plane of line 11--11 of FIG. 10.
DETAILED DESCRIPTION
System 20 as shown includes a compact housing structure 22 which provides a decorative and attractive enclosure for the system components as well as providing a weight support contoured for the user. All of the components of system 20 are incorporated within the housing and thus it is an entirely self-contained system designed for disposal of sewage waste. In this manner, it is particularly useful in the marine environment and more so since it will satisfy certain stringent EPA requirements for handling of human waste.
The basic parts of system 20 within housing 22 are shown in FIGS. 1-3 and include a control panel assembly 24 positioned within the upper portion of the housing and encaptured by a cover panel assembly 26. A conventional seat and cover arrangement 28 is positioned on the housing for the user and is aligned with a bowl assembly 30 on the housing and extending within. An electrolytic cell assembly 32 is positioned within housing 34.
The bowl extends within lower portion 34 of the housing 22 which has a hollow interior 36. Mounted within the interior of housing portion 34 is a motor assembly drive 38. A flush valve assembly 40 is in the interior 36 and is supported at the bottom opening in the bowl assembly 30.
A pump 42 is in the lower rear portion of the housing interior 36. Removably positioned within the bottom end of housing portion 34 is a filter cassette assembly 44. In the upper portion of housing 22 a decoloring cell assembly 46 is mounted and a coloring cell assembly 48 is mounted below the decoloring cell 46 and is in the lower portion of the housing 22. A four way valve 50 is positioned adjacent the coloring cell and mounted within the interior of the lower portion of the housing.
All of the components are mounted in a conventional manner and are interconnected in the desired manner for operation of the system as described in detail below by appropriate tubing.
Toilet bowl assembly 30 is a conventional type of bowl shaped device, of ceramic or other conventional material, for receiving human waste. The bowl 30 is bolted to the housing by a conventional bolt assembly, has a hollow interior 54, a large upper access opening 56 at the top and a smaller discharge opening 58 at the bottom for discharge or dumping of the waste material collected therein. A conventional flush ring 60 surrounds the upper rim portion of the bowl assembly 30. The flush ring is conventionally connected for introduction of fluid. Fluid introduced through the flush ring into the bowl is normally retained in the bowl for dilution of the waste. This fluid adds in the transport of the waste material from the bowl into the next stage of the system 20. The bowl fluid also assists in rinsing or cleaning the bowl.
Seat and cover assembly 28 is shown in the closed position in FIG. 3 and in phantom is shown in the open position hinged in a conventional manner about pivot pin 62. Naturally one or both of the seat and cover components can be shifted between the open and closed positions.
Flush valve 40 is an electromagnetic flush valve normally closing discharge opening 58 at the bottom of the bowl. In this manner, flush valve 40 is used to maintain the fluid in the bowl until such time as the operator commands the dumping of the bowl contents and a subsequent refilling of the bowl with clean recycled fluid.
Electrolytic cell assembly 32 is mounted on the interior of the housing by a conventional mounting plate 64 and extends downward allowing gas bubbles to leae its enclosure. Appropriate connectors 66 extend from the electrolytic cell for circulating fluid through the cell. The purpose of the circulation is to convert the chlorides found normally in human urine into chlorine compounds which in turn are capable of sanitizing and deodorizing the recirculated fluid within the system.
The motor and drive assembly 38 is also mounted in a conventional manner to the interior of the housing and includes a drive shaft 68 interconnectable by a suitable chain 70 to an extending shaft on the filter cassette for advancing a take up roll within the cassette. The motor and drive assembly is a conventional well known commercial product.
Pump 42 is also a conventional commercially available product and is the type of fluid pump which can accomplish three functions within the system 20. It is used to transport fluid from the interior of system 20 to fill the toilet bowl 30 after a flush. It also transports fluid from the filter cassette 44 beneath the filter material in the cassette and places it on top of the filter material to provide for recirculation. It also transports fluid from the interior of the system when it is in excess. This fluid is transported out through the exterior of the unit to a location determined by an effluent pipe.
The pump 42 is beneath a coloring cell 48 which is vertically aligned with a decoloring cell 46. Appropriate fluid connections are made for recirculation of fluid through the decoloring cell by means of connectors 71, 72, 73 and 74 and similarly, circulation of fluid through the coloring cell during bowl refill is accomplished by means of connectors 76 and 78. Decoloring cell 46 is a common type of element in waste disposal systems generally referred to as a carbon canister and is for the purpose of removing color from the recirculated system fluid as well as providing fine filtration. The decoloring is achieved by activated carbon adsorption. The fine filtration is achieved through the "deep bed effect" of the carbon particles. Common commercial alternatives are acceptable as well for color removal and for fine filtration.
The coloring cell 48 is located in the toilet bowl flush circuit and functions to convert the slightly yellow tinted cloudy fluid into a masked blue solution to improve its aesthetic appearance in the bowl.
Filter cassette assembly 44 is removable from housing structure 22 for disposal and replacement. The details of filter cassette 44 can be best seen in FIGS. 10 and 11. The cassette 44 includes a casing 80 to house the filter components. The shape of the casing is designed to conform with the available space in the bottom of the housing 22 of system 20 to facilitate formation of a compact low cost self-contained structure.
An entrance opening 82 is in the upper side of the cassette for introduction of the waste material to be filtered. A suitable female disconnect 84 is at the bottom rear of the casing of a cassette for removal of filtered fluid for further treatment and recirculation and reuse. A horizontal shaft 86 is mounted for rotation within casing 80 and extends outwardly through a side opening in the cassette to be keyed to an external drive shaft 88 attached to chain 70 from the motor assembly 38 to thereby drive and rotate the shaft 86 when the filter cassette is placed in the system, interconnected therein and flushed.
A pressure plate 90 is in the casing and affixed at one end thereto and aligned with entrance opening 82 in the upper side of the casing. The pressure plate 90 provides support for the filter material passing thereover and extending above the plate and the solid waste material collected thereon.
A splash guard 92 extends interiorally of the casing in cantilever fashion into overlying and resilient engagement with take up roll 94 to prevent undesirable bypassing of waste as it is being stored on the roll. Take up roll 94 is mounted in fixed position on rotatable shaft 86 to rotate therewith when it is driven by the motor and drive assembly and thereby advance filter material within the cassette and collect solid waste thereabout. In addition to the take up roll within casing 80 a pair of supply rolls 96 and 98 are mounted in the casing and are spaced from take up roll 94. The rolls are positioned so that filter material from both of the supply rolls 96 and 98 will pass across the casing beneath entrance opening 82 and then will travel onto the take up roll 94 for collection.
Supply roll 98 contains a coarse filter material or screening material 100 which will first contact the waste discharged into the cassette and separate the majority of the solid particles contained therein. The other supply roll 96 includes a fine particle filter media 102 for secondary filtering of the waste material which is predominantly fluid that has passed through the screening filter material 100. Thus, fine filter media 102 provides a secondary filtering action. Both supply rolls 96 and 98 are rotatably mounted within the casing about suitable horizontal axes and are positioned adjacent to one another and substantially spaced from the take up roll 94.
The coarse filter material 100 extends from the upper side of supply roll 98 and is supported intermediate its travel path by pressure plate 90. It then extends unsupported into direct engagement with the exposed surface of take up roll 94.
The coarse filter material 100 extends from the upper side of supply roll 98 and is supported intermediate its travel path by pressure plate 90. It then extends unsupported into direct engagement with the exposed surface of take up roll 94.
Material 102 from supply filter roll 96 takes a somewhat different path. It extends about roller guide 104 mounted beneath the supply roll 96 in the casing and then extends beneath screen material 100 over the portion of the cassette where waste material will travel through onto the filter. The filter guide 106 then directs the filter media 102 onto the take up roll 94 with the coarser or screen filter material 100 being captured between the outer surface of roll 94 and the inner surface of filter media 102.
A filter table 108 is fixed in position in the casing beneath the filter material and provides a further support for the filter material.
After the take up roll enlarges through the storage of waste it then comes in contact with filter table 108 which supports filter media 102 and keeps it from sagging due to the weight of recirculated fluid.
Filter table 108 includes a resilient cantilever end portion 109 to apply compression to the filter material being collected on the take up roll and support the exterior of the roll as it enlarges.
A suitable conventional collar 110 is provided where the take up roll extends through opposing side apertures in the casing for keying and interconnection with the motor and drive assembly. Collar 110 is a conventional sealing means to prevent leakage at those apertures in the casing and to facilitate journaling and rotation of the shaft of the take up roll. To facilitate the seal a conventional O ring 112 can be mounted within the collar 110 and in engagement with the outwardly extending shaft of the take up roll.
A further splash guard 114 is positioned adjacent the entrance opening 82 to the cassette to facilitate the prevention of waste material being dumped or splashed behind the filter supply rolls and instead being directed to the filtering portion of the screen material 100 and thereafter the secondary fine filtering media 102.
The filter table 108 is spaced from the bottom of the casing and mounted on suitable ribs 116. Table 108 includes a plurality of spaced parallel bars with the openings therebetween permitting the passage of fluid. The space beneath the filter table 108 forms a storage chamber for filtering fluid for further treatment and recirculation and reuse when it is pumped from the cassette. It also serves as a weir and allows sediment to settle out of the fluid during periods of non-use. The ribs serve to entrap the fluid to alleviate the danger of fluid contacting the roll and leaching solids and color.
Cassette 44 can be mounted in housing 22 in a quick and efficient manner and can be similarly removed for replacement after collection of waste material therein without contamination and basically with a white glove procedure. Cassette 44 is introduced through an access opening 116 in the front of the bottom portion 34 of housing structure 22. It is introduced completely within the housing until male disconnect 118 from pump 42 passes through female disconnect 84 in the bottom of the casing of the cassette into communication with the storage chamber for filtered fluid in the bottom of the casing. At the same time, chain 70 and interconnected conventional connecting structure is attached to a portion of the take up roll 94 extending outwardly of the casing of the cassette to provide for drive and rotation of the take up roll. In this position, entrance opening 82 in the upper side of the casing is in alignment with a corresponding opening 120 in a surrounding plenum on the interior of housing structure 22 which generally conforms with the outer upper configuration of the cassette. The two aligned apertures 120 and 82 are also in alignment with the discharge opening 58 from the bowl 30. In this condition, the cassette 44 is in position and ready for use as part of system 20.
It should also be noted that cassette 44 is affixed or locked in position by means of a reciprocally shiftable locking pin 160 passing through aligned apertures in the housing structure 22 and the casing of cassette 44. Withdrawal of the pin 160 as shown in phantom in FIG. 2 will remove the end of the pin from the cassette casing and permit removal of the cassette for disposal and replacement. Spring 162 surrounding the pin normally biases the pin into locking position in the casing of the cassette.
Four way valve 50 is shown in detail in FIGS. 6-9. The valve housing 124 includes connector ports 126, 127, 128 and 129 extending through a front cover 130. A spacer 132 spaces the cover 130 from the back cover 134. A vane 136 is within the spacer 132 and adjacent to the inner wall of back cover 134. A second spacer 138 is positioned between the outer surface of the back cover 134 and a mounting plate 140. A cam shaft 142 extends through a central opening in back plate 134 and is rotatably mounted in position. The vane is mounted on the cam shaft 142 to rotate therewith and sequentially close and open the ports. A suitable O ring seal 144 is located in the central aperture through the back cover plate to seal against the outer surface of the cam passing therethrough. A group of three micro switches 146 are annularly spaced about the inner surface of mounting plate 140 in position to be sequentially actuated by a cam 148 on cam shaft 142 as it is rotated. These are conventional commercially available micro switches.
Since the valve assembly is a four way valve assembly, there are four ports in front cover 130 with three of the ports being annularly arranged around the central port 128 as shown in FIG. 6.
Screw and nut arrangements 150 serves to interconnect the bottom of the front and rear cover plates and spacer 132 positioned therebetween by passing through aligned apertures in those three elements. Similarly, screw, nut and washer assemblies 152 passing through aligned apertures interconnects the upper ends of front cover plate 130, rear cover plate 134 and spacer 132 and also connects therewith spacer 138 and mounting plate 140. In fact, as shown in end view in FIGS. 6 and 9, there are three annularly spaced screw assemblies 150 and similarly three annularly interspaced screw assemblies 152 about the periphery of the valve assembly 50. In this manner, all of the components are retained in fixed position.
Mounted on the exposed face of mounting plate 140 is a conventional gear motor 154 of a commercially available type. The rotatable drive shaft 156 of the motor extends through a central aperture in the mounting plate and into a recess in cam shaft 142. In this manner, the cam shaft and motor are mounted together with the assistance of a set screw 158 projecting through a side orifice in the cam shaft and into engagement with the drive pin of the motor. Thus, rotation of the motor shaft 156 will rotate the cam shaft and accordingly the cam 148 will actuate the three micro switches 146 in sequence. Four way valve assembly in this form is then mounted in fixed position in a conventional manner within system housing structure 22 and is interconnected for facilitating operation of fluid flow within the system in the manner described below. The operation of valve 50 is such that a voltage is supplied to motor 154 through a selected normally closed micro switch 146 upon the command of the electronic control circuit in the system through a relay. Each micro switch 146 corresponds to a desired position for the valve 50, which when moved to this position will cause cam shaft 142 attached to the output shaft 156 of the motor to break the electrical supply to the motor in accordance with the circuitry arrangement for the plurality of micro switches 146. In this manner, the flow through the valve 50 is channeled through the required passages to perform the necessary functions in the system 20. The vane 136 serves to block the chosen outlet port 126, 127 or 129 depending on rotation of the cam 142 to which it is attached. The central inlet port 128 is thus sequentially brought into communication with one or more of the outlet ports to provide the desired flow path in the system at any given point in time. Each outlet port is designed for a particular function in the system, a flushing operation, a recirculation of fluid operation, removal of excess fluid or effluent. It is contemplated that a valve assembly of this type can be made entirely of inexpensive material such as plastic with the exception of the shaft and motor combination which is normally formed of non-corrosive steel.
Filter cassette 44 receives fluid from the toilet bowl passing through flush valve 40 into the filter cassette 44. The primary function of the cassette 44 is to separate both the coarse and fine solid particles from the fluid. A second function of the cassette is to store the solids in a compact manner for subsequent disposal.
The conduits for fluid flow through the system 20 can be best seen in FIGS. 2 and 3 with arrows showing the direction of flow. Pump 42 pumps fluid through conduit 43 into the four way valve 50. One outlet of the valve 50 is for directing fluid through conduit 45 through connector 78 into the bottom of the coloring cell 48. Fluid exiting from the coloring cell 48 travels through conduit 49 extending from connector 76 at the upper end of the coloring cell. Conduit 49 extends into communication with the flush ring assembly through which the fluid is introduced to the interior 54 of the toilet bowl. A second outlet from four way valve 50 is interconnected with conduit 51 for directing effluent fluid from the system when that appropriate valve outlet or connector port is opened.
The remaining outlet port of four way valve 50 is interconnected with conduit 53 which communicates and is attached to the two entrance connectors 71 and 73 of decoloring cell 46. In this manner the fluid can be passed into the decoloring cell and exits, after being suitably treated therein, through exit connectors 72 and 74 into conduit 75. Conduit 75 extends onto inlet connector 66 of electrolytic cell assembly 32. In this manner the fluid can be introduced into the electrolytic cell for further treatment. The fluid passes from exit connector 66 of the electrolytic cell through conduit 77 through the flush valve assembly and into the base of the bowl for of fluid therethrough into the bowl. In this manner, the fluid flow functions of the system can be accomplished through the various interconnected conduits. For example, excess or effluent fluid can be discarded, fluid can be introduced for flushing of the bowl, and fluid can be directed for recirculation through the system.
For operation of the system 20, reference is made to the schematic electrical circuitry of FIG. 4 and the flow diagram as shown in FIG. 5. The flush switch 164 is depressed to the L position. This starts the main cycle time portion of the dual solid state timer 166. This timer in turn energizes the electrolytic cell relay 168. In this manner the electrolytic cell 32 is energized. While the flush switch 164 is depressed, the flush valve coil 198 is de-energized and the bowl content is allowed to drop into the interior of the system to provide a rinshing action. As soon as the switch is allowed to spring return to its neutral position, the flush valve coil is then reenergized. At the same time as the electrolytic cell is energized the fluid pump 42 is also energized. When the flush switch is released, the pump provides the refilling of the toilet bowl with clean recycled fluid. The fluid rises in the bowl until the liquid level sensor which is called "bowl level control" 170 is electrically "made". When the switch is "made", the bowl level control relay 172 then becomes energized. This relay then causes the four way valve 50 to switch from the bowl "fill" position to the "fluid recirculation" position. This recirculation will continue until the main cycle timer 166 completes its timing cycle.
When the main cycle time period for processing the fluid is not occurring, that is the system 20 is at rest, the system can execute the detection and disposal of excess fluid from the system. This fluid is referred to as effluent. The existance of excess fluid is determined by the effluent level control switch 186. When it is "made" by the conductivity of the effluent and when the toilet system is in an approximate horizontal position as determined by the effluent level control horizontal switch 190, the effluent level control relay 188 becomes energized. This causes the fluid pump 42 to operate and also causes the four way valve 50 to direct the effluent to the effluent discharge. When the fluid level falls below the intermediate electrode of the effluent level control switch 186 the circuit is broken, and the effluent system ceases functioning.
If the flush switch 164 is depressed into the "S" position to achieve "solid flush", both the main cycle timer and the filter advanced timer portions of the dual solid state timer 166 are energized. The main cycle timer portion of the timer 166 functions in the same manner as previously described. The filter advance portion of the timer 166 causes the filter advance control relay 200 to be energized. This in turn energizes the filter advance drive motor 38. This drive motor advances the filter material in the filter cassette 44 by approximately 6 inches. Any solid waste collected on the filter material is rolled up around the take up roll 94. Relay 200 also de-energizes the flush valve coil 198 so that the unit operates in a bowl "rinse" mode while the filter material is being advanced.
While this is occurring the filter change signal light 184 is incapable of being energized. In order to verify and detect proper advancement of the filter material, a system is devised whereby a tiny amount of magnetic material 202 is implanted in the end of the filter supply roll 98 or, alternatively supply roll 96, located within filter cassette 44. Filter advance sensor switch 174 and filter advance travel sensor switch 180 are located outside of cassette 44 within system 20. As the filter supply roll 98 rotates to supply filter media at the drive take up roll 94, the magnet 202 will "make" switch 180. This in turn will energize filter advance travel relay 182. This relay establishes a hold circuit around switch 180 as well as opens one of the possible voltage paths to the filtered change signal light 184. The magnet continues to rotate until it reaches a position where it actuates the switch 174. This energizes the filter advance relay 178. When this relay is energized, it opens one of the possible paths to filter change signal light 184. It also de-energizes the filter advance control relay 200 which in turn stops the filter advance drive 38. The circuit is designed so that subsequent liquid flushes will not cause filter advance roll operation and also maintains relay 178 and relay 182 in their energized positions. If the filter media detaches from the filter supply roll, the magnet 202 will cease rotation and switch 174 and switch 180 will not close during a solid flush. This will cause relay 200 to become de-energized without energizing relay 178 or relay 182. When this sequence of events occurs, the filter change signal light 184 becomes illuminated and the filter advance drive ceases to be actuated. This light tells the operator to install a new filter cassette. If the filter roll, instead of being depleted of filter material, becomes full; the full filtered switch 192 will illuminate the filter change signal light 184 and stop the filter advance drive.
In order to have a filter cassette change the operator switches the filtered change switch 196. This action causes the flush valve coil 198 to be maintained regardless of other controls. The operator then calls for a liquid flush by depressing the flush switch 164 to the "L" position. This causes the pump 42 to provide the bowl with clean recycled fluid. The bowl level control relay 172 is disabled by the actuation of switch 196. Therefore, pump 42 continues to remove fluid from the interior of the system and place it in the bowl until no pumpable fluid remains in the system. This will be ascertained by observing that no more liquid is entering the bowl from the flush ring of the bowl. At this point cassette 44 can be removed and a new cassette installed by simply removing pin 160 from engagement with the cassette casing and biasing spring 162 to permit withdrawal of the cassette through opening 116 in the housing structure 22. The new cassette is introduced through the same access opening and the pin released so that spring 162 biases the pin into engagement with the casing of the new cassette. The other appropriate connections to the system as described above are accomplished and, thereafter, switch 196 can be switched back to the normal operating mode and the operator can give the unit a solid flush command to put it into a "ready" condition.
Replacement of the decoloring canister 46 can be accomplished at the same time as the filter cassette replacement. The decoloring contents can be either activated carbon, and other similar decoloring materials. The sequence of events related to the electrical control system are as described above. Once all the pumpable fluid is in the bowl, the pump will continue to pump until the processing period has transpired. This is controlled by the main cycle timer 166. When the pump is off, the carbon canister and filter cassette may be removed and replaced. After the new cassette and canister are in place approximately one quart of water should be added to the bowl to make up for the fluid lost in the transfer. The unit is now ready for a solid flush command to put the unit into a "ready" condition.
There are certain advantages in utilizing a triangular configuration or any other polyagonal configuration for the take up roll 94. Round spools can cause difficulty in consuming semi-solid material, such as human waste, into a storage take up roll without slippage. The triangular configuration provides straight sides leading at a point which accomplishes biting of the material and thus facilitating the breakdown, collecting and storing of the material on the roll. This is particularly advantageous when the spool size is relatively small as with a compact system of the present type. A further modification that will also work adequately would be to provide the sides of the triangularly shaped take up roll with concave surfaces. This acts in a similar manner and breakdown collection and storage of the solid waste material.
After several revolutions, the take up roll beings to round out. It eventually becomes eliptical in shape and, as the sides get larger, the included angle is such that the triangular configuration is not necessarily required and the eliptical roll will consume the semi-solid material. The variation with concave sides permits even more semi-solid material to be stored in the take up roll and minimizes the final take up roll size.
As discussed above, there are numerous advantageous features obtained with the use of a filter cassette of the present design. Improved filtering ability, white-glove service, compactness, minimum cost and minimum energy are clear advantages. Another feature of the unit is the realization that most filter devices of a disposable nature usually are fully loaded when they have collected solids in a quantity which never exceeds one to five percent of the total volume of the device. But when the filter has this much solid material in it, it becomes plugged up or blocked. The two stage filter concept utilized here is such that very large quantities of material are separated from the fluid and then conveyorized into storage. This is achieved by wrapping the coarse or screen filter material and the fine filter media around a take up mandrel or roll. The coarse media or screen material provides the traction necessary to move this solid material into the mandrel. As the solid material is entering the mandrel area, there is a tendency for it to compress or extrude through the coarse screen media. The fine filtered media is immediately behind the coarse filter media and stops or prevents the possibility of extrusion. By the time the filter cassette is totally used up, approximately forty to fifty percent of its volume has solidly filled with waste plus the filter media. A conventional type of filter device would have to be ten to twenty times larger to do the same job.
It should also be noted that the filter cassette of the present design is constructed to facilitate removal and disposal of solid waste collection stored in the device. It is provided with quick-couplings both to the fluid inlet and its fluid outlet. When it is removed for disposal, the fluid outlet automatically seals itself. The fluid inlet is "capped off". The exterior of the cassette is totally clean and bacteria free.
Thus the several aforenoted objects and advantages are most effectively attained. Although several somewhat preferred embodiments have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.
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A self-contained sewage waste disposal system is provided including a housing structure and a toilet bowl adapted to receive human waste and fluid for diluting the waste, transporting the waste and rinsing the bowl is provided in the housing structure. A removable filter cassette is placed in the housing structure in communication with the toilet bowl. The bowl is adapted to be flushed to dump the contents into the filter cassette and to be subsequently refilled. The coarse and fine particles of solid waste material are separated from the fluid received from the bowl by filter material in the cassette. The solid material is stored in the cassette in a compact manner for subsequent disposal upon removal of the cassette from the housing. A pump and interconnected conduits in the housing transport fluid from the interior of the system to fill the bowl after a flush, to transport filtered fluid from the filter cassette to a position for recirculation, and to transport excess fluid from the interior of the housing to the exterior thereof. The recirculated fluid is sanitized and deodorized in the housing. Controls are provided to pass the fluid through the system to facilitate the collection and disposal of sewage waste within the system in a predetermined sequence.
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This is a continuation of application Ser. No. 423,123, filed Dec. 10, 1973, and subsequently abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to product filling machinery and particularly to machines and methods for filling an intermediate receptacle with a predetermined amount of product for transfer to an ultimate container.
2. Description of the Prior Art
My U.S. Pat. Nos. 3,517,708, issued June 30, 1970; No. 3,621,891, issued Nov. 23, 1971; and No. 3,696,581, issued Oct. 10, 1972 describe rotary-drum machines for filling intermediate receptacles with predetermined amounts of materials for transfer to ultimate containers, and their disclosures are incorporated herein by reference.
In these prior machines, elongated rake members spaced circumferentially around a horizontal or inclined drum mounted for rotation about its axis each have a plurality of inward-projecting tines for picking up portions of materials such as food products in the bottom of the drum as the drum rotates and for carrying the portions to a predetermined release point near the top of the drum for discharge onto a chute or shaker tray for delivery into a line of intermediate receptacles extending through the drum. The receptacles are fastened to an endless conveyor that includes means for shaking the receptacles as they are filled to eliminate voids and to obtain a uniform packing density in each receptacle corresponding to a predetermined package amount. After being filled, the intermediate receptacles are transported by the conveyor to a separate station outside the drum where their contents are transferred to a line of ultimate containers on a second conveyor that is synchronized with the movement of the receptacle conveyor.
One method shown in these prior patents (U.S. Pat. No. 3,517,708) for transferring products from the intermediate receptacles to the ultimate containers includes pivoting each receptacle on an arm for 180° rotation outward around the line of the conveyor to an upended position over the container to which the product is to be transferred. A close-fitting cylindrical shell located on the arc of receptacle rotation prevents the loss of any material until each receptacle is fully upended and has advanced to a position directly over the corresponding container.
An alternate method shown in U.S. Pat. No. 3,621,891 and 3,696,581 for transferring products involves the use of automatically controlled doors mounted directly under an open-bottom receptacle, the doors being rotatable in synchronism from a horizontal position where they close the bottom of the receptacle to a vertical position over the container line where they funnel the product into the underlying container.
The above-described product transfer methods of my prior inventions require relatively complex mechanical arrangements for synchronizing the receptacle rotating or door opening mechanisms, as well as a large number of parts that add to the cost and difficulty of cleaning these prior machines. In addition, the intermediate receptacles used in these machines comprise a single open volume, exactly sized to accommodate a predetermined weight of uniformly packed products. For packing stringy or tangly products, they may include various cutters and soft rollers for trimming excess materials hanging over the edges of the containers and for compressing materials to a uniform packing density at a height even with the top edges of the receptacles.
In many filling applications, instead of filling to a predetermined weight or packed volume of materials it is desired to fill a predetermined number of items into a container, the items having a relatively uniform size. Examples in the packaging of food include such items as meatballs, crab cakes, croquettes, egg rolls, doughnuts, graded size fruits, and the like. In such applications it is quite difficult to fill accurately and repeatably a single open receptacle with the exact number of items desired in each ultimate container because an individual item may take only a small percentage of the total receptacle volume and the shape of the receptacle volume does not conform to the shape of the items so that extra items may squeeze into corners of the receptacle. Also, in many packaging applications it is desirable to place items in desired relative positions in a container as, for example, apples, peaches or oranges in columns and rows on a flat tray or in a partitioned box. Such predetermined placement cannot be obtained reliably by merely filling a single-volume transfer receptacle with the desired number of items to be packaged in each container.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and apparatus for filling containers with a predetermined number of items.
Another object of the invention is to measure a predetermined number of items into an intermediate receptacle from a source of such items at a first filling location and subsequently to transfer the items to a container at a second station that is displaced from the first station.
Another object of the invention is to provide subdivided intermediate receptacles for a transfer filling machine, the subdivisions forming compartments shaped to fit the items and each compartment sized to accommodate only a predetermined small number of the items.
It is another object of the invention to provide easily replaceable intermediate receptacles for a transfer filling machine to permit filling different numbers, sizes and shapes of items by means of different intermediate receptacles.
Another object of the invention is to provide a locking pin attachment for replaceable receptacles of a transfer filling machine to permit easy replacement of receptacles without the need for tools.
It is another object of the invention to provide an arrangement of intermediate receptacles and an associated conveyor for a transfer-type filling machine of simplified construction for low cost and ease of maintenance and cleaning.
These and other objects are achieved in a machine that includes an endless conveyor for transporting intermediate receptacles from a first location for filling the receptacles from a source of items with a predetermined number of the items to a second location for transferring the predetermined number of items from each receptacle to a corresponding container.
Each receptacle is subdivided into bottomless pockets that are shaped and sized to fit the items being transferred, the depth of each pocket being sufficient to accommodate exactly a predetermined small number of the items and the number of pockets in each receptacle being chosen so that each receptacle will hold the total predetermined number of items to be packaged in the corresponding container.
The receptacle conveyor is preferably a link type conveyor, the links being trained about wheels that rotate about vertical axes and the link line travelling in a substantially horizontal plane.
A base plate is positioned under the receptacles and extends from the filling location to just short of the transfer location. The receptacles have flat bottoms that rest on and slide over the base plate in the path between the filling location and the transfer location, the base plate thereby serving to close the bottoms of the receptacle pockets between the filling and transfer locations.
The source of items for filling the receptacles at the filling location preferably includes an open-ended drum mounted for rotation about either a horizontal or an inclined axis. The items are delivered to the bottom of the drum, preferably by means of a chute through one of its open ends, and shelf members circumferentially spaced around the inside of the drum carry items from the bottom of the drum to a discharge point near the top of the drum as it rotates. At the discharge point, the items are released, preferably to a chute or shaker tray from which they are delivered to the receptacles.
Preferably, means are provided for shaking the receptacles at the filling location to assist in placing the predetermined number of items in proper orientation in each pocket and to shake off any excess items from the tops of the receptacles, the excess items then falling to the bottom of the drum of recycling.
The receptacles preferably comprise a base member and an extension member, the base member having a number of pockets of sufficient depth to accommodate the total predetermined number of items for the smallest size container to be filled. The extension member includes thin-shell cylindrical inserts for a tight sliding fit within each pocket of the base member, the height of the inserts above the base plate being adjustable to accommodate additional items for filling a complete range of container sizes. For ease of cleaning in food packaging applications the extension members may be fabricated from stainless steel and the base member from nylon, which also provides a low friction, non wearing surface in contact with the base plate.
To permit rapid changeover from one size or arrangement of receptacles to another, the invention features a quick-disconnect receptacle attachment system preferably in the form of two spaced upright pins, one at each of a conveyor link for mating engagement with two holes near one edge of each receptacle base member. Receptacles are easily replaced by simply lifting one receptacle off the pins and substituting another. Preferably one of the pins includes a plunger-actuated detent for locking the receptacle in place against the vibrational environment of the machine.
In operation, each intermediate receptacle attached to the transfer conveyor slides over the base plate and passes in turn under a product delivering means, such as the aforementioned rotary drum and chute or shaker tray. Items cascade from the chute over the top of the receptacle and fall into the individual pockets of the receptacle, which is simultaneously shaken to aid the filling process and help orient the items in the pockets. The shaking continues for a short distance after the receptacle leaves the filling location to dislodge any extra items remaining on the top of the receptacle.
The conveyor then transports the receptacle, still sliding along the base plate so that no items are lost from its open bottom, to a transfer location outside the drum. The transfer location is situated immediately above open containers on a second conveyor that is synchronized with the movement of the transfer conveyor. The base plate terminates at this transfer location, and as the receptacle passes over the end of the plate, the open-bottom pockets are progressively exposed, allowing the items to drop into the container below.
Additional features and advantages of the invention will become apparent from the following description of the preferred embodiment as disclosed in the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the preferred arrangement of transfer conveyor and intermediate receptacles looking toward the exit end of a drum-type machine for filling the receptacles.
FIG. 2 is an exploded view of an intermediate receptacle, including base member and extension member, and a corresponding conveyor link showing the upright mounting pins.
FIG. 3 is a section view of a locking detent arrangement for one of the mounting pins shown in FIG. 2, with the receptacle locked in place.
FIG. 4 is a section view of the locking detent arrangement of FIG. 3 with the detent unlocked to allow removal of the receptacle.
FIG. 5A is a perspective view of the filling location showing in schematic form the combination of an intermediate receptacle base member and extension member arranged to receive exactly a predetermined number of items in each pocket.
FIG. 5B is a perspective view of the filling location showing in schematic form a receptacle base member arranged to receive exactly one item in each pocket.
FIG. 5C is a side view of an alternate arrangement of the receptacle of FIG. 5B.
FIG. 5D is a perspective view of the filling location showing in schematic form a multi-pocket receptacle for receiving exactly one item in each pocket in a predetermined spatial relation.
FIG. 5E is a perspective view at the transfer location of the multi-pocket receptacle of FIG. 5D, showing synchronized transfer of the items to a multi-pocket container.
FIG. 6 is a side view of the transfer location showing the spatial relation between the transfer conveyor and the second conveyor carrying containers to be filled.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, FIG. 1 shows a perspective view of filled intermediate receptacles 10 of the invention leaving the exit end of a drum-type filling machine 11 of the type fully described in my prior patents incorporated by reference in the present application.
Each intermediate receptacle includes a base member 12, preferably molded of white nylon, and an optional extenson member 13, preferably fabricated of stainless steel sheet material. Base member 12 is formed with a plurality of vertical-walled pockets 14 extending through the member from top to bottom, each pocket being sized and shaped to accommodate the particular items being transferred. In the illustrative example, the pocket cross sections are circular, a shape suitable for substantially spherical items such as apples, oranges, or meatballs and also for flatter items, either round like doughnuts or square like ravioli, for example. When elongated items like croquettes or egg rolls are being handled, however, it is preferably to have oblong or slot-like pockets of the proper dimensions so that there is not a large amount of extra space for capturing more items in a pocket than are desired.
Receptacle base members 12 are detachably mounted to links 15 of an endless conveyor passing around a large diameter sprocket wheel 16, that rotates about a vertical axis adjacent to the exit end of the filler drum, and around a similar wheel (not shown) adjacent to the entrance end of the drum. The links in the foreground of FIG. 1 have been removed to show the construction of sprocket wheel 16.
Adjacent links 15 are joined by intermediate links 17 pivotally mounted at each end on corresponding upper and lower pins 18, 19 on the adjacent ends of corresponding links 15.
As shown more clearly in FIG. 2, receptacle base members 12 have a flange-like extension 20 in which are formed a pair of mounting holes 21. Mounting holes 21 are sized and spaced to slidingly fit over upright mounting pins 22 and 23 that are affixed to protruding lugs 24 of each conveyor link 15, the receptacles thereby being cantilevered from mounting pins 22, 23, with lugs 24 providing a locating stop in conjunction with the undersurface of extension 20 on the receptacle base member.
FIG. 2 also shows the construction of receptacle extension member 13, which comprises a plurality of sheet metal cylinders 25 equal in number to pockets 14 in the base member and joined to a sheet metal top 26 in properly spaced relation to coincide with the spacing of pockets 14. In the embodiment shown in FIG. 2, cylinders 25 have a circular cross section, with their outside diameters chosen to provide a tight sliding fit within the pockets of the base member so that the extension member can be telescoped up or down with respect to the base member for accommodating a range of integral numbers of items in each pocket depending on the total number of items desired to be transferred by each intermediate receptacle.
Alternatively, different extension members with cylindrical portions of graduated length corresponding to integral increments in items per pocket can be substituted in a base member of height corresponding to one item per pocket to provide any desired total number of items in multiples of the number of pockets per base member. Furthermore, total numbers intermediate these multiples can be easily obtained by covering one or more of the pockets with a removable lid (not shown).
With reference to the receptacle mounting arrangement, pin 22 is a plain cylindrical rod, but pin 23 is equipped with means for locking base member 12 to conveyor link 15. As shown in FIGS. 3 and 4, mounting pin 23 has a hollow cylindrical interior portion 27 in which is located a loose-fitting grooved piston member 28 that is biased to an upper position against the upper end of cylinder 27 by a coil spring 29 in the bottom of the cylinder. In this upper position, the full diameter of piston 28 is opposite a hole 30 through the side wall of pin 23.
A stainless steel ball 31 fits loosely in hole 30, the outer edge of which is peened over to prevent the ball from falling out while allowing it to protrude sufficiently to produce a detent locking action in conjunction with a mating indentation 32 in the side wall of the corresponding mounting hole 21.
To unlock the detent, downward force must be applied to the top of a plunger 33, that extends upward from the top of piston 28 through a reduced diameter hole in the top of pin 23, until a groove 34 in piston 28 is aligned with hole 30, thereby allowing ball 31 to retract flush with the surface of pin 23, as shown in FIG. 4. Thus the locking device of the preferred embodiment permits easy and quick mounting and removal of intermediate receptacles on the transfer conveyor without the need for any tools.
As mentioned earlier, when the receptacle base members are slipped onto mounting pins 22, 23, the upper surfaces of lugs 24 act as stops to further downward movement of the receptacle by contacting the lower surfaces of flange-like extensions 20. The height of lugs 24 above a stationary base plate or dead plate 35 that extends under the receptacles in a path from a filling location inside drum 11 to a transfer location outside the drum is adjusted to be equal to the vertical distance between the bottom of each receptacle base member 12 and the undersurface of its flange-like extension 20; so that the receptacles, when locked in place on the mounting pins, will contact dead plate 35 while travelling between the filling location and the transfer location.
FIGS. 5A through 5E depict in schematic fashion various intermediate receptacle arrangements for receiving and transferring predetermined exact numbers of items. In FIG. 5A a two-pocket intermediate receptacle has a base member 12a (shown as two separate cylinders for simplicity) that has a capacity for two items in each pocket. An extension member having two cylindrical shells 25a and a top plate 26a fits snugly into the pockets of the base member and has been raised to provide an extended capacity of exactly four items in each pocket, as shown.
The items are discharged from the shelves of a rotary drum (not shown) onto an inclined chute 36 which delivers them to the intermediate receptacles. The slope of the chute is adjusted so that the items have just enough momentum to cross top plate 26a of the extension member, in the event they do not fall into one of the pockets, and drop into the bottom of the drum for recycling. The rate of delivery of the items from the rotary drum must be at least enough to assure complete filling of each pocket of every receptacle, but at the same time, excessive delivery rates should be avoided to minimize injury to the items from too much recycling.
In FIG. 5B, flat patty-shaped items are delivered from the inclined chute 36 to intermediate receptacle base members 12b having a pocket depth no greater than the thickness of one of the items. Because the flat patties must slide instead of rolling like the more spherical items shown in FIG. 5A, the slope of the chute should be greater to counteract the greater frictional resistance. In addition, it may be desirable to include means for laterally shaking the intermediate receptacles as they pass the filling location to assist the items into the pockets and to shake off excess items from the top of the receptacle. Such shaking means are shown in FIGS. 1 and 3 and described at column 5, lines 34-45 of my U.S. Pat. No. 3,621,891, referred to above.
Alternatively or in addition to the shaking means, the dead plate 35 can be warped to an angle at the filling location, as shown in FIG. 5C, and the links of the conveyor (not shown) twisted accordingly so that the top of the receptacle serves as an extension of the slope at the end of chute 36, thereby allowing excess items to slide across the receptacle and fall back into the bottom of the drum.
FIGS. 5D and 5E illustrate the use of the intermediate receptacle of the present invention for transferring an exact number of items in a predetermined spatial relation for filling a compartmented container. In FIG. 5D, an open bottom intermediate receptacle 12d is partitioned into a number of pockets arranged in rows and columns, each pocket being just deep enough to hold one of the items shown. The intermediate receptacle is filled with the predetermined exact number of items, in this case one dozen, at the filling location shown in FIG. 5D and is then conveyed, in sliding contact with dead plate 35, to the transfer location, as shown in FIG. 5E.
Dead plate 35 terminates at the transfer location, thereby allowing each column of items to drop in turn through the open bottoms of the receptacle pockets into corresponding compartments of a container 37 that is moved in synchronism with the movement of the intermediate receptacle 12d by means of a second conveyor (not shown).
The transfer location is shown in more detail in FIG. 6. Filled intermediate receptacles, which have been conveyed over dead plate 35 past the filling location inside drum 11 then out the exit end of the drum and around sprocket wheel 16 (FIG. 1), travel back (to the left) along the outside of the drum. The transfer location occurs at the end 38 of base plate 35. Just underneath this terminal point pass a second line of containers 37' on a conveyor belt 39, which is synchronized in its movement with the movement of the intermediate receptacle conveyor so that containers 39 arrive at the transfer location simultaneously and in synchronism with the arrival of intermediate receptacles 12.
As the intermediate receptacles pass over end 38 of dead plate 35, the open bottoms of the pockets are uncovered, allowing the items to drop into the container below, which then moves off conveyor 39 to a slide 40 and a third conveyor 41 to a closing and sealing station (not shown).
From the foregoing description it can be seen that the improved transfer apparatus of the present invention permits accurate count filling of a variety of shapes and sizes of containers by means of easily and rapidly exchanged intermediate receptacles; so that one rotary-drum filling machine can be adapted to count fill an almost endless variety of containers with a wide variety of size graded products.
In addition, the pin-detent receptacle mounting means described as a feature of the present invention permits use of the transfer filling machine for weight or volume filling of intermediate receptacles in a manner shown in my prior U.S. patents made of reference herein. At the same time, the simple dead plate arrangement described herein reduces the cost of construction and maintenance of the filling machine and greatly simplifies the task of cleaning, which is such an important concern with food handling machinery.
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A transfer type of product filling machine includes means for delivering items of substantially uniform size to an intermediate receptacle for subsequent transfer to an ultimate container. The intermediate receptacle is subdivided into separate product receiving volumes, each receiving volume being sized to hold a predetermined small number of the items. The total capacity of the receptacle is exactly equal to the number of items to be delivered to the ultimate container.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/148,903 filed on Jan. 30, 2009 which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to snow barriers or guards that are coupled to a roof to inhibit the sliding of accumulated snow from the roof up to a pre-determined load, thereby preventing damage to the roof due to excessive accumulation of snow.
BACKGROUND
[0003] It is well known in the art to apply brackets, stops, or fences to a roof in order to prevent snow that has accumulated upon the roof from sliding from the roof. These devices help to keep snow from damaging eavestroughs, landscaping on the ground below, etc., or falling dangerously onto pedestrians or vehicles. Nonetheless, the devices serve to maintain snow loads on the roof itself, thereby contributing to the roof caving in or causing undue stress to the roof when the snow load is excessive.
[0004] There have been some attempts to address the problem of excessive snow load accumulation in the prior art.
[0005] U.S. Pat. No. 5,522,185 to Cline discloses a snow stop for attachment to a metal roof seam, comprising a flat, rigid blade formed with curved upper and lower edges. There are openings extending through the blade that permit the passage of air and fluids, and in particular, water. The device described in Cline is restricted to seams of metal roofs. In addition, the openings of the flat blade are not designed to allow for the flow of solids such as snow or ice. Consequently, the snow stop cannot effectively reduce the snow load on a roof in order to prevent a roof from caving in.
[0006] U.S. Pat. No. 6,357,184 to Alley discloses a device capable of being attached to a roof as part of a snow guard system to better restrain snow or ice from falling off the roof. The device includes flags attached to pipes that run longitudinally along the edge of the roof. The flags are designed not to rotate, and extend below the bottom-most pipe in order to restrain snow from sliding off a roof. Alley further discloses prior art devices comprising flags attached to pipes, wherein the bottom of the flags is spaced from the roof. In addition, these prior art flags are secured to the pipes using screws, thereby providing essentially a grid-like snow stop at the edge of the roof. According to Alley, such a prior art device allows a portion of the snow load to fall from the roof, thereby preventing snow from accumulating to dangerous levels. However, there are a number of drawbacks generally associated with these snow guards. In particular, the securing means to attach flags to the pipes do not entirely prevent rotation of the flags when subjected to disturbances such as wind gusts. In addition, the securing means are expensive to manufacture and difficult to install. Furthermore, while the device may haphazardly permit a small portion of the snow load to fall from the roof, it is not designed to fail under the weight of dangerous snow load.
[0007] U.S. Pat. No. 6,536,166 also to Alley discloses a snow guard assembly adapted to be attached to a metal roof seam by a mounting assembly. The mounting assembly includes a mounting block having a seam-receiving groove formed in its bottom surface, and at least one coupling element, which can function as a shear pin, extending through a first side portion of the mounting block. This coupling element provides the snow guard assembly with a break-away feature, wherein the second member of the coupling element is enabled to shear at a predetermined location under a force exceeding a predetermined threshold force to release the entire snow guard assembly from the metal roof seam. The break-away feature is meant to prevent portions of the metal roof itself from lifting and loosening under the weight and force from an excessive snow load on the snow guard attached thereto. The material selection is an important consideration when engineering the coupling member as a shear pin, since some materials are known to shear under more or less force than others. This device, for use with metal roofs only, is designed to prevent roof damage at the point of attachment only, and does not prevent the dangerous accumulation of snow on the entire metal roof.
[0008] U.S. Patent Publication No. 2007/0245636 to Ayer et al. discloses a snow guard for roofs that comprises a plurality of slotted brackets, which are permanently installed atop the roof. A snow fence is removably installed in the slots of the brackets, permitting the user to remove the fence as needed for the deliberate removal of snow from the roof in a safe and predetermined manner. This device requires the user to monitor the snow accumulation and manually remove the device before a significant snow load should threaten damage to the roof.
[0009] None of the cited prior art disclose a snow barrier having a load sensitive mechanism to prevent large snow deposits from damaging roofs or even causing them to cave in.
[0010] There is a need for a snow guard or barrier device that prevents snow from sliding off a roof in regular or normal snow conditions, yet automatically collapses once a given snow load threshold is reached in order to prevent catastrophic damage to the roof. The device should not require cumbersome reattachment of the entire device to the roof.
SUMMARY OF THE INVENTION
[0011] The present invention keeps snow from sliding off a roof during regular snow conditions, while allowing excessive snow to safely slide off once a given snow load threshold is reached in order to prevent catastrophic damage to the roof.
[0012] In one aspect of the present invention, there is provided a snow-retaining device or barrier comprising an upper member attached to a base anchor which is coupled to a roof. The upper member retains snow accumulated on the roof during regular snow conditions. Once an allowable snow load against the upper member is attained, the upper member collapses to allow some or all of the snow to slide off the roof. The maximum allowable snow load against the upper member may be set to, for example, 750 lb, although this threshold may vary in accordance with the location and expected snow conditions.
[0013] The device is designed to allow the upper member to be flexibly attached to the base anchor, preferably by a spring-load means; or the upper member may comprise a fold-away means.
[0014] Alternatively, the upper member can be removably attached to the base anchor and detaches from the base anchor when the maximum allowable snow load is attained.
[0015] The base anchor is attached to the roof using adhesive or mechanical means. Furthermore, the snow-retaining device may comprise a mechanism to assist in melting the snow and ice.
[0016] The upper member and base anchor are comprised of a suitable material such as polycarbonate. The upper member may be of any shape, so long as it can function as a snow barrier during normal snow conditions. In one embodiment, the upper member has a flat surface that has a shape of a polygon, circle, or an area defined by a combination of lines and curves. In another embodiment, the upper member can have a recognizable shape such as an eagle or star silhouette.
[0017] In another aspect of the present invention, there is provided a method of protecting a roof from damage due to excessive snow accumulation, comprising placing a plurality of the snow-retaining devices described herein on the roof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIGS. 1( a ) and 1 ( b ) illustrate first and second perspective views, respectively, of a snow barrier device of one embodiment of the present invention.
[0019] FIG. 2 illustrates a perspective view of another embodiment of the present invention.
[0020] FIG. 3 illustrates a rear view of an upper member of another embodiment of the present invention.
[0021] FIG. 4 illustrates the upper member of FIG. 3 in relation to a base member of the snow barrier of one embodiment of the present invention, prior to assembly.
[0022] FIG. 5( a ) illustrates a side view of the assembled snow barrier of FIG. 4 .
[0023] FIG. 5( b ) illustrates a perspective side view of the partially-assembled snow barrier of FIG. 4 .
[0024] FIG. 6 illustrates a perspective view of another embodiment of the present invention attached to a roof, along with the integration of a heating cable.
[0025] FIG. 7 illustrates a side view of another embodiment of the present invention that folds back under an excessive snow load.
[0026] FIG. 8 illustrates examples of shapes of the flat face of the upper member of the snow barrier of the present invention.
DETAILED DESCRIPTION
[0027] General features of the present invention are shown in FIGS. 1( a ) and 1 ( b ). The base anchor ( 10 ), which may be made of a polycarbonate material, is attached to a roof using bolts or screws that are inserted through holes ( 20 ) and ( 25 ). Base anchor ( 10 ) optionally includes a base surface ( 45 ) that serves as a waterproof seal. The upper member ( 30 ) is removably attached to the base anchor ( 10 ) at an attachment assembly junction ( 35 ). The upper member ( 30 ) may also be made of polycarbonate material.
[0028] As illustrated, upper member ( 30 ) preferably has a generally flat face ( 32 ), that may be of any shape. The illustrated shape is generally octagonal. Other contemplated geometrical shapes for the flat face ( 32 ) of upper member ( 30 ) are depicted in FIG. 8 . Further shapes for the flat face ( 32 ) of upper member ( 30 ) are contemplated (not shown), and include shapes with or without holes, screens and other barrier shapes. Such shapes may also be of recognizable silhouettes including an eagle, star or other known shape.
[0029] The base anchor ( 10 ) can be mounted to the roof using adhesive, mechanical or other known coupling means. When mounted, in normal operating conditions, upper member ( 30 ) is about perpendicular to base anchor ( 10 ).
[0030] The device of the present invention may be installed on roofs where the average snow accumulation per year is known.
[0031] When there is heavy snow accumulation on the roof, once the horizontal load against upper member ( 30 ) exceeds a certain threshold, the upper member ( 30 ) fails, such as by detaching from anchor base ( 10 ), thereby allowing for some or all of the snow in proximity to the device to slide off the roof. By failing at the given threshold, the device fails as a snow barrier but succeeds in preventing the dangerous load of snow from causing damage to the roof by allowing a path to fall off the roof. Conditional failure of upper member ( 30 ) is therefore a safety mechanism.
[0032] A device with a failed upper member ( 30 ) may be repaired or replaced on the same base member ( 10 ), typically after the dangerous accumulation of snow is no longer present. If repaired, the broken-away upper member ( 30 ) may be used if it was not damaged during the failure. Alternatively, a new upper member ( 30 ) may be coupled to the base member ( 10 ). While upper member ( 30 ) must be attached subsequent to failure in order to continue using the device, the base anchor ( 10 ) of the present invention remains coupled to the roof, and does not need to be re-anchored.
[0033] In another embodiment, upper member ( 30 ) is flexibly attached to the base anchor by using, for example, a spring-load mechanism. Once the snow load reaches a certain threshold, upper member ( 30 ) fails by receding or falling back, thereby allowing some or all of the snow to slide off the roof. Once the excessive snow has fallen, the upper member ( 30 ) may be biased back to its original operating position, typically about perpendicular to base anchor ( 10 ). Alternatively, after the excessive snow has fallen, upper member ( 30 ) may be manually adjusted to its operating position.
[0034] The base anchor ( 10 ) assembly also functions as a lesser snow brake in the event snow loads exceed a certain threshold per anchor, which can be set as the same threshold required for the upper member ( 30 ) to give way.
[0035] Whether the upper member ( 30 ) is attached flexibly or removably to the base anchor ( 10 ), an optional means for melting the snow, such as a heating cable, can be integrated into the snow barrier of the present invention, such as at groove ( 40 ) in base anchor ( 10 ).
[0036] FIG. 2 illustrates an example of a snow barrier of the present invention designed to operate without an optional means for melting the snow. Upper member ( 42 ) is attached to base anchor ( 44 ) at assembly junction ( 46 ), while base anchor ( 44 ) comprises a hole ( 48 ) for attaching the snow barrier to a roof by use of a screw or other equivalent fastening means. Unlike the base anchor ( 10 ) of FIGS. 1( a ) and ( b ), base anchor ( 44 ) of FIG. 2 does not incorporate a groove for incorporation of a heating element.
[0037] An example of a snow barrier with a detachable upper member is shown in FIGS. 3-6 . FIG. 3 illustrates the attachment features of an upper member ( 50 ) of another embodiment of the present invention. These attachment features, used to attach the upper member ( 50 ) to the base anchor ( 80 ) (shown in FIG. 4 ), include snap-in-place lugs ( 55 ) and ( 56 ), and side/twist load lugs ( 60 ) and ( 61 ). The accompanying base anchor ( 80 ) of FIG. 4 includes an attachment assembly junction ( 105 ), to which a portion of the upper member ( 50 ) attaches as follows: snap-in-place lug ( 55 ) fits into mating slot ( 90 ), snap-in-place lug ( 56 ) fits into a mating slots ( 91 ), and side/twist load lugs ( 60 ) and ( 61 ) fit into mating slot ( 95 ). In addition, base anchor ( 80 ) includes: a groove ( 85 ) for an optional heating cable; holes ( 110 ) and ( 111 ) for bolts/screws for the attachment of the base anchor to the roof; and a base ( 75 ) for a waterproof seal of the base anchor ( 80 ). Alternatively, an adhesive can be applied to the underside of base ( 75 ) in order to secure the base anchor ( 80 ) to the roof. The base anchor ( 80 ) and upper member ( 50 ) are preferably each made of polycarbonate material.
[0038] The upper member ( 50 ) and base anchor ( 80 ) of FIGS. ( 3 ) and ( 4 ) are shown assembled together in FIG. 5( a ) and partially assembled in FIG. 5( b ). In particular, the perspective view of FIG. 5( b ) illustrates the fitting of snap-in-place lugs ( 55 ) and ( 56 ), and side/twist load lugs ( 60 ) and ( 61 ) and into their respective mating slots. In addition, both means for attaching the base anchor ( 80 ) to the roof are shown in FIG. 5( b ): holes ( 110 ) and ( 111 ) for bolts or screws, and base ( 75 ) for application of an adhesive.
[0039] FIG. 6 shows another embodiment of the invention comprising upper member ( 50 ) and base anchor ( 80 ) attached to a roof ( 130 ) via screw ( 140 ) (another screw on the other side of the base anchor ( 80 ) is not shown). In addition, a heating cable ( 120 ) passes through a groove ( 85 ) on the underside of the base anchor ( 80 ).
[0040] In this embodiment, upper member ( 50 ) breaks off when the snow load on the face of the upper member exceeds a certain threshold. In this instance, side/twist load lugs ( 60 ) and ( 61 ) detach from mating slot ( 95 ), and snap-in-place lugs ( 55 ) and ( 56 ) detach from mating slots ( 90 ) and ( 91 ) respectively. Once detached, the upper member ( 50 ) can be recovered and attached once again to the base anchor ( 80 ) as described above.
[0041] An example of a snow barrier with an upper member ( 150 ) that is flexibly attached to the base anchor ( 160 ) is shown in FIG. 7 . The base anchor ( 160 ) includes a groove ( 170 ) for optional inclusion of a heating cable, and an attachment junction ( 180 ) where upper member ( 150 ) is attached to the base anchor ( 160 ). The upper member ( 150 ) includes a notch ( 200 ) that extends across the face ( 190 ); the notch ( 200 ) acts as a failure mechanism allowing a portion of the upper member to fail or fold back when the snow load against the face ( 190 ) of upper member ( 150 ) exceeds a certain threshold, thereby allowing some or all of the snow to slide off the roof. Once the excessive snow has fallen, the upper member ( 150 ) may be replaced or manually adjusted to its operating position.
[0042] Depending on the embodiment illustrated, grooves ( 40 , 85 , 170 ) allow a heating cable to be integrated with the snow barrier. For example FIG. 6 illustrates the snow barrier fixed to roof ( 130 ) wherein heating cable ( 120 ) is integrated in groove ( 85 ). Together, the heating cable ( 120 ) and snow barrier perform the dual task of melting snow and ice deposits on the roof and keeping snow from sliding off the roof.
[0043] For roofs that presently incorporate a heating cable, the device of the present invention can be fixed at a plurality of locations on the heating cable. Alternatively, a heating cable and one or more snow barriers may be attached to a roof.
[0044] A plurality of snow barrier devices of the present invention may be placed at various intervals along one or more sides of a roof. The number of devices and the spatial distance between each device depends on various factors including where the building is located, the average annual snow accumulation in the area, the snow dump area on failure, the size/slope/material composition of the roof, presence of eave troughs or other roofing accessories, etc.
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A snow-retaining device comprises a detachable upper member attached to a base anchor. The base anchor is adapted to be coupled to a roof. The upper member prevents snow from sliding off the roof during regular snow conditions. In order to prevent catastrophic damage to the roof, if a snow load on the roof exceeds a maximum threshold, the upper member detaches from the base anchor to allow some or all of the snow to slide off the roof. The device optionally integrates a snow melting device.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sewing machine, and more particularly to a drive structure for driving an upper thread wiper of a sewing machine.
2. Description of the Prior Art
Conventionally, the power source of a drive structure for an upper thread wiper of a sewing machine is transmitted by a mainshaft which is mounted on a base of the sewing machine, which a continuous power transmitting system. The structure of this kind of power transmitting system is complicated and difficult to adjust, and consequently has a high manufacturing and maintenance cost. Hence, the applicant of this application has invented “a coaxially clockwise driven needle shaft and upper thread wiper of a sewing machine”, wherein the structures of the power of the upper thread wiper and the needle shaft have been simplified. However, the applicant of the present invention is not satisfied with the improvement made in the “a coaxially clockwise driven needle shaft and upper thread wiper of a sewing machine” and has made further improvement to the drive structure for the upper thread wiper.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide a drive structure for an upper thread wiper of a sewing machine, wherein the upper thread wiper and a drive device for driving the upper thread wiper are disposed on the cantilever and located close to the end of the needle shaft. In addition to that the drive device simplifies relative motion transmission structure, the cooperative arrangement between the upper thread wiper and the drive device further improves the power transmission efficiency and stability.
To achieve the above object, a drive structure for driving an upper thread wiper of a sewing machine, the sewing machine comprises a base and a cantilever extending from the base, on the cantilever is disposed a needle-shaft driving shaft for driving a needle shaft mounted on the cantilever to repeatedly move up and down. The upper thread wiper of the sewing machine is disposed on a wiper arm. A drive device is disposed between the needle-shaft driving shaft and the wiper arm. The drive device is provided with a drive member and a motion-transmission rod for converting rotation of the needle-shaft driving shaft into swing motion of the wiper arm. One end of the drive member is drivingly connected to and driven by the needle-shaft driving shaft. Another end of the driving member is pivoted to one end of the motion-transmission rod via a pin. Another end of the motion-transmission rod is formed with a cylindrical inserting portion. One end of the wiper arm is formed with a second pivot portion for insertion of a fixing pivot which is fixed to the cantilever, and the upper thread wiper is fixed at another end of the wiper arm, and the wiper arm is formed with a pivot hole for insertion of the inserting portion.
Another object of the present invention is to provide a drive structure for an upper thread wiper of a sewing machine, wherein the upper thread wiper can be quickly and easily assembled onto or removed from the wiper arm.
To achieve the above object, a quick release device is disposed between the upper thread wiper and the wiper arm. A free end of the wiper arm is an engaging end which is formed with a first stop portion. The upper thread wiper has a connecting end. The quick release device includes a positioning sleeve and a key, the positioning sleeve is formed with an inserting portion for accommodation of the connecting end and also for insertion of the engaging end of the wiper arm, the positioning sleeve includes an elastic portion which is provided with a spiral spring to push against the key, the positioning sleeve is formed with a second stop portion, the elastic portion is provided with an engaging portion to be elastically engaged with the first stop portion of the wiper arm, the key is formed with a first chamber for accommodation of the spring and the elastic portion so as to provide an elastic force for separating the key and the positioning sleeve from each other, the key is formed with an extending portion which extends toward the second stop portion, and at a distal end of the extending portion is formed a stop flange which is stopped and pressed against the second stop portion to make the engaging portion elastically engaged in the first stop portion, or pressing the key can make the engaging portion of the elastic portion disengage from the first stop portion, so that the upper thread wiper is removed from wiper arm.
Yet, another object of the present invention is to provide a drive structure for an upper thread wiper of a sewing machine, which is capable of effecting or interrupting power transmission.
To achieve the above object, the drive device is further provided with a clutch device for driving the needle shaft, the oscillating member is provided with a clutch hole for the clutch rod to engage in and disengage from the clutch hole, the clutch rod is pivotally inserted in the driven portion of the drive member, and one end of the clutch rod that extends out of the driven portion is driven by the clutch device, the clutch device includes a clutch member, a switch member, a press member, an flexible member, and a support pivot, the clutch member is slidably mounted on the needle-shaft driving shaft and fixed on the clutch rod, a push member is sleeved on the needle-shaft driving shaft to provide an elastic force to push the clutch member toward the drive member.
The switch member is formed with a third pivot portion for insertion of a pivot which is fixed on the cantilever, the switch member is formed with a push portion which extends toward the clutch member, so that the clutch member is pushed by the push member to rest against the push portion, when the switch member moves, the push portion will push the clutch member to make the clutch rod engage in or disengage from the oscillating member.
The support pivot is inserted through the press member and the flexible member and has one end fixed to the switch member and another screwed with a bolt, so that the flexible member is pushed by the bolt to provide a force for pushing the press member toward the cantilever, the press member is formed with a press portion for a user to press.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a drive structure for driving an upper thread wiper of a sewing machine in accordance with a first preferred embodiment of the present invention;
FIG. 2 is an assembly view of a drive device, a quick release device and a clutch device in accordance with the present invention;
FIG. 3 is an exploded view of the drive device, the quick release device and the clutch device in accordance with the present invention;
FIG. 4 is an operational view of the drive device of a drive structure for driving an upper thread wiper of a sewing machine in accordance with the present invention;
FIG. 5 is a side view showing that the drive member of the drive device in accordance with the present invention cooperates with the rod-inserting member;
FIG. 6 is a perspective view of a drive structure for driving an upper thread wiper of a sewing machine in accordance with a second preferred embodiment of the present invention;
FIG. 7 is a perspective view of a drive structure for driving an upper thread wiper of a sewing machine in accordance with a third preferred embodiment of the present invention;
FIG. 8 is an exploded view of a drive device of the present invention;
FIG. 9 is a cross sectional view of the drive device in accordance with the present invention;
FIG. 10 is an operational cross sectional view of the drive device in accordance with the present invention; and
FIG. 11 is an operational view of the assembly the drive device, the quick release device and the clutch device shown in FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention.
Referring to FIGS. 1-4 , a drive structure for driving an upper thread wiper 18 of a sewing machine 10 in accordance with a first preferred embodiment of the present invention is shown, wherein the sewing machine 10 essentially comprises a base 11 and an L-shaped cantilever 12 extending upward from the base 11 . In the base 11 is disposed a mainshaft 13 to be rotated by a motor (not shown). On the cantilever 12 is disposed a needle-shaft driving shaft 14 which is in parallel with and rotated by the mainshaft 13 . The needle-shaft driving shaft 14 has one end rotated by the mainshaft 13 and has another end provided with an oscillating member 17 which is connected by a connecting rod 16 to a connecting block 150 disposed on a needle shaft 15 , so that the needle shaft 15 is driven by the needle-shaft driving shaft 14 to repeatedly move up and down. Since the driving structure for driving the needle shaft 15 to move is a conventional structure, further descriptions are omitted.
The upper thread wiper 18 of the sewing machine 10 is driven by a wiper arm 19 , and this is also a conventional structure. The present invention is characterized in that a drive device 20 is disposed between the oscillating member 17 for driving the needle shaft 15 and the wiper arm 19 , so as to make the wiper arm 19 swing horizontally, unlike the conventional up-and-down movement of the needle shaft 15 driven by the needle-shaft driving shaft 14 .
Referring to FIGS. 3 and 4 , the oscillating member 17 is such a structure that the outer diameter at both ends of the oscillating member 17 is larger than the outer diameter in the middle portion of the oscillating member 17 . One end of the oscillating member 17 is formed an inserting hole 170 , and the needle-shaft driving shaft 14 is inserted and fixed in the inserting hole 170 of the oscillating member 17 by bolts 171 . Another end of the oscillating member 17 is connected to one end of the connecting rod 16 by a connecting shaft 172 , and another end of the connecting rod 16 is pivoted to the connecting block 150 and serves to drive the needle shaft 15 to move. In the middle portion of the oscillating member 17 is defined a clutch hole 173 for insertion of one end of a clutch rod 174 , and another end of the clutch rod 174 is connected to the drive device 20 .
The drive device 20 is provided with a drive member 21 , a motion-transmission rod 22 , a rod-inserting member 23 , an oscillating element 24 and a linking rod 25 which are interconnected to one another and serve to transmit power to the wiper arm 19 . The drive member 21 is an elongated block whose middle portion is slightly bent, in the middle portion of the drive member 21 is formed a through hole 210 for insertion of the needle-shaft driving shaft 14 , one end of the drive member 21 is formed with a driven portion 211 in the form of a hole for insertion of the clutch rod 174 , and another end of the drive member 21 is formed with two ears 212 . The motion-transmission rod 22 has one end inserted between the two ears 212 , each of the ears 212 is formed with a pin hole 213 , and a pin 214 is inserted through the pin holes 213 of the ears 212 and the end of the motion-transmission rod 22 , so that the motion-transmission rod 22 is pivoted to the drive member 21 by the pin 214 .
The end of the motion-transmission rod 22 inserted between the ears 212 is formed with a first pivot portion 220 which includes two opposed flat surfaces and two opposed arc-shaped surfaces (not numbered). The pin 214 is inserted through the two opposed flat surfaces, and there is a clearance between the first pivot portion 220 and the two ears 212 , so that the first pivot portion 220 can move along the pin 214 between the two ears 212 so as to absorb the displacement of the motion-transmission rod 22 caused when the motion-transmission rod 22 moves up and down while being driven to swing back and forth by the drive member 21 , and caused by the horizontal swing of the rod-inserting member 23 . At a bottom of the first pivot portion 220 is a cylindrical first inserting portion 221 whose outer diameter is smaller than that of the first pivot portion 220 .
The rod-inserting member 23 is L-shaped and includes a perpendicular inserting rod 230 at one end thereof. The first inserting portion 221 of the motion-transmission rod 20 is inserted through the inserting rod 230 , and on an end of the first inserting portion 221 that extends out of the inserting rod 230 is sleeved an elastic member 222 . The end of the first inserting portion 221 that extends out of the inserting rod 230 is formed with an annular groove (not numbered) in which a washer (not numbered) and a C-shaped retainer 223 are engaged to prevent the elastic member 222 from disengaging from the first inserting portion 221 . The elastic member 222 has one end pushed against the end of the inserting rod 230 of the rod-inserting member 23 , so as to provide an elastic force between the rod-inserting member 23 and the motion-transmission rod 22 , making the rod-inserting member 23 and the motion-transmission rod 22 slide more stably with respect to each other.
Another end of the rod-inserting member 23 is U-shaped to form a shaft-retaining portion 231 in the form of a hole and a slit 232 in communication with the shaft-retaining portion 231 . A rotary shaft 234 has one end inserted in the shaft-retaining portion 231 , and a bolt 233 is screwed through the slit 232 to retain the rotary shaft 234 within shaft-retaining portion 231 in a clamping manner, so that the rotary shaft 234 can be driven to rotate by the rod-inserting member 23 .
One end of the oscillating element 24 is formed with a rotary-shaft hole 240 for insertion of another end of the rotary shaft 234 , and two bolts 241 are laterally screwed in the rotary-shaft hole 240 to fix the rotary shaft 234 , so that the oscillating element 24 is drivingly connected to the rotary shaft 234 . At another end of the oscillating element 24 is formed a horizontal oscillating portion 242 which is formed with a central hole 243 for insertion of a first bolt 244 , so as to pivotally connect the oscillating element 24 to the linking rod 25 .
The linking rod 25 is an elongated block with two circular ends. Each end of the linking rod 25 is formed with a bolt hole 250 for insertion of the first bolt 244 and a second bolt 251 , respectively, and the second bolt 251 has one end inserted in the wiper arm 19 so as to drive the wiper arm 19 .
The wiper arm 19 is an L-shaped structure, and one end of the wiper arm 19 is formed with a cylindrical hollow second pivot portion 190 which is to be pivotally connected a corresponding part of the cantilever 12 . For example, in the second pivot portion 190 is inserted a fixing pivot 260 which has one end fixed to a first corner of a triangle mounting frame 26 , the rotary shaft 234 is pivoted to a second corner of the mounting frame 26 , and another fixing pivot 260 is fixed to a third corner of the mounting frame 26 , so as to fix the mounting frame 26 to a bottom of the cantilever 12 .
At a middle portion of the wiper arm 19 is defined a pivot hole 191 for insertion the one end of the second bolt 251 , and a bolt 192 is laterally screwed in the pivot hole 191 to fix the second bolt 251 , so that the wiper arm 19 is pivotally and drivingly connected to the linking rod 25 .
When the needle-shaft driving shaft 14 rotates back and forth, the drive member 21 , the drive member 21 will swing synchronously and coaxially with the oscillating member 17 since it is drivingly connected to the oscillating member 17 by the clutch rod 174 . The motion-transmission rod 22 , as shown in FIGS. 4 and 5 , will move up and down repeatedly between two positions a 1 and b 1 to make the inserting rod 230 of the rod-inserting member 23 and the first inserting portion 221 slide with respect to each other. Meanwhile, the inserting rod 230 moves horizontally between the positions a 1 and b 1 , so that the rotary shaft 234 at another end of the rod-inserting member 23 will have a rotating angle θ, and the oscillating element 24 will rotate by the rotating angle θ. Consequently, the first bolt 244 of the linking rod 25 is driven to move repeatedly between two positions a 2 and b 2 , and the second bolt 251 of the linking rod 25 is driven to move repeatedly between two positions a 3 and b 3 , so that the wiper arm 19 will rotate around the second pivot portion 190 to drive the upper thread wiper 18 to rotate.
A drive device 20 in accordance with a second embodiment of the present invention can also be simplified as shown in FIG. 6 , wherein the drive member 21 and the oscillating member 17 on the needle-shaft driving shaft 14 can be integral with each other, so that the power can be transmitted directly to the drive member 21 and the oscillating member 17 from the needle-shaft driving shaft 14 . The drive member 21 is pivoted to a motion-transmission rod 22 which has an first inserting portion 221 inserted in the pivot hole 191 of the wiper arm 19 , and on an end of the first inserting portion 221 that extends out of the pivot hole 191 are sleeved an elastic member 222 and a C-shaped retainer 223 . The second pivot portion 190 at one end of the wiper arm 19 is pivoted to a corresponding part of a sewing machine, and another end of the wiper arm 19 is assembled to the upper thread wiper 18 . The drive device 20 of this embodiment is also capable of transmitting power as the drive device 20 of the first embodiment. The drive member 21 has two ears 212 at two ends thereof, a pin 214 is inserted through the two ears 212 . The end of the motion-transmission rod 22 inserted between the ears 212 is a formed with a first pivot portion 220 for insertion of the pin 214 , there is a clearance between the first pivot portion 220 and the two ears 212 , and another end of the oscillating member 17 is drivingly connected to the needle shaft 15 by a connecting shaft 172 .
Further, a drive device 20 in accordance with a third embodiment of the present invention can also be simplified as shown in FIG. 7 , wherein the drive member 21 and the oscillating member 17 on the needle-shaft driving shaft 14 can be integral with each other, so that the power can be transmitted directly to the drive member 21 and the oscillating member 17 from the needle-shaft driving shaft 14 . The drive member 21 is pivoted to a motion-transmission rod 22 which has a first inserting portion 221 inserted in one end of an oscillating element 24 . The oscillating element 24 has a middle portion pivoted in the cantilever 12 and another end pivoted to one end of a linking rod 25 , and another end of the linking rod 25 is pivoted in a pivot hole 191 of the wiper arm 19 to drive the wiper arm 19 to swing.
In the middle portion of the oscillating element 24 is defined a rotary-shaft hole 240 for insertion of a connecting pivot 245 fixed on the cantilever 12 , and both ends of the oscillating element 24 are formed with an passing hole 246 for insertion of the first inserting portion 221 . On an end of the first inserting portion 221 that extends out of the passing hole 246 are sleeved an elastic member 222 and a C-shaped retainer 223 , so as to provide an elastic force between the first inserting portion 221 and the oscillating element 24 .
At another end of the oscillating element 24 is formed a horizontal oscillating portion 242 which is formed with a central hole 243 for insertion of a first bolt 244 , so as to pivotally connect the oscillating element 24 to the linking rod 25 .
The linking rod 25 is an elongated block with two circular ends. Each end of the linking rod 25 is formed with a bolt hole 250 for insertion of the first bolt 244 and a second bolt 251 , respectively, and the second bolt 251 has one end inserted in the wiper arm 19 so as to drive the wiper arm 19 .
At a middle portion of the wiper arm 19 is defined a pivot hole 191 for insertion the one end of the second bolt 251 , and a bolt is laterally screwed in the pivot hole 191 to fix the second bolt 251 , one end of the wiper arm 19 is formed with a second pivot portion 190 which is to be pivotally connected a corresponding part of the cantilever 12 , and another end of the wiper arm 19 is assembled to the upper thread wiper 18 . The drive device 20 of this embodiment is also capable of transmitting power as the drive device 20 of the first embodiment. The drive member 21 has two ears 212 at two ends thereof, a pin 214 is inserted through the two ears 212 . The end of the motion-transmission rod 22 inserted between the ears 212 is a formed with a first pivot portion 220 for insertion of the pin 214 , there is a clearance between the first pivot portion 220 and the two ears 212 , and another end of the oscillating member 17 is drivingly connected to the needle shaft 15 by a connecting shaft 172 .
Between the upper thread wiper 18 and the wiper arm 19 can also be disposed a quick release device 30 and corresponding structures for enabling the upper thread wiper 18 to be quickly assembled onto or removed from the wiper arm 19 , as shown in FIGS. 3 , 8 - 10 , the quick release device 30 , wherein the free end of the wiper arm 19 is formed with a laminar engaging end 193 which is formed with a first stop portion 194 in the form of a cavity opens upward. Adjacent to the first stop portion 194 is disposed a laminar elastic piece 195 which is bent upward to provide an upward elastic force.
The upper thread wiper 18 has a hooking end for cooperating with the needle shaft 15 to hook thread, another end of the upper thread wiper 18 is a horizontal connecting end 180 which is formed with two threaded connecting holes 182 , and at both sides of the connecting end 180 is formed a protruding third stop portion 181 .
The quick release device 30 includes a positioning sleeve 31 and a key 32 . The positioning sleeve 31 is rectangular in cross section and formed with an second inserting portion 310 which has a width approximately equal to that of the connecting end 180 so as to accommodate the connecting end 180 . At an opening end of the second inserting portion 310 are formed two concave engaging portions 311 for engaging with the stop portions 181 . Two bolts 33 are inserted through a bottom surface of the positioning sleeve 31 and screwed into the connecting holes 182 of the connecting end 180 , and the engaging end 193 of the wiper arm 19 is inserted in the second inserting portion 310 .
At a top surface of the positioning sleeve 31 are formed two parallel slots 312 so as to create an elastic portion 313 which is integral with the positioning sleeve 31 at a position close to the engaging end 193 of the wiper arm 19 and has a free end extending toward the upper thread wiper 18 . The free end of the elastic portion 313 extends out of the second inserting portion 310 and is formed with a positioning groove 314 for holding one end of a spiral spring 34 , and another end of the spiral spring 34 is pushed against the key 32 . At the opening end of the second inserting portion 310 of the positioning sleeve 31 is formed a U-shaped second stop portion 315 which is located above the free end of the elastic portion 313 to restrict the key 32 . The elastic portion 313 is provided at a bottom surface thereof with a triangle protruding engaging portion 316 to be elastically engaged with the first stop portion 194 of the wiper arm 19 , as shown in FIG. 9 .
The key 32 is a rectangular block which is formed with a first chamber 320 which opens toward the positioning sleeve 31 for accommodation of the spiral spring 34 and the free end of the elastic portion 313 . The spiral spring 34 pushes against the bottom of the first chamber 320 to provide an elastic force for separating the key 32 and the positioning sleeve 31 from each other. At an upper edge of an opening end of the first chamber 320 is formed an extending portion 321 which extends toward the second stop portion 315 , and at a distal end of the extending portion 321 is formed a stop flange 322 perpendicular to the extending portion 321 . At the corner defined between the extending portion 321 and the stop flange 322 are formed two slanting guide portions 323 which are lower than the stop flange 322 , and at a top surface of each of the guide portions 323 is formed a horizontal stop surface 324 .
The key 32 is sleeved on the free end of the elastic portion 313 in such a manner that the stop flange 322 is inserted into the positioning sleeve 31 and stopped against the second stop portion 315 . When the key 32 is pressed to compress the spiral spring 34 , the extending portion 321 of the key 32 is located under the second stop portion 315 , the free end of the elastic portion 313 is elastically deformable upward and downward. At this moment, as shown in FIG. 10 , the engaging portion of the elastic portion 313 can be disengaged from the first stop portion 194 by pulling the upper thread wiper 18 from the wiper arm 19 , and thus the upper thread wiper 18 can be removed from wiper arm 19 . Similarly, to assemble the upper thread wiper 18 to the wiper arm 19 , the key 32 is firstly pressed to make the engaging portion 316 elastically engaged in the first stop portion 194 , when the key 32 is released, it will be pushed back by the spiral spring 34 to the position where the stop flange 322 is stopped against the second stop portion 315 again, and the key 32 and the free end of the elastic portion 313 will be pressed toward the first stop portion 194 of the wiper arm 19 , so that the engaging portion 316 is engaged in the first stop portion 194 to prevent the upper thread wiper 18 from disengaging from the wiper arm 19 , as shown in FIG. 9 .
Moreover, the drive device 20 is further provided with a clutch device 40 for driving the needle shaft 15 , as shown in FIGS. 1-3 , the oscillating member 17 is provided with a clutch hole 173 for the clutch rod 174 to insert in and out. The clutch rod 174 is pivotally inserted in the driven portion 211 of the drive member 21 , and the end of the clutch rod 174 that extends out of the driven portion 211 is driven by the clutch device 40 , so as to control the clutch rod 174 to insert in or disengage from the clutch hole 173 of the oscillating member 17 .
The clutch device 40 includes a clutch member 41 , a switch member 42 for controlling the position of the clutch member 41 , a press member 43 , a flexible member 44 in the form of a spiral spring, and a support pivot 45 fixed to the switch member 42 . At the bottom of the cantilever 12 is provided a base frame 121 for mounting the aforementioned structures. The base frame 121 is bent to form an L-shaped structure and has a vertical end fixed to a rear surface of the cantilever 12 by two bolts. A horizontal end of the base frame 121 is formed with a limiting hole 122 located adjacent to the vertical end, and is further formed with two symmetrical first positioning portions 123 and 124 and a connecting portion 125 connected between the two first positioning portions 123 , 124 in such a manner that the two first positioning portions 123 , 124 are two holes located on the same circle whose center is the limiting hole 122 , and a width of the connecting portion 125 is smaller than a diameter of the two first positioning portions 123 .
The clutch member 41 of the clutch device 40 is a disc-shaped structure and formed with a driving-shaft hole 410 for insertion of the needle-shaft driving shaft 14 , so that the clutch member 41 is slidably mounted on the needle-shaft driving shaft 14 . Around a periphery of the clutch member 41 is formed a positioning hole 411 for insertion of the clutch rod 174 when the clutch rod 174 is in parallel to the needle-shaft driving shaft 14 . A push member 412 in the form of a spiral spring is sleeved on the needle-shaft driving shaft 14 and biased between the driving-shaft hole 410 of the clutch member 41 and the needle-shaft driving shaft 14 to provide an elastic force for the clutch member 41 to push the clutch rod 174 toward the drive member 21 .
The switch member 42 is a polygonal plate abutted against a top surface of the horizontal end of the base frame 121 , and at one end of the switch member 42 is formed a third pivot portion 420 in the form of a hole. A pivot 46 is inserted through the limiting hole 122 and the third pivot portion 420 and retained by a C-shaped retainer. At the middle portion of a top surface of the switch member 42 is formed a cylindrical push portion 421 which extends to an end of the clutch member 41 that is not pushed by the push member 412 , so that the clutch member 41 can be pushed by the push member 412 to rest against the push portion 421 , and thus the clutch member 41 can be driven to move by the push portion 421 . When the switch member 42 moves, the push portion 421 will push the clutch member 41 to make the clutch rod 174 engage in or disengage from the oscillating member 17 .
The press member 43 is disposed below the horizontal end of the base frame 121 and aligned with the first positioning portions 123 , 124 and the connecting portion 125 . The press member 43 is formed with a second chamber 430 open downward for accommodation of the flexible member 44 . The support pivot 45 is inserted through the flexible member 44 and the second chamber 430 and fixed by a bolt 450 , so that the flexible member 44 is pushed by the bolt 450 toward the bottom of the second chamber 430 , so as to provide a force for pushing the press member 43 toward the bottom surface of the horizontal end of the base frame 121 . At a top surface of the press member 43 is formed a protruding second positioning portion 431 to be selectively engaged with the first positioning portions 123 and 124 . At a bottom surface of the press member 43 is formed a press portion 432 which horizontally extends out of the press member 43 , so that the user can press the press portion 432 and push it to move along the connecting portion 125 to control the positions of the switch member 42 and the clutch member 41 , so as to effect or interrupt power transmission.
When the second positioning portion 431 of the press member 43 is engaged in the positioning portion 123 of the drive member 21 , the switch member 42 which is driven by the press member 43 via the support pivot 45 will rotate around the pivot 46 to rotate to the push portion 421 and toward the drive member 21 . The clutch member 41 will drive the clutch rod 174 to move toward the drive member 21 , so that the clutch rod 174 can be inserted into the clutch hole 173 of the oscillating member 17 to effect power transmission. When the second positioning portion 431 of the press member 43 is engaged in the positioning portion 124 of the drive member 21 , the switch member 42 is simultaneously driven to rotate to the push portion 421 to push the clutch member 41 to move away from the drive member 21 , the clutch rod 174 will be disengaged from the clutch hole 173 of the oscillating member 17 to interrupt power transmission, namely, the power from the needle shaft 15 will be blocked from being transmitted to the upper thread wiper 18 .
The rotary shaft 234 of the mounting frame 26 and the fixing pivot 260 can be pivoted or fixed to the bottom surface of the horizontal end of the base frame 121 .
What mentioned above are the structural relations of the main components of the present invention, for a better understanding of the function and operation of the present invention, please refer to the following descriptions.
Firstly, the power of the drive device 20 for driving the upper thread wiper 18 directly comes from the needle-shaft driving shaft 14 that drives the needle shaft 15 instead of coming from the base 11 of the sewing machine, so that the structure of the sewing machine base is simplified. The drive device 20 is directly mounted on the cantilever 12 , so that it can move synchronously with the needle shaft 15 , reducing action error and power loss.
Secondly, the drive device 20 is located on the cantilever 12 which is within the user's vision, instead of on the base 11 or at the bottom of the sewing machine 10 which is beyond the user's vision, making the maintenance, operation and assembly of the drive device 20 much easier.
Thirdly, the quick release device 30 enables the upper thread wiper 18 to be quickly assembled onto or removed from the wiper arm 19 .
Fourthly, the user can press the clutch device 40 to effect or interrupt power transmission while doing sewing, making the power transmission control easier. Furthermore, the press member 43 uses the second positioning portion 431 to selectively engage with the two symmetrical first positioning portions 123 and 124 , improving the positioning effect of the clutch.
While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
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A drive structure for driving an upper thread wiper of a sewing machine is provided, wherein the upper thread wiper and a drive device for driving the upper thread wiper are disposed on the cantilever and located close to the end of the needle shaft. In addition to that the drive device simplifies relative motion transmission structure, the cooperative arrangement between the upper thread wiper and the drive device further improves the power transmission efficiency and stability. The upper thread wiper can be quickly and easily assembled onto or removed from the wiper arm through a quick release device. Moreover, the drive structure is further provided with a clutch device which is capable of effecting or interrupting power transmission as desired.
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FIELD OF THE INVENTION
The invention relates to an extruder for processing and producing rubber and thermoplastic plastics materials;
BACKGROUND OF THE INVENTION AND PRIOR ART
In the past, so-called pin-barrel extruders were always used as discharge and homogenizing extruders, such as are known, for example, from German Offenlegungsschrift No. 2 235 784 or German Offenlegungsschrift No. 3 003 615 belonging to the assignee of the present invention. In extruders of this type of construction, metal pins protrude radially through the extruder housing into the processing chamber of the extruder, the extruder screw having interrupted screw flights in this region.
These extruders are distinguished by their very high discharge rate and good homogenizing effect upon the material to be processed and permit also an increased throughput of material per unit of time, compared with conventional cold-feed extruders having a screw with a shearing section, with the r.p.m. of the screw remaining constant.
These advantages have resulted in pin-barrel extruders becoming the most commonly used extruders in the rubber industry in the last 15 years.
Independently of this, a mixing section for an extruder has been developed, which has become known as a transfer mixing section (DE-A 11 42 839). This mixing section is substantially characterised in that both the extruder screw and the internal wall of the extruder housing are provided with grooves and flights over a predetermined length, the thread depth of the extruder screw, when viewed in the longitudinal direction of the extruder housing, decreasing to zero and subsequently increasing again at the same rate as the thread depth of the grooves in the housing respectively increases and decreases again. As a result of this configuration for the extruder screw and housing, the extruded material can be exchanged fully between the screw grooves and the housing grooves, thereby producing a good mixing effect.
Compared with the pin-barrel extruder, the transfer extruder could claim for itself a certain corner of the market, especially when the overall length of the extruder had to be kept small.
It is additionally known from U.S. Pat. No. 3,613,160 to provide extruders with throttle components, whereby the conveyance of extruded material in the extruder may be variably controlled externally. For this purpose, according to this publication, a substantially cylindrical component is disposed on the screw shaft of the extruder screw, said component rotating jointly with the screw and completely blocking the processing chamber downstream. In the region of this cylindrical component, two throttle pins each extend externally through the extruder housing radially into an axially oriented overflow conduit, which is incorporated into the internal wall of the extruder housing.
When the throttle pins are retracted, a portion of the extruded material situated upstream of the cylindrical component may pass through these conduits to the downstream section of the extruder. This flow of extruded material can be controlled by the insertion of the throttle pins into these overflow conduits to different depths.
SUMMARY OF THE INVENTION
Since the technology for these extruders has not changed in the last 15 years, apart from detail improvements, the basic object of the invention was to provide a mixing and homogenizing extruder which, compared with known apparatus, permits an increased discharge output with reduced investment costs, yet with at least an equally good mixing effect, and allows a considerably shorter overall length together with an expansion of the hitherto fields of application of mixing and homogenizing extruders. Finally, the plasticising work which is achievable by the extruder should be freely adjustable depending on the properties of the extruded material.
As a result of combining the two known types of construction for the mixing sections, it was possible to create an extruder having considerable advantages over the mixing and homogenizing extruders of prior art.
Thus, by utilizing an extruder which has a pin-barrel section and a transfer section with additional pins, it has been possible to ascertain that, while retaining the same mixing quality and the same screw r.p.m., the driving forces of the extruder could be reduced by up to 50%, and the throughput of material could be increased by up to 60% to 100%.
These excellent results also produce a 50% reduction in the driving torque, thereby resulting in a considerable reduction in the drive costs when manufacturing the extruder. In addition, as a result of combining the pin-containing barrels and the transfer section technology, the overall length of the mixing section required for the same mixing quality can be reduced by approximately 50% compared with an extruder which operates only according to the pin-barrel principle.
Because of the provision of adjustable throttle pins, which protrude radially into the portion of the transfer section of the extruder housing where the housing threads substantially have their greatest thread volume, the proposed extruder can be adjusted for processing various rubber mixtures. In consequence, with the depth of penetration of the throttle pins into the housing threads and into the processing chamber of the extruder, it is possible for the plasticizing work, or respectively the friction energy which is converted in the transfer section, to be pre-selected for the extruded material as desired and with regard to the mixture. In consequence, compared with hitherto known extruders of such type, reference may be made to a further, freely selectable process parameter in addition to the screw r.p.m. and the temperature of the processing section.
BRIEF DESCRIPTION OF THE APPLICATION DRAWINGS
The invention can be explained with reference to the described embodiments and the application drawings.
In the drawings:
FIG. 1 is a longitudinal sectional view through a single-screw extruder without any throttle pins in the transfer section;
FIG. 2 is a longitudinal sectional view through a single-screw extruder having throttle pins in the transfer section;
FIGS. 3a-c are graphs showing the results of tests using an extruder of the proposed type of construction compared with the conventional pin-containing extruder.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic longitudinal sectional view through a single-screw extruder 1 in the structural form of a pin transfer extruder. One extruder screw 6 is disposed internally of the extruder housing 2 and is drivable about its longitudinal axis by a drive unit 5. In the region of its upstream end, the housing 2 has an inlet opening 3 for receiving the material, which is to be extruded and leaves the extruder, ready mixed and homogenized, through the outlet opening 4.
In the feed section 9, the extruder screw 6 has a screw geometry which is suitable for drawing into the extruder, in a manner known per se, the material which has been supplied through the inlet opening 3 and for plasticizing such material.
A pin-barrel section 7 is provided downstream of this feed section, and in said pin-barrel section two rows of pins 11 (shown diagrammatically) protrude radially through the extruder housing 2 towards the screw axis and into the processing chamber 14 of the extruder. The screw flights 12 are interrupted in known manner in the pin plane in this section 7, in order to avoid colliding with the pins 11.
Downstream of the pin-barrel section 7, there is disposed a transfer section 8, wherein, in this embodiment, the angles between the flights 18 of the extruder screw 6 and the flights 13 of the extruder housing 2 are greater than or equal to 105° and do not form any angles with one another which are complementary to 90°. The transfer section 8 may be divided into an inlet region and an outlet region, both regions being separated from each other by the housing thread having the greatest thread depth. In this transfer section 8 of the extruder also, the number of threads in the inlet and outlet regions is constant, whereby the number of flights in the inlet and outlet regions depends on the cross-section of the threads in the housing and of the screw.
The final processing section of the extruder screw 6 is formed by the pressure increasing section 10, in which the screw geometry is so selected that the pressure of the molten mass can be increased to the required tool pressure in known manner.
In addition to this embodiment, other possible embodiments are also conceivable for this pin transfer extruder. Thus, for example, the transfer section 8 could also be disposed upstream of the pin-barrel section 7, although the above-mentioned variant produces better mixing and homogenizing results. In addition, it may be mentioned here that the pin-barrel section also fulfils its mixing and homogenizing task with more than two rows of pins. In view of the ratio between costs and mixing quality, it is best to provide the pin-barrel section with one to five rows of pins.
The preferred length of the individual extruder sections, with an extruder length of 10 screw diameters (D), is substantially 3 D for the feed section, 1.5 to 10 D, preferably 1.5 to 2 D, for the pin-barrel section, 2 to 2.5 D for the transfer section, and approximately 3 D for the pressure augmenting section.
Independently of these particulars, however, additional processing sections may also be disposed upstream of, downstream of or between the pin-barrel and transfer sections, such as, for example, degassing or kneading sections.
FIG. 2 shows a pin transfer extruder 1 with throttle pins 11 in the transfer section. The feed section 9 of this extruder also corresponds here to the conventional cold-feed extruder and has a ratio of screw length (D) to screw diameter of three.
The feed section 9 has disposed downstream thereof an extruder portion with a total length of 6 D, in which there is situated the pin-barrel section 7 with two pin planes with extruder pins 11 disposed one behind the other. Downstream of the pin-barrel section 7, the transfer section 8 is provided with a length of substantially 2 D, and the pressure augmenting section 10 has a length of substantially 1.5 D.
The temperature of the extruder barrel 2 is controlled in known manner by temperature control bores 19 in the housing wall 2. In this embodiment, housing sleeve 20, and thus the transfer section 8 of the extruder housing, is locked in the housing 2.
The pitch of the threads of the extruder screw and transfer section sleeve are so selected that the flights between the screw and the sleeve form an angle equal to or more than 105°. This advantageously results in the extruded material being subjected to an intensive shearing process as it passes through this transfer section, caused by the resultant large number of intersections between screw and sleeve flights per screw revolution.
In contrast to the screw threads, the sleeve threads in the transfer section are not interrupted. Rather, they wind continuously and constantly from the inlet region of the transfer section to its outlet region respectively in a substantially increasing and decreasing spiral manner around the imaginary longitudinal axis of the extruder.
In the first third of the transfer section, the screw core diameter increases from the maximum thread depth to the external diameter, i.e. the thread volume of the screw 6 decreases from the maximum value in the inlet region to zero. The thread volumes of the sleeve 20 have the reverse tendency. In consequence, the throughput volume which is effective for the extruded material is kept constant in the axial and radial directions of conveyance. Because of these circumstances, there is, of necessity, a one hundred percent exchange of extruded material between screw 6 and barrel sleeve 20.
When the outlet region of the transfer section shown in FIG. 2 has a length of approx. 1.4 D, the thread volume of the screw 6 continuously increases and that of the sleeve 20 continuously decreases, whereby, in turn, the total thread volume of screw and sleeve for the extruded material is kept constant.
Extensive experiments produced the result that, especially when processing highly viscous natural rubber mixtures, the pre-plasticizing in the pin section of the extruder with low shearing gradients prior to the intensive plasticizing work in the transfer section have both a discharge increasing effect and a positive effect on the pulsation behavior of the machine.
In addition to the screw r.p.m. and the processing section temperatures, the machine has a further processing parameter which is freely preselectable and expands the versatility of the machine with regard to its ability to process a large strip width of various rubber mixtures.
In this embodiment, there is situated at the end of the first third of the transfer section 8 a throttle means which has pins 17, which are distributed equiangularly over the periphery of the transfer section and protrude radially into the uninterrupted threads of the transfer section sleeve 20, said pins being able to reduce the thread volume of the sleeve 20 in this section from the maximum value to zero.
With these throttle pins 17, which are either manually, pneumatically, mechanically or hydraulically adjusted externally, the plasticizing work, or the friction energy converted in the transfer section, may be prescribed as desired for the extruded material.
These throttle pins 17 serve, inter alia, to permit the pin transfer extruder to process for the first time rubber mixtures having qualities which hitherto were not processable with sufficient homogeneity using cold-feed extrusion, even by using specifically optimized pin-barrel extruders. These are natural rubber qualities used, for example, for the production of tank chain supports and tread strip mixtures with the same basic polymer for truck and large earth moving vehicle tires.
If the test results obtained with an extruder of the present invention, identified as GE 150 STx9D type, are collated, it can be ascertained that, compared with the pin-barrel extruder, increases in the discharge rate of 25% to 50% can be achieved with low-viscosity synthetic rubber mixtures up to viscosities of 55 to 60 ML 1+4 (100° C.), with a reduction in the specific energy up to 20%.
With high-viscosity, difficult-to-process natural rubber qualities between 90 to 120 ML 1+4 (100° C.), the advantages are even more relevant since, as was shown, the homogeneity limit of the extruded material with a pin-barrel extruder is already reached with a discharge of approx. 800-1000 kg/h and, in consequence, double rates with the pin transfer extruder appear possible in individual cases.
FIGS. 3 a-c are graphs of test results which were achieved with an extruder of prior art (dotted curves) and a laboratory transfer pin extruder (solid curves) of the present invention, of a comparable size. A natural rubber mixture NK 90-95 ML 1+4 (100° C.) was used as the extruded material, which is known to be highly-viscous and particularly difficult to process. In all three graphs, the speed of 25 revolutions per minute is marked by a vertical line with hatching alongside, up to which speed conventional extruders could process such a rubber mixture and produce a reasonable quality.
In FIG. 3a, the discharge of rubber is plotted in dependence upon the screw r.p.m., while FIG. 3b represents the mass temperature, and FIG. 3c represents the specific energy requirement per kg extruded material, each being a function of the screw r.p.m. The combination of these three graphs shows that, with the concept of an extruder as proposed here, a high discharge of extruded material becomes possible with an excellent mixing and homogenizing effect at a reasonable temperature for the extruded material and with a considerably reduced consumption of energy.
In addition, problems regarding product porosity in the profile, which already arose in the lower performance range in the pin-barrel extruder, could not be found at all in the pin transfer extruder of the present invention.
In conclusion, it should be pointed out that the proposed pin-barrel extruder may be used with or without throttle pins in the transfer section, although throttle pins should not be eliminated in the optimum structural form. Finally, the positioning of such pins permits the extruder to be set to the most varied rubber mixtures and to their processing parameters and, in consequence, it can be used by the operator universally. In a less preferred embodiment, the adjustable throttle pins may also be disposed at the downstream end of the extruder, substantially at the end of the pressure augmenting section 10.
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A pin transfer extruder is provided, wherein the pin-barrel and transfer mixing sections, which are known per se and have only been used individually hitherto, are jointly used in one extruder. Throttle pins, which are disposed in the transfer mixing section in the region of the greatest housing thread volume, permit universal use of the extruder in respect of the extruded material. The combination of both mixing systems permits the throughput of material to be increased in a surprising manner by 60% to 100%, while a constant mixing quality is maintained and the driving torque is halved.
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This application is a continuation-in-part of prior pending U.S. patent application Ser. No. 09/435,646, filed Nov. 9, 1999 now U.S. Pat. No. 6,190,389.
BACKGROUND OF THE INVENTION
This invention relates generally to the alignment and fixation of bone segments as required for appropriate bone healing, for example after fracture or surgical intervention, and specifically to a device, and the tools needed to install the said device, for the alignment and fixation of cranial bone fragments.
In cases of bone fragmentation where bone fixation is desired, the appropriate alignment of the bone is also a desired result. This is especially true in the cranium, where bone fragmentation can occur as a result of trauma, congenital deformity, or of surgical intervention. In the field of neurosurgery, cranial bone fragments are frequently cut and removed to create defects to allow for access into the cranial cavity and the brain.
The bony cranium is generally regarded to have two surfaces: the outer surface which is characterized by the outer cortex of the bone and is adjacent to the scalp and soft tissue; and the inner surface which is characterized by the inner cortex of the bone and which is adjacent to the cranial cavity and the brain. Between the inner cortex and the outer cortex, which are dense layers of bone, lies the diploe which generally consists of soft bone and bone marrow. When a bone fragment is created, a cut between the bone fragment (the primary bone zone) and the remainder of the cranium (the secondary bone zone) is present.
Several methods of alignment and fixation of primary and secondary bone zones are known. Traditional techniques involve the use of several pieces of filament, such as wire, that are tied after being threaded through holes drilled obliquely through the outer cortex to the cut surface of both bone zones. Precise alignment of the two zones can be difficult and the technique can be cumbersome.
Commonly, the zones of bone can be aligned and fixated with a system of plates and screws (U.S. Pat. Nos. 5,372,598; 5,413,577; and 5,578,036). A plate made of metal or other substance can be fixated to the outer cortex of the primary bone zone with screws whose penetration of the bone can be limited to the outer cortex. With three of more plates attached to the primary bone in such a way that the plates protrude beyond the edges of the primary bone zone, the primary bone zone can be introduced into a defect and aligned to the outer cortex of the secondary bone zone without danger of the primary bone zone falling too deeply into the defect in the secondary bone zone and exerting pressure on the underlying tissue such as the brain. Fixation can then be achieved by employing additional screws fixating the plates to the outer cortex of the secondary bone zone. Plates and screws systems allow for the alignment and fixation of the zones, while preventing the primary bone zone from falling below the level of the secondary bone zone without actually introducing a component of the device below the secondary bone zone. A plate with a spring clip extension has been described (U.S. Pat. No. 5,916,217). Plate and screw systems can be expensive and time consuming to use.
Devices that align the two bone zones by way of compressing them between the two disks positioned along the inner and outer cortex have been described. (Foreign Patents: DE 19603887C2, DE 19634699C1, DE 29812988U1, EP 0787466A1.) A pin connects the two disks aligning and securing two bone zones. These devices introduce foreign material that is left below the inner cortex, and they do not protect the underlying tissue from compression during the installation procedure.
Devices that fixate bone zones using friction forces created by a cam without a component that extends below the inner cortex are known and described (Patent DE 19634697C1). These devices also do not protect the brain from compression during the installation procedure.
Intramedulary pins are well known in the orthopedic fields for alignment of long bones. Such pins have also been described for cranial fixation (U.S. Pat. No. 5,501,685); however, the bone zones can not be aligned in three dimensions with this technique.
There is a need for an alignment and fixation device that is simple and rapid to use, versatile, and ultimately cost effective.
OBJECTS OF THE INVENTION
The object of the invention is to provide a device and instruments for its use and installation that aligns one cortex of a primary zone with one cortex of a secondary bone zone without extending to the opposing cortex, and which accurately fixates the bone zones to each other. When used in the field of neurosurgery, the device is applied to the primary bone zone and it aligns the outer cortex of the primary bone zone with the outer cortex of the secondary bone zone; it prevents the primary bone zone from entering the cranial cavity; and it provides fixation of the two bone zones. The alignment feature can be used independently from the fixation feature. An example of the use of the alignment feature is in the replacement of a cranial bone fragment which will be held in place by the tissue forces of the scalp, which allows for the bone fragment to be elevated away from the cranial cavity in cases where brain swelling occurs. Fixation can also be applied to attach the alignment device to the bone, using elements alone or in combination such as filaments, screws, rivets, pins, clips, cams, friction or adhesives. The alignment aspect of the invention can also be applied to situations where it is desired to offset the alignment of the bone fragment to the adjacent bone such as where the object is to create a more prominent chin by cutting the bone of the chin and advancing the bone fragment.
The fixation feature of the invention is likewise independent from the alignment feature. The fixation feature of the device relies on the principle that the device is fixated to the primary bone zone and the fixation feature grips the secondary bone zone by means of spring loaded tab or hook elements engaging the soft areas of the medullary space, irregularities along the cut surface, or a slot cut into the cut surface of the secondary bone zone.
SUMMARY OF THE INVENTION
The invention provides an improved clip meeting the above need or needs.
As will be seen the preferred clip is configured to interconnect primary and secondary bone zones having edges spaced apart by a gap, the clip comprising
a) a tab such as a small plate to extend over and generally parallel to a surface of the secondary bone zone, and above a first level defined by that surface, and
b) a first projection carried by the tab and configured to penetrate the primary bone zone at the edge thereof, and below said surface level.
As will be seen, a second projection may be provided and carried by the tab and configured to engage the secondary bone zone at the edge thereof, and below said surface level.
It is another object to provide an extension of the tab projecting below said first level. That extension may carry the first projection, and may carry the second projection, if it is provided. In this regard, the second projection is typically located beneath the tab; and the first projection extends generally parallel to the tab and forwardly from a part of the tab extension below said surface level, and it preferably has a sharp terminal to enable penetration of diploe.
A further object is to provide the second projection to have a sharp terminal, and to extend at an angle toward the tab, in order to resist removal relative to the secondary bone zone.
Yet another object is to provide another second projection carried by the tab in sidewardly spaced relation to the first mentioned second projection, and configured to engage the secondary bone zone at the edge thereof, and below said surface level.
An additional object is to provide a tab extension as referred to, but having S-shape or configuration, whereby enhanced spring support of one or both projections is realized; and also the S-shape of the extension facilitates its formation or manufacture.
An additional object is to provide a plate or flap defining the primary bone zone, and to provide multiple of the clips having their first projections penetrating the primary bone zone at different edges thereof, below a surface defined by the plate or flap.
The method of using the clip as referred to includes the steps
i) advancing the first projection to penetrate the primary bone zone,
ii) and locating the tab to extend over the surface of the secondary bone zone, and attaching the tab to that surface.
As will be seen, the step i) preferably includes pushing the clip toward the primary bone zone to effect push-in penetration of the first projection into the primary bone zone. The method may further include providing a second projection carried by the tab and configured to engage the secondary bone zone at the edge thereof, and below its top surface level, the method including displacing the clip and said second projection to engage the secondary bone zone at the edge thereof, below said surface level. An additional step includes displacing the clip in a direction to effect scraping of the edge of the secondary bone zone by the second projection, the second projection oriented to resist reverse displacement of the clip in an upward or opposite direction relative to the secondary bone zone. In this regard, the method may include effecting penetration of the edge of the secondary bone zone by the second projection in an angular direction toward the tab. The bowed or S-shape of the extension provides enhanced spring effect to aid in effecting such penetration.
These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which:
DRAWING DESCRIPTION
FIG. 1 is a perspective view showing a bone flap fixated on a skull, employing fixation clips;
FIG. 2 is an enlarged perspective view showing a clip employing the invention;
FIG. 3 is a top plan view of the FIG. 2 clip;
FIG. 4 is an end view of the clip taken on lines 4 — 4 of FIG. 3;
FIG. 5 is a side elevational view taken on lines 5 — 5 of FIG. 3;
FIG. 6 is a plan view of a clip blank in one plane, prior to deformation to FIG. 2 configuration;
FIG. 7 is a section showing the FIG. 1 clip attached to primary and secondary bone zones;
FIG. 8 is a perspective view showing clip attachment to a primary bone zone;
FIG. 9 shows multiple clips attached to opposite edges of a bone flap defining primary bone zones;
FIG. 10 shows the clips installed in a skull opening;
FIG. 11 is a perspective view like FIG. 2, showing a modified clip;
FIG. 12 is a perspective view like FIG. 11 showing another modified clip;
FIG. 13 is a perspective view similar to FIG. 8, and showing attachment of a clip of FIG. 11 form, to a primary bone zone, such as a bone flap;
FIG. 14 is a section taken through a cranial bone flap, having two FIG. 11 type clips attached at opposite edges, and positioned for clip attachment to secondary bone zone sections;
FIG. 15 is a perspective view showing a cranial bone flap having four FIG. 11 type clips attached, at its four edges;
FIG. 16 is a perspective view of a further modified clip, of FIG. 2 type;
FIG. 17 is a perspective view of a tool usable in conjunction with the FIG. 16 clip, to effect penetration of a clip projection into a primary bone zone;
FIG. 18 shows use of a barb;
FIG. 19 is a top plan view of a further modified clip using a barb;
FIG. 20 is an end view taken on lines 20 — 20 of FIG. 19;
FIG. 21 is a side elevational view taken on lines 21 — 21 of FIG. 19;
FIG. 22 is a plan view of a clip blank in one plane, prior to deformation to FIG. 19 configuration;
FIG. 23 is a perspective view of a modified clip, of the type shown in FIG. 16;
FIG. 24 is a top plan view of the FIG. 23 clip;
FIG. 25 is a front elevation view of the FIG. 24 clip, and taken on lines 25 — 25 of FIG. 24;
FIG. 26 is a right side elevation taken on lines 26 — 26 of FIG. 24;
FIG. 27 is a view like FIG. 26, but showing use of the clip of FIGS. 23-26, in the manner of FIG. 21;
FIG. 28 is a view like FIG. 24, but showing a further modification; and
FIG. 29 is a front elevation of the FIG. 28 modified clip, taken on lines 29 — 29 of FIG. 28 .
DETAILED DESCRIPTION
Referring to FIGS. 2-5 and 7 , the illustrated clip 10 is configured to interconnect primary and secondary bone zones 11 and 12 having opposed and spaced apart edges 11 c and 12 c. A cut or gap 13 is formed between the opposed edges of the primary and secondary bone zones. Diploe is shown at 15 between the top and bottom surfaces 11 a and 11 b of zone 11 ; and at 16 between the top and bottom surfaces 12 a and 12 b of zone 12 . As also seen in FIG. 1, primary bone zones 11 may be defined by bone flap 17 ; and secondary bone zones 12 may be defined by skull 18 and its zone extents at 12 opposing zones 11 . In the adult, cranial bone or skull averages 7 mm in thickness, but varies between 3 and 12 mm.
The clip 10 , which is preferably metallic includes the following
a) a tab 20 to extend over a surface 12 a of the secondary bone zone 12 , above surface level and generally parallel to surface 12 a;
b) a first projection 21 carried by the tab and configured to penetrate the exposed diploe of the primary bone zone 11 at the edge 11 c of that zone (and typically into diploe 15 );
c) and at least one second projection 22 carried by the tab and configured to engage (for example gouge into) the exposed diploe of the secondary bone zone 12 at its edge 12 c, below the level of surface 12 a.
In the example, two such second projections are provided, as is clear from FIGS. 4 and 6, and they are located at opposite sides of a lengthwise plane 23 bisecting the clip, including projection 21 . See FIGS. 4 and 6. Such projections are equally spaced from plane 23 , as indicated by dimensions D 1 , seen in FIG. 4 . The projections 21 and 22 have legs 21 a and 22 a, and their terminals are sharpened at 21 b and 22 b, to facilitate penetration of the diploe zones, as seen in FIG. 7 . Leg 21 a and projection 21 extend forwardly in direction 24 from a tab downward extension 20 a; and projection 22 extends back upwardly at an approximate angle of 30° toward the underside of the tab 20 . Note that leg 22 a extends from tab extension 20 a and is U-shaped. A bend is formed at 22 d. Projections 22 may also diverge laterally oppositely, as seen in FIG. 4, to provide greater stability of the plate or flap 17 , as in FIG. 10 installed condition. Four edges 11 c of that flap are seen in FIGS. 1 and 9, and corresponding four edges 12 c of the skull face the flap edges and receive penetration of the stabilizing clip projections 22 , as described.
The method of use of the clip or clips includes the following steps:
i) causing the first projection or projections 21 to penetrate the primary bone zone or zones;
ii) and then causing the second projection or projections 22 to grip the secondary bone zone at the edge thereof.
Step i) includes pushing the clip 10 relatively toward the edge 11 c of the primary bone zone 11 , as in direction 30 seen in FIG. 8 . This effects push-in penetration of the first projection 21 into the bone zone 11 , as for example into diploe 15 . Push-in is typically completed when bent down tab extension 20 a closely approaches and/or engages edge 11 c of the primary bone zone 11 defined by the plate or flap 17 . Four such pushed-in clips are seen in FIG. 9, the clips located in opposed pair positions, at four sides of the flap 17 . Each tab 20 has a through hole 40 drilled or formed therein to receive a fastener such as a retention screw, indicated at 41 in FIG. 5, to penetrate and attach to the skull proximate the secondary bone regions.
The step ii) preferably also includes displacing the clip in a direction (typically relatively downwardly toward the skull to bring 21 , 22 , and 20 a into gap 13 as seen in FIG. 7) to effect scraping of the edge 12 c of the secondary bone zone 12 by the tip of the angled second projection. That projection is oriented, i.e. angled, to resist displacement of the clip in an upward or opposite direction, relative to bone zone 12 . For example, attempted upward and outward displacement would increase the “gouge-in” movement of the second projection, into the diploe 16 .
Note further that the installed spacing d 2 of the bone zone edges 11 c and 12 c is slightly less than the spacing d 3 as measured from the sharp terminal of the projection 22 to the surface 32 of the tab extension facing the edge 11 c. The width d 2 of gap 13 between 11 c and 12 c is slightly less than the dimension d 3 , i.e.
d 2 <d 3 ,
to provide a desirably tight installation of plate 17 into the corresponding skull opening.
In FIG. 3 note angularity β of the sharpened taper of projection 21 , where β is approximately 67°, and the through opening 43 in tab extension 20 a to receive a fastener 44 (if used to attach extension 20 a to 11 .
Projections 22 can resiliently deflect, slightly to accommodate the multiple clips to the gaps 13 between 11 and 12 , as during plate or tab downward installation, as seen in FIG. 10 .
Reference is now made to the modified clip 110 of FIGS. 11 and 14. It includes:
a) a tab or plate 120 to extend over a surface 112 a of secondary bone zone or zones 112 (see FIG. 14 ), above a level defined by that surface; and
b) a first projection 121 carried by the tab 120 , and configured to penetrate the edge of exposed diploe 111 a of primary bone zone 111 , below the levels of tab 120 and surface 112 a.
The projection or tang 121 has a leg 121 a, and its forward terminal is sharpened at 121 b to facilitate penetration into the bone marrow zone, as seen in FIG. 14 . Leg 121 a extends forwardly from a tab downward extension 120 a in the form of a flange. The method of use of the clip 110 includes the following steps:
i) causing the projection 121 to penetrate the primary bone zone, such as into diploe, (see FIG. 13 ); and
ii) locating the tab 120 to extend over the surface 112 a of the secondary bone zone, as in FIG. 14 for example, and attaching the tab to that surface, one mode of attachment being by use of a screw seen at 150 in FIG. 14, to penetrate through a hole 151 in tab 120 , and into secondary bone zone 112 .
FIG. 14 shows two such clips 110 attached to opposite edges 111 b and 111 c of a primary bone zone 111 , such as a flap removed from the skull. When the flap is attached to the skull, as into opening 130 , the tabs 120 are attached to the upper surfaces 112 a of the skull, at opposite sides of the opening. FIG. 15 shows four such clips attached to the flap 111 , at four edges 111 b- 111 e.
FIG. 12 illustrates a modified clip 210 , having elements 220 , 220 a, 221 , 221 a and 221 b, like corresponding elements of clip 110 . Extension 120 a in FIG. 11 has two laterally spaced legs 120 a′ and 120 a″ that extend downwardly below the level of projection 121 , and projection 121 has flat upper and lower surfaces; whereas in FIG. 12 the extension lower extent 220 a′ is laterally continuous, and projection 221 is cylindrical, and tapers at its forward end.
A further modified clip 250 is shown in FIG. 16, and has elements like those of clip 10 , as viewed in FIGS. 2-7. Such corresponding elements are given the same numbers. Also, the clip downward extension 20 a has left and right wings 20 a′ and 20 a′.
FIG. 17 shows a hand tool 80 to receive the FIG. 16 clip in position for forward, push-in attachment to bone zone 11 , as described. Tool 80 has a body 81 , with a top recess 82 to fit the tab 20 . Forward facing surface 83 engages and positions the clip downward extensions 20 a and its two wings 20 a′ and 20 b′. Tool pins 84 and 85 closely fit into holes 86 and 87 in those two wings, for alignment. Aligners in the form of alignment bars 87 and 88 projecting forwardly from body 81 ride onto the top surface 11 a of the flap 11 , prior to penetration of the projection 21 a into the marrow 15 , so that the proper level of the projection 21 relative to top surface 11 a is selectively established by operation of the aligners. A tool handle appears at 89 , and facilitates forward pushing of the tool and clip, and retraction of the tool, off the clip after its push-in assembly to the flap. In this way, accurate assembly is rapidly achieved.
The clips as disclosed herein may consist of metal or plastic (synthetic resin) material. One desirable metal is titanium.
Clips 10 , 110 , and 210 may be inverted, for alternate installations relative to the bone zones.
Referring to FIGS. 19-22, the illustrated views of modified clip 200 correspond to views 3 - 6 of clip 10 .
The clip 200 , which is preferably metallic, includes the following:
a) a tab 220 to extend over a surface 212 a of the secondary bone zone 212 above surface level;
b) a first projection 221 carried by the tab and configured to penetrate the exposed diploe of the primary bone zone 211 at the edge 11 c of that zone (and typically into diploe 215 );
c) and at least one second projection such as barb 222 carried by the tab and configured to engage (for example gouge into) the exposed diploe 216 of the secondary bone zone 212 , below the level of surface 212 a.
In the example, two such second projections or barbs 222 are provided, as is clear from FIGS. 20 and 22, and they are located at opposite sides of a lengthwise plane 223 bisecting the clip, including projection 221 . One such barb is seen in FIG. 18 . Such projections are equally spaced from plane 223 , and are formed in lower portions 222 a of 220 a, with adjacent through openings 222 a′. The projection 221 has a leg 221 a, and its terminal is sharpened at 221 b, to facilitate penetration of the bone zone 215 , as seen in FIG. 21 . Leg 221 a and projection 221 extend forwardly from a tab downward extension 220 a; and projection or barb 222 extends back upwardly at an acute toward the underside of the tab 220 . Note that projection 222 extends from tab lower extension 220 a and is U-shaped. A bend is formed at 222 d.
Side wings 240 and 241 integral with downward extension 220 a contain through openings 243 to receive fasteners (if used) to attach to 221 .
Referring to FIGS. 23-27, the illustrated and preferred clip 310 is configured to interconnect primary and secondary bone zones 311 and 312 having opposed and spaced apart edges 311 c and 312 c. A cut or gap 313 is formed between the opposed edges of the primary and secondary bone zones. Diploe is shown at 315 between the top and bottom surfaces 311 a and 311 b of zone 311 ; and at 316 between the top and bottom surfaces 312 a and 312 b of zone 312 . As also seen in FIG. 1, primary bone zones 11 may be defined by bone flap 17 ; and secondary bone zones 12 may be defined by skull 18 and its zone extents at 12 opposing zones 11 . In the adult, cranial bone or skull averages 7 mm in thickness, but varies between 3 and 12 mm.
The clip 310 , which is preferably metallic includes the following
a) a tab 320 to extend over and generally parallel to a surface 312 a of the secondary bone zone 312 , above surface level;
b) a first projection or tang 321 directly or indirectly carried by the tab and configured to penetrate the exposed diploe of the primary bone zone 311 at the edge 311 c of that zone (and typically into diploe 315 ); and wherein the tang 321 may have barbed edges at 321 d and 321 e;
c) and at least one second projection 322 carried by the tab and configured to engage (for example gouge into) the exposed diploe of the secondary bone zone 312 at its edge 312 c, below the level of surface 312 a.
