US3854848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for preventing back-flow in centrifugal pumps operating in parallel
Assignee: Individual
•
Filing: 1972-09-28
•
Granted: 1974-12-17
•
Expires: 1992-09-28
Abstract
Abstract A device for preventing back-flow through one of several centrifugal pumps connected in parallel in a common circuit when the impeller of the pump is stationary. The device has a closure member in the form of a cylindrical relatively rotationally displaceable closure element, which in one position permits free passage of the back-flow and in another position closes off the back-flow. The closure element has guide elements which are angularly displaced about the axis of rotation of the pump impeller in one direction by the swirl of the stream of medium being conveyed.
Inventors
- 👤 N Laing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:18
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/08; F04D29/10; F04D29/14; F04D29/146; F04D13/00; F04D13/02; F04D13/06; F04D13/0653; F04D13/12; F04D13/14; F04D15/00; F04D15/0077; F04D15/0083; F04D15/02; F04D15/029; F04D29/04; F04D29/046; F04D29/0467; F04D29/18; F04D29/186; F04D29/40; F04D29/52; F04D29/54; F04D29/548; F04D29/58; F04D29/586; F04D3/00; F04D7/00; F04D7/02; F04D7/08; F04D9/00; F04D9/007; F04D9/008; F16; F16C; F16C17/00; F16C17/04; F16C17/08; H; H01; H01F; H01F30/00; H01F30/06; H01F30/12; H02; H02J; H02J3/00; H02J3/38; H02K; H02K17/00; H02K17/02; H02K17/12; H02K17/16; H02K3/00; H02K3/04; H02K3/12; H02K3/28; H02K3/32; H02K3/38; H02K5/00; H02K5/04; H02K5/12; H02K5/128; H02K5/1282; H02K5/16; H02K5/167; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
183 words
A flow responsive valve device for preventing back-flow of fluid through a centrifugal pump when the pump is not operating and when said pump creates a fluid swirl in a pump discharge area when the pump is operating, said valve device comprising a fixed valve member in the discharge area having apertures therein, a rotatable valve member in the discharge area having apertures therein adapted in a first rotatable position thereof to overlie the apertures in said fixed member to allow fluid flow through the apertures and in a second rotatable position thereof to be masked by the space between the apertures of said fixed member to prevent fluid flow through the apertures, spring means urging said rotatable valve member towards said second rotatable position, and blading on said rotatable member located in said discharge area adapted to be contacted by the fluid swirl when said pump is operating to urge said rotatable member to the first position against the force of the spring means such that the apertures of the first and second members overlie each other when the pump is operating.
Claim 2
Dependent Claim
183 words
A flow responsive valve device for preventing back-flow of fluid through a centrifugal pump when the pump is not operating and when said pump creates a fluid swirl in a pump discharge area when the pump is operating, said valve device comprising a fixed valve member in the discharge area having apertures therein, a rotatable valve member in the discharge area having apertures therein adapted in a first rotatable position thereof to overlie the apertures in said fixed member to allow fluid flow through the apertures and in a second rotatable position thereof to be masked by the space between the apertures of said fixed member to prevent fluid flow through the apertures, spring means urging said rotatable valve member towards said second rotatable position, and blading on said rotatable member located in said discharge area adapted to be contacted by the fluid swirl when said pump is operating to urge said rotatable member to the first position against the force of the spring means such that the apertures of the first and second members overlie each other when the pump is operating.
Claim 3
Dependent Claim
38 words
A flow responsive valve device according to claim 1 wherein each said valve member comprises a hollow cylinder and wherein said apertures comprise slots with the space between adjacent slots being at least as wide as the slots.
Claim 4
Dependent Claim
47 words
A flow responsive valve device according to claim 1 having in addition two spherical bearings mounting the rotatable valve member where the center of both bearings lie on the longitudinal axis of the pump, and adjustable means for moving one of said bearings in an axial direction.
Claim 5
Dependent Claim
17 words
A flow responsive valve device according to claim 3 wherein said spring means comprises a spiral spring.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |