(57) A switch (10) for providing a safety function when its main contacts are fused or
stuck together in the "ON" position, comprising a housing (16) containing a pair of
main contacts (42, 54), one being designated an ON contact, and the other main contact
being carried by a movable switch arm (50) in the housing (16). This switch arm (50)
has a first end which carries the movable main contact (54) and a second end, and
spring means (56) mechanically coupled to the movable switch arm (50) normally bias
the movable main contact (54) toward open position away from engagement with the ON
contact. Switch operating means including movable actuator means (78) overcome the
biasing force of the spring means (56) for moving the movable main contact (54) to
closed position into engagement with the ON main contact. There are auxiliary safety
contact means (60) within the switch housing for completing a safety circuit and/or
for deenergizing the main circuit in response to abnormal movement of the movable
switch arm (50) when the actuator means (78) is moved to OFF position, but the movable
main contact (54) remains fused or stuck to the ON main contact. Fig. 1.
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