GB1293899A - Flat pack reed relays - Google Patents

Abstract

1293899 Polarized electromagnetic relays AMF Inc 3 Feb 1970 [26 Feb 1969] 5022/70 Heading H1N A polarized electromagnetic relay arranged in a "low profile or flat pack" form providing all its components disposed substantially in a single mean plane has a permanent magnet 19, an electromagnet 14 and one or more sealed magnetic reed contact units 20 arranged to extend between polepieces 23, 24. When the coil 16 is not energized its core provides a flux path for permanent magnet flux so as to shunt this flux away from the contact units 20 which are thus inoperative. When the coil 16 is energized to oppose the permanent magnet flux in its core 15 the combined flux serves to operate the contact units. The polepieces 23, 24 may extend around the ends of the contact units and the relay may be encapsulated in plastics material (Fig. 1, not shown). The permanent magnet may be mounted between polar extensions (Figs. 5 and 6, not shown) allowing the magnetic axis to be parallel or normal to the cone axis. Contact units may be mounted on opposite sides of the magnet and electromagnet and the core may be remanent to provide for magnetic holding of the operated contacts until the electromagnet is energized in a reverse direction by the same or an additional coil. Fig. 10 shows a balanced layout with the electromagnet having two cores 15 surrounded by series coils 16. In a further alternative relay there are two permanent magnets (Fig. 11, not shown) on opposite sides of a single core.