US3628372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluidic angular position sensor
Assignee: General Electric Co
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Filing: 1970-06-01
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Granted: 1971-12-21
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Expires: 1990-06-01
Abstract
Abstract The relative angle of a rotary shaft is sensed by a fluidic bridge circuit consisting of a pair of fixed restrictors and a pair of variable restrictors. The variable restrictors are formed by an axial groove in the rotary shaft and a vented, constant pitch, helical groove in a sleeve member surrounding the shaft. The vented point of overlap of the helical groove with respect to the shaft axial groove divides the axial groove into the two variable restrictors. Pressurized fluid is supplied to the juncture of the fixed restrictors, and the fluid pressure at the juncture of each fixed and variable restrictor varies linearly with change in shaft angular position.
Inventors
- 👤 Thomas S Honda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:41
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/42; G01D5/44; G01D5/46; F; F15; F15C; F15C1/00; F15C1/005
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
182 words
A linear fluidic bridge circuit comprising a rotary shaft having an axial groove in the outer surface thereof, means surrounding a portion of said shaft including the axial groove in fluidtight relationship and having a vented helical groove of constant pitch in overlapping fluid communication with the axial groove, said shaft being rotatable relative to said helical groove means, first passage means including a pair of fixed fluid flow restrictors therein for forming one-half of the fluidic bridge circuit, first ends of said fixed restrictors connected at a juncture supplied from a source of pressurized fluid, and second passage means interconnecting nonjuncture second ends of said fixed restrictors with the two ends of the axial groove on said rotary shaft for forming the second half of the fluidic bridge circuit consisting of a pair of variable fluid flow restrictors formed by the axial groove divided into two variable length parts defined between the ends thereof and the vented point of overlap thereof with the helical groove wherein the point of overlap varies linearly with change in angular position of the rotary shaft.
Claim 2
Dependent Claim
182 words
A linear fluidic bridge circuit comprising a rotary shaft having an axial groove in the outer surface thereof, means surrounding a portion of said shaft including the axial groove in fluidtight relationship and having a vented helical groove of constant pitch in overlapping fluid communication with the axial groove, said shaft being rotatable relative to said helical groove means, first passage means including a pair of fixed fluid flow restrictors therein for forming one-half of the fluidic bridge circuit, first ends of said fixed restrictors connected at a juncture supplied from a source of pressurized fluid, and second passage means interconnecting nonjuncture second ends of said fixed restrictors with the two ends of the axial groove on said rotary shaft for forming the second half of the fluidic bridge circuit consisting of a pair of variable fluid flow restrictors formed by the axial groove divided into two variable length parts defined between the ends thereof and the vented point of overlap thereof with the helical groove wherein the point of overlap varies linearly with change in angular position of the rotary shaft.
Claim 3
Dependent Claim
100 words
The linear fluidic bridge circuit set forth in claim 1 and further comprising a housing for supporting said rotary shaft and helical groove means, said helical groove means being retained within said housing in a fixed position, said second passage means having first ends in fluid communication with the two ends of the axial groove and second ends comprising the output of said bridge circuit across which is developed a differential pressure that varies linearly with change in angular displacement of the rotary shaft from a reference angular position whereby said bridge circuit functions as a fluidic angular position sensor.
Claim 4
Dependent Claim
109 words
The fluidic bridge circuit set forth in claim 2 wherein said first passage means having first ends in fluid communication with the juncture supplied from the source of pressurized fluid, the source of pressurized fluid being maintained at a relatively constant pressure, said first passage means having second ends in fluid communication with said second passage means intermediate the ends thereof, and said rotary shaft provided with reduced diameter portions adjacent both sides of the shaft portion including the axial groove, the reduced diameter shaft portions forming angular-shaped chambers for providing fluid communication between the ends of the axial groove and the first ends of said second passage means.
Claim 5
Dependent Claim
104 words
The linear fluidic bridge circuit set forth in claim 1 and further comprising a housing for supporting said rotary shaft and helical groove means, said helical groove means provided with means for rotary motion relative to said rotary shaft, said second passage means having first ends in fluid communication with the two ends of the axial groove and second ends comprising the output of said bridge circuit across which is developed a differential pressure that varies linearly with change in relative angular displacement between said rotary shaft and said helical groove means whereby said bridge circuit functions as a fluidic relative angular motion transducer.
Claim 6
Dependent Claim
63 words
The fluidic relative angular motion transducer set forth in claim 4 and further comprising negative feedback means connected from the second ends of said second passage means to the means for providing rotary motion of said helical groove means to obtain a null-type operation of said fluidic transducer whereby the differential pressure across the second ends of said second passage means approaches zero.
Claim 7
Dependent Claim
124 words
The transducer set forth in claim 5 wherein means for providing rotary motion of said helical groove means comprises a first gear mounted on the outer surface of said helical groove means, said negative feedback means comprises third passage means having first ends connected to the second ends of said second passage means, a fluid motor, said third passage means having second ends connected to the input of said fluid motor, and a second gear driven by said fluid motor, said second gear in meshing engagement with said first gear, said second gear being driven to an angular displacement relative to the angular displacement of said rotary shaft to obtain the nulled differential pressure output across the second ends of said second passage means.
Claim 8
Dependent Claim
20 words
The transducer set forth in claim 6 wherein said third passage means comprise a third pair of fluid flow passages.
Claim 9
Dependent Claim
55 words
The linear fluidic bridge circuit set forth in claim 1 wherein said helical groove means comprises a sleeve member concentric with said rotary shaft and surrounding a portion thereof including the major part of the axial groove, the vented helical groove consisting of a helical groove formed completely through the side of said sleeve member.
Claim 10
Dependent Claim
122 words
The fluidic bridge circuit set forth in claim 1 wherein said helical groove means comprises a sleeve member concentric with said rotary shaft and surrounding a portion thereof including the major part of the axial groove, the vented helical groove consisting of a helical groove formed into the inner surface of said sleeve member but not passing completely through the side thereof, and vent means provided from the helical groove to the outer surface of said sleeve member, said axial groove having constant narrow width and depth dimensions to provide a relatively high restriction to fluid flow therethrough, said helical groove having larger width and, or depth dimensions than the axial groove to provide a negligible restriction to fluid being vented therethrough.
Claim 11
Dependent Claim
26 words
The fluidic bridge circuit set forth in claim 1 wherein said first and second passage means comprise first and second pairs of fluid flow passages, respectively.
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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) | 1974-12-20 | 1975-06-21 | 1975-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-20 | 1979-06-21 | 1979-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-20 | 1983-06-21 | 1983-12-21 | $7700.00 | Window Closed / Lapsed |