Process for forming improved carbon fiber reinforced composite coil spring
AssigneeCelanese Corporation
InventorHoward S. Kliger
Life of this patent
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Abstract
A carbon fiber reinforced composite coil spring is provided which is made from a braid formed of carbon fibers oriented at a preferred angle to the braid axis of approximately plus or minus 45.degree. and impregnated with a resin which serves as a substantially continuous matrix phase. Longitudinal reinforcing fiber may be incorporated into the braid to prevent it from straightening under longitudinal tension. The carbon fiber reinforced composite coil spring is formed by wrapping the braid, impregnated with a non-solidified resin, within a groove which extends helically along the surface of a helical mandrel and solidifying the resinous matrix material, and then removing the solid composite coil spring from the helical mandrel.
Claims12
A method for forming a carbon fiber reinforced composite coil spring comprising:
- (a) impregnating a carbon fiber braid wherein said carbon fibers are oriented at an angle in the range of approximately plus or minus 30.degree. to plus or minus 60.degree. to the braid axis and wherein there is incorporated into said braid a quantity of longitudinal reinforcing fibers which are oriented longitudinally to the braid axis so as to minimize change in said angle of said carbon fibers within said braid when placed under tension with a quantity of non-solidified resin to serve as a substantially continuous matrix material;
- (b) winding said impregnated braid in multiple layers while under longitudinal tension within a groove which extends helically along the surface of a cylindrical mandrel to provide the coil configuration of said carbon fiber reinforced composite coil spring;
- (c) solidifying the resinuous matrix material of the composite spring while maintaining said longitudinal tension;
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- (d) removing said solid spring from said mandrel.
Dependencies are inferred from the claim text.