Patent GB-1129278-A (GB)
Title: Clamping device
Inventor: HONERT TAKO HAJO VAN DEN
IPC: G06K1/02
Filed: 1966-04-18
Abstract: 1,129,278. Selective punching. INTERNATIONAL BUSINESS MACHINES CORP. 18 April, 1966 [20 April, 1965], No. 16855/66. Heading B4B. [Also in Division E2] A clamping device for use in selective punching comprises two clamping members 2 resiliently urged together by an external force and having respective clamping surfaces between which an article may be clamped, wherein each clamping surface is formed with a recess 1, the device including means to introduce pressurized fluid into the recesses, whereby, upon the introduction into the recesses of fluid at a suitable pressure, the clamping members are forced apart to release a clamped article. In the construction shown there are a large number of clamping members each having a clamping surface on each side so that articles 4 can be clamped between adjacent clamping members. The fluid introduced to the recesses is air under pressure applied via pipes 5, the air forcing the adjacent surfaces apart and allowing the articles to be withdrawn from between them. The clamping device is for use in a paper tape punch, the clamped articles being selectively releasable; each clamping member 2 is suspended from a square shaft 9 by means of a resilient strip 8 secured to a lug of the clamping member and having a square hole by which it is threaded on to the shaft; the strips 8 are spaced along the shaft by collars 10 and the spring 3 is a leaf spring which urges the clamping members 2 against a frame upright to which one end of the shaft 9 is secured; the tension of the leaf spring is adjustable by means of a screw 11. The articles are flat plates 4 each having a central hole so that the recesses in adjacent clamping members are connected together via the hole so that it is only necessary to bring a pipe 5 into one recess of each pair. Each plate 4 terminates in a tongue which is pivotaly attached to a latching arm of a three arm lever 6 and each lever 6 is biased by a spring 12 for clockwise movement and thus tends to pull the plate 4 to which it is attached to the left. A yoke-shaped cam follower 14 is pivoted at 15 and carries an interposer 7 which is pivotally attached at 17 to one arm of the yoke. The other arm carries a roller which bears on a cam 16 under the bias of a spring 19. One end of the interposer 7 is engaged in a slot in a punch 18 while the other end is adapted to be engaged by a lug 13 on the latching arm of the three arm lever 6. When fluid uner pressure is admitted to the coupled recesses in a pair of clamping members, the corresponding plate 4 is selectively released and this releases the three armed lever 6 connected to the plate so that the spring 12 rotates it clockwise and the end of the interposer 7 becomes engaged by the lug 13 on the lever. As a cam 16 rotates, cam follower 14 rocks anti-clockwise about pivot 15 with the result that interposer 7 is also rocked clockwise about the fulcrum formed by lug 13 and operates punch 18; when the plate remains clamped, cam follower 14 is rocked anti-clockwise by cam 16 and interposer 7 rocks clockwise about the fulcrum formed by its engagement with punch 18 without moving the punch.