GB538320A - Improvements relating to time-lag devices such as incorporate gearing - Google Patents

Abstract

538,320. Intermittent toothed gearing. ROTHERHAM & SONS, Ltd., and LITCHFIELD, S. E. March 2, 1940, No. 3939. [Class 80 (i)] Relates to a time-lag device of the kind including a driving element in the form of a rack, quadrant or like gear with discontinuous teeth, which is always returnable after an operation to the same position, a time-delay mechanism and a train of gearing there-between, the timedelay mechanism including a vaned member, escapment wheel or the like which is not itself adjustable. According to the invention, the train of gearing includes a pinion meshed with the driving element which pinion can be positioned by an irreversible mechanism relatively to the teeth of the driving element when stationary, so that the period of operation of the time-lag device may be varied without varying the length of the operating stroke. The driving element comprises a toothed sector 11, Fig. 1, integral with an arm 12 pivoted to an actuating rod 13 which may be spring or solenoid actuated, a stop 14 being provided to limit the return movement. The sector meshes with a pinion 15 which is long enough to mesh also with a wheel 21 which drives a pinion 22 which, through a ratchet wheel 24, Fig. 2, and gearing 25, 26, 28 drives the escapement wheel 27. The pinion 15 is mounted on an arm 16 carrying a toothed portion 17 with which a worm 18 engages. By rotating this worm, the pinion 15 can be moved to any position on the sector 11 to vary the time during which the delay mechanism is effective. After the sector 11 leaves the pinion 15, it completes the remainder of its stroke rapidly. Specification 537,697 is referred to and the Provisional Specification refers also to Specification 538,209.