Geophone with mass position sensing
AssigneeInput/Output, Inc.
InventorArend L. Hagedoorn
Life of this patent
Estimating the term…
Abstract
A motion sensing element with position sensing includes a case, a magnet positioned within the case, a spring assembly having an electrically conductive member and a coil assembly coupled to the spring assembly. The coil assembly and magnet are moveable with respect to one another. A capacitor plate is proximate the electrically conductive member with a distance between the capacitor plate and electrically conductive member being variable as the magnet and coil assembly move. Leads connect the capacitor plate and electrically conductive member to a sensing circuit for estimating the relative positions of the magnet and coil assembly.
Claims14
A sensing element with position sensing, said sensing element comprising:
- a) a case
- b) a magnet positioned within the case;
- c) a spring assembly including an electrically conductive member;
- d) a coil assembly coupled to the spring assembly, the coil assembly and magnet being moveable with respect to one another via the spring assembly;
- and
- e) a capacitor plate disposed proximate the electrically conductive member and separated therefrom by a distance, the distance being variable by respective movement of the magnet and the coil assembly, the capacitor plate and electrically conductive member being each adapted for electrical connection to a sensing circuit for sensing an electrical capacitance formed by the capacitor plate and the electrically conductive member, the electrical capacitance being used for estimating a position of the coil assembly with respect to the magnet.
A sensing element with position sensing, said sensing element comprising:
- a) a spring assembly having an outer ring, an inner ring and a plurality of legs connecting the outer ring and the inner ring, the spring assembly having an electrically conductive member;
- b) a magnet coupled to the spring assembly;
- c) a coil assembly coupled to the spring assembly, the coil assembly and magnet being moveable with respect to one another via the spring assembly;
- d) a first capacitor plate coupled to an end of the coil assembly proximate the spring assembly, the first capacitor plate having a top side and a bottom side;
- e) a second capacitor plate disposed on a case endplate and proximate the top side of the first capacitor plate and separated therefrom by a first distance;
- f) a third capacitor plate disposed on the case endplate and electrically isolated from the second capacitor plate, the third capacitor plate being proximate the bottom side of the first capacitor plate and separated therefrom by a second distance,
- wherein, the first distance and the second distance being variable by respective movement of the magnet and the coil assembly, the first capacitor plate, second capacitor plate and third capacitor plate being each adapted for electrical connection to a sensing circuit for sensing a first electrical capacitance formed by the first capacitor plate and the second capacitor plate and for sensing a second electrical capacitance formed by the first capacitor plate and the third capacitor plate.
A method of sensing the position of an inertial mass in a sensing element, said sensing element comprising, a case, a magnet positioned within the case, a spring assembly including an electrically conductive member, a coil assembly coupled to the spring assembly, the coil assembly and magnet being moveable with respect to one another via the spring assembly, a capacitor plate disposed proximate the electrically conductive member and separated therefrom by a distance, the method comprising:
- a) moving the coil assembly with respect to the magnet to vary the distance between the capacitor plate and the electrically conductive member;
- b) sensing an electrical capacitance formed by the capacitor plate and the electrically conductive member;
- and
- c) estimating a position of the coil assembly with respect to the magnet using the sensed capacitance.
A sensing element with position sensing, said sensing element comprising:
- a) a case;
- b) a magnet positioned within the case;
- c) a spring assembly coupled to the magnet;
- d) a coil assembly coupled to the spring assembly, the coil assembly and magnet being moveable with respect to one another via the spring assembly;
- e) a first capacitor plate disposed on the coil assembly, the first capacitor plate having a first plate area;
- and
- f) a second capacitor plate coupled to the case, the second capacitor plate having a second plate area,
- wherein, the first capacitor plate and the second capacitor plate are spaced apart by a distance and having at least a portion of the first capacitor plate area and second capacitor plate area overlapping and wherein relative movement of the magnet and coil assembly causes the overlapping portion of first capacitor plate area and the second capacitor plate area to vary while the distance remains substantially constant, the varying overlapping plate areas creating a variable electrical capacitance used for estimating a position of the coil assembly with respect to the magnet.
A sensing element with position sensing, said sensing element comprising:
- a) a case;
- b) a magnet positioned within the case;
- c) a spring assembly coupled to the magnet;
- d) a coil assembly coupled to the spring assembly, the coil assembly and magnet being moveable with respect to one another via the spring assembly;
- e) a first capacitor plate disposed on the coil assembly, the first capacitor plate having a first plate area;
- and
- f) a second capacitor plate disposed on a pole piece of the magnet, the second capacitor plate having a second plate area,
- wherein, the first capacitor plate and the second capacitor plate are spaced apart by a distance and having at least a portion of the first capacitor plate area and second capacitor plate area overlapping and wherein relative movement of the magnet and coil assembly causes the overlapping portion of first capacitor plate area and the second capacitor plate area to vary while the distance remains substantially constant, the varying overlapping plate areas creating a variable electrical capacitance used for estimating a position of the coil assembly with respect to the magnet.
Dependencies are inferred from the claim text.