GB547595A - Improvements in or relating to machines for and methods of applying and securing a metallic band around an object - Google Patents

Abstract

547,595. Bale-ties. WORKMAN, E. R. May 13 1940, No. 8612. Convention date, May 3, 1939 [Class 45] The strip or wire by which a box &c. or a structural element, is banded has its ends butt welded together. The wire 6 leaves an adjustable slip-spring drum reservoir 4 and after passing over a jockey pulley 7 is gripped between a row of pairs of power-driven rolls 14. From the end rolls it is threaded through a rockable sleeve 51 and thence passes round a stationary circular track 9 till its free end enters grippers 20 and abuts against a stop 18. The wire is located medially of the track 9 by two rows of staggered studs 17 having a flared form to retain the wire except when the latter is given a sharp tug as when the tightening thereof takes place during the wrapping process. Alternatively the track has a groove covered by a lid slid thereover by a serpentine spring and made self-opening by the reverse drag of the wire; or for a band two U-springs with turned-up rims may be employed. The tightening is effected by reversing the direction of rotation of the rolls 14 which are driven by one or the other of two electromagnetic clutches mounted on the drive counter-shaft. The clutch members are given a continuous rotation in opposite directions by a V-belt 31 passing round the clutches and round a lay-off pulley 34, and are automatically switched on and off by cams on a shaft 43 continuously driven from the shaft of pulley 34. The wire 6 before entering the track 9 passes between spring jaws 56 which gape apart to accommodate a bight of the wire formed by the inertia of the latter when its end comes against the stop 18. The stop 18 forms the top of one member of scissors 53, 63 which sever the wire when a cam on shaft 43 lowers the member 53 immediately after the loop is complete and tightened about the parcel. The newly severed end of the wire is held between grippers 55 which are then automatically raised by a cam on shaft 43 to bring it into abutting relationship with the end held by grippers 20. The tightening of the wire has previously raised a frame 10 carrying the roll, clutch, &c. parts about a pivoted lever 11, and pulled it into position close under the parcel lying on the platform 2, this movement being assisted by a crank 48 on the end of shaft 43 striking against an abutment 49, the crank serving subsequently gently to lower the frame. The current is passed through the grippers 20 and 55, which are insulated from one another, at the required moment by a cam contact on shaft 43, and after welding both grippers 20, 25 are released and the frame 10 lowered. The cycle may be made to terminate with the striking of the wire end against the stop 18. Each gripper has a serrated and a plain jaw, to prevent the wire welding itself to the jaws.