Patent US457561A successfully refreshed from Google Patents.
Patent US3159175A successfully refreshed from Google Patents.
US3159175A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid check valve unit
Assignee: Delman Co
•
Filing: 1961-12-12
•
Granted: 1964-12-01
•
Expires: 1981-12-12
Abstract
No abstract record available.
Inventors
- 👤 Robert E Macmillan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:10
CPC Classifications
B; B67; B67D; B67D7/00; B67D7/02; B67D7/0205; F; F04; F04B; F04B53/00; F04B53/10; F04B53/1037; F04B53/1047; F04B53/106; F04B53/1067; F04B9/00; F04B9/14; F16; F16K; F16K15/00; F16K15/14; F16K15/144; F16K15/147; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7771; Y10T137/7837; Y10T137/7879; Y10T137/788; Y10T137/7881
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
59 words
A CHECK VALVE UNIT COMPRISING A SUBSTANTIALLY FLAT ELEMENT OF RESILIENT MATERIAL HAVING A NORMALLY CLOSED Z-SHAPED SLIT FORMED THEREIN, AND MEANS SECURING THE EDGES OF SAID ELEMENT AGAINST MOVEMENT, SAID ELEMENT DISTORTABLE TO OPEN SAID SLIT FOR THE PASSAGE OF FLUID THERETHROUGH IN RESPONSE TO THE APPLICATION OF A FLUID UNDER PRESSURE AGAINST EITHER SIDE OF SAID ELEMENT.
Claim 2
Dependent Claim
59 words
A CHECK VALVE UNIT COMPRISING A SUBSTANTIALLY FLAT ELEMENT OF RESILIENT MATERIAL HAVING A NORMALLY CLOSED Z-SHAPED SLIT FORMED THEREIN, AND MEANS SECURING THE EDGES OF SAID ELEMENT AGAINST MOVEMENT, SAID ELEMENT DISTORTABLE TO OPEN SAID SLIT FOR THE PASSAGE OF FLUID THERETHROUGH IN RESPONSE TO THE APPLICATION OF A FLUID UNDER PRESSURE AGAINST EITHER SIDE OF SAID ELEMENT.
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) | 1967-12-01 | 1968-06-01 | 1968-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-12-01 | 1972-06-01 | 1972-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-12-01 | 1976-06-01 | 1976-12-01 | $7700.00 | Window Closed / Lapsed |