Method of manufacturing a bicycle fork

US5039470A · kind A · utility

Assignee

• Look S.A. · FR

Inventors

• Michel Bezin · Nevers, FR
• Joris V. Raemdonck · Bazel, BE

Key dates

• Filing date: Jul 24, 1989
• Grant date: Aug 13, 1991
• Expiry date: Jul 24, 2009

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B62K19/16
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A method of manufacturing a bicycle fork including forming a manufactured blank comprising a metallic steering spigot 11, two fork arms 13 and a pair of metallic axle mounts 14. Each fork arm 13 includes a hard foam core 19 at the lower straight portion of each fork arm 13 and a flexible foam core 22 at the upper end of each fork arm 13. Alternatively, a single flexible foam core having an internal pressurization may be advantageously used. The axle mounts 14 have a connection spigot 21 which is inserted into the free ends of each fork arm 13. A polymer impregnated flexible foam sheath 20 is laid around foam core 19, flexible foam core 22 or 37 and connection spigots 21. Subsequently, various polymer impregnated fiber reinforced sleeves 15, 16, 17, 18 are laid around the foam sleeve 20. The upper parts of the fork arms 13 are brought together to form a fork head 12 having a single steering spigot connection part 12a and fork arm transition parts 12b. Connection part 12a is introduced at least substantially into the lower end of the steering spigot 11. A pressure piston is inserted into the blank and, in a heatable mold, the blank is molded into its final shape upon application of b…