GB1152411A - Plate Stretcher - Google Patents

Abstract

1,152,411. Stretching. BALDWIN-LIMAHAMILTON CORP. 24 May, 1966 [24 May, 1965], No. 23053/66. Heading B3E. A plate stretcher including a stationary gripper head assembly and a movable gripper head assembly has each gripper head assembly comprising a pair of angular disposed spaced apart faces, a plurality of paired sets of gripper jaws slidingly supported in opposed relation on the faces, the faces being at an angle such that the forward edges thereof are closer than the rear edges whereby the jaws move closer together as they slide toward the forward edge of the face, blocking means including edges behind selected sets of jaws and means for moving the wedges to a position blocking rearward movement of the gripper jaws. A fixed gripper head assembly (16), Figs. 1B, 2 (not shown), is positioned by locking pins (30) engaging elongated holes (26) in side rails (22), (24). The assembly (16) is connected through shock absorbers (52), (54) with a back-up block (32) positioned on the rails (22), (24) and the machine base itself is provided with shock absorbers (56), (58) bearing on the foundation (13). A movable gripper head assembly 14 is slidably mounted on the rails (22), (24) and is moved in the stretch direction by a ram (60), Fig. 1A (not shown), acting through four connecting rods 88, 90. Hydraulic cylinders (102), (104) also serve to advance and retract the gripper head 14. Gripper jaws 18, 20 are moved down inclined supports 110, 112 on the gripper heads, by a piston 142 connected to the jaws by rods 152, 154, so as to grip a plate 106 to be stretched. To block rearward movement of the jaws 18, 20, if the plate 106 should break, a wedge 168 is moved by a piston 184 to engage the rear of the jaws, the wedge 168 sliding on a block 176 on the gripper head. To prevent the remnant of plate 106 from flying back, the jaw 20 is provided with a stop 192 engaging the edge of the plate.