Taper ties for concrete formwork and related devices, systems, and methods

Abstract

A rolled threaded rod is overmolded with a suitable material to create a taper tie for use with formwork in concrete construction. The various implementations may use a continuous high-strength threaded rod which is used to carry the structural loads necessary for the design while the overmolded material creates the void in the cast concrete from which the taper tie can be removed.

What is claimed is: 
     
         1 . A taper tie comprising:
 (a) a threaded rod; and   (b) an overmolded element,   wherein the overmolded element is molded directly on the rolled threaded rod to create a tapered section.   
     
     
         2 . The taper tie of  claim 1 , wherein the threaded rod is a hot rolled steel rod. 
     
     
         3 . The taper tie of  claim 1 , wherein the threaded rod has an oblong cross-section comprising two flat faces and two deformed thread faces. 
     
     
         4 . The taper tie of  claim 1 , wherein the overmolded element is comprised of one or more of TPU (thermoplastic urethane), thermoplastic, thermoset plastic, and die cast metal alloys. 
     
     
         5 . The taper tie of  claim 4 , wherein the overmolded element is comprised of thermoplastic urethane. 
     
     
         6 . The taper tie of  claim 1 , wherein the overmolded element is mechanically interlocked with the threaded rod. 
     
     
         7 . The taper tie of  claim 1 , wherein the overmolded element comprising a sloped section at each end of the overmolded element. 
     
     
         8 . The taper tie of  claim 1 , wherein the overmolded element is shaped to form a void in concrete during forming. 
     
     
         9 . The taper tie of  claim 1 , wherein the threaded rod is a cold rolled steel rod. 
     
     
         10 . The taper tie of  claim 9 , further comprising a bonding agent on the cold rolled steel rod providing bonding between the cold rolled steel rod and the overmolded element. 
     
     
         11 . The taper tie of  claim 10 , wherein the bonding agent is a heat sensitive adhesive. 
     
     
         12 . The taper tie of  claim 1 , wherein the threaded rod is between about 36 inches to about 52 inches in length. 
     
     
         13 . The taper tie of  claim 1 , wherein the overmolded element is between about 15 inches to about 37 inches in length. 
     
     
         14 . The taper tie of  claim 1 , wherein the overmolded element tapers from about 1 1/16 inches in diameter to about ⅞ inches in diameter. 
     
     
         15 . The taper tie of  claim 1 , wherein the threaded bar is a ⅝ inch galvanized steel bar. 
     
     
         16 . A formwork tie, comprising:
 (a) a hot-rolled threaded steel rod; and   (b) an overmolded element formed around a center portion of the hot-rolled threaded steel rod, wherein the overmolded element is tapered decreasing in diameter along a length of the overmolded element,   wherein the hot-rolled threaded steel rod and the overmolded element are mechanically interlocked.   
     
     
         17 . The formwork tie of  claim 16 , wherein the overmolded element is comprised of one or more of TPU (thermoplastic urethane), thermoplastic, thermoset plastic, and die cast metal alloys. 
     
     
         18 . The formwork tie of  claim 16 , wherein the overmolded section element from about 1 1/16 inches in diameter to about ⅞ inches in diameter. 
     
     
         19 . The formwork tie of  claim 16 , wherein the hot-rolled threaded steel rod is galvanized. 
     
     
         20 . The formwork tie of  claim 16 , wherein the hot-rolled threaded steel rod has an oblong cross-section comprising two flat faces and two deformed thread faces.