GB1290482A - - Google Patents

Abstract

1290482 Electromagnetic relays A REYROLLE & CO Ltd 7 Oct 1969 [9 July 1968] 32622/68 Heading H1N An electromagnetically operated time delay relay as its armature 16 arranged to move, on coil energization, to a position in a cylinder 13 in which it stresses a spring 24 to a predetermined extent and the spring acts on a non- magnetic contact operating plunger 21 of the dash-pot cylinder 13 so that the time delay is substantially independent of the voltage of the supply by which the relay is energized. The dash-pot is filled with a fluid such as a silicone oil and the armature has a central passage 17 allowing undamped movement thereof whilst the plunger 21 has a non-return valve comprising a passage 22 and ball 23 so that its movement is only damped in its upward movement. At the end of its upward movement the plunger 21 engages a ring 25 which operates contacts 15 in an upper compartment 14 of the dash-pot. The plunger armature when attracted bridges a gap 20 in a magnetic coil casing 10 and its travel, and thus the spring stress and time log, can be adjusted by altering the position of the dash-pot within the coil. Alternatively the relay contacts may be located outside the dash-pot and operated by a diaphragm or bellows thrust transmission arrangement (not shown).