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US4437662A Expired / Lapsed US ⏱️ 0.0 years remaining

String load apportioned racket

Assignee: Individual
•
Filing: 1982-05-10
•
Granted: 1984-03-20
•
Expires: 2002-05-10
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Abstract

Abstract Longitudinal strings 15 or 25 of tennis or other sports rackets 10 or 20 are lengthened to be at least 30% longer than transverse strings 17 or 27 and are strung with at least 30% more tension than the transverse strings. The longitudinal strings are also functionally related in length and tension to the transverse strings to effectively apportion to the longer longitudinal strings from approximately half to substantially more than half of the string force for decelerating a ball pentrating the string network as the ball is hit. The functional relationship for selecting appropriate lengths and tensions for the longer and shorter strings is mathematically derived, analyzed, and related to practical working mechanics of a string network. The advantages of lengthening, tightening, and apportioning more of the load to the longitudinal strings include a higher coefficient of restitution for the string network; a larger and more responsive sweet spot area; smaller hysteresis losses from string stretching; less interstring friction and ball deformation; higher velocity ball rebound; better shot control; and less torque shock to the arm of the user from off center hits.

Inventors

  • 👤 Tsai C. Soong

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 17:03
CPC Classifications
A; A63; A63B; A63B51/00

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 123 words
A racket having a hand grip joined to a frame supporting a string network having transverse and longitudinal strings extending throughout a ball-hitting region spaced from said grip, said frame having a shank region extending from said grip and flaring outward in a throat region and a generally oval region extending around said ball-hitting region, said racket comprising: a. at least a central plurality of said longitudinal strings having a strung length at least 30% longer than the longest transverse string in said network; b. said central plurality of longer longitudinal strings including at least one-third of all the longitudinal strings in said ball-hitting region; and c. said longer longitudinal strings being strung with at least 30% more tension than said transverse strings.
Claim 2
Dependent Claim 123 words
A racket having a hand grip joined to a frame supporting a string network having transverse and longitudinal strings extending throughout a ball-hitting region spaced from said grip, said frame having a shank region extending from said grip and flaring outward in a throat region and a generally oval region extending around said ball-hitting region, said racket comprising: a. at least a central plurality of said longitudinal strings having a strung length at least 30% longer than the longest transverse string in said network; b. said central plurality of longer longitudinal strings including at least one-third of all the longitudinal strings in said ball-hitting region; and c. said longer longitudinal strings being strung with at least 30% more tension than said transverse strings.
Claim 3
Dependent Claim 17 words
The racket of claim 1 wherein said longer longitudinal strings extend at least into said throat region.
Claim 4
Dependent Claim 19 words
The racket of claim 2 wherein said longer longitudinal strings are arranged to fan outward across said ball-hitting region.
Claim 5
Dependent Claim 26 words
The racket of claim 2 including guide means in said throat region for angling said longer longitudinal strings between said shank region and said ball-hitting region.
Claim 6
Dependent Claim 22 words
The racket of claim 1 wherein said longer longitudinal strings are strung with at least 50% more tension than said transverse strings.
Claim 7
Dependent Claim 28 words
The racket of claim 1 wherein longitudinal strings shorter than said longer longitudinal strings are strung at an intermediate tension larger than the tension of said transverse strings.
Claim 8
Dependent Claim 38 words
The racket of claim 1 wherein said longer longitudinal strings bear from about half or more of the string force that decelerates a ball penetrating said string network in a central region occupied by said longer longitudinal strings.
Claim 9
Dependent Claim 17 words
The racket of claim 7 wherein said longer longitudinal strings extend at least into said throat region.
Claim 10
Dependent Claim 22 words
The racket of claim 8 wherein said longer longitudinal strings are strung with at least 50% more tension than said transverse strings.
Claim 11
Dependent Claim 19 words
The racket of claim 9 wherein said longer longitudinal strings are arranged to fan outward across said ball-hitting region.
Claim 12
Dependent Claim 28 words
The racket of claim 7 wherein longitudinal strings shorter than said longer longitudinal strings are strung at an intermediate tension larger than the tension of said transverse strings.

References Cited (Backward Citations)

FR413753A Cited
US2206548A Cited
US3999756A Cited
US3999756B1 Cited
US4196901A Cited
US4196901B1 Cited
DE2752624A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-03-20 1987-09-19 1988-03-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-03-20 1991-09-19 1992-03-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-03-20 1995-09-19 1996-03-20 $7700.00 Window Closed / Lapsed

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