Claims
- 1. A method for manufacturing a composite shaft comprising:
- providing an impregnated fibrous material comprising a fiber impregnated with a hardenable polymeric material;
- forming an impregnated fiber preform by wrapping the impregnated fiber material around a shaped bladder having an inner cavity for pressurization of the bladder;
- placing the assembly of the bladder and the impregnated fiber preform into female tooling, the bladder being the sole support for the impregnated fiber in the female tooling, the female tooling having inner dimensions to form a shaft with a middle portion of the shaft having a diameter larger than adjacent portions on either side of said middle portion or having a diameter smaller than said adjacent portions, the bladder having a wall of variable thickness to permit outer contours of the bladder to conform to inner contours of the female tooling;
- pressurizing the bladder to press the impregnated fiber against the female tooling;
- heating the tooling while maintaining pressure in the bladder to form a hardened composite shaft of the polymeric material;
- releasing the pressure in the bladder;
- removing the bladder from the interior of the shaft.
- 2. The method of claim 1 wherein the inner cavity of the bladder is tapered along the length of the bladder.
- 3. The method of claim 1 wherein the outer dimensions of the bladder are less than the inside dimensions of the female mold by an amount that is less than the wall thickness of the final composite shaft.
- 4. The method of claim 1 wherein the outer dimensions of the bladder are less than the inside dimensions of the female mold by and amount that is less than one-third the wall thickness of the final composite shaft.
- 5. The method of claim 1 wherein the bladder and female mold are dimensioned to form a composite shaft with a circular cross-section.
- 6. The method of claim 1 wherein the female tooling has inner dimensions to form a shaft with circular cross-section and with a middle portion of the shaft having a diameter larger than both adjacent portions to the middle portion.
- 7. The method of claim 1 wherein the female tooling has inner dimensions to form a shaft with circular cross-section and with a middle portion of the shaft having a diameter smaller than both adjacent portions to the middle portion.
- 8. The method of claim 1 wherein the bladder is molded from an elastomeric material, and the bladder is stretched to remove it from the shaft.
- 9. The method of claim 1 wherein the bladder is molded from an elastomeric material.
- 10. The method of claim 9 wherein the bladder is manufactured by injecting a curable liquid resin into a mold with a shaped mold cavity with a central mandrel to form a tubular cured shape.
- 11. The method of claim 1 wherein the bladder is pressurized to between about 200 and 250 psig.
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 08/195,461, filed Feb. 9, 1994, now U.S. Pat. No. 5,534,203.
US Referenced Citations (25)
Foreign Referenced Citations (5)
Number |
Date |
Country |
90 15388 |
Dec 1990 |
FRX |
90 15387 |
Dec 1990 |
FRX |
2670120 |
Jun 1992 |
FRX |
53-34870 |
Sep 1976 |
JPX |
2250443B |
Jun 1992 |
GBX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
195461 |
Feb 1994 |
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