Patent GB-632441-A (GB)
Title: Oscillating raceway grinders and methods of grinding raceways
IPC: B24B19/06
Filed: 1947-06-11
Abstract: 632,441. Oscillating raceway grinders. NORMA-HOFFMANN BEARINGS CORPORATION. June 11, 1947, No. 15382. Convention date, June 26, 1946. [Class 60] [Also in Group XXXVII] An oscillating raceway grinder having a workhead rotating a workpiece, a wheel-head rotating a grinding wheel, and a power - driven mechanism for oscillating the work-piece about an axis of oscillation, is characterized by the provision of a power-driven mechanism for feeding the work-piece relatively to the axis of oscillation, and a mechanism for feeding the wheel relatively to the axis ot oscillation. The work-piece 19 is mounted on  work-spindle 25 mounted in work-head 26 and  is belt-driven by motor 27. The work-head 26  is laterally adjustable on ways 28 integral with  work-slide 30 movable longitudinally on ways 31 integral with table 32 which is oscillated about vertical axis 17-17 by lever 44, connecting-rod 45, eccentric 47 and motor 48.  The feed of the work-slide 30 relative to the table 32 is effected by a feed-screw 35 operated through gear-box 36 by a reversible, variablespeed motor 37. Adjustable screws 39, 43 on the work-slide 30 actuate limit switches 38, 42. The grinding wheel 11 is mounted on spindle 50 mounted in wheel-head 51 and is belt-driven by motor 52. The wheel-head 51 is laterally adjustable on ways 53 integral with wheel-slide 55 movable longitudinally on ways 56 integral with base 49. The feed of the wheel-slide 55 relative to the base 49 is effected by a feed-screw 57 operated through gear-box 58 by a reversible, variable-speed motor 59. The various motors are controlled by an electrical system, Fig. 3, which can be set to give any one of six automatic cycles, as follows: Cycle " A." Of the switches 86, 87, 88, 89 controlling the wheel feed motor 59, switches 86, 88 are closed and switches 87, 89 open. To start the cycle, the operator momentarily closes switch 62, thus energizing solenoid 63 of relay 64, which is provided with a holding circuit. The work feed motor 37 and wheel feed motor 59 both start forwardly, feeding the work and wheel towards the centre of oscillation 17. As the work-slide 30 moves forwards, screw 43 thereon allows limit switch 42 to close; oscillation drive motor 48 and work drive motor 27 both start. Feeds of work and wheel continue until screw 39 on work-slide 30 actuates limit-switch 38 ; work feed motor 37 and wheel feed motor 59 both stop. A pneumatic timelag relay 83 is energized, and after a dwell (" sparking-out "), the work feed motor 37 starts in reverse direction and the wheel feed motor 59 starts in a forward direction, so that the wheel continues to feed towards the centre of oscillation 17 while the work is being withdrawn. When the withdrawal is complete, screw 43 actuates limit switch 42, and the work feed motor 37, wheel feed motor 59, work drive motor 27 and oscillation drive motor 48 all stop. Cycle " B." With switches 86, 87, 89 open and switch 88 closed, the operation is as in Cycle " A," except that there is wheel feed during feed of the work but not during withdrawal of the work. Cycle " C." With switches 87, 88, 89 open and switch 86 closed, the operation is as in Cycle "A," except that there is wheel feed during withdrawal of the work but not during feed of the work. Cycle " D." With switches 86, 88 open and switches 87, 89 closed, the operation is as in Cycle " A," except that there is no automatic feed of the wheel either during feed of the work or during withdrawal of the work. During feed of the work, manual closing of switch 91 will cause wheel feed; during withdrawal of the work, manual closing of switch 90 will cause wheel feed. Cycle " E." With switches 86, 87, 88 open and switch 89 closed, the operation is as in Cycle " D," except that only switch 91 is effective, to give wheel feed during work feed. Cycle " F." With switches 86, 88, 89 open and switch 87 closed, the operation is as in Cycle " D," except that only switch 90 is effective, to give wheel feed during work withdrawal. Other controls.-Jogging movements of work feed motor 37 may be effected by opening switches 94, 95 and actuating normally open momentary contact switches 96, 97 to causs forward and reverse jog movements respectively. A reversing switch 72 is provided for the wheel feed motor 59 whereby the wheel can be withdrawn for replacement of a worn wheel. The grinding wheel motor 52 can be stopped by manually-operated switch 61; the whole circuit can be de-energized by manuallyoperated switch 60.