GB1131760A - Bell hammer driving device for alarm mechanism - Google Patents

Abstract

1,131,760. Alarm clocks. FABRIQUE D'HORLOGERIE CHS. TISSOT ET FILS S.A. Dec.22, 1966 [Dec. 27, 1965], No.57525/66. Heading G3T. A bell ringing mechanism for an alarm clock comprises a hammer 1, a hammer drive lever 9, a spring driven gear 25 and a pinion 17, the pinion being adapted to alternately drive the lever with either of two different amounts of energy, the hammer being adapted to strike the bell at a varying rate in accordance with the varying amount of driving energy imparted to the lever. The pinion 17 engages an escape wheel 14 by Breguet toothing 23 and has toothings 34, 35, each toothing 34, 35 having the same number of teeth. The toothing 34 engages identical toothing 31 on the gear 25, whilst the toothing 35 engages identical toothing 30 on the gear 25. The toothings 30, 31 alternate around the circumference of the gear 25. On winding the spring 28, the pinion 17 rotates with respect to the escape wheel and the spring is held fully wound by the Breguet toothing, stud 24 engaging a blocking device (not shown). At the alarm time, the blocking device releases the escape wheel so that the pinion 17 is driven alternately by the toothings 31 and 30. The lever 9 is therefore oscillated between two positions and imparts an impulse to the hammer by striking the pin 8 when it is urged by the wheel 14 from a first to a second position. During its return movement the hammer strikes the lever which locked the wheel 14 during the oscillation of the hammer, so that the lever pivots again from the second to the first position thus freeing the wheel 14 which urges the lever back to the second position thus giving another impulse to the hammer. A greater driving energy is imparted to the lever when the toothing 30 drives the pinion so that the hammer strikes the bell at each end of its pivoting stroke whereas the bell is only struck at one end of the hammer stroke when the pinion is driven by the toothing 31.