Improvements in or relating to means for obtaining a reciprocatory movement for grinding, lapping or polishing machines

摘要

646,028. Grinding and polishing machines. TAYLOR, D. Feb. 20, 1947, No. 4924. [Class 60] [Also in Group XXIX] Means for effecting axial reciprocation of a rotating member of a grinding, lapping or polishing machine comprises a member mounted to rotate and reciprocate having a piston thereon which is mounted in a cylinder, means for intermittently applying liquid pressure on one side of the piston to force the piston in one direction and means for applying spring pressure to the piston for returning the piston in the intervals between the application of liquid pressure. As shown, toric lens runners 6 are driven by a belt (not shown) and pulley 7. On the shaft 5 of the runners is a piston 8 working in a cylinder 1. The arrangement is duplicated at the right hand side of the cylinder the parts at the right hand side not being shown in the Fig. At each end of the cylinder is a spring pressed member 11 having ports 14 which co-operate with ports 13 in the piston. Liquid under pressure is applied at a port 15. Each time a port 13 in a piston registers with a port 14 in the member 11 the space between the pistons is connected to exhaust at 16 and the springs force the pistons towards the middle of the cylinder. The ports 13, 14, are distanced apart so that the rotation of both pistons must have a period when all the ports are closed in both pistons to allow pressure to build up and both pistons will be moved outwardly against the springs 12. If any one set of ports 13, 14 on either side of the cylinder register with one another both pistons will move inwardly and the speed of movement and the stroke of the pistons will vary according to the number of ports open in either or both pistons. If one piston is rotated at a speed slightly faster than the other piston a variable total port opening will be obtained so that the stroke of the pistons will vary. The pistons reciprocate the shafts 5 and runners 6. Fig. 3 shows a toric lap 20 acted on through pins 22 with conical ends by a spring pressed member 21. A catch 24 holds the lap tool in a withdrawn position.