Trek Bicycle Corporation

Robert F Read

Ronald Harry Nelson

Dimitrije Milovich

Weston M Wilcox

The bicycle frame of the invention is formed by selecting and adhesively joining previously formed and precured composite tubes to previously formed and precured composite lug components. The precured lug components are separately shaped from preforms comprising a plurality of resin impregnated fibrous layers formed into a stack in which the fibers of adjacent layers cross one another, with such preforms of each such lug component being in the nature of a set of similarly shaped overlapping halves of the frame lug component to be formed therefrom, with such overlapping halves being brought together in a hollow nature and placed around an inflatable bladder to form an assemblage that is applied between a set of female mold halves of molding tools that are closed for forming the lug component itself, and the resulting assemblage is subjected to a curing heat, with such bladder of each two hundred (200) set of preforms being arranged to first be pressurized to a pressure greater than or equal to two hundred (200) pounds per square inch, for urging the respective preforms against the mold shaping surfaces opposing same, thereby providing a high laminate compaction pressure during cure that produces a uniform, thin walled, strong, tubular, lug component. The said lug components are also each formed with one or more male members or plugs for closely fitting into adjacent open ends of the aforementioned all-composite tubes. Such composite tubes are formed by wrapping a preform, that is similar to the lug component preform, around a mandrel and cured, with the wrap being subject to a compaction pressure therearound during cure, thereby providing a thin walled high strength tube, for forming of the bicycle frame as above indicated.

Composite bicycle frame and methods for its construction

The bicycle frame of the invention is formed by selecting and adhesively joining previously formed and precured composite tubes to previously formed and precured composite lugs. The precured lugs are shaped from preforms comprising a plurality of resin impregnated fiber reinforced layers formed into a stacks having the fibers of adjacent layers cross one another, with preforms of each lug component being a set of shaped overlapping segments of the lug to be formed. The overlapping segments are then brought together and placed around an inflatable bladder to form an assemblage that is placed in a female mold, preferably of two halves, that are closed for forming the lug. The resulting assemblage is cured, with the bladder pressurized for urging the respective preforms to the mold shaping surfaces, providing a high laminate compaction during cure for a uniform, thin walled, strong, tubular, lug. The lugs are preferably formed with one or more plugs for closely fitting into adjacent open ends of the tubes. The composite tubes may be formed by a method similar to the lug forming method described, or by wrapping a preform up of a number of reinforced fiber layers, around a mandrel, and subjecting the preforms to an inward compaction pressure during cure. These methods provide a thin walled high strength tube.

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Edgerton, WI, United States of America

Robert F Read