Patent GB-995603-A (GB)
Title: Improvements in or relating to machines suitable for applying pressure to shoe bottom members
Inventor: KESTELL THOMAS AUBREY
IPC: A43D25/06
Filed: 1960-05-24
Abstract: 995,603. Applying pressure to shoe bottom members. BRITISH UNITED SHOE MACHINERY CO. Ltd. Aug. 23, 1961 [May 24, 1960], Nos. 18210/60 and 749/61. Heading A3B. A machine for applying pressure to shoe bottom members comprises opposed clamp members and a fluid pressure system to bring about relative movement of approach between said clamp members, control means to determine the pressure to which the sole is subjected and means for reducing the initial pressure and speed during the later stage of the relative movement between the clamps. Each one of two operating stations incorporates an electrical circuit including a solenoid arranged to be automatically energized at the end of a 'dwell' period to cause release from pressure of the work held under pressure between the clamps. One of the clamps comprises a ram 6 in the form of a cylinder slidably mounted as a stationary piston 90. A spool valve 128 is opened to initiate upward movement of the ram, oil being pumped into the ram via a non- return valve 136. The oil escaping from the ram returns to the sump via an oilway 218 and check valve 602 which is normally held open by a spring 612 so that initially the ram is raised relatively fast. When the work supported thereon engages abutments 18, 20 associated with the other clamp member mounted in a pressure head 10 associated with that operating station, the abutments yield to actuate a switch 22 in an electrical circuit to cause a low pressure relief valve 190 to take over control of the pressure in the hydraulic system from a maximum pressure relief valve 156 which initially controls the pressure in the system. As a result oil is automatically bled through a communicating passage 618 between the low pressure relief valve 190 and the check valve 602 to close the check valve so that the passage of oil escaping from the ram is restricted to slow down the ram. When the work is correctly supported under low pressure a hand control 600 is actuated to raise the clamping pressure to the maximum desired. On said actuation the maximum pressure relief valve 156 takes over control and the check valve 602 automatically opens so that oil can escape freely from the ram thus allowing the ram to move as quickly as possible to apply the maximum pressure. A toe abutment 18 and heel abutment 20 are supported on depending legs 42, 44 respectively which are adjustable towards and away from each other or slides 48 and 50 provided on the ends of shafts 52, 54 which are adjustable heightwise. In operation the work is first engaged in the toe region by abutment 18, further upward movement of the work support causes the abutment 18 and shaft 52 to yield upward to rotate a load balancing lever about its pivot pin 70, said lever bridging the two shafts 52, 54 and rotation of which urges the shaft 54 downwardly until abutment 20 engages the top of the last in the heel end region. Further upward movement of the work support causes both shafts to yield upwardly, the lever being raised by movement of its pivot 70 up a slot 72 so that the switch 22 is actuated.