Patent GB-295880-A (GB)
Title: Improvements in apparatus for coating strips
IPC: A43D25/18
Filed: 1927-11-29
Abstract: 295,880. Hansen, S. M., and Farco Specialty Co. Nov. 29, 1927. Coating webs; apparatus for making compound fabrics. - Adhesive tape which may be fabric covered and used for purposes such as binding tapes for shoes or strips for surgical dressings is produced by a machine in which the tape is fed continuously under a valve controlled outlet from a tank 10, Fig. 1 containing cementitious matter and is afterwards dried and covered by a strip of fabric. The cylindrical valve 13, Fig. 20, is automatically and gradually closed when the feed ceases and opened abruptly when the feed commences. The tank may be connected to a source of fluid pressure and the strip may be coated over a part only of the width of the strip. The strip may be coated near one margin only or near both margins only, means being provided to determine the width of the coated part or parts and the thickness of the coating. Automatic stop motions are provided to operate when a predetermined length of tape has been coated and when the tape slackens or breaks. The supply tank is sealed as shown in Fig. 9 by a removable cover 250 having an annular groove 256 for a compressible gasket 255 arranged between the walls of the tank and the cover, pressure means 254 coacting with a slotted lug 253 on the cover. The base of the supply tank is funnel-shaped as shown in Fig. 20, the cylindrical valve 13 having a correspondingly-shaped aperture 16 leading in the position shown to an outlet passage 15 beneath which the strip 14 to be coated is supported by a spring-pressed work support 20. The outlet passage 15 may be formed in a removable and replaceable shoe, which may be provided with two apertures to allow the adhesive being applied in two narrow strips. This shoe may be replaced by others which feed a different width or depth of the cementitious material. The tape passes from a spool 30, Figs. 1 and 5, through a tensioning device 31, which may comprise a series of staggered pins, to a position beneath the tank 10 at G from which after coating it is fed round a large electrically-heated drying drum D, and a co-operating roller 46, the tape passing spirally in grooves round the drum and roller. A tensioning device 39 and a comb beneath the teeth of which the convolutions of the strip pass, maintain the strip in proper relationship with the grooves. A measuring device M receives the tape from the drying drum and consists of cooperating rollers 70, 71 provided with grooves for the tape. The periphery of the roller 71 is of such dimension that a yard, say, of the tape is wrapped round in each rotation of the shaft 79 on which the roller is mounted, and when the required amount of tape for which the machine is set has been fed the automatic stop motion illustrated in Fig. 13 comes into operation to stop the machine. A stop 92 capable of being set to any position on a graduated guide 91 determines the starting position of the traverse of a collar 90 attached to a pivoted arm 89 which carries a half nut 82 moving along a screw 86. The arm 89 also carries a pin 101 which at the end of the traverse of the half nut engages a shoulder on a stop member 100, thereby lifting the half nut out of engagement with its screw. The disengagement of the half nut may be used in conjunction with an electric control system for stopping the machine or with the mechanical declutching device shown in Fig. 13 and comprising a pivoted bell crank 109 operated by a bell crank 108 connected to a link 106 moved by the half nut. The bell-crank 109 engages a horizontally slidable block 118 having a cam groove 120 which engages a pin on a rod to transmit motion to a collar and thereby operate the friction clutch 84. An arm 153 connected to the slidable block 118 is also operated to close the supply valve. An electric control for the clutch and valve may be employed and may be operated from the half-nut mechanism as shown in Fig. 6. An armature 290 which is connected by a link 291 with a clutch lever 292 and with a link 294 connected to the valve control, is energized by a solenoid 289, Figs. 6 and 30. An operating lever 186 makes contact at 300 to energize the system including the motor 2, solenoid 289 and spring switch 333 for the guide roller 328 of the tape. A main swith is provided at 3400. Should the tape slacken or break the roller 328 which is spring-pressed against the tape, moves to open the switch 333. The gradual closing of the valve is obtained by the aid of the escapement mechanism shown in Fig. 26 and by telescopic links which are maintained apart by spring action. An escape lever 276 provided with pallets 281 engaging an escape wheel 279, is provided with a weight and with an air resistance leaf 280. The wheel 279 is in train with a series of gear wheels 275, 272, and when the clutch is thrown out and the brakes applied either by hand or by the automatic stop motion, one of the telescopic links compresses the spring and an arm 270 connected to the telescopic links gradually moves on its shaft 271 so that the flow of adhesive goes on until slightly after the rolls, drums &c. have stopped. When the machine is started the valve opens quickly as the telescopic links then act rigidly. A strip of fabric 121 is applied to the adhesively coated strip 40 as shown in Fig. 5, the strip 121 emerging from a spool 122 and passing through a braking device 124, the pressure of which may be adjusted by a fly nut and spring. The strips pass round a grooved pulley 139 with the covering strip undermost and in contact with the adhesive, and thereupon pass between rolls 147; 148 yieldingly pressed towards one another.