GB1252767A - - Google Patents

Abstract

1,252,767. Remotely controlled fastening. TEXAS INSTRUMENTS Inc. 9 Dec., 1968 [15 Dec., 1967; 4 April, 1968], No. 58419/68. Heading E2A. An electrically controlled locking device includes a locking element 12 which is movable into and out of a locking position respectively to close and open a current flow path between electrical terminals 1, 2, the current flow path including a thermally responsive element 3 movable, in response to flow of operating current therethrough, to an operating position in which the thermally-responsive element 3 prevents movement of the locking element 12 out of the locking position and an electrical resistance element 6 is connected in parallel with the thermally responsive element 3 to reduce the current flow therethrough, the resistance element 6 being in heat-exchange relationship with the thermallyresponsive element to maintain the latter in the operating position during the passage of the current between the terminals 1, 2. The device is applied to a washing machine, the locking element 12 being used to lock a spring loaded slidable plate 24 in latching engagement with a hook member 27, on the machine. During the latching engagement, the plate 24 carries with it a slide 21 which connects contacts 20, 5 and establishes a circuit between terminals 1, 2 via one arm of the element 3 and contact 5 which is carried by the other arm 4 which also carries a contact 8. The resistance 6 which is U-shaped is carried at the free end of an arm 7 extending from terminal 1 and the free end of the resistance 6 carries a contact 9. The element 3 is connected to the element 12 by a strip 10, and the arrangement is such that after initial deformation of the element 3, the latter moves the element 12 to the locking position, Fig. 3, thereby closing contacts 8, 9 and connecting the resistance 6 in parallel with the element 3. A permanent magnet 31 on the element 12 prevents disengagement of the latter from the plate 24 due to vibration of the machine. In a similar arrangement, Figs. 6-11 (not shown) a further resistance (104) is connected in series with, and wound on, the thermallyresponsive element, and the contacts connecting the parallel-connected resistance in circuit are adjustable.