Patent GB-359978-A (GB)
Title: Improvements in or relating to machines for grinding ball races
IPC: B24B19/06
Filed: 1930-07-30
Abstract: 359,978. Grinding, LANDIS TOOL CO., Waynesboro, Pennsylvania, U.S.A.- (Assignees of Steiner, A. P. ; Wine, E. P. ; and Balsiger, H. E.; of Landis Tool Co., Waynesboro, Pennsylvania, U.S.A.) July 30, 1930, No. 22936. Convention date, Aug. 30, 1929. [Class 60.] Round holes, enlarging and trueing ; gauges.- A machine for grinding the bearing surfaces of ball races consists of a work-head, in which the race is rotatably mounted, carried by a bracket which is oscillated about a vertical axis by a fluid pressure motor, and a grinding-wheel mounted for longitudinal and transverse movements by fluid pressure means. A gauging-device is provided which controls the movements of the machine electrically, solenoids being energized thereby to actuate the valves controlling the various fluid pressure motors. The machine consists of a bed 10 upon which is longitudinally movable, by a cylinder 30 and a piston 29, a carriage 11, upon which is movable transversely a wheel-base 12 carrying a grinding- wheel 13 ; the base is movable either by a cylinder 39 and a piston 40 or by a hand-wheel 15 which, through gearing 69, 70 rotates the piston rod 41, which is screwed, in a threaded bracket 72 depending from the base. The work 20 is rotatably carried by a headstock 19 on a bracket 16 adapted to be oscillated about a shaft 17 by a fluid pressure motor 18, and the headstock is adjustable transversely on a slide 21 and longitudinally by a screw 22. The headstock also carries a gauging-device 25 comprising an arm 26 carrying a diamond 27 adapted to engage within the work 20, and movable into and out of position by a fluid pressure motor 28 ; this device acts to slow down the speed of oscillation of the work for finishing, to stop it when to size, to stop the automatic feed of the grinding wheel, to remove the device from the work and to return the wheel base and carriage to inoperative position. The cylinder 29 has a port 33 at one end, and at the other end two ports 34, 35 connected by a spring- pressed check-valve 38 having a restricted opening to allow fluid to flow freely through the port 34 into the cylinder but to restrict its flow outwards, whereby the movement of the carriage is slowed down after the port 35 is closed by the piston; the cylinder 39 has similarly arranged ports and a checkvalve. The longitudinal movement of the carriage is controlled from a valve 48, and the timing of the movements of the base 12 and the carriage are controlled by a valve 55 operated by a lever 56 which engages an abutment 57 when the carriage almost reaches its working position; the return movement of the carriage is controlled by a valve 67 moved by a collar 65 on the piston rod 41. The wheel-base moves forward until it nearly reaches the grinding position, and the rod 41 then strikes a lead screw 73 and also depresses a plunger 76, which, through links moves a valve 86 to move a piston 89 which, through rack gearing rotates the screw 73, allowing the base 12 to move forward. The oscillation of the headstock is controlled by a valve 98 movable either by a hand-lever 108 or by fluid pressure controlled by a solenoid 109, and the reversal of the motor 18 oscillating the head is controlled by a valve 116 moved through a shaft 118 and dogs 122 on a ring 123 secured to the frame 16, the arrangement being such that when the work is nearly to size, closing of contacts by the gauging- device slows down the speed of oscillation of the head and when the work is to size other contacts are closed and the motor is stopped. Movement of the lever 108 will then swing the work towards the front of the machine. The gauging-device is swung clear of the work by the motor 28, which is controlled by a valve 144 moved by a solenoid energized by the closing of the second contacts.