David A Crane

US Patent:

53245636, Jun 28, 1994

Filed:

Mar 23, 1993

Appl. No.:

8/035910

Inventors:

Charles W. Rogers - Arlington TX
David A. Crane - Fort Worth TX
Habib G. Rai - Bedford TX

Assignee:

Bell Helicopter Textron Inc. - Ft. Worth TX

International Classification:

B32B 512
B32B 900
D04H 300
B64C 100

US Classification:

428114

Abstract:

A pultruded shaped composite material of carbon fiber having a diameter not greater than 0. 001 inch aligned linearly with a degree of waviness defined by an average amplitude to length (A/L) ratio of less than 0. 9 percent, the matrix formed around the fiber and solidified or cured into a rigid form that will not melt during subsequent processing steps to prevent an increase in waviness during subsequent processing steps. The matrix material consists essentially of a resin present in the range of about 10 to 50 percent by volume of the composite material. The A /L ratio is determined by measuring the distribution of angularity found in the aligned carbon fibers in a selective cross section cut at five degrees to the fiber plane, wherein the standard deviation for a 300 sample angularity measurement is not greater than 0. 88 degrees.

US Patent:

54626188, Oct 31, 1995

Filed:

Jun 2, 1994

Appl. No.:

8/252927

Inventors:

Charles W. Rogers - Arlington TX
David A. Crane - Fort Worth TX
Habib G. Rai - Bedford TX

Assignee:

Bell Helicopter Textron Inc. - Fort Worth TX

International Classification:

B65H 8100
B32B 3100
B29C 6700
B29C 7100

US Classification:

156161

Abstract:

A method of forming a pultruded shaped composite material comprising carbon fiber having a diameter not greater than 0. 001 inch aligned linearly with a degree of waviness defined by an average amplitude to length (A/L) ratio of less than 0. 9 percent in a matrix is formed around the fiber and solidified or cured into a rigid form that will not melt during subsequent processing steps to prevent an increase in waviness during subsequent processing steps. The compressive strength of the composite material approaches the tensile strength of the material. The matrix material consists essentially of a resin present in the range of about 10 to 50 percent by volume of the composite material. The A/L ratio is determined by measuring the distribution of angularity found in the aligned carbon fibers in a selective cross section cut at five degrees to the fiber plane, wherein the standard deviation for a 300 sample angularity measurement is not greater than 0. 88 degrees.