GB886943A - Rotary clutch for use between rotary electric switches and their drive - Google Patents

Abstract

886,943. Ratchet clutches. NAIMER, H. L. Oct. 20, 1959 [Oct. 29, 1958], No. 35571/59. Class 80 (2). [Also in Group XXXVII] A ratchet clutch between a driving shaft rotated by a half-revolution magnetic motor which is returned by spring means to its initial position following each driving motion, and a driven shaft which actuates a series of switches (see Group XXXVII), comprises a driving hub 10 fast on the motor shaft, formed with partradial grooves 10a in which slide the ends 12b of pins 12a mounted for radial movement in slots 14a in an intermediate clutch disc 14, a driven clutch disc 11 having radial slots 13 which can be engaged by the pins 12a. The intermediate clutch disc 14 is restrained from rotation either by light friction engagement with a housing 15. On initiation of rotation of the driving clutch disc 10 in the direction of the arrow A, the intermediate clutch disc 14 is at first held stationary so that the inclined grooves 10a cam the pins 12b radially outwards into engagement with the slots 13. The driven clutch disc 11 then rotates, the rotation of the driving clutch disc 10 overcoming the friction resistance to rotation of the intermediate clutch disc 14, until the magnetic motor has performed its driving halfrevolution. The driving magnetic motor is finally restored to its initial position by spring bias, rotating the driving clutch disc 10 backwards, so that the pins 12a are drawn inwardly out of engagement with the slots 13, and the intermediate clutch disc 14 is itself restored to the initial position. To avoid transmission of a substantial torque through the relatively narrow pin ends 12b to the intermediate clutch disc 14, bolts &c. 10b carried by the driving clutch disc 10 engage in arcuate slots 14b in the intermediate disc, these latter slots being of a reduced length so that the bolts engage the driving ends thereof before the pin ends 12b have reached the ends of the grooves 10a. Parts of the clutch may be made from synthetic thermoplastics, such as polyamides &c. A cam roller 16 engaging the intermediate disc 14 may control a switch 17 in the circuit of the driving magnetic motor in such a way as to re-start the motor when the initial position has been reached, whereby a series of impulses are given to the driven clutch disc 11. The clutch according to the invention is described as applied to the drive of a multiple switch arrangement, disengagement of the clutch when the driving motor is stationary permitting the driven clutch disc 11 and the switch shaft fast therewith to be turned in either direction by a separate hand control knob. Specification 880,458 is referred to.