GB291905A - Improvements in or relating to apparatus for moulding and vulcanising pneumatic tyre covers and the like - Google Patents

Abstract

291,905. Dunlop Rubber Co., Ltd., Willshaw, H., Norcross, T., and Broadbent, F. G. March 19, 1927. Moulding wheel tyres.-The usual clip or bead rings of a vulcanizing mould are not-removed with the tyre after each use of the mould but are permanently associated with the two halves of the mould. Fig. 5 shows a mould of the type in which the upper steam chest 2 is hinged at 4 to the lower chest 1, and in which through linkage connected with the hinged chest 2 the tyre mounted on a carrier ring 6 is automatically stripped from the mould when the latter is opened. The lower clip ring 9 is secured to or integral with the carrier ring 6 but the upper clip ring 9<a> is yieldingly attached to the upper chest 2 by means of brackets 11 on the ring 9<a> connected through springs 14 to brackets 13 on the chest 2. In order to remove the tyre from the upper mould member the tyre is prevented from rising during the initial movement of the upper chest by spring-controlled plungers 19 engaging above a, flange 9<b> on the upper ring 9<a>. During this movement arms 22 on the brackets 13 tilt pivoted members 17 which through bifurcations 18 withdraw the plungers 19, so that on further opening of the mould the tyre, lower clip ring 9, and carrier ring 6 are lifted clear of the lower chest, whilst the upper ring 9<a> is drawn by the springs 14 into position in the upper chest. In order that the carrier ring 6 may be wholly stationary during the initial movement of the chest 2, a lost-motion device such as a slot may be provided in the linkage between the ring 6 and hinge 4, and in such case a detent controlled by the linkage prevents the ring 6 from being pulled up by the tyre. The chests may be clamped together when closed by cam clamps as described in Specification 272,992 combined with means for controlling the supply of fluid-pressure to the interior of the tyre, or by eccentric, crank or toggle mechanism as described in Specification 290,405. Fig. 8 shows an arrangement in which the lower chest 30 is movable vertically with respect to the upper (fixed) chest 29 by a hydraulic ram 32. The upper clip ring 29<b> is secured to slidable pillars 37 controlled by springs 40 the force exerted by which is greater than that exerted by gravity on the moving parts so that when the pressure on the piston 32 is released the tyre is first stripped from the upper mould member. The platform 35 carrying the lower clip ring 30b and the tyre, and the platform 36 carrying the lower chest 30 descend together until the former strikes the stops 31b when the latter continues alone and strips the tvre from the lower mould member. Alternatively, the upper clip ring and the tyre may be stripped from the upper chest by spring plungers carried by the ram head engaging with a flange on the clip ring and controlled by a cam on the upper chest. Specification 252,415 also is referred to.