GB410554A - Improvements in and relating to electrically driven clocks, particularly savings clocks - Google Patents

Abstract

410,554. Coin -- freed savings clocks. JENSEN, T. A., 16, Eriksgade, Copenhagen. Jan. 4, 1933, No. 249. [Classes 27 and 139.] An electric clock, particularly a savings clock, is driven by magnetic interaction between the balance ring, comprising permanent magnets 3, 4 having like poles adjacent, and a coil 7 encircling the balance. The balance arbor carries a disc 8, which supports the ring 3, 4 by an arm 2, and has an eccentric pin 9 coacting with the forked end of a lever 10, 12 pivoted at 11 which drives the minute shaft 24 through a pawl 18, ratchet wheel 19 and worm gearing 22, 23. The coil circuit is controlled by an extension 13 of arm 12 which oscillates between the prongs of a fork 14, one prong 15 of which is insulated. The fork 14 is carried by an insulated rotatable shaft 16 on which bears a stressed contact brush 17, the coil circuit thus being closed during movement of the balance in one direction only. Alternatively the fork 14 may be fixed to the arm 12 and the shaft 16 may carry a contact rod moving between the fork prongs. When the apparatus is applied as a savings clock, the coil circuit includes a rotary contact mechanism (not shown) carried by a shaft 26, Fig. 3, rigid with a toothed wheel 27. Periodically a stop mechanism in the clock rotates this wheel one tooth towards the open circuit position of the contact mechanism, the clock eventually stopping unless coins are inserted, each coin advancing the wheel 27 one tooth in the reverse direction through a lever 29 in known manner. Stop mechanism. This comprises plate levers A, B, Figs. 3, 4, pivotally mounted side by side at 44, and biassed by springs 45, 47, respectively, normally to abut against a stop 46. A pin 48 journalled in plate B and connected to spring 47 passes through a clearance hole in a member 30 pivoted to A at 49, and engages in an elongated hole 51 in plate A thereby allowing a small relative angular movement between A and B. Each day a pin 43 on a week wheel 42 rocks the levers A, B. As lever A is longer than B, the latter slips off the pin 43 before A and is slightly rotated relative thereto by spring 47, Fig. 4. The member 30 is also rotated relative to A, so that when lever A slips off pin 43 and the biassing springs rock their respective levers to the stop 46, B moves slightly in advance of A, and the nose 50 of member 30 engages and advances the wheel 27 one tooth, being retracted from the path of the wheel teeth as lever A comes into alignment with B against the stop 46. A spring 52 ensures the wheel 27 moving only one tooth at a time. The week wheel 42 is driven through pinion 41 and ratchet wheel 40 by a pawl 38 carried by a bell crank lever 34, actuated by one or more pins 32 on a disc 31 rigid with the minute shaft 24. The number of pins 32 and 43 may be varied to control the number of coins necessary for insertion to keep the clock going.