Patent US4212191A successfully refreshed from Google Patents.
US4212191A
Expired / Lapsed
US
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Differential pressure gauge
Assignee: United States Department of the Army
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Filing: 1979-03-15
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Granted: 1980-07-15
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Expires: 1999-03-15
Abstract
Abstract A gauge for measuring differential pressure in an explosive blast wave, w tunnel, or shock tube, utilizes a tubular housing having a conical axially aligned inlet port, a cylindrical cavity which is divided into fore and aft sections by a transversely disposed pressure responsive diaphram. A plurality of symmetrically disposed off-set stagnation inlet tubes and a plurality of circumferentially positioned flow compensated side-on overpressure input slots are used to communicate with each of the respective fore and aft sections of the cavity. Variation in stagnation and side-on overpressures cause diaphram movement which is detected by a friction-free sensing member.
Inventors
- 👤 Noel H. Ethridge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:21
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0076; G01L9/0077; G01L9/007
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
127 words
An apparatus for measuring differential pressure that an explosion produced blast wave produces on a target comprising: a tubular housing having a stagnation inlet end and a threaded mounting end; removable stagnation inlet overpressure means operatively disposed in said stagnation inlet end of said housing and adapted for responsively sampling incident fluid flow of said blast wave; compensating side-on inlet overpressure means for sampling side-on inlet pressure produced by said blast wave; diaphram means, transversely positioned in said housing, for moving in response to said differential pressure between said stagnation inlet overpressure means and said compensating side-on inlet overpressure means; and friction-free sensing means operatively positioned in said housing for detecting motion in said diaphram means and for generating an output signal in response to said motion.
Claim 2
Independent Claim
127 words
An apparatus for measuring differential pressure that an explosion produced blast wave produces on a target comprising: a tubular housing having a stagnation inlet end and a threaded mounting end; removable stagnation inlet overpressure means operatively disposed in said stagnation inlet end of said housing and adapted for responsively sampling incident fluid flow of said blast wave; compensating side-on inlet overpressure means for sampling side-on inlet pressure produced by said blast wave; diaphram means, transversely positioned in said housing, for moving in response to said differential pressure between said stagnation inlet overpressure means and said compensating side-on inlet overpressure means; and friction-free sensing means operatively positioned in said housing for detecting motion in said diaphram means and for generating an output signal in response to said motion.
Claim 3
Dependent Claim
20 words
An apparatus as recited in claim 1 wherein said tubular housing comprises a rounded nose inlet end for subsonic flow.
Claim 4
Dependent Claim
72 words
An apparatus as recited in claim 2 wherein said removeable stagnation inlet overpressure means comprises: a cylindrically shaped stagnation inlet member having a converging conically shaped inlet cavity having a cone half-angle α, which preferably does not exceed 15° , a plurality of equally spaced off-set passageways communicate on one end with a narrow base end of said conical inlet cavity and on another end with a fore sensing cylindrical diaphram cavity.
Claim 5
Dependent Claim
43 words
An apparatus as recited in claim 3 wherein said off-set passageways form a path having approximately a 90° change in direction leading to an aft sensing cylindrical diaphram cavity, said off-set passageways preventing incoming dust particles from impacting directly on said diaphram means.
Claim 6
Dependent Claim
36 words
An apparatus as recited in claim 4 wherein said compensating side-on inlet overpressure means comprises a plurality of circumferentially disposed equally spaced slots which admit side-on overpressure flow to a rear side of said diaphram means.
Claim 7
Dependent Claim
62 words
An apparatus as recited in claim 5 wherein said compensating side-on inlet overpressure means includes a plurality of circumferentially disposed equally spaced slots having rounded leading edges, said rounded leading edges producing an increase in pressure in said slots which partially compensate for the lowering of overpressure at slot inlet orifices caused by higher-than-free-stream velocity proximate to said round nose inlet end.
Claim 8
Dependent Claim
83 words
An apparatus as recited in claim 6 wherein said compensating side-on inlet overpressure means includes a plurality of equally spaced side-on inlet slots wherein rear peripheral edges of said slots are made larger in diameter than the leading edges of said slots, said larger diameter rear peripheral edges being adjusted to change the amount of pressure increase in said slots to compensate for the lowering of overpressure at slot inlet orifices caused by higher-than-free stream velocity proximate to said round nose inlet end.
Claim 9
Independent Claim
40 words
An apparatus as recited in claims 6 or 7 wherein said diaphram means comprises a disk shaped metal member circumferentially soldered and transversely positioned under tension intermediate said fore sensing cylindrical diaphram cavity and said aft sensing cylindrical diaphram cavity.
Claim 10
Dependent Claim
63 words
An apparatus as recited in claim 8 wherein said plurality of equally spaced off-set passageways of said stagnation inlet overpressure means and said plurality of equally spaced side-on inlet slots of said compensating side-on inlet overpressure means includes a filter material operatively disposed therein to keep out dust particles from said off-set passageways and said side-on inlet slots and to provide acoustic damping.
Claim 11
Dependent Claim
53 words
An apparatus as recited in claim 9 wherein said sensing means comprises a pair of fiber optical cables for carrying a light beam to illuminate said diaphram means and to carry out a reflected light output signal related to the deflections of said diaphram and to dynamic pressure being sensed by said apparatus.
Claim 12
Dependent Claim
39 words
An apparatus as recited in claim 10 wherein said sensing means comprises variable inductance sensing coils proximately disposed to said diaphram means and adapted to be responsive to changes in magnetic flux produced by deflection of said diaphram means.
Claim 13
Dependent Claim
20 words
An apparatus as recited in claim 11 wherein said disk shaped metal member comprises a 42% nickel 58% iron alloy.
Claim 14
Dependent Claim
15 words
An apparatus as recited in claim 10 wherein said filter material includes fine glass wool.
Claim 15
Dependent Claim
19 words
An apparatus as recited in claim 11 wherein said tubular housing comprisesa sharp-edged nose for supersonic measurement of flow.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-07-15 | 1984-01-14 | 1984-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-15 | 1988-01-14 | 1988-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-15 | 1992-01-14 | 1992-07-15 | $7700.00 | Window Closed / Lapsed |