GB1243074A - Improvements in or relating to clutches - Google Patents

Abstract

1,243,074. Positive clutches; clutch control. ELEKTRONISCHE RECHENMASCHINENWISSENSCHAFTLICHER INDUSTRIEBETRIEB-KARL-MARX-STADT. VEB. 25 Nov., 1968, No. 55890/68. Headings F2C and F2L. A positive action rotary clutch particularly suitable for use in high-speed office machinery comprises a driving member 2 having a driving element 12 which continuously drives a clutchengaging member 11. A clutch-actuating rod 10 is secured to the member 11 and passes through bores 8, 9 in the driving member 2 and in a gear 3. Dogs 6 on one face of the gear 3 may engage the member 11 and drive is then transmitted to an output gear 4. The other face of the gear 3 has dogs 7 which may be engaged by a brake 13 axially movable with the rod 10. The rod also carries an armature 15 of an electromagnet 16. A cam 18 is continuously driven with the driving member 2 and the rod 10 is biased to the left by a spring 17. The cam rotates at the same speed as the member 2 and engages the rod 10 with maximum lift when the plane through the dogs 6 and the rod is substantially at right angles to the longitudinal axial plane of the member 11. If the magnet is energized at this point of lift the rod 10 is held against return, the member continues to rotate until it engages the dogs 6 and the gears 3, 4 are driven. To disengage the drive, the magnet is de-energized and, as the cam 18 passes the maximum lift position, the brake arms 13A move into the path of the dogs 7. With the cam now in its minimum lift position, the member 11 moves clear of the dogs 6. Although the member 11 moves axially into the path of the dogs 6 during each revolution there is no engagement due to the relative rotational positions of the dogs 6 and the member. In place of the cam 18, a cam secured to the housing 1, by co-operating with a detent on the member 11, causes one forward-and-return movement of the rod 10 for every revolution of the driving member 2.