Patent GB-837763-A (GB)
Title: Improvements in and relating to mechanism for tying packages and the like
Inventor: MOSEY FREDERICK WILLIAM
IPC: B65B13/30
Filed: 1956-08-31
Abstract: 837,763. Banding-machines. SEAL-LESS STRAPPING Ltd. Aug. 7, 1957 [Aug. 31, 1956], No. 26627/56. Class 94(1). [Also in Group XV] A machine for tying packages with flexible binding material S1 Fig. 4, of the type in which a reversible feed 19, 20, feeds the strip past a severing device 16, through a jointing device 14, 15, around the interior of a guide surrounding the package, past a gripper 13 and back again into the jointing device 14, 15, against a retractable end stop 18, at which stage the free end S2 of the strip is then held by the gripper 13 whilst the feed 19, 20, is reversed to tension the strip around the package ; the machine is characterised in that the jointing device comprises at least two dies 14 and 15, the first die 14 serving to unite the strip to itself sufficiently to permit the cutter to be operated, where after the second die 15 is closed to complete the joining of the strip to itself. Before the second die 15 operates, the gripper 13 is preferably opened to permit the tension in the encircling strip to be assumed by that portion of the end S2 that extends between the die 14 and the gripper 13. The dies 14 and 15 punch shouldered incisions through the overlying portions of the strip such that the shoulders become interengaged. Electrode welding. After the dies 14 and 15 have operated, a welding electrode may be moved on to the coextending portions of the strip, if of metal, to weld a supplementary connection between them. The electrode may slide within a retractable alignment guide 17. Cutter. The strip S1 is severed by a cutter on the die 15 coacting with a shearing blade 16 as the die 15 moves to its closed position. Reverse feed wheels. The feed wheel 19 comprises a roller freely mounted on a shaft between two constantly but oppositely rotating coaxial clutch members, the clutch members being moved in turn by cam means axially along the shaft and into frictional engagement with the roller. The frictional clutch means limits the tenison set up in the end S1 of the strip during the reverse feed. Additional tensioning device. A final tensioning device 22 may be disposed between the gripper 13 and the reversible feed 19, 20. This device, in its non-working position, permits free passage of the strip S1 in both directions, but after the strip has been initially tensioned by the rollers 19, 20, the device 22 is displaced in the direction of the roller 19 and, in doing so, it closes on the strip and exerts an additional tension in the band around the package. Following the completion of this additional tensioning, the die 14 operates and the device 22 is then caused to reopen and move back to its inoperative position whilst the cutter and the die 15 operate. As shown in Fig. 9, the additional tensioning device comprises a gripper 22 slidable along a shaft 62 by cam operated means 61 acting through a spring 64. The metal strip (not shown) passes between an upper jaw 66 and a lower eccentric jaw 67, the lower jaw 67 being normally held open when the gripper 22 is inoperative by an extension 68 of the jaw 67 abutting against a stop 69, thus permitting free passage of the strip under the influence of the feed in both directions. When the block 63 moves to the right this extension 68 leaves the stop 69 and the jaw 67 closes on the strip under the influence of a spring 70. During this stroke a pair of pawls 71 mounted on the extension 68 ride along a toothed ratchet 72, this engagement being under the influence of springs 73 weaker than the spring 70 so that there is no tendency for the jaw 67 to re-open at this stage. During the return motion of the block 63, following completion of the tensioning, the pawls 71 engage the steep faces of the ratchet 72, thereby overcoming the spring 70 and causing positive partial opening of the jaw 67 sufficient to permit a free return of the gripper 22 along the strip, until finally said jaw is fully opened again by the stop 69. Specifications 578,854, 805,765, 837,761 and 837,762 are referred to.