GB477390A - Improvements in coin-freed electric switches - Google Patents

Abstract

477,390. Coin - freed apparatus. STOTZ-KONTAKT GES. June 25, 1936, Nos. 17599 and 17600. Convention dates, June 26, 1935 and Dec. 4, 1935. [Class 27] In prepayment apparatus for controlling delivery of electricity on a quantity or time basis, and having a single switch adapted to break the circuit on overload as well as when the amount or period prepaid is exhausted, a handle for reclosing the switch is connected therewith by mechanism which prevents retention of the switch in circuit-closing position when tripped, and a movable element renders such mechanism inoperative until a coin is inserted. In Fig. 1, a movable switch arm b is connected by knuckle-jointed links e, d to a pivoted operating handle c. A slidable bolt i is normally held by a spring-actuated lever m in the position shown in which a bevelled stop g thereon engages behind the connecting pin f of the links e and d, so that if the handle c is operated the stop g causes the links to fold, and the switch arm b is not closed. An inserted coin o momentarily depresses the lever m to release the bolt i which rises under the action of a spring h, Movement of the handle c is then transmitted through the links e and d to the contact b. During such movement, a bell-crank s linked with the contact b engages a pin r on the bolt i to re-engage it with the coin lever m. The means serving to break the circuit on overload and when the prepaid period has expired, are adapted to fold the links e and d so that the contact b opens under the action of a supporting spring a. In Fig. 3, the switch operating mechanism is similar to that shown in Fig. 1, but the bolt i controlling the links d and e is replaced by a pivoted cranked lever 19 one arm v of which is normally engaged by a pin 6 on a disc 5 driven by clockwork mechanism, so that the other arm engages the links to prevent closure of the switch by operation of the handle c. A plate 7 is pivoted coaxially with the disc 5, and a torsion spring 9 acts between the pin 6 and a pin 8 on the plate 7. The latter is normally locked by a coin lever m in the position shown in which it masks the winding shaft 18 of the clockwork. An inserted coin trips the lever m to free the plate 7 which turns anticlockwise to uncover the winding shaft 18. The consumer then winds the clockwork which causes the disc 5 to turn clockwise to the position shown in which the pin 6 releases the lever 19 which is, however, temporarily held by engagement of the plate 7 with a pin 10 thereon. When the winding key is withdrawn, the plate 7 returns to its masking position shown under the action of the spring 9 which now acts in the opposite direction owing to the rotation of the disc 5 : the plate 7 releases the lever 19 so that it disengages the knuckle-jointed links d and e. The switch can now be closed by operation of the handle c. When the prepaid period has expired, the pin 6 on the disc 5 re-engages the lever 19 which is displaced to the position in which it folds the links d and e causing the switch to open. In order to allow the prepaid period to be varied, the pin 6 may be insertable in any one of a number of threaded holes in the disc 5. Means may be provided to stop the clockwork mechanism when the switch is tripped.