Patent ID: 8264309

Claim:
A magnetic target assembly comprising: a magnetic target adapted to be coupled to a valve closure member, the valve closure member being disposed within a valve enclosure and being displaceable relative to the valve enclosure, the magnetic target comprising: a body tube having an open proximal end, a distal end opposite the proximal end, and a distal surface adjacent to the distal end, the open proximal end defining a bore longitudinally disposed within the body tube; an adjusting member having an adjustment portion, an engagement portion coupled to the adjustment portion, and a contact surface disposed adjacent to a distal end of the engagement portion, wherein the engagement portion is received into the bore and is displaceably coupled to the body tube; a stationary magnet disposed within the bore such that a second pole of the stationary magnet is proximate to the distal end of the body tube and a first pole of the stationary magnet is opposite the second pole; and a movable magnet disposed within the bore between the adjusting member and the stationary magnet such that a first pole of the movable magnet is adjacent to the first pole of the stationary magnet and a second pole of the movable magnet is proximate to the contact surface of the adjusting member, wherein the movable magnet is longitudinally displaceable relative to the stationary magnet, and wherein a top surface of the movable magnet adjacent to the second pole is arranged to engage the contact surface of the adjusting member such that a longitudinal displacement of the adjusting member towards the distal end of the body tube displaces the movable magnet towards the stationary magnet, thereby causing a magnetic flux field of the stationary magnet to extend away from a longitudinal axis of the stationary magnet and a magnetic flux field of the movable magnet to extend away from a longitudinal axis of the movable magnet; and a magnetically-triggered proximity switch having a sensor, the proximity switch disposed external to the bore and adapted to be fixed to a portion of the valve enclosure, wherein the sensor is adapted to detect the magnetic flux field of the stationary magnet or the magnetic flux field of the movable magnet when the magnetic target is within a predetermined distance of the sensor.