GB1094469A - Strap tensioning and severing tool - Google Patents

Abstract

1,094,469. Strap tensioning tools. PANDUIT CORPORATION. June 6, 1966 [July 26, 1965], No. 25196/66. Heading F2G. A tool for tensioning, securing and severing flexible binder straps around bundles of wire &c. includes a toothed gripper 64 urged in a counter-clockwise direction by a spring and pivoted on a tension-rod 41 and for cooperation with a back-up boss 67 to grip the free end of a strap 56, and a cutter blade 76 for severing the strap after a predetermined tension has been applied thereto. The strap is looped about a bundle of wires 59 and the free end thereof fed through a connector 57 and between the gripper 64 and boss 67 and squeezing of the actuator handle 65 causes the latter to pivot about a pin 91, the motion of the handle being transmitted to an actuator link 95, pin 97, drive link 98, and pin 99 to a lever link 100 which pivots in a clockwise direction about pin 103 whereby the rod 41 is pulled to the right as seen in the Figure to disengage the gripper from the face 52 of the boss 50; the gripper rotates in a clockwise direction causing the teeth 65 thereof to grip the underside of the strap and the connector 57 comes to bear on the plate 80 of the tool as the tension builds up in the strap. The force exerted on the pin 103 is applied to link plates 104 also pivotally mounted on the pin 91 and carrying a roller 123 seated in a recess 127 of a detent 125. As the tension in the strap reaches a predetermined maximum, the restraining force applied by the detent is overcome and the roller cams the detent in a clockwise direction so that the roller snaps out of the recess to instantly relieve or reduce the restraining force on the plates 104 to permit the plates to pivot to the normal position thereof. This latter movement causes a pin 120 to pivot a lever arm 70 about a pin 71 to raise the cutter blade 76 and to sever the strap at which moment the rod 41 is drawn further to the right to bring the gripper into contact with the screw 62 to cause the gripper to be cammed to the normal position thereof and release the grip on the strap. After severance of the strap the surface 129 of the detent cams the roller 123 into the recess 127 and to return the plates 104 and blade 76 to the normal positions thereof. Release of the handle 85 permits spring 33 through yoke 111 to return the handle to the normal position thereof, the link 100 to move the rod 41 to the left and the gripper 64 into contact with the boss 50. A tension adjustment knob 162 is rotatable to selectively raise or lower a block 135 to vary the compression of the spring 155 and thus vary the restraining force applied by the detent 125 to the plates 104 and therefore the tensioning force applied to the strap. The block 135 may have inscribed thereon an index line visible through an opening in the tool handle and for co-operation with reference lines to indicate the tension which will be produced in the strap. In modifications, the spring 155 is replaced by an electromagnet or a pneumatic piston-cylinder device.