Patent GB-811481-A (GB)
Title: Improvements in or relating to bending apparatus
IPC: B21D3/10
Filed: 1957-02-21
Abstract: 811,481. Angular bending; straightening. SHEFFIELD CORPORATION. Feb. 21, 1957 [Feb. 29, 1956], No. 5873/57. Class 83 (4). [Also in Group XIX] Apparatus for bending a part to a predetermined configuration comprises a base adapted to support said part, controllable force applying means on said base for application of force of selected magnitude and direction to said part, means on said base for gauging the part configuration, and control means operatively interconnecting said force applying means and said gauging means for determining a force application to the part in response to the amount the part is bent by an applied force and the deviation of the part from its predetermined configuration. Air leakage type gauging spindles 11 and 12 (Group XIX) are moved down by hydraulic pressure means 38, into piston pin and crank holes of a connecting rod 10, positioned by pins 27 on a slide 25 pushed into the gauging and bending station, to gauge the parallelism of the holes and the bend of the rod in a plane including the spindle axes. The gauging results are fed to an electric circuit which automatically controls solenoids in an air hydraulic system, Fig. 9, to open or close valves to retract the gauging spindles 11 and 12 and apply the proper one of upper and lower hydraulic plungers 14, 15 to the centre of the rod with one of four different forces, provided by pressure regulators 105, 106, 107, 108 in a pneumatic system, and selected, according to the deviation of the holes from the desired parallelism, by solenoid-operated valves in the pneumatic circuit between the regulators and an hydraulic booster 134. Solenoid-operated valves 140, 141 direct hydraulic pressure from the booster 134 to the proper one of the hydraulic plungers 14, 15. The rod 10 is then automatically regauged. If the deviation of the rod 10 is still in the same direction a greater force is applied to the rod and if the deviation is in the opposite direction a lesser force is applied. The cycle is automatically repeated, selecting the force to be applied from six values, a pressure regulator 109 for very light forces and 110 for very heavy forces now being available, until either the rod is brought to a satisfactory configuration or a predetermined number of force applications have been made. If at any time after the first force application the maximum pressure available is inadequate or the minimum pressure excessive, the rod is gauged as a reject. Gauging. Each gauging spindle 11, 12 has orifice outlets in its walls for the leakage of pressure air, Fig. 8. The spindle 11 has opposed orifices 42, 43 and the spindle 12 orifices 44, 45 all connected to a common gauging circuit 46. Opposed orifices 48, 49 in the spindle 11 and 50, 51 in the spindle 12 are connected to another circuit 52. The pressure difference between the circuits indicates the deviation of the holes in the connecting rod 10 from parallelism. The circuits 46, 52 are connected to four differential gauging heads 340, 341, 342, 343 each comprising a diaphragm 80 between the circuits which is deflected towards one or other switch contact 340A, 340B. A visual indication of the gauge finding is given by a float 91 in a tapered tube 92.