1321819 Electromagnetically released switches JOSEPH LUCAS (INDUSTRIES) Ltd 6 Nov 1970 [18 Dec 1969] 61642/69 Heading H1N A switch arranged for step-by-step movement in response to a sequence of electrical signals has a control member 10 slidable in a body 11 as biased by means (not shown) between successive latched positions defined by projections 19 on the member 10 engaging latch members 24 mounted on the armatures 22, 23 of two electromagnets 20, 21 which are energized in turn through printed circuit contacts 26, to 32 bridged by contacts (36, 37, Fig. 3, not shown) carried on the member 10. The member 10 may be moved to the left (Fig. 1) by means of a plunger 15 to a position in which contacts 27, 28 are bridged to connect the latching electromagnet to a circuit which when complete causes energization of the electromagnet to unlatch the member which moves to the left until the next projection engages a member 24. In this position the contacts 27, 30 one bridged ready for energization of the other electromagnet. The plunger 15 may be moved to the right to engage a conducting end thereof with contacts (38, 40, Fig. 3, not shown) arranged to effect energization of both coils so that both latch members 24 are lifted to allow the member 10 to complete its travel to the right. The contact bridges may be spring biased rollers (Fig. 6, not shown). In place of the conductive plunger end and contacts 38, 40 the plunger 15 may be arranged to move a part of the member 10 downward to disengage the projections from the latch members (Figs. 8, 9, 10, not shown).