Patent GB-564534-A (GB)
Title: Improvements in or relating to method and machine for stripping rubber tread blocks from rubber treaded links or the like
IPC: B26D1/00
Filed: 1943-07-21
Abstract: 564,534. Cutting-machines for rubber &c. STEVENS, A. H. (Burgess-Norton Mfg. Co.). July 21, 1943, No. 11881. [Class 31 (i)] A cutting-machine is constructed to strip rubber tread blocks from links such as are employed in endless treads of vehicles such as is indicated in Fig. 2, in which a rubber tread 10 is moulded around the two tubular pivot members 11 of the tread which .are connected to metal cross members 12 and receive pivot pins 15 fitted with rubber sleeves 16. To renew a worn tread with rubber or metal, the old tread 10 is removed by being inserted between chuck members 25, 26, Fig. 3, which are geared to a common shaft 38 driven by a reversible electric motor 41, Fig. 4, which is controlled by starting and limit switches adapted to reverse the drive automatically and also to stop the drive automatically after the motor is started by a hand-operated switch. The chucks are provided with apertures for receiving the pins 15, and the lower pin is secured so as to be concentric with the axis of rotation of the chuck. The stripping of the rubber tread 10 is effected by means ot cuttmg knives 85, 86 with cutting-edges 91, 92, Fig. 12, which are brought into operation alternately, the knives being mounted in a carriage 72, Fig. 3, which is advanced radially of the axis of the chuck simultaneously with the movement of the chuck member 26 to grip the tread 10. The movements are effected by a pneumatic pressure acting upon a piston, the rod 70 of which operates a lever 61 which displaces axially a rod 60 connected to the chuck 26 by a yielding connection. The rod 70 also actuates a lever 74 connected to the knife carriage 72. A rack 101 actuated from a pneumatic cylinder 100 rotates a shaft fitted with eccentrics 96, 97 which control the knives 85, 86 so as to bring them into action alternately. From the position shown in Fig. 12, in.which the knife edge 91 engages the tread close to the tubular member 11, the chucks are rotated clockwise by starting the motor 41, and the knife blade 91 cuts through the rubber into the tubular member 11 and cuts through the relatively thin rubber covering and the rotation continues until the knife cuts into the body of the tread so as to reach a line adjacent the medial plane including the axes of the tubular members 11. On reversal of the motor, the knife 85 is retracted, and the knife 86 advanced so that the knives take the position shown in Fig. 14, and the counterclockwise movement of the chucks causes the edge 92 to cut into the body of the tread and the cutting is continued so as to,cut almost completely around the tubular member 11. The machine then stops and the chuck 26 is, withdrawn to permit the cutting of the tread around the second tubular member 11 to be effected in the same manner as the first. The tread is preferably reversed end for end before inserting it for the second cut, so that the initial cut will be made from the same side of the tread surface, and thus facilitate the final removal of the severed rubber block by a punching operation. Details of the electric control switches and of the valve control of the fluid pressure control devices are described in the Specification. The limit switches are controlled by cams on the shaft of the chucks.which grip the treads.