Patent GB-808314-A (GB)
Title: Improvements relating to grinding machines
IPC: B24B5/01
Filed: 1955-08-04
Abstract: 808,314. Grinding shouldered work. JONES & SHIPMAN Ltd., A.A., and HOULDSWORTH, J. Oct. 17, 1956 [Aug. 4, 1955], No. 22436/55. Class 60. A method of grinding a shoulder 2, Fig. 3, on a cylindrical workpiece 1 comprises automatically imposing an axial in-feed on the grinding wheel 41 in timed relationship with a radial in-feed of the wheel, terminating this axial in-feed automatically before the cessation of the radial in-feed, reversing the axial in-feed to withdraw the wheel axiailly from the shoulder, and retracting the wheel, axially and radially from the workpiece to a starting position. The grinding wheel 41 is mounted on a shaft 29 journalled for rotation and axial movement in bearings 32 in a wheel head 21. Axial movements of the grinding wheel are effected by a lever 28 which is connected by a rod 31 to the shaft 29 and is actuated by a double-acting cylinder-and-piston device 20 and a single-acting cylinder-and-piston device 34 controlled by solenoid operated valves 15, 16. The shaft is rotated by a belt-driven pulley 44 and is secured to a universal-coupling, shown in Fig. 4, through which the rod 31 imparts the movements of the lever 28. In operation, the wheel head 21 is fed radially inward by known means and, by controls connected electrically to the wheel head, energises the solenoidoperated valves 15, 16 to supply fluid pressure to the right-hand ends of the pistons 20, 34. A throttle valve 18 restricts the flow of fluid to the piston 20 so that an eccentric 27, adjustably mounted on a shaft 25 in a bearing 26, moves slowly to pivot the lever 28 about a pin 40 and impart a slow axial feed to the wheel 41. The flow of fluid is unrestricted to the piston 34, which moves rapidly to rotate a lever 37 on a shaft 38 to cause the pin 40, eccentrically mounted on the lever 37, to impart a rapid movement to the lever 28 and provide an additional small axial feed to the wheel 41. The axial feed is terminated a little before the radial feed which, when it is completed, causes an electrical signal to be emitted from the radial feed mechanism to actuate a timing device to provide a " dwell and to de-energise the solenoid-operated valve 16 ; the piston 34 is then connected to the exhaust E and a spring 36 urges the lever 37 and pin 40 to move the wheel 41 a small axial distance from the shoulder 2. On completion of the dwell, the wheel head is radially withdrawn and the solenoid-operated valve 15 de-energised ; fluid pressure is then supplied to the left-hand end of the piston 20, which, since the throttle-valve 18 is by-passed, rapidly withdraws the wheel axially from the workpiece. The wheel axis may be slightly out of parallel with the work axis to avoid " crisscross " markings on the shoulder. The universal coupling, which imparts the axial movement from the rod 31 to the shaft 29 comprises the pulley 44, Fig. 4, secured to the shaft 29 by a nut 45 and to a bearing housing 46 ; bearings 47, 48 in the housing and mounted on a member 49 provided with seatings 50, 51 engaging with the hemi-spherical head 52 of a rod 53 and a distance piece 54 having hemi-spherical ends, a bush 58, which contacts the rod 31 and engages the distance piece 54 and a spring 61 and locknuts 62 to urge the seatings together. Also described in what is stated to be a known machine, Fig. 2 (not shown) comprising a grinding wheel which is arranged to feed angularly into the shoulder to be formed and has its edge shaped to the form necessary to provide the shoulder.