Patent GB-837901-A (GB)
Title: Improvements in or relating to devices for controlling the feed of a tool performingrepetition work
IPC: B23K11/31
Filed: 1957-02-04
Abstract: 837,901. Welding by pressure; stamping; drilling-machine details. REGIE NATIONALE DES USINES RENAULT. Feb. 4, 1957 [Feb. 4, 1956], No. 3824/57. Classes 83 (3) and 83 (4). A device for controlling the feed of a tool which performs repetition work includes two blocks, at least one of which carries a tool, guided on a track and connected together so that within predetermined limits, they can perform relative movement along the track under the action of pressure fluid supplied to the blocks, each block having clamping means controlled by fluid supplied thereto and arranged to co-operate with a part fixed relatively to the track to prevent displacement of the associated block along the track, the arrangement being such that in operation, first one block is prevented by its clamping means from moving with respect to the track while the other is moved, and then said other block is prevented by its clamping means from moving while said one block is moved, the blocks both moving in the same direction along the track so that the tool is fed stepwise along the track. The assembly comprises blocks 1, 2 carrying rollers 19 guided on rails 21 in a track 22, the block 1 carrying a spot-welder 51, or a drill &c., and having grooves 54 in which extensions 53 on the block 2 are slidable. A hollow piston 6 is secured in a bore in the block 1, is supplied with hydraulic fluid from a source A through a tube 3<SP>1</SP>, and slides within the front of a piston 8 secured to the block 2. Hydraulic-fluid from a source B is supplied to the space behind the piston 8, bounded by a stop 15 in the block 1, through a bore 8<SP>1</SP> in the piston. The area of the piston 8 contacted by piston 6 is less than that of the rear face of piston 8. Pistons 26 carrying jaws 1<SP>1</SP> are located in the block 1, and are connected from below with the tube 3<SP>1</SP>, and from above with passages 27, 28 connected to the source B. Similar pistons 12 are in the block 2, and are connected from below with the bore 8<SP>1</SP> and from above with passages connected to the source A. In the first stage of operation, with the pressure supplied only from source B, Fig. 2, the pistons 12 are urged outwards, their jaws 2<SP>1</SP> gripping the rails 21 to lock the block 2 thereto, and the fluid supplied through the bore 8<SP>1</SP> forces the blocks together. In the next stage, with pressure supplied from both sources, the pistons 26 are urged outwardly to lock the block 1 also. In this stage, the welder is closed. In the third stage, with the welder still closed, pressure is supplied only from source A. Jaws 2<SP>1</SP> are withdrawn and the blocks are separated, Fig. 5. In the next stage, pressure is supplied from both sources to move the jaws 2<SP>1</SP> outwardly to grip the rails. Supply of fluid from source A is then terminated, and the jaws 1<SP>1</SP> retract, and pressure acting in space SP3 at the rear of piston 8 moves the block 1 into contact with the block 2, thus moving the welder one step. The relative movement of the blocks may be adjusted by moving the sleeve 3 in the block 1. The application of hydraulic pressure may be controlled by electronic or clockwork means, and the block 1 may carry a number of welders, or each block may carry one or more welders. It is stated that the tool feed-assembly may be applied to a stamping, slotting or drilling machine.