Abstract: A device for providing displacement information includes a housing holding a displacement sensor. The displacement sensor includes a coil and a captive core. An electrical measurement of the coil provides information about displacement of the core. The coil has an axis extending in a first direction, wherein the housing has a minimum outside dimension that is less than 3.00 mm when measured perpendicular to that first direction. The housing has an inner surface having a housing inside dimension. The housing is for holding a displacement sensor and a guidance mechanism. The displacement sensor includes a coil and a captive core having a core outside dimension. The guidance mechanism includes a first part and a second part for guiding the core. The first part includes a bearing connected to the housing. The bearing has an axial hole having a hole dimension about equal to the core outside dimension. The core slidably extends through this axial hole.

Abstract: Improved coils and clamps for variable reluctance sensors are disclosed. A method of fabricating a discrete coil involves providing a conductor wound in a coil on a tube. The coil has a coil outer surface that has insulation. A window is opened in the insulation on the coil outer surface to expose conductor of the coil for a contact. A movable core is provided within the tube for adjusting inductance of the coil. In one embodiment, the coil and tube are diced into small coils after the windows for each coil are opened. Another aspect the invention is a clamp comprising an elastic material, a shape memory alloy, and an apparatus for activating the shape memory alloy. The clamp holds the moveable core in its peak position. When the alloy is activated it changes shape and provides a force on the elastic material to change clamping state for resetting the transducer. The coils and clamps can be used for a variety of purposes in addition to the variable reluctance sensors.

Abstract: A device for providing displacement information includes a housing holding a displacement sensor. The displacement sensor includes a coil and a captive core. An electrical measurement of the coil provides information about displacement of the core. The coil has an axis extending in a first direction, wherein the housing has a minimum outside dimension that is less than 3.00 mm when measured perpendicular to that first direction. The housing has an inner surface having a housing inside dimension. The housing is for holding a displacement sensor and a guidance mechanism. The displacement sensor includes a coil and a captive core having a core outside dimension. The guidance mechanism includes a first part and a second part for guiding the core. The first part includes a bearing connected to the housing. The bearing has an axial hole having a hole dimension about equal to the core outside dimension. The core slidably extends through this axial hole.

Abstract: The novel sensor assembly is comprised of a threaded housing with pressure relief tracks through the threads that terminate at a hole through the housing and a displacement sensor. In the preferred embodiment, we have included an integral connector, a super-elastic core carrier and a Differential Variable Reluctance Transducer. Other sensor types could be used to construct a pressure equalized displacement sensor as described herein, these may include: capacitive, resistive, Hall effect, eddy current, and differential variable transformer. The sensor is attached to a keyed connector and the entire assembly is potted into the housing. A temperature probe can also be potted with this assembly to allow for multiple tasks t1o be performed by this one housing. The housing is threaded on one end to allow for easy mounting. A hole is drilled through the housing just in back of the sensor and two tracks run perpendicular to and slightly deeper than the threads. The tracks connect to the through hole.

Abstract: Improved coils and clamps for variable reluctance sensors are disclosed. A method of fabricating a discrete coil involves providing a conductor wound in a coil on a tube. The coil has a coil outer surface that has insulation. A window is opened in the insulation on the coil outer surface to expose conductor of the coil for a contact. A movable core is provided within the tube for adjusting inductance of the coil. In one embodiment, the coil and tube are diced into small coils after the windows for each coil are opened. Another aspect the invention is a clamp comprising an elastic material, a shape memory alloy, and an apparatus for activating the shape memory alloy. The clamp holds the moveable core in its peak position. When the alloy is activated it changes shape and provides a force on the elastic material to change clamping state for resetting the transducer. The coils and clamps can be used for a variety of purposes in addition to the variable reluctance sensors.