Lock-out relay with adjustable trip coil

A lockout relay for use in protecting electrical systems,

• said lockout relay comprising a tripping solenoid for use in connection with actuating a mechanical movement in said relay,
• said solenoid comprising,
• a coil determining a magnetic field therein and aiding in defining an air gap between a plunger and a stop plug,
• said plunger having a first end and a second end and being mounted for reciprocal movement along a center line toward and away from said stop plug,
• a push rod aligned with said center line for reciprocal movement and having an inner end positioned to be actuated by said plunger second end and having an outer end positioned to actuate said mechanical movement,
• a return spring means opposing movement of said plunger toward said push rod inner end,
• and adjusting means for positioning said plunger second end with respect to said coil magnetic field in accordance with a predetermined threshold voltage, reluctance and response time to activation of said plunger by said magnetic field.