Reinforcing bar splice with cutting edge bolts

Abstract

A bolt has a pointed end with cutting edges. The cutting edges may have knurls (grooves) or ridges, and may have a spiral arrangement. The bolt may have a convex end, such as a cone end or a curved end. A plurality of bolts may be used as part of a reinforcing bar splice that also includes a sleeve. The bolts engage threaded holes of the sleeves. As the bolts are tightened, they bore into the receiving bar ends, securing the bar ends within the sleeve. Cutting edges on the bolts aid in boring the ends of the bolts into the reinforcing bar ends. Using cutting edges on the bolt ends allows deeper penetration of the bolts into the reinforcing bar ends, without increasing the amount of torque used.

1 . A reinforcing bar splice comprising:
 a sleeve having openings for receiving bar ends of reinforcing bars; and   threaded bolts that engage threaded holes in the sleeve to press against the reinforcing bar ends;   wherein at least some of the threaded bolts include respective tips with respective cutting edges.   
   
   
       2 . The reinforcing bar splice of  claim 1 , wherein the bolts have convex tips. 
   
   
       3 . The reinforcing bar splice of  claim 2 , wherein the convex tips include conical tips. 
   
   
       4 . The reinforcing bar splice of  claim 3 ,
 wherein the conical tip includes a smooth region around a sharp point; and   wherein the cutting edges do not extend into the smooth region.   
   
   
       5 . The reinforcing bar splice of  claim 2 , wherein the convex tips include rounded tips. 
   
   
       6 . The reinforcing bar splice of  claim 1 , wherein the cutting edges are knurls. 
   
   
       7 . The reinforcing bar splice of  claim 6 , wherein the knurls have a U-shape cross-section. 
   
   
       8 . The reinforcing bar splice of  claim 7 , wherein the knurls have a V-shape cross-section. 
   
   
       9 . The reinforcing bar splice of  claim 7 , wherein the knurls have a depth of 0.13 mm (0.005 inch) to 0.76 mm (0.03 inch). 
   
   
       10 . The reinforcing bar splice of  claim 7 , wherein at least some of the knurls have a width that varies along a length of the knurls. 
   
   
       11 . The reinforcing bar splice of  claim 1 , wherein the cutting edges are ridges. 
   
   
       12 . The reinforcing bar splice of  claim 1 , wherein the cutting edges have a spiral orientation. 
   
   
       13 . The reinforcing bar splice of  claim 12 , wherein the spiral orientation is a left-hand spiral. 
   
   
       14 . The reinforcing bar splice of  claim 12 , wherein the spiral orientation is a right-hand spiral. 
   
   
       15 . A method of joining reinforcing bar ends, the method comprising:
 placing the reinforcing bar ends in openings on opposite sides of a sleeve; and   screwing bolts through threaded holes in the sleeve, wherein the screwing the bolts includes using cutting edges on tips of the bolts to cut into the reinforcing bar ends, thereby securing the reinforcing bar ends within the sleeve.   
   
   
       16 . The method of  claim 15 ,
 wherein the cutting edges include knurls; and   wherein the using the cutting edges includes abrading reinforcing bar ends with the knurls.   
   
   
       17 . The method of  claim 16 , wherein the knurls include spiral knurls. 
   
   
       18 . A bolt comprising:
 a threaded shaft;   a head attached to a first end of the threaded shaft; and   a convex tip at a second end of the threaded, opposite the first end;   wherein at least part of the convex tip includes cutting edges; and   wherein the convex tip has a substantially circular cross-section.   
   
   
       19 . The bolt of  claim 18 , wherein the convex tip is a conical tip. 
   
   
       20 . The bolt of  claim 19 ,
 wherein the conical tip includes a smooth region around a sharp point; and   wherein the cutting edges do not extend into the smooth region.   
   
   
       21 . The bolt of  claim 18 , wherein the convex tip is a rounded tip. 
   
   
       22 . The bolt of  claim 18 , wherein the cutting edges are knurls. 
   
   
       23 . The bolt of  claim 22 , wherein the knurls have a U-shape cross-section. 
   
   
       24 . The bolt of  claim 22 , wherein the knurls have a V-shape cross-section. 
   
   
       25 . The bolt of  claim 22 , wherein the knurls have a depth of 0.13 mm (0.005 inch) to 0.76 mm (0.03 inch). 
   
   
       26 . The bolt of  claim 22 , wherein at least some of the knurls have a width that varies along a length of the knurls. 
   
   
       27 . The bolt of  claim 18 , wherein the cutting edges are ridges. 
   
   
       28 . The bolt of  claim 18 , wherein the cutting edges have a spiral orientation. 
   
   
       29 . The bolt of  claim 28 , wherein the spiral orientation is a left-hand spiral. 
   
   
       30 . The bolt of  claim 28 , wherein the spiral orientation is a right-hand spiral. 
   
   
       31 . The bolt of  claim 18 , wherein the cutting edges are straight. 
   
   
       32 . The bolt of  claim 18 , wherein the cutting edges are substantially evenly circumferentially spaced around the convex tip. 
   
   
       33 . A method of making a bolt, the method comprising:
 forming a convex tip on the bolt; and   stamping the convex tip against a die to form knurls in the convex tip.   
   
   
       34 . The method of  claim 33 , wherein the forming and the stamp are performed in a single step that involves placing round stock in the die, and driving the round stock against a conical surface of the that has protrusions corresponding to the knurls.