Patent US3831494A successfully refreshed from Google Patents.
US4098302A
Expired / Lapsed
US
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Method of charging pneumatic suspension element
Assignee: Stabilus GmbH
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Filing: 1977-01-05
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Granted: 1978-07-04
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Expires: 1997-01-05
Abstract
Abstract The cylinder cavity of a pneumatic suspension element of the piston-and-cylinder type in which the escape of compressed gas from the cylinder cavity is prevented by a liquid in a portion of the cylinder cavity through which the piston rod passes is charged with compressed gas and liquid through resiliently sealed gaps about the piston rod and/or through a porous partition separating the liquid-filled cavity portion from the gas-filled portion.
Inventors
- 👤 Herbert Freitag
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:12
CPC Classifications
F; F16; F16F; F16F9/00; F16F9/02; F16F9/32; F16F9/43; F16J; F16J15/00; F16J15/16; F16J15/40
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
164 words
A method of charging an element having a cylinder, a partition axially dividing the cavity of the cylinder into two chambers, a piston rod movably extending from one of said chambers through the partition, through the other chamber, and through an apertured wall of the cylinder outward of the cavity, first pressure-responsive sealing means preventing flow of fluid from said other chamber outward of said cavity, and second pressure-responsive sealing means preventing flow of fluid between said chambers in the absence of a predetermined pressure differential, which method comprises: (a) forcing a gas under pressure sequentially through said first and second sealing means until said chambers are filled with said gas at a first pressure higher than atmospheric pressure; and (b) thereafter forcing a liquid through said first sealing means into said other chamber at a pressure higher than said first pressure until gas is displaced from said other chamber by said liquid and forced through said second sealing means into said one chamber.
Claim 2
Independent Claim
164 words
A method of charging an element having a cylinder, a partition axially dividing the cavity of the cylinder into two chambers, a piston rod movably extending from one of said chambers through the partition, through the other chamber, and through an apertured wall of the cylinder outward of the cavity, first pressure-responsive sealing means preventing flow of fluid from said other chamber outward of said cavity, and second pressure-responsive sealing means preventing flow of fluid between said chambers in the absence of a predetermined pressure differential, which method comprises: (a) forcing a gas under pressure sequentially through said first and second sealing means until said chambers are filled with said gas at a first pressure higher than atmospheric pressure; and (b) thereafter forcing a liquid through said first sealing means into said other chamber at a pressure higher than said first pressure until gas is displaced from said other chamber by said liquid and forced through said second sealing means into said one chamber.
Claim 3
Dependent Claim
28 words
A method as set forth in claim 1, wherein said liquid is forced through said first sealing means while said other chamber is located below said one chamber.
Claim 4
Dependent Claim
34 words
A method as set forth in claim 1, wherein said liquid is forced into said other chamber until said gas is substantially completely displaced from said other chamber and forced into said one chamber.
References Cited (Backward Citations)
US3948540A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |