Patent GB-966476-A (GB)
Title: Mechanism for rotating slabs and billets
IPC: B23Q7/16
Filed: 1963-07-17
Abstract: 966,476. Grinding. MID-WEST ABRASIVE CO. July 17, 1963 [April 9, 1963], No. 28362/63. Heading B3D. A mechanism for supporting and turning a workpiece B, such as a metal billet or slab, to present different surfaces to the action of a grinding wheel, comprises a first support 36, Fig. 1, for one edge portion of the workpiece, a second support 38 for the opposite edge portion of the workpiece, and means 46 for lowering the second support from a supporting position level with the first support to cause the workpiece to rock about the first support as a fulcrum, and for thereafter returning the second support to the supporting position. A number of mechanisms may be arranged side-by-side to support the workpiece, and devices having jaws 104 for clamping the workpiece against abutment surfaces 37 may be disposed between adjacent pairs of the mechanisms. Each mechanism has a first support 34 and a second support comprising an arm 38 which is mounted on a pin 42 extending between a pair of side plates and is connected by a toggle linkage 50, 52 to a pin 54 in an eye 72 carried by the rod 20 of a piston-and-cylinder device 66. Fluid pressure to the device 66 is controlled by a valve 122 and in the extended position of the device, the toggle link 50, 52 is straight and the upper surface 40 of the arm horizontal and in the same plane as the upper surface 36 of the first support 34. The jaws 104 of the clamping devices are carried by arms 96 which are movable about pivots 102 by piston-and-cylinder devices 112 so that the jaws clamp the workpiece against vertical abutment surfaces 37 on the support mechanisms during the grinding of a face of the workpiece. After the upper face has been ground, the jaw 104 is retracted and the arm 38 lowered to the position shown in Fig. 1 to cause the workpiece to rock about the first support 34. Thereafter the arm is raised to a horizontal position, the workpiece now having rotated 90 degrees, and the jaw advanced to clamp the workpiece against the surfaces 37 for grinding a second face on the workpiece. In another embodiment for supporting and turning slabs through 180 degrees, the mechanisms have first supports 236, Fig. 9, and second supports in the form of arms 238 movable about pivots 242 by toggle linkages 248 connected to a pin 254 on piston-andcylinder devices 246. The clamping devices between the supporting mechanisms each have a pair of arms 296, 298 which, at one end, have jaws 304, 326, and, at the other end, are mounted on a pin 302 about which they are movable by piston-and-cylinder devices 308, 330. During grinding, the slab is supported on the first supports 236 and on the arms 238, which are disposed in their horizontal positions by the toggle linkages 248 and piston-andcylinder devices 246, and is clamped against vertical abutment surfaces 232 by the jaws 326. When it is desired to rotate the slab through 180 degrees in preparation for grinding the other side, the jaws 326 are retracted and the arms 238 lowered so that the slab pivots about the first supports 236. The piston-and-cylinder devices 308, 330 are then operated so that the jaws 304, 326 engage the slab, as shown in Fig. 9, and rock it about its lower end to place the previously-ground side on the arms 238; the slab may be held by the jaws in an intermediate vertical position to enable the longitudinal edges of the slab to be ground. Thereafter, the arms 238 are raised to the horizontal position, the jaws 304 are retracted, and the jaws 326 extended to clamp the slab against the abutment surfaces 232 for the grinding of the second side of the slab.