Patent US3556690A successfully refreshed from Google Patents.
US3556690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor-driven pump for delivering liquids at a pressure substantially constant and independent from the delivery
Assignee: Harry Krueger GmbH
•
Filing: 1968-08-21
•
Granted: 1971-01-19
•
Expires: 1988-08-21
Abstract
Abstract A PISTON PUMP WHICH DELIVERS LIQUIDS AT A PRESSURE CONSTANT AND INDEPENDENT FROM THE QUANTITY DELIVERED. THE PUMP COOPERATES WITH A CONTROL UNIT WHICH ALLOWS AUTOMATIC VARIATION OF THE PISTON STROKE WITH CHANGE OF DELIVERY, BUT WITHOUT SUBSTANTIAL CHANGE OF DISCHARGE PRESSURE. THIS STROKE VARIATION IS PERFORMED BY MEANS OF A YIELDING LIQUID CONNECTION BETWEEN THE PISTON PER- FORMING THE SUCTION STROKE AND THE PISTON PERFORMING THE DELIVERY STROKE. THE DRIVE IS RESILIENTLY COUPLED WITH THE PISTONS DURING THE SUCTION STROKE SO THAT PARTIAL STORKES ARE PERFORMED WITH A PARTIAL IDLING DRIVE.
Inventors
- 👤 Harry Scheffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:49
CPC Classifications
F; F04; F04B; F04B5/00; F04B1/00; F04B1/02; F04B1/04; F04B1/06; F04B1/066; F04B49/00; F04B49/12; F04B49/121; F04B53/00; F04B53/16; F04B53/162; F04B53/164; F04B9/00; F04B9/02; F04B9/04; F04B9/042
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |