US3877834A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-priming centrifugal pumps
Assignee: SPECK PUMPEN
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Filing: 1973-11-26
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Granted: 1975-04-15
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Expires: 1993-11-26
Abstract
Abstract A self-priming centrifugal pump having an inlet leading to a rotary impeller which has a given axis of rotation. The impeller is surrounded by a fluid guide which is located in a housing provided with an outlet through which fluid is discharged from the pump. The fluid guide is formed with a gap situated in a plane which is perpendicular to the above axis so that during self-priming operations liquid can return back toward the axis of the impeller through the latter gap.
Inventors
- 👤 Walter Speck
- 👤 Oskar Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:31
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/40; F04D29/42; F04D29/44; F04D29/445; F04D9/00; F04D9/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
234 words
In a self-priming centrifugal pump, rotary impeller means having a given axis of rotation, a central suction inlet, and an outer peripheral outlet circumferentially surrounding said axis, fluid-guiding means situated at the periphery of said impeller means and being in the form of a hollow volute means formed with an inner relatively substantially constant width axial gap circumferentially surrounding and situated directly next to the periphery of said impeller means for directly receiving fluid therefrom, the hollow interior of said volute means being substantially wider than said inner gap along substantially all of the length of said volute means with the hollow interior of said volute means extending axially in both directions beyond said inner gap of said volute means, and said volute means having an outer wall formed in a plane perpendicular to said axis and through which said outer periphery of said impeller means extends with an outer relatively narrow axial gap extending substantially through the entire length of the outer wall of said volute means and through which liquid can return toward said axis during selfpriming operations, and a housing means housing said impeller means and said volute means which is formed with said outer gap in said plane, said housing means having an outlet through which fluid from said volute means is discharged while liquid can return toward said axis during self-priming operations through said gaps in said volute means.
Claim 2
Dependent Claim
234 words
In a self-priming centrifugal pump, rotary impeller means having a given axis of rotation, a central suction inlet, and an outer peripheral outlet circumferentially surrounding said axis, fluid-guiding means situated at the periphery of said impeller means and being in the form of a hollow volute means formed with an inner relatively substantially constant width axial gap circumferentially surrounding and situated directly next to the periphery of said impeller means for directly receiving fluid therefrom, the hollow interior of said volute means being substantially wider than said inner gap along substantially all of the length of said volute means with the hollow interior of said volute means extending axially in both directions beyond said inner gap of said volute means, and said volute means having an outer wall formed in a plane perpendicular to said axis and through which said outer periphery of said impeller means extends with an outer relatively narrow axial gap extending substantially through the entire length of the outer wall of said volute means and through which liquid can return toward said axis during selfpriming operations, and a housing means housing said impeller means and said volute means which is formed with said outer gap in said plane, said housing means having an outlet through which fluid from said volute means is discharged while liquid can return toward said axis during self-priming operations through said gaps in said volute means.
Claim 3
Dependent Claim
18 words
The combination of claim 1 and wherein said outer gap has a width of 0.5 to 5 mm.
Claim 4
Dependent Claim
51 words
The combination of claim 1 and wherein said volute means includes a pair of volute sections which are separated from each other at said gaps, and spacer means distributed along said outer gap at a small number of locations and situated between said sections for determining the width of said gap.
Claim 5
Dependent Claim
25 words
The combination of claim 1 and wherein a connecting means connects said volute means to said housing means for determining the width of said gaps.
Claim 6
Dependent Claim
56 words
The combination of claim 1 and wherein said volute means includes a pair of sections separated from each other by said gaps, and means operatively connected with at least one of said sections for determining the position thereof along said axis with respect to the other of said sections foR determining the width of said gaps.
Claim 7
Dependent Claim
78 words
The combination of claim 1 and wherein said housing means defines a chamber in which said outer gap is located, so that during self-priming operations liquid will return from said chamber toward said axis in one direction through said outer gap while subsequent to self-priming operations liquid will flow from said impeller means through said outer gap into said chamber and out of said housing means through said outlet thereof in an opposite direction through said outer gap.
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) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |