A method of controlling a subsidiary clock and subsidiary clocks controlled thereby

摘要

1,106,041. Clocks. LABORATORNI PRISTOJE, NARODNI PODNIK. April 6, 1965 [April 11, 1964 (2)], No. 14495/65. Heading G3T. A secondary clock having hour and minute hands is driven by its own power supply such as a constantly running synchronous electric motor (not shown) through an energy storage device or spring barrel 125-127 wound by the motor. The control is by an escapement comprising a pivoted armature 116 operated at one minute intervals by successive pulses of opposite polarity received from a master clock. The armature alternately moves out of the path of one arm of an escape lever which has two arms 114, 115 of unequal length, and moves into the path of the other arm. The minute hand 104 is connected to the escapement through a train 105, 106, 108, 110 from the barrel. The motor, through a pinion 129, drives a wheel 128. This wheel is automatically clutched to the barrel to re-wind the spring, as disclosed in Specification 1,090,187. Wheel 128 also drives a seconds hand 102 through a frictionally mounted wheel 130 which rotates an arm 134 so that at the twelve o'clock position this arm co-operates with a star release wheel 109 fast with wheel 108 of the other train. To allow for frequency variations affecting the motor speed, and to ensure that the seconds hand registers precisely with the twelve o'clock position at the time of the impulse from the master, this hand is normally driven slightly fast and is held momentarily at the twelve o'clock position by the star wheel 109 without the motor being arrested. The hour hand (not shown) is driven by suitable reduction from the minute train. In another embodiment, Figs.1 and 2 (not shown) the seconds hand and train are omitted. The escapement carries an air brake 112.