Method of producing strings for ball rackets, particularly for tennis rackets, and a string produced by this method
US4568415A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 11, 1984 |
| Grant date | Feb 4, 1986 |
| Priority date | — |
| Expiry date | Jan 11, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2936
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
In the method for manufacturing strings, a plurality of narrow strip layers (22) of synthetic material are successively and coaxially helically wound on the cylindrical surface of a continuous core. The winding (3) thus produced is conveyed hot to a welding area (7) wherein the narrow strips (22) of synthetic material are mutually assembled by welding. The temperature of the welding area is adjusted high enough so that a welding between the narrow strips (22) takes place without substantially decreasing the breaking strength of the narrow strips (22) by such heat treatment. The appropriate materials for the narrow strips are olefines such as homopolymer polypropylene or terpolymer polypropylene-polyethylene-dienes. To reduce the tendency to flow, the material forming the narrow strips may contain a nucleation agent. The characteristics of the strings thus manufactured are similar to those of gut strings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.