Multi-turn, non-contacting rotary shaft position sensor

A rotary shaft position sensor comprising:

• a housing;
• a magnetic element producing a magnetic field and located within said housing,
• means to affix said magnetic element to said housing to allow said magnetic element to move along a linear path but to prevent said magnetic element from rotating with respect to said housing;
• said magnetic element having a threaded shaft extending therefrom, said threaded shaft extending outwardly from said housing
• a rotatable input shaft threadedly affixed to said threaded shaft, said rotatable input shaft adapted to be rotated to translate said magnetic element along said linear path within said housing, and
• a magnetically sensitive sensor;
• means to mount said magnetically sensitive sensor within said housing in proximity to said magnetic element and within said magnetic field, wherein said linear movement of said magnetic element causes a change in the magnetic influence of said magnetic field on said sensor.

An instrument for determining a positional parameter of a rotatable shaft, said instrument comprising;

• a housing;
• a magnetic element producing a magnetic field and located within said housing, said magnetic element adapted to be translatable along a linear path within said housing but constrained from rotational movement;
• said magnetic element having a threaded shaft extending therefrom;
• a rotatable input shaft threadedly affixed to said threaded shaft, said rotatable input shaft adapted to be rotated to translate said magnetic element along said linear path within said housing,
• a sensor positioned in close proximity to said magnetic element and within said magnetic field, wherein said linear movement of said magnetic element causes a change in the magnetic influence of said magnetic field on said sensor;
• and
• means to derive a signal based upon said change in the magnetic influence sensed by said sensor to determine a positional parameter of said input shaft.

A method of detecting a positional parameter of a rotatable shaft, said method comprising the steps of:

• providing a housing,
• providing a magnetic element within the housing emitting a magnetic field and having a shaft extending therefrom,
• providing a magnetically sensitive sensor in a fixed position within the housing within the magnetic field of the magnetic element,
• allowing the magnetic element to move along a linear path with the housing while constraining the magnetic element for rotational movement,
• providing a input shaft threadedly engaged to the shaft, and
• rotating the input shaft to translate the magnetic element to move the magnetic element along the linear path toward and away from the magnetically sensitive sensor to change the effect of the magnetic field on the sensor.

A rotary shaft position sensor comprising:

• a housing;
• a magnetic element producing a magnetic field and located within said housing, said magnetic element adapted to be translatable along a linear path within said housing but constrained from rotational movement;
• said magnetic element having an shaft extending therefrom;
• a rotatable input shaft operatively interconnected to said magnetic element shaft, said rotatable input shaft adapted to be rotated to translate said magnetic element along said linear path within said housing, and
• a sensor positioned in proximity to said magnetic element and within said magnetic field, wherein said linear movement of said magnetic element causes a change in the magnetic influence of said magnetic field on said sensor.