GB942108A - Control device for a grinding machine - Google Patents

Abstract

942,108. Grinding machines. FORTUNAWERKE SPEZIALMASCHINENFABRIK A.G. March 23, 1962 [March 25, 1961], No. 11205/62. Heading B3D. A work-positioning device for a grinding machine comprises first and second sensing levers 7 and 13 respectively coupled by gearing 4, 5 so that they are rotatable about pivots 17, 18 equally and oppositely, and a control lever 2 so attached to the lever 13 that relative movement between them can only occur when the lever 13 senses the workpiece 21. The lower arm 8 of the first sensing lever 7 is operated by a piston 9 of an hydraulic actuator to move a feeler contact 20 on the upper arm towards a shoulder 32 of the work, the contact 19 of the second sensing lever 13 being simultaneously moved towards a spaced shoulder 33, but the lower arm of the second lever is, effectively, the control lever 2, to which the lower extension 10 of the second lever 13 is held by a spring 11 against an abutment 12 until the sensing contact 19 meets the shoulder 33 when the lever " breaks " at the joint 17 thus effecting the separation of a contact between a " hold-off " microswitch 3 and the end of an adjustable screw 14 so that the switch is closed whereby a control impulse is transmitted to the grinding machine, terminating work-positioning operation and shutting off pressure to the actuator 27; this control may be effected by known hydraulic, electric or other means. The device may be integral with the machine or moved manually or automatically to the region to be ground in such manner that when in their " rest " positions the sensing levers have clearance between the shoulders of the portion to be ground, the workpiece 21 and its supports having been brought by known means to a position such that the middle 26 of the region is at a distance b, Fig. 2, from the middle 23 of the adjustment device, this being aligned with the central plane 24 of the grinding wheel 25. When the actuator 27 is operated the levers 7, 13 spread apart uniformly until the contact 20 meets the face 32 and the work-field is shifted by the machine control so that the face 33 approaches the feeler face 19, when spreading of the levers ceases as described above and the workpiece has been so positioned that the centre of the space between the shoulders is aligned with the central plane of the grinding wheel.