GB1255133A - Electromagnetic relays - Google Patents

Abstract

1,255,133. Polarized electromagnetic relays. MATSUSHITA ELECTRIC WORKS Ltd., and H. SAYER. 19 Jan., 1970 [20 Jan., 1969], No. 2446770. Heading H1N. A polarized relay which may be one side stable, bi-stable, centre-stable or three position stable has a permanent magnet which provides a magnetic flux that falls with rising temperature, an armature which is displaced by the permanent magnet flux on energization of a coil and forces are transmitted to a contact via spring means which are stressed after the contacts have engaged. As shown, two permanent magnets 5, 5<SP>1</SP> are mounted between pole members 4, 4<SP>1</SP> and may have different temperature characteristics. Contact actuating arms 14 are attached to the ends of the centrally pivoted armature 1 which is surrounded by the coil 7 on a former 6. The insulated ends 15 of the arms 14 each extend between the blades 23, 23<SP>1</SP> of a respective bifurcated contact spring 22 which is mounted on a terminal pin in the base 19 and carries two movable contact members 24, 24<SP>1</SP> which co-operate with fixed contacts 21, 21, on terminals 20, 20<SP>1</SP>. The blades 23, 23<SP>1</SP> are bent to a considerable extent after contact engagement to provide a restoring force which permits reverse operation of the relay at smaller power than would otherwise be required. The contact force can be varied by adjustment in direction V of the end 15 of the arm 14. A lug 81 or 811 on the member 4 or 4<SP>1</SP> can be bent to influence the end of a respective bent spring 11 attached to the armature 1 and forming a non-remanent spacer between the armature and pole member. Without the influence of a spring 11 the relay is bi-stable (Fig. 7, not shown) and is one side stable with a spring 11 effective (Fig. 8, not shown). Fig. 11 shows an alternative armature biasing arrangement with a projection 17 on the armature 1 engaged between blade springs 12, 12<SP>1</SP> which can be adjusted by bending mountings 1 and by bending a stop 16. With strong springs 12, 12<SP>1</SP> the relay is centre-stable (Fig. 9, not shown), but with weaker springs the relay can be three position stable (Fig. 10, not shown).