In the example, two such second projections are provided, as is clear from FIGS. 23-25, and they are located at opposite sides of a lengthwise plane 323 bisecting the clip, including projection 321 . Such projections are equally spaced from plane 323 , as indicated by dimensions D 1 , seen in FIG. 24 . The projections 321 and 322 have legs 321 a and 322 a, and their terminals are sharpened at 321 b and 322 b, to facilitate penetration of the diploe zones, as seen in FIG. 7 . Leg 321 a and projection 321 extend forwardly in direction 324 from a tab downward extension 320 a; and projections 322 extend back upwardly at an angle γ between 25° and 45° toward the underside of the tab 320 . Note that each projection 322 extends from tab ring-shaped extension 320 a and is U-shaped. A bend is formed at 322 d.
Four edges 11 c of the flap 17 are seen in FIGS. 1 and 9, and corresponding four edges 12 c of the skull face the flap edges and receive penetration of the stabilizing clip projections 22 or 322 , as described.
It will be noted that the generally upright extension 320 a is bowed to produce an enhanced spring effect for urging one or more of the projections, and also to facilitate ease of manufacture. See extension sections 380 and 381 , the former bowed frontwardly in the direction of projection 321 ; and the latter section 381 bowed in the general direction of the projections 322 extents. Section 380 is curved at 380 a to merge with the tab. Projection 321 is carried by section 380 , and projections 322 are carried by section or sections 381 , whereby movements of the projections 322 are isolated from movements of the projection 321 , enhancing completeness and permanence of fastening to bone. See for example FIG. 25, showing such isolation.
The method of use of the clip or clips includes the following steps:
i) causing the first projection or projections 321 to penetrate the primary bone zone or zones;
ii) and causing the second projection or projections 322 to grip the secondary bone zone at the edge thereof.
Step i) includes pushing the clip 310 relatively toward the edge 311 c of the primary bone zone 311 , as in direction 324 seen in FIG. 27 . This effects push-in penetration of the first projection 321 into the bone zone 11 , as for example into diploe 15 . Push-in is typically completed when bent-down and bowed tab extension 380 closely approaches and/or engages edge 311 c of the primary bone zone 311 defined by the plate or flap 17 (or bone zone 311 ). As described above, four pushed-in clips are seen in FIG. 9, the clips located in opposed pair positions, at four sides of the flap 17 . Each tab 320 has a through hole 340 drilled or formed therein to receive a fastener such as a retention screw, indicated at 41 in FIG. 5 and also in FIG. 27, to penetrate and attach to the skull proximate the secondary bone regions.
The step ii) preferably also includes displacing the clip in a direction (typically relatively downwardly toward the skull to bring 322 , and 320 a into gap 313 as seen in FIG. 27) to effect scraping of the edge 312 c of the secondary bone zone 312 by the tip or tips of the angled second projection or projections. Projection or projections 322 is or are oriented, i.e. angled, to resist displacement of the clip in an upward or opposite direction, relative to bone zone 12 . For example, attempted upward and outward displacement would increase the “gouge-in” movement of the second projection, into the diploe 16 .
As described above, the installed spacing d 2 of the bone zone edges 11 c and 12 c is slightly less than the spacing d 3 as measured from the sharp terminal of the projection 322 to the surface 332 of the tab extension facing the edge 311 c. The width d 2 of gap 13 between 311 c and 312 c is slightly less than the dimension d 3 , i.e.
d 2 <d 3 ,
to provide a desirably tight installation of plate 17 into the corresponding skull opening.
Projections 322 can resiliently deflect, as by spring bending of sections 381 , to accommodate the multiple clips to the gaps 13 between 11 and 12 , as during plate or tab downward installation, as seen in FIG. 10 . In FIG. 25, the lateral spacing of bowed sections 381 enhances clip installed stability.
Reference is now made to FIGS. 28 and 29 showing a clip 350 like clip 310 ; except that projection 321 is carried by an L-shaped arm 370 having horizontal and vertical extents 370 a and 370 b. The former extent 370 a is integral with the tab at 372 , horizontally spaced from 370 b , the tab being relieved at horizontal slits 373 along the edge lengths of 370 a, providing for greater or enhanced bending movement of the arm 370 , as during penetration of the projection 321 into bone tissue. Projection 321 is integral with the vertical extent 370 b of the arm. Projections 322 are carried and formed as in FIGS. 23-27.
The clips as referred to above are metallic, and preferably consist essentially of one of the following:
i) titanium
ii) titanium alloy
iii) an alloy consisting essentially of titanium, aluminum and vanadium
iv) an alloy consisting essentially of:
about 90% by weight of titanium
about 6% by weight of aluminum
about 4% by weight of vanadium.
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This invention concerns a device, and instruments for its insertion, that aligns two sections of bone and fixates the two sections to one another. The alignment feature and the fixation feature are typically independent, but they are incorporated into one device. The device is particularly well adapted to the alignment and fixation of a fragment of cranial bone with the remainder of the cranium. The device can be applied to a cranial bone fragment, and it allows the bone fragment to be aligned with the outer cortex of the cranium; prevents the bone fragment from entering the cranial cavity; and if desired, fixates the bone fragment to the cranium. The device may take the form of a clip having a tab to surface engage one section of bone, two projections to respectively engage edge portions of two bone sections, and an S-shaped flange integral with the tab and at least one of the projections.
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FIELD OF THE INVENTION
[0001] This invention relates to probes for measuring density and strength characteristics of soil or snow.
BACKGROUND TO THE INVENTION
[0002] Soil or snow strength characteristics in vertical plane are important in determining load bearing capacity and in snow characterisations of the snow layers is important in predicting the likelihood of avalanches.
[0003] U.S. Pat. No. 4,806,153 discloses a soil penetrometer incorporating sensors to measure penetration resistance and pore water pressure and a recording and control unit to store the sensor readings for transfer to an above ground computer for analysis.
[0004] U.S. Pat. No. 6,062,090 discloses a method and penetrometer for measuring as a function of time the resistance to penetration of a soil bed for evaluating highway and railroad bed surfaces.
[0005] Since the middle of the century there have been several hundred documented fatal avalanche accidents claiming hundreds of lives. Recent years have seen an increase in the occurrence of fatalities. Over 80% of the fatalities are climbers, back country skiers, out of bounds down hill skiers and snowmobiles.
[0006] U.S. Pat. No. 5,831,161 discloses a snow penetrometer in which the penetrating head is mounted on a tripod and driven at constant speed. A force transducer measures the resistance so that a resistance profile through a vertical section can be obtained.
[0007] U.S. Pat. No. 5,864,059 discloses a probe for measuring snow depth that uses a floating plate that slides on the shaft and a magnetorestrictive transducer filament senses the travel of the shaft.
[0008] The commonly used method for predicting avalanches is to dig a trench [called a snow pit] to assess snow pack stability from the stiffness and temperature in the snow wall. This takes about 35 minutes and does not provide a cross-slope profile of a slope unless several snow pits are dug. The snow penetrometers discussed above do not provide a measure that can be used to predict the likelihood of an avalanche.
[0009] It is an object of this invention to provide a probe that can provide a vertical profile of soil or snow strength parameters and other soil or snow condition parameters such as water content or temperature and present this data to assist in assessing stability.
BRIEF DESCRIPTION OF THE INVENTION
[0010] To this end the present invention provides a penetrating probe for testing soil or snow stability which includes
a) a head shaped for penetrating soil or snow b) a sensing unit mounted in said head to sense the resistance to penetration which includes a load cell incorporating a low duro polymer wherein the impact of the head impacting the soil or snow is transferred to the low duro polymer c) an accelerometer to sense the acceleration of the head as it moves d) a processor able to receive signals from said sensing unit and programmed to analyse the data and present it as a vertical profile of penetration resistance with depth of penetration.
[0015] By positioning the sensor unit in the head and not at the end of the shaft as proposed in U.S. Pat. No. 5,831,161 noise from the vibration of the drive shaft is eliminated and makes interpretation of the sensor signals easier.
[0016] An important advantage derived from the use of the accelerometer is the ability to manually insert the probe into soil or snow. The manual insertion results in acceleration and velocity changes from which the distance travelled can be calculated knowing the time taken. The distance traveled gives the depth of snow and by correlating the resistance to penetration with time the resistance at different depths can be calculated and graphed.
[0017] This invention is partly predicated on the discovery that using a low duro polymer in the load cell reduces the interference of external noise in the load cell signals.
[0018] In another aspect this invention provides a force sensor which includes
a) a low duro polymer b) an impact head arranged to seat on said low duro polymer such that forces acting on said impact head are transmited to said low duro polymer c) a sensor in contact with said low duro polymer to provide a measure of the forces transmitted to said low duro polymer.
[0022] The low duro polymer preferably has a low shore hardness of 5 to 30 more preferably 8-10 and may be selected from rubber like materials preferably with linear compression gradients such as natural and synthetic rubbers, polyurethanes and preferably silicone polymers such as those sold by Dow Corning. It is preferred that the material has a low coefficient of thermal expansion, low shear strength, a high bulk modulus and remains flexible at low temperatures. The selected low duro polymers provide an hydraulic advantage with low hysteresis.
[0023] The load cell preferably consists of at least one strain gauge mounted to sense the variation in impact forces imparted to the low duro polymer. The low duro polymer is selected on its ability to behave as a non-compressible fluid. The load cell abuts the shaped impact portion of the head or a shaft on which the impact portion is mounted. The interface between the impact shaft and the load cell polymer is spherically domed. The shaped head is preferably domed.
[0024] This load cell of this invention does not suffer from noise in the signals due to the use of the low duro polymer and because of the combination of the polymer and the shape of the bearing area on the polymer the sensitivity is much greater than for sensors of comparable cost. Sensitivity is of the order of 0.1 grams in 40 kgms or 1:400,000.
[0025] The use of an accelerometer eliminates the need for the head to have a constant velocity and enables the head to be manually driven in the soil or snow and does away with the need for a constant velocity penetrometer which requires a tripod, a motor and a drive shaft. This saves component cost and improves the portability of the probe. The accelerometer may be part of the sensing unit or a separate unit in the head or may be at any point on the probe shaft to which the head is attached as long as its movement parallels the movement of the head.
[0026] Thus in another aspect the present invention provides a penetration probe which includes
a) a head shaped for penetrating soil or snow b) a sensing unit mounted in said head to sense parameters of the soil or snow c) an accelerometer to sense the acceleration of the head as it moves d) a processor able to receive signals from said accelerometer and programmed to analyse the accelerometer data and present it as a measurement of depth of penetration e) said processor also receiving signals from said sensing unit and programmed to analyse the sensing signals as a function of depth of penetration.
[0032] The sensor unit may also incorporate sensors other than resistance to penetration sensors. For determining snow stability, a vertical temperature profile of the snow is an important guide to the likelihood of future metamorphism of the snow layers and the likelihood of an avalanche. Thus a temperature sensor capable of measuring the changes in temperature as the penetrometer moves through the snow is an important addition to a snow probe.
[0033] Another method of measuring snow properties is to measure snow density using a capacitor to measure changes in the capacitance which varies with the density of the snow.
[0034] Water content as measured by moisture levels or water pressure is an important guide to soil stability and its capacity to bear loads. A water sensor or water pressure sensor is therefor a desirable addition to the sensor unit when the probe is intended for soil testing.
[0035] For snow testing additional information can be gleaned from the penetration resistance data if multiple heads are used. An array of 3 heads equally spaced from the central shaft and of different diameters will provide 3 different resistance readings due to the different ratios of circumferences of the impact heads in relation to the bearing area. This enables vertical and or shear strength of the snow to be determined.
[0036] In another aspect this invention provides a method of assessing the stability of a snow slope which includes the steps of
a) using a probe to produce a profile of resistance to penetration as a function of penetration depth b) repeating step a) at different points on the slope c) integrating the results of step b) to produce a profile of the slope
[0040] This enables a slope to be assessed for avalanche risk in a very short time.
[0041] Preferably the measurements are made at several points in line across a contour of the slope and several such lines down the slope are measured and analysed. Alternatively lines of points down the slope may be measured. The points are preferably 10 to 15 metres apart and the contour lines are 50 to 75 metres apart. The best sections of a slope to take points on are adjacent convex rolls as experience shows that these are more likely sites for avalanches.
DETAILED DESCRIPTION OF THE INVENTION
[0042] A preferred embodiment of this invention is a snow probe for testing the stability of snow slopes in order to assess the risk of avalanches.
[0043] FIG. 1 illustrates a schematic view of the sensor head of this invention.
[0044] FIG. 2 shows a detail of the penetrating heads of the other two sensor tubes in the device of FIG. 1 ;
[0045] FIG. 3 is a schematic cross section of another version of a sensor tube according to this invention;
[0046] FIG. 4 is an exploded view of the sensor tube of FIG. 3 ;
[0047] FIG. 5 is a schematic cross section of another version of the penetrating tip according to this invention;
[0048] FIG. 6 is a cross sectional view of the shaft and load cell tip of the device shown in FIG. 3 ;
[0049] FIG. 7 is a view of the gland nut that fits about the shaft of FIG. 6 ;
[0050] FIG. 8 is a cross sectional view of the load cell from the sensor tube of FIG. 3 ;
[0051] FIG. 9 illustrates data from a probe into a snow pack;
[0052] FIGS. 10 to 13 are plots of a multiple set of readings across a snow slope.
[0053] The snow probe equipment required for the present invention is a probe head containing the sensors attached to a collapsible shaft up to 5 metres in length with a portable control box containing the programmed controller and processor and a display screen or printer for displaying the output.
[0054] As shown in FIG. 1 the probe has a central shaft 11 and 3 sensor tubes 12 equally spaced from each other and the central shaft 11 .
[0055] The sensor tubes 12 are rigidly attached to the shaft 11 by way of the struts 13 .
[0056] At the lower end of each sensor tube 12 is a penetrator head 20 which is of a predetermined diameter. Each of the 3 heads 20 is of varying diameter up to a diameter equal or greater to the diameter of the sensor tube 12 . Each penetrator head, 20 in FIG. 1 and 20 A and 20 B in FIG. 2 , is domed to present a shaped surface to provide an optimum resistance to penetration. Each penetrating head 20 , 20 A or 20 B is mounted on a piston 22 that is mounted within the sensor tube 12 . The piston 22 is seated on the low duro silicone polymer 25 of the load cell 24 . The ratio of the sensing head area to the bearing area is about 1:8 which increases the signal about 20 times
[0057] The load cell has a strain gauge attached to sense to sense the pressure generated in the low duro polymer by the penetrator head passing through the snow. The low duro polymer is Silastic 3487 sold by Dow Corning with a hardness of Shore A 8-10. The strain guage is a Micro Measurements E A 06-228 JB of 350 ohm.
[0058] The second version of the sensor tube as illustrated in FIGS. 3,4 and 6 - 8 includes a penetrating tip 30 having a domed head. A sharper tip is shown in FIG. 5 where the tip 50 is shown in cross section with the cavity 51 to accommodate the shaft 33 and a wider cavity 52 to accommodate the spring 32 .
[0059] The nut 31 slides down the top of the shaft 33 to abut the cylindrical flange 65 shown in FIG. 6 .
[0060] The body of the tip 30 fits within the gland nut 35 shown in more detail in FIG. 7 the shaft 33 , 63 passes through the tube 76 . A screw threaded lock can be inserted in the hole 77 to lock the shaft 33 , 63 when the sensor tube is not in use. The transducer or load cell 37 seats about the top of the gland nut 35 so that the end 34 ( FIG. 3 ) and 64 ( FIG. 6 ) of the shaft 33 sits on the low duro polymer 38 . The end of the gland nut 35 , 75 seats in the widened portion 85 of the load cell 87 ( FIG. 8 ). A strain guage 40 lies across the base of the polymer 38 . The electronics circuitry 41 for the strain guage 40 (shown as 86 in FIG. 8 ) is housed in the housing 39 . The housing 39 and the load cell 37 ( 87 in FIG. 8 ) are contained within tube 36 the tube 36 is attachable to the main shaft 43 . The probe is protected from damage by overload, by the provision of shaft screws.
[0061] The load cell is formed by casting the low duro polymer into the recess containing the strain guage with a domed shaft end similar to that of the end 64 of the pentetrometer shaft 63 to shape the cast polymer. The curved interface between the polymer 38 and the base 64 of the penetrometer shaft ensures repeatability of the measurements and prevents fragments of the polymer being dislodged. The polymer material is such that although it behaves as a fluid it does not creep up the shaft.
[0062] An accelerometer [not shown] is mounted on the central probe shaft. The accelerometer is preferably a solid state micro electromechanical sensor which generates an electrical signal based on the speed of change of its position. The preferred accelerometer is an ADXL 105 single axis with a range of ±5 gm an analogue output ratiometric to supply 2 mg resolution, a 10 KHz bandwidth an on board temperature sensor, low power and voltage 0.2 mA at 5V operation down to 2.7 V.
[0063] The readings from the accelerometer are integrated twice to give depth measurements from the surface and is accurate to within a mm per metre.
[0064] During the push or insertion of the probe three primary signals are taken with a resolution of 500 readings per second. In snow these signals are acceleration, force and temperature. The process is as follows:
1. the acceleration is integrated to velocity and a check is made based on start and finish to ensure velocity is zero at both ends of the measured push. 2. data slope adjustments are performed to modify the signals which is then integrated again. Once the velocity is zeroed a final integration is performed to compute displacement 3. over sampling is used during integration to ensure noise reduction in the signal; 4. the displacement is then related to the force reading which is also oversampled and averaged. 5. once the velocity of the push is calculated a look up table can be used based on the force and velocity to cancel out any inertial effe3cts leading to incorrectforce cradings due to strain hardening of the snow pack. 6. the data is stored to flash memory 7. Frequency decimation and smoothing of the data is performed to allow display on a graphics screen with limited re4solution and to allow pattern recognition 8. Frequency decimation ensures that all peaks and valleys are maintained during smoothing. 9. Approximately 8000 readings sre decimated to around 120 10. A pattern recognition program is is used to break up the readings into layers more commonly used by ski guides.
[0075] In FIG. 9 a single probe measurement shows the penetration resistance plotted against depth. The layer was about 800 mm deep and the plot shows a weakness at about 500 mm indicative of instability which can lead to an avalanche.
[0076] This data is down loaded onto a portable computer for analysis and presentation as a screen report.
[0077] FIG. 10 shows a succession of probe measurements which in FIG. 11 are plotted as depth versus distance across slope with colours indicating the hardness of the snow. In FIGS. 12 and 13 this data is presented on a three axis contour chart.
[0078] The controller for the probe contains software to provide a read out of the results of an insertion of the probe. This controller may be a handheld computer.
[0079] The following description of the probe operation relates to one particular embodiment of the invention.
[0080] As the probe is inserted data is generated from the force probe the accelerometer and the temperature probe and stored into a temporary buffer during the push.
[0081] A/d conversion starts immediately and the data is put into the FIFO. When the conversion is stopped the most recent 16.384 s of data are preserved to allow an arbitrary set up time. For analysis the probe is expected to be at rest for 0.5 s at the beginning and end of the data in the FIFO.
[0082] The two main data transformations are to analyse the acceleration and analyse the force data.
[heading-0083] Acceleration Algorithm
[0084] The start and end points are not zero due to low frequency noise in solid state accelerometers. This means that integration to velocity gives values even when the probe is at rest and thus the low frequency noise gives a positional error. To correct for this effect an iterative process is used to straighten the velocity and acceleration to give a zero velocity at rest.
2. straighten acceleration
get mean of start segment [pause time before push] get mean of end segment [pause time before push] find slope between start and end [should be zero] if not zero then adjust acceleration based based on a non zero slope
3. straighten velocity
integrate acceleration to velocity get mean of start segment [pause time before push] get mean of end segment [pause time before push] find slope between start and end [should be zero] ie: zero velocity if not zero then adjust acceleration based based on a non zero slope
4. find new limits
find the start and end position of scan from the trial velocity adding ±50 data pointes as a safety margin so as not to cut off non paused data. This subroutine minimizes the effect of the slope adjustment leading to a negative/positive velocity/positional effect at the beginning and end of the scan after the first adjustment. Find maximum and minimum of velocity Set threshold Find start Subtract margin Find end Add margin
5. Use the new limits
Repeat steps 1
6. Integrate new velocity profile to position
Analyse Force
[0108] The algorithm used is analogous to that used by a guide during a snow pit test each layer is stored with depth and an additional algorithm is used to determine the appropriate force for that layer. A look up table is used to correlate the force reading to a hand scale used by guides.
[0109] The force data is converted from bit data to mV/N using calibration factors. It should be noted that snow may have inertial effects causing strain rate sensitivity. This means that if the speed of the probe is varied the force required will change. Hence based on velocity of the push through each layer a correction factor can be introduced modifying the force to the correct value.
[0110] This will not be needed if inertial effects are not observed.
[heading-0111] Analysing Force Data for Layer Interpretation, Storage and Display
[0112] The initial force data is 8192 readings which is the default size of the FIFO buffer.
[heading-0113] Storage
[0114] To enable storage of as many scans as possible the data is decimated to 1000 readings
1. divide data into equal length [positions] bins to give 1000 bins 2. find the maximum value in each bin. This becomes the new force value 3. store the new force and positions to flash memory.
Display
[0119] The graphics display used in this embodiment has only 128 pixels and hence only 120 points can be displayed
1. divide data into equal length [positions] bins to give 1000 bins 2. find the maximum value in each bin. This becomes the new force value 3. display to graphics screen
Layer Interpretation
[0124] The layer interpretation is based on using a number of logic statements for pattern recognition in the force-position data.
[0125] The routine may use a single pass [iteration] nine possible events are considered to ascertain whether a layer change has occurred, the type of layer and whether the layer is constant or stiffens or softens within the layer. A typical value of force for each layer is designated and correlated to the standard pit test. This gives rise to one of 5 designations.
FIST HAND FINGER PEN KNIFE
[0131] The data is then displayed on the graphics screen as text form
Layer number, Force in Newton's of each layer, depth of layer, Designation of each layer, slope of each layer as a + increasing
− decreasing N no change in layer
[0139] The probe can be manually inserted into the snow and a reading obtained within two minutes. An entire slope can be measured in the time it takes to dig a single snow pit. To obtain a cross slope projection the point data can be processed into a 3 dimensional image using software such as tech plot that provides images such as those in FIGS. 5 and 6 .
[0140] From the above it can be seen that this invention provides a soil or snow probe that can give point data for the strength/depth measurements which can be taken quickly and which can be processed to give a profile of the layers of a soil area or a snow slope. The absence of subjective interpretation allows the collection of objective quantitative measurements of snow pack strength and enables an assessment to be made of stability.
[0141] Although this invention has been described in relation to one embodiment of a snow probe those skilled in the art will realise that the invention is adaptable to being used for any material where a manual insertion to measure properties that are depth related is required such as soil, sand or bogs.
[0142] Variations and modifications may be made to adapt this device and method to provide additional sensed data such as temperature or water content in soils.
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A soil or snow probe which incorporates a load cell in the probe head and also an accelerometer so that a vertical strength profile of the snow or soil can be established. The device does not need to be driven at a constant speed and can be manually driven into the soil or snow. The resistance to penetration is measured using a load cell which incorporates a low duro polymer selected for its ability to behave like a non compressible fluid. The device is portable and provides data quickly.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a packaging case of a wiper blade used to wipe rain or dirt from a windscreen of automobiles, and more particularly to a wiper blade packaging case that has not only a fundamental function of accommodating and packaging wiper blades in a compact state, but also additional functions of protecting an appearance of the wiper blades thereby to prevent damage of the wiper blades during delivery or distribution.
[0003] 2. Description of the Related Art
[0004] Almost all automobiles are equipped with a wiper blade serving to clean or wipe a windshield in order to prevent unclear view caused by contamination of the windshield due to dirt in air or various weather conditions. The wiper blade wipes the windshield while pivoting at a predetermined angle in a state of closely contacting the windshield, thereby securing a driver's sight for safe driving.
[0005] When such a wiper blade is worn out or lowered in contacting or wiping force due to long term use, it is necessary to replace it with a new wiper blade, which is generally encased in a separate packaging case and sold therewith.
[0006] FIG. 1 is a perspective view of an inner case of a conventional wiper blade packaging case and FIG. 2 is a perspective view of an outer case to receive the inner case of FIG. 1 .
[0007] The conventional wiper blade packaging case as shown in FIGS. 1 and 2 comprises an inner case 10 to receive and secure a wiper blade or a wiper strip 1 , and an outer case 20 to receive the inner case 10 with the wiper blade 1 secured therein. Therefore, such a conventional wiper blade packaging case makes packaging of the wiper blade or the wiper strip 1 cumbersome and often results in escape of the inner case 10 from the outer case 20 due to an impact during delivery or distribution of the packaging case. Furthermore, to check condition of the wiper blade or the wiper strip 1 packaged in the packaging case, consumers have the inconvenience of opening the outer case 20 . In this regard, although some conventional packaging cases are provided with a window 22 in the outer case 20 to overcome such inconvenience, the outer case 20 having the window 22 formed therein increases manufacturing costs of the packaging case.
[0008] FIG. 3 is a perspective view of another conventional wiper blade packaging case.
[0009] Referring to FIG. 3 , the conventional wiper blade packaging case 30 is an integral packaging case that comprises a body 32 to receive a wiper blade 40 , and a cover 34 connected to the body 32 to cover the body 32 . The body 32 is formed on the perimeter thereof with a plurality of protrusions 33 , and, the cover 34 is formed with a plurality of recesses 35 to which the protrusions 33 are fitted and secured.
[0010] For the packaging case 30 having such a configuration as mentioned above, the protrusions 33 are press-fitted and secured into the recesses 35 , with the cover 34 covering the body 32 .
[0011] However, since the packaging case 30 is not provided with means to hold the wiper blade 40 securely therein, the wiper blade 40 accommodated in the packaging case 30 is likely to experience scratching, peeling-off of paint, and the like due to contact with the packaging case 30 during delivery or distribution. Furthermore, since the wiper blade 40 is accommodated in a curved shape corresponding to a rounded face of the windshield, the packaging case occupies a large volume in a packaging state, causing an increase in delivery and distribution costs.
[0012] Moreover, as the various wiper blades having a variety of shapes have been recently developed to improve performance, there is a need for a new wiper blade packaging case having a proper internal shape corresponding to the various wiper blades.
BRIEF SUMMARY OF THE INVENTION
[0013] The present invention is conceived to solve the problems of the conventional techniques as described above, and an object of the present invention is to provide a wiper blade packaging case that protects a wiper blade from external force to prevent damage of the wiper blade during delivery and distribution, and that enables compact, simple and tight packaging of the wiper blade such that the packaging case is not easily separated during the distribution.
[0014] In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of a packaging case of a wiper blade including a wiper strip to wipe a windshield of an automobile, comprising: a body having an accommodation space to accommodate the wiper blade and an opening to open the accommodation space; a cover connected pivotally to one side of the body via a first connecting part to cover the opening; and a locking section connected pivotally to the other side of the body via a second connecting part to be engaged with the body with one end of the cover interposed between the locking section and the body.
[0015] In accordance with another aspect of the present invention, a packaging case of a wiper blade including a wiper strip to wipe a windshield of an automobile is provided, comprising: a body having an accommodation space to accommodate the wiper blade and an opening to open the accommodation space; a cover to cover the opening; and locking sections respectively connected pivotally to opposites sides of the body in a longitudinal direction via connecting parts to be engaged with the body with one end of the cover interposed between each of the locking sections and the body.
[0016] The body may comprise a plurality of securing protrusions formed on a face adjacent to the locking section, and the locking section may comprise a plurality of fitting holes press-fitted to the securing protrusions. The cover may comprise a plurality of through-holes through which the securing protrusions pass and are inserted. Further, each of the connecting parts has a ring-shaped cross-section and is elastically deformable. The packaging case may further comprise a projection formed in the accommodation space of the body to secure the wiper blade accommodated in the body. In particular, the accommodation space of the body may have a space to accommodate the wiper strip and preferably having a size to prevent the wiper strip from contacting an inner surface of the body when the wiper blade is completely accommodated in the body. The body may further comprise a plurality of clips formed therein to secure printed matter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0017] The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:
[0018] FIG. 1 is a perspective view of an inner case of a conventional wiper blade packaging case;
[0019] FIG. 2 is a perspective view of an outer case to receive the inner case of FIG. 1 ;
[0020] FIG. 3 is a perspective view of another conventional wiper blade packaging case;
[0021] FIG. 4 is a perspective view of a packaging case of a wiper blade according to an embodiment of the present invention, in which the packaging case is opened to accommodate the wiper blade;
[0022] FIG. 5 is a perspective view of the packaging case of the wiper blade according to an embodiment of the present invention, in which the wiper blade is accommodated in the packaging case;
[0023] FIGS. 6 to 8 are cross-sectional views illustrating the packaging case of the wiper blade according to an embodiment of the present invention from an open state to a closed state to accommodate the wiper blade.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Exemplary embodiments of the present invention are described in detail with reference to the accompanying drawings hereinafter.
[0025] FIG. 4 is a perspective view of a packaging case of a wiper blade according to one embodiment of the present invention, in which the packaging case is opened to accommodate the wiper blade, and FIG. 5 is a perspective view of the packaging case of the wiper blade according to one embodiment of the present invention, in which the wiper blade is accommodated in the packaging case.
[0026] Referring to FIGS. 4 and 5 , the packaging case 60 of a wiper blade is used for packaging the wiper blade 50 serving to clean or wipe dirt from a windshield of an automobile in a state of closely contacting the windshield.
[0027] Generally, the wiper blade 50 comprises a wiper strip 52 to make close contact with the windshield, a frame 54 configured to mount the wiper strip 52 thereon, and a connector 56 coupled to the frame 54 so as to be coupled to a wiper arm of the automobile.
[0028] The windshield of the automobile has a predetermined curvature to lessen air resistance and the frame 54 elastically compresses the wiper strip 52 to make close contact with the windshield. Therefore, the wiper blade 50 is given a predetermined curvature corresponding to the curvature of the windshield.
[0029] Such a wiper blade 50 is provided as a replaceable component and is commonly available from automobile specialty shops, large distribution and discount stores, etc.
[0030] The wiper blade 50 can be sold in a separate packaging case 60 for identification and protection of the products. The packaging case 60 prevents damage of the wiper blade 50 accommodated therein and enables the wiper blades 50 to be maintained in an optimal state. In addition, the packaging case 60 allows the wiper blade 50 to be maintained in an unfolded state, reducing a volume occupied by the wiper blade 50 .
[0031] Such a packaging case 60 of the wiper blade comprises a body 70 having a predetermined accommodating space 71 defined therein to accommodate the wiper blade 50 , and a cover 80 connected with the body 70 to cover the accommodating space 71 .
[0032] The body 70 has an opening, through which the wiper blade 50 is placed in or taken out from the accommodating space 71 , and a flange 72 extending horizontally from the perimeter of the opening.
[0033] The cover 80 has a receiving section 81 to receive a portion of the wiper blade 50 accommodated in the body 70 and a cover flange 82 extending from an outer periphery of the receiving section 81 .
[0034] The cover 80 is connected pivotally to a first side of the body 70 by means of a first connection part 76 formed therebetween. The first connection part 76 may include a ring-shaped cross section and a predetermined elasticity.
[0035] Further, the body 70 is formed at a second side of the body 70 , opposed to the first side, with a locking section 90 to restrict the cover 80 when the cover 80 covers the opening of the body 70 . The locking section 90 is connected pivotally to the other side of the body 70 by means of a second connection part 78 . The second connection part 78 may include a ring-shaped cross section so as to have a predetermined elasticity.
[0036] With the cover 80 covering the opening of the body, the locking section 90 is coupled to the case flange 72 such that a portion of the cover flange 82 is interposed between the case flange 72 and the locking section 90 .
[0037] Preferably, the case flange 72 is formed with securing protrusions 75 adjacent the locking section 90 , and the locking section 90 is formed with fitting holes 95 into which the securing protrusions 75 will be fitted and coupled.
[0038] More preferably, the cover flange 82 of the cover 80 is formed with through-holes 85 corresponding to the securing protrusions 75 . Thus, with the through-holes 85 fitted to the securing protrusions 75 , the securing protrusions 75 are inserted into the fitting holes 95 and the locking section 90 restricts the cover 80 .
[0039] In the embodiment described above, the body 70 and the cover 80 are described as an integral component and are pivotally connected to each other via the first connecting part 76 . Alternatively, the body 70 and the cover 80 can be formed as separate components, and the first connecting part 76 has the same configuration as that of the second connecting part 78 .
[0040] Furthermore, the packaging case 60 of the wiper blade according to the present invention may have projections 74 respectively formed on opposite sides in the inner space of the body 70 to secure the wiper blade 50 received therein.
[0041] At this time, each of the projections 74 is formed to have a predetermined elasticity, so that, when the wiper blade 50 is packaged in the packaging case, the wiper frame 54 is fitted between the projections 74 and maintained in an unfolded state. Each of the projections 74 is not necessarily continuous and can be divided so as not to interfere with the connector 56 of the wiper blade 50 . Additionally, the projections 74 are not necessarily formed in a symmetrical shape. Rather, it is sufficient that the projections 74 are disposed to maintain the unfolded state of the wiper frame 54 when the wiper frame 54 is received in the body 70 and secured by the projections 74 . Furthermore, the projections 74 may be disposed in a staggered pattern on the opposite sides in the body, so that the wiper blade 50 can be more easily inserted or taken out from between the projections 74 .
[0042] And, a space where the wiper strip 52 is accommodated, that is, a lower portion of the accommodation space 71 of the body 70 where the wiper blade 50 is accommodated, preferably has at least a size to prevent the wiper strip 52 from contacting the inner surface of the body 70 when the wiper blade 50 is completely accommodated in the body 70 .
[0043] The body 70 may further comprise a plurality of clips 88 therein to secure printed matter such as publicity prints or product manual. Each of the clips 88 is formed to have a predetermined elasticity and is configured to fit and secure the printed matter therebetween. Preferably, the clips 88 are formed at one side of the cover 80 so that the printed matter can be more easily recognized from the outside.
[0044] The packaging case 60 of the wiper blade having such a configuration as described above may be formed of synthetic resins. Specifically, a portion or all of the packaging case 60 may be formed of a transparent material to allow a serviceman or a user to see the interior of the packaging case. Furthermore, the packaging case 60 may have various colors to allow more easy recognition of the products from other products or to provide distinction of the products and more appealing appearance to the products.
[0045] The packaging case 60 may have a display part 62 formed at one side such that the packaging case 60 can be hung on and kept in a display rack used for storage or selling of wiper blinds encased in the packaging case 60 . The display part 62 is formed by a combination of a circular hole 63 and a linear groove 64 such that the packaging case 60 can be hung on any display rack having a circular rack rod or a thin plate-shaped rack rod. The circular hole 63 is formed at the center of the linear groove 64 . The packaging case 60 of the wiper blade having such a configuration can be displayed in a state wherein the packaging case is suspended from a rack rod of the display rack through the display part 62 when displaying the products for sale and/or storage.
[0046] FIGS. 6 to 8 are cross-sectional views illustrating the packaging case of the wiper blade according to the present invention from an open state to a closed state to accommodate the wiper blade.
[0047] Hereinafter, a process of accommodating the wiper blade in the packaging case according to an embodiment of the present invention is described with reference to FIGS. 6 to 8 .
[0048] First, the wiper blade 50 is put in the accommodating space 71 of the body 70 . At this time, when the frame 54 of the wiper blade 50 is forced to be located under lower surfaces of the projections 74 of the body 70 , the wiper blade 50 is maintained in an unfolded state without any bending, and, the wiper strip 52 is maintained without contact with the inner surface of the body 70 .
[0049] Then, the cover 80 connected to the one side of the body 70 is rotated to cover the opening of the body 70 . At this time, the securing protrusions 75 formed on the case flange 72 penetrate the through-holes 85 formed in the cover flange 82 of the cover 80 .
[0050] Then, the locking section 90 connected to the second side of the body 70 is rotated to force the fitting holes 95 of the locking section 90 to be fitted onto the securing protrusions 75 of the body 70 with the cover flange 82 of the cover 80 interposed between the locking section 90 and the case flange 72 of the body 70 .
[0051] On the other hand, the packaging case 60 of the wiper blade 50 is provided therein with printed matter such as publicity paper or product manual by inserting the printed matter into the clips 88 before the cover 80 is coupled to the body 70 .
[0052] As apparent from the above description, according to the present invention, a wiper blade can be held and firmly secured in a packaging case so that the wiper blade can be protected from the outside and prevented from being damaged by the packaging case. Furthermore, since the packaging case according to embodiments of the preset invention encases the wiper blade in an unfolded state, the packaging volume of the packaging case occupied by the wiper blade is decreased, thereby reducing physical distribution costs related to delivery and distribution. Moreover, since the packaging case can secure a cover to a body of the packaging case with ease and tightness, it can reduce time required for packaging.
[0053] Although the present invention has been described with reference to the embodiments and the accompanying drawings, it is not limited to the embodiments and the drawings. It should be understood that various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present invention defined by the accompanying claims.
[0054] All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety.
[0055] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
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Disclosed herein is a packaging case of a wiper blade used to wipe a windscreen of automobiles. The wiper blade includes a wiper strip to wipe a windshield of an automobile. The packaging case includes a body having an accommodation space to accommodate the wiper blade and an opening to open the accommodation space, a cover connected pivotally to a first side of the body via a first connecting part to cover the opening, and a locking section connected pivotally to a second side of the body, opposed to the first side, via a second connecting part to be engaged with the body with one end of the cover interposed between the locking section and the body. The packaging case can protect the wiper blade from external force and prevent damage of the wiper blade during delivery and distribution, and can ensure simple, compact and tight packaging of the wiper blade.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to hybrid elements of an electrically writable non-volatile memory and a DRAM and other elements such as a Logic IC, etc.
2. Description of the Related Art
Conventionally, in a non-volatile memory such as a flash memory having floating gates and control gates, a gate oxidation film below the floating gates (hereinafter referred to as a first oxidation film) is used as an oxidation film for memory cell transistors, and information is stored by causing a threshold value of a memory cell transistor to change as a result of removing or injecting electrical charge into the floating gate using CHE (channel Hot Electron) current or FN (Fowler-Nordheim) tunnel current by applying a high voltage to the first gate oxidation film.
It is required that the film thickness of the first gate oxidation film in the memory cell transistor is thin, for example 100 Å, so as to carry out rewriting. However, even if a gate oxidation film as thin as, for example, 100 Å is used underneath the floating gate of the memory cell, if a capacitive coupling ratio between the control gates and the floating gates is assumed to be 0.7 then a voltage required for rewriting becomes 10V or more. If the first gate oxidation film is used directly on peripheral transistors, an electric field applied to the oxidation film becomes 10MV/cm and it is not possible to ensure the reliability of the oxidation film.
As a result, a gate oxidation film thicker than an ordinary first gate oxidation film is applied to peripheral transistors. Specifically, a common manufacturing method forms peripheral transistors with a gate oxidation film of approximately 200 Å, and to with electrodes of the same material as control gates of memory cell transistors.
In the example of the related art described thus far, the case has been described where only one type of gate oxidation film is used for peripheral circuits, namely a gate oxidation film with a thickness of 200 Å. However, there are also cases where transistors are formed having gate oxidation films of differing thicknesses, such as those for high withstand pressure or low voltage use. As such a manufacturing method, there is a method of respectively forming two types of gate oxidation film separately for transistors of peripheral circuits and transistors of memory cells, as disclosed in, for example, Japanese Patent Laid-open Publication No. Hei. 6-177360.
However, with the above described method, since it is necessary to respectively form two types of gate oxidation film for the memory cells and separate portions, there is a problem that the number of manufacturing steps is increased compared to a method where one only type of gate oxidation film is formed for the memory cells and other portions.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a non-volatile memory in which there is no need to form two types of gate oxidation films for memory cells and separate portions, and in which gates of transistors of peripheral circuits have low resistance, and to provide a method of manufacturing the same.
The non-volatile memory of the present invention comprises memory cells having floating gates formed of first polysilicon and control gates formed of second polysilicon formed directly on top of a silicide layer, and peripheral circuits provided with transistors having gates formed of the first polysilicon formed directly on a silicide layer.
Also, the method of manufacturing the non-volatile memory having memory cells comprised of floating gates formed of first polysilicon and control gates formed of a second polysilicon comprises the steps of: forming a first oxidation film on a semiconductor substrate, forming a first polysilicon film on the first oxidation film, forming an insulating film on the first polysilicon film, forming a second polysilicon film on the insulating film, selectively removing the insulating film and the second polysilicon film at specified regions for forming transistors, forming a silicide layer on the second polysilicon film and on fixed regions of the first polysilicon film for forming transistors, and respectively patterning floating gates and control gates of transistors and memory cells.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention, the objects and features of the invention and further objects features and advantages thereof will be better understood from the following description taken in connection with the accompanying drawings in which:
FIGS. 1(a)-(d) show manufacturing steps of the present invention;
FIGS. 2(e)-(h) show manufacturing steps of the present invention;
FIG. 3 is an enlarged view of a memory cell and peripheral circuit of the present invention; and
FIG. 4 shows a fourth embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A manufacturing process of a first embodiment of the present invention will be described in detail using FIG. 1 and FIG. 2. First of all, an N-well 102, P-well 103, element separators 105 and memory cell channels 104 are formed on a P-type Si substrate 101 (FIG. 1(a)). Next, ion injection is carried out to adjust the Vt of the memory cells. At the same time, although not shown in the drawings, ion injection is carried out at a dosage amount that is different from that for the memory cells for Vt control of peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film as gate electrodes. A first gate oxidation film 106 is then formed using a thermal oxidation method over the entire surface of the substrate to a thickness of approximately 100 Å, constituting places for tunnel current of the memory cells to flow. After that, the first polysilicon film 107 is deposited to 1000 Å and impurities such as phosphor are injected. Next, regions of the first polysilicon film and the first oxidation film corresponding to the peripheral circuits using the second polysilicon film 111 as gate electrodes (2G NMOS/PMOS in the drawings) are removed (FIG. 1(b)).
Subsequently, an IPD (Inter Poly Dielectric) insulating film 109 constituted by, for example, an ONO 3 layer insulating film, is formed on the memory cells and regions for the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes. Also, at the time of forming the IPD insulating film, heat processing is carried out at a temperature close to 1000° C. for improving film quality. Following that, a second gate oxidation film 110 is formed to a thickness of 200 Å on regions for the peripheral circuits using the second polysilicon film 111 as gate electrodes (2G NMOS/PMOS in the drawings). Next, the second polysilicon film is deposited to a thickness of 1000 Å and injected with impurities such as phosphor.
A resist 201 is then subjected to patterning so as to expose regions for the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes. After that, with the resist 201 as a mask, regions of the second polysilicon film 111 and the IPD insulating film 109 for the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes are etched, so as to expose the first polysilicon film 107.
Accordingly, the outermost surfaces are the second polysilicon 111 at regions for the peripheral circuits using the second polysilicon film 111 as gate electrodes (2G NMOS/PMOS in the drawings) and regions for the memory cells, and the first polysilicon 107 at regions for the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes (FIG. 1(c)).
A silicide film 112 is then formed to a thickness of 1500 Å on the entire surface of the substrate (FIG. 1(d)). Following that, each of the films, namely the silicide film of the memory cell portion 112, the second polysilicon film 111, the IPD insulating film 109 and the first polysilicon film 107 are etched in a self-aligned manner with the resist pattern 202 as a mask. At this time, regions for the peripheral circuits (2G NMOS/PMOS in the drawings) using the second polysilicon film 111 as gate electrodes and regions for the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes are covered by the resist 202 (FIG. 2(e)).
Next, with the resist 203 as a mask, portions of the peripheral circuits (2G NMOS/PMOS in the drawings) using the second polysilicon film 111 as gate electrodes and portions of the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes are simultaneously etched to form gate electrodes of the peripheral circuits. At this time, memory cell regions are covered by the resist 203. Also, the films to be etched are the silicide film 112 and the second polysilicon film 111 at parts of the peripheral circuits (2G NMOS/PMOS in the drawings) using the second polysilicon film 111 as gate electrodes, and the silicide film 112 and the first polysilicon film 107 at parts of the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes (FIG. 1(f)).
Following that, source/drain diffusion films are formed. A side wall 117 is also formed if an LDD structure is required (FIG. 2(g)). Next, aBPSG film is deposited as an intermediate insulating film, contact hole openings and metal 119 to the contact holes are embedded. Further, aluminum wiring is formed and the surface is protected by a passivation layer 121, to thus complete wafer processing (FIG. 2(h)).
FIG. 3 is an enlarged view of the memory cells and peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes. The gate oxidation film of the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes uses the first gate oxidation film 106 of the memory cells. Also, a silicide film 112 is formed directly on the second polysilicon film for the memory cells and directly on the first polysilicon film 107 for the peripheral circuits (1G NMOS/PMOS in the drawings). Specifically, the memory cells are constructed from the first gate oxidation film 106, the first polysilicon film 107, the IPD insulation film 109, the second polysilicon film 111 and the silicide film 112. The peripheral circuits (1G NMOS/PMOS in the drawings) are constructed from the first gate oxidation film 106, the first polysilicon film 107, the silicide film 112 and the source/drain diffusion films. The peripheral circuits have an LDD structure, but are not thus limited.
In the first embodiment of the present invention as described above, compared to the method of forming a gate oxidation film of one thickness for transistors of the peripheral circuits, it is possible to form gate oxidation films of differing thicknesses for the transistors of the peripheral circuits without increasing heat processing steps. Also, since regions of the second polysilicon film 111 and the IPD insulation film for the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes are selectively removed and a silicide film 112 is formed directly on the first polysilicon film 107, more stable electrical connection within electrodes is possible because of the natural oxidation film reduction function of the silicide film 112.
Further, with the resist 203 as a mask, even in the case where the peripheral circuits (2G NMOS/PMOS in the drawings) using the second polysilicon film 111 as gate electrodes and the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes are simultaneously etched, the problem of over etching or under etching is also solved when the film thickness of the first polysilicon film 107 and the second polysilicon film 111 are almost the same.
A second embodiment of the present invention will now be described. Points that are the same as in the first embodiment have been described in detail above, so further description thereof will be omitted. Description will be given in the following of parts that are different from the first embodiment.
The second embodiment of the present invention, as shown in FIG. 1(c), comprises removing the second polysilicon film 111 and the IPD insulating film 109 with the resist 201 as a mask, and after that injection of ions is carried for controlling Vt of the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes with the resist 201 unaltered as a mask.
According to the above described second embodiment of the present invention, prior to ion injection for controlling Vt, the heat processing at the time of forming the insulation film 109 has also been completed and a comparatively low applied energy can be selected so as to enable ions to pass through the first polysilicon film of approximately 1000 Å, which means that a concentration distribution in the depth direction of the peripheral circuits (1G NMOS/PMOS in the drawings) using the first polysilicon film 107 as gate electrodes can be finely controlled.
A third embodiment of the present invention will now be described. Points that are the same as in the first embodiment have been described in detail above, so further description thereof will be omitted. Description will be given in the following of parts that are different from the first embodiment.
In FIG. 1(c) of the third embodiment, after formation of the first polysilicon film 107, the phosphor concentration within the polysilicon film 107 is set to a concentration that just prevents a depletion layer, for example a low value of 2×10 20 [cm -3 ]. Next, after removal of the second polysilicon film 111 and the IPD insulation film 109 by etching, phosphor or arsenic is ion injected at a low energy of, for example, 10 KeV using the resist 201 as a mask, so as to increase the impurity concentration within the first polysilicon film 107.
According to the above described third embodiment, the impurity concentration within the first polysilicon film 107 is set to a level that prevents a depletion layer in an initial step, and after completion of heat processing at the time of forming the IPD insulation film 109 ion injection is carried out to increase the impurity concentration within the first polysilicon film 107. This means that there is no degradation in film quality caused by impurities being diffused in the first gate oxidation film 106, and a depletion layer cannot be formed within the first polysilicon film 107 even if there is diffusion of impurities in to the silicide film 112. Also, Since the resist 201 at the time of removing the second polysilicon film and the IPD insulating film 109 can be used as it is, there is no need for an additional photolithography step, and processing can be completed with the addition of only one ion injection step.
A fourth embodiment of the present invention will now be described. Points that are the same as in the first to third embodiments have been described in detail above, so further description thereof will be omitted.
The fourth embodiment is applied to a hybrid processor comprising flash memory of the first to third embodiments and DRAM. In FIG. 4, peripheral circuits (2G NMOS/PMOS in the drawings) having a gate oxidation film with a thickness of approximately 200 Å and using a second polysilicon film 111 as gate electrodes are used as transistors for flash memory. Also, peripheral circuits (1G NMOS in the drawings) having a gate oxidation film with a thickness of 100 Å and using a first polysilicon film 107 as gate electrodes are used as transistors for DRAM.
Here, gate electrodes of the transistors for flash memory (2G NMOS/PMOS in the drawings) are formed as a polycide film comprising a second polysilicon film 111 and a silicide film 112 formed using the same steps as in the first to third embodiments. Further, the electrodes of the transistors for DRAM (1G NMOS in the drawings) are formed as a polycide film comprising a first polysilicon film 107 and the silicide film 112 formed using the same steps as in the first to third embodiments.
In the fourth embodiment, as additions to the first to third embodiments, DRAM capacitors are formed after formation of sources and drains of the DRAM transistors (1G NMOS in the drawings). The capacitors are constructed of sequentially formed polysilicon film 401, insulating film 402 and polysilicon film 403, as shown in FIG. 4.
According to the above described fourth embodiment, high voltage flash memory transistors and low voltage DRAM transistors can be formed at the same time, and their gate electrodes can be made into polycide and made low resistance without degrading the IPD insulation film 109 of memory cells of the flash memory.
As has been described in detail above, according to the present invention a second polysilicon film 111 and an IPD insulating film 109 are selectively removed using a resist 201 as a mask and a first gate oxidation film 106 and a first polysilicon film 107 of memory cells are used for peripheral circuits, which means that there is no need to form a gate oxidation film for the peripheral circuits in a separate step, a silicide film 112 can be formed directly on the first polysilicon film 107, and a stable electrical connection within electrodes is possible using the natural oxidation reduction function of the silicide film.
Further, according to the present invention, after removal of the second polysilicon film 111 and the IPD insulating film using the resist 201 as a mask, ion injection is carried out to control Vt of the peripheral circuits using the first polysilicon film as a gate oxidation film also using the resist 201 as the mask. Prior to ion injection, heat processing for formation of the IPD insulating film is also completed and it is possible to select a comparatively low acceleration energy as long as ions can pass through the first polysilicon film of approximately 1000 Å thick, which means that it is possible to finely control the concentration distribution of impurities in a depth direction of the peripheral circuit region.
The present invention has been described using illustrative embodiments, but it should be understood that description not restrictive. Various modifications to these illustrative embodiments, as well as other embodiments, will be clear to one skilled in the art upon reference to this description. Accordingly, the appended claims are considered to encompass all such modifications and embodiments as are within the spirit and scope of the present invention.
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In a non-volatile memory, memory cells have respective floating gates formed of a first polysilicon and respective control gates formed of a second polysilicon. Further, in the non-volatile memory, peripheral circuits include transistors having respective gates formed of the first polysilicon. In addition, a silicide layer is formed directly on the control gates of the memory cells and directly on the gates of the transistors.
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TECHNICAL FIELD
The invention concerns a method and a device for measuring a fluid flow, in particular an air flow, flowing in a flow canal to an engine or from an engine, by means of a fluid mass measuring means connected to an evaluation means. Methods and devices of this kind serve for example during operation of an internal combustion engine to measure the air instantaneously drawn in by the engine.
BACKGROUND OF THE INVENTION
Control means which allow optimum possible operation of the engine as a function of the varying requirements of the vehicle driver are used to control modem internal combustion engines, in particular those which are used in motor vehicles. The control means for this purpose record all essential operational parameters of the engine and, depending on the standards of the vehicle driver and taking the properties of the engine into account, transmit control commands to the engine and the associated supply units, which are adapted to the respective operating status. One aim of this so-called “engine management” is to provide optimum performance with low fuel consumption and low emission of noxious substances in every operating situation.
The fuel consumption and emission of noxious substances in an internal combustion engine are essentially determined by the ratio of the air mass and the fuel mass which are drawn in by the engine. Here the air mass flowing to the engine is directly influenced by the vehicle driver who causes adjustment of the choke valve in the air intake. If the choke valve is closed, only a low air mass flows through the intake. With the choke valve fully open, on the other hand, nearly the whole intake cross-section is available for the air flow.
In order to provide a performance which meets the respective requirements of the vehicle driver, a fuel mass corresponding to the air mass flowing to the engine must be supplied to the combustion chamber of the engine which is active at any given time. For this purpose the air mass flowing through the intake is recorded, and the fuel mass which is sufficient for low-exhaust combustion is determined by means of the engine control device. The precision with which the optimum ratio of fuel mass provided for combustion to air mass drawn in is maintained here, depends directly on the exactness with which the air mass flow is measured. It has been established that even minor deviations of the measurement result from the air mass actually supplied lead to a multiplication of the proportion of certain noxious components of the combustion gases. With respect to the legal requirements for the reduction of pollutant emissions, which are getting stricter and stricter, higher and higher demands are therefore being made on the accuracy of measurement of devices with which the air flow in the intake of an internal combustion engine is recorded.
A basic problem in the measurement of a fluid flow which is drawn in by an engine or discharged from it lies in that the curve of the flow is not constant. This is caused inter alia by the fact that as a rule the fluid is not drawn in or conveyed through the engine in a continuous operation. Instead this operation is usually performed in pulsed fashion. As a result, the flow of the fluid is not constant. Added to this is the fact that the resonance properties of the canals through which the fluid flows lead to reverse flows of the fluid.
The flow behaviour of an air stream which is drawn in through an intake common to the combustion chambers of an internal combustion engine is particularly problematic. Since it is not only the combustion chamber which is to be supplied with air and fuel at any given time and which is active with respect to the air intake, but also the other combustion chambers which are connected to this flow canal, due to for example the movement of the inlet valves which control access to the combustion chambers, due to movements of the cylinders in the combustion chambers, due to exhaust gas recirculation, etc. there are pressure pulses which trigger a pulsed air flow in a direction opposite the intake direction. Here the maximum pulsation occurs with maximum choke valve opening or maximum exhaust gas recirculation. The non-uniformity of flow caused inter alia by this disturbance leads for example to considerable impairment of the accuracy of the measurement results in air mass measurement.
Attempts have been made to solve the problems described above in the measurement of a fluid flow by compensating for the pulsation with a corresponding structural arrangement of the measuring sensors. Thus for example a so-called “bidirectional air mass measuring means” in which a temperature sensor is arranged both in front of and behind a heating element in the direction of flow, is known from practical experience for the measurement of an air mass flow drawn in by a motor vehicle internal combustion engine. The heating element is maintained at a constant temperature. If there is no air flow, the same temperature occurs at both temperature sensors. If on the other hand the flow approaches from a certain direction of flow, a temperature difference arises between the sensors. This temperature difference delivers not only information on the mass flow of the air, but also on its direction of flow.
With the fluid mass measuring means described above, of course an improvement in quality of the measurement result can be obtained in comparison with a conventional hot-wire or hot-film air mass measuring means. In practice however it turns out that this improvement is not sufficient to meet the requirements which are getting stricter and stricter.
SUMMARY OF THE INVENTION
It is the object of the invention to provide a method and a device which allow sufficiently precise measurement of a fluid stream flowing through a canal.
With reference to the method, this object is achieved by a method of the kind mentioned hereinbefore, in which in a regularly performed cycle
an operational parameter characterizing the operating status of the engine is recorded,
the data supplied by the fluid mass measuring means are recorded,
at least one extreme value is determined from the data recorded since the beginning of a time period,
an average value is determined from the recorded data,
a pulsation amplitude is determined by dividing the extreme value by the average value, and
the average value is corrected by multiplying it by a correction factor which is selected in dependence on the operational parameter and the pulsation amplitude, from a plurality of correction factors stored in a memory of the evaluation means and being determined in an operation test for the type of fluid mass measuring means in relation to the type of engine.
The invention is based on the concept of reducing the error in the measurement of a mass flow of a fluid by the fact that first an average value is formed from the data recorded within a given time period and then a correction of this average value, which is still subject to error, is made in dependence on certain parameters which characterize the respective operating status of the engine, the properties of the air mass measuring means and the behaviour of the measured fluid flow during the measuring period. The average value corrected in this way is available as the result of fluid mass flow measurement for further processing. In this way the method according to the invention delivers, without elaborate structural alterations to the flow canal, the fluid mass measuring means, the evaluation means or other components which influence the measurement, a measurement result which can be used for example for control of an engine and which lies within the required narrow error tolerance limits.
To prepare for the correction of the previously determined average value, with the method according to the invention an extreme value is recorded. This extreme value is standardised by means of the average value. In this way, according to the invention a quantity referred to as the “pulsation amplitude” is available, which makes a statement about the behaviour of the fluid flow during recording of the data, particularly about the periodically occurring fluctuations in the speed and direction of flow of the fluid flow. Calculation of the pulsation amplitude furthermore allows, taking the also recorded engine parameter into account, a prediction of the error which the fluid mass measuring means typically delivers with the operating status of the engine concerned and with the behaviour of the fluid flow concerned.
Surprisingly it turned out that on the basis of the pulsation amplitude a correction of the average values can be made reliably even when the external conditions such as ambient temperature and pressure and air humidity vary, owing to which the flow and pulsation behaviour of the fluid is varied.
The measurement behaviour which is typical of the fluid mass measuring means used at any given time in connection with the engine used at any given time is determined according to the invention in an operation test in which a prototype of the fluid mass measuring means is tested in connection with a prototype of the engine. Both the prototype of the fluid mass measuring means and the prototype of the engine are in this case representative of the fluid mass measuring means and engine models used in series.
In the course of the operation test, the correction factors are determined with which the measurement result which is assigned in each case to a given engine parameter and a given pulsation amplitude and which is subject to error can be typically corrected in such a way that it is within the permitted tolerance. It has been established that the measurement behaviour determined in this way for the fluid mass measuring means model in connection with the engine model and the correspondingly determined correction factors apply to all other fluid mass measuring means of this model which are used on engines of the engine model concerned. This is true even when changes are made to the flow canal, it being obvious that the effectiveness of the correction made with the aid of the correction factors is checked before final use of the altered flow canal. The invention thus makes it possible to appreciably shorten the time needed for development of the air path or adjustment of engine management of for example an internal combustion engine. Unlike known methods for determining the air mass flow, it is now no longer necessary to readjust the measuring device as such to every change in parameters of engine management or of the flow canal.
The correction factors obtained in the operation test are stored in a memory of the evaluation means, a given correction factor being accessed in each case as a function of the pulsation amplitude respectively assigned to it and the engine parameter respectively assigned to it. A change of the correction factors stored in this way during use of the engine is as a rule not provided for. It is however also possible within the scope of the invention to make a change to the correction data in the sense of a self-learning system when it is established by suitable check instances that the correction made at any given time to an average value is not sufficient.
Basically any time period within which a number of data sufficient for reliable averaging can be recorded, can be selected as the time period. In those cases in which the engine exhibits periodically repeated operation sequences, it is however favourable to relate the time period to the time within which the engine passes through the period concerned. In the case of internal combustion engines, in this connection for example it proved advantageous if the time period corresponds to a fraction, particularly half, of the time needed for one crankshaft revolution.
In particular when the engine is an internal combustion engine which is moreover preferably used to drive a motor vehicle, it is also advantageous if the speed and/or the angle position of the crankshaft of the engine is recorded as the operational parameter.
Digitalized processing of the data can be made easier by the fact that the data supplied by the fluid mass measuring means are recorded in a cycle-controlled manner. Preferably the cycle-controlled recording is carried out in this case with a sampling frequency of at least 1 kHz.
In particular with cycle-controlled recording of the data it is favourable if always one measured value is recorded at the end of each time period. In this way it is ensured that the measuring point at the end of the time period, which is in many cases important for averaging, is recorded even when the length of the time period does not correspond to an integral multiple of the cycle time.
Basically any suitable numerical method can be employed to determine the average value of the data of a measuring period. With respect to practical implementation of the method according to the invention, in this connection it proved favourable if the average value is the trapezoidal average of the measured data.
The extreme value used to determine the pulsation amplitude is determined as a function of the characteristic curve of the respective system formed from engine, flow canal and fluid mass measuring means. If for example positive or negative data deviations are predominant in such a system, it may be advantageous if the extreme value corresponds to the greatest positive or negative deviation of the measured data from the average value. In other cases in which for example there is a relatively balanced distribution of deviations between positive and negative, it may be advantageous to record the positive and negative extreme values of the measured data and for the calculation of the pulsation amplitude to divide the average of the amounts of both these extreme values by the average value of the measured data.
The method according to the invention can be employed particularly advantageously in the measurement of an air flow drawn in by a motor vehicle internal combustion engine. The corrected data made available for engine management by the evaluation means fulfil even the strictest requirements of the automobile industry. This applies particularly when the air mass flow drawn in by the engine is measured by the method according to the invention.
With respect to the device, the object stated above is achieved by a device for measuring a fluid flow, in particular an air flow, flowing in a flow canal to an engine or from an engine, said device having an evaluation means and a fluid mass measuring means connected to the evaluation means, which is characterized in that the evaluation means comprises
a data recording means recording the measured values supplied by the fluid mass measuring means,
a means for recording an operational parameter of the engine,
a timer signalling the beginning and the end of a measuring period,
a memory storing the data supplied by the fluid mass measuring means,
a memory in which correction factors are stored in such a way as to permit access to a particular factor of these correction factors depending on the respective operational parameter and on a respective pulsation amplitude, and
a calculating unit, which calculating unit determines an extreme value from the data recorded during a time period, determines an average value from the data and files it in a memory, determines a pulsation amplitude by dividing the extreme value by the average value, and corrects the determined average value by multiplying it by the correction factor which is read out of the memory depending on the respective operational parameter and the respective pulsation amplitude.
Preferably with the device according to the invention a bidirectional fluid mass measuring means arranged in the flow canal in which a temperature sensor is arranged both in front of and behind a heating means in the direction of flow is used as the fluid mass measuring means. A fluid mass measuring means of this kind is as a rule used to measure the air flow drawn in by an engine, particularly an internal combustion engine. On account of its special design with short response times it delivers measurement results which are subject to a relatively minor measurement error. This measurement error too, however, increases as a function of the pulsation amplitude.
A particularly advantageous design of the device according to the invention is characterized in that the fluid mass measuring means and the evaluation means form a constructional unit. This makes it possible for a supply firm, particularly in case of mass production such as is the rule in automobile construction, to provide the further processing firm with a ready-made constructional unit which at an interface provides a reliable measurement signal to be further processed without problems. Also in this variant the evaluation means can be adjusted specifically for the application in production.
According to another variant of the device according to the invention which is also advantageous, depending on the application, the evaluation means is part of a controlling apparatus used to control the respective engine.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a device used on an internal combustion engine for measuring the air mass flow drawn in by the internal combustion engine, in a schematic view;
FIG. 2 a bidirectional air mass measuring means in a perspective view;
FIG. 3 the sensor of the air mass measuring means in an enlarged view;
FIG. 4 errors of the average value plotted against the pulsation amplitude before error correction at certain operating points;
FIG. 5 the errors of the average value plotted against the pulsation amplitude and shown in FIG. 4, after error correction for the operating points indicated in FIG. 4;
FIG. 6 the curve of the data supplied by the bidirectional fluid mass measuring means, plotted against the recording cycles;
FIG. 7 the storage schema whereby the correction factors are stored in the memory of an evaluation means which processes the measurement results of the bidirectional fluid mass measuring means.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The device 1 for measuring the air mass flow L drawn in by an internal combustion engine VM comprises an evaluation means 2 and an air mass measuring means 3 which is constructed as a bidirectional air mass measuring means and connected to the first signal input 4 of the evaluation means 2 . The air mass measuring means 3 is positioned in the region of the input of a distributor chamber V on a connecting pipe R by which the distributing chamber V is connected to an air filter F. In addition the intakes S 1 , S 2 , S 3 , S 4 of the combustion chambers of the engine VM are connected to the distributor chamber V. The air filter F, the connecting pipe R and the distributor chamber V form the flow canal through which the internal combustion engine VM draws the air mass flow L. Operation of the internal combustion engine M, particularly the quantity of fuel injected into the combustion chambers of the engine, is controlled by an injection control device G which is connected by a signal wire 5 to the output 6 of the evaluation means 2 . The control unit G and the evaluation means 2 can together form part of an engine controlling apparatus, not shown further.
At a second signal input 7 of the evaluation means 2 is the signal of a speed measuring means Z by which the speed and the angle position of the crankshaft of the internal combustion engine VM are available to the evaluation means 3 . Apart from other elements not described here, which are usually needed for the operation of such devices, the evaluation means 2 is equipped with a data recording means 8 , a calculating unit 9 , a timer 10 , a first memory 11 and a second memory 12 .
The timer 10 of the evaluation means 2 indicates as a function of the crankshaft angle position the beginning t a and the end t e of successive time periods t 1 , t 2 , . . . , t n within which the data M 1 , M 2 , . . . , M n supplied by the air mass measuring means 3 are recorded cyclically by the data recording means 8 . The data M 1 , M 2 , . . . , M n recorded in this way are temporarily stored in the first memory 11 of the evaluation means 2 . The length of the time periods t 1 , t 2 , . . . , t n indicated by the timer 10 here corresponds in each case to the length of time which the crankshaft of the internal combustion engine VM needs for half a revolution. In addition the data recording means 8 records the respective speed D 1 , D 2 , . . . , D n of the internal combustion engine VM in the respective time period t 1 , t 2 , . . . , t n .
In the second memory 12 of the evaluation means 2 are stored correction factors K 11 , K 12 , . . . , K mn (n, m from the quantity of natural numbers) according to the schema shown in FIG. 7 . Here each correction factor K 11 , K 12 , . . . , K mn is assigned a given speed D 1 , D 2 , . . . , D n and a given pulsation amplitude P 1 , P 2 , . . . , P m . In this way the calculating unit 9 can, after a given speed D 1 , D 2 , . . . , D n has been detected and after it has been determined a given pulsation amplitude P 1 , P 2 , . . . , P m , directly access the respectively associated correction factor K 11 , K 12 , . . . , K mn . If for example the speed D 3 occurs in the time period t 1 and if at the same time the pulsation amplitude P 2 has been determined, the calculating unit accesses the correction factor K 23 . The latter is then, as described in detail below, multiplied by the average value W ma of the data M 1 , M 2 , . . . , M n recorded in the time period t 1 in order to provide the injection control device G with a corrected average value W kma .
The air mass measuring means 3 comprises a housing 20 to whose end wall 21 , which extends into the connecting pipe R, is attached a ceramic support 22 protruding perpendicularly from the end wall 21 into the connecting pipe R. The ceramic support 22 carries a sensor 23 which is formed from a heating element 24 extending essentially transversely to the direction of flow LR of the air mass flow L, and temperature sensors 25 , 26 extending with parallel axis and at a distance from the heating element 24 in front of and behind the heating element 24 in the direction of flow LR. Above the ceramic support 23 a pin-like projection 27 is formed integrally with the end wall 21 .
As soon as the timer 10 has indicated the beginning t a of a time period t 1 , t 2 , . . . , t n as a function of the crankshaft angle position (FIG. 6 ), the data M 1 , M 2 , . . . , M n supplied by the air mass measuring means 3 are recorded cyclically at a sampling frequency of 1 kHz by the evaluation means 2 and filed in the first memory 11 . At the same time the positive extreme value E p and as the operational parameter the instantaneous speed D a are recorded.
According to a first variant of the invention the data M 1 , M 2 , . . . , M n are stored in the first memory 11 at least for the duration of the respective time period t 1 , t 2 , . . . , t n . The calculating unit 9 in this case after the end of the respective time period t 1 , t 2 , . . . , t n determines an average value W ma from the data M 1 , M 2 , . . . , M n .
Alternatively it is possible that the calculating unit 9 forms an (intermediate) average value already during recording of the data M 1 , M 2 , . . . , M n on the basis of the data M 1 , M 2 , . . . , M n currently being recorded at the time, and files it in the memory 11 . This average value is updated with every newly recorded data M 1 , M 2 , . . . , M n , so that at the end of the respective time period t 1 , t 2 , . . . , t n it corresponds to the desired average value W ma of all data M 1 , M 2 , . . . , M n recorded during this time period t 1 , t 2 , . . . , t n . In this variant it is only necessary in each case to store in the first memory 11 the (intermediate) average value and for example the number of recorded measuring points or the last but one measuring point for averaging. The memory 11 can in this case be very much smaller than in the first variant.
Next the pulsation amplitude P b is determined by dividing the positive extreme value E p by the determined average value W ma . Then the correction factor K ba corresponding to the speed D a and the pulsation value P b is read out of the memory 12 of the evaluation means 3 and multiplied by the average value W ma . The correspondingly corrected average value W kma is made available to the control device G or the engine controlling apparatus, not shown, for further processing.
The method sequence described above is repeated as long as the internal combustion engine is running.
In FIG. 4 are shown by way of example for plurality of pulsation amplitudes P 1 , P 2 , . . . , P n the errors of the associated uncorrected average values, which have been determined from the data recorded by the air mass measuring means 3 at given speeds D 1 , D 2 , D 3 , D 4 , D 5 . It is clear that with this type of air mass measuring means in connection with the engine model at given speeds typically errors of more than 25% occur, the commonest deviations being between −10% and −20%. It is noteworthy that the error in by far the most cases increases with increasing pulsation amplitude P 1 . . . P 16 .
In FIG. 5 are plotted the corrected average values according to the representation in FIG. 4 . It can be seen that by far the majority of the deviations of data corrected by the correction factors K 11 , K 12 , . . . , K mn from the reference value of air mass L are within a range of +/−5%. They therefore meet even the strictest requirements.
The correction factors K 11 , K 12 , . . . , K mn have been determined in an operation test, testing the measurement behaviour of an air mass measuring means which belongs to the type of air mass measuring means 2 used in each case and which has been operated in connection with an internal combustion engine belonging to the type of internal combustion engine VM used in each case. In this operation test, at a plurality of speeds specified each time, the actual air mass (reference air mass value) which was drawn in by the internal combustion engine was determined by a reference air mass measuring means which was unaffected in its range by the disturbances of air flow due to a corresponding design of the flow canal. At the same time the measurement results of the air mass measuring means whose position corresponds to the position of the air mass measuring means in practical use were recorded. An average value was then formed from the data recorded in this way within a time period at a given speed. This average value was compared with the reference air mass value measured by the reference air mass measuring means. The result of this comparison supplied the correction factor multiplied by which the data subject to error can be harmonised with the reference air mass value. Finally according to the procedure described above an associated pulsation amplitude was determined from the data of the air mass measuring means in order to allow assignment of the respective correction factor to the respective operating status of the internal combustion engine (speed) and the respective status of the air flow (pulsation amplitude).
Due to the type of correction according to the invention in dependence on the pulsation amplitude, there is independence of resonance variations in the intake pipe, which are dependent on the ambient status such as the temperature, the pressure or the air humidity.
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Method for measuring a fluid flow, in particular an air flow (L), flowing in a flow canal to an engine (VM) or from an engine (VM), by means of a fluid mass measuring means ( 3 ) connected to an evaluation means ( 2 ), wherein in a regularly performed cycle
an operational parameter (D 1 , D 2 , . . . , D n ) characterizing the operating status of the engine (VM) is recorded,
the data (M 1 , M 2 , . . . , M n ) supplied by the fluid mass measuring means ( 3 ) are recorded,
at least one extreme value (E p , E n ) is determined from the data (M 1 , M 2 , . . . , M n ) recorded since the beginning of a time period (t 1 , t 2 , . . . , t n ),
an average value (W ma ) is determined from the recorded data (M 1 , M 2 , . . . , M n ),
a pulsation amplitude (P 1 , P 2 , . . . , P m ) is determined by dividing the extreme value (E p ) by the average value (W ma ), and
the average value (W ma ) is corrected by multiplying it by a correction factor (K 11 , K 12 , . . . , K mn ) which is selected in dependence on the operational parameter (D 1 , D 2 , . . . , D n ) and the pulsation amplitude (P 1 , P 2 , . . . , P m ) from a plurality of correction factors (K 11 , K 12 , . . . , K mn ) stored in a memory ( 12 ) of the evaluation means ( 2 ) and being determined in an operation test for the type of fluid mass measuring means ( 3 ) in relation to the type of engine.
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FIELD OF THE INVENTION
[0001] This invention relates to the field of data processing applications, and in particular to a system and method for quality performance evaluation and reporting.
BACKGROUND
[0002] In running an organization providing products or services, quality performance data regarding the products or services may be received by the organization from customers, affiliates, and internal sources.
[0003] There are many types of quality performance data, and each type may be collected in different ways by an entity or organization—through internal reviews or by receiving external comments or feedback. Quality performance data may include:
[0004] Product complaints—written or oral expressions from a customer alleging a deficiency in the product.
[0005] Customer support data—data regarding the provision of services to customer, e.g. to ensure the proper installation, safe and reliable operation, maintenance, technical consulting, or logistical backup for a product.
[0006] Repair support data—data regarding returned product evaluation, product repair, or product upgrade services.
[0007] Stability data—data regarding a product's ability to meet shelf-life specifications by remaining suitable throughout the shelf-life of the product or until an expiration date.
[0008] An organization also may have established procedures and practices regarding quality. Such established procedures or practices can include information from disparate sources: corporate procedures, quality policies, process specifications, site procedures, work instructions, blueprints, test methods, instrument accuracy specifications, operator manuals, material or finished goods specifications, or manufacturing instructions.
[0009] An organization may wish to monitor compliance with or deviations from established procedures/practices. The results of this monitoring are another source of quality performance data; these types of quality performance data may track deviations that are planned (temporary change data) or those that are unplanned (non-conformances). A non-conformance or other compliance issue is rectified by means of a corrective action, which will be assigned an associated completion date. Before a corrective action has been assigned a completion date it is known as an uncommitted corrective action. When a completion date is extended it is known as a delayed/rescheduled corrective action. If the date is past and the corrective action is not complete, it is an overdue corrective action. Information regarding the corrective action is yet another type of quality performance data.
[0010] A change control system may be used to define the requirements for and to document changes to raw materials, suppliers, equipment, facilities, utilities, and documents (including specifications, analytical methods, manufacturing procedures, cleaning procedures, packaging, and labeling procedures). Temporary changes are managed in the change control system; the tracking of these changes yields another type of quality performance data.
[0011] When a product is being launched, there may be an associated schedule, including the events and milestones up to launch (and deadlines for each of these) and post-launch procedures and milestones. Whether those deadlines are being met is another form of quality performance data.
[0012] As described, there are many types of quality performance data. Previously, data on each different type of quality performance data, if it is tracked, is stored using a different system. Systems used include paper logbooks and computer spreadsheets. Storage is in many different formats, depending on the system used and the quality performance data being tracked. Quality performance data can be looked at and analyzed, but no system exists which tracks two or more different types of quality performance data for a given product, division, or other common element. Additionally, no system exists which initiates reporting if there is an a typical situation (a trend which is outside of set parameters for normality.) It would be useful for there to be a method to track trends in quality performance data and quality performance data.
SUMMARY OF THE INVENTION
[0013] In accordance with the present invention, a system and method is provided which allows for collection of quality compliance data, storage of such data, scanning of the data to identify a typical trends and values, provide early warning of quality compliance risks, generate reports of a typical situations in graphic and tabular format, and display quality compliance data.
[0014] Data types are defined, and elements of these data types are defined. In addition, the elements can be grouped together in order to allow for searching across data types in those elements. For example, all quality data which deals with a specific product or all events with a critical date during a certain period may be searched for.
[0015] Other aspects of the present invention are described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The foregoing summary, as well as the following detailed description of presently preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings exemplary constructions of the invention; however, the invention is not limited to the specific methods and instrumentalities disclosed. In the drawings:
[0017] [0017]FIG. 1 is a block diagram of an expemplary network environment according to one embodiment of the invention.
[0018] [0018]FIG. 2 is a block diagram of a computing device according to one embodiment of the invention.
[0019] [0019]FIG. 3 is a flow chart illustrating the flow of a search according to one embodiment of the invention.
[0020] [0020]FIG. 4 is a flow chart illustrating the flow of a typical reporting according to one embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] Overview
[0022] The system and method of the present invention provide a coherent system, implemented on one or more computers, for defining parameters for the quality performance data, accumulating and storing quality performance data, and generating reports and displays of the quality performance data across multiple data types, and automatic reports and displays of a typical quality performance trends.
[0023] Exemplary Operating Environment
[0024] The system and method of the present invention can be deployed as part of a computer network, and that the present invention pertains to any computer system having any number of memory or storage units, and any number of applications and processes occurring across any number of volumes. Thus, the invention may apply to both server computers and client computers deployed in a network environment, having remote or local storage. FIG. 1 illustrates an exemplary network environment, with a server in communication with client computers via a network, in which the present invention may be employed. As shown, a server 110 is interconnected via a communications network 114 (which may be a LAN, WAN, intranet or the Internet) with a number of client computers 112 a , 112 b , 112 c , etc. In a network environment in which the communications network 114 is the Internet, for example, the server 110 can be a Web server with which the clients 112 communicate via any of a number of known protocols such as hypertext transfer protocol (HTTP).
[0025] Each client computer 112 and server computer 110 may be equipped with various application program modules, other program modules, and program data and with connections or access to various types of storage elements or objects. Thus, each computer 110 or 112 may have performance data. Each computer 112 may contain computer-executable instructions that carry out the quality performance evaluation and reporting of the invention. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. The quality performance data is stored in database 116 that is coupled to server 110 . Client computers 112 may be affiliate or entity computer systems that collect, maintain, and forward data that is stored in database 116 .
[0026] [0026]FIG. 2 provides a block diagram of an exemplary computing environment in which the computer-readable instruction of the invention may be implemented. The further details of such computer systems as 110 and 112 (FIG. 1) are shown in FIG. 2. Generally, computer-executable instructions are contained in program modules such as programs, objects, data structures and the like that perform particular tasks. Those skilled in the art will appreciate that the invention may be practiced with other computer system configurations, including multi-processor systems, network PCs, minicomputers, mainframe computers and so on. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network.
[0027] [0027]FIG. 2 includes a general-purpose computing device in the form of a computer system 112 (or 110 ), including a processing unit 222 , and a system memory 224 . The system memory could include read-only memory (ROM) and/or random access memory (RAM) and contains the program code 210 and data 212 for carrying out the present invention. The system further comprises a storage device 216 , such as a magnetic disk drive, optical disk drive, or the like. The storage device 216 and its associated computer-readable media provides a non-volatile storage of computer readable instructions, data structures, program modules and other data for the computer system 220 .
[0028] A user may enter commands and information into the computer system 220 by way of input devices such as a keyboard 226 and pointing device 218 . A display device 214 such as a monitor is connected to the computer system 220 to provide visual indications for user input and output. In addition to the display device 214 , computer system 220 may also include other peripheral output devices (not shown), such as a printer.
[0029] Defining Parameters for Quality Performance Data
[0030] According to one embodiment of the invention, the system accepts quality performance data. Quality performance data may be of varying types—each data type has specific elements associated with it.
[0031] For example, a complaint should include information about which product the complaint regarded. Therefore, one element of a complaint is a product identification element. When a complaint is entered into the system, some or all of the complaint elements are included. In one embodiment, numerous different types of quality performance data are supported including complaints, non-conformances, corrective actions, change control information, compliance to stability protocols, and product launch readiness information. These are described below.
[0032] Data may be entered in collective form. For example, if complaints are collected and entered into the system of the invention once per week, the complaint data type supports these aggregated complaint data. In such cases, single complaints may also be entered, by using the element which specifies the number of complaints.
[0033] In the illustrative embodiment of the invention, the following data types and elements are included:
[0034] Complaint Data
[0035] Complaint data, describing complaints received about products, comprises the following elements: product number/name; product family; information regarding the type of complaint (including a class and category/sub-class in the class); site (if applicable); number of complaints being entered; number of complaints closed late; and number of complaints filed late.
[0036] In another embodiment, the system can accept data on each complaint separately.
[0037] Non-Conformance Data
[0038] Non-conformance data is data regarding unplanned deviations from established procedures/practices. Such data comprises the following elements: product number/name; product family; information regarding the type of non-conformance (including a category designation); site; disposition; and information regarding the cause of non-conformance (including a category designation).
[0039] Change Control Data
[0040] Change control data is data about planned deviations from established procedures/practices. Change control data comprises: product number/name; product family; information regarding the type of change control including a category designation); severity; site; time period; and number of changes.
[0041] Corrective Action Data
[0042] Corrective action data is data regarding actions taken to rectify a compliance issue. Corrective action data comprises: source (of the request for corrective action); a unique identification number for the corrective action; product number/name; product family; commit date (date by which the corrective action should be finished); revised commit date (revisions to commit date); and actual completion date.
[0043] Product Launch Readiness Data
[0044] Product launch readiness data describes the parameters of a planned product launch. Product launch readiness data comprises: product number/name; launch time period; and checklist items (items which must be accomplished to launch) and associated due dates.
[0045] Compliance to Stability Protocol Data
[0046] Compliance to stability protocol data tracks the ability to meet performance requirements throughout product shelf life. Compliance to stability protocol information tracks problems with adherence to the stability protocol including: product number/name; date of problem; site of origin of product; problem observed; number of units of product involved in the problem.
[0047] Most of the elements of each type of quality performance data are optional; some will have limits on their values (e.g. number of complaints must be non-negative). Other quality performance data types or elements of these types may be supported in other embodiments. For each type of quality performance data, data elements (such as those listed above) can be defined.
[0048] When the parameters for data types and elements are being defined, it is important that associations are made between like elements in different data types. For example, product number/name is an element of each of the exemplary data types listed above. An information element specifying a site associated with a quality performance data is an element of some, but not all of the data types listed. Not only can these very similar data types be associated, but so can others—for example, commit dates for corrective actions and dates associated with checklist items for product launches may be grouped, along with other elements, as elements which refer to deadlines. Because the definition of sets of grouped elements are made as part of the definition process, cross data-type reporting becomes possible, as described below.
[0049] Accumulating Quality Performance Data
[0050] Users accessing the system must be able to enter data. Data may be entered into the system from a spreadsheet or other file of a specified format. The user enters the location of the data, and the system will process the data and store it. Data may also be entered manually via a keyboard or other user interface with prompts to the user. When data has been entered (either from a file or manually), a check is performed to ensure that all of the mandatory data elements have been entered and that any value which has been entered for an element is within the ranges set for the data element (if any) or is of the type which has been defined for the data element (if any). Conversion to standard field formats is performed, to standardize date formats, for example. Where duplicate records can be identified, duplication is checked for and the user alerted or, in another embodiment, duplication is automatically eliminated.
[0051] Reporting and Displaying Performance Data of Multiple Types Using a Common Element
[0052] In order to provide users with information regarding quality performance data, the system allows the user the ability to review data on-line. In one embodiment, user access to the system is provided via a user interface including a display area and pull down menus offering users different data viewing and reporting options.
[0053] Users may choose to display only one type of data. For example, the user may request all complaints. This data may be further limited with reference to the elements of the data type. For example, all complaints received in a given month may be requested. Data being displayed may be sorted on date or on other parameters, as requested by the user. Data may be displayed in a table, or graphically, depending on the user's request, and report displays may be viewed on screen or viewed through the use of intermediate files stored by the system or emailed to users.
[0054] In addition to reporting data in only one data type, however, users are provided with the ability to create reports of data of many data types, by selecting specific data to view from the entire corpus of quality data. This is possible because different data types may have elements from among a single set of grouped data elements. So, by using the correct set of grouped data elements, users are able to search among different data types by site, by product, by product family, by deadline, or any combination of these options.
[0055] With reference to the flow chart of FIG. 3, the system prompts the user to specify a request, including a set of grouped data elements (such as “site” or “deadline”, as described above) and a value or range to search for in the data elements included in that group 300 . When the user does, the system receives that request 310 . For each data type, the system determines whether the request is applicable for the data type 320 . If the request is applicable to that data type (if the element involved in the request is an element of that data type), the system performs the request on data of that data type and temporarily stores the results 330 . When that is done, or if the request was not applicable, the system determines whether there are any more data types to consider 340 . If there are, the system determines whether the request is applicable to the next data type (step 320 ) and continues from there. If there are not, the system formulates a report of the temporarily stored data 350 .
[0056] In this way reports can be formulated which include multiple data types, even if not all of the elements in the set of grouped elements requested exist in all the data types. The request received by the system in step 310 may involve more than one set of grouped elements—it can be a combination of requests conjunctively (data which are included in the results of request 1 and also in the results of request 2 ), disjunctively (data which are included in the results of request 1 and the results of request 2 ), or negatively (all data not included in the results of the request). For example, instead of requesting all quality data entered for a given product family, it may request all quality data entered for a given product family in a specific month, not including complaints. Or all quality data may be requested for two specified product families.
[0057] Again, data being displayed may be sorted on date or on other parameters, as requested by the user, and graphical and tabular reports are available. Report displays may be viewed on screen or viewed through the use of intermediate files stored by the system or emailed to users. A user may also request that a report be run on a periodic basis or on any other trigger which the system can perceive (introduction of new data; opening of application, etc.)
[0058] Reporting and Displaying Performance Data of Multiple Types Using a Common Element
[0059] A typical reporting is also provided by the system. For example, all available complaint data may be evaluated on a month-by-month basis, and months with an increase of more than 10% more complaints than the previous month are highlighted. Multi-variant assessments that take into account the compounding effect of quality activity and performance associated with more than one measurement are provided for.
[0060] With reference to the flow chart of FIG. 4, the system prompts the user to input an a typical report request in step 400 and receives the request in step 410 . The request will contain an a typical condition, which the quality performance data is to be monitored for, and a triggering event. The system according to one embodiment of the invention may be running continually, as a background process, or as an application which is started by a user, among other possibilities. The triggering event of the request specifies when the data will be evaluated to see if the a typical condition is present. Either the request is to be run once at a given time, or the request is to be run on a periodic basis with a specified period, or the request is to be run every time the program is restarted. The system waits for the triggering event 420 , and then evaluates whether the a typical condition has occurred 430 . If it has not, the system waits for the next triggering event 420 . If the a typical condition has occurred, a report will be created and provided to the user 440 . The provision of the report to the user will be done in a way specified in the request (or according to a default if none was specified.) The report may be displayed, emailed to a user, or a message may be sent to the user or displayed indicating that the report is available. In this way, a typical conditions may be monitored.
[0061] Just as searches may be done using sets of grouped events, so may a typical conditions be done on groupings—for example, an request may ask that the number of deadlines for a given month be monitored and that if any month has more than a threshold number of deadlines, that situation be reported as a typical. A request may also ask that if deadlines for any month rise more than 10% over any other month, that situation be reported. In this way, all the quality performance data may be used to monitor work flow, problems, or other quality issues.
[0062] In one embodiment, data used for reports and displays is from a 13-month rolling horizon, allowing 13 months of data to be input and used. Data is backed up regularly, and data which is older than 13 months is archived.
CONCLUSION
[0063] In the foregoing description, it can be seen that the present invention comprises a new and useful system and method for quality performance evaluation and reporting. It should be appreciated that changes could be made to the embodiments described above without departing from the inventive concepts thereof. It are understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within should be spirit and scope of the present invention as defined by the appended claims.
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A system and method for quality performance evaluation and reporting allows for easy entry of quality performance data via spreadsheet or other file format, or directly, into a quality performance system. Data elements are associated across data types, allowing searches to be performed on the entire corpus of quality performance data. A typical data may be displayed as well, allowing users to focus on problematic quality performance. Data in reports may be displayed graphically or in tabular form; printed or displayed on screen; and searched for once, periodically, or upon other triggers.
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BACKGROUND OF THE INVENTION
The present invention is in the field of electrical power generation and distribution systems and, more particularly, systems which may be employed in aerospace vehicles.
In a typical prior-art aerospace vehicle such as an aircraft, there may be many different requirements for electrical power. Many functions may be performed with electrical motors and controls.
On-board generators may be driven with various prime movers such as turbine engines. In many cases, a prime mover may drive a generator only as an ancillary function. A typical primary function for a prime mover, such as a turbine engine, may be to provide propulsion thrust for the aircraft. In the context of its primary function, the prime mover may operate at varying rotational speeds. A generator coupled to a shaft of such a variable-speed prime mover may rotate at varying speeds.
As aircraft designs evolve, more of the ancillary power requirements are being met with electrical systems instead of previously used bleed air and hydraulic systems. An evolving design concept has become known as “more electric aircraft” (MEA). In the context of MEA designs, electrical loads on generators may be become quite large. Indeed, a generator load may become large enough to negatively affect engine thrust output. Because of these increased electrical power demands in MEA design, a single generator driven by a single prime mover may not be capable of producing all of the electrical power for an aircraft. Consequently, an aircraft may be provided with multiple generators, each driven by different prime movers.
Because prime movers have varying rotational speed during operation of the aircraft, rotational speed of any particular generator may differ from rotational speed of other generators on the aircraft. In the case of alternating current (AC) generators, each AC generator may produce AC power at a frequency and phase angle different from the other AC generators. It may be said that, each generator may produce “variable frequency” electrical power.
Certain aircraft operating conditions may arise in which a particular generator may be subjected to a particularly high load demand during a time when its associated prime mover may be performing its primary function (e.g. producing thrust) at a relatively low speed. In order to meet the high electrical power requirement of an attached generator, it may be necessary to increase the speed of the prime mover, even though such an increase in speed may not otherwise be required for the primary function of the prime mover.
Excessive fuel may be consumed if and when a prime mover is operated at a speed greater than required for its primary role. Certain design efforts have been directed to this issue. For example U.S. Pat. No. 7,285,871 (Jean Luc Derouineau) issued Oct. 23, 2007, discloses multiple generators that may be driven on different shafts of a turbine machine. The turbine machine may have a low-pressure turbine output shaft and a high-pressure turbine output shaft. A separate generator may be driven by each of the shafts. Electrical outputs of the generators may be shared and controlled so that electrical loads may be allocated to either the low-pressure turbine or the high-pressure turbine as a function of turbine operating speed. This allocation may facilitate efficient operation of the turbine machine.
This prior-art power allocation method may require paralleling of two or more AC generators onto a common power bus. Successful paralleling of AC generator outputs may require matching of frequency of the generators. Thus this prior-art method, when employed with AC generators, may be practical only when the AC generators operate at the same rotational speed. Alternatively, as in well understood prior art, the generators may be driven via a constant speed transmission to match their frequency and phase, or may use power electronics to synthesize a matched AC output. Both of these techniques require large, complex and expensive devices to facilitate paralleling.
Many MEA aircraft employ multiple turbines that may operate at different speeds. Each of the turbines may drive AC generators. It has heretofore not been practical to allocate electrical power requirements of multiple-engine aircraft to all of the generators of the aircraft as required by the operational conditions.
As can be seen, there is a need to provide power generation and distribution systems in which AC power produced by multiple generators operating at different speeds may be paralleled to a common bus. Additionally, there is a need to provide such a system in which electrical loads may be allocated to any prime mover of a multiple-engine aircraft, or any turbine of a multiple-turbine prime mover.
SUMMARY OF THE INVENTION
In one aspect of the present invention, an apparatus for generating and distributing electrical power comprises a first alternating current (AC) generator driven at a first rotational speed, a second AC generator driven at a second rotational speed different from the first speed, a common direct current (DC) bus, fed from either of the generators (e.g., via a rectifier), supplying electrical power to electrical loads connected to the common bus, and a controller for allocating portions of the electrical load among the first and the second generators.
In another aspect of the present invention, an apparatus for generating and distributing electrical power in an aircraft with multiple turbines comprises a first alternating current (AC) generator driven by a first turbine at a first rotational speed, a second AC generator driven by a second turbine at a second rotational speed different from the first speed, and a common direct current (DC) bus interconnected with the first and second generators (e.g., via rectifiers). The common bus is selectively connected to electrical loads that produce the electrical power demand. A controller is provided to selectively allocate portions of the electrical power demand among the first and the second generators.
In still another aspect of the present invention, a method for producing and distributing electrical power in an aircraft comprises the steps of driving a first AC generator at a first rotational speed, driving a second AC generator at a second rotational speed different from the first speed, supplying electric power from the first and second generators to a common DC bus (e.g. via rectifiers), supplying electric power from the DC bus to electrical loads that produce the electrical power demand, and allocating the electrical power demand among the first and second generators.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is block diagram of a power system in accordance with the invention;
FIG. 2 is a block diagram of the power system of FIG. 1 in an engine starting mode of operation in accordance with the invention;
FIG. 3 is a block diagram of the power system of FIG. 1 in a failed-generator mode of operation in accordance with the invention;
FIG. 4 is a block diagram of the power system of FIG. 1 in a failed-bus mode of operation in accordance with the invention; and
FIG. 5 is a flow chart of a method of generating and controlling electrical power in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
Broadly, the present invention may be useful for distributing electrical power demands among various prime movers. More particularly, the present invention may provide a power allocation system that may distribute electrical power requirements among multiple prime movers of a vehicle. The present invention may be particularly useful in vehicles such as aircraft with multiple turbines.
In contrast to prior-art aircraft electrical power systems, among other things, the present invention may provide for combining, on a common bus, electrical power produced by multiple AC generators which may be driven at rotational speeds which may differ for each generator. The present invention, instead of paralleling AC power from different generators as in the prior art, may convert AC power from individual generators into DC power and then parallel the resultant DC power of multiple generators onto a common bus. Additionally, the present invention may provide generator output controls to allocate electrical power demands to various prime movers having differing rotational speeds.
Referring now to FIG. 1 , an exemplary electrical power system is designated generally by the numeral 100 . The power system 100 may be utilized in an aircraft (not shown) which may have multiple turbines and/or multiple engines. The power system 100 may comprise multiple electrical generators, such a left-hand HP starter/generator 12 which may be driven by a high-pressure turbine 112 of a left engine 140 , a left-hand LP generator 14 which may be driven by a low-pressure turbine 114 of the left engine 140 , an APU starter/generator 16 which may be driven by an auxiliary power unit 116 , a right-hand HP starter/generator 18 , which may be driven by a high-pressure turbine 118 of a right engine 180 , and a right-hand LP generator 20 which may be driven by a low-pressure turbine 120 of the right engine 180 .
The power system 100 may also comprise electrical buses. A left bus 22 may be interconnected with the generators 12 and 14 . A main power bus 24 may be interconnected with the generator 16 and may also be selectively interconnected with a ground power unit (GPU) at an external power entry point 25 . A right power bus 26 may be interconnected with the generators 18 and 20 . The buses 22 , 24 and 26 may also be interconnected with one another with bus-tie contactors 28 and 30 . In that regard, the buses 22 , 24 and 26 may be considered to be sub-buses of a common bus 27 . The buses 22 , 24 and 26 may be direct current (DC) buses and may operate with an exemplary voltage of about +/−270 volts DC
During normal flight operation of the aircraft the contactors 28 and 30 may be closed so that the buses 22 , 24 and 26 may be electrically interconnected. Contactors 12 - 1 , 14 - 1 , 16 - 1 , 18 - 1 and 20 - 1 may also be closed during normal flight conditions. It may be seen that all of the generators 12 , 14 , 16 , 18 and 20 may be interconnected with all of the buses 22 , 24 and 26 in normal flight conditions.
The left engine HP generator 12 may be an AC generator operating at a first speed and the right engine HP generator 18 may be an AC generator operating at a second speed different from the first speed. But the generators 12 and 20 may be interconnected with their respective DC buses 22 and 26 though rectifiers 12 - 2 and 18 - 2 respectively. Similarly the APU generator 16 may be an AC generator operating at still another speed and its output power may be applied to the DC bus 24 through a rectifier 16 - 2 .
The generators 14 and 20 may be DC generators and may supply power to their respective buses 22 and 26 in parallel with the AC generators 12 , and 18 . It may be seen then, that electrical power from the generators 12 , 14 , 16 , 18 and 20 may be pooled together on the buses 22 , 24 and 26 during normal flight operations, irrespective of whether the generators produce AC or DC power.
The bus 24 may be interconnected to provide power to various motor controllers or other loads, symbolically designated herein as motor controllers 31 and 32 . Any number of motor controllers may be interconnected with the bus 24 in accordance with the present invention. An exemplary number of two motor controllers, 31 and 32 are illustrated in FIG. 1 . The exemplary motor controllers 31 and 32 may control exemplary motors 31 - 1 and 32 - 1 which may perform general aircraft operating functions that may be associated with normal flight conditions.
The buses 22 and 26 may be interconnected with engine starting controllers 34 and 36 respectively. The controllers 34 and 36 may be employed during APU and engine starting operations for the aircraft, which operations are hereinafter described. Additionally, the motor controller 34 and 36 may control other exemplary motors designated by the numerals 34 - 1 and 36 - 1 respectively.
During normal flight operations, the exemplary motor controllers 31 , 32 , 34 and 36 may provide control for their respective exemplary motors 31 - 1 , 32 - 1 , 34 - 1 and 36 - 1 . The motors may be either AC or DC motors and they may be configured to operate at high or low voltages. The motor controllers may extract +−270 volt DC power from the bus 27 and convert the power into a form that may be properly used by the motors.
A supervisory controller 38 may be interconnected with sensors (not shown) to monitor generator power and engine control units (not shown) so that proper portions of loads may be allocated to any one or more of the generators 12 , 14 , 16 , 18 or 20 during normal flight operations. Allocation may be performed by appropriate signaling from the supervisory controller 38 to generator control units (GCU) 12 - 3 , 14 - 3 , 16 - 3 , 18 - 3 and 20 - 3 . Each of the GCU's 12 - 3 , 14 - 3 , 16 - 3 , 18 - 3 and 20 - 3 may provide control of electrical output of their respective generators 12 , 14 , 16 , 18 and 20 .
By way of example, the GCU's may define a power share their respective generators. Each of the generators may produce power in according to its commanded share. Thus a generator that is assigned an exemplary share of 25% may produce 25% of the total power demand. Power share of the generators 12 , 14 , 16 , 18 and 20 may be changed continuously by the GCU's in response to changes of electrical power requirements and availability of turbine power.
Allocation of electrical power requirement may be performed to optimize turbine efficiency. For example, if flight conditions demand particularly low power extraction from the high-pressure turbines 112 and 118 , electrical load may be reduced on generators 12 and 18 by reducing their duty cycle. The motors 31 - 1 , 32 - 1 , 34 - 1 and 36 - 1 may still consume an undiminished amount of electrical energy during this period, but the balance of the total electrical energy may be provided by the low pressure turbine generators 14 and/or 20 . In other words, a larger portion of the overall electrical power requirements of the aircraft could be extracted from the low-pressure turbines during this period.
Conversely, electrical power requirements may be allocated to the high-pressure turbines 112 and/or 118 at times when this may provide the best engine operating performance. Additionally electrical power requirements may be re-allocated or shifted from the low pressure generators 14 and/or 20 or the high pressure generators 12 and/or 18 to the APU generator 16 .
Referring now to FIG. 2 , it may be seen how the power system 100 may be employed during a start-up on an exemplary engine. In this case, startup of the left engine 140 may be illustrated. In FIG. 2 , it may be seen that a starter bus 40 may be provided power for starting from the motor controller 34 through a contactor 40 - 1 . Power to the motor controller 34 may be provided from the generators 16 , 18 and/or 20 because the contactors 16 - 1 , 18 - 1 and 20 - 1 may be closed. For main engine starting, power from the starter bus 40 may be provided to the starter/generator 12 through a contactor 40 - 2 which may be closed. The GCU 12 - 3 may produce commands which actuate the starter/generator 12 as a starter motor.
For APU starting, power from the starter bus 40 may be provided to the APU starter/generator 18 through a contactor 40 - 3 which may be closed.
If starting with ground power is required, a contactor 25 - 1 may also be closed so that power from the ground power unit may be supplied through the entry point 25 . The external power may be converted to DC by rectifier 25 - 2 , to the common bus 27 and the motor controller 34 and then on to the starter/generator 12 .
It may be noted that the bus-tie contactors 28 and 30 may remain closed during starting operations, just as they may remain closed during normal flight operation of the aircraft. Thus the buses 22 , 24 and 26 may continue to provide collective pooling of electrical power for the aircraft.
Referring now to FIG. 3 , it may be seen how the power system 100 may operate in the event of a failure of a generator. By way of example a failure of the generator 14 may be illustrated. In this case, the contactor 14 - 1 may be opened and the generator 14 may be disconnected from the bus 22 . The contactors 28 and 30 may remain closed so that the buses 22 , 24 and 26 may remain interconnected. Thus in spite of a partial loss of power to the bus 22 , the motor 34 - 1 may be provided with power from the other generators 12 , 16 , 18 and 20 .
Referring now to FIG. 4 , it may be seen how the power system 100 may operate in the event of a short-circuit failure of a bus. By way of example, a short-circuit failure of the bus 22 may be illustrated. In this case, the contactor 12 - 1 , 14 - 1 and 28 may be opened. The bus 22 may be thus electrically isolated from the electrical power of the aircraft. The contactor 30 may remain closed so that the buses 24 and 26 may remain interconnected. Thus in spite of failure of the bus 22 , the motors 31 - 1 , 32 - 1 and 36 - 1 may still be provided with power from the generators 16 , 18 and 20 . This is because the buses 22 , 24 and 26 may selectively be isolated from one another electrically by the contactors 28 and 30 .
Referring now to FIG. 5 , in one embodiment of the present invention, a method may be provided for generating and distributing electrical power on an aircraft. In step 502 of a method 500 , electrical power may be generated in a first generator (e.g. the AC generator 12 driven by the left hand high-pressure turbine 112 ). In a step 504 , electrical power may be generated in a second generator (e.g. the AC generator 18 driven by the right hand high-pressure turbine 118 ).
In a step 506 , power generated in steps 502 and 504 may be supplied to a common bus (e.g. by rectifying AC outputs of generators 12 and 18 and supplying power to interconnected buses 22 , 24 and 26 ). In a step 508 , power may be delivered to electrical loads (e.g. through interconnections between motor controller 31 , 32 , 34 and 36 and the buses 22 , 24 and 26 ).
In a step 510 , a load allocation calculation may be performed (e.g. with the supervisory controller 38 ). In a step 512 , a calculated power requirement allotment may be provided to a GCU for the first generator (e.g. the GCU 12 - 3 for the generator 12 ). In a step 514 , a calculated power requirement allotment may be provided to a GCU for the second generator (e.g. the GCU 18 - 3 for the generator 18 ).
In a step 516 , a power share for the first generator may be produced on the basis of the power requirement allotment provided in step 512 . Step 502 may then be performed in accordance with the power share produced in step 516 . Similarly, in a step 518 , a power share for the second generator may be produced on the basis of the power requirement allotment provided in step 514 . Step 504 may then be performed in accordance with the power share produced in step 518 .
It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
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A power generation and distribution system utilizes two or more AC generators each of which may be driven by a separate prime mover such as a turbine. The generators may be driven at different rotational speeds. AC power from the generators may be rectified and applied to a common DC bus. Electrical loads may be applied to the common bus and may establish an electrical power requirement. Allocation of electrical power requirement may be made among the generators based on power available from the turbines.
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This invention relates to an improved method of recovery of metal values from ferromanganese nodules, commonly referred to as sea nodules, and more particularly to the recovery of molybdenum values from such nodules.
Sea nodules are aptly named in that they are found in the deep-sea beds and are primarily constituted of iron and manganese for which reason names such as ferromanganese and manganiferous have been employed. In addition to iron and manganese, recoverable quantities of valuable metals such as Ni, Co, and Cu are also present and it is the presence of such metals which has led to intensified efforts to develop practical and economical processes for recovery of the said metal values from sea nodules. Sea nodules also contain a considerable number of other metals at such low levels that they have not been separated and recovered, either because of prohibitive economics or the extreme difficulty of separation techniques. Included among such metal values are molybdenum values which are known to be present in sea nodules at levels of approximately 0.1% and lower. Such levels are not economically practical to separate and recover by the usual known methods. Nodule deposits can be found in all oceans but the Pacific Ocean remains the richest source with estimates of some 1.5 trillion metric tons of nodules present on the Pacific seafloor being replenished at the impressive rate of 10 million tons annually. The extraction and separation of copper, nickel, cobalt and manganese from sea nodules have proved to be an exceedingly complex metallurgical problem. Part of the complexity of course is the necessary consideration of the economics of commercial recovery of the said metals for which a number of various processes have been developed.
Of particular attractiveness are processes predicated on sulfation of sea nodules with sulfur dioxide. U.S. Pat. No. 3,169,856 describes a process of treating sea nodules with aqueous solution of sulfur dioxide to selectively separate nickel from cobalt, the bulk of the Ni, Mn and Cu being solubilized and the Co remaining in the insoluble nodule ore, presumably the iron oxide matrix. U.S. Pat. No. 3,810,827 describes a sulfation process wherein the ore is treated with gaseous sulfur dioxide in the absence of oxygen and then leached with water to separate the water-soluble manganese sulfate from the solid residue, which was subsequently treated as by sulfation with SO 2 and O 2 followed by water-leaching to obtain the water-soluble salts of Cu, Ni and Co. U.S. Pat. No. 3,869,360 describes a sulfation process which involves sulfation of an aqueous slurry of sea nodules using sulfur dioxide and oxygen including oxidation of the iron content of the sea nodule to iron oxide, and leaching the ore with water to separate the water-soluble salts.
With these various processes of sulfation, however, only incomplete and inefficient recovery of the Ni, Co and Cu are realized and there still remains a need for an improvement in the efficiency of recovery of the said metals.
An improved process for sulfation of nodule ores is described in concurrently filed, commonly assigned copending patent application Ser. No. 000,676 in which the sulfation, i.e., contact with sulfur dioxide is carried out in the presence of oxygen and in the substantial absence of water. Using the said process it is possible under preferred conditions to effect quantitative separation of nickel and cobalt and high yield separation of copper. Thus, the high recovery efficiency is particularly desirable in evaluation of this process from the viewpoint of economy, particularly in comparison with the prior art sulfation methods which are not known to achieve such high levels of efficiency.
BRIEF DESCRIPTION OF THE INVENTION
This invention provides an improvement in the process of sulfating sea nodule ores and is predicated on the discovery that the molybdenum values of the nodule ore can be volatilized after or during the sulfation process, in the latter instance, when sufficiently high temperature is employed in the sulfation step.
Thus, the molybdenum values of the nodule ore after volatilization can be recovered by condensing the volatilized form by the mere expediency of cooling the volatilized molybdenum values and collecting the condensed form to obtain the molybdenum values in substantially pure state. The initially condensed molybdenum values collected as a brown deposit which on cooling and exposure to atmospheric conditions turns blue, due to hydration to form molybdenum blue.
Accordingly, any sulfation process for treatment of sea nodules to convert the metal values to water-soluble salts can be employed to liberate the molybdenum values from the nodule ore structure which values can then be recovered by volatilization and condensation. Accordingly, low-temperature sulfation can be used, in the presence or absence of water, and high temperature sulfation can be used. Particularly effective sulfation processes are those carried out in the presence of oxygen, especially at elevated temperature and particularly under substantially dry conditions.
Accordingly, when the sulfation reaction is carried out at elevated temperatures, the molybdenum values can be volatilized at the reaction temperature as liberated from the nodule structure. Conveniently, a carrier gas can be passed through the heated sulfation mixture to entrain the volatile molybdenum values. When the sulfation reaction is carried out at low temperatures, e.g., 100° C. or lower, after completion of the reaction the dry reaction mass can be heated up to elevated temperatures where the molybdenum values are volatilized, preferably with a carrier gas.
After the molybdenum values are volatilized, the volatile product, i.e., oxides of molybdenum such as MoO 3 can then be conducted to a suitable collection apparatus and there collected by cooling.
For most purposes, elevated temperatures in the range of about 300° C. to about 600° C. preferably about 375° C. to about 400° C. will permit volatilization of the molybdenum values.
The present invention therefore provides a desirable by-product from the sulfation process for recovery of metal values and the overall economy of the recovery process is favorably affected by the value of the by-product.
DESCRIPTION OF PREFERRED EMBODIMENTS
The preferred sulfation process is that described in the aforesaid concurrently filed, commonly-assigned patent application.
The sea nodule ore selected for processing is preferably in finely-divided form in order to increase the efficiency of contact with the gaseous reactants, sulfur dioxide and oxygen. Thus, the ore can be pulverized or powdered to a finely-divided state. For most purposes, standard mesh sizes of about 30-200 are found quite suitable although larger or even smaller size can be employed. The size of the particles will merely dictate the time required for reaction and is otherwise not critical.
The sea nodule ore must be substantially dry before contact with the sulfur dioxide and oxygen. Drying of the ore, preferably in finely-divided state for increased efficiency, is accomplished by heating at elevated temperatures to remove water contained therein; the usual water content amounts to about 30% by weight of the sea nodule ore. Heating is continued until constant weight prevails, as is usual practice in such operation. Normally, temperatures in the range of from about 300° C. to about 600° C. are preferred for the drying step. Typically, a sample of the ore is heated in an oven while a stream of inert gas, e.g., helium, is passed through the sample. When constant weight is attained, the sample is substantially free of contained water. While it is preferred to drive out all of the contained water, it is possible to use samples of ore which contain small amounts of water, up to about 1-2% by weight based on the ore weight, which amounts of water can be driven out of the sample in the pre-heating to reaction temperature.
In a preferred form of the invention, the sample of ore is heated to the reaction temperature to remove contained water, i.e., until constant weight is attained, and is then reacted with the gaseous sulfation mixture.
For all purposes, the sample of ore should be "substantially free of water" and, as employed herein and in the appended claims, by this is meant that the sample should contain not more than 1% by weight of water based on the total sample weight.
The sulfation reaction, i.e., contact with sulfur dioxide and oxygen is to be carried out under substantially dry conditions by which is meant water should be preferably totally excluded from the reaction system but can be tolerated up to a level of about 1% by weight of the reaction system. Thus, minor amounts of water, i.e., less than 1% by weight, can be tolerated without significant effect on the reaction.
Any source of sulfur dioxide gas can be employed in the present process and the gas is dried before it enters the reaction zone. Conventional drying of the reaction gas can be employed where greater than 1% by weight of water, e.g., as water vapor, is present in the gas. The oxygen employed, which is dried conveniently along with the sulfur dioxide, or separately as desired, can be pure oxygen gas or air or mixtures thereof. The amounts of each gas added to the reaction zone is not critical since, being gaseous and inexpensive, the gases can be used in excess of the stoichiometric quantities required. The reactive gases may be employed as such or diluted with carrier gas such as helium. Thus, the sulfur dioxide and oxygen gases are added until take-up of the reacting gas ceases. Normally, the take-up of sulfur dioxide gas will vary somewhat with temperature so that, for example, the ore sample can absorb 379 mg. of gas per gram of sample at 300° C. whereas at higher temperatures, the absorption will increase and dramatically at certain temperature ranges. For example, at 350° C., 447 mg/g. is the absorption value, while at 400° C., 493 mg/g., but at 500° C. and above the up take of gas decreases, e.g., at 600° C., 379 mg/g. The optimum absorption of gas occurs within the range of from about 375° C. to about 425° C., and best results are obtained at optimum absorption of sulfur dioxide.
Accordingly, the temperature of the sulfation reaction is preferably that at which absorption of sulfur dioxide occurs at a reasonable rate, i.e., between about 300° C. and about 600° C., with the preferred range being from about 375° C. to about 425° C. Of course, sulfur dioxide absorption does occur at lower or higher temperatures but the reaction is slower due to lower absorption of gas, and such temperatures therefore are not preferred.
Conveniently, as sulfation of the ore proceeds, the original ore which is dark colored, usually dark brown, lightens to eventually a light tan color at full sulfation so that the process is conveniently monitored by visual inspection of the color of the sample. Completeness of sulfation is indicated by no further change in the color of the reaction mixture.
At this point, the molybdenum values will be substantially completely volatilized and collected in a suitable trap, e.g., an air-cooled trap in which they first condense as a brown deposit that turns blue on exposure to the atmosphere. The molybdenum compound is then recovered from the trap by any suitable means, e.g., water-washing to dissolve the molybdenum compound to provide a water solution thereof. The reaction vessel, of course, should be operatively connected to the trap during the heating step in order to collect the molybdenum as volatilized during the sulfation reaction.
After the sulfation reaction is completed and the molybdenum values collected, the reaction mixture is then treated with water to dissolve the water-soluble salts therefrom. For this purpose, the reaction mixture is usually pulverized into finely-divided state if the particles have coalesced during the sulfation step. This step, commonly referred to as leaching with water, can be accomplished with hot or cold water, as desired, depending on the concentration desired in the resulting solution. The leach water may contain sources of complex-formers or ligands to complex the various metal ions contained in the leach solution, permitting separation of these metal ions, e.g., based on differential solubility in organic solvents of the said complexes.
The leach solution should be separated from insoluble residues, mostly iron values, from the ore. The separation method is not critical and can be effected by any of the usual methods of separation of solids from liquid phases, e.g., filtration, centrifugation and decantation.
After separation, the metal values contained in the leach solution can be separated and thereafter recovered by art-recognized procedures, e.g., electrodeposition of the separated metal ions from solution.
Separation of the metal ions from the aqueous leach solution can be brought about in accordance with the procedures described in the aforesaid U.S. Pat. Nos. 3,169,856; 3,810,827; and 3,869,360, the recovery and separation disclosures of which are incorporated herein by reference.
A specific method which can be employed follows. The leach solution is adjusted to alkaline pH with ammonia to form ammine complexes of the contained metal ions. From this solution, the copper, nickel and cobalt can be successively extracted at successively higher pH values obtained by stepwise addition of ammonia employing known chelating agents and extraction techniques employing organic solvents. For example, a commercial chelating agent (LIX 64N) consisting of a mixture of 2-hydroxy-5-nonylbenzophenone oxime and 5,8-diethyl-7-hydroxy-6-dodecane oxime dissolved in kerosene (1.5% solution) can be used to effect the separation which is accomplished by raising the pH stepwise and extracting the so-adjusted solution with the kerosene solution of chelating agent. Successively, the copper, nickel and cobalt are removed leaving manganese in solution.
A variety of factors including stability of complexes, distribution coefficients between aqueous and organic phases, acid dissociation constants of ligands, and concentrations of various species control the extraction of the various metals. Thus, the pH for optimum results will vary with the chelating agent selected as well as the aforesaid factors.
The metal values can be separated from the complexes by methods known to the art, as by springing with a mineral acid such as sulfuric in the known manner. The resulting aqueous solutions can then be used for electrodeposition of the metal from solution by known methods.
The following examples further illustrate the invention.
EXAMPLE 1
Nodule ores are ground to higher than 200 mesh. One gram of the powdered ore was packed into a Vycor glass column with several layers of glass wool to avoid pressure build-up during gas flow. SO 2 (15 ml/min.) and O 2 (5 ml/min.) in helium was passed through the sample at a temperature of about 400° C. for two hours. The volatilized molybdenum values were condensed from the effluent in an air-cooled Vycor tube. The removal efficiency was 75%.
When this procedure was repeated using 80-100 mesh powdered ore, a 30% removal of molybdenum was realized under the same conditions, indicating that the sulfation reaction is somewhat incomplete with the larger particle size ore.
EXAMPLE 2
The procedure of Example 1 was repeated with a number of samples of nodule ore previously dried in an oven at 110° C. which removed 24.17% by weight of water based on the sample weight. The additional water (approximately 6%) was removed when the sample was heated to sulfation temperature the initial stages of sulfation at and during that temperature.
The samples employed were of 200 mesh size and the sulfation was carried out at various temperatures at 50° increments from 300° C. to 600° C. with the following weight increases of the sample (due to sulfation). The flow rates of the reactive gases was 15 ml/min for each gas and 30 ml/min. for helium.
The weight increases are given in Table 1.
TABLE 1______________________________________ Weight increase after sulfationSulfation (original sample weight was 1.0 g.)Temp (°C.) 2 hr. 3 hr. 4 hr. 5 hr.______________________________________300 0.30 0.43 0.44 0.50350 0.51 0.55 0.58 0.59400 0.58 0.61 0.62 0.65450 0.47 0.53 0.56 0.58500 0.44 0.50 0.56 0.57550 0.45 0.48 0.50 0.51600 0.45 0.48 0.48 0.50______________________________________
For each sample, the molybdenum values were trapped as in Example 1.
EXAMPLE 3
The procedure of Example 1 was repeated but at a sulfation temperature of 550° C. for 22 minutes using 15 ml/min. flow rate for O 2 and SO 2 .
The sample was previously dried by heating at 550° C. for 24 hours. After the reaction was completed, the brown deposit of molybdenum values was removed from the condensing tube with 0.1 N NaOH.
EXAMPLE 4
The procedure of Example 3 was repeated except that 0.1 g of water was added to the sample prior to introducing SO 2 and O 2 .
The formation of the brown deposit was less than that obtained in Example 3.
EXAMPLE 5
The procedure of Example 3 was repeated using only O 2 in lieu of SO 2 and O 2 and no colored deposit was obtained in the condensing tube.
This procedure was repeated using only SO 2 in lieu of O 2 with identical results, i.e., no colored deposit was obtained.
