GB418930A - Improvements in and connected with apparatus for applying treads to the covers of pneumatic tyres - Google Patents

Abstract

418,930. Moulding wheel tyres. BURCH, A. E., and SMITH, F. W., 561, Mt. Alexander Road, Moonee Ponds, Victoria, Australia. Aug. 9, 1933, No. 22241. [Class 87 (ii).] A mould for re-treading and repairing the outer covers of pneumatic tyres comprises a combined full-circle mould and a sectional mould, each of which can be used alone or simultaneously, and each capable of adjustment for treating tyres of varying pattern, diameter, and width. In treating a cover in the fullcircle mould, one of a range of annular packing rings 32, Fig. 8, of varying thickness is selected and placed in the mould to reduce the diameter to that of the tyre plus the thickness of the matrix. One of a series of skirt rings 10 is then placed inside the ring 32 and is flanked by as many interlocking matrix rings 33 as are necessary to build up the required width of tyre. A second skirt ring 10 mounted on the swinging door of the mould completes the assemblage when the door is closed. A packing- ring 31 may be placed between the door and the mould casing when very wide covers are being treated. Prior to closing the door, the cover is placed in the mould with an extensible sand-bag core 16, Fig. 7, in its interior. Pressure applied to the radial screw arms 13, Fig. 2, then forces the sand-bag outwards and forces the cover into close engagement with the matrix for the vulcanizing operation. The sectional mould comprises a casing 9 which receives the covers of larger tyres direct, and which also is adapted to receive any one of a series of inner members 17 each carrying a tread section 18 for a particular size and make of tyre. Pressure is applied to the cover by means of a sand-bag actuated by the screws 20 mounted on the pivoted arms 21. Steam for vulcanizing is passed through channels in the various casings, and passes through the fullcircle mould and the main casing of the sectional mould in series, but a separate branch from the main supply pipe is used to supply the inner member 17.