Carbon fiber arrow and continuously winding method thereof

• US 6,251,036 B1
• Filed: 03/01/2000
• Issued: 06/26/2001
• Est. Priority Date: 03/25/1999
• Status: Expired due to Fees

• Current Assignee: Baimtec Material Company Limited
• Original Assignee: Beijing Institute of Aeronautical Materials (Aviation Industry Corporation of China, Ltd.)
• Inventors: Chen, Weifang, Wu, Xiang, Chen, Wenhao, Mao, Qingzhu, Sun, Dahai, Liu, Minyong
• Primary Examiner(s): Ricci, John A.
• Application Number:
  US09/516,576
• Time in Patent Office: 482 Days
• Field of Search: 473/578, 473/FOR.216
• US Class Current: 473/578
• CPC Class Codes: F42B 6/04 Archery arrows F42B6/08, F41B5/06, F42B12/362 take precedence

Abstract

A carbon fiber arrow shaft comprises a hollow tube, a reinforced carbon fiber, and a resinoid binder. The hollow tube has a length between 500-900 mm, an inner diameter between 2-10 mm, and a tube wall thickness between 0.3-2 mm. The reinforced carbon fiber and the resinoid binder form a resin-impregnated carbon fiber. The carbon fiber arrow shaft is formed by directly and continuously winding the resin-impregnated carbon fiber around the hollow tube. The carbon fiber arrow shaft has a head section (L1), a middle section (L2) and a tail section (L3). A winding angle of the carbon fiber at the head section (L1) is changed from a larger winding angle to a smaller winding angle, a winding angle at the middle section (L2) stays constant, and a winding angle at the tail section (L3) is changed from a smaller winding angle to a larger winding angle. The lengths of the head section (L1) and the tail section (L3) are between 25-250 mm. The initial winding angle at the head section (L1) is between 30-90 degrees and is gradually decreased to between 2-30 degrees at the boundary of the head section (L1) and the middle section (L2). The winding angle at the middle section (L2) stays constant, and the winding angle at the tail section (L3) is gradually increased from between 2-30 degrees at the boundary of the middle section (L2) and the tail section to between 30-90 degrees at the end of the tail section (L3). The peripherally located winding angles at both the head section (L1) and the tail section (L3) are at least two times the winding angle at the middle section (L2). The shaft provides uniformity of wall thickness and eliminates overlapping joints or surface protrusions.

Claims

1. A carbon fiber arrow shaft comprising a hollow tube having a length between 500-900 mm, an inner diameter between 2-10 mm, and a tube wall thickness between 0.3-2 mm, a reinforced carbon fiber, and a resinoid binder, the reinforced carbon fiber binder forming a resin-impregnated carbon fiber, the carbon fiber arrow shaft being formed by directly and continuously winding said resin-impregnated carbon fiber around the hollow tube, said carbon fiber arrow shaft having a head section (L1), a middle section (L2) and a tail section (L3), a winding angle of the carbon fiber at the head section (L1) being changed from a larger winding angle to a smaller winding angle, a winding angle at the middle section (L2) being kept constant, and a winding angle at the tail section L3 being changed from a smaller winding angle to a larger winding angle, each of the lengths of the head section (L1) and the tail section (L3) being between 25-250 mm, the initial winding angle at the head section (L1) being between 30-90 degrees and being gradually decreased to between 2-30 degrees at the boundary of the head section (L1) and the middle section (L2), the winding angle at the middle section (L2) being kept constant, and the winding angle at the tail section (L3) being gradually increased from between 2-30 degrees at the boundary of the middle section (L2) and the tail section to between 30-90 degrees at the end of the tail section (L3), the winding angles at the head section (L1) and the tail section (L3) being at least two times of the winding angle at the middle section (L2).

2. The carbon fiber arrow shaft according to claim 1, wherein each of the lengths of the carbon fiber at the head section (L1) and the tail section (L3) is between 100-200 mm, the initial winding angle at the head section (L1) being between 40-60 degrees and being gradually decreased to between 5-10 degrees at the boundary of the head section (L1) and the middle section (L2), the winding angle at the middle section (L2) being kept constant, and the winding angle at the tail section (L3) being gradually increased from between 5-10 degrees at the boundary of the middle section (L2) and the tail section (L3) to between 40-60 degrees at the end of the tail section (L3).

3. A continuously winding method for carbon fiber arrow shaft including the following steps:

(1) selecting the materials of a carbon fiber and a binder, wherein the carbon fiber is 3-24K reinforced carbon fiber and the binder is a thermoset epoxy which is used for winding of the arrow shaft, said carbon fiber arrow shaft having a head section (L1), a middle section (L2) and a tail section (L3), each of the lengths of the head section (L1) and the tail section (L3) being between 25-250 mm;

(2) setting up a winding program for a winding machine, an initial winding angle at the head section (L1) being set between 30-90 degrees, and the winding angle being gradually decreased to between 2-30 degrees at the boundary of the head section (L1) and the middle section (L2), a winding angle at the middle section (L2) being kept constant, and a winding angle at the tail section (L3) being gradually increased from between 2-30 degrees at the boundary of the middle section (L2) and the tail section (L3) to between 30-90 degrees at the end of the tail section (L3), and the winding angles of the head section (L1) and the tail section (L3) being at least two times of that at the middle section (L2)

(3) initiating the winding machine to form a carbon fiber arrow shaft blank by continuously and directly winding the carbon fiber on an arrow shaft mandrel according to the preset winding program;

(4) unloading the arrow shaft blank from the winding machine.

4. The continuously winding method for the carbon fiber arrow shaft according to claim 3 wherein in the step of setting up the winding program, the lengths of the head section (L1) and the tail section (L3) are set in the range of 100-200 mm, the initial winding angle at the head section (L1) being between 40-60 degrees, and being gradually decreased to between 5-10 degrees at the boundary of the head section (L1) and the middle section (L2), the winding angle at the middle section (L2) being kept constant, and the winding angle at the tail section (L3) being gradually increased from between 5-10 degrees to between 40-60 degrees.