EXAMPLE 6
The procedure of Example 3 was repeated at room temperature up to 95° C., and no colored deposit was obtained.
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A process for separating molybdenum values from sea nodules which includes sulfation of the sea nodules, volatilization of the molybdenum values from the sea nodules and collection of the volatile molybdenum values.
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FIELD OF THE INVENTION
[0001] This invention relates generally to overhead doors, and in particular, to an overhead door with stacking panels.
BACKGROUND OF THE INVENTION
[0002] Overhead doors are utilized to provide security and access control in institutional, industrial and commercial buildings. They fall into two general design categories: coiling doors and segmented panel doors. Each have their advantages and disadvantages making one better suited for a given design application.
[0003] Often times a segmented panel door is better suited for a particular application but cannot be used due to the increased space requirement needed to house the panels once the door is opened. Various attempts have been made to reduce the profile of the opened door, such as stacking the panels as taught in U.S. Pat. No. 4,460,030 to Tsunemura et al. and in U.S. Pat. No. 5,685,355 to Cook et al.
[0004] The stacking design of those two patents, as do all other known panel stacking designs, maintain a connection point between the panels such as a hinge, or otherwise link the opened panels, for example, with chains, to support the weight of the panels during opening.
[0005] Having to maintain a connection point between the panels presents many disadvantages such as placing limitations on the ease of repair of damaged panels and requiring higher energy consuming operators to open the door. Accordingly, there is still a continuing need for improved stacking panel overhead door designs. The present invention fulfills this need and further provides related advantages.
BRIEF SUMMARY OF THE INVENTION
[0006] The following disclosure describes a stacking panel overhead door design wherein the panels are independent of one another.
[0007] One advantage of unconnected stacking panels is the spring torque to door weight ratio is easy to control. The weight of the door decreases as the door is lifted and a panel disengages completely from its adjacent panel as it reaches the stacked position. This allows for a linear spring torque to door weight relationship requiring a smaller motor compared to existing designs to provide the lifting torque necessary to operate the door, thereby providing concomitant energy savings. Chart A represents the spring torque to door weight ratio.
[0008] A second advantage of independent stacking panels is the ease of replacement or repair of a damaged panel.
[0009] Other features and advantages of the present design will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying drawings are included to provide a further understanding of the present invention. These drawings are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the present invention, and together with the description, serve to explain the principles of the present invention.
[0011] Chart A represents an ideal spring torque curve.
[0012] FIG. 1 is a front view of the overhead door system.
[0013] FIG. 2 is a perspective view of a panel.
[0014] FIG. 3 is an end view of a panel without the end cap.
[0015] FIG. 4 is a side view of two engaged panels without the end cap.
[0016] FIG. 5 is a front view of an end cap with the roller assemblies.
[0017] FIG. 6 is a side view of stacked door panels in the open position.
[0018] FIG. 7 is a perspective view of the drive mechanism.
[0019] Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate by way of example the principles of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] As required, detailed embodiments of the present invention are disclosed; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms. The figures are not necessary to scale and some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed are not to be interpreted as limiting but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. Where possible, like reference numerals have been used to refer to like parts in the several alternative embodiments of the present invention described herein.
[0021] Turning now to FIG. 1 , in a preferred embodiment, the overhead door 2 comprises a plurality of unconnected panels 4 which operatively travel at each end within a first 6 and second 8 track ( FIG. 6 ).
[0022] As shown in FIGS. 2 and 3 , each panel 4 comprises an outer 10 and inner 12 surface with preferably an insulating material 14 in-between. A top 16 and bottom 18 edge each comprise a geometry that allows for engagement and disengagement of its adjacent panel during operation.
[0023] Turning to FIG. 5 , end caps 46 are fastened at each panel end. While end caps 46 in and of themselves are not required for operability, the end caps 46 provide esthetic advantages, operative engagement advantages, and fewer panel component parts. When the panels 4 are stacked, the end caps 46 contact each other, not the panels 4 , thereby limiting the bumping and disfigurement of the panels 4 . Instead of the time consuming task of separately mounting a first 26 and second 28 positioning assembly, activation engagement member 34 , and panel guide 38 (described in detail below) to each panel 30 , a prefabricated end cap 46 containing those components is fastened to each panel end 30 . The end caps 46 are preferably molded of high impact plastic.
[0024] All panels 4 , including the bottom panel 48 are interchangeable to allow for easy removal of a damaged panel and replacement. The bottom panel 48 ( FIG.1 ) includes a removably attached weather seal and/or sensing edge 50 affixed to its bottom edge 18 that is removed and reattached to the replacement bottom panel. The end caps 46 of the bottom panel 48 are operatively engaged to a drive mechanism 64 ( FIG. 7 ), for example a cable, chain, belt, or piston.
[0025] When the drive mechanism 64 is a cable, the cable arrangement provides the cable 64 an effective operative cable geometry that will allow the cable 64 to operatively wrap on a cable drum 66 . As shown in FIG. 7 , to achieve this, in a preferred embodiment, the cable 64 is positioned vertically from the panel cable attachment 68 , around a first pulley 70 mounted to a vertical pulley bracket 78 , and then around a second pulley 72 mounted to a horizontal pulley bracket 80 and positioned about 15 inches to about 17 inches, optimally about 16 inches behind a wall attachment 82 before the cable 64 wrap on the cable drum 66 .
[0026] Turning to FIGS. 3 and 4 , for the top edge geometry a lip 20 is angled in relation to outer panel surface 10 forming angle α. Likewise, trough 22 is angled in relation to inner panel surface 12 forming angle β. For the bottom edge geometry the lip 20 is angled in relation to inner panel surface 12 forming angle α. Trough 22 is angled in relation to outer panel surface 10 forming angle β. When two panels 4 are fully engaged ( FIG. 4 ) the lip 20 of the first panel nests intimately within the trough 22 of its adjacent panel. The lip 20 /trough 22 geometry allows adjacent panels to nest and prevents engaged panels from separating, thereby insuring security, improving the wind load rating, and providing added weather protection. Preferably, a thermal break piece 24 , shown in FIG. 3 , is attached to each panel 4 . Multiple points of contact between the panel top edge thermal break piece 54 and panel bottom edge thermal break piece 56 increase the surface area of the joint to provide a more complete air infiltration seal. In the preferred embodiment, top and bottom thermal break pieces 54 , 56 are fabricated from PVC.
[0027] To insure proper panel engagement/disengagement during door closing and opening and to prevent water from traveling from the outside environment to the inside environment, angles α and β are about 10 degrees to about 25 degrees, preferably about 15 degrees to about 20 degrees and optimally about 18 degrees.
[0028] While the following elements may be attached directly to a panel 4 , for the advantages described above, in a preferred embodiment they are fabricated as part of the end cap 46 . As shown in FIG. 5 , a first 26 and second 28 positioning assembly, for example, bearing assemblies, are attached to each end 30 of panel 4 . The first positioning assembly 26 comprises a first engagement member, for example, a bearing 32 , extending outward from panel outer surface 10 to operatively engage the first track 6 . An activation engagement member, for example, an activation bearing 34 , is positioned to operatively engage the panel guide 38 of the adjacently superior panel during opening and closing of the door 2 .
[0029] Activation engagement member 34 aids in engaging/disengaging the lip 20 and trough 22 of adjacent panels by riding on the panel guide 38 around the panel bottom edge radius 40 to nest the panels in the fully engaged (door closed) position. Bearing 34 remains in contact with panel guide 38 in the stacked position, the fully closed position, and throughout the panel engagement/disengagement operation.
[0030] The second positioning assembly 28 comprises an engagement member, for example, a bearing 36 , extending inward from the panel inner surface 12 to operatively engage the second track 8 .
[0031] Although optional panel stiffeners may be added to the panel 4 , the present design does not require any stiffeners to be operatively effective, providing additional benefit over known sectional door designs which require stiffeners to achieve equivalent wind load ratings. In a preferred embodiment the insulating material 14 comprises an expandable foam injected between the outer 10 and inner 12 panel surface. While bearings have been used as exemplars for the engagement members, any low friction member, for example, PTFE pads are also contemplated.
[0032] Turning now to FIG. 6 , each set of first 6 and second 8 tracks are fixed to both sides of a door opening frame member 76 in known fashion. In a horizontal section 42 of tracks 6 , 8 , the tracks 6 , 8 are separated by a distance equal to the width of a panel 4 . In a vertical section 44 of tracks 6 , 8 , the tracks 6 , 8 are separated by a distance equal to the thickness between the first engagement member (bearing) 32 and the second engagement member (bearing) 36 . The transition between the horizontal section 42 and the vertical section 44 is accomplished through radii γ and δ. Ideally, the radii γ and δ are sized to support only two panels 4 simultaneously. The ideal spring torque curve indicated by Chart A is most closely achieved by having as few panels simultaneously engage radii γ and δ as possible. Since effective disengagement of adjacent panels will not occur if radii γ and δ are sized to only accept one panel, two panels is optimum.
[0033] The optimal sizing of the radii γ and δ allows for the advantageous reduced force required to operate the door 2 . Larger radii would require increased initial force to hold the panels, thereby causing the spring torque to door torque to become out of balance near the closed position as those panels are no longer traveling within the radii. Larger radii would also increase the height of the stacked panels 4 above the door opening creating the need for additional overhead space. In the preferred embodiment, the radii γ and δ are about three inches to about five inches, and optimally, about four inches. Along with providing the optimal spring torque to door torque ratio, the optimal radii allow the footprint of the panel stack 58 to fit within the current requirements for a typical rolling steel door construction, thereby allowing easy retrofit.
[0034] In operation of a preferred embodiment, to close the overhead door 2 a motor 60 turns a shaft 62 in a direction to unwind a cable 64 from a cable drum 66 attached to the shaft 62 . The bottom panel 48 gravity closes as the cable 64 unwinds. The bottom panel 48 maintains the panel immediately superior to it in the panel stack 58 until the point of transition to the engaged position. As the lip 20 and trough 22 of adjacent panels 4 become engaged, the process begins again as the newly engaged panel maintains its immediately superior panel in the panel stack 58 until the point of transition to the engaged position. The process repeats until all of the panels necessary to close the opening are in place.
[0035] To open the door 2 , the opposite occurs. As the motor 60 turns the shaft 62 winding the cable 64 onto the cable drum 66 the bottom panel 48 is raised thereby raising all the panels above it. As a panel 4 travels through the radii γ and δ, the activation bearings 34 located at each panel end disengage the lip 20 and trough 22 of adjacent panels as the activation bearings 34 ride on the panel guide 38 around the panel bottom edge radius 40 . As each succeeding panel is disengaged it pushes the preceding panel into and forms the panel stack 58 .
[0036] In this manner, the weight of the door 2 decreases as each panel 4 disengages and joins the panel stack 58 . This allows for easier control of the spring torque to door weight ratio. This linear relationship (indicated by Chart A) requires a much smaller motor to provide the lifting torque necessary to operate the door when compared to known technology where the panels cannot separate from one another.
[0037] Because the panels 4 are independent from and unconnected to one another, repair or replacement is easily and quickly accomplished. Returning to FIG. 6 , in the door open position each independent stacked panel 4 can be slid out the rear of the stack until the damaged panel is retrieved. Once repaired or replaced, the removed panels 4 are easily and quickly replaced within the track. No time is lost to removing hinges or otherwise disconnecting and reconnecting one panel to adjacent panels as required with existing technology.
[0038] Although the present design has been described in connection with specific examples and embodiments, those skilled in the art will recognize that the present design is capable of other variations and modifications within its scope. For example, although a cable lifting mechanism has been described, any motion that provides for raising and lowering the bottom panel is contemplated. These examples and embodiments are intended as typical of rather than in any way limiting on the scope of the present design as presented in the appended claims.
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An overhead door system featuring independent, unconnected panels is described. Each panel end is operatively carried within a pair of parallel tracks. The weight of the door decreases as the door is lifted and each panel completely disengages from its adjacent panel as it reaches the stacked position. This allows for a linear spring torque to door weight relationship requiring a very small motor compared to existing designs to provide the lifting torque necessary to operate the door.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of co-pending application Ser. No. 666,196 filed Oct. 29, 1984, allowed.
FIELD OF THE INVENTION
This invention relates to a process for selectively separating ethylbenzene from a feedstream containing one or more isomeric xylenes by using a Beta zeolite and one or more of a group of organic desorbents. The preferred desorbents are monosubstituted benzenes where the substituent contains a heteroatom, monoalkylbenzenes, and paradialkylbenzenes.
BACKGROUND OF THE INVENTION
Some crystalline aluminosilicates, or zeolites, are useful as adsorbents in separating a particular hydrocarbon compound from mixtures of hydrocarbons containing the compound. In particular, zeolites are widely used for selective separation of paraxylenes from mixtures containing other C 8 aromatic compounds such as metaxylene, orthoxylene, or ethylbenzene. For example, U.S. Pat. Nos. 3,636,121; 3,686,342; 3,686,343; 3,835,043; 3,855,333; 3,878,127; 3,894,108; 3,903,187 and 4,265,788 are all directed towards a method of removing paraxylene from mixtures or of selectively separating paraxylene and ethylbenzene from mixtures containing other components, using various types of zeolites as adsorbents. Paraxylene is a commercially important aromatic hydrocarbon isomer since its use in the manufacture of terephthalic acid is a critical step in the subsequent production of various fibers such as Dacron.
This invention, however, relates to a process for separating ethylbenzene from a feed mixture containing ethylbenzene and at least one other xylene isomer and is therefore unrelated to paraxylene separation processes. Additionally, in the process disclosed herein, ethylbenzene is selectively adsorbed in relation to the less selectively adsorbed xylene isomers.
While a separation of paraxylene from other xylene isomers is desirable in certain circumstances, it has become increasingly desirable to recover ethylbenzene from streams containing both ethylbenzene and xylene isomers. Ethylbenzene has great commercial importance since it is a building block in the production of styrene. Further, the cost of producing ethylbenzene by the reaction of benzene with ethylene has steadily increased. These costs have prompted research efforts in the recovery of ethylbenzene from various C 8 aromatic feedstreams which already contain ethylbenzene. Such feedstreams may be C 8 aromatic extracts resulting from various solvent extraction processes, from pyrolysis gasoline, or from reformed naphtha.
It is known that zeolite Beta has been used to adsorb mixtures of paraxylene and ethylbenzene selectively from mixtures comprising ethylbenzene, orthoxylene, metaxylene and paraxylene using toluene as a desorbent. See U.S. Pat. No. 3,793,385 to Bond et al., issued Feb. 19, 1974. Bond et al. additionally suggests a large number of cations including Li, K, Cs, Mg, Ca, Sr, Ba, La and Ce may be included in the zeolite. Cs and K are especially preferred.
However, the invention disclosed herein is based on the discovery that certain desorbents modify the behavior of zeolite Beta so that it adsorbs ethylbenzene in substantial preference to paraxylene and the other isomeric xylenes. Generically, these desorbents belong either to the family of monosubstituted benzenes wherein the substituent contains a heteroatom selected from the group consisting of O, S, P, and the halogens (particularly halobenzenes; for instance, iodobenzene) and alkylbenzenes with a linear side chain, or to the family of paradialkylbenzenes (particularly, p-ethyltoluene, p-diethylbenzene and p-methyl n-propylbenzene).
Other zeolite systems are known which selectively adsorb ethylbenzene from mixed C 8 aromatic streams in the presence of diethylbenzene as desorbent. One such process is disclosed in U.S. Pat. No. 3,943,182 to Neuzil et al., issued Mar. 9, 1976. However, the zeolites disclosed therein are either Type X or Type Y. The adsorptive activity of a particular type of zeolite is not easily predictable, if it is predictable at all. Indeed, the direction in which zeolite selectivity is affected by a particular desorbent is even less predictable.
SUMMARY OF THE INVENTION
The invention disclosed herein is directed to a process for selectively adsorbing ethylbenzene from feedstreams containing both ethylbenzene and mixtures of xylenes. The process utilizes Beta zeolites and certain desorbents. The desorbents may be generically described as monoalkylbenzenes, paradialkylbenzenes and mono-substituted benzenes having a heteroatom selected from the group consisting of O, S, P and the halogens in the substitutent group. This combination of desorbent and zeolite provides simultaneously acceptable values for the selectivities of the ethylbenzene as compared to paraxylene, metaxylene, or orthoxylene. These desorbents are unique in that they increase each ethylbenzene selectivity factor with respect to the xylene isomers.
Ethylbenzene can be separated and recovered from a feedstream mixture containing at least one and preferably all isomeric xylenes by the process made up of (a) contacting the hydrocarbon mixture with a Beta zeolite, so that the contacting takes place under conditions to affect a selective adsorption of ethylbenzene by the zeolite, (b) passing through the zeolite, during or after the contacting step, a desorbent which produces a selectivity factor (α EB/xylene) for each xylene which is greater than about 2 under the same conditions, and which has a desorbent strength factor (α EB/desorbent) in the range of 0.1 to 10, and (c) recovering from the zeolite a stream enhanced in the concentration of ethylbenzene relative to the isomeric xylenes.
The selectivity factor, which represents the selectivity of the adsorbent for ethylbenzene over a particular xylene, is defined by the expression: ##EQU1##
The desorbent strength factor, which represents the selectivity of the adsorbent for ethylbenzene over the desorbent, is defined by the expression: ##EQU2##
DESCRIPTION OF THE PREFERRED EMBODIMENT
The feedstream mixtures which are applicable to the present invention comprise at least ethylbenzene and one xylene isomer. Preferably the feedstream contains ethylbenzene and all of the xylene isomers. In addition, the feedstream mixture may contain up to about 20%, preferably less than about 10 volume percent, of non-aromatic components such as paraffins, cycloaliphatic or olefinic compounds. Such components will tend to be adsorbed by the zeolite in smaller amounts than the aromatic components. Whatever else may be present in the mixture, however, the process embodies the technique of separating ethylbenzene from various xylenes.
Feedstream mixtures containing C 8 aromatics such as ethylbenzene and xylene isomers are generally obtained via such processes as reforming, pyrolysis and isomerization. The paraxylene isomer is often extracted from this mixture by the processes of crystallization, extraction, or selective adsorption, thus leaving a feedstream relatively rich in ethylbenzene and metaxylene and substantially depleted in paraxylene. The process steps described herein as part of the invention may be used after such a paraxylene separation process or preferably may be used before such a process. The latter method improves the efficiency of the overall process since the paraxylene recovered should then have a higher purity with no ethylbenzene impurity.
In the process described herein, the ethylbenzene is separated from the xylene isomers in the feedstream mixture by contacting the mixture with the zeolite adsorbent defined below in such a manner that the ethylbenzene is more selectively adsorbed than the xylene isomers. Concurrently with this contacting step, or subsequent thereto (if the operation is a batch operation), desorbents are passed through zeolites so as to desorb the enriched ethylbenzene containing phase formed adsorbed on the zeolite.
The zeolite contacting step may be conducted in a batch or continuous mode of operation. For example, the adsorbent may be placed in a fixed bed which is intimately contacted with a feedstream mixture containing ethylbenzene and xylene along with a desorbent or it may be placed in a fluidized bed which is contacted with a mixture and a desorbent in a continuous operation. The fluidized bed may be used with or without magnetic stabilization and with or without real or simulated co- or countercurrent flows. Where the adsorbent is employed in a static bed, the process may be semicontinuous, e.g., or operated as a pulsed chromatographic process. The adsorbent may be placed in a set of two or more static beds such that the feedstream mixture is contacted with one bed while the desorbent is passed through one of the others. In some instances, it may be desirable to remove a least-adsorbed component from the voids in a bed by flushing with a very weakly adsorbed material, e.g., a paraffin, before recovery of ethylbenzene by addition of the desorbent. Moving or simulated moving beds represent a preferred mode of operation because of the greater efficiency in the resulting separation.
Temperatures for contacting and desorption steps of the process herein may vary broadly depending, inter alia, on the desorbent used, but generally will range from about room temperature to about 300° C. Similarly operating pressures will vary considerably but generally will range from about atmospheric to about 30 atmospheres (3 megapascals) pressure.
The desorbent employed in the present invention may be defined as a compound which is characterized by its minimum ability to enhance the selectivity of Beta zeolites in separating ethylbenzene from xylene isomers and by maintaining those selectivities above about 2.0. The selectivity is expressed herein as a selectivity factor, designated α EB/xylene isomer, which is defined above. The value of the selectivity factors should be as high as possible. Too low a factor will result in poor separation between two components.
Another parameter which characterizes the desorbent herein is the strength of the desorbent, which is expressed by a desorbent strength factor, designated α EB/desorbent as defined above. This factor represents the ratio of the adsorption strength of the zeolite for the ethylbenzene to the adsorption strength of the zeolite for the desorbent. If the desorbent is too strongly adsorbed relative to the ethylbenzene, i.e., so that the desorbent strength factor is less than 0.1, then both ethylbenzene and the xylenes will be eluted at a similar time. On the other hand, a desorbent having a desorbent strength factor of greater than about 10 will not compete favorably with the ethylbenzene, necessitating large volumes of desorbent to recover all the ethylbenzene. The ethylbenzene thus collected would be contained in a large amount of desorbent so that an expensive and energy-consuming distillation procedure would be required to recover the ethylbenzene. The desorbent strength factor ratio is preferably in the region of about 1 to about 2, but for the purposes herein is generally in the range from about 0.1 to about 10.
The desorbents applicable to the disclosed process may be generically described as monoalkylbenzenes, paradialkylbenzenes and monosubstituted benzenes having a heteroatom substituted in the ring.
The alkyl substituent of the monoalkylbenzene preferably contains two to twelve carbon atoms. Especially preferred are those compounds belonging to the group consisting of n-butylbenzene, n-pentylbenzene, n-heptylbenzene, n-nonylbenzene and dodecylbenzene. Most preferred of this group is n-nonylbenzene. In addition, mixtures of two or more desorbents which have the requisite characteristics may also be employed as desorbents desired. The desorbent may be diluted with a liquid inert material such as a paraffin or a cycloparaffin.
Another class of desorbents producing excellent ethylbenzene selectivity on Beta zeolites is made up of the paradialkylbenzenes. The alkyl chains may be of any convenient length. Preferably the alkyl moieties are fairly short chains, i.e., less than five carbon atoms. Especially preferred compounds include p-ethyltoluene, p-diethylbenzene and paramethyl-n-propylbenzene. Again, these compounds may be used as mixtures either with other paradialkylbenzenes, monosubstituted benzenes or inert diluents such as paraffins, cycloparaffins or olefins.
Monosubstituted benzenes having a heteroatom in the substituent group are also quite useful in this invention. The heteroatom should be selected from the group consisting of S, O, P, and the halogens. Especially preferred are the monohalobenzenes, particularly iodobenzene.
The zeolite Beta has a poorly understood structure. However, U.S. Pat. No. 3,308,069 (which is incorporated by reference) describes a method of preparing the zeolite. Bond et al., discussed above, additionally describes methods for producing the zeolite and for exchanging the zeolites with various alkali and alkaline earth metal cations. An integral portion of this invention involves use of Beta zeolites containing at least one cation selected from the group consisting of alkali and alkaline earth metals, and mixtures thereof. It has been found that the selectivity of zeolite Beta increases with the size of the substituent cations. Consequently, rubidium substituted Beta provides better selectivity than does potassium and cesium substituted Beta is even better still. Zeolite Beta substituted with potassium gives better selectivity than do those substituted with sodium.
By zeolite Beta is meant the zeolite having as its structure that disclosed in U.S. Pat. No. 3,793,385. The zeolite within this definition may have any atomic Si/Al and the framework may include other atoms such as Ga or B partially or fully substituted for aluminum, or Ge or P partially or fully substituted for silicon. The positive charges of the zeolitic framework must be substantially neutralized by one or more types of cations.
Zeolite Beta containing gallium has been found effective in the separation of ethylbenzene from the xylene isomers. When cesium-substituted gallium Beta is the adsorbent and p-diethylbenzene is the desorbent, the observed order of selectivity with respect to C 8 aromatic isomers is as follows: ethylbenzene >paraxylene >orthoxylene >metaxylene.
After the feedstream mixture and desorbent have been contacted with the zeolite, the respective eluted product streams containing the various components are directed to separate recovery vessels. The stream which is enhanced in ethylbenzene content due to the separation achieved by the adsorption and desorption operations may be further processed to recover the ethylbenzene by, e.g., distillation, or other suitable recovery techniques.
The following examples further illustrate the efficacy of the present invention and in these examples all parts or percentages are given by weight and all temperatures are in degrees Centigrade unless otherwise indicated.
EXAMPLE 1
Beta zeolite was produced in the presence of excess tetraethylammonium hydroxide using the procedure outlined in U.S. Pat. No. 3,308,069. The starting zeolite had an atomic Si/Al ratio of 13.3 and contained (weight %) SiO 2 =94.71%, Al 2 O 3 =6.0%, Na=0.37%, K=500 ppm and N=1.6%. About 90% of the cations saturating the framework negative charges were tetraethylammonium and there were excess ions trapped in the cages. The zeolite was then calcined at about 500° C. for more than 15 hours to remove the organic cations. Other methods of removing the template organic cations would, of course, be acceptable. Separate portions of the cationated zeolite were then exchanged with chloride solutions of the various alkaline cations, dried, exchanged at room temperature, dried, exchanged at room temperature, washed and dried again. The exchanged zeolites were then dehydrated in a 550° C. oven flushed with dry nitrogen for at least 15 hours.
About three hundred milligram samples of the dried zeolite were transferred each to a series of 2-ml vials sealed with a septum cap. To each bottle was added, by syringe, the respective feed in an amount representing the capacity of the zeolite. The vials were agitated at room temperature for 2 to 24 hours under ambient conditions to reach adsorption equilibrium. The vapor phase above the zeolite was analyzed by gas chromatograph. Due to the selectivity of adsorption, the vapor pressures reflect the composition of the liquid phase in equilibrium with the zeolite. From the gas chromatograph peaks, the α EB/xylene isomer and α EB/desorbent factors were calculated.
TABLE 1______________________________________Changes in Selectivities withDesorbents for Various Beta ZeolitesFeed Equimolar C.sub.8 Aromatics:Desorbent EB C.sub.8 :Desorbent PX MX OX Des (by Mole)______________________________________H--BetaNo desorbent 1.2 2.4 2.0 -- --Na--BetaNo desorbent 1.4 3.1 2.6 -- --p-diethylbenzene 1.5 2.3 1.9 1.7 1:2K--BetaNo desorbent 1.6 5.2 4.3 -- --n-butylbenzene 1.4 4.3 3.0 1.4 1:2Benzene 1.6 2.8 5.2 0.9 1:3.2Toluene 1.8 4.1 3.2 1.3 1:2p-diethylbenzene 2.5 4.7 3.3 3.6 1:2Rb--BetaNo desorbent 2.0 7.4 5.2 -- --Benzene 1.6 2.7 1.8 1.1 1:3.2Toluene 1.7 4.9 3.6 2.2 1:2n-butylbenzene 2.1 4.7 3.1 1.4 1:2n-pentylbenzene 2.4 4.3 2.9 2.3 1:2Iodobenzene 2.6 10.1 5.9 8.7 1:2p-diethylbenzene 4.6 9.3 5.1 5.6 1:2______________________________________
Table 1 shows that when zeolite Beta is substituted by the alkali metal cations, benzene and toluene as desorbents provide generally unacceptable selectivities for zeolite Beta. Substitution of the larger cations into the zeolite allows for enhanced selectivities with a number of desorbents. Paradiethylbenzene was clearly best in all cases.
EXAMPLE 2
An additional amount of zeolite Beta was produced as in Example 1. After calcining to remove the included organic ammonium template cation, one portion was exchanged with cesium chloride twice (with drying) to produce Cs-Beta I. Other methods of removing any such organic template would, of course, also be acceptable. A second portion was treated with the process described for Cs-Beta I, dried at 120° C., dried at 550° C. under flushing nitrogen, cooled and re-exchanged twice at room temperature. The second portion is referred to as Cs-Beta II. A third and separate portion of the starting batch was treated in the manner described for CS-Beta II and is referred to as Cs-Beta III.
Various desorbents were added to the zeolites in the method specified in Example 1. The resulting selectivities are shown in Table 2.
TABLE 2______________________________________Changes in Selectivities (α) withDesorbents for Cs--Beta ZeolitesFeed Equimolar C.sub.8 Aromatics:Desorbent EB C.sub.8 :Desorbent PX MX OX Des (by Mole)______________________________________Cs--Beta INo desorbent 2.1 7.6 6.1 -- --Benzene 2.0 3.0 2.4 0.6 1:3.2Toluene 2.2 4.6 3.7 1.9 1:2n-butylbenzene 2.4 4.3 3.3 1.8 1:2n-pentylbenzene 2.4 3.9 3.0 1.8 1:2Iodobenzene 2.5 7.7 5.0 4.9 1:2Cs--Beta IIPrehnitene 1.2 7.8 7.3 40.0 1:2o-diethylbenzene 1.2 11.0 13.0 11.0 1:2Isodurene 1.2 16.0 14.0 50.0 1:2n-dodecylbenzene 2.0 6.1 4.3 Not 1:2 deter.n-heptylbenzene 2.7 4.8 3.9 Not 1:2 deter.n-pentylbenzene 2.8 5.2 3.7 1.1 1:2n-nonylbenzene 3.3 6.6 4.7 Not 1:2 deter.Cs-Beta IIINo desorbent 2.2 9.0 5.2 -- --o-methyl 0.9 12.3 16.0 18.0 1:2n-propylbenzenem-diethylbenzene 1.3 16.1 17.0 26.0 1:2Isobutylbenzene 1.4 5.4 4.9 2.0 1:2p-methyl 4.0 8.1 5.4 4.0 1:2n-propylbenzenep-diethylbenzene 5.5 11.3 7.3 8.0 1:2______________________________________
As in Example 1, monosubstituted benzenes and paradiakylbenzenes provide superior selectivities. If the differing processes for exchanging Cs into the zeolite gave different cation loading, the difference in loading appear to result in only minor difference in performances.
EXAMPLE 3
This example compares the selectivities obtained by using the best desorbents of Example 1 and 2 on zeolites which are outside the scope of this invention. Table 3 demonstrates about unique combination of zeolite and desorbent result in enhanced selectivities.
TABLE 3______________________________________Effect of p-dialkylbenzenes on VariousEthylbenzene Selective ZeolitesFeed Equimolar C.sub.8 Aromatics:Desorbent(1:2 by Mole) EBZeolite Desorbent PX MX OX Desorbent______________________________________RbX paradiethylbenzene 3.1 2.4 1.5 6.0CsX paradiethylbenzene 1.7 1.8 1.6 2.2CsX para methyl 3.6 3.9 2.3 9.0 n-propylbenzeneRb--Beta paradiethylbenzene 4.6 9.3 5.1 5.6Cs--Beta paradiethylbenzene 5.5 11.3 7.3 8.0Cs--Beta para methyl 4.0 8.1 5.4 4.0 n-propylbenzene______________________________________
EXAMPLE 4
Gallium zeolite Beta in its hydrogen form prepared from a synthesis gel having an SiO 2 /Ga 2 O 3 molar ratio of 31.25 was cation exchanged with cesium. A C8 aromatic liquid feedstream containing 1.1% ethylbenzene, 1.1% paraxylene, 1.0% orthoxylene, 1.0% metaxylene, 1.0% triisopropyl benzene (an internal standard for the gas chromatograph), 84.7% n-heptane and 10.1% paradiethylbenzene desorbents all by weight, was added at ambient temperature (about 25° C.) to the adsorbent, with the feedstream being in excess of that which the zeolite can adsorb. After allowing this mixture to reach equilibrium, the mixture was allowed to settle and a sample was removed and analyzed by gas chromatography. The amount of C8 isomers and desorbent in the solution was measured, and the amount of isomers and desorbent was obtained by difference from the standard feedstream. The capacity and the (α) separation factor were calculated for the C8 aromatic isomers and desorbent as listed in Table 4.
TABLE 4______________________________________Run No. EB/PX EB/MX EB/OX EB/p-DEB______________________________________1 4.2 22.3 11.4 6.22 4.7 32.4 14.4 7.43 6.7 31.8 8.2 9.2______________________________________
In summary, improved separation of ethylbenzene from isomeric mixtures of xylenes are possible by use of Beta zeolites in combination with certain desorbents.
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The invention relates to a process for selectively adsorbing ethylbenzene from a stream containing one or more isomeric xylenes. The ethylbenzene is adsorbed on a gallium Beta zeolite. A desorbent comprising para-dialkylbenzene gives the zeolite good ethylbenzene selectivity over the xylenes.
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FIELD OF THE INVENTION
[0001] The invention relates to a safety closure device for a container, the mouth of which is provided with an external screw thread, a child-proof device, in addition comprising a first-opening indicator and a dehydrating element.
[0002] The invention relates more particularly to a safety closure device by screwing for a container, comprising a single stopper to be screwed onto the said container, the said stopper having the ability to be disengaged from a locking position by means of a double lateral pressure, the said device being equipped in addition with a first-opening indicator collar cooperating with the neck of the container on which the closure device is mounted and a dehydrating element.
PRIOR ART
[0003] Closure devices offering safety for children, of the screw stopper type, may be of different natures. In particular the safety may be either the consequence of a deformation by opposing lateral pressure of the stopper allowing release of the unscrewing function, followed by the rotation of the stopper, or a vertical movement triggering a device allowing unscrewing, this vertical movement having to be conducted simultaneously with a rotation.
[0004] Child-safe stoppers functioning on the principle of a double vertical and rotation movement equipped with a first-opening indicator collar exist, but are relatively complex to implement since they involve the presence of an internal stopper to be screwed onto the said container and a coaxial external stopper entirely covering the internal stopper, the external stopper having the ability to drive the internal stopper by means of an engagement system, when an axial pressure and a rotation are practiced on the external stopper.
[0005] The following documents illustrate the various technical solutions proposed in the case of stoppers for which deformation by radial lateral pressure, exerted in opposition, on the skirt of the stopper, enables the unscrewing function to be released.
[0006] The document WO 9850283 describes a stopper with a child-safety screw of the single stopper type, operating on the method of a double opposed radial pressure and a rotation allowing unscrewing, the said stopper being equipped with a first-opening indicator collar. The stopper comprises, on its external bottom periphery, that is to say its skirt, two diametrically opposed zones on which lateral pressures can be exerted. Child-safety serrations in the form of protuberances, towards the inside of the stopper, enable the stopper to be locked with respect to rotation. These serrations are positioned at 90° from the pressure zones and extend downwards at the bottom level of the stopper skirt. First and second child-safety serrations are placed on the neck of the dedicated container with which the stopper is associated, and are positioned above the first-opening indicator collar. The connection between the first-opening indicator collar and the bottom part of the stopper is provided by breakable bridges positioned at 45° with respect to the pressure zones. It is important to dispense with the child safety before the first-opening indicator collar can be disconnected by rupture of the breakable bridges, a rupture obtained by contrasting rotation of the said collar when the stopper is rotated at the time of unscrewing. The first-opening indicator collar is removed after opening.
[0007] The document U.S. Pat. No. 4,452,363 describes a container equipped with a stopper with a child-safety screw with a first-opening indicator collar, the child safety being obtained by means of diametrically opposed lateral pressures exerted on the bottom part of the skirt of the stopper. The skirt is conical in shape and comprises a system of serrations and notches that enable the first-opening indicator collar to be connected and disconnected.
[0008] The document U.S. Pat. No. 5,836,465 describes a container equipped with a stopper with a child-safety screw with a first-opening indicator collar. The neck of the container comprises a screw thread and two first locking serrations below the screw thread, and diametrically opposed. The stopper is produced from material enabling the stopper skirt to be deformed under the effect of a lateral pressure. The internal part of the stopper comprises two second locking serrations positioned diametrically opposed on the internal bottom part of the deformable skirt. The first and second locking serrations have the ability to engage in each other when the stopper is completely screwed into the neck of the container and thus prevent any rotation of the stopper with respect to the neck of the container unless there is deformation of the said stopper, then releasing the locking system. The screw thread is of the multiple thread type, making it possible to disengage the stopper from the neck of the associated container by a simple rotation at 180° or less.
[0009] Such stoppers do not however have any functionalities for ensuring the controlled dehydration of the container with which they are associated, then forcing the use of separate dehydration means, in order to be able to be used in applications such as for example the packing and storage of moisture-sensitive products, such as in particular medications.
OBJECTIVES OF THE INVENTION
[0010] Numerous objectives are consequently assigned to the device according to the invention, so that it can afford designed solutions improved compared with the various means implemented in the known safety closure devices intended for packaging moisture-sensitive products.
[0011] A first object of the invention is to produce a safety closure device for a container by screwing, child-proof on unscrewing, this device being composed of a single stopper rather than, for reasons of simplicity and cost reduction, two stoppers fitted together, functioning by deformation of the skirt of the said stopper, thus releasing an engagement means, during the application of radial pressures exerted in opposition on two diametrically opposed zones of the deformable skirt of the said stopper of the device, followed by a rotation allowing unscrewing.
[0012] Another object of the invention is to produce a safety closure device for a container by screwing, child-proof on unscrewing, comprising a dehydrating means integrated in the said closure means and a tamper-evidence device of the first-opening indicator collar type.
[0013] Another object of the invention is to produce a safety closure device for a container by screwing, child-proof on unscrewing, comprising a dehydrating means integrated in the said closure means and a means of indicating a first opening cooperating with the neck of the container on which the closure device is screwed.
SUMMARY OF THE INVENTION
[0014] Consequently the invention concerns a child-safety closure device for a screwed container, composed of:
[0015] (i) a stopper enabling it to be screwed on the neck of a container with which it is associated, said stopper being composed of a bottom and a cylindrical lateral wall, comprising on its internal face a screw thread and a first set of so-called child-safety serrations, referred to as child-safety serrations, and
[0016] (ii) a first-opening indicator collar, connected to a cylindrical lateral wall by breakable bridges, the said collar also being equipped, on its internal face, with a second set of serrations, referred to as tamper-evidence serrations, the first set and the second set of serrations cooperating with corresponding sets of serrations positioned on the base of the neck of the container, and which is characterised in that the cylindrical lateral wall of the stopper is formed by two zones, a first rigid and non-deformable top zone, of diameter d 1 , forming the body of the stopper, comprising the screw thread, and a second bottom zone of diameter d 2 , forming a flexible skirt deformable under a double centripetal lateral symmetrical pressure.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The closure device for a screw container, according to the invention, is composed of a stopper with a screw thread enabling it to be screwed onto the neck of a container with which it is associated, the said stopper being composed of a bottom and a cylindrical lateral skirt, comprising internally in the part associated with the bottom a screw thread and in the open part, on its internal face, a first set of serrations, referred to as child-safety serrations, and a first-opening indicator collar, connected to the skirt by breakable bridges, the said collar also being equipped, on its internal face, with a second set of serrations, referred to as tamper-evidence serrations, the first set and the second set of serrations cooperating with corresponding serrations positioned on the base of neck of the container.
[0018] The stopper also comprises in its bottom a housing for storing a dehydrating composition or element, the said housing being inserted freely in the neck of the container.
[0019] The screw-thread closure device comprising a stopper and first-opening indicator collar is intended for a container of the type, for example an injection blow moulded bottle, comprising a neck preferentially with several threads and a steep pitch, intended to receive moisture-sensitive products that it is consequently necessary to keep in a dehydrated state.
[0020] According to the invention, the stopper comprises a cylindrical lateral wall formed by two zones, a first rigid non-deformable top zone, of diameter d 1 , forming the body of the stopper, comprising the screw thread, a second bottom zone of diameter d 2 , forming a flexible deformable skirt, under a double centripetal lateral symmetrical pressure, the top and bottom zones being connected together by a rigid shoulder. The diameter d 1 is less than the diameter d 2 .
[0021] The flexible cylindrical skirt comprises two diametrically opposed gripping surfaces situated at the bottom periphery of the said skirt and making it possible to precisely position the force exerted by the thumb and index finger of the user of the device when the child-safety mechanism is released before unscrewing and opening of the said device. This skirt is made from a material such that the said skirt can be deformed, in particular ovalised, elastically, when a force is exerted on the two gripping zones and the skirt recovers its initial shape when this force ceases. The body and skirt of the stopper are in a single piece and therefore manufactured from the same material.
[0022] Preferentially, the wall thickness of the skirt is such that it allows easy deformation thereof when the pressure is exerted on the two gripping surfaces. On the other hand, the wall thickness of the body comprising the screw thread is such that the rigidity is reinforced. In addition the external surface of the body of the stopper is architectured so that a succession of concave shapes, facilitating the gripping of the stopper by hand, also increases the rigidity of the said body.
[0023] The maintenance of the rigidity of the body of the stopper while the skirt is deformable and deformed by lateral pressures makes it possible not to risk impairing the unscrewing and screwing performance of the screw thread.
[0024] The skirt of the stopper comprises, on its internal face, a first set of two serrations, referred to as child-safety serrations, positioned respectively on the internal face of the skirt of the stopper, diametrically opposite each other, on a diameter itself parallel to the orientation plane of the two gripping surfaces and the function of which is to prevent the rotation of the stopper when the skirt is not deformed during an attempt at unscrewing the device, by cooperating with two corresponding serrations disposed on the neck of the associated container. On the other hand, when the skirt is deformed, that is to say ovalised by double pressure exerted on the two diametrically opposed gripping surfaces, situated at the bottom periphery of the skirt of the stopper, then there is a separation of the two serrations in the first set of serrations secured to the skirt, with respect to the two corresponding serrations situated on the neck of the container, and consequently a possibility of rotation and therefore of unscrewing of the device.
[0025] The two serrations in the first set of serrations present on the internal surface of the skirt of the stopper have a height such that they cooperate with the corresponding two serrations situated on the neck of the associated container.
[0026] The diametral plane passing through the abrupt faces of the two opposite serrations in the first set of serrations positioned inside the skirt of the stopper is perpendicular to the diametral plane merging with the bisecting plane of symmetry of the gripping surfaces situated on the bottom part of the skirt of the stopper.
[0027] The stopper thus remains locked with respect to rotation when the said skirt is its non-deformed state, that is to say not ovalised. The freedom of rotation of the stopper is regained when the said skirt is put in an ovalised state, thus causing the pulling away of the breakable bridges by rotation of the stopper since the first-opening indicator collar is not able to follow this rotation. This movement causes the disconnection of the first-opening indicator collar with respect to the stopper.
[0028] The serrations in the first set of so-called child-safety serrations are positioned in a plane perpendicular to the two gripping surfaces. Preferentially, the axial plane formed by the abrupt faces of the two diametrically opposed serrations of the first set of serrations is perpendicular to the axial plane formed by the abrupt faces of the two serrations in the second set of so-called tamper-evidence serrations constituting the means of locking the first-opening indicator collar, situated in the axial plane of symmetry of the gripping zones. The two serrations in the first set of so-called child-safety serrations are distributed in a regular fashion, also for reasons of balancing of force when the child-safe closure device is unscrewed and for reasons of ease of mould design. The positioning on two perpendicular planes of the tamper-evidence serrations with respect to the child-safety serrations limits the undercut angle of orientation of the abrupt faces of the serrations to a low value, for reasons of ease of moulding and better locking of a serration on its opposite number.
[0029] The profile of the serrations in the first set of serrations present on the internal part of the skirt of the stopper and on the outside of the neck of the associated container is such that it enables the stopper to be screwed, by virtue of a profile with a gentle slope, giving rise to a slight deformation of the skirt of the stopper, but does not allow unscrewing thereof, through an abrupt profile that prevents any rotation of the said non-deformed skirt during the unscrewing of the closure device.
[0030] The height of the two serrations positioned on the neck of the container, cooperating with the two serrations in the first set of serrations, is such that the said serrations are positioned towards the bottom before the area of the screw thread on the neck of the container, and extend as far as the level of the peripheral bottom zone of the first-opening indicator collar, when the latter is in place, all the other serrations having a lower height.
[0031] Such a height makes it possible, if required, also to lock the two serrations in the second set of serrations present inside the first-opening indicator collar, if they happen to pass over the two corresponding dedicated serrations on the neck of the container, with which they cooperate.
[0032] In addition, the difference in diameter between d 1 and d 2 affords an optimised contact surface homogeneous over the entire height of the serrations and reinforces child safety.
[0033] In a variant, two additional tamper-evidence serrations positioned on the inside of the collar are provided for cooperating with the bottom part of the corresponding serrations positioned on the neck of the container. They are consequently positioned in a plane perpendicular to the first set of tamper-evidence serrations.
[0034] The stopper of the child-safety closure device according to the invention comprises a first-opening tamper-evidence collar, secured by means of breakable bridges to the skirt of the stopper, the said bridges being positioned on the bottom annular periphery of the skirt of the stopper.
[0035] The first-opening indicator collar has, on its internal surface, a second set of two so-called tamper-evidence serrations, the function of which is to prevent the rotation thereof, when the device is unscrewed, by cooperating with the two corresponding serrations disposed on the neck of the associated container, with a view to causing the rupture of the bridges by shearing.
[0036] The two serrations in the second set of serrations present on the internal surface of the said collar, when integral with the stopper, are of a height such that they cooperate with the two corresponding serrations present on the neck of the container.
[0037] The rupture of the breakable bridges connecting the top circumference of the collar to the bottom circumference of the skirt of the stopper takes place by shearing at the time of first opening and thus represents tamper evidence. The two serrations in the second set of serrations are regularly distributed on the circumference of the collar and on the neck of the container with regard to their opposite numbers with which they cooperate.
[0038] The two serrations in the second set of so-called tamper-evidence serrations are positioned in line with the two gripping surfaces. Preferentially the diametral plane passing through the two abrupt faces of the two serrations in the second set of serrations, positioned inside the first-opening indicator collar, is in the diametral plane of symmetry of the two diametrically opposed gripping zones, positioned on the external surface of the skirt of the stopper. The two serrations in the second set of serrations positioned on the internal surface of the first-opening indicator collar, engaged in the corresponding two serrations positioned on the neck of the container, mean that the collar remains locked with respect to rotation, consequently causing the pulling away of the breakable bridges and therefore the disconnection of the collar with respect to the stopper. This engagement of the serrations in the second set of serrations is reinforced by the fact that the pressure exerted on the two diametrically opposed gripping zones, and positioned in line with these two serrations in the second set of serrations cooperating with the corresponding serrations positioned on the neck of the container. The purpose of the presence of a set of two tamper-evidence serrations positioned on either side of the gripping zones is to guarantee that the tamper-evidence serrations are in engagement with the corresponding serrations on the neck of the container, the deformation of the external skirt mainly being transmitted to the tamper-evidence collar through the tamper-evidence bridges.
[0039] The first-opening indicator collar is connected to the skirt by breakable bridges, so that the deformation of the skirt does not cause an equivalent deformation of the collar.
[0040] The breakable bridges are preferentially four in number, distributed close to and on either side of each serration in the second set of serrations situated on the internal face of the collar.
[0041] Thus the bridges, taken two by two, are situated close to and on either side of the serrations in the second set of so-called tamper-evidence serrations.
[0042] This provision makes it possible to transmit the deformation of the gripping zones to the first-opening indicator collar, when ovalisation of the skirt is caused, and consequently to better lock the collar in its rotation, thus enabling facilitated rupture of the bridges.
[0043] This provision is also favoured for reasons of balancing of shearing force at the first unscrewing of the child-safety closure device, and also for reasons of ease of mould design.
[0044] In a less preferential design, six bridges can also be considered.
[0045] The two serrations in the second set of serrations are distributed at 180° over the circumference of the neck of the container and over the circumference of the first-opening indicator collar, the diametral plane defining the abrupt face of these serrations being perpendicular to the diametral plane defining the abrupt face of the two serrations in the first set of serrations. This regular circumferential distribution allows a balancing of force when the child-safe closure device is unscrewed. Such a regular distribution is also so for reasons of ease of mould design.
[0046] The profile of the serrations in the second set of serrations present on the internal part of the first-opening indicator collar and on the outside of the neck of the associated container is such that it allows the screwing of the stopper and the positioning of the connected collar, by virtue of a profile with a gentle ramp, causing a deformation of the first-opening tamper-evidence collar, but does not allow its unscrewing without rupturing of the bridges connecting the first-opening indicator collar to the bottom part of the skirt of the stopper, through an abrupt profile that prevents any rotation of the said collar when the closure device is unscrewed.
[0047] Finally, and more precisely, the profiles of the serrations in the first and second sets of serrations, when observed on a cutting plane perpendicular to the rotation axis, comprise a gentle ramp, followed by an abrupt slope, the profiles of the serrations with which they cooperate being disposed in an opposing fashion, so that, for two cooperating serrations, the gentle slopes slide on each other on closure and the abrupt slopes lock on opening.
[0048] The serrations in the second set of serrations disposed on the neck of the container are situated below the serrations in the first set of serrations fulfilling the child-safety function. They have a height less than that of the serrations in the first set of serrations and correspond substantially to the height of the first-opening indicator collar.
[0049] Any attempt at rotation of the first-opening indicator collar integral with the stopper, when the stopper is unscrewed, causes the rupture of the breakable bridges connecting the top periphery of the collar to the bottom periphery of the skirt of the stopper, since this collar is locked with respect to rotation by the serrations disposed on the neck of the container, while the stopper for its part can make this rotation.
[0050] On unscrewing, at first opening, the two serrations in the second set of serrations lock the rotation of the tamper-evidence collar, the first-opening indicator, causing the breakage of the breakable bridges. This first-opening indication function is thus activated.
[0051] Continuation of the unscrewing can be effective only through a pressure on the two diametrically-opposed gripping surfaces positioned in the bottom part of the peripheral skirt of the stopper. This pressure causes ovalisation of the cylindrical part of the skirt and releases the two anti-rotation serrations: the child safety function is then deactivated.
[0052] Thus the gripping surfaces are defined on the flexible part of the skirt of the stopper in order to represent the points where the forces are applied. The first-opening indicator collar is connected to the external skirt of the stopper by two sets of two breakable bridges, each breakable bridge being situated on either side of the two gripping surfaces. Thus the deformation applied to the gripping surfaces is for the main part transmitted to the tamper-evidence collar guaranteeing contact between the serrations in the second set of so-called tamper-evidence serrations and the corresponding serrations positioned on the neck of the container. The security of operation of the tamper-evidence operating security is reinforced thereby.
[0053] It is also clear that the first-opening indicator collar connected to the skirt by the two sets of breakable bridges, disposed on either side of the two gripping surfaces, deforms in the same way as the skirt in the gripping surfaces but does not undergo a deformation equivalent to that of the skirt in the perpendicular plane because it is not connected in these zones to the skirt by bridges.
[0054] According to the invention, the seal between the internal part of the neck of the container and the threaded stopper is provided by means of a cylindrical element, coaxial and concentric with the stopper, positioned inside the stopper by bearing on the bottom of said stopper. This cylindrical element fits, by means of an end bevel, in the neck of the container through the fact that its outside diameter is adjusted to the inside diameter of the neck of the container and it is of a certain height.
[0055] The stopper of the child-safe closure device according to the invention also comprises a dehydrating means of the attached type, the dehydrating agent being placed in an appropriate housing, situated on the bottom of the internal stopper, the said housing being closed by a closure means not impervious to ambient moisture, for example a membrane made from porous cardboard, to ensure the rapid desiccation of the moisture-sensitive products packaged in the container.
[0056] The housing is thus coaxial and concentric with the stopper, and is freely inserted in the neck of the container.
[0057] The dehydrating agent used in the container is chosen from the group consisting of silica gels, molecular sieves, diatomaceous earths or other dehydrating products, in a powdery form or deposited on a powdery carrier. They can also be in the form of mixtures.
[0058] The dehydrating agent can also be a capsule contained in the said housing and produced from a dehydrating polymer material containing or not dehydrating fillers and more generally from any material containing a dehydrating agent.
[0059] Like the safety closure devices belonging to the prior art, the stopper of the device according to the invention is produced by injection moulding from thermoplastic polymers preferentially chosen from the group consisting of polyethylenes, polypropylenes and ethylene/propylene copolymers used above or in a mixture, formulated or not.
[0060] Other thermoplastic polymers can also be used, such as polyamides (PA), polystyrenes (PS), acrylonitrile-butadiene-styrene copolymers (ABS), styrene-acrylonitrile copolymers (SAN), polymethyl methacrylates (PMMA), polyethyleneterephthalates (PET), polybutyleneterephthalates (PBT), polyacetals (POM), polyvinyl chlorides (PVC) and polycarbonates (PC). Semi-rigid elastomers can also be envisaged.
[0061] Thermoplastic elastomers can be added to such compositions formulated from the aforementioned thermoplastic polymers.
[0062] The invention will be better understood by means of the description, with reference numbers, of the figures mentioned below, these figures having only an illustrative and non-limitative character.
[0063] FIG. 1 is a perspective view from above of the container onto which the child-safe closure device with a first-opening indicator collar is screwed.
[0064] FIG. 2 is a perspective view from below of the closure device and more specifically of the stopper, showing in particular a serration in the first set of serrations positioned inside the skirt of the stopper and a serration positioned at 90° from the previous serration, and belonging to the second set of serrations positioned inside the first-opening indicator collar.
[0065] FIG. 3 is a transverse section of the dehydrating closure device, with child safety and first-opening indicator collar, mounted by screwing on the corresponding container according to the invention.
[0066] FIG. 1 is a perspective view from above of the container ( 1 ) on which the child-safe closure device with first-opening indicator collar ( 16 ) is screwed.
[0067] The container comprises a neck ( 2 ) equipped with a screw thread ( 3 ) and a first set of two serrations ( 4 ) fulfilling the function of child safety, cooperating with the corresponding notches situated on the inside of the skirt ( 11 ) of the stopper of a the closure device, only one of which is visible in FIG. 1 , and a second set of two serrations ( 7 ) fulfilling the function of locking the first-opening indicator collar, when cooperating with the corresponding serrations situated on the inside of the said collar, only one of which also is visible in FIG. 1 .
[0068] The serration ( 4 ) in the first set of serrations has a profile with a gentle ramp, represented by the face ( 5 ) supplemented by an abrupt profile represented by the face ( 6 ).
[0069] The serration ( 7 ) in the second set of serrations comprises a profile with a gentle ramp, represented by the face ( 8 ) supplemented by an abrupt profile represented by the face ( 9 ).
[0070] FIG. 2 is a perspective view from below of the closure device and more specifically of the stopper.
[0071] The stopper is composed of a cylindrical lateral wall formed by two zones, a first rigid and non-deformable top zone ( 10 ), of diameter d 1 , forming the body of the stopper, comprising the screw thread, a second body zone of diameter d 2 , forming a flexible deformable skirt ( 11 ), under a double centripetal lateral symmetrical pressure, the top and bottom zones being connected together by a rigid shoulder ( 24 ). The skirt ( 11 ) is equipped with two gripping surfaces ( 12 ) formed by a flat, only one of which is visible. The stopper also comprises a housing ( 20 ) for inserting a dehydrating material closed off by a porous membrane ( 21 ).
[0072] The stopper also comprises a first-opening indicator collar ( 16 ) showing in particular a serration ( 13 ) in the first set of serrations positioned inside the skirt ( 11 ) of the stopper and a serration ( 17 ) positioned at 90° from the previous serration, and belonging to the second set of serrations positioned inside the first-opening indicator collar ( 16 ).
[0073] The serration ( 13 ) in the first set of serrations situated on the inside of the internal face of the skirt ( 11 ) of the stopper comprises a profile with a gentle ramp, represented by the face ( 14 ) supplemented by an abrupt profile represented by the face ( 15 ).
[0074] The serration ( 17 ) in the second set of serrations situated on the inside of the internal face of the first-opening indicator collar ( 16 ) comprises a profile with a gentle slope, represented by the face ( 18 ) supplemented by an abrupt profile represented by the face ( 19 ).
[0075] The breakable bridges ( 22 ) connect the first-opening indicator collar ( 16 ) to the skirt ( 11 ) of the stopper.
[0076] FIG. 3 shows a transverse section of the dehydrating closure device, with child safety and first-opening indicator collar ( 16 ), mounted by screwing on the corresponding container ( 1 ) according to the invention. The first-opening indicator collar ( 16 ) is also connected, by means of the breakable bridges ( 22 ), to the skirt ( 11 ) of the stopper ( 10 ).
[0077] The stopper also comprises a cylindrical sealing zone ( 23 ) fitting in the neck ( 2 ) of the container ( 1 ) equipped with its screw thread ( 3 ).
[0078] The stopper also has, in its bottom, a housing ( 20 ) filled with a dehydrating material, retained by means of a porous membrane ( 21 ).
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The invention relates to a child-safe closure device for a container ( 1 ), consisting of: i) a stopper having a base and a cylindrical side wall, the inside face of which has a screwthread and a first series of teeth ( 13 ), and ii) a collar ( 16 ) for revealing the first opening, said collar ( 16 ) being connected to said side wall and being equipped with a second series of teeth ( 17 ), these two series of teeth engaging with corresponding series of teeth ( 4,7 ) positioned on the base of the neck ( 2 ) of the container ( 1 ), which is characterized in that: a) the cylindrical side wall of the stopper is made up of two zones, one rigid ( 10 ), and the other, or skirt ( 11 ), being flexible and deformable, b) the collar ( 16 ) for revealing the first opening is attached to the skirt ( 11 ) by frangible bridges ( 22 ), in such a way that deformation of the skirt ( 11 ) does not result in an equivalent deformation of the collar ( 16 ).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for reducing off-taste and/or odor from hygienic paper packages (such as food and beverage packaging). Such methods of this type, generally, remove undesirable compounds that create off-taste and/or odor from the paper package in a simple, cost-effective manner.
2. Description of Related Art
Packaging materials can impart a taste and/or odor to items contained inside. This is particularly a problem if the package is used for food products. The strong odor from the package can be absorbed by the food, thereby, making the food unpalatable.
The sources of the off-taste/odor are either the materials in printing the package (solvents, inks, etc.) or compounds of the package (paper, plastic coating, etc.). In many situations, printing materials are the predominate source of taste and/or odor in the package.
While there has been considerable work done in minimizing tastes/odors from the printing process, there has been minimal work on decreasing the taste from unprinted paper materials.
Taste and odor are subjective qualities. What may be objectionable to one person can be acceptable to another. This subjectiveness makes identifying the source of an off-taste/odor difficult. To further complicate identifying the source of the problem, taste and odor are rarely the result of a single chemical compound. Typically, it is a combination and/or interaction of multiple chemicals that results in a certain taste. For example, hundreds of compounds have been detected in coffee and are responsible for its characteristic taste and odor. To limit the subjectivity, odor and taste panels are used to evaluate a product.
While certain inorganic materials have a strong taste or odor (ammonia or hydrogen sulfide) most odors are due to organic compounds. Of the organic compounds, humans have more taste/odor sensitivity towards oxygenated compounds. For example, the average odor threshold for n-butane is 1000 ppm while for butyric acid it is 0.0001 ppm. This is also the reason most perfumes are esters. This is also the reason ketones give distilled spirits their characteristic taste. Another characteristic of odor causing compounds is their volatility.
As mentioned earlier, many off-taste/odor problems are due to solvents and materials used in the printing operations. However, there are several compounds in unprinted paper packaging that will affect the taste such as Octenol, Hexanal, Butyric acid, etc. These compounds are likely inherent to the papermaking process and are probably the result of the chemical reactions that occur in the pulping and/or bleaching process.
Prudence dictates that the best way to minimize off-taste/odor is to prevent it from occurring. For example, in the papermaking process, volatile fatty acids are apparently formed by microbiological fermentation. The fermentation occurs mainly in the holding tanks and the papermachine forming section ("wet end"). Fermentation can be minimized by adding biocides or slimicides at specific points in the pulp and papermaking process. By eliminating/minimizing the microbiological contamination present, the fatty acids are precluded from forming.
Similarly with the printing process, it is preferable to prevent them from occurring instead of treating them. For example, one can use low odor inks and varnishes in the printing process thereby avoiding some of the problems in the printing area. Similarly, one can use a solvent that does not contain high boiling residues ("tails") which can cause an odor.
Another solution used in the printing industry is to operate the printing process so that the solvent retained in the paper is low. Low solvent retention is achieved by increasing the temperature and/or time in the drying hoods. Exemplary of such prior art is U.S. Pat. No. 4,818,342 ('342) to D. G. Wagle et al., entitled "Heat Treatment of Paper Products". While the '342 patent describes a method for which the paper is dried to an extremely low moisture content then rewet, care must be exercised because if the paper is "over dried", the physical properties of the paper deteriorate and the print quality decreases. This "over drying" causes embrittlement of the paper and affects the ink's absorption properties.
Plastic and extruded paperboard also can be a source of off-taste/odors. For example, it is well recognized in the industry that extruding at higher temperatures increases the likelihood of forming an off-taste. In this instance, the problem is corrected by lowering the extruder die temperature.
Previous work suitable for use with unprinted packaging focused on absorption to reduce the concentration of compounds that generate off-taste and/or odor. The absorption is accomplished by adding aluminum silicate to the pulp going to the wet end of the paper machine. Typical addition rates are 0.5-2 kg/ton. While this may be a solution to the off-taste/odor problem it has several drawbacks. One drawback is that the effectiveness is dependent on the retention of the aluminum silicate in the paper fiber. If there is naturally poor retention, then additional chemicals must be used to promote adhesion of the aluminum silicate onto the paper fibers. Also, this does not eliminate the compounds causing taste and odor problems, it merely adsorbs them.
It is apparent from the above that there exists a need in the art for a method which reduces off-taste and/or odor from a paper package, and which at least equals the off-taste/odor removal characteristics of the known techniques, but which at the same time substantially removes the off-taste and/odor in a simple, cost-effective manner. It is the purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.
SUMMARY OF THE INVENTION
Generally speaking, this invention fulfills these needs by providing a method for reducing off-taste and/or odor from a paper package, comprising the steps of: constructing a paper web; heating a surface of said paper web to a temperature greater than 100° C.; and removing moisture from said paper web such that a residual moisture content within said paper web is less than 5 percent whereby off-taste and/or odor from said paper web is reduced.
In certain preferred embodiments, the heating of the surface of the paper web is accomplished between the press section at the wet end of the paper machine and the first operation that applies coating, sizing or the like to the paper web. Also, the preferable residual moisture content is less than 4 percent.
In another further preferred embodiment, the off-taste and/or odor from the paper package is reduced by the method of the present invention in a simple, cost-effective manner.
The preferred method, according to this invention, offers the following advantages: reduced off-taste in the paper; reduced odor in the paper; ease of reduction of off-taste and/or odor; and excellent economy. In fact, in many of the preferred embodiments, these factors of reduced off-taste, reduced odor, ease of reduction of off-taste and/or odor and economy are optimized to the extent that is considerably higher than heretofore achieved in prior, known off-taste and/or odor reduction methods.
BRIEF DESCRIPTION OF THE DRAWING
The subject matter which is regarding as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, may be best understood by reference to the following description taken in conjunction to the accompanying drawing FIGURE which is a graphical illustration of taste value versus percent raw stock moisture, according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Most solutions described above are designed to prevent, not alleviate, additional off-taste/odor from being introduced into the packaging material. For example, using low odor inks and varnishes reduces the risk of having an ink taste in the package and proper use of a biocide can prevent the formation of fatty acids. While for many food packaging applications this may be sufficient, there are certain items that are very sensitive to packaging odors. Examples of such foods include water, chocolate, certain fruit juices, etc. While not a food stuff, tobacco is another product packaged in paperboard that is very sensitive to odors. For these items, the paper packaging must produce little or no odor. The use of aluminum silicate is designed to alleviate odors however, it does have some drawbacks which were described previously.
For these types of hygienic packaging and other applications where low odor is desirable (i.e. perfume packaging), this invention was developed. The invention actively treats the paper to remove various compounds inherent in the pulp and papermaking process that may cause off-taste/odor. Also, this process is capable of removing impurities in chemicals added to the pulp and papermaking process. To remove these odoriferous compounds, the present invention requires the heating of the surface of paper web during certain portions of the paper forming process to a temperature in excess 100° C. and to a very low average moisture content.
In the preferred embodiment, the heating occurs prior to the size press operation and the sheet is dried until the average moisture is less than 2 percent and, ideally, less than 1 percent. The drying to a low moisture can also occur concurrently in the drying section after the size press and prior to the coating operations. In this case, the summation of the residual average moistures prior to the size press and prior to the coating operations should be less than 5 percent and, preferably, less than 4.
It is theorized that the removal of odoriferous compounds during this particular section of the papermaking process occurs by a combination of evaporation of low volatility compounds and removal by "steam stripping". Steam stripping is a process in which steam is passed through a mixture and the steam soluble components are removed. This method of separation is employed in removing essential oils (typically, odoriferous) from plant materials. By using this process, compounds with boiling points greater than 100° C. can be separated by using a combination of heat and solubility. In papermaking, the steam is generated by heating the wet paper web on the steam heated drying cans.
While it is typical to dry the sheet on the paper machine, drying down to these moisture concentrations is not usually done, or if it is done, it is by happenstance and not for the reason to remove odoriferous compounds. This is especially true with the thicker paperboard used in packaging. When running thicker paperboard, the drying performed prior to the size press limits the speed of the paper machine, and, therefore, limits production. Consequently, the drying in this section may not be as complete as with other sections on the paper machine.
While in some circumstances, it is obvious that volatile compounds can be driven off by heating, it is not obvious in the case of paper. As stated above, the physical and printing properties of paper are very dependant on moisture content. Therefore, care must be taken whenever you change the moisture content. The advantage with the present invention is that final sheet moisture of the paper (typically, 5 percent) can be obtained in the subsequent machine processes such as the coating operations and the gloss calender roll. Furthermore, heating of the completed paper product will not result in the same steam stripping efficiencies as discussed earlier in the process because of the vapor barrier properties of the size and the coating.
Trials were conducted on a papermaking machine. In these trials, the moisture before the size press (raw stock) was targeted at less than 2 percent and, preferably, less than one percent. Finished paperboard samples (Samples 1 and 2) were subjected to a taste panel for analysis. The grading system used by the panel is a modification of a conventional one. In the grading system of the present invention, 5 equals no taste, 4 equals a weak taste and 3 equals a strong taste. Thus, it is desirable to have a high number for the taste value.
The results of the taste analysis are shown on the FIGURE, The graph of the FIGURE shows scatter but that is to be expected because of the subjective and complicated nature of taste analysis. The graph does show the general trend in that low moisture results in higher taste results (less taste) while high moisture has the opposite effect.
Once given the above disclosure, many other features, modifications or improvements will become apparent to the skilled artisan. Such features, modifications or improvements are, therefore, considered to be a part of this invention, the scope of which is to be determined by the following claims.
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This invention relates to a method for reducing off-taste and/or odor from hygienic paper packages (such as food and beverage packaging) by heating and steam stripping the surface of the paper web. Such methods of this type, generally, remove undesirable compounds that create off-taste and/or odor from the paper package in a simple, cost-effective manner.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to jamb installation and for clip systems for installing such jambs.
2. Description of Related Art
Door assemblies are often packaged as a pre-hung door hinged to a prefabricated jamb, and sold as a single unit. The door is usually temporarily secured in position so it does not swing during shipment. The door jamb is ultimately installed in a rough opening that is framed with studs edged by liners. The traditional installation involves placing the door jamb in the rough opening and plumbing it. This step requires great skill since the jamb needs to be adjusted over many degrees of freedom. Also complicating matters, the door is usually left free to swing so that the installer can reach the other side in order to make adjustments or insert wedge-shaped shims.
In U.S. Pat. No. 5,119,609 a flange-like nailing fin is shown secured to the perimeter of a window frame, and described as being useful for door assemblies as well. This nailing fin can be folded from a stored position in front, to a working position along the side. The fin runs the full length and width of the window frame. To achieve adequate attachment strength the fin could be made relatively thick and therefore relatively heavy. The alternative, apparently chosen in this reference, is to make the fin thinner and provide many nail holes. Either approach however is disadvantageous.
In U.S. Pat. No. 4,840,002 an F-shaped clip has one arm embedded in the edge of a door jamb, and another arm acting as a backer for the jamb. The leg of the clip is screwed into the edge of the jamb and into a steel support stud. By screwing into the edge of the jamb and by embedding an arm into that edge, one produces an obstruction that hampers attaching trim around the door jamb. The reference deals with this problem by providing specialized tongue flanges designed to fit into customized bores in the wood trim. Therefore, one cannot use standard door trim.
In U.S. Pat. No. 3,189,137 a J-shaped clip is pressed into an extruded door frame before being nailed to a support wall. This clip has an arm that extends away from the wall and therefore would interfere with standard door trim. This clip is only appropriate with the nonstandard support wall and extruded door frame disclosed in this reference.
See also U.S. Pat. Nos. 4,986,044; 5,692,350; and 5,771,644.
SUMMARY OF THE INVENTION
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a system for installing in a wall a jamb for a door. The jamb has an inward face facing inwardly toward the door and a peripheral face facing away from the door. The system has, in combination, a spaced plurality of clips each having an external arm and a transverse internal arm. The internal arm is adapted for attachment to the peripheral face of the jamb. The external arm is adapted for longitudinally directed, surficial attachment to the wall.
According to another aspect of the invention a method employing clips is provided. The clips each have an external arm and a transverse internal arm for installing in a wall a door jamb. The jamb has an inward face facing inwardly toward the door and a peripheral face facing away from the door. The method includes the step of separately attaching the internal arms of the clips at spaced positions along the peripheral face of the jamb. Another step is positioning the jamb in the wall. The method also includes the step of plumbing the jamb and surficially attaching the external arms of the clips to the wall longitudinally.
By employing a system and method of the foregoing type, installation of door jambs is greatly facilitated, especially for pre-hung doors. In one preferred embodiment, a clip can have a long arm designed for attachment to a jamb, and a short transverse arm designed for attachment to a wall. The preferred clip can be fairly thin and have fairly tight bending radiuses, so that the clip can be mounted flush without obstructing the installation of trim. Preferably, the long arm will be first installed on the jamb before attempting to install the jamb in a rough opening. In some embodiments the long arm can be temporarily secured to the jamb by a prefabricated, pointed tang that was struck from the long arm.
In one preferred clip, the short arm has a mark for orienting a level to determine whether the jamb is plumb. This mark can be made by inking, engraving, or by striking a tab out of the arm. In one highly preferred embodiment, the short arm can swing semaphore-like. Accordingly, the long arm can be secured to the jamb, and the short arm can be swung back to overlap the jamb and door. In this position, the short arm can be held against the edge of the jamb to establish the depth of insertion of the long arm along the jamb before securing the long arm to the jamb. In some instances, the short arm can then be tacked to the door to secure it for transportation.
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a clip for a system and method in accordance with the principles of the present invention;
FIG. 2 is a partial, perspective view of a rough opening in a wall about to receive a door jamb fitted with the clips of FIG. 1;
FIG. 3 is an elevational view of the door jamb of FIG. 1 installed in the rough opening;
FIG. 4 is a detailed perspective view of the installation of one of the clips of FIG. 1;
FIG. 5 is a cross-sectional view taken along line 5 — 5 of FIG. 3;
FIGS. 6A and 6B are detailed cross-sectional views showing the effect on tolerances if the clip has appreciable rounding at its bend;
FIG. 7 is a cross-sectional view of a clip that is an alternate to that of FIG. 2;
FIG. 8 is a fragmentary, detailed perspective view of the distal end of the long arm of the clip of FIG. 6;
FIG. 9 is a detailed, perspective view of the clip of FIG. 7 positioned against a jamb;
FIG. 10 is a perspective view of the clip of FIG. 7 installed on a door jamb with the short arm swung back over the edge of the jamb;
FIG. 11 is a perspective view similar to that of FIG. 10, but with the short arm swung away from the jamb;
FIG. 12 is a fragmentary, elevational view of the assembly of FIG. 9 installed in a rough opening;
FIG. 13 is an elevational view of the short arm of a clip that is an alternate to that of FIG. 1; and
FIG. 14 is an elevational view of the short arm of a clip that is an alternate to that of FIG. 13 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the illustrated clip 10 is one of a plurality of clips that are used as part of a system for installing a jamb. A relatively long, internal arm 12 is integrally formed with a relatively short, external arm 14 . Arms 12 and 14 each have a circular fastener hole 16 and 20 , respectively. Arm 12 has a fastener slot 18 .
Tab 22 is punched or struck from arm 14 to act as an indicia or plumb means. As described further hereinafter, a level can be pressed against tab 22 to determine whether the jamb attached to clip 10 is plumb. Instead of a punched tab, other embodiments may use an inked or engraved indicia.
Referring to FIGS. 2-5, a rough opening 24 in wall 26 is framed by studs 28 and a header 30 supported by liners 32 . Header 30 can support an additional stud 29 . Wall 26 is covered in the usual fashion by sheet rock 34 or the like. While only a fragment of sheet rock 34 is illustrated, in actual embodiments it will cover the studs 28 and 29 , as well as liners 32 and header 30 . A pre-hung door 36 is shown attached by hinges 38 to a door frame assembly, including jambs 40 and 42 , and door frame header 44 , to form an assembly 35 . Doors stops 46 and 48 are secured to the inward faces of jambs 40 and 42 . A similar door stop (not shown) is secured to the inward face of header 44 .
In this embodiment six clips as shown in FIG. 1 have their internal arms 12 attached to the peripheral faces of the jambs, three on jamb 40 and three on jamb 42 . It will be understood that a different number of clips may be used in other embodiments, depending upon the desired strength, rigidity, speed of installation, etc. Each of the clips are positioned with the internal arms 12 at right angles to the length of the jambs, and with the outside face of external arm 14 substantially flush with the edges of the jambs 40 and 42 .
The installer can initially secure the internal arm 12 through slot 18 with a nail 49 . Slot 18 allows a substantial amount of adjustment. Thereafter, the installer can fix the clip 10 in place by nailing through hole 16 and, optionally, placing an additional nail through slot 18 . Instead of nails, the installer may use screws, staples, or other fastening devices. While avoiding an overlapping placement at the same height as a hinge or other door hardware, two of the clips 10 will be placed near the top of the jambs, two near the bottom, and two near the middle. The top and bottom clips may be spaced 15 cm from the top and bottom, although other spacings are contemplated.
Next, door assembly 35 is positioned in the rough opening 24 with the external arms 14 placed flush against wall 26 . Next, the installer will slightly lift an upper corner of the door assembly 35 (for example, where clip 10 is closest to the top hinge 38 ) by inserting a pry bar or other lifting lever under the assembly. This top clip may now be nailed into place using fastener hole 20 of external arm 14 . The installer may now place a level against the tabs 22 (FIG. 1) of the top and bottom clip 10 , and make adjustments to ensure that clips 10 and therefore jamb 40 are plumb. The installer will now nail bottom clip 10 in place. This procedure will now be repeated with the top and bottom clip 10 on knob-side jamb 42 . Next, the two middle clips 10 will be nailed in place through their fastener holes 20 . At this time, the installer may wish to hammer tabs 22 flush, so they no longer protrude and will not interfere with the trim installation, to be described presently.
Significantly, this procedure is performed without shims and without the need to open door 36 .
The installer may now nail trim pieces 50 to cover the border of wall 26 and the edges of jambs 40 and 42 . An important feature of clips 10 is that they are arranged to remain substantially flush and do not obstruct or interfere with the installation of trim pieces.
Referring to FIG. 6A, jamb 42 is positioned to be substantially co-planar with the outside surface of sheet rock 34 of wall 26 . Arms 12 and 14 are nailed to and therefore flush with jamb 42 and sheet rock 34 , respectively. The transition between arms 12 and 14 is shown occurring with a bend radius R, which is somewhat exaggerated for illustrative purposes. To accommodate the bend radius, arm 12 must be spaced at least the distance R from the edge of sheet rock 34 of wall 26 . When the thickness of arm 12 is added, the minimum separation between wall 26 and jamb 42 is distance D. If one were to attempt to bring jamb 42 adjacent to wall 26 , jamb 42 would need to the shifted outwardly as shown in FIG. 6B, in which case arm 14 will not lie flush against sheet rock 34 . Instead, arm 14 would be separated by previously mentioned distance D. Thus the jamb would be misaligned and the arm 14 would be difficult to secure to the wall 26 .
For this reason, in the preferred embodiment arms 12 and 14 are made relatively thin, preferably about ⅛ inch (3.2 mm), or less. Also, the bend radius R is also made relatively small, preferably about ⅛ inch (3.2 mm), or less. It is important to keep these dimensions relatively small so that the jamb can be brought relatively close to the wall, if needed: otherwise, adjustment of the jamb will be rather restricted.
Referring to FIGS. 7-9, an alternate clip 52 is shown with an internal arm 54 whose proximal end is bent into a stub 58 . External arm 56 is a swing member of that is pivotally attached to stub 58 by means of rivet 60 . FIG. 9 shows this pivoting feature by showing in phantom, rotation from an alternate position for arm 56 .
Arm 56 has a fastener hole 68 and a tab 66 similar to the ones previously shown in FIG. 1 (e.g., tab 22 ). Arm 56 also has a tacking hole 70 , used for purposes to be described presently.
Arm 54 is shown with three spaced fastener holes 62 . A pointed tang 64 is punched out of arm 54 arm between the two outermost ones of the holes 62 . Tang 64 is a triangular element that is bent outwardly at a right angle from arm 54 . As will be described presently, tang 64 can be embedded into the jamb to temporarily secure arm 54 .
Referring to FIG. 10, arm 56 is shown rotated 180° from the position shown in FIG. 7 . Consequently, arm 56 can be pressed along the edge of jamb 40 to determine the insertion depth of arm 54 . With clip 52 positioned as shown, a hammer may be struck against tang 54 , embedding it in jamb 40 temporarily. Thereafter, nails 63 may be hammered through fastener holes 62 to permanently secure arm 54 to jamb 40 .
As previously mentioned, jamb 40 is part of a door assembly having pre-hung door 36 . In some instances, clip 52 may be installed on the door assembly by the original equipment manufacturer. In that case, arm 56 can be tacked to door 36 by hammering tack 72 through tacking hole 70 into door 36 . Consequently, door 36 will be held in place and will not swing during shipment. Also, when the door assembly is delivered, its outline will be relatively compact. In preferred embodiments, the door assembly can be squarely pushed through a rough opening, since arm 56 does not extend excessively from the peripheral face of jamb 40 .
Referring to FIG. 11, arm 56 was untacked from door 36 and swung 180° to extend outwardly and perpendicularly from the peripheral face of jamb 40 . Thus positioned, clips 52 can be used for installing the door assembly in the same manner described in connection with the embodiment of FIGS. 1-5.
Referring to FIG. 13, a clip 74 is shown, which is an alternate to that of FIG. 1 . Clip 74 is shown with a fastener hole on its shorter, external arm 78 . Instead of the previously mentioned tab (tab 22 of FIG. 1) external arm 78 has a diamond-shaped hole 80 punched therein. The installer can visually align the edge of a level with this diamond to determine whether the assembly is plumb. Alternatively, the installer can align the string of a plumb bob with diamond-shaped holes 80 .
Referring to FIG. 14, an alternate clip 82 is shown with a fastener hole 84 in its external arm 86 . In this embodiment, the previously mentioned plumb means is replaced with a hook-like projection 88 that is stamped from the body of clip 82 . As before, a level can be pressed against the tip of projection 88 to determine whether the assembly is plumb.
It is appreciated that various modifications may be implemented with respect to the above described, preferred embodiment. While the clips of the preferred embodiment are steel stampings, in other embodiments the clips can be made by molding, machining, or otherwise fashioning other metals, plastics, or other materials. Furthermore, alternate clips can be made from a number of discrete components that can be made from different materials to form a composite. In some embodiments, the inside corner between the internal and external arms of the clip can be relieved to provide additional clearance. In addition, the number and the shape of the various fastening holes can be varied depending upon the requirements of a particular application. Moreover, the shape of the arms need not be rectangular but can be rounded or may be broken into Y-shaped or T-shaped branches. Additionally, the foregoing installation steps can be supplemented with additional steps or the steps can be performed in a different order depending upon the circumstances.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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A door jamb that can be installed in a wall has an inward face facing inwardly toward the door and a peripheral face facing away from the door. The system has, in combination, a spaced plurality of clips each with an external arm and a transverse internal arm. The external arm is adapted for longitudinally directed, surficial attachment to the wall. Being adapted for its purpose, the internal arms are separately attached along the peripheral face of the jamb. Thereafter, with the jamb positioned in the wall, the jamb is plumbed and the external arms of the clips are surficially attached to the wall longitudinally.
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BACKGROUND OF THE INVENTION
1. Field of art
The present invention relates to a process for the preparation of a highly homogeneous fluoride glass which may be used as a material for optical fibers, laser glasses, glass coatings and lens, and also to a process for the preparation of a fluoride optical fiber and a preform therefor which can provide a long optical fiber having low transmission loss.
2. Prior Art Statement
Fluoride glasses have heretofore been known as optimal materials for optical fibers, glass coatings or films, laser glasses and lens because of their excellent transmission properties within the infrared region range, and are as glass materials for optical fibers which are better than silica glasses because they have transmission losses of less than 10 -2 dB/km which is superior to the silica glasses.
U.S. Pat. No. 4,718,929 discloses a CVD (chemical vapor deposition) process for preparing metal halides. This prior publication discloses a CVD process for preparing a metal halide glass material which may be used to produce optical fibers used in the infrared region or other optical members, wherein a β-diketone complex containing a fluoride of Be or Al is decomposed in a gaseous phase without using highly corrossive hydrogen fluoride (HF) gas to deposit a BeF 2 (85 to 100 mol %)/AlF 3 (15 to 0 mol %) glass on a substrate. However, strong toxicity and deliquescence of BeF 2 system glasses obstacle practical application thereof. Moreover, the specification of this prior patent fails to describe the preparation of fluoride glasses containing Ba.
U.S. Pat. No. 4,378,987 discloses a low temperature process for the preparation of an optical fiber in which an organic metal compounds is used. In this prior art process, a gaseous halogenation agent, such as BF 3 , SiF 4 , COF 2 , HF, HCl, SiCl 4 or BCl 3 , is used for preparing a metal halide so that the halogenation agent is reacted with a gaseous reactant of an organic metal compound to produce a glass material made of a solid metal halide. However, the specification of this patent does not disclose the use of complexes of Ba and β-diketones.
In conventional processes, fluoride glasses are generally produced through a so-called batch melting process in which solid materials are used. In the batch melting process, solid materials are first weighed, followed by pulverization and mixing, and then the mixed materials are melted in a batch. Thereafter, the melt is rapidly cooled to produce a glass.
However, the process described in the preceding paragraph has the problems that the materials are apt to be contaminated with transition metals, such as iron, nickel, copper, chromium, cobalt, during the weighing and pulverization steps, and that the materials tend to absorb moisture. Since the impurities including transition elements have absorption peaks within the infrared region, they cause absorption loss within the infrared region of the resultant product. Absorbed water or moisture causes scattering loss. There is also a problem that the wall of a used melting apparatus is corroded during the step of melting the glass, leading to contamination of impurities. A further disadvantage is that a large size fluoride glass product cannot be produced since the melt is cast into a mold followed by rapid cooling.
Other processes disclosed for the preparation of a preform for optical fibers include a built-in-casting process (reference should be made to Japanese Journal of Applied Physics, Vol 21, No. 1, pp. 55 to 56 (1982)), and a modified built-in-casting process.
However, as has been described above, since a melt is cast into a mold, a large size preform cannot be produced. Furthermore, the known casting processes for production of a core cladding structure by a casting process include a process wherein a cladding glass melt is flowed out before the cladding glass melt has not solidified and then a core glass melt is cast (such a process being referred to as build-in-casting process), and a process wherein a core glass melt is cast above the cladding glass melt and the cladding glass melt is flowed out from the lower end as the core glass melt is in the semi-solidified state so that the core glass is introduced into the center portion of the cladding glass (modified built-in-casting process). However, these known processes have the disadvantages that a preform for fibers which has uniform core/clad diameter ratio cannot be produced and that the refraction index profile of the resultant preform for fibers cannot be controlled.
On the other hand, the CVD process has been known as a process for preparing silicaglass optical fibers. It is suited for the synthesis of high purity homogeneous glass. However, when a glass is prepared by the CVD process, compounds of elements constituting the product glass must be heated to vaporize. Since the fluoride glass is mainly composed of compounds of alkali metals, alkaline earth metals and rare earth elements which are scarcely have sufficiently high vapor pressures at a relatively low temperature, it was difficult to prepare fluoride glasses by the CVD process.
OBJECT AND SUMMARY OF THE INVENTION
An object of this invention is to provide a process for preparing an optically uniform fluoride glass which may be used as optical fibers, glass coatings, lens or laser glass by a CVD process.
A further object of this invention is to provide a process for preparing a preform for optical fluoride glass fibers which are adapted for use to transmit light between long distances.
The tasks to be solved by the invention is to enable production of a fluoride glass containing barium through the CVD process by the development of a vaporizable material containing barium to provide a pure glass and to enable production of glass product on a large scale. According to a further advantageous feature of the invention, there is provided a process wherein a glass material is deposited internally of a cylinder followed by solidification by collapsing to prepare a preform for long length and low loss optical fiber of fluoride glass.
According to the first aspect of the invention, provided is a process for preparing a fluoride glass comprising the step of introducing a gaseous mixture into a reaction system containing a substrate to react the ingredients of said gaseous mixture in a gaseous phase or on said substrate to deposit a metal fluoride to form a fluoride glass, an improvement characterized in that said gaseous mixture comprising:
a barium-β-diketonate complex serving as a first starting material and represented by the following general formula (1) of: ##STR2## wherein R is an alkyl group having 1 to 7 carbon atoms, R' is a substituted alkyl group having fluorine atoms substituting hydrogen atoms and represented by C n F 2n+1 where n is an integer of from 1 to 3;
a gaseous or vaporizable compound of the metallic element constituting said fluoride glass, the gaseous or vaporizable compound serving as a second starting material; and
a fluorine-contained gas serving as fluorinating agent.
The above-noted structural formula (1) may also be depicted as shown in the structural formula below: ##STR3##
According to the second aspect of the invention, provided is a process for preparing a fluoride glass comprising the step of introducing a gaseous mixture into a reaction system containing a cylindrical substrate to react the ingredients of said gaseous mixture in a gaseous phase or on the interior wall of said substrate to deposite a layer or fine particles of a fluoride glass, an improvement characterized in that said gaseous mixture comprising:
a barium β-diketonate complex serving as a first starting material and represented by the following general formula (1) of: ##STR4## wherein R is an alkyl group having 1 to 7 carbon atoms, R' is a substituted alkyl group having fluorine atoms substituting hydrogen atoms and represented by C n F 2n+1 where n is an integer of from 1 to 3;
a gaseous or vaporizable compound of the metallic element constituting said fluoride glass, the gaseous or vaporizable compound serving as a second starting material; and
a fluoride-contained gas serving as a fluorinating agent.
The process being further characterized in that said cylindrical substrate containing therein deposited layer or fine particles of a fluoride is heated to solidify by collapsing the same to form a preform for optical fibers.
In the process of the invention, the first starting material is a barium β-diketonate complex, and the second starting material is a gaseous and/or vaporizable compound of one or more metals, other than barium, which can constitute a fluoride glass. The gaseous and/or vaporizable compounds which may be used as the second starting material include metal halides, organic metal compounds and metal-β-diketonate complexes. Examples of metal halides are halides of metal elements such as the Group Ia, Group IIa, Group IIIa, Group IVa, Group Va, Group Ib, Group IIb, Group IIIb, Group IVb, Group Vb, Group VIb, Group VIIb and Group VIIIb elements. Illustrative examples of the organic metal compounds are trialkyl aluminum and tetraalkoxy titanium. Gaseous or vaporizable metals which constitute complexes with 8-diketone include Li and Na of the Group Ia elements, Be, Ca and Sr of the Group IIb elements, Al and In of the Group IIIa elements, Sn and Pb of the Group VIa elements, Sb and Bi of the Group Va elements, Cu of the Group Ib elements, Zn and Cd of the Group IIb elements, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu of the Group IIIb elements, Ti, Zr, Hf and Th of the Group VIb elements, V, Nb and Ta of the Group Vb elements, Cr, Mo and W of the Group VIb elements, and Fe, Co and Ni of the Group VIIIb elements. These metal elements constitute complexes with β-diketone, and the complexes thus formed have high vapor pressures at relatively low temperature. Two or more of these complexes of metals with β-diketone may be used in the CVD process for the preparation of a fluoride glass.
The barium-β-diketonate complexes are complexes of barium with a diketone represented by the general formula of R--CO--CH--CO--R' wherein R is an alkyl group having 1 to 7 carbon atoms, R' is a fluorinated alkyl group C n F 2n+1 which is produced by substituting hydogen atoms in alkyl groups by fluorine atoms, and n is an integer of from 1 to 3. Examples of the alkyl group include methyl, ethyl, propyl, butyl, heptyl, phenyl, tertiary butyl and isopropyl groups. Trivial names and abridged notations of beta-diketones which may be used in this invention will be set forth in Table 1.
TABLE 1______________________________________ Trivial NamesLigand Compound; Formula (Symbol)______________________________________1 (CH.sub.3).sub.3 C--CO--CH.sub.2 --CO--C(CH.sub.3).sub.3 Dipivaloyl- 2,2,6,6,-tetramethyl methane 3,5-heptanedione (TMH)2 CH.sub.3 CH.sub.2 CH.sub.2 --CO--CH.sub.2 --CO--C(CH.sub.3).sub.3 (DMO) 2,2-dimethyl 3,5-octanedione3 CF.sub.3 --CO--CH.sub.2 --CO--C(CH.sub.3).sub.3 Pivaloyltrifluoro- 2,2-dimethyl 6,6,6-trifluoro- methyl 3,5-hexanedione Acetylacetone (PTA)4 CF.sub.3 --CO--CH.sub.2 --CO--CF.sub.3 Hexafluoroacetyl- 1,1,1,5,5,5-hexafluoro acetone 2,4-pentanedione (HFA)5 CF.sub.3 --CO--CH.sub.2 --CO--CH.sub.3 Trifluoroacetyl- 5,5,5-trifluoro acetone 2,4-pentanedione (TFA)6 C.sub.2 F.sub.5 --CO--CH.sub.2 --CO--C(CH.sub.3).sub.3 (DPH) 2,2-dimethyl 6,6,7,7,7- pentafluoro 3,5-heptanedione7 C.sub.3 F.sub.7 --CO--CH.sub.2 --CO--C(CH.sub.3).sub.3 (DHO) 2,2-dimethyl 6,6,7,7,8,8,8- heptafluoro 3,5-octanedione______________________________________
Fluorine-containing gas used in this invention include fluorine gas, and gaseous compounds of fluorine with one or more of hydrogen, halogen elements other than fluorine, carbon, nitrogen, boron, sulfur and silicon. One or more of such gases may be used singly or in combination.
BRIEF DESCRIPTION OF THE DRAWINGS
Appended drawings include schematic illustrations of processing apparatus which may be used to practice the invention wherein:
FIG. 1 is a schematic illustration showing an apparatus for preparing a fluoride glass according to one
embodiment of the invention;
FIG. 2 is a schematic illustration showing another apparatus for preparing a fluoride glass according to another embodiment of the invention;
FIG. 3 is a schematic illustration of an apparatus for preparing a preform for a fluoride optical fiber;
FIG. 4 is a graphic representation showing the results of thermogravimetric analysis of Zr(HFA) 4 and Ba(DHO) 2 ;
FIG. 5 is a chart of X-ray diffraction of the 65ZrF 4 --35BaF 2 glass;
FIG. 6 is a chart showing by the real line the infrared absorption spectrum of the 65ZrF 4 --35BaF 2 glass, and also showing by the broken line the infrared absorption spectrum of a fluoride glass having the same composition and containing ZrF and BaF 2 in the same molar ratio but prepared by the conventional melting process:
FIG. 7 contains upper and lower charts wherein the upper chart shows the scattering distribution of the 65ZrF 4 --35BaF 2 glass, and the lower chart shows the scattering distribution of a fluoride glass having the same composition and containing ZrF 4 and BaF 2 in the same molar ratio but prepared by the conventional melting process;
FIG. 8 is a spectrum chart showing the result of X-ray photoelectron spectroscopy of the 65ZrF 4 --35BaF glass;
FIG. 9 is a chart showing the result of differential thermal analysis of the 65ZrF 4 --35BaF 2 glass;
FIG. 10 is a chart showing the result of differential thermal analysis of a 57ZrF 4 --34BaF 2 --4.5LaF 3 --4.5AlF 3 glass;
FIG. 11 is a chart showing the result of differential thermal analysis of a 22BaF 2 --22CaF 2 --16YF 3 --40AlF 3 fluoride glass which has been prepared without using HF gas serving as a fluorinating agent;
FIG. 12 is a schematic illustration showing an apparatus used for collapsing the fluoride glass according to the invention;
FIG. 13 are charts showing scattering characteristics along the axes of fluoride optical fibers, wherein the upper chart shows the scattering for an optical fiber prepared in accordance with the invention and the lower chart shows the scattering for an optical fiber prepared by the conventional melting process; and
FIG. 14 is a chart showing the transmission loss spectrum of a fluoride optical fiber prepared in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the process of the present invention, the barium-β-diketonate complex which constitutes the vaporizable first component and or vaporizable second component containing one or more of metal halides and β-diketonate complexes of metals other than barium may be reacted with a fluorine-containing gas through the CVD technique at a temperature of 0° C. to 500° C. and at a pressure of atmospheric pressure or subatmospheric pressure.
The substrate contained in a reaction section of the reactor should have a thermal expansion coefficient approximately equal to that of the produced fluoride glass in order that the substrate causes no stress or strain to the resultant fluoride glass during the cooling step, the substrate being desirously made of a glass having excellent anticorrosive property. The fluoride glass formed is pertinently a so-called fluoride glass or calcium fluoride.
The temperature of the substrate is maintained in a temperature of not higher than the crystallization temperature of the formed fluoride glass, preferably not higher than the glass transition temperature of the formed fluoride glass.
One or more vaporized complexes of β-diketone and metals and fluorine-containing gases, which are introduced into the reaction section of the reactor, are reacted on the surface of the substrate or in the gas phase to form a fluoride glass. As to the configulation or state of the formed fluoride glass, a glass film or coating is formed when the fluorination reaction takes place on the surface of the substrate, and fine particles are formed due to homogeneous nucleation when the fluorination reaction takes place in the gas phase. Irrespective of either state or configulation the fluoride glass has, the vaporised complexes of β-diketone and metals and fluorine-containing glass are absorbed on the surface of the substrate or the surfaces of fine particles by chemical adsorption, and then the complexes of β-diketonate and metals and fluoride-containing gases react accompanying with thermal decomposition to form fluorinated metal fluorides. When the temperature of the substrate or the temperature of gas phase is maintained at a temperature of not higher than the glass transition temperature of the formed fluoride glass, the mobility of fluoride molecules on the growing surface is maintained at a low level so that the random adsorption state of the metal-β-diketonate complexes is frozen even after the fluorination, for example, by HF gas. As a result, the amorphous state can be frozen without any special measure similarly as in the case of being rapidly cooled by quenching. Thus, a highly homogeneous fluoride glass containing no separated crystallite can be produced. A fluoride glass having a composition which could not be prepared by the conventional process because of the poor glass-forming ability can be prepared by the invention.
In the process for preparing a fluoride glass, according to the invention, fluoride glass coatings are serially deposited on the substrate, or alternatively fine particles of fluoride glass are initially formed and then solidified. Accordingly, by varying the reaction time, the thickness of the resultant fluoride glass coating may be easily controlled. Also, a large size fluoride glass block may be produced by continuing the reaction for a long time.
A further advantage of the process for preparing a fluoride glass, according to the invention, resides in exclusion of contamination by impurities from external sources. This is due to the fact that the starting organic metal compound, i.e. a metal-β-diketonate complex, is processed continuously from the vaporization thereof to the formation of a fluoride glass without exposure to air. A still further advantage of the process of the invention resides in exclusion of contamination caused by corrosion of the wall of the crucible or container used at the melting step, since a crucible or like container is not needed in practice of the process of the invention. Upon vaporization of the starting material, impurities, such as transition elements or metals, may be separated. Accordingly, a high purity fluoride glass containing extremely little impurity, which might cause absorption or scattering, can be prepared by this invention.
The preform for a fluoride optical fiber, according to the invention, may be produced initially by depositing a fluoride glass over the inner peripheral wall of a cylindrical substrate and then heating the cylinder to collapse the deposited glass. In accordance with the process of the invention, by heating the glass coating deposited over the inner wall of the cylinder or fine glass particles are heated to a temperature of not higher than the crystallization temperature of the formed glass while maintaining the pressure in the cylinder at a subatmospheric pressure, a preform may be produced by collapsing without causing crystallization of the formed glass. Prior to collapsing, oxygen-containing impurities, such as OH groups, adsorbed on the surface of the coating or fine particles of the granules are removed by heating the glass to a temperature of not higher than the glass transition temperature while purging the interior of the cylinder with a halogen-containing gas, such as F 2 , Cl 2 , NF 3 , CF 4 , SF 6 , HF or HCl. These oxygen-containing impurities cause scattering by oxides if they remain in the product, and thus should be removed. According to a further aspect of the invention, one end of the produced preform may be drawn during the heating and collapsing step so that collapsing and drawing may be effected simultaneously.
Since oxygen-containing impurities are removed by the use of a halogen-containing gas and then a preform or an optical fiber can be produced without exposing to external environment, according to the process of the invention, the resultant fluoride optical fiber is free from absorption or scattering due to the presence of impurities and has the low transmission loss. Moreover, by varying the time during which the product glass is deposited, the core/cladding diameter ratio of the optical fiber can be easily controlled. The refractive index profile of the optical fiber can also be easily controlled by changing the feed rate of the starting material continuously. The cylindrical substrate on which the fluoride glass is deposited may be selected from any materials as far as they have the viscosities approximately equal to that of the product at the temperature at which collapsing or drawing is effected in addition to the condition that the interior wall of the cylindrical substrate withstands the corrosive reaction of the fluorine-containing gas. An example of such cylindrical substrate is a cylindrical tube made of a glass, metal or polymer or a tube having multi-layered structure made of one or more of glasses, metals and/or polymers. A large size preform may be produced by selecting a material from which a large size substrate tube is prepared, so that a long fluoride optical fiber may be produced therefrom.
The process for preparing a fluoride glass, according to the invention, realizes chemical vapor deposition of a fluoride glass which could not be practised by the conventional technology. The process of the invention produces a homogeneous fluoride glass which contains lesser amount of impurities as compared with those produced by the conventional melting processes. Alkali metals, and alkaline earth metals, the compounds thereof having high vapor pressures at low temperature being not known by now, form complexes with β-diketonate and the thus formed complexes have high vapor pressures at low temperature, so that the CVD process can be applied by using them to prepare fluoride glasses having the compositions which could not be produced by the conventional processes. Since the metal-β-diketonate complexes have high vapor pressures at low temperature, the processing temperature during the glass preparation step can be maintained at a low temperature. Thus, even a thermally unstable glass composition can be prepared at a temperature lower than the crystallization temperature thereof. Further, it is made possible to prepare a fluoride optical fiber having a controlled core/cladding diameter ratio and having controlled refractive index distribution, which could not be prepared by the conventional casting process.
An exemplified apparatus for preparing a fluoride glass, according to the invention, is shown in FIG. 1. Referring to FIG. 1, the interior of a reaction chamber 1 is controlled to have an adjusted reduced pressure by means of an evacuation system including a rotary pump, and has a fluorine-containing gas inlet 1a and a vaporizable material inlet 1b. The reaction chamber 1 is heated by a heater 2 surrounding the reaction chamber 1. At the substantial center of the reaction chamber 1, a substrate 3 is placed on Two evaporators 6a, 6b contains two different vaporizable materials 5a, 5b, and are connected to the vaporizable material inlet 1b of the reaction chamber 1 through vaporizable material feed pipes 7a, 7b which meet with each other upstream of the inlet 1b. Not-shown carrier gas introduction means are provided at the side opposite to the feed pipes 7a, 7b connected to the evaporators 6a, 6b so that a carrier gas, such as argon, is introduced into the reaction chamber 1. Each of the evaporators 6a, 6b is heated respectively by heaters 8a, 8b to a proper temperature. Outer peripheries of the feed pipes 7a, 7b are heated by heaters 9a, 9b. A fluorine-containing gas, such as hydrogen fluoride gas HF is supplied from the fluorine-containing gas inlet 1a through a fluorine-containing gas supply pipe 11 which is kept warm by a heater 9c.
The reaction chamber 1, the evaporators 6a, 6b and vaporizable gas feed pipes 7a, 7b may be made of aluminum, nickel, copper, iron or a nickel alloy of Ni--Cu system. It is preferred that aluminum is used for the material of these parts, since it is excellent in thermal conductivity to prevent condensation of the vaporizable materials and also anticorrosive to fluorine-containing gases. When aluminum is used to construct the reaction chamber 1, the evaporators 6a, 6b and vaporizable gas feed pipes 7a, 7b , the temperature in the apparatus is uniformalized to prevent condensation of the starting materials. As the result, a fluoride glass having a stable composition is prepared, and hydrogen fluoride (HF) gas and fluorine (F 2 ) gas which are effective fluorination agents for the fluorination of metal β-diketonate complexes may be used in the apparatus. Of course, contamination of impurities due to corrosion of the interior wall of the apparatus is excluded.
As the heat source for the heater 4, ultraviolet rays, infrared rays, far infrared rays, radio frequency induction plasma and microwave induction plasma may be used.
By the provision of a window made of, for example, CaF 2 over the substrate 3, the fluoride glass may be prepared while inspecting the depositing glass through a silica fiber scope.
Another embodiment of the apparatus for preparing a fluoride glass is shown in FIG. 2, wherein aluminum reaction chamber 1 is maintained at a pressure of 10 mmHg by means of a rotary pump (RP). Within the reaction chamber 1 placed is a substrate 3 which is a plate of CaF 2 . Only the substrate 3 is heated by a heater 4. The reaction chamber 1 has inlet ports 1a, 1b through which a gas stream containing an organic metal compound and a metal halide and a stream of a fluorine-containing gas are introduced. In a sublimation chamber, zirconium particles 5 are reacted with a bromine gas to form ZrBr 4 . The reaction chamber 1 is supplied with ZrBr 4 while using argon as a carrier gas through a feed pipe 7 which is connected through a variable leak valve to the inlet port 1a.
On the other hand, a metal-β-diketonate complex of an organic metal compound is vaporized and fed to the reaction chamber 1 while using argon as a carrier gas. The inlet port 1a is connected to a feed pipe through a variable leak valve. A feed pipe 11a is connected to an evaporator 14 which is surrounded by a feed furnace 12, a beta-diketonate metal complex 13 being contained in the evaporator 14. Argon is introduced into the mass of metal-β-diketonate complex 13 while heating the evaporator 14 so that the vaporized metal-β-diketonate complex is fed to the reaction chamber 1.
As the fluorine-containing gas, hydrogen fluoride gas HF is fed through a feed pipe 11b and an inlet port 1b to the reaction chamber 1. A variable leak valve adjusts the feed rate of HF. A fluoride glass is deposited on the substrate 3 in the reaction chamber 1 by the thermal decomposition of the metal-β-diketonate complex and the fluorination by the metal halide and hydrogen fluoride gas.
FIG. 3 shows an apparatus for preparing a preform for fluoride optical fibers. In FIG. 3, a reaction chamber 1 is evacuated by an evacuation system having a rotary pump so that the pressure in the reaction chamber 1 is reduced to subatmosphric pressure. The reaction chamber 1 is made of aluminum and has an inlet port 1a through which a vaporizable starting material is introduced and another inlet port 1b through which a fluorine-containing gas is introduced. The reaction chamber 1 is maintained at 250° C., in its entirety, by a heater 2a, and the pressure in the chamber 1 is maintained at a pressure of 10 mmHg.
Into the reaction chamber 1, a cylindrical tube 3 is disposed and made of a fluoride glass having a composition in molar ratio of 39.7ZrF 4 --13.3HfF 4 --18.0BaF 2 --4.0LaF 3 --3.0AlF 3 --22NaF. Through the inlet ports 1a, 1b of the reaction chamber 1 introduced are a gas flow of a metal-β-diketonate complex and a fluorine-containing gas, respectively.
EXAMPLES OF THE INVENTION
In order that the invention should be more fully understood, presently preferred Examples of the invention will be set forth below. However, it is to be noted that the following Examples are given by way of example only and not intended to limit the scope of the invention which is definitely recited in the appended claims.
EXAMPLE 1
In the apparatus shown in FIG. 1, a complex Zr(HFA) 4 which was a complex of hexafluoroacetylacetone (hereinafter referred to as HFA) and zirconium was used together with a complex Ba(DHO) 2 which was a complex of 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedione (hereinafter referred to as DHO)and barium. Hydrogen fluoride gas (HF) was used as the fluorine-containing gas. The interior of the reaction chamber 1 was maintained at a pressure of 10 mmHg, and maintained at 205° C. by using the heater 2. The substrate 3 is a CaF 2 plate which was heated to 250° C. by the heater 4.
The results of thermogravimetric analyses of Zr(HFA) 4 and Ba(DHO) 2 used as the vaporization shown in FIG. 4. Weight decrease due to vaporization was observed at about 60° C. for Zr(HFA) 4 and at about 200° C. for Ba(DHO) 2 . Zr(HFA) 4 was maintained at 60° C. in the evaporator 6a by means of the heater 8a and Ba(DHO) 2 was maintained at 200° C. in the evaporator 6b by means of the heater 8b. The vaporized gases were introduced into the reaction chamber 1 while being carried by argon supplied from a not-shown carrier gas supply means. The feed rate of HF was controlled by a mass flow controller. The feed pipes 7a, 7b and 11 were maintained, respectively, at 65° C., 205° C. and 30° C. by the heaters 9a, 9b and 9c.
Zr(HFA) 4 and Ba(DHO) 2 introduced in the reaction chamber 1 were converted into fluorides in the gaseous phase by the following reactions, and deposited on the substrate 3 to form a fluoride glass.
Zr(HFA).sub.4 (g)+4HF(g)→ZrF.sub.4 (g)+4HFA(g)
Ba(DHO).sub.2 (g)+2HF(g)→BaF.sub.2 (g)+2DHO(g)
xZrF.sub.4 (g).sup.2 +yBaF.sub.2 (g)→xZrF.sub.4 --yBaF.sub.2 (s)
In the reaction equations set forth above, (g) indicates the gaseous state and (s) indicates the solid phase.
ZrF 4 and BaF 2 formed by the above reactions and deposited on the substrate 3 had low mobilities on the substrate since the temperature of the substrate was maintained at a temperature lower than the transition temperatures of the fluoride glasses, and thus frozen in situ without changing the positions. As a result, the non-equilibrium state was realized similarly as in the case of quenching. The fluoride glasses were serially deposited to prepare a glass coating or a glass bulk.
The fluorination reactions of Zr(HFA) 4 and Ba(DHO) 2 took place independently. The rates of preparation of ZrF 4 and BaF 4 by the reaction between Zr(HFA) 4 and HF and between Ba(DHO) 2 and HF were kept unchanged in the reaction of Zr(HFA) 4 --Ba(DHO) 2 --HF. Accordingly, the Zr/Ba ratio in the formed glass could be easily controlled by adjusting the flow rate of argon used as the carrier gas.
In this Example, Zr(HFA) 4 was supplied at a feed rate of 100 cc/min, Ba(DHO) 2 was supplied at a feed rate of 50 cc/min and HF was supplied at a feed rate of 150 cc/min and reaction was continued for 2 hours, whereby a glass block having a composition of 65ZrF 4 --35BaF 2 was obtained.
The X-ray diffraction chart of the thus prepared glass is shown in FIG. 5, and the infrared absorption spectrum chart is shown in FIG. 6. In FIG. 6, the infrared absorption spectrum of a fluoride glass having the same composition and prepared by the conventional melting process is shown by the broken line. The distribution of scattered light intensity relative to the substrate of 65ZrF 4 --35BaF 2 glass upon launching of a He--Ne laser was measured. For comparison purpose, a similar scattering distribution of a fluoride glass prepared through the conventional process is also shown in FIG. 7. The lower chart of FIG. 7 shows the scattering distribution of the 65ZrF 4 --35BaF 2 prepared by the process of the invention, and the upper chart in FIG. 7 shows the scattering distribution of a glass having the same composition and prepared by the conventional process.
In the X-ray diffraction chart, the fluoride glass prepared by this Example does not show a diffraction peak due to the presence of crystal. In the infrared absorption spectrum, the fluoride glass prepared by this Example does not show an absorption peak at about 2.9 μm due to the presence of OH group, whereas the fluoride glass prepared by the conventional process show an absorption due to the presence of OH group. It is appreciated from the result of infrared absorption spectrum that the fluoride glass prepared by the process of this invention is a fluoride glass in which the concentration of hydroxyl group is extremely low. It should be appreciated, by comparing the results of the fluoride glass prepared by the conventional process, that the scattering of oxides is significantly decreased. In the fluoride glass prepared by the conventional process, a portion of hydroxyl group present on the surfaces of starting materials remains and forms oxides during the melting step to be scattered in the formed glass. On the contrary, the fluoride glass of the invention is prepared through continuous steps including the step of vaporizing the starting materials and the step of formation of glass, leading to reduction of oxide impurities as shown in FIG. 7.
FIG. 8 is a spectrum chart showing the result of X-ray photoelectron spectroscopy of 65ZrF 4 --35BaF 2 glass. The fluoride glass prepared by the process of the invention is composed only of zirconium, barium and fluorine and signals showing the presence of C 1S and O 1S are not detected to show that no organic materials are present. It should be appreciated from the result that the reaction between a metal-β-diketonate complex and a fluorine-containing gas can be proceeded at a low temperature to prevent remaining of impurities in the resultant glass. Since the metal-β-diketonate complex in the process of this invention can be vaporized at a low temperature so that the temperature throughout the overall preparation step can be maintained at a relatively low temperature, a homogeneous glass can be prepared at a temperature lower than the crystallization temperature of the formed fluoride glass even for the preparation of fluoride glasses which have low glass transition temperatures and are thermally unstable.
By using β-diketonate complexes of other metal elements, fluoride glasses containing different metallic constituents may be prepared. The compositions of formed fluoride glasses may be easily controlled by adjusting the flow rate of argon used as the carrier gas. The result of differential thermal analysis of 65ZrF 4 --35BaF 2 glass is shown in FIG. 9. The glass transition temperature of the glass was 270° C. and the crystallization temperature was 330° C.
EXAMPLE 2
The same apparatus used in Example 1 and shown in FIG. 1 was used. Additional two evaporators similar to the evaporators 6a, 6b were provided and connected to the feed pipe 7b. Similarly as in Example 1, a fluoride glass was prepared. La(DHO) 3 was contained and maintained at 180° C. in one of the additional evaporators, and Al(DHO) 3 was contained and maintained at 90° C. in the other of the additional evaporators.
A 5.5 mm thick glass was deposited on a CaF 2 substrate for a reaction time of 2 hours. The formed fluoride glass had a composition, in mol %, 57ZrF 4 --34Ba 2 F 2 --4.5LaF 3 --4.5AlF 3 .
The formed fluoride glass had an improved thermal stability by the addition of LaF 3 and AlF 3 , and no change in density of scatters was observed even after subjected to a heating treatment for an hour.
The result of differential thermal analysis of the 57ZrF 4 --34BaF 2 --4.5LaF 3 --4.5AlF 3 glass prepared by Example 2 is shown in FIG. 10. The glass transition temperature of the glass was 301° C., and the crystallization temperature thereof was 395° C.
EXAMPLE 3
A fluoride glass was prepared similarly as in Example 2 except that triethylaluminum Al(C 2 H 5 ) 3 was contained in the evaporator in place of Al(DHO) 3 while using a similar apparatus as used in Example 2. The evaporator containing Al(C 2 H 5 ) 3 was maintained at 40° C.
A glass having a thickness of about 5.5 mm was deposited on the CaF 2 substrate for a reaction time of 2 hours. The formed fluoride glass had the same composition as that of the glass prepared by Example 2, the composition of the formed glass being represented by 57ZrF 4 --34BaF 2 --4.5LaF 3 --4.5AlF 3 . The result of X-ray photoelectron spectroscopy revealed that no carbon was remained in the resultant glass. The results of infrared spectroscopy, X-ray diffraction, scattering distribution analysis and differential thermal analysis were equivalent to those of the glass prepared by Example 2, and it was revealed that an optically homogeneous glass could be prepared by using organic metal compounds in lieu of β-diketonate complexes. Likewise, glasses could be prepared by using 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedione (DHO) complexes of other rare earth metal elements, such as Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu are used in place of the complex of La. The results of differential thermal analyses showed that the glasses had equivalent thermal stabilities. Particularly, a glass having no absorption peak within the medium infrared region was obtained by using a complex of Gd.
EXAMPLE 4
While using the same apparatus as used in Example 1 and shown in FIG. 1, three additional evaporators were provided similarly as Example 2 and a fluoride glass was prepared through a similar procedure as described in Example 2. The additional evaporators contained La(DHO) 3 , Al(DHO) 3 and Na(TMH) and maintained, respectively, at 180° C., 60° C. and 150° C.
A glass having a thickness of about 6.5 mm was deposited on the CaF 2 substrate within a reaction time of 2 hours. The formed glass had a composition represented by 51ZrF 4 --20BaF 2 --4.5LaF 3 --4.5AlF 3 --20NaF (in mol %).
By the addition of NaF to the fluoride glass of Example 2, the thermal stability of the fluoride glass was improved. The density of scatters was not changed even after the thermal treatment effected at 300° C. for 5 hours. The result of differential thermal analysis showed that the glass prepared by this Example had a glass transition temperature of 260° C. and a crystallization temperature of 373° C. A similar glass was prepared by using Li(TMH) in place of Na(TMH), and the formed glass containing 20 mol % of LiF was subjected to differential thermal analysis to reveal that it had a glass transition temperature of 252° C. and a crystallization temperature of 348° C.
Also the La(DHO) 3 was mixed, respectively, with 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedione (DHO) complexes of In, Sn, Pb, Sb, Bi, Zn, Cd, Ti. Th, Nb, Ta, Mo and Mn to prepare glasses containing 1 to 10 mol % of each of fluorides of these metals. The fluoride glasses showed a crystallization temperature shift by 2° to 15° C. to the lower temperature side, as compared to the glass of this Example. Each of these glasses had a thickness of about 5 mm and no scattering was observed.
EXAMPLE 5
A fluoride glass was prepared similarly as in Example 2 except that Hf(HFA) 4 was charged in the evaporator in place of Zr(HFA) 4 . The evaporators charged with Hf(HFA) 4 , Ba(DHO) 2 , La(DHO) 3 and Al(DHO) 3 were maintained, respectively, at 55° C., 200° C., 180° C. and 90° C. The feed rates were 100 cc/min for Hf(HFA) 4 , 150 cc/min for Ba(DHO) 2 , 13 cc/min for La(DHO) 3 , 13 cc/min for 2Al(DHO) 3 and 200 cc/min for HF.
The reaction was continued for 2 hours, whereby a fluoride glass having a thickness of about 5 mm was deposited on the CaF 2 substrate. The result of elementary analysis through the X-ray photoelectron analysis revealed that the formed glass had a composition in molar ratio of 57HfF 4 --34BaF 4 --4.5LaF 3 --4.5AlF 3 . The refractive index of the thus formed glass was n D =1.50.
The result of differential thermal analysis revealed that the glass transition temperature of the glass was 315° C. and the crystallization temperature was 403° C. Thus, an HfF 4 system fluoride glass having a thermal stability substantially equivalent to that of the ZrF 4 system glass was prepared.
EXAMPLE 6
A fluoride glass was prepared similarly as in Example 2, except that Ba(DHO) 2 , Ca(DHO) 2 , Y(DHO) 3 and Al(DHO) 3 were used as the starting materials and the hydrogen fluoride (HF) gas was not used as the fluorine-containing gas.
The evaporators charged with Ba(DHO) 2 , Ca(DHO) 2 , Y(DHO) 3 and Al(DHO) 3 were maintained, respectively, at 200° C., 180° C., 140° C. and 95° C. The feed rates of the metal-β-diketonate complexes were kept at 55 cc/min for Ba(DHO) 2 , 55 cc/min for Ca(DHO) 2 , 40 cc/min for Y(DHO) 3 and 100 cc/min for Al(DHO) 3 . The temperature of the substrate was maintained at 380° C. The reaction was continued for 2 hours to obtain an about 8 mm thick fluoride glass deposited on the CaF 2 glass. The formed fluoride glass was analyzed by the X-ray photoelectron analysis to find that it had a composition of 22BaF 2 --22CaF 2 --16YF 3 --40AlF 3 (molar ratio). No residual carbon was observed. It was thus found that the ligands of β-diketonate complexes used as the starting materials were decomposed in the gaseous phase to act as the fluorinating agents. Meantime, DHO is represented by 2,2-dimethyl6,6,7,7,8,8,8-heptafluoro-3,5-octanedione and thus contains fluorine atoms. The result of differential thermal analysis of the formed fluoride glass is shown in FIG. 11. The result shows that the glass transition temperature of the formed fluoride glass is 430° C., and the crystallization temperature thereof is 560° C. While the crystallization temperature of a fluoride glass having the same composition and prepared through the conventional melting process is 535° C., and thus the crystallization temperature of the fluoride glass obtained by the process of the invention is higher than that of the glass prepared by the conventional process by 25° C. This shows that the thermal stability of the fluoride glass prepared by the present invention is improved over that of the fluoride glass prepared by the conventional melting process. The improvement in thermal stability was attributed by removal of oxide impurities in the fluoride glass prepared according to the invention, the oxide impurities being not removed in the fluoride glass prepared by the conventional fusing process. The refractive index of the fluoride glass prepared by this Example was n D =1.44. Fluoride glasses were prepared by using Sr(DHO) 2 and Ca(DHO) 2 in place of Mg(DHO) 2 and using MgF 2 and SrF 2 as the substrate in place of CaF 2 . About 7 mm thick glasses free of scatters were prepared.
