Adjustable magnetic target

A system of determining the position of a valve element comprising:

• a valve disposed within a housing, the valve having a gate coupled to a valve stem;
• a magnetic target coupled to the valve stem, the magnetic target comprising:
• a body tube having an open proximal end, a distal end opposite the proximate end, and a distal surface adjacent to the distal end, the open 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 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 at a proximate end of the switch, the switch being stationary and disposed outside of the housing, wherein the sensor is adapted to detect the magnetic flux field of the stationary magnet or the magnetic flux field of the movable magnet.

A method for simulating the magnetic flux field of a radially-magnetized permanent magnet using two axially-magnetized permanent magnets, the method comprising:

• providing an axially-magnetized first permanent magnet having a first pole, a second pole, and a first magnetic flux field;
• providing an axially-magnetized second permanent magnet having a first pole, a second pole, and a second magnetic flux field;
• positioning the first permanent magnet and the second permanent magnet within a bore of a body tube such that a longitudinal axis of the first permanent magnet is substantially coaxial with a longitudinal axis of the second permanent magnet, and the first pole of the first permanent magnet is proximate to the first pole of the second permanent magnet, wherein the first permanent magnet and the second permanent magnet are separated by a longitudinal distance;
• providing a mechanism to reduce the longitudinal distance between the first permanent magnet and the second permanent magnet, thereby causing the first magnetic flux field of the first permanent magnet to extend away from a longitudinal axis of the first permanent magnet and the second magnetic flux field of the second permanent magnet to extend away from a longitudinal axis of the second permanent magnet;
• providing a sensor external to the body tube to detect at least one of the first magnetic flux field and the second magnetic flux field, wherein the sensor generates a signal when the sensor detects at least one of the first magnetic flux field and the second magnetic flux field;
• and
• sending the signal to a controller to generate an alert indicating that the sensor detects at least one of the first magnetic flux field and the second magnetic flux field.

A method for simulating the magnetic flux field of a radially-magnetized permanent magnet using two axially-magnetized permanent magnets, the method comprising:

• providing an axially-magnetized first permanent magnet having a first pole, a second pole, and a first magnetic flux field;
• providing an axially-magnetized second permanent magnet having a first pole, a second pole, and a second magnetic flux field;
• positioning the first permanent magnet and the second permanent magnet such that a longitudinal axis of the first permanent magnet is substantially coaxial with a longitudinal axis of the second permanent magnet, and the first pole of the first permanent magnet is proximate to the first pole of the second permanent magnet, wherein the first permanent magnet and the second permanent magnet are separated by a longitudinal distance;
• providing a mechanism to reduce the longitudinal distance between the first permanent magnet and the second permanent magnet, thereby causing the first magnetic flux field of the first permanent magnet to extend away from a longitudinal axis of the first permanent magnet and the second magnetic flux field of the second permanent magnet to extend away from a longitudinal axis of the second permanent magnet;
• providing a valve having a displaceable gate within a contained valve housing, the gate being secured to a displaceable valve stem;
• coupling the mechanism to reduce the longitudinal distance between the first permanent magnet and the second permanent magnet to the body tube and securing the body tube to the valve stem;
• and
• providing a sensor outside of the valve housing, the sensor being capable of detecting either the first magnetic flux field or the second magnetic flux field when the valve stem is displaced to a desired location.