GB1278706A - Grinding machine - Google Patents

Abstract

1278706 Grinding HEALD MACHINE CO 24 Sept 1969 [27 Sept 1968] 46974/69 Heading B3D A grinding machine comprises an elongate base 11, a wheel-head table 12 movable longitudinally of the base by an hydraulic piston- and-cylinder device 77 and a work-head table 13 movable transversely of the base and carrying a work-head 14. The work-head table 13 can be controlled-force fed or controlled-rate fed. The table 13, which is mounted in ways 32, 33 by means of hydrostatic bearings, is connected to a rod 68 rigidly connected to traverse and damping pistons 67, 69 reciprocable respectively in cylinders 64, 71. A finger 58 depending from the table 13 projects into a recess of a block 35 which is movable relative to the base 11 by means of an electronic pulse actuated stepping motor 57 and a nut-and-screw arrangement 52, 53. The block carries a manually adjustable stop 48 and a fixed stop 51; these stops, in use, contact electrical sensing elements 61, 63 which energize lamps on a control panel (not shown). A diamond dressing tool 82 is mounted on the work-head table. The wheel-head table carries a grinding wheel 19 driven by a motor (17) (Fig. 1, not shown). An oscillator 78 produces axial oscillation of the wheel 19 in a workpiece during grinding. The machine may be used for grinding the bores of miniature bearing races. For controlled force feed, the throttle 75 is open and fluid at a constant pressure is introduced via port 66 into cylinder 64. The piston- and-cylinder arrangement 69, 71 acts as a damper. For a first controlled-rate feed, the sensing element 61 is maintained in contact with the stop 48 by introduction of fluid into the cylinder 64 and the block 35 is moved by operation of the motor 57. For a second controlled-rate feed the opening of the throttle 75 is reduced and fluid is introduced via port 66 into the cylinder 64. Simultaneously the block 35 is moved so as not to contact the finger 58.