Patent GB-125481-A (GB)
Title: Improvements in or relating to Pincers or Grippers.
Inventor: BAUER CHARLES
IPC: A43D21/16
Filed: 1917-05-16
Abstract: 125,481. Bauer, C., (Eddels, C. W.). May 16, 1917. Pincers.-Pincers or a gripping-tool, which may be used in boot-lasting machines for stretching the upper about the last, comprises two gripping-jaws, one of which is adapted to receive a compound movement consisting of a movement of translation from its open position to a position beyond the other jaw and over the object to be gripped and a swinging movement towards the other jaw, the latter jaw being mounted to yield in the direction of the closing pressure, and the jaw-operating mechanism being adapted to impart successively in one operation the closing movement of the jaws and a bodily movement of the closed jaws, together with the object gripped, in a direction approximately at right-angles to the direction of the closing pressure. The tool comprises a main lever 27, Figs. 1 and 13, pivoted on a stud 7 extending between side plates 1. One gripping-jaw 22 is carried by a plate 21 pivoted on a pin 55 carried by an arm 20 pivoted on the stud 7 and the other jaw 23 is carried by a member 24 slidable on the lever 27 against the action of a spring 51. The arm 20 is connected by a link 26 and pin 44 to a cam comprising a member 18 pivoted by a pin 41 to the lever 27 and a member 19 slidable on the member 18 against the action of a spring 29. A spring 30 normally holds the cam member 19 in contact with a cam 17 pivoted by a pin 40 to the lever 27 and operated by a chain 15 which passes round a guide 3 and sprocket 12 so as to be operated by the foot. The cam 17 carries a pin 37 engaging the edge of a. fixed guide 4, one part of which is concentric with the pin 40 and the other part concentric with the pin 7. The cam 17 also carries a pin 38 engaging a slot 39 in a lever 16 pivoted by a pin 42 on the lever 27 and provided with another slot 62 engaging a pin 46 on the plate 21. The plate 21 is connected by a slotted link 25 to a pin 50 adjustable on the lever 27. Springs 31, 28 hold the lever 27 and cam 17 in their normal positions shown in Fig. 1. In operation, by pulling the chain 15, the cam 17 is turned, first throwing forward the cam 19, link 26, arm 20, and jaw 22 and then, by the action of the pin 38, depressing the lever 16 to turn the plate 21 about the pivot 55 to cause the jaw 22 to approach the jaw 23 as shown in Fig. 4. Further movement of the cam 17 permits the return of the cam 19, link 26, and arms 20 to normal position, causing the jaw 22 to grip the object between itself and the jaw 23 which yields in the direction of the closing pressure. The pin 37 is now in engagement with the part of the guide 4 which is concentric with the stud 7 so that, on further pulling the chain 15, the lever 27 moves about the stud, and the jaws 22, 23 move bodily in a direction approximately at right-angles to the direction of the closing pressure. When the chain 15 is released, the springs 31, 28 return the parts to normal position, but owing to the yielding sliding connexion of the cam members 18, 19, the opening of the jaws is effected without a forward movement of the arm 20, but if desired the spring 29 may be replaced by a link so that the movements of the parts during the opening of the jaws is similar to that during the closing movement. The angle at which the jaws 22, 23 meet may be varied by adjusting the position of the pin 50. The sprocket 12 is mounted on a plate 10 slidable against the action of a spring 6 so that it may yield under excessive strain. The plates 1 are connected by tubular members 8 which permit a number of the tools to be threaded upon a wire so as to grip an object at a number of points.