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US3601732A Expired / Lapsed US ⏱️ 0.0 years remaining

Linear variable electrical transducer

Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1969-09-29
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Granted: 1971-08-24
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Expires: 1989-09-29
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Abstract

Abstract A linear variable electrical transducer characterized by high accuracy and sensitivity, compact size, relatively long stroke, very low breakaway friction, and rugged damage and clog resistant construction. The transducer has a housing containing a flexuresupported coupling shaft and an electrical sensor laterally displaced from and operatively connected to the shaft for producing an electrical signal representing the position of the shaft relative to the housing. The flexure supports provide stiff radial positioning of the coupling shaft while requiring very low force for axial movement and no breakaway resistance of the shaft. The sensor is isolated from all external loads applied to the coupling shaft, thus permitting the use of a relatively fragile miniature sensor to substantially reduce the overall size and weight of the transducer. A novel flexure configuration for the transducer characterized by a high aspect ratio.

Inventors

  • 👤 Ronald L Samuels
  • 👤 Josef E Friederichs

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 06:51
CPC Classifications
H; H01; H01F; H01F29/00; H01F29/08; H01F29/10

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 146 words
A linear electrical transducer comprising: a housing; a coupling shaft extending through and having an end accessible externally of said housing; means supporting said shaft for axial movement relative to said housing; and a shaft position sensor within said housing at one side of said shaft including a pair of relatively movable sensing elements having an axis of relative movement parallel to and spaced laterally from said shaft, means for generating a position signal representing the relative positions of said elements along said axis, said sensing elements including a relatively stationary element and a relatively movable element having opposite ends, means mounting said stationary sensing element within said housing, and relatively rigid crossbeams extending between and fixed to said shaft and the ends of said movable element securing said movable sensing element to said shaft for axial movement with said shaft relative to said stationary element.
Claim 2
Dependent Claim 146 words
A linear electrical transducer comprising: a housing; a coupling shaft extending through and having an end accessible externally of said housing; means supporting said shaft for axial movement relative to said housing; and a shaft position sensor within said housing at one side of said shaft including a pair of relatively movable sensing elements having an axis of relative movement parallel to and spaced laterally from said shaft, means for generating a position signal representing the relative positions of said elements along said axis, said sensing elements including a relatively stationary element and a relatively movable element having opposite ends, means mounting said stationary sensing element within said housing, and relatively rigid crossbeams extending between and fixed to said shaft and the ends of said movable element securing said movable sensing element to said shaft for axial movement with said shaft relative to said stationary element.
Claim 3
Dependent Claim 34 words
A transducer according to claim 1, wherein: said shaft-supporting means comprise flexures having outer marginal portions secured to said housing and movable inner sections secured to said shaft and seating against said beams, respectively.
Claim 4
Dependent Claim 16 words
A transducer according to claim 2, including: means securing said beams to said center flexure section.
Claim 5
Dependent Claim 207 words
A linear electrical transducer comprising: a housing including a central block having opposite ends; a pair of spaced parallel bores extending through said block normal to said ends; end plates opposite said ends, respectively, of said block, spacer plates between said end plates and said block, and means joining said block and plates in assembled relation; said spacer plates having similar open rectangular configurations and defining with said block and end plate cavities at the ends of said housing; a coupling shaft extending centrally through one of said bores; one end of said shaft projecting into one of said housing cavities and the opposite end of said shaft extending through the other housing cavity and the adjacent end plate to the exterior of said housing; a linear electrical shaft position sensor within the other bore including a relatively stationary sensing element fixed to said housing and a relatively movable sensing element movable relative to said stationary element along the axis of the latter bore; the ends of said movable sensing element projecting into said housing cavities; and connecting means joining the ends of said movable sensing eleMent and said coupling shaft for axial movement of said movable element with said shaft relative to said stationary sensing element.
Claim 6
Dependent Claim 207 words
A linear electrical transducer comprising: a housing including a central block having opposite ends; a pair of spaced parallel bores extending through said block normal to said ends; end plates opposite said ends, respectively, of said block, spacer plates between said end plates and said block, and means joining said block and plates in assembled relation; said spacer plates having similar open rectangular configurations and defining with said block and end plate cavities at the ends of said housing; a coupling shaft extending centrally through one of said bores; one end of said shaft projecting into one of said housing cavities and the opposite end of said shaft extending through the other housing cavity and the adjacent end plate to the exterior of said housing; a linear electrical shaft position sensor within the other bore including a relatively stationary sensing element fixed to said housing and a relatively movable sensing element movable relative to said stationary element along the axis of the latter bore; the ends of said movable sensing element projecting into said housing cavities; and connecting means joining the ends of said movable sensing eleMent and said coupling shaft for axial movement of said movable element with said shaft relative to said stationary sensing element.
