Patent EP0585972A2 successfully refreshed from Google Patents.
US4006639A
Expired / Lapsed
US
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Temperature compensation for liquid filled pressure gauge
Assignee: Dresser Industries Inc
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Filing: 1975-09-29
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Granted: 1977-02-08
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Expires: 1995-09-29
Abstract
Abstract The transparent crystal of a liquid filled pressure gauge casing is physically characterized by a controlled stiffness correlated to the volumetric temperature expansion coefficient of the fill liquid. By virtue of temperature induced expansion of the fluid being accommodated through crystal displacement, affected changes in fluid pressure are substantially minimized in maintaining accuracy of the gauge instrument.
Inventors
- 👤 Richard H. Wetterhorn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:05
CPC Classifications
G; G01; G01L; G01L7/00; G01L7/02; G01L7/04; G01L19/00; G01L19/04; G01L19/14
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
105 words
In a casing for a fluid filled pressure gauge including a case and a crystal comprising walls supported forming a fluid-tight enclosure containing a pressure sensitive element extending to outward of the enclosure for receiving an internally applied pressure input, compensating means comprising said crystal to compensate against temperature induced volumetric changes incurred by the fluid fill, said crystal having a controlled volumetric stiffness substantially correlated to the anticipated temperature induced volumetric changes to be incurred by the fluid fill with a specific volume stiffness on the order of less than about 0.1 pounds per square inch per percent volume increase of the fluid fill.
Claim 2
Dependent Claim
105 words
In a casing for a fluid filled pressure gauge including a case and a crystal comprising walls supported forming a fluid-tight enclosure containing a pressure sensitive element extending to outward of the enclosure for receiving an internally applied pressure input, compensating means comprising said crystal to compensate against temperature induced volumetric changes incurred by the fluid fill, said crystal having a controlled volumetric stiffness substantially correlated to the anticipated temperature induced volumetric changes to be incurred by the fluid fill with a specific volume stiffness on the order of less than about 0.1 pounds per square inch per percent volume increase of the fluid fill.
Claim 3
Dependent Claim
15 words
In a casing according to claim 1 in which said crystal comprises a plastic composition.
Claim 4
Dependent Claim
147 words
In a pressure gauge comprising the combination of: a. a casing including a case and crystal comprising walls supported forming a fluid-tight enclosure; b. a fluid fill within said casing; c. a Bourdon tube within said casing extending to outward of said enclosure defining an input for receiving a pressure applied internally of said tube, said Bourdon tube being immersed in said fluid fill for operatively responding to pressure changes incurred by a pressure source received at said input; and d. compensating means comprising said crystal for operably compensating against temperature induced volumetric changes incurred by said fluid fill, said crystal having a controlled volumetric stiffness substantially correlated to the anticipated temperature induced volumetric changes to be incurred by the fluid fill with a specific volume stiffness on the order of less than about 0.1 pounds per square inch per percent volume increase of the fluid fill.
Claim 5
Dependent Claim
147 words
In a pressure gauge comprising the combination of: a. a casing including a case and crystal comprising walls supported forming a fluid-tight enclosure; b. a fluid fill within said casing; c. a Bourdon tube within said casing extending to outward of said enclosure defining an input for receiving a pressure applied internally of said tube, said Bourdon tube being immersed in said fluid fill for operatively responding to pressure changes incurred by a pressure source received at said input; and d. compensating means comprising said crystal for operably compensating against temperature induced volumetric changes incurred by said fluid fill, said crystal having a controlled volumetric stiffness substantially correlated to the anticipated temperature induced volumetric changes to be incurred by the fluid fill with a specific volume stiffness on the order of less than about 0.1 pounds per square inch per percent volume increase of the fluid fill.
Claim 6
Dependent Claim
15 words
In a casing according to claim 3 in which said crystal comprises a plastic composition.
References Cited (Backward Citations)
US3080758A
Cited
US3837225A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-08 | 1980-08-09 | 1981-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-08 | 1984-08-09 | 1985-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-08 | 1988-08-09 | 1989-02-08 | $7700.00 | Window Closed / Lapsed |