Patent GB-1177564-A (GB)
Title: Improvements in Means for Bending Plates.
IPC: B21D5/00
Filed: 1967-06-30
Abstract: 1,177,564. Bending. COMMISSARIAT A L'ENERGIE ATOMIQUE. 30 June, 1967 [30 June, 1966], No. 30377/67. Heading B3E. A process for bending composite plates comprising a core disposed inside a casing which covers the faces of the core and encloses the lateral edges of the core, the process being characterized in that the plates are bent solely in their central part while leaving them plane in the neighbourhood of the two edges which are moved towards each other by the bending, along a length such that said plane parts include the junction of the lateral edge of the core and the casing. The plates 1 each comprise a core 2 of fissionable material, two light metal alloy sheets 3a, 3b and a frame 4 which surrounds the core. If the plates are curved from edge-to-edge there is a danger of the outer sheet 3a cracking adjacent the inter-face between the core 2 and the frame 4 and to prevent this the edges of the plates are not curved. After bending, the plates are assembled to a support 5 as shown in Fig. 1. The plate bending machine comprises a table T against which the plate is clamped by the end B of a gripper S. The opposite edge of the plate is clamped by a member 12 against the former 8 which rolls without slipping along the table T. The gripper S is attached to a block 43 which is biased by a spring 45 to move to the left in Fig. 5. A lever 39 is pivoted to the frame at 40, to the block 43 at 41 and to a link 37 at 38. The link 37 is also pivotally connected to a rocker arm 34 at 36, the rocker arm being pivoted to the frame at 35 and having a nose which engages under the head 33a of the pistonrod 33 of an hydraulic jack. The jack raises the table to clamp the plate against the end B of the gripper S, which moves forward to abut the edge of the plate as the upward movement of the piston-rod allows the rocker arm to rotate. The forward movement of the gripper is terminated when the end 15a of a groove 15 in the gripper abuts a stop 14. Bending former.-The former 8 is secured by a tenon 16 to a lever 9 which in turn is connected to an intermediate piece 19. An arm 22 is pivotally connected at one end 21 to the intermediate piece and at the other end to a spindle 23 carried by the piston-rod of a trunnion-mounted hydraulic jack 24. The gripper 12 is connected to a lever 12a which has a horizontal slot 25 in which runs a roller 23a mounted on the spindle 23. The lever 12a also has a vertical slot 26 in which runs a roller 21a mounted on the pivot-pin 21. The former 8 has projecting from one side of it a shaft 50a which is concentric with the centre of curvature of the former and has the same radius. Two flexible metal tapes 50 are wound around the shaft and their ends secured to the frame at opposite sides of the shaft so that as the shaft rotates the former rolls on the Table T. When the jack 24 is actuated the lever 22 rotates about the pivot 21 and causes the roller 23a to lift, carrying with it the lever 12a and the gripper 12, to clamp the plate against the former 8. Rotation of the lever 9 is prevented by a lug 27 on the lever 12a which engages a stop 28 on the frame until the plate is clamped. When the lug disengages from the stop, the lever 9 is rotated by continued movement of the jack 24.