Spring operation device for switchgear

A spring operation device for use in a switchgear, comprising:

• a main shaft that is rotatably supported by a casing;
• an output lever that is fixed to the main shaft, is rotatable about the main axis, and is coupled to a switching contact;
• an opening biasing unit that biases the output lever so as to rotate the output lever in a predetermined direction;
• a four-joint link that
• is fixed at one end to the main shaft,
• is rotatably coupled at the other end to the output lever, and
• is flexible and extendable;
• a guide that
• is rotatably supported by the casing, and
• includes a guide surface that is capable of guiding the four-joint link, while coming into contact with the four-joint link;
• a tripping latch that is rotatably supported by the casing and is capable of locking the guide;
• a tripping trigger that is rotatably supported by the casing and is capable of locking the tripping latch;
• a tripping electromagnet that
• has a plunger capable of moving back and forth toward the tripping trigger, and
• moves the plunger forward to rotate the tripping trigger when an opening command is input so as to make it possible to disengage the tripping latch from the tripping trigger;
• a switch-on lever that is fixed to the main shaft and is rotatable about the main shaft;
• a closing bias unit that biases the switch-on lever so as to rotate the switch-on lever in a reverse direction to the predetermined direction;
• a switch-on latch that is rotatably supported by the casing and is capable of locking the switch-on lever;
• a switch-on trigger that is rotatably supported by the casing and is capable of locking the switch-on latch;
• a switch-on electromagnet that
• has a plunger capable of moving back and forth toward the switch-on trigger, and
• moves the plunger forward to rotate the switch-on trigger when a closing command is input so as to make it possible to disengage the switch-on latch from the switch-on trigger;
• an opening-operation prevention unit that includes
• a lock member that is attached to the four-joint link and that moves along with the rotation of the output lever, and
• a lock plate that rotates due to being pushed by the lock member along with the rotation of the output lever in the reverse direction, wherein
• when a closing operation is performed by the switching contact, engages with the tripping trigger so as to stop the tripping trigger from rotating, and
• when an opening operation is performed by the switching contact, is pushed by the lock member and disengages from the tripping trigger so as to allow the tripping trigger to rotate;
• and
• a closing-operation prevention unit that includes
• an interlock bar that is substantially-crank-shaped and is attached at one end to the lock plate to operate in conjunction with the lock plate, and
• a flange portion that is provided on the plunger of the switch-on electromagnet, wherein
• the other end of the interlock bar,
• when an opening operation is performed by the switching contact, is arranged above the flange portion and stops the plunger of the switch-on electromagnet from moving forward so as to stop the switch-on trigger from rotating, and
• when a closing operation is performed by the switching contact, is arranged at a position that does not stop the plunger of the switch-on electromagnet from moving forward so as to allow the switch-on trigger to rotate.