Claim 7
Dependent Claim 36 words
A transducer according to claim 4, wherein: said shaft position sensor comprises a linear variable differential transformer including a coil which provides said stationary sensing element and a magnetic core which provides said movable sensing element.
Claim 8
Dependent Claim 42 words
A transducer according to claim 4, including: flexures within said housing cavities having outer marginal portions clamped between adjacent spacer plates and center flexible sections secured to said coupling shaft to support said shaft for axial movement within said first mentioned bore.
Claim 9
Dependent Claim 29 words
A transducer according to claim 6, wherein: said connecting means comprise rigid crossbeams fixed to said shaft and movable element in seating contact with said center flexure sections, respectively.
Claim 10
Dependent Claim 15 words
A transducer acccording to claim 7, including: means joining said crossbeams and center flexure sections.
Claim 11
Dependent Claim 56 words
A transducer according to claim 8, including: a spring within said second mentioned bore for urging said stationary sensing element in one direction along said axis, and an externally accessible adjusting screw threaded in said housing and engageable with said stationary element for adjusting said stationary element relative to said core independently of said coupling shaft.
Claim 12
Dependent Claim 125 words
A transducer comprising: a housing; a shaft movable axially within said housing; a shaft position sensor within said housing at one side of said shaft including a pair of relatively movable sensing elements having an axis of relative movement parallel to and spaced laterally from said shaft, means for generating a position signal representing the relative positions of said elements along said axis, said sensing elements including a relatively stationary element and a relatively movable element having opposite ends; and a pair of flexures secured to said housing, said shaft, and the ends of said movable element, said flexures supporting and interconnecting said shaft and movable element for axial movement in unison, whereby said sensor produces a signal representing the axial position of said shaft.
Claim 13
Dependent Claim 125 words
A transducer comprising: a housing; a shaft movable axially within said housing; a shaft position sensor within said housing at one side of said shaft including a pair of relatively movable sensing elements having an axis of relative movement parallel to and spaced laterally from said shaft, means for generating a position signal representing the relative positions of said elements along said axis, said sensing elements including a relatively stationary element and a relatively movable element having opposite ends; and a pair of flexures secured to said housing, said shaft, and the ends of said movable element, said flexures supporting and interconnecting said shaft and movable element for axial movement in unison, whereby said sensor produces a signal representing the axial position of said shaft.
Claim 14
Dependent Claim 36 words
A transducer according to claim 10 wherein: said flexures have outer marginal portions secured to said housing and inner movable sections secured to said shaft and movable element, and means reinforcing said inner sections against flexing.
Claim 15
Dependent Claim 80 words
A transducer according to claim 10 wherein: said housing has an opening containing and slightly larger in diameter than said shaft; said sensor comprises a linear variable differential transducer and said stationary and movable sensing elements comprise the coil and core of said latter transducer, said coil having an opening containing and of slightly larger diameter than said core; and said flexures support said shaft and core concentrically within and in spaced relation to the walls of their respective openings.
Claim 16
Dependent Claim 122 words
A transducer comprising: a housing; a shaft movable axially within said housing; means supporting said shaft for axial movement relative to said housing; and a shaft position sensor within said housing at one side of said shaft including a pair of relatively movable sensing elements having an axis of relative movement parallel to and spaced laterally from said shaft, means for generating a position signal representing the relative positions of said elements along said axis, said sensing elements including a relatively stationary element and a relatively movable element having opposite ends, and relatively crossbeams extending between and joining the ends of said movable sensing element and shaft for axial movement of said movable element with said shaft relative to said stationary element.
Claim 17
Dependent Claim 122 words
A transducer comprising: a housing; a shaft movable axially within said housing; means supporting said shaft for axial movement relative to said housing; and a shaft position sensor within said housing at one side of said shaft including a pair of relatively movable sensing elements having an axis of relative movement parallel to and spaced laterally from said shaft, means for generating a position signal representing the relative positions of said elements along said axis, said sensing elements including a relatively stationary element and a relatively movable element having opposite ends, and relatively crossbeams extending between and joining the ends of said movable sensing element and shaft for axial movement of said movable element with said shaft relative to said stationary element.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1974-08-23 1975-02-22 1975-08-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1978-08-23 1979-02-22 1979-08-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1982-08-23 1983-02-22 1983-08-24 $7700.00 Window Closed / Lapsed

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