Patent GB-1007125-A (GB)
Title: Improvements in or relating to machines for progressively operating on workpieces
IPC: A43D1/08
Filed: 1961-10-06
Abstract: 1,007,125. Folding edges of sheet material. BRITISH UNITED SHOE MACHINERY CO. Ltd. Oct. 6, 1961 [Oct. 10, 1960], No. 35956/61. Heading B5K. An edge-folding machine for progressively operating on a workpiece comprises an operating tool 38; a work support 17 on which the workpiece is supported during operation of the tool 38 thereon; feeding means 18, 20 to effect step-by-step feeding of the workpiece relatively to the tool 38 comprising a pair of opposed workgripping members mounted to oscillate about an axis 44 and mechanism for causing the workgripping members to grip a portion of the workpiece, then to advance about the axis 44 and then to release the workpiece and return about the axis 44 to grip a following portion of the workpiece; and curvature sensing means 140, 142, 144 arranged to sense curvature in the outline shape of the workpiece and having operative connection with the feeding means 18, 20, the arrangement being such that the sensing means automatically effects shifting of the axis 44 and thus variations in the direction of advancement of the work-gripping members in accordance with changes in the outline curvature of the workpiece fed past the sensing means. The leather workpiece is fed intermittently over a table 17 by a hammer 18 and an anvil 20. Adhesive is applied by a nozzle 42 to the margin of the workpiece which margin is then folded as it is fed against a post 38 having an upwardly projecting finger 40. The anvil 20 having a work-engaging jaw 64, Figs. 1 and 6, is mounted on a carrier 58 pivoted on a stem 56 to a support 54 pivotally mounted about an axis A, Fig. 8, on a bracket 50 pivoted at 15 to the machine frame 10. The hammer 18 is constituted by the upper end of a lever 70 pivoted at 68 to the carrier 58 and the lower end of which is connected by pins 86, 88 to a shaft 46 axially reciprocable in rockshaft 44 driven by the main shaft of the machine. The shaft 46 has a hollow extension 76 with a key 74, Fig. 10 (not shown), engaging the shaft 44 so that the shaft 46 is oscillated therewith. A plunger 82 connected to the pin 86 is urged inwardly by a compression spring 80. Rearward movement of the shaft 46 closes the hammer 18 to grip the workpiece against the anvil 20, the spring 80 allowing for work of varying thicknesses. After this rearward movement the shaft 44 rotates in an anticlockwise direction, as viewed in Fig. 8, to cause a lever 94 mounted thereon to tilt the carrier 58 about the stem 56 to feed the workpiece which is then released. The shaft 44 rotates clockwise and the anvil and hammer return to their original position. During this return a member 22 on a rockshaft 14 is raised through a slot in the table 17 and clamps the workpiece against a lever 24 urged downwardly by a spring 30 into a position determined by adjustment of a screw 36. To stear a curved peripheral portion of the workpiece relatively to the post 38 the support 54 is swung about the axis A by steering means 100. The means 100, Fig. 8, comprises a servomotor 102, Fig. 1, to rotate a shaft 108 carrying at one end thereof a balancing potentiometer 101 and at the other end a resolver 112 having a guideway 114 to receive a segment 116. A shaft 121 is secured to the segment 116 and passes through the end plate 120 of the carrier 58. To enable the carrier 58 to move about the axis A the shaft 121 carries a gear 122 to mesh with teeth 124 on a key 126 disposed in a channel 60 in the carrier 58. The key 126 is carried between plates 132, 134 and provides a link between the lever 94 secured to the plate 132 and the carrier 58, pivots being provided by enlargements 128, 130. Swinging of the support 54 about the axis A causes swing- ing of the lever 94 in the opposite direction about the axis of trunnion pins 92 and blocks 98 limit the swinging of the lever 94 to prevent jamming of the key 126. A photo-electric cell 140, Figs. 3 and 8, is adjustably mounted above the workpiece to receive light through a bent rod 144, of known optical construction, from a bulb 142 and is connected to the motor 102 to position the resolver 112 to swing the support 54 about the axis A, the motor 102 acting to shift the resistance element of the potentiometer 101 to match the balancing signal therefrom to the signal from the cell 140. Specification 749,660 is referred to.