Patent GB-1018238-A (GB)
Title: Polyethylene strip coating machine
IPC: B29C65/48
Filed: 1964-08-04
Abstract: 1,018,238. Web coating apparatus. PAULSON MACHINE CO. Ltd. Aug. 4, 1964 [Aug. 2, 1963], No. 31200/64. Heading D1L. A machine for applying an adhesive coating to a surface of a strip 110 comprises an adhesive supply receiving bath 280 mounted on the machine frame 229, an adhesive applying roll 277 rotatably mounted in the frame 229 and extending into the bath 280, means 279 for driving the roll 277, guide rollers 243, 244, 252, 254, 274, 276 for directing the strip on to the roll 277, a drying rack comprising spaced-apart plural-grooved pulleys 288, 289 rotatably mounted in the frame 229 and means 291, 292 for driving the pulleys 288, 289. The strip 110, e.g. of polyethylene, is supplied from a reel 231 by a friction roll 234 resting thereon and fixed to a driven shaft 235 journalled in a frame 236 so that anticlockwise rotation of the roll 234 rotates the reel 231 clockwise. The strip 110 passes around pulleys 243, 244, the latter being resiliently mounted by a rod 245 reciprocally mounted in a bracket 246 and urged downwardly by a spring 247. The strip then passes through a strip accumulator 250 which comprises idler pulleys 252, Fig. 2 (not shown), rotatably mounted in a frame 251 on a fixed axis 253 and idler pulleys 254 rotatably mounted in the frame 251 about a floating axis 255. The strip is trained back and forth over the pulleys 252, 254. The axis or shaft 255 carries a yoke 257 which will contact a switch 259 to stop the machine if the strip 110 breaks and the pulleys 254 drop. The shaft 255 also carries a bar 261 having projections 262, 263 so that if the shaft 255 drops to a predetermined level, due to slackness in the strip 110, the projection 262 actuates a mercury switch 265 to energize a solenoid 267, Fig. 1, having an actuating plunger 268 pivoted at 269 to an arm 270 pivoted at 271 to the frame 236. A cylindrical shoe 273 is carried by the end portion 272 of the arm 270 to overlie the reel 231. Upon energization of the solenoid 267 the plunger 268 moves upwardly and swings the shoe 273 into engagement with the reel 231 to act as a brake, the pressure on the reel 231 by the shoe 273 causing the adjacent end of the frame 236 to swing slightly upwardly to disengage the roll 234 from the reel 231. When the slack in the strip 110 has been taken up by the pulleys 252, 254 the shaft 255 rises and the projection 263 contacts the switch 265 to de-energize the solenoid 267. From the accumulator 250 the strip passes over a wheel 274 on a driven shaft 275 which wheel slightly abrades the lower surface thereof. The strip 110 then passes under an idler pulley 276 to the roll 277 having a slightly pocked surface 281, Fig. 4 (not shown), to facilitate retention of adhesive thereon. The thickness of the adhesive layer on the surface 281 may be accurately determined by a U-shaped plate 282, Fig. 4, mounted on top of the bath 280 by screws 284 extending through, slots 285 in the plate so that an edge 283 can be adjustably spaced, by a screw 286, from the surface 281. An idler pulley 290 directs the coated strip 110 into the first groove of the pulley 288 and it is trained back and forth between the pul-. leys 288, 289. The shafts 240, 275 on which the pulleys 288, 289 are mounted and a sprocket 279 on the shaft 278 of the roll 277 are suitably driven. As the strip 110 leaves the last groove of the pulley 289 it passes through a second accummulator 299, Fig. 2, similar to the accummulator 250, and comprising pulleys 301 on a fixed axis shaft 302 and pulleys 303 on a floating shaft 304 to which a bar 306 is attached. When the pulleys 303 drop to a predetermined level a projection 307 on the bar 306 actuates a switch 309 to de-energize a clutch 312, Fig. 4, on the shaft 275 to interrupt the drive until there is sufficient tension in the strip 110 to raise the pulleys 303 so that a projection 308 on the bar 306 actuates the switch 309 to energize the clutch 312. The strip 110 is then led over a pulley 111. The shoe 273 and the pulleys 252, 254, 288, 289, 301,202 may be made of polytetrafluorethylene.