GB378447A - Improvements in electromagnetically operated relays - Google Patents

Abstract

378,447. Electric signalling systems. LISTER, H., Oaklands, Woodstock Road, Chorltoncum- Hardy, ASH, F. S., 20, Malvern Avenue, Flixton, both in Manchester, and ASSOCIATED ELECTRICAL INDUSTRIES, Ltd., Crown House, Aldwych, London. May 7, 1931, No. 13591. [Class 40 (i).] An electromagnetically-operated relay which may be employed in a tele-metering system is operated by electromagnets 2, 3, Fig. 1, on a core 1, an armature 4 being mounted on a pivot 5 between the polepieces 1a, 1b. On energization of the electromagnets the armature is drawn into line with the polepieces against a return spring 5 and by means of a link 7 and pawl 9 moves a ratchetwheel 10 through a single step so operating indicating recording or other apparatus through gearing 12, 12a. Also mounted on the shaft 11 carrying the ratchet 10 is a plate 13 bearing half as many pins 14 as there are ratchet teeth, the pins being adapted to change-over a snap-action switch 15, 17, 18 at each stepping-movement, so interrupting the circuit of the magnets 2, 3 slightly in advance of the completion of the stroke of the armature, and preparing a circuit for a subsequent energization. The switchoperating mechanism shown in Figs. 2 and 3 comprises an arm 23 pivoted at a fixed point 24 and an arm 21 pivoted to the arm 23 at 22 and carrying a pin 20 engaging a slot 19 in the pivoted switch arm 15, the arm 21 being acted upon by an adjustable spring 25. In moving a step between the positions shown in Figs. 2 and 3 the lengthened upper end of the arm 23 escapes from a pin 14 and the two arms are moved together to change over the contact arm 15 to the position shown in Fig. 3. In the next step the shorter arm 21 escapes past a pin 14 and is pivoted around the point 22 to restore the arm 15 to its former position. The movement of the switch arm in each case breaks the circuit of the electromagnets 2, 3 with a snap action and prepares the circuit for a subsequent energization. In the circuit arrangement shown in Fig. 4 in which the relay is employed for recording at a distance the movements of a meter 29, operating current impulses are sent through the switch 15, 17, 18 alternately over pilot wires 31, 32 from the brushes 33, 34 of an interrupter driven from the meter through gearing 29, the return path including a pilot wire 27 and a brush 28.