GB389908A - Improvements in and relating to electric time-measuring and time-switching devices - Google Patents

Abstract

389,908. Time switches. INTERNATIONAL GENERAL ELECTRIC CO., Inc., 120, Broadway, New York, U.S.A.- (Assignees of Allgemeine Elektricitõts-Ges.; 2, Friedrich Karl-Ufer, Berlin.) Nov. 18, 1931, No. 32016. Convention date, Nov. 18, 1930. [Class 38 (v).] A clock or time-switching mechanism (e.g. a switch-clock or time-relay) having a synchronous motor 1 and a spring (or equivalent) driving device, may be driven (1) directly by the electric motor or (2) by the spring, manuallyoperated control means 13, 15 being provided for changing from one drive to the other. When the electric motor drives directly, it keeps the spring wound up and the latter comes into action on cessation of the current. In the second case the motor 1 keeps the spring wound also. The driving shaft 4 of the self-starting motor 1, 2 has a gear 23 engaging a wheel 6 loose on the minute arbor 10. Also loose on this arbor is a wheel 5 connected by pinion 17 with the escapement of the auxiliary mechanism, of which 20 is the balance. Wheels 5, 6 form overtaking couplings which operate the wheel 7 rigid with arbor 10. Integral with gear 23 is a cam 8 which raises and lowers an arm 9 about pivot 24; to the other end of arm 9 are pivoted (1) a link 18 winding up the spring barrel 19 of the auxiliary clockwork and (2) a link 11 which rubs against the axis of the balance 20 so that the balance is constantly rotated to keep it in order. Rigid with an armature 22, pivoted at 25 and attracted by a stator pole against the action of a spring 26, is a bell crank 12 having a pin 12<1> which coacts with arm 11. Whilst current is flowing the motor drives the minute arbor 10 through members 23, 6, 7 : but when current fails, spring 26 raises armature 22 so that bell crank 12 removes arm 11 from balance 20 and the auxiliary mechanism 20, 19, 17 drives the arbor 10 through coupling 5, 7. To drive arbor 10 by the auxiliary mechanism, whilst current is flowing, a cam 15 on axis 13 is manually rotated to rock arm 12 and remove link 11 to free the balance. At the same time cam 15 shifts a lever 21, which latter moves a gear 23, in opposition to a spring 16, out of engagement with wheel 6. Cam 8 is of such width, however, that it still oscillates link 18 to keep spring 19 wound. Means, such as a contact or arbor 10, may periodically interrupt the motor circuit for any desired duration to prevent the parts such as lever 12, from becoming stiff.