Patent US3677076A successfully refreshed from Google Patents.
US3677076A
Expired / Lapsed
US
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Method of measuring web tension
Assignee: Agfa Gevaert AG
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Filing: 1970-10-05
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Granted: 1972-07-18
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Expires: 1990-10-05
Abstract
Abstract The web tension of webs of material guided on rolls is measured and regulated to a constant value. For measuring the web tension, the web is sucked in between two rolls by means of a negative pressure and the curvature of the web resulting therefrom is used as measurement value for the web tension. As an alternative, the curvature of the web is kept constant and the negative pressure used for the sucking-in effect is used as measurement value for the web tension.
Inventors
- 👤 Peter Herzhoff
- 👤 Hans Gref
- 👤 Wolfgang Schweicher
- 👤 Hans Frenken
- 👤 Peter Assenmacher
- 👤 Dietmar Westen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:23
CPC Classifications
G; G01; G01L; G01L5/00; G01L5/04; G01L5/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
156 words
A device for measuring the tension of a thin web of material guided on rollers comprising a pair of closely spaced rollers, said web being guided over one side of said closely spaced rollers, a suction chamber disposed in sealing engagement with the other side of said closely spaced rollers whereby a negative pressure is developed therebetween which causes said web to deflect inbetween said closely spaced rollers toward said suction chamber, a depth sensing device for determining the distance to which said web is deflected between said closely spaced rollers, suction pumping means connected to said suction chamber for developing a negative pressure therein, a regulating means connected to said suction pumping means, said depth sensing device being connected to said regulating means whereby said regulating means is actuated to maintain said depth of deflection of said web substantially constant, and said regulating means providing an output reading corresponding to the tension in said web.
Claim 2
Independent Claim
156 words
A device for measuring the tension of a thin web of material guided on rollers comprising a pair of closely spaced rollers, said web being guided over one side of said closely spaced rollers, a suction chamber disposed in sealing engagement with the other side of said closely spaced rollers whereby a negative pressure is developed therebetween which causes said web to deflect inbetween said closely spaced rollers toward said suction chamber, a depth sensing device for determining the distance to which said web is deflected between said closely spaced rollers, suction pumping means connected to said suction chamber for developing a negative pressure therein, a regulating means connected to said suction pumping means, said depth sensing device being connected to said regulating means whereby said regulating means is actuated to maintain said depth of deflection of said web substantially constant, and said regulating means providing an output reading corresponding to the tension in said web.
Claim 3
Dependent Claim
23 words
A device as set forth in claim 1 wherein said suction pumping means comprises a fan driven by a variable speed electric motor.
Claim 4
Dependent Claim
19 words
A device as set forth in claim 2 wherein said variable speed electric motor comprises a direct current motor.
References Cited (Backward Citations)
GB445761A
Cited
US3115037A
Cited
US3201985A
Cited
US3156109A
Cited
US3538765A
Cited
US3439536A
Cited
US3550828A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |