Patent GB-643707-A (GB)
Title: Improvements in or relating to heel-attaching machines
IPC: A43D79/00
Filed: 1948-09-10
Abstract: 643,707. Heel-attatching machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation.). Sept. 10, 1948. No. 23790. [Class 17(i)]. A heel attaching machine has a power operated device for holding the work or on work support. The device acts through pressure limiting means which can be pre-set and which disconnect the power - operated mechanism when the predetermined clamping pressure has been reached. Means are provided for locking the devices in the clamping position while heel attaching nails are driven. A shoe S is mounted on a jack 20 having nail drivers 24. Clamping pressure is applied by mechanism P through holddown abutments 40, 42 mounted on a primary slide 36, (not shown). A projection 50, Fig. 4, on this slide has a tnrust bearing 52 mounting sleeves 56, 58 which are engaged by a spring 60 the top end of which is engaged by an arm 48 of a secondary slide 46. The loading of the spring 60 is pre-set by a handle 88. The secondary slide 46 is raised and lowered by a screw 93 on a shaft 94 engaging a nut 92 in a projection 90. A sleeve 96 on the upper part of the shaft 94 is rotated through gearing 98 by a shaft 100 driven from the main drive shaft 26 and through bevel gearing 104 drives a sleeve 106 in the opposite direction. A clutch c controlled by a double bell-crank lever system l engages either sleeve to drive the screw 93. The clutch c is held in up, neutral or down position by engagement of a roll 124 with recesses 134, 128, 214 respectively in an arm 130 of the levers l. The slides are locked in the pressure applying position by an oil cylinder 178 suspended by rods 180, '180 from the primary slide and containing a piston 182 carried by a bridge-piece 184 on the frame 22. When the valve 186 is closed, fluid is trapped in the lower part of the cylinder 178 locking the slide to the frame. In operation, after positioning the shoe parts, a treadle 30 is depressed against a light spring 132 to depress the arm 116 and move the levers l, counterclockwise, so that the clutch c engages the sleeve 96 to lower the slide 46 through the screw 93. Both slides move together until the spring 60 yields at the pre-set load, when a pin 61 on a rod 59 extending from the arm 48 moves a slide 63 rearwardly. An arm 144, Fig. 1, of the slide 63 engages a roll 140 on an arm 142 to move the levers l clockwise and the clutch c into the neutral position, while the rear of the slide engages a roll on a pivoted segment which turns a rod 160 to engage the main clutch C by raising a rod 174. The shaft 26 then moves one revolution, at the start of which a cam 176 closes the valve 186 to lock the holddown after which the nails are driven. At the end of the revolution, another cam 200, Fig. 4, acts through a roll 212, which moves the levers l to engage the sleeve 106 to raise the holddown, the valve 186 having been first opened by the cam 176. A rod 218 has at the top a locknut 222 which reaches a lug on the projection 90 when the holddown reaches its top position and raises the arm 112 of the levers l to bring the clutch c into the neutral position. A locknut 224 on the lower part of the rod 218 similarly prevents the holddown reaching the jack 20 if a shoe is not in place. The holddown can be raised or lowered by the use of the hand lever 145.