GB535724A - Improvement in method and apparatus for slitting tyre treads - Google Patents

Abstract

535,724. Slitting tyre treads. UNITED STATES RUBBER CO. March 28, 1940, No. 5596. Convention date, April 28, 1939. [Class 31 (i)] [Also in Group XXXIV] Tyre treads are provided with two sets of transverse slits, one extending from the surface, the other submerged. For this purpose the tyre is mounted on an intermittently rotatable clutch and the cuts are made simultaneously by a reciprocating rotary cutter and by a pair of arcuate cutters respectively, the latter being projected from the opposite sides of the tyre so as to meet in the middle. Fig. 11 shows a tyre with the two sets of cuts 138, 139, the former being made by cutter 54, Fig. 9, while the latter are made by the knives 76, 77, Fig. 10, which are moved in arcuate paths and are guided by a member 88 apertured teeth 89 on which project into the grooves on the tyre tread. The tyre is mounted on a flexible plate 32, Fig. 5, carried by radial members 12 operated by a central wedge member actuated by pneumatic means. The radial members 12 carried by a hub 11 mounted in a bearing which can be raised and lowered to accommodate different sizes of tyres by means of a screw adjustment 37. The rotary cutter 34 operates by a motor 51 carried on an arm 49 adjustably mounted on a member 48 on a rocking shaft 47 actuated by a link 73. The arcuate blades are operated by links 98 actuated by crank pins on inter connected gears 99. The guides are vertically adjustable and the whole mechanism can be moved by means of a pneumatic piston working in a cylinder 84 to allow a fresh tyre to be placed in position. The tyre is moved step by step by ratchet-mechanism, a locking detent being provided.