Patent GB-1480987-A (GB)
Title: Bundle tie tools
IPC: B25B25/00
Filed: 1975-10-20
Abstract: 1480987 Strap tensioners AMP Inc 20 Oct 1975 [25 Nov 1974] 42954/75 Heading F2G A stainless steel self-latching bundle tie (Specification 1,413,458, Divisions E1-E2) is tensioned to a pre-determined value and then trimmed by inserting a free end 16 into a tool 10 and operating a handle 88 of an actuator 36 to first produce the pre-determined tension by drawing the tie into the tool and then, having released the tie to allow it to latch, cutting off the excess by means of blades 186, 188. Tensioning.-To draw the tie into the tool 10 a pawl 146 grips it against the sloping upper surface 76 of a reaction plate 56. The pawl 146 is connected to the handle 88 by a tensioning arrangement comprising a pair of longitudinal guide plates (126, 128, Fig. 4, not shown), a first slide block 120, a draw bar 106, a second slide block 114 and a pair of cranks 92, so that movement of the handle 88 in the direction of the arrow 228, Fig. 3, causes the pawl 146 and hence the tie end 16 to be drawn to the right. The reaction plate 56 is slidable longitudinally and spring-urged 70 to the left Fig. 3, so that it moves with the pawl 146 during tensioning. Pre-defermined tension.-This is produced by an arrangement which disengages the pawl 146 from the tie end 16 when the level has been reached; the arrangement comprises a block 158 spring-urged away from the first slide block 120 of the tensioning arrangement by means of Belleville washers 160, the end of the block 158 nearest the pawl 146 being connected to the pawl by a pair of plates 140, 142 pivoted on pins 138, 180 that fit into elongated holes allowing the ends of the plates 140, 142 to move vertically, the plates being so arranged that the washers 160 tend normally to urge the pawl 146 against the reaction plate 56. When the tension in the tie exceeds the value of the compressive force of the washers 160 the plates 140, 142 rotate clockwise to reduce the grip of the pawl 146 on the tie, the reaction plate 56 returning to its initial position and providing a flat surface 78 beneath the pawl 146 to allow the tie to slide and latch. A cam adjustable through an aperture in the frame of the tool 10 allows the force generated by the washers 160 to be altered. Trimming.-The tie end 16 is cut by a blade 188 moving against a fixed blade 186, the movement being produced by the handle 88 through the tensioning arrangement and a cutting arrangement comprising a pair of slides 212, a pair of cranks 202, a pair of links 198 and a slidable mounting member 194 which carries the movable blade 188. The tensioning arrangement and cutting arrangement are connected by a pair of connecting slides 174 fixed to the pivot pin 180 joining the plates 140, 142 to the block 158, the connecting slides 174 engaging the end surfaces 234 of the slides 212 only when the plates 140, 142 rotate on reaching the predetermined tension. A spring 124 around the draw bar 106 returns the tensioning mechanism on release of the handle 88. A projection 222 engages one of the vanes of the tie and so retains the tension in the event that more than one movement of the handle 88 is necessary to produce the pre-determined tension.