EXAMPLE 7
A fluoride glass was deposited on the substrate while using the apparatus shown in FIG. 2. ZrBr 4 and Ba(pivaloyltrifluoromethylacetyacetone) 2 (hereinafter referred to Ba(PTA) 2 ) were introduced through the inlet 1a. ZrBr 4 was prepared by sublimating granular zirconium 5 from the heater 2a which was heated to 350° C. and reacting the sublimated zirconium with bromine gas.
The feed pipe 7 having the variable leak valve was connected to the container in which granular zirconium 5 was contained. Bromine gas and argon were fed to the container so that ZrBr 4 was sublimated by the reaction between Zr and Br 2 , and the sublimated ZrBr 4 was supplied through the inlet 1a to the reaction chamber 1 together with argon. The feed pipe 7 is heated by the heater 9. The content of transition metal impurities in ZrBr 4 was suppressed below 1 ppb (part per billion).
On the other hand, argon acting as the carrier gas is passed through the evaporator 14 saturated with vaporized Ba(PTA) 2 , which was vaporized from solid Ba(PTA) 2 and maintained at 120° C. in the evaporator 14, and through the feed pipe 11, the variable leak valve and the inlet 1a to the reaction chamber 1. A fluorine containing gas, hydrogen fluoride HF in this Example, was supplied through the feed pipe 11 and the inlet 1b to the reaction chamber 1. The feed rate of HF was adjusted by the variable leak valve. The reaction chamber 1 was maintained at 200° C. and the substrate 3 was maintained at 250° C.
ZrBr 4 and Ba(PTA) 2 introduced into the reaction chamber 1 were converted on the substrate 3 to ZrF 4 and BaF 2 as shown by the following reaction equations. In the following reaction equations, (g) indicates the gaseous state, (ad) indicates the adsorbed solid phase and (s) indicates the solid phase.
ZrBr.sub.4 (g)→ZrBr.sub.4 (ad)
Ba(PTA).sub.2 (g)→Ba(PTA).sub.2 (ad)
HF(g)→HF(ad)
ZrBr.sub.4 (ad)+4HF(ad)→ZrF.sub.4 (s)+4HBr(ad)
Ba(PTA).sub.2 (ad)+2HF(ad)→BaF.sub.2 (S)+2(CH.sub.3).sub.3 --C--CO--CH.sub.2 --CO--CF.sub.3 (ad)
HBr(ad)→HBr(g)
(CH.sub.3).sub.3 C--CO--CH.sub.2 CO--CF.sub.3 (ad)→(CH.sub.3).sub.3 C--CO--CH.sub.2 --CO--CF.sub.3 (g)
Since the temperature of the substrate is lower than the glass transition temperature of the formed fluoride glass, ZrF 4 and BaF 2 formed by the above reactions and deposited on the substrate 3 had low mobilities and then frozen in situ on the substrate 3. Accordingly, likewise in the case of quenching, a non-equilibrium state can be realized on the substrate 3. A glass bulk may be prepared by continuing deposition of the fluoride glass.
In the reactions described above, fluorinations of ZrBr 4 and Ba(PTA) 2 by HF take place independently from each other. Therefore, the production rate of ZrF 4 by the reaction of ZrBr 4 --HF system and the production rate of BaF 2 by the reaction of Ba(PTA) 2 --HF system are maintained also in the reaction system of ZrBr 4 --Ba(PTA) 2 --HF. Accordingly, the ratio of Zr/Ba in the formed glass can be easily controlled.
In this Example, the feed rates were 100 cc/min for ZrBr 4 , 70 cc/min for Ba(PTA) 2 and 150 cc/min for HF. After reacting for 3 hours, a 6.5 mm thick fluoride glass having a composition of 60ZrF 4 --40BaF 2 was formed.
The results of X-ray diffraction, infrared absorption spectroscopy and analysis of scattering distribution measured by launching a He--Ne laser into the glass block were substantially equivalent to those described in Example 1.
The result of radioactivation analysis of the formed fluoride glass revealed that the content of Fe, Cu, Ni. Co and Cr were less than 1 ppb (part per billion) which was the detection limit of the radioactivation analysis.
Further, by varying the feed rates of the starting materials, fluoride glasses having various compositions were prepared and the thus prepared fluoride glasses were analyzed through the fluorescent X-ray analysis. Fluoride glass blocks having widely distributed compositions ranging within 90ZrF 4 --10BaF 2 to 35ZrF--65BaF 2 were formed. It was hard to prepare fluoride glasses having such compositions by the conventional melting or casting processes.
EXAMPLE 8
The fluoride glass block prepared by Example 6 and having the composition of 60ZrF 4 --40BaF 2 was cut to have a rod shape and the surface thereof was polished to be used as a deposition substrate.
The heating means for glass deposition was changed from heater heating to CO 2 laser heating and the deposition substrate was changed from CaF 2 to a glass rod, the remaining conditions and the used apparatus being the same as used in Example 6, whereby a fluoride optical fiber preform was prepared.
The glass rod had an outer diameter of 4 mm and a length of 300 mm. Both ends of the glass rod were clamped by chucks, and a glass was deposited on the glass rod while the glass rod was rotated at 60 rpm and moved along its longitudinal direction at a moving speed of 10 mm/min. In order to establish a desired distribution of refractive index, AlBr 3 was introduced in addition to ZrBr 4 and Ba(PTA) 2 to deposite serially on the glass rod substrate a fluoride glass having a composition of 58ZrF 6 --37BaF 2 --5AlF 3 which is to be used as a fluoride optical fiber preform. The feed rates of the starting materials were 30 cc/min for ZrBr 4 , 14 cc/min for Ba(PTA) 2 and 2 cc/min for AlBr 3 . The temperature of the glass rod substrate was 250° C.
The preform had a diameter of 8 mm and a length of 300 mm, and the relative refractive index difference between the core and the cladding was 0.7%. The preform was drawn into a fluoride optical fiber having a length of 500 meters. The transmission loss of the optical fiber was measured. The minimum loss was 8 db/km at 2.55 μm. The result reveals that a long fluoride optical fiber having low loss can be produced by the invention.
EXAMPLE 9
Used starting materials were Ba(DHO) 2 which was a complex of Ba with 2,2-dimethyl6,6,7,7,8,8,8-heptafluoro-3,5-octanedione (DHO), Zr(HFA) 4 which was a complex of Zr with hexafluoroacetylacetone (HFA), La(DHO) 3 complex, Al(DHO) 3 complex and Na(DHO) complex. These five starting materials, Ba(DHO) 2 , Zr(HFA) 4 , La(DHO) 3 , Al(DHO) 3 and Na(DHO), were vaporized by heating and maintaining in the gaseous state, respectively, at 210° C., 60° C., 180° C., 70° C. and 190° C., and supplied into the reaction chamber while using argon as the carrier gas. Using the apparatus shown in FIG. 3, aluminum evaporators 8a to 8e charged respectively with complexes Ba(DHO) 3 , Zr(HFA) 4 , La(DHO) 3 , Al(DHO) 3 and Na(DHO) were heated and argon gas was introduced into respective evaporators so that vaporized starting materials were supplied through an aluminum feed pipe 7 and the inlet 1a into the reaction chamber 1.
As a fluorine-containing gas, a mixed gas of HF(95 vol %)-F (5 vol %) was supplied through the feed pipe 4 and the inlet 1b into the reaction chamber 1.
The feed rate of the metal-β-ketonate complexes and the mixed gas could be adjusted by means of mass flow controllers.
Using heaters, the feed pipes 7a to 7e were maintained at 215° C., 65° C., 185° C., 75° C. and 195° C. in order to prevent condensation of gases.
The β-diketonate complexes of respective metals introduced into the reaction chamber 1 were converted to fluorides in a form of fine glass particles due to homogeneous nucleation in the gaseous phase.
In fluorination by HF of β-diketonate complexes of respective metals, Ba(DHO) 2 , Zr(HFA) 4 , La(DHO) 3 , Al(DHO) 3 and Na(DHO), respective complexes are fluorinated independently so that the composition of resultant glass can be easily controlled by varying the feed rates of respective complexes.
In this Example, reaction was continued for 2 hours while maintaining the feed rates of the starting materials at 50 cc/min for Ba(DHO) 3 , 100 cc/min for Zr(HFA) 4 , 10 cc/min for La(DHO) 3 , 7.5 cc/min for Al(DHO) 3 and 7.5 cc for Na(DHO) and 15 cc/min for HF--F 2 mixture gas. The composition of the fine glass particles was 53ZrF 4 --20BaF 2 --4LaF 3 --3AlF 3 --22NaF, and the formed product was deposited on the interior wall of the cylindrical glass tube 3. The composition of the cylindrical glass was 39.7ZrF 4 --13.3HfF 4 --18.0BaF 2 --4.0LaF 3 --3.0AlF 3 --22NaF.
FIG. 12 shows schematically an apparatus used for collapsing a cylindrical tube having its interior wall deposited with fine glass particles.
Both ends of the cylindrical glass tube 3 having fine glass particles deposited over the interior wall by the process as aforementioned were allowed to contact with an aluminum connector 18, and the internal pressure of the cylindrical tube was controlled to 500 mmHg while introducing F 2 gas from the downside as viewed in FIG. 12 and evacuating by a rotary pump (not shown) from the upside as viewed in FIG. 12. The temperature was set to 200° C. by a heater 12, and processing was continued for 2 hours. The temperature was then raised to 280° C. to collapse entirely, whereby a preform was obtained.
In this Example, a cylindrical tube of fluoride glass having an outer diameter of 12 mm, an inner diameter of 8 mm and a length of 150 mm was used. However, by increasing the diameter of the used glass tube, the size of the preform can be further increased. For instance, a cylindrical tube having an outer diameter of 20 mm, an inner diameter of 12 mm and a length of 300 mm was used and deposition of fine glass particles was effected for 3 to 5 hours, followed by collapsing, whereby a large size collapsed preform was obtained.
In collapsing the cylindrical tube 13 deposited with fine glass particle 20, it is desirous that the temperature is maintained within the range of from 50° C. to 500° C., although the temperature may be changed corresponding to the composition of the fluoride glass.
Fluorine gas was used in this Example to remove oxide impurities absorbed on the surface of the deposited particles. However, other halogen-containing gases, such as gaseous compounds of fluorine or chlorine with hydrogen, carbon, nitrogen, boron, sulfur and silicon or mixture of at least two of said gases, may also be used for this purpose.
EXAMPLE 10
The collapsed preform prepared by Example 9 was placed in an drawing furnace filled with an inert gas, and drawn at 285° C. into a fluoride optical fiber.
A He--Ne laser was launched into the thus produced fluoride optical fiber and the scattered light intensity along the fiber axis was measured. For comparison purpose, the scattering distribution of a fluoride fiber produced by the conventional casting process was also measured. The results are shown in FIG. 13.
It is apparently seen from FIG. 13 that scatters can be significantly reduced according to the process of the invention. In the process of the invention, vaporization of the starting materials for glass and deposition or synthesis of glass particles can be effected by a single step. As an advantageous result of the single step processing, fine glass particles containing no oxide impurities could be produced. The oxide impurities adsorbed on the surface of the deposited mass could be removed by treatment with a fluorine-containing gas, without exposing to the outside atmosphere, whereby a preform was obtained.
The transmission loss of the produced optical fiber was measured. The result is shown in FIG. 14. The minimum loss at 2.55 μm of the produced optical fiber was 0.9 db/km which was not attainable by the conventional technology, with the length being so long as could not be produced by the conventional technology.
EXAMPLE 11
Generally following to the procedure as described in Example 9, fine particles of a fluoride glass constituting the core composition was deposited over the interior wall of a glass tube 3 constituting the cladding glass composition. The glass tube was then placed in an drawing furnace where it was processed at 200° C. for an hour in a flowing F 2 gas stream. Thereafter, the internal pressure was set to 700 Torr by evacuating the interior of the tube from the upper end which was connected to a rotary pump. The drawing furnace was heated to 285° C. and the glass tube was elongated simultaneously with collapsing operation to obtain a fluoride optical fiber having a minimum loss of 0.7 db/km at 2.55 μm. A long fluoride optical fiber having a low loss factor was produced by the Example, by simultaneous drawing and collapsing. Similar effects can be obtained by using Cl 2 , HF, HCl, BF 3 , SF 6 , SiF 4 , CF 4 or a mixture thereof in place or in addition of F 2 in the processing step with a halogen-containing gas carried out prior to the drawing step.
EXAMPLE 12
A fluoride optical fiber was produced similarly as in Example 10 except that a Teflon (Trade name) FEP tube was used in place of the glass tube.
In addition to the metal-β-diketonate complexes used in Example 10, Hf(HFA) 4 was used. The feed rates of respective metal-β-diketonate complexes are set forth below:
______________________________________Zr(HFA).sub.4 87.5 cc/minHf(HFA).sub.4 12.5 cc/minBa(DHO).sub.2 45 cc/minLa(DHO).sub.3 10 cc/minAl(DHO).sub.3 7.5 cc/minNa(DHO) 40 cc/min______________________________________
The flow rate of HF--F 2 was 100 cc/min. Glass particles were deposited over the interior wall of the FEP (fluoroethylene pipe) tube. The deposited fine glass particles had a composition of 39.7ZrF 4 --13.3HfF 2 --18.0BaF 2 --4.0LaF 3 --3.0AlF 3 22NaF. Thereafter, feeding of Hf(HFA) 4 was stopped to form a core layer. Then, in order to form a core layer, feed rates of respective metal-β-diketonate complexes were adjusted to the rates as set forth below:
______________________________________Zr(HFA).sub.4 100 cc/minBa(DHO).sub.2 50 cc/minLa(DHO).sub.3 10 cc/minAl(DHO).sub.3 7.5 cc/minNa(DHO) 40 cc/min______________________________________
The deposition was effected for 2 hours with the flow rates of the starting materials as set forth above and the flow rate of HF--F 2 was set to 100 cc/min. The composition of the formed glass was 53ZrF 4 --20BaF 2 --4LaF 3 --3AlF 3 --22NaF.
The fluoride glass deposited on the interior wall of the FEP (fluoroethylene pipe) tube and including the cladding layer and core layer was drawn similarly as described in Example 10. The thus produced fluoride optical fiber covered by a Teflon FEP had a long size and a low transmission loss. The core/cladding diameter ratio may be freely changed by varying the times for deposition of fine fluoride glass particles for the formations of core and cladding layers.
EXAMPLE 13
Aluminum was coated by vapor deposition over the interior wall of a tube made of an oxide glass having a composition of 22B 2 O 3 --48PbO--30Tl 2 O 3 . This oxide glass tube was used in place of the FEP tube as used in Example 12. The following procedure was the same as described in Example 12 to deposite fluoride glasses followed by collapsing and drawing to produce fluoride optical fiber having a appreciable length and low loss. The cylindrical tube used as the substrate on which fine particle of fluoride glass is deposited, may be a single layer or multi-layered cylindrical tube made of any of glasses, metal and organic polymers.
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Provided is a process for preparing a homogeneous fluoride glass containing high purity BaF 2 through the CVD process characterized in that the used gaseous mixture comprising: a barium β-diketonate complex serving as a first starting material and represented by the following general formula (1) of: ##STR1## wherein R is an alkyl group having 1 to 7 carbon atoms, R' is a substituted alkyl group having fluorine atoms substituting hydrogen atoms and represented by C n F 2n+1 where n is an integer of from 1 to 3;
a gaseous or vaporizable compound of the metallic element constituting said fluoride glass, the gaseous or vaporizable compound serving as a second starting material; and a fluorine-containing gas serving as fluorinating agent. Further provided is a process for preparing a preform for a fluoride optical fiber which is low in transmission loss, by depositing the fluoride glass over the interior wall of a cylindrical tube or the wall of rod-like glass substrate through the CVD process followed by collapsing.
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[0001] The present invention relates to a process for accelerating the conversion of linear polymers of polyhydric alcohols from their monomers in the presence of catalysts using microwave irradiation.
BACKGROUND ART
[0002] The present invention relates to the process of the production of polyhydric alcohols from their monomers. Examples of monomers that could be subjected to this process are glycerol, ethylene glycol, propylene glycol, sorbitol, sucrose, D-glucose and fructose. This list is by no means exhaustive. Polyglycerol is defined as a polymer containing two or more units of glycerol and it may be either linear or branched.
[0003] Numerous methods are known for the preparation of polyglycerols with earlier works evolved around the use of thermal dehydration of glycerol. The polymerisation was carried out at atmospheric pressure and at an elevated temperature, which is about 270° C. −280° C. as mentioned in U.S. Pat. No. 2,487,208. The process can be accomplished without the use of catalyst but the yield of polyglycerol is considerably low as reported by Hauschild and Petit (1956). Therefore, various catalysts have been introduced to aid in the formation of polyglycerol such as mixtures of sulphuric acid and triacetin as described in U.S. Pat. No. 3,968,169, hypophosphorus acid with sodium hydroxide as appeared in U.S. Pat. No. 4,551,561, alkaline carbonates such as potassium carbonate with aluminium oxide as in J.P. No. 61,238,749 and sodium or potassium hydroxide as in U.S. Pat. No. 5,710,350.
[0004] Polyglycerol formation was also reported with either solketal, glycidol or glycerol carbonate as the reactants when reacted with hydrotalcite at elevated temperatures as described in W.O. Pat. No. 9,516,723. Other than that, rubidium, caesium and potassium fluoride salts on alumina or zeolites were used as catalyst for the polymerisation of glycerol. In addition, glycidol, glycerol carbonate and solketal were polymerised using the above fluoride salts into polyglycerol as reported in W.O. Pat. No. 9,521,210. Other than that, in U.S. Pat. No. 5,635,588, both linear and cyclic polyglycerols were products of reaction between glycidol, glycerol carbonate and solketal with beta-zeolites as catalysts.
[0005] While some other literatures reported the use of epichlorohydrin in the process to prepare polyglycerol, in U.S. Pat. No. 4,960,953, Jakobson et. al. disclosed a process to produce polyglycerol, which comprised reacting glycerol, diglycerol or higher polyglycerol with epichlorohydrin at 90° C. to 170° C. to produce a crude chlorohydrin/ether mixture, followed by adding an amount of strong base at least substantially equivalent to the organically bound chlorine content of the chiorohydrin/ether mixture, and desalting the mixture and recovering the glycerol, diglycerol and higher polyglycerol fractions.
[0006] Allyl alcohol is another route in preparing polyglycerols. The process involve depoxidation of the ally/alcohol, in which glycidol would be formed and then followed by polymerisation of the glycidol. This was proven as another effective method to prepare polyglycerol as shown in J.P. No. 2,169,535.
[0007] Despite the fact that the background art in preparing polyglycerol is crowded and diverse, it is evident that the synthesis of polyglycerol and diglycerol from glycerol has one major drawback, which is the duration of reaction. It is a usual practice to have a reaction time of minimum 5 hours to 72 hours to carry out polymerisation with a mixed yield of glycerol, digycerol, triglycerol and other higher polyglycerols. Other preparation such as those that involve epichlorohydrin may polymerise at a faster rate, but polyglycerols produced from epichlorohydrin are not particularly favoured by the industry, as there may still be organically bound chlorine in the polyglycerols.
SUMMARY OF THE INVENTION
[0008] Prior art for the preparation of diglycerols and higher polyglycerols suffer from low yields and/or very long reaction times. This invention provides a process to reduce the reaction time required for the production of diglycerol and higher polyglyerols. This is achieved by subjecting glycerol to the irradiation of microwave, which acts as a heat element for the polymerisation reaction. Microwave irradiation is proven to have accelerated the reaction greatly, in which the reaction time may be reduced to minutes. This new approach was coupled with the use of specific catalysts for the formation of linear diglycerol and higher polyglycerols from glycerol.
[0009] In the present invention, glycerol is exposed to microwave irradiation for a certain period of time in the presence of a specific catalyst. Prolonged heating is to be avoided, as it will favour the formation of high degree polyglycerols such as heptaglycerol, which is not favourable. Therefore, the duration and/or strength of the microwave irradiation are critical in determining the composition of the end products.
[0010] The specific catalysts used in the process are chosen to give significantly high conversion percentage of glycerol to its polymers which are preferably, only linear diglycerol and higher polyglycerols. In this invention, high temperatures are employed to drive the conversion of glycerol to diglycerol and polyglycerols as milder temperatures tend to give poor yields of diglycerol and polyglycerols. However, colouration of the end products will result if the reaction temperature employed is too high. Therefore, an optimal range of reaction temperature is chosen to produce high yields of diglycerol and polyglycerols of a good quality.
[0011] After the specific required reaction time, the end product obtained from the process is subjected to filtration to remove the catalyst. Further removal of the catalyst may be achieved by subjecting an aqueous solution of the end product through an ion exchange column. The crude end product mixture is then dried from water by means of distillation. The dried crude end product is sent for HPLC analysis and based on the HPLC chromatogram; the composition of the crude end product may comprise of unreacted glycerol, diglycerol, tiglycerol, tetraglycerol, pentaglycerol and hexaglycerol.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The present invention provides a significantly expedited process when compared with conventional processes for the preparation of diglycerol and polyglycerols from glycerol. The reaction time taken to produce diglycerol and polyglycerols, is reduced to about 20 to 30 minutes whereas the conventional methods may take about 5 hours to 72 hours. This reduction in the conversion time is as a result of the use of microwave irradiation, in which the glycerol is heated in a 900 W microwave oven in the presence of a specific catalyst and stirred with the aid from a magnetic stirrer.
[0013] It has been reported that polymerisation of glycerol to form polyglycerols can be carried out without the use of catalyst but the reaction suffered low yield of polyglycerols. Therefore, in this invention, a catalyst is selected to increase the yield of the desired polyglycerols. It is found out that organic acid salts of alkaline metals gave good yields and selectivity in producing diglycerol and polyglycerols from glycerol. Examples of catalysts employed in the reaction are potassium acetate, sodium acetate anhydrous, sodium acetate trihydrate, sodium formate, tri-sodium citrate and potassium citrate. In the process, about 0.5 to 10 wt percent and, more preferably 0.5 to 1.0 percent of catalysts are employed based on the weight of glycerol.
[0014] For this invention, the temperature may be in the range of 200° C. to 310° C., but preferably in the range of 250° C. to 270° C. By employing temperatures in this range, it is possible to achieve good conversion with minimal undesired side products while still obtaining acceptable reaction rates. It is preferred that the process is conducted at atmospheric pressure and therefore the use of costly high-pressure equipment is avoided.
[0015] The yield of crude end products, which will typically comprise of unreacted glycerol and between 78%-85% of diglycerol and polyglycerols by weight of the glycerol. The yield of individual glycerol polymers and the selectivity of the reaction can be ascertained by analysing the crude end product of the products using High Performance Liquid Chromatography (HPLC). The conversion percentage of glycerol to polyglycerol typically ranges from 75%-85%, with about 15%-20% of unreacted glycerol. The following is a typical composition percentage of the glycerol polymers analysed through HPLC.
[0000] Typical composition of glycerol polymers:
[0016] 15%-20% of unreacted glycerol
[0017] 25%-30% of diglycerol
[0018] 20%-25% of triglycerol
[0019] 10%-15% of tetraglycerol
[0020] 15%-10% of pentaglycerol
[0021] 1%-5% of hexaglycerol
[0022] From the HPLC chromatogram, there is little or no evidence of cyclic diglycerol or polyglycerols found in the crude end product when compared to standard polymers of glycerol. Therefore, the process selectively produces linear diglycerol and polyglycerols from glycerol.
[0023] The crude end product may be diluted with an equal amount of deionised water and is then subjected through a column of cationic ion exchanger such as Amberlite 1R-120 to remove dissolved catalysts. The crude end product is then subjected distillation to remove the water added earlier.
[0024] The following examples illustrate the process of the invention but are limitative thereof.
Example 1
[0025] Glycerol (50 g) was charged into a 250 ml round bottom flask and then into the same flask was added 0.5 g of potassium acetate. The mixture was stirred for a minute with a magnetic stirrer in the 900 W microwave oven cavity in order to homogenise the mixture. Then, the microwave oven was programmed to raise the temperature from ambient to 270° C. in 2 minutes and this temperature was maintained for another 15 minutes, after which the cooling process was started to mark the end of reaction. The total reaction time was just mere 17 minutes. After the end product was cooled, an equal amount of deionised water was added to the end product in order to dilute the viscous product. The diluted product was then subjected through an ion exchange column to remove dissolved catalysts. The treated end product was later subjected to distillation to remove water. The treated end product was then subjected to High Performance Liquid Chromatography (HPLC) and the compositions of each polymers of glycerol were as below. The treated polyglycerols yield was 81% and the conversion percentage of glycerol to polyglycerol was 80%.
[0000] Typical composition of glycerol polymers for reaction product of Example 1:
[0026] 19.6% of unreacted glycerol
[0027] 25.4% of diglycerol
[0028] 22.0% of triglycerol
[0029] 15.6% of tetraglycerol
[0030] 10.5% of pentaglycerol
[0031] 6.9% of hexaglycerol
Example 2
[0032] The same experiment was repeated with 50 g of glycerol and 0.5 g (1%) of sodium acetate anhydrous as the catalyst. The microwave oven was programmed to raise the temperature from ambient to 270° C. in 2 minutes and this temperature was maintained for another 23 minutes, after which the cooling process was started to mark the end of reaction. The total reaction time was 25 minutes. The reaction product was worked-up as described in Example 1 and HPLC analysis revealed the compositions of each polymers of glycerol were as below. The treated polyglycerols yield was 83% and the conversion percentage of glycerol to polyglycerol was 74%.
[0000] Typical composition of glycerol polymers for reaction product of Example 2:
[0033] 26.1% of unreacted glycerol
[0034] 28.9% of diglycerol
[0035] 20.7% of triglycerol
[0036] 12.7% of tetraglycerol
[0037] 7.4% of pentaglycerol
[0038] 4.2% of hexaglycerol
Example 3
[0039] The same experiment was repeated with 50 g of glycerol and 0.5 g (1%) of sodium formate as the catalyst. The microwave oven was programmed to raise the temperature from ambient to 270° C. in 2 minutes and this temperature was maintained for another 28 minutes, after which the cooling process was started to mark the end of reaction. The total reaction time was 30 minutes. The reaction product was also worked-up as described in Example 1 and HPLC analysis revealed the compositions of each polymers of glycerol were as below. The treated polyglycerols yield was 81% and the conversion percentage of glycerol to polyglycerol was 79%.
[0000] Typical composition of glycerol polymers for reaction product of Example 3:
[0040] 18.5% of unreacted glycerol
[0041] 25.0% of diglycerol
[0042] 22.0% of triglycerol
[0043] 16.0% of tetraglycerol
[0044] 11.0% of pentaglycerol
[0045] 7.5% of hexaglycerol
Example 4
[0046] The same experiment was repeated with 50 g of glycerol and 0.5 g (1%) of tri-sodium citrate as the catalyst. The microwave oven was programmed to raise the temperature from ambient to 270° C. in 2 minutes and this temperature was maintained for another 38 minutes, after which the cooling process was started to mark the end of reaction. The total reaction time was 40 minutes. The reaction product was also worked-up as described in Example 1 and HPLC analysis revealed the compositions of each polymers of glycerol were as below. The treated polyglycerol yield was 85% and the conversion percentage of glycerol to polyglycerol was 74%.
[0000] Typical composition of glycerol polymers for reaction product of Example 4:
[0047] 26.0% of unreacted glycerol
[0048] 29.1% of diglycerol
[0049] 20.6% of triglycerol
[0050] 12.7% of tetraglycerol
[0051] 7.7% of pentaglycerol
[0052] 3.9% of hexaglycerol
Example 5
[0053] The same experiment was repeated with 50 g of glycerol and 0.5 g (1%) of potassium citrate as the catalyst. The microwave oven was programmed to raise the temperature from ambient to 270° C. in 2 minutes and this temperature was maintained for another 23 minutes, after which the cooling process was started to mark the end of reaction. The total reaction time was 25 minutes. The reaction product was also worked-up as described in Example 1 and HPLC analysis revealed the compositions of each polymers of glycerol were as below. The treated polyglycerol yield was 84% and the conversion percentage of glycerol to polyglycerol was 72%.
[0000] Typical composition of glycerol polymers for reaction product of Example 5
[0054] 28.0% of unreacted glycerol
[0055] 30.0% of diglycerol
[0056] 20.4% of triglycerol
[0057] 11.9% of tetraglycerol
[0058] 6.5% of pentaglycerol
[0059] 3.2% of hexaglycerol
Example 6
[0060] The same experiment was repeated with 50 g of glycerol and 0.5 g (1%) of sodium acetate trihydrate as the catalyst. The microwave oven was programmed to raise the temperature from ambient to 270° C. in 2 minutes and this temperature was maintained for another 23 minutes, after which the cooling process was started to mark the end of reaction. The total reaction time was 25 minutes. The reaction product was worked-up as described in Example 1 and HPLC analysis revealed the compositions of each polymers of glycerol were as below. The treated polyglycerol yield was 78% and the conversion percentage of glycerol to polyglycerol was 79%.
[0000] Typical composition of glycerol polymers for reaction product of Example 6
[0061] 20.7% of unreacted glycerol
[0062] 24.4% of diglycerol
[0063] 21.0% of triglycerol
[0064] 15.7% of tetraglycerol
[0065] 10.9% of pentaglycerol
[0066] 7.27% of hexaglycerol
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The present invention relates to a process for accelerated preparation of linear polymers of polyhydric alcohols using microwave irradiation as the heat element in the presence of specified catalysts.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to post supports and more particularly pertains to a new support attachment for a post for reinforcing posts and straightening leaning posts.
2. Description of the Prior Art
The use of post supports is known in the prior art. More specifically, post supports heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art includes U.S. Pat. Nos. 4,296,584; 5,011,107; 4,593,872; 4,923,164; 5,135,192; and 354,792.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose a new support attachment for a post. The inventive device includes a generally L-shaped angle iron coupled to the post towards the lower end of the post. A pair of first arms are coupled to a lower end of the angle iron, and a pair of second arms are pivotally coupled to free ends of the first arms.
In these respects, the support attachment for a post according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of reinforcing posts and straightening leaning posts.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of post supports now present in the prior art, the present invention provides a new support attachment for a post construction wherein the same can be utilized for reinforcing posts and straightening leaning posts.
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new support attachment for a post apparatus and method which has many of the advantages of the post supports mentioned heretofore and many novel features that result in a new support attachment for a post which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art post supports, either alone or in any combination thereof.
To attain this, the present invention generally comprises a generally L-shaped angle iron coupled to the post towards the lower end of the post. A pair of first arms are coupled to a lower end of the angle iron, and a pair of second arms are pivotally coupled to free ends of the first arms.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
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.
It is therefore an object of the present invention to provide a new support attachment for a post apparatus and method which has many of the advantages of the post supports mentioned heretofore and many novel features that result in a new support attachment for a post which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art post supports, either alone or in any combination thereof.
It is another object of the present invention to provide a new support attachment for a post which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new support attachment for a post which is of a durable and reliable construction.
An even further object of the present invention is to provide a new support attachment for a post which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such support attachment for a post economically available to the buying public.
Still yet another object of the present invention is to provide a new support attachment for a post which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
Still another object of the present invention is to provide a new support attachment for a post for reinforcing posts and straightening leaning posts.
Yet another object of the present invention is to provide a new support attachment for a post which includes a generally L-shaped angle iron coupled to the post towards the lower end of the post. A pair of first arms are coupled to a lower end of the angle iron, and a pair of second arms are pivotally coupled to free ends of the first arms.
Still yet another object of the present invention is to provide a new support attachment for a post that can be used to straighten a leaning fence post without removing the post from the ground. The attachment is merely coupled to the post and buried in packed dirt or concrete beside the post.
These together with other objects of the invention, along with 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 the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a schematic side view of a new support attachment for a post according to the present invention.
FIG. 2 is a schematic side view of the present invention.
FIG. 3 is a schematic perspective view of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular to FIGS. 1 through 3 thereof, a new support attachment for a post embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described.
As best illustrated in FIGS. 1 through 3, the support attachment for a post 10 generally comprises a generally L-shaped angle iron 12 coupled to the post 13 towards the lower end 14 of the post. A pair of first arms 15 are coupled to a lower end 16 of the angle iron, and a pair of second arms 17 are pivotally coupled to free ends of the first arms.
The elongate post may be of a type having opposite upper and lower ends and a longitudinal axis extending between the ends. The lower end is secured in a ground surface by a first quantity of concrete 19 .
Preferably, the post has a generally rectangular transverse cross section taken perpendicular to the longitudinal axis thereof. The post has a pair of generally vertically aligned apertures 20 therethrough positioned above the ground surface.
A generally L-shaped angle iron is coupled to the post towards the lower end of the post. Preferably, the angle iron has a pair of vertically aligned holes therethrough that are aligned with the apertures of the post.
A first threaded fastener 21 extends through a first of the holes and through a first of the apertures of the post for coupling the angle iron to the post.
Preferably, each of the first arms has proximal and distal apertures positioned towards opposite ends thereof. The proximal aperture of one of the first arms is positioned towards and aligned with a second of the holes of the angle iron. The proximal aperture of the other of the first arms is positioned towards a second of the apertures of the post such that the post is interposed between the first arms.
A second threaded fastener 22 extends through the proximal apertures of the first arms and the post for coupling the first arms and the angle iron to the post.
Preferably, the pair of second arms are pivotally coupled to free ends of the first arms by a bolt, nut and washer.
Also preferably, a horizontal support bar 23 extends through lower ends of the second arms.
The preferred height of the angle iron is between about 6 and 10 inches, ideally about 8 inches between its upper and lower edges 24, 25. This range of heights has been found to provide sufficient support to the post. The holes of the angle iron are preferably positioned between about 1 and 3 inches, ideally about 2 inches, from the upper edge of the angle iron. This range provides sufficient distance between the holes and the upper and lower edges of the angle iron so that the post will not break off when an outside force is brought to bear on the post.
The preferred length of each of the first arms is between about 6 and 12 inches, ideally about 9 inches, between its opposite ends. This range provides sufficient distance from the angle iron that the post may be based in a first portion of concrete and the second arms buried in the ground or another portion of concrete adjacent the first portion of concrete.
The preferred length of each of the second arms is between about 6 and 12 inches, ideally about 9 inches, between its opposite ends. This range provides sufficient depth to anchor the post without risk of pulling up the horizontal support bar.
The preferred length of the horizontal support bar is greater than at least 6 inches. A support bar of at least 6 inches is required to prevent the support bar from is pulled out of soil when an outside force is brought to bear on the post.
In use, the angle iron and first arms are attached to the post. The second arms are buried in the ground or in concrete adjacent the post. Any movement of the post would require the second arms to displace soil or concrete surrounding it. The horizontal support bar increases the amount of soil or concrete that must be displaced to move the post.
As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A support attachment for a post for reinforcing posts and straightening leaning posts. The support attachment for a post includes a generally L-shaped angle member for coupling to the post towards the lower end of the post. A pair of first arms are coupled to a lower end of the angle member for coupling, and a pair of second arms are pivotally coupled to free ends of the first arms.
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FIELD OF THE INVENTION
The present invention relates to an actuator for a rotatable or linearly movable component with at least one defined stop position, and also to an actuator of a braking component of a yarn brake.
BACKGROUND OF THE INVENTION
An actuator for a yarn brake of a disk brake type known from EP-A-05 97 239 is structured as a permanent magnet motor carrying out a 360°-rotational movement of a component actuating the yarn within four extremely quick steps. The respective stop position after a step has been carried out is adjusted purely by magnet forces and such that a respective braking position or release position for the yarn is defined. The armature is electromagnetically arrested by the magnet field generated by the excited coil. Due to inertia, the armature tends to continue its rotation beyond an equilibrium position where it is parallel to the respective exciting magnet field. The angle opening between both magnet fields then causes a return torque for the armature. Said return torque defines a quasi-electromagnetic stop. The return torque generated to define the stop position leads to a disadvantageous backwards jerk of the component of the yarn brake which may influence the braking or releasing behaviour of the yarn brake in undesired fashion, i.e., any transition to the respective braking position or releasing position cannot be controlled properly.
Furthermore, controlled yarn brakes having an electric turning actuator are known in practice. Said yarn brakes include a resilient rubber stop defining a stop position. The component of the yarn brake hits the stop after the quick adjustment movement. The result is a jerking motion backwards which may lead to the undesirable effect that the component undesirably influences the yarn even in the braking position or the releasing position, respectively. A jerking movement in the backward direction also may occur at a stopper of a stopping device which is actuated by a linear magnet between a blocking position and a releasing position. Such stop devices are known in yarn feeding devices for jet weaving machines. In this case, the backward jumping motion may allow the weft yarn to slip through, or the withdrawn weft yarn is caught at the stopper.
It is an object of the invention to provide a quick and compact actuator of the kind as disclosed as well as a controlled yarn brake including such an actuator, wherein despite quick adjustment movements the moveable component achieves the respective stop position without jumping back.
Said object can be achieved by providing an additional body at the stop position, the additional body having substantially the mass or the moment of inertia of the drive element and the rotatable or linearly movable component, the additional body being displaceably supported at a returnable motion damping device.
The mass (in case of a linear movement) or the moment of inertia (in case of a rotational movement) of the additional body is precisely matched to the mass or the moment of inertia of the moveable parts. The additional body takes over the entire impact energy without inducing a backward motion. At the stop position, the moveable parts abruptly are brought to a stand still. The additional body continues to move such that its energy will be dissipated in the motion damping device before the additional body returns in delayed fashion into its home position. Said additional body reaches its home position without displacing the parts in the opposition direction which parts already were brought into a stand still condition without jumping back. This results in a yarn brake having the advantage that the moveable parts do not undergo any further swinging motion during the transition from one braking position to another or to a releasing position, and that the intended braking or releasing effect is not influenced detrimentally. Within the time period usually existing for the actuation of controlled yarn brakes, e.g. about 5 ms, the moveable parts are brought to a stand still at a precisely determined position and without jumping back. This is particularly expedient for actuators or yarn brakes, respectively, the working operation of which takes place with a rotation or a linear movement. The actuator may comprise a drive element which is actuated magnetically, electromagnetically, electrically, hydraulically, mechanically or pneumatically. The expedient function results from the inventive measure to first introduce the impact energy totally into the additional body to achieve an absolute stand still and a correct positioning of the moveable parts, and to dissipate the impact energy and to then return the additional body with a delay and damped into the home position such that even then no backwards jump will be generated.
Expediently, the motion damping device for the additional body includes resilient friction damping means and a damped return function with a precisely limited stroke. The additional body brings the moveable part in its home position abruptly to a stand still and then has a longer time to let its energy dissipate and to return into its home position. The time period available for this function corresponds at maximum to the time period between two subsequent working cycles of the actuator in the same direction of movement. Employing the additional body results in a time buffer for energy dissipation and offers the possibility of carrying out the energy dissipation in a precisely predetermined fashion and relatively slowly. During the impact a part of the kinetic energy is converted into heat energy while the remaining part of the kinetic energy is transmitted from the additional body into the motion damping device and is converted into heat energy there. The return function brings the additional body exactly back into the home position, preferably relatively slowly and without causing a jerking motion in a backward direction of the earlier stopped parts.
The additional body can be manufactured simply from a hard or non-resilient material, e.g. from a plastic material like polyurethane. The motion damping device with its return components can be made from a highly resilient material like soft elastic plastic material, e.g. in the form of a polyurethane-foam cushion, which supports the additional body or provides the energy dissipation and return function to return the additional body with a delay to avoid a backward jump of the moveable parts.
It is advantageous to provide two stop devices limiting the working stroke of the actuator or the component, respectively. In each stop device at least one additional body is used to stop the moveable parts. Each stop device, furthermore, can be separated into at least two symmetrical halves which are symmetrical with respect to the axis of the movement of the component such that for a single stop position two additional bodies and two motion damping devices are provided. The mass (for a linear movement of the actuator) or the moment of inertia (for a rotational movement of the actuator) of the additional body should correspond relatively precisely to the mass or the moment of inertia, respectively, of all parts to be moved into the stop position. When separating a stop device into at least two symmetrical halves, of course, the respective additional body only needs to have half of the mass or of the moment of inertia transmitted by the stop element.
An expedient embodiment employs an electric actuator including a linear electromotor or a rotating electromotor. Particularly advantageous is a permanent magnet motor constituting said linear motor or said rotational electromotor. It can be manufactured with few structural components, with high operation reliability and quick response behaviour.
It is advantageous to incorporate the stop device or each stop device structurally into the electromotor or the permanent motor, respectively. This allows the manufacturer to provide the necessary precise settings.
In case of a reversing permanent magnet motor or a rotating actuator expediently each stop device is located between the armature and a rotational bearing for an armature shaft and/or a shaft of the component, or between two rotational bearings of the armature shaft. In this area sufficient mounting space is available to receive the stop device.
In a permanent magnet motor the full cross-section of the armature preferably should be useable for the electromagnetic polarisation, in view of a quick response behaviour and a high power. At the same time, the armature shaft has to guarantee an accurate rotational support and long lift duration with optimum low rotational resistance. Both requirements are opposite to each other. In order to avoid a penetration of the armature by the armature shaft the component or a section of the armature shaft may comprise a hub part which either grips the front end of the armature like a pot or which is inserted like a plate into said front end. Since the armature shaft or component does not need to be an electromagnetically active part of the armature, it can be optimised in view of strength and functionality. To the contrary, the armature which is not penetrated by the armature shaft in this case can be designed for optimum magnetic function and can be polarised over its full cross-section.
Expediently the armature is supported for rotation at both ends by means of coaxial spindles. However, said spindles do not penetrate the armature. This facilitates manufacturing of the permanent magnet motor and improves its operation performance.
In case that the armature of an electromotor constitutes the drive element for the component of a yarn brake, quick linear or rotating adjustment movements can be generated.
In a yarn brake the driving element expediently is constituted by the magnetically polarised armature of a permanent magnet motor.
The stop device which is responsible for the positioning of the moveable parts of the yarn brake without backwards jumps expediently is incorporated into the actuator.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will be explained with reference to the drawings, in which:
FIG. 1 is a perspective view of a yarn brake including an actuator;
FIG. 2 is an axial section of a further embodiment of a yarn brake including a rotational actuator designed as a permanent magnet motor;
FIG. 3 schematically shows the internal structure of the permanent magnet motor of FIG. 2, in cross-section;
FIG. 4 is a perspective partial section in section plane IV—IV of FIG. 5 of a permanent magnet motor including a structurally integrated stop device;
FIG. 5 is a cross-section in section plane V—V of FIG. 4;
FIGS. 6 & 7 are detail axial sections of two variants;
FIG. 8 is a perspective view of a detail;
FIGS. 9-11 diagrammatically illustrate three operational conditions of the actuator or the yarn brake; and
FIG. 12 illustrates in the form of a diagram an operational condition of a conventional actuator or a yarn brake.
DETAILED DESCRIPTION
FIG. 1 shows a yarn brake B for variably braking a running yarn Y. A block-shaped actuator A, e.g. a permanent magnet motor, is fixed at a holder 1 . Actuator A serves to drive a component 2 for rotation about a rotational axis. The running path of a yarn Y through the yarn brake B is determined by yarn guiding elements 4 , 7 . Yarn guiding element 4 is provided in an end wall 3 . Furthermore, as an active braking element a spring lamella 5 is secured to holder 1 such that it is pressed resiliently against a cylindrical braking part 8 integrated into component 2 . The contact pressure can be adjusted at 6 . A recessed window 9 is formed in at least one circumferential portion of component 2 . The window 9 is defined by transitions 10 which extend into the cylindrical braking part 8 . The yarn Y is pulled through between the spring lamella 5 and component 2 . Depending on the rotational position of component 2 the yarn either is clamped and braked between 8 and 5 or is pulled without clamping through window 9 . Any switchover of yarn brake B is made by rotating component 2 by means of actuator A, for example about 90°, into an exactly defined position such that either the cylindrical braking part 8 will contact the spring lamella 5 or such that a free space is created between spring lamella 5 and window 9 .
The yarn brake B shown in FIG. 2 is a so-called deflection brake. A braking part is formed as a U-shaped bracket 8 ′ fixed to component 2 which can be rotated about its centre axis. The yarn Y indicated by dashes and dots, may interfere with the bracket 8 ′. Depending on the rotational position of component 2 , yarn Y is deflected stronger or weaker (stronger or weaker braking effect) or the yarn is not deflected at all (no braking effect or release position). At least two stop devices C incorporated into actuator A define two different rotational positions of component 2 between which component 2 is rapidly rotated back and forth by actuator A, e.g. within a few milliseconds.
The component 2 (a kind of a spindle) is connected to a rotating drive element D constituted by a magnetically polarised armature 11 of a permanent magnet motor M (which will be explained with the help of FIGS. 3 to 5 ). Housing parts 12 comprise rotational bearings 13 , 14 for armature 11 and component 2 , respectively. Component 2 contains a pin-like stop element 29 which is aligned in a rotational direction with the stop devices C defining the respective stop position. For each sense of rotation a pair of stop devices C may be provided. Permanent magnet motor M is reversible. Stop devices C are integrated into housing parts 12 at locations between the rotational bearings 13 , 14 . Alternatively, it is possible to locate stop devices C close to the lower end of armature 11 within or outside of housing parts 12 , or—as shown in dotted lines—within the motion path of bracket 8 ′ fixed to component 2 .
Component 2 does not penetrate armature 11 but has a top shaped hub part 15 which is put onto armature 11 and grips over the armature front end.
Armature 11 of permanent magnet motor M in FIG. 3 (which may serve as the actuator A of the yarn brakes shown in FIGS. 1 and 2) is a permanent magnet magnetically polarised lateral to the axis of rotation such that it has a magnetic north pole N and a magnetic south pole S. Armature 11 is supported for rotation by means of component 2 and at housing parts 12 . Armature 11 is surrounded by an annular core 17 of an exciting coil 18 . Exciting coil 18 may consist of several partial windings corresponding to the step number of the permanent magnet motor, and in the illustrated embodiment includes at least two partial windings. Corresponding with the step positions of armature 11 , coil core 17 has pole pairs 19 , 20 opposite exciting coil 18 . In accordance with the polarisation of the exciting coil 18 , the armature 11 will orient itself between said pole pairs. Diametrically opposed partial windings will be polarised in the same sense to build up a magnetisation which is parallel to the magnet filed of the armature. In case that the armature is to be rotated by 90°, the second pole pair oriented laterally with respect to the first pole pair will be magnetised accordingly. Current will flow in the same direction in the partial windings located between said poles such that a magnet field is generated between the associated magnet poles. The armature then will orient in the new rotational position corresponding to the turned or offset magnet field. In this fashion the armature can be rotated back and forth.
According to FIGS. 4 and 5 the armature 11 is not stopped at its respective stop position purely by magnetic forces but the respective stop position is defined by mechanical coaction between stop element 29 and a respective stop device C. Stop devices C are structurally integrated into the permanent magnet motor M of FIG. 4 such that they are located between hub part 15 and rotational bearing 14 .
Stop device C (FIGS. 4, 8 ) comprises an additional body Z and a motion damping device F, G, H having a return function. Stop device C is supported by a stationary stop 21 . Additional body Z consists of relatively hard and non-resilient material, expediently of a dense polyurethane or of metal, e.g. with the shape of a block or cushion 22 . Additional body Z has a moment of inertia I 1 which corresponds to the moment of inertia I of the parts of the actuator A or the actuator A and the yarn brake B, respectively, which rotate. Additional body Z can be displaced in relation to stationary stop 21 or the motion damping device F, G, H, respectively. Motion damping device F, G, H comprises a body 23 with the shape of a block or a cushion made from highly resilient material, e.g. a polyurethane plastic material like a foam, to which additional body Z can be bonded. Body 23 has a surface 24 which can be supported at stationary stop 21 . Body 23 is able to dissipate energy by deformation and to return its deformation elastically.
In case of a rotating actuator, as already mentioned, the moment of inertia I 1 of the additional body Z is matched with the moment of inertia I of the rotating parts. Alternatively, an actuator could be provided which carries out linear movements between both stop positions. In this case additional body Z is matched in its mass ml with the mass m of the moving parts.
The function of stop device C will be explained with the help of FIGS. 9, 10 and 11 for a linear actuator, and particularly in comparison to a conventional stop device C of a linear actuator, as symbolically shown in FIG. 12 .
FIGS. 1 to 8 illustrate actuators A for components 2 which are adjusted by rotation. When discussing FIGS. 9 to 12 the function of a linear actuator A is explained. Said explanations are true in analogous fashion also for rotating actuators A, e.g. as shown in FIGS. 1 to 8 , provided that instead of the mass the moment of inertia is considered. A linear actuator A could be constituted by the so-called stopper magnet (not shown) of a stop device of a weft yarn feeding device for a jet weaving machine.
As shown in FIG. 12 in the conventional stop device C, mass m of the moving parts driven by drive element D is just approaching stop device C with a speed V. The conventional stop device C comprises a motion damping device F, G, H, consisting of a friction damping means F, additively or alternatively a displacement damping means G, and a return component H. As soon as mass m impacts with speed V on stop device C in FIG. 12 kinetic energy is dissipated by friction or displacement and friction, respectively, within motion damping device F, G, H. This is carried out within a movement stroke of mass m with gradually decreasing speed. In this case, it cannot be avoided that mass m undergoes a jerking motion in a backward direction. As soon as the energy is dissipated, i.e., friction is converted into heat energy, mass m is returned by the return function H into the home position. This occurs with a backward motion of mass m beyond the home position.
To the contrary and according to the invention (FIGS. 9 to 11 ), stop device C provided with additional body Z has the task to define the correct stop position for mass m of the moving parts and, furthermore, to receive the entire impact energy and to transmit same into the motion damping device F, G, H. By taking over the entire impact energy from mass m, mass m stops without any jumping motion in the backward direction precisely at the initial position or stop position. For this purpose mass Ml of additional body Z is the same as mass m. In case of a rotating actuator A this is true for the moment of inertia of the moving part and the moment of inertia of the additional body, in relation to the axis of rotation.
In FIG. 9 the moving parts are traveling by their mass m with speed V of driving element D, while additional body Z is at a stand still (speed V is zero). Motion damping device F, G, H still is passive and is supported at stationary stop 21 .
The impact happens between the phases of FIGS. 9 and 10. Mass m gives the entire kinetic impact energy to additional body Z or to the mass ml of additional body Z, and thus stops without motion in a backward direction (FIG. 10, speed V equals zero). Additional body Z then moves further on with its mass ml in the same direction such that its energy is dissipated by motion damping device F, G, H. Thereafter, the return function becomes active such that additional body Z will change its direction of movement with a delay (arrow 25 ) and will return in the direction towards its home position (FIG. 9 ). Said return motion is delayed and at the same time damped by motion damping device F, G, H.
According to FIG. 11 additional body Z is returned precisely and damped into its home position. Its speed V at home position equals zero. The mass m of the already stopped parts remains stationary with speed V zero.
At least one stop device C may be provided for each of both stop positions of the armature 11 in FIGS. 4 and 5 or the yarn brakes B in FIGS. 1 and 2, respectively. Expediently, the stop devices C are structurally integrated into the actuator A. Alternatively, it is possible to situate stop devices C externally of actuator A. Furthermore, it may be desirable to separate each stop device into two halves which are situated symmetrically with respect to the axis of the moving components. In this case each additional body Z of one of said halves only has to have half of the mass m or half of the moment of inertia I of the moving parts.
According to FIG. 6 armature 11 is connected to the hub part 15 of component 2 or to hub parts 15 of two spindle shaped shafts 26 such that neither component 2 nor the armature shafts 26 penetrate armature 11 . It is a purpose of hub parts 15 to properly support the armature for rotation without penetrating it. Both hub parts 15 may grip over the entire length of cylindrical armature 11 .
Each armature shaft 26 or component 2 , respectively, is provided in FIG. 7 with a hub part 15 ′ set against or inserted in a front side 16 of armature 11 . For this purpose form fitting engagement elements 28 can be provided.
FIG. 8 illustrates a stop device C having the form of a block. Additional body Z is a polyurethane block 22 bonded with its base to a polyurethane foam material cushion having the form of a block 23 . Block 23 forms the movement damping device F, G, H comprising frictional damping means and/or displacement damping means F, G and a return component H, analogous to the diagram of FIGS. 9 to 12 . A surface 24 of block 23 can directly abut stop 21 or can be bonded thereto.
In the cross-sectional view of FIG. 5 it can be seen that stop element 29 is a pin penetrating component 2 (or the shaft of the armature). Both ends of said pin are coacting respectively with a stop device C provided in the housing, such that an operational stroke of more than 90° can be achieved for component 2 . Stop devices C are received in pockets defining stops 21 in housing parts. Stop devices C optionally can be clamped or bonded in place. In order to achieve an even larger operational stroke than 90° stop element 21 instead could protrude by just one of its ends such that this sole protruding end selectively will co-operate with the stop devices C provided for both stop positions.
Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.
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An actuator (A) for a component ( 2 ), comprising at least one defined stop position, in particular to a brake component actuator of a yarn brake (B), for a selective braking of a running yarn (Y) which actuator has a drive element (D) for linear or rotational adjustment of the component ( 2 ). Said actuator is provided with at least one stop device (C). The stop device (C) consists of an additional body (Z), supported in a displaceable manner on a motion damping device (F, G, H). The actuator (A) in the yarn brake is a reversible motor, suitably a magneto-electric motor (M) for rotational movement. An additional body (Z), supported in a displaceable manner on a motion damping device, is provided in each stop device, at which the yarn brake is to stop. During a linear adjustment of the component ( 2 ), the mass (m 1 ) of the additional body (Z) matches the mass (m) of the displaced parts. In contrast, with a component ( 2 ) that can be rotatably adjusted, the moment of inertia(I 1 ) of the additional body (Z) matches the moment of inertia (I) of the displaced parts, in relation to the axis of rotation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the papermaking and related arts. More specifically, the present invention is an industrial fabric of the on-machine-seamable variety, such as an on-machine-seamable press fabric for the press section of a paper machine.
2. Description of the Prior Art
During the papermaking process, a cellulosic fibrous web is formed by depositing a fibrous slurry, that is, an aqueous dispersion of cellulose fibers, onto a moving forming fabric in the forming section of a paper machine. A large amount of water is drained from the slurry through the forming fabric, leaving the cellulosic fibrous web on the surface of the forming fabric.
The newly formed cellulosic fibrous web proceeds from the forming section to a press section, which includes a series of press nips. The cellulosic fibrous web passes through the press nips supported by a press fabric, or, as is often the case, between two such press fabrics. In the press nips, the cellulosic fibrous web is subjected to compressive forces which squeeze water therefrom, and which adhere the cellulosic fibers in the web to one another to turn the cellulosic fibrous web into a paper sheet. The water is accepted by the press fabric or fabrics and, ideally, does not return to the paper sheet.
The paper sheet finally proceeds to a dryer section, which includes at least one series of rotatable dryer drums or cylinders, which are internally heated by steam. The newly formed paper sheet is directed in a serpentine path sequentially around each in the series of drums by a dryer fabric, which holds the paper sheet closely against the surfaces of the drums. The heated drums reduce the water content of the paper sheet to a desirable level through evaporation.
It should be appreciated that the forming, press and dryer fabrics all take the form of endless loops on the paper machine and function in the manner of conveyors. It should further be appreciated that paper manufacture is a continuous process which proceeds at considerable speeds. That is to say, the fibrous slurry is continuously deposited onto the forming fabric in the forming section, while a newly manufactured paper sheet is continuously wound onto rolls after it exits from the dryer section.
Referring, for the moment, specifically to press fabrics, it should be recalled that, at one time, press fabrics were supplied only in endless form. This is because a newly formed cellulosic fibrous web is extremely susceptible to marking in the press nip by any nonuniformity in the press fabric or fabrics. An endless, seamless fabric, such as one produced by the process known as endless weaving, has a uniform structure in both its longitudinal (machine) and transverse (cross-machine) directions. A seam, such as a seam which may be used to close the press fabric into endless form during installation on a paper machine, represents a discontinuity in the uniform structure of the press fabric. The use of a seam, then, greatly increases the likelihood that the cellulosic fibrous web will be marked in the press nip.
For this reason, the seam region of any workable on-machine-seamable press fabric must behave under load, that is, under compression in the press nip or nips, like the rest of the press fabric, and must have the same permeability to water and to air as the rest of the press fabric, in order to prevent the periodic marking of the paper product being manufactured by the seam region.
Despite the considerable technical obstacles presented by these requirements, it remained highly desirable to develop an on-machine-seamable press fabric because of the comparative ease and safety with which such a fabric could be installed on the press section. Ultimately, these obstacles were overcome with the development of press fabrics having seams formed by providing seaming loops on the crosswise edges of the two ends of the fabric. The seaming loops themselves are formed by the machine-direction (MD) yarns of the fabric. The seam is closed by bringing the two ends of the press fabric together, by interdigitating the seaming loops at the two ends of the fabric, and by directing a so-called pin, or pintle, through the passage defined by the interdigitated seaming loops to lock the two ends of the fabric together. Needless to say, it is much easier and far less time-consuming to install an on-machine-seamable press fabric, than it is to install an endless press fabric, on a paper machine.
One method to produce a press fabric that can be joined on the paper machine with such a seam is to flat-weave the fabric. In this case, the warp yarns are the machine-direction (MD) yarns of the press fabric. To form the seaming loops, the warp yarns at the ends of the fabric are turned back and woven some distance back into the fabric body in a direction parallel to the warp yarns. Another technique, far more preferable, is a modified form of endless weaving, which normally is used to produce an endless loop of fabric. In modified endless weaving, the weft, or filling, yarns are continuously woven back and forth across the loom, in each passage forming a loop on one of the edges of the fabric being woven by passing around a loop-forming pin. As the weft yarn, or filling yarn, which ultimately becomes the MD yarn in the press fabric, is continuous, the seaming loops obtained in this manner are stronger than any that can be produced by weaving the warp ends back into the ends of a flat-woven fabric.
It should be noted that the bending of the yarn back to create the loop, particularly about a small radius, can result in undesired stresses in the yarn portion creating the loop. This results in weakening the yarns at the seam such that they may fail before the yarns in the body, which is undesirable.
In still another technique, an on-machine-seamable multiaxial press fabric for the press section of a paper machine is made from a base fabric layer assembled by spirally winding a fabric strip in a plurality of contiguous turns, each of which abuts against and is attached to those adjacent thereto. The resulting endless base fabric layer is flattened to produce first and second fabric plies joined to one another at folds at their widthwise edges. Crosswise yarns are removed from each turn of the fabric strip at the folds at the widthwise edges to produce seaming loops. The first and second fabric plies are laminated to one another by needling staple fiber batt material therethrough. The press fabric is joined into endless form during installation on a paper machine by directing a pintle through the passage formed by the interdigitation of the seaming loops at the two widthwise edges.
In each case, spiral seaming coils may be attached to the seaming loops at the ends of the fabric by interdigitating the individual turns of a spiral seaming coil with the seaming loops at each end of the fabric and by directing a pintle through the passage formed by the interdigitated yarns and seaming loops to join the spiral seaming coil to the end of the fabric. Then, the fabric may be joined into the form of an endless loop by interdigitating the individual turns of the seaming coils at each end of the fabric with one another, and by directing another pintle through the passage formed by the interdigitated seaming coils to join the two ends of the fabric to one another.
A final step in the manufacture of an on-machine-seamable press fabric is to needle one or more layers of staple fiber material into at least the outer surface thereof. The needling is carried out with the press fabric joined into the form of an endless loop. The seam region of the press fabric is covered by the needling process to ensure that that region has permeability properties as close as possible to those of the rest of the fabric. At the conclusion of the needling process, the pintle which joins the two ends of the fabric to one another is removed and the staple fiber material in the seam region is cut to produce a flap covering that region. The press fabric, now in open-ended form, is then crated and shipped to a paper-manufacturing customer.
In the course of the needling process, the press fabric inevitably suffers some damage. This is because the barbed needles, which drive individual fibers of the staple fiber material into and through the press fabric, also encounter and break or weaken the yarns of the press fabric itself. And, when the seam region of the press fabric is being needled, at least some of the MD yarns which form the seaming loops and, if present, the spiral seaming coils will be somewhat weakened. Damage of this type inevitably weakens the seam as a whole and can lead to seam failure. In this regard, it should be realized that, in the case of a spiral seaming coil, only a small amount of damage could lead to premature seam failure. Because a spiral seaming coil extends transversely across the fabric at the seam region, a break at any point can weaken the seam for a considerable portion of its length, and cause it to unzip or come apart.
In addition to press fabrics, many other varieties of industrial fabric are designed to be closed into endless form during installation on some equipment. For example, papermaker's dryer fabrics may be joined into the form of an endless loop during installation on a dryer section. Dryer fabrics may be so joined with either a pin seam or a spiral seam, seams which are similar to those described above. Other industrial fabrics, such as corrugator belts, pulp-forming fabrics and sludge-dewatering belts, are seamed in similar fashions and are susceptible to seam failure for the same reasons.
Moreover, spiral seaming coils are available in only a limited number of configurations. That is to say, they may only be obtained in a limited number of diameters and pitches (number of turns per unit length). Clearly, an alternative to spiral seaming coils would be greatly appreciated by industrial fabric designers.
A papermaker's “link belt” fabric is disclosed in PCT/US98/05908 and comprises hinge wires extending in the cross-machine direction and a plurality of ring link elements extending in the machine direction. Each ring link element opens in the cross-machine direction and encloses at least two of the hinge wires. The ring link elements may either be solid, or continuous, or split, the latter being used, preferably, to make repairs in a damaged belt. This publication also includes descriptions of two methods for manufacturing the paper machine belts.
U.S. Pat. No. 4,469,221 discloses a papermaker's fabric comprising pintles extending in a cross machine direction and links snapped onto the pintles so that the links extend in a machine direction. Variously shaped link elements are shown. Each link element has holes at its ends for accepting neighboring hinge wires. The holes are not closed completely, but rather are slit to permit them to be expanded and snapped around the hinge wires.
The link belts disclosed in PCT/US98/05908 and U.S. Pat. No. 4,469,221 have the ring link elements only oriented in the machine direction, and not in the cross-machine direction. Further, the hinge wires are only shown to extend in the cross-machine direction, and not in the machine or diagonal directions. With such limited configurations, fabric strength and resistance to needling damage are compromised.
The present invention addresses these shortcomings in the prior art by providing an on-machine-seamable fabric having improved strength and resistance to needling damage.
SUMMARY OF THE INVENTION
Accordingly, the present invention is an industrial fabric manufactured from preformed rings. The rings may be of any shape, including, but not limited to, circular, oval, rectangular, oblique, oblong and tetrahedral, and are connected with machine-direction yarns, pintles or wires to form a flat fabric, whose ends may be joined to one another to form a continuous loop. Alternatively, the rings may be oriented in the cross-machine direction, and connected by yarns oriented in the machine direction. In a further embodiment, the rings, again oriented in the machine direction, are connected by yarns running at an oblique angle, that is, diagonally, relative to the machine direction.
The rings may be manufactured from rigid materials, and may have a solid, homogeneous nature. Alternatively, the rings may be filaments or copolymers, may be of metallic and/or non-metallic materials, and may be either flexible or inflexible. They may be solid, or open at one end and closable by way of a snap. They may also have preformed caps that provide a flatter pressure distribution along their surface. They may further have a hole at each end for the pintles used to connect them to one another. Other materials may be inserted within the rings to reduce the air or liquid permeability, to equalize the differences in permeability between land and open areas, and to help support the rings from deformation within a press.
Several methods of manufacturing the fabric are also described herein.
The present invention eliminates the capital-intensive weaving looms needed for the manufacture of a woven fabric that provides the body of the papermaker's fabric, offers improved strength over spirals used to provide loops that are used in the seaming of the product, provides the ability to create stock that may easily be seamed together to form the finished product, and improves uniformity of the entire structure by eliminating the fundamental difference between the body of the fabric and the seam area.
The present invention will now be described in more complete detail, with reference being made to the figures identified below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of a first embodiment of the industrial fabric of the present invention.
FIG. 2 is a schematic perspective view of a second embodiment of the industrial fabric of the present invention.
FIG. 3 is a schematic perspective view of rings included in the industrial fabric of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now specifically to the figures, which incidentally are not drawn to scale but rather to illustrate the invention and the components thereof, FIG. 1 is a schematic perspective view of a first embodiment of an on-machine-seamable industrial fabric. The fabric 10 takes the form of an endless loop once its two ends have been joined to one another.
In such embodiment, the industrial fabric 10 is comprised of a plurality of preformed rings 2 . The rings 2 are oriented in the machine direction and connected by, for example, yarns (or alternatively, pintles or wires) 3 , running at oblique angles, that is, diagonally, relative to the machine direction.
FIG. 2 is a schematic perspective view of an alternative embodiment of the industrial fabric 20 of the present invention. In this embodiment, the rings 2 are oriented in the cross machine direction and connected by yarns 3 extending in the machine direction.
Both FIGS. 1 and 2 show the industrial fabric constructed as a single layer of rings. However, such construction is shown as an example only, and the industrial fabric may also have two-, three- or higher number layers of rings, or may be laminated and include several fabric layers. In the latter case, where the fabric is laminated and includes several fabric layers, one or more, including all, of the fabric layers may be on-machine-seamable, and may be made so in accordance with the present invention.
The industrial fabric as described above could be produced without further “treatments.” Or, in the case where the industrial fabric is, for example, a press fabric, it may be needled with one or more layers of staple fiber batt material on one or both sides, or may be coated in some manner.
More specifically, staple fiber may be needled into all portions of the industrial fabric in order to mask the body of the fabric, increase stability, and provide a finer surface for improved pressure distribution. The staple fibers may be of any polymeric resin used in the production of paper machine fabrics and other industrial process fabrics, but are preferably of the group including polyamide and polyester resins.
As noted, the industrial fabric may also include coatings on either or both of its two surfaces of polymeric resins, such as polyurethanes or polyamides, applied by methods known in the art, such as full width coating, dip coating and spraying.
Alternatively, the industrial fabric may be used on one of the other sections of a paper machine, that is, on the forming or drying sections, or as a base for a polymeric-resin-coated, paper-industry process belt (PIPB). Moreover, the industrial fabric may be used as a corrugator belt or as a base thereof; as a pulp-forming fabric, such as a double-nip-thickener belt; or as other industrial process belts, such as sludge-dewatering belts.
Where yarns are used to join the rings, they may each be of any of the yarn types used in paper machine fabrics or other industrial process fabrics. That is to say, monofilament yarns, which are monofilament strands used singly, or plied/twisted yarns, in the form of plied monofilament or plied multifilament yarns, may be used as either of these yarns.
Further, the filaments comprising the yarns may be extruded from synthetic polymeric resin materials, such as polyamide and polyester, or are metal wire, and incorporated into yarns according to techniques well-known in the industrial textile fabrics industry and particularly in the papermaking clothing industry.
Where pintles are instead used to join the rings, each pintle may be a single strand of monofilament; multiple strands of monofilament; multiple strands of monofilament untwisted about one another, or plied, twisted, braided or knitted together; or of any of the other pintle types used in paper machine clothing. The pintle may be of metal wire or extruded from synthetic polymeric resin materials.
As shown in FIG. 3 , the rings can have any one of several shapes, such as, for example, circular, oval (elliptical), oblique, oblong, tetrahedral or D-shaped. The material from which the rings are fashioned may be of circular, oval (elliptical), square, rectangular or other cross-sectional shapes, and may have diameters in the range from 0.15 mm to 1.0 mm.
The rings may be manufactured from rigid materials, and may have a solid, homogeneous nature. The rings may be metal or extruded from any of the polymeric resin materials being used for yarns in the industrial textile fabrics industry (e.g., polyamides, polyurethanes, polyketones or polyesters). The rings can be flexible or inflexible. The rings may be solid, or open at one end and mechanically closed at the other by way of, for example, a snap interlock or clamp. The rings may further have a hole at each end to receive, for example, elongated pintles used to connect them to one another. Incidentally, joining the rings in this fashion allows them to pivot on each end, providing the fabric with added flexibility and strength.
The rings could also utilize a preformed cap 4 on one or both sides of the ring that provides a flatter pressure difference across the surface of the ring. The cap 4 could be permeable or impermeable. The rings may be monofilament, plied/twisted filaments or braided filaments. Any of these may be coated with an additional polymeric resin material.
Void volume, if desired, may be provided by the open area included within the fabric structure formed by the rings. Other materials may be inserted in the open areas to reduce the air or liquid permeability, to equalize the differences in permeability between land and open areas, and to help support the rings from deformation within a press. Further, the rings and pintles themselves may be made porous, having, for example, flow-through voids through their solid portions.
Several methods for manufacturing the industrial fabric are suggested. In one method, a woven cloth is used as a “Platform” onto which the rings are snapped or closed about the yarns in one of the two directions of the fabric. More specifically, a flat woven cloth is provided, having a small yarn system in the warp and single monofilament in the weft. This fabric is then placed on an indexing system to allow the rings to be snapped onto the yarns in one of the two directions of the fabric. These steps are repeated until a desired length fabric is produced.
In another method, a length of pintle is inserted onto a frame, rings are snapped about the pintle and indexed forward, and these steps are repeated until a full-length fabric is obtained. This full-length fabric is then joined by bringing the ends together and snapping the rings to a common pintle.
Either of these methods may produce a quantity of “stock” material which could then be sized from a master roll to the desired dimensions. This process may be automated or performed manually.
Modifications to the above would be obvious to those of ordinary skill in the art, but would not bring the invention so modified beyond the scope of the appended claims.
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An on-machine-seamable industrial fabric comprising rings connected by pintles. In one principal embodiment, the rings are oriented in the machine direction and the pintles extend at an angle, connecting the rings. Such configuration improves the strength of the fabric and provides resistance to needling damage. In another principal embodiment, the rings are oriented in the cross-machine direction and the pintles extend in the machine direction, joining the rings.
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FIELD OF THE INVENTION
[0001] The present invention relates to the compression moulding of plastic articles, in which an article is obtained by the compression of a quantity of plastic in the molten state between the two parts of a mould.
[0002] The present invention is applied more particularly to the production of plastic tubes, for example for toothpaste or cosmetics, the tube being formed from a flexible cylindrical body attached to a head comprising a shoulder and an orifice. In this particular case, the head of the tube is formed and simultaneously welded to the body in one operation. The head of the tube is produced from a metered quantity of molten material which is moulded and compressed between a lower tool known as the die assembly and an upper tool known as the mandrel, onto which the flexible cylindrical body is fitted. The temperature of the material is such that it is welded to the body of the tube. In a machine for producing tubes, a plurality of moulds are generally moved by a discontinuous (or continuous) movement, each mould being subjected to the various steps of the method (loading of the tube body, depositing the metered quantity of plastic, compression moulding, cooling, demoulding and discharge of the tube).
PRIOR ART
[0003] Devices and methods for producing such tubes are known in the prior art. By way of example, mention may be made of application DE 103 49 837 and U.S. Pat. No. 4,943,405, the contents of which is incorporated by way of reference in the present application as regards the description of said methods and devices.
[0004] Application DE 103 49 837 describes a device and a method for producing tubes in which a metered quantity of annular shape is deposited on a sleeve acting as intermediate support and through which a rod is mounted so as to slide. The rod is held in the high position by means of a spring and is pushed back against the force of the spring when the mandrel is being introduced into the die to form the head.
[0005] In U.S. Pat. No. 4,943,405, and as shown in FIG. 1 thereof, a metered quantity of plastic in annular form is deposited from a supply of material onto the upper face of a sleeve and around the rod which is used to form the orifice in the shoulder. The outlet of the supply of material is surrounded by an annular nozzle which allows the projection of pressurized air to separate the metered quantity of deposited material from the supply of material, once the desired metered quantity of material has been deposited. Once the metered quantity of material has been deposited on the sleeve, the supply of material is removed and a mandrel is introduced which has the shape of the shoulder to be created. The front face of the mandrel comes into contact with the upper face of the rod and the sleeve-rod assembly is pushed back inside the shoulder die and thread-forming die to form the head which is to become the end of the tube. FIGS. 3 and 4 of this patent illustrate this step of forming the head and the welding thereof on the body of the tube carried by the mandrel. The orifice of the head is formed by the rod which is longitudinally displaced in the sleeve. During this step of forming the head and the displacement of the mandrel in the die, the rod is pushed back axially into the sleeve by the mandrel from an upper position to a lower position in which it is used to form an orifice in the shoulder by protruding beyond the upper face of the sleeve.
[0006] One problem encountered in U.S. Pat. No. 4,943,405 and in application DE 103 49 837 is due to the temporary positioning of the metered quantity of plastic on the sleeve. Depending on the distribution of the plastic between the upper surface and the lateral wall of the sleeve, the quality of the moulded article may be considerably improved or degraded.
[0007] Thus one of the objects of the invention is to improve the known methods and devices.
[0008] More particularly, one of the objects of the invention is to propose a system allowing suitable distribution of the plastic on the sleeve.
[0009] A further object of the invention is to propose a method for forming shoulders of tubes which is more efficient than the known methods.
GENERAL DESCRIPTION OF THE INVENTION
[0010] The invention, therefore, relates to a device for moulding a plastic article in which the article is obtained by the compression of a metered quantity of plastic in the molten state between the two parts of a mould, comprising at least one supply of plastic, a rod, sliding in a sleeve suitable for temporarily supporting said metered quantity of plastic, a mould for the head of the article and a mandrel cooperating with said mould, the sleeve having an upper face and a lateral wall. The device according to the invention is characterized in that it includes means for depositing the metered quantity on the sleeve, which means are designed so that the amount of plastic lying above a plane coinciding with the upper face of the sleeve is between 20% and 40% of the total mass of the metered quantity.
[0011] Preferably, the ratio of the mass of plastic lying above the plane to the mass of plastic lying below the plane is approximately 30/70.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The invention will be better understood by the following description of an embodiment thereof and the accompanying figures, in which:
[0013] FIG. 1 shows the lower part of the mould, the die assembly;
[0014] FIG. 1 a shows a variant of the embodiment of FIG. 1 ;
[0015] FIG. 1 b shows a variant of the embodiment of FIG. 1 ;
[0016] FIG. 2 shows an open metering nozzle forming a metered quantity of plastic in the lower part of the mould;
[0017] FIG. 3 shows a closed metering nozzle and the metered quantity of material in position in the lower part of the mould;
[0018] FIG. 4 corresponds to FIG. 3 but with an orifice rod of small diameter;
[0019] FIG. 5 corresponds to FIG. 3 but with an orifice rod of large diameter;
[0020] FIG. 6 shows the mandrel and the die assembly at the start of the compression phase;
[0021] FIG. 7 shows the end of the compression phase; and
[0022] FIG. 8 illustrates the manner in which the metered quantity of material is deposited on the sleeve.
[0023] FIG. 1 shows the lower part of the mould, known as the die assembly, in the resting position, comprising a shoulder die 6 which is to form the external part of the head of the tube, a thread-forming die 7 in a plurality of parts to allow the demoulding of the threaded portion and, within the axis of symmetry of the device, a sleeve 8 able to be displaced in translation according to the axis A. The sleeve 8 comprises a first shoulder 8 a which limits its path between two stops 9 and 10 .
[0024] The die assembly also comprises an orifice rod 11 which is used to form the orifice of the shoulder. The orifice rod 11 comprises a shoulder 24 in its lower part and may slide in the sleeve 8 . The path of the orifice rod 11 is limited in the upper position by means of the shoulder 24 and by a stop 12 arranged on the sleeve. The path of the orifice rod 11 is also limited in the lower position by a pin 13 , for example of cylindrical shape, and by a stop 14 arranged on the sleeve 8 , the stop 14 being formed by the lower wall of an elongate hole 8 b in said sleeve 8 . The pin 13 is preferably placed, for example driven-in, perpendicularly into a hole in the rod 11 . This pin allows the relative displacement in the axial direction of the rod 11 and the sleeve 8 to be blocked in a straight-forward manner. This blocking is particularly important once the metered quantity of material has been deposited and the mandrel is in contact with the upper face of the rod, to form the shoulder. In the known systems using springs, in such a position, the rod was still able to be displaced, in particular under the effect of the material which is moulded by compression in this method and thus could give rise to faults, such as for example a blocked or deformed orifice or an orifice of diameter equivalent to the external diameter of the sleeve 8 .
[0025] FIG. 1A shows a variant of the device of FIG. 1 in which the shoulder 24 of the orifice rod 11 is dispensed with and the upper stop 23 is produced by the contact of the cylindrical pin 13 on the upper wall of the elongate hole 8 b . This variant has the advantage of a great simplicity of manufacture and implementation. By using a single pin for the two stops 14 , 23 , the construction of the device is simplified.
[0026] The relative displacements of the sleeve 8 and the orifice rod 11 are performed by an actuator (not shown) such as a spring or pneumatic cylinder acting on the orifice rod 11 .
[0027] In FIGS. 2 and 3 , the steps for depositing a metered quantity of molten plastic are shown. A metering nozzle 1 positioned above the die 6 and concentric to the sleeve 8 forms a metered quantity 3 of molten plastic. The metering nozzle 1 is supplied by an extruder (not illustrated) known in the prior art.
[0028] In FIG. 2 , the valve 2 executes a linear path generated by an actuator (not illustrated) which allows the formation of an annular metered quantity of material 3 through the passage 4 and the depositing thereof on the upper face 16 and the periphery 17 of the sleeve 8 .
[0029] In FIG. 3 , the actuator subsequently drives the valve 2 in the reverse direction which causes the closure of the outlet orifice 4 . The metered quantity of plastic is cut and released by blowing a gas through the passage 5 .
[0030] So that the metered quantity of plastic 3 is correctly deposited on the sleeve 8 as FIG. 3 illustrates, i.e. so that it is in contact with its upper face 16 and its periphery 17 , it is necessary to combine several conditions:
the distance between the upper face 15 of the orifice rod 11 and the upper face 16 of the sleeve 8 has to be slightly greater than the thickness of the corresponding wall of the moulded part (head of the tube); the valve 2 has to be very close or preferably has to come into contact with the surface 15 of the orifice rod 11 during the phase of opening the metering nozzle; and. the diameter of the valve 2 is chosen according to the diameter of the sleeve 8 . For example, for a sleeve with a diameter D 2 =14.5 mm, the diameter of the valve is D 1 =13 mm. The swelling of the material on leaving the metering nozzle allows the lower part of the metered quantity to pass onto the periphery of the sleeve over a distance of 13 mm and the valve has performed a travel of 7 mm ( FIG. 2 ). Upon closing the metering nozzle, the valve performs the reverse travel, the position of the material not changing relative to the sleeve 8 . The metered quantity of material is separated from the nozzle by a short jet of air so that the upper part of the metered quantity shrinks onto the upper face of the sleeve 8 ( FIG. 3 ). Finally, about 75% of the height of the metered quantity lies on the periphery of the sleeve and about 25% lies above the upper face of the latter, resulting in a mass distribution of the metered quantity of 20 to 40% lying above a plane 20 coinciding with the upper face of the sleeve and 80 to 60% lying beneath it, respectively.
[0034] In the case of this invention, the metered quantity of material is deposited on the sleeve 8 (on the upper face 16 and on the periphery 17 ). It is, therefore, perfectly centred and is not liable to be displaced during the movements of the tools. Moulding errors are eliminated. In addition, if, for the same diameter of tube, the diameter of the orifice varies, it is possible to maintain the same diameter of metering valve because the diameter of the sleeve 8 remains identical (see FIG. 4 small orifice (D 5 ), FIG. 5 large orifice (D 6 )). In factories for producing cosmetic tubes, it is usual that a production line produces a tube which is always of the same diameter but with frequent changes to the diameter of the orifice. The invention, therefore, makes it possible to gain time in the changing of tools as this avoids changing the diameter of the metering nozzle as well as further adjustments thereto. In addition, this allows the required range of diameters of metering nozzles to be reduced for the production of a range of tube diameters (for example if 6 different nozzles were necessary, the new method would only require 3 different diameters).
[0035] In the following step shown in FIG. 6 , the lower part of the mould, known as the die assembly and comprising the die 6 has left the metering nozzle 1 and a mandrel 18 is positioned above and centred relative thereto. The cylindrical body of the tube 19 is fitted in position on the mandrel 18 . The mandrel 18 is displaced towards the die 6 and comes into contact with the orifice rod 11 on its upper face 15 . It thus drives the assembly of the orifice rod 11 and the sleeve 8 until said sleeve bears against the stop 10 (see FIG. 7 ). During this displacement, the cylindrical pin 13 may come into contact with the lower stop 14 which guarantees that the lower face of the mandrel 18 never comes into contact with the face 16 of the sleeve 8 . At the end of the displacement, the shoulder 8 a of the sleeve 8 comes into contact with the stop 10 . The upper face 15 of the orifice rod 11 always remains in contact with the mandrel 18 and the pin 13 is not in contact with the stop 14 . This configuration has the advantage of easily forming the orifice of the tube around the orifice rod 11 . The metered quantity of plastic 3 is progressively deformed until it fills the cavity formed by the die assembly and the mandrel 18 and is welded to the end of the body of the tube 19 . The assembly remains under pressure during the cooling phase.
[0036] FIG. 8 shows the same device and the same configuration as the device and the configuration illustrated in FIG. 3 , and it differs solely therefrom in the manner in which the metered quantity of material 3 deposited on the sleeve 8 is illustrated.
[0037] The plastic forming the metered quantity of material 3 is located both on the upper face 16 and the lateral wall 17 of the sleeve 8 .
[0038] The metered quantity of plastic deposited along or in the extension of the lateral wall 17 of the sleeve 8 is much greater than the metered quantity of plastic deposited above the upper face 16 of the sleeve 8 .
[0039] However, the presence of plastic above the upper face 16 of the sleeve 8 has several advantages, in particular the fact of efficiently retaining the metered quantity of material 3 in a specific position. The risk of premature falling of the metered quantity of material 3 along the sleeve 8 is thus eliminated. It will be revealed here that this risk is present in the device disclosed in German patent application DE 103 49 837, as in this case, the entire metered quantity of material is located on the lateral wall of the sleeve.
[0040] Surprisingly, it has been observed that the quality of moulded articles was improved if the plastic was distributed in a specific manner between the areas which are respectively located above and below a plane 20 coinciding with the upper face of the sleeve 8 . More specifically, the quality of the moulded articles is improved if the metered quantity of plastic 22 lying above the plane 20 represents between 20 and 40% of the total mass of the metered quantity of material 3 and if the metered quantity of plastic 21 lying below the plane 20 respectively represents between 80 and 60% of the total mass of the metered quantity of material 3 . Preferably, the upper mass/lower mass ratio is approximately 30/70.
[0041] It goes without saying that the invention is not limited to the examples shown above.
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The invention relates to a device for moulding a plastic article in which the article is obtained by the compression of a metered quantity of plastic ( 3 ) in the molten state between the two parts of a mould, comprising at least one supply of plastic ( 1 ), a rod ( 11 ), sliding in a sleeve ( 8 ) suitable for temporarily supporting said metered quantity of plastic ( 3 ), a mould for the head of the article ( 6, 7 ) and a mandrel ( 18 ) cooperating with said mould ( 6, 7 ), the sleeve ( 8 ) having an upper face ( 16 ) and a lateral wall ( 17 ), the device being characterized in that it includes means for depositing the metered quantity on the sleeve ( 1, 2 ), which means are designed so that the amount of plastic ( 22 ) lying above a plane ( 20 ) coinciding with the upper face ( 16 ) of the sleeve ( 8 ) is between 20% and 40% of the total mass of the metered quantity ( 3 ). The invention also relates to a method using the aforementioned device.
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TECHNICAL FIELD
This invention relates generally to improvements in commercial printing systems and more particularly to a system for removing contaminants from and thereby extending the life of fountain solutions utilized in commercial printing plants.
BACKGROUND AND SUMMARY OF THE INVENTION
A typical offset lithographic printing press has a plate cylinder upon which the negative of the text and illustrations to be printed are etched by a photographic and/or an electronic process. Dampening rollers apply a fountain solution to the plate cylinder which adheres to the plate cylinder except in the areas in which the text and illustrations are located.
Next, a series of form rollers, also known in the art as inking rollers, apply a layer of ink to the plate cylinder. The ink adheres to the plate cylinder only in the etched areas comprising the text and illustrations.
The plate cylinder then presses the inked text and illustrations onto a rubber blanket cylinder. An impression cylinder then presses a sheet of paper or other substrate to be printed against the blanket cylinder as the paper or other substrate passes between the blanket cylinder and the impression cylinder. The inked text and illustrations on the blanket cylinder are transferred onto the paper or other substrate to effect printing thereof.
Over time, ink, paper fiber, spray powder, and other contaminants build up in the fountain solution. These contaminants negatively impact print quality. Additionally, as the fountain solution degrades water, adjustments are required. Eventually the fountain solution becomes so contaminated that it needs to be replaced. The present invention comprises a system for minimizing fountain solution contamination thereby extending the useful life of the fountain solution by a substantial period of time.
The fountain solution recycling system of the present invention utilizes a unique multi-stage separation technology and a recirculation pump to clean and restore the fountain solution. Removal of contaminants is achieved by processing the solution through three separate treatment stages resulting in a reusable, stabilized fountain solution. Components of the fountain solution which are consumed due to carry-off by the printing substrate and evaporation are replaced in the conventional manner.
Use of the fountain solution recycling system of the present invention easily and reliably reduces costs and improves productivity in an aspect of the commercial printing business that has traditionally been neglected. Simply extending the life of the fountain solution typically adds 1-2 hours of productivity per week per printing press because changing the fountain solution and cleaning the system are no longer required.
Additionally, by extending the life of the fountain solution waste, disposal costs associated with fountain solution replacement are dramatically reduced. In those instances in which spent fountain solution is drained, use of the present invention greatly reduces the copper, zinc, ink, glycols, phosphates and suspended solids going into the drain thereby lessening the impact on the environment.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be had by reference to the following Detailed Description when taken in connection with the accompanying Drawings, wherein:
FIG. 1 is a perspective view of a fountain solution recycling system for commercial printers incorporating the invention; and
FIG. 2 is a schematic illustration of the fountain solution recycling system of FIG. 1 and the interaction thereof with a commercial printing press.
DETAILED DESCRIPTION
Referring now to the Drawings, and particularly to FIG. 1 thereof, there is shown a fountain solution recycling system 10 incorporating the present invention. The system 10 includes a pump 12 which receives fountain solution from a commercial printing press through a line 14 . The output of the pump 12 is directed to a sediment prefilter 16 through a line 18 . The sediment prefilter 16 comprises a housing 20 which contains a strainer or filter formed from melt blown polypropylene and having a consistency generally similar to that of a fibrous web. The function of the sediment prefilter 16 is to remove relatively large particles from the flowing fountain solution.
From the sediment prefilter 16 the fountain solution is directed to a separation cartridge 22 through a line 24 . The separation cartridge 22 comprises a housing which contains a diatomaceous earth filter and functions to remove sub-micron sized particles from the flowing fountain solution. Thus, having passed through the sediment prefilter 16 and the separation cartridge 22 the fountain solution is substantially free of particulate and colloidal contaminants.
From the separation cartridge 22 the fountain solution is directed to a post treatment cartridge 26 through a line 28 . The post treatment cartridge 26 comprises a housing which contains a natural zeolite filter material which removes copper ions, zinc ions, and other ions from the flowing fountain solution thereby substantially removing metal ion contaminants from the fountain solution. After flowing through the post treatment cartridge 26 the fountain solution is returned to the dampener recirculating device of the commercial pressing press through a line 30 .
The sediment prefilter 16 , the separation cartridge 22 , and the post treatment cartridge 26 comprise a three stage treatment system in which each stage has a symbiotic relationship with the former stage. The use of the combined system comprising the prefilter 16 , the separation cartridge 22 , and the post treatment cartridge 26 affords two highly beneficial results. First, the use of the combined system substantially extends the life of fountain solution flowing therethrough. Second, the combined system renders the fountain solution much more environmentally friendly upon ultimately disposal.
FIG. 2 illustrates the use of the fountain solution recycling system 10 in conjunction with a commercial printing press 32 . A recirculation pump 34 withdraws fountain solution from a fountain solution recirculation tank 36 and directs the fountain solution to one or more printing press dampener pans 38 as indicated by the arrows 40 and 42 . From the printing press dampener pans 38 the fountain solution is applied to dampening rollers which in turn apply the fountain solution to the plate cylinder of the printing press 32 . In the operation of the printing press 32 fountain solution is continuously withdrawn from the printing press dampener pans 38 and returned to the tank 36 as indicated by the arrows 44 and 46 .
The fountain solution recycling system 10 of the present invention withdraws fountain solution from the tank 36 through the line 14 and returns the fountain solution to the tank 36 through the line 30 . Thus, the system 10 of the present invention functions to maintain the fountain solution within the tank 36 in a substantially clean condition characterized both by a lack of particulate contamination and a reduction of metal ion contamination.
As is best shown in FIG. 1 , the components of the fountain solution recycling system of the present invention may be mounted on a pallet. By mounting all of the components of the system on a pallet, installation of the system at a convenient location within a commercial printing plant is readily accomplished. All that remains to be done is the connection of the lines 14 and 30 to one or more printing presses within the plant, whereupon operation of the system can be commenced.
EXAMPLE
A typical eight-color 40″ 0 printing press requires the disposal of about 40 gallons of fountain solution per week, or about 2100 gallons per year. 2100 gallons equals about 40 barrels of spent fountain solution that must be disposed of annually. At a typical disposal cost of about $250/barrel the annual fountain solution disposal cost is about $10,000 per year per printing press. Conversely, when the present invention is used the annual fountain solution disposal requirement is about 2 barrels or about $500 per year per press. Elimination of press downtime for fountain solution change out is another benefit resulting from the use of the present invention. At just one hour of eliminated downtime per week the use of the present invention saves over $15,000 per year per press. When down time savings are combined with disposal cost savings use of the present invention results in about $25,000 in annual savings per press.
Although preferred embodiments of the invention have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions of parts and elements without departing from the spirit of the invention.
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A method of and apparatus for extending the life of fountain solutions used in commercial printing presses comprises withdrawing fountain solution from the dampener recirculation system of a printing press and directing the withdrawn fountain solution through a sediment prefilter, a separation filter, and a posttreatment filter. The sediment prefilter preferably comprises a melt blown polypropylene filter; the separation filter preferably comprises a diatomaceous earth filter; and the post-treatment filter preferably comprises a zeolite filter.
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FIELD OF THE INVENTION
This invention relates to capillary electrophoresis instruments and, more particularly, to an improved system for controlling electroosmotic flow velocities in the capillary of a capillary electrophoresis instrument.
BACKGROUND OF THE INVENTION
This patent application is related to U.S. patent application Ser. No. 08/077,214, filed on even date and having a common title herewith.
Zone electrophoresis in capillaries is widely used to accomplish liquid-phase separations of various solutes. Capillary electrophoresis has been used for separation of small and large molecules, various amino acids, alkylamines and various proteins. In brief, a zone capillary electrophoresis device includes a buffer filled capillary tube that is placed between two buffer reservoirs. A potential field is applied across the length of the capillary tube and ionic solutes in one buffer reservoir then differentially migrate through the capillary into the other reservoir. Small diameter silica based tubes are employed as the capillaries in capillary zone electrophoresis (CZE) instruments.
A distinguishing property of flow through a capillary is electroosmotic flow. Immediately adjacent to the solid-liquid interface at the interior of the silica-based capillary wall, a stagnant double layer of solute/solvent is found. Under normal aqueous conditions, the silica capillary wall surface has an excess of charge resulting from an ionization of surface functional groups. Thus, SiOH groups are ionized leaving SiO - at the wall surface and H + ions in the solution and in the stagnant double layer adjacent to the capillary wall. This action creates a potential across the layers which is termed the zeta potential. The zeta potential is dependent upon the viscosity of the fluid, the dielectric constant of the solution and the coefficient of electroosmotic flow of the solution. The cationic counter ions (H + ) in the diffuse solvent/solute layer migrate towards the cathode and because these ions are solvated, they drag solvent with them. The extent of the potential drop across the double layer governs the rate of flow. It is known that control of electroosmotic flow is effective in improving electrophoretic resolution and efficiency and is a controlling factor in obtaining reproducible results in CZE apparatus.
The prior art evidences a number of ways to alter electroosmotic flow. Hjerten indicates that inner surfaces of a capillary can be derivatized by coating them with a mono-molecular layer of non-cross-linked polyacrylamide. This coating encourages the osmotic effect and discourages adsorption of solutes onto the inside of the capillary. See "High Performance Electrophoresis, Elimination of Electroendosmosis and Solute Adsorption", Hjerten, Journal of Chromatography, 347 (1985), pp. 191-198. Others have taught that electroosmotic flow may be altered by altering the buffer pH, the concentration of the buffer, the addition of surface-active species such as surfactants, glycerol, etc. or various organic modifiers to the buffer solution.
For additional details regarding capillary electrophoresis instrumentation and methods of control of electrophoretic separation, the following papers provide a useful oversight of the field: "Capillary Electrophoresis", Ewing et al., Analytical Chemistry, 1989, Volume 61, 292A and "Capillary Electrophoresis", Kuhr, Analytical Chemistry, 1990, Volume 62, 403R-414R.
Independent control of electroosmotic flow (i.e., not related to changes in the buffer or inner capillary structures) have been accomplished by application of external electric fields. As indicated above, it is known that separation resolution can be enhanced and protein adsorption prevented by dynamically controlling the polarity and magnitude of the zeta potential at the boundary between the aqueous fluid and the capillary wall. Lee et al. in "Direct Control of the Electroosmosis in Capillary Zone Electrophoresis by Using an External Electric Field", Analytical Chemistry, 1990, Volume 62, pp. 1550-1552, employ an additional electric field from outside the capillary to enable external control of the zeta potential. Lee et al. mounted a capillary tube inside another tube, filled the annular space therebetween with a potassium phosphate buffer and applied high voltage across the annular space to achieve an electric field along the entire length of the capillary. A pump was used to provide fluid flow of the potassium phosphate buffer to enhance transfer of the heat created by current flow through the buffer. It was determined that by varying the electric field, changes in both the direction and flow rate of electroosmosis in the inner capillary could be achieved. In U.S. Pat. No. 5,151,164, to Blanchard and Lee, the concepts disclosed in the aforementioned Lee et al. article are expanded to include a non-aqueous conductive member surrounding capillary along its entire length.
Hayes et al., "Analytical Chem.", Vol. 64, (1992) pp. 512-516, have achieved a similar control of electroosmotic flow by the application of a radial voltage field about the length of the capillary, but avoided the necessity for an annular fluid flow region as taught by Lee et al. Hayes et al. coated the exterior surface of a capillary with a flexible conductive polymer sheath and then applied a voltage thereacross to achieve a radial field effect within the capillary. Both Hayes et al. and Lee et al. teach the control of electroosmotic flow via an applied radial voltage field and depend upon an application of a radial voltage to all or nearly all of the length of the electrophoresis capillary. Furthermore, all employ a current flow in the material surrounding the capillary to achieve the radial electric field. Such current flows create additional Joule heating within the capillary which adds to the Joule heating that occurs as a result of current flow through the buffer (caused by the voltage applied across the capillary to achieve electrophoretic flow). As is also apparent from the prior art, all flow control fields taught in the prior art were of the electrodynamic variety wherein the fields were created by a current flow in a conductive media adjacent the capillary.
Accordingly, it is an object of this invention to provide an improved system for controlling electroosmotic flow in CZE apparatus.
It is another object of this invention to provide an electroosmosis control structure for a CZE apparatus which is readily manufacturable.
It is yet another object of this invention to provide an electroosmotic flow control system for CZE apparatus which avoids creation of unnecessary Joule heating of the capillary.
SUMMARY OF THE INVENTION
An electrophoretic separation apparatus includes a capillary tube having a length, a cross section, an inlet and an outlet. A first reservoir containing a solvent and, during injection, a solute is in fluid-flow communication with the inlet and a second reservoir containing at least a solvent is also in fluid flow communication with the outlet, the capillary thereby being filled at least with the solvent. A first power supply applies a separation potential between the first and second reservoirs and along the length of the capillary to thereby establish an electrophoretic flow of the solute therethrough. An electrically isolated plate is juxtaposed to an external surface of the capillary tube and is connected to a second power supply. An electrostatic field is thereby applied across the cross section of the capillary tube to control the electroosmotic flow therein. The electrical isolation of the plate prevents current flow between the power supply and the plate. The plate achieves effective electroosmotic flow control even though it extends only over a small portion of the length of the capillary tube.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of a CZE separation apparatus with a capillary coated with conducting silver paint that is connected to an externally applied potential.
FIG. 2 is a schematic drawing of a CZE separation apparatus with a metal plate covering a small segment of the center of the capillary.
FIG. 3 plots absorption versus time to determine a migration peak for a neutral solute (phenol) obtained without control of electroosmotic flow.
FIG. 4 is a plot of absorption versus time to obtain a migration peak for neutral solute (phenol) obtained with control of electroosmotic flow using an external potential field applied to a capillary coated with an encircling region of conductive paint such as shown in FIG. 1.
FIG. 5 is a plot of adsorbents versus time to determine a migration peak for a neutral solute (phenol) obtained without control of electroosmotic flow.
FIG. 6 is a plot of absorption versus time to determine a migration peak for a neutral solute (phenol) obtained with control of electroosmotic flow using an external potential field applied to a conductive plate adjacent the capillary, such as is shown in FIG. 2.
FIG. 7 is plot showing variation in migration rates for a neutral solute (histidyl-phenylalanine) versus percent coverage by the conductive sheath and comparing experimental data to two theoretical predictions.
FIG. 8 is an equivalent circuit for the electroosmotic flow control apparatus shown in FIGS. 1 and 2.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. a schematic drawing of a CZE apparatus is shown that includes a capillary 10 and first and second reservoirs 12 and 14. Reservoirs 12 and 14 are each filled with a solvent. Reservoir 12 also temporarily contains an injected solute that is to be separated by electrophoretic action. Within reservoir 12 is an electrode 16 that is connected to a power supply 18. Reservoir 14 has a similar electrode 20 that is connected to a source of reference potential 22.
Separation within capillary 10 is detected by changes in light absorption across capillary tube 10. Those changes are detected by detector 24 that determines variations in the luminance of a light beam 26 emanating from a light source 28. The structure described to this point is conventional and is well known to those skilled in the art of CZE.
In contrast to the prior art, this invention controls electroosmotic flow through capillary 10 by application of a large voltage to a relatively small length, non-grounded conductor along the outside of capillary 10. In brief, the electrically isolated (i.e., non-grounded) nature of the conductor enables creation of an electrostatic field across the capillary while preventing current flow in the conductor that could create Joule heating. Such electroosmotic flow control is achieved in one embodiment of the invention by applying a small annulus 30 of a metallic paint (or other conductive coating) about the external circumference of capillary 10. A power supply 32 is connected to annulus 30 and causes the creation of an electrostatic potential across the cross section of capillary 10.
As will become hereinafter apparent, it has been determined that the length 1 of conductive annulus 30 can vary between wide limits (e.g., from approximately 5% to more than 60% of the length of capillary 10) without significantly affecting the ability to control electroosmotic flow through capillary 10. As a result, it has been found that the length 1 of annulus 30 can be made very short with respect to the overall length L of capillary 10, while still enabling control of the electroosmotic flow therethrough.
Referring to FIG. 2, a substantially identical CZE apparatus is shown except that annulus 3 has been replaced by a flat plate 40 that contacts only a small portion of the circumference of capillary 10. The length of plate 40 can be similarly proportioned to the overall length of capillary 10 as is the proportion of annulus 30 to capillary 10 in FIG. 1, and still effectively control electroosmotic flow through capillary 10.
In both FIGS. 1 and 2, power supply 32 is indicated as applying a control potential to annulus 30 and plate 40, respectively. The control potential has the effect of controlling (e.g., speeding up) flow of solute through capillary 10, thereby enabling a substantial increase in the speed of separation. By altering the control potential, the electrophoretic action can be speeded up, stopped or reversed For instance, when the control potential is at a high negative value, electrophoretic action is substantially accelerated. As will become apparent from the detailed experimental description below, the electroosmotic control apparatus shown in FIG. 1 (power supply 32 and conductive annulus 30) reduces separation time by almost 50% when compared to a system without electroosmotic flow control. The structure shown in FIG. 2 enables a decrease in separation time of approximately 30% when compared to a system without electroosmotic flow control.
EXPERIMENTAL
The separation capillary is a 20 um i.d., 144 um o.d. fused silica microcolumn with a length of 52.5 cm for silverpaint coating experiments and 50 um i.d., 370 um o.d. with a length of 57 cm for the experiments with a stainless steel plate (Polymicro Technologies, Phoenix, Arizona). Reversible high voltage power supplies (Spellman, Plainview, NY) were used to apply the voltages across the capillary and to the conductors outside the capillary.
Voltages applied to the inlet of the capillary ranged from 0 to 30 kV with the outlet of the separation capillary at ground potential. Voltages applied to the conductor outside the model of the capillary ranged from 0 to ±20 kV.
Capillary 10 is liquid-filled with electrolyte and terminates just after passing through a Linear 200 absorbance detector (Linear Instruments, Reno, NE). All aspects of this experiment are common to capillary electrophoresis experiments with the exception that this apparatus allows the application of a high potential to a conductor along a relatively short outer segment of capillary 10.
Apparatus.
The system used two plexiglas interlock boxes to house the high potential field portions of the capillary. The high potential lead for the separation potential and the injection end of the polyimide-coated fused silica capillary were enclosed in the first box. The second box contained the portion of the capillary coated with conducting silver paint or a conducting plate.
An ultraviolet detector (Linear 200, Reno, NE) was installed on-line. Approximately 6 cm from one end of the capillary a 1-cm section of the polyimide coating was removed by heat as a UV detection window. Data was collected at a wavelength of 200 nm.
Chemicals.
Solutions were made from NaH 2 PO 4 (Sigma Chemical, St. Louis, MO) and adjusted to the desired pH with H 3 PC 4 (Baker Chemical, Phillipsburg, NJ) or NaOH. Histidyl phenylalanine (Sigma Chemical Co.) was used as a probe molecule.
RESULTS
The effect of a radial voltage in capillary electrophoresis across the capillary wall on eleotroosmotic flow created by a conductive sheath covering only a small portion of the capillary has been examined. These experiments have been related to the double layer and surface conductivity inside the capillary.
Electroosmotic flow can be altered by chemical modification of the capillary wall and by adjustment of buffer pH. Electroosmotic flow can also be controlled electronically by the application of a radial voltage field. The prior art teaches the application of a radial voltage field over a majority of the length of the capillary. The theory developed by the prior art has assumed that the radial voltage effects the flow only in those portions of the capillary covered by the sheath providing the radial voltage field. In the experiments presented here, a relatively small portion of the outside center of the capillary is covered with a conductive silver paint (or a metal plate) and attached to a 0-30 kV power supply. Using this configuration, it has been found that electroosmotic flow may be controlled to a similar extent as with the prior art systems. The results apparently defy previous theories on the electronic and molecular mechanism of electroosmotic flow control. Theory and experiments are presented, however, to suggest that surface conductance along the inside surface of the capillary leads to a double layer potential that is distributed over sections of the capillary outside the area of direct radial voltage coverage. Thus, an applied radial voltage over a small portion of the capillary (at substantially any point along its length) has been found sufficient to effectively control electroosmotic flow.
The radial voltage field created by a conductive sheath effects the zeta (ζ) potential on the inner surface of the capillary. This ζ potential is related to electroosmotic flow (υ eo ) by υ eo ζD o E app /η o , where D o is the permittivity of the solution, η o is the viscosity of the solution and E app is the separation potential field. Various lengths of the center portion of the capillary have been coated, followed by experimental evaluation of the electroosmotic flow.
Under the experimental conditions, according to current theory, a zone of high flow rate at the inner wall along this coated region would be generated, effectively forming a pump in the middle of the capillary. Application of the prior art model leads to a prediction of varied flow rates along the capillary when electroosmotic flow is increased (or decreased) in the region of the applied radial voltage. The slower (or faster) moving buffer in unsheathed portions of the capillary is expected to lessen the effectiveness of the radial voltage control. In such a model, the bulk flow across the capillary is the weighted average of the sheathed and unsheathed flow zones. This results(in the following relationship (Chien, Helmer, Anal. Chem. 63 (1991) 1354-1361):
υ.sub.b =xυ.sub.s +(1-x) υ.sub.us, (1)
where υ b the bulk electroosmotic flow, x is the portion of the capillary covered by the sheath, υ s is the flow with 100% sheath coverage and υ us is the flow without any sheath.
The change in electroosmotic flow rate has been evaluated by examining the elution time of a neutral solute from the capillary as a function of the potential applied to the conductor in contact with the capillary. FIGS. 3-6 show eluting peaks compared for applied voltages at a capillary coated with conducting silver paint (FIG. 4) and a capillary in contact with a metal plate (FIG. 6), respectively. Those results show that an externally applied potential to only a relatively small portion of the capillary can effectively control electroosmotic flow (as compared to non controlled flows (i.e., see FIGS. 3 and 5). The effect of contacting different fractions of the capillary on the ability to control electroosmotic flow have also been examined.
Data for these experiments are plotted and compared to theory in FIG. 7. The experimental data () is compared to predictions derived from the literature and summarized in equation 1 (). In this experiment, the effect of electroosmotic flow generated in the unsheathed portions of the capillary on the overall flow is significantly smaller than that predicted by the original theory, both in magnitude and slope of the resulting plot.
An explanation for the deviation from accepted theory is that the charge induced by the radial voltage in only a small percent of the capillary is dispersed over the entire double layer on the inner surface of the capillary. Thus, the ζ potential varies less than predicted between sheathed and unsheathed regions.
Modification of existing theory to include a surface resistance (or conductance) can account for this new experimental evidence. This new model (FIG. 8) accounts for the separation potential, bulk buffer resistance, outer sheath potential, and the fused silica capacitance with the addition of a resistor along the inner surface, Rs, and the realization that the potential generated by the ionized silanol groups occurs at all points along the capillary. This modification to the theory may be quantitated. A surface conductance (Rs) along the double layer interface has been documented (Sheludko, Colloid Chemistry, Elsevier, Amsterdam, 1966; Overbeek, In "Colloid Science", Vol. 1, Kruyt, Ed., Elsevier, Amsterdam, 1952, pp. 197-237) and has been estimated at the glass/water interface to be 10 12 -10 13 Ω/m. In addition, the potential caused by the ionization of the surface silanol groups, may be calculated and is a complex function of buffer pH and other physical properties of the buffer/inner surface interface (e.g. Hayes, Ewing Anal. Chem. 64 (1992) 512-516). The model indioates that the additional surface charge from the radial voltage is effectively spread along the inner surface of the capillary through R s and directly effects the ζ potential over the entire capillary length. This effect can be quantitated by assuming the ζ potential forms a linear gradient through R s from ζ s (100% sheathed, υ s s) in the center to ζ us (unsheathed, υ us ) at the ends, across the unsheathed portions of the capillary. In the sheathed sections, the potential is equal to ζ s . Since the flow is directly proportional to ζ, the average flow, υ ave , in the unsheathed sections is (υ s +υ us )/2. this average velocity may be substituted into equation 1 to give a new relationship for the fraction of capillary covered by the conducting sheath, x, versus bulk electroosmotic flow, υ b ;
υb=xυ.sub.s +(1-x)υ.sub.ave (2)
The plot of equation 2 in FIG. 7 (∇) more closely reflects the experimental values than the plot of equation 1(). In fact, the slope of the experimental data is even smaller than that predicted by theory, even accounting for conductance along the inner surface of the capillary. The data make a strong case for a spreading of the ζ potential along the inner wall of the capillary.
The design for electronic control of electroosmotic flow in a capillary electrophoresis system requires application of only a small section of silver paint (or a conductive plate) to the outside surface of the capillary and only one power supply. It has been found with silica capillaries that have uncoated internal surfaces, that the buffer should preferably have a pH in the acidic range. If the buffer is basic, control of electroosmotic flow is difficult. However, by applying a non-absorptive coating on the capillary's interior, a higher pH buffer is usable. Such a coating may be dextran, polyimides, polyethylene glycols, etc.
It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.
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An electrophoretic separation apparatus includes a capillary tube having a length, a cross section, an inlet and an outlet. A first reservoir containing a solvent and, upon injection, a solute is in fluid-flow communication with the inlet and a second reservoir containing at least a solvent is also in fluid flow communication with the outlet, the capillary thereby being filled at least with the solvent. A first power supply means applies a separation potential between the first and second reservoirs and along the length of the capillary to thereby establish an electrophoretic flow of the solute therethrough. An electrically isolated plate is juxtaposed to an external surface of the capillary tube and is connected to a second power supply. An electrostatic field is thereby applied across the cross section of the capillary tube to control the electroosmotic flow therein. The electrical isolation of the plate prevents current flow between the power supply and the plate. The plate achieves effective electroosmotic flow control even though it extends only over a small portion of the length of the capillary tube.
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RELATED APPLICATIONS
[0001] This application is a divisional of, claims the benefit of and priority to U.S. Non-Provisional application Ser. No. 13/811,151, titled, “A Safety Mechanism For A Well, A Well Comprising The Safety Mechanism, And Related Methods,” filed Feb. 26, 2013, which is a National Stage Entry of PCT Application No. PCT/GB2011/051377, titled, “A Safety Mechanism For A Well, A Well Comprising The Safety Mechanism, And Related Methods,” filed Jul. 20, 2011, which is a PCT Application of GB 1012175.4, titled, “A Well comprising a Safety Mechanism and Sensors,” filed Jul. 20, 2010 each of which is incorporated herein by reference in its entirety.
FIELD
[0002] This invention relates to a safety mechanism, such as a valve, sleeve, packer or plug, for a well; a well comprising the safety mechanism; and methods to improve the safety of wells; particularly but not exclusively subsea hydrocarbon wells.
BACKGROUND
[0003] In recent years, oil and gas has been recovered from subsea wells in very deep water, of the order of over 1 km. This poses many technical problems in drilling, securing, extracting and abandoning wells in such depths.
[0004] In the event of a failure in the integrity of the well, wellhead apparatus control systems are known to shut the well off to prevent dangerous blow-out, or significant hydrocarbon loss from the well. Blow-out-preventers (BOPs) are situated at the top of subsea wells, at the seabed, and can be activated from a control room to shut the well, or may be adapted to detect a blow-out and shut automatically. Should this fail, a remotely operated vehicle (ROV) can directly activate the BOP at the seabed to shut the well.
[0005] In a completed well, rather than a BOP, a “Christmas” tree is provided at the top of the well and a subsurface safety valve (SSV) is normally added, “downhole” in the well. The SSV is normally activated to close and shut the well if it loses communication with the controlling platform, rig or vessel.
[0006] Despite these known safety controls, accidents still occur and a recent example is the disastrous blow-out from such a subsea well in the Gulf of Mexico, causing a massive explosion resulting in loss of life, loss of the rig and a significant and sustained escape of oil into the Gulf of Mexico, threatening wildlife and marine industries.
[0007] Whilst the specific causes of the disaster are, at present, unclear, some aspects can be observed: an Emergency Dis-connect System (EDS) controlled from the rig failed to seal and disconnect the vessel from the well; a dead-man/AMF system at the seabed failed to seal the well; subsequent Remotely Operated Vehicle (ROV) intervention also failed to activate the safety mechanisms on the BOP. Clearly the conventional systems focused primarily on the blow-out-preventer did not activate at the time of the blow-out and also failed to stem the tide of oil into the sea after control communication was lost with the rig.
SUMMARY
[0008] Thus there is a need to improve the safety of oil wells especially those situated in deep water regions.
[0009] Given the difficulty in communicating and controlling downhole tools (that is tools in the well), especially where communications are severed, one might consider the provision of a further shut off mechanism with the BOP situated at the seabed. However the inventors of the present invention have noted that the addition of more equipment at this point will be extremely difficult because it will increase the size and height of the components placed at this point, which immediately prior to installation, will be difficult for rigs to accommodate. Moreover, whilst this would add a further protective measure, it is largely the same concept as the existing safety systems. Indeed, increasing the complexity of the control systems to support these additional features may potentially have a detrimental impact on reliability of the over-all system rather than increasing the level of safety provided.
[0010] In the case of adding a further conventional control mechanism for devices, such as a valve, or sensor downhole; the inventors of the present invention also note limitations since, in the event of a blow-out, the ability to function these devices may be lost due to the inability to fluctuate pressure to control pressure activated devices, or due to the loss of control lines.
[0011] Thus it is difficult for a skilled person to design a further safety system which can practically add to the safety systems already provided in oil wells.
[0012] An object of the present invention is to mitigate problems with the prior art, and preferably to improve the safety of wells.
[0013] According to a first aspect of the present invention there is provided a safety mechanism comprising:
[0000] an obstructing member moveable between, normally from, a first position where fluid flow is permitted, and, normally to, a second position where fluid flow is restricted;
a movement mechanism;
and a wireless receiver normally a transceiver, adapted to receive, and normally transmit, a wireless signal;
wherein the movement mechanism is operable to move the obstructing member from one of the first and second positions to the other of the first and second positions in response to a change in the signal being received by the wireless transceiver.
[0014] The obstructing member can in certain embodiments therefore start at either the first or second positions.
[0015] The transceiver, where it provided, is normally a single device with a receiver functionality and a transmitter functionality; but in principle a separate receiver and a separate transmitter device may be provided. These are nonetheless considered to be a transceiver as described herein when they are provided together at one location.
[0016] Relays and repeaters may be provided to facilitate transmission of the wireless signals from one location to another.
[0017] The invention also provides a well comprising at least one safety mechanism according to the first aspect of the invention.
[0018] Typically the well has a wellhead.
[0019] Thus the present invention provides a significant benefit in that it can move, normally shut, an obstructing member, such as a valve, packer, sleeve or plug in response to a wireless signal. Significantly this is independent of the provision of control lines, such as hydraulic or electric lines, between a well and a wellhead apparatus, for example the BOP. Thus in the event of a disastrous blowout or explosion, a wireless signal can be sent to the valve merely by contacting the wellhead apparatus typically at the top of the well with a wireless transmitter, which will send the appropriate signal. For certain embodiments the wireless transmitter may be mounted onto the wellhead apparatus. Indeed this can be achieved even if the wellhead apparatus has suffered extensive damage, and/or the hydraulic, electric and other control lines have been damaged and the conventional safety systems have lost all functionality, since the wireless signal requires no intact control lines in order to shut off the valve. Thus this removes the present dependence on a functioning BOP/wellhead apparatus to prevent the egress of oil, gas or other well fluids into the sea.
[0020] In certain embodiments the transmitter may be provided as part of a wellhead apparatus.
[0021] Wellhead apparatus as used herein includes but is not limited to a wellhead, tubing and/or casing hanger, a BOP, wireline/coiled tubing lubricator, guide base, well tree, tree frame, well cap, dust cap and/or well canopy.
[0022] Typically the wellhead provides a sealing interface at the top of the borehole. Typically any piece of equipment or apparatus at or up to 20-30 m above the wellhead can be considered for the present purposes as wellhead apparatus.
[0023] Said “change in the signal” can be a different signal received, or may be receiving the control signal where no control signal was previously received and may also be loss of a signal where one was previously received. Thus in the latter case the safety mechanism may be adapted to operate when wireless communication is lost which may occur as a consequence of an emergency situation, rather than necessarily requiring a control signal positively sent to operate the safety mechanism.
[0024] Indeed the invention more generally provides a transceiver configured to activate and send signals after an emergency situation has occurred as defined herein.
[0025] In preferred embodiments the transceiver is an acoustic transceiver and the control signal is an acoustic control signal. In alternative embodiments, the transceiver may be an electromagnetic transceiver, and the signal an electromagnetic signal. Combinations may be provided—for example part of the distance may be travelled by an acoustic signal, part by an electromagnetic signal, part by an electric cable, and/or part from a fiber optic cable; all with transceivers as necessary.
[0026] The acoustic signals may be sent through elongate members or through well fluid, or a combination of both. To send acoustic signals through the fluid, a pressure pulser or mud pulser may be used.
[0027] Preferably the obstructing member moves from the first to the second position.
[0028] Preferably the safety mechanism incorporates a battery.
[0029] The safety mechanism is typically deployed subsea.
[0030] The transceiver comprises a transmitter and a receiver. The provision of a transmitter allows signals to be sent from the safety mechanism to a controller, such as acknowledgement of a control signal or confirmation of activation.
[0031] The safety mechanism may be provided on a drill string, completion string, casing string or any other elongate member or on a sub-assembly within a cased or uncased section of the well. The safety mechanism may be used in the same wells as a BOP or a wellhead, tree, or well-cap and may be provided in addition to a conventional subsurface safety valve.
