US3841158A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential pressure transmitter overrange protection
Assignee: Elsag International BV
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Filing: 1973-06-18
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Granted: 1974-10-15
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Expires: 1993-06-18
Abstract
Abstract A fluid-filled differential pressure transmitter using sensing diaphragms and a pressure sensitive transducer as the sensing element. The transducer is protected from overrange pressure damage by an easily deflected bellows. A break-away coupler maintains the bellows substantially rigid during normal pressure ranges and becomes disengaged during an overrange pressure condition to allow the bellows to easily deflect and accommodate the excess fluid displaced by the high pressure sensing diaphragm without excessive increase in the pressure sensed by the transducer.
Inventors
- 👤 R Hunter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:28
CPC Classifications
G; G01; G01L; G01L19/00; G01L19/06; G01L19/0618; G01L13/00; G01L13/02; G01L13/023; G01L19/0627; G01L19/0645
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
143 words
An overrange pressure limiting device for pressure sensing instruments comprising: an easily deflected bellows subjected to the pressure sensed by the instrument; a break-away coupler remaining intact and stationary up to a predetermined force level by providing an equal but opposite restoring force beyond which force level said coupler becomes inoperative to exert a restoring force including a magnetically coupled permanent magnet and strike plate enclosed in said bellows; and means for joining said break-away coupler to said bellows to render said bellows rigid when said coupler is intact, and render said bellows free to deflect when said coupler is inoperative, said joining means including a rod connecting said bellows to said permanent magnet to prevent said bellows from deflecting while said magnet and strike plate are magnetically coupled, said bellows changing in volume in response to pressure to limit the pressure thereby.
Claim 2
Dependent Claim
143 words
An overrange pressure limiting device for pressure sensing instruments comprising: an easily deflected bellows subjected to the pressure sensed by the instrument; a break-away coupler remaining intact and stationary up to a predetermined force level by providing an equal but opposite restoring force beyond which force level said coupler becomes inoperative to exert a restoring force including a magnetically coupled permanent magnet and strike plate enclosed in said bellows; and means for joining said break-away coupler to said bellows to render said bellows rigid when said coupler is intact, and render said bellows free to deflect when said coupler is inoperative, said joining means including a rod connecting said bellows to said permanent magnet to prevent said bellows from deflecting while said magnet and strike plate are magnetically coupled, said bellows changing in volume in response to pressure to limit the pressure thereby.
Claim 3
Dependent Claim
37 words
An overrange pressure limiting device as set forth in claim 1 wherein said predetermined force level of the break-away coupler is set to occur upon said bellow being subjected to a pressure in excess of range pressure.
Claim 4
Dependent Claim
140 words
An overrange pressure limiting device for pressure sensing instruments comprising: an easily deflected bellows subjected to the pressure sensed by the instrument; a break-away coupler including a mechanically coupled ball and indent and remaining intact and stationary up to a predetermined force level by providing an equal but opposite restoring force beyond which force level said coupler becomes inoperative to exert a restoring force; and means for joining said break-away coupler to said bellows including a rod having said indent and connecting said bellows to said ball and indent coupling to prevent said bellows from deflecting while said ball is retained in said indent, to render said bellows rigid when said coupler is intact, and render said bellows free to deflect when said coupler is inoperative, said bellows changing in volume in response to pressure to limit the pressure thereby.
Claim 5
Dependent Claim
140 words
An overrange pressure limiting device for pressure sensing instruments comprising: an easily deflected bellows subjected to the pressure sensed by the instrument; a break-away coupler including a mechanically coupled ball and indent and remaining intact and stationary up to a predetermined force level by providing an equal but opposite restoring force beyond which force level said coupler becomes inoperative to exert a restoring force; and means for joining said break-away coupler to said bellows including a rod having said indent and connecting said bellows to said ball and indent coupling to prevent said bellows from deflecting while said ball is retained in said indent, to render said bellows rigid when said coupler is intact, and render said bellows free to deflect when said coupler is inoperative, said bellows changing in volume in response to pressure to limit the pressure thereby.
Claim 6
Dependent Claim
31 words
An overrange pressure limiting device as set forth in claim 3 including means for spring loading said ball to retain it in said indent and prevent said rod from moving thereby.
Claim 7
Dependent Claim
49 words
An overrange pressure limiting device as set forth in claim 4 wherein said spring loading means includes means for adjusting the force on said ball by deflecting the spring of said spring loading means thereby changing the predetermined force at which said break-away coupler becomes disengaged from said bellows.
Claim 8
Dependent Claim
36 words
An overrange pressure limiting device as set forth in claim 5 wherein said spring loading means is adjusted to render said break-away coupler disengaged when said bellows is subjected to a pressure greater than range pressure.
References Cited (Backward Citations)
GB895748A
Cited
US3187711A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |