GB909094A - Improvements relating to visual indicating assemblies - Google Patents

Abstract

909,094. Electric selective signalling systems. SOLARI & C./UDINE S.p.A. June 29, 1959, No. 22256/59. Class 40 (1). The stepping circuit for a seeking switch of an indicating arrangement comprises two relays A (not shown) and X, Fig. 3, one bank of contacts II on the switch and the solenoid I for advancing the switch. Each energization of the driving solenoid I advances the switch arm 9 from a position between two contacts (as shown) to a position between the next two contacts. Relays A and X are both slow to release and have their contacts A1 and X1 respectively open and closed when they are de-energized. In operation, application of a voltage V energizes relay A which energizes the driving solenoid I via its contact A1 (contact XI being normally closed). This causes the arm 9 to advance one step and in so doing it brushes over one of the fixed contacts 10. This, in turn, momentarily energizes relay X, thereby opening its contact XI (which remains open as relay X is slow to release) and finally contact A1 opens followed by the closure of contact X1 (relay X having a longer release time than relay A). The circuit has then returned to its initial condition and if the voltage V is still present a further advance, as before, of the switch takes place. The switch is caused to stop at a selected position by means of a further bank of contacts IIa, Fig. 4, one of which is marked by a selected contact 25. When the switch reaches the marked contact (switch 9a unlike switch arm 9 steps from contact to contact) a relay D is energized to open its contact D1 which is interposed in the circuit for the driving solenoid I. A final embodiment, Fig. 6, shows a master seeking-switch with a driving solenoid I and two slave or follower stepping switches, situated at remote points, with driving solenoids III and V, all three driving solenoids being connected in series. Only the master seeking-switch has means (contacts 25 as in Fig. 4) for selecting a desired stopping position. In operation a contact of a bank of the master switch is marked by a selected contact 25 and a potential V is applied. Relays A, B and P then close, energizing all the driving solenoids in series. As each switch arm 9 advances it brushes over a contact 10, thereby energizing an associated relay X, Y or Z. When all three relays have been energized, signifying that all three switches have advanced, relay A is de-energized and a further step is made until eventually when the switches reach the desired position relay D is energized to open the circuit to the driving solenoids by its contact D1.