[0032] Typically a plurality of safety mechanisms are provided.
[0033] The transceiver may be spaced apart from the movement mechanism and connected by conventional means such as hydraulic line or electric cable. This allows the wireless signal to be transmitted over a smaller distance. For example the wireless signal can be transmitted from the wellhead apparatus to a transceiver up to 100 m, sometimes less than 50 m, or less than 20 m below the top of the well which is connected though hydraulics or electric cabling to the obstructing member. This allows the safety mechanism in accordance with the present invention to operate even when the wellhead, wellhead apparatus or the top 100 m, 50 m or 20 m of the well is damaged and control lines therein broken. Thus the benefits of embodiments can be focused on a particular areas. Accordingly embodiments of the present invention can be combined with fluid and/or electric control systems.
[0034] Preferably a sensor is provided to detect a parameter in the well, preferably in the vicinity of the safety mechanism.
[0035] Thus such sensors can provide important information on the environment in all parts of the well especially around the safety mechanism and the data from the sensors may provide information to an operator of an emergency situation that may be occurring or about to occur and may need intervention to mitigate the emergency situation.
[0036] Preferably the information is retrieved wirelessly, although other means, such as data cables, may be used. Preferably therefore the safety mechanism comprises a wireless transmitter, and more preferably a wireless transceiver.
[0037] The sensors may sense any parameter and so be any type of sensor including but not necessarily limited to temperature, acceleration, vibration, torque, movement, motion, cement integrity, pressure, direction and inclination, load, various tubular/casing angles, corrosion and erosion, radiation, noise, magnetism, seismic movements, stresses and strains on tubular/casings including twisting, shearing, compressions, expansion, buckling and any form of deformation; chemical or radioactive tracer detection; fluid identification such as hydrate, wax and sand production; and fluid properties such as (but not limited to) flow, density, water cut, pH and viscosity. The sensors may be imaging, mapping and/or scanning devices such as, but not limited to, camera, video, infra-red, magnetic resonance, acoustic, ultra-sound, electrical, optical, impedance and capacitance. Furthermore the sensors may be adapted to induce the signal or parameter detected by the incorporation of suitable transmitters and mechanisms. The sensors may also sense the status of equipment within the well, for example valve position or motor rotation.
[0038] The wireless transceiver may be incorporated within the sensor, valve or safety mechanism or may be independent from it and connected thereto. The sensors may be incorporated directly in the equipment comprising the transmitters or may transfer data to said equipment using cables or short-range wireless (e.g. inductive) communication techniques. Short range is typically less than 5 m apart, often less than 3 m apart and indeed may be less than 1 m apart.
[0039] The sensors need to operate only in an emergency situation but can also provide details on different parameters at any time. The sensors can be useful for cement tests, testing pressures on either side of packers, sleeves, valves or obstructions and wellhead pressure tests and generally for well information and monitoring from any location in the well.
[0040] The wireless signals may be sent retroactively, that is after an emergency situation has occurred, for example after a blow out.
[0041] Typically the sensors can store data for later retrieval and are capable of transmitting it.
[0042] The safety mechanism may be adapted to move the obstructing member to/from the first position from/to the second position automatically in response to a parameter detected by the sensor. Thus at a certain “trip point” the safety mechanism can close the well, if for example, it detects a parameter indicative of unusual data or an emergency situation. Preferably the safety mechanism is adapted to function in such a manner in response to a plurality of different parameters all detecting unusual data, thus suggesting an emergency situation. The parameter may be any parameter detected by the sensor, such as pressure, temperature, flow, noise, or indeed the absence of flow or noise for example.
[0043] Such safety mechanisms are particularly useful during all phases when a BOP is in use and especially during non-drilling phases when a BOP is in use.
[0044] Preferably the trip point can be varied by sending instructions to a receiver coupled to (not necessarily physically connected thereto) or integral with, the sensors and/or safety mechanism. Such embodiments can be of great benefit to the operator, since the different operations downhole can naturally experience different parameters which may be safe in one phase but indicative of an emergency situation in another phase. Rather than setting the trip point at the maximum safety level for all phases, they can be changed by communications including wireless communication for the different phases. For example, during a drilling phase the vibration sensed would be expected to be relatively high compared to other phases. Sensing vibration to the same extent in other phases may be indicative of an emergency situation and the safety mechanism instructed to change their trip point after the drilling phase.
[0045] For certain embodiments, a sensor is provided above and below the safety mechanisms and can thus monitor differential parameters in these positions which can in turn elicit information on the safety of the well. In particular any pressure differential detected across an activated safety mechanism would be of particular use in assessing the safety of the well especially on occasions where a controlling surface vessel moves away for a period of time and then returns.
[0046] Sensors and/or transceivers may also be provided in casing annuli.
[0047] In use, an operator can react to any abnormal and potentially dangerous occurrence which the sensors detect. This can be a variety of different parameters including pressure, temperature and also others like stress and strain on pipes or any other parameters/sensors referred to herein but not limited to those.
[0048] Moreover with a plurality of sensors, the data may provide a profile of the parameters (for example, pressure/temperature) along the casing and so aid identification where the loss of integrity has occurred, e.g. whether the casing, casing cement, float collar or seal assembly have failed to isolate the reservoir or well. Such information can allow the operator to react in a quick, safe and efficient manner; alternatively the safety mechanism can be adapted to activate in response to certain detected parameters or combination of parameters, especially where two or three parameters are showing unusual values.
[0049] Such a system may be activated in response to an emergency situation.
[0050] Thus the invention provides a method of inhibiting fluid flow from a well in an emergency situation, the method comprising:
[0000] in the event of an emergency, sending a wireless signal into the well to a safety mechanism according to the first aspect of the invention.
[0051] Preferred and other optional features of the previous embodiment are preferred and optional features of the method according to the invention immediately above.
[0052] An emergency or emergency situation is where uncontrolled fluid flow occurs or is expected to occur, from a well; where an unintended explosion occurs or there is an unacceptable risk that it may occur, where significant structural damage of the well integrity is occurring or there is an unacceptable risk that it may occur, or where human life, or the environment is in danger, or there is an unacceptable risk that it may be in danger. These dangers and risks may be caused by a number of factors, such as the well conditions, as well as other factors, such as severe weather.
[0053] Thus normally an emergency situation is one where at least one of a BOP and subsurface safety valve would be attempted to be activated, especially before/during or after an uncontrolled event in a well.
[0054] Furthermore, normally an emergency situation according to the present invention is one defined as the least, more or most severe accordingly to the IADAC Deepwater Well Control Guidelines, Third Printing including Supplement 2000, section 4.1.2. Thus events which relate to kick control may be regarded as an emergency situation according to the present invention, and especially events relating to an underground blowout are regarded as an emergency situation according to the present invention, and even more especially events relating to a loss of control of the well at the sea floor (if a subsea well) or the surface is even more especially an emergency according to the present invention.
[0055] Methods in accordance with the present invention may also be conducted after said emergency and so may be performed in response thereto, acting retroactively.
[0056] The method may be provided during all stages of the drilling, cementing, development, completion, operation, suspension and abandonment of the well. Preferably the method is provided during a phase where a BOP is provided on the well.
[0057] Optionally the method is conducted during operations on the well when attempts have been made to activate the BOP.
[0058] During these phases, embodiments of the present invention are particularly useful because the provision of physical control lines during these phases would obstruct the many well operations occurring at this time; and indeed the accepted practice is to avoid as much as possible installing devices which require communication for this reason. Embodiments of the present invention go against this practice and overcome the disadvantages by providing wireless communications. Thus an advantage of embodiments of this invention is that they enable the use of a safety valve or barrier in situations where conventional safety valves or barriers could not, or would not, normally be deployed.
[0059] The safety mechanism may comprise a valve, preferably a ball or flapper valve, preferably the valve may incorporate a mechanical over-ride controlled, for example, by pressure, wireline, or coiled tubing or other intervention methods. The valve may incorporate a ‘pump through’ facility to permit flow in one direction.
[0060] The obstructing member of the safety mechanism may be a sleeve.
[0061] Optionally the safety mechanism may be actuated directly using a motor but alternatively or additionally may be adapted to actuate using stored pressure, or preferably using well pressure acting against an atmospheric chamber, optionally used in conjunction with a spring actuator.
[0062] The safety mechanism may incorporate components which are replaceable, or incorporate key parts, such as batteries, or valve bodies which are replaceable without removing the whole component from the well. This can be achieved using methods such as side-pockets or replaceable inserts, using conventional methods such as wireline or coiled-tubing.
[0063] In order to retrieve data from the sensors and/or actuate the safety mechanism, one option is to deploy a probe. A variety of means may be used to deploy the probe, such as an electric line, slick line wire, coiled tubing, pipe or any other elongate member. Such a probe could alternatively or additionally be adapted to send signals. Indeed such a probe may be deployed into a casing annulus if required.
[0064] In other embodiments, the wireless signal may be sent from a device provided at the wellhead apparatus or proximate thereto, that is normally within 300 m. In one embodiment wireless signals can be sent from a platform, optionally with wireless repeaters provided on risers and/or downhole. For other embodiments, the wireless signals can be sent from the seabed wellhead apparatus, after receiving sonar signals from the surface or from an ROV. In other embodiments, the wireless signals can be sent from the wellhead apparatus after receiving a satellite signals from another location. Furthermore if the wellhead is a seabed wellhead, the wireless signals can be then sent from the seabed wellhead apparatus, after receiving sonar signals, which had been triggered/activated after receiving a satellite signal from another location.
[0065] The surface or surface facility may be for example a nearby production facility standby or supply vessel or a buoy.
[0066] Thus the device comprises a wireless transmitter, or transceiver and preferably also comprises a sonar receiver, to receive signals from a surface facility and especially a sonar transceiver so that it can communicate two-way with the surface facility. For certain embodiments an electric line may be run into a well and the wireless transceiver attached towards one end of the line. In other embodiments the signal may be sent from an ROV via a hot-stab connection or via a sonar signal from the ROV.
[0067] Therefore the invention also provides a device, in use fitted or retro-fitted to a top of a well, comprising a wireless transmitter and a sonar receiver; especially for use in an emergency situation.
[0068] The device is relatively small, typically being less than 1 m 3 , preferably less than 0.25 m 3 , especially less than 0.10 m 3 and so can be easily landed on the wellhead apparatus. The resulting physical contact between the wellhead apparatus and the device provides a connection to the well for transmission of the wireless signal. In alternative embodiments the device is built into the wellhead apparatus, which is often at the seabed but may be on land for a land well.
[0069] Thus such devices also operate wirelessly and do not require physical communication between the wellhead apparatus and a controlling station, such as a vessel or rig.
[0070] Embodiments of the invention also include a satellite device comprising a sonar transceiver and a satellite communication device. Such embodiments can communicate with the well, such as with said device at the wellhead apparatus in accordance with a previous aspect of the invention, and relay signals onwards via satellite. The satellite device may be provided on a rig or vessel or a buoy.
[0071] Thus according to one aspect of the invention there is provided a well apparatus comprising a well and a satellite device comprising a satellite communication mechanism, and a sonar, the device configured to relay information received from the sonar by satellite.
[0072] Preferably the device is independent of the rig, for example it may be provided on a buoy. Thus in the event that the rig is lost, the buoy may relay a control signal from a satellite to the well to shut down the well.
[0073] In a further embodiment the device at the wellhead apparatus may be wired to a surface or remote facility. Preferably however, the device is provided with further wireless communication options for communication with the surface facility. Typically the device has batteries to permit operation in the event of damage to the cable.
[0074] The safety mechanism may comprise a subsurface safety valve, optionally of known type, along with a wireless transceiver.
[0075] In alternative embodiments, the safety mechanism comprises a packer and an expansion mechanism. The movement mechanism causes the expansion mechanism to activate which expands the packer and so moving the packer from said first position to said second position.
[0076] Thus according to a further aspect of the present invention there is provided a packer apparatus comprising a packer and an activation mechanism, the activation mechanism comprising an expansion mechanism for expanding the packer and a wireless transceiver adapted to receive a wireless control signal and control the activation mechanism.
[0077] The wireless signal is preferably an acoustic signal and may travel through elongate members and/or well fluid.
[0078] Alternatively the wireless signal may be an electromagnetic or any other wireless signal or any combination of that and acoustic.
[0079] References throughout to “expanding” and “expansion mechanisms” etc include expanding a packer by compression of an elastomeric element and/or inflating a packer and inflation mechanisms etc and/or explosive activation with explosive mechanisms, or actuation of a swell mechanism by exposure of a swellable element to an activating fluid, such as water or oil.
[0080] The packer apparatus may be provided downhole in any suitable location, such as on a drill string or production tubing and, surprisingly, in a casing annulus between two different casing strings, or between the casing and formation or on a sub-assembly within a cased or uncased section of the well.
[0081] In use after deployment and wireless activation downhole according to the present invention, the packer may be provided in the expanded state to provide a further barrier against fluid movement therepast, especially those provided on an outer face of an elongate member in a well. Those between said casing and a drill string/production tubing, are preferably reactive to an emergency situation that is unexpanded.
[0082] Thus the invention also provides a well apparatus comprising:
[0083] a plurality of casing strings:
[0084] a packer apparatus provided on one of the casing strings;
[0085] the packer apparatus comprising a wireless transceiver, and adapted to expand in response to a change in a wireless signal in order to restrict flow of fluid through an annulus between said casing string and an adjacent elongate member.
[0086] As noted above, the packer may be provided in use in the expanded configuration and act as a permanent barrier to resists fluid flow or may be provided in the unexpanded configuration and activated as required, for example in response to an emergency situation. Moreover the packer may be adapted to move from an expanded configuration, corresponding to the second position of the safety mechanism where fluid flow is restricted (normally blocked) and retract to the first position where fluid flow is permitted.
[0087] The adjacent elongate member may be another of the casing strings or may be a drill pipe or may be production tubing.
[0088] The invention also provides a packer as described herein for use on a production string in an emergency situation.
[0089] For example in a gas lift operation the packer may be provided on the production tubing and activated only in the event of an emergency.
[0090] Typically the packer is provided as a permanent barrier when the adjacent member is another casing string, and in the unexpanded configuration when the elongate member is a drill pipe of production tubing that is they remain unexpanded until they expand in response to an emergency situation.
[0091] Whilst the packer of the packer apparatus may expand in an inward or outward direction, preferably it is adapted to expand in an inward direction.
[0092] The annulus may be a casing annulus.
[0093] Thus an advantage of such embodiments is that fluid flow through an annulus can be inhibited, preferably stopped, by provision of such a packer in an annulus. Normally fluid does not flow through the casing annulus of a well and so the skilled person would not consider placing a packer in this position. However the inventors of the present invention have realized that the casing annulus is a flow path through which well fluid may flow in the event of a well failure and blow out. Such an event may be due to failure of the formation, cement and/or seals provided with the casing system and wellhead.
[0094] Preferably a plurality of packer apparatus are provided. Different packer apparatus may be provided in the same or in different annuli.
[0095] Preferably the packer apparatus is/are provided proximate to the top of the well. In this way the packers can typically inhibit fluid flow above the fault or suspected fault, in the casing. Therefore the packer(s) may be provided within 100 m of the wellhead, more preferably within 50 m, especially within 20 m, and ideally within 10 m.
[0096] The packers provided in a casing annulus may be non-weight packers, that is they do not necessarily have engaging teeth for example the packers may be inflatable or swell types.
[0097] The casing packers may be installed above the cemented-in section of the casing and they thus typically provide an additional barrier to flow of fluids above that traditionally provided by a portion of the well being cased in.
[0098] In alternative embodiments the packers may be provided on an inner side of the casing adjacent to a cemented in portion of the casing, thus inhibiting a flow path at this point, whilst the cement inhibits the flow path on the outside portion of the casing.
[0099] The safety mechanism may be a packer-like element without a through bore and so in effect function as a well plug or bridge plug.
[0100] In certain embodiments, the packer may be provided on a drill string.
[0101] Thus the invention provides a method of drilling, comprising during a drilling phase providing a drill string comprising a packer apparatus as defined herein.
[0102] As drill strings typically rotate and move vertically in a well during a drilling phase, a skilled person would not be minded to provide a packer thereon since a packer resists movement. However the inventors of the present invention note that a packer provided thereof can be used in an emergency situation and so provides advantages.
[0103] Thus the packer may be provided on drill string, production string, production sub-assembly and may operate in cased or uncased sections of the well.
[0104] The safety mechanisms and packers described herein may also have additional means of operation such as hydraulic and/or electric lines.
[0105] Thus the present invention also provides a method of deploying a safety mechanism according to the present invention, monitoring the well using data received from sensors as described herein associated with the safety mechanism whilst abandoning the well and/or cementing the well and/or suspending the well.
[0106] Unless otherwise stated methods and mechanisms of various aspects of the present invention may be used in all phases including drilling, suspension, production/injection, completion and/or abandonment of well operations.
[0107] The wireless signal for all embodiments is preferably an acoustic signal although may be an electromagnetic or any other signal or combination of signals.
[0108] Preferably the acoustic communications include Frequency Shift Keying (FSK) and/or Phase Shift Keying (PSK) modulation methods, and/or more advanced derivatives of these methods, such as Quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (QAM), and preferably incorporating Spread Spectrum Techniques. Typically they are adapted to automatically tune acoustic signaling frequencies and methods to suit well conditions.
[0109] Embodiments of the present invention may be used for onshore wells as well as offshore wells.
[0110] An advantage of certain embodiments is that the acoustic signals can travel up and down different strings and can move from one string to another. Thus linear travel of the signal is not required. Direct route devices thus can be lost and a signal can still successfully be received indirectly. The signal can also be combined with other wired and wireless communication systems and signals and does not have to travel the whole distance acoustically.
[0111] Any aspect or embodiment of the present invention can be combined with any other aspect of embodiment mutatis mutandis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0112] An embodiment of the present invention will now be described, by way of example only, and with reference to the accompanying figures in which:
[0113] FIG. 1 is a diagrammatic sectional view of a well in accordance with one aspect of the present invention;
[0114] FIG. 2 is a schematic diagram of the electronics which may be used in a transmitting portion of a safety mechanism of the present invention;
[0115] FIG. 3 is a schematic diagram of the electronics which may be used in a receiving portion of a safety mechanism of the present invention; and,
[0116] FIGS. 4 a - 4 c are sectional views of a casing valve sub in various positions.
DETAILED DESCRIPTION
[0117] FIG. 1 shows a well 10 comprising a series of casing strings 12 a , 12 b , 12 c , and 12 d and adjacent annuli A,B,C,D between each casing string and the string inside thereof, with a drill string 20 provided inside the innermost casing 12 a.
[0118] As is conventional in the art, each casing strings extends further into the well than the adjacent casing string on the outside thereof. Moreover, the lowermost portion of each casing string is cemented in place as it extends below the outer adjacent string.
[0119] In accordance with one aspect of the present invention, safety packers 16 are provided on the casing above the cemented as well as on the drill string 20 .
[0120] These can be activated acoustically at any time including retroactively i.e. after the emergency, in order to block fluid flow through the respective annuli. Whilst normal operation will not require the activation of such packers, they will provide a barrier to uncontrolled hydrocarbon flow should the casing or other portion of the well control fail.
[0121] Moreover sensors (not shown), in accordance with one aspect of the present invention, are provided above and below said packers in order to monitor downhole parameters at this point. This can provide information to operators on any unusual parameters and the sealing integrity of the packer(s).
[0122] Acoustic relay stations 22 are provided on the drill pipe as well as various points in the annuli to relay acoustic data retrieved from sensors in the well.
[0123] A safety valve 25 is also provided in the drill string 20 and this can be activated acoustically in order to prevent fluid flow through the drill string.
[0124] In such an instance a device (not shown) comprising a sonar receiver and an acoustic transceiver installed or later landed at a wellhead apparatus such as a BOP structure 30 at the top of the well. The operator sends a sonar signal from a surface facility 32 which is converted to an acoustic signal and transmitted into the well by the device. The subsea valve 25 picks up the acoustic signal and shuts the well downhole (rather than at the surface), even if other communications are entirely severed with the BOP.
[0125] In alternative embodiments a packer picks up the signal rather than the safety valve 25 . The packer can then shut a flowpath e.g. an annulus.
[0126] Thus embodiments of the present invention benefit in that they obviate the sole reliance on seabed/rig floor/bridge BOP control mechanisms. As can be observed by disastrous events in the Gulf of Mexico in 2010, the control of a well where the BOP has failed can be extremely difficult and ensuing environmental damage can occur given the uncontrolled leak of hydrocarbons in the environment. Embodiments of the present invention provide a system which reduce the risk of such disastrous events happening and also provide a secondary control mechanism for controlling subsurface safety mechanisms, such as subsurface valves, sleeves, plugs and/or packers.
[0127] For certain embodiments a control device is provided on a buoy or vessel separate from a rig. The device comprises sonar transmitter and a satellite receiver. The device can therefore receive a signal from a satellite directed from an inland installation, and communicate this to the well in order to shut down the well; all independent of the rig. In such embodiments, the well can be safely closed down even in the disastrous event of losing the rig.
[0128] A casing valve sub 400 is shown FIGS. 4 a - 4 c comprising an outer body 404 having a central bore 406 extending out of the body 404 at an inner side through port 408 and an outer side through port 410 . A moveable member in the form of a piston 412 is provided in the bore 406 and can move to seal the port 408 . Similarly a second moveable member in the form of a piston 414 is provided in the bore 406 and can move to seal the port 410 . Actuators 416 , 418 control the pistons 412 , 414 respectively.
[0129] The casing valve sub 400 is run as part of an overall casing string, such as a casing string 12 shown in FIG. 1 , and positioned such that the port 408 faces an inner annulus and the port 410 faces an outer annulus.
[0130] In use, the pistons 412 , 414 can be moved to different positions, as shown in FIGS. 4 a , 4 b and 4 c , by the actuators 416 , 418 in response to wireless signals which have been received. Thus the pressure between the inner and outer annuli can be sealed from each other by providing at least one of the pistons 412 , 414 over or between the respective ports, 408 , 410 as shown in FIG. 4 a , 4 c.
[0131] In order to equalize the pressure between the inner and outer annuli, the pistons 412 , 414 are moved to a position outside of the ports 408 , 410 so they do not block them nor block the bore 406 therebetween, as shown in FIG. 4 b . The pressures can thus be equalized.
[0132] Thus such embodiments can be useful in that they provide an opportunity to equalize pressure between two adjacent casing annuli if one exceeded a safe pressure and/or if an emergency situation had occurred.
[0133] The port can then be isolated and pressure monitored to see if pressure is going to build-up again. Thus, in contrast to for example a rupture disk, where it cannot return to its original position, embodiments of the present invention can equalize pressure between casing strings, be reset, and then repeat this procedure again, and for certain embodiments, repeat the procedure indefinitely.
[0134] In one scenario the pressure in a casing string may build up due to fluid flow and thermal expansion. A known rupture disk can resolve problems of excessive pressure, and the well can continue to function normally. However a further occurrence of such excess pressure cannot be dealt with. Moreover it is sometimes difficult to ascertain whether the excess pressure was caused by such a manageable event or whether it is indicative of a more serious problem especially if repeated occurrences of the excess pressure cannot be detected nor alleviated in known systems. Embodiments of the present invention mitigate these problems. For some embodiments, a number of different casing subs 401 may be used in one string of casing.
[0135] FIG. 2 shows a transmitting portion 250 of the safety mechanism. The portion 250 comprises a transmitter (not shown) powered by a battery (not shown), a transducer 240 and a thermometer (not shown). An analogue pressure signal generated by the transducer 240 passes to an electronics module 241 in which it is digitized and serially encoded for transmission by a carrier frequency, suitably of 1 Hz-10 kHz, preferably 1 kHz-10 kHz, utilizing an FSK modulation technique. The resulting bursts of carrier are applied to a magnetostrictive transducer 242 comprising a coil formed around a core (not shown) whose ends are rigidly fixed to the well bore casing (not shown) at spaced apart locations. The digitally coded data is thus transformed into a longitudinal sonic wave.
[0136] The transmitter electronics module 241 in the present embodiment comprises a signal conditioning circuit 244 , a digitizing and encoding circuit 245 , and a current driver 246 . The details of these circuits may be varied and other suitable circuitry may be used. The transducer is connected to the current driver 246 and formed round a core 247 . Suitably, the core 247 is a laminated rod of nickel of about 25 mm diameter. The length of the rod is chosen to suit the desired sonic frequency.
[0137] FIG. 3 shows a receiving portion 360 of the safety mechanism. A receiving portion 361 comprises a filter 362 and a transducer 363 connected to an electronics module powered by a battery (not shown). The filter 362 is a mechanical band-pass filter tuned to the data carrier frequencies, and serves to remove some of the acoustic noise which could otherwise swamp the electronics. The transducer 363 is a piezoelectric element. The filter 362 and transducer 363 are mechanically coupled in series, and the combination is rigidly mounted at its ends to one of the elongated members, such as the tubing or casing strings (not shown). Thus, the transducer 363 provides an electrical output representative of the sonic data signal. Electronic filters 364 and 365 are also provided and the signal may be retransmitted or collated by any suitable means 366 , typically of a similar configuration to that shown in FIG. 2 .
[0138] An advantage of certain embodiments is that the acoustic signals can travel up and down different strings and can move from one string to another. Thus linear travel of the signal is not required. Direct route devices thus can be lost and a signal can still successfully be received indirectly. The signal can also be combined with other wires and wireless communication systems and does not have to travel the whole distance acoustically.
[0139] Improvements and modifications may be made without departing from the scope of the invention. Whilst the specific example relates to a subsea well, other embodiments may be used on platform or land based wells.
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A well ( 10 ) comprising a packer apparatus, the packer apparatus comprising: a packer ( 16 ) and an activation mechanism; wherein the activation mechanism comprises an expansion mechanism for expanding the packer ( 16 ) and a wireless receiver ( 360 ) optionally a transceiver. For certain embodiments the wireless receiver may be acoustic and/or electromagnetic. The receiver is adapted to receive a wireless control signal and control the activation mechanism and wherein the packer apparatus is provided downhole in any one of the following locations, (i) on a production tubing; (ii) in a casing annulus between two different casing strings; (iii) between the casing and formation; (iv) on a sub-assembly within an uncased section of the well and (v) on a drill string.
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TECHNICAL FIELD
[0001] The present invention relates to a semiconductor device provided with a Schottky barrier diode made of SiC and a method of manufacturing the same.
BACKGROUND ART
[0002] Conventionally, attention is paid to a semiconductor power device used mainly for a system in various types of fields of power electronics such as a motor control system and a power conversion system. As a semiconductor power device, an SiC Schottky barrier diode is well-known (for example, Patent Documents 1 and 2).
CITATION LIST
Patent Literature
[0003] Patent Document 1: Japanese Patent Application Publication No. 2005-79339
[0004] Patent Document 2: Japanese Patent Application Publication No. 2011-9797
SUMMARY OF INVENTION
Technical Problem
[0005] An object of the present invention is to provide a semiconductor device capable of reducing forward voltage while suppressing a reverse leakage current to a comparable level as in the conventional technology and decreasing a variation in the reverse leakage current, and to provide a method of manufacturing the same.
Solution to Problem
[0006] The semiconductor device of the present invention includes a first conductive-type SiC semiconductor layer, and a Schottky metal being made of molybdenum contacting a surface of the SiC semiconductor layer and having a thickness of 10 nm to 150 nm, in which the SiC semiconductor layer has a first junction portion contacting the Schottky metal and the first junction portion is a flat structure or a structure having unevenness of 5 nm or less.
[0007] According to the arrangement, the first junction portion of the SiC semiconductor layer to the Schottky metal is a flat structure or a structure having unevenness of 5 nm or less. This reduces forward voltage while suppressing a reverse leakage current to a comparable level as in the conventional technology.
[0008] Further, in this structure, a thickness of the Schottky metal made of molybdenum is 10 nm to 150 nm, and thus, the stress applied to the SiC semiconductor layer from the Schottky metal can be alleviated and a variation in the stress can be decreased. Thus, when the semiconductor device of the present invention is mass-produced, it is possible to decrease a variation in the reverse leakage current. As a result, it is possible to stably supply a semiconductor device having quality in which the reverse leakage current stays within a constant range. When the thickness of the Schottky metal is 10 nm to 100 nm, it is possible to further decrease the variation in the reverse leakage current.
[0009] It is preferable that the Schottkymetal has a single crystalline structure of which the crystalline interface is not exposed in a vertical cross section. According to the arrangement, it is possible to make uniform a characteristic of the entire Schottky metal.
[0010] It is preferable that the semiconductor device includes an anode electrode formed on the Schottky metal, and the anode electrode includes a second junction portion made of a titanium layer contacting the Schottky metal. In that case, the anode electrode may include an aluminum layer formed on the titanium layer.
[0011] It is preferable that the semiconductor device includes a nickel contact layer contacting a back surface of the SiC semiconductor layer.
[0012] The semiconductor device may include a cathode electrode including a titanium layer formed on the nickel contact layer. In that case, an alloy layer may be further formed which contains titanium and carbon between the nickel contact layer and the cathode electrode.
[0013] The semiconductor device may further include a carbon layer formed on the nickel contact layer.
[0014] The semiconductor device may include a second conductive-type guard ring formed to surround the first junction portion. In that case, the SiC semiconductor layer may be made of n-type SiC and the guard ring may be made of p-type SiC.
[0015] It is preferable that the guard ring is formed to extend outward with respect to an outer circumferential edge of the Schottky metal.
[0016] When a load connected to the semiconductor device is inductive, if a current passing through the load is blocked, then counter-electromotive force generated to the load. Resulting from the counter-electromotive force, reverse voltage in which the anode side is positive may apply between an anode and a cathode. In such a case, it is possible to relatively decrease a resistance value of the guard ring, and thus, it is possible to suppress heat generated by the current passing within the guard ring. As a result, it is possible to prevent a device from being thermally destroyed. That is, it is possible to improve an inductive load resistance (L load resistance).
[0017] Further, it is preferable that when the semiconductor device includes a field insulating film formed on a surface of the SiC semiconductor layer, the field insulating film formed therein with an opening through which the first junction portion and an inner peripheral portion of the guard ring are selectively exposed, the Schottky metal is joined to the SiC semiconductor layer within the opening and rides on the field insulating film by a riding amount of 10 μm to 60 μm from a circumferential edge of the opening.
[0018] According to the arrangement, when the reverse voltage is applied between the anode and the cathode as described above, it is possible to shorten a distance over which a current passes within the guard ring, and thus, it is possible to suppress heat generated by the current. As a result, it is possible to prevent a device from being thermally destroyed.
[0019] Therefore, when a dopant concentration of the guard ring and the riding amount on the field insulating film in the Schottky metal are combined, it is possible to realize an excellent inductive load resistance (L load resistance).
[0020] The Schottky metal may be formed so that an outer circumferential edge thereof contacts the guard ring.
[0021] A method of manufacturing a semiconductor device according to the present invention includes a step of forming a Schottky metal made of molybdenum having a thickness of 10 nm to 150 nm, on a surface of a first conductive-type SiC semiconductor layer, and a step of performing a heat treatment on the Schottky metal in a state where the surface of the Schottky metal is exposed so that a first junction portion with the Schottky metal in the SiC semiconductor layer is made a flat structure or a structure having unevenness of 5 nm or less.
[0022] According to the method, the first junction portion of the SiC semiconductor layer to the Schottky metal is made a flat structure or a structure having unevenness of 5 nm or less. This provides a semiconductor device capable of reducing forward voltage while suppressing a reverse leakage current to a comparable level as in the conventional technology.
[0023] Further, in this structure, a thickness of the Schottky metal made of molybdenum is 10 nm to 150 nm, and thus, the stress applied to the SiC semiconductor layer from the Schottky metal can be alleviated and a variation in the stress can be decreased. Thus, when the semiconductor device obtained by the method is mass-produced, it is possible to decrease a variation in the reverse leakage current. As a result, it is possible to stably supply a semiconductor device having quality in which the reverse leakage current stays within a constant range.
[0024] It is preferable that the step of performing a heat treatment on the SiC semiconductor layer is executed in an atmosphere where oxygen is not present. Specifically, it is preferable that the step of performing a heat treatment on the SiC semiconductor layer is executed in a nitrogen atmosphere. In that case, it is preferable that the step of performing a heat treatment on the SiC semiconductor layer is executed in a resistance heat furnace.
[0025] According to these methods, it is possible to prevent an oxidation of the Schottky metal (molybdenum) during the heat treatment and deterioration of a surface portion of the Schottky metal into a molybdenum oxide.
[0026] It is preferable that the method of manufacturing a semiconductor device includes a step of forming an anode electrode on the Schottky metal, and in the step of forming the anode electrode, a titanium layer is formed so as to contact the Schottky metal. In that case, the step of forming the anode electrode may include a step of forming an aluminum layer so as to contact the titanium layer.
[0027] Further, it is preferable that the method of manufacturing a semiconductor device includes a step of forming a nickel contact layer on a back surface of the SiC semiconductor layer before the formation of the Schottky metal and performing a heat treatment on the nickel contact layer.
BRIEF DESCRIPTION OF DRAWINGS
[0028] FIG. 1 is a plan view of a semiconductor device according to a embodiment of the present invention.
[0029] FIG. 2 is a cross-sectional view taken along a cutting plane line II-II in FIG. 1 .
[0030] FIG. 3 is an enlarged view of a portion within a broken line circle in FIG. 2 .
[0031] FIG. 4 is a flowchart for describing one example of a process of manufacturing the semiconductor device.
[0032] FIG. 5 is a view showing a modified embodiment of the semiconductor device in FIG. 1 .
[0033] FIG. 6 is a view showing a modified embodiment of the semiconductor device in FIG. 1 .
[0034] FIG. 7 is a view showing a modified embodiment of the semiconductor device in FIG. 1 .
[0035] FIG. 8 is a TEM image of a Schottky interface in a Reference Example 1.
[0036] FIG. 9 is a TEM image of a Schottky interface in Comparative Example 1.
[0037] FIG. 10 is a correlation diagram between Vf and Ir of Example 1 and Comparative Example 1, respectively.
[0038] FIG. 11 shows If-Vf curves (Ta=25° C.) of Example 1 and Comparative Example 1, respectively.
[0039] FIG. 12 shows If-Vf curves (Ta=125° C.) of Example 1 and Comparative Example 1, respectively.
DETAILED DESCRIPTION OF EMBODIMENTS
[0040] Embodiments of the present invention will hereinafter be described in detail with reference to the accompanying drawings.
[0041] FIG. 1 is a plan view of a semiconductor device according to a embodiment of the present invention. FIG. 2 is a cross-sectional view taken along a cutting plane line II-II in FIG. 1 . FIG. 3 is an enlarged view of a portion within a broken line circle in FIG. 2 .
[0042] A semiconductor device 1 includes an element in which SiC is adopted, and is of a squared chip shape in a plan view, for example. The semiconductor device 1 maybe of a rectangular shape in a plan view. The size of the semiconductor device 1 has 0.5 mm to 20 mm in the respective vertical and horizontal lengths in the sheet of FIG. 1 . That is, the chip size of the semiconductor device 1 is 0.5 mm square to 20 mm square, for example.
[0043] The surface of the semiconductor device 1 is divided by an annular guard ring 2 into an active region 3 inside the guard ring 2 and an outer circumferential region 4 outside the guard ring 2 . The guard ring 2 is a semiconductor layer containing a p-type dopant, for example. As the dopant to be contained, B (boron), Al (aluminum), Ar (argon), etc., may be used. The depth of the guard ring 2 may be about 100 nm to 1000 nm.
[0044] With reference to FIG. 2 , the semiconductor device 1 includes a substrate 5 made of n + -type SiC and a drift layer 6 made of n − -type SiC laminated on a surface 5 A of the substrate 5 . In the embodiment, the substrate 5 and the drift layer 6 are shown as one example of the SiC semiconductor layer of the present invention.
[0045] The thickness of the substrate 5 may be 50 μm to 600 μm, and the thickness of the drift layer 6 thereon may be 3 μm to 100 μm. As an n-type dopant contained in the substrate 5 and the drift layer 6 , N (nitrogen), P (phosphorus), As (arsenic) , etc., maybe used. As for a relationship in dopant concentration between the substrate 5 and the drift layer 6 , the dopant concentration of the substrate 5 is relatively higher, and the dopant concentration of the drift layer 6 is relatively lower than that of the substrate 5 . Specifically, the dopant concentration of the substrate 5 may be 1×10 18 to 1×10 20 cm −3 , and the dopant concentration of the drift layer 6 may be 5×10 14 to 5×10 16 cm −3 .
[0046] On a back surface 5 B ((000-1) C plane, for example) of the substrate 5 , a nickel (Ni) contact layer 7 is formed to cover the entire back surface 5 B. On the nickel contact layer 7 , a cathode electrode 8 is formed. The nickel contact layer 7 is made of a nickel containing metal forming an ohmic j unction with the substrate 5 . Such a metal may include a nickel silicide layer, for example. In the cathode electrode 8 , a structure (Ti/Ni/Au/Ag) is formed in which titanium (Ti) ,nickel (Ni), gold (Au), and silver (Ag) are laminated in order from the nickel contact layer 7 side, for example, and an Ag layer is exposed to the topmost surface.
[0047] On a surface 6 A ((0001) Si plane, for example) of the drift layer 6 , a field insulating film 10 is formed which has a contact hole 9 through which one portion of the drift layer 6 , as the active region 3 , is exposed and covers the outer circumferential region 4 surrounding the active region 3 . The field insulating film 10 maybe arranged by SiO 2 (silicon oxide) for example. A film thickness of the field insulating film 10 may be 0.5 μm to 3 μm.
[0048] On the field insulating film 10 , Schottky metal 11 and an anode electrode 12 are laminated.
[0049] The Schottky metal 11 contacts, via the contact hole 9 , the surface 6 A of the drift layer 6 , and forms a Schottky barrier with the drift layer 6 . Specifically, the Schottky metal 11 is made of molybdenum (Mo), and has a thickness of 10 nm to 150 nm. The Schottkymetal 11 is embedded in the contact hole 9 and rides on the field insulating film 10 to cover a circumferential edge portion of the contact hole 9 in the field insulating film 10 from above. More specifically, the Schottky metal 11 preferably rides on the field insulating film 10 so that the guard ring 2 extends (projects) outward with respect to an outer circumferential edge 19 of the Schottky metal 11 . In order that the guard ring 2 is projected outward, for example, a width W (riding amount) from a circumferential edge of the contact hole 9 of a portion that rides on the field insulating film 10 (riding portion 18 ) of the Schottky metal 11 to the outer circumferential edge 19 preferably is 10 μm to 60 μm.
[0050] It is noted that in the embodiment, the circumferential edge of the contact hole 9 indicates a position at which the thickness of the field insulating film 10 is 0 (zero). Therefore, for example, when the contact hole 9 is formed in a tapered shape in which the diameter is narrower from the upper end to the lower end, the width W is measured from the lower end of the circumferential edge of the contact hole 9 .
[0051] The Schottky metal 11 is relatively thin, that is, 10 nm to 150 nm, and therefore, in the Schottky metal 11 , it is possible to decrease a step between an upper portion that rides on the field insulating film 10 and a lower portion contacting the surface 6 A of the drift layer 6 . This decreases the step in the topmost surface of the anode electrode 12 , and therefore, it is possible to easily join a bonding wire to the topmost surface.
[0052] The Schottky metal 11 may have a single crystalline structure of which the crystalline interface is not exposed in a vertical cross section. Whether or not the Schottky metal 11 is of single crystalline structure can be confirmed by photographing and observing an image of a cross section of the Schottky metal 11 by using TEM (Transmission Electron Microscope), for example. With the arrangement, it is possible to make uniform a characteristic of the entire Schottky metal 11 .
[0053] As shown in FIG. 3 here, when an uneven structure 13 is formed in a junction portion 61 (one portion of the surface 6 A) of the drift layer 6 to the Schottky metal 11 , a height H 1 of the uneven structure 13 is 5 nm or less. As in FIG. 3 , when a plurality of recessed portions are formed in the uneven structure 13 , the height H 1 of the uneven structure 13 may adopt a depth at the deepest recessed portion. It is noted that the embodiment shows an example where the uneven structure 13 is formed in the junction portion 61 , and the junction portion 61 of the semiconductor device 1 may be a flat structure where the unevenness is scarcely present.
[0054] The anode electrode 12 may be of a two-layered structure including a titanium layer 121 formed on the Schottky metal 11 and an aluminum layer 122 formed on the titanium layer 121 . The anode electrode 12 is a portion which is exposed to the topmost surface of the semiconductor device 1 and to which a bonding wire, etc., are joined. Similar to the Schottky metal 11 , the anode electrode 12 rides on the field insulating film 10 to cover a circumferential edge portion of the contact hole 9 in the field insulating film 10 from above. Preferably, the titanium layer 121 has a thickness of 70 nm to 230 nm, and the aluminum layer 122 has a thickness of 3.2 μm to 5.2 μm (4.2 μm, for example). More particularly, the titanium layer 121 maybe of a two-layered structure including a lower layer, that is, Ti, and an upper layer, that is, TiN. At this time, a thickness of Ti is 10 nm to 40 nm (25 nm, for example), and a thickness of TiN is 60 nm to 190 nm (130 nm, for example).
[0055] The guard ring 2 dividing the drift layer 6 into the active region 3 and the outer circumferential region 4 is formed along the profile of the contact hole 9 to cross over the inside and outside of the contact hole 9 in the field insulating film 10 (to cross over the active region 3 and the outer circumferential region 4 ). Therefore, the guard ring 2 has an inside portion 21 (inner peripheral portion) that projects inward of the contact hole 9 and contacts a terminal end portion of the Schottky metal 11 within the contact hole 9 , and an outside portion 22 that projects outward of the contact hole 9 and faces the Schottky metal 11 with the circumferential edge portion of the field insulating film 10 being interposed therebetween.
[0056] On the topmost surface of the semiconductor device 1 , a surface protective film 14 is formed. At a central portion of the surface protective film 14 , an opening 15 is formed through which the anode electrode 12 is exposed. The bonding wire is joined, via the opening 15 , to the anode electrode 12 . The surface protective film 14 may be of a two-layered structure including a silicon nitride (SiN) film 141 formed on the anode electrode 12 and a polymide film 142 formed on the silicon nitride film 141 . Preferably, the silicon nitride film 141 has a thickness of 800 nm to 2400 nm (1600 nm, for example) , and the polymide film 142 has a thickness of 5 μm to 14 μm (9 μm, for example).
[0057] When the semiconductor device 1 is in a forward bias state where positive voltage is applied to the anode electrode 12 and negative voltage is applied to the cathode electrode 8 , an electron (carrier) moves from the cathode electrode 8 to the anode electrode 12 via the active region 3 in the drift layer 6 , and as a result, an electric current passes. Thus, the semiconductor device 1 (Schottky barrier diode) operates.
[0058] According to the semiconductor device 1 , the junction portion 61 of the drift layer 6 to the Schottky metal 11 is flat or an uneven structure 13 of 5 nm or less. Thus, it is possible to reduce a forward voltage irrespective of a use environment (ambient temperature, etc.) while suppressing a leak current (reverse leakage current) passing in a reverse bias state to a comparable level as in the conventional technology.
[0059] Further, in this structure, the thickness of the Schottky metal 11 made of molybdenum is 10 nm to 150 nm (100 nm, for example), and thus, the stress (compressive stress indicated by an arrow in FIG. 3 , for example) applied to the drift layer 6 from the Schottky metal 11 can be alleviated and a variation in the stress can be decreased. Thus, when the semiconductor device 1 is mass-produced, it is possible to decrease a variation in the reverse leakage current. For example, a process capability index Cpk may be 1.0 or more (preferably, 1.3 to 3.0) . As a result, it is possible to stably supply the semiconductor device 1 of quality in which the reverse leakage current stays within a constant range.
[0060] The Schottky metal 11 rides on the field insulating film 10 so that the guard ring 2 extends (projects) outward with respect to the outer circumferential edge 19 of the Schottky metal 11 . When a load connected to the semiconductor device 1 is inductive, if a current passing through the load is blocked, then counter-electromotive force is generated to the load. Resulting from the counter-electromotive force, reverse voltage in which the anode side is positive may apply between an anode and a cathode. In such a case, it is possible to relatively decrease a resistance value of the guard ring 2 , and thus, it is possible to shorten a distance over which a current passes within the guard ring 2 . Thus, it is possible to suppress heat generated by the current passing within the guard ring 2 , and therefore, it is possible to prevent the device from thermally being destroyed. That is, it is possible to improve an inductive load resistance (L load resistance) of the semiconductor device 1 .
[0061] FIG. 4 is a flowchart for describing one example of a process of manufacturing the semiconductor device 1 .
[0062] First, on the surface 5 A of the substrate 5 , the drift layer 6 is epitaxially grown (step S 1 ). Next, by a CVD (Chemical Vapor Deposition) method, for example, a mask is formed on the surface 6 A of the drift layer 6 , and via the mask, an impurity is implanted toward the surface 6 A of the drift layer 6 . Thereafter, a heat treatment is performed on the drift layer 6 , and the guard ring 2 is thereby formed selectively on the surface portion of the drift layer 6 (step S 2 ).
[0063] Next, by a thermal oxidation method ora CVD method, for example, the field insulating film 10 that completely covers the guard ring 2 is formed on the surface 6 A of the drift layer 6 (step S 3 ). Next, by a sputtering method, for example, the nickel contact layer 7 is formed on the back surface 5 B of the substrate 5 . Thereafter, the substrate 5 is placed in an electric furnace, in which the nickel contact layer 7 is subjected to a heat treatment at a predetermined first temperature (step S 4 ) . It is preferable that the heat treatment on the nickel contact layer 7 is performed in an induction heater of which the interior is adjusted to a nitrogen atmosphere, for example. Next, the field insulating film 10 is patterned to form the contact hole 9 , and the guard ring 2 is selectively exposed to within the contact hole 9 (step S 5 ).
[0064] Next, by a sputtering method, for example, on the entire surface 6 A of the drift layer 6 , the Schottky metal 11 made of molybdenum (Mo) having a thickness of 10 nm to 150 nm is formed. Then, the substrate 5 is placed in an electric furnace, and subjected to a heat treatment at a predetermined second temperature in a state where the surface of the Schottky metal 11 is exposed (step S 6 ). The heat treatment in a state where the surface of the Schottky metal 11 is exposed means applying a heat treatment on the Schottky metal 11 when a protective cap such as metal and a film is not formed on the surface of the Schottkymetal 11 . The heat treatment on the Schottky metal 11 preferably is performed, for example, in a resistance heat furnace of which the interior is adjusted to an atmosphere where there is substantially no oxygen inside the furnace (in the embodiment, a nitrogen atmosphere). If the heat treatment is performed under a nitrogen atmosphere, then the surface portion of the Schottky metal 11 is not deteriorated into molybdenum oxide due to an oxidation of the Schottky metal 11 (molybdenum) during the heat treatment. This eliminates a need for forming a protective cap on the surface of the Schottky metal 11 , and thus, it is possible to prevent the Schottky metal 11 from being raised by the thickness of the protective cap. As a result, it is possible to maintain the thickness of the Schottky metal 11 to 10 nm to 150 nm.
[0065] Next, on the Schottky metal 11 , the titanium layer 121 and the aluminum layer 122 are laminated in order to form the anode electrode 12 (step S 7 ), and the surface protective film 14 is thereafter formed (step S 8 ).
[0066] Finally, the cathode electrode 8 is formed on the nickel contact layer 7 , and the semiconductor device 1 shown in FIG. 1 , etc., is thereby obtained.
[0067] Although the embodiments of the present invention have heretofore been described, the present invention can be further embodied in other forms.
[0068] For example, the semiconductor device 1 may be embodied in a modified embodiment shown in FIG. 5 to FIG. 7 .
[0069] In FIG. 5 , between the nickel contact layer 7 and the cathode electrode 8 , a carbon layer 16 is formed. The carbon layer 16 is formed, during the formation of nickel silicide (nickel contact layer 7 ) as a result of the reaction of nickel deposited on the back surface 5 B of the substrate 5 with silicon in the substrate (SiC) 5 by the heat treatment in step S 4 in FIG. 4 , when redundant carbon (C) not contributing to the reaction is deposited on the surface of the nickel contact layer 7 .
[0070] On the other hand, in FIG. 6 , between the nickel contact layer 7 and the cathode electrode 8 , an alloy layer 17 containing carbon is formed. The alloy layer 17 is formed when the carbon (C) made redundant during the formation of the above-described nickel silicide layer and titanium (Ti) of the cathode electrode 8 are alloyed as a result of an electrode material (Ti/Ni/Au/Ag) for the cathode electrode 8 being deposited and then subjected to a heat treatment, for example.
[0071] That is, FIG. 5 and FIG. 6 show between the nickel contact layer 7 and the cathode electrode 8 , a layer resulting from the redundant carbon during the formation of the nickel silicide layer may be formed, and only one of the carbon layer 16 and the alloy layer 17 shown in each figure may be formed and both of these layers may be laminated and formed.
[0072] In FIG. 7 , the field insulating film 10 is omitted, and the entire guard ring 2 is exposed to the surface 6 A of the drift layer 6 . A terminal end portion of the Schottky metal 11 riding on the field insulating film 10 in FIG. 2 covers across the entire circumference of the inner peripheral portion of the guard ring 2 so that the guard ring 2 extends (projects) outward with respect to the outer circumferential edge 19 of the Schottky metal 11 . Thus, the terminal end portion of the Schottky metal 11 is joined to the inner peripheral portion of the guard ring 2 .
[0073] For example, an arrangement obtained by inverting a conductive type of each semiconductor portion in the semiconductor device 1 may be adopted. For example, in the semiconductor device 1 , the p-type portions may be n-type and the n-type portions may be p-type.
[0074] The nickel contact layer 7 may be subjected to a heat treatment in a resistance heat furnace and the Schottky metal 11 may be subjected to a heat treatment in an induction heater.
[0075] It is possible to incorporate the semiconductor device (semiconductor power device) of the present invention into a power module used for an inverter circuit arranging a drive circuit for driving an electric motor utilized as a drive source for an electric vehicle (including a hybrid car) , a train, and an industrial robot, etc. It is also possible to incorporate the semiconductor device of the present invention into a power module used for an inverter circuit that makes a conversion so that power generated by a solar cell, a wind power generator, other power generators (in particular, a private power generator) is coordinated with power of a commercially-available power supply.
[0076] It is possible to combine the characteristics understood from the disclosure of the above-described embodiment even between different embodiments. Further, it is possible to combine the constituent components presented in each embodiment within the scope of the present invention.
[0077] The embodiments of the present invention are only a specific example used to clarify the technical content of the present invention, and the present invention should not be interpreted by limiting to these specific examples and the spirit and scope of the present invention are limited only by the attached scope of claims.
[0078] The present application corresponds to Japanese Patent Application No. 2012-129219 submitted on Jun. 6, 2012 to Japan Patent Office, the entire disclosure of which is incorporated herein by reference.
EXAMPLES
[0079] Next, the present invention will be described on the basis of an example and a comparative example, however, the present invention shall not be limited to the following examples.
<Example 1, Comparative Example 1, and Reference Example 1>
[0080] According to a flowchart in FIG. 4, 12 (in SiC wafers) semiconductor devices 1 having a structure shown in FIG. 1 were manufactured (Example 1). The thickness of the Schottky metal 11 was set to 100 nm.
[0081] On the other hand, 20 semiconductor devices were manufactured (Comparative Example 1) in much the same way as in Example 1 except that the Schottky metal 11 was subjected to a heat treatment in the same process (oxygen atmosphere) as the nickel contact layer 7 in a state where the surface of the Schottky metal 11 (molybdenum) having a thickness of 400 nm was protected with molybdenum nitride (MoN) having a thickness of 200 nm. A semiconductor device arranged to have molybdenum nitride (MoN) having a thickness of 200 nm on the Schottky metal 11 (molybdenum) having a thickness of 400 nm was manufactured (Reference Example 1) according to a flowchart in FIG. 4 .
<Evaluation>
(1) TEM Image
[0082] A Schottky interface of the semiconductor devices obtained by the Reference Example 1 and Comparative Example 1 were photographed by TEM. The obtained images are shown in FIG. 8 and FIG. 9 .
[0083] As shown in FIG. 8 , it was found that in the Reference Example 1, the Schottky interface (joined portion with the Schottky metal in SiC) was a smooth flat structure. It was also found that the molybdenum (Mo) was a single crystalline structure in which the crystalline interface was not exposed. It is noted that Example 1 also had a similar structure.
[0084] On the other hand, as shown in FIG. 9 , it was found that in Comparative Example 1, an uneven structure including a plurality of recessed portions (darkish portions in FIG. 9 ) having a depth of about 20 nm was formed at the Schottky interface . It was also found that the crystalline interface appeared inside the molybdenum (Mo).
(2) Relationship Between Vf and Ir
[0085] Next, in each of Example 1 and Comparative Example 1, a relationship between a forward voltage Vf (1 mA) necessary for passing forward current of 1 mA and a reverse leakage current Ir was examined. FIG. 10 is a correlation diagram between Vf and Ir of Example 1 and Comparative Example 1, respectively.
[0086] As shown in FIG. 10 , it was found that in Example land Comparative Example 1, there was a conflicting relationship between Vf and Ir, and when the reverse leakage current Ir was suppressed to a comparable level, Vf could be reduced in Example 1. That is, in Example 1 where the Schottky interface was flat (having a smaller amount of surface roughness) , it is possible to reduce the forward voltage while suppressing the reverse leakage current to a comparable level as in Comparative Example 1.
(3) Vf-If Characteristic
[0087] Next, a Vf-If characteristic of each of Example 1 and Comparative Example 1 was examined. FIG. 11 shows If-Vf curves (Ta=25° C.) of Example 1 and Comparative Example 1, respectively. FIG. 12 shows If-Vf curves (Ta=125° C.) of Example 1 and Comparative Example 1, respectively.
[0088] As shown in FIG. 11 and FIG. 12 , it was found that in temperature regions where the ambient temperature Ta was either 25° C. or 125° C., it was possible to decrease the forward voltage Vf in Example 1 as compared to Comparative Example 1.
(4) Variation in Reverse Leakage Current
[0089] The process capability index Cpk of the reverse leakage current in each of Example 1 and Comparative Example 1 was examined. As a result, it was revealed that Example 1 having Cpk=1.82 had a smaller variation in reverse leakage current than the Reference Example 1 having Cpk=0.38.
REFERENCE SIGNS LIST
[0000]
1 Semiconductor device
2 Guard ring
5 Substrate
6 Drift layer
6 A Surface
61 Junction portion
7 Nickel contact layer
11 Schottky metal
12 Anode electrode
121 Titanium layer
122 Aluminum layer
13 Uneven structure
16 Carbon layer
17 Alloy layer
18 Riding portion
[0105] 19 Outer circumferential edge
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A semiconductor device according to the present invention includes a first conductive-type SiC semiconductor layer, and a Schottky metal, comprising molybdenum and having a thickness of 10 nm to 150 nm, that contacts the surface of the SiC semiconductor layer. The junction of the SiC semiconductor layer to the Schottky metal has a planar structure, or a structure with recesses and protrusions of equal to or less than 5 nm. A method for manufacturing a semiconductor device according to the present invention includes: a step of forming a Schottky metal, comprising molybdenum and having a thickness of 10 nm to 150 nm, on the surface of a first conductive-type SiC semiconductor layer; and a step for heat treating the Schottky metal whilst the surface thereof is exposed, and structuring the junction of the SiC semiconductor layer to the Schottky metal to be planar, or to have recesses and protrusions of equal to or less than 5 nm.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 12/163,948 filed on Jun. 27, 2008, which is a Continuation of U.S. Ser. No. 09/976,475 filed on Oct. 12, 2001, which claims priority and benefit under 35 USC §119 (e) to U.S. Provisional Application No. 60/297,817, filed Jun. 11, 2001, each of which is incorporated herein by reference in its entirety.
BACKGROUND
1. Field of the Invention
The present invention is related generally to a user interface for a personal digital assistant device.
2. Description of the Related Art
Carrying a personal digital assistant (PDA) around is very convenient for tasks such as taking notes at a meeting or lecture, scheduling appointments, looking up addresses, and for performing a whole host of other functions. However, one function not easily performed with a PDA is that of telecommunications. A typical cellular telephone, meanwhile, offers a range of features, from speed dial to speakerphone to caller-ID, phonebook, etc. In order to have the functionality of a cellular telephone and the functionality of a PDA, consumers have generally had to choose from a selection of largely unsatisfactory options. The most common option is to carry both a PDA and cell phone. This is undesirable, however, because of the obvious impractical aspects of having to deal with two separate devices, both in terms of sheer bulk as well as the inconvenience of switching between units. Simply put, there are more things to buy, more things to break, and more things to lose.
Another option is to purchase an add-on telephone device for a PDA. While this option is preferable to carrying two devices around, it still has limitations. For example, an add-on telephone device adds bulk to and changes the form factor of the PDA. In addition, since such a PDA must be designed to operate without an add-on telephone, the degree to which the user interface of the PDA can be integrated with the user interface of the add-on telephone is limited. Thus, an add-on solution is of only limited value, since there is not a true integration between the cellular telephone device and the PDA, but rather two separate devices at best co-existing side-by-side.
Accordingly, what is needed is a system and method for providing a user interface to a device featuring integrated functionality of both a PDA and cellular telephone.
SUMMARY
In accordance with the present invention there is provided a system and method for using an integrated device featuring functionality of both a PDA and cellular telephone. Features of the present invention include a power button offering control of both the computing and telephony functions of the device; a lid that turns the device on and off depending on its state, and can also be used to begin and terminate calls; a jog rocker that activates the device and is used to select from a variety of menu options; application buttons that offer direct access to applications stored on the device, and which can be configured to operate in conjunction with secondary keys to offer added functionality; an override-able ringer switch; a keyboard; and an Auto Word Completion function that verifies and corrects a user's typing in real time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a device with keyboard in accordance with an embodiment of the present invention.
FIG. 2 is an illustration of a device without keyboard in accordance with an embodiment of the present invention.
FIG. 3 is a flow chart illustrating power-on behavior of a device in accordance with an embodiment of the present invention.
FIG. 4 is a flow chart illustrating power-off behavior of a device in accordance with an embodiment of the present invention.
FIG. 5 is an illustration of a matrix describing behavior of a lid attached to a device in accordance with an embodiment of the present invention.
FIGS. 6 a and 6 b are illustrations of a keyboard layout in accordance with an embodiment of the present invention.
FIGS. 7 a and 7 b illustrates views of a display screen when Option mode and Option Lock mode are activate in accordance with an embodiment of the present invention.
FIG. 8 is an illustration of a dialog box presented to a user when a call is incoming in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
In the discussion set forth below, for purposes of explanation, specific details are set forth in order to provide a thorough understanding of the invention. It will be appreciated by those skilled in the art that the present invention may be practiced without these specific details. In particular, those skilled in the art will appreciate that the methods described herein can be implemented in devices, systems and software other than the examples set forth. In other instances, conventional or otherwise well-known structures, devices, methods and techniques are referred to schematically or shown in block diagram form in order to facilitate description of the present invention.
The present invention includes steps that may be embodied in machine-executable software instructions, and includes method steps that are implemented as a result of one or more processors executing such instructions. In other embodiments, hardware elements may be employed in place of, or in combination with, software instructions to implement the present invention. The software instructions may be stored in RAM or ROM, or on other media including removable media.
The present invention includes a user interface for the operation of an integrated handheld personal computing device and wireless communication device. Referring now to FIG. 1 , there is shown an example of such an integrated device 100 . As illustrated in FIG. 1 , device 100 includes a base section 102 , a lid 104 , application and scroll buttons 106 , power button 110 , antenna 112 , jog rocker 114 , and ringer switch 116 , and display 118 . In addition, device 100 includes a keyboard 108 . As will be appreciated by those of skill in the art, the present invention may exist in a variety of embodiments, including embodiments in which the integrated device includes more or fewer physical components than are illustrated in FIG. 1 . For example, FIG. 2 illustrates another device 200 that does not have a keyboard, but instead has a writeable area 202 enabling input to the device 200 via, for example, a stylus. For convenience and clarity, device 100 of FIG. 1 serves as the illustration that will be referenced throughout this specification, but such reference should in no way be understood to restrict what is disclosed to such an embodiment.
Device 100 includes an integrated GSM radio (also referred to as a cellular telephone), and while in alternative embodiments is of varying sizes and shapes, in one embodiment the device is designed to fit comfortably in a pocket. While the radio uses the GSM standard in one embodiment, in alternative embodiments the radio may use the CDMA standard, or any of a variety of other well-known wireless standards.
Power Button
Device 100 has a power button 110 , located in one embodiment on the top face, next to the antenna 112 . In one embodiment, the power button 110 performs the following functions:
A single press and release of the power 110 button toggles device 100 on/off. Pressing and holding the power button 110 toggles the radio on/off. Double-tapping the power button 110 toggles a backlight on/off. Triple-tapping the power button 110 inverts the display 118 and insures that the backlight is on. A single press of the power button 110 when an incoming call is ringing silences the ring but does not turn off the device 100 .
Referring now to FIG. 3 , there is shown a flowchart of the operation of the power button functionality starting from a device-off state. Initially, the device 100 is off and the power key is pressed 300 . If the key is being pressed for the first time within a given period 302 (e.g., it has not been pressed for at least the previous half second), the device 100 is switched on 304 . If the power button is held down for longer than a threshold amount of time, e.g., 1 second 306 then the radio is toggled on or off 308 . If the power button is held down for less than the threshold amount 306 , then upon release a countdown of predetermined length, e.g., ½ second, is begun 310 . If the power button is pressed 312 during the countdown, then the backlight is toggled on or off 314 . If the cycle is repeated and the power button is pressed for a third time during the countdown 312 , then the display 118 is inverted 316 , and the backlight is preferably turned on if it is not already on. If the power button is not pressed 312 during the countdown, then no additional actions take place as a result of the power button press. After the display is inverted in step 316 , the countdown is once again begun 318 . However, if the power button is pressed during this or subsequent countdowns 320 , the display is again inverted at step 316 . This countdown cycle continues until the power button is not pressed during the countdown 320 .
Referring now to FIG. 4 , there is shown a flowchart of the operation of the power button functionality starting from a device-on state. Initially, the device is on, and the power key is pressed 400 . If the power key is being pressed for the first time 402 (e.g., it has not been pressed for at least the previous half second), no action is initially taken. If the power button is held down for longer than a threshold amount of time, e.g., 1 second 404 then the radio is toggled on or off 406 . If the power button is held down for less than the threshold amount 404 , then upon release a countdown of predetermined length, e.g., ½ second, is begun 408 . If the power button is not pressed 410 during the countdown, then the device is turned off 416 . If the power button is pressed 410 during the countdown, then the backlight is toggled on or off 412 . If the cycle is repeated and the power button is pressed for a third time during the countdown, then the display is inverted 414 , and the backlight is turned on if not already on. After the display is inverted 414 , another countdown is begun 416 . If the power button is pressed again 418 during the countdown, then the display is once again inverted 414 , and countdown 416 restarted. This continues until the countdown expires without the power button being pressed 418 .
In addition, in one embodiment pressing the power button 110 when there is an incoming call silences the ring or vibrate. Further, if a call is in progress, pressing the power button turns off the device 100 but does not terminate the call. Finally, if the device is off when a call comes in, the device is turned on, and the backlight is illuminated, which helps to locate the device 100 , e.g., in a poorly-lit room.
Lid
Referring again to FIG. 1 , there is shown a view of device 100 , having a lid 104 attached to base 102 . In FIG. 1 , lid 104 is connected to base 102 via a hinge or other mechanism that allows lid 104 to open and close. Note that the lid 104 may be connected to base 102 in any of a variety of ways while still including features described herein. The particular embodiment of FIG. 1 is therefore meant to illustrate only one of many possible configurations.
In one embodiment, lid 104 features a hardware switch for lid open and lid close detection, and may additionally include an integrated speaker for flip phone-like functionality. When closed, in one embodiment, lid 104 covers all of base 102 except for application and scroll buttons 106 . In one embodiment, lid 104 also includes a transparent window for viewing the display 118 of device 100 while the lid 104 is closed.
The effect of opening and closing the lid 104 varies according to the state of device 100 at the time the lid 104 is opened or closed. In one embodiment, and referring now to FIG. 5 , opening and closing the lid 104 has the following effect:
If the device is off, opening the lid turns on the device 100 , and launches 502 a predetermined application. In one embodiment, the predetermined application is a speed dial view of a telephone application, however in other embodiments the application can be any application on the device 100 , assignable by the user in one embodiment via a preferences control panel-type application. If the device is off, closing the lid has no effect 504 .
If the device is on, then it is in one of three states: either a call is in progress, a call is incoming, or there is no call activity.
If a call is incoming, then an incoming call notification is given to the user. An illustration of such a notification is shown in FIG. 8 . It will be appreciated that a user may be in the process of opening the lid when a call comes in. In such a situation, the user may not want to actually take the incoming call. For that reason, if the lid is opened within, in one embodiment, one second of the incoming call notification, no action is taken 506 (although the user can still answer the call in other ways, e.g., by tapping a dialog box 802 on the display of device 100 ). In other embodiments, the time maybe shorter or longer than one second. If the lid is opened more than one second after the initial incoming call notification, then the call is answered 508 . Note also that in one embodiment a user can choose to accept or ignore any incoming telephone call by selecting the answer 802 or ignore 804 options presented in a popup dialog box.
Similarly, if the user is in the process of closing the lid when a call comes in, it is desirable to assume that the lid is being closed not in response to the incoming call, but rather by coincidence. Thus if the lid is closed within an initial time, e.g., one second, of the first notification of an incoming call, no action is taken 510 . After this initial period, if the lid is closed, then in one embodiment the ring is silenced, the call is ignored, and the device is turned off 512 .
During an active call, the lid is open in a preferred embodiment, unless a headset is plugged in. If a call is in progress and the headset is being used, then opening the lid has no effect on the call 514 . If the lid is closed while a headset call is in progress, the device is turned off, but the call is not disconnected 516 . If a telephone call is in progress without using a headset, then closing the lid hangs up the telephone, in one embodiment after displaying a warning message confirming that the call is about to be disconnected, and turns the device off 518 . During the confirmation warning message, the user has the opportunity to tell the device not to disconnect the call, e.g. by pressing the scroll-up button. In alternative embodiments, the call is disconnected as soon as the lid is closed.
If a telephone call is not in progress, then in one embodiment, opening the lid when the device is already on has no effect 520 . That is, even if there is an application assigned to be launched upon the opening of the lid, when the power is already on, opening the lid does not launch the assigned application, but rather has no effect on what application is currently executing. Also, in one embodiment, if a call is not in progress, closing the lid turns the device off 522 .
In addition, in one embodiment keyboard 108 is deactivated when the lid 104 is closed, whether the device 100 is on or off This guards against inadvertent input to the device when pressure is applied to the lid, e.g., if the device is carried in a pocket, or if something heavy is placed on top of the device. In alternative embodiments, the keyboard 108 remains active at all times regardless of lid position. In one embodiment, application and scroll buttons 106 remain active even when the lid 104 is closed. This allows the scroll buttons to be used to respond to dialog boxes that may be presented to the user when the lid is closed. For example, if an alarm goes off, the user can dismiss the alarm by pressing a scroll button, instead of having to open the lid to tap the display 118 or press a button on the keyboard 108 .
Jog Rocker
Device 100 includes a jog rocker 114 such as is pictured in FIG. 1 . A jog rocker in one embodiment allows four input actions: up, down, press in, and press and hold.
While individual applications provide specific responses to input from jog rocker 114 , in one embodiment pressing the jog rocker 114 when device 100 is turned off wakes device 100 up and launches a predefined application, such as the phone application in one embodiment.
In one embodiment, this behavior is executed on jog rocker 114 press, not release, so that a press and hold of the jog rocker 114 wakes the device up, launches the predefined application on the press, and then executes within the application whatever that application has specified for a jog rocker 114 hold on the hold.
In another embodiment, jog rocker 114 can be used to provide a scroll-up and scroll-down function similar to that provided by scroll buttons 106 . In one embodiment this is the default use for jog rocker 114 when an application does not provide additional functionality for the jog rocker.
Ringer Switch
Ringer switch 116 is used in a preferred embodiment to select whether incoming telephone calls should produce an audible ringing sound on device 100 . In a first position, device 100 produces such a ring tone, which is customizable in one embodiment using application software stored on device 100 . In a second position, device 100 does not produce a ring tone for an incoming call. In one embodiment, device 100 is configured to vibrate in response to an incoming telephone call. The vibrate feature of device 100 may additionally be activated by applications executing on device 100 , for example even when ringer switch 116 is in the first position (the audible ring position).
In one embodiment, when ringer switch 116 is in the second position, all sounds made by device 100 are muted, and not just the ring tone. Thus, for example, while a number of applications executed on device 100 , e.g., an alarm, a message alert, etc., may instruct device 100 to produce a sound, the location of the switch in the second position will stop device 100 from actually making the sounds. In yet another embodiment, device 100 allows software resident on device 100 to override the physical setting of ringer switch 116 . This may be of particular use, for example, if the ringer switch is in the first position while a call is in progress and it is undesirable to have sounds from device 100 interfering with the call in an annoying fashion.
Application Buttons
A device such as device 100 typically has one or more application and scroll buttons 106 located physically on the device, providing direct access to applications associated with the buttons, as well as up-down and left-right scroll functionality. Using a keyboard 108 of device 100 , different applications are assignable to the application buttons 106 being pressed in combination with a modifier key. In one embodiment, an “option” key is the modifier key for these key combinations.
In one embodiment, the following applications are mapped to option and (“+”) application button combinations:
Option+Phone Application button maps to Memo Pad. Option+Calendar Application button maps to To-Do. Option+Internet Browser Application button maps to CityTime. Option+Messaging Application button maps to the calculator.
In one embodiment, the Option +Application button key combination works both in series and in parallel. For example, pressing and releasing the Option button (a serial combination), then pressing an application button 106 launches the application that is mapped to that application button's option modification. Similarly, pressing and holding the Option button while pressing the application button 106 (a parallel combination) also launches that application button's option modification.
If the option modification times out before the application button 106 is pressed, then the functionality is the same as if only the application button had been pressed.
Pressing and holding Option, and then pressing an application button 106 while Option is still held down also launches the application that is mapped to that applications button's option modification. What occurs if the user continues to hold the application button in is controlled on an application-by-application basis.
In one embodiment, the following application buttons 106 and combinations are mappable:
a Phone Application button a Calendar Application button an Internet Browser Application button a Messaging Application button
In alternative embodiments, the following combinations are also mappable:
Option+Calendar Application button Option+Phone Application button Option+Internet Browser Application button Option+Messaging Application button
Keyboard
In one embodiment, keyboard 108 includes the following keys:
a-z (26 keys) . (period) Symbol key Space Return Backspace Shift key Option key Menukey
FIG. 6 a illustrates one embodiment of a keyboard 108 layout. In FIG. 6A , the bottom label of each key indicates its normal character, while the top left label indicates its shift key character, and the top right label indicates its option key character.
FIG. 6 b illustrations just the number/punctuation keys extracted from FIG. 6 a.
In an unmodified state, the keys produce the main character printed on them. In one embodiment, there is no on screen-modification state indicator for the unmodified keyboard state. In Shift state, the keys produce a capital version of the main character printed on them, as illustrated in FIG. 6 a.
In Option state, the keys produce the alternate character illustrated in FIG. 6 b.
In one embodiment, pressing the Option key once puts device 100 in Option state. Pressing Option in Option state puts the device in Option Lock state. Pressing Option in Option Lock state clears the state. Option state is canceled upon the entry of the Option-modified character. Option Lock state is not canceled upon the entry of the Option-modified character, hence the Lock-ness. Option state can be canceled without entering a character by pressing the Option key twice (once for lock, the second for clear) or pressing backspace. Note that in one embodiment, backspace cancels Option state, but not Option Lock state.
Referring now to FIG. 7 a , in one embodiment, an on-screen modification state indicator 702 for Option state, which indicates to the user that the Option key has been pressed, is an oval tilted to have the same appearance as the shape of the Option key itself.
Referring now to FIG. 7 b , the on-screen modification state indicator 704 for Option Lock state is similar to the Option state indicator except with a “bottom bar”.
Holding down a key for a prolonged period causes the key to repeat. In one embodiment, all text entry has the same repeat rate, i.e. holding down the j produces j's at the same rate as holding down shift+j produces J's and option +j produces 5's. The Option and Shift keys both “time out” if additional input is not received within a prescribed period of time, e.g., 3 seconds in one embodiment. Note that in one embodiment the Option Lock and Shift Lock states do not time out.
In addition, in a preferred embodiment, when the currently executing application on device 100 changes from a first application to a second application, the Shift state is cleared to avoid unintended Shifted input into the second application.
Auto Word Completion
In order to provide a fast and easy way to enter awkward or often-misspelled text, device 100 includes a word auto-completion/correction system that in one embodiment checks every word that a user enters against a database of common misspellings and convenient abbreviations and replaces the entered word with a preset correct or complete version of the word. For example, if a user enters ‘beleive’, it will automatically be replaced with ‘believe’. If a user enters ‘im’, it will be replaced with ‘I'm’.
In one embodiment, Word Completion executes whenever a user enters any character that signals that they are finished typing the previous word, e.g.:
Space Any punctuation Tab Return Next or Previous Field
For instance, when a user types b,e,l,e,i,v,e the word ‘beleive’ is still displayed. If the user then enters a space (or any of the characters listed above) then ‘beleive’ is replace by ‘believe’. Typing backspace once will erase the space (or tab, new line, etc.) that invoked the Word Completion. Typing backspace a second time will undo the word completion without deleting the last character of the word. At this point, typing any of the characters that usually invoke Word Completion will not invoke it again.
If the replacement word in the database is not capitalized, then the capitalization of the word to be replaced is maintained. For instance, there is an entry in the Word Completion database that has the wrong word “feild” marked to be replaced with “field” so:
feild becomes field Feild become Field
If the replacement word in the database is capitalized, then the resulting word is capitalized no matter what the capitalization of the word to be replaced was. For instance, there is an entry in the Word Completion database that has the wrong word “im” marked to be replaced with “I'm” so:
im becomes I'm lm becomes I'm
Keyboard Navigation and Commands
In one embodiment, device 100 switches off or “sleeps” in order to conserve power after a predefined period of time. In such circumstance, pressing a key on the keyboard 108 wakes the device back up, i.e. restoring the device to a power on state in the same condition that it was in prior to going to sleep. In other embodiments, waking the device 100 up is equivalent to a power on command, which starts the device with a predefined initial application. Note that the keys which will wake the device up may be predetermined, or may be changeable by the user.
In one embodiment, some navigational activities of device 100 are keyboard enabled. Buttons such as “OK,” “Done,” and “Cancel” are mapped to certain keys and key combinations. Common actions, which may also be on-screen buttons like “New” and “Details . . . ,” are frequently included as menu items. These menu items have menu button+letter combinations assigned to them so that they may be executed easily from the keyboard 108 .
In one embodiment, menus on device 100 are navigable via a menu key and menu mode. Pressing and releasing a dedicated hardware menu key on keyboard 108 displays a first pull-down menu of the current view. Pressing and releasing the menu key a second time dismisses the menu.
While the menu is being displayed, in one embodiment the user can navigate the menus and execute menu items with the following actions:
Scroll Up displays the next menu list to the right.
Scroll Up from the last menu list scrolls back to the first. Holding Scroll Up repeats this action at the normal repeat rate.
Scroll Down moves a highlight down through the current displayed list of menu items.
Ifthere is no highlighted item, such as when the menu list is first displayed, then the first press of Scroll Down highlights the first menu item. Scroll Down from the last menu item in the list scrolls back to the first item in the same list. Holding Scroll Down repeats this action at the normal repeat rate.
Space executes the highlighted menu item on press. Return also executes the highlighted menu item on press. Backspace dismisses the menu. At any time when any menu is displayed, pressing any of the short cut letters executes the corresponding menu item, even if that menu item is in a menu list that is not currently displayed. Typing any character that is not detailed above or a short cut letter plays an error beep.
At any time, whether or not a menu is displayed, pressing and holding the menu key and pressing a one of the shortcut letters executes the corresponding menu item, in one embodiment, without the menu being drawn on the screen. Pressing and releasing the menu key and then pressing the shortcut letter will display the menu, however, in one embodiment.
Any menu that is being displayed is dismissed whenever a menu item is executed. Shift Lock and Option Lock are ignored when entering short cut letters. It is possible, however, to enter an option character as a short cut character in parallel:
User presses the menu button to enter menu mode User presses and holds Option User presses x for instance The menu item with the short cut character? would get executed, because the question mark (?) is formed by pressing Option-x. Pressing and releasing Option and then pressing x would execute the menu item with the short cut letter x.
Menu mode itself will not clear the modification state, but the execution of a menu item may clear the modifications state depending on what that menu item does.
User starts in Option Lock User presses the menu button User presses the menu button again to dismiss the menu The user should still be in Option Lock
Thus, when buttons containing certain text are on the screen, certain keys or key combinations can be pressed that will execute the buttons as if they were pressed on the screen.
The buttons that are mapped to the keyboard in one embodiment are:
OK Done Cancel Yes No Next Previous
The following four keys/key combinations are used for mapping to certain common on-screen buttons in one embodiment:
Return Backspace Option+Return Option+Backspace
Option+Return and Option+Backspace will work only in parallel.
Globally, in one embodiment:
Option+Return executes:
OK Done Yes Next Send Accept
Option+Backspace executes:
Cancel No Previous Back Reject
In one embodiment, if there is no opportunity for text entry on a particular screen, then the holding down of the Option key may be unnecessary. Thus, for example, within the context of alert dialogs:
Return executes:
OK Done Yes Next Send Accept
Backspace executes:
Cancel No Previous Back Reject
Return and Backspace do not map to buttons in other contexts in one embodiment, since in other contexts there will likely be text areas in which Return and Backspace benefit from their normal functionality.
In addition, in one embodiment the mappings described above also apply to non-English based applications. For example, Option+Return is mapped to “Oui” in a French language application. This allows a user to execute a foreign-language application on device 100 while providing similar functionality to an English-language application.
The foregoing discloses exemplary methods and embodiments of the present invention. It will be understood that the invention may be embodied in other forms and variations without departing from the spirit or scope of the invention. Accordingly, this disclosure of the present invention is illustrative, but not limiting, of the invention, the scope of which is defined by the following claims.
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An integrated device provides functionality of both a PDA and cellular telephone. Features include a power button offering control of both the computing and telephony functions of the device; a lid that turns the device on and off and controls additional telephony functions; a jog rocker that activates the device and is used to select from a variety of menu options; application buttons that offer direct access to applications stored on the device, and which can be configured to operate in conjunction with secondary keys to offer added functionality; a keyboard that enables data input into the device; an automatic word completion function that verifies and corrects a user's typing in real time; and a simplified keyboard navigation system that allows the navigation of menus using keyboard shortcuts.
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BACKGROUND
[0001] In the downhole drilling and completions industry packers or seal elements are ubiquitously used for a myriad of sealing and inhibition applications. There are many kinds of sealing elements available in the industry but since conditions encountered are ever changing, the industry is always receptive to new configurations providing sealing capability.
BRIEF DESCRIPTION
[0002] An assembly for reducing a radial gap between radially proximate components including a setting member having a first dimension that partially defines the radial gap, the setting member including a circumferential groove extending radially from the first dimension, and a first toroid having a second dimension, the setting member operatively arranged to engage with the first toroid, wherein increasingly engaging the setting member with the first toroid enables a boundary dimension of the assembly to be extended toward the radial gap for reducing the radial gap, the circumferential groove operatively arranged to catch the first toroid when the setting member is fully engaged with the first toroid.
[0003] A system including a pair of assemblies, each assembly including a setting member having a first dimension that partially defines the radial gap, the setting member including a circumferential groove extending radially from the first dimension, and a first toroid having a second dimension, the setting member operatively arranged to engage with the first toroid, wherein increasingly engaging the setting member with the first toroid enables a boundary dimension of the assembly to be extended toward the radial gap for reducing the radial gap, the circumferential groove operatively arranged to catch the first toroid when the setting member is fully engaged with the first toroid, and a plurality of subsequent toroids arranged in a sealing area between the first and second end assemblies.
[0004] A method of reducing a radial gap between radially proximate components including engaging a first toroid with a setting member, the setting member at least partially defining the radial gap and having a radially extending circumferential groove, increasingly engaging the setting member with the first toroid, wherein increasingly engaging the first toroid enables a boundary dimension of the assembly to be extended toward the radial gap for reducing the radial gap, and locating the first toroid in the circumferential groove when the setting member becomes fully engaged with the first toroid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
[0006] FIG. 1 is a quarter-sectional schematic view of an assembly for reducing an extrusion gap or the like, as described herein in a pre-deployment position;
[0007] FIG. 2 is a quarter-sectional schematic view of the assembly of FIG. 1 in a deployed position;
[0008] FIG. 3 is a quarter-sectional schematic view of another embodiment of a gap reducing assembly as described herein in a pre-deployment position;
[0009] FIG. 4 is a quarter-sectional schematic view of the assembly of FIG. 3 in a deployed position;
[0010] FIG. 5 is a quarter-sectional schematic view of the assembly of FIG. 3 in an alternate deployed position;
[0011] FIG. 6 is a quarter-sectional schematic view of an embodiment of a system including two end assemblies, each resembling the assembly of FIGS. 3-5 , in a pre-deployment position;
[0012] FIG. 7 is a quarter-sectional schematic view of the system of FIG. 6 in a deployed position;
[0013] FIG. 8 is perspective schematic view of two zones of a tubular or borehole isolated from each other according to an assembly resembling the assembly of FIGS. 1 and 2 ;
[0014] FIG. 9 is a quarter-sectional schematic view of the assembly of FIG. 8 generally taken along line 9 - 9 in FIG. 8 ; and
[0015] FIG. 10 is a quarter-sectional schematic view of an assembly resembling the assembly of FIG. 9 , but including a separate sealing element.
DETAILED DESCRIPTION
[0016] A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. Referring now to the drawings, FIGS. 1 and 2 show a quarter-section of an assembly 10 . The assembly 10 includes a mandrel 12 having a setting member or wedge 14 . The assembly 10 is located in an annulus 16 , which is formed between an outer circumferential surface 18 of the mandrel 12 and a bore wall 20 of a borehole 22 . However, it is to be appreciated that the assembly 10 could be installed in an annulus formed between any set of tubulars and/or boreholes. As used herein the term “tubular” may generally include any tube-like structure, whether cylindrical or not, such as a tube, pipe, collar, casing, tubing, liner, etc.
[0017] Wedge 14 has an outer dimension 24 and borehole 22 has a dimension 26 , with a gap 28 formed between the outer dimension 24 of the wedge 14 and wall 20 of the borehole 22 . For example, the dimensions 24 and 26 , or any other dimension referred to herein, could be radii, major radii, minor radii, diameters, distances from a reference point, etc. As described in more detail below, a toroid 30 (or a plurality of toroids 30 ) is included to seal, block, obstruct, close, or otherwise alleviate or prevent extrusion of a sealing element through the gap 28 . It is to be appreciated that with reference to the embodiments described herein, the term “toroid” as used herein relates generally to any annular, ring, or donut shaped body, regardless of cross-sectional geometry, and that the body may be solid, hollow, or otherwise hollow, but packed or filled with another material. The toroids described herein are generally stretchable, compressible, durable, resilient, and/or otherwise able to change in shape, size, thickness, etc. When applicable, the term “toroid” is to be interpreted broader than “torus” or “ring”, which both imply circumferential continuity. For example, as used herein, the term “toroid” encompasses bodies that are not only circumferentially continuous, but also bodies which contain a split, break, or open end, for example resembling a ‘c’ shape, such as is common with piston rings or the like. Thus, a toroid may be formed by rotating a cross-sectional shape at least partially about a line, where the line is in the same plane as the shape and does not intersect the shape. For example, the cross-sectional shape of each of the toroids 30 in FIG. 1 is a circle having a diameter 34 , with the diameter 34 defining the thickness of each of the toroids 30 , with toroid arranged coaxially with the borehole, mandrel, tubulars, etc. It is also to be understood however that toroids with varying cross-sectional shapes and varying dimensions may be used together in embodiments contemplated herein. That is, any assembly described herein could utilize consistently shaped and sized toroids, or have toroids of various shapes and sizes. For example, although each toroid shown herein has a generally circular cross-sectional shape, other shapes, such as ellipses, rings, etc. could be used. Furthermore, “toroid” could also refer to a body that is wound or coiled or woven, such as a coil spring or garter spring. For example, each toroid 30 could be a coil of a coil spring.
[0018] The term “wedge” is used herein to refer to the setting member and components or portions of the setting member, because the setting member is illustrated throughout the drawings as having a conical or frustoconical wedge shape. However, it is to be appreciated that the setting member could take various other shapes and arrangements. For example, in lieu of a tapered wedge, the setting member could include: discrete tiers or steps; a rounded bump or bulge; a lever; an inflatable portion, etc., for engaging under, in, or with the toroids in order to pry, stretch, expand, compress, or otherwise alter the shape, size, and/or position of the toroids (i.e., to set the toroids). Furthermore, it is to be appreciated that the setting member does not need to be circumferentially continuous, for example, the setting member could include a plurality of discrete portions (e.g., each having a wedge-shaped cross-section) spaced about a circumference of a mandrel.
[0019] The toroids 30 could act alone as a seal in order to isolate between zones of a borehole, or the toroids 30 could act as a backup for preventing a separate sealing element from extruding through the gap 28 . In the embodiment of FIGS. 1 and 2 , a material 32 is associated with the toroids 30 , e.g., the material 32 could be packed inside the toroids, surrounding the toroids, etc. The material 32 could be, for example, a filler material, an elastomer, a stainless steel mesh containing the toroids 30 , etc.
[0020] In order to obstruct the gap 28 for inhibiting or preventing extrusion, the wedge 14 is moved axially in the direction indicated by arrows 35 . This axial movement results in the toroids 30 engaging with the wedge and expanding as the wedge is inserted further into the toroids 30 . Effectively, this interplay between the wedge 14 and the toroids 30 enables a maximum outer dimension 36 of the assembly 10 to increase in order to block or obstruct the gap 28 . In FIG. 2 , the maximum outer dimension equals dimension 26 of the borehole 22 . The maximum outer dimension 36 is defined by the radially outermost point of the assembly 10 , which in FIG. 2 is the outer portion of a lead toroid 30 a , and in FIG. 1 is the outer dimension 24 of the wedge 14 . That is, the lead toroid 30 a is expanded as the wedge 14 is inserted until the lead toroid 30 a becomes lodged between the wedge 14 and the wall 20 of the borehole 22 . It is to be appreciated that the lead toroid 30 a is marked with an identifier ‘a’ for sake of discussion only, and otherwise any description of toroids 30 applies generally to lead toroid 30 a . Expansion of the lead toroid 30 a creates a blockage in gap 28 for, as noted above, isolating zones of the borehole 22 on opposite sides of the gap 28 or providing a backup function for a separate sealing element that seals and isolates the zones of the borehole 22 . In one embodiment, the sealing element takes the form of a plurality of toroids 30 behind the lead toroid 30 a , with the other toroids 30 lodging together behind the lead toroid 30 a . In addition to the toroids 30 , the material 32 may also assist to obstruct or seal the gap 28 and/or annulus 16 by further impeding passage of sediment, hydrocarbons, debris, or any other substance or particles present in the borehole 22 .
[0021] Wedge 14 also includes a circumferential groove 38 extending radially inwardly from the outer dimension 24 of the wedge 14 . In the event that one of the toroids 30 traverses the entirety of the tapered portion of the wedge, and expands over the outer dimension 24 of the wedge, the groove 38 is included to catch that toroid. This locks the toroid to the wedge so that the toroid essentially becomes a part of the wedge, and further toroids that traverse the entirety of the wedge 14 may engage with, and expand around, the locked toroid. This is described in more detail below with respect to FIG. 5 .
[0022] Referring to FIGS. 3-5 , a second embodiment is shown, designated generally as an assembly 40 . The assembly 40 resembles the assembly 10 in several respects, and unless otherwise noted, any description of elements of assembly 10 applies generally to corresponding elements of the assembly 40 . The assembly 40 includes a mandrel 42 having a wedge device 44 made up of an inner wedge 46 and an outer wedge 48 . That is, the inner wedge 46 is generally positioned radially inwardly from the outer wedge 48 . In the embodiment of FIG. 3 , the assembly 40 is located in an annulus 50 between a wall 52 of a borehole 54 and an outer surface 56 of the mandrel 42 . The inner wedge 46 and the outer wedge 48 are substantially conical or frustoconical in shape, and include tapered shoulders 58 and 60 , respectively. In the currently described embodiment, a toroid 62 is located axially in front of the wedge device 44 and has an outer dimension 64 , which is approximately equal to an outer dimension 66 of the wedge device 44 .
[0023] Initially, as shown in FIG. 3 , the inner wedge 46 and the outer wedge 48 are arranged such that the inner wedge 46 is located radially inwardly of the outer wedge 48 . This initial arrangement deters the toroid 62 from engaging with the shoulder 58 of the inner wedge 46 until the wedge device 44 is set. The toroid 62 is also deterred from engaging with the shoulder 60 of the outer wedge 48 because a minimum outer dimension 68 of the shoulder 60 of the outer wedge 48 of the wedge device 44 is located radially outwardly from a center 70 of the cross-sectional shape that forms the toroid 62 (e.g., in FIG. 3 a circle is the cross-sectional shape that forms the toroid).
[0024] By moving the inner wedge 46 axially toward the toroid 62 in the direction indicated by arrows 72 in FIG. 4 , the inner wedge 46 of the wedge device 44 is inserted radially inwardly of the toroid 62 , and the toroid 62 engages with the shoulder 58 of the inner wedge 46 . The inner wedge 46 could be moved, for example, via an electrical, hydraulic, and/or mechanical actuating configuration that in one embodiment applies a load on a radially extending projection or flange 74 of the inner wedge 46 . As the inner wedge 46 is loaded further, the toroid 62 expands radially outwardly around the wedge device 44 , effectively enabling an increase in the maximum outer dimension of the assembly 40 in order to close or block a gap 76 formed between the wedge device 44 and the wall 52 of the borehole 54 . A lead toroid 62 a is shown in FIG. 4 engaged with, and expanded by, the shoulder 60 of the outer wedge 48 to the extent that the lead toroid 62 a has also engaged the wall 52 of the borehole 54 . In other words, since the gap 76 is smaller than a dimension 78 of the cross-section of the toroid 62 a , the wedge device 44 has lodged the lead toroid 62 a in the gap 76 between the outer wedge 48 and the wall 52 of the borehole 54 . Similarly to the lead toroid 30 a , the identifier ‘a’ is used with lead toroid 62 a for the sake of discussion only, and any description generally to toroids 62 is applicable to lead toroid 62 a . Thus, as can be seen by comparing FIGS. 3 and 4 , the maximum outer dimension of the assembly 40 has shifted from the outer dimension 66 of the wedge device 44 to the outer dimension of the lead toroid 62 a , which equals a dimension 80 of the borehole 54 because the lead toroid 62 a has contacted the wall 52 of the borehole 54 .
[0025] Relative movement between the inner wedge 46 and the outer wedge 48 is possible, for example, by the lead toroid 62 a blocking forward movement of the outer wedge 48 . The radially extending flange 74 of the inner wedge 46 acts as a stop for limiting the amount of relative movement between the inner wedge 46 and the outer wedge 48 by receiving a radially extending flange 82 of the outer wedge 48 . Relative movement is also prevented in the opposite direction because the inner wedge 46 and the outer wedge 48 include complementary ratcheting teeth 84 . The complementarily arranged ratchet teeth 84 restrict the axial movement of the inner wedge 46 relative to the outer wedge 48 to only the direction indicated by the arrows 72 . Thus, once the flange 82 of the outer wedge 48 has contacted the flange 74 of the inner wedge 46 , the two wedge portions are essentially locked together such that the shoulders 58 and 60 form a single ramp for expanding the toroids 62 (as shown in FIGS. 4 and 5 ).
[0026] In FIG. 5 , the borehole 54 is illustrated having a dimension 80 ′ greater than the dimension 80 as shown in FIGS. 3 and 4 . For example, this could occur if the borehole 54 later became washed out. As a result, a gap 76 ′ in FIG. 5 is larger than the gap 76 in FIGS. 3 and 4 , and also larger than the dimension 78 of the cross-sectional shape of the toroids 62 . As a result, the lead toroid 62 a is able to completely traverse the shoulder 60 of the outer wedge 48 . Similar to groove 38 , a circumferential groove 86 is included in the outer wedge 48 . Also similar to the groove 38 , if one of the toroids 62 , such as lead toroid 62 a , traverses the entirety of the shoulder 60 of the outer wedge 48 , that toroid will become locked in the groove 86 . For example, lead toroid 62 a is shown locked in groove 86 in FIG. 5 .
[0027] Once one of the toroids 62 becomes locked in the groove 86 , that toroid effectively becomes part of the wedge device 44 . That is, the lead toroid 62 a that becomes locked may act like a ramp to essentially increase the size of the wedge device 44 , for subsequent toroids, such as a secondary toroid 62 b , to engage with and expand around. Similar to the identifiers ‘a’ discussed above, it is to be appreciated that the identifier ‘b’ is used for the sake of discussion only, and any description of toroids 62 generally applies to secondary toroid 62 b . Thus, in the embodiment depicted in FIG. 5 , it is the secondary toroid 62 b , not the lead toroid 62 a , that obstructs the gap 76 ′ by engaging with the wall 52 of the borehole 54 . It is to be appreciated that up to three toroids can stack themselves in a stable arch in order to bridge a gap, such as the gap 76 or 76 ′. Therefore, the gap 76 or 76 ′, measured between the outer dimension 66 of the wedge device 44 (which could be measured as shown in any of FIGS. 3-5 ), and the wall 52 of the borehole 54 , can equal up to three times the dimension 78 of the cross-sectional shape of the toroids 62 .
[0028] A packer device 90 is shown in FIGS. 6 and 7 . The device 90 includes a mandrel 92 having a first end assembly 94 and a second end assembly 96 . The end assemblies 94 and 96 both generally resemble the wedge device 44 in that they include two conical or frustoconical wedge portions that can be arranged into single ramp by way of relative movement between the two portions. Specifically, the first end assembly 94 includes an inner wedge 98 and an outer wedge 100 , while the second end assembly 96 includes an inner wedge 102 and an outer wedge 104 . Similar to the wedge device 44 , each of the first and second end assemblies 94 and 96 may include complementarily arranged ratcheting teeth between their corresponding inner and outer wedges, and/or radially extending projections, for limiting the relative movement between their corresponding inner and outer wedges, as described above.
[0029] Also similar to the assemblies discussed above, the device 90 is located in an annulus 106 formed between a wall 108 of a borehole 110 and an outer surface 112 of the mandrel 92 . Additionally, the device 90 is included to engage with toroids 114 in order to cause the toroids 114 to seal, block, obstruct, or close a set of gaps 116 and 118 , located between the wall 108 of the borehole 110 and the first and second end assemblies 94 and 96 , respectively. A first lead toroid 114 a is positioned in front of first end assembly 94 and a second lead toroid 114 b is positioned in front of second end assembly 96 , with a plurality of other toroids 114 located between the lead toroids 114 a and 114 b.
[0030] The first end assembly 94 operates similarly to the wedge assembly 44 . A setting device presses the first end assembly 94 axially in the direction of arrows 120 in order to move the first end assembly 94 along the mandrel 92 . Unlike the wedge assembly 44 , the first end assembly 94 includes a dog 122 that restricts relative movement between the inner wedge 98 and the outer wedge 100 , for example, by being held in an opening 124 of the inner wedge 98 and a notch 126 in the outer wedge 100 . Then, when the first end assembly 94 passes over a receiving area 128 , the dog 122 can drop out, thereby enabling relative movement between the inner wedge 98 and the outer wedge 100 (at least until the relative movement is restricted again, for example by ratcheting teeth and/or radially extending flanges, as described above with respect to FIGS. 3-5 ).
[0031] The inner wedge 98 of the first end assembly 94 is connected to the outer wedge 104 of the second end assembly 96 via a connecting element 130 , which could be, for example, a fixed length of stainless steel mesh. Movement of the inner wedge 98 will exert a force on the lead toroid 114 a , which will transfer to the outer wedge 104 via the toroids 114 and 114 b . Since the inner wedge 98 is fixed to the connecting element 130 , movement of the inner wedge 98 will result in the connecting element 130 also moving, which will in turn enable the outer wedge 104 to move in the direction of the arrows 120 . The movement of the outer wedge 104 exposes the tapered shoulder of the inner wedge 102 so that second lead toroid 114 b can engage with the shoulder of the inner wedge 102 and expand. The inner wedge 102 does not move because it is fixed to the mandrel 92 at an anchor point 132 .
[0032] Once the dog 122 is released into the receiving area 128 and relative movement between the inner wedge 98 and outer wedge 100 is possible, the inner wedge 98 will move away from the toroids 114 , exposing the tapered shoulder of the inner wedge 98 to the toroids 114 , thereby enabling the lead toroids 114 a to engage with the shoulder of the inner wedge 98 and expand as the inner wedge 98 is inserted therethrough. Inner wedge 98 will be pressed in the direction of the arrows 120 until the gaps 116 and 118 are obstructed by toroids 114 a and 114 b , respectively, as shown in FIG. 7 . Also, the outer wedges 100 and 104 may include circumferential grooves 134 and 136 , respectively, which are included for the same purpose as grooves 38 and 86 . Thus, additional toroids 114 may expand over the lead toroids 114 a or 114 b if the lead toroids become locked in their respective grooves 134 or 136 , with up to three of the toroids 114 able to bridge in a stable arch in order to obstruct the gaps 116 and 118 .
[0033] From FIGS. 8 and 9 it can be better appreciated how a system according to the current invention could be used in order to isolate zones of a borehole, or tubular, from each other. For example, an assembly 140 is shown including a plurality of toroids 142 in a sealing area 144 , with the sealing area 144 separating a first zone 146 from a second zone 148 in a sealed manner. In FIGS. 8 and 9 , the toroids 142 are shown specifically in the form of garter springs located between a first wedge 150 and a second wedge 152 . The toroids 142 are arranged to obstruct extrusion gaps located between the sealing area 144 and the zones 146 and 148 . For example, FIG. 9 shows a gap 154 , located between the wedge 150 and a wall 156 of a borehole 158 , being obstructed by a plurality of the toroids 142 . The wedges 150 and 152 may include grooves 160 and 162 , respectively. Grooves 160 and 162 resemble grooves 38 and 86 , and are included for the same reasons. In view of FIGS. 8 and 9 , it is to be appreciated that sealing of an annulus 164 , located between a mandrel 166 and the borehole 158 , is accomplishable by packing and lodging many of the toroids 142 together.
[0034] FIG. 10 illustrates an alternate embodiment for the assembly 140 , generally designated as an assembly 140 ′. Specifically with respect to the embodiment of FIGS. 8 and 9 , many of the toroids 142 in the sealing area 144 have been replaced with a sealing element 168 . The sealing element 168 could be any suitable sealing element used with packer assemblies. As is further appreciable in view of FIG. 10 , the toroids 142 are acting as a backup to prevent extrusion of the sealing element 168 through the gap 154 , so that the sealing element 168 can seal the annulus 164 between the mandrel 166 and the borehole 158 .
[0035] It is of course to be appreciated that the components of the various embodiments discussed herein could be interchanged with corresponding or similar components in other discussed variants, or with any other equivalents or substitutes, and that such modifications are within the intended scope of the current disclosure. For example, first and second wedges 150 and 152 could be replaced by any of the other assemblies discussed herein, or the sealing area 144 could be filled with, or surrounded by, stainless steel mesh, steel wool, elastomers, filler material, etc. Furthermore, it is to be appreciated that any of the assemblies described herein could be used as both a backup and a sealing element, or as a backup for a separate sealing element.
[0036] It is also to be understood that while the above-described embodiments refer to expanding the toroids to obstruct radially outwardly located gaps, these dimensions could be reversed or inverted. That is, for example, instead of a conical wedge, the setting member could take the form of a funnel arranged radially outwardly from the toroids, for compressing the toroids to obstruct a radially inwardly located gap. For example, the toroids could be made from a partially compressible material, or could take the form of a pre-stretched or plastically deformed garter spring. It is to be noted that illustrations for such inverted embodiments would virtually identically resemble the Figures disclosed herein, as the cross- or quarter-sections would be essentially mirror images of each other. Thus, generally according to the embodiments of the current invention, increasingly engaging a toroid with a suitable setting member (regardless of expansion or compression) results in the setting member altering the toroid (e.g., enlarging or compressing) in order to change a boundary dimension (e.g., a maximum outer dimension, a minimum inner dimension, etc.) of an assembly by extending the boundary dimension of the assembly radially toward the gap to be obstructed.
[0037] While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
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A method and assembly for reducing a radial gap between radially proximate components including a setting member having a first dimension that partially defines the radial gap, the setting member including a circumferential groove extending radially from the first dimension, and a first toroid having a second dimension, the setting member operatively arranged to engage with the first toroid, wherein increasingly engaging the setting member with the first toroid enables a boundary dimension of the assembly to be extended toward the radial gap for reducing the radial gap, the circumferential groove operatively arranged to catch the first toroid when the setting member is fully engaged with the first toroid.
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PRIORITY INFORMATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/356,061 on Feb. 11, 2002.
FIELD OF THE INVENTION
[0002] The field of this invention relates to techniques for repair of collapsed or otherwise damaged tubulars in a well.
BACKGROUND OF THE INVENTION
[0003] At times, surrounding formation pressures can rise to a level to actually collapse well casing or tubulars. Other times, due to pressure differential between the formation and inside the casing or tubing, a collapse is also possible. Sometimes, on long horizontal runs, the formation surrounding the tubulars in the well can shift in such a manner as to kink or crimp the tubulars to a sufficient degree to impede production or the passage of tools downhole. Past techniques to resolve this issue have been less than satisfactory as some of them have a high chance of causing further damage, while other techniques were very time consuming, and therefore expensive for the well operator.
[0004] One way in the past to repair a collapsed tubular downhole was to run a series of swages to incrementally increase the opening size. These tools required a special jarring tool and took a long time to sufficiently open the bore in view of the small increments in size between one swage and the next. Each time a bigger swage was needed, a trip out of the hole was required. The nature of this equipment required that the initial swage be only a small increment of size above the collapsed hole diameter. The reason that small size increments were used was the limited available energy for driving the swage using the weight of the string in conjunction with known jarring tools. Tri-State Oil Tools, now a part of Baker Hughes Incorporated, sold casing swages of this type.
[0005] Also available from the same source were tapered mills having an exterior milling surface known as Superloy. These tapered mills were used to mill out collapsed casing, dents, and mashed in areas. Unfortunately, these tools were difficult to control with the result being an occasional unwanted penetration of the casing wall. In the same vein and having similar problems were dog leg reamers whose cutting structures not only removed the protruding segments but sometimes went further to penetrate the wall.
[0006] What is needed and is an object of the invention is a method and apparatus to allow repair of collapsed or bent casing or tubulars in a single trip using an expansion device capable of delivering the desired final internal dimension. The method features anchoring the device adjacent the target area, using a force multiplier to obtain the starting force for expansion, and stoking the swage as many times as necessary to complete the repair. These and other advantages of the present invention will become clearer to those skilled in the art from a review of the detailed description of the preferred embodiment and the claims below.
SUMMARY OF THE INVENTION
[0007] A method of repairing tubulars downhole is described. A swage is secured to a force magnification tool, which is, in turn, supported by an anchor tool. Applied pressure sets the anchor when the swage is properly positioned. The force magnification tool strokes the swage through the collapsed section. The anchor can be released and weight set down on the swage to permit multiple stroking to get through the collapsed area. The swage diameter can be varied.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIGS. 1 a - 1 d show the anchor in the run in position;
[0009] [0009]FIGS. 2 a - 2 d show the anchor in the set position;
[0010] [0010]FIGS. 3 a - 3 e show the force magnification tool in the run in position;
[0011] [0011]FIG. 4 is a swage that can be attached to the force magnification tool of FIGS. 3 a - 3 e.
[0012] [0012]FIGS. 5 a - 5 c are a sectional elevation view of the optional adjustable swage shown in the run in position;
[0013] [0013]FIGS. 6 a - 6 c are the view of FIGS. 5 a - 5 c in the maximum diameter position for actual swaging;
[0014] [0014]FIGS. 7 a - 7 c are the views of FIGS. 6 a - 6 c shown in the pulling out position after swaging
[0015] [0015]FIG. 8 is a perspective view of the adjustable swage during run in;
[0016] [0016]FIG. 9 is a perspective view of the adjustable swage in the maximum diameter position;
[0017] [0017]FIG. 10 is a perspective view of the adjustable swage in the pulling out of the hole position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring to FIG. 1 a , the anchor 10 has a top sub 12 , which is connected at thread 14 to body 16 . A rupture disc 20 closes off a passage 18 . At its lower end, the body 16 is connected to bottom sub 22 at thread 24 . Body 16 supports a seat 26 with at least one snap ring 28 . A seal 30 seals between body 16 and seat 26 . The purpose of seat 26 is to receive a ball 31 (FIG. 1C) to allow pressure buildup in passage 32 to break rupture disc 20 , if necessary. A passage 34 communicates with cavity 36 to allow pressure in passage 32 to reach the piston 38 . Seals 40 and 42 retain the pressure in cavity 36 and allow piston 38 to be driven downwardly. Piston 38 bears down on a plurality of gripping slips 40 , each of which has a plurality of carbide inserts or equivalent gripping surfaces 42 to bite into the casing or tubular. The slips 40 are held at the top and bottom to body 16 using band springs 44 in grooves 46 . The backs of the slips 40 include a series of ramps 48 that ride on ramps 50 on body 16 . Downward, and by definition outward movement of the slips 40 is limited by travel stop 52 located at the end of bottom sub 22 . FIG. 2 shows the travel stop 52 engaged by slips 40 . The thickness of a spacer 54 can be used to adjust the downward and outward travel limit of the slips 40 .
[0019] Located below the slips 40 is closure piston 56 having seals 58 and 60 and biased by spring 62 . A passage 64 allows fluid to escape as spring 62 is compressed when the slips 40 are driven down by pressure in passage 34 . Closure piston 56 is located in chamber 57 with ratchet piston 59 . A ratchet plug 61 is biased by a spring 63 and has a passage 65 though it. A dog 67 holds a seal 69 in position against surface 71 of ratchet piston 59 . A seal 73 seals between piston 59 and bottom sub 22 . Area 75 on piston 59 is greater than area 77 on the opposite end of piston 59 . In normal operation, the ratchet piston 59 does not move. It is only when the slips 40 refuse to release and rupture disc 20 is broken, then pressure drives up both pistons 56 and 59 to force the slips 40 to release and the ratchet teeth 79 and 81 engage to prevent downward movement of piston 56 . Passage 65 allows fluid to be displaced more rapidly out of chamber 83 as piston 59 is being forced up.
[0020] Referring now to FIG. 3, the pressure-magnifying tool 66 has a top sub 68 connected to bottom sub 22 of anchor 10 at thread 70 . A body 72 is connected at thread 74 to top sub 68 . A passage 76 in top sub 68 communicated with passage 32 in anchor 10 to pass pressure to upper piston 78 . A seal 80 is retained around piston 78 by a snap ring 82 . Piston 78 has a passage 84 extending through it to provide fluid communication with lower piston 86 through tube 88 secured to piston 78 at thread 90 . Shoulder 92 is a travel stop for piston 78 while passage 94 allows fluid to move in or out of cavity 96 as the piston 78 moves. Tube 88 has an outlet 98 above its lower end 100 , which slidably extends into lower piston 86 . Piston 86 has a seal 102 held in position by a snap ring 104 . Tube 106 is connected at thread 108 to piston 86 . A lower sub 110 is connected at thread 112 to tube 106 to effectively close off passage 114 . Passage 114 is in fluid communication with passage 76 . Passage 116 allows fluid to enter or exit annular space 118 on movements of piston 86 . Shoulder 120 on lower sub 110 acts as a travel stop for piston 86 . A ball 122 is biased by a spring 124 against a seat 126 to seal off passage 128 , which extends from passage 114 . As piston 86 reaches its travel limit, ball 122 is displaced from seat 126 to allow pressure driving the piston 86 to escape just as it comes near contact with its travel stop 120 . Thread 130 allows swage body 132 (see FIG. 4) to be connected to pressure magnifying tool 66 .
[0021] The illustrated swage 134 is illustrated schematically and a variety of devices are attachable at thread 130 to allow the repair of a bent or collapsed tubular or casing 136 by an expansion technique.
[0022] The operation of the tool in the performance of the service will now be explained. The assembly of the anchor 10 , the force magnifying tool 66 and the swage 134 are placed in position adjacent to where the casing or tubular is damaged. Pressure applied to passage 32 reaches piston 38 , pushing it and slips 40 down with respect to body 16 . Ramps 48 ride down ramps 50 pushing the slips 40 outwardly against the return force of band springs 44 . Inserts 42 bite into the casing or tubing and eventually slips 40 hit their travel stop 52 . Piston 56 is moved down against the bias of spring 62 . The pressure continues to build up after the slips 40 are set, as shown in FIG. 2. The pressure applied in passage 76 of pressure magnification tool 66 forces pistons 78 and 86 to initially move in tandem. This provides a higher initial force to the swage 134 , which tapers off after the piston 78 hits travel stop 92 . Once the expansion with swage 134 is under way, less force is necessary to maintain its forward movement. The tandem movement of pistons 78 and 86 occurs because pressure passes through passage 84 to passage 98 to act on piston 86 . Movement of piston 78 moves tube 88 against piston 86 . After piston 78 hits travel stop 92 , piston 86 completes its stroke. Near the end of the stroke, ball 122 is displaced from seat 126 removing the available driving force of fluid pressure as piston 86 hits travel stop 120 . With the pressure removed from the surface, spring 62 returns the slips 40 to their original position by pushing up piston 56 . If it fails to do that, a ball (not shown) is dropped on seat 26 and pressure to a high level is applied to rupture the rupture disc 20 so that piston 56 can be forced up with pressure. When piston 56 is forced up so is piston 59 due to the difference in surface areas between surfaces 75 and 77 . Ratchet plug 61 is pushed up against spring 63 as fluid is displaced outwardly through passage 65 . Ratchet teeth 79 and 81 lock to prevent downward movement of piston 56 . If more of casing or tubing 136 needs to be expanded, weight is set down to return the force-magnifying tool 66 to the run in position shown in FIG. 3 and the entire cycle is repeated until the entire section is repeated to the desired diameter with the swage 134 .
[0023] Those skilled in the art can see that the force-magnifying tool 66 can be configured to have any number of pistons moving in tandem for achieving the desired pushing force on the swage 134 . Optionally, the swage can be moved with no force magnification. The nature of the anchor device 10 can be varied and only the preferred embodiment is illustrated. The provision of an adjacent anchor to the section of casing or tubular being repaired facilitates the repair because reliance on surface manipulation of the string, when making such repairs is no longer necessary. Multiple trips are not required because sufficient force can be delivered to expand to the desired finished diameter with a swage such as 134 . Even greater versatility is available if the swage diameter can be varied downhole. With this feature, if going to the maximum diameter in a single pass proves problematic, the diameter of the swage can be reduced to bring it through at a lesser diameter followed by a repetition of the process with the swage then adjusted to an incrementally larger diameter. Optionally the anchor 10 can also include centralizers 138 and 140 . A single or multiple cones or other camming techniques can guide out the slips 40 . Spring 63 can be a bowed snap ring or a coiled spring. Slips 40 can have inserts 42 or other types of surface treatment to promote grip into the casing or tubular.
[0024] Additional flexibility can be achieved by using flexible swage 138 . FIG. 8 shows it in perspective and FIGS. 5 a - 5 c show how it is installed above a fixed swage 134 . The adjustable swage 138 comprises a series of alternating upper segments 140 and lower segments 142 . The segments 140 and 142 are mounted for relative, preferably slidable, movement. Each segment, 140 for example, is dovetailed into an adjacent segment 142 on both sides. The dovetailing can have a variety of shapes in cross-section, however an L shape is preferred with one side having a protruding L shape and the opposite side of that segment having a recessed L shape so that all the segments 140 and 142 can form the requisite swage structure for 360 degrees around mandrel 144 . Mandrel 144 has a thread 146 to connect, through another sub (not shown) to thread 130 shown in FIG. 3 e at the lower end of the pressure magnification tool 66 . The opening 148 made by the segments 140 and 142 (see FIG. 8) fits around mandrel 144 .
[0025] Segments 140 have a wide top 150 tapering down to a narrow bottom 152 with a high area 154 , in between. Similarly, the oppositely oriented segments 142 have a wide bottom 156 tapering up to a narrow top 158 with a high area 160 , in between. The high areas 154 and 160 are preferably identical so that they can be placed in alignment, as shown in FIG. 6 a . The high areas 154 and 160 can also be lines instead of bands. If band areas are used they can be aligned or askew from the longitudinal axis. The band area surfaces can be flat, rounded, elliptical or other shapes when viewed in section. The preferred embodiment uses band areas aligned with the longitudinal axis and slightly curved. The surfaces leading to and away from the high area, such as 162 and 164 for example can be in a single or multiple inclined planes with respect to the longitudinal axis.
[0026] Segments 140 have a preferably T shaped member 166 engaged to ring 168 . Ring 168 is connected to mandrel 144 at thread 170 . During run in a shear pin 172 holds ring 168 to mandrel 144 . Lower segments 142 are retained by T shaped members 174 to ring 176 . Ring 176 is biased upwardly by piston 178 . The biasing can be done in a variety of ways with a stack of Belleville washers 180 illustrated as one example. Piston 178 has seals 182 and 184 to allow pressure through opening 186 in the mandrel 144 to move up the piston 178 and pre-compress the washers 180 . A lock ring 188 has teeth 190 to engage teeth 192 on the fixed swage 134 , when the piston 178 is driven up. Thread 194 connects fixed swage 134 to mandrel 144 . Opening 186 leads to cavity 196 for driving up piston 178 . Preferably, high areas 154 and 160 do not extend out as far as the high area 198 of fixed swage 134 during the run in position shown in FIG. 5. The fixed swage 134 can have the variation in outer surface configuration previously described for the segments 140 and 142 .
[0027] The operation of the method using the flexible swage 138 will now be described. The assembly of the anchor 10 , the force magnifying tool 66 , the flexible swage 138 shown in the run in position of FIG. 5, and the fixed swage 134 are advanced to the location of a collapsed or damaged casing 133 until the swage 134 makes contact (see FIG. 4). At first, an attempt to set down weight could be tried to see if swage 134 could go through the damaged portion of the casing 133 . If this fails to work, pressure is applied from the surface. This applied pressure could force swage 134 through the obstruction by repeated stroking as described above. If the fixed swage 134 goes through the obstruction, the flexible swage could then land on the obstruction and then be expanded and driven through it, as explained below. As previously explained, the slips 40 of anchor 10 take a grip. Additionally, pressure from the surface can start the pistons 78 and 86 moving in the force magnification tool 66 . Finally, pressure from the surface enters opening 186 and forces piston 178 to compress washers 180 , as shown in FIG. 6 b . Lower segments 142 rise in tandem with piston 178 and ring 176 until no further uphole movement is possible. This can be defined by the contact of the segments 140 and 142 with the casing or tubular 133 . This contact may occur at full extension illustrated in FIG. 6 b or 9 , or it may occur short of attaining that position. The full extension position is defined by alignment of high areas 154 and 160 . Washers 180 apply a bias to the lower segments 142 in an upward direction and that bias is locked in by lock ring 188 as teeth 190 and 192 engage as a result of movement of piston 178 . At this point, downward stroking from the force magnification tool 66 forces the swage downwardly. The friction force acting on lower segments 142 augments the bias of washers 180 as the flexible swage 138 is driven down. This tends to keep the flexible swage at its maximum diameter for 360 degree swaging of the casing or tubular 133 . The upper segments do not affect the load on the washers 180 when moving the flexible swage 138 up or down in the well, in the position shown in FIG. 6 a.
[0028] When it is time to come out of the hole it will be desirable to offset the alignment of the high areas 154 and 160 . When aligned, these high areas exceed the nominal inside diameter of the casing or tubing 133 by about 0.150 inches or more. To avoid having to pull under load to get out of the hole, the mandrel 144 can be turned to the right. This will shear the pin 172 as shown in FIG. 7 a . Ring 168 will rise, taking with it the upper segments 140 . High areas 154 and 160 will be offset and at a sufficiently reduced diameter due to this movement to be brought out of the casing or tubing without expanding it on the way out. The reason the dimension on full alignment of high areas 154 and 160 exceeds the nominal casing or tubing inside diameter is that the casing or tubing 133 has a memory and bounces back after expansion. The objective is to have the final inside diameter be at least the original nominal value. Therefore the expansion with the flexible swage 138 has to go about 0.150 inches beyond the desired end dimension. The angled configuration of the segments, which interlock on a straight track allows the desired outer diameter variation and could be configured for other desired differentials between the smallest diameter for run in and the largest diameter for swaging. It should be noted that the swaging could begin at a diameter less than that shown in FIGS. 6 a or 9 . The swaging diameter can grow as the swaging progresses due to the combined forces of washers 180 , friction forces on surfaces 164 and the condition of the casing or tubular 133 .
[0029] Those skilled in the art will appreciate that swaging can be done going uphole rather than downhole; if the flexible swage 138 shown in FIG. 5 is inverted above the fixed swage 134 . The flexible swage 138 can be used in the described method or in other methods for swaging downhole using other associated equipment or simply the equipment shown in FIG. 5. The advantages of full 360 degree swaging at variable diameters makes the flexible swage 138 an improvement over past spring or arm mounted roller swages, which had the tendency to cold work the pipe too much and cause cracking. The collet type swages would not always uniformly extend around the 360 degree periphery of the inner wall of the casing or tubular causing parallel stripes of expanded and unexpanded zones with the potential of cracks forming at the transitions. The interlocking or side guiding of the segments 140 and 142 presents a more reliable way to swage around 360 degrees and provides for simple run in and tripping out of the hole. It can also allow for expansions beyond the nominal inside dimension, with the ability to trip out quickly while not having to do any expanding on the way in or out.
[0030] The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the spirit of the invention.
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A method of repairing tubulars downhole is described. A swage is secured to a force magnification tool, which is, in turn, supported by an anchor tool. Applied pressure sets the anchor when the swage is properly positioned. The force magnification tool strokes the swage through the collapsed section. The anchor can be released and weight set down on the swage to permit multiple stroking to get through the collapsed area. The swage diameter can be varied.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35 U.S.C. §119(e) to copending U.S. Provisional Patent Application No. 61/431,888, filed Jan. 12, 2011, the content of which is incorporated herein by reference in its entirety.
BACKGROUND AND SUMMARY
[0002] The present disclosure is related to a tool for cleaning hooves of hooved animals, such as horses. In particular, the present disclosure is directed to a tool, commonly known as a hoof pick, which is used to remove dirt, mud, stones, and like material from animal hooves. Further, the present disclosure includes an illumination source configured to direct a light beam in the direction of the working area of the tool.
[0003] For example, hooved animals such as domesticated horses are frequently used for recreational riding or rock trips. Such recreational riding frequently occurs on surfaces of dirt, clay, mud, etc. or on paved or gravel roads. The surface material is impacted into the animal's hooves forming a hard dense concrete-like mass. Stones and/or gravel often become wedged in the grooves of the hoof or between the hoof and a protective shoe. If left for extended periods, this can result in injury to the animal, such as lameness. Before and after the animal has been ridden, it is good practice for the rider or other caretaker to groom the animal including removing the impacted material from the animal's hooves. A hoof pick is a tool having a prong or tip for breaking up and loosening the impacted material. Such grooming activities are commonly done in a barn and/or stall that is dimly lighted, making it difficult to see whether there remains any material in the animal's hooves. The present disclosure provides a hoof pick with an illumination source to facilitate use in dimly lighted areas.
[0004] One aspect of the present disclosure includes a tool having a housing which is configured to have two substantially planar parallel faces and a sidewall disposed between and connecting the faces. The housing further includes a head section and handle section. The head section is formed at one end of the housing with the handle section extending from the head section generally linearly along a first axis. A prong extends from the housing at the head section. The prong includes a tip adapted to engage and clean an animal's hoof. The prong is secured within the housing, extending through the sidewall of the head section along the first axis for a distance, wherein the prong is bent at an angle relative to the first axis. The housing also includes an aperture formed within the sidewall of the head section adapted to receive an illumination source. The aperture is oriented along a second axis and configured such that the illumination source projects a light beam in the general direction of the tip of the prong. The tool also includes a switch mounted internal to the head section and connected to the illumination source. The switch having an actuator positioned to be operated from the outside of the housing and having an ON position and an OFF position. The tool also includes a power source positioned inside the housing and connected to the switch, wherein the power source provides electrical energy to the illumination source when the switch is in the ON position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The present disclosure will be described hereafter with reference to the attached drawings which are given as a non-limiting example only, in which:
[0006] FIG. 1 is a perspective view of a first embodiment of a illuminated hoof pick of the present disclosure;
[0007] FIG. 2 is a cut-away side view of the tool of the present disclosure; and
[0008] FIG. 3 is an exploded view of a second embodiment of an illuminated hoof pick of the present disclosure.
DETAILED DESCRIPTION
[0009] The present disclosure is directed to a tool 10 for cleaning hooves of hoofed animals, for example horses. The tool includes a housing 12 . In an exemplary embodiment shown in FIG. 1 , the housing 12 is configured to include two substantially planar parallel faces 14 , 16 and a sidewall 18 disposed between and connecting faces 14 , 16 . The housing 12 further includes a head section 20 formed at one end of the housing 12 and a handle section 22 extending from the head section 20 generally linearly along a first axis 24 .
[0010] The tool 10 further includes a prong 26 extending from the housing 12 at the head section 20 . Prong 26 includes tip 28 adapted to engage and clean a hoof. In the exemplary embodiment, the prong 26 extends through the sidewall 18 of the housing generally along the first axis 24 for a distance and then is bent at an angle A from about 75 degrees to about 110 degrees relative to the first axis 24 and extends along a second axis 27 . In an exemplary embodiment, the prong 26 may be constructed from a wear-resistant metal such as stamped steel and bent at the desired angle. Prong 26 may be held in place in the housing 12 by methods commonly known in the art, such as by an epoxy, ultrasonic welding, press fit, or other suitable means.
[0011] As best seen in FIGS. 1 and 3 , the prong 26 of the tool 10 includes a top surface 80 , a bottom surface 82 , and side edges 84 , 86 . The side edges 84 , 86 taper inwardly toward the tip 28 of the prong 26 .
[0012] The housing 12 further includes an aperture 30 formed within the sidewall 18 of the head section 20 . Aperture 30 is adapted to receive an illumination source 32 , such as a light bulb, light emitting diode, and the like. Aperture 30 is oriented along a third axis 34 . Aperture 30 is configured such that the illumination source 32 disposed therein projects a light beam outward from the housing generally along third axis 34 in the direction of the tip 28 of prong 26 . The third axis 34 is generally disposed at an angle B from the first axis 24 from about 70 degrees to about 110 degrees. In addition, the second axis 27 and the third axis 34 are at an angle C from about 15 degrees to about 55 degrees from one another.
[0013] A power source 36 , such as a battery, is provided to supply electrical energy to the illumination source 32 . A switch 38 may also be provided, mounted within the housing 12 , electrically connected between the illumination source 32 and the power source 36 . Switch 38 is configured with an ON position and an OFF position allowing a user to turn the illumination source 32 on and off. In the exemplary embodiment shown in FIG. 2 , a battery compartment 40 is provided within the handle section 22 configured to hold the power source 36 and the switch 38 is provided in the head section 20 of housing 12 . Switch 38 includes an actuator 42 adapted to make and break electrical contact between the power source 36 and the illumination source 32 , allowing the illumination source 32 to be turned on and off. In an exemplary embodiment, the actuator 42 is configured as a pushbutton disposed within an aperture 44 located in one of the faces 14 , 16 of the housing 12 in the head section 20 . Switch 38 is located so as to allow a user grasping the tool 10 of the present disclosure by the handle portion 20 to operate the switch 38 using his or her thumb. The actuator 42 of the switch 38 may be configured to lie flush with the face of the housing 12 to prevent inadvertent activation if carried in a pocket or jacket.
[0014] The tool 10 of the present disclosure further includes a brush 46 mounted in the head section 20 . The brush 46 includes a plurality of bristles 48 embedded in a mounting block 50 . The mounting block 50 is adapted to be received and secured within the head section 20 of the housing 12 such that the bristles 48 extend outwardly from the sidewall 18 . Brush 46 may be held in place my methods known in the art, such as by an epoxy, ultrasonic welding, press fit or other suitable means. The brush 46 is configured to allow a user to clear sweep away dirt, mud, stones and other debris from an animal hoof after loosening the material with the tip 28 of prong 26 .
[0015] In an exemplary embodiment, housing 12 may include a number of internal ribs 52 disposed within the interior of the housing 12 and adapted to provide strength to the housing 12 . Further, handle section 22 may include a suspension aperture 54 through faces 14 , 16 of housing 12 . The suspension aperture 54 is adapted to allow the tool 10 to be suspended from a hanger, such as a nail, attached to an animal stall for storage when not in use. Additionally, suspension aperture 54 is adapted for attachment of a lanyard or strap to allow a user to carry and/or hang the tool 10 .
[0016] The housing 12 for the tool of the present disclosure may be constructed from a high density polyethylene (HDPE) injection molded into the desired form. HDPE provides a desirable combination of impact toughness and tensile strength. HDPE has an opaque appearance and may be colored depending on aesthetic considerations. Further HDPE provides excellent resistance to chemicals and low temperature impact properties. HDPE is provided by way of non-limiting example only and other materials and plastics (such as acrylonitrile butadiene styrene (ABS)) may be equally acceptable for constructing the housing 12 of the present disclosure.
[0017] The housing 12 may be molded in two portions, each portion corresponding to a face 14 , 16 and part of the sidewall 18 . The internal components such as the prong 26 , illumination source 32 , power source 36 , switch 38 , and brush 46 , may be positioned within one portion of the housing 12 and two portions of the housing may then be fitted together and ultrasonically welded together. Further, the interior of the housing 12 may include guide pins 56 protruding from one of the housing portions configured to mate with guide pin receptacles 58 formed in the other housing portion. The guide pins 56 and guide pin receptacles 58 are positioned to ensure proper alignment of the two portions of the housing when fitted together.
[0018] FIG. 3 depicts a second embodiment of a tool 10 for cleaning hooves of animals.
[0019] The embodiment of FIG. 3 is similar to the embodiment of FIGS. 1 and 2 except that the embodiment of FIG. 3 further includes a gasket material 70 disposed between sections of the sidewall 18 associated with the faces 14 , 16 . The gasket material 70 prevents water and/or other fluids from penetrating an entering the tool 10 , in particular, the electrical components of the tool 10 . In addition, a number of ribs 72 are disposed on internal sides of the faces 14 , 16 to add strength and support to the tool 10 .
[0020] Still referring to the embodiment of FIG. 3 , the prong 26 includes a support piece 74 integral with the prong 26 . The support piece 74 adds a lever arm to the prong 26 to prevent withdrawal of the prong 26 from the tool 10 and allow the prong 26 and the tip 28 to withstand greater forces. The support piece 74 includes a first segment 75 extending at the angle A ( FIG. 2 ) and extending longitudinally away from the prong 26 and a second segment 76 extending generally perpendicular from the first segment 75 and extending laterally away from the prong 26 , wherein the first and second segments 75 , 76 generally form an L-shape. The support piece 74 further includes a third segment 77 generally perpendicular to the second segment 76 and extending longitudinally away from the prong 26 and a lip 78 curving laterally away from the third segment 77 and the prong 26 to generally form an L-shape with the third segment 77 . In this embodiment, the tool 10 preferably includes an internal retaining structure(s) or channel(s) to maintain the first, second, and third segments 75 , 76 , 77 and lip 78 in position and retain the prong 26 within the tool 10 . For example, the structures 79 aid in retaining and preventing movement or extraction of the support piece 74 and prong 26 . Any number of retaining structures, channels, etc. may be utilized to support, position, and retain the support piece 74 and prong 26 .
[0021] The illuminated hoof pick tool of the present disclosure allows a user to have an illuminated work area by holding the tool in one hand for normal use while allowing the other hand to be free to grasp the animal hoof.
[0022] While preferred embodiments of the present disclosure are shown and described, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the present disclosure.
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An illuminated tool for cleaning hooves of hooved animals includes a prong having a tip adapted to engage and clean an animal's hoof and an illumination source configured to direct a light beam in the general direction of the tip of the prong.
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[0001] This application is a national phase filing, under 35 U.S.C. §371(c), of International Application No. PCT/US2010/047059, filed Aug. 28, 2010 and claims the benefit and priority of U.S. Provisional Patent Ser. No. 61/278,815, filed Oct. 13, 2009, which is herein fully incorporated by reference for all purposes.
BACKGROUND
[0002] 1. Field Of The Disclosure
[0003] This disclosure relates to systems and methods for harnessing wind energy, and more specifically to wind turbines for producing electricity from wind energy.
[0004] 2. Related Art
[0005] Typical horizontal axis wind turbines having multiple rotating blades are made to endure enormous destructive wind forces during operation. The wind forces may be created by wind conditions that vary from a no wind condition to an extreme wind condition. The rotating blades are generally designed such that the entire length of the blade is externally configured as an airfoil in cross-section since the airfoil shape of the rotor blade generally provides for a higher efficiency of performance.
[0006] However, because of the extremes in the variation of the wind conditions, the design considerations of the rotor blades must include a careful balancing of many factors. For example, the rotor blades must be constructed such that they are as lightweight as possible to reduce the strain on the tower. At the same time, however, consideration must be given to the possibility that the blades may be subject to resonance and harmonic vibration at their operating speeds. Moreover, the rotor blades need considerable strength to endure the buffeting of the winds and the stress they experience being constantly exposed to natural forces.
[0007] The horizontal axis wind turbines also suffer from several disadvantages due to their typically large-scale design. These concerns include not only the obscuring of the landscape with banks of rotating turbines, noise, and environmental safety, but that they are impractical for smaller, owner-controlled applications. Vertical axis turbines are generally much less efficient and exhibit frequent failures of the main top bearings due to the radial stress on the bearings. The blades also have to endure great shear forces from bottom to top due to the nature of wind shear.
[0008] As the use of wind turbines continues to present an environmentally friendly solution to help reduce the need for burning fossil fuels to generate electricity, what is needed is a wind turbine system that overcomes the aforementioned drawbacks.
SUMMARY
[0009] In one aspect, a wind energy collection system is provided that includes a wind lever assembly coupled to a base; and a rotatable support member supported by the base and coupled to the wind lever assembly. The wind energy collection system also includes a generator coupled to the rotatable support member. The wind lever assembly is moveable to a first displaced position causing the rotatable support member to rotate in a first direction, and moveable to a return position causing the rotatable support member to rotate in a second direction, where each rotation of the rotatable support member turns the generator.
[0010] In another aspect, a wind energy collection system is provided including a wind lever assembly having a wind lever and a counterweight. The wind lever is displaceable to a first displaced position in response to a wind load impinging on a surface area of the wind lever, and to a return position in response to the absence of the wind load impinging on the surface area of the wind lever. A rotatable support member is supported by a base and coupled to the wind lever assembly, where a displacement of the wind lever causes a rotation of the rotatable support member. A generator is also coupled to the rotatable support member. The generator generates a current as the wind lever displaces to the first displaced position, and generates a current as the wind lever displaces to the return position.
[0011] In yet another aspect, a method is provided for collecting wind energy using a reciprocating wind energy collection system. The method includes displacing a wind lever to a first displaced position in response to a wind load impinging on a surface area of the wind lever; rotating a rotatable support member in response to the displacing of the wind lever to the first displaced position; displacing the wind lever to a return position in response to the absence of the wind load impinging on the surface area of the wind lever; rotating the rotatable support member in response to the displacing of the wind lever to the return position; and generating a current as the wind lever displaces to the first displaced position, and generating a current as the wind lever displaces to the return position.
[0012] Advantageously, the wind energy collection system of the present disclosure is efficient in capturing the energy from the wind and converting it to power. For example, typical horizontal axis wind turbines are limited to capturing only about 60% maximum of the impinging energy. With the wind energy collection system of the present disclosure, higher energy efficiencies are possible.
[0013] Other features and advantages of the present disclosure will be set forth, in part, in the descriptions which follow and the accompanying drawings, wherein the implementations of the present disclosure are described and shown, and in part, will become apparent to those skilled in the art upon examination of the following description taken in conjunction with the accompanying drawings or may be learned by practice of the present disclosure. The advantages of the present disclosure may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the disclosure and any appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a simplified view of an exemplary implementation of a wind power system in accordance with an embodiment;
[0015] FIG. 2 is a simplified view of an exemplary implementation of a wind power system in accordance with an embodiment;
[0016] FIG. 3 is a simplified view of exemplary implementation of a wind power system in accordance with an embodiment;
[0017] FIG. 4 is a simplified partial side view of an exemplary implementation of a wind power system in accordance with an embodiment;
[0018] FIG. 5 is a simplified end view of the wind power system if FIG. 4 in accordance with an embodiment;
[0019] FIG. 6 is a simplified side view of an exemplary implementation of a wind power system in accordance with an embodiment;
[0020] FIG. 7 is a simplified end view of the wind power system of FIG. 6 in accordance with an embodiment;
[0021] FIG. 8 is a simplified view of an implementation of a wind lever energy collection system in accordance with an embodiment;
[0022] FIG. 9 is a simplified perspective view of an implementation of a wind lever energy collection system in accordance with an embodiment;
[0023] FIGS. 10( a ) and 10 ( b ) are simplified illustrations of embodiments of a wind lever;
[0024] FIGS. 11( a ) and 11 ( b ) are side and perspective views, respectively, of a wind lever in accordance with an embodiment;
[0025] FIGS. 11( c ) and 11 ( d ) are side and perspective views respectively, of a wind lever in accordance with an embodiment; and
[0026] FIG. 12 is a simplified schematic view of a wind lever and a counterweight in a substantially horizontal orientation in accordance with an embodiment.
[0027] It should be appreciated that for simplicity and clarity of illustration, elements shown in the Figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to each other for clarity. Further, where considered appropriate, reference numerals have been repeated among the Figures to indicate corresponding elements.
DESCRIPTION
[0028] A wind-energy conversion system includes at least three primary subsystems, an aerodynamic system, a mechanical transmission system and an electrical generating system. Generally, the physical configuration of the wind-energy conversion system produces an asymmetric force in the naturally occurring air currents or “wind” to control the air movement. The controlled air movements cause the physical configuration, including but not limited to, flow directing structures and collectors, to rotate, oscillate or translate, thus providing a mechanical energy from which electrical power may be generated. In some instances, a physical condition may be created, such as a pressure or temperature gradient, to control the air movement and create the motion that provides the mechanical energy. If the mechanical energy is used directly by machinery, for example, to pump water, cut lumber or grind stones, the machinery is generally referred to as a windmill. If the mechanical energy is instead converted to electricity, the machinery is generally referred to as a wind generator or wind turbine.
[0029] A Wind Metric refers to a mapping or measure of the ambient wind flow at a location or in a region. The metric is a measurement of a variable used to document and forecast the potential or actual wind energy associated with a location per that metric measure. Such information may be used to in determining placement of high-density wind turbines and determining support configuration and strength requirements to match the wind mapping of the area. Metrics may include but are not limited to measuring the variables over a determined or known time/date period of total amount of wind at a particular height, total amount of wind per direction, wind per direction, wind per height, wind speed overall (all directions-an average), wind speed per direction, wind speed per height, wind acceleration (all directions-an average) wind acceleration per direction, wind acceleration per height, wind duration (overall-an average), wind duration per direction, wind direction per height wind gusts (overall), wind gusts per direction, wind gusts per height, wind turbulence (overall), wind turbulence per direction, wind turbulence per height, wind angle (overall), wind angle per direction, and wind angle per height from the ground.
[0030] The Wind Power is equal to the air density multiplied by the cube of the wind velocity. The Wind Energy is the Wind Power accumulated over time.
[0031] FIG. 1 is a simplified side view of an exemplary wind power system 100 in accordance with an embodiment. The wind power system 100 includes a blade 102 moveable on a pivot 102 . The blade 102 is an extended element or member that is displaceable by the wind. The blade 102 may extend beyond the pivot 102 , or alternately, a pivot arm (not shown) may be extended from the pivot 104 with the pivot arm coupled to the blade 102 . In one example, the blade 102 may be an airfoil, a sheet, a sail and the like. In some embodiments, the blade being a member displaceable by the wind may take the form of a sail, an airfoil and the like. In some embodiments described below, the blade 102 may encompass or be referred to as a wind lever. The wind lever is a device where the wind provides a force against a surface area of the device to leverage that force against a horizontally rotatable shaft. The rotating shaft provides mechanical energy to a generator while the device is either moving with, or recovering from the effects of the force.
[0032] The pivot 104 refers to a fixture or system that may support from one to a plurality of blades in a moveable fashion. In one embodiment, the pivot allows the blade to rotate from a fixed point or pivot point in any desired direction. For example, the pivot 104 allows the blade 102 to oscillate, back and forth as represented by arrows 106 .
[0033] The blade 102 via the pivot 104 is mounted on a base 108 , which is used to support the blade 102 and the pivot 106 . The base 108 may or may not be raised above ground level. For example, the base 108 may be supported on a tower, a rooftop or any other raised structure that is capable of supporting the wind power system 100 . The base 108 is not intended to be limited to any specific structure, and may include a conical, cylindrical, multisided, multipart, tubular structure, having openings, closed walls, solid walls, and flexible and/or stiff walls. The base 108 may be made to any suitable height dimension that places the blade 102 in an optimal position for receiving a suitable wind current and that minimizes ground effects on the wind current. For example, in one embodiment, the height of the base 108 may be between about 50 meters and 100 meters, and preferably, between about 60 meters and 90 meters. In an alternative embodiment, for smaller, owner-controlled applications, the height of the base may be between about 1 meter and 15 meters, and preferably, between about 2 meters and 5 meters.
[0034] FIG. 2 is a simplified illustration of an embodiment of a wind power system 100 a , which includes a plurality of blades 102 . In this multi-blade embodiment, base 108 may support a plurality of pivots 104 , with each pivot supporting a blade 102 . In one embodiment, the blades 102 are independently movable on one or more pivots 108 by the wind. It should be understood that the embodiments described below, which describe the implementation of wind power systems using a single blade or the equivalent, may also be implemented as a multi-blade system as shown in FIG. 2 .
[0035] In one implementation, the base 108 may define or include a space 110 , that provides a location for positioning an electrical power generation system 112 ( FIG. 3 ). In addition to providing a support structure for optimally positioning the blade 102 , the base 108 may include an enclosed space 110 to provide for the protection of the power generation system 112 from debris and adverse weather or temperature conditions.
[0036] FIG. 3 is a schematic view of an exemplary implementation of a wind power system 300 in accordance with an embodiment including electrical power generation system 112 . In one embodiment, electrical power generation system 112 may include an extended member 304 , a line fixture 306 , a moveable magnet 308 , and a wire coil 314 along with additional support structures provided for securing and operating the components of the power generation system 112 .
[0037] As shown in FIG. 3 , the extended member 304 is coupled to, or adjacent to, the pivot 104 and extends in-line with, but in the opposite direction of the blade 102 . A first end of the line fixture 306 , such as a cable, a wire, a chain, a rope, or other similar structure is coupled to the extended member 304 . A second end of the line fixture 304 is coupled to the magnet 308 . One or more guides 310 along or around which the line fixture 306 may pass, may be interposed between the first end and the second end of the line fixture 304 . The one or more guides 310 may include, for example, a wheel, a gear, a pulley, an idler or other similar guiding elements.
[0038] As indicated in FIG. 3 , the magnet 308 is configured to move relative to the wire coil 314 . For example, in one embodiment, the magnet 308 is configured to move up and down, as indicated by arrow 312 , which moves the magnet in-and-out of the wire coil 314 . The wire coil 314 is sized and shaped to receive at least a portion of the magnet within the boundaries of the coiled wire.
[0039] In one alternative embodiment, the magnet 308 may be one to a plurality of magnets fixed relative to the wire coil 314 . In this embodiment, the wire coil 314 may be moved relative to the magnets, for example, within a space surrounded by one or more of the magnets 308 . The wire coil 314 includes contacts 316 through which current can pass.
[0040] In operation, in the embodiment of FIG. 3 , wind pressure and air currents impinge on the blade causing the blade to move about a pivot point 302 . As the wind currents naturally ebb and flow, the blade 102 may oscillate back and forth about the pivot point 302 . The back and forth movement of the blade 102 may be quantified as a variable degree of rotation relative to a centerline 318 of the wind power system 300 . The blade 102 may oscillate less than 360 degrees from the centerline 318 . In some embodiments, the blade 102 may oscillate from between approximately 0 and ±90 degrees from the centerline 318 , for example, approximately between 0 and ±10 degrees, preferably approximately between 0 and ±5 degrees.
[0041] Movement of the blade 102 above the pivot point 302 causes the extended member 304 to also move below the pivot point 302 , albeit in an opposite direction. The rotation of the extended member 304 pulls on the first end of the line fixture 306 . The tension on the line fixture 306 substantially simultaneously causes the second end of the line fixture 306 to pull on the at least one magnet 308 . The magnet 308 is thus made to move relative to the nest of coiled wire 314 . The relative movement between the magnet and the wire creates a current within the coiled wire that may be passed to an electrical grid, or a storage device, such as a battery or capacitor, via electrical contacts 316 .
[0042] As previously mentioned, although a single electrical power generation system 112 is shown in FIG. 3 , this is not to be taken as a limitation and it should be understood that multiple blades 102 coupled to multiple electrical power generation systems 112 may be used in implementations, such as the wind power system 100 a shown in FIG. 2 .
[0043] FIGS. 4 and 5 are simplified side and end views of an exemplary implementation of a wind power system 400 in accordance with an embodiment. Wind power system 400 is generally configured to operate as described above, however with the exceptions and alternatives described below. The wind power system 400 includes at least one to a plurality of blades 102 affixed to the one to a plurality of pivots 104 , which are mounted to base 108 (not shown). With no intent to be limiting, the embodiment is described hereafter with reference to only a single blade/pivot system.
[0044] The blade 102 is movable on pivot 104 in response to the wind pressure and air currents impinging on the blade 102 . In one embodiment, the blade 102 may extend beyond the pivot 104 , or alternatively, a pivot arm may be extended from the pivot 104 coupled to the blade 102 .
[0045] In one embodiment, the wind power system 400 includes the extended member 304 coupled to, or near the pivot 104 and extending in-line with, but in the opposite direction of the blade 102 . As shown in FIGS. 4 and 5 , one or more magnetic elements 402 are coupled to an end of extended member 304 . The wind power system 400 also includes a coiled wire 404 that is positioned below the one or more magnetic elements 402 disposed at the end of the extended member 304 . As shown in the figures, the coiled wire 404 may be formed as a channel defining an arched trough 406 . The one or more magnetic elements 402 are sized and shaped to at least partially fit within the arched trough 406 . The arched trough 406 is configured to receive at least partially, the one or more magnetic elements 402 .
[0046] In operation, in the embodiment of FIGS. 4 and 5 , as wind pressure and air currents impinge on the blade 102 , the blade 102 moves about the pivot point 302 . As the wind currents naturally ebb and flow, the blade 102 oscillates back and forth about the pivot point 302 . Movement of the blade 102 above the pivot point 302 causes the extended member 304 to move below the pivot point 302 , albeit in an opposite direction. The rotation of the extended member 304 causes the one or more magnetic elements 402 to move. The movement of the one or more magnetic elements 402 resembles the swinging of a pendulum. The magnet 402 positioned within the arched trough 406 “swings” at least partially within the confines of the coiled wire 404 . The relative movement between the magnet and the wire creates a current within the coiled wire 404 that may be passed to an electrical grid, or a storage device, such as a battery or capacitor, via electrical contacts 316 .
[0047] FIGS. 6 and 7 are simplified side and end views of an exemplary implementation of a wind power system 500 in accordance with an embodiment. Wind power system 500 is generally configured to operate as described as the wind power systems described above, however with the exceptions and alternatives described below. The wind power system 500 includes at least one to a plurality of blades 102 affixed to the one to a plurality of pivots 502 , which are mounted to the base 108 (not shown). With no intent to be limiting, the embodiment is described hereafter with reference to only a single blade/pivot system.
[0048] As shown in FIG. 7 , in one embodiment, the pivot 502 includes a first pivot section 502 a and a second pivot section 502 b. The first and second pivot sections are coupled together via a pivot member 503 positioned at the pivot point 302 of the wind power system 500 . The wind power system 500 also includes a contact support member 504 . The contact support member 504 may be coupled to, or formed as part of, the blade 102 . In this embodiment, the contact support member 504 is positioned at the end of the blade 102 and is positioned between the first and second pivot sections 502 a and 502 b of the pivot 502 . The contact support member 504 is seated approximately concentric with the pivot member 503 at pivot point 302 .
[0049] In one embodiment, the blade 102 and contact support 504 are coupled to an extended arm 510 , which extends in-line with, but in an opposite direction, from the blade 102 . The extended arm 510 moves about pivot point 302 as the blade 102 moves about pivot point 302 albeit in an opposite direction relative to the centerline of the system. A coiled wire 512 may be coupled to the end of the extended arm 510 . The coiled wire 512 is operatively and electrically connected via a wire or other conductive element, to the contact elements 506 and 508 positioned on contact support member 504 . In this manner, current generated in the wire coil 512 may be passed to the contacts 506 and 508 .
[0050] One or more magnetic elements 514 may be positioned below the coiled wire 512 in proximity to the wire coil 512 . The magnetic elements 514 may be formed in an arc ( FIG. 6 ) so that the magnetic elements remain in proximity to the wire coil 512 as the wire coil is made to move.
[0051] In operation, as wind pressure and air currents impinge on the blade 102 , the blade 102 moves about the pivot point 302 . As the wind currents naturally ebb and flow, the blade 102 oscillates back and forth about the pivot point 302 . Movement of the blade 102 above the pivot point 302 causes the extended arm 510 to move below the pivot point 302 , albeit in an opposite direction. The rotation of the extended arm 510 causes the wire coil 512 to move. The movement of the wire coil 512 resembles the swinging of a pendulum. The coiled wire 512 positioned within the arc of magnetic elements “swings” through the magnetic field created by the magnetic elements 514 . The relative movement between the magnetic elements 514 and the wire coil 512 creates a current within the coiled wire. Operationally, the current may be collected at the contacts 506 and 508 via a connection with out bound contacts 516 positioned on the pivot section 502 a and passed to an electrical grid, or a storage device, such as a battery or capacitor.
[0052] FIG. 8 is a simplified view of a wind lever energy collection system 800 (hereinafter, the “wind lever system 800 ”) in accordance with an embodiment. In one implementation, the wind lever system 800 includes a wind lever assembly 802 , a generator 804 , associated electronics 804 a, and a mechanical drive assembly 806 . The wind lever assembly 802 includes an extended element 808 , such as a blade or sail, a pivot 810 and a counterweight 812 .
[0053] The extended element 808 may be supported on an upper arm or pivot arm 814 to extend the reach of the extended member 808 , if desired, and coupled directly to a rotatable support element 816 . In one embodiment, the extended element 808 may include a sail pivot 809 interposed in the pivot arm 814 . Using the sail pivot 809 , at predetermined times, locations or in response to varying wind conditions, the extended element 808 may be pivoted to allow for at least one of, allowing wind energy capture, improving wind energy capture, preventing damage from high winds, adjusting the angle of the extended element to the wind and adjusting the extended element's return profile.
[0054] The rotatable support element 816 couples the wind lever assembly 802 to a support base 818 , which is used to support the entire wind lever system 800 . The base 818 may or may not be raised above ground level 820 . For example, the base 818 may be lifted above the ground level 820 and supported on, for example, a tower, a rooftop or any other raised structure that is capable of supporting the base 818 . The base 818 is not intended to be limited to any specific structure, and may include a conical, cylindrical, multisided, multipart, tubular structure, having openings, closed walls, solid walls, and flexible and/or stiff walls. The base 818 may be made to any suitable height dimension that places the extended element 808 in an optimal position for receiving a suitable wind current and that minimizes ground effects on the wind current.
[0055] The counterweight 812 is coupled to the pivot point via an extendable arm 824 . The arm 824 supporting the counterweight 812 may be an extendable arm to change the distance of the weight from the pivot point to vary the amount of torque required to move the extended element 808 . By controlling the required torque, the size of the oscillations that the extended element 808 is made or allowed to perform may also be controlled. The extension of the extendable arm may be done automatically in response to achieving a threshold value of preset criteria, or may be adjusted manually.
[0056] The counterweight 812 may be any suitable structure or other means that provides a counterbalancing function for the extended element 808 . For example, in addition to a conventional gravitational mass, such as a metal weight, the counterweight 812 may include a waterway current, a piston, hydraulics, belts, gears, wheels, pulleys, chains, clutches, transmissions and the like. In one embodiment, the base 818 defines an open space 822 between the supporting structures that form the base 818 . The open space 822 is sized and configured to provide an area below the extended element 808 to receive the counterweight 812 and provide enough room to allow the counterweight 812 to move (i.e. swing) within the space 822 without contacting the supporting structures.
[0057] In one alternative embodiment, the counterbalancing function provided by counterweight 812 may be provided using the electrical current generation systems described above with regard to FIGS. 3-7 . For example, the function of the counterweight 812 shown in the embodiments of the wind lever assembly 802 may be provided by replacing the counterweight 812 with one or more magnetic elements, or a wire coil, disposed at the end of the extended arm 824 . The magnetic elements, or the wire coil, are used in conjunction with a corresponding wire coil or magnetic element, respectively, which are positioned, for example, in the open space 822 . The relative movement between the magnetic elements and wire coil may be used to generate an electric current as described above.
[0058] Referring again to FIG. 8 , the mechanical drive assembly 806 may be used to couple and translate the kinetic energy provided by the movement of the extended element 808 , and pass it to the generator 804 for generating a current. In some implementations, the generator 804 is a coil magnet type device, such as are well known in the art. The generator 804 may be connected to the associated electronics package 804 a to provide at least one of, but without limitation: output, power conditioning, inversion to AC, DC to DC conversion, and conversion for storage. The generator 804 may include a uni-directional or bi-directional generator as is appropriate for use in a particular implementation as further described below.
[0059] In one implementation, the mechanical drive assembly 806 includes the capability to turn a bi-directional generator 804 to produce power. In this embodiment, the capability includes a direct drive system for use with the bi-directional generator. The direct drive system may include a rotating/reciprocating shaft 826 coupled to the extended element 808 , the counterweight 812 , and the bi-directional generator 804 . The shaft 826 is capable of moving in a clockwise and counterclockwise direction. In this implementation, as the extended element 808 and counterweight 812 move or reciprocate back and forth, the shaft 826 also moves and thus turns the generator 804 in either the clockwise or the counterclockwise direction to produce power while moving in either direction.
[0060] In some implementations, a drive mechanism 828 , such as a chain, gear or belt drive assembly, may be used to alter the rotational speed of the shaft 826 . The drive mechanism 828 may include fixed or variable gears, pulleys, wheels, belts, pulleys, and chains, hydraulic coupling and may include a clutch, a transmission (either regular or continuously variable) and the like, that may be used to alter the rotational movement transferred to the generator 804 . In this implementation, the drive 828 may be a bi-directional drive, so that both the clockwise and counterclockwise rotation of the shaft 826 is transferred to the bi-directional generator.
[0061] In some implementations, a uni-directional generator may be selected, and accordingly, the drive mechanism 828 may be a one-way drive that only translates rotation in one direction to the generator 804 .
[0062] The current generated by the generator 804 , and any other current generated, for example, through the optional use of the current generating systems shown in FIG. 3-7 , may be passed to a storage device, such as a battery or capacitor. Unless being stored, the output from the electronics package 804 a may be fed out of the system via one or more line outs 830 .
[0063] In operation, the wind lever system 800 is a reciprocating wind energy collection system that operates in a wind capture/lever return cycle in accordance with an embodiment. The wind is captured by the extended element 808 , in the form of a blade or sail. From a generally vertical orientation relative to the ground, the sail is displaced either clockwise or counterclockwise about the pivot point during a “wind capture ½ cycle.” The movement of the sail, in turn, moves or rotates the shaft 826 . The shaft may be directly connected to the generator 804 , or may be connected to an intervening drive assembly 828 . As described above, the drive assembly 828 provides a capability for adjusting the rotational speed of the shaft for providing an altered rotational speed to the generator 804 , if desired.
[0064] Once the displacement of the sail is complete, the wind capture ½ cycle is complete. The lever return ½ cycle is then initiated. The counterweight 812 or other equivalent means suspended from or acting on the extendable arm 824 (or an additional structure below the sail, such as described with regard to FIGS. 3-7 ) provide a force to at least partially restore the displaced sail back towards the substantially vertical orientation where the wind capture ½ cycle began. The return of the sail completes the wind capture-lever return cycle.
[0065] In one embodiment, it is understood that changing the sail or blade surface area and keeping other system variables, such as wind speed, wind acceleration, wind turbulence, counter weight and magnetic fields constant, corresponds to an increase or decrease in the wind energy that may be harvested using the wind power system 800 . For example, using the sail pivot 809 , the sail 102 may be deployed to provide a large wind facing surface area for initial wind capture during the wind capture ½ cycle. The surface area profile of the sail 102 may then be altered by turning the sail so that it does not face the wind direction. By reducing the surface of the sail exposed to the wind direction, the force against which the sail pushes against is reduced. The sail returns during the lever return ½ cycle to its initial position.
[0066] Reducing the force that the sail must work against during the return ½ cycle makes the system more efficient. Reducing the drag on the sail for the return ½ cycle of the movement may also reduce the forces needed to complete the lever return ½ cycle. Changing the counter weight position is a means to use the balance of plant (BOP) to adjust sail, device, system and method parameters in response to variables, such as wind speed, power demands, magnetic fields and the like.
[0067] FIG. 9 is a perspective view of a wind lever energy collection system 900 (hereinafter, the “wind lever system 900 ”) in accordance with an exemplary embodiment. In one implementation, the wind lever system 900 includes a wind lever assembly 902 , a generator 904 , associated electronics 904 a, and a mechanical drive assembly 905 . The wind lever assembly 902 includes an extended element 906 , such as a blade, sail or wind lever, pivots 908 and a counterweight 910 .
[0068] In this exemplary implementation, the extended element 906 (hereinafter, the “wind lever 906 ”) may have a frame 912 that supports a flexible wind deflector 914 . The wind deflector 914 is capable of blocking, deflecting, redirecting, reflecting or otherwise responding to the movement of wind currents that impinge on a surface area 916 of the deflector 914 . In one embodiment, the wind deflector 914 may be made of a solid, a mesh, or a multi-part material. For example, as shown in FIG. 10( a ) the wind deflector 914 may be made of the same discrete material 1002 throughout. As shown in FIG. 10( b ) the wind deflector 914 may have multi-zones 1004 and 1006 , where each zone includes a different type of material. Each wind deflector material may be made from a variety of individual homogenous materials, or may be made from a combination of materials, each of which is capable of providing adequate structural support to withstand the variable wind loads that may be experienced by the wind deflector 914 at the various zones. For example, the wind deflector 914 may be a made of a metal, a polymer, Dacron, a canvas material, a composite material, such as carbon, fiberglass, and fiberglass-reinforced plastic, or any combination of these materials.
[0069] The wind deflector 914 may be formed with any suitable surface geometric shape depending on the specific implementation. For example, the wind deflector 914 may have a flat surface that is capable of being positioned perpendicular to the wind direction, a multifaceted surface that includes multiple flat surfaces positioned at various angles to the wind direction, or a curved surface, that may have a circular, parabolic, hyperbolic, elliptical or similarly curved geometry. In some implementations, the geometry of the wind deflector 914 may include a combination of the geometries thus described.
[0070] The size of the lever 906 may vary based on many variables, for example, depending upon the requirements for energy production and the space available for implementation. In one embodiment, the size of the wind lever 906 may be between about 1 meter and 2 meters, for example, about 1.5 meters in width, and between about 1.5 meters and 3 meters, for example, 2 meters in length.
[0071] In one embodiment, as shown in FIGS. 11( a ) and 11 ( b ), a wind deflector 1102 may be mounted on frame 912 such that the edges of the wind deflector 1102 , with the exception of the top edge, or at least the top corners, are not rigidly or fixedly mounted to the frame 912 . In this embodiment, the bottom corners 1106 may be attached to a slidable member 1108 , which is slidably attached to the frame 912 , such that the slidable members may move along the frame. The slidable member 1108 may include any suitable member that can attach to the wind deflector and be capable of sliding along the frame. For example, the slidable member 1108 may be a circular ring, or a cylindrical bushing, which allow a portion of the frame to pass therethrough. Since the side edges of the wind deflector 1102 are not mounted to the frame 912 , the bottom corners 1106 of the wind deflector 1102 may rise and fall as the wind impinges on the surface of the wind deflector 1102 . As the wind pressure increase on the wind deflector 1102 , the wind deflector 1102 rises up to reduce the amount of surface area of the wind deflector effectively exposed to the wind. In one embodiment, physical stops 1104 may be positioned on the frame 912 to limit the movement of each slidable member 1108 along the frame 912 to control the amount that the wind deflector 1102 rises, and thus control the change in the effectively exposed surface area of the wind deflector. Thus, the deflector is moveable between a fully deployed configuration, where substantially all of a surface area of the deflector is effectively exposed to a wind vector, and a partially deployed configuration, where only a portion of the surface area of the deflector is effectively exposed to the wind vector.
[0072] As shown in FIG. 11( c ) and ( d ), in an alternative embodiment, the wind deflector 1110 may be divided into two sections. A first section 1110 a may be fixedly and rigidly attached to the frame 912 . The first section 1110 a may generally comprise approximately the top quarter to top half of the wind deflector surface area. A second section 1110 b may be mounted on frame 912 such that the edges of the second section 1110 b, with the exception of the top edge, or at least the top corners, are not rigidly or fixedly mounted to the frame 912 . In this embodiment, the bottom corners may be attached to the slidable members 1108 , which are slidably attached to the frame 912 , such that the slidable members may move along the frame. As the wind pressure increases on the wind deflector 1110 , the second section 1110 b rises up to reduce the exposed surface area of the second section 1110 b of the wind deflector. It should be understood that the amount of surface area of the wind deflector that is allotted to be included in either the first or the second sections 1110 a and 1110 b might vary for any given implementation.
[0073] Referring again to FIG. 9 , the wind deflector 914 and frame 912 are supported on a rotatable support element 918 via pivots 908 . In one embodiment, pivots 908 may include, for example ball bearings, bushings and the like, located at opposing ends of the rotatable support element 918 and mounted on a support base 920 . The counterweight 910 is also coupled to the rotatable support member 918 via an extendable arm 922 . Thus, as the wind lever 906 and the counterweight are displaced, the rotatable support element 918 may be made to rotate.
[0074] The rotatable support element 918 couples the wind lever assembly 902 to the support base 920 . The base 920 may be seated on the ground or may be raised above ground level. For example, the base 920 may be lifted above the ground level, or the base 920 may be supported on a tower, a rooftop or any other raised structure that is capable of supporting the base 920 . The base 920 is not intended to be limited to any specific structure, and may include a conical, cylindrical, multisided, multipart, tubular structure, having openings, closed walls, solid walls, and flexible and/or stiff walls.
[0075] The base 920 may be made to any suitable height dimension that places the lever 906 in an optimal position for receiving a suitable wind current and that minimizes ground effects on the wind current. In one embodiment, by way of example and not limitation, the base 920 may have a height of between about 2 meters and 5 meters, for example, about 3 meters. It should be understood that the footprint of the base may vary depending upon the application of the wind lever system. By way of example, and not limitation, the footprint of the base 920 maybe approximately 2 meters by 2 meters.
[0076] The counterweight 910 may be any suitable structure or other means that provides a counterbalancing function for the wind lever 906 . For example, the counterweight 910 is a conventional gravitational mass, such as a metal weight. In one embodiment, the base 920 defines an open space 926 that is configured to receive the counterweight 910 and provide enough space to allow the counterweight 910 to move (i.e. swing) within the space 926 without contacting the base 920 as the wind lever 906 is being displaced.
[0077] Contrary to lock out, braking and other systems that are known in the art to dampen or reduce blade movement and speed during high winds on horizontal axis wind turbines and vertical axis wind turbines, the wind lever system “self-adjusts” to high wind conditions with no braking or stopping. In some embodiments, the wind lever continues to generate power when high wind speed results in forcing the wind lever into a substantially horizontal position. As described below, the instability of the wind lever caused generally by the counterweights and variations in wind currents also provides the desired movement for the generation of power. For example, in one embodiment, when confronted with high winds of continuous high velocity, the open space 926 allows the wind lever 906 and counterweight 910 to rotate to a substantially horizontal orientation without interference from the supporting structures of the base 920 . FIG. 12 is a simplified schematic view of the wind lever assembly 902 in a substantially horizontal orientation caused by exposure to continuous high winds. As shown in the figure, the wind lever assembly 902 is generally unstable in the horizontal orientation. The instability is caused by the imbalance created by inconsistent wind forces impinging on both surfaces 1204 and 1206 of the wind lever 906 , and the inability of the counterweight 910 to overcome the imbalance and right the orientation of the wind lever assembly 902 to a vertical orientation along the centerline of the wind lever assembly 902 . In this orientation, the wind causes the wind lever 906 to oscillate up and down relative to the ground as indicated by arrow 1202 . These oscillations, however, still cause the wind lever system 900 to cycle through the wind capture-lever return cycle. In this orientation, the oscillations occur about the horizontal axis of the wind lever system 900 . The cycling of the system about the horizontal axis, causes the rotatable shaft 918 to turn the generator 904 and generate a current as described below. Thus, advantageously, one of ordinary skill in the art should understand that in either low or high wind environments or conditions, the wind lever system is capable of generating useable energy, and is not limited by the use of lockout, brake and similar systems that typically limit movements in high wind.
[0078] Referring again to FIG. 9 , the extendable arm 922 coupled to the counterweight 910 may be extendable so as to vary the amount of torque required to displace the wind lever 906 about the pivots 908 . By controlling the required torque, the size of the oscillations that the wind lever 906 is made to perform may also be controlled. The extension of the extendable arm may be done automatically in response to arriving at threshold of a preset criteria, or may be adjusted manually. The preset criteria may be for example, the amount of wind speed or acceleration experienced at the wind lever 906 . An anemometer 924 may be positioned adjacent the lever 906 for recording the wind speed and other associated parameters for determining when the particular threshold has been reached.
[0079] The wind lever system 900 is a reciprocating wind energy collection system that operates in the wind capture-lever return cycle in accordance with an embodiment. The wind captured by the wind lever 906 displaces the lever in either the clockwise or the counterclockwise direction relative to a vertical centerline of the system during the wind capture ½ cycle. The wind lever rotates about the pivots 908 . The displacement of the wind lever 906 may be between about 0 degrees from the centerline to about ±90 degrees from the centerline, preferably between about 0 and about ±10 degrees, for example, about ±5 degrees. The rotatable support element 918 may be used to couple and translate the kinetic energy provided by the movement of the wind lever 906 and pass it to the generator 904 for generating a current. The generator 904 may be connected to the associated electronics package 904 a to provide at least one of, but without limitation: output, power conditioning, inversion to AC, DC to DC conversion, and conversion for storage. In this exemplary embodiment, the generator 904 is a bi-directional generator capable of being driven directly by the rotating/reciprocating support shaft 918 .
[0080] Once the displacement is complete, the lever return ½ cycle is initiated. The counterweight 910 suspended from or acting on the extendable arm 922 provides a force to at least partially restore the displaced wind lever back towards the substantially vertical orientation where the wind capture ½ cycle began. In turn, the movement of the wind lever 906 as its position is being restored again moves or rotates the rotatable support shaft 918 , which is directly connected to the generator 904 for producing power. The return of the wind lever 906 to the initial position completes the wind capture-lever return cycle. As the wind continues to blow, the rotating/reciprocating support shaft 918 continues to be moved in the clockwise and the counterclockwise reciprocating directions to produce power in the generator 904 as the wind lever assembly 902 continues to cycle through the wind capture-lever return cycle.
[0081] While the present disclosure has been shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description, as shown in the accompanying drawing, shall be interpreted in an illustrative, and not a limiting sense.
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Systems and methods to generate power using wind and controlled air movement and related structures to more cost effectively produce energy and protect system components.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the method and apparatus used for stenciling selected indicia upon and into surfaces of structures for identification purposes and more particularly relates to a system of automobile identification marking.
2. Description of the Prior Art
Stenciling apparatus are well known. In its most basic form a stencil consists of an impervious material perforated with letters, numbers or designs through which a substance such as paint, ink or other medium is forced onto the surface to be printed. Stencils are primarily used for lettering where ease of application, sharpness of line and ease of reproduction are important factors.
With regard to the present invention's system of automobile identification marking, it should be noted that currently automobile manufacturers usually place at least two identification marks on their automobiles. One mark is usually impressed into the motor block and the other is usually a plate welded somewhere onto the frame. These markings are utilized not only to identify the vehicle for title and registration purposes, but also to reduce car thefts by making it theoretically impossible for stolen vehicles to be sold as a state registry would recognize the identification numbers as being those of a stolen vehicle. Unfortunately, these identification marks can be altered or obliterated with the expenditure of time and effort by a skilled individual. The device of this invention embodies a new method of identification which not only requires time, effort and skill to alter or remove, but also involves a significant cost factor to the person desiring to remove such marking making it uneconomical to steal a vehicle so marked.
SUMMARY
This invention relates to the method and apparatus used for stenciling selected indicia upon and into surfaces of structures for identification purposes. The apparatus of the present invention basically comprises an outer casing, an aperture for insertion of a stencil holding unit in the front of the casing of sufficient size to hold the unit stencils desired to be used, means for detachably inserting and retaining the unit stencils in the stencil holding unit, and means for applying the stenciling medium from within the apparatus through the unit stencils onto the surface to be marked. The casing aperture can be rectangular in shape and have retaining means along its edges for holding a series of unit stencils whose stenciling indicia can be individual numbers, letters or symbols having interlocking edge engagements on each unit stencil member.
One embodiment of the device of this invention is designed to sandblast a sequence of indicia into glass. In this embodiment the aperture in the front of the outer casing is covered by a stencil holding unit made of a resilient material which has a front rectangular opening surrounded by a unit stencil receptacle area which has horizontal lips undercut along it upper and lower sides and with vertical end flange receptacle slots for receipt of the end flange portion of the end unit stencil members. It is envisioned that the front rectangular opening of the stencil holding unit can be of varied sizes to accommodate a plurality of unit stencils. At the rear of the outer casing is a circular aperture into which an "0"-shaped rubber, or equivalent flexible material, gasket is affixed to the inner circumference of the aperture. The inner circumference of this gasket makes tight contact with the nozzle of a pistol-type compressed air supply and the outer circumference of the gasket making tight contact with the circumference of the aperture in the rear of the casing thereby preventing the escape of air and stenciling medium through this aperture when the apparatus is in use. This nozzle supplies high-velocity air through the interior of the casing directed toward the stencil holding unit. The flow of compressed air is trigger-controlled and an air outlet is provided in the casing covered by a grid and a mesh to allow the passage of air and still prevent the escape of sand. Before using, one places sandblast sand or other stenciling medium to be used into the casing through the front aperture and replaces the stencil holding unit. In operation, the sand is cycled from the sand holding area at the bottom of the casing through the sand pickup pipe in which is contained a venturi communicating with the nozzle of the pistol-type compressed air supply whereby the sand is carried into the air stream. The pistol-type compressed air supply member is pivotally mounted for limited azimuthal movement of the nozzle in order to scan the unit stencils within the stencil holding unit in order to blast the sand through the indicia openings. The unit stencils can be provided in sets to allow for a plurality of different indicia combinations. The unit stencils are engaged with one another in such manner as to be easily and quickly interchangeably attached and can be placed in any desired sequence. These unit stencils can be engaged with end unit stencils whose indicia, usually a dot, indicate the beginning and end of a sequence of indicia to prevent later alteration or addition of stenciled indicia. When the unit stencils are in position, they lie flush with the flat front face of the stencil holding unit. The end unit stencils have end flanges to fit into the end flange receptacle slots located along the vertical sides of the unit stencil receptacle area of the stencil holding unit, which end flanges prevent sand from leaking out around the vertical edges of the series of unit stencils and thereby preventing marring of the surface to be marked.
When the apparatus is ready for use, the stencil holding unit contains a series of unit stencils in a desired sequence. The front of the apparatus is then pressed against the glass surface to be marked thereby causing the resilient material of the unit stencil holder to form a seal against the glass. When the trigger of the apparatus is pulled, compressed air shoots forward causing sand to be drawn up from the sand holding area in the bottom of the casing through the sand pickup pipe and the venturi. The sand is carried up the sand pickup pipe into the nozzle member by the suction created by the venturi and is then drawn into the strong current of the pistol-type compressed air supply and is forced through the stencil openings in the unit stencils in order to mark the glass. This sandblasting process marks the glass by wearing away portions of the glass surface under the indicia of the unit stencils. During the sandblasting process the air nozzle moves slowly back and forth between the sides of the nozzle azimuthal movement limiter thereby causing the sandblasting through the unit stencils to give even markings on the glass. The sand not passing through the unit stencils settles into the sand holding area at the bottom of the casing and is picked up again by the venturi-caused vacuum into the sand pickup pipe and thereby recycled. The apparatus of this invention can be used not only horizontally but also at an angle without the sand from the sand holding area falling forward through the unit stencils because the curvature of the lower front casing helps to keep the sand in the sand holding area.
The method of use of the apparatus of this invention can be of great value in identifying automobiles and other motor vehicles incorporating glass in their design. It is envisioned that this apparatus can mark the same identification indicia upon each pane of glass of a vehicle in an inobtrusive spot and each vehicle so marked would possess its own combination of indicia. For example, on a four-door sedan there could be six similar identification marks on each pane of glass, one being on the windshield, another on the rear window, and one on each of the panes of glass of the doors. It has been found that the stencil indicia can be comprised of letters wherein a five-letter series would give a large number of combinations sufficient for a nationwide coding system. Of course the length of the series could be expanded to include more than five letters. These combinations can be preselected by a computer and preassigned in registration-form booklets to dealers authorized to place the identification markings upon the automobile windows. It should be noted that the same letter combination would not be issued more than once. It is also anticipated that objectionable combinations of letters could be eliminated. The code of each identification mark, the owner's name, address and other pertinent information could be filed in a central depository and, should a motor vehicle so marked be stolen and later recovered, the owner could be located not only through the vehicle's own identification numbers, if these have not been altered, but also through the code indicia of the glass markings. While it is possible at this time to change the automobile identification number of a car by removing the sheet metal panel in which it is located and also possible to obliterate the engine number of a vehicle by grinding it off the engine block, the cost of these changes would not deter thieves from engaging in these practices. However, if a thief wished to remove identification sandblasted into the panes of glass on a motor vehicle by installing new panes of glass, the cost of such installation would be prohibitive. An alternative to total replacement of each pane of glass so marked could be the grinding off of the indicia. However, the removal of the marked indicia by grinding would be fruitless since it would be immediately obvious that the indicia had been ground off. Other alterations of the sandblasted identification marks would be difficult and the change would be noticeable on visual and manual inspection.
Therefore it is an object of this invention to provide an easy-to-use self-contained stenciling apparatus in which the medium used for stenciling, such as sandblasting sand, paint, dye or equivalent is contained within the device so that the imprinting can be performed quickly and easily.
Further it is an object of this invention to provide an apparatus in which the unit stencils can be changed quickly and easily by minimally trained individuals to make a large scale motor vehicle identification system economical.
Another object of this invention is to provide a system of motor vehicle identification which would act as a deterrent to the theft of a motor vehicle so marked.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a side view of the device of this invention.
FIG. 2 illustrates a perspective three-quarter rear view of the device of this invention.
FIG. 3 illustrates a cross-sectional view showing the pistol-type compressed air supply member, its nozzle and associated sand pickup pipe.
FIG. 4 illustrates the nozzle with azimuthal movement limiter in position within the body of the apparatus.
FIG. 5 illustrates the air outlet covering member with its supporting grid and associated fine mesh covering.
FIG. 6 illustrates a cut-away side view of the body of the apparatus showing the nozzle and sand holding area.
FIG. 7 illustrates a stencil holding unit.
FIG. 8 illustrates section A -- A through the stencil holding unit.
FIG. 9 illustrates section B -- B through the stencil holding unit shown in FIG. 7.
FIG. 10 illustrates a unit stencil in two positions and an end unit stencil.
FIG. 11 shows an enlarged sectional view of the triangular supportive member of the unit stencils illustrating their means of interlocking.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates the embodiment of the stenciling apparatus 10 of the present invention showing stencil holding unit 11, body 12, sand pickup pipe 14 and pistol-type compressed air supply member 16. The body can be comprised of fiberglas or other rigid material with sufficient strength to withstand the air pressure utilized and of sufficient hardness so as not to be worn away by the sandblasting operations carried on within the body. Stencil holding unit 11 can be constructed of a resilient material such as rubber, synthetic plastic or equivalent and is discussed in further detail below. Shown within stencil holding unit 11 are a series of unit stencils 90.
In FIG. 2 air pressure outlet 18 has air outlet covering member 20 fitted tightly within its opening. Grid 22 has large openings and mesh 24, with fine openings, is located behind the grid. The air outlet and its associated grid and mesh covering are further illustrated in FIG. 5. This mesh must be fine enough to prevent sand or other stenciling medium from escaping, but the openings in the mesh must be large enough to allow air to escape from the body of the apparatus. Further shown in FIG. 2 is rear circular aperture 32 through which pistol-type compressed air supply member 16 is introduced into the body of the apparatus. To seal this pistol-type compressed air supply member and prevent air from escaping through aperture 32, rear gasket member 36 is utilized. This doughnut-shaped gasket has a groove around its outer circumference which fits tightly over the front and rear of the rim of circular aperture 32. The inner circumference of gasket 36 fits tightly around the barrel 37 of pistol-type compressed air supply member 16 and effectively prevents air from escaping while allowing the pistol-type compressed air supply member 16 to have horizontal azimuthal movement. It has been found that an air pressure range of between 60 lbs/square inch and 120 lbs/square inch gives satisfactory results.
FIG. 3 shows a cross-sectional view of pistol-type compressed air supply member 16. Trigger 40 of handle 38 actuates spring-loaded plunger 42 to allow air to enter from air inlet 44 and pass through first entry chamber 41, barrel entry chamber 43, and proceed down barrel 37 terminating in elongated nozzle 46 which has a diameter less than that of barrel 37. Trigger 40 pivots about axial point 45 to actuate plunger 42. As the air passes through barrel 37 towards outlet 48, it passes over venturi 50 which terminates sand pickup pipe 14. This passage of air over the venturi creates a vacuum causing a suction which draws sand up through sand pickup pipe 14 from stenciling medium holding area 62. The stenciling medium holding area, pickup pipe and venturi are further shown in FIG. 6. The sand is then blown through barrel 37 and the nozzle and forced through the indicia openings of the unit stencils retained within stencil holding unit 11.
FIG. 4 illustrates in a cutaway view of the casing to expose nozzle 46 and azimuthal movement limiter 58 which is positioned between the sides of the outer casing and which limits the horizontal movement of nozzle 46 and barrel 37 of the pistol-type compressed air supply member. Sides 60 of azimuthal movement limiter 58 prevent nozzle 46 from being directed beyond the areas where the unit stencils have their indicia. In FIG. 3, barrel 37 is pivotally mounted on member 51 through which the venturi and sand pickup pipe are interconnected allowing horizontal azimuthal movement.
FIG. 5 illustrates air outlet covering member 20 showing supporting grid 22 and fine mesh 24 which is illustrated in a separated position from the air outlet member. In practice, mesh 24 is sealed against grid 22.
FIG. 6 illustrates a sectional cutaway view of the casing body 12 showing stenciling medium holding area 61 formed of slanted false bottom 62 which slantingly extends from a low front portion to a rear high portion of which is located inlet 64 of the pickup pipe which runs up to nozzle 66 of the pistol-type compressed air supply member. It should be noted that inlet 64 of the pickup pipe is located at the lowest point of the sand holding area. It has been found that this position of the inlet assists the sand after it has been blown against the stencil holding unit and has fallen back down the curved slanted lower front section of the casing into the sand holding area to be recycled in the sand blasting process. A flexible section 63 of the sand pickup pipe made of plastic or other flexible material assists in allowing the pivotal movement of the pistol-type air supply member.
FIG. 7 illustrates stencil holding unit 11 to be fitted within aperture 13 of FIGS. 1 and 6 which can be constructed of rubber, vinyl plastic or equivalent material and shows the unit stencil horizontal inner and outer complementary retaining members which retain each unit stencil. These retaining members are comprised of angular converging horizontal inner lips, 70a and 70, and outer lips, 72a and 72, within which the unit stencils are positioned and secured and end unit stencil member side flanges 73a and 73b which define receptacle slots 75a and 75b.
FIG. 8 shows a sectional view through section A -- A of FIG. 7 wherein can be seen retaining member angular lips 78 and along with rectangular aperture 80 through which the sand is blasted and the wall section 81 of the stencil holding unit which engages the body of this device.
FIG. 9 illustrates a sectional view through section B -- B of FIG. 7 wherein end unit stencil member flange receptacle slots 75 and 75a are visible. Also illustrated are retaining angular converging lips 70 and 72 retaining member 90 with aperture 80 through which the stencil medium passes. Body engagement section 81 is partially visible in this cross section.
FIG. 10 illustrates unit stencil 90 with its indicia "L" 100 in an upright position and with its right side visible. The unit stencil 90a in FIG. 11 with its indicia "L" 100 but is shown turned 180 degrees so that its left side is visible. At the upper and lower end of the unit stencil are triangular end members 102 and 104 which when placed in the stencil holding unit are retained by the lips 70 and 72 and lips 70a and 72a as best shown in FIG. 8. The flexibility of the stencil holding unit allows the lip portions to be manually opened for insertion of the unit stencils and upon release to return to its original position, thereby retaining the unit stencils within the stencil holding unit. In FIG. 12 unit stencils 11 are shown retained within stencil holding unit 11. The end unit stencil member 98 has end flange member 110 which is received within the end flange receptacle slot 75 or 75a of the stencil holding unit. End flange receptacle slot 86 is best shown in FIG. 9. End flange receptacle slot 110 assists the unit stencils as a group to be held firmly within the stencil holding unit and also prevents sand or other stenciling medium from leaking through the vertical edges of the series of unit stencils when in position.
FIG. 13 illustrates enlarged sectional views of the unit stencil member 90 as shown in FIG. 10 in order to illustrate this unit's interlocking mechanism. At the upper and lower end of each unit stencil is triangular end member 102 (member 104 not illustrated), having on its inner edge of one side, triangular protrusion 106 and on its other side, a matching receiving indentation 108. Further interlocking is achieved by protrusion 105 along the body of unit stencil member 90 which is received by indentation 107. These interlocking units are also found on the side of an end unit stencil which meshes with the other unit stencils. These interlocking members serve to strengthen the structures of the series of unit stencils and to prevent sand from leaking between the unit stencils. It should be noted that the resiliency of the stencil holding unit allows for sufficient lateral movement for manual flexing of the stencil holding unit to easily disengage one unit stencil from another in order to change the stenciling indicia identification marking. It should be further noted as more clearly seen in FIG. 10 that the indicia are not centered on the unit stencil but are offset to one end so that one may see whether a letter is backwards as it would be out of line with the other letters. Also if a letter is inserted in an upside down position, its interlocking mechanism will not mesh with the adjacent unit stencils.
Numerous modifications, embodiments and changes will be readily apparent to those skilled in the art. The invention is therefore not to be construed to be strictly limited to the foregoing disclosure as such changes, modifications and embodiments may be made without departing from the spirit and scope of the present invention.
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An apparatus and method used for stenciling selected indicia upon and into surfaces of structures for identification purposes, the apparatus comprising a hollow body with air pressure release outlet means, an aperture in the body wherein a detachable stencil holding unit having a stencil receptacle for affixing desired unit stencils over said aperture and a unit for applying the stenciling medium from within said body to said indicia; and a method of automobile identification marking wherein stenciled markings are placed on the panes of glass of a vehicle, the markings on each vehicle being unique and stored with other information in a central depository, the information being retrievable.
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TECHNICAL FIELD
The present invention relates to a gas-solid phase catalytic reaction process and the apparatus for the embodiment of the method. Said process is useful for gas-solid phase catalytic reactions and heat transfer in the field of chemical engineering, in particular for the synthetic reaction of ammonia, as well as the synthesis of methanol, methane and methyl ether.
BACKGROUND OF THE INVENTION
In gas-solid phase exothermic catalytic reactions such as the synthesis of ammonia from hydrogen and nitrogen under pressure, there exists an optimal temperature for fixed pressure and fixed composition of reactant gases, under which temperature the reaction rate is the highest. This optimal temperature, however, decreases as the synthesis rate increases, and with the proceeding of the reaction, the temperature of the catalyst layer will be raised by the continuous releasing of the reaction heat. Thus, in order to improve the efficiency of the reactor, it is necessary to remove the reaction heat out of the reactor. One method that has been widely used is the multi-stage feed-gas-quench reactor, such as the Kellogg four-stage catalyst beds used in large scale ammonia plants. In such systems, feed-gas-quench is used between the stages to reduce the reaction temperature. But as the temperature of the reactant gases is reduced by feed-gas-quench, the concentration of the product of reaction is reduced at the same time, so the synthesis rate is also affected. Improved forms have appeared, in the better ones, the catalyst is divided into three beds. While feed-gas-quench is used between the first and the second section, indirect heat exchange is used between the second and the third section, see, for example, the Chinese patent application CN1030878 filed by the Casale Co. and published on Feb. 8, 1989. The affect on the concentration of the product of reaction by feed-gas-quench has not been completely overcome in this kind of reactors, and the structure of the equipment is made complicated by the adding of indirect heat exchangers between the layer beds.
SUMMARY OF THE INVENTION
The object of the present invention is, in accordance with the characteristics of the gas-solid phase catalytic exothermic reversible reactions, to provide an improved reactor that can overcome the disadvantages of the prior art and a method in which the reaction is operated under the optimal temperature. The technical features of the reactor are reasonable temperature distribution in the bed layers, high activity of the catalyst, simple and reliable structure, and good operating performance.
The reversible gas-solid catalytic exothermic reaction and the releasing of heat mainly occur at the initial stages of the reaction process. The purpose of the present invention is fulfilled by the following improvements. Firstly, the feed gas is divided into two streams, streams 1 and 2 , to be warmed respectively. Stream 1 is warmed by exchanging heat with the reaction gases exiting from the catalyst bed, and stream 2 flows in the cold tubes in the upper part of the catalyst layer and is warmed by exchanging heat with the counter-flowing reactant gases outside of the tubes. The flow rate and temperature of stream 2 in the cold tubes can be adjusted in accordance with the temperature of the catalyst layer. Secondly, the warmed streams 1 and 2 are combined together, react in the cold tube catalyst layer and exchange heat with the feed gas in the cold tubes, and then the reactant gases enter the lower part of the catalyst layer and react adiabatically. Thus, in the initial stage of the reaction, heat exchange is effected by counter-flow cold tubes, the reaction can start at an approximately adiabatic condition, so that the optimal temperature can be reached more quickly. As the heat exchange with the counter-flow cold tubes proceeds, the temperature difference between the interior and exterior of the tubes increases with the depth in the catalyst layer, so that the temperature of the catalyst decreases along the optimal line. At the outlet of the cold tube layer, the temperature of the catalyst decreases below the optimal line, and the catalyst is ready for the adiabatic reaction in the next stage.
The synthetic reactor of the present invention consists substantially of a housing P, a catalyst basket R and an heat exchanger E. The housing P can withstand pressure, the reaction pressure therein is typically 14-32 MPa. The catalyst basket R consists of a cover plate H, a cylinder S and a catalyst supporting grid J, the catalyst in the basket is supported on the supporting grid J at the bottom of the basket R. The catalyst layer consists of a cold tube catalyst layer K 1 having therein counter-flow cold-tube bunch Cb and an adiabatic catalyst layer K 2 . The cold tube bunch Cb consists substantially of an inlet tube a, the cold tubes b and a ring tube d 1 connecting the inlet tube a and the cold tubes b. The cold tube bunch Cb may also consist of an inlet tube a, cold tubes b, an outlet tube c, a ring tube d 1 connecting the inlet tube a and the cold tubes b, and a ring tube d 2 connecting the cold tubes b and the outlet tube c. The cold tube catalyst layer K 1 may have one or more cold tube bunch(es) Cb arranged concentrically, each bunch has a plurality of cold tubes b arranged concentrically at circles of different radii, and a central tube I connecting the heat exchanger E is located at the center of the catalyst layer. The feed gas enters the reactor from the inlet tube a, and is distributed to the plurality of cold tubes through the ring tube d 1 . The feed gas stream 2 in the tubes is heated by the high temperature reaction gases outside the tubes counter flowing in the catalyst layer K 1 . The heated stream either exits from the cold tubes b directly or exits through the ring tube d 2 and the outlet tube c. The exit stream 2 is then mixed with stream 1 , which has been heated in the heat exchanger and exited from the central tube I. The temperature of the mixture is elevated to a temperature above the active temperature of the catalyst. And the gas stream enters successively into the cold tube catalyst layer K 1 and the adiabatic catalyst layer K 2 . In cold tube catalyst layer K 1 the gases react and exchange heat with gas stream in the cold tubes b in a counter flowing manner, and the gases react adiabatically in the adiabatic catalyst layer K 2 . The ratio of the temperature of the gas stream 2 exiting the cold tubes to the temperature of the mixed gases entering the cold tube catalyst layer is 0.75-1.25. The amount of the catalyst in the cold tube catalyst layer is 15-80% by weight, preferably 30-50% by weight of the total amount of the catalyst, depending on the reaction conditions. The gas in the cold tube catalyst layer K 1 and the adiabatic catalyst layer K 2 may both flow in the axial direction; or the gas may first flow axially in the cold tube catalyst layer K 1 , and then flow radially and axially in the adiabatic catatyst layer K 2 ; or flow counter-currently in the adiabatic catatyst layer K 2 . The cold tubes b may be round or flattened ones. The ratio of the heat-conducting area of the cold tubes to the volume of the catalyst is 3-20 M 2 /M 3 .
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an embodiment of the reactor of the present invention, wherein the reactor consists of an axially flowing cold tube catalyst layer and an adiabatic catalyst layer;
FIG. 2 and FIG. 3 are schematic views of the reactor of the present invention, wherein the reactor consists of an axially flowing cold tube catalyst layer and a radially flowing adiabatic catalyst layer;
FIG. 4 is a schematic view of a reactor of the present invention having an axially flowing cold tube catalyst layer and a radially flowing adiabatic catalyst layer, the reactor may be used for the modification of existing large scale ammonia converters;
FIG. 5 is a schematic view of a reactor of the present invention, wherein the reactor consists of an axially flowing cold tube catalyst layer and a convective adiabatic catalyst layer;
FIG. 6 is a diagram showing the connection of the facilities outside of the reactor;
FIG. 7 and FIG. 8 are t-x diagrams of the reactor, wherein the abscissa t represents temperature in degree Celsius, and the ordinate x represents the concentration of ammonia in mol %.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a reactor such as ammonia converter with moderate height-radius ratio is shown. An inner cylinder is provided inside the pressure-withstanding housing P, there is a ring-shaped space between the outer wall of the reactor and the wall S of the inner cylinder. Catalyst basket R is placed in the upper part of the inner cylinder, with the central tube I at the center thereof The catalyst is placed in the catalyst basket. The upper catalyst layer K 1 is provided with a cold tube bunch Cb. Cold tube bunch Cb has a plurality of cold tubes arranged in 2-4 concentric circles, the tubes connect the lower ring tube d 1 and the upper ring tube d 2 . The lower ring tube d 1 connects to the inlet tube a, while the upper ring tube connects to the outlet tube c. The inlet tube a passes through the cover plate H of the catalyst basket, the gap between them being movably sealed with a stuffing box, or it may be connected with a corrugated pipe. Ring tube d 2 is located at the space above the catalyst layer that has been reduced. The cold tube bunch is supported by the shelf L and held on the supporting grid J together with the catalyst, and it may expand and contract freely during operation. At the lower part of the inner cylinder, a tube-array type heat exchanger E is shown in the figure, but it can also be a spiral plate heat exchanger. The feed gas stream 1 and stream 2 are separated by the cylinder body and the bottom sealing-head U, while the feed gas stream 1 and the outlet gas stream 4 are separated by the bottom plate V of the heat exchanger. When the catalyst is heated for reduction, cold gas enters into the reactor through the space between the bottom sealing-head U and the bottom plate V of the heat exchanger, and flows into the heat exchanger E to exchange heat with the hot gas exiting from the catalyst layer, then it is further heated by an electric heater in the central tube I, finally it enters the catalyst layer to reduce it by heating. In normal operation, the feed gas is divided into two streams, i.e. stream 1 and stream 2 . Stream 1 passes through heat exchanger E and exchanges heat with the reactant gases, then exits from the central tube I. Stream 2 enters the converter through the ring-shaped spacing between the housing P and the inner cylinder, then enters the cold tube bunch Cb via the inlet tube a. Stream 2 is then distributed uniformly into each cold tube in the bunch by the lower ring tube d 1 , each branch stream flows upward in the cold tubes and is heated by exchanging heat with the counter-flowing reactant gases outside of the tubes, the branch streams are then combined in the upper ring tube d 2 and exit from outlet tube c, finally, the stream exiting from the outlet is combined with feed gas stream 1 from the central tube I. For the synthesis of ammonia, for example, mixed gases in the temperature range of 350-430° C. first perform reaction over the catalyst in the cold tube catalyst layer K 1 , the concentration of the product is raised through the reaction, and the temperature of the gases is raised by the heat released from the reaction, said reactant gases also exchange heat with the counter-flowing cold gas in the cold tubes, so that the temperature thereof increases to the hot-point temperature of 450-510° C. and then decreases to 380-430° C. The reactant gases then react in the adiabatic catalyst layer K 2 , the temperature thereof is raised again to approximately 460° C., and the concentration of the product is further increased, for the synthesis of ammonia, for example, to 15-20 mol %. Reactant gases in said cold tube catalyst layer K 1 and said adiabatic catalyst layer K 2 are both flowing axially, the reactant gases exiting from the catalyst layer enter heat exchanger E and exchange heat with the inlet stream 1 , then exit from the reactor as stream 4 . Stream 3 in the figure is a gas stream from the auxiliary line for adjusting the inlet temperature of the catalyst bed.
Referring to FIG. 2, a reactor with a larger height-radius ratio is shown. The reactant gases in the cold tube catalyst layer are again flowing axially, the difference with the reactor in FIG. 1 is that a radially flowing adiabatic catalyst layer is located at the lower part of the catalyst basket R, and the catalyst supporting plate J of the basket has no perforation for the gas to pass through. Instead, there is an outer distributing cylinder X at the inner side of the body S of the basket body, and there is an inner distributing cylinder Y at the outer side of the central tube I, both distributing cylinders have a multiplicity of perforations thereon. Most part of the reactant gases that have passed through the cold tube catalyst layer K 1 first enters the ring-shaped spacing between the outer distributing cylinder X and the basket wall S, then passes through the outer cylinder X into adiabatic layer K 2 and flows radially inward and perform reaction, finally passes through the inner distributing cylinder Y into the ring-shaped spacing between the inner cylinder Y and the central tube I. The reactant gases flowing into said spacing are combined with the axially flowing minor part of the reactant gases that enters therein, the combined gases then enters the heat exchanger E and exchange heat with the feed gas stream 1 in the tube array type heat exchanger, finally the reactant gases exit the reactor as stream 4 . There are two cold tube bunches in FIG. 2, hanged on the basket wall S by the supporting shelf L. Other notations of the reactor and the reference numerals in FIG. 2 are the same as those in FIG. 1 . Of course, the gas in the lower adiabatic layer may be designed to flow radially outward, wire screens may be provided for the distributing cylinders, and other component parts well known in the art, such as strengthening supporters, separators and nozzles, although not shown in the figure, may be included in the reactor.
FIG. 3 shows a reactor in which the manner of reaction and heat exchange flowing is the same as those in FIG. 2, the difference with the reactor in FIG. 2 is that the cold tube bunch consists substantially of an inlet tube a, cold tubes b, and a ring tube d 1 connecting the inlet tube a and cold tubes b. The cold tubes b extend outside of the catalyst layer, allowing the gases in the tubes to exit directly. So this kind of reactor has a simple structure, and is easy to be fabricated. However, the structure of FIG. 2, wherein the cold tubes are connected to the outlet tube c via the ring tube d 2 , facilitates the installation of the system as well as the pressure test and leak detection thereof. Other notations in FIG. 3 and the reference numerals therein are the same as those in FIG. 2 .
FIG. 4 shows a reactor for the modification of existing large scale ammonia plants, for example, a large scale Kellogg bottle type ammonia converter may be modified by this type of reactor. As in FIG. 2, the upper part of the catalyst layer in FIG. 4 is a cold tube layer K 1 where the reactant gases flow axially. There are a plurality of cold tube bunches Cb 1 , Cb 2 , etc., coaxially arranged in the cold tube layer, although only two are shown in the figure. Each cold tube bunch consists of an inlet tube a, an outlet tube c, cold tubes b, ring tube d 1 , and ring tube d 2 . The inlet tube may connect to a section of corrugated pipe when it passes through the cover plate H of the inner cylinder. The lower part of the catalyst layer is an adiabatic catalyst layer K 2 wherein the reactant gases flow both axially and radially. Heat exchanger E is installed at the upper part of the reactor, the catalyst may be released through the bottom hole Q when its cover is opened. Feed stream 2 enters the converter from the bottom, passes through the ring-shaped spacing between the outer housing P and the inner cylinder to the top of the converter, and then enters into the cold tube bunch. Feed stream 1 enters into the shell side of the heat exchanger E through the space between the sealing head U and the sealing head V of the heat exchanger. After exchanging heat with the reactant gases 4 in the tube side of the heat exchanger, stream 1 passes out of the heat exchanger, and combines with the heated stream 2 exiting from cold tube bunch Cb. The combined gas stream first perform reaction in the cold tube catalyst layer K 1 and exchanges heat with the counter flowing gas in the cold tubes b. The gas exiting from the cold tube layer, apart from a small portion that flows axially, enters into the adiabatic layer through the outer distributing cylinder X and performs reaction while flowing radially. The reactant gases then collect in the interior of the inner distributing cylinder Y, and flow into the tube side of heat exchanger E at the upper part of the converter via the central tube I, after exchanging heat with the feed stream 1 , the reactant gases exit out of the converter as stream 4 . Stream 3 in the figure is a cold feed stream for adjusting the inlet temperature of the catalyst layer. The resistance in the axial-radial reactor is lower than that of the axially flowing reactor, so the operating space velocity, i.e. the ratio of the total amount of the gas entering the converter to the volume of the catalyst, may have a larger value.
FIG. 5 shows another type of the reactor of the present invention. There is a cold tube catalyst layer K 1 wherein the reactant gases flow axially at the upper part of the catalyst layer K 1 . Counter flow cold tube bunch Cb is hanged on the wall S of the inner cylinder by a supporting shelf L. There is a gas-collecting chamber W adjacent immediately to the lower end of the cold tube bunch Cb, chamber W is provided with a tube M connecting the grid J at the bottom of the catalyst basket. And a gas-collecting chamber Z is provided at the center part of the adiabatic catalyst layer K 2 , there are many small holes that allow gas but not catalyst to pass on the walls of the gas-collecting chambers W and Z. Gas collecting chamber Z is connected to heat exchanger E by a sleeve tube N. The heat exchanger shown in the figure is a tube array type heat exchanger. There is a separating plate G between the perforated grid J of the catalyst basket and the heat exchanger E. After being heated in the heat exchanger E, feed stream 1 combines with feed stream 2 , which has been heated by passing through the cold tube bunch. The combined gases first react in the cold tube catalyst layer K 1 at the upper part of the reactor and exchange heat with the counter flowing gas in the cold tubes b. One half of the gas exiting the cold tube layer continues to flow downward in the upper part of the catalyst layer K 2 . The other half of the gas enters the gas-collecting chamber W and passes through the tube M to the space under the grid J of the catalyst basket, then flows upward and reacts at the lower part of the adiabatic catalyst layer K 2 . These two parts of the reactant gases flow counter-currently to the center part of the catalyst layer, combine in the gas-collecting chamber Z, and pass through the ring-shaped spacing between the sleeve tube N and the central tube I downward to the space under the separating plate G. After passing through the tube side of the heat exchanger E and exchanging heat with the incoming feed stream 1 , the reactant gases exit the reactor as stream 4 . The stream 3 entering the reactor at the bottom is from an auxiliary line for adjusting the temperature of the catalyst layer.
FIG. 6 is a connection diagram of the facilities outside of the reactor. In the diagram, R 1 is the reactor, the structure of which may be seen in FIGS. 1-5; E 2 is a heat exchanger for the cold and hot gas outside the reactor; E 3 is a by-product steam boiler; E 4 is a cold condenser; V 1 is a product separator, such as an ammonia separator; T 1 is a recycle compressor. The feed gas delivered from the recycle compressor is divided into three streams. Among them, stream 1 , after being heated in the heat exchanger E 2 outside of the reactor, enters the heat exchanger in the reactor to be further heated; stream 2 enters the cold tube bunch in the reactor to absorb the reaction heat in the cold tube catalyst layer. The flow rates of streams 1 and 2 can be adjusted, the stream 2 entering the cold tube bunch typically includes about 30-70% of the total amount of the gas. The temperature of stream 2 can be adjusted by the ratio of the amount of the gas that has passed through the heat exchanger E 2 to the amount of the gas that has not passed through heat exchanger E 2 , so as to vary the temperature of the catalyst layer in accordance with different periods of the operation of the catalyst. Stream 3 is an auxiliary line cold gas for adjusting the inlet temperature of the catalyst layer. Stream 4 is the stream exiting the reactor, after recovering the heat thereof in the boiler E 3 , it flows into heat exchanger E 2 to heat the feed gas. Stream 5 in the figure is the separated product, such as liquid ammonia or methanol. Stream 6 is the vent gas. Stream 7 is the supplementary feed gas. In the figure, the recycle compressor is placed between the ammonia separator V 1 and the heat exchanger E 2 , however, in large-scale ammonia plants, the recycle compressor is usually placed between heat exchanger E 2 and heat exchanger E 4 .
The heat exchangers inside the reactor in FIGS. 1-5 may also be placed outside of the reactor. In this case, feed stream 1 , after being heated by the heat exchanger E 2 outside of the reactor, enters the reactor R 1 and combines directly with the feed stream 2 heated in the cold tube bunch, and then passes into the catalyst layer to react. Stream 2 in the figure may also enter the reactor from the upper part of the outer cylinder, and flow through the ring-shaped spacing downward to the bottom (in this case, the inlet tube a of the cold tube bunch extends from the bottom upward). When the reactor uses a hot wall vessel and no outer cylinder is present, the inlet tube a may enter the reactor either from the bottom or from the middle.
The present invention has the following advantages over the prior art:
1. The reactor has excellent process performance and high conversion efficiency. FIG. 7 is the curves showing the ammonia concentration in the reacted gases vs. the corresponding temperature during the process of synthesizing ammonia from hydrogen and nitrogen. Te is the equilibrium temperature curve for ammonia synthesis, Tm is the optimal temperature curve, both Te and Tm decrease with the increasing of the reactant concentration. The operation curve of the above-mentioned Casale reactor, which uses feed-gas-quench between the first and second stage and uses indirect heat exchange between the second and third stage, is shown in the figure as the solid curve ABCDEF. The operation curve of the above-mentioned Kellogg 4-bed layer ammonia synthesis reactor, which uses feed-gas-quench between any two stages, is shown in the figure as the dotted curve. As can be seen from the figure, when cold quenching gas is added, the temperature decreasing of the reactant gas is accompanied by the decreasing of the ammonia concentration. Most parts of the reaction in these two reactors are performed under conditions far from the optimal temperature curve Tm. The curve ALMN in FIG. 8 shows the operation of an ammonia synthesis reactor using the improved method of the present invention, since the reaction begins in the cold tube catalyst layer, as the reaction proceeds, part of the reaction heat is transferred out of the layer, so the hot point temperature L corresponding to the same ammonia concentration is lower than the point B of the adiabatic operation curve mentioned above, this is advantageous for preventing the catalyst from deactivation by overheating. And since heat exchange is effected in a counter flowing manner, in the reaction performed continuously after passing the hot point, the heat transferred to the cold gas is more than the reaction heat produced, so the reaction temperature decreases along the optimal line, until it reaches the point M corresponding to the exit of the cold tube layer, this decreasing of the temperature prepares the condition for further reaction in the adiabatic layer. And since the stream 2 entering the cold tube bunch is separated from the stream 1 passing through the heat exchanger, their proportion may be adjusted, the inlet temperature of stream 2 may be varied in the range of 30-190° C., thus facilitate the control of temperatures at other points in the catalyst layer. For example, in the early stage of using the catalyst, in order to prevent the hot point temperature from becoming too high, the temperature of stream 2 may be reduced, so that the temperature of the gas exiting from the cold tubes is lower than that of the mixed gas entering the cold tube catalyst layer. The reaction product concentration and temperature at the exit of the adiabatic reaction reach the condition N. It can be seen from the figure that the operation curve of the reactor comprising of a counter-flowing cold tube catalyst layer and an adiabatic layer is closer to the optimal temperature line Tm, so the conversion efficiency of the present reactor is higher than that of the prior art, and a high production rate can be obtained, the content of ammonia in the outlet gas is raised from 12-14 mol % to 15-20 mol %.
2. The structure of the reactor is simple and reliable, it is easy to install and operate. Many of the existing reactors have three or more catalyst beds, the beds are separated or heat exchangers are installed between the beds, their structure is complicated. The reactor of the present invention has a single catalyst bed layer, the bed layer consists of a cold tube layer and an adiabatic layer that are connected together and are not separated, so the amount of catalyst contained in it can be significantly increased, and the catalyst can be put in and taken out conveniently. For each cold tube bunch, only the inlet tube a passes through the cover plate of the catalyst basket, the gap between the inlet tube and the cover plate can be sealed by a stuffing box, or a corrugated pipe can be used to connect the inlet. There are typically two inlet tubes located symmetrically to the center, so the number of gaps to be sealed is reduced, and the structure is simple and reliable. For reactors with a large radius, any one of the axial, radial, axial-radial and counter-current flowing modes can be adopted, so that the resistance can be efficiently reduced, and power can be conserved.
EMBODIMENT EXAMPLE
An embodiment example is given below in connection with the reactor in FIG. 4 .
A 1000 ton/day ammonia converter is selected, the inner radius of the exterior cylinder is 2.87 M, total height 25 M, synthesis pressure 24 MPa. The internals thereof are modified by using the present invention, the total amount of catalyst is 58 M 3 . Ammonia catalyst of Φ 4.7-6.7 mm is used in the upper axial counter flowing cold tube layer, its total amount therein is 20 M 3 . Ammonia catalyst of Φ 1.5-3 mm is used in the lower radial flowing adiabatic layer, its total amount therein is 38 M 3 . Stream 1 has a flow rate of 261,000 NM 3 /h, it enters the heat exchanger to be heated. Stream 2 has a flow rate of 319,000 NM 3 /h, it flows into the cold tube bunch to be heated. Stream 1 and stream 2 are then combined, the temperature of the combined gas being 390° C., the combined gas enters the cold tube layer to synthesize ammonia, the hot point being 492° C., the gas exiting the cold tube layer at a temperature of 415° C., the content of ammonia in the reacted gases is raised from 1.78 mol % to 15.2 mol %. Then it enters the radially flowing adiabatic layer to further synthesize into ammonia, the temperature of stream 4 exiting the adiabatic layer is 448° C., the content of ammonia is 19.5 mol %. Total amount of the feed gas entering the converter is 580,000 NM 3 /h, and total amount of the gas exiting from the converter is 493,974 NM 3 /h, the situations are shown in the operation curve ALMN in FIG. 8 . The exiting gas passes through the heat exchanger in the converter to exchange heat with stream 1 , then flows to the boiler to recover the heat contained in it. The pressure drop of the reactor is 0.2 MPa. The composition of the inlet and outlet gases are as follows:
Inlet (mol %)
Outlet (mol %)
H 2
65.83
51.27
N 2
21.94
17.06
CH 4
7.39
8.68
Ar
3.06
3.59
NH 3
1.78
19.50
As shown in the data, the throughput of the modified reactor is as high as 1567 ton/day, 56% higher than that of the prior art, and the net gain of ammonia is increased from 11.1% (prior art) to 17.72% (the present invention).
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The present invention discloses a method of catalytic reaction operated near the optimal temperature and an apparatus for its embodiment. The catalyst bed in the apparatus consists of two parts of catalyst located respectively in the cold tube layer and the adiabatic layer. The feed gas in the cold tubes, after having exchanged heat with the reactant gases in the catalyst layer outside of the tubes, are mixed with the feed gas from the heat exchanger. While the mixed gases flow axially, radially or convectively in the catalyst layer, the gases contact successively with the catalyst in the cold tube layer and that in the adiabatic layer, and react with each other.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to maintenance of sperm viability to increase the success rate of artificial insemination (AI).
[0002] AI is now a fundamental technology for the intensive breeding of domestic animals, in human infertility treatments and in wildlife conservation programmes for the breeding of threatened species. Nevertheless, it has become clear that current semen preservation techniques severely compromise the sperm's survival in the female reproductive tract and hence limit the successful application of the technique.
[0003] Sperm survival is particularly compromised when spermatozoa cannot be delivered directly into the uterus because the cervical anatomy is too complex, for example in sheep. This significantly reduces the efficiency of AI. Large numbers of viable spermatozoa must be used to maximize the chance of fertilization, therefore making this technique uneconomical. Surgical intrauterine insemination by laparoscopy is an efficient way of solving this problem and through use of this method conception rates of 80% are now common in sheep and other species. However, this method increasingly is regarded as unacceptable for routine agricultural use on grounds of welfare; routine use of this surgical approach is expected to be curtailed within a relatively short period.
[0004] Means to improve the success rate of non-surgical methods is therefore urgently required. One means of achieving this will be by extending the lifespan of spermatozoa in the female reproductive tract.
[0005] Following mating (natural insemination), inseminated mammalian spermatozoa are transported to the oviduct where a reservoir of spermatozoa is formed. Studies in several species have shown that the reservoir is limited to the caudal isthmus. The spermatozoa are held in the isthmus until ovulation, when a small number are released to meet the egg(s). During storage in the isthmus, many spermatozoa attach to the oviductal epithelial cells. Attachment to oviductal epithelial cells is important in maintaining sperm viability both in vivo and in vitro. Spermatozoa attachment to oviductal epithelial cells is initiated by uncapacitated spermatozoa. The process of capacitation, along with the switch to the hyperactivated flagellar beating pattern, appears to coincide with the ability of spermatozoa to be released from the oviductal reservoir.
[0006] Coculture with whole oviductal epithelial cells in vitro improves the viability of sperm from a number of species including rabbit, cow, sheep, horse, pig and human. It seems this is a widespread characteristic of oviductal cells. However the mechanism by which oviductal cells maintain sperm viability is unknown. Both oviductal secretory products and direct membrane contact between spermatozoa and oviductal epithelial cell membranes have been reported to bestow this beneficial effect.
[0007] Many studies in the past have only investigated the role of oviductal secretory products (proteins) on spermatozoa.
[0008] Oviductal secretory products have been reported to improve the viability of sperm. These secreted proteins are present in oviduct fluid and the fluids from which they are derived are collected via indwelling cannulae in the ampulla and isthmus of the oviduct. These secreted proteins are not derivable from whole oviductal cells in vitro, but must be collected by cannulation of the oviduct of cycling animals.
[0009] Catalase is an example of a secretory protein; this enzyme is known to protect spermatozoa against damage by reactive oxygen species.
[0010] The inventors have shown previously that whole oviduct epithelial cells could be isolated and cultured, and that when co-incubated with spermatozoa at 39° C., the life of the spermatozoa could be extended for 2 to 3 days beyond the maximum lifespan of control spermatozoa incubated without cells. Sperm lifespan was judged by the use of tests for plasma membrane integrity.
[0011] The inventors have further shown that incubation of spermatozoa with porcine oviductal apical plasma membrane (APM) extends the life of the cultured spermatozoa.
SUMMARY OF THE INVENTION
[0012] According to a first aspect of the present invention there is provided a method of improving and/or prolonging sperm viability which comprises contacting spermatozoa with an isolated, cell-free protein fraction of oviductal APM.
[0013] By “protein” is meant a protein associated with the apical plasma membrane, but which does not form an integral part of the phospholipid bilayer. An example of such a protein is a peripheral membrane protein; these are associated with membranes but do not penetrate the hydrophobic core of the membrane. They are often found in association with integral membrane proteins and can be removed from membranes by means that do not require the disruption of the membrane structure, for example salt washes.
[0014] By “fraction” is meant a part obtainable by precipitation and centrifugation of the APM of oviductal epithelial cells, which contains proteins associated with the apical membrane. This fraction does not include secretory proteins present in oviductal fluid.
[0015] By “isolated, cell-free” is meant the fraction is substantially free from any intact cells and other proteins not originating from plasma membrane.
[0016] By “improving sperm viability” is meant that the proportion of spermatozoa which are viable is greater in comparison with control spermatozoa.
[0017] By “prolonging sperm viability” is meant that the spermatozoa maintain their viability for a longer time period than the normal lifespan of control spermatozoa which is not contacted with the membrane fraction. This longer time period preferably extends for from one day to three days, or greater than three days.
[0018] Preferably the spermatozoa are contacted with an isolated, cell-free peripheral membrane protein fraction of oviductal APM in vitro.
[0019] In another aspect of the present invention the spermatozoa are boar spermatozoa and the peripheral membrane fraction is of porcine oviductal APM.
[0020] According to the present invention there is provided a method of improving and/or prolonging sperm viability following cryopreservation which comprises contacting spermatozoa with an isolated, cell-free peripheral membrane protein fraction of oviductal apical plasma membrane (APM).
[0021] According to the present invention there is provided a method of improving and/or prolonging sperm viability during cryopreservation which comprises contacting spermatozoa with an isolated, cell-free peripheral membrane protein fraction of oviductal apical plasma membrane (APM).
[0022] According to the present invention there is provided a method of improving and/or prolonging sperm viability during in vitro fertilisation which comprises contacting spermatozoa with an isolated, cell-free membrane protein fraction of oviductal apical plasma membrane (APM).
[0023] According to the present invention there is provided a method of isolating a protein having sperm viability improving and/or prolonging activity from oviductal APM comprising the steps of:
[0024] (i) harvesting mammalian oviduct epithelial cells;
[0025] (ii) separation and isolation of a plasma membrane preparation using a magnesium chloride solution, and centrifugation to obtain a crude APM fraction;
[0026] (iii) extraction of a soluble fraction from the crude APM fraction using a salt solution and centrifugation of the solution obtained;
[0027] (iv) concentration of the supernatant and washing, to obtain protein.
[0028] Preferably the salt solution used in step (iii) above is sodium chloride solution.
[0029] According to the present invention there is provided an oviductal APM protein having sperm viability improving and/or prolonging activity, the oviductal APM peripheral membrane protein(s) obtainable according to the following method:
[0030] (i) harvesting mammalian oviduct epithelial cells;
[0031] (ii) separation and isolation of a plasma membrane preparation using a magnesium chloride solution, and centrifugation to obtain a crude APM fraction;
[0032] (iii) extraction of a soluble fraction from the crude APM fraction using a salt solution and centrifugation of the solution obtained;
[0033] (iv) concentration of the supernatant and washing, to obtain protein.
[0034] Preferably the salt solution used in step (iii) above is sodium chloride solution.
[0035] According to the present invention there is provided a method of improving and/or prolonging sperm viability comprising contacting spermatozoa with an isolated, cell-free protein fraction of oviductal apical plasma membrane (APM) in which the spermatozoa are microencapsulated.
[0036] By “microencapsulated”, is meant that the spermatozoa are enclosed within a semi-permeable membrane. Examples of membranes which can be used include beeswax, starch, gelatine, and polyacrylic acid and polylysine.
[0037] Preferably, the treated spermatozoa are microencapsulated in a semi-permeable membrane comprising poly-lysine.
[0038] According to the present invention there is provided a method for improving and/or prolonging sperm viability which comprises contacting spermatozoa with an isolated, cell-free peripheral membrane protein fraction of oviductal apical plasma membrane (APM) in which the protein is linked to an inert polymer.
[0039] Preferably, hydrophilic polymers are used; these are defined as polymers having a solubility of greater than 10 g/L in an aqueous solution, at a temperature between 0 to 50° C. The aqueous solution can include small amounts of water-soluble organic solvents, such as dimethylsulfoxide, dimethylformamide, alcohols or acetone. Examples of polymers which may be used in the present invention include synthetic polymers such as polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, hydroxylated celluloses, polypeptides, polysaccharides such as polysucrose or dextran and alginate. An example of a polymer which may be used in the present invention is amine and carbonyl-reactive dextran.
[0040] By “linked” it is meant that the polymers are joined to the proteins; the join may be through an ionic or covalent bond.
[0041] Linking proteins to inert polymers can result in the advantages of increased efficiency and reduced toxicity.
[0042] According to the present invention there is provided a method for improving and/or prolonging sperm viability which comprises contacting spermatozoa with an isolated, cell-free peripheral membrane protein fraction of oviductal apical plasma membrane (APM) in which the peripheral membrane protein fraction(s) of oviductal APM or component(s) obtainable therefrom is at a concentration of between approximately 0.1 μg/L and approximately 1 g/L.
[0043] Preferably a concentration of between approximately 5 μg/L and approximately 400 μg/L is used. More preferably the concentration used is between approximately 25 μg/L and approximately 200 μg/L.
[0044] According to the present invention there is provided a method of improving and/or prolonging semen survival following sex-sorting of the spermatozoa for X- (female) and Y-bearing (male) spermatozoa cells which comprises contacting spermatozoa with an isolated, cell-free protein fraction of oviductal apical plasma membrane (APM).
[0045] According to the present invention there is provided an isolated, cell-free protein fraction of oviductal apical plasma membrane (APM), having sperm viability improving and/or prolonging activity.
[0046] According to the present invention there is provided a sperm diluent which includes an additive comprising an isolated, cell-free peripheral membrane protein fraction of oviductal apical plasma membrane (APM) having sperm viability improving and/or prolonging activity.
[0047] Preferably, the sperm diluent or additive is synthetic. By synthetic we mean the diluent or additive is synthesised de novo. The advantage of synthetic diluents or additives is that these substantially eliminate the risk of transmitting viruses or other contaminants which might be associated with products obtained directly from mammalian tissue.
[0048] According to the present invention there is provided a use of an isolated, cell-free peripheral membrane protein fraction of oviductal apical plasma membrane (APM), in the manufacture of a composition for improving and/or prolonging sperm viability following cryopreservation.
[0049] According to the present invention there is provided a use of an isolated, cell-free peripheral membrane protein fraction of oviductal apical plasma membrane (APM), in the manufacture of a composition for improving and/or prolonging sperm viability during cryopreservation.
[0050] According to the present invention there is provided spermatozoa together with an isolated, cell-free peripheral membrane protein fraction of oviductal APM having sperm viability improving and/or prolonging activity, which are microencapsulated with a semi-permeable membrane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] The invention will next be described in more detail by way of example with reference to the accompanying drawings in which:
[0052] [0052]FIG. 1 shows the viability index (Mean±SEM) of boar spermatozoa incubated with different concentrations of oviductal APM preparations; and
[0053] [0053]FIG. 2 shows the viability index (Mean±SEM) of boar spermatozoa incubated for 24 hrs with peripheral oviductal APM proteins, pellet left after recovery of peripheral membrane proteins, oviductal APM preparation, lung APM preparation, duodenum APM preparation and control (medium only).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] Oviduct and Lung Tissue Preparation
[0055] Porcine lung and oviduct tissues were obtained and oviducts (attached to ovaries) were cleaned and washed with cold PBS. The oviducts were divided into two groups designated: FOL (follicular) and LUT (luteal), based on the appearance of the associated ovaries. Those oviducts attached to ovaries containing large follicles (8-12 mm in diameter) with signs of recent ovulation and no corpora lutea were assigned to the FOL group, those with ovaries containing several corpora lutea, without large follicles were assigned to the LUT group. Oviducts in both groups were trimmed from the ovaries and washed by passing four times through PBS. Each oviduct was divided into three sections; the first, designated as ampulla, was a section between the fimbria and the middle (thicker part) of the oviductal tube. The second section designated as isthmus, consisted of 1-2 cm of the caudal part of the uterine horn, the uterotubal junction, and up to nearly the middle (thinner part) of the oviductal tube. Finally, a section around the junction of the thin and thick part of the oviductal tube, approximately 2-3 cm long, was excised and discarded to assure differentiation of isthmic and ampullar parts of the oviduct. Each oviduct section (isthmic or ampullar) was processed separately. They were opened longitudinally and epithelia were scraped into a petri dish using a clean glass microscope slide. Scraped tissues collected from approximately 8-12 oviduct sections were collected separately (FOL isthmus, FOL ampulla, LUT isthmus and LUT ampulla) into 20 ml of cold PBS and kept on ice. These suspensions were centrifuged for five minutes at 200 g. The supernatants were discarded and pellets were resuspended in 20 ml of buffer 1 containing 60 mM mannitol, 5 mM EGTA, 1 μM phenylmethylsulfonylfluoride (PMSF), Tris base (pH 7.4). Suspensions (5 ml) were snap frozen in liquid nitrogen and stored at −80° C. until subsequent use for APM preparation.
[0056] Porcine lung tissues were chopped finely to a volume of 5 ml to which 20 ml of Buffer 1 was added. The lung tissue homogenates were snap frozen in liquid nitrogen and stored at −80° C. until subsequent use for APM preparation.
[0057] Porcine duodenal tissues (8-12 cm) were opened longitudinally and epithelia were scraped into a petri dish using a clean glass microscope slide. Scraped tissues were collected into 20 ml of cold PBS and kept on ice. These suspensions were centrifuged for five minutes at 200 g. The supernatants were discarded and pellets were resuspended in 20 ml of buffer 1 (pH 7.4). Suspensions (5 ml) were snap frozen in liquid nitrogen and stored at 80° C. until subsequent use for APM preparation.
[0058] APM Preparation
[0059] Tissue homogenates were thawed and homogenized on ice for one minute using a small homogeniser (Silverson, Waterside, UK). Two hundred microliter aliquots of this initial homogenate were snap-frozen in liquid nitrogen and stored at −80° C. for subsequent analysis. The homogenate was supplemented with 200 μl of 1 M MgCl 2 followed by 30 minutes incubation on ice. Thereafter the homogenate was centrifuged for 15 minutes at 3000 g. The pellet was discarded and the supernatant was centrifuged for 30 minutes at 90,000 g. After centrifugation, the pellet was resuspended in 20 ml of buffer 2 containing 60 mM mannitol, 7 mM EGTA, Tris base (pH 7.4) with ten strokes of a Potter S homogenizer. The homogenate was supplemented with 200 μl 1 M MgCl 2 and incubated on ice for 30 minutes. Afterwards, the mixture was centrifuged at 3000 g for 15 minutes. The pellet was discarded and the supernatant was centrifuged at 90,000 g for 30 minutes. The pellet, following ultracentrifugation, was resuspended in 20 ml of a modified Tyrode's medium containing 2 mM CaCl 2 , 3.1 mM KCl, 0.4 mM MgCl 2 6H 2 O, 100 mM NaCl, 25 mM NaHCO 3 , 0.3 μM NaH 2 PO 4 2H 2 O, 10 mM HEPES, 21.6 mM Sodium lactate and 1 mM sodium pyruvate with ten strokes of a Potter S homogenizer. The suspension was centrifuged for 30 minutes at 90,000 g. The supernatant was discarded and the pellet was resuspended in 900 μl of the modified Tyrode's medium by aspiration through a 0.9×90 mm Yale spinal needle (Becton Dickinson, Oxford, UK). This fraction was portioned, snap-frozen in liquid nitrogen and stored at −80° C.
[0060] Protein and γ-glutamyl Transpeptidase Activity Analysis
[0061] Protein concentrations of initial homogenates, final APM preparations from different tissues, and peripheral membrane protein fractions obtained from oviductal APM, were measured (Bio-Rad Protein Assay kit, Bio-Rad, Hemel Hempstead, UK). The kit is based on a dye-binding assay, in which the colour of the dye changes differentially, in response to change in protein concentration.
[0062] γ-glutamyl transpeptidase has previously been shown to reside mainly in the APM of polarized epithelial cells. The activity of γ-glutamyl transpeptidase in the initial homogenate and in the APM preparations was measured calorimetrically, using the Sigma diagnostic kit 545 (Sigma, Poole, Dorset, UK). The assay is based on the transfer of the glutamyl group from L-glutamyl-p-nitroanilide to glycylglycine catalyzed by γ-glutamyl transpeptidase. The liberated p-nitroaniline is diazotized by the addition of Sodium Nitrite and Ammonium Sulfamate. The absorbance of the pink azo-dye resulting from the addition of N-(1-napthyl)-ethyl-enediamine, measured at 530-550 nm, is proportional to γ-glutamyl transpeptidase activity. The degree of enzyme enrichment was expressed as fold increase in γ-glutamyl transpeptidase activity in the final APM preparations compared to the initial homogenate. This demonstrated the success of the method employed to isolate APM preparations from the initial homogenates. In addition, distinct differences in the protein profile of APM preparations were observed compared to that of original homogenates. Three proteins diminished and three were enriched in APM preparations compared to that of the initial oviductal homogenates.
[0063] Gel Electrophoresis
[0064] Protein separation was performed using the discontinuous buffer system. Five μg protein of original homogenate and purified APM preparations obtained from FOL isthmic, FOL ampullar, LUT isthmic, LUT ampullar and lung tissues were loaded on SDS-polyacrylamide gels (12% separation, 5% stacking). Gels were electrophoresed for between approximately 45 mins to 1 hr at between approximately 180 to 200 volts. Gel electrophoresis procedures were carried out using a Bio-Rad Modular Mini Electrophoresis System (Bio-Rad Labs, Hemel Hempstead, Herts, UK). Following electrophoresis the gels were fixed and then stained with Brilliant Blue G-Colloidal concentrate (Sigma). A digital image was produced from stained gels using a Hewlett Packard Scanjet 6200c scanner (CA, USA). The image was further analyzed using Scion image Beta 4.0.2 software program (Scion Corporation, Maryland, USA). Protein profiles of oviduct peripheral membrane proteins, pellet left after the recovery of peripheral membrane proteins and oviductal APM were produced and analyzed using the methodology described above.
[0065] Semen Preparation
[0066] Boar semen, diluted and stored for 24 hrs in Beltsville thawing solution was obtained and the semen (45 ml) washed three times with PBS by centrifugation and resuspension (600 g for 10 min). After the last centrifugation the supernatant was discarded, and the pellet was resuspended in the modified Tyrode's medium supplemented with 12 mg/ml BSA, 200 U/ml penicillin, 200 μg/ml streptomycin and 0.5 μg/ml amphotericin B (Life Technologies, Paisley, UK) (supplemented Tyrode's medium). One ml of washed semen sample was overlaid with 500 μl of supplemented Tyrode's medium in a test tube. The tube was placed at a 45° angle in an incubator held at 39° C. in a humidified atmosphere saturated with 5% CO2. After one hour the top 0.5 ml of medium containing the swim-up spermatozoa fraction was collected. Spermatozoa concentration was measured using a counting chamber. Sperm viability was assessed using a combination of Ethidium homodimer-1(ETHD-1; Molecular Probes, Leiden, The Netherlands) and SYBR-14 (Molecular Probes). One μl of 2 mM ETHD-1 and 2.5 μl of 20 pM SYBR-14 were diluted in 1 ml of PBS. An equal volume of the dye mixture was added to the semen sample and incubated for 20 minutes at 39° C. An aliquot of this preparation was placed on a slide and evaluated by epifluorescence microscopy (×40 objective). Viable spermatozoa with intact membrane excluding ETHD-1 demonstrated green fluorescence over the nucleus due to SYBR-14 staining. Spermatozoa with disrupted membranes showed red nuclear fluorescence due to ETHD-1 staining. Two hundred spermatozoa were evaluated by fluorescence microscopy and classified as membrane intact (green) or membrane damaged (red).
[0067] Sperm-APM Coincubation
[0068] Swim-up spermatozoa fractions (50×10 6 spermatozoa/ml) in 25 μl aliquots were added to 25 μl of APM (variable concentrations depending on experimental design). Sperm-APM coincubation droplets were covered with mineral oil, incubated at 39° C., 5% CO 2 for 24 hrs. After coincubation 50 μl of PBS containing 20 μM SYBR-14 and 2 μM ETHD-1 was added to each droplet and further incubated for 15 min. Thereafter the sperm viability was assessed as described above.
[0069] Microencapsulation of Sperm
[0070] Suspensions of sperm in physiological saline containing 1% sodium alginate (w/v), pH 6.8, were passed through a syringe pump to form droplets having a mean diameter of between 0.75 and 1.5 mm. Briefly, the sperm suspension within a 10 ml syringe was forced through a 19 gauge hypodermic needle contained within an encapsulating jet at a rate of approximately 1.5 ml/min to form droplets which were collected in a beaker containing aqueous solution (80 ml) of 1.5% CaCl 2 -Hepes buffer (50 mM) pH 6.8. Immediately on contact with the CaCl 2 -Hepes buffer solution, the droplets absorb calcium ions, which causes solidification of the entire-cell suspension resulting in a shape-retaining, high viscosity microcapsule. To form a semi-permeable membrane on the surface of the microcapsules, the microcapsules were rinsed three times with physiological saline and suspended in physiological saline containing 0.4% polylysine having a molecular weight range of 25 to 50 kDa, the excess polylysine was aspirated and the microcapsules rinsed with 0.1% CHES buffer, pH 8.2. After three rinses with physiological saline, the alginate gel inside the microcapsules was liquefied by suspending the capsules in isotonic 3% sodium-citrate saline solution, pH 7.4 for approximately 5 minutes.
[0071] Cryopreservation of Sperm.
[0072] Collected semen was allowed to cool slowly to room temperature over a period of around 2 hours. Semen was aliquoted into tubes containing approximately 6×10 9 spermatozoa and centrifuged at room temperature for 10 minutes at 300 g. The supernatant was removed by aspiration and the spermatozoa resuspended into Beltsville F5 extender (5 ml).
[0073] The tubes containing the extended spermatozoa were then placed in a beaker containing water (50 ml) at room temperature, which was then placed into a refrigerator and cooled to 5° C. over a two hour period. After the spermatozoa were cooled, 5 ml of Beltsville F5 extender containing 2% glycerol was added to each tube. The contents of the tubes were mixed by immersion and frozen immediately into pellets of 0.15 ml to 0.2 ml on dry ice. The pellets were then transferred to liquid nitrogen for storage.
[0074] When required for insemination, 10 ml of pellets were removed from the liquid nitrogen and held at room temperature for 3 minutes before being placed in a 250 ml beaker containing 25 ml Beltsville thawing solution which had been pre-warmed to 50° C. to thaw the semen.
[0075] Preparation of Fertilized Oocytes for IVF Treatment
[0076] Ovaries were collected and placed in 0.9 wt % saline containing at 25 to 30° C. Oocytes were aspirated from follicles using a 20 gauge needle connected to a 10 ml disposable syringe, transferred to a 50 ml conical tube and allowed to sediment at room temperature. Supernatant was discarded and follicular contents washed with Tyrode's Lactate (TL)-Hepes medium supplemented with 0.01% PVA (TL-Hepes-PVA). Oocytes with an evenly granulated cytoplasm and surrounded by compact cumulous cells were washed twice with TL-Hepes-PVA and three times in IVM medium. Oocytes were suspended in 500 μl of IVM medium in a four well multidish and cultured for 42 to 44 hours.
[0077] On completion of IVM, cumulus cells were removed by treatment with 0.1% (w/v) hyaluronidase in basic IVM medium and vortexed for 1 minute. Denuded oocytes were washed three times in 500 μl of IVM medium and then washed three times in IVF medium containing 1 mM caffeine and 1 mg/ml BSA. Oocytes were placed into 50 μl drops of pre-equilibrated IVF medium and covered with warm paraffin oil in a 35×10 mm 2 polystyrene culture dish. A frozen semen pellet was thawed and washed three times by centrifugation (1900×g for 4 minutes) in Dulbecco's PBS supplemented with 1 mg/ml BSA, 75 μg/ml potassium penicillin G and 50 μg/ml streptomycin sulfate (pH 7.2) The sperm pellet was then resuspended in IVF medium containing 1 mM caffeine and 0.1% (w/v) BSA and 50 μl of the sperm suspension was added to 50 μl drops of IVF medium containing the oocytes. The final sperm concentration was 2.5 to 3.5×10 5 /ml. Spermatozoa and oocytes were incubated for 6 hours at 39° C., 5% CO 2 (w/v) in air.
[0078] Statistical Analysis
[0079] The data were expressed as mean viability index±SEM. Viability index was defined as percentage of viable spermatozoa after 24 hours incubation in comparison to that of the initial viability of the same semen sample at the beginning of incubation period. Sperm viability data were tested for normal distribution. Analysis of variance was used for the statistical analysis of the data. The level of significance was considered p=0.05.
[0080] The invention will now be further illustrated by means of the following examples.
EXAMPLE 1
[0081] Recovery of APM
[0082] APM was obtained from isthmic, ampullar, lung and duodenum preparations. The amount of APM recovered from different tissues after each isolation procedure varied on different days (0.65 to 1.1, 1.47 to 4.3, 1.1 and 4.4 mg protein/ml for isthmic, ampullar, lung and duodenum APM preparations, respectively). The γ-glutamyl transpeptidase activity showed an overall increase in APM preparations compared to that of the initial homogenate (5- to 16-fold for isthmic, 5- to 7-fold for ampullar, 7-fold for lung and 3 fold for duodenum).
EXAMPLE 2
[0083] Determination of the dose response effect of FOL isthmic APM preparations on the maintenance of boar sperm viability in vitro.
[0084] To investigate whether the maintenance of boar sperm viability by APM preparations follows a dose-dependent response, spermatozoa were incubated in the presence of 0 (control), 100, 200 and 400 μg/ml of FOL isthmic APM preparations. Spermatozoa from 6 different boars were used in the experiments.
[0085] The overall viability of sperm after swim-up and at the start of coincubation was 68%±3 (mean±SEM). Generally, after swim-up procedures most recovered samples showed different degrees of head to head agglutination.
[0086] Agglutination was particularly apparent after incubation in the presence of oviductal APM preparations. This (head to head agglutination) was not induced in samples incubated in the presence of lung APM or control.
[0087] The viability index of boar spermatozoa incubated in the presence of FOL isthmic APM preparations was higher than that of the control after 24 hr incubation (FIG. 1). There was a significant concentration effect on the longevity of boar spermatozoa (p<0.01). 100 μg/ml APM increased sperm viability by about 10% over that of control, but viability was almost doubled by incubating 400 μg/ml APM.
EXAMPLE 3
[0088] Determination of the specificity of the effect of FOL isthmic APM preparations on the longevity of boar spermatozoa in vitro.
[0089] To investigate the specificity of the effect of APM preparations obtained from reproductive tissue in comparison to that of non-reproductive tissue on the maintenance of boar sperm viability, spermatozoa were co-incubated with FOL isthmic APM preparations (200 μg/ml), lung APM preparations (200 μg/ml) and control. Spermatozoa from 6 different boars were used in the experiments.
[0090] The viability index of boar spermatozoa incubated for 24 hours in supplemented Tyrode's medium (control) was significantly (p=0.005) lower than that incubated with FOL isthmic APM preparations (31%±9 and 60%±11; respectively). However the viability index of spermatozoa incubated with lung APM preparations (39%±7) was not different from that of the control and it was significantly (p=0.05) lower than that incubated with FOL isthmic APM preparations.
EXAMPLE 4
[0091] The effect of oviductal APM origin on the maintenance of boar sperm viability: comparison between FOL phase isthmic and ampullar APM preparations.
[0092] To investigate whether the sperm viability maintenance effects of APM depend on the region of oviduct from which APM is obtained, a comparison was made between FOL phase isthmic and FOL phase ampullar APM preparations. Spermatozoa were incubated with FOL phase isthmic APM preparations (200 μg/ml), FOL phase ampullar preparations (200 μg/ml) and control (medium only). Spermatozoa from 6 different boars were used in experiments.
[0093] There was no significant difference between the viability index of spermatozoa co-incubated with APM preparations obtained from FOL phase isthmic or FOL phase ampullar tissues (76%±5 and 74%±16; respectively). However there was a significant decrease in the viability of sperm in control (39%±6) compared to that incubated with either of oviductal APM preparations (p=0.001).
EXAMPLE 5
[0094] The effect of oviductal APM cycle stage on the maintenance of boar sperm viability: comparison of the effect of FOL and LUT phase oviductal APM preparations on the maintenance of boar sperm viability.
[0095] To investigate whether the maintenance of sperm viability effect by oviductal APM depends on the oestrous cycle stage of the sows from which oviductal APM is obtained, a comparison was made between oviductal APM preparations obtained from sows in FOL and LUT stages of the oestrous cycle. Since in the previous experiment no difference was seen between isthmic and ampullar preparations, equal amounts of FOL isthmic and FOL ampullar APM preparations were mixed to provide a FOL oviductal APM preparation. In the case of LUT APM preparation, this was achieved by mixing equal amounts of LUT isthmic and LUT ampullar APM preparations. Spermatozoa were incubated with FOL oviductal APM preparations at 200 μg/ml, LUT oviductal APM preparations at 200 μg/ml and control (medium only). Spermatozoa from 8 different boars were used in these experiments.
[0096] Both oviductal APM preparations obtained from sows in the FOL and LUT stages of the reproductive cycle maintained boar sperm viability in vitro to the same extent ( 82 ±6 and 84±6; respectively). The viability of sperm co-incubated with these preparations was significantly (p=0.0001) higher than the control (49±9) at the end of the coincubation period (24 hr).
EXAMPLE 6
[0097] The effect of heat treatment on the ability of APM preparations to maintain boar sperm viability in vitro. The oviductal APM preparations were heat treated to investigate whether the maintenance of sperm viability by oviductal APM preparations would be altered. Since in the previous experiment no difference was seen between FOL and LUT phase oviductal preparations, a mixture of both preparations was used in the following experiments. An aliquot of oviductal APM was incubated at 100° C. for 20 minutes. Spermatozoa were incubated with heat-treated oviductal APM preparations at 200 μg/ml, standard oviductal APM preparations at 200 μg/ml and control (medium only). Spermatozoa from 8 different boars were used in experiments.
[0098] The non-heated APM (78±/−9) showed significantly (P<0.04) increased viability-enhancing effect than that of the heat treated APM (59+/−5) and the control (65+/−5).
EXAMPLE 7
[0099] Determination of the effect of oviductal peripheral membrane protein fraction on the maintenance of boar sperm viability.
[0100] To investigate whether peripheral oviductal membrane proteins can maintain the viability of boar spermatozoa in vitro, spermatozoa were co-incubated with aliquots of peripheral membrane proteins (200 μg/ml), aliquots of pellet left after the recovery of peripheral membrane proteins (200 μg/ml), oviductal APM preparations (200 μg/ml), lung APM preparations (200 μg/ml), duodenum APM preparations (200 μg/ml) and control (medium only). Spermatozoa from 12 different boars were used in experiments.
[0101] The viability indices of spermatozoa co-incubated with peripheral membrane proteins, pellet left after peripheral membrane proteins recovery and oviductal APM were all significantly (p<0.05) higher than that incubated with lung, duodenum or control (medium only) (FIG. 2). The capacity of peripheral membrane proteins in maintaining sperm viability was significantly higher than that of pellet left after peripheral membrane proteins recovery (p<0.0001) and oviductal APM (p<0.004). The capacity of the pellet left after peripheral membrane proteins recovery in maintaining sperm viability was also lower than oviductal APM (p<0.01).
EXAMPLE 9
[0102] Microencapsulation of Sperm
[0103] A gel containing the spermatozoa is formed in an alginate matrix by means of exposure to calcium (divalent ion) and then forming a hydrogel layer of polymer shell, from materials such as poly-1-lysine, polyvinylamine, polyarginine or protamine sulphate.
[0104] The content is then changed to a sol by removing the divalent ions with ethylenediaminetetraacetic acid (EDTA)
[0105] The invention has been described and illustrated by means of a number of different specific examples. It will be appreciated, however, that the invention is not limited to the disclosure of these examples.
[0106] The inventors have described a distinct dose response effect of APM preparations on the maintenance of boar sperm viability.
[0107] The present inventors have shown that heat treatment of oviductal APM preparations abolished their biological activity. Proteins unfold or denature under various conditions; thermal energy from heat can break the weak bonds, destabilising protein native conformation and causing loss of biological activity. The inventors have therefore shown that proteins in these membrane fractions as the active factor(s) responsible for oviductal APM biological activity.
[0108] The present inventors have identified that biological activity is still present in the peripheral membrane fraction. Therefore, the inventors have shown that active protein(s) responsible for the maintenance of sperm viability by oviductal APM belongs to the peripheral membrane protein category. This finding has physiological significance, and important technical implications regarding future strategies for purification and characterisation of active protein(s) responsible for maintaining boar sperm viability by oviductal APM preparations.
[0109] Preparation of the APM fractions involved extensive washing steps. These washing steps did not remove the biological activity. Thus, the inventors have shown that the membrane components responsible for the bioactivity are not readily soluble.
[0110] The proteins obtained by preparation of the APM fractions are unlike soluble proteins which are derived from the oviduct. These oviduct proteins are secreted into the oviduct and, if any were present at the start of the preparation of APM to obtain the present invention, these would certainly have been washed away by the washing steps.
[0111] The present invention shows that peripheral membrane protein fractions isolated from oviduct epithelial cells, when co-incubated with spermatozoa at 39° C., extend the life of the spermatozoa for 2-3 days beyond the maximum lifespan of control spermatozoa incubated without peripheral membrane protein fractions.
[0112] The present invention further identifies a method by which APM fractions of freshly collected porcine oviductal cells can be isolated and tested for activity. Using this method, fractions have been studied extensively, and are shown to retain the ability to prolong the life of spermatozoa at 39° C., beyond the lifespan of control spermatozoa. To confirm that APM fractions from reproductive, rather than any, tissues are required for the prolongation of spermatozoa life, membrane fractions from duodenum, lung and kidney were also tested. These preparations were shown not to be comparable to those from the oviduct.
[0113] In conclusion, the present invention has demonstrated the ability of oviductal APM to support and prolong sperm viability in a dose dependent manner. This effect was limited to APM obtained from oviductal tissue. Furthermore it seems the active factor(s) involved in the maintenance of sperm viability by oviductal APM can be categorised as peripheral membrane proteins.
[0114] The use of AI has expanded considerably in the UK over the last 10 years, from around 14% in the early 1990's to about 50-60% of breeding at the present time.
[0115] Semen can be stored in dilute suspension in commercial diluents for about 3-5 days at ambient temperature. AI centres specialise in the collection of semen; they send it in diluted form by guaranteed next-day mail delivery to farmers, who then perform the AI on-farm using equipment also supplied by the AI centres. The semen can be kept alive on farms for 3-5 days, provided the temperature at which it is stored does not fall below 15° C.
[0116] Semen is known to be difficult to freeze; the viability of sperm is greatly reduced following cryopreservation. The present invention provides means for sperm viability to be higher following cryopreservation, thus enabling efficient freezing and subsequent provision of high numbers of viable sperm following freezing.
[0117] The present invention provides an effective diluent additive which enables AI centre operators to extend the shelf-life of the diluted semen beyond the 3-5 days currently guaranteed. Further, the present invention enables cryopreservation of the semen without loss of fertility. In addition, the present invention enables increased dilution of the semen without loss of fertility and further the present invention provides a means of increasing fertility.
[0118] The present invention thus enables AI centres to reduce the size of their herds, thus reducing the output of waste, a goal that has recently been given high priority by the UK government and the EU.
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A method of improving and/or prolonging sperm viability which comprises contacting spermatozoa with an isolated, cell-free protein fraction of oviductal apical plasma membrane (APM). This finds use in maintenance of sperm viability to increase the success rate of artificial insemination (AI).
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BACKGROUND OF THE INVENTION
[0001] This invention relates to liquid chromatographic methods and apparatuses and more particularly to methods and apparatuses for monitoring the solvent in a liquid chromatographic system.
[0002] Liquid chromatographic apparatuses that automatically monitor the solvent are known. This feature has become increasingly significant with the increasing use of flash chromatography, arrays of columns that use solvent from the same reservoir and automated unattended operation of the chromatographic systems. Such systems are monitored to avoid having the system run out of solvent in the middle of a chromatographic run and nonetheless continue operation of some parts of the system without one or more of the solvents required. The increased rate at which solvent is used and the ability of some systems to automatically increase the amount of solvent needed during a chromatographic run has resulted in systems unexpectedly running out of solvent during chromatographic runs. For example, some systems can increase the length of a chromatographic run without operator intervention, such as when the programmed time has elapsed but a peak is being detected.
[0003] One prior art system having the feature of monitoring the solvent during a chromatographic run tracks the amount of solvent used during a run in accordance with the program for the run and when the solvent is predicted to run out, terminates the chromatographic run. This system has several disadvantages, such as: (1) it requires that the operator correctly enter into the system the starting amount of solvent; (2) it requires operator intervention when the chromatographic system is terminated to replenish the solvent and reset the system; (3) it is more complicated than desired; and (4) it can fail to provide a warning ahead of time that the system needs to have solvent replenished when the run is automatically extended.
SUMMARY OF THE INVENTION
[0004] Accordingly, it is an object of the invention to provide a novel chromatographic system and method.
[0005] It is a still further object of the invention to provide a novel low-cost method for reliably providing substantial amounts of solvent to a chromatographic system.
[0006] It is a still further object of the invention to provide a novel system for avoiding running out of solvent before a chromatographic run is completed.
[0007] It is a still further object of the invention to provide a novel system for stopping a chromatographic run before the solvent is exhausted, which system is relatively simple and inexpensive.
[0008] It is a still further object of the invention to provide a novel system for monitoring solvent that does not require entering the correct amount of solvent into the controller before starting operation.
[0009] In accordance with the above and further objects of the invention, a chromatographic system includes as part of the system a solvent reservoir and a solvent level sensor. When the solvent is low, a solvent-level indicating signal is provided to the operator so that additional solvent can be added by the operator before the system runs out or additional solvent automatically is added. In the preferred embodiment, a bubbler is used to determine the depth of the solvent in a reservoir. The bubbler may also be used to purge the solvent of air and thus reduce the bubbles in the detector. For example, the gas used by the bubbler may be helium which will remove some air and avoid the introduction of air from an air-operated bubbler.
[0010] One unexpected difficulty with this system occurs because the same system is intended to be used with different solvents and in some circumstances, different shaped solvent reservoirs. This circumstance, if not compensated for, increases operator's involvement to adjust readings in accordance with the density of the solvent and the shape of the containers. However, in one embodiment, the signal from the bubbler or other pressure sensing instrument is used to compensate for possible changes to solvents with different densities and/or changes in the reservoir shape. This is accomplished by determining the rate of change of pressure signal with respect to the rate of usage of solvent as known from the programmed run. These two parameters can be used to determine the time at which the solvent will reach a level that predicts a possible exhaustion of solvent. This information can be provided to the operator or it can be used to automatically replenish the solvent.
[0011] It can be understood from the above description that the liquid chromatographic apparatus and technique of this invention has several advantages, such as: (1) it avoids having solvent run out during a chromatographic run, resulting in wasted solvent, a compromised column, lost sample and/or lost operator time; (2) it reduces the monitoring effort that must be supplied by persons operating the chromatograph; and (3) it is relatively inexpensive and can be implemented principally as software.
SUMMARY OF THE DRAWINGS
[0012] The above noted and other features of the invention will be better understood from the following detailed description when considered with reference to the accompanying drawings in which:
[0013] FIG. 1 is a block diagram of a liquid chromatographic system in accordance with an embodiment of the invention;
[0014] FIG. 2 is a flow diagram of a process of controlling a run in accordance with the invention;
[0015] FIG. 3 is a flow diagram of the operation of the solvent monitoring technique useful in the embodiment of FIG. 1 ; and
[0016] FIG. 4 is a flow diagram of a program for determining the solvent volume indicating a signal in a manner independent of the density of solvent and the shape of the reservoir used in the embodiment of FIG. 1 .
DETAILED DESCRIPTION
[0017] In FIG. 1 , there is shown a block diagram of a preparatory liquid chromatographic system 10 having a pumping system 12 , a column and detector array 14 , a collector system 16 , a controller 18 , a purge system 20 A and 20 B and a liquid level sensor 22 A and 22 B. The pumping system 12 supplies solvent to the column and bands are sensed by a detector array 14 under the control of the controller 18 . The purge system 20 A and 20 B communicates with a pump array 34 to purge the pumps and the lines between the pumps and the columns between chromatographic runs. The pump array 34 supplies solvent to the column and detector array 14 from which effluent flows into the collector system 16 under the control of the controller 18 . The controller 18 receives signals from detectors in the column and detector array 14 indicating bands of solute and activates the fraction collector system 16 accordingly in a manner known in the art. One suitable fraction collection system is the FOXY® 200 fraction collector available from Isco, Inc., 4700 Superior Street, Lincoln, Nebr. 68504. A chromatographic system which may use the novel solvent monitor is described in greater detail in U.S. Pat. No. 6,427,526, to Davison, et al., the disclosure of which is incorporated by reference.
[0018] To detect if solvent in either of solvent reservoirs within solvent reservoir and manifold 30 or 32 is running low, the liquid level sensors 22 A and 22 B are in communication with the solvent reservoir and manifold 30 and the solvent reservoir and manifold 32 respectively to receive signals indicating the pressure near the bottom of the reservoirs 30 and 32 and to supply that information to the controller 18 to which each of them is electrically connected. In the preferred embodiment, the liquid level sensors are bubblers which have Teflon tubing or other tubing that is compatible with the solvent extending to the bottom of the reservoirs to measure the pressure at the bottom of the reservoirs. The use of bubblers is advantageous since they are inexpensive and only the tubing, which can be selected for compatibility with the solvent extends into the reservoir. They may operate from a gas supply which, in some embodiments, may operate the purge systems 20 A and 20 B as well. A suitable bubbler is disclosed in U.S. Pat. No. 5,280,721 to Douglas T. Carson, the disclosure of which is incorporated by reference although many bubblers are available on the market and are suitable for use in this invention.
[0019] Generally, the bubblers will operate from an air supply that may also be used in the purge system. However, an additional benefit can be obtained by using helium or other suitable gas in the bubbler. This will permit the gas escaping from the end of the tubing in the bubbler to also remove air or moisture or other undesirable substances within the reservoir. For example, helium is commonly used to remove air from solvent.
[0020] To supply solvent to the pump array 34 , the pumping system 12 includes a plurality of solvent reservoirs and manifolds, a first and second of which are indicated at 30 and 32 respectively, a pump array 34 and a motor 36 which is driven under the control of the controller 18 to operate the array of pumps 34 . The controller 18 also controls the valves in the pump array 34 to control the flow of solvent and the formation of gradients as the motor 36 actuates pistons of the reciprocating pumps in the pump array 34 simultaneously to pump solvent from a plurality of pumps in the pump array 34 and to draw solvent from the solvent reservoirs and manifolds such as 30 and 32 . Valves in the pump array 34 control the amount of liquid, if any, and the proportions of liquids from different reservoirs in the case of gradient operation that are drawn into the pump and pumped from it. The manifolds communicate with the reservoirs so that a plurality of each of the solvents such as the first and second solvents in the solvent reservoir manifold 30 and 32 respectively can be drawn into the array of pumps 34 to permit simultaneous operation of a number of pumps. In some embodiments, the controller 18 may provide a signal on conductor 97 to cause solvent to flow from a large source of solvent into individual reservoirs that are low on solvent. In some embodiments, the controller 18 stops the run when a low level signal is received or causes the read-out display 125 to indicate a low solvent level.
[0021] While in the preferred embodiment, arrays of pumps, columns and detectors are used, any type of pump, column or detector is suitable. A large number of different liquid chromatographic systems are known in the art and to persons of ordinary skill in the art and any such known system may be adaptable to the invention disclosed herein with routine engineering. . While two solvents are disclosed in the embodiment of FIG. 1 , only one solvent may be used or more than two solvents.
[0022] To process the effluent, the collector system 16 includes a fraction collector 40 to collect solute, a manifold 42 and a waste depository 44 to handle waste from the manifold 42 . One or more fraction collectors 40 communicate with the column and detector array 14 to receive the solute from the columns, either with a manifold or not. A manifold 42 may be used to combine solute from more than one column and deposit them together in a single receptacle or each column may deposit solute in its own receptacle or some of the columns each may deposit solute in its own corresponding receptacle and others may combine solute in the same receptacles. The manifold 42 communicates with the column and detector array 14 to channel effluent from each column and deposit it in the waste depository 44 . The fraction collector 40 may be any suitable fraction collector such as that disclosed in U.S. Pat. No. 3,418,084 or the above-identified FOXY fraction collector.
[0023] In FIG. 2 , there is shown a block diagram of a purge system 20 A, a liquid level sensor 22 A, 22 B, and the solvent reservoir and manifold 30 . In FIG. 1 , two such identical systems are used but for clarity only one will be described herein. As explained in conjunction with FIG.1 , the purge system 20 A supplies gas to any of a plurality of liquid level sensors, liquid level sensors 22 A and 22 B being shown in FIG. 2 for illustration. Each of the liquid level sensors 22 A and 22 B communicates with a different reservoir and with the controller 18 ( FIG. 1 ) to monitor the solvent level in a corresponding reservoir. Several reservoirs may be associated with a single manifold so that different solvents may be utilized in chromatographic runs by operation of a valve with purge operation occurring between runs. Thus, different reservoirs with different solvents in them may be selected easily. In a simplified system, only one reservoir would be utilized with a single solvent. In any of the systems, the reservoirs may communicate with a large source of solvent and a signal indicating a low solvent level, instead of only informing the operator, could cause a replenishment of solvent into the reservoir from a larger supply or a main supply 95 illustrated with respect to reservoir 50 A in FIG. 2 .
[0024] In one embodiment, the purge system 20 A includes a gas source 90 , a plurality of three-way valves, two of which are shown at 94 A and 94 B, a tank pressure monitor 92 and a gas pump 99 . The gas source 90 may be a reservoir which is supplied by the gas pump 99 and may contain air or in some embodiments, helium. In a simplified version, the gas pump 99 alone pumps air that may or may not be utilized to supply air for purging purposes. A simple diaphragm pump without pressure regulation or a reservoir may be adequate for some applications. For a more reliable operation, the tank pressure monitor 92 is connected to the gas source 90 and controls the pressure of the gas in the gas source 90 so that the purge operation may be done reliably at a selected gas pressure and more significantly, the gas pressure used in the bubblers may be reliably controlled. The embodiment shown in FIG. 2 has the gas pump 99 communicating through the tank pressure monitor 92 with the gas source 90 which is a gas reservoir to maintain a reliable preset gas pressure in the gas source. The gas source is then connected to the liquid level sensors, two of which are shown at 22 A and 22 B. In the preferred embodiment, the liquid level sensors are bubblers and the gas source supplies gas to the bubblers for the purpose of sensing the amount of solvent in the reservoirs. A plurality of three-way valves, valves 94 A and 94 B being shown by way of example in FIG. 2 , may communicate with the gas source 90 to receive gas and, in one position of the three-way valve, supply it to purge systems through corresponding ones of check valves 101 A and 101 B.
[0025] The liquid level sensor 22 A includes an adjustable or fixed orifice 115 connected to the gas source 90 to supply a continuous flow of air through tubing 103 to the bottom of reservoir 50 A to cause bubbles to flow from the outlet at 105 of the tubing 103 against the pressure of liquid 54 at the bottom of the reservoir 50 A. A transducer in the bubbler console 107 provides a signal indicating the pressure needed to maintain the air flow from the head of solvent in the reservoir. This signal may be used by the controller 18 ( FIG. 1 ) to indicate when solvent is low and the system should be stopped or the solvent should be automatically replenished by main supply 95 and/or a message provided to the operator in a display on the controller 18 ( FIG. 1 ). The signal representative of the pressure as measured by the bubbler console 107 is supplied to the controller 18 ( FIG. 1 ) through a conductor 117 A to indicate the level of the solvent in reservoir 50 A. The second liquid level sensor 22 B functions in the same manner as the first liquid level sensor 22 A and is shown only generally in FIG. 2 .
[0026] In one embodiment, the solvent reservoir and manifold 30 utilizing more than one reservoir with the more than one solvent as indicated at reservoirs 50 A and 50 B includes a valve 119 communicating with all of the reservoirs, two of which are shown at 50 A and 50 B as well as with manifold 52 and the liquid level sensor 22 B so that the valve 119 receives fluid from the plurality of reservoirs, two of which are shown at 50 A and 50 B containing different solvents and selects one ofthem forapplicationtothe manifold 52 . Eachofthe reservoirs such as 50 A and 50 B is connected to a corresponding liquid level sensor such as 22 A or 22 B, which in turn provides signals to the controller 18 through their electrical outlets 117 A and 177 B respectively.
[0027] The first solvent reservoir and manifold 30 includes a first manifold 52 having one inlet and ten outlets 58 A- 58 J, a conduit 56 and a first solvent reservoir 50 A, which solvent reservoir 50 A holds a first solvent 54 . The conduit 56 communicates with the solvent 54 in the solvent reservoir 50 A through the valve 119 on one end and communicates with the interior of the manifold 52 at its other end. Each of the outlets 58 A- 58 J of the manifold 52 communicate with the interior of a different one of ten cylinders of the pumps (not shown in FIG. 2 ) through appropriate valves. Similarly, the second manifold ( FIG. 1 ) communicates with a second solvent in a second solvent reservoir through a another conduit. The second manifold also includes a plurality of outlet conduits that communicate with the interiors of a corresponding number of pump cylinders through appropriate valves as described in more detail in the aforesaid U.S. Pat. No. 6,427,526, to Davison, et al., so that the solvent from the reservoir 50 A and the solvent from the second reservoir may be mixed together in a proportion that is set in accordance with the timing of the valves.
[0028] The check valves 101 A and 101 B communicate with purge manifolds (not shown in FIG. 2 ) to provide communication with the gas source 90 through conduits 91 A, and 91 B and the pressure monitor 92 and the three-way valves 94 A and 94 B to maintain an appropriate pressure for purging the lines. These purge manifolds each have ten outlets, each communicating with a different one of the ten conduits connecting a corresponding one of the corresponding pumps to a corresponding one of ten corresponding columns to transmit gas back through the piston pumps to purge the cylinders of the piston pumps and the conduits connecting the pumps to the columns. Each of the conduits connected to the purge connector arrangement lead to a corresponding pump in the pump array 34 ( FIG. 1 ) which in turn communicates with the corresponding one of the columns in the column and detector array 14 ( FIG. 1 ). Between chromatographic runs, the pressurized gas source 90 , which is commonly a source of air, nitrogen or helium gas, communicates through the pressure regulator 92 and the three-way valves 94 A, and 94 B with the manifold to provide purging fluid to each of the corresponding outlets for each of the pump and column combinations.
[0029] While in the embodiment shown in FIG. 2 as an example, the manifolds each have ten outlet conduits which communicate with ten pump cylinders through appropriate valves as will be described hereinafter, each could have more or less than ten outlets and a manifold is not required for many chromatographic systems in which this novel solvent monitoring system has utility. Each of the reservoirs in the embodiment of FIG. 2 is similar to the reservoir 30 and operates in a similar manner to provide the same solvent from the same reservoir to a plurality of pump cylinders for simultaneous pumping of the solvent into a plurality of columns and therefore only one is shown in detail in FIG. 2 for simplicity.
[0030] In FIG. 3 , there is shown a flow diagram 120 of the operation of the solvent monitoring technique having the step of selecting a solvent 122 , the step of programming a chromatographic run 124 , the step 126 of measuring the volume of solvent in the reservoir with a solvent compatible sensor, the step 128 of generating a solvent level indicator signal when the solvent is low and the step 130 of stopping the chromatographic run at a preset solvent level. With this process, in some embodiments, a particular solvent may be selected as shown at step 122 from selection valves which connect different solvent reservoirs through a multi-position valve to supply fluid from any of the reservoirs into the system. Each of the reservoirs has associated with it a solvent monitoring system, which in the preferred embodiment, includes a bubbler to sense the depth of the solvent.
[0031] With this arrangement, the chromatographic run is programmed as shown at step 124 . For example, a gradient may be programmed into the controller 18 ( FIG. 1 ) to draw one selected fluid from one reservoir and supply it to a mixer together with another solvent from another reservoir, typically with the strongest solvent starting at zero and the weakest solvent starting at 100% and then gradually increasing the stronger solvent and decreasing the weaker solvent to maintain the total flow equal. The timing of the mixture is programmed in accordance with the separation to be performed.
[0032] As shown in step 126 , as the volume of the solvent in each of the reservoirs is supplied to the chromatographic system, the volume left in the reservoir is measured. This measurement may be accomplished in several different ways. In a preferred embodiment, the change in pressure with respect to the volume of solvent supplied to the columns during the chromatographic run is determined by measuring the pressure at several points during the run. This rate of change of pressure with respect to volume of solvent can be used to predict when the level when the reservoir will run out of solvent, which corresponds to zero pressure, or when it will reach a value preset by the operator to stop the run or provide a message to the operator or automatically supply more solvent to the reservoir. The pressure measured at any point minus the product of the rate of decrease of the pressure per unit of solvent supplied to the columns and the amount of solvent that will be supplied to the columns as programmed in the chromatographic run provides an indication of how close to zero pressure which is an empty reservoir the system will be at any point in the run. Thus a signal indicating a low level of solvent can be given when needed without knowing the exact amount of solvent is in the reservoir at the start of the run.
[0033] Of course the signal can be generated in other ways such as by filling the reservoir to a predetermined level and measuring the amount of solvent that is being supplied to the columns by measuring the change in pressure. The amount of the solvent is programmed and the sensor can determine the change in pressure in the reservoirs. From these determinations, based on a change from maximum pressure to a zero pressure, the curve indicating the drop with respect to solvent used indicates the amount of solvent left in a manner independent of the density of the solvent and the shape of the container. On the other hand, the system may be programmed to take into account the density of the liquid and thus indicate the height of the liquid, and the shape of the container can be programmed so as to easily calculate the amount of solvent that is left in the reservoir.
[0034] As shown at step 128 , when the solvent reaches a generally low level, a low volume indicator signal may be generated to stop the system. Also, as the solvent is depleted, the controller can generate an indication of the amount of solvent left and indicate the amount of solvent to the operator. Thus, as shown at step 130 , the chromatograph may be automatically stopped so as to avoid ruining the column and the run until an operator can replenish the reservoir. In the alternative, the solvent level indicating signal can be used to automatically open a valve to a master source of solvent so that the solvent can replenish the reservoirs.
[0035] In FIG. 4 , there is shown a flow diagram of a program 140 for determining the solvent volume indicating signal in a manner independent of the density of the solvent and the shape of the reservoir. As shown in flow diagram 140 , a volume of solvent is supplied to the reservoir. A pressure measurement is taken before the chromatographic run so as to obtain a signal indicating the total amount of solvent in the reservoir as shown as step 144 . As shown at step 146 , a series of pressure measurements at known volumes in the reservoir during the chromatographic run are taken as the program proceeds and each of these steps is correlated with the programmed amount of solvent to be supplied from the reservoir. As shown in step 148 , at least an approximate rate of change of pressure is determined with respect to the volume of solvent. As shown in step 150 , the remaining volume of solvent in the reservoir is projected from the rate of change of said starting volume. This succession of steps and progress through the program indicates a rate of use of the solvent with respect to the stage of the chromatographic run so as to be able to predict when a low volume of solvent will be left. At that point in time, a low solvent signal may be provided to inform the operator that the solvent is low. The stage of the chromatographic run may be determined in either of terms of volume or in terms of time of the run. In the preferred embodiment, it is determined in terms ofvolume and the read-out with peaks is correlated with the volume of fluid that has flown through the column. The starting solvent minus the rate of change of pressure with respect to time or volume programmed multiplied by the starting volume in the run indicates the amount of solvent left.
[0036] It can be understood from the above description that the liquid chromatographic apparatus and technique of this invention has several advantages, such as: (1) it avoids having solvent run out during a chromatographic run, resulting in wasted solvent, a compromised column, lost sample and/or lost operator time; (2) it reduces the monitoring effort that must be supplied by persons operating the chromatograph; and (3) it is relatively inexpensive and can be implemented principally as software.
[0037] Although a preferred embodiment of the invention has been described with some particularity, it is to be understood that the invention may be practiced other than as specifically described. Accordingly, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described.
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A bubbler is positioned within a solvent reservoir of a chromatographic system with its opening near the bottom of the system to measure the pressure of solvent. The bubbler may use air or may use helium or some other gas so that the solvent can be purged of excess air while its level is being monitored by the bubbler. The bubbler provides a depth signal to a microcontroller that records the drop in pressure and projects a low level of pressure at which point solvent should be replenished. The microprocessor may provide a signal to the operator or terminate operation or automatically replenish solvent depending upon the program.
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TECHNICAL FIELD
[0001] The present invention relates to a method of manufacturing a film dressing comprising the steps of feeding, a composite web consisting of a first layer of thin plastic film and a second carrier layer releasably attached to the thin film, and a web of release material in a machine direction, applying a layer of adhesive onto the web of release material or onto the layer of thin plastic film, bringing together the composite web consisting of a first layer of thin plastic film and a second carrier layer with the web of release material after the layer of adhesive has been applied to either the web of release material or the layer of thin plastic film, cutting the web of release material along a line extending in the machine direction.
BACKGROUND OF THE INVENTION
[0002] The adhesive coatings on dressings are usually covered by release sheets which have to be removed from the dressing before application of the dressing. The release sheets are necessary for enabling easy handling of the dressings before application and also for protecting the adhesive layer of the dressing from being contaminated by dust and other contaminants and for preventing dry-out of the adhesive. A common solution of the problem to enable easy removal of the release sheet is to make the release sheet in two parts, one of the parts having an edge bent to provide a grip flap and the other part overlapping the first part and its grip flap.
[0003] In film dressings, the film is so thin that it is impossible to handle both before application of the dressing and during application thereof if no support is available. In order to enable handling and application of the dressing after removal of the release sheet a stiffening layer is releasably attached to the thin film. After application of the dressing this stiffening layer is removed. For a film dressing, easy removal of both the release sheet and the stiffening layer is a requirement. In order to provide easy removal of the stiffening layer, this layer often has parts that extend beyond the extension of the film for forming grip tabs. Film dressings having release sheets and stiffening layers which both extend beyond the thin film of the dressing are known, see for example US 2004/0138603 A1. It is also known to affix separate grip tabs or the like to stiffening layers and release sheets.
[0004] Film dressings are often made by manufacturers that do not produce the films themselves but acquire the films from manufactures of plastic films. For ease of handling and processing such films are produced by co-extruding of the thin film and a carrier film of plastic material having poor affinity to each other so that the thin film easily can be removed from the carrier film or vice versa. Such carrier film can be used as a stiffening layer or carrier layer in a film dressing. However, if such carrier film is used as stiffening layer, no edge of the stiffening layer would extend beyond the edge of the thin film.
[0005] The objective of the present invention is to provide a method of manufacturing a film dressing, in which the release sheet and the stiffening layer are easy to remove without these layers extending beyond the thin film. It is also an objective of the present invention to provide such a method in which the release sheet can be applied as a single piece of material.
SUMMARY OF THE INVENTION
[0006] These objectives are obtained by a method of manufacturing a film dressing comprising the steps of feeding, a composite web consisting of a first layer of thin plastic film and a second carrier layer relasably attached to the thin film, and a web of release material in a machine direction, applying a layer of adhesive onto the web of release material or onto the layer of thin plastic film, bringing together the composite web consisting of a first layer of thin plastic film and a second carrier layer with the web of release material after the layer of adhesive has been applied to either the web of release material or the layer of thin plastic film, cutting the web of release material along a line extending in the machine direction, characterised by the further step of weakening the first layer of thin film along a line coincident to the line cut in the web of release material. In such a method, the stiffening layer delivered by the manufacturer of the thin film can be used which considerably reduces waste of material. Furthermore, since the release sheet in a film dressing produced by this method is divided into two parts solely by a cut line, no folding of an edge of one part of the release sheet in order to form a grip tab is needed nor has the other part of the release sheet an overlapping edge. The web of release material can then be used as a so called process paper, i.e. a web onto which the adhesive layer and the composite of carrier layer and thin film can be laid, which simplifies the manufacture of dressings and reduces material waste.
[0007] According to a preferred embodiment the weakening line is a line of perforations and said the cutting line is a straight line. Said cutting line is preferably distanced 5-50 mm, preferably 10-30 mm from one of the edges of the web of release material. The distance between the perforations in the perforation line is 0.1-5 mm and the perforations in the perfotration line are preferably made through the whole composite web consisting of carrier material and a layer of thin plastic film. The release material is preferably silicone coated paper.
[0008] The invention also relates to a film dressing comprising a thin plastic film, a stiffening layer releasably attached to one side of the plastic film, a layer of adhesive applied to the plastic film on the side opposite to the stiffening layer and a release sheet covering the adhesive layer, wherein a cutting line extending along an edge of the dressing at a distance (d) therefrom is made through the release sheet, characterised in that a weakening line coincident to the cutting line in the release sheet is made in the plastic film.
[0009] According to a preferred embodiment, the weakening line is a perforation line, and the perforations in the perforation line preferably also penetrates the stiffening layer. The thin plastic film can be a polyurethane film and the stiffening layer can consist of polyethylene film. The adhesive in the adhesive layer can be an acrylate adhesive and the release sheet a silicone coated paper sheet. Alternatively, the adhesive in the adhesive layer can be a silicone adhesive and the release sheet a polyethylene sheet or a polypropylene sheet. In another alternative, the release sheet is a laminate of a paper sheet and a polyethylene sheet or a laminate of a paper sheet and a polypropylene sheet.
BRIEF DESCRIPTION OF THE DRAWING
[0010] The invention will now be described with reference to the enclosed figures, of which;
[0011] FIG. 1 schematically discloses a side view of a manufacturing line for film dressings illustrating the method according to a preferred embodiment of the invention,
[0012] FIG. 2 schematically discloses a plan view from above of manufacturing line in FIG. 1 ,
[0013] FIG. 3 schematically shows a perspective view of a film dressing manufactured in the manufacturing line according to FIGS. 1 and 2 , and
[0014] FIG. 4 schematically illustrates the first step in the application of a film dressing manufactured in the manufacturing line according to FIGS. 1 and 2 .
DESCRIPTION OF EMBODIMENTS
[0015] In FIGS. 1 and 2 a manufacturing line for continuous production of film dressings is schematically shown. A web 2 of release material is unwound from storage roll 1 and laid onto a conveyer (not shown) and transported on the conveyer in the direction of arrow A. An adhesive coating 3 is applied onto web 1 by a suitable glue applicator 4 , which for example can be a blade coater or a slot nozzle. A composite web, consisting of a thin film 5 and a carrier layer 6 releasably attached to the film 5 , is thereafter unwound from a storage roll 7 and laid onto the adhesive layer 3 . A continuous line 8 extended in the machine direction, i.e. the transport direction of the conveyer, is then cut through the web 2 of release material without reaching into the film layer 5 with the aid of a suitable cutting tool 9 , such as a rotating cutting device.
[0016] A line of perforations 10 is then made through the carrier layer 6 and the film layer 5 by any suitable means 11 , such as a laser a ultrasonic device or a rotating cutting tool. Said perforation line is coincident to the cutting line 8 .
[0017] Finally, the composite web consisting of layers 2 , 3 , 5 , 6 is transversely cut into single film dressings 13 with the aid of a suitable cutting device 12 .
[0018] After manufacturing the film dressings 13 are transported to a packaging station (not shown in the figures).
[0019] The layers in each film dressing 13 are given the same reference numerals as corresponding webs 2 , 3 , 5 , 6 with the addition of numeral 1 . In FIG. 3 a film dressing 13 is shown in a perspective view. The carrier layer in film dressing 13 is referred to by numeral 61 , the film layer by numeral 51 , the layer of adhesive by numeral 31 and the release sheet by 21 . The cutting line 81 and the coincident perforation line 101 divide each film dressing 13 into two parts 14 and 15 , as can be seen in FIGS. 2 and 3 . As will be explained later, part 15 serves as a grip part and has therefore a rather short extension perpendicular to the closest edge of the dressing directed in the machine direction, i.e. the direction indicated by arrow A. Preferably, the distance d from the closest edge of the dressing and the coincident lines 8 , 10 is 5-50 mm. and more preferably 10-30 mm.
[0020] In FIG. 4 , an example of how the first step in the application of a film dressing 13 can be performed is schematically illustrated. The dressing 13 is gripped in part 15 with one hand, the right hand in FIG. 4 , and held so that part 14 is allowed to form an angle with part 15 by gravity. The release sheet 21 of dressing 13 should be turned upwards as illustrated in FIG. 4 . If needed, the free left hand can be used to fold part 14 downward. With the dressing 13 in this position, as illustrated in FIG. 4 , it is easy for the user to release an upper corner of the release sheet from the rest of part 14 by slightly moving the part 14 upwards in relation to part 15 thereby releasing a small upper part of the release sheet from the film or by loosening the release sheet from the thin film by peeling with a thumb. The released corner is then gripped between the fingers of the left hand and wholly or partly removed from the rest of part 14 . If partly removed, the part of dressing 13 having an uncovered adhesive area is then attached to the skin and the remaining part of the release sheet of part 14 is then removed during attaching of the thereby uncovered adhesive area. After having attached the dressing, the carrier layer 61 is then removed from the thin film. The outermost part of the carrier layer 61 , the part in proximity to the perforation line, has in the method of manufacture been lifted so that a small portion of the carrier layer is no longer attached to the thin film thereby providing an easily grasped flap for removal of the carrier film. After removal of the carrier layer 61 , the remaining portion of part 15 , i.e. a portion of the release sheet and the thin film attached thereto is firmly gripped. Thereafter, the film attached to the release sheet in part 15 of the dressing is removed from the part of the film attached to skin, i.e. the portion of the film located in part 14 , by tearing along the perforation line, and the release sheet in part 15 and the portion of the film attached thereto are then discarded.
[0021] In order to provide an easy tearing of the film in part 15 of the dressing the distance between adjacent perforations in the perforation line 101 should be 0.1-5 mm.
[0022] In FIG. 4 , the angle between parts 14 and 15 of dressing 13 is large. This is not necessary, the corners of release sheet 21 on part 14 are easily released and gripped even if the angle is smaller.
[0023] Thus, by the described method a film dressing which is easy to handle and apply to skin is produced. Moreover, due to the stiffening characteristics of the carrier the dressing can be cut into any suitable shape by the user of the dressing 13 provided that at least a part of the connection between parts 14 and 15 of dressing 13 is unbroken.
[0024] As stated above, the composite web consisting of a thin film 5 and a carrier layer 6 delivered from the manufacturer of the film is used in the method according to the invention. Thereby, a removal of this carrier layer and an application of another carrier layer by heat and pressure or adhesive is not necessary in the manufacturing method according to the present invention. Furthermore, since the release sheet is divided into two parts solely by a cutting line, there is no need to remove the web 2 of release material and apply a web of release material consisting of two parts, one part having an edge fold and the other part having an edge portion overlapping said fold. The method according to the present invention thus allows an efficient use of materials without any waste of material in the manufacturing line.
[0025] The web 2 of release material is preferably a web of silicone coated paper of the type commonly used as release sheet material in wound dressings. However, any material used as release material in wound dressings, such as plastic foil material, can be used. An example of a suitable material is silicone coated paper with the trade name Lopasil CCK from Loparex BV, Apeldoorn, NL. Since the release material should be easily removable from the adhesive coating 3 , the choice of release material is dependent on the adhesive used in the dressing. If, for example, a silicone adhesive is used, a silicone coated material is unsuitable and known release materials for dressings having silicone adhesive is used, such as a web of polyethylene, a laminate of paper and polyethylene or a laminate of paper and polypropylene.
[0026] The adhesive layer 3 is preferably a layer of acrylate adhesive or hot melt. A suitable adhesive is Dispomelt® 70-4647 from National Starch and Chemical Company, Bridgewater, N.J., USA. Other adhesives known to be used in wound dressings, such as silicone adhesives, can also be used.
[0027] The thin film 5 having a thickness less than 70 micrometer is preferably of polyurethane. A suitable film is Platilon® 2202 from Epurex Films Gmbh & Co KG, Bomlitz, Germany. Such a film is delivered carried on a web of polyethylene. Other types of film materials used for film dressings can also be used delivered carried by webs of carrier material.
[0028] The carrier layer 6 is of a material which is easily removable from the film 5 and is thus dependable of the film material. For a polyurethane film, a carrier of polyethylene is suitable. All known combinations of films and carrier material for film dressings can be used in the present invention.
[0029] In the embodiment according to FIGS. 1 and 2 the adhesive layer is applied to the web of release material. In another embodiment (not shown) the adhesive layer can instead be applied onto the thin film of the composite web consisting of a carrier material and a thin film delivered from the film manufacturer. A web of release material is then laid onto the the adhesive layer applied on the thin film. Thereafter, the cutting steps described in connection with the embodiment according to FIGS. 1 and 2 are performed, the only difference being that the cutting of the continuous line in the web of release material is performed from above instead of from below as in FIG. 1 and the perforation is made from below instead of from above.
[0030] The last step of transverse cutting to form individual film dressings is omitted if the produced film dressing is to be wound up onto a roller as a continuous film dressing.
[0031] It is preferred that the perforation line 10 and the cutting line 8 through the web of release material are perfectly aligned with each other but this is not strictly necessary. A difference of up to one or two millimetres can be allowed without seriously impairing the function of the end product.
[0032] It is also preferred that the cutting line and thereby also the perforation line is straight. However, these lines can be curved, for example having wave form, or have curved parts.
[0033] For ease of manufacturing, the perforation line 10 is described as passing trough both the carrier layer 6 and the film layer 5 . However, it is only necessary that the perofration line passes through the film layer 5 . It is thus possible, but not preferred, to produce the perforation line from below so that it only passes through the film layer 5 .
[0034] Instead of a perforation line, another type of weakening line can be cut into the film. Such a line can be made simultaneously with the cutting of the continuous line through the web of release material just by making a deeper cut. Such a cut should reach into 15-75% of the thickness of the film on order to make the film easily tearable, depending of the htickness and mechanical strength of the film.
[0035] It is pointed out that even if the method had been developed for manufacturer of film dressings that themselves do not manufacture films, the method is not restricted thereto. A manufacturer of films can of course also be manufacturing film dressings. It is also possible to make the manufacturer of films to use a specific carrier material chosen by the manufacturer of film dressings. The use of the carrier material that the film is delivered with in the present manufacturing method is thus not per se restrictive for the choice of carrier material.
[0036] The embodiment described with reference to the figures can of course be modified without leaving the scope of invention. For example, the carrier layer 6 stiffening the film 5 can be divided into two or more parts by a cutting line by equipment similar to the equipment used for cutting line 8 . The perforation of the release layer 6 and the film 5 can be made before the step of cutting line 8 through the release web 2 . The scope of invention shall therefore only be restricted by the content of the enclosed patent claims.
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Disclosed is a film dressing and a method of manufacturing a film dressing including the steps of feeding a composite web consisting of a first layer of thin plastic film and a second carrier layer releasably attached to the thin film, and a web of release material in a machine direction, applying a layer of adhesive onto the web of release material or onto the layer of thin plastic film, bringing together the composite web consisting of a first layer of thin plastic film with a second carrier layer and the web of release material after the layer of adhesive has been applied to either the web of release material or the layer of thin plastic film, cutting the web of release material along a line extending in the machine direction.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is entitled to the benefit of and incorporates by reference essential subject matter disclosed in International Patent Application No. PCT/DK2006/000507 filed on Sep. 14, 2006 and German Patent Application No. 10 2005 043 952.7 filed Sep. 15, 2005.
TECHNICAL FIELD
[0002] The invention concerns a heat exchanger with a housing having arranged in it a primary side with a primary-side flow path between an upstream connector and a downstream connector and a secondary side with a secondary-side flow path between an inflow connector and an outflow connector, wherein the primary side and the secondary side stand in heat exchange connection with one another along a heat exchange stretch with a temperature sensor being arranged in the region of the outflow connector. The invention further concerns a method for the control of a heat exchanger having a primary-side flow path and a secondary-side flow path where the primary-side flow path and the secondary-side flow path stand in heat exchange connection with one another and a temperature sensor is arranged in the region of the secondary-side flow path.
BACKGROUND OF THE INVENTION
[0003] One such type of heat exchanger often is used to heat consumable water and heating water in living units, with the heat energy being supplied from a remote heating system. The heat carrying fluid, most often hot water, delivered by the heating system flows through the primary-side flow path and in doing so transfers heat to the consumble water or to the heating fluid which flows through the secondary-side flow path. As a rule, the fluids flowing through the primary-side flow path and the secondary-side flow path flow in opposite directions, so that the water of the secondary side can be heated to a temperature higher than the temperature of the fluid at the downstream connector of the primary side.
[0004] To maintain a quite exact temperature adjustment at the outflow connector, the flow of the heat carrying fluid of the primary side is controlled in dependence on the heat given off by the secondary side. This will be explained below by way of example, in which consumable water is heated in the heat exchanger. As soon as consumable water is taken from the outflow connector of the secondary side, cold consumable water flows into the inflow connector. Accordingly, at almost the same time, heat carrying fluid must be able to flow through the primary-side flow path so that sufficient heat can be transferred to the secondary side.
[0005] In order to control or regulate a valve so that the fluid flow of the primary side is controlled, frequently a temperature sensor is used to regulate the valve.
BRIEF DESCRIPTION OF THE INVENTION
[0006] It is the object of the invention to improve the ability to regulate and monitor a heat exchanger.
[0007] This object is solved in the case of a heat exchanger of the previously mentioned kind in that at least a second temperature sensor is arranged at the heat exchange stretch and in that both of the temperature sensors are connected with an evaluation device. Through the use of additional temperature sensor, more condition information about the heat exchanger is obtained. The more information made available, the more accurately the through flow of the heat carrying medium through the primary side can be controlled. Moreover, the additional temperature sensor enables the making of an assertion about the fouling of the heat exchanger. This is especially advantageous in the case of heat exchangers which can be dismantled for maintenance.
[0008] Preferably, the second temperature sensor is arranged at a pre-determined spacing along the heat transfer stretch relative to the first temperature sensor. The second temperature sensor is accordingly arranged at another position different from that of the first temperature sensor. This for example has the advantage that a temperature change can be recognized by the second temperature sensor before the first temperature sensor is in the position to report this temperature. Therefore, if wanted, the actuation of the valve on the primary side can be performed earlier, for example, to earlier open or to earlier close the valve. With two temperature sensors the course of the temperature over the heat exchanger can be roughly portrayed. The portrayal becomes improved when the greater number of temperature sensors are provided.
[0009] Preferably, the second temperature sensor is arranged in the middle of the heat exchanger stretch. This temperature sensor arrangement in the middle of the heat exchanger stretch permits an assessment of the loading of the heat exchanger. If the loading is known, the control of the valve on the primary side can be improved so that a quicker and more exact reaction is achieved when one wants to take water from the outflow connector.
[0010] Alternatively or additionally to this, the second temperature sensor can be arranged in the region of the inflow connector. The second temperature sensor in this case detects the temperature of the inflowing fluid. This also is a piece of worthwhile information. If the input temperature of the consumable water or of the heating water to the secondary side is known, then the valve on the primary side can be controlled depending on the temperature difference between the temperature at the inflow connector and the desired temperature at the outflow connector.
[0011] In a preferred implementation, the second temperature sensor is connected with a controller which controls a valve, controlling fluid flow through the primary side depending on a temperature detected by a first temperature sensor, with the second temperature sensor having an effect on at least one control parameter of the controller. For example, the second temperature sensor can have an effect on the amplification of the controller if the controller is a P-controller or a controller with a P-part (PI-controller or PID-controller). If the chosen amplification is too high, then a risk of oscillation occurs. If on the other hand, the chosen amplification is to low, then a danger exists that the controller will take to long to react. If now the information coming from the second temperature sensor is evaluated, it can be seen to that the amplification is always suited to certain data. For example, if the loading of the heat exchanger is relatively high, which can be detected by a placement of the second temperature sensor somewhat in the middle of the heat exchanger stretch, then a relatively high amplification is chosen, without having to fear a high oscillation. The same is true if the second temperature sensor is placed at the inflow connector. If the second temperature sensor in this case detects a low temperature, then the amplification of the controller can be set high. In the reverse of this, the amplification is lowered if already the input temperature at the inflow connector is high or if the second temperature sensor determines that the loading of the heat exchanger is low.
[0012] It is also beneficial if the evaluation device includes a difference former which detects the temperature difference between the first and the second temperature sensors. Such a temperature difference can not only be used to effect the controller, but one can also determine whether the heat exchanger over time has become clogged. This so called “fouling” causes the heat transfer between the primary side and the secondary side with time to become impaired. This impairment can be detected by way of the temperature difference, as well as also by way of the course of a temperature characteristic line.
[0013] This is then especially the case if the difference former is connected with a course monitoring device. It can therefore be determined at different times how the temperature differences are maintained. If one determines, for example, that the temperature difference between the first temperature sensor and the second temperature sensor has become smaller while the same amount of heat is delivered to the primary side, then a clogging of the heat exchanger can be surmised.
[0014] An object of the invention is also solved by a method of the previously mentioned kind in that an evaluation device utilizes several temperature sensors to determine a temperature course of the primary side flow path and/or the secondary-side flow path and that the evaluation device with the help of the temperature sensors determines a temperature difference between the primary side and the secondary side flow paths.
[0015] If a temperature course is known, the control of the heat carrying medium through the primary side can be improved. Monitoring the temperature difference enables an assessment of when the heat exchanger must be attended to.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention is described in more detail in the following by way of a preferred embodiment in combination with the drawings. The drawings are:
[0017] FIG. 1 is a schematic illustration of a heat exchanger, and
[0018] FIG. 2 is characteristic lines of a heat exchanger with oppositely directed through flows.
DETAILED DESCRIPTION
[0019] A heat exchanger 1 has a housing 2 with a primary side 3 and a secondary side 4 . The primary side 3 has a primary-side flow path 5 , which extends between an upstream connector 6 and a downstream connector 7 , and through which path a heat carrying fluid can flow in the direction of the arrow 8 . The heat bearing fluid can, for example, be supplied by a remote heater. The heat exchanger 1 in the present case serves to heat consumable water for a one family house.
[0020] A valve 9 is provided to control the flow through the primary-side flow path 5 , the valve in the present case is located outside of the housing 2 . The control of the valve 9 is described in greater detail below.
[0021] The secondary side 4 has a secondary-side flow path 10 which extends between an inflow connector 11 and an outflow connector 12 . The secondary-side flow path accommodates flow in the direction of the arrow 13 when a tapping station 14 is open. The tapping station 14 can, for example, be implemented by a hot water faucet.
[0022] As indicated by a broken line, the primary side 3 is in heat exchanging connection with the secondary side 4 along a heat exchanging stretch 15 . The illustration of FIG. 1 is however only schematic. In the case of actual heat exchangers, the primary-side flow path 5 and the secondary-flow path 10 are, for example, realized in that corrugated or bent sheets so lie on one another, that in cross section, a honeycomb structure of flow paths is provided with some of these “flow paths” belonging to the primary-side flow path 5 and with the remaining “flow paths” belonging to the secondary-side flow path 10 . The heat exchanging surface arrangement is then formed by the walls of the honeycomb. The heat carrying fluid which flows on the primary side 3 in opposition to the fluid on the secondary side 4 gives along the heat exchange stretch 15 its heat to the liquid on the secondary side. Because of the oppositely directed through flows one can heat the fluid of the secondary side to a relatively high temperature. In a typical operation the fluid flowing into the upstream connector 6 has a temperature in the range of between 60 and 120° C. and leaves the heat exchanger at the downstream connector 7 with a temperature in the region of 15 to 40° C. (depending on the amount of heat exchanged). The fluid on the secondary side enters the inflow connector 11 with a temperature in the region of 5 to 15° C. and in its flow through the secondary side is heated to a temperature in the region of 50 to 60° C.
[0023] A first temperature sensor 16 is arranged in the region of the outflow connector 12 for the control of the valve 9 . This first temperature sensor 16 determines essentially the temperature of the fluid, for example, consumable water, dispensed from the tapping station 14 . It can, in narrower circumstances, also be influenced by the temperature on the primary side 3 . The first temperature sensor 16 is connected with a controller 17 , which depending on a temperature difference between a desired value and the actual value determined by the first temperature 16 , controls the valve so that heat carrying fluid with an increased temperature flows through the primary side 3 . Thereby heat is transferred to the secondary side 4 so that the temperature at the outflow connector 12 after a short or long time achieves the desired value.
[0024] If the tapping station 14 is opened, then fresh consumable water flows through the secondary flow path so that the temperature in the region of the first temperature 16 falls.
[0025] Additionally, a second temperature sensor 24 is provided on the secondary side 4 of the heat exchanger 1 . This second temperature sensor 24 is arranged along the heat exchange stretch 15 at a certain spacing from the first temperature sensor 16 . In the illustrated case it is arranged at the middle of the heat exchange stretch 15 .
[0026] With the help of the second temperature sensor 24 , it is possible to determine the course of the temperature along the length of the secondary side 4 of the heat exchanger 1 . To still better determine this temperature course, still further sensors can be used: for example, a third temperature sensor 19 arranged at the inflow connector 11 .
[0027] The temperature course provides evidence of the loading of the heat exchanger 1 . This is particularly so, if one evaluates the temperature information supplied by the second temperature sensor 24 .
[0028] If one evaluates the temperature information of the third temperature sensor 19 , one obtains information about external conditions, for example, the temperature of the inflowing consumable water.
[0029] Finally, one can also arrange a fourth temperature sensor 20 in the region of the upstream connector 6 . With the help of this fourth temperature sensor 20 one can make a statement about the input temperature of the primary side or about the temperature difference between the input temperature on the primary side and the output temperature on the secondary side. In a similar way the primary side 3 also has a fifth temperature sensor 18 and a sixth temperature sensor 25 so that the temperature course of the primary side can also be determined.
[0030] In this exemplary embodiment, the input temperature at the upstream connector 6 is controlled by a remote heating system. With the help of the temperature sensors 16 , 20 it is possible to control relatively exactly the temperature at the tapping station 14 .
[0031] If one comprehends the temperature course then one can react more quickly to load changes. The load changes show themselves in advance of a point in time at which one can recognize a corresponding temperature fall at the outflow connector 12 of the secondary side 4 .
[0032] FIG. 2 shows the temperature course of the heat exchanger on the secondary-side flow path 10 . Four different characteristic lines A to D are shown. Line A shows the temperature course in the case of a normal loading of the heat exchanger. The inflow temperature on the primary side at the upstream connector 6 is 65° C., and the inflow temperature of the consumable water at the inflow connector 11 is 10° C. The temperature increases the longer the supplied consumable water moves into the heat exchanging stretch. With the application of the second temperature 24 in the middle, that is at an effective heat exchange surface of 0.5, a temperature of about 34° C. is measured. At a lower loading of 15% the temperature of the heat exchanger at the middle falls to 28° C., as is shown by the characteristic line B. The characteristic lines C and D show respectively the temperature course at normal loading and at 15% loading when the inflow temperature of the primary side is at 100° C. The characteristic lines of the heat exchanger change greatly with the loading and the inflow temperature, and the temperature change is greatest in the middle of the heat exchanger, so that the temperature sensor 24 is advantageously applied here.
[0033] Finally, it is also possible, from the temperature course, with the help of the temperature sensors, that is at least with the help of the second temperature sensor 18 or with the help of the third temperature sensor 19 , to conclude that a “fouling” has occurred, that is that a slow clogging of the heat exchanger has taken place.
[0034] As is to be recognized from FIG. 1 , the temperature sensors 16 , 18 - 20 , 24 , 25 (not all of these temperature sensors need be provided) are connected with the controller 17 . These temperatures sensors 16 , 18 - 20 , 24 , 25 are in the position to affect at least one control parameter of the controller 17 . As to this control parameter, it can, for example, be the amplification of the P component of a P of a P-, PI- or PID controller. If, for example, the temperature difference between the upstream connector 6 and the outflow connector 12 is too large, the amplification is decreased. If, for example, the temperature at the position of a further temperature sensor 18 falls while the outer temperature at the secondary side remains the same, then the control parameter of the controller 17 is changed. If the controller is formed as a PI controller, then the parameter P or the parameter I or both are changed in order to achieve an improved reaction of the controller 17 to changes. For example, in the case of a load increase with a high inlet temperature, the controller need not open as much as it would with a low input temperature. Similar considerations also apply when the load or loading changes. In the case of a low temperature, then under given circumstances larger changes in the opening of the valve 9 on the primary side 3 are necessary than with the high temperatures.
[0035] The controller 17 is a component of an evaluation device 21 also having a difference former 22 and a course supervising device 23 . The difference former 22 determines a temperature difference between the first temperature sensor 16 and the sensor 20 , between the sensor 24 and the sensor 18 , and between the sensor 19 and the sensor 25 . The course supervising apparatus supervises these temperature differences over time. The difference former thereby creates point wise local temperature differences measured at the primary and secondary sides of the flow paths 5 and 10 . The controller 17 determines an average of each of the local differences. A cross section can, for example, be calculated over 24 hours. The temperature difference between the temperature sensors 19 and 25 is of special interest because at these spots in the case of a fouling of the heat exchanger the temperature difference is the greatest and therefore most evident. If it is, for example, determined that in the case of otherwise unchanged conditions the temperature difference between the inflow connector 11 and the in turn connector 7 has become larger, then the water which flows through the primary side 3 is no longer so well cooled. In other words, the heat transfer from the primary side 3 to the secondary side 4 is hindered which is a clear indication that the heat exchanger 1 is slowly becoming clogged.
[0036] While the present invention has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this invention may be made without departing from the spirit and scope of the present invention.
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A heat exchanger ( 1 ) is specified having a housing ( 2 ), in which a primary side ( 3 ) having a primary-side flow path ( 5 ) is arranged between an upstream connector 6 ) and a downstream connector ( 7 ) and a secondary side ( 4 ) having a secondary-side flow path ( 10 ) is arranged between an inflow connector ( 11 ) and an outflow connector ( 12 ), wherein the primary side ( 3 ) and the secondary side ( 4 ) are in heat-transferring connection along a heat exchanger section ( 15 ) and a first temperature sensor ( 16 ) is arranged in the region of the outflow connector ( 12 ). The desire is to improve the ability to regulate and monitor the heat exchanger ( 1 ). To this end, there is provision for at least one second temperature sensor ( 18 - 20, 24, 25 ) to be arranged on the heat exchanger section ( 15 ) and for both temperature sensors ( 16; 18 - 20, 24, 25 ) to be connected to an evaluation device ( 21 ).
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This application is a continuation of application Ser. No. 07/904,255 filed Jun. 25, 1992, now abandoned, which is a division of application Ser. No. 07/666,649 filed Mar. 08, 1991 now U.S. Pat. No. 5,172,402.
FIELD OF THE INVENTION AND RELATED ART
This invention relates to an exposure apparatus and, more particularly, to an exposure apparatus for transferring and printing an image of an original, such as a mask, onto a workpiece such as a semiconductor wafer, with high precision.
With the increasing degree of integration of semiconductor integrated circuits, in an exposure apparatus (aligner) for manufacture of the same, further enhancement of transfer precision is required. As an example, for an integrated circuit of a 256 megabit DRAM, an exposure apparatus capable of printing a pattern of a linewidth of 0.25 micron order is necessary.
As such super-fine pattern printing exposure apparatus, an exposure apparatus which uses orbit radiation light (SOR X-rays) has been proposed.
The orbit radiation light has a sheet beam shape, uniform in a horizontal direction. Thus, for exposure of a plane of a certain area, many proposals have been made, such as:
(1) A scan exposure method wherein a mask and a wafer are moved in a vertical direction whereby the surface is scanned with X-rays of sheet beam shape in a horizontal direction;
(2) A scan mirror exposure method wherein X-rays of a sheet beam shape are reflected by an oscillating mirror whereby a mask and a wafer are scanned in a vertical direction; and
(3) Simultaneous exposure method wherein X-rays of a sheet beam shape in a horizontal direction are diverged in a vertical direction by an X-ray mirror having a reflection surface machined into a convex shape, whereby an exposure region as a whole is irradiated simultaneously.
The inventors of the subject application have cooperated to devise such a simultaneous exposure type X-ray exposure apparatus, which is disclosed in Japanese Laid-Open Patent Application No. 243519/1989.
In this type of exposure apparatus, exposure light (X-ray) has uniform illuminance in a horizontal direction (hereinafter "X direction"). However, in a vertical direction (hereinafter "Y direction"), it has non-uniform illuminance such as depicted by an illuminance distribution curve 1i in FIG. 3A, for example, wherein the illuminance is high at a central portion and decreases away from the central portion. In the proposed apparatus, a blocking member having a rectangular opening (shutter aperture) is used, and the relationship of the time moment (t) of passage and the position in the Y direction of each of two edges, of four edges defining the opening, is controlled independently as depicted in FIG. 3B, whereby the exposure time (ΔT) at each portion in an exposure region is controlled, as depicted in FIG. 3C. More specifically, the time period from the passage of a leading edge la of the blocking member (the preceding one of the two edges with respect to the movement direction of the blocking member), for allowing transmission of the exposure light (X-rays), to the passage of a trailing edge 1b of the opening of the blocking plate (the succeeding edge with respect to the movement direction of the blocking member), for interception of the exposure light, is controlled to thereby attain correct and uniform exposure of the whole exposure region. In that case, the exposure quantity control is effected on the basis of an X-ray illuminance distribution curve (hereinafter "profile") in the Y direction, such as depicted in FIG. 3A, as measured in the exposure region.
SUMMARY OF THE INVENTION
In this X-ray exposure apparatus, however, any deviation between the aforementioned profile and an edge drive curve produces a non-negligible effect upon the transfer precision.
For example, if edge drive curves as depicted by solid lines 1a and 1b in FIG. 3B, corresponding to the profile of solid line 1i in FIG. 3A, shift by Δy to the positions of broken lines 2a and 2b in FIG. 3B, respectively, corresponding to the profile of broken line 2i in FIG. 3A, then the illuminance I of the exposure light at a position y changes by "(dI/dy) x Δy". Accordingly, in order to suppress the change in illuminance I to a quantity not greater than 0.1%, the following relation has to be satisfied:
Δy<(I/1000)×[1/(dI/dy)]=(1/1000)×{1/[(dI/I)/dy)]}
More particularly, if the view-angle size of the exposure region in the Y direction is 30 mm, if the profile such as depicted by the solid line 1i in FIG. 3A is represented by a quadratic function which is vertically symmetric with respect to a center line and if the lowest illuminance is 80% of the highest illuminance, then it follows that:
Δy<(1/1000)×[1/(0.4/15)]≈0.04 (mm)
Thus, it is seen that, in order to suppress non-uniformness in illuminance to a quantity not greater than 0.1%, the shift Δy in relative position of the exposure light to the exposure region has to be kept at a quantity not greater than 40 microns.
A deviation in the edge drive curve or profile may result from a change in the relative attitude of a SOR device and a major assembly of the exposure apparatus, in a case of SOR X-ray exposure apparatus, and, generally, it may be attributable to an error between coordinate axes of a wafer stage and an edge driving system.
It is accordingly an object of the present invention to provide an exposure apparatus by which an exposure quantity error ΔI attributable to a relative deviation Δy between the edge drive curve and the profile can be reduced to thereby enhance transfer precision.
In accordance with an aspect of the present invention, to achieve this object, there is provided an exposure apparatus, comprising: a radiation source with non-uniformness in illuminance generally in one-dimensional direction with respect to a predetermined exposure region; illuminance measuring means for measuring an illuminance distribution in the one-dimensional direction in the exposure region and in an area adjacent thereto; shutter means having a leading edge effective to start exposure in the exposure region and a trailing edge effective to stop the exposure; a memory with a drive table for setting a drive curve for the leading and trailing edges in accordance with the measured illuminance distribution; shutter driving means for causing the leading and trailing edges to move through the exposure region in the one-dimensional direction, independently of each other, in accordance with the drive table; edge position detecting means for detecting, with an illuminance detector of the illuminance measuring means and at different two points spaced in the one-dimension direction, a position of a shadow of one of said leading and trailing edges; and coordinate conversion means for effecting conversion of a coordinate system of the drive table and a coordinate system for the positioning of the illuminance detector during the illuminance distribution measurement, in accordance with results of the edge position detection.
With this structure, the position of the shadow of the edge as detected by the illuminance distribution measuring means with respect to at least two points, spaced in the direction of illuminance distribution, does correspond to the position of the edge, designated in terms of the coordinate system of the drive table, as projected upon the coordinate system used for the measurement of the illuminance distribution.
Accordingly, it is possible to detect the relationship between the coordinate system of the drive table and the coordinate system in the measurement of illuminance distribution and, by converting the coordinate system for the illuminance distribution measurement into the coordinate system of the drive table, an error between the coordinate systems of the illuminance distribution measurement and the drive table can be corrected and, as a result, non-uniformness in exposure (exposure quantity error) ΔI attributable to such error can be reduced.
The inventors of the subject application have made investigations into an exposure apparatus of the aforementioned type to attain further enhancement of the transfer precision, and have found that a change in the relative position of the exposure region and the exposure light provides a non-negligible effect on the transfer precision. Particularly, in the proximity exposure process, a change in the angle of incidence of the exposure light to the exposure region results in degradation of the superposing precision.
For example, if the proximity gap G between a mask and a wafer is 50 microns, then, in order to suppress a superposition error Δδ due to a change in the angle of incidence to a quantity not greater than 0.002 micron, the change Δθ in the angle of incidence has to be suppressed to satisfy:
Δθ=Δδ/G<0.002/50=4×10.sup.-5 (rad)
Namely, it has to be suppressed to a quantity not greater than 4×10 -5 rad.
Further, if the exposure light has a divergent angle, the angle of incidence of the exposure light to the exposure region changes with the shift Δy of the relative position as described above. If the interval between the surface to be exposed and the point of divergence (e.g. the position of incidence of X-rays upon a divergence convex mirror of a SOR X-ray exposure apparatus) is 5 m, then the quantity Δθ of change in the angle of incidence is given by:
Δθ=Δy/5000<4×10.sup.-5 (rad)
From this change Δθ in the angle of incidence, the above-described superposition error Δδ results. The superposition error Δδ in this case appears at different portions of the surface to be exposed, as a run-out error of distributed transfer magnifications. From the above equation, it is seen that the change Δy in the relative position has to be suppressed to a quantity not greater than 0.2 mm.
Further, if in the positional relationship between the exposure light and the exposure region there occurs a rotational deviation Δω z about an axis (Z axis) of the path of the exposure light, then, at a position (X, Y) on the X-Y plane having an origin on that axis, there are caused an error Δθ in the angle of incidence as well as an illuminance change ΔI and an error Δδ, equivalently as there is caused a change Δy wherein Δy=Y·cosω z .
As regards the variations, such as the relative positional deviation Δy and Δω z , one of which is attributable to an attitude change of the exposure apparatus resulting from movement of a wafer stage of about 200 microns, a displacement resulting from a temperature change may be of about 10 microns and a displacement resulting from vibration of a floor may be about 2 microns.
It is another object of the present invention to provide an exposure apparatus by which an exposure quantity error ΔI and a superposition error Δδ attributable to the rotational deviation Δω z can be reduced, to thereby attain further enhancement of the transfer precision.
In accordance with another aspect of the present invention, to achieve this object, there is provided an exposure apparatus, comprising: a radiation source with non-uniformness in illuminance generally in a one-dimension direction with respect to a predetermined exposure region; exposure quantity correcting means for setting an exposure time distribution in accordance with the non-uniformness in illuminance so as to assure a substantially uniform exposure quantity in the exposure region; illuminance distribution measuring means for measuring an illuminance distribution in the exposure region; computing means for calculating a constant-illumination line on the basis of a measured data of the measuring means; and paralleling means for making the constant-illumination line and a constant-exposure-time line of said exposure quantity correcting means parallel.
In this structure, the illuminance distribution measuring means serves to measure an illuminance distribution in the exposure region and an area adjacent thereto, the computing means serves to calculate a constant-illuminance line on the basis of measured illuminance distribution data, and the paralleling means serves to execute an operation making the calculated constant-illuminance line and a constant-exposure-time line determined by the exposure quantity correcting means parallel. By this paralleling operation, the rotational deviation ω z can be corrected and, therefore, the exposure quantity error ΔI and the superposition error Δδ attributable to such rotational deviation ω z can be reduced.
It is a further object of the present invention to provide an exposure method and apparatus by which uniform exposure is attained and, thus, a resist pattern of uniform linewidth is assured.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic and diagrammatic view of an X-ray exposure apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view, showing details of an exposure shutter device of the FIG. 1 embodiment.
FIGS. 3A-3C are graphs, respectively, for explaining the operation of the exposure apparatus of the FIG. 1 embodiment, wherein FIG. 3A shows an illuminance distribution (profile) of illumination light, FIG. 3B shows shutter drive curves and FIG. 3C shows an exposure time distribution.
FIG. 4 is a flow chart for explaining the coordinate system converting operation in the exposure apparatus of the FIG. 1 embodiment.
FIG. 5 is a flow chart for explaining the paralleling operation in the exposure apparatus of the FIG. 1 embodiment.
FIGS. 6A-6D are schematic views, respectively, for explaining detection of constant-intensity lines in the exposure apparatus of the FIG. 1 embodiment.
FIG. 7 is a schematic view for explaining edge detection in the exposure apparatus of the FIG. 1 embodiment.
FIGS. 8 and 9 are graphs, respectively, for explaining the operation of an X-ray detector for the edge detection, in the exposure apparatus of the FIG. 1 embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a general structure of an X-ray exposure apparatus according to an embodiment of the present invention. Denoted in the drawing at 101 is a synchrotron orbit radiation light (SOR X-ray), and denoted at 102 is an exposure mirror having a reflection surface machined into a convex shape, for expanding the SOR X-ray 101, of a sheet beam shape elongated in the X (substantially horizontal) direction, in the Y (substantially vertical) direction. The bundle of X-rays from the exposure mirror 102 diverging in the Y direction is inputted into an exposure apparatus main assembly 100 as an illumination light (exposure beam) 103 for the exposure process.
In the exposure apparatus main assembly 100, denoted at 104 is a beryllium window for isolating an exposure X-ray input path, maintained at a high vacuum, and a helium ambience in a chamber 105, from each other. Denoted at 106 is an auxiliary shutter unit (movable aperture unit) comprising an endless steel (SUS) belt having openings. It cooperates with a main shutter unit 107 of a similar structure to provide an exposure shutter device. Denoted at 108 is a mask having a pattern, to be transferred, formed thereon by use of an X-ray non-transmissive material such as gold, for example, Denoted at 109 is a wafer chuck with which a wafer 110, onto which an image of the mask 108 is to be transferred, can be held fixed on a wafer stage that comprises an X stage 121 and a Y stage 122, for example. The wafer 110 is coated with a resist which is sensitive to X-rays. Denoted at 111 is an alignment optical unit for measuring the relative positional relationship between the mask 108 and the wafer 110; denoted at 123 is an X stage motor for driving the X stage 121; denoted at 124 is a Y stage motor for driving the Y stage 122; denoted at 125 and 126 are motor drivers for the X stage motor 123 and the Y stage motor 124, respectively; denoted at 127 is a stage actuator control unit for controlling the operations of the motor drivers 125 and 126, respectively; denoted at 128 is a laser length-measuring device for measuring the position of the wafer stage; denoted at 129 is a mirror for the laser length-measurement; and denoted at 130 is a length measuring system control unit. Denoted at 131 is a central processing unit (CPU) which is communicated with a main controller 191 through a common bus 190, to control the stage actuator control unit 127 and the measuring system control unit 130.
Denoted at 151 is an auxiliary shutter motor for driving the auxiliary shutter unit 106, and denoted at 152 is a main shutter motor for driving the main shutter unit 107. Denoted at 153 and 154 are motor drivers, respectively, for driving the motors 151 and 152 in accordance with the number of pulses outputted from pulse generators 155 and 156, respectively. Denoted at 157 is a subsidiary CPU which is communicated with the main controller 191 through the common bus 190 and which serves to control the pulse generators 155 and 156 through a local bus 158. Denoted at 161 is an X-ray detector, and denoted at 162 is a detector signal processing unit.
Denoted at 171 is a Y guide bar for guiding the Y stage 122, and it is fixed to a main frame 172. The main frame 172 is fixed to the chamber 105 through an upper support 173 and a lower support 174. Denoted at 175 is a frame base, and the chamber 105 is supported by actuators 176-178 provided at three locations on the chamber top (at front side and rear left and rear right sides of the top). The attitude of the chamber 105 can be controlled by these actuators. Adjacent to these actuators 176-178, there are provided three distance sensors 179-181. By measuring through these sensors 179-181 the distances to the frame base 175 from the mounting positions of these sensors, respectively, the attitude of the chamber 105 can be detected. Denoted at 182 is a driver for driving the actuators 176-178. Denoted at 183 is a main assembly attitude control unit which serves to detect the attitude of the chamber 105 on the basis of the outputs from the sensors 179-181 and to control the attitude of the chamber 105 through the drive of the driver 182.
Denoted at 191 is a main controller which serves to control the operation of the exposure apparatus as a whole through the common bus 190, in accordance with the content memorized in a memory 192.
FIG. 2 is a perspective view schematically showing the exposure shutter device, comprising the auxiliary shutter unit 106 and the main shutter unit 107 of FIG. 1, as well as some elements necessary for explaining the function of the exposure shutter device. In non-exposure period, the exposure beam 103 is blocked in the auxiliary shutter unit 106, as shown in FIG. 2, by an auxiliary shutter belt 201 which is provided by a steel belt made of stainless steel. In the exposure period, on the other hand, the exposure beam 103 goes through a front opening 202 formed in the auxiliary shutter belt 201 as well as a rear opening 203 of the auxiliary shutter belt, moved to a position approximately opposed to the front opening 202, and the exposure beam arrives at a main shutter belt 221 of the main shutter unit 107 disposed behind the auxiliary shutter belt 201. Like the auxiliary shutter belt 201 of the auxiliary shutter unit 106, also the main shutter belt 221 is provided with two openings, namely, a front opening 222 and a rear opening (not shown). The above-described function of controlling local exposure time at each of different portions of the exposure region in the Y direction is accomplished by controlling, at each portion in the Y direction, the time period from the passage, through that portion, of a leading edge 223 of the front opening 222 of the main shutter belt 221 to the passage of the trailing edge (not shown) through that portion, so as to provide an inversely proportional relationship between the time period and the illuminance of X-rays. In other words, the time period is so controlled that, at different portions in the Y direction, the quantity of energy absorption by the resist applied to the wafer is regular and correct.
The auxiliary shutter belt 201 is tensioned between an auxiliary shutter driving drum 204, driven by the auxiliary shutter motor 151, and an auxiliary shutter idler drum 205, and it is driven through the friction between the inside surface of the shutter belt 201 and the outside surface of the driving drum 204. In order to assure stable driving of the shutter belt 201 so as to avoid snaking, the driving drum 204 is crowned such that the diameter at the central portion of the drum with respect to the widthwise direction is made larger by 50-100 microns than the diameter at the end portion. The shutter belt 201 is provided with small rectangular slits 208 and 211, formed in the neighborhood of the left-side and right-side edges thereof, for the position detection and the timing detection, respectively. These slits cooperate with a photointerruptor 209 and a reflection sensor 210, respectively, to produce a start signal for the driving of the auxiliary shutter motor 151 to be made in accordance with a predetermined drive pattern, or to discriminate whether the exposure beam 103 is allowed to pass or is blocked.
The main shutter device has a similar mechanical structure as of the auxiliary shutter device, described above.
Denoted at 231 is a pinhole formed in a front face of a detection portion of the X-ray detector 161, which is mounted to the X stage 121 (see FIG. 1).
X-ray intensity profile such as at 1i (2i) in FIG. 3A can be measured by bringing the two shutter units 106 and 107 into open states, respectively, and by moving the Y stage 122 (see FIG. 1) so as to scanningly displace the X-ray detector 161 in the Y direction within the exposure view angle (exposure region). On the basis of measured data, drive tables 1a and 1b (2a and 2b) such as is shown in FIG. 3B for the leading edge 223 and the trailing edge 107 can be prepared, and corrected drive such as shown in FIG. 3C for attaining constant quantity of energy absorption by the resist in the exposure region can be executed.
In this case, the X-ray intensity profile measurement is made on the basis of a coordinate system of the X-ray detector 161 (X-Y coordinate system of the wafer stage, comprising X stage 121 and Y stage 122, as measured through the laser length-measuring device 128). On the other hand, the corrected drive of the shutter is made on the basis of a shutter drive coordinate system (x-y coordinate system of the drive table). For this reason, if there is a deviation between these coordinate systems, it is not possible to accomplish proper drive correction. In the present embodiment, in consideration thereof, after a drive table representing the position (Y) versus passage time (t) relation of each edge with respect to the wafer stage coordinate system is prepared on the basis of the profile measured data, the relationship between the wafer stage coordinate system and the shutter drive coordinate system is detected and conversion is made to the position coordinate of the edge, from a coordinate value Y with respect to the wafer stage coordinate system into a coordinate value y with respect to the shutter drive coordinate system. By this, the drive table is converted into a table that represents the position (y) versus passage time (t) relation of the edge with respect to the shutter drive coordinate system, and, as a result, precise exposure quantity correction is assured.
The details of such coordinate system conversion in this exposure apparatus will now be explained. The coordinate system conversion may be executed together with the profile measurement, at the time of assembling of the exposure apparatus, at the time of setting of the same or at the time of maintenance thereof (in maintenance mode).
Referring to the flow chart of FIG. 4, first, at step 401, the main shutter belt 221 is stopped at such a position that, as shown in FIG. 7, the leading edge 223 of the opening 222 of the main shutter belt 221 blocks a portion of the exposure view angle. It is assumed that the shutter drive coordinate at this time is y N . In FIG. 7, denoted at 701 is an illuminance detecting area corresponding to the exposure view angle; denoted at 702 is a high-precision reflection type sensor at the main shutter unit 107 side (see FIG. 1); denoted at 703 is a slit which is cooperable with the high precision reflection type sensor 702 to determine an origin of the coordinate system representing the position of the edge 223; and denoted at 704 is the shadow of the edge 223. At step 402 in FIG. 4, the wafer stage is moved so as to scanningly displace the X-ray detector 161 in the Y direction to thereby detect the wafer stage coordinate (the position with respect to the illuminance distribution measurement coordinate system) Y N of the shadow 704 of the edge 223 (FIG. 7).
FIG. 8 illustrates the relationship between the Y-direction position of the pinhole 231 of the X-ray detector 161 and the output of the X-ray detector 161. In this drawing, reference character Y N denotes the position of the shadow of the edge 223, and a broken line depicts the exposure profile to be defined in the region blocked by the shutter 221, which otherwise is exposed with the exposure beam 103 when the shutter is open. Enlarging the portion near y N in FIG. 8 in the Y direction, the change in the output depending on the relationship between the shadow Y N of the edge and the pinhole 231 at the front face of the X-ray detector 161 is such as shown in FIG. 9. In FIG. 9, reference character P O denotes the position of the pinhole 231 just at the moment as the pinhole 231 goes out of the shadow 704 of the edge 223. Reference character P N denotes the position of the pinhole 231 at which the center of the pinhole coincides with the shadow 704 of the edge 223. Reference character P S denotes the position of the pinhole 231 Just at the moment as the pinhole 231 is completely shaded by the shadow 704 of the edge 223. It is seen from FIG. 9 that accurately the position Y N of the shadow 704 of the edge is at the middle point (ΔY 1 =ΔY 2 ) between a coordinate Y O corresponding to the position P O and a coordinate Y S corresponding to the position P S . In this embodiment, in consideration thereof, the middle point between the coordinate Y S at the rise of the output of the X-ray detector 161 and the coordinate Y O at the saturation point of the detector output is determined as the coordinate (edge position) Y N corresponding to the end line of the shadow 704 of the edge 223.
When the pinhole 231 is at the position P N , the output of the X-ray detector 161 is not always equal to a half of the output when the pinhole 231 is at the position P O , i.e., E 1 ≠E 2 . This is because the output component based on the edge position and the component based on the illuminance distribution (profile) are not discriminated separately. Referring back to FIG. 4, at step 403, the motor 152 is driven so that the leading edge 223 is moved to a position, blocking another portion of the exposure view angle 701, namely, to a position of a shutter drive coordinate y M . Then, at step 404, like step 402, a wafer stage coordinate Y M of the shadow 704 of the edge 223 is detected.
When the wafer stage coordinates Y N and Y M corresponding to the shutter drive coordinates y N and y M at two different points in the exposure view angle 701, spaced in the Y direction, are detected in the manner described above, then at step 405, the coordinate of the edge position in the drive table of edge position (Y) versus passage time (t) relation with respect to the wafer stage coordinate system, having been calculated on the basis of the profile measured data and having been stored in the memory 192, is converted from a coordinate Y with respect to the wafer stage coordinate system into a coordinate y with respect to the shutter drive coordinate system, by using the following equation:
y=y.sub.N +(Y-Y.sub.N)×(y.sub.M -y.sub.N)/(Y.sub.M -Y.sub.N)
By this, the drive table is converted into one that represents the position (y) versus passage time (t) relation of the edge with respect to the shutter drive coordinate system. Then, by using the obtained table, the main shutter unit 107 is controlled and the exposure process of the wafer 110 to the mask 108 with the exposure beam 103 is executed. The table obtained by the conversion is stored in into the memory 192.
In the foregoing example, the shadow of the leading edge 223 is detected and the coordinate system of the illuminance distribution detector is converted into a coordinate system of the edge drive table. However, in place of detecting the shadow of the leading edge 223 of the opening 222 of the main shutter belt 221, the shadow of the trailing edge may be detected and the coordinate system conversion may be made accordingly.
Next, a description will be provided of a paralleling operation of the exposure apparatus. Such a paralleling operation may be executed at the time of assembling of the exposure apparatus, at the time of setting of the exposure apparatus or at the time of maintenance of the apparatus (in maintenance mode).
Referring to the flow chart of FIG. 5, first, at step 501, while holding the shutter in its open state, the wafer stage is moved to scanningly displace the X-ray detector 161 in the X and Y directions, and an illuminance distribution of a part of or the whole of the exposure view angle 601 is measured. At step 502, from measured data, a line or lines of constant illuminance (constant-intensity lines) are detected. FIGS. 6A-6C show examples of manner of scan. Since the exposure beam 103 (see FIG. 1) has non-uniformness in intensity substantially only in the Y direction, where as shown in FIG. 6A the scan is made along a path 602 which includes a small distance in the Y direction at a rightward end portion of the illuminance detection plane 601 as well as a small distance in the Y direction at a leftward end portion of the illuminance detection area and when a straight line 605 is drawn to connect points 603 and 604 having the same measured values of illuminance, then the line 605 provides a constant-intensity line. FIG. 6B shows an example wherein, as compared with the scan method shown in FIG. 6A, the Y-direction scanning lengths at the leftward and rightward portions are increased so as to obtain a larger number of constant-intensity lines 605a-605e. FIGS. 6C and 6D show examples wherein, as compared with the scanning methods of FIGS. 6A and 6B, a larger number of Y-direction scanning lines are used. By using multiple measuring points for obtaining a single constant-intensity line, even in the case where a constant-intensity line is not straight, an approximate straight line can be drawn on the basis of a least square method or the like to determine the constant-intensity line with a reduced error. In FIG. 6, denoted at 601 is the illuminance detecting area; denoted at 602 is the path of scan of the X-ray detector 161; denoted at 603 and 604 are those points at which the X-ray detector 161 produces outputs of the same level; and denoted at 605 and 605a-605e are constant-intensity lines.
Then, at step 503 in FIG. 5, the main shutter motor 152 is driven to move and stop the main shutter belt 221 at a position at which, as shown in FIG. 7, the leading edge 223 of the opening 222 of the main shutter belt 221 blocks a portion of the exposure view angle 701. In FIG. 7, denoted at 701 is the exposure view angle of a size corresponding to or slightly smaller than the illuminance detecting area 601 in FIG. 6. The illuminance detecting area 601 is so set that it is larger than the exposure view angle 701 at least with respect to the Y direction and that the whole exposure angle 701 is included inside the illuminance detecting area 601, so as to allow measurement of the illuminance at a portion around the exposure view angle 701 through the X-ray detector 161. Denoted at 702 is a high-precision reflection type sensor at the main shutter unit 107 side (see FIG. 1), and denoted at 703 is a slit which is cooperable with the high-precision reflection type sensor 702 to determine the origin of a coordinate system representing the position of the edge 223. It is to be noted here that, at step 503, in place of using the leading edge 223 of the opening 222 of the main shutter belt 221, the trailing edge (not shown) thereof may be used to block a portion of the exposure view angle. Subsequently, at step 504, the X-ray detector 161 on the wafer stage is used to measure the position of the shadow 704 of the edge 223 in the Y direction, at two different points spaced in the X direction, to thereby detect any inclination of the edge shadow 704 with reference to the X axis (Y axis) of the X-Y plane.
FIG. 8 illustrates the relationship between the Y-direction position of the pinhole 231 of the X-ray detector 161 and the output of the X-ray detector 161. In this drawing, reference character Y N denotes the position of the shadow of the edge 223, and a broken line depicts the exposure profile to be defined in the region blocked by the shutter 221, which otherwise is exposed with the exposure beam 103 when the shutter is open. Enlarging the portion near y N in FIG. 8 in the Y direction, the change in the output depending on the relationship between the shadow Y N of the edge and the pinhole 231 at the front face of the X-ray detector 161 is such as shown in FIG. 9. In FIG. 9, reference character P O denotes the position of the pinhole 231 just at the moment as the pinhole 231 goes out of the shadow 704 of the edge 223. Reference character P N denotes the position of the pinhole 231 at which the center of the pinhole coincides with the shadow 704 of the edge 223. Reference character P S denotes the position of the pinhole 231 Just at the moment as the pinhole 231 is completely shaded by the shadow 704 of the edge 223. It is seen from FIG. 9 that accurately the position Y N of the shadow 704 of the edge is at the middle point (ΔY 1 =ΔY 2 ) between a coordinate Y O corresponding to the position P O and a coordinate Y S corresponding to the position P S . In this embodiment, in consideration thereof, the middle point between the coordinate Y S at the rise of the output of the X-ray detector 161 and the coordinate Y O at the saturation point of the detector output is determined as the coordinate (edge position) Y N corresponding to the end line of the shadow 704 of the edge 223.
When the pinhole 231 is at the position P N , the output of the X-ray detector 161 is not always equal to a half of the output when the pinhole 231 is at the position P O i.e., E 1 ≠E 2 . This is because the output component based on the edge position and the component based on the illuminance distribution (profile) are not discriminated separately.
In the manner described above, the edge position Y N is detected at least at two locations including the leftward and rightward end portions in the X direction. Subsequently, at step 505 in FIG. 5, from the results of detection of the edge position Y N and the constant-intensity line or lines 605 determined beforehand, any inclination of the leading edge 223 or the trailing edge 207 in the X-Y plane with respect to the constant-intensity line 605 is determined. At step 506, discrimination is made as to whether the inclination of the edge 223 with respect to the constant-intensity line 605 is not greater than a predetermined inclination. If not, the paralleling operation is finished. If on the other hand the inclination is greater than the predetermined inclination, the sequence goes to step 507 whereat drive quantities for the actuators 176-178 (FIG. 1) necessary for the paralleling of the edge 223 with the constant-intensity line 605, are calculated. Then, at step 508, these actuators 176-178 are driven and, after this, the sequence goes back to 501 and the operations at steps 501-506 are repeated. After completion of the paralleling operation, the wafer 110 is exposed to the mask 108 with the exposure beam 103, while being controlled by the main shutter 107.
While the foregoing description has been made of an exposure apparatus wherein the exposure beam 103 comprises SOR X-rays, the present invention is not limited thereto but is applicable also to an exposure apparatus which uses an exposure beam comprising g-line light, i-line light, an excimer laser light or the like.
While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
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An exposure method for manufacture of semiconductor devices, includes moving a shutter having an edge so that the edge is related to a predetermined exposure region; projecting an exposure beam to the edge of the shutter and to at least a portion of the exposure region; determining a position of a shadow of the edge of the shutter formed by the exposure beam with respect to a predetermined coordinate system related to movement of a movable chuck; adjusting the shutter in accordance with the determination; placing a substrate on the chuck; moving the chuck so that the substrate is related to the exposure region; and controlling the exposure of the substrate with the exposure beam through the shutter.
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FIELD
Printed Circuit Boards.
BACKGROUND
Mobile and handheld products are trending towards thinner form factors. Studies show that consumers are willing to pay for thinner and lighter devices to achieve true mobility. Thus device manufacturers are putting emphasis on engineering resources to satisfy consumers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross-sectional side view of an embodiment of a portion of a printed circuit including a package embedded therein.
FIG. 2 shows a cross-sectional side view of another embodiment of a portion of a printed circuit board including a package embedded therein.
FIG. 3 shows a cross-sectional side of a portion of a core of a printed circuit board.
FIG. 4 shows the structure of FIG. 3 following the formation of contact points, lands or pads on a surface of the core of the printed circuit board and the attachment of a package thereto.
FIG. 5 shows the structure of FIG. 4 following the addition of a buildup layer portion on one side of the core and the introduction of buildup layers to form a buildup layer portion on an opposite side of the core.
FIG. 6 shows the structure of FIG. 5 following the embedding of the package in the printed circuit board.
FIG. 7 illustrates a schematic illustration of a computing device.
DETAILED DESCRIPTION
One component of a computing device that affects an overall thickness of a device, particularly mobile and handheld products, is the motherboard. Currently, a thickness of mobile handheld devices, including mobile personal computers (PCs) and notebooks, is limited by a total of a motherboard stack over the keyboard due to the physical size of the motherboard. Even where the motherboard is installed at a similar level to a battery and other discreet boards, the size of the motherboard impacts these components, such as impacts the battery size which is a key performance specification. One technique to reduce a thickness or Z height and/or a motherboard size is utilizing a high density interconnect (HDI) printed circuit board process. Generally, the HDI process utilizes build up layers on a multilayer core with laser drilled microvias on each buildup to perform signal connections as opposed to a conventional type 3 printed circuit board that uses plated through holes. The use of the laser drilled microvia process in the HDI process enables higher density routing with smaller dimensioned interconnect vias, hence reducing the total board size as well as z-height.
A printed circuit board such as a motherboard is used to mechanically support and electrically connect an electronic component such as a microprocessor or application processor. FIG. 1 shows a cross-sectional side view of a portion of a printed circuit board having an embedded component, in this case a package including a microprocessor (e.g., central processing unit, system on chip), connected to the core of the printed circuit board. Referring to FIG. 1 , in this embodiment, printed circuit board 110 includes core 120 of an insulative material such as a prepreg material onto which conductive planes (e.g., ground plane, power plane) or tracks or pathways or signal traces are formed. In this embodiment, a top conductive plane or signal line includes an array of conductive pads 160 that may be connected to the conductive plane of signal line or other planes or signal lines through, for example, conductive microvias. Pads 160 are configured for and are aligned to connect to conductive pads or points of package 140 . Package 140 is, for example, a flip-chip package (e.g., ultra thin core flip-chip package) or a Bumpless Build-Up Layer (BBUL) package having, for example, a land grid array defining contact points, lands or pads 165 to connect to conductive pads 160 . The connection of contact points 165 to conductive pads may be through solder connections or, in another embodiment through a conductive paste, such as an anisotropic conductive film (ACF) epoxy adhesive. FIG. 1 also shows die 150 that is, for example, a microprocessor, connected to package 140 on a side opposite the side in contact with conductive pads 160 .
As noted above, package 140 is connected to a pad array on core 120 of printed circuit board 110 . Package 140 including die 150 is embedded in circuit board 110 in the sense that since it is coupled to the core at its base and buildup layers of a printed circuit board surround the opposing sides of the package. FIG. 1 shows buildup layer portion 130 A and buildup layer portion 130 B connected to core 120 . Each of buildup layer portion 130 A and buildup layer portion 130 B includes alternating layers of conductive material and dielectric material. The conductive material forms, for example, planes, signal traces or pathways while the insulating material insulates one conductive layer from another. In the embodiment shown in FIG. 1 , each of buildup layer portion 130 A and buildup layer portion 130 B includes two build up layers (e.g., two layers of conductive material and insulating material). It is appreciated that in other embodiments, less than or more than two buildup layers may be utilized and the number of layers of conductive material and insulating material need not be the same in each of buildup layer portion 130 A and buildup layer portion 130 B.
In the embodiment shown in FIG. 1 , package 140 includes contact points, lands or pads 165 on a bottom side of the package (as viewed) as well as contact points, lands or pads 170 on a topside (device side). Contact points, lands or pads 165 and contact points, lands or pads 170 may be used to connect to printed circuit board 110 . Additionally, contact points, lands or pads 165 and contacts points, lands or pads 170 may be utilized to connect package 140 to a device external to the printed circuit board, such as a memory device (e.g., a dynamic random access memory (DRAM)). FIG. 1 shows conductive microvias 180 formed, for example, by a laser drill process connecting to contact points of external device 190 A through a contact material such as a solder ball. Similar microvias may be used to connect one or more contact points of device 190 B with package 140 .
As noted, in the embodiment shown in FIG. 1 , package 140 and die 150 are embedded in printed circuit board 110 in the sense that at least package 140 , and opposing sides and a bottom of die 150 are surrounded by a material of buildup layer portion 130 A. By embedding package 140 and die 150 in printed circuit board 110 , it can be seen that a z-height of the board and package is reduced as the package and die are no longer connected to contact points on a surface (e.g., a superior surface (as viewed)) of printed circuit board 110 . The z-height is reduced in the sense that the z-height of printed circuit board 110 and package 140 is the z-height of printed circuit board 110 as package 140 is no longer connected to contact points on a superior surface of printed circuit board 110 . Also, in this embodiment, a portion of a topside of die 150 is exposed. In one embodiment, overlying chip 150 on a surface of printed circuit board 110 (top surface as viewed) may be a heat-transfer device 198 , such as heat spreader, or other device.
FIG. 2 shows another embodiment of a printed circuit board including an embedded package. In this embodiment, printed circuit board 210 , such as an HDI printed circuit board, includes core 220 of an insulating material having one or more planes and/or pathways or signal traces. Overlying a surface of core 220 is an array of contact points lands or pads 260 positioned to connect and connected to an array of contact points, lands or pads 265 of package 240 . Package 240 is, for example, a flip-chip package or a BBUL package having contact points 265 as a land grid array patterned to connect to conductive points 260 through, for example, a solder connection or ACF.
Referring to FIG. 2 , package 240 including die 250 is embedded in buildup layers of printed circuit board 210 . FIG. 2 shows buildup layer portion 230 A and buildup layer portion 230 B connected to core 220 with package 240 including die 250 embedded in buildup layer portion 230 A. Buildup layer portion 230 A and buildup layer portion 230 B are each defined by are alternating layers of conductive material and insulating material. In the embodiment shown in FIG. 2 , buildup layer portion 230 A and buildup layer portion 230 B each include two conductive layers and two insulating layers. It is appreciated that in other embodiments, less than or more than two conductive layers may be included and the number of conductive and insulating layers may be different for each of buildup layer portion 230 A and buildup layer portion 230 B.
In the embodiment shown in FIG. 2 , package 240 includes contact points, lands or pads 265 on a bottom surface thereof (as viewed). Package 240 also includes contact points, lands or pads 270 as a land grid array on a superior or device side surface. As noted, contact points or pads 260 are connected to contact points 260 on core 220 that are connected to signal lines or planes (ground planes, power planes). In this embodiment, contact points or pads 270 on a superior surface of package 240 may be connected to signal traces or planes associated with buildup layer portion 230 A and/or to an external device. FIG. 2 shows external device 290 that is, for example, a memory device (e.g., a DRAM device) connected to contact points 270 thorough conductive microvias 280 in buildup layer portion 230 A.
In the embodiment shown in FIG. 2 , package 240 including die 250 is embedded in buildup layer portion 230 A. In this embodiment, the buildup layers surround sides and a top or superior surface each of package 240 and die 250 so that the package and die are completely embedded within printed circuit board 210 . By completely embedding package 240 and die 250 within the circuit board 210 , it can be seen that the z-height of the printed circuit board and package is reduced to that of the z-height of the printed circuit board as the package and die are no longer connected to contact points on a surface of the printed circuit board but the package is embedded in the printed circuit board.
FIGS. 3-6 describe a process of forming a printed circuit board with an embedded package. In this embodiment, the process relates to forming a printed circuit board/embedded package similar to structure 200 shown in FIG. 2 . Referring to FIG. 3 , FIG. 3 shows printed circuit board core 310 that is, for example, a core formed according to an printed circuit board process. Core 310 is, for example, a multilayer core including dielectric layer 315 of, for example, a prepreg material onto which conductive and insulative layers are introduced, such as by a film process wherein a film or sheet of insulative material and conductive material are alternately laid on, in this case, opposite sides of core 315 . FIG. 3 shows conductive layer 320 A and conductive layer 320 B of, for example, a copper that is, for example, is a conductive material that serves as, for example, a power or ground plane or pathway or signal trace. A plane, such as a ground plane or power plane may simply be a conductive sheet or may be patterned as desired. Similarly, where conductive layer 320 A is a pathway or signal trace, the layer may be patterned. A film or sheet may be patterned using photolithographic and etch techniques.
Overlying respective ones of conductive layer 320 A and conductive layer 320 B is insulating layer 325 A and 325 B. Insulating layer 325 A and insulating layer 325 B may be introduced as a film or sheet of, for example, a prepreg material to a thickness suitable to insulate conductive layer 320 A and conductive layer 320 B, respectively. Overlying respective lines of insulating layer 325 A and insulating layer 325 B is conductive layer 330 A and 330 B similar to conductive layer 320 A and 320 B, each of conductive layer 330 A and conductive layer 330 B may be a power or ground plane or pathway or signal trace. Where desired, each conductive layer may be patterned as is appropriate. The total number of conductive layers and insulating layers can be more or less than illustrated.
Overlying conductive layer 330 A on a surface of core 310 are an array of contact points, lands or pads 335 . Contact points 335 are a conductive pattern resulting from an etching and plating process. Contact points 335 may be arranged in an array to correspond to an array of contact points, lands or pads of a package to be placed on core 310 . Overlying contacts points 335 , in one embodiment, is bonding material 340 . In one embodiment, bonding material 340 is a conductive adhesive such as an epoxy adhesive such as anisotropic film (ACF). In another embodiment, bonding material 340 may be a solder material. An advantage to a conductively adhesive for bonding material 340 is that it will tend to increase the reliability of the circuit board contact point to package contact point connection while providing a relatively minimal z-height contribution.
FIG. 4 shows the structure of FIG. 3 following the introduction of package 345 onto core 310 . In one embodiment, package 345 is a flip-chip package including device 350 such as a die including a microprocessor. In another embodiment, package 345 is a BBUL package. On a bottom side of package 345 (as viewed) the package includes an array of contact points, lands or pads 360 arranged, for example, as a land grid array. The array of contact points 360 may be aligned with one or more of contact points 335 on core 310 . In this manner, desired ones of the array of contact points 360 may be connected to contact points 335 using, for example, bonding material 340 (e.g., a conductive epoxy adhesive).
A superior or device side of package 345 in the embodiment shown in FIG. 4 , also, includes contact points, lands or pads 365 . Contact points 365 may be routed to signal lines or traces or planes associated with core 310 subsequent build up layers and/or a device that could be external to the ultimate printed circuit board that is fabricated.
FIG. 5 shows the structure of FIG. 4 with package 345 connected to core 310 and shows the addition of buildup layers to the printed circuit board structure. Buildup layers may be introduced using an HDI printed circuit board process wherein a film or sheet of conductive or insulative material is introduced. In the embodiment shown in FIG. 5 , package 345 and die 350 extend from a superior surface (surface 332 A) of core 310 . Accordingly, a film or sheet of insulating or conductive material cannot be directly applied to core 310 as a conventional HDI printed circuit board process without contacting package 345 and/or die 350 . Therefore, in one embodiment, prior to applying an insulating or conductive material as a sheet or film, an opening having dimensions equivalent to the dimensions of the wider of package 345 and die 350 is made in the films where necessary to place the film(s) on core 310 . One way an opening may be made in a film or a sheet is by a laser cutting process. Once an opening is made, the film(s) may be introduced onto core 310 . FIG. 5 shows insulating film 370 being introduced initially on core 310 and on surface 332 A of conductive layer 330 A. In one embodiment, insulating film 370 A is a prepreg material introduced to a desired thickness as an insulator in an HDI printed circuit board process. Overlying insulating layer 370 A is conductive film 375 A of, for example, a copper material. Conductive layer 375 A may be introduced as a sheet and, where necessary, patterned, using, for example, photolithography and etch techniques. The addition of buildup layers to core 310 may continue as desired. FIG. 5 shows additional buildup layers of insulating film 380 A and conductive film 385 A to define a buildup layer portion on one side of core 310 . It is appreciated that where an opening are formed in a film prior to the film being applied to the core, the opening in such film need only be as large of an area as necessary or desired to surround package 345 and/or die 350 . Accordingly, an area of an opening of insulating layer 380 A and/or conductive film 385 A may be less than an area of openings in conductive film 375 A and/or insulating film 370 A. FIG. 5 finally shows insulating films 370 B and 380 B and conductive films 375 B and 385 B defining another buildup layer portion on a second side of core 310 .
FIG. 6 shows the structure of FIG. 5 following the introduction of multiple buildup layers on core 310 . In this embodiment, two pairs of conductive and insulative layers constitute the buildup layers. It is appreciated, that the buildup layers may consist of less than or more than two pairs of buildup layers. Referring to FIG. 6 , the structure shows insulating layer 370 A on a superior surface of core 310 and insulating layer 370 B on the bottom surface of core 310 . Overlying insulating layer 370 A is conductive layer 375 A and underlying insulating layer 370 B is conductive layer 375 B. Overlying conductive layer 375 A is insulating layer 380 A and underlying conductive layer 375 B is insulating layer 380 B. Overlying conductive layer 375 A is insulating layer 380 A followed by conductive layer 385 A. Underlying conductive layer 375 B is insulating layer 380 B followed by conductive layer 385 B. It is appreciated that in addition to introducing insulating and conductive layers or core 310 , a HDI printed circuit board process may be followed. This includes patterning conductive films as desired (e.g., through photolithography and etch techniques) and locating and forming conductive microvias by way of, for example, laser drilling and filling operation.
FIG. 6 illustrates a printed circuit board including an embedded package therein. The z-height of the printed circuit board and package is equivalent to a z-height of the printed circuit board. In this embodiment, package 345 includes contact points, pads or lands on a superior on top side surface (as viewed) contact points or pads 365 provide an increased density of second level of interconnects that allows for signal breakout on the superior side of the board and improves signal integrity performance with shorter signal paths to component(s) that are placed on a superior side of the die. Embedding package 345 in a printed circuit board also eliminates the need for an interposer that has been used, for example, in package on package configurations, since the build-up layer portion around package 345 can function as an interposer. Further, power delivery is improved since decoupling capacitors can be mounted directly on top of die 350 as viewed (e.g., directly on top of a central processing unit or system on a chip). In another embodiment, one or more decoupling capacitors may be embedded.
To form the structure of FIG. 1 , the insulating and/or conductive build-up films of the printed circuit board may be applied with an opening to expose a surface of die 350 or the opening(s) may be cut in the film(s) after their introduction. Representatively, a die 350 can be a device operating at higher power where it may be desirable to include thermal dissipation. In such an embodiment, a heat spreader or other thermal solution may be introduced on an exposed surface of the die (see FIG. 1 ). Additional devices (e.g., a DRAM device) can then be mounted beside the heat spreader using, for example, an embedded conducting film (e.g., a microstrip) to perform the input/output connection through microvias.
In each of the embodiments described with reference to FIG. 1 and FIG. 2 and the process of FIGS. 3-6 , a single component, a die, is embedded in a printed circuit board. In another embodiment, additional components may be embedded using the same techniques.
FIG. 7 illustrates a computing device 400 in accordance with one implementation of the invention. Computing device 400 houses board 402 . Board 402 may include a number of components, including but not limited to processor 404 and at least one communication chip 406 . Processor 404 is physically and electrically coupled to board 402 . In some implementations the at least one communication chip 406 is also physically and electrically coupled to board 402 . In further implementations, communication chip 406 is part of processor 404 .
Depending on its applications, computing device 400 may include other components that may or may not be physically and electrically coupled to board 402 . These other components include, but are not limited to, volatile memory (e.g., DRAM), non-volatile memory (e.g., ROM), flash memory, a graphics processor, a digital signal processor, a crypto processor, a chipset, an antenna, a display, a touchscreen display, a touchscreen controller, a battery, an audio codec, a video codec, a power amplifier, a global positioning system (GPS) device, a compass, an accelerometer, a gyroscope, a speaker, a camera, and a mass storage device (such as hard disk drive, compact disk (CD), digital versatile disk (DVD), and so forth).
Communication chip 406 enables wireless communications for the transfer of data to and from computing device 400 . The term “wireless” and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communications channels, etc., that may communicate data through the use of modulated electromagnetic radiation through a non-solid medium. The term does not imply that the associated devices do not contain any wires, although in some embodiments they might not. Communication chip 406 may implement any of a number of wireless standards or protocols, including but not limited to Wi-Fi (IEEE 802.11 family), WiMAX (IEEE 802.16 family), IEEE 802.20, long term evolution (LTE), Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT, Bluetooth, derivatives thereof, as well as any other wireless protocols that are designated as 3G, 4G, 5G, and beyond. Computing device 400 may include a plurality of communication chips 406 . For instance, first communication chip 406 may be dedicated to shorter range wireless communications such as Wi-Fi and Bluetooth and second communication chip 406 may be dedicated to longer range wireless communications such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others.
Processor 404 of computing device 400 includes an integrated circuit die packaged within processor 404 . In some implementations of the invention, the integrated circuit die of the processor includes one or more devices, such as transistors and CMOS implementations, that are formed in accordance with embodiments herein. The term “processor” may refer to any device or portion of a device that processes electronic data from registers and/or memory to transform that electronic data into other electronic data that may be stored in registers and/or memory.
Communication chip 406 also includes an integrated circuit die packaged within communication chip 406 . In accordance with another implementation, the integrated circuit die of the communication chip includes one or more devices, such as transistors and CMOS implementations, that are formed in accordance with implementations described above.
In further implementations, another component housed within computing device 400 may contain an integrated circuit die that includes one or more devices, such as transistors and CMOS implementations, that are formed in accordance with implementations described above
In various implementations, computing device 400 may be a laptop, a netbook, a notebook, an ultrabook, a smartphone, a tablet, a personal digital assistant (PDA), an ultra mobile PC, a mobile phone, a desktop computer, a server, a printer, a scanner, a monitor, a set-top box, an entertainment control unit, a digital camera, a portable music player, or a digital video recorder. In further implementations, computing device 400 may be any other electronic device that processes data.
In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiments. It will be apparent however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. The particular embodiments described are not provided to limit the invention but to illustrate it. The scope of the invention is not to be determined by the specific examples provided above but only by the claims below. In other instances, well-known structures, devices, and operations have been shown in block diagram form or without detail in order to avoid obscuring the understanding of the description. Where considered appropriate, reference numerals or terminal portions of reference numerals have been repeated among the figures to indicate corresponding or analogous elements, which may optionally have similar characteristics.
It should also be appreciated that reference throughout this specification to “one embodiment”, “an embodiment”, “one or more embodiments”, or “different embodiments”, for example, means that a particular feature may be included in the practice of the invention. Similarly, it should be appreciated that in the description various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects may lie in less than all features of a single disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of the invention.
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An apparatus including a printed circuit board including a body of a plurality of alternating layers of conductive material and insulating material; and a package including a die disposed within the body of the printed circuit board. A method including forming a printed circuit board including a core and a build-up section including alternating layers of conductive material and insulating material coupled to the core; and coupling a package including a die to the core of the printed circuit board such that at least a portion of a sidewall of the package is embedded in at least a portion of the build-up section. An apparatus including a printed circuit board including a body; a computing device including a package including a microprocessor disposed within the body of the printed circuit board; and a peripheral device that provides input or output to the computing device.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical element, namely reflector that alters the properties of light intentionally interacting with it. The present invention also relates to an optical element incorporated in to a display device and a method of manufacturing such a display device.
2. Description of the Related Art
Reflective display devices are well known. In principle, these consist of a light-modulating element, and a reflector disposed behind the light-modulating element. Light incident on the front of the light-modulating element passes through the element, is reflected by the reflector, and passes back through the light-modulating element. A reflective device had the advantage that, under suitable illumination conditions, it can utilise ambient light and does not require its own light source. For such a display to operate effectively, it is necessary that sufficient of the ambient light incident on the display is directed towards the observer so that a sufficiently bright display is produced.
Blazed reflectors can be used to redirect ambient light impinging on a reflective display at an oblique angle so that, after reflection, it exits the display substantially at normal incidence. This is advantageous since viewers of a display generally view the display from the normal direction, or from a near-normal direction, and the use of a blazed reflector creates a higher reflectance of the display towards such a viewer.
The principle of operation of a blazed reflector is illustrated in FIGS. 1 ( a ) and 1 ( b ).
In FIG. 1 ( a ), light is incidence on a block 1 of material with a refractive index n i which has upper and lower surfaces that are parallel to one another. If light is incident on the front surface of the block 1 at an angle θ 0 to the normal, it will undergo refraction at the front surface of the block 1 . It will propagate within the block at an angle θ i to the normal, where θ 0 and θ i are connected by Snell's Law, namely sin θ i =sin θ 0 /n i (assuming that the medium outside the block has a refractive index n 0 =1).
A reflective layer 1 ′, such as a metallic or dielectric layer, is disposed on the lower face of the block 1 of FIG. 1 ( a ). Light transmitted through the block 1 is specularly reflected by the reflective layer 1 ′ when it reaches the lower surface of the block, and is again refracted at the upper surface of the block so that it leaves the block at an angle θ 0 to the normal. It can thus be seen that if light is incident on the upper surface of the block 1 at an oblique angle to the normal to the block, it will be reflected at an oblique angle of the same absolute value, and so will not reach an observer viewing the block from the normal direction.
The advantages of using a blazed reflector are illustrated in FIG. 1 ( b ). In FIG. 1 ( b ), the lower surface of the block is not a plane surface parallel to the upper surface of the block, but is in the form of a blazed reflector. As is well known, the reflective surface of a blazed reflector consists of segments, with each segment being inclined at an angle θ m (known as “the angle of blaze”). A reflective layer 1 ′ is disposed on the lower face of each segment.
Since the lower surface of the block is a series of inclined segments, light transmitted through the block at an oblique angle will be reflected closer to the normal of the display. Indeed, if the angle of blaze is chosen such that θ m =θ i /2, then the reflected light will be reflected in the normal direction. Use of a blazed reflector will thus increase the brightness of the display in a normal or near-normal direction.
If the refractive index of the block 1 is assumed to be n i =1.5, the angle of blaze required to direct reflected light in the normal direction is θ m =10° for the case θ 0 30°. If θ 0 =45°, then the required angle of blaze is θ m =14°.
FIG. 2 ( a ) is a polar diagram showing the preferred reflection cone 2 from a reflective display device for collimated light that is incident on the display at an azimuthal angle of 90° and a polar angle of +30°. If light is reflected within this cone, it will reach an observer viewing the display at a normal, or near-normal, angle.
FIG. 2 ( b ) is a polar diagram showing a typical range 3 of possible positions for a light source for use with a reflective display device that incorporates a blazed reflector.
Reflective display devices are known which consist of a conventional liquid crystal display device, and a blazed reflector disposed behind the liquid crystal display device. A blazed reflector suitable for this application is typically produced by embossing a thermoplastic polymer film 4 disposed on a substrate 5 , by moving a suitable embossing tool over the layer of photopolymer. This is illustrated schematically in FIG. 3 . Once the photopolymer layer 4 has been embossed, a metallic film is then disposed over the photopolymer 4 to produce the blazed reflector. Manufacture of a blazed reflector in this way to described in U.S. Pat. Nos. 5,245,454 and 5,128,787.
Simply disposing a blazed reflector behind a conventional passive matrix LCD is only satisfactory if the extension of the second substrate normal to the display plane is small compared to the extension of the picuture element (pixel) in the display plane. This approach is not compatible with active matrix LCDs, since components of the active matrix LCD, for example such as thin film transistors (TFTs), will shade the blazed reflector. A significant amount of light passing through the LCD will thus not reach the blazed reflector, but will instead be reflected at an oblique angle by the pixel electrodes or absorbed by other components of the LCD. Furthermore, the use of a blazed reflector that is external to the LCD can give rise to optical cross-talk between adjacent pixels, and it can also cause parallax problems. This leads to a loss of resolution of the display.
It is desirable for a blazed reflector to be disposed within a LCD, so that the problems of shading of the reflector and of optical cross-talk and parallax are eliminated or at least reduced in severity.
A further desired property of a reflector for use in a reflective display is that it reflects light into a range of angles around the exact direction of specular reflection. If such a reflector is used, it is then possible for the direct specular reflection of a light source to be directed away from the position of an observer while still ensuring that a significant amount of light is directed to the observer. This means that the glare at the observer's position is reduced, as the observer will not see an image of the light source.
U.S. Pat. Nos. 5,204,765, 5,408,345 and 5,576,860 in the name of Sharp Kabushiki Kaisha describe an internal electrode for a liquid crystal display which has diffuse reflecting properties. The reflector will direct light into a range of angles around the direction of specular reflection, and it also will preserve polariation of light incident on the reflector. However, this reflector is a symmetric reflector, and this technology has not yet been extended to produce an asymmetric diffuse reflector. Indeed, no-one has yet produced a blazed reflective TFT electrode suitable for internal use in a high resolution active matrix display. Furthermore, no-one has yet produced an asymmetric reflector which has diffuse reflecting properties.
It is, in principle, possible to create an internal blazed reflector using the embossing technique illustrated in FIG. 3, but in practice it is difficult to do this. One particular problem that arises with an active matrix LCD in which the blazed reflector is acting as a pixel electrode is that the metallic layer disposed over the photopolymer must be electrically connected to a thin film transistor (TFT) disposed on the substrate of the LCD. This requires that a through hole, or via, is created through the photopolymer layer 4 , but this is difficult to do using conventional embossing techniques.
P. F. Grey discloses, in “Optica Acta”, Vol. 25, pp. 765-75 (1978), forming optical diffusers having a defined profile using a laser speckle pattern. Coherent laser light is optically diffused, and is used to expose a photoresist. Different diffuser properties can be obtained from the photoresist, for example by varying the light dose, the exposure duration, or by using single or multiple exposures.
A known method for creating a grating structure in a layer of photoresist is a near field holography method which uses self-interference of the zero and first order diffraction below a phase shift mask. This is shown schematically in FIG. 4 . Light from a light source 7 is directed onto a transmission diffraction grating 8 . Zeroth order light transmitted by the grating 8 is directed by a first mirror 43 towards a phase shift mask 9 , while first-order diffracted light from the grating is directed by a second mirror 44 towards the phase shift mask. The zeroth order light and the first order light interfere with one another, and a standing wave extending a few microns below the phase-shift mask 9 is set up. This allows a layer of photoresist 4 disposed on a substrate to be exposed in the non-contact mode preferred in production processes. The main drawbacks of this technique are the cost of the phase-shift mask, and the limited mask size which also limits the size of the grating structure that can be defined in the photoresist layer. Furthermore, this method cannot produce angles of blaze that are sufficiently small for the present application of a blazed reflector for a display device.
Another method for defining a diffraction grating in a layer of photoresist is disclosed by M. C. Hutley in “Diffraction Gratings”, Academic Press, London, 1982, pp. 95-125. This method is schematically illustrated in FIG. 5 . Light from a light source 10 , such as an argon ion laser, is expanded by the combination of a stationery diffuser 11 and a rotating diffuser 11 ′ and is then focused by a lens 12 to produce an expanded beam. This is incident on a semi-transparent mirror 13 which partially reflects the beam, and partially transmits the beam. The reflected portion is incident on a first mirror 14 , and the transmitted portion is incident on a second mirror 15 . The mirrors 14 , 15 are arranged such that the two portions of the beam are directed onto a layer 4 of photoresist disposed on a substrate 5 . An interference pattern is set up by the two beams, and the photoresist layer 4 is exposed by the interference pattern. This method has the advantage that either symmetric or asymmetric gratings can be defined in the photoresist layer, but it is disadvantageous since complicated optical path adjustment is required in order to set up the interference pattern. Furthermore, an asymmetric grating can only be produced if the layer 4 of photoresist is disposed on a transparent substrate. A TFT substrate is not uniformly transparent and contains opaque components.
U.S. Pat. Nos. 4,935,334 and 5,111,240 describe a method of producing a photoresist mask. These patents are specifically directed to varying the wall profile of a hole in the photoresist layer. These patents disclose a method of producing holes having a tapered wall profile, by partially exposing the photoresist layer through a mask, moving the mass and the photoresist layer with respect to one another, and subsequently exposing the photoresist layer again. Once the photoresist mask has been made, it is used as a mark in further processing steps, for example in the production of VLSI circuits; once these processing steps have been completed the photoresist layer is completely removed.
W. Dächner et al. (Appl. Optics, Vol. 36, p. 4675 (1997) describe a method for producing blazed structures in photoresist. It comprises the exposure of the photoresist with electromagnetic radiation through a grey-scale mask and the manufacture of a grey-scale mask.
SUMMARY OF THE INVENTION
A first aspect of the present invention provides reflective optical element comprising a microscopically structured surface with a reflective layer thereon. The reflective element allows for oblique incident light to be redirected and scattered into pre-determined directions by means of irregular piece-wise linear blazed structures. The reflective optical element may be manufactured by a method taught below.
A blazed structure is described by two angles. One describes the Shallow inclination (θ m in FIG. 1 b ), the other the steep inclination (90° in FIG. 1 b ) with respect to the normal to the crest of a blazed segment. The blazed segment can have an additional curvature to it, for example convex or concave or a multitude of both in varying portions. Multiple segments are stringed together in a piece-wise linear method so that the plurality of normals to each segment's crest vary over a range of azimuthal angles with respect to the averaged of the normal to all crests. The relative probability of occurrence of a particular azimuthal angle can be pre-determined using for example a Gaussian distribution as the probability function of a pre-determined range of azimuthal angles.
