Inductive sensor for shock absorber

Patent metadata

Field	Value
Publication number	US-10278288-B2
Application number	US-201715493650-A
Country	US
Kind code	B2
Filing date	Apr 21, 2017
Priority date	Apr 22, 2016
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

An inductor sensor assembly for determining to position of object includes a layer of ferrite overlaying exciting and receiving coils formed on a substrate. A magnet attached to the target produces a virtual coupler in an area of ferrite overlaying the coils. An application for a shock absorber includes a sensor module mounted in a recess in a dust cover and a magnet mounted to a cylinder tube of the shock absorber.

First claim

The invention claimed is:

1. An inductive sensor assembly for determining a position of a target on an object, the inductive sensor assembly comprising:
a substrate having at least one transmitting coil and at least one receiving coil mounted to the substrate;
a resonator connected to the at least one transmitting coil;
a processing module connected to the at least one receiving coil, the processing module measuring eddy currents produced in the receiving coil;
a layer of ferrite having magnetic permeability greater than 10 covering the at least one transmitting coil and the at least one receiving coil;
a magnet mounted to a movable object spaced apart from the layer of ferrite, the magnet producing a magnetic field acting on an area of the ferrite layer to inductively couple the at least one transmitting coil with the at least one receiving coil in a region adjacent the area.

2. The sensor assembly of claim 1 , wherein the substrate is a printed wiring board having a top surface.

3. The sensor assembly of claim 1 , wherein the layer of ferrite has one side having an adhesive.

4. The sensor assembly of claim 2 , wherein the layer of ferrite is mounted to the top surface of the printed wiring board.

5. The sensor assembly of claim 1 , wherein the layer of ferrite is flexible.

6. The sensor assembly of claim 1 , wherein the object is formed of aluminum non-magnetic material.

7. A sensor assembly for sensing a position of a shock absorber, the sensor assembly comprising:
a housing;
a sensor module mounted to the housing, the module having at least one transmitting coil and at least one receiving coil, the module further having a layer of ferrite covering the at least one transmitting coil and at least one receiving coil;
a magnet mounted to the shock absorber, the magnet spaced apart from the ferrite layer, the magnet having a magnetic field action on the ferrite layer to inductively couple the at least one transmitting coil to the at least one receiving coil to produce a signal indicative of the position of the magnet and object relative to the housing.

8. The sensor assembly of claim 7 , wherein the housing has a generally circular cross section defining a center cavity.

9. The sensor assembly of claim 7 , wherein the housing has a recess for housing the sensor module.

10. The sensor assembly of claim 7 , wherein the shock absorber has an aluminum tube movable with respect to a rod.

11. The sensor assembly of claim 7 , wherein the sensor module includes a connector.

12. The sensor assembly of claim 7 , wherein the sensor module includes a printed wire board and a printed wire assembly.

13. The sensor assembly of claim 12 , wherein the printed wire assembly includes a resonator.

14. The sensor assembly of claim 13 , wherein the printed wire board includes at least one exciting coil and at least one receiving coil.

Assignees

• Ksr Ip Holdings Llc

Inventors

• Elliott Ryan W
• Shao Lingmin
• Fuller Shaun
• Hill Benjamin Scott

Classifications

• H05K1/181

  associated with surface mounted components · CPC title

• H05K2201/10151

  Sensor · CPC title

• H05K2201/086

  for inductive purposes, e.g. printed inductor with ferrite core · CPC title

• F16F9/38

  Covers for protection or appearance · CPC title

• G01D5/204 Primary

  by influencing the mutual induction between two or more coils (G01D5/22 takes precedence) · CPC title