Composite Development Corporation

Steven C Nolet

Peter A Quigley

James L Gallagher

Stephen Briggi

The invention provides a tubular composite member which has a plurality of plies and a generally elongate and selectively curved axis. The plies can include helically oriented fiber components, a matrix material, and thermoplastic tubes. An intermediate layer preferably has two tri-axially braided plies arranged at selective angles relative to the member's axis and as a function of the curvature of the member. Interior and exterior plies of circumferential windings can be part of the member such that the intermediate ply is contiguous and between the interior and exterior ply. In one practice, the member can be formed into a selective shape and then cured. Alternatively, the member is formed between a thermoplastic core and a thermoplastic sheath to facilitate a secondary process of heating and bending the member into a selective axially-curved shape.

High strength, high stiffness, curved composite member

The invention provides improvements to a composite member that has a plurality of plies. The improved composite member has (1) an interior ply which functions to dampen or resist sudden forces exerted on the composite member, (2) an intermediate load-carrying ply, and (3) an exterior abrasion-resistant ply. These plies have multiple, often intertwined fiber components disposed or imbedded with a matrix material, preferably Nylon-6 thermoplastic, to inhibit sharp edges during breakage. One or more of the plies typically has 'bi-axial' or 'tri-axially' braided fiber geometries wherein one or more fibers are helically wound about the circumference of the member. The helically oriented fibers are oriented at a selectively variable angle which influences the overall bending strength of the composite material. In one aspect, the angles of the fiber components and other factors are used to maintain substantially uniform cross-sectional area over the length of the tubular member while simultaneously varying the bending stiffness. A composite member constructed according to the invention resists sudden or impact forces and has high, selectively variable bending strength, high impact resistance, and safe failure modes.

Composite shaft structure and manufacture

The invention provides improvements to a composite member that has a plurality of plies. The improved composite member has (1) an interior ply which functions to dampen or resist sudden forces exerted on the composite member, (2) an intermediate load-carrying ply, and (3) an exterior abrasion-resistant ply. These plies have multiple, often intertwined fiber components disposed or imbedded with a matrix material, preferably Nylon-6 thermoplastic, to inhibit sharp edges during breakage. One or more of the plies typically has 'bi-axial' or 'tri-axially' braided fiber geometries wherein one or more fibers are helically wound about the circumference of the member. The helically oriented fibers are oriented at a selectively variable angle which influences the overall bending strength of the composite material. In one aspect, the angles of the fiber components and other factors are used to maintain substantially uniform cross-sectional area over the length of the tubular member while simultaneously varying the bending stiffness. In another aspect, the intermediate ply is constructed with two or more sub-plies. Such sub-plies can include tri-axially extending plies, and circumferentially-wound plies. The circumferentially-wound plies are often wound more tightly at the ends of the composite member to increase resistance to stresses caused by objects within the tubular shaft. A composite member constructed according to the invention resists sudden or impact forces and has high, selectively variable bending strength, high impact resistance, and safe failure modes.

An article for assembly with the application of heat to a selected temperature range to activate a thermoresponsive constituent, wherein the article avoids deterioration due to heating above the selected temperature range by including a thermochromatic material visibly disposed on the article. The thermochromatic material provides a visual indication in response to the thermoresponsive constituent being heated to the selected temperature range.

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Leominster, MA, United States of America

Steven C Nolet