GB1062491A - Improvements in or relating to manually operable crimping tools - Google Patents

Abstract

1,062,491. Jointing by stamping. PLESSEYU.K. Ltd. Jan. 1, 1964 [Jan. 11, 1963; Sept. 6, 1963], Nos. 1343/63 and 35339/63. Heading B3Q. [Also in Division B4] A manually operable crimping tool comprises a rotary cam (5, Fig. 1) and a follower (10) for effecting the crimping stroke, and a buffer spring (12) for conveying the crimping force from the cam to a crimping die. Rotation of the eccentric (5) is by a ratchet wheel (6) turned by a tooth (16) which is moved by a hand-lever (14), a pawl (18) preventing reverse rotation of the wheel (6). The follower (10) supports the elements of spring (12) in a plunger (9) operating a die-actuating rod (1). The follower (10) and plunger (9) move together until the die engages the work, when relative movement between the follower and plunger builds up the crimping force in the spring (12). In a modification (Fig. 2), rolls (21) located in discs (23) are interposed between the follower (25) and cam (24). As the cam is rotated the rolls rotate like planet wheels in contact with the plunger and cam, the discs being rotated between index positions in which they are located by a device (26). In a further construction (Fig. 3) the ratchet wheel (36) drives the eccentric (35) by means of a clutch (37, 38). This permits the eccentric, when it has been rotated just beyond its dead-centre position at the end of a crimping stroke, to rapidly over-run the ratchet-wheel as the buffer spring expands. The over-run, passing the opposite dead-centre position, re-compresses the spring, which reverses the direction of rotation of the cam, reverse-rotation being stppped by re-engagement of the clutch dog (37) in the next recess (38). Spring latches (39) on the ratchet wheel (36) engaging a post (40), prevent the wheel (36) from being carried around by the cam on the over-run. Rotation of the wheel (36) by the pawl (46) causes deflection of the operative latch (39) which, on passing the post and returning to its extended position, propels the wheel forward, causing it to over-run the pawl (46) and take-up any free movement of the crimping die. Alternatively, two posts (40) on the ratchet wheel (36) may co-operate with a spring-latch (39) on the machine-frame. A counter (41) for counting the crimping operations is operated by the latches (39). A twolobe cam may be used if the number of clutchnotches (38) and spring-latches (39) are increased. In another construction permitting over-running of the cam (Fig. 4), this is driven by a pin on the cam engaging the trailing and of an arcuate slot in the ratchet-wheel. The slot permits the cam to over-run the pin, which is biased by a spring towards the trailing end of the slot. A spring-latch may prevent the ratchet-wheel participating in the over-run and an operation counter may be provided. In a further construction (Fig. 5), the eccentric is mounted on a roller bearing and may be surrounded by a roller bearing carrying a collar which engages the follower (10). This is biased towards the eccentric by a spring (58). A rubber buffer (14b) is provided on the hand lever (14), and the crimping aperture (E) between the dies (1A-10) remains square during crimping movements of the dies. The die (10) may be moved against the pressure of a spring (1E) to permit lateral insertion of the work.