US3861824A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for regulating medium flow, in particular the flow of air of a radial fan
Assignee: Svenska Flaktfabriken AB
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Filing: 1973-02-14
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Granted: 1975-01-21
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Expires: 1993-02-14
Abstract
Abstract Device for regulating medium flow of a radial fan, comprising means for reducing the active surface of a blade wheel or the like for generating said flow. The device consists of a cylindrical tubular member bearing against the inward radial edges of the blades and rotating therewith. The member extends axially of the blades to impede the outward flow along the blades between the inner and outer axial ends of the member. The regulation is effected by selectively positioning the outer end of the member at a point along the length of the blades. The member may extend to the inner axial end of the blades and effect regulation by varying the axial length of the member, or the member may be of a fixed length and effect regulation by varying the axial position of the member.
Inventors
- 👤 Lennart Sjoqvist
- 👤 Stig Lidbamn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:44
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/40; F04D29/42; F04D29/44; F04D29/46; F04D29/462; F04D29/464; F04D27/00; F04D27/003; F05; F05D; F05D2250/00; F05D2250/50; F05D2250/51
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
222 words
A device for regulating medium flow comprising a casing having a fan wheel mounted therein for rotation about a central axis, said casing having an axial inlet for the medium, said fan wheel having a radial inner wall confronting said inlet and mounting a circle of generally radially disposed blades extending axially from said wall toward said inlet in surrounding relation thereto, whereby upon rotation of said wheel, said blades effect flow of the medium through said inlet and radially outward across said blades, said blades having inner radial edges disposed in an imaginary cylindrical surface coaxial with said fan axis, andmeans for regulating the flow capacity of said wheel comprising a substantially cylindrical hollow tubular elastic ring member having an axial length less than the axial length of said blades and mounted for rotation with said fan wheel, the cylindrical surface coinciding with the imaginary cylindrical surface within said blade circle to frictionally bear against the inner radial edges of said blades, adapted to be displaced along the inner edges of the blades throughout their length whereby the capacity reGulation is effected by selectively positioning the outer end of the member at a point along the length of said blades to provide a limited flow area between the outer end of said member and the inlet radially outward across said blades.
Claim 2
Independent Claim
222 words
A device for regulating medium flow comprising a casing having a fan wheel mounted therein for rotation about a central axis, said casing having an axial inlet for the medium, said fan wheel having a radial inner wall confronting said inlet and mounting a circle of generally radially disposed blades extending axially from said wall toward said inlet in surrounding relation thereto, whereby upon rotation of said wheel, said blades effect flow of the medium through said inlet and radially outward across said blades, said blades having inner radial edges disposed in an imaginary cylindrical surface coaxial with said fan axis, andmeans for regulating the flow capacity of said wheel comprising a substantially cylindrical hollow tubular elastic ring member having an axial length less than the axial length of said blades and mounted for rotation with said fan wheel, the cylindrical surface coinciding with the imaginary cylindrical surface within said blade circle to frictionally bear against the inner radial edges of said blades, adapted to be displaced along the inner edges of the blades throughout their length whereby the capacity reGulation is effected by selectively positioning the outer end of the member at a point along the length of said blades to provide a limited flow area between the outer end of said member and the inlet radially outward across said blades.
Claim 3
Dependent Claim
23 words
A device according to claim 1 wherein said cylindrical tubular member extends into abutting relation with the radial inner wall of said wheel.
Claim 4
Dependent Claim
32 words
A device according to claim 2 wherein said cylindrical tubular member comprises a series of telescoping rings to afford adjustment of the position of the outer axial end of said tubular member.
Claim 5
Dependent Claim
40 words
A device according to claim 1 wherein said cylindrical tubular member has an inner axial end spaced from said inner radial wall to provide a complementary limited flow area between the inner end of said member and said radial wall.
Claim 6
Dependent Claim
41 words
A device according to claim 4 wherein said ring has an axial length between 20 percent and 50 percent of the length of the blades and is slidable axially of said wheel to assume various positions to change the regulating characteristics.
Claim 7
Dependent Claim
20 words
A device according to claim 1 wherein said tubular member consists of a slightly flexible or hard elastic cellular plastic.
Claim 8
Dependent Claim
42 words
A device according to claim 1 wherein said blade wheel has on its inner radial wall an outwardly projecting truncated cone tapering toward the inlet of the casing for cooperating with said cylindrical tubular member to regulate the capacity of the device.
References Cited (Backward Citations)
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US1846379A
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US2430225A
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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) | 1978-01-20 | 1978-07-22 | 1979-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-20 | 1982-07-22 | 1983-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-20 | 1986-07-22 | 1987-01-21 | $7700.00 | Window Closed / Lapsed |