GB212437A - Improvements in or relating to vehicle tires - Google Patents

Abstract

212,437. Wade, H., (O. & W. Co.). 'April 4, 1923. Moulding wheel tyres.-Fig. 1 shows a mould for preliminarily shaping and partially vulcanizing the tyre shown in Fig. 3. This mould comprises a continuous central core 1, spacing-rings 3, and segmental cores 2 against which the outer profiled rings 4 are secured by bolts 16, these elements being mounted on a ring 15. Outer mould members 5 are formed with centering keys 17, 18 to enter grooves in the ring 15, and with heating cavities 19 for effecting a partial vulcanization of the tread portion of the tyre. The tread-forming cores 6 are secured by threaded studs 6<a> engaging staggered slots in the meeting edges of the members 5. After removal from the mould, wire rings E are fitted in the spaces F and the tyre is moulded to final shape and vulcanized in the mould shown in Fig. 2, the walls A, B becoming permanently, united along the surfaces D. Collapse of the walls during this stage is prevented by means of capsules of gasforming substance introduced into the chambers F. The pressure thus set up is relieved by venting through apertures which are normally closed by screw-plugs 47. In building up the tyre, the uncured rubber is preferably wound into bands of the required width and thickness which are then twisted into flat form and worked into the spaces between the core and mould elements.