Patent US2014970A successfully refreshed from Google Patents.
Patent US4833928A successfully refreshed from Google Patents.
US4833928A
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US
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Method and apparatus for noncontacting tension measurement in a flat foil and especially in a paper web
Assignee: ABB Stromberg Oy
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Filing: 1987-06-04
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Granted: 1989-05-30
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Expires: 2007-06-04
Abstract
Abstract A method and apparatus for measuring the tension of a thin, plane membrane (1). In accordance with the method, a burst of a membrane wave (2) is generated by a transducer element (3) e.g. a loudspeaker (3). The velocity of the membrane wave (2) is measured. The velocity measurement value of the membrane wave (2) is squared and multiplied by the basis weight of the membrane (1) in order to determine the tension. According to the invention, a light beam (10) is generated by at least one light emitting element (5), each light beam (10) is projected with help of projecting members (6 or 14, 15, 17) onto the membrane (1) in order to generate a light spot (4 or 19), the light spot (4 or 19) vibrating on the membrane (1) is converted into an electrical signal dependent on the position of the light spot (19) by means of at least one detector element (8 or 18 ) in order to determine the membrane wave (2) and the signal is processed in a processor (9) in order to determine the velocity of the membrane wave (2). With help of the invention, the tension of a plane membrane (1) can be measured reliably without contact to the membrane.
Inventors
- 👤 Mauri Luukkala
- 👤 Tapio Marttinen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:39
CPC Classifications
G; G01; G01L; G01L5/00; G01L5/04; G01L5/042
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
139 words
A method for measuring a tension of a thin, plane membrane comprising the following steps: generating a burst of a membrane wave by a transducer element; generating a light beam by at least one light emitting element; splitting the light beam into a plurality of light beams; aligning each light beam by alignment members on the membrane for generating light spots; converting the light spots formed on the membrane into an electrical signal dependent on the position of the light spots by means of at least two detector elements in order to determine the membrane wave; and processing the signal in a processor element in order to determine the velocity of the membrane wave; determining the tension of the membrane by squaring the velocity measurement value of the membrane wave and multiplying by the basis weight of the membrane.
Claim 2
Independent Claim
139 words
A method for measuring a tension of a thin, plane membrane comprising the following steps: generating a burst of a membrane wave by a transducer element; generating a light beam by at least one light emitting element; splitting the light beam into a plurality of light beams; aligning each light beam by alignment members on the membrane for generating light spots; converting the light spots formed on the membrane into an electrical signal dependent on the position of the light spots by means of at least two detector elements in order to determine the membrane wave; and processing the signal in a processor element in order to determine the velocity of the membrane wave; determining the tension of the membrane by squaring the velocity measurement value of the membrane wave and multiplying by the basis weight of the membrane.
Claim 3
Dependent Claim
21 words
A method in accordance with claim 1, characterized in that the at least one light emitting element (5) is a laser.
Claim 4
Dependent Claim
22 words
A method in accordance with claim 1, characterized in that the at least one light emitting element (5) is a light-emitting diode.
Claim 5
Independent Claim
54 words
A method in accordance with any of claims 1, 2 or 3, characterized in that each light beam (10) is projected approximately perpendicular to the plane of the membrane (1) in order to detect the position of the light spots (4) in a vertical plane by means of said at least two detector elements.
Claim 6
Independent Claim
49 words
A method in accordance with any of claims 1, 2 or 3, characterized in that each light beam (10) is projected obliquely to the plane of the membrane (1) in order to detect the deflection of the light spots (4) by means of said at least two detector elements.
Claim 7
Dependent Claim
22 words
A method in accordance with claim 1, characterized in that said at least one light emitting element is a solid state emitter.
Claim 8
Independent Claim
90 words
An apparatus for measuring a tension of a thin, plane membrane comprising: a transducer member for generating a burst of a membrane wave; at least one light emitting element for generating a light beam; projection members for projecting the light beam onto the membrane for producing light spots; at least two detector elements for converting the light spots formed on the membrane into an electrical signal dependent on the position of the light spots; and a processor for processing the electrical signal for determining the velocity of the membrane wave.
Claim 9
Independent Claim
90 words
An apparatus for measuring a tension of a thin, plane membrane comprising: a transducer member for generating a burst of a membrane wave; at least one light emitting element for generating a light beam; projection members for projecting the light beam onto the membrane for producing light spots; at least two detector elements for converting the light spots formed on the membrane into an electrical signal dependent on the position of the light spots; and a processor for processing the electrical signal for determining the velocity of the membrane wave.
Claim 10
Dependent Claim
23 words
An apparatus in accordance with claim 7, characterized in that a laser is used as the at least one light emitting element (5).
Claim 11
Dependent Claim
22 words
An apparatus in accordance with claim 7, characterized in that the at least one light emitting element (5) is a light-emitting diode.
Claim 12
Dependent Claim
21 words
An apparatus according to claim 1, characterized in that said at least one light emitting element is a solid state emitter.
Claim 13
Independent Claim
150 words
A method for measuring a tension of a thin, plane membrane comprising the following steps; generating a burst of a membrane wave by a transducer element; generating a light beam by at least one light emitting element; expanding the light beam emitted from the laser by a beam expander and collimating by a condenser lens for generating a coherent plane wave which is projected onto an interference-generating wedge-shaped glass plate for projecting the light subjected to interference thereby onto the membrane; generating an electrical signal from an interference pattern formed on the web membrane resulting from the use of the interference generating means by a row camera; processing the signal in a processor element in order to determine the velocity of the membrane wave; and determining the tension of the membrane by squaring the velocity measurement value of the membrane wave and multiplying by the basis weight of the membrane.
Claim 14
Independent Claim
150 words
A method for measuring a tension of a thin, plane membrane comprising the following steps; generating a burst of a membrane wave by a transducer element; generating a light beam by at least one light emitting element; expanding the light beam emitted from the laser by a beam expander and collimating by a condenser lens for generating a coherent plane wave which is projected onto an interference-generating wedge-shaped glass plate for projecting the light subjected to interference thereby onto the membrane; generating an electrical signal from an interference pattern formed on the web membrane resulting from the use of the interference generating means by a row camera; processing the signal in a processor element in order to determine the velocity of the membrane wave; and determining the tension of the membrane by squaring the velocity measurement value of the membrane wave and multiplying by the basis weight of the membrane.
Claim 15
Independent Claim
88 words
An apparatus for measuring a tension of a thin, plane membrane comprising: a transducer element for generating a membrane wave; at least one light emitting element for generating a light beam; a light beam expander and a condenser lens for producing a coherent plane wave; an interference generating means for projecting the light subjected to interference thereby onto the web membrane; and a row camera for generating an electrical signal from an interference pattern formed on the web membrane resulting from the use of the interference generating means.
Claim 16
Independent Claim
88 words
An apparatus for measuring a tension of a thin, plane membrane comprising: a transducer element for generating a membrane wave; at least one light emitting element for generating a light beam; a light beam expander and a condenser lens for producing a coherent plane wave; an interference generating means for projecting the light subjected to interference thereby onto the web membrane; and a row camera for generating an electrical signal from an interference pattern formed on the web membrane resulting from the use of the interference generating means.
Claim 17
Dependent Claim
18 words
An apparatus in accordance with claim 12, characterized in that the interference generating means is a wedge-shaped glass.
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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) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |