MXPA97001613A - Appliance for coating a t - Google Patents

Abstract

An apparatus for coating a fabric (20) includes a supply roll (26) of the fabric (22) and a winder spindle (86) to receive a discrete length of the fabric (22). The fluid is discharged from a coating die (92) in a direction toward the winder spindle (86) to coat the fabric (22) as the fabric (22) is wound around the winder spindle (86). A variable speed pump (108) directs the fluid through the coating die at the feed rate of the fabric (22). The apparatus (20) is particularly useful for coating discrete lengths of an orthopedic splinting and splinting tape that is packaged for the use of a single patient.

Description

APPARATUS FOR COATING A FABRIC BACKGROUND OF THE INVENTION 1__. Field of the invention This invention relates to an apparatus for applying a coating to a fabric. The invention is particularly useful for applying a precise amount of a coating to a discrete length of fabric in automated form. 2. Description of Related Art The fabric coating apparatus is widely used in the manufacture of a variety of articles. For example, the apparatus for coating a fabric is commonly used to manufacture pressure-sensitive adhesive tapes, wherein the adhesive is applied to a fabric that serves as a substrate or backing for the tape. Other examples include an apparatus for manufacturing a photographic film, coated paper, audio, video and data storage tapes, as well as other products. During the manufacture of coated fabrics, it is often desired to regulate the flow rate of the REF: 24120 liquid material applied to the fabric, in such a way that a coating is obtained which generally has a uniform thickness (see for example US-A-4068614). In the manufacture of many articles, coatings are applied by spraying the liquid through nozzles to the fabric at a flow rate that is controlled by valves. Such a practice is generally satisfactory for fabrics that are relatively long once the fabric reaches a constant speed during its displacement after the nozzles. In some cases, valves for fluid control operated by solenoids or variable flow rate pumps have been provided to automatically increase or decrease the flow velocity of the fluid in proportion to the speed of movement of the fabric. In certain other cloth coating processes, a cloth is directed onto a cylinder and is overcoated, or flooded, with a quantity of fluid material. Before the fabric is released from the cylinder and advanced to a winder roll, a blade scrapes the excess fluid from the fabric, such that a smooth, substantially uniform coating is achieved. Overcoating processes for coating fabrics are used for the manufacture of orthopedic splinting or splinting tapes, such as the Scotchcast ™ brand and the Scotchcast Plus ™ brand of synthetic, cast (3M) tape. The Scotchcast ™ brand and the Scotchcast Plus ™ brand of cast, synthetic tape includes a woven, porous fiberglass backing that is coated with a water-curable polyurethane resin. Many processes involving the coating of fabrics include a conversion operation that occurs after the fabric has been coated and wound on an intermediate roll. The conversion operation includes a rewinding or rewinding step, where the intermediate roll is unwinded and the coated cloth is wound into a final roll. The conversion operation includes the cutting steps, such that a relatively long coated fabric is cut into relatively small sections as may be appropriate for the end use. In recent years, there has been an increased interest in ribbons for orthopedic splinting and plaster that are available in a variety of colors. The Scotchcast ™ brand casting tape and the Scotchcast Plus ™ brand, for example, include a resin having suitable colorants to provide a desired color. Some individuals ask for the emptying tape with bright colors, while others ask for the emptying tapes that are less striking. Unfortunately, the polyurethane resin is tough and difficult to clean from the overcoating apparatus and the conversion apparatus at the end of a coating operation, causing difficulties when attempts are made to manufacture ribbons cast in different colors. In addition, the resin immediately begins to heal when exposed to ambient air, due to the moisture vapor that is present in the air. For these reasons, the cleaning of the overcoating apparatus and the conversion apparatus is typically a laborious, time-consuming task that often involves the use of hazardous solvents. Another issue during the operations of coating the fabric is the amount of tension that is present in the finished coated fabric. For example, orthopedic casting tape having a woven, porous glass fiber backing is an advantage in that the backing can be stretched as needed, when applied to the patient to conform to the anatomy of the patient. During the manufacture of such a casting tape, it is advantageous to roll the tape into a final roll, in which the glass fiber backing as packaged is not stretched to any significant degree. The backing is then capable of being stretched when needed during application as the final roll is unrolled to facilitate forming the tape to the patient's anatomy. The desirability of a coated fabric that is packaged in roll form in a substantially unstretched condition is not limited to coated fabrics used in the orthopedic field. For example, it may be advantageous to provide a fabric impregnated with resin in an unstretched state for use in the construction or repair of automotive, marine or aerospace bodies, such that the backrest can be stretched as needed by the user and shaped to an appropriate configuration. Many conventional fabric coatings and conversion operations are carried out by applying tension to a fabric to keep the fabric taut. Such processes may be suitable for the coating of non-elastic fabrics, but are generally unsatisfactory for the covering of elastic fabrics such as backs of an orthopedic tape. In addition, if sufficient tension is applied to the fabric during the coating operation to stretch the fabric past its point of deformation, the fabric can no longer have physical characteristics that are suitable for its intended use.

BRIEF DESCRIPTION OF THE INVENTION The present invention in one embodiment is directed toward a fabric coating apparatus that includes a supply roll having a quantity of fabric and a winder spindle to receive at least a portion of the fabric from the supply roll. Means are provided for directing a leading edge portion of the fabric toward a winder spindle. The apparatus also includes a variable speed drive to rotate the winder spindle to wind the fabric around the winder spindle, and a controller connected to the drive mechanism to control the speed of rotation of the winder spindle. A source of fluid is provided and a pump is connected to the fluid source. The tubing is in communication with the pump and the fluid source and the tubing includes at least one outlet for directing the fluid on the fabric. The medium is connected to the controller to automatically increase and decrease the flow velocity of the fluid through at least one outlet in proportion to the speed of movement of the fabric. A cutter is connected to the controller to cut the fabric lengthwise. Another embodiment of the invention is directed to a fabric coating apparatus comprising a supply roll having an amount of fabric and a winder spindle to receive at least a portion of the fabric of the supply roll. A drive mechanism is provided to advance the web of the supply roll to the winder spindle. A source of fluid is provided for coating the fabric and a pump is connected to the fluid source. The tubing is in communication with the pump and the tubing includes an outlet that is located in a position to discharge the fluid directly onto the portion of the fabric that has been received over the winder spindle, to coat the fabric as the fabric is received on the winder spindle. The present invention in another embodiment is directed to a method of coating a fabric and comprises the step of winding a length of fabric around a winder spindle. The method further includes the step of directing a fluid directly over a portion of the fabric that has been received over the winder spindle, to coat the fabric as the fabric is wound around the winder spindle. The present invention provides a significant advantage over the fabric coating apparatus and conventional methods, in that the conversion operation can be eliminated in such a way that the capital costs and costs associated with the cleaning of the apparatus are substantially reduced. The invention is particularly suitable for coating relatively short lengths of fabric, which are individually packaged and can be transported in such a way that the fabric is not stretched to any significant degree during the coating operation or once packaged in roll form. Other details of the invention are defined in the features of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side elevational view in partially schematic form of a fabric coating apparatus according to the principles of the present invention and in which an automated fabric uncoiling and cutting apparatus is also shown; Figure 2 is an enlarged side elevational view in partially schematic form of a portion of the fabric coating apparatus illustrated in Figure 1; Figure 3 is a view somewhat similar to Figure 2, except that a fabric has descended from its orientation shown in Figure 2, the air stream assembly is advanced towards a leading edge of the fabric and a coating matrix a rotary winder spindle is advanced to apply fluid to a core received in the winder spindle; Figure 4 is a view somewhat similar to Figure 3, except that the leading edge of the fabric is partially wound around the winder spindle, the air stream assembly is retracted to an intermediate portion and the additional fluid has been applied to the core; Figure 5 is a view somewhat similar to Figure 4, except that the coating matrix has been -sworn slightly separating it from the spindle as the additional fabric is wound around the core; Figure 6 is a view somewhat similar to the Figure 5, but in which the coating matrix is illustrated as moving away from the spindle, in which the additional bead has been wound around the core, in which a cutter has been advanced to cut the fabric and in which the air stream assembly has been advanced promptly to push the trailing edge of the fabric towards the winder spindle; Figure 7 is a view somewhat similar to the Figure 6, except that the trailing edge of the fabric has been wound around the spindle, the coating matrix has been moved away from the winder spindle, the air stream assembly has been retracted to its intermediate position and the cutter has been retracted for allow the subsequent passage of the fabric; Figure 8 is a schematic illustration showing the functional relationship of certain elements of the apparatus together with a controller for controlling the various elements; and Figure 9 is an exemplary synchronization diagram, which illustrates the sequence of operation of the various elements.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Initially with reference to Figure 1, an automated fabric coating apparatus is broadly designated by the numeral 20 and is adapted to apply an accurately measured amount of a fluid or coating to an elongated fabric 22. The apparatus 20 receives the fabric 22 from an automated unwinding and cutting apparatus 24. The unwinding and cutting apparatus 24 contains many rolls 26 initially separated (for example, up to ten rolls) from the fabric material. Up to five rolls 26 are supported on each of the two carriages 28. As a roll 26 is depleted, a detector detects the trailing edge of the fabric material and a pair of cutting members 29 are activated to push a leading edge of the fabric. another roll 26 in contact with the trailing edge of the spent roll 26. A section of pressure sensitive adhesive tape, having adhesive on both sides and previously fixed to a leading edge portion of the waiting roll 26, joins the leading edge portion of the roll 26 that awaits the rear edge portion of the roll 26 exhausted to cut the cloth material together. After each roll 26 is unwound, its support carriage 28 is advanced to bring another roll 26 into a standby position for subsequent cutting and unrolling.

The fabric coating apparatus 20 includes a de-tensioning device 30 to decrease the tension in the fabric as it moves along its travel path. The deceleration device 30 is located immediately downstream of the unwinding and cutting apparatus 24 and includes a drive roller 34 and a clamping pressure roller 36. Both of the rollers 34, 36 are covered with a synthetic rubber material having a hardness of about 60 durometer. The driving roller 34 is mounted on a horizontal axis, which is connected to a variable speed motor, CD ( model No. CDB 3538-11, from Baldor) shown schematically in Figure 8. The motor 35 is connected to a servo unit 37 (Brushless CD Unit BR from Saftronics). The motor 35 is operable to rotate the roller 34 about a horizontal axis. A bearing block connects the shaft to a frame 32 of the de-tensioning device 30. The roller 36 is mounted on a bracket that is connected to a piston rod of a double-acting pneumatic piston and the cylinder assembly 38 (model No. SE5-4.0, Mills Specialty Products). The piston of the piston and cylinder assembly 38 is movable in a horizontal direction to move the roller 36 either towards or away from the roller 34.

A programmable logic controller 40 (series 90-30; GE Fanuc), shown schematically in Figure 8, is electrically connected to the solenoid-operated air valves, which are inter-arranged in separate lengths of pipe that interconnect a source of pressurized air and each end of the cylinder of the piston and cylinder assembly 38. As such, the controller 40 is operable to open or close the fastener between the rollers 34, 36. The controller 40 is also electrically connected to the unit 37. An inactive roller 42 is mounted on a fixed axis to the frame 32 in a horizontally adjacent position to the roller 36. The slant chamber 44 having an open top portion is located below the rollers 36, 42. As the cloth 22 passes from the point of clamping between the rollers 34, 36 and the roller 42, a Fabric section 22 hangs freely in chamber 44 as illustrated in Figure 1. Air bellows 46 (model No. R4310A-2; Gast Mfg. Corp.) is electrically connected to the controller 40. The air bellows 46 is connected by flexible tubing to an opening near the lower end of the chamber 44. When the air bellows 46 is activated by the controller 40, the air bellows 46 it draws air through the chamber 44 in a downward direction, to facilitate the fabric 22 to hang without becoming entangled, generally in a U-shaped configuration with no appreciable tension. Four photocells 48 are mounted on the frame 32 in a vertically spaced arrangement, near the lower end of one side of the chamber 44 and each photocell 48 is positioned to receive light from one of four light sources 50 located on the opposite side of the chamber 44. A fifth photocell 52 is mounted on the frame 32 near the upper end of the chamber 44 and is arranged to receive light from a light source 54 mounted on the opposite side of the chamber 44. The photocells 48, 52 and the light sources 50, 54 are all connected to the controller 40. The lower photocells 48 provide an indication to the controller 40 of the extension of the fabric 22 hanging in the chamber 44. When, for example, the upper photocell of the four photocells 48 detect light from the upper light source 50, the controller 40 increases the speed of the motor 35 connected to the roller 34 to increase the extension of the fabric 22 hanging in the chamber 44. By On the other hand, if the lower photocell of the four photocells 48 fails to detect light from the lower light source of the light sources 50, the speed of the motor 35 is decreased to decrease the length of the fabric 22 hanging in the chamber 44. .

The fifth photocell 52 provides an emergency function. If, for example, the photocell 52 detects light from the light source 54, the extension of the fabric 22 hanging in the chamber 44 is almost exhausted as it should occur, for example when the fabric supply of the unwinding and cutting apparatus 24 is exhausted, or when the fabric 22 is stuck in the apparatus 24 and is unable to move forward. In such a case, the controller 40 will immediately interrupt another operation of the apparatus 20 and provide a signal to the operator that attention is needed. A brush 56 is fixed to the frame 32 and is immediately mounted downwardly of the idle roll 42 for contact with the cloth 22, as the cloth 22 advances. Another brush 58, similar to the brush 56, is fixed to the frame 32 immediately downward from the fastening point between the rollers 34, 36 for engagement with the advancing fabric 22. The brushes 56, 58 are made of carbon fiber or stainless steel and reduce the amount of static electricity in the fabric 22. The cloth coating apparatus 20 includes a second frame 60 which is secured to and optionally integral with the frame 32. An inclined guide 62 is mounted on the brackets fixed to the frame 60. The guide 62 has a channel that receives and guides the movement of the fabric 22 as the latter advances from the inactive roller 42 and towards a point of attachment between a roller 64 meter and a clamping pressure roller 66. The clamping pressure roller 66 rotates in the bearings about an axis that is fixed to a bracket. The bracket is connected to a piston rod of a double-acting piston and cylinder assembly 68 (model SE5-4.0, Mills Specialty Products). Each end of the cylinder of the cylinder and piston assembly 68 is connected by pipe to the source of pressurized air mentioned in the above. The piston and cylinder assembly 68 is connected by the brackets to the frame 60. A pair of solenoid operated air valves are interposed in the pipe, interconnecting the pressurized air source and the piston and cylinder assembly 68 and the air valves. they are electrically connected to the controller 40. As such, the controller 40 can open or close the clamping point between the rollers 64, 66 when desired. Both of the rollers 64, 66 are covered with synthetic rubber material having a durometer hardness of 60 and which is similar to the synthetic rubber material on the rollers 34, 36. The measuring roller 64 is connected to a shaft supported by bearings which are connected to the frame 60. The roller 64 and the shaft are connected to a servomotor 70 (model DXM-340; Emerson Electronic Motor Controls) for rotation about a horizontal axis. The servomotor 70 is illustrated schematically in Figure 8 and is electronically connected to a servo unit 72 (PCM-5 ratio controller, Model No. DXA-340, from Emerson Electronic Motor Controls) which is electrically connected to the controller 40. The servomotor 70 includes a separator installed, connected to the servo unit 72 to confirm the rotary position of the servomotor 70 and therefore of the measuring roller 64 every time the apparatus 20 is in operation. A brush 74, similar to the brushes 56, 58 is optionally mounted immediately below the measuring roller 64 for contact with the passing fabric 22 to reduce any static electricity load on the fabric 22. As another option, the element 76 which reduces the static electricity of ionized, electric gas (such as the Shockless Static Bar, Model No. D1G7RY, from Simco Co.) is mounted to the frame 60 below the clamping pressure roller 66 or optionally below the measuring roller 64 in the space occupied by the brush 74 in Figures 1-7. Alternatively, a nuclear ionizer or a high voltage ionizer can be used to reduce the charge of static electricity in the fabric 22. As illustrated in Figure 1, as well as in Figures 2-7, a stationary guide member 78 it is fixed to the frame 60 below the clamping point between the rollers 64, 66 and includes a vertical channel to guide the movement of the fabric 22 as it descends. From the guide member 78, the fabric 22 passes through an opening of a cutter (model SC-6); Azco Corp.). The cutter includes a guillotine-type cutting blade 80 as well as an anvil 82. The blade 80 is connected to a piston rod of a double-acting piston and pneumatic cylinder assembly 84. A pair of solenoid operated air valves are connected to a pipe interconnecting the pressurized air source and each end of the cylinder of the piston and cylinder assembly 84, and the air valves are electrically connected to the controller 40. A spindle 86 winder it includes an axis that is connected to a servomotor 88 (model No. DXE-316W; Emerson Electronic Motor Controls). The shaft rotates about a horizontal axis that is below and laterally offset from a vertical reference axis, which passes through the channel of the guide member 78 and the cutter channel. The servomotor 88 is electrically connected to a servo unit 90 (PCM-5 Model No. DXA-340 proportion controller, from Emerson Electronic Motor Controls) and includes a separator to confirm the rotary position of the winder spindle 86 each time. As illustrated in Figure 8, the servo unit 90 is electrically connected and is a repeater for the servo unit 72. A coating die assembly 92, shown in greater detail in Figures 2-7, is mounted on one side of and slightly above the winding spindle 86. The coating die assembly 92 includes a screw drive mechanism 94 (THM LM guide driver) having a subframe secured by brackets to the frame 60. The mechanism 94 includes a slide carriage 96 that is movable along a channel upper of the sub-frame in a direction inclined up or down. A screw unit of the screwing mechanism 94 is rotatably driven by a servo motor 98. (model DXM-205; Emerson Electronic Motor Controls) that is mounted on the sub-frame. The servomotor 98 is electrically connected to a servo unit 100 (PCM-5 ratio controller, Model No. DXA-340 from Emerson Electronic Motor Controls) which in turn is electrically connected to and is a repeater for the servo unit 90 as shown schematically in Figure 8. A coating die 102 is detachably mounted on a bracket that is located at the upper end of the slide carriage 96. The cover die includes an inlet duct, an outlet duct and an inner cylindrical chamber, which serves as a distributor to distribute the fluid that enters from the inlet duct to all regions of the outlet duct. The outlet duct has a width that is approximately equal to the width of the cloth 22 and preferably includes a series of separate nozzles, so that an aligned arrangement of separate, separate outlets is provided. Each nozzle is made of a rigid metal tube that has a flattened outer end. An insert is slidably received, removably in the chamber of the cover matrix 102 and includes a body portion with a shape that is adapted to distribute fluid at equal flow rates, through each of the nozzles through the width of the coating matrix 102. For this purpose, the body portion of the insert is machined in a lathe to a configuration, such as a dog bone shape or a convex shape as may be needed to provide equal fluid flow velocities through each outlet of the conduit. departure. Preferably, the cover matrix 102 also includes a channel extending through the die housing parallel to the chamber. The channel is connected to a source of hot water or other fluid controlled by the controller 40, to raise the temperature of the matrix housing above room temperature to increase the flow of fluid moving through the chamber. A thermocouple is also connected to the matrix housing and electrically connected to the controller 40 to monitor the temperature of the housing. The coating die 102 is part of the line 104 for directing the fluid from a fluid source 106 on the fabric 22. The fluid source 106 comprises a 5 gallon (19 liter) storage cylinder having a cover and a gas dry such as nitrogen by purging the cylinder to prevent curing of the fluid (which, as described in the following, may be a water-curable synthetic resinous material). An electric heater is also connected to the storage cylinder of the fluid source 106 to maintain fluid in the cylinder at a temperature of about 50 ° C. The heater for the fluid source 106, as well as a thermocouple for monitoring the temperature of the fluid source 106, are electrically connected to the controller 40. The line 104 includes a section of tubing interconnecting the fluid source 106 and a pump 108, as well as a second pipe section interconnecting the pump 108 and the coating die 102. The pump 108 is a gear pump (100 cc / rev, gear reduction 20/1, series BPB, from Zenith) which it is rotated by a servomotor 110 (model No. DXM-6120, Emerson Electronic Motor Controls). The servomotor 110 is electrically connected to a servo unit 112 (PCM-5 model controller Model No. DXA-340, from Emerson Electronic Motor Controls) which is illustrated schematically in Figure 8. The servo unit 112 is electrically connected and is a repeater for the servo unit 72. In this way the servo unit 112 represents a means for automatically increasing or decreasing the fluid flow velocity through the outlet of the die, in proportion to the rotational speed of the measuring roll 66, for the rotational speed of the winder spindle 86 and therefore also the speed of movement of the fabric 22. The servomotor 110 includes a repeater to confirm its rotational position. Preferably, a dye injection system is provided for injecting a colorant into line 104 and specifically into the second section of the line interconnecting pump 108 and coating matrix 102. The colorant injection system includes a container ( not shown) to retain a quantity of colorant and a gear pump (gear production 3/1, 1168 cc / rev., BPB series); from Zenith) connected by a third section of pipe to the container. A fourth section of the pipe is connected to the pump and the second section of the pipe. A static mixer is located in the second section of the tubing downstream of its junction with the fourth section of the tubing and completely mixes the colorant with the resin or other fluid from the fluid source 106. The dye injection pump is driven by a servo motor 111 (VN-MD; S3016, from Emerson Electronic Motor Controls) which is shown schematically in Figure 8. The servo motor is connected by a right angle unit (Model No. MH015A129- 2, Textron) to the pump. The servomotor is electrically connected to a servo unit 113 (controller of the electronic synchronous ratio PCM-2S Model No. DXA-318, from Emerson Electronic Motor Controls) which in turn is electrically connected and a repeater for the servo unit 112. A mounting 114 of air stream slider includes a support 116, which is fixed to the frame 60. A first slider 118 of the assembly 114 is slidably connected to the support 116 and is guided for movement by a piston rod of a piston and cylinder assembly 120 pneumatic, double action (Model No. SE2-4.0, Mills Specialty Products). The piston and cylinder assembly 120 is connected by the pipe to the aforementioned pressurized air source. The solenoid-operated air valves connected to the pipeline are electrically connected to the controller 40 for horizontal movement of the first slide 118 relative to the housing 115, when desired. The air stream slider assembly 114 also includes a second slider 122, which is slidably connected to the support 116. The second slider 122 is connected to a piston rod in a dual-action piston and pneumatic cylinder assembly 124 (Model No. SE2-4.0, from Mills Specialty Products) that is connected by the pipe to the pressurized air source. The solenoid-operated air valves connected to the pipe are electrically connected to the controller 40 to move the second slide 122 relative to the support 116 horizontally when desired. A bar 125 is fixed to the first slide 118 and extends vertically upwardly for releasable contact with the second slide 122. As the first slide 118 is moved by the piston and cylinder assembly 120 to a fully extended position (it is say, towards the right side of Figures 1-7), the bar 125 engages the second slide 122 and moves the latter in synchronization with the movement of the first slide 118. When the second slide 122 moves to a fully extended position by the piston and cylinder assembly 124, in the cases when the first slide 118 is fully extended, the second slide 122 decouples the bar 125 and moves it so that it moves to its previous position that was directly adjacent to the first slide 118. air nozzle 126 having a series of separate air outlets, is secured to a front end of the second slider 122. Air nozzle 126 is connected through the pipe to the pressurized air source and a solenoid operated air valve connected to the controller 40 allows the air nozzle 126 to emit a pressurized air jet when desired. The air stream slider assembly 114 is shown in its fully retracted position in Figures 2 and 7. In Figure 3, both of the first slider 118 and the second slider 122 are shown in their extended orientation. In Figures 4-6, the first slide 118 is in its extended position, while the second slide 122 is in its retracted position. The assembly 114 serves as a means for pushing the leading and trailing edge of the discrete length of the fabric 22 toward and in contact with the winder spindle 86. The operation of coating the fabric 22 with fluid will now be described. Figure 9 is an exemplary timing chart of the cloth coating apparatus 20, illustrating the sequence of movement of various elements over a relatively short period of time, eg, 2.68 seconds) to cover a discrete length of the fabric 22. Figure 2 illustrates the apparatus 20 as schematically displayed at time 0.00 on the graph of synchronization, at the beginning of a coating operation. The drive roller 34 is controlled for rotational movement by the controller. 40, independently of the movement of the servomotors 70, 88, 98 or 110. In Figure 2, the leading edge of the fabric 22 is located just above the blade 80 and a polypropylene core 128 has been placed in the spindle 86. winder The core 128 includes a longitudinally extending projecting tongue which is received in a mating slot of the winder spindle 86. As shown in Figure 9, the servomotor 98 for the coating die assembly 92 is activated by the initiation of a coating cycle. The servomotor 98 is rotated to move the carriage 96 and the die 102 toward the core 128. Immediately thereafter, the servomotor 110 is energized to rotate the pump 108 slowly, or in a "drip" fashion, to ensure that the fluid in the coating matrix 102 is then present at the die output in readiness for application.

At 0.10 seconds, the servomotors 70, 88 are energized to rotate the measuring roller 64 and the winder spindle 86, respectively. At the same time, the speed of the servomotor 110 is increased, such that the pump 108 increases the fluid flow rate in the line 104. As a consequence, the fluid is immediately discharged from the coating matrix 102 in the core 128 to as the latter rotates. The servomotor 98 continues to rotate for an additional 0.05 seconds to bring the cover matrix 102 a little closer to the core 128. At 0.15 seconds, however, the servomotor 98 reverses the direction to cause the carriage 96 and the cover matrix 102 begin to ascend in a direction away from the spindle 86 winder. Both slides 118, 122 also begin to extend at this time. Figure 3 illustrates the apparatus 20 at 0.325 seconds in the coating cycle. At this time, the leading edge of the fabric 22 has descended to a position horizontally adjacent to the air nozzle 126 and slightly less than a half of the periphery of the core 128 has been coated with fluid. At 0.325 seconds, the rotation of the servomotors 70, 88, 98 and 110 is interrupted, although the piston and cylinder assemblies 120, 124 continue to move the slides 118, 122 towards their respective fully extended orientations. At 0.35 seconds, the pressurized air is supplied to the air nozzle 126 to push the leading edge of the fabric 22 into contact with the fluid present in the core 128. The fluid is tenacious and easily joins the leading edge to the core 128. At 0.425 seconds, the servomotors 70, 88, 98 and 110 are energized to begin winding the fabric 22 in the core 128. As the fabric 22 is wound on the core 128, the coating die assembly 92 continue to coat the remaining portions of the core 128 and then apply a fluid coating to the fabric 22 as it passes during winding in the core 128. At 0.70 seconds, the air for the air nozzle 126 and the assembly is interrupted 124 of piston and cylinder is operated to retract the second slide 122 to the position shown in Figure 4. Figure 5 is a schematic illustration of the apparatus 20 after 0.775 seconds of operation of a cycle. At this time, approximately two wraps of the fabric 22 have been received in the core 128. Next, all the servomotors 70, 88, 98 and 110 are increased in speed and continue to run at the increased speed up to 1,975 seconds. As can be seen by comparison of Figures 4, 5 and 6, the movement of the carriage 96 supporting the coating die 102 is synchronized with the winding of the fabric 22 in the core 128. As a consequence, the output of the coating matrix 102 is spaced approximately the same distance from fabric 22 (or core 128 at the beginning of the operation) to facilitate the application of a coating having a uniform thickness. As the diameter of the coated roll of fabric over the spindle 86 increases, the servomotors 88, 98 decrease in speed relative to the speed of the servo motor 70 to couple the linear speed of the fabric 22 as it advances to the spindle 86. At 1,975 seconds, the rotation of the servomotor 110 is reversed to allow the pump 108 to draw or "suck back" a small amount of fluid into the coating die 102. Such a stage facilitates control of the fluid stream, such that drip or leakage of water is avoided. Immediately after 2.05 seconds, the servo motors 70, 88 and 98 are energized again to wind an additional short length of the fabric 22 over the underlying roller that has been previously coated with fluid. At 2.125 seconds, the servo motor 70 of the measuring roller is rotated slightly to eliminate any tension, in the downward portions of the fabric 22 and the piston and cylinder assembly 84 is driven to move the blade 80 towards the anvil 82 and cut the fabric 22 as illustrated in Figure 6. The pressurized air is directed through the the air nozzle 126 at 2225 seconds and at 2.25 seconds the servomotor 88 is energized again to allow the rear end portion of the cutting length of the fabric to be wound on the roller at the winding spindle 86. Both of the pressurized air for the air and power nozzle 126 of servomotor 88 continues up to 2.60 seconds. Advantageously, as can be seen by reference to Figure 6, the cut but the undrawn portion of the fabric 22 (i.e., the free end portion of the fabric 22 after cutting) has a length that is approximately equal to the length of the coating applied to the fabric wound in a circumferential direction, such that little, if any, excess coating is present on the outside of the finished wrapped fabric. At 2.60 seconds, the air pressure to the nozzle 126 is interrupted and the servomotor 88 is de-energized to stop the rotation of the winder spindle 86. At 2.60 seconds, the air pressure is directed to the cylinder of the piston and cylinder assembly 120 to retract the first slider 118, such that the air stream slider assembly 114 is returned to its fully retracted position. Figure 7 is an illustration of apparatus 20 at 2675 seconds. The winding, the discrete length of coated cloth 22 and the core 128 are then immediately removed from the spindle 86 and packaged to avoid any of the adverse effects that may occur from exposure of the fluid to the atmosphere. Optionally, a removal mechanism comprising a slide plate along the spindle 86 may be provided. The plate is connected to a piston rod of a double action pneumatic piston and cylinder assembly which is connected by the solenoid operated air valves to a source of pressurized air. The air valves are electrically coupled to the controller 40 for movement of the plate to eject the coated fabric and the spindle core 86 horizontally once the air stream slider assembly 114 has retracted. As another option, the winder spindle 86 is not directly connected to the frame 60, but on the contrary is a spindle of (for example such as 8) of the multiple winder spindles which are mounted on a horizontal turntable. The rotary table is rotatable about a vertical axis by a servomotor that is connected to a servo unit connected to the controller 40. The rotary table is rotated in increments about a partial arc to sequentially carry each winder spindle to the position of the winder spindle shown in Figures 1-7. Preferably, a core feeding apparatus places a core such as the core 128 in each spindle before the spindle reaches the position of the spindle 86 shown in Figures 1-7. In addition, an automated removal mechanism is provided to remove the length of coated cloth 22, wound from each spindle after the spindle has been moved away from the position shown in Figures 1-7. The removal mechanism includes a pair of fingers that are movable to pull the coated and core fabric arriving from each spindle on a semi-cylindrical, concave groove of a transport guide. Then the guide is swung up around a horizontal axis to find a semi-cylindrical, vertical, stationary guide. Next, the push rod pushes the coated fabric and the core to descend through the adjacent semi-cylindrical guides and into a packaging machine. Preferably, the controller 40 is the same controller, or is electrically connected to a controller, which is controlling the operation of the unwinding and cutting apparatus 24. The controller 40 determines the location of any of the cuts that arrive, which may be present in the web 22 that advances. Once the cut portion of the fabric 22 has been wound on a core 123 received on the rotating table and the rotating table is advanced, a second pair of fingers located upwardly of the semi-cylindrical transport guide pulls the cut cloth and the core in a waste deposit for disposal. The apparatus 20 is particularly useful for the manufacture of an orthopedic splinting or splinting tape, such as the Scotchcast ™ brand or the Scotchcast Plus ™ plastering tape in single patient lengths. Such tape is coated with a water curable polyurethane resin as described in U.S. Patent Nos. 4,570,622, 4,502,479, 4,667,661 and 4,774,937. A suitable fabric is a woven, porous, annealed fiberglass material as described in U.S. Patent No. 4,609,578. Water-curable polyurethane resins used in an orthopedic splinting and splinting tape begin to heal when exposed to water vapor in the atmosphere. For this reason, the apparatus 20 is particularly useful in the manufacture of discrete lengths of the tape that are of a size (such as 3.6 m or 12 feet) that is adapted for use by a single patient. If desired, the apparatus 20 can be used in a dehumidified room to reduce the likelihood of improper curing of the resin. Alternatively, a cover or screen can be placed on the frame 60 and purged with a dry gas such as dehumidified air or nitrogen. Preferably, the length of coiled, coated discrete cloth 22 is packed immediately after coating and before the resin has a chance to absorb any significant amount of moisture. Preferably, the apparatus 20 is adapted to allow the coating of fabrics having different widths. For example, the typical widths for the orthopedic casting tape can be in the range of about 2.5 cm (1.0 inches) to about 12.5 cm (5.0 inches). The various rollers such as the rollers 34, 36, 42, 64, 66 and the guides 62 are wider than the expected widest fabric and the sides of the chamber 44 are adjustable, so that fabrics of various widths can be adjusted. As can now be appreciated, the metering roller 64, the winder spindle 86 and the servomotors 70, 88 serve as a means for advancing the fabric 22 from the supply roll 26 to the winder spindle 86 and for winding the fabric 22 around the winder spindle. 86. Other driving mechanisms are also possible. For example, the measuring roller 64 and the winder spindle 86 can be driven by other types of motors or devices for advancing the fabric. Some of the motors (i.e., servomotors 88 and 98) can be replaced by a single common motor that utilizes an appropriate motion transfer means, such as a toothed belt or a drive chain. It can also be seen that the servo unit 112 comprises a means for increasing or decreasing the fluid flow rate through the outputs of the coating die 102 in synchronous coordination, timed with the movement of the fabric 22 and in proportion to the speed of the movement or winding of the web 22 as it proceeds along its travel path to the winder spindle 86. Other means are also possible. For example, the pump 108 can be mechanically attached to the measuring roller 64, such that both of the measurement roller 64 and the pump 108 rotate simultaneously and the fluid is discharged through the outlets of the coating matrix 102 in coordination with the movement of the fabric 22. As another option, the detectors operable to determine the movement or speed of displacement of the fabric 22 can be electrically connected to a controller that consequently energizes the servomotor of the pump 110. It can also be seen that the present invention is an advantage, in which little cleaning of the apparatus 20 is necessary to change the fluid, as it must happen for example, when the resins of a different color are used. More specifically, while the coating matrix 102 directs fluids only to the fabric 22 and the core 28, little cleaning, if any, of other adjacent areas of the apparatus 20 will be necessary apart from cleaning the coating die assembly. , pipe 104 and pump 108. Other changes or additions to the embodiments described in detail in the foregoing may also be apparent to those skilled in the art. Thus, the scope of the present invention should not be limited to the currently preferred embodiments described in the foregoing, but only by the following claims and their equivalents. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, the content of the following is claimed as property.

Claims (11)

1. An apparatus for coating cloth, characterized in that it comprises: a supply roll having a quantity of fabric; a winder spindle for receiving a length of the fabric from the supply roll; a variable speed drive for rotating the winder spindle to wind the fabric around the winder spindle; a controller connected to the drive to control the speed of rotation of the winder spindle; a source of fluid; a pump connected to the fluid source; pipe which communicates with the pump and the fluid source, the pipe includes at least one outlet for directing the fluid on the fabric; a means connected to the controller for automatically increasing and decreasing the speed of fluid flow through at least one outlet in proportion to the speed of movement of the fabric; characterized in that the apparatus comprises a means for directing a leading edge portion of the fabric toward the freewheel spindle; and a cutter connected to the controller to cut the fabric in a discrete length.

2. The apparatus according to claim 1, characterized in that the means for directing a leading edge of the fabric towards the winder spindle, is also operable to direct a rear edge portion of the length of the fabric towards the winder spindle after which. the cutter has cut the fabric.

3. The apparatus according to claim 1, characterized in that the means for directing a leading edge portion of the fabric towards the winder spindle includes an air nozzle to direct a stream of pressurized air -to the winder spindle.

4. The apparatus according to claim 1, characterized in that at least one outlet is movable away from the winder spindle as the fabric is received on the winder spindle.

5. A fabric coating apparatus comprising: a supply roll having a quantity of fabric; a winder spindle for receiving at least a portion of the fabric of the supply roll; a drive mechanism for advancing the fabric from the supply roll to the winder spindle; a source of fluid to coat the fabric; a pump connected to the fluid source; and tubing in communication with the pump, characterized in that the tubing includes at least one outlet that is located in a position to discharge the fluid directly onto the portion of the fabric, which has been received on the coil spindle to coat the custom fabric that the fabric is received in the spindle of the winder.

6. The apparatus according to claim 5, characterized in that at least one outlet is movable away from the winder spindle as the fabric is received on the winder spindle.

7. The apparatus according to claim 5, characterized in that it includes an air nozzle located next to the winder spindle to push the leading edge of the fabric toward the winder spindle.

8. A method for coating a fabric, comprising the steps of: winding a length of the fabric around a winder spindle; and directing a fluid directly on the fabric, characterized in that the step of directing a fluid on the fabric comprises the step of directing the fluid directly on a portion of the fabric that has been received on the coil spindle, to coat the fabric as the fabric is wound around the spindle of the winder.

9. The method in accordance with the claim 8, characterized in that the step of directing a fluid to the winder spindle comprises the steps of passing the fluid through at least one outlet and moving the outlet away from the winder spindle as the fabric is wound around the winder spindle.

10. The method according to claim 8, characterized in that it includes the initial steps of advancing a leading edge portion of the fabric toward the winder spindle, and directing a pressurized stream of gas toward the leading edge portion of the fabric to push the front edge portion towards the winder spindle.

11. The method according to claim 8, characterized in that it includes the step of varying the fluid flow velocity according to the winding speed of the fabric around the winder spindle.