Method and apparatus for detecting a relative movement between two bodies being in frictional contact with each other

Claim 3

The method set forth in claim 1, further comprising selecting from said electrical noise signal predetermined frequency components and processing said components to form an electrical indicating signal.

Claim 4

The method set forth in claim 2, wherein said electrical indicating signal is a direct current signal.

Claim 5

The method of claim 2, wherein the selected frequency components are greater than about 1 kilohertz.

Claim 6

The method of claim 4, wherein the selected frequency components are in the range between about 5 kilohertz and 50 kilohertz.

Claim 7

In a system for detecting relative movement between two frictionally contacting bodies by sensing an electrical charge characteristic generated by such movement, including means responsive to an electrical noise signal representing such characteristic to provide an output signal indicative of such movement, a sensing device comprising a friction body formed of an electrically insulating material and providing a surface adapted for frictional contact with a relatively moving body, and electrically conducting means associated with said friction body for sensing the electrical noise signal indicative of the instantaneous charge changes between the frictionally contacting bodies and independent of the absolute accumulated charge at each thereof, said electrically conducting means including a terminal connection for providing an electrical signal to the signal responsive means.

Claim 8

In a system for detecting relative movement between two frictionally contacting bodies by sensing an electrical charge characteristic generated by such movement, including means responsive to an electrical noise signal representing such characteristic to provide an output signal indicative of such movement, a sensing device comprising a friction body formed of an electrically insulating material and providing a surface adapted for frictional contact with a relatively moving body, and electrically conducting means associated with said friction body for sensing the electrical noise signal indicative of the instantaneous charge changes between the frictionally contacting bodies and independent of the absolute accumulated charge at each thereof, said electrically conducting means including a terminal connection for providing an electrical signal to the signal responsive means.

Claim 9

Apparatus for detecting the relative motion of an element comprising a dielectric friction body providing a charge transfer surface to be engaged by the relatively moving element, an electrically conductive member associated with the friction body and disposed to be influenced by the electrical charges produced at such surface by the frictional contact therewith of the moving element and thereby to develop at the conductive member an electrical noise signal, and means responsive to the electrical noise signal for developing an electrical signal independent of the absolute electrical potential of the moving element and indicative of such relative motion.

Claim 10

Apparatus for detecting the relative motion of an element comprising a dielectric friction body providing a charge transfer surface to be engaged by the relatively moving element, an electrically conductive member associated with the friction body and disposed to be influenced by the electrical charges produced at such surface by the frictional contact therewith of the moving element and thereby to develop at the conductive member an electrical noise signal, and means responsive to the electrical noise signal for developing an electrical signal independent of the absolute electrical potential of the moving element and indicative of such relative motion.

Claim 11

Apparatus in accordance with claim 7, wherein the means responsive to the electrical noise signal includes amplifying means operatively connected with the electrically conducting means and operative to strengthen at least certain frequency components of the electrical noise signal.

Claim 12

In a system for detecting relative movement between two frictionally contacting bodies by sensing electrical charge characteristics associated with such movement and including means responsive to an electrical noise signal for developing an output signal indicative of such movement, a sensing device comprising a friction body formed of an electrically insulating material and adapted to be placed in frictional contact with a relatively moving body, electrically conducting means adapted for electrical coupling to the responsive means and associated with said friction body for sensing said electrical noise signal produced by instantaneous charge changes between the frictionally contacting bodies and independent of the absolute accumulated charge at each thereof, and conductive shielding means providing a conductive element in proximity to and electrically isolated from the electrically conducting means for establishing a reference potential therefor.

Claim 13

In a system for detecting relative movement between two frictionally contacting bodies by sensing electrical charge characteristics associated with such movement and including means responsive to an electrical noise signal for developing an output signal indicative of such movement, a sensing device comprising a friction body formed of an electrically insulating material and adapted to be placed in frictional contact with a relatively moving body, electrically conducting means adapted for electrical coupling to the responsive means and associated with said friction body for sensing said electrical noise signal produced by instantaneous charge changes between the frictionally contacting bodies and independent of the absolute accumulated charge at each thereof, and conductive shielding means providing a conductive element in proximity to and electrically isolated from the electrically conducting means for establishing a reference potential therefor.

Claim 14

A sensing device in accordance with claim 9, wherein the friction body has a substantially circular cross section, and wherein the electrically conducting means is embedded in the friction body to be isolated from the relatively moving body by a portion of said friction body.

Claim 15

A sensing device as claimed in claim 9, wherein the electrically conducting means comprises at least two electrically conducting sensing members embedded in the friction body and mutually spaced and electrically isolated from each other by a portion of such friction body.

Claim 16

A sensing device as defined in claim 9, wherein said conductive shielding means foRms a casing for at least a portion of friction body and is contoured to provide a surface for guiding the relatively moving body.

Claim 17

A sensing device in accordance with claim 9, further comprising yieldable pressure applying means for contacting the relatively moving member and thereby yieldingly urging such member into contact with the friction body.