Thermoplastic composite bow riser, limb, and cam
View Patent ↗A riser for an archery bow is formed from a fibrous composite material, the matrix of which may be a high heat distortion thermoplastic polymer, a very high heat distortion thermoplastic polymer, or a combination thereof. The riser may incorporate a spine formed from a different polymer or composite than the rest of the riser, or from metal. A method for producing a riser for an archery bow includes the steps of introducing a polymeric composite into a mold from a first end of the mold to facilitate a particular orientation of components of the polymeric composite, molding the polymeric composite to produce a billet that approximates a net shape of the riser, and then machining the billet to the final shape of the riser.
1. An archery bow, comprising:
a riser having a first end surface and an opposing second end surface;
a first limb having a first end and a second end, said first end of said first limb being attached to said first end surface of said riser;
a second limb having a first end and a second end, said first end of said second limb being attached to said second end surface of said riser; and
a string connected between said second end of said first limb and said second end of said second limb; and
said riser being fabricated from a thermoplastic polymer formed to a desired shape and flexibility selected from the group consisting of high heat distortion thermoplastic polymers, very high heat distortion thermoplastic polymers, and combinations thereof; and
wherein said first limb and said second limb comprise a thermoplastic composite layer disposed over a thermoset material.
2. The archery bow of claim 1 , wherein said thermoplastic polymer is a matrix material for said thermoplastic composite.
3. The archery bow of claim 2 , wherein said thermoplastic composite further comprises reinforcing fibers.
4. The archery bow of claim 3 , wherein said reinforcing fibers are formed from an aramid.
5. The archery bow of claim 3 , wherein said reinforcing fibers are formed from a material selected from the group consisting of metal, glass, cellulose-based materials, natural materials, and combinations of the foregoing materials.
6. The archery bow of claim 1 , wherein said thermoplastic polymer is molded using a technique selected from the group consisting of compression molding techniques, injection molding techniques, thermoplastic form forging techniques, and combinations of the foregoing techniques.
7. The archery bow of claim 1 , further comprising,
a first pocket formed in said first end surface of said riser, said first pocket being sized to receive said first limb, and
a second pocket formed in said second end surface of said riser, said second pocket being sized to receive said second limb.
8. The archery bow of claim 7 , wherein said first pocket and said second pocket are integrally molded into said riser.
9. The archery bow of claim 7 , wherein said first pocket and said second pocket are machined into said riser.
10. The archery bow of claim 7 , wherein said first pocket and said second pocket are over-molded into said riser.
11. The archery bow of claim 1 , wherein said thermoplastic composite layer is a wrapped fiber-filled composite tape, a woven material, or a combination of wrapped fiber-filled composite tape and woven material.
12. The archery bow of claim 11 , wherein said thermoplastic composite layer comprises a material selected from the group of materials consisting of nylons, urethanes, and combinations of the foregoing materials.
13. The archery bow of claim 1 , wherein said thermoplastic composite layer is laminated to said thermoset material.
14. The archery bow of claim 1 , wherein said first limb and said second limb are mechanically fastened to said riser.
15. The archery bow of claim 1 , wherein said first limb and said second limb are integrally formed with said riser.