GB1149965A - Improvements relating to apparatus to feed superposed webs for seaming - Google Patents

Abstract

1,149,965. Seaming non-metallic sheet material. DETEXOMAT Ltd. 5 Dec., 1966 [10 Dec., 1965], No. 52632/65. Heading B5K. [Also in Division D1] A clamp feed for a seaming machine comprises mounting means carrying work-clamp means and being rotatable for feeding the work along a seam path of one predetermined radius, carrier means rotatably carrying the mounting means and also being movable to feed the work along another seam path, common drive means for selectively moving the carrier means and/or rotating the mounting means relatively to the carrier means, and control means to effect such selection automatically according to the predetermined form of the seam line. A shaft 18, adapted to be motor-driven in one direction through a predetermined angle and to be returned to its initial position by spring means, is rigid with an arm 23 carrying at its free end an arcuate rack 24 concentric with shaft 18. An arm 25 is pivoted at one end on shaft 18 and journals at its other end a shaft 28. The lower end of the latter is rigid with a gear sector 29 meshing with rack 24, and the upper end is rigid with the lower arm of a yoke 32. A lower work clamp plate 42 is rigid with two pins 40, 43 slidably supported in the upper arm of yoke 32, pin 40 being coaxial with shaft 28. A spring 46 biases plate 42 upwardly. An upper work clamp plate 39 is rigid with a pin 41, coaxial with pin 40 and slidably supported in the upper end of an arm 36, the lower end of which is rigid with arm 25. A spring 47 biases plate 39 downwardly. Upper and lower clamp jaws 12U and 12L are detachably secured to respective plates 39, 42 by means of spring catches 51, 52, and are held from rotation relative to one another by a pin (53). The clamp jaws each comprise a margin 55 of rubber or plastics shaped to the contour of the seam required. An arm 30, rigid with gear sector 29, carries a follower roller 31 engaged in a cam groove 22 formed in a fixed plate 21. The clamp jaws are separated by means of lever arms (59), (60) engaged in recesses 63, 64 provided in plates 42, 39 respectively, for the reception of the flattened toe end of a stocking blank 1, roller 31 then occupying an initial position 31S. Arm 23 is then moved counterclockwise, whereby roller 31 travels along portion 66 of groove 22 and the workpiece is moved to the starting position 4. Roller 31 then travels along a portion 67 concentric with shaft 18, whereby sector 29 does not rotate and arms 23 and 25 turn together to move the workpiece past the seaming elements along an initial curved path 5 corresponding to a radius R1 about a centre C1. Roller 31 then travels along a portion 68 concentric with pin 28, whereby sector 29 rotates and arm 25 remains stationary, while the workpiece moves along an intermediate curved path 6 corresponding to a radius R2 about a centre C2. Roller 31 finally travels along a portion 69 concentric with shaft 18, whereby sector 29 does not rotate and the arms 23, 25 turn together to move the workpiece along a final curved path 7 corresponding to the radius R1 about a centre C3. The direction of rotation of shaft 18 is then reversed, whereby roller 31 travels along portion 69 and a portion 70 to its initial position 31S. In a modification the cam groove is adapted for closing a stocking blank along the sole portion