Patent GB-933625-A (GB)
Title: Grinding machine
IPC: B24B5/16
Filed: 1962-06-05
Abstract: 933,625. Grinding. CINCINNATI MILLING MACHINE CO. June 5, 1962 [Nov. 22, 1961], No. 21632/62. Class 60. [Also in Group XXIX] A grinding machine comprises a base structure having means to support and move a workpiece in a predetermined path, a wheelhead having a rotatable grinding wheel carried thereby slidably received on said base structure for movement toward and away from said predetermined path, first means operable to move said wheelhead a fixed distance, second means operable to move said wheelhead a selected distance, and third means operable in response to a predetermined movement of the workpiece along said predetermined path to effect a predetermined movement of said wheelhead. A wheelhead 10 is mounted on ways 12, 14 in an intermediate member 16 pivotally adjustable on the machine base 18. The wheelhead includes a grinding wheel 20 rotated by a motor 22 mounted on an upper portion 28 of the wheelhead. A wheelguard 26 extends laterally from the portion 28 and a truing mechanism 24 is mounted on the wheelguard behind the grinding wheel. The portion 28 is pivotally adjustable about a horizontal shaft 31 extending through yokes 30 on a lower portion 32 of the wheelhead so that the grinding wheel may be tilted for grinding a helical groove on a workpiece, the portion 28 being clamped in adjusted position by stud bolts 33, 34, 35. A workpiece is rotatably supported on a table 36 longitudinally movable on the base 18. A fixture 38 pivotally mounted on the table may be swung, as the table is moved longitudinally, by mechanism contained in a housing 40 fixed on the base 18 so that a crowned roll as well as a straight roll may be ground. The fixture is adapted to support the entire regulating wheel housing of a centreless grinding machine so that the regulating wheel therein occupies the position 39. The regulating wheel is rotated by a motor 42 and drive unit 44 supported on the table. Front and rear hand wheels 46, 48 are mechanically connected for manual movement of the table and motor means are also provided for automatic table movement. A bracket 50 fixed to the side of the table 36 holds a cam 52 for engagement by an hydraulic tracing mechanism 54 fixed to the base 18 below the wheelhead and connected for movement of the wheelhead on the base in accordance with the contour of the cam and the movement of the table. A rack 60 fixed to the underside of the wheelhead portion 32 is engaged by a pinion 56 on the end of a drive shaft 58 journalled in the base 18 on the axix about which the intermediate member 16 is pivotally adjustable. Supported on the shaft 58 is a rapid advance motor 62 having a worm wheel 64 integral therewith. The motor 62 comprises an annular housing 66 with an inwardly-extending wall member 68 fixed therein and a paddle 70 fixed to the drive shaft 58, interdrilling 72, 74 in the shaft 58 supplying pressure fluid to one side or the other of the paddle 70 to swing it from one side to the other of the wall 68. The worm wheel 64 meshes with a worm gear 76 integral with a shaft 78 mounted in a portion 80 of the machine base for rotation and limited axial movement. Pressure fluid supplied through a conduit 86 acts on a piston 88 to urge the end of the shaft 78 against a pin 90. The pin 90 is fixed in a member 92 slidable in a member 94 fixed to the side of the base 18 below the wheelhead 10. Movement of the slide 92 is limited by a pin 96 engaging a slot 100 in the slide. A roller 102 on the slide 92 engages a cam 106 fixed in a bracket 108 fixed to the body 110 of a tracing valve 112. The valve contains a plunger 126 having a stem 134 on which is fixed a collar 140 acted on by a spring 136 so as to urge the plunger 126 to the right-hand end of the valve whereby operating ports 122, 124 are connected respectively to pressure port and return port. The plunger 126 may be moved against the spring 136, to connect the operating ports 122, 124 respectively to return port and pressure port, by shifting a tracing plunger 144 axially movable on balls 146, one end of the plunger engaging the end of the stem 134 and the other end of the plunger holding a tracing rib 150 adapted to engage the cam 52 on the table 36. A member 152 extending from the valve body 110 carries a piston 162, 164 working in a cylinder 158 forming part of the tracing housing 156. The left-hand and right-hand sides of the piston are respectively connected by passages 166, 168 to the operating ports 122, 124. Thus the valve body 110, and therefore the cam 106, is caused to follow the changes in axial position of the tracer plunger 144 and the shape of the cam 52 determines the position of the plunger 144 as the table 36 is moved across the peripheral surface of the grinding wheel 20. The position of the cam 106 determines the axial position of the shaft 78, the worm 76 acting as a rack and the worm wheel 64 acting as a pinion to rotate the entire motor 62 with the shaft 58 thereby changing the position of the wheelhead 10. The shaft 78 is connected by a coupling 178, permitting axial movement of the shaft 78 by the tracing mechanism 54, to a shaft 176 on which is fixed a gear 174 rotated by a handwheel 172. A motor may be provided for rotating the shaft 176.