GB464899A - An improved time measuring apparatus employing a synchronous motor and an auxiliary movement for driving time-controlled apparatus - Google Patents

Abstract

464,899. Electric clocks. LANDIS & GYR AKT.-GES. Oct. 3, 1936. No. 26865. Convention date, Oct. 5, 1935. [Class 139] The invention relates to a time-measuring apparatus employing (i) a synchronous motor 4 normally driving a time-controlled device, e.g. a twenty-four hour disc 23, through gearing 2, 3, a double ratchet device 1 and gearing 22, (ii) an auxiliary spring 8 which drives the disc 23 through gearing 5, 6 and ratchet 1 under the control of the usual escapement 7 when the current supply fails and (iii) an additional escapement device 18 the releasing member 21 of which is driven bv the time controlled disc 23 by a pin 24 or 25 and the escaping or detent member 17 of which mounted on a shaft 161 operates time switch contacts 16, actuates a clock or effects any other timed operation. According to the invention a differential mechanism 10 is provided, one member of which, sun-wheel 11, is connected through gearing 12 to the winding arbor of'the auxiliary spring 8, sun-wheel 15 being connected to the shaft 16<1> carrying the detent member 17, and the planet member 13 being connected through gearing 14, 3, 2 to the synchronous motor. As the sun-wheel 15 is normally locked by the member 21 holding detent 17, the synchronous motor, through gearing 14, planet 13, sun-wheel 11, and gearing 12 winds the auxiliary spring 8. When the member 21 releases detent 17 the end thereof escapes through the notch 19 or 20 and shaft 16<1> is rapidly rotated through 180‹ by the auxiliary spring 8 acting through the differential mechanism 10, to operate the switch contacts 16. Such an arrangement permits the use of a comparatively light spring 8. A detent 26 actuated electromagnetically by the current supply may be provided to lock the detent 17 and thus the switch 16 against operation when the current fails.