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US4590808A
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US
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Method and apparatus for determining tension and pressure
Assignee: Individual
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Filing: 1984-08-24
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Granted: 1986-05-27
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Expires: 2004-08-24
Abstract
Abstract A device and method for determining a tension factor in grids such as tennis rackets and the like, which have different sized string areas, the device including a frame structure defining a fixed, predetermined test area within a larger size racket string area and having a mechanism for relating two measurement components, a deflection component and a force component, an element for applying a first measurement component to the grid test area and an element for sensing the other component resulting from the application of the first component, and determining from the two components a tension factor in the strings forming the grid, the method including defining a predetermined test area within a larger grid area, applying one of two measurement components to a portion of the grid test area, determining the other component resulting from the application of the one component to the grid test area, and determining a tension factor in the strings forming the grid from the values of the two components; the apparatus also including a mechanism and method for determining the compressibility of balls such as tennis balls.
Inventors
- 👤 Benjamin H. Lightfoot
- 👤 Harold W. Atkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:55
CPC Classifications
A; A63; A63B; A63B71/00; A63B71/06; A63B71/0619; A63B71/0622; A63B51/00; A63B51/005; G; G01; G01L; G01L5/00; G01L5/04; G01L5/10; G01L5/102; G01L5/106; G01L5/107; A63B2220/00; A63B2220/50; A63B2220/51; A63B2220/58; A63B47/00; A63B47/008
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
115 words
A device for determining the tension factor in a grid, said device having in combination, a frame structure defining a predetermined test area and adapted to be mounted on a first side of the grid in contact therewith, means for producing two measurement components, comprising a deflection component and a force component, application means for applying one of said measurement components to the defined test area of the grid on the second side of the grid, sensing means for sensing the value of the other measurement component resulting from the application of the first component, and means for producing from the values of the two components the tension factor in the elements forming the grid.
Claim 2
Independent Claim
115 words
A device for determining the tension factor in a grid, said device having in combination, a frame structure defining a predetermined test area and adapted to be mounted on a first side of the grid in contact therewith, means for producing two measurement components, comprising a deflection component and a force component, application means for applying one of said measurement components to the defined test area of the grid on the second side of the grid, sensing means for sensing the value of the other measurement component resulting from the application of the first component, and means for producing from the values of the two components the tension factor in the elements forming the grid.
Claim 3
Dependent Claim
50 words
The structure set forth in claim 1 wherein the application means for applying said one measurement component constitutes a deflection producing mechanism, and the sensing means constitutes an electronic load cell assembly for sensing the force component and calibrated electronic circuity for producing the tension factor in the grid elements.
Claim 4
Dependent Claim
23 words
The structure set forth in claim 2 and display means for permitting the direct reading of the tension factor in the grid elements.
Claim 5
Dependent Claim
46 words
The structure set forth in claim 1 and ball-supporting means mounted on said frame structure and said application means to support a ball inserted between the frame structure and the application means to permit the compressibility of a ball to be sensed by said sensing means.
Claim 6
Independent Claim
126 words
A device for determining the tension factor in a grid formed by the strings of a racket, said device comprising, a generally annular frame structure adapted to be mounted in engagement with a first side of the racket strings to define a predetermined test area within the area of the racket face, a string deflecting element removably connected with said frame structure for engagement with the second side of the strings of said racket, means for moving the deflecting element against the back-up force exerted by the frame structure in engagement with the first side of the racket strings to produce an increment of deflection of the strings within the test area, and means for measuring the force exerted by the strings during by said deflection.
Claim 7
Independent Claim
126 words
A device for determining the tension factor in a grid formed by the strings of a racket, said device comprising, a generally annular frame structure adapted to be mounted in engagement with a first side of the racket strings to define a predetermined test area within the area of the racket face, a string deflecting element removably connected with said frame structure for engagement with the second side of the strings of said racket, means for moving the deflecting element against the back-up force exerted by the frame structure in engagement with the first side of the racket strings to produce an increment of deflection of the strings within the test area, and means for measuring the force exerted by the strings during by said deflection.
Claim 8
Dependent Claim
77 words
The structure set forth in claim 5 and the connection formed between the deflecting element and the frame structure comprising, a spindle connected at one end to said frame structure and the other end to said deflecting element and extending through the strings of the grid to permit the deflecting element to be attached thereto on the second side of the racket strings when the frame structure has been positioned on the first side of said grid.
Claim 9
Dependent Claim
37 words
The structure set forth in claim 6 wherein said spindle is slidably mounted on said frame structure and said means for moving the deflecting element works in a direction normal to the plane defined by the strings.
Claim 10
Dependent Claim
43 words
The structure set forth in claim 5 wherein the force-measuring means consists in an electronic load cell including a strain gauge calibrated to produce a signal proportional to the force exerted by the strings when the same are deflected by said deflecting element.
Claim 11
Dependent Claim
84 words
The structure set forth in claim 5 and a pair of pivotally-connected arms of sufficient length to traverse a portion of the width of a racket head and extend therebeyond, wherein the annular frame structure is mounted on one arm and the string-deflecting element is mounted on the other arm in opposed relation to the frame structure, and the means for moving the deflecting element comprising a handle portion connected to one of said arms to move the two arms into predetermined closed position.
Claim 12
Dependent Claim
20 words
The structure set forth in claim 9 and an overcenter clamping linkage for holding the handle portion in clamped position.
Claim 13
Dependent Claim
21 words
The structure set forth in claim 9 and stop means for preventing the handle portion from moving into overcenter, locked position.
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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) | 1989-05-26 | 1989-11-25 | 1990-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-26 | 1993-11-25 | 1994-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-26 | 1997-11-25 | 1998-05-27 | $7700.00 | Window Closed / Lapsed |