Archery recurve bow limb

Abstract

The making of carbon steel recurve bow limbs involves a number of procedures. Strips of annealed or softer carbon steel 18 to 20 inches long and 1.5 inches wide have a hole drilled at one end of each strip for attaching the limb to the bow, and grooves made at the other end for attaching the bowstring. After forming the limbs into the curvature shown in FIGS. 1. and 3. they are heated in a furnace for 45 minutes at about 1550 degrees F. and then quenched (cooled quickly) in oil which makes the steel hard and brittle. The hardened limbs are then reheated for two hours at about 700 degrees F. depending on the steel percent carbon content and then air cooled. This tempering makes the steel strong, tough, and elastic; the finished limbs act as cantilever springs when used on a bow. This is a new application of the art and science heat treating to make the limbs of very effective sporting recurve style archery bows.

1 . An archery recurve bow limb made from hardened and tempered carbon steel, where the percentage carbon content range of the steel is from 0.30% to 1.30%. 
     
     
         2 . An archery recurve bow limb as defined in  claim 1 , where the thickness range of the carbon steel used is from 0.050 inches to 0.150 inches. 
     
     
         3 . An Archery recurve bow limb as defined in  claims 1  and  2 , where the carbon steel is tempered to a range of Rockwell “C” scale hardness, from 35 to 55 (HRc 35 to HRc 55).