GB401423A - An electrically-operated automatic ratchet-and-pawl mechanism - Google Patents

Abstract

401,423. Ratchet gearing. GREATOREX, A., 115, Upton Road, BRAHAM, G. W., 49, Palmar Crescent, and MELHUISH, E. C., 79, Upton Road, both in Bexleyheath, Kent. July 5, 1932, No. 19050. [Class 80 (iii).] A self-acting electromagnetic ratchet and pawl device comprises an armature c carrying a pawl d, a toothed wheel a fast on a spindle b, a spring-pressed pivoted lever g adapted to engage one arm p of a contact breaker r and an electromagnet m. When a current passes, the pawl is carried to the position d, in which it engages the lever g to cause the arm o to raise the arm p and so break contact. A spring n thereupon pulls back the armature and with it the wheel a through the agency of the pawl d. A continuous step-by-step automatic rotation of the spindle b is thus set up. A sliding bar armature may be used instead of an oscillating rotary one, the pawl being carried by it either directly or through the intermediary of a link. The lever g prevents over-running. A device for controlling the movement of the ratchet comprises a switch arm v, Fig. 4, rotated by the spindle b. In the resting positions of the ratchet, the arm contacts with one of the studs w. If one of these is disconnected, the ratchet will stop in the corresponding position. If a gapped switch 2 is connected as shown with the studs, the displacement of the ratchet can be controlled in varying amounts.