Safety switch

A safety switch assembly for providing ON/OFF control of a main circuit comprising:

• a switch body having an operation section with an actuator;
• a switch section having an operative rod displaceable by said actuator;
• a connection contact for closing a connection to the main circuit which is switched by the operative rod;
• an operation section including a drive cam formed with a lock step in its periphery and rotated according to ingress or egress of the actuator;
• a main lock mechanism juxtaposed with the switch body and including:
• a switchable portion selectively switched between Lock position and Unlock position,
• an operation piece removably mounted to the switchable portion for switching operation of the switchable portion and removable at transfer of the switchable portion to Unlock position;
• and
• a lock body which, during the ingress of the actuator, is locked to the lock step as interlocked with the switchable portion switched to Lock position thereby disabling the rotation of the drive cam for inhibition of the egress of the actuator and is released from the lock step as interlocked with the switchable portion switched to Unlock position thereby enabling the rotation of the drive cam for permission of the egress of the actuator,
• an auxiliary lock mechanism juxtaposed with the switch body and including:
• a drive portion operated by a trigger signal externally applied when the switchable portion is at Lock position;
• an auxiliary contact connected in series with the main circuit jointly with the connection contact;
• and
• an operative portion which, during a non-operative state of the drive portion, maintains the switchable portion at Lock position for keeping the auxiliary contact closed and which, during an operative state of the drive portion, permits transfer of the switchable portion to Unlock position for opening the auxiliary contact;
• wherein the main circuit is closed on condition that the drive portion of the auxiliary lock mechanism is non-operative, the switchable portion of the main lock mechanism is at Lock position, and the actuator is inserted.