| 摘要 |
1,256,274. Grinding. LANDIS TOOL CO. 20 March, 1969 [28 March, 1968], No. 14656/69. Heading B3D. A steady rest for a grinding machine, having means for rotatably supporting a workpiece W in a generally horizontal position and a generally vertically disposed grinding wheel, comprises a frame 20 for mounting on the bed of the machine an upper work engaging member 26 slidably carried by the frame for supporting the workpiece against horizontal forces, a lower workengaging member 27 for supporting the workpiece against vertical forces, individual hydraulic means 32, 44 for positioning each work engaging member in engagement with the workpiece, a supply 52 of fluid under pressure, and means 57, 60 for regulating the pressure supplied to each of the members in accordance with the forces acting on the respective members. The frame 20 is mounted on a pivot 21 on the bed 11 and is movable between operative and inoperative positions by a piston-and-cylinder device 22, 23. The work-engaging member 26 is carried by a support 28 which is slidable in the frame and has a plunger 31 engaging a wedge 36 in the hydraulic means 32, the wedge being acted on in one direction by a piston 37 and in the other by a piston 38. The work engaging member 27 is mounted on a support 29 movable about a pivot 30 on the frame by a linkage 42, 40 acted on by a plunger 43 engaging a wedge 48 in the hydraulic means 44, the wedge being acted on in one direction by a piston 50 and in the other by a piston 49. The fluid supply from a pump 52 is connected to a reversing valve 53 which, in one position, connects a line 55 to the pistons 38 and 50 to move the wedges to a position retracting the work engaging members, and, in another position, connects the pump to a line 54 joined by lines 58 and 61 to the pistons 37 and 49 to urge the members 26, 27 against the workpiece, the pressure of fluid in the lines, and hence the force of the members against the workpiece, being determined by adjustable pressure reducing valves 57, 60 in the lines 58, 61. During grinding, the members 26, 27 are advanced by the wedges so the workpiece is reduced to final size as determined by a gauge (15, Fig. 2, not shown), the valve 53 then being moved to a neutral position to lock the members 26, 27 in their advanced position until the grinding wheel is retracted. |
