GB229423A - An improved tyre building machine - Google Patents

Abstract

229,423. Dunlop Rubber Co., Ltd., Macbeth, C., and Kay, A. Dec. 4, 1923. Tyre covers, making.-A machine for use in building tyre casings in flatband form comprises a collapsable drum 3 adapted to be moved into and out of co-operation with a rotary turret 4 which is fitted with sets of rollers for pressing the various plies and beads of the casing. The machine shown comprises two such sets mounted on upright pillars 1. Each drum 3 is mounted on a shaft 2 fitted in a bracket 2a pressed upwardly by a spring 17 and lowered, to bring the drum clear of the turret, by means of a treadle 18. A trip 21 normally retains the treadle 18 in its depressed position, being withdrawn by means of a second treadle 22. The turret 4 is adjustable about the shaft 5 to bring the desired rollers up to the drum, being locked in such adjusted positions by a cam-controlled spring-plunger 7 adapted to enter corresponding holes in a fixed plate 8. Each turret is fitted with four spindles carrying (1) spaced flat rollers 16 for driving the drum by frictional contact with the fabric thereon, (2) spring-pressed pairs of bead-rollers 30, and a pair of rollers 31 on spring-pressed radius arms for rolling-down the bead heels, (3) a roller 29 which is resiliently-mounted and of a width equal to that required between the tyre beads, and (4) a hand-operated roller 35h for rotating the drum during the bead-laying operation. The turret is also fitted with a cross-bar 34 carrying a pair of spring-pressed rollers 33 for working the overbead plies into the bead clinches. In this step, the beads are held clear of the fabric by lugs 35b on jaws 35a which are normally held in the operative position shown in Fig. 13 by a tension-device 35g. A hand-operated cam 35d is provided to spread the jaws for allowing the bead to contract on to the fabric. To steady the upward movement of the drum, a dash-pot 40 is mounted on the bracket 2a, that shown at the left of Fig. 4 being in the lowered position. In this position, oil has flowed from the upper part 40a into the reduced lower cylinder 40f through a small lateral vent 40d and a larger lateral port 40c leading from the axial passage 40e in the fixed plunger. When the treadle 18 is released, the dash-pot rises relatively freely until the port 40c is covered by the wall of the cylinder 40f. The oil then trapped in the cylinder 40f escapes slowly through the vent 40d, to damp the further upward movement of the drum.