GB1271651A - Grinding machine wheel head operating means - Google Patents

Abstract

1,271,651. Grinding. COVENTRY GAUGE & TOOL CO. Ltd. 19 May, 1969 [20 Feb., 1968], No. 8104/68. Heading B3D. [Also in Division G3] A grinding machine wheel head operating means comprises an electric stepping motor arranged for programmed operation and to directly or indirectly drive the wheel head actuating mechanism. The machine may be used to grind threads, gears, splines or other forms, the programme being determined by a punched or magnetic tape. The wheel head 1 carries a grinding wheel 10 which is adjustable to the helix of a thread to be ground by a gear mechanism. 9. The head is slidable on hydrostatic slideways on a base 2 and is movable by a lead screw 12 which has a threaded portion 14 engaging a nut 15 on the base and a splined portion 14a engaging a wheel 13a meshing with a worm 13 driven by the stepping motor 11. The end of the lead screw is formed with a piston 16 disposed in a cylinder secured to the wheel head for effecting rapid advance and withdrawal movements the stepping motor, under the programmed operation effecting fine control and compensation for dressing. The screw and nut may be of the recirculating ball type. The workpiece 5 is carried by a work-table 3 and is rotatable by a face plate 40 connected by high or low gearing 43, change gears 44 and gearing 42 to a motor driven splined shaft 20. The gears 42 are connected by gearing 45 to a lead screw 30 which engages a recirculating ball nut 22 and a thrust bearing 37, the arrangement providing for thread or similar grinding. For compensating for dressing and the like, the nut 22 is rotatable by gearing 34 connected to a differential gear 32 driven either through worm gearing 33 from a stepping motor 31 under programme control or by worm gearing 36 from an induction motor 35. The motors 31, 35 may be operated to effect-spaced apart grinding operations of the workpiece. The grinding wheel may be dressed by a diamond tool 52a carried by a holder 52 vertically adjustable by a re-circulating ball lead screw 53 driven by worm gearing 55 from a stepping motor 51 under programme control. The motor may operate the dresser so that the tool performs a number of passes with force applied at each or either end. A hydraulic actuator may move the tool 52a linearly or arouately or in some other movement in conjunction with the stepping motor for producing a desired profile on the wheel. The tool may be rapidly advanced by an hydraulic actuator and the final feed be effected by the stepping motor. The dresser may have two or more tools for forming the flanks and crest of a V-profile on the wheel. During dressing the grinding wheel is rotated at a slow speed by a motor 56, the main motor 6 being clutched out.