Patent GB-1171321-A (GB)
Title: Strapping Apparatus
IPC: A01D59/00
Filed: 1967-07-21
Abstract: 1,171,321. Bundling machines. GERRARD WIRE TYING MACHINES CO. PROPRIETARY Ltd. 21 July, 1967 [21 July, 1966], No. 33755/67. Heading B8C. Bale strapping apparatus includes a sealing head for securing a seal blank about overlapped portions of the strap, the sealing head having gripping means for releasably gripping the leading portion of the strap to permit the strap to be tensioned, seal blank crimping means and strap severing means, and is characterized in that the sealing head is operated in two stages, viz. (i) a first stage in which the gripping means adopts its strap-gripping position, and (ii) a second stage in which the crimping and severing means are moved to their crimping and severing positions respectively, control means causing a delay between the two stages during which delay the strap is tensioned to a predetermined degree about the bale. General arrangement (Fig. 1).-The invention is applied to a press in which a wool bale 12 is first compressed vertically between a stationary platen 3 and a platen 4 moved by an hydraulic ram 7. It is then compressed horizontally between a stationary platen 11 and a platen 9 moved by a ram 8. An inlet door (13), Fig. 2 (not shown), to the press chamber is hinged at (16) and operated by a ram (17). An outlet door (14) is slidable vertically by a ram (18). A bale ejector (23) is operated by a ram (19) attached to the outer side of the inlet door (13) Strap feeding and tensioning means (Fig. 12). The straps may be of metal, rayon, nylon, polypropylene &c. and are fed from reels (not shown) and between the guide blocks 164 by rollers 31, 32. Rollers 31 are driven by a reversible motor (38). Each roller 32 is biased towards one of the rollers 31 by a spring (53), Fig. 5 (not shown), acting through an arm (51) and an eccentric mounting (47) for the roller 32 (see Fig. 6, not shown). Reverse rotation of the rollers 31 effects tensioning of the straps. Strap gripping means (Fig. 19).-The strap 194 is clamped against an anvil 59 by jaws 63 which are moved by toggle arms 65 pivotally connected at 68 to a connecting rod 66. The jaws 63 are carried on pins 73 sliding in slots 72 in a guide block 71 having surfaces 74 which co-operate with pivot pins 69 to cause swinging of the jaws. The connecting rod 66 is reciprocated by means of a crank-shaft (67), Fig. 5 (not shown). Crank-shaft (67) is oscillated by a two-stage piston-cylinder assembly (106), Figs. 14 to 16 (not shown), through a rack (112) and pinion (111), Figs. 4, 5 (not shown). Crimping means (Fig. 9).-A seal blank 136 is secured about the ends of the strap 194 by e.g. three pairs of crimping jaws 77 which are of similar construction to the gripper jaws 63. The seal blank crimping means also includes notching plates 83 mounted between the crimping jaws and each provided with two notching lands 84. The crimping jaws 77 are operated by the reciprocating connecting rod 66 through toggle arms 86 in a similar manner to the gripper jaws 63. The seal blank is held in position during crimping by one or more pressure bars 97 each having an arcuate recess formed in its side and engaged by an arcuate projection 98 on the jaw arms 82. Strap severing means (Fig. 12).-This ineludes a cutter plate 99 actuated by movement of the crimping jaws 77 and co-operating with the upper edge of the anvil 59. Seal blank feeder.-The seal blanks 136, which are of divergent channel form (Fig. 9) are housed in a magazine 139 (Fig. 12) and biased towards the inner end thereof by a spring biased member (141) (Figs. 5, 7, not shown). The seal blanks are fed downwardly one at a time by means of a vertically slidable ejector tongue 148. (Fig. 12) which is urged downwardly by a spring 152, under the control of a cam-operated bell-crank lever 153. This lever 153 is pivoted to the ejector at 157 and to the magazine 139 at 158. A cam follower 159 attached to the lever 153 is engaged by a cam plate 161 during reciprocal movement of the connecting rod 66.