US3785209A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure gauge
Assignee: Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO
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Filing: 1971-10-28
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Granted: 1974-01-15
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Expires: 1991-10-28
Abstract
Abstract A pressure gauge for extrusion and injection moulding machines, in which a push rod connects a membrane at one end and a displacement meter at the other end of the casing. The usual thermal sensitivity of this kind of pressure gauges has been suppressed by the use of a hollow, thin-walled push rod that fits in the casing with a narrow clearance.
Inventors
- 👤 J Schijf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:08
CPC Classifications
G; G01; G01L; G01L19/00; G01L19/04; B; B29; B29C; B29C45/00; B29C45/17; B29C45/76; B29C45/77; B29C48/00; B29C48/25; B29C48/92; G01L7/00; G01L7/02; G01L7/08; B29C2948/00; B29C2948/92; B29C2948/92009; B29C2948/92019; B29C48/03
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
136 words
A pressure gauge useful for measurements during extrusion and injection moulding of thermoplastic materials and similar materials, comprising a substantially tubular casing, a pressure responsive means closing said casing at its one end and deforming elastically under the influence of the pressure to be measured, a displacement meter containing a feeler means and provided at the other end of said casing, and a push rod coaxial within the inner wall of said casing and connecting said feeler means of said displacement meter with said pressure responsive means, said feeler means closing that end of said push rod opposite to said pressure responsive means, said push rod is hollow, its wallthickness is less than 15 percent of its diametEr, and there is only a slight clearance between said push rod and the inner wall of said casing.
Claim 2
Dependent Claim
136 words
A pressure gauge useful for measurements during extrusion and injection moulding of thermoplastic materials and similar materials, comprising a substantially tubular casing, a pressure responsive means closing said casing at its one end and deforming elastically under the influence of the pressure to be measured, a displacement meter containing a feeler means and provided at the other end of said casing, and a push rod coaxial within the inner wall of said casing and connecting said feeler means of said displacement meter with said pressure responsive means, said feeler means closing that end of said push rod opposite to said pressure responsive means, said push rod is hollow, its wallthickness is less than 15 percent of its diametEr, and there is only a slight clearance between said push rod and the inner wall of said casing.
Claim 3
Dependent Claim
23 words
A pressure gauge according to claim 1, wherein the average clearance between said push rod and said casing is less than 0.5 mm.
Claim 4
Dependent Claim
22 words
A pressure gauge according to claim 2, wherein the clearance between said push rod and said casing is filled with a liquid.
Claim 5
Dependent Claim
23 words
A pressure gauge according to claim 1, wherein the wall-thickness of said casing is more than twice the wall-thickness of said push rod.
Claim 6
Dependent Claim
32 words
A pressure gauge according to claim 4, wherein a part of said casing is enclosed by a coaxial tubular member whose inside diameter is greater than the outside diameter of said casing.
References Cited (Backward Citations)
US2472045A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |