Linear variable capacitance transducer

Claim 2

A linear variable capacitance transducer to monitor the axial position of an object comprising: a quartz tube having a pair of capacitor plates disposed on the outer surface thereof extending longitudinally and occupying each substantially one-half of the circumference, said plates being diametrically opposed to each other; a metallic rod slidingly reciprocal within said qUartz tube, said rod being electrically insulated from the capacitor plates; and means for connecting respectively the capacitor plates and the rod to an AC signal source for varying the signal output of said source dependent upon the position of said rod with respect to said capacitor plates and in which said rod is maintained at ground potential.

Claim 3

The transducer according to claim 1 in which said capacitor plates are disposed in a helical relationship about the outer surface of said quartz tube.

Claim 4

The transducer according to claim 1 or 2 in which said rod is hollow and provided with a means including a connecting rod extending therethrough for maintaining positive contact with said rod regardless of the position or movement of said rod with respect to said quartz tube.

Claim 5

The transducer claimed in claims 1 or 2 in which means for maintaining connection between said rod and ground comprises a segmented bushing and spring means urging said segmented bushing radially inwardly against said rod.

Claim 6

The transducer claimed in claims 1 or 2 further including a housing encompassing said transducer means and sealing means within said housing through which said rod may reciprocate yet provide a means for preventing the entry of foreign matter within said housing to protect said transducer from adverse environment.

Claim 7

A linear variable capacitance transducer to monitor the axial position of an object comprising: a tube of dielectric material having a pair of capacitor plates formed on the outer surface thereof as a coating of electrically conductive material on said outer coating which are diametrically opposite each other and electrically insulated from each other, each of said plates comprising substantially one-half of the circumference; a metallic rod mounted for reciprocal axial movement within said tube, said rod being electrically insulated from said capacitor plates and being connected to ground potential; and means for connecting respectively the capacitor plates and the rod to an AC signal source for varying the signal output of said source dependent upon the position of said rod with respect to said capacitor plates.

Claim 8

A linear variable capacitance transducer to monitor the axial position of an object comprising: a tube of dielectric material having a pair of capacitor plates formed on the outer surface thereof as a coating of electrically conductive material on said outer coating which are diametrically opposite each other and electrically insulated from each other, each of said plates comprising substantially one-half of the circumference; a metallic rod mounted for reciprocal axial movement within said tube, said rod being electrically insulated from said capacitor plates and being connected to ground potential; and means for connecting respectively the capacitor plates and the rod to an AC signal source for varying the signal output of said source dependent upon the position of said rod with respect to said capacitor plates.

Claim 9

The transducer according to claim 6, in which said capacitor plate coatings are disposed in a helical relationship about the outer surface of said tube.