US3745756A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Construction of tennis strings
Assignee: Ashaway Line and Twine Manufacturing Co
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Filing: 1972-02-07
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Granted: 1973-07-17
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Expires: 1992-02-07
Abstract
Abstract A string for use in connection with athletic rackets, such as tennis, badminton, squash and the like comprising a thermoplastic core made from a plurality of twisted thermoplastic strands, said core having a coating of plastic material covering and integrated therewith, a thermoplastic filament wrap extending spirally around said coated core, the pitch of said wrap being such that substantial spacing exists between adjacent convolutions, and a further coating of plastic material covering and integrated with said coated and wrapped core.
Inventors
- 👤 J Crandall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:59
CPC Classifications
D; D07; D07B; D07B1/00; D07B1/16; D07B1/162; A; A63; A63B; A63B51/00; A63B51/02; D02; D02G; D02G3/00; D02G3/22; D02G3/38; D02G3/40; D02G3/404; D02G3/44; D02G3/444; D07B1/02; D07B1/165; A63B51/026; D07B2201/00; D07B2201/20; D07B2201/2083; D07B2201/2087; D07B2201/2088
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
46 words
In the string of claim 1, a second thermoplastic filament wrap extending around said further coating, said second wrap being of substantially the same pitch as said first wrap, and an outer coating of plastic material coverning and integrated with said second wrap and said string.
Claim 2
Dependent Claim
32 words
In the string of claim 2, the pitch of said thermoplastic filament wraps being substantially the same as the pitch at which said groups are twisted together, but in the opposite hand.
Claim 3
Dependent Claim
28 words
In the string of claim 1, each of said groups having a coating of plastic material thereover, said coated groups then being twisted together to form said core.
Claim 4
Dependent Claim
40 words
In the string of claim 3, said strands being twisted together at approximately three to seven turns per inch to form said groups, said groups being twisted together at approximately 1.5 to 3.5 turns per inch to form said core.
Claim 5
Independent Claim
114 words
The method of manufacturing an integrated string comprising the following steps: A. twisting a plurality of the thermoplastic strands together to form a group, B. twisting a plurality of said groups together to form a core, C. dipping said core into a thermoplastic formulation. D. passing said coated core through a drying chamber, E. stretching the integrated string under heat; F. repeating steps C and D supra, G. spirally wrapping a thermoplastic strand around said coated string with the adjacent convolutions of said strand substantially spaced from each other, H. repeating steps C, D and E; and I. repeating steps C and D at a substantial time interval after the completion of step H.
Claim 6
Dependent Claim
22 words
The method of claim 6 further characterized in that between steps G and H steps C, D and G are again performed.
Claim 7
Dependent Claim
15 words
In the method of claim 7, all of said strands and said formation being nylon.
Claim 8
Dependent Claim
27 words
In the method of claim 7, said thermoplastic strands being wrapped in the opposite hand from the twist of said groups, but at substantially the same pitch.
Claim 9
Dependent Claim
40 words
In the method of claim 9, said strands being twisted together at approximately three to seven turns per inch to form said groups, said groups being twisted together at approximately 1.5 to 3.5 turns per inch to form said core.
Claim 10
Dependent Claim
20 words
In the method of claim 6, said groups each being coated with a plastic material prior to performing step B.
Claim 11
Dependent Claim
18 words
In the method of claim 6, the time interval between steps H and I being approximately 24 hours.
Claim 12
Dependent Claim
19 words
In the method of claim 6, the string being elongated approximately 15 percent during the performance of Step E.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |