Patent GB-183208-A (GB)
Title: Improvements in and relating to the manufacture of tyres
IPC: B29D30/16
Filed: 1921-04-13
Abstract: 183,208. Stevens, A. H., (Firestone Tire & Rubber Co.). April 13, 1921. Tyre covers, special apparatus for making.-In ,a machine for use in building up the fabric foundation of a tyre cover on a rotary core, the operations of underbead ply-laying, bead assembling, overhead ply-laying, and trimming, &c. are effected successively at four positions to which the cores are carried by a turntable 81, Fig. 4, fitted with four core-supporting standards. The edge of the table is notched at 82 to receive a holding-roller 80 on a spring-actuated slide 78. Each core-supporting device comprises a housing 113 for a radial shaft 114 whose outer end drives (through bevel gears) the shaft 128 supporting the core-holding chuck. Clutch mechanism is provided for connecting the shafts 114 to driving-means within the table 81. Core-holders. The cores 131 are detachably mounted on arms 130, Fig. 40, which are radially adjusted by a 3-throw cam 145 carried on a sleeve 144. A gear 148 keyed to the sleeve is arranged alongside a gear 146 fast with the casing-flange 138, one gear having a few more teeth than the other. The outward throw of the arms 130 (or their release for spring-actuated return) is effected by a small rotary movement of the cover 152 which carries a pair of pinions 155 meshing with the gears 148, 146. Fabric assembling, feeding, stretching, and applying, Figs. 1 and 2. The fabric strips, delivered directly from the biascutting means instead of from stock-rolls, are assembled side by side, the narrow (underbead) and wider (overbead) strips diverging during the feeding motion to the corresponding core-stations. Each sectional strip is led on a conveyer-belt 186 passing over pulleys 187, 188, which are automatically rotated, when required to feed fabric to the cores, by clutches operated from trip-levers 210. This operation is effected by means of carriages 213 slidingly mounted on divergent guide-rods 212 and carrying rollers 214 over which the (fabriccanving) belts 186 pass from the pulleys 187, 188. From the roller 214 each belt passes over a fixed roll 215 to a guide 216 forming part of the fabric-stretching device. Each lever 210 is connected by a rod 217 to a second trip-lever 218 adapted to be operated by the carriage 213 at the lower limit of its travel. In this position. there is a sufficient supply of fabric in the loop formed bv roll 214. and the actuation of the. lever 218 unclutches the corresponding pulley 187 or 188; the reverse process taking place when the carriage engages the lever 210, in which position the supply-loop is exhausted. From this feeding-device, the fabric is guided between rollers 246. 249, which are driven at less surface-speed than the core. The rollers 246. 249 are mounted on a swinging frame 225 carrying a friction driving-roll 240 which is geared to the rolls 246, 249. When the frame, 225 is lowered, the roller 240 rests on a second friction-roll 232 on the driven shaft 230. To ensure correct alignment of the fabric strip (with respect to the core) it is led over a guide 216 and roller 256 on a frame 251 which is pivotally mounted on the upper end of the bracket carrying the roller 249. Beads, applying, Fig. 4. The bead cores are assembled on profiled rollers 161 on rings 159 which are carried by spiders 157 and moved to and from the core 131 by means of a handle 165. The outer spider is mounted on jointed arms 174 pivoted on a bracket with provision for vertical adjustment. Stitching-devices, Fig. 16. The stitchins-rolls 305 are mounted on a carriage which is moved towards the core by rack-and-pinion mechanism. Fig. 16 shows the underbead stitchers at the end of their forward movement, in which position a pin 292 on the rack strikes a clutch-operating lever, whereupon the carriage is automaticallv returned. This return movement may be effected by a pneumatic or spring dashpot device, or by means of a weight. In the return movement the stitcher arms 327 are separated to clear the core 131 by a toggle 320, 321 rocking the pivoted links 323 to swing the arms 327 about their pivots 334. The yielding pressure of the rolls 305 on the core (obtained by springs 331 on pins projecting from the arms 323) is maintained uniform by means of cam tracks 336 in which rollers 335 on the arms 323 are guided. For the overhead operation, means are provided for varying the inclination of the stitchers at the bead positions. This adjustment may be relied on to retard the advance of the stitchers at these, places. In addition, the feed-motion for the overhead stichers may comprise two racks with differential pinion drives, the slow-speed drive being automatically thrown in when the stitchers reach the beads. Trimming operation, Fig. 33. The trimming- knives 442 are mounted on pivoted arms 409 on a carriage 402 which is advanced to the core bv rack-and-pinion mechanism controlled by a handlever. After the knives have cleared the wide part of the core, the pivot of a toggle 414 connecting the arms 409 is arrested so that in the further forward motion the knives are caused to approach and engage the work.