An improved method of and means for compensating for wear in driving chains
187,042. Nuttall, P. July 21, 1921. Rivet and bush extractors.-The pitch of worn chains is restored by turning the pins and bushes to bring unworn parts thereof into bearing contact. A roller chain is secured upon a support by teeth 2, 3, 4 engaging between the rollers, and by a wedge pin 6 inserted through an aperture in the tooth 3. The narrow ends of stepped plungers 16 are pressed against two chain studs by a screw 13 to force them out of one of the outer link plates. These plungers are then withdrawn and corresponding plungers 18 actuated from the opposite side of the chain to free the second outer link plate. The plungers abut against plates 24 slidable upon rods 11 which carry slides 9, 10 wherein the plungers are slidable and rotatable. The slides can be pressed towards the chain by reduced ends 14 of the screws 13, and the plates 24 are similarly actuated by the main body of the screws. After freeing the outer link plates, the studs are held between the opposing plungers and these are turned together with the studs by handles 21, 23. Packing pieces 27, 28 are then removed from behind the plate 24 of the slide 10, which allows this to be advanced, without moving the plungers, to replace one outer plate upon the turned studs. These connected studs and link plate are then removed from the chain, and the adjacent inner link plates are operated upon similarly, but by the wider parts of the plungers, to remove, turn, and replace the bushes. The connected studs and outer link plate are then replaced, and the remaining outer link plate forced on to the studs. To enable " silent " chains to be operated upon, they are secured by screws 52 upon holders 47 shaped as shown in Fig. 7. Interchangeable chain-holders may be clamped between the opposing halves 7, 8 of the bed of the apparatus.