Patent US3228658A successfully refreshed from Google Patents.
US3228658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic lift
Assignee: Enerpac Tool Group Corp
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Filing: 1963-12-11
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Granted: 1966-01-11
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Expires: 1983-12-11
Abstract
No abstract record available.
Inventors
- 👤 Alvan G London
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:05
CPC Classifications
B; B66; B66F; B66F3/00; B66F3/24; B66F3/25; B66F17/00; F; F15; F15B; F15B13/00; F15B13/01; F15B15/00; F15B15/08; F15B15/14; F15B15/1423; F15B15/1433; F15B15/149; F15B15/20; F15B15/202; F15B21/00; F15B21/04; F15B21/041; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7781; Y10T137/7784; Y10T137/7785
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
206 words
A HYDRAULIC DEVICE FOR LOADING AND UNLOADING A PRESSURE CHAMBER COMPRISING A BASE CLOSING ONE END OF SAID CHAMBER, SAID BASE HAVING A BORE FORMED THEREIN, A FLUID POWER SOURCE, A FIRST FLUID CONDUIT MEANS COMMUNICATING SAID POWER SOURCE TO SAID BORE, A SECOND CONDUIT MEANS COMMUNICATING SAID FIRST CONDUIT MEANS TO A FLUID RESERVOIR HAVING A RESERVOIR PRESSURE, AN ADJUSTABLE VALVE ALONG SAID SECOND CONDUIT MEANS, SAID BASE HAVING A PASSAGEWAY COMMUNICATING SAID BORE WITH SAID CHAMBER, A REDUCED PORTION ALONG SAID PASSAGEWAY DEFINING A VALVE SEAT, A BEARING SURFACE BETWEEN SAID REDUCED PORTION AND SAID FIRST CONDUIT MEANS, A VALVE MEMBER IN SAID PASSAGEWAY FOR CLOSING SAID VALVE SEAT, A SPRING SUPPORTED ON SAID SURFACE AND EXTENDING INTO SAID PASSAGEWAY IN ENGAGEMENT WITH SAID MEMBER FOR NORMALLY BIASING SAID MEMBER IN SPACED RELATIONSHIP WITH SAID SEAT, SAID ADJUSTABLE VALVE HAVING A FIRST SETTING WHEREIN FLUID IN SAID CHAMBER UNDER PRESSURE HIGHER THAN SAID RESERVOIR PRESSURE WILL RETURN TO SAID RESERVOIR WITHOUT OVERCOMING THE BIAS OF SAID SPRING AND A SECOND SETTING PERMITTING FLUID FLOW OF SUFFICIENT VELOCITY TO OVERCOME THE BIAS OF SAID SPRING AND CAUSE THE PRESSURE IN SAID CHAMBER TO FORCE SAID MEMBER AGAINST SAID VALVE SEAT AND THEREBY CLOSE SAID PASSAGEWAY.
Claim 2
Dependent Claim
206 words
A HYDRAULIC DEVICE FOR LOADING AND UNLOADING A PRESSURE CHAMBER COMPRISING A BASE CLOSING ONE END OF SAID CHAMBER, SAID BASE HAVING A BORE FORMED THEREIN, A FLUID POWER SOURCE, A FIRST FLUID CONDUIT MEANS COMMUNICATING SAID POWER SOURCE TO SAID BORE, A SECOND CONDUIT MEANS COMMUNICATING SAID FIRST CONDUIT MEANS TO A FLUID RESERVOIR HAVING A RESERVOIR PRESSURE, AN ADJUSTABLE VALVE ALONG SAID SECOND CONDUIT MEANS, SAID BASE HAVING A PASSAGEWAY COMMUNICATING SAID BORE WITH SAID CHAMBER, A REDUCED PORTION ALONG SAID PASSAGEWAY DEFINING A VALVE SEAT, A BEARING SURFACE BETWEEN SAID REDUCED PORTION AND SAID FIRST CONDUIT MEANS, A VALVE MEMBER IN SAID PASSAGEWAY FOR CLOSING SAID VALVE SEAT, A SPRING SUPPORTED ON SAID SURFACE AND EXTENDING INTO SAID PASSAGEWAY IN ENGAGEMENT WITH SAID MEMBER FOR NORMALLY BIASING SAID MEMBER IN SPACED RELATIONSHIP WITH SAID SEAT, SAID ADJUSTABLE VALVE HAVING A FIRST SETTING WHEREIN FLUID IN SAID CHAMBER UNDER PRESSURE HIGHER THAN SAID RESERVOIR PRESSURE WILL RETURN TO SAID RESERVOIR WITHOUT OVERCOMING THE BIAS OF SAID SPRING AND A SECOND SETTING PERMITTING FLUID FLOW OF SUFFICIENT VELOCITY TO OVERCOME THE BIAS OF SAID SPRING AND CAUSE THE PRESSURE IN SAID CHAMBER TO FORCE SAID MEMBER AGAINST SAID VALVE SEAT AND THEREBY CLOSE SAID PASSAGEWAY.
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) | 1969-01-10 | 1969-07-12 | 1970-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-10 | 1973-07-12 | 1974-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-10 | 1977-07-12 | 1978-01-11 | $7700.00 | Window Closed / Lapsed |