Patent GB-1406120-A (GB)
Title: Cam-controlled grinding machines
IPC: B23Q1/00
Filed: 1973-06-28
Abstract: 1406120 Grinding TRI-ORDINATE CORP 28 June 1973 [13 July 1972] 30851/73 Heading B3D [Also in Division F2] A cam-controlled machine for grinding the surface 11 of a workpiece 3, such as the stator of a Wankel-type engine, comprises a cam member 7 having a first surface 10 facing in one direction and a second surface 24, 25 facing in the opposite direction, the first surface corresponding to the surface to the ground and being engaged by a follower 9 supported for movement relative to the cam. Guide follower means 22, 23 engage the second surface and are resiliently connected to the cam follower which is thus held against the first surface. The workpiece 3 is fixed relative to the cam member with the surface to be ground facing in the said opposite direction and engaged by grinding means 36 movable on the support for the cam follower towards the surface to be ground. The workpiece 3 is fixed to a support which is slidable on vertical parts by action of a hydraulic cylinder to a grinding position wherein its internal surface is engaged by the grinding wheel 36 carried by a spindle 37 driven by a belt 40 from a hydraulic motor 39. A bracket 38 secures the motor and grinding spindle to a bearing plate 5 supported by hydraulic pressure at its periphery 35 for rotation and horizontal movement in a housing 4 to which the cam member 7 is fixed, the housing also being fixed relative to the base of the machine carrying the support for the workpiece. The upper surface of the bearing plate carries a support 34 for a slide housing 20. The cam follower 9 is carried by a spindle 13 belt driven from a hydraulic motor 18, the spindle and motor being carried by a slide member 14 slidable in the housing 20. A second slide member is slidable on member 14 and carries a bracket 27 for the guide follower means 22, 23 which engage tracks 24, 25 on the inner surface of the cam member, the tracks facing the opposite direction to the cam surface 10. The second slide member 26 is adjustable by a nut 30 relative to slide member 14 and is resiliently connected thereto by springs on the nut to resiliently urge the guide followers and cam follower towards each other and thus into engagement with the cam member. A stepping motor 41 moves the slide member 14 relative to the housing 20 and thereby effects feed of the grinding wheel relative to the cam follower and workpiece. When the cam follower is rotated by its motor 18 it rolls around the surface 10 of the cam member 7 being retained in engagement therewith by the resiliently pressed guide followers 22, 23 engaging the tracks 24, 25, the grinding wheel moving in the same path to grind the surface 11 of the workpiece. The cam member and grinding wheel are retained in a plane P1 which always extends perpendicular to the points of contact of the cam follower with the cam surface 10 by the guide followers 22, 23 which are in the form of rollers spaced one each side and at an equal distance from the plane P1, the tracks having slightly different contours, shown in dotted lines, one from the other. Grinding may be effected under the control of automatic gauging equipment which stops the machine for automatic replacement of the workpiece. The wheel may be dressed when the support for the workpiece is in its lowered position.