GB378507A - Improvements in or relating to one-revolution clutch mechanism for telegraph apparatus - Google Patents

Abstract

378,507. Operating clutches. CREED & CO., Ltd. and SALMON, R. D., Telegraph Works, Croydon. May 14, 1931, No. 14253. [Class 80 (ii).] In one-revolution clutch mechanism for start-stop telegraph receivers in which a member actuated by a relay responsive to successive elements of received signals releases the clutch on receipt of the first element of a series of impulses and actuates selecting- mechanism in accordance with the character of succeeding permutation impulses, a spring- biased clutch-controlling detent is tripped by the relay to release the clutch and, on commencement of the resulting rotation, is mechanically returned to the clutch-arresting position, being thereafter out of operative relation with the relay. A clutch trigger 2 is engageable by a detent 3, which is pivoted at 4 and biased by a spring 5 to the release position against a stop 6 except when held by a spring-pulled latch 7 coacting with a fixed part 8. On the operation of the relay-magnet, acting through a link 13 and rock-shaft 12, a release-member 11 acts on a lug 10 to disengage the parts 7, 8, so throwing in the clutch 1, which rotates a cam 14. A bell-crank lever 15, 17 is then cammed out of a depression 19 and acts by a projection 18 to position the detent 3 for declutching at the end of the revolution. Until the revolution is nearly completed, the projection 18 holds the detent far enough forward to keep the lug 10 clear of the member 11, which bears under a spring 21 against a stop 20. By this means, reciprocations of the member 11 caused by oscillations of the rock-shaft 12 to actuate selecting-mechanism during rotation of the clutch are not impeded by the load of the spring 5. The member 11, if depressed at the instant of declutching, will be slightly swung aside by the lug 10. Adjustment of the spring 5 by a screwed head 22 varies the delay-period between the starting-impulse and clutch engagement. Specification 245,149, [Class 40 (iii), Telegraphs, Electric], is referred to.