Compared to the prior art this invention has the following advantages: At the same time, the angle of blaze, its profile (concave, convex or both) and the azimuthal distribution and its relative probability of the blazed structure can be pre-determined. This allows the precise prediction of the distribution of the scattered reflection.
A second aspect to the present invention provides an electro-optic display device comprising: first and second substrates; a layer of electro-optic material disposed between the first and the second substrate; and a reflector as defined above disposed behind the electro-optic material when the electro-optic display device is viewed. In this second aspect the reflector has only the function as described in the first aspect of the present invention. This aspect of the present invention is particularly useful where the extension of the second substrate normal to the display plane is small compared to the extension of the picture element (pixel) in the display plane.
A third aspect to the present invention provides an electro-optic display device comprising: first and second substrates; a layer of electro-optic material disposed between the first and the second substrate; and a reflector as defined above disposed between the electro-optic material and the second substrate, wherein the said reflector has electrically conductive properties and acts an electrode to the electro-optic material. This aspect of the present invention is particularly useful where the extension of the second substrate normal to the display plane is large compared to the extension of the picture element (pixel) in the display plane and therefore would cause parallax problems.
A method of manufacturing an optical element may be comprising the steps of:
(a) exposing a first part of a layer of photoresist;
(b) exposing a second part of the layer of photoresist to a different depth than the first part of the layer of photoresist; and
(c) developing the photoresist.
When the layer of photoresist is developed, the resultant layer of photoresist will have regions of different thickness. Although the steps used in the method of this invention are similar to those disclosed in U.S. Pat. Nos. 4,935,334 and 5,111,240, in the present invention the layer of developed photoresist is incorporated into the optical element. This is in contrast to the prior art, which relate only to the production of a mask for use in subsequent processing steps such as, for example blocking liquid or dry etchants or as a graded resist for an ion implantation process. Once these processing steps have been completed, the mask of photoresist is completely removed.
This method of manufacturing an optical element is suitable for manufacturing an internal optical element within a display device such as, for example, an LCD or other electro-optical display device.
The method may comprise the further step of (d) disposing a reflective layer over the layer of developed photoresist. This will provide a reflector with an inclined reflecting surface.
The duration of the second exposure step may be different to the duration of the first exposure step. Alternatively, the intensity of radiation used in the second exposure step may be different to the intensity of radiation used in the first exposure step. These are convenient methods of exposing the second part of the layer of photoresist to a different depth than the first part of the layer of photoresist.
The photoresist layer may be exposed through a mask, and the mask may be moved relative to the layer of photoresist between the two exposure steps, or the mask may be moved relative to the layer of photoresist continuously during steps (a) and (b). Alternatively, the light source may be moved relative to the layer of photoresist between the two exposure steps, or the light source may be moved relative to the layer of photoresist continuously during steps (a) and (b). These are convenient ways of ensuring that different parts of the layer of photoresiut are exposed in the two exposure steps.
The method may comprise the further step of (e) exposing a third part of the layer of photoresist through the entire depth of the layer of photoresist, with this step being carried out before the step of developing the photoresist. This will create a through hole, or via, through the layer of photoresint, and this can be used to allow electrical connection between components on opposite sides of the layers of photoresist. For example, if the layer of photoresist is disposed over an active matrix substrate, the via can be used to connect a thin film transistor (TFT) on the active matrix substrate to an electrode disposed over the layer of photoresist.
The reflective layer may be an electrically conductive layer. The reflective layer can then be used as a reflective electrode. Furthermore, if a via has been created in the layer of photoresist, the step of disposing the electrically conductive layer over the photoresist will result in the via being filled with the electrically conductive material, thus creating an electrical connection through the layer of photoresist. This allows the reflective electrode to be connected to an associated switching element disposed on the other side of the layer of photoresist.
The reflective layer may be a metallic layer.
The mask used in the exposure steps may comprise a plurality of transparent lights defined in an opaque background. (The word “transparent” and “opaque” as used herein mean that the mask is transparent or opaque to the wavelength of light used to expose the photoresist.) Use of such a mask in the exposure steps will lead to the formation of a plurality of regions of reduced depth in the layer of developed photoresist, so that a blazed reflector having a plurality of inclined reflective surfaces will be formed when the reflective layer is disposed over the layer of developed photoresist.
The transparent lights defined in the mask may be piece-wise linear and irregular. In this case the “crests” of the blazed grating will not form straight lines, but will be irregular lines. This will mean that light reflected from the reflector will also be diffused, so that light will be reflected in a range of angles around the direction of specular reflection. Thus, a an asymmetric reflector that also diffuses light—that is, one that reflects light into a range of angles around the direction of specular reflection—is formed.
The transparent lines may be substantially parallel to one another. Alternatively, the separation between adjacent transparent lines may have random variations. These will result in corresponding random variations in the separation between adjacent crests of the reflector; these will cause scattering of reflected light in different azimuthal angles, and so will increase the diffuse nature of the reflected light.
The method may comprise the further step of (f) exposing the layer of photoresist to light having an intensity that varies randomly over the area of the layer of photoresist, this step being carried out before step of developing the photoresist. The exposure dose is set so that it does not fully expose the photoresist, but only creates additional, small variations in the thickness of the photoresist layer after development. These small thickness variations further increase the scattering of reflected light.
Step (f) may comprise exposing the layer of photoresist to a laser speckle pattern. The size and intensity of the laser speckle pattern will determine the size of the thickness variations in the developed photoresist layer.
While the method described above is preferred, the aspects 1 to 3 of the invention may also be achieved by employing a gray-scale mask which may be prepared by the method described above. In particular for the second aspect of the invention others methods of manufacture are conceivable, for example the embossing technique described above.
The method taught above provides a method of manufacturing an electro-optic display device comprising the steps of:
i) manufacturing an active matrix substrate;
ii) disposing a layer of photoresist over the active matrix substrate; and
iii) exposing and developing the layer of photoresist by a method defined above.
This allows the manufacture of a display device incorporating an internal optical element. As an example, an active matrix display can be provided with an internal blazed reflector, with the reflector also acting as the pixel electrode. The reflector can easily be connected to TFTs on the active matrix substrate, through a via in the layer of photoresist. Since the blazed ref lector is disposed over the active matrix substrate it is not shaded by any of the components of the active matrix substrate, in contrast to the prior art case of an external reflector disposed behind the display. Disposing the reflector within the display also reduces both parallax and cross-talk between adjacent pixels.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will now be described by way of illustrative examples with reference to the accompanying Figures, in which:
FIGS. 1 ( a ) and 1 ( b ) are schematic diagrams illustrating operation of a reflective display device incorporating a conventional reflector and a blazed reflector respectively;
FIG. 2 ( a ) is a polar diagram showing the preferred direction of light reflected from a reflective display device;
FIG. 2 ( b ) is a polar diagram illustrating possible positions for a light source used with a reflective display device incorporating a blazed reflector;
FIG. 3 is a schematic diagram of a conventional method of embossing a blazed reflector in a layer of photo-polymeric material;
FIG. 4 is a schematic illustration of a conventional near-field holography method of defining a diffraction grating in a layer of photoresist;
FIG. 5 is a schematic illustration of an optical system for interferometric exposure of a photoresist in order to define a blazed grating within the photoresist;
FIGS. 6 ( a ) to 6 ( d ) are schematic illustrations of a process for producing holes having a tapered profile in a layer of photoresist;
FIGS. 7 ( a ) and 7 ( b ) are a schematic illustrations of masks suitable for use in the present invention;
FIG. 8 is a schematic illustration of the displacement as a function of time of the mask of FIG. 7;
FIG. 9 is a schematic cross section of the resultant profile of the photoresist layer if the descending step function of FIG. 8 is used;
FIGS. 10 ( a ) and 10 ( b ) are schematic isometric views of a blazed photoresist layer produced by the method using the masks of FIGS. 7 ( a ) and 7 ( b ) respectively;
FIG. 11 is a schematic diagram of an apparatus suitable for depositing a reflective layer on the photoresist layer of FIG. 9;
FIG. 12 is a schematic detailed view of a liquid crystal device incorporating a reflector according to the present invention disposed within the device; and
FIG. 13 is a schematic isometric view of a liquid crystal display device according to another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 6 ( a ) is a schematic illustration of a method useful for the present invention. This shows a layer of positive photoresist 4 disposed on a substrate 5 . The layer of photoresist 4 is illuminated through a mask 16 having apertures (transparent lights) 17 . The mask 16 can be moved laterally relative to the layer of photoresist 4 , so that different regions of the layer of photoresist 4 can be exposed by radiation from the light source 50 . Two apertures 17 in the mask 16 , spaced by a distance X from one another, are shown in FIG. 6 ( a ), but the invention is not limited to a mask having two apertures. Using projection photolithography the distance between the photoresist 4 and the mask 16 can be increased to more than 1 micrometer.
A method of producing recesses, which have a varying depth, in the layer of photoresist 4 will now be described with reference to FIGS. 6 ( b ) to 6 ( d ). For clarity, only one aperture 17 is shown in the mask 16 in FIGS. 6 ( b ) to 6 ( d ).
FIG. 6 ( b ) shows a first exposure step. In this step, a first region 18 of the photoresist layer is exposed to light through the aperture 17 in the mask 16 . The intensity of the exposing radiation, and the duration of the exposure step, are controlled such that the first region 18 is exposed to a depth d 1 .
As the layer of photoresist 4 , a layer of pre-baked (soft-baked) positive photoresist such as, for example, photoresist 1828 by Shipley, having a thickness in the range 1-4 μm is suitable. In general, a photoresist exhibiting a close to linear dependency between the exposure depth and the dose of exposure light are preferred. The radiation used in the exposure step can be of any wavelength to which the photoresist is sensitive. For the case of the 1828 photoresist by Shipley, ultraviolet radiation from the so-called i-line from a mercury light to suitable.
Once the first exposure step has been completed, the mask 16 is displaced laterally with respect to the layer of photoresist 4 . A second exposure step is then carried out, as shown in FIG. 6 ( c ). A second region 19 of the photoresist layer is then exposed to radiation. The intensity of the exposing radiation and/or the duration of the exposure step are chosen such that the region 19 of the photoresist layer 4 is exposed to a depth d 2 , where d 2 >d 1 .
The photoresist layer 4 is then developed. A suitable development step would be a wet etch in an aqueous sodium hydroxide solution (Microposit™ 351 CD 51 by Shipley) for 60 seconds. Alternatively, a dry plasma etch would be suitable.
During the development step, the photoresist exposed to radiation in the exposure steps will be removed at a greater rate than the non-exposed photoresist. This will mean that the layer of developed photoresist 4 ′ will have a recess 40 with a base 41 that partially slopes in a direction parallel to the direction of movement of the mask during the exposure steps. The profile of the developed layer of photoresist in shown in FIG. 6 ( d ).
The method described above with regard to FIGS. 6 ( b ) to 6 ( d ) is generally similar to the method disclosed in U.S. Pat. Nos. 4,935,334 and 5,111,240. In the present invention, however, the layer of developed photoresist is incorporated into an optical element, whereas the photoresist layer in U.S. Pat. Nos. 4,935,334 and 5,111,240 is used as a mask in subsequent processing steps and then removed.
When the developed photoresist layer of FIG. 6 ( d ) is coated with a reflective coating, such as a metallic coating, the portion of the reflector corresponding to the portion A of the layer of photoresist will be inclined with respect to the remaining portion of the reflector. If a mask having a plurality of apertures is used, a blazed reflector having a plurality of inclined regions will be produced.
In the FIGS. 6 ( b ) to 6 ( d ) the first and second exposed regions of photoresist 18 , 19 do not overlap. However, it is possible for the second exposed region of photoresist to partially overlap one another, since this will still produce a recess having an inclined base upon development of the exposed photoresist.
FIG. 7 ( a ) shows a plan view of one mask suitable for use in the present invention. This mask consists of a plurality of transparent lines defined in an opaque background. The transparent lines are substantially parallel to one another. The mask is preferably moved in a direction that is substantially perpendicular to the transparent lines between the exposure steps, although it can in principle be moved in any direction that is not parallel to the transparent lines.
In the method described with regard to FIGS. 6 ( b ) to 6 ( d ), there are only two exposure steps. In practice, there will be more than two exposure steps. FIG. 8 illustrates two possibilities for the displacement of the mask a function of time for a method similar to that of FIGS. 6 ( b ) to 6 ( d ) but containing 8 exposure steps.
The upper step function shown in FIG. 8 shows the displacement of the mask over time required to give a positive slope in the exposed photoresist relative to the direction of movement of the mask. In this method, the first exposure step, which occurs from t=0 to t=t 1 is the longest, so that the depth of exposure of the photoresist will be the greatest. The duration of the subsequent exposure steps is reduced successfully, so that the depth of exposure of the photoresist in each subsequent exposure step will be less than in the preceding exposure step.
The lower step function shown in FIG. 8 will produce a negative slope in the developed photoresist, compared to the direction of movement of the mask. In the step function shown in the lower trace of FIG. 8, the first exposure step from t=0 to t=t 1 ′ has the smallest duration, and so will expose the photoresist layer to the shallowest depth. The duration of the subsequent exposure steps increases.
In the displacement/time relationships of FIG. 8, the time occupied by movement of the mask from one exposure position to the next is very much smaller than the duration of the shortest exposure step. It is thus possible for the mask to be continuously illuminated—that is during the movement of the mask as well as during the exposure steps. If, however, the time occupied by movement of the mask from one exposure position to the next is comparable with, or greater than, the duration of the shortest exposure step, it is preferable to use an intermittent illumination method in which the mask is illuminated only during the exposure steps but not during the movement of the mask.
The cross-section of the developed photoresist that is obtained by using the mask of FIG. 7 ( a ), and moving it according to the lower step function of FIG. 8 is shown schematically in FIG. 9 . (FIG. 9 assumes that the mask is moved from right to left relative to the layer of photoresist.) It will be seen that the developed photoresist layer has a blazed profile.
FIG. 10 ( a ) is a schematic isometric view of the layer of developed photoresist 4 ′ of FIG. 9 .
In an alternative method, the mask is continuously illuminated during the process of exposing the photoresist, and is moved continuously across the layer of photoresist. In this embodiment, the depth of exposure of the photoresist is varied by varying the speed of movement of the mask relative to the photoresist. To provide a positive slope in the layer of photoresist, the speed of movement of the mask with respect to the photoresist would initially be small, and would be increased with time. As the speed of movement the mask increased, the depth of exposure of the photoresist would decrease. Conversely, to produce a negative slope in the layer of developed photoresist, the mask would initially be moved at a low speed relative to the photoresist and the speed of movement of the mask would be increased with time so as to decrease the exposure depth of the photoresist. The acceleration of the mask is selected to provide the desired profile in the developed photoresist, and can either be constant or vary with time.
In another embodiment said blazed scattering reflector is produced with a grey-scale photomask. The grey-scale photomask can be used in conjunction with a relative movement between the photomask and the substrate. This is particularly useful if the grey-scale mask has only very few grey-scales. Alternatively, the grey-scale photomask can be used avoiding the relative movement between photomask and substrate described above.
One of several known techniques may be employed to produce a grey-scale mask, for example E beam sensitive produce a grey-scale mask, for example E beam sensitive glass which darkens with increasing dose (HEBS-glass, Canyon Materials, Inc.) as described by W. Däschner et at., Appl. Optics, Vol. 36,p. 4675 (1997).
At any particular position the exposure of the photoresist through a grey-scale photomask results in varying exposure depth according to the optical density of the photomask.
In another embodiment said blazed scattering reflector with the described properties shown in FIG. 10 ( b ) is produced by another method, for example embossing as schematically shown in FIG. 3 . The blazed scattering reflector may preferentially be used behind the second substrate in conjunction with a passive matrix LCD. The methods described above may be used in the manufacture of the metal shim 6 .
Once the photoresist has been developed, it is provided with a reflective coating in order to form a reflector. In principle, any reflective coating can be applied to the photoresist, but it is convenient in practice to apply a reflective coating that is the reflective coating is electrically conductive, the reflector can be used as a reflective electrode.
FIG. 11 is a schematic view of an apparatus for providing a developed layer of photoresist with a metallic coating, by evaporating metal onto the photoresist layer. The apparatus essentially comprises an evaporation source 21 disposed within a vacuum container 20 . The evaporation source 21 comprises a source of metal 22 and a heater 23 , such as for example a resistive heater, for heating the metal.
The metal source 22 is disposed on a tray, or is loaded into a tungsten coil. The substrate 5 is loaded into the vacuum chamber 20 , with the layer of developed photoresist facing the metal source 21 . The vacuum chamber is made sufficiently large that the substrate will not be deformed by heat from the metal source 21 .
In operation, the vacuum chamber 20 is initially evacuated. When the pressure falls below 10 −6 mbar, the heater 23 for heating the metal 22 is switched on, and the metal is heated until the rate of deposition of metal has reached 1 nm/s. The deposition rate is monitored by a monitor 24 .
Once the deposition rate has reached the desired value, a shutter 25 disposed between the metal source 21 and the substrate 5 is opened, and remains open until a metallic layer having a predetermined thickness has been deposited on the developed photoresist. The shutter 25 is then closed, and the heater 23 is turned off. The pressure within the vacuum chamber 20 is brought back to atmospheric pressure and the substrate 5 is removed from the chamber.
It should be pointed out that the method is not limited to the developed photoresist being metallised by an evaporation process. Any suitable process for depositing a metal film on the developed photoresist can be used. For example, a sputtering process can be used to deposit the metallic layer.
Once the metallic film has been deposited on the layer of developed photoresist it can then be further processed if necessary. For example, where the reflector is to be incorporated into an active matrix display device, the metallic layer can be patterned to define a plurality of pixel electrodes. This can be done by any conventional technique.
FIG. 7 ( b ) illustrates a mask used for another embodiment of the present invention. This mask again consists of a plurality of transparent lines defined in an opaque background (only one of the lines is shown in FIG. 7 ( b ) for convenience). The transparent lines in the mask of 7 ( b ) are not straight as in the mask of FIG. 7 ( a ). Instead, the transparent lines are piece-wise linear and irregular.
FIG. 10 ( b ) is a schematic isometric view of the layer of developed photoresist that is obtained if the mask of 7 ( b ) is used in place of the mask of FIG. 7 ( a ) in the process described above. The developed layer of photoresist again has a blazed structure, but the “crests” of the blazes are not straight lines. Instead, the crests of the blazed structure vary piece-wise linearly and irregularly in the x and y directions, in a manner generally corresponding to the shape of the transparent lines in the mask of FIG. 7 ( b ). The height of the crests above the substrate will, however, be substantially constant, and will be substantially the same as the height of the create in the developed photoresist layer shown in FIG. 10 ( a ).
The displacement of the crests of the blazed structure in the x and y directions will result in an azimuthal distribution of slopes with identical inclination. When a developed layer of photoresist having the form shown in FIG. 10 ( b ) is provided with a reflective layer so as to form a reflector, the resultant reflector will scatter reflected light into a range of azimuthal angles. Thus, the presented method makes possible the production of the present invention, an asymmetric diffuser-reflector.
A further advantage of the irregular crests is that diffraction will occur if a reflector having linear, evenly-spaced crests is illuminated by a single light source. The use of irregular crests will prevent this diffraction occurring.
A through hole or via in the layer of developed photoresist, can be easily produced during the process of exposing the un-developed photoresist. Once the photoresist layer 4 has been exposed as described hereinabove in order to define the blazed structure in the photoresist, a portion of the photoresist layer is then exposed such that the depth of exposure of the photoresiut is equal to the thickness of the layer of photoresist. This can be done, for example, using another mask which contains transparent portions corresponding in number, position and size to the required vias. Alternatively, the mask 16 can have apertures large enough to fully expose the photoresist 4 in its entire depth at the appropriate location to create the through hole.
When the photoresist is developed, a through hole will be formed in each region where the photoresist was completely exposed. The through hole(s) will be filled with metal when the metallic layer is deposited on the photoresist, so forming an electrical connection through the layer of developed photoresist. This allows the reflective layer to be electrically connected to components on the substrate 5 . The invention thus provides a reflector suitable for use inside an active matrix display device.
Where the reflective layer is patterned to define a plurality of pixel electrodes or sub-pixel electrodes, a separate via is required to connect each pixel electrode or sub-pixel electrode with its associated switching element.
Where a through hole is produced in the photoresist layer, the evaporation source and the photoresist layer are preferably moved in a circular fashion with respect to one another during the evaporation of the metallic layer onto the photoresist layer. This is to ensure that a continuous metallic coating on the wall of the via.
For a further embodiment of the invention the separation between adjacent transparent lines of the mask contains random variations. These variations will cause corresponding random variations in the separation between adjacent crests of the layer of developed photoresist, and these will increase the azimuthal scattering of light. This enhances the non-diffractive nature of the reflections from the reflective layer.
FIG. 12 is a cross-sectional detailed view of a liquid crystal display device incorporating a reflector according to the present invention. The reflector is disposed internally within the liquid crystal device, so that problems with optical cross-talk and parallax will be minimized and so that the reflector will not be shaded by other components of the device.
The liquid crystal display device of the invention comprises a front substrate 30 and a rear substrate 31 . The rear substrate 31 is an active matrix substrate, and is provided with switching elements 42 such as thin film transistors (TFTs) for controlling the pixel electrodes. Electrode lines (not shown) are also disposed on the rear substrate 31 .
A reflector is provided over the rear substrate, over the thin film transistors. The reflector consists of a layer of developed photoresist 32 with a blazed profile, which is produced as described above, and a metallic thin film 33 disposed over the layer of photoresist. The reflector acts as, firstly, an optical reflector and, secondly, a pixel electrode.
A via 34 is formed in the layer 32 of developed photoresist. This via is filled with metal, during the step of depositing the metallic electrode 33 on the photoresist layer, and this enables the electrode 33 to be electrically connected to the switching element 42 on the rear substrate 31 .
The front substrate 30 is provided with a planar front electrode 35 , which acts as a common electrode.
A liquid crystal layer 36 18 disposed between the front and rear substrates. Alignment layers (not shown) are disposed on the front electrode 35 and on the mirror electrode 33 to control the orientation of the liquid crystal molecules in the liquid crystal layer 36 .
A colour filter array may be used between the front substrate 30 and the front electrode 35 .
Finally, a polariser 37 and a retarder 38 may be disposed in front of the front substrate 30 if required by the liquid crystal mode employed.
In use, the device is illuminated from the front, by an off-axis light source 43 . Since the device contains a blazed reflector, light from the off-axis light source is reflected substantially in the normal direction.
The device of FIG. 12 is manufactured generally using conventional techniques. In particular, the active matrix substrate 31 carrying the thin film transistors or other switching elements is manufactured by any conventional manufacturing process. The active matrix substrate is then coated with photoresist, and exposed as described above in order to define the blazed structure in the photoresist. If required, it is then exposed again, in order to define a via 34 for each pixel electrode in the photoresist. The photoresist layer is subsequently developed, and the metallic coating is then deposited on the developed layer of photoresist, and patterned to define the pixel electrodes.
The front substrate 30 is manufactured by any conventional technique. The front and rear substrates are then incorporated into a liquid crystal device by conventional techniques.
FIG. 13 is a schematic isometric view of a liquid crystal display device according to another embodiment of the present invention. This generally corresponds to the device shown in FIG. 12, except that FIG. 13 shows a full colour device in which each pixel is provided with colour filters 39 R, 39 G, 39 B to produce red, green and blue sub-pixels. Each sub-pixel is provided with a separate reflective electrode 33 R, 33 G, 33 B on the rear substrate 31 , Each of these electrodes has the blazed structure shown in FIG. 12, and consists of a layer 32 R, 32 G, 32 B of photoresist having a blazed structure coated with a metallic layer.
Each of the reflective electrodes 33 R, 33 G, 33 B is controlled independently by an associated switching element such as a thin film transistor (not shown). Each electrode is connected to its associated switching element by means of a via 34 R, 34 G, 34 B defined in the photoresist layer and filled with metal so as to provide a conductive path between the electrode and the switching element.
The upper electrode 35 has been omitted from FIG. 13, for clarity.
A black and white display would have the same general structure as the full colour display of FIG. 13, except that the colour filters 39 R, 39 G, 39 B would not be required. Furthermore it would not be necessary to divide a pixel into sub-pixels (although this could be done to provide intermediate grey levels).
Although the present invention has been described with reference to preferred embodiments, the invention is not limited to these preferred embodiments.
Although the method described above use a layer of positive photoresist, the method could in principle be used with a negative photoresist.
In FIGS. 7 ( a ) and 7 ( b ) the transparent lines in the masks are continuous across the width of the mask. It is, however, possible for the transparent lines to be intermittent. For example, in a pixellated display parts of the reflector will be correspond to the inter-pixel gaps and will be obscured by a black mask; there is no need to provide such regions of the reflector with a blazed structure.
The bases of the recesses in the layer of developed photoresist are shown with a straight profile in FIG. 9 . However, the bases of the recesses are not limited to this profile and could alternatively have a concave or a convex profile. This will produce increased scattering in the zenithal direction.
A blazed reflector of the present invention can be used as the reflector in a transflective display device of the type disclosed in co-pending UK patent application No. 9820516.4. For use in this application, the reflective coating must be sufficiently thin for the blazed ref lector to be partially reflective and partially transmissive, Alternatively, the reflective coating must cover only part of each pixel of the display (or only part of each sub-pixel if the pixels are divided into sub-pixels).
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A reflective optical element is described comprising a microscopically structured surface with a reflective layer thereon. The reflective element allows for oblique incident light to be redirected and scattered into pre-determined angles by means of irregular piece-wise linear blazed structures.
The reflective optical element can be used as a blazed scattering reflector internal or external to a display device.
Several methods are described to produced such a reflective optical element.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of co-pending application Ser. No. 39,539, filed May 16, 1979, now U.S. Pat. No. 4,244,951.
BACKGROUND OF THE INVENTION
This invention relates to the chemotherapy of bacterial infections in mammalian subjects. More particularly it relates to penicillanoyloxylmethyl penicillanate 1,1,1', 1'-tetraoxide, a new chemical substance useful in the field of antibacterial chemotherapy.
One of the most well-known and widely used of the classes of antibacterial agents is the class known as the beta-lactam antibiotics. These compounds are characterized in that they have a nucleus consisting of a 2-azetidinone (beta-lactam) ring fused to either a thiazolidine or a dihydro-1,3-thiazine ring. When the nucleus contains a thiazolidine ring, the compounds are usually referred to generically as penicillins, whereas when the nucleus contains a dihydrothiazine ring, the compounds are referred to as cephalosporins. Typical examples of penicillins which are commonly used in clinical practice are benzylpenicillin (penicillin G), phenoxymethylpenicillin (penicillin V), ampicillin and carbenicillin; typical examples of common cephalosporins are cephalothin, cephalexin and cefazolin.
However, despite the wide use and wide acceptance of the beta-lactam antibiotics as valuable chemotherapeutic agents, they suffer from the major drawback that certain members are not active against certain microorganisms. It is thought that in many instances this resistance of a particular microorganism to a given beta-lactam antibiotic results because the microorganism produces a beta-lactamase. The latter substances are enzymes which cleave the beta-lactam ring of penicillins and cephalosporins to give products which are devoid of antibacterial activity. However, certain substances have the ability to inhibit beta-lactamases, and when a beta-lactamase inhibitor is used in combination with a penicillin or cephalosporin it can increase or enhance the antibacterial effectiveness of the penicillin or cephalosporin against certain microorganisms. One useful beta-lactamase inhibitor is penicillanic acid 1,1-dioxide, the compound of the formula I: ##STR1## West German Offenlegungsschrift No. 2,824,535 describes the preparation of penicillanic acid 1,1-dioxide, and methods for its use as a beta-lactamase inhibitor in combination with beta-lactam antibiotics.
My co-pending application Ser. No. 39,539, filed May 16, 1979 now U.S. Pat. No. 4,244,951, discloses compounds of the formula ##STR2## in which R 1 is an acyl group of an organic carboxylic acid, especially an acyl group from a natural, biosynthetic or semisynthetic penicillin compound. In one method of preparing the compounds of formula II, a carboxylate salt of a penicillin compound is reacted with a compound of the formula ##STR3## wherein X is a good leaving group. Examples of X are chloro, bromo, iodo, alkylsulfonyloxy, phenylsulfonyloxy and tolylsulfonyloxy. Example 25 of application Ser. No. 39,539 now U.S. Pat. No. 4,244,951 specifically describes the preparation of the compound of formula III, wherein X is chloro, by reaction of the diisopropylethylamine salt of penicillanic acid 1,1-dioxide with chloroiodomethane. However this reaction also produces the compound of the formula ##STR4## and it has been found that the compound of formula IV acts as a bio-precursor of penicillanic acid 1,1-dioxide in mammalian, especially human, subjects.
Belgian Pat. No. 764,688, granted Mar. 23, 1971, and British Pat. No. 1,303,491, published Jan. 17, 1973, disclose: (a) certain 6'-acylaminopenicillanoyloxymethyl 6-acylaminopenicillanates; (b) certain 6'-acylaminopenicillanoyloxymethyl 6-aminopenicillanates; and (c) 6'-aminopenicillanoyloxymethyl 6-aminopenicillanate.
SUMMARY OF THE INVENTION
This invention provides penicillanoyloxymethyl penicillanate 1,1,1', 1'-tetraoxide, the compound of the formula: ##STR5##
The compound of the formula IV is converted into penicillanic acid 1,1-dioxide, a known beta-lactamase inhibitor, in vivo. Accordingly the compound of formula IV is useful for enhancing the activity of beta-lactam antibiotics in a mammalian subject, especially man. However, the compound of formula IV is sparingly soluble in water, and therefore it is particularly useful for the slow release of penicillanic acid 1,1-dioxide. Under these circumstances it is particularly valuable for use with slow release (depot) forms of beta-lactam antibiotics, especially the sparingly water soluble salts of penicillins.
Preferred sparingly water soluble penicillin antibiotic salts with which the compound of formula IV can be co-administered are procaine penicillin G, benzathine penicillin G, benethamine penicillin G, procaine penicillin V, benzathine penicillin V and benethamine penicillin V.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to derivatives of penicillanic acid, which is represented by the following structural formula ##STR6## In formula V, broken line attachment of a substituent to the bicyclic nucleus indicates that the substituent is below the plane of the bicyclic nucleus. Such a substituent is said to be in the alpha-configuration. Conversely, solid line attachment of a substituent to the bicyclic nucleus indicates that the substituent is attached above the plane of the nucleus. This latter configuration is referred to as the beta-configuration.
Using this system, the compounds of formulae II and IV are named as derivatives of penicillanoyloxymethyl penicillanate (VI), in which primed and unprimed locants are used to distinguish between the two ring systems, viz.: ##STR7##
Also, in this specification, reference is made to certain penicillin compounds, viz: ##STR8## R is benzyl: penicillin G. R is phenoxymethyl: penicillin V.
Procaine penicillin G is the 1:1 salt of penicillin G with 2-(N,N-diethylamino)ethyl 4-aminobenzoate, benzathine penicillin G is the 2:1 salt of penicillin G with N,N'-dibenzylethylenediamine and benethamine penicillin G is the 1:1 salt of penicillin G with N-benzyl-2-phenylethylamine. In like manner, procaine penicillin V is the 1:1 salt of penicillin V with 2-(N,N-diethylamino)ethyl 4-aminobenzoate, benzathine penicillin V is the 2:1 salt of penicillin V with N,N'-dibenzylethylenediamine and benethamine penicillin V is the 1:1 salt of penicillin V with N-benzyl-2-phenylethylamine.
In one method according to the invention, the compound of formula IV is prepared by reacting a carboxylate salt of the formula ##STR9## with a compound of the formula III, wherein M is a carboxylate salt forming cation, and X is a good leaving group. A variety of cations can be used to form the carboxylate salt in the compound of formula VII, but salts which are commonly used include: alkali metal salts, such as sodium and potassium salts; alkaline earth metal salts, such as calcium and barium salts; and tertiary amine salts, such as trimethylamine, triethylamine, tributylamine, diisopropylethylamine, N-methylmorpholine, N-methylpiperidine, N-methylpyrrolidine, N,N'-dimethylpiperazine and N-methyl-1,2,3,4-tetrahydroquinoline salts. Typical examples of groups for X are chloro, bromo, iodo, alkylsulfonyloxy having one to four carbon atoms, phenylsulfonyloxy and tolylsulfonyloxy.
The reaction between a compound of formula VII and a compound of formula III is usually carried out by contacting the reagents in a solvent, at a temperature in the range from 0° to 80° C., and preferably from 25° to 50° C. The compounds of formula VII and III are usually contacted in substantially equimolar proportions, but an excess of either reagent, for example up to a ten-fold excess, can be used. A wide variety of solvents can be used, but it is usually advantageous to use a relatively polar solvent, since this has the effect of speeding up the reaction. Typical solvents which can be used include N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide and hexamethylphosphoramide. The reaction time varies according to a number of factors, but at about 40°-50° C. reaction times of several hours, e.g. 12 to 24 hours, are commonly used. When X is chloro or bromo, it is sometimes advantageous to add up to about one molar equivalent of an alkali metal iodide, which has the effect of speeding up the reaction.
The compound of formula IV is isolated in conventional fashion. When a water-miscible solvent is used, it is usually sufficient simply to dilute the reaction medium with an excess of water. The product is then extracted into a water immiscible solvent, such as ethyl acetate, and then the product is recovered by solvent evaporation. When a water immiscible solvent is used, it is usually sufficient to wash the solvent with water, and then recover the product by solvent evaporation. The compound of formula IV can be purified by well-known methods, such as recrystallization or chromatography, but due regard must be given to the lability of the beta-lactam ring system.
The compounds of formula III can be prepared from a compound of formula VII by reaction with a compound of the formula X--CH 2 --Y, wherein M and X are as defined previously, and Y is a good leaving group. Y can be the same as or different than X, and typical groups for Y are chloro, bromo, iodo, alkylsulfonyloxy having one to four carbon atoms, phenylsulfonyloxy and tolylsulfonyloxy. This reaction is carried out in the same manner that was described for reaction of a compound of formula VII with a compound of formula III, except that it is preferable to use an excess of the compound of formula X--CH 2 --Y (e.g. at least a fourfold excess).
Penicillanic acid, 1,1-dioxide and salts thereof (compounds of the formula VII) are prepared by published procedures (see West German Offenlegungsschrift No. 2,824,535).
Preparation of a compound of the formula IV has been described in terms of a two-step procedure which comprises reaction of a salt of penicillanic acid 1,1-dioxide with a compound of the formula X--CH 2 --Y, to give a compound of formula III, followed by reaction of a compound of formula III with a further quantity of a salt of penicillanic acid 1,1-dioxide. As will be appreciated by one skilled in the art, it is possible effectively to combine these two steps into a single step simply by contacting a salt of penicillanic acid 1,1-dioxide with 0.5 molar equivalents of a compound of formula X--CH 2 --Y, wherein X and Y are as defined previously. This reaction is carried out in the same manner as described previously for reaction of a compound of the formula VII with a compound of formula III.
As indicated hereinbefore the compound of formula IV acts as a bio-precursor to penicillanic acid 1,1-dioxide. In other words, when the compound of formula IV is exposed to mammalian blood or tissue, it is converted into penicillanic acid 1,1-dioxide. Under these circumstances, the compound of formula IV can be used to enhance the antibacterial effectiveness of beta-lactam antibiotics in mammals, particularly man. However, the compound of formula IV is sparingly soluble in water, and this makes it useful as a slow-release form of penicillanic acid 1,1-dioxide. Thus, administration of the compound of formula IV gives sustained blood levels of penicillanic acid 1,1-dioxide. Consequently, the compound of formula IV is especially useful for co-administration to a mammalian subject with slow-release forms of beta-lactam antibiotics, such as the salts of penicillins and cephalosporins which are sparingly soluble in water. Thus, the compound of formula IV can conveniently be administered to a mammalian subject as a single dose at approximately the same time as the subject first receives a dose of a sparingly water soluble penicillin antibiotic. Subsequent doses can be given as necessary to maintain the desired blood levels of penicillanic acid 1,1-dioxide. During treatment of a mammalian subject with the compound of formula IV and a sparingly water soluble penicillin antibiotic salt, the weight ratio of the compound of formula IV to the penicillin salt will be in the range from 6:1 to 1:6, and preferably 1:1 to 1:3.
In this context, a salt of a penicillin or cephalosporin is considered sparingly soluble in water if its solubility is in the range from 0.05 to 1.5 mg./ml. at about 25° C. Preferred sparingly-soluble beta-lactam antibiotic salts with which the compound of formula IV can be used are: procaine penicillin G, benzathine penicillin G, benethamine penicillin G, procaine penicillin V, benzathine penicillin V and benethamine penicillin V.
When considering use of the compound of formula IV as a slow-release form of penicillanic acid 1,1-dioxide, it is preferably administered subcutaneously. For this purpose, it is usual to prepare an aqueous suspension of the compound of the formula IV, in substantially the same manner as that currently used for formulation of a sparingly water-soluble salt of a beta-lactam antibiotic such as benzathine penicillin G. The proportional ratio of the compound of formula IV and the water can vary, depending on the dosage contemplated. However, aqueous suspensions of the compound of formula IV will usually contain from 50 to 200 milligrams of the compound of formula IV per milliliter of suspension. Small amounts of other ingredients conventionally used in preparing aqueous suspensions can also be added. For example, it is possible to add emulsifiers, such as lecithin, sorbitan mono-oleate, sorbitan monopalmitate and polyoxyethylene (20) sorbitan mono-oleate; hydrocolloids, such as carboxymethyl cellulose; dispersing agents, such as polyvinylpyrrolidone; and preservatives, such as sodium benzoate, methylparaben and propylparaben. Additionally it is preferable to buffer the suspension to a pH in the range from 6 to 7, and a sodium citrate/citric acid buffer is convenient for this purpose.
The prescribing physician will ultimately decide the appropriate dosage for a human subject when the compound of formula IV is being co-administered with a sparingly water-soluble salt of a beta-lactam antibiotic. This dosage will be expected to vary according to a variety of factors, such as the weight, age and response of the individual subject, as well as the nature and severity of the subject's symptoms and the particular sparingly water-soluble salt with which the compound of formula IV is being co-administered. However, single, subcutaneous doses of from about 4 to about 40 mg. per kilogram of body weight will normally be used. The dose will be repeated when the blood level of penicillanic acid 1,1-dioxide has fallen below the desired level. Also, dosing will continue until the desired therapeutic effect has been obtained.
The following examples are being provided to further illustrate this invention; however they should not be construed as limiting the scope of the invention in any way.
EXAMPLE 1
Penicillanoyloxymethyl
Penicillanate 1,1,1',1'-Tetraoxide
A mixture of 2.55 g of sodium penicillanate 1,1-dioxide, 3.3 ml. of bromochloromethane, a few milligrams of sodium iodide and 60 ml. of N,N-dimethylformamide was stirred at 40° to 50° C. overnight. The reaction mixture was cooled, and then it was poured into an excess of water. The resulting mixture was extracted with ethyl acetate, and the extracts were washed with water and dried (Na 2 SO 4 ). Evaporation of the dried solution in vacuo afforded 0.44 g of penicillanoyloxymethyl penicillanate 1,1,1',1'-tetraoxide. The nuclear magnetic resonance spectrum of this product, in deuterochloroform, showed absorptions at 1.45 (singlet, 6H), 1.60 (singlet, 6H), 3.50 (multiplet, 4H), 4.50 (singlet, 2H), 4.80 (multiplet, 2H) and 6.00 (singlet, 2H) ppm downfield from internal tetramethylsilane.
The penicillanoyloxymethyl penicillanate 1,1,1',1'-tetraoxide was recrystallized from chloroform, giving 0.18 g. of material having a melting point of 185°-187° C. The infrared spectrum, as a potassium bromide disc, showed significant absorptions at 1800, 1325, 1212, 1143, 1117, 1005 and 948 cm -1 .
EXAMPLE 2
Penicillanoyloxymethyl
Penicillanate 1,1,1',1'-Tetraoxide
A mixture of 2.55 g. of sodium penicillanate 1,1-dioxide, 0.41 ml. of diiodomethane and 30 ml. of N,N-dimethylformamide is stirred at 25° C. for 2 hours and then at 40° C. for an additional 4 hours. The reaction mixture is cooled and then it is poured into an excess of water. The resulting mixture is extracted with ethyl acetate, and the extracts are washed with water and dried (Na 2 SO 4 ). Evaporation of the dried solution in vacuo affords penicillanoyloxymethyl penicillanate 1,1,1',1'-tetraoxide.
EXAMPLE 3
Formulation
A typical formulation contains the following ingredients:
______________________________________Ingredient Weight (in grams)______________________________________Sodium benzoate 0.3Sodium citrate 0.45Citric acid 0.05Lecithin 0.3Sodium carboxymethyl cellulose 0.5Polyoxyethylene (20) sorbitanmono-oleate 0.07Penicillanoyloxymethyl penicillanate1,1,1',1'-tetraoxide 15.0______________________________________
The above ingredients are combined and the volume is made up to 100 ml. with deionized water. An appropriate volume is used to provide the dosage required.
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Penicillanoyloxymethyl penicillanate 1,1,1',1'-tetraoxide; a method of treating a bacterial infection in a mammalian subject using penicillanoyloxymethyl penicillanate 1,1,1',1'-tetraoxide and a beta-lactam antibiotic; and pharmaceutical compositions comprising a suspension of penicillanoyloxymethyl penicillanate 1,1,1',1'-tetraoxide in water.
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This a divisional, of application Ser. No. 08/303,997, filed Sep. 9, 1994.
TECHNICAL FIELD
This invention relates to an apparatus, an assembly, a system, and a method for manual knitting, and more particularly, to an improved device and method for manual knitting of diverse types of knit fabrics, wherein a greater variety
BACKGROUND ART
Garments made out of knit fabrics are extremely popular consumer items, especially garments such as heavy sweaters which have intricate designs and patterns. However, garments such as elaborate sweaters and the like are, for many people, prohibitively expensive to purchase. In order to more easily afford these items, and often for enjoyment as a hobby, people often opt to make their own knitted garments. Unfortunately, traditional manual knitting using a pair of standard knitting needles is a complicated process and can be extremely difficult to learn well. In addition, manual knitting with a traditional pair of needles is extremely time consuming, because the fabric is created one stitch at a time, and even a simple knitted garment is constructed of thousands of stitches. Creating intricate designs by traditional knitting methods is extremely tedious, as only one color of yarn may be stitched at a time. Moreover, traditional hand knitting can be difficult and uncomfortable, or even impossible, for people (especially elderly people) whose eyes are easily strained or whose hands are susceptible to pain and swelling such as from arthritis or other afflictions, which may be exacerbated by manipulation of the needles and yarn.
In response to these problems, attempts have been made to create inexpensive manual knitting assemblies which simplify the traditional manual knitting process; however, knitting with these known manual devices may still be a slow process, and the variety of stitches that may be made is limited in comparison to traditional knitting needles. Thus, there is a significant need for an improved manual knitting apparatus that allows a user to more easily and conveniently make more varieties of stitches and intricate designs at a faster pace.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to obviate the above-described problems and shortcomings of manual knitting assemblies and methods previously and currently available in the industry.
It is another object of the present invention to provide improved manual knitting assemblies which have simple and economical constructions.
It is yet another object of the present invention to provide improved manual knitting assemblies which can be used with a minimum of instruction to perform diverse types of knitting operations and produce a variety of different
It is a further object of the present invention to provide improved manual knitting assemblies and methods with which knit fabrics can be quickly made.
It is still another object of the present invention to provide improved manual knitting assemblies and methods which are less tedious and stressful on a person's eyes and hands.
It is still a further object of the present invention to provide improved manual knitting assemblies and methods that employ multiple needles which are selectively arranged in a distinct order so that different patterns may be made in the fabric in accordance with the order of the needles being used.
It is yet another object of the present invention to provide an improved manual knitting apparatus and method that utilizes different types of interchangeable needles for creating different types of stitches.
Additional objects, advantages, and other novel features of the invention will be set forth in part in the description that follows, and in part, will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention disclosed herein, an improved knitting assembly is provided for use with a knitting apparatus for producing patterned knitted fabric. The knitting assembly comprises a needle assembly including a handle portion having a distal edge, and a plurality of needles associated with the handle portion and arranged in a spaced, selectively determined order adjacent to the distal edge. Each of the needles terminates in a needle tip which extends from the distal edge. At least one of the needle tips has predetermined and distinct operational and nonoperational positions, whereby the order of the needles may be effectively reconfigured by selectively positioning the needle tips in desired operational or nonoperational positions.
The assembly may further include a plurality of independent handle portions, wherein the independent handle portions each have means for detachably and selectively connecting adjacent individual handle portions. The order of the needle tips preferably may be rearranged by detaching at least one of the handle portions, repositioning the handle portion(s) in a different order, and reattaching the handle portion(s) in the new order. Alternatively, at least one of the needle tips may be movably mounted to the handle portion for altering the needle tip between the operational and nonoperational positions.
In a preferred embodiment, the assembly further comprises a hook assembly including a handle having a distal edge and a hook associated with the handle. Each hook terminates in a hook tip that extends from the distal edge. The assembly may further comprise a plurality of hook tips extending from the distal edge of the handle portion, with the hook tips being arranged in a spaced and selectively determined order. At least one of the hook tips preferably has predetermined and distinct operational and nonoperational positions, whereby the order of the hooks may be effectively reconfigured by selectively positioning the hook tips in desired operational or nonoperational positions.
Like the needle tips, the hook assembly may further include a plurality of individual handle portions, wherein the individual handle portions each have means for being detachably connected with adjacent independent handle portions. In such an embodiment, the hook tips of the assembly may be rearranged by disassembling the individual handle portions, either changing the order of the hook tips or adding or removing hook tips from the assembly, and reassembling the handle portions in the new order. Additionally, at least one of the hook tips also may be movably mounted to the handle portion for selectively altering the hook tip between an operational and nonoperational position as desired.
The assembly is designed for use within a system for producing knitted fabric, where the system preferably comprises a frame having a plurality of spaced prongs and the needle assembly having a plurality of needles associated with a handle portion. In addition, the system preferably includes the hook assembly for creating different types of stitches. Methods for producing patterned knitted fabric are provided which comprise the steps of changing the order of the needle and hook tips by selectively reconfiguring the assembly and/or switching at least one hook or needle tip between operational and nonoperation positions.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed the same will be better understood from the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a top plan view of a prior art needle assembly having a single handle portion in a plurality of fixed needle tips extending therefrom;
FIG. 2 is a perspective view of a needle assembly of the present invention comprising a plurality of needle tips and individual needle handles connected in a predetermined order;
FIG. 3 is a top plan view of the needle assembly of FIG. 2 illustrating the attachment of additional needle tips;
FIGS. 4A-4D are sequential illustrations showing the movement of the needle tip relative to a frame prong of the assembly when creating an exemplary basic knit stitch;
FIG. 5 is a partial front elevation view of a fabric being knit on a frame of the needle assembly of FIG. 3, wherein the six needle tips are numbered from 1 to 6;
FIG. 6 is a perspective view of an alternative needle assembly of this invention which includes a movably mounted needle tip, and wherein all of the needle tips are illustrated in operational position;
FIG. 7 is a perspective view of the needle assembly of FIG. 6 showing one of the needle tips in nonoperational position;
FIG. 8 is a perspective view of a hook assembly made in accordance with this invention;
FIG. 8A is a side elevation view of an alternative embodiment of a single hook of the hook assembly of FIG. 8; and
FIGS. 9A-D illustrate a sequence of views showing the steps of creating an exemplary purl stitch with the hook assembly of this invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings in detail, wherein like numerals indicate the same elements throughout the views, FIG. 1 shows a top plan view of an exemplary needle assembly (120) of prior art which can be modified in accordance with the the present invention, including a handle portion (122) having a distal edge (124) and a plurality of needle tips (126) extending from distal edge (124). Although FIG. 1 shows eight needle tips (126) extending from handle (122) adjacent the distal edge (124), it should be understood that the number of needle tips (126) may vary such that a suitable number of needle tips may be determined by one skilled in the art according to the particular application.
FIG. 2 shows a preferred needle assembly of the present invention (20) having four independent handle portions (22A, 22B, 22C, 22D) connected together in accordance with the present invention. Although FIG. 2 shows an individual handle portion (22) for each needle tip (26), it is not necessary that each needle tip (26) have its own handle portion. As will be appreciated, any convenient number of needle tips (26) may be attached to each handle portion (22) as determined by those skilled in the art, so long as the order of such needle tips may be selectively arranged by the user to alter resulting stitches, as will be explained below. Each individual handle portion (22) has a distal edge (24) and at least one needle tip (26) which extends from the distal edge (24).
FIG. 3 is a partially exploded top plan view of the needle assembly (20) showing two additional needles (22E and 22F) being added to assembly (20). One of the primary advantages of this invention is the ability to change the number and order of needle tips (26) in the needle assembly (20). Therefore, each handle portion (22) includes means (e.g. 28) for detachably connecting adjacent independent handle portions (22), wherein the connecting means (28) preferably includes corresponding interlocking portions or other corresponding quick-detach structure to facilitate convenient assembly and disassembly as desired. The interlocking portions of the independent handle portions (22) preferably can comprise an elongated recess (30) and a flange (32) which is sized for fitting into the recess (30) of the adjacent handle portion (22) when the handle portions are aligned adjacent one another.
Preferably, each independent handle portion (22) has a recess (30) and a flange (32) disposed on opposing sides so that the handle portions (22) may be aligned and securely interlocked. Preferably, each recess (30) further includes at least one post (34) disposed therein, and each flange (32) has at least one slot (36) disposed so as to receive the post (34) of an adjacent handle portion (22). Other snap-type, latch-type, or male/female interlocking arrangements could easily be substituted for this recess and flange combination. Having a plurality of needle tips (26) in one assembly (20), wherein the order of the needle tips (26) may be selectively changed, allows a user to knit more than one stitch at a time which expedites the garment making process, allows knitting of exclusive and new stitches, and simplifies knitting simultaneously with multiple colors of yarn material (40). The needle tips (26) may be as described in U.S. Pat. Nos. 4,246,768, 4,193,273, and 4,362,032 which are incorporated in their entirety by reference herein. Preferably, each needle tip (26) also has three spaced eyes (38) as described below and in U.S. Pat. No. 4,362,032. As will be appreciated, the order of needle tips (e.g. 1-6) as shown in FIG. 3 can be rearranged as desired by disassembling handle portions (22A-22F) and reassembling in the preferred interlocked order.
As shown in FIGS. 4A-D, the needle assembly (20) is to be used in conjunction with a frame (42) to make stitches with yarn material (40) from a yarn supply (S). The frame (42) has a plurality of spaced upstanding prongs (44) around which the yarn material (40) is stitched. The spacing between adjacent prongs (44) generally coincides with the spacing between adjacent needle tips (26), although every prong is not always utilized for each stitch. The yarn material (40) from a yarn material supply (not shown but indicated generally as (5) is threaded first through eye (38A) (shown in FIG. 2) of handle portion (22) (as shown in FIG. 2), the yarn extending along the handle portion (22) and passing through eye (38B), which is located through the needle tip (26) adjacent distal edge (24), extending along needle tip (26), passing through eye (38C) which is located near a crest of the curved needle tip (26), and extending further along needle tip (26) and through eye (38D) so that it is provided for stitching onto the frame.
A single needle tip (26) of the needle assembly (20) is used to cast stitches onto the frame (42), generally starting at one edge or end of the frame. The yarn material (40) is knotted around a first prong (44), and the needle tip (26) is used to wind the yarn material (40) around each such prong that is being used. The number of prongs (44) used varies according to the garment that is being constructed, generally being higher for tighter stitches, lower for looser knit fabrics. Once stitches have been placed on all of the prongs being used, the needle tip (26) is then used to knit a second connected line of stitches beginning with the last prong (44) onto which the yarn material (40) was cast. FIGS. 4A-4D demonstrate how the basic knit stitch is created.
The first step, as shown in FIG. 4A, requires placing the threaded needle tip (26) at the left side of the prong (44) and sliding the needle tip (26) in the direction of the arrow into the loop of yarn material (40) which surrounds the prong (44). FIG. 4B illustrates the position of the needle tip (26) when inserted into the loop of yarn material (40), and, as illustrated in FIG. 4C, the loop is then lifted so that the yarn material (40) slips off of the prong (44) and rests on the needle tip (26). FIGS. 4D show how the needle tip (26) is then moved to the right side of the prong (44) and pulled back such that a new loop of yarn material (40) is formed around prong (44). This process is continued until the needle tip (26) reaches the opposite end of the frame (42).
The process is then repeated in the opposite direction (from right to left) beginning with the prong (44) on which the last stitch was knitted.
By employing more than one needle tip (26), the needle assembly (20) of this invention is extremely advantageous because it allows faster knitting (one row for each needle tip (26) used), knitting of exclusive and new stitches which cannot be made with a single needle tip (26), and simultaneous knitting with multiple colors of yarn material (40). A primary advantage of the preferred embodiment of this invention is the ability to initially use needle assembly (20) with a single needle tip (26) to first cast the stitches onto the frame (42), and then to attach one or more additional needle tips (26) to the needle assembly (20) to knit more than one row of stitches at a time. In order to attach additional needle tips (26) to the assembly (20), after the first stitch of a new row is made by the single needle tip (26), a second needle tip (26) is aligned with the first needle tip and its handle portion connection means (28) is attached to the corresponding connection means (28) of the handle portion of the first or original needle tip (26) which had been used to cast the stitches on the frame. The original needle tip (26), thereafter, stitches on the second prong while the added needle tip (26) stitches on the first prong, so that two rows of stitches are being made simultaneously. As many needle tips as desired may be added in this manner, however, it is preferred that the number of needle tips (26) not exceed the number of prongs (44) on the frame (42), because it would be unnecessary to have extra needle tips (26) during the knitting process.
When the needle assembly (20) reaches the end of the frame (42) during the stitching process, the needle tips (26) are moved consecutively beyond the last prong (44) of the frame (42) such that, for example, after the original needle tip (26) stitches on the last prong (44), the assembly (20) is progressively moved as if actually stitching, but only the added needle tip (26) actually stitches on the last prong (44). To begin stitching the next two rows, the added needle tip (26) stitches a second stitch at the last prong (44) that it just stitched on, then moves over to the second prong (44) and stitches on the second prong (44) while the original needle tip (26) stitches on the last prong (44). In this way, the overall knitting process is greatly speeded up in a simple and efficient manner.
New and exclusive stitches also may be created by interchanging various needle tips (26), or by skipping stitches to produce the desired pattern. For example a Jacquard or flame stitch can be produced by using the needle assembly (20) having six attached needle tips (26) (as best seen in FIG. 5), wherein the first and third needle tips (26) are threaded with a colored yarn material (40a) which is indicated by hatching, and the remaining needle tips (26) are threaded with white yarm material (40) of a different color (e.g. white). If fabric is knitted using this arrangement of needle tips (26), two colored stripes are then formed on a white background. The Jacquard stitch is created by disassembling the needle assembly (20) and changing the order of the needle tips (26) between stitches so that the colored yarn material (40a) of the first and third needle tips is crossed over the white yarn material (40).
By crisscrossing the yarn material (40 and 40a), the stitches of colored yarn material (40) are diagonally disposed on the white background which can be used to produce a Jacquard pattern. Other exclusive stitches can be created by skipping certain stitches in a row. Stitches can be skipped by disassembling the needle assembly (20) and removing one or more needle tips (26) from the assembly (20), or as will be discussed below, by moving one or more needle tips to their non-operative position. The remaining needle tips (26) are then used to stitch the next stitch.
Another arrangement for moving a needle tip to its non-operative position includes providing a rotatable connection (not shown) between adjacent handle portions (22) so that the "removed" needle tip can be rotated about its horizontal axis so that its needle tip (26) is not aligned with the other needle tips (26) in the assembly. The entire assembly (20), including the handle portion (22) of the nonoperational needle tip (26), is then used to knit. When the needle tip (26) is physically removed from the assembly (20), rather than moved in or out of operational position, the needle tips on either side of it must be used separately in order to skip that particular stitch. This slows the knitting process, especially if multiple needle tips are to be moved from operational position.
An alternative preferred embodiment of the present invention provides an easier method for changing the order of the needle tips (26), because the step of disassembling the needle assembly (20) is eliminated. This embodiment of the invention provides one or more of the needle tips (26) movably mounted to the distal edge (24) of the handle portion (22) of the needle assembly (220). As illustrated in FIGS. 6 and 7, the first needle tip (26) is movably mounted between an operational position (46) wherein the needle tip (26) is aligned with other needle tips for knitting, and a nonoperational position (48) wherein the needle tip (26) is not aligned with other needle tips for knitting. By moving the needle tip (26) into nonoperational position (48), the order of needle tips (26) is effectively changed for that stitch. The needle tip (26) may be movably mounted to the distal edge (24) by a means for selectively pivoting the needle tip (26) between its two position. There are several suitable reciprocation means that may be determined by those skilled in the art; however, the preferred pivoting means comprises a hinge (50) and a slot (52) disposed within the handle portion (22). The slot (52) allows the needle tip to rotate about the hinge (50) between its operational (46) and nonoperational (48) positions.
Alternatively, a longitudinal sliding connection means may movably mount the needle tip (26) to the handle portion (22) such that the needle tip (26) can be longitudinally retracted rearwardly relative to distal edge (24) into a nonoperational position from its operational position. Another alternative means for movably mounting the needle tip (26) is to have the independent handle portions (22) rotatable relative to one another so that the entire needle tip (26) and corresponding handle portion (22) can be rotated between operational and non-operational positions. For example, a push button catch (not shown) could be released in the handle portion (22) of the needle assembly (20) to allow the handle portions (22) to rotate relative to one another. Once the needle tips (26) are in the desired positions, the catch would re-engage to lock the needle tip in one of the two positions. All of these embodiments of the needle assembly (20) are quicker and easier to use than manually interchanging the individual handle portions (22), however, interlocking independent handle portions (22) are most preferred, because they allow a user to select and vary the number of needle tips (26) which comprise the needle assembly (20).
The preferred embodiment of this invention further comprises a hook assembly that is used with the needle assembly and frame for creating additional stitches, such as purl stitches. Previously, the only knitting apparatus other than conventional knitting needles that was capable of knitting purl stitches was a knitting machine having two opposing needle beds. It is a significant advantage over the prior art that this invention can knit purl stitches easier and faster than conventional knitting needles, and yet, can be done at home instead of by commercial knitting machines. FIG. 8 illustrates a preferred hook assembly (54) of the present invention which includes a handle (56) with a distal edge (58) and at least one hook tip (60) that extends outwardly from the distal edge (58). Hook tip (60) has a generally planar and serpentine shape for retaining yarn material for stitching and facilitating easy release of the yarn material as desired. One embodiment of hook tip (60) has a more pronounced serpentine shape as shown in FIG. 8A wherein the hook tip (60) includes a concave portion disposed between, and continuous with, two convex members, a first convex portion (66) that is adjacent the distal edge (58), and a second convex portion (68) that is located at a free end of the hook tip (60). If a plurality of hook tips (60) are present, they can be arranged in a spaced and selectively determined order so that the hook assembly can be used in conjunction with a corresponding needle assembly (20). For example, if the needle assembly (20) employs six needle tips (26), then hook assembly (54) should similarly provide six hook tips (60). The spacing between hook tips (60) preferably also coincides with the spacing of the prongs (44) on the frame (42) and the spacing of the needle tips (26) of needle assembly (20). In a preferred embodiment, handle (56) comprises a plurality of handle portions (57), with each independent handle portion (57) having means (e.g. 62) for detachably connecting adjacent independent handle portions. The connecting means (62) preferably comprise corresponding interlocking portions of the handle portions similar to those described above for the needle assembly. Preferably, the interlocking portions of connecting means (62) include an elongated recess and a corresponding flange sized for interlocking connection with a recess of the adjacent independent handle portion. The recess further includes at least one post disposed within the recess and the flange further includes at least one slot for lockingly receiving the post of an adjacent independent handle portion in secure connected condition.
As illustrated in FIG. 9A, a purl stitch is created by introducing the hook tip (60) from the back of the frame (42) and inserting it down into the yarn loop on prong (44). The hook tip (60) catches the yarn material (40) extending between the corresponding needle tip (26) and the previous stitch on the frame (42). FIG. 9B shows how the hook tip (60) is then used to pull the yarn material (40), upwardly and backwards through the loop. As seen in FIG. C, the lifting action of the hook tip (60) lifts the loop off of the prong (44a), and as shown in FIG. 9D, the hook tip (60) is used to place the new loop over the prong (44a).
Like the needle assembly (20), the order of the hook tips (60) may be selectively changed by disassembling, interchanging or removing, and reassembling the individual handle portions of the hook assembly. However, the preferred embodiment of the hook assembly (54) includes movably mounting the hook tip (60) to the handle portion (56) for selectively reciprocating the hook tip (60) between operational (46) and nonoperational (48) positions. Preferably, the hook assembly (54) is substantially identical in structure to the needle assembly (220) except for the serpentine shape of the hook tip (60) and the absence of eyes.
As shown in FIG. 4A-D, each prong (44) has a groove (G) along each side for accommodating a needle or hook tip. The groove (G) is more fully described in U.S. Pat. Nos. 4,246,768 and 4,362,032 which have been incorporated by reference herein.
Having shown and described the preferred embodiments of the present invention, further adaptations of the knitting assembly and method shown and described herein can be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of these potential modifications have been mentioned, and others will be apparent to those skilled in the art. Accordingly, the scope of the present invention should be considered in terms of the following claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.
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An improved knitting assembly for producing patterned knitted fabric includes a needle assembly having a handle portion and a plurality of needle tips associated with the handle portion and arranged in a spaced, selectively determined order. At least one of the needle tips has predetermined and distinct operational and nonoperational positions, whereby the order of the needles may be effectively reconfigured by selectively positioning the needle tips in desired operational or nonoperational positions. The assembly further preferably includes a plurality of detachably connected independent handle portions, and the order of needle tips may be changed by detaching the handle portions, rearranging the handle portions, and reattaching the handle portions in the new order.
The knitting assembly also preferably includes a hook assembly for creating purl stitches. The hook assembly includes at least one handle portion and a plurality of hook tips, wherein the order of the hook tips may be rearranged in the same manner as the needle tips of the needle assembly. Stitches and patterns are created with this assembly that were previously difficult or impossible to create with manual knitting apparatus.
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This application is a divisional application of U.S. Ser. No. 08/944,400, filed Oct. 6, 1997, U.S. Pat. No. 5,962,481 which claims the benefit of prior U.S. Provisional application Ser. No. 60/028,969 filed Oct. 16, 1996.
BACKGROUND OF THE INVENTION
The present invention relates to the discovery of novel, low molecular weight, non-peptide inhibitors of matrix metalloproteinases (e.g. gelatinases, stromelysins and collagenases) and TNF-α converting enzyme (TACE, tumor necrosis factor-α converting enzyme) which are useful for the treatment of diseases in which these enzymes are implicated such as arthritis, tumor metastatis, tissue ulceration, abnormal wound healing, periodontal disease, bone disease, proteinuria, aneurysmal aortic disease, degenerative cartilage loss following traumatic joint injury, demyelinating diseases of the nervous system and HIV infection.
Matrix metalloproteinases (MMPs) are a group of enzymes that have been implicated in the pathological destruction of connective tissue and basement membranes [Woessner, J. F., Jr. FASEB J. 1991, 5, 2145; Birkedal-Hansen, H.; Moore, W. G. I.; Bodden, M. K.; Windsor, L. J.; Birkedal-Hansen, B.; DeCarlo, A.; Engler, J. A. Crit. Rev. Oral Biol. Med. 1993, 4, 197; Cawston, T. E. Pharmacol. Ther. 1996, 70, 163; Powell, W. C.; Matrisian, L. M. Cur. Top. Microbiol. and Immunol. 1996, 213, 1]. These zinc containing endopeptidases consist of several subsets of enzymes including collagenases, stromelysins and gelatinases. Of these classes, the gelatinases have been shown to be the MMPs most intimately involved with the growth and spread of tumors, while the collagenases have been associated with the pathogenesis of osteoarthritis [Howell, D. S.; Pelletier, J. -P. In Arthritis and Allied Conditions; McCarthy, D. J.; Koopman, W. J., Eds.; Lea and Febiger: Philadelphia, 1993; 12th Edition Vol. 2, pp. 1723; Dean, D. D. Sem. Arthritis Rheum. 1991, 20, 2; Crawford, H. C; Matrisian, L. M. Invasion Metast. 1994-95, 14, 234; Ray, J. M.; Stetler-Stevenson, W. G. Exp. Opin. Invest. Drugs, 1996, 5, 323].
It is known that the level of expression of gelatinase is elevated in malignancies, and that gelatinase can degrade the basement membrane which may lead to tumor metastasis [Powell, W. C.; Matrisian, L. M. Cur. Top. Microbiol. and Immunol. 1996, 213, 1; Crawford. H. C; Matrisian, L. M. Invasion Metast. 1994-95, 14, 234; Ray, J. M.; Stetler-Stevenson, W. G. Exp. Opin. Invest. Drugs, 1996, 5, 323; Himelstein, B. P.; Canete-Soler, R.; Bernhard, E. J.; Dilks, D. W.; Muschel, R. J. Invasion Metast. 1994-95, 14, 246; Nuovo, G. J.; MacConnell, P. B.; Simsir, A.; Valea, F.; French, D. L. Cancer Res. 1995, 55, 267-275; Walther, M. M.; Levy, A.; Hurley, K.; Venzon, D.; Linehen, W. M.; Stetler-Stevenson, W. J. Urol. 1995, 153 (Suppl. 4), 403A; Tokuraku, M; Sato, H.; Murakami, S.; Okada, Y.; Watanabe, Y.; Seiki, M. Int. J. Cancer, 1995, 64, 355; Himelstein, B.; Hua, J.; Bernhard, E.; Muschel, R. J. Proc. Am. Assoc. Cancer Res. Ann. Meet. 1996, 37, 632; Ueda, Y.; Imai, K.; Tsuchiya, H.; Fujimoto, N.; Nakanishi, I.; Katsuda, S.; Seiki, M.; Okada, Y. Am. J. Pathol. 1996, 148, 611; Gress, T. M.; Mueller-Pillasch, F.; Lerch, M. M.; Friess, H.; Buechler, M.; Adler, G. Int. J. Cancer, 1995, 62, 407; Kawashima, A.; Nakanishi, I.; Tsuchiya, H.; Roessner, A.; Obata, K.; Okada, Y. Virchows Arch., 1994, 424, 547-552.]. Angiogenesis, required for the growth of solid tumors, has also recently been shown to have a gelatinase component to its pathology [Crawford, H. C; Matrisian, L. M. Invasion Metast. 1994-95, 14, 234; Ray, J. M.; Stetler-Stevenson, W. G. Exp. Opin. Invest. Drugs, 1996, 5, 323.]. Furthermore, there is evidence to suggest that gelatinase is involved in plaque rupture associated with atherosclerosis [Dollery, C. M.; McEwan, J. R.; Henney, A. M. Circ. Res. 1995, 77, 863; Zempo, N.; Koyama, N.; Kenagy, R. D.; Lea, H. J.; Clowes, A. W. Arterioscler. Thromb. Vasc. Biol. 1996, 16, 28; Lee, R. T.; Schoen, F. J.; Loree, H. M.; Lark, M. W., Libby, P. Arterioscler. Thromb. Vasc. Biol. 1996, 16, 1070.]. Other conditions mediated by MMPs are restenosis, MMP-mediated osteopenias, inflammatory diseases of the central nervous system, skin aging, tumor growth, osteoarthritis, rheumatoid arthritis, septic arthritis, corneal ulceration, abnormal wound healing, bone disease, proteinuria, aneurysmal aortic disease, degenerative cartilage loss following traumatic joint injury, demyelinating diseases of the nervous system, cirrhosis of the liver, glomerular disease of the kidney, premature rupture of fetal membranes, inflammatory bowel disease, periodontal disease, age related macular degeneration, diabetic retinopathy, proliferative vitreoretinopathy, retinopathy of prematurity, ocular inflammation, keratoconus, Sjogren's syndrome, myopia, ocular tumors, ocular angiogenesis/neovascularization and corneal graft rejection.
The hypothesis that MMPs are important mediators of the tissue destruction that occurs in arthritis has long been considered, since it was first recognized that these enzymes are capable of degrading collagens and proteoglycans which are the major structural components of cartilage [Sapolsky, A. I.; Keiser, H.; Howell, D. S.; Woessner, J. F., Jr.; J. Clin. Invest. 1976, 58, 1030; Pelletier, J. -P.; Martel-Pelletier, J.; Howell, D. S.; Ghandur-Mnaymneh, L.; Enis, J. E.; Woessner, J. F., Woessner, J. F., Jr., Arthritis Rheum. 1983, 26, 63.], and continues to develop as new MMPs are identified. For example, collagenase-3 (MMP-13) was cloned from breast cancer cells in 1994, and the first report that it could be involved in arthritis appeared in 1995 [Freiji, J. M.; Diez-Itza, I.; Balbin, M.; Sanchez, L. M.; Blasco, R.; Tolivia, J.; Lopez-Otin, C. J. Biol. Chem. 1994, 269, 16766; Flannery, C. R.; Sandy, J. D. 102-17, 41st Ann. Meet. Orth. Res. Soc. Orlando, Fla. Feb. 13-16, 1995.]. Evidence is accumulating that implicates MMP-13 in the pathogenesis of arthritis. A major structural component of articular cartilage, type II collagen, is the preferred substrate for MMP-13 and this enzyme is significantly more efficient at cleaving type II collagen that the other collagenases [Knauper, V.; Lopez-Otin, C.; Smith, B.; Knight, G.; Murphy, G. J. Biol. Chem., 1996, 271, 1544-1550; Mitchell, P. G.; Magna, H. A.; Reeves, L. M.; Lopresti-Morrow, L. L.; Yocum, S. A.; Rosner, P. J.; Geoghegan, K. F.; Hambor, J. E. J. Clin. Invest. 1996, 97, 761.]. MMP-13 is produced by chondrocytes, and elevated levels of MMP-13 has been found in human osteoarthritic tissues [Reboul, P.; Pelletier, J-P.; Hambor, J.; Magna, H.; Tardif, G.; Cloutier, J-M.; Martel-Pelletier, J. Arthritis Rheum. 1995, 38 (Suppl. 9), S268; Shlopov, B. V.; Mainardi, C. L.; Hasty, K. A. Arthritis Rheum. 1995, 38 (Suppl. 9), S313; Reboul, P.; Pelletier, J-P.; Tardif, G.; Cloutier, J-M.; Martel-Pelletier, J. J. Clin. Invest. 1996, 7, 2011]. Potent inhibitors of MMPs were described over 10 years ago, but the poor bioavailability of these early peptidic, substrate mimetic MMP inhibitors precluded their evaluation in animal models of arthritis. More bioavailable, non-peptidic MMP inhibitors may be preferred for the treatment of diseases mediated by MMPs.
TNF-α converting enzyme catalyzes the formation of TNF-α from membrane bound TNF-α precursor protein. TNF-α is a pro-inflammatory cytokine that is now thought to have a role in rheumatoid arthritis, septic shock, graft rejection, insulin resistance and HIV infection in addition to its well documented antitumor properties. For example, research with anti-TNF-α antibodies and transgenic animals has demonstrated that blocking the formation of TNF-α inhibits the progression of arthritis [Rankin, E. C.; Choy, E. H.; Kassimos, D.; Kingsley, G. H.; Sopwith, A. M.; Isenberg, D. A.; Panayi, G. S. Br. J. Rheumatol. 1995, 34, 334; Pharmaprojects, 1996, Therapeutic Updates 17 (Oct.), au197-M2Z.]. This observation has recently been extended to humans as well. Other conditions mediated by TNF-α are congestive heart failure, cachexia, anorexia, inflammation, fever, inflammatory disease of the central nervous system, and inflammatory bowel disease.
It is expected that small molecule inhibitors of gelatinase and TACE therefore have the potential for treating a variety of disease states. While a variety of MMP and TACE inhibitors have been identified and disclosed in the literature, the vast majority of these molecules are peptidic or peptide-like compounds that may have bioavailability and pharmacokinetic problems that would limit their clinical effectiveness. Low molecular weight, potent, long-acting, orally bioavailable inhibitors of gelatinases, collagenases and/or TACE are therefore highly desirable for the potential chronic treatment of the above mentioned disease states. Several non-peptide, sulfur-containing hydroxamic acids have recently been disclosed and are listed below.
U.S. Pat. Nos. 5,455,258, 5,506,242 and 5,552,419, as well as European patent application EP606,046A1 and WIPO international publications WO96/00214 and WO97/22587 disclose non-peptide matrix metalloproteinase inhibitors of which the compound CGS27023A is representative. The discovery of this type of MMP inhibitor is further detailed by MacPherson, et. al. in J. Med. Chem., (1997), 40, 2525. Additional publications disclosing sulfonamide based MMP inhibitors which are variants of the sulfonamide-hydroxamate shown below, or the analogous sulfonamide-carboxylates, are European patent application EP-757984-A1 and WIPO international publications WO95/35275, WO95/35276, WO96/27583, WO97/19068 and WO97/27174. ##STR2##
Publications disclosing β-sulfonamide-hydroxamate MMP inhibitor analogs of CGS 27023A in which the carbon alpha to the hydroxamic acid has been joined in a ring to the sulfonamide nitrogen, as shown below, include WIPO international publications WO96/33172 and WO97/20824. ##STR3##
The German patent application DE19,542,189-A1 discloses additional examples of cylic sulfonamides as MMP inhibitors. In this case the sulfonamide-containing ring is fused to a phenyl ring to form an isoquinoline. ##STR4##
Analogs of the sulfonamide-hydroxamate MMP inhibitors in which the sulfonamide nitrogen has been replaced by a carbon atom, as shown in the general structure below, are European patent application EP-780386-A1 and WIPO international publication WO97/24117. ##STR5##
SUMMARY OF THE INVENTION
The TACE and MMP inhibiting ortho-sulfonamido heteroaryl hydroxamic acids of the present invention are represented by the formula ##STR6## where the hydroxamic acid moiety and the sulfonamido moiety are bonded to adjacent carbons of group A where:
A is a 5-6 membered heteroaryl optionally substituted by R 1 , R 2 and R 3 ; having from 1 to 3 heteroatoms independently selected from N, O, and S;
Z is aryl or heteroaryl, or heteroaryl fused to a phenyl,
where aryl is phenyl, naphthyl, or phenyl fused to a heteroaryl, wherein heteroaryl is as defined above, and wherein aryl and heteroaryl may be optionally substituted by R 1 , R 2 , R 3 and R 4 ;
where heteroaryl is as defined above and optionally substituted by R 1 , R 2 , R 3 and R 4 ;
R 1 , R 2 , R 3 and R 4 are independently defined as --H, --COR 5 , --F, --Br, --Cl, --I, --C(O)NR 5 OR 6 , --CN, --OR 5 , --C 1 -C 4 -perfluoroalkyl, --S(O) x R 5 where x is 0-2, --OPO(OR 5 )OR 6 , --PO(OR 6 )R 5 , --OC(O)NR 5 R 6 , --COOR 5 , --CONR 5 R 6 , --SO 3 H, --NR 5 R 6 , --NR 5 COR 6 , --NR 5 COOR 6 , --SO 2 NR 5 R 6 , --NO 2 , --N(R 5 )SO 2 R 6 , --NR 5 CONR 5 R 6 , --NR 5 C(═NR 6 )NR 5 R 6 , 3-6 membered cycloheteroalkyl having one to three heteroatoms independently selected from N, O, and S, optionally having 1 or 2 double bonds and optionally substituted by one to three groups each selected independently from R 5 , -aryl or heteroaryl as defined above, SO 2 NHCOR 5 or --CONHSO 2 R 5 where R 5 is not H, -tetrazol-5-yl, --SO 2 NHCN, --SO 2 NHCONR 5 R 6 or straight chain or branched --C 1 -C 6 alkyl, --C 3 -C 6 -cycloalkyl optionally having 1 or 2 double bonds, --C 2 -C 6 -alkenyl,
or --C 2 -C 6 -alkynyl each optionally substituted with --COR 5 , --CN, --C 2 -C 6 alkenyl, --C 2 -C 6 alkynyl, --OR 5 , --C 1 -C 4 -perfluoroalkyl, --S(O) x R 5 where x is 0-2, --OC(O)NR 5 R 6 , --COOR 5 , --CONR 5 R 6 , --SO 3 H, --NR 5 R 6 , --NR 5 COR 6 , --NR 5 COOR 6 , --SO 2 NR 5 R 6 , --NO 2 , --N(R 5 )SO 2 R 6 , --NR 5 CONR 5 R 6 , --C 3 -C 6 cycloalkyl as defined above, --C 3 -C 6 cycloheteroalkyl as defined above, -aryl or heteroaryl as defined above, --SO 2 NHCOR 5 or --CONHSO 2 R 5 where R 5 is not hydrogen, --OPO(OR 5 )OR 6 , --PO(OR 6 )R 5 , -tetrazol-5-yl, --C(O)NR 5 OR 6 , --NR 5 C(═NR 6 )NR 5 R 6 , --SO 2 NHCONR 5 R 6 or --SO 2 NHCN;
with the proviso that when R 1 and R 2 are on adjacent carbons of A, R 1 and R 2 together with the carbons to which they are attached can form a 5-7 membered saturated or unsaturated carbocyclic ring or heterocyclic ring containing one to two heteroatoms selected independently from N, O, and S, each optionally substituted with one to four groups selected independently from R 4 ;
R 5 and R 6 are independently defined as H, aryl and heteroaryl as defined above, --C 3 -C 6 -cycloalkyl as defined above, --C 3 -C 6 -cycloheteroalkyl as defined above, --C 1 -C 4 -perfluoroalkyl, or straight chain or branched --C 1 -C 6 alkyl,
--C 2 -C 6 -alkenyl, or --C 2 -C 6 -alkynyl each optionally substituted with --OH, --COR 8 , --CN, --C(O)NR 8 OR 9 , --C 2 -C 6 -alkenyl, --C 2 -C 6 -alkynyl, --OR 8 , --C 1 -C 4 -perfluoroalkyl, --S(O) x R 8 where x is 0-2, --OPO(OR 8 )OR 9 , --PO(OR 8 )R 9 , --OC(O)NR 8 R 9 , --COOR 8 , ----CONR 8 R 9 , --SO 3 H, --NR 8 R 9 , --NCOR 8 R 9 , --NR 8 COOR 9 , --SO 2 NR 8 R 9 , --NO 2 , --N(R 8 )SO 2 R 9 , --NR 8 CONR 8 R 9 , --C 3 -C 6 cycloalkyl as defined above, --C 3 -C 6 - cycloheteroalkyl as defined above, -aryl or heteroaryl as defined above, --SO 2 NHCOR 8 or --CONHSO 2 R 8 where R 8 is not hydrogen, -tetrazol-5-yl, --NR 8 C(═NR 9 )NR 8 R 9 , --SO 2 NHCONR 8 R 9 , --SO 2 NHCN;
R 7 is hydrogen, straight chain or branched --C 1 -C 6 -alkyl, --C 2 -C 6 -alkenyl, or --C 2 -C 6 -alkynyl each optionally substituted with --OH, --COR 5 , --CN, --C 2 -C 6 -alkenyl, --C 2 -C 6 -alkynyl, --OR 5 , --C 1 -C 4 perfluoroalkyl, --S(O) x R 5 where x is 0-2, --OPO(OR 5 )OR 6 , --PO(OR 5 )R 6 , --OC(O)NR 5 R 6 , --COOR 5 , --CONR 5 R 6 , --SO 3 H, --NR 5 R 6 , --NR 5 COR 6 , --NR 5 COOR 6 , SO 2 NR 5 R 6 , --NO 2 , --N(R 5 )SO 2 R 6 , --NR 5 CONR 5 R 6 , --C 3 -C 6 cycloalkyl as defined above, --C 3 -C 6 -cycloheteroalkyl as defined above, -aryl or heteroaryl as defined above, --SO 2 NHCOR 5 or --CONHSO 2 R 5 where R 5 is not hydrogen, -tetrazol-5-yl, --NR 5 C(═NR6)NR 5 R 6 , --C(O)N R 5 OR 6 , --SO 2 NHCONR 5 R 6 or --SO 2 NHCN;
or R 7 is phenyl or naphthyl, optionally substituted by R 1 , R 2 , R 3 and R 4 or a 5 to 6 membered heteroaryl group having 1 to 3 heteroatoms selected independently from N, O, and S and optionally substituted by R 1 , R 2 , R 3 and R 4 ;
or R 7 is C 3 -C 6 cycloalkyl or 3-6 membered cycloheteroalkyl as defined above;
or R 7 --CH 2 --N--A--, where A is as defined above, can form a non-aromatic 1,2-heteroaryl-fused 7-10 membered heterocyclic ring optionally containing an additional heteroatom selected from O, S and N wherein said heterocyclic ring may be optionally fused to another benzene ring;
R 8 and R 9 are independently H, aryl or heteroaryl as defined above, --C 3 -C 7 -cycloalkyl or cycloheteroalkyl as defined above, --C 1 -C 4 -perfluoroalkyl, straight chain or branched --C 1 -C 6 -alkyl, --C 2 -C 6 -alkenyl, or --C 2 -C 6 -alkynyl, each optionally substituted with hydroxy, alkoxy, aryloxy, --C 1 -C 4 -perfluoroalkyl, amino, mono- and di-C 1 -C 6 -alkylamino, carboxylic acid, carboalkoxy and carboaryloxy, nitro, cyano, carboxamido primary, mono- and di-C 1 -C 6 -alkylcarbamoyl;
and the pharmaceutically acceptable salts thereof and the optical isomers and diastereomers thereof.
Preferred compounds are those wherein both of the carbons of A adjacent to the carbon bearing the sulfonamido group having a substituent other than hydrogen. Also preferred are compounds where Z is 4-alkoxyphenyl, 4-aryloxyphenyl or 4-heteroaryloxyphenyl.
The term "heteroaryl" as defined hereinabove includes, but is not limited to, pyrrole, furan, thiophene, pyridine, pyrimidine, pyridazine, pyrazine, triazole, pyrazole, imidazole, isothiazole, thiazole, isoxazole and oxazole. The term "5 to 7 membered saturated or unsaturated heterocyclic ring" includes, but is not limited to oxazolidine, thiazolidine, imidazolidine, tetrahydrofuran, tetrahydrothiophene, tetramethylene sulfone, dihydropyran, tetrahydropyran, piperidine, pyrrolidine, dioxane, morpholine, azepine and diazepine. The term "heteroaryl fused to a phenyl" includes, but is not limited to, indole, isoindole, benzofuran, benzothiophene, benzoisothiazole, quinoline, isoquinoline, quinoxaline, quinazoline, benzotriazole, indazole, benzimidazole, benzothiazole, benzisoxazole, and benzoxazole.
The following compounds (I-V) which may be used in preparing compounds of the invention are known and references are given hereinbelow. This list is included for illustrative purposes only and is not to be constituted as limiting in any way. ##STR7## Literature references for these materials are as follows: Compound I
a) Dolle, R E; Hoyer, D W; Schmidt, S J; Ross, T M; Rinker, J M; Ator, M A Eur. Pat. Appl. EP-628550
b) Wermuth, C-G; Schlewer, G; Bourguignon, J-J; Maghioros, G; Bouchet, M-J et. al. J. Med. Chem (1989), 32, 528-537
c) Yutugi, S et. al. Chem. Pharm. Bull, (1971) 19, 2354-2364
d) Dolle, R E; Hoyer, D; Rinker, J M; Ross, T M; Schmidt, S J Biorg. Med. Chem. Lett (1977) 7, 1003-1006
Compound II: Camparini, A; Ponticelli, F; Tedeschi, P. J. Chem. Soc., Perkin Trans. 1 (1982), 10, 2391-4.
Compound III: Muller, C. E.; Geis, U.; Grahner, B.; Lanzner, W.; Eger, K. J. Med. Chem. (1996), 39, 2482.
Compound IV: Muller, C. E.; Geis, U.; Grahner, B.; Lanzner, W.; Eger, K. J. Med. Chem. (1996), 39, 2482.
Compound V: Commercially available.
The compounds of this invention are shown to inhibit the enzymes MMP-1, MMP-9, MMP-13 and TNF-α converting enzyme (TACE) and are therefore useful in the treatment of arthritis, tumor metastasis, tissue ulceration, abnormal wound healing, periodontal disease, graft rejection, insulin resistance, bone disease and HIV infection.
DETAILED DESCRIPTION OF THE INVENTION
The following reaction scheme (Scheme I) depicts the general method of synthesis of the invention compounds from an ortho amino heteroaryl carboxylic acid ester. For purposes of illustration only, the ortho amino heteroaryl carboxylic acid ester shown is 3-amino-thiophene-4-carboxylic acid methyl ester, wherein A is thiophene, which is sulfonylated with p-methoxybenzenesulfonyl chloride, wherein Z is 4-methoxyphenyl, and then alkylated with benzyl bromide, wherein R 7 is benzyl. The resulting ester is subsequently converted into the corresponding hydroxamic acid in 2 steps. Obviously, other heteroaromatic groups having an amino group adjacent to a carboxy group and having optional substituents R 1 , R 2 and R 3 where Z and R 7 are as defined hereinabove can be used in the general reaction scheme to prepare invention hydroxamic acids. ##STR8##
Shown in Scheme II is the synthesis of an example of the invention wherein A is pyridyl. The ortho-amino ester is constructed via metalation and subsequent carboxylation of the BOC-protected amino-pyridine. Deprotection of the resulting ester compound, (2), followed by sulfonylation of the amine, (3), provides (4) where Z is 4-methoxyphenyl. Alkylation of the NH-sulfonamide of (4) as in Scheme I, followed by hydrolysis of the ester functionality and conversion of the resulting carboxylic acid, (6), into the corresponding hydroxamic acid results in the desired pyridyl-hydroxamate, (7). Additional pyridyl-hydroxamates are available through the same route. ##STR9##
Schemes III and IV illustrate two methods for incorporating amino groups into the substituent attached to the sulfonamide nitrogen of the compounds of the invention. Thus, in Scheme III the NH-sulfonamide is alkylated with propargyl bromide to provide the propargyl sulfonamide. This alkyne is reacted with paraformaldehyde in the presence of a primary or secondary amine and cuprous chloride to give the propargyl amine which is converted, as before, to the desired hydroxamid acid. ##STR10##
In Scheme IV, selective hydrolysis of the ester of the p-carboethoxybenzyl sulfonamide group provides a mono-carboxylic acid. This acid may be converted into an amide (not shown), followed by conversion of the second ester, A--CO 2 R, into the corresponding hydroxamate, or reduced to the corresponding alcohol with diborane. The alcohol may be converted into the analogous amine via the benzylic bromide, followed by conversion of the ester, A--CO 2 R, into the corresponding hydroxamate. ##STR11##
Methods for synthesizing variations of substituents on the sulfonyl aryl group are shown in Schemes V through VIII. As shown in Scheme V, biaryl sulfonyl groups are synthesized by Suzuki couplings on a bromo-substituted benzene sulfonamide. The starting bromo-substituted benzene sulfonamide is synthesized from the commercially available bromobenzenesulfonyl chloride and the amino-acid or amino-ester, H 2 N--A--CO 2 R, followed by alkylation of the resulting NH-sulfonamide. Alternatively, the bromo aryl sulfonamide is converted into the corresponding boronic acid by the method of Ishiyama, et. al. [J. Org. Chem. (1995), 60, 7508] followed by coupling with an appropriate aryl halide. ##STR12##
Methods for synthesizing sulfonyl aryl ethers are shown in Schemes VI through VIII. In Scheme VI biaryl ethers, or aryl heteroaryl ethers, are synthesized starting from the known sulfonyl chlorides (see for example: Zook S E; Dagnino, R; Deason, M E, Bender, S L; Melnick, M J WO 97/20824). ##STR13##
Alternatively, the biaryl ethers may be prepared from the corresponding boronic acids or via the sulfonyl phenols as shown in Scheme VII. ##STR14##
Aryl ethers may also be prepared via displacement of the fluorine from a para-fluorobenzene sulfonamide, as shown in Scheme VIII. Aryl or alkyl ethers may be prepared in this manner. ##STR15##
Basic salts of the hydroxamic acids can be formed with pharmaceutically acceptable alkali-forming metal cations such as lithium, sodium, potassium, calcium and aluminum. Acid addition salts can be formed when a substituent contains a basic amino group using a pharmaceutically acceptable inorganic or organic acid such as hydrochloric, hydrobromic, phosphoric, sulfuric, acetic, benzoic, succinic, lactic, malic, maleic, fumaric or methanesulfonic acids.
The following specific examples are included for illustrative purposes and are not to be construed as limiting to this disclosure in any way. Other procedures useful for the preparation of compounds of this invention may be apparent to those skilled in the art of organic synthesis.
EXAMPLE 1
3-(4-Methoxy-benzenesulfonylamino)-thiophene-2-carboxylic acid methyl ester
To a solution of 5.00 g (0.032 mol) of 3-amino-2-carbomethoxythiophene dissolved in 40 mL of chloroform was added 7.73 mL (0.032 mol) of pyridine followed by 6.57 g (0.032 mol) of p-methoxybenzenesulfonyl chloride. The reaction mixture was stirred at room temperature for 5 h and then washed with 3N HCl and water. The organics were then dried over Na 2 SO 4 , filtered and concentrated in vacuo. The resulting cream colored solid was washed with ether and dried in vacuo to provide 6.89 g (66%) of the desired sulfonamide. Electrospray Mass Spec 328.2 (M+H).
EXAMPLE 2
4-(4-Methoxy-benzenesulfonylamino)-thiophene-3-carboxylic acid methyl ester
In the same manner as described in Example 1, 5.00 g (0.026 mol) of 3-amino-4-carbomethoxythiophene hydrochloride provided 3.50 g (41%) of the desired sulfonamide as a brown solid after trituration with ether. Electrospray Mass Spec 328.2 (M+H).
EXAMPLE 3
5-(4-Methoxy-benzenesulfonylamino)-1-methyl-1H-pyrazole-4-carboxylic acid ethyl ester
In the same manner as described in Example 1, 2.00 g (0.012 mol) of 1-methyl-2-amino-3-carboethoxy-pyrazole provided 0.923 g (23%) of the desired sulfonamide as a white solid after recrystallization form EtOAc/Hexanes. Electrospray Mass Spec 340.2 (M+H).
EXAMPLE 4
3-(4-Methoxy-benzenesulfonylamino)-4-methyl-thiophene-2-carboxylic acid methyl ester
In the same manner as described in Example 1, 4.14 g (0.024 mol) of 3-amino-4-methyl-2-carbomethoxy thiophene provided 4.89 g (47%) of the desired sulfonamide as a white solid after trituration with ether. EI Mass Spec 340.9 (M + ).
EXAMPLE 5
3-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-thiophene-2-carboxylic acid methyl ester
To a solution of 2.0 g (6.116 mmol) of the product of Example 1 in 25 mL of DMF was added 0.257 g (6.422 mmol) of 60% sodium hydride. The resulting mixture was stirred for 30 min at room temperature and then 0.76 mL (6.422 mmol) of benzyl bromide was added. This reaction mixture was stirred overnight at room temperature, poured into water and then extracted with ether. The combined organics were washed with water and brine, dried over MgSO 4 , filtered and concentrated in vacuo. The residue was chromatographed on silica gel eluting with EtOAc/Hexanes (1:3) to provide 1.62 g (65%) of the desired product as white crystals. CI Mass Spec: 418 (M+H).
EXAMPLE 6
4-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-thiophene-3-carboxylic acid methyl ester
In the same manner as described in Example 5, 1.50 g (4.587 mmol) of the product of Example 2 provided 1.257 g (66%) of the desired product as a brown oil after chromatography on silica gel eluting with EtOAc/Hexanes (1:10). CI Mass Spec: 418 (M+H).
EXAMPLE 7
5-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-1-methyl-1H-pyrazole-4-carboxylic acid ethyl ester
In the same manner as described in Example 5, 0.843 g (2.484 mmol) of the product of Example 3 provided 0.924 g (87%) of the desired product as a white solid after trituration with ether. CI Mass Spec: 430 (M+H).
EXAMPLE 8
3-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-4-methyl-thiophene-2-carboxylic acid methyl ester
In the same manner as described in Example 5, 2.00 g (4.64 mmol) of the product of Example 4 provided 1.648 g (68%) of the desired product as a white solid after trituration with ether. CI Mass Spec: 432 (M+H).
EXAMPLE 9
3-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-thiophene-2-carboxylic acid
To a mixture of 1.494 g (3.583 mmol) of the product of Example 5 dissolved in 15 mL of methanol and 15 mL of THF was added 15 mL of 1N NaOH solution. The reaction mixture was stirred at room temperature for 36 h and the organics were removed in vacuo. The resulting mixture was acidified with 10% HCl and extracted with EtOAc. The combined organics were washed with water and brine, dried over MgSO 4 , filtered and concentrated in vacuo. The resulting residue was triturated with ether and filtered to provide 1.327 g (92%) of the desired carboxylic acid as a white solid. CI Mass Spec: 404 (M+H).
EXAMPLE 10
4-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-thiophene-3-carboxylic acid
In the same manner as described in Example 9, 1.157 g (2.775 mmol) of the product of Example 6 provided 0.94 g (84%) of the desired carboxylic acid as a tan solid after trituration with ether. Electrospray Mass Spec: 404 (M+H).
EXAMPLE 11
5-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-1-methyl-1H-pyrazole-4-carboxylic acid
To a solution of 0.799 g (1.862 mmol) of the product of Example 7 in 20 mL of methanol/THF (1:1) was added 9.3 mL of 1N sodium hydroxide solution and the resulting mixture was heated to reflux for 18 h. The reaction was then cooled to room temperature and the organics were removed in vacuo. The resulting mixture was acidified with 10% HCl and extracted with EtOAc. The combined organics were washed with water and brine, dried over MgSO 4 , filtered and concentrated in vacuo. The resulting residue was triturated with ether and filtered to provide 0.697 g (93%) of the desired carboxylic acid as a white solid. Electrospray Mass Spec: 402 (M+H).
EXAMPLE 12
3-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-4-methyl-thiophene-2-carboxylic acid
In the same manner as described in Example 11, 1.366 g (2.622 mmol) of the product of Example 8 provide 1.16 g (87%) of the desired carboxylic acid as a white solid after trituration with ether. Electrospray Mass Spec: 416 (M-H)--.
EXAMPLE 13
3-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-thiophene-2-carboxylic acid hydroxyamide
To a solution of 0.80 g (1.985 mmol) of the product of Example 9 in 20 mL of dichloromethane was added 0.154 mL of DMF followed by 2.0 mL of 2.0M oxalyl chloride and the resulting reaction mixture was stirred at room temperature for 1 h.
In a separate flask, 1.66 mL (11.91 mmol) of triethylamine was added to a 0° C. mixture of 0.552 g (7.94 mmol) of hydroxylamine hydrochloride in 8.7 mL of THF and 2.2 mL of water. After this mixture had stirred for 15 min at 0 degrees, the acid chloride solution was added to it in one portion and the resulting solution was allowed to warm to room temperature with stirring overnight. The reaction mixture was then acidified to pH 3 with 10% HCl and extracted with EtOAc. The combined organic layers were dried over Na 2 SO 4 , filtered and concentrated in vacuo. The crude residue was triturated with ether to provide 0.66 g (80%) of the desired hydroxamic acid as a white solid. Electrospray Mass Spec: 419 (M+H).
EXAMPLE 14
4-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-thiophene-3-carboxylic acid hydroxyamide
In the same manner as described in Example 13, 0.80 g (1.985 mmol) of the product of Example 10 gave 0.61 g (73%) of the desired hydroxamic acid as a white solid. Electrospray Mass Spec: 419 (M+H).
EXAMPLE 15
5-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-1-methyl-1H-pyrazole-4-carboxylic acid hydroxyamide
In the same manner as described in Example 13, 0.580 g (1.446 mmol) of the product of Example 11 gave 0.446 g (74%) of the desired hydroxamic acid as a white solid. Electrospray Mass Spec: 417 (M+H).
EXAMPLE 16
3-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-4-methyl-thiophene-2-carboxylic acid hydroxyamide
In the same manner as described in Example 13, 0.50 g (0.986 mmol) of the product of Example 12 gave 0.30 g (58%) of the desired hydroxamic acid as a white solid. CI Mass Spec: 433 (M+H).
EXAMPLE 17
5-Bromo-4-(4-methoxy-benzenesulfonylamino)-thiophene-3-carboxylic acid methyl ester
To a solution of the product of Example 2 in 5.0 mL of AcOH--CHCl 3 (1:1) at room temperature was added 0.299 g (1.682 mmol) of N-bromosuccinimide. The reaction was stirred for 18 h and then diluted with ether, washed with water and saturated sodium bicarbonate solution, dried over MgSO 4 , filtered and concentrated in vacuo. The tan solid residue was washed with ether-hexanes (1:1) to provide 0.504 g (81%) of the desired product as a tan solid. Electrospray Mass Spec: 406.1 (M+H)+
EXAMPLE 18
4-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-5-bromo-thiophene-3-carboxylic acid methyl ester
In the same manner as described in Example 5, 0.424 g (1.044 mmol) of the product of Example 17 gave 0.400 g (77%) of the desired hydroxamic acid as a white solid. Electrospray Mass Spec: 496.1 (M+H)+
EXAMPLE 19
4-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-5-bromo-thiophene-3-carboxylic acid
In the same manner as described in Example 11, 0.356 g (0.718 mmol) of the product of Example 18 gave 0.290 g (84%) of the desired hydroxamic acid as a white solid. Electrospray Mass Spec: 482.1 (M+H)+
EXAMPLE 20
4-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-5-bromo-thiophene-3-carboxylic acid hydroxyamide
In the same manner as described in Example 13, 0250 g (0.519 mmol) of the product of Example 19 gave 0.222 g (86%) of the desired hydroxamic acid as a white solid. Electrospray Mass Spec: 497.1 (M+H)+
EXAMPLE 21
4-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-5-ethynyl-thiophene-3-carboxylic acid methyl ester
To a solution of 0.294 g (0.634 mmol) of the product of Example 18 in 2.5 mL of DMF and 2.5 mL of triethylamine was added 0.448 mL (3.168 mmol) of trimethylsilylacetylene, 0.022 g (0.032 mmol) of bis(triphenylphosphine)-palladium(II)dichloride and 3 mg of copper(I)iodide. The reaction mixture was then heated to 80° C. for 6 h and then cooled to room temperature and diluted with ether. The organics were washed with 5% HCl solution, water and brine, dried over MgSO 4 , filtered and concentrated in vacuo. The residue was dissolved in 5 mL of THF, 1 mL of 1M tetrabutylammonium fluoride-THF solution was added and the reaction was stirred at room temperature for 1 h, then diluted with ether, washed with 5% HCl solution, water and brine, dried over MgSO 4 , filtered and concentrated in vacuo. The residue was chromatographed on silica eluting with EtOAc-Hex (1:5) to provide 0.159 g (61%) of the desired product as a brown oil. Electrospray Mass Spec: 442.2 (M+H) +
EXAMPLE 22
4-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-5-ethynyl-thiophene-3-carboxylic acid
In the same manner as described in Example 11, 0.136 g (0.333 mmol) of the product of Example 21 provided 0.075 g (57%) of the desired product as a tan solid after chromatography on silica eluting with EtOAc-Hexanes (1:1). Electrospray Mass Spec: 428.1 (M+H)+
EXAMPLE 23
4-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-5-ethynyl-thiophene-3-carboxylic acid hydroxyamide
In the same manner as described in Example 13, 0.055 g (0.634 mmol) of the product of Example 22 provided 0.044 g (77%) of the desired product as a brown foam. Electrospray Mass Spec: 443.1 (M+H)+.
EXAMPLE 24
5-Bromo-4-[(4-methoxybenzenesulfonyl)-pyridin-3-ylmethylamino]thiophene-3-carboxylic acid methyl ester
To a solution of 4.80 g (11.82 mmol) of the product of Example 17 dissolved in 5.0 mL of DMF was added 2.04 g (12.41 mmol) of 3-picolyl chloride hydrochloride and 4.89 g (35.46 mmol) of potassium carbonate. The reaction mixture was then stirred at room temperature for 18 h, diluted with water and extracted with ether. The organics were then extracted with 6N HCl solution and the aqueous acid layer was then basified with 6N NaOH solution and then extracted with ether. The resulting ether layer was dried over sodium sulfate, filtered and concentrated in vacuo to provide 4.16 g (71%) of the desired product as a tan solid. Electrospray Mass Spec: 498 (M+H).
EXAMPLE 25
5-Bromo-4-[(4-methoxy-benzenesulfonyl)-pyridin-3-ylmethyl-amino]-thiophene-3-carboxylic acid
To a solution of 0.40 g (0.860 mmol) of the product of Example 24 in 9.0 mL of THF-MeOH (1:1) was added 0.072 g (1.72 mmol) of lithium hydroxide monohydrate. The reaction mix was heated to reflux for 18 h and then concentrated in vacuo. The residue was was washed with THF and filtered. The filtrate was concentrated in vacuo to provide 0.388 g (100%) of the desired product as a white foam. Electrospray Mass Spec: 483 (M+H).
EXAMPLE 26
5-Bromo-4-[(4-methoxy-benzenesulfonyl)-pyridin-3-ylmethyl-amino]-thiophene-3-carboxylic acid hydroxyamide
To a solution of 0.82 mL (1.63 mmol) of a 2M solution of oxalyl chloride in CH 2 Cl 2 at 0° C. was added 0.126 mL (1.63 mmol) of DMF and the mixture was stirred at 0° C. for 15 min, then let warm to room temperature and stirred for an additional 1 h. A solution of 0.374 g (0.817 mmol) of the product of Example 193, in 1 mL of DMF, was then added to the reaction mixture and the reaction was stirred for 1 h at room temperature.
In a separate flask, 1.70 mL (12.25 mmol) of triethylamine was added to a 0° C. mixture of 0.567 g (8.165 mmol) of hydroxylamine hydrochloride in 8.1 mL of THF and 2.3 mL of water. After this mixture had stirred for 15 min at 0° C., the acid chloride solution was added to it in one portion and the resulting solution was allowed to warm to room temperature with stirring overnight. The reaction mixture next was diluted with CH 2 Cl 2 and washed with water and saturated sodium bicarbonate solution. The organic layer was dried over Na 2 SO 4 , filtered and concentrated in vacuo. The crude residue was triturated with ether to provide 0.235 g (61%) of the desired hydroxamic acid as a tan foam.
Electrospray Mass Spec: 498 (M+H).
EXAMPLE 27
tert-Butyl N-(2,6-dimethoxy-3-pyridyl)carbamate
To a suspension of 3-amino-2,6-dimethoxypyridine (1.5 g, 7.87 mol) was added di-tert-butyl dicarbonate (3.43 g, 15.7 mmol). The solution was heated at reflux for 36 hours, cooled to room temperature, and diluted with H 2 O. The aqueous solution was extracted 3 times with EtOAc, the organic extracts were combined, washed with brine, dried over MgSO 4 , concentrated in vacuo. The residue was purified by column chromatography using hexane/ethyl acetate as eluant (gradient 100% to 4/1) to provide 2.00 g (100%) of tert-butyl N-(2,6-dimethoxy-3-pyridyl)carbamate a yellow oil. Electrospray Mass Spec: 254.9 (M+H)+
EXAMPLE 28
tert-Butyl N-(4-carbomethoxy-2,6-dimethoxy-3-pyridyl)carbamate
The product of Example 27 (1 g, 3.93 mmol) was dissolved in Et 2 O (35 mL) and TMEDA (1.7 mL, 1.18 mmol) and cooled to -78° C. n-Butyllithium (4.75 mL, 11.87 mmol) was added dropwise and the reaction was allowed to stir for 15 minutes at -78° C. before warming to -10° C. for 2.5 hours. The solution was cooled back to -78° C. and methyl chloroformate (0.6 mL, 7.8 mmol) dissolved in Et 2 O (4.5 mL) was added dropwise. The reaction was held at -78° C. for 10 minutes and then warmed to -10° C. and allowed to stir for 1.5 hours before quenching with NH 4 Cl(sat). The reaction mixture was extracted 3× with EtOAc. The organics were combined, washed with brine, dried over MgSO 4 , concentrated in vacuo. The residue was purified by column chromatography using hexane/ethyl acetate as eluant (gradient 9/1 to 4/1) to provide 0.423 g (34%) of tert-butyl N-(4-carbomethoxy-2,6-dimethoxy-3-pyridyl)carbamate as a white solid. Electrospray Mass Spec: 312.8 (M+H)+
EXAMPLE 29
Methyl 3-amino-2,6-dimethoxyisonicotinate
p-Toluene sulfonic acid hydrate (0.282 g, 1.48 mmol) was dissolved in toluene (11 mL) and heated to reflux overnight with azeotropic removable of H 2 O (Dean-Stark trap). The next day, the reaction was cooled to room temperature and the product of Example 28, dissolved in toluene (4 mL), was added. The reaction was heated back to reflux for 0.5 hours. The reaction was cooled to room temperature and poured into NaHCO 3 (sat) and extracted 3 times with ether. The organics were combined, washed with brine, dried over MgSO 4 , concentrated in vacuo. The residue was purified by column chromatography using hexane/ethyl acetate as eluant (gradient 100% to 9/1) to provide 0.278 g (97%) of methyl 3-amino-2,6-dimethoxyisonicotinate as a yellow solid. Electrospray Mass Spec: 212.8 (M+H)+
EXAMPLE 30
Methyl 3-(4-methoxy-benzenesulfonylamino)-2,6-dimethoxy-isonicotinate
To a solution of the product of Example 29 (0.278 g, 1.31 mmol) in pyridine (2 mL) was added p-methoxybenzenesulfonyl chloride (0.28 g, 1.38 mmol). The reaction mixture was stirred at room temperature overnight and was then quenched with H 2 O. The mixture was extracted 3 times with ether. The organics were combined, washed with brine, dried over MgSO 4 , concentrated in vacuo to provide 0.444 g (89%) of methyl 3-(4-methoxy-benzenesulfonylamino)-2,6-dimethoxy-isonicotinate as a solid. Electrospray Mass Spec: 382.8 (M+H)+
EXAMPLE 31
Methyl 3-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-2,6-dimethoxy-isonicotinate
The product of Example 30 (0.444 g, 1.16 mmol) was dissolved in DMF (4 mL) and cooled to 0° C. Benzyl bromide (0.186 mL, 1.6 mmol) followed by NaH (56 mg, 1.39 mmol, 60% dispersion in mineral oil) were added and the reaction was allowed to warm to room temperature. After 1 h, the reaction was diluted with water and extracted 4× Et 2 O. The organics were combined, washed with brine, dried over MgSO 4 , concentrated in vacuo to provide 0.545 g (100%) of pure methyl 3-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-2,6-dimethoxy-isonicotinate as an oil. Electrospray Mass Spec: 472.9 (M+H)+
EXAMPLE 32
3-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-2,6-dimethoxy-isonicotinic acid
The product of Example 31 was hydrolyzed to the corresponding carboxylic acid using the procedure of Example 25 to provide 3-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-2,6-dimethoxy-isonicotinic acid. Electrospray Mass Spec; 459.0 (M+H)+
EXAMPLE 33
3-[Benzyl-(4-methoxy-benzenesulfonyl)-amino]-N-hydroxy-2,6-dimethoxy-isonicotinamide
The carboxylic acid product of Example 32 was converted to the corresponding hydroxamic acid, 3-[benzyl-(4-methoxy-benzenesulfonyl)-amino]-N-hydroxy-2,6-dimethoxy-isonicotinamide using the procedure of Example 26. Electrospray Mass Spec: 474.0 (M+H)+
Pharmacology
Procedures for Measuring MMP-1, MMP-9, and MMP-13 Inhibition
These assays are based on the cleavage of a thiopeptide substrates such as Ac-Pro-Leu-Gly(2mercapto-4 methyl-pentanoyl)-Leu-Gly-OEt by the matrix metalloproteinases MMP-1, MMP-13 (collagenases) or MMP-9 (gelatinase), which results in the release of a substrate product that reacts colorimetrically with DTNB (5,5'-dithiobis(2-nitro-benzoic acid)). The enzyme activity is measured by the rate of the color increase. The thiopeptide substrate is made up fresh as a 20 mM stock in 100% DMSO and the DTNB is dissolved in 100% DMSO as a 100 mM stock and stored in the dark at room temperature. Both the substrate and DTNB are diluted together to 1 mM with substrate buffer (50 mM HEPES pH 7.5, 5 mM CaCl 2 ) before use. The stock of enzyme is diluted with assay buffer (50 mM HEPES, pH 7.5, 5 mM CaCl 2 , 0.02% Brij) to the desired final concentration. The assay buffer, enzyme, vehicle or inhibitor, and DTNB/substrate are added in this order to a 96 well plate (total reaction volume of 200 μl) and the increase in color is monitored spectrophotometrically for 5 minutes at 405 nm on a plate reader and the increase in color over time is plotted as a linear line.
Alternatively, a fluorescent peptide substrate is used. In this assay, the peptide substrate contains a fluorescent group and a quenching group. Upon cleavage of the substrate by an MMP, the fluorescence that is generated is quantitated on the fluorescence plate reader. The assay is run in HCBC assay buffer (50 mM HEPES, pH 7.0, 5 mM Ca +2 , 0.02% Brij, 0.5% Cystein), with human recombinant MMP-1, MMP-9, or MMP-13. The substrate is dissolved in methanol and stored frozen in 1 mM aliquots. For the assay, substrate and enzymes are diluted in HCBC buffer to the desired concentration. Compounds are added to the 96 well plate containing enzyme and the reaction is started by the addition of substrate. The reaction is read (excitation 340 nm, emission 444 nm) for 10 min. and the increase in fluorescence over time is plotted as a linear line.
For either the thiopeptide or fluorescent peptide assays, the slope of the line is calculated and represents the reaction rate. The linearity of the reaction rate is confirmed (r 2 >0.85). The mean (x±sem) of the control rate is calculated and compared for statistical significance (p<0.05) with drug-treated rates using Dunnett's multiple comparison test. Dose-response relationships can be generated using multiple doses of drug and IC 50 values with 95% CI are estimated using linear regression.
Procedure for Measuring TACE Inhibition
Using 96-well black microtiter plates, each well receives a solution composed of 10 μL TACE (Immunex, final concentration 1 μg/mL), 70 μL Tris buffer, pH 7.4 containing 10% glycerol (final concentration 10 mM), and 10 μL of test compound solution in DMSO (final concentration 1 μM, DMSO concentration <1%) and incubated for 10 minutes at room temperature. The reaction is initiated by addition of a fluorescent peptidyl substrate (final concentration 100 μM) to each well and then shaking on a shaker for 5 sec.
The reaction is read (excitation 340 nm, emission 420 nm) for 10 min. and the increase in fluorescence over time is plotted as a linear line. The slope of the line is calculated and represents the reaction rate.
The linearity of the reaction rate is confirmed (r 2 >0.85). The mean (s±sem) of the control rate is calculated and compared for statistical significance (p<0.05) with drug-treated rates using Dunnett's multiple comparison test. Dose-response relationships can be generate using multiple doses of drug and IC 50 values with 95% CI are estimated using linear regression.
Results of the above in-vitro matrix metalloproteinase inhibition and TACE inhibition pharmacological assays are given in Table I below.
Table I. Inhibition of MMP and TACE
______________________________________Example MMP-1.sup.1 MMP-9.sup.1 MMP-13.sup.1 TACE.sup.1______________________________________13 19.3(1) 57.3(10)14 40(1) 66.8(10)15 22.1(1) 93016 104.120 638.5 236.4 471.523 48.9(1) 38.4(300) 35(300)26 1000 70 296 42%(1)33 1227 15 47 294______________________________________ .sup.1 1C.sub.50 nM or % inhibition (concentration, μM)
Pharmaceutical Composition
Compounds of this invention may be administered neat or with a pharmaceutical carrier to a patient in need thereof. The pharmaceutical carrier may be solid or liquid.
Applicable solid carriers can include one or more substances which may also act as flavoring agents, lubricants, solubilizers, suspending agents, fillers, glidants, compression aids, binders or tablet-disintegrating agents or an encapsulating material. In powders, the carrier is a finely divided solid which is in admixture with the finely divided active ingredient. In tablets, the active ingredient is mixed with a carrier having the necessary compression properties in suitable proportions and compacted in the shape and size desired. The powders and tablets preferably contain up to 99% of the active ingredient. Suitable solid carriers include, for example, calcium phosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, methyl cellulose, sodium carboxymethyl cellulose, polyvinylpyrrolidin, low melting waxes and ion exchange resins.
Liquid carriers may be used in preparing solutions, suspensions, emulsions, syrups and elixirs. The active ingredient of this invention can be dissolved or suspended in a pharmaceutically acceptable liquid carrier such as water, an organic solvent, a mixture of both or pharmaceutically acceptable oils or fat. The liquid carrier can contain other suitable pharmaceutical additives such a solubilizers, emulsifiers, buffers, preservatives, sweeteners, flavoring agents, suspending agents, thickening agents, colors, viscosity regulators, stabilizers or osmo-regulators. Suitable examples of liquid carriers for oral and parenteral administration include water (particularly containing additives as above, e.g., cellulose derivatives, preferable sodium carboxymethyl cellulose solution), alcohols (including monohydric alcohols and polyhydric alcohols, e.g., glycols) and their derivatives, and oils (e.g., fractionated coconut oil and arachis oil). For parenteral administration the carrier can also be an oily ester such as ethyl oleate and isopropyl myristate. Sterile liquid carriers are used in sterile liquid form compositions for parenteral administration.
Liquid pharmaceutical compositions which are sterile solutions or suspensions can be utilized by, for example, intramuscular, intraperitoneal or subcutaneous injection. Sterile solutions can also be administered intravenously. Oral administration may be either liquid or solid composition form.
The compounds of this invention may be administered rectally in the form of a conventional suppository. For administration by intranasal or intrabronchial inhalation or insufflation, the compounds of this invention may be formulated into an aqueous or partially aqueous solution, which can then be utilized in the form of an aerosol. The compounds of this invention may also be administered transdermally through the use of a transdermal patch containing the active compound and a carrier that is inert to the active compound, is non-toxic to the skin, and allows delivery of the agent for systemic absorption into the blood stream via the skin. The carrier may take any number of rooms such as creams and ointments, pastes, gels, and occlusive devices. The creams and ointments may be viscous liquid or semi-solid emulsions of either the oil in water or water in oil type. Pastes comprised of absorptive powders dispersed in petroleum or hydrophilic petroleum containing the active ingredient may also be suitable. A variety of occlusive devices may be used to release the active ingredient into the blood stream such as a semipermeable membrane covering a reservoir containing the active ingredient with or without a carrier, or a matrix containing the active ingredient. Other occlusive devices are known in the literature.
The dosage to be used in the treatment of a specific patient suffering a MMP or TACE dependent condition must be subjectively determined by the attending physician. The variables involved include the severity of the dysfunction, and the size, age, and response pattern of the patient. Treatment will generally be initiated with small dosages less than the optimum dose of the compound. Thereafter the dosage is increased until the optimum effect under the circumstances is reached. Precise dosages for oral, parenteral, nasal, or intrabronchial administration will be determined by the administering physician based on experience with the individual subject treated and standard medical principles.
Preferably the pharmaceutical composition is in unit dosage form, e.g., as tablets or capsules. In such form, the composition is sub-divided in unit dose containing appropriate quantities of the active ingredient; the unit dosage form can be packaged compositions, for example packed powders, vials, ampoules, prefilled syringes or sachets containing liquids. The unit dosage form can be, for example, a capsule or tablet itself, or it can be the appropriate number of any such compositions in package form.
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The present invention relates to the discovery of novel, low molecular weight, non-peptide inhibitors of matrix metalloproteinases (e.g. gelatinases, stromelysins and collagenases) and TNF-α converting enzyme (TACE, tumor necrosis factor-α converting enzyme) which are useful for the treatment of diseases in which these enzymes are implicated such as arthritis, tumor growth and metastasis, angiogenesis, tissue ulceration, abnormal wound healing, periodontal disease, bone disease, proteinuria, aneurysmal aortic disease, degenerative cartilage loss following traumatic joint injury, demyelinating diseases of the nervous system, graft rejection, cachexia, anorexia, inflammation, fever, insulin resistance, septic shock, congestive heart failure, inflammatory disease of the central nervous system, inflammatory bowel disease, HIV infection, age related macular degeneration, diabetic retinopathy, proliferative vitreoretinopathy, retinopathy of prematurity, ocular inflammation, keratoconus, Sjogren's syndrome, myopia, ocular tumors, ocular angiogenesis/neovascularization. The TACE and MMP inhibiting ortho-sulfonamide aryl hydroxamic acids of the present invention are represented by the formula ##STR1## where the hydroxamic acid moiety and the sulfanamido moiety are bonded to adjacent carbons on group A where A is defined as:
a 5-6 membered heteroaryl having from 1 to 3 heteroatoms independently selected from N, O, and S and optionally substituted by R 1 , R 2 and R 3 ;
and Z, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are described in the specification,
and the pharmaceutically acceptable salts thereof and the optical isomers and diastereomers thereof.
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