Transmission cross arm

Abstract

A cross arm is provided, for use in a support structure for conductors within an electrical grid. The cross arm is made of weather resistant glass fibre reinforced two component polyurethane based polymers and has a “C” cross sectional shape typically arranged in a double configuration. Pairs of the cross arms are attached to utility poles in a parallel position on opposite sides of the utility pole to meet predefined design conditions. Alternatively, a single cross arm may be attached to a utility pole.

1 . A structure for supporting a conductor, the structure comprising:
 a transmission class structural cross arm comprising: a pultruded glass fibre reinforced polymer composite C-channel comprising a two-component polyurethane resin and layers of continuous filament mat, unidirectional roving and triax fabric, glass of the pultruded glass fibre reinforced polymer composite C-channel being E-glass to electrically insulate the transmission class structural cross arm and a volume fraction ratio of the E-glass to the two-component polyurethane resin of the pultruded glass fibre reinforced polymer composite C-channel being between 50 and 58 to between 50 and 42; and   UV inhibitors incorporated into the two-component polyurethane resin of the pultruded glass fibre reinforced polymer composite C-channel;   wherein the transmission class structural cross arm is sized to fit into an existing electrical power transmission grid.   
     
     
         2 . The structure of  claim 1 , wherein the continuous filament mat comprises 1.5 oz/ft 2  internal layers and 2.0 oz/ft 2  surface layers with polyester veil stitched. 
     
     
         3 . The structure of  claim 1 , wherein the unidirectional roving is 56-yield with approximately 608 total ends. 
     
     
         4 . The structure of  claim 1 , wherein the triax fabric is E-TTXM4008-10 triax fabric comprising 12 oz/yd 2  in each ±45°, 16 oz/yd 2  in 90° and 6.75 oz/yd 2  chopped mat. 
     
     
         5 . The structure of  claim 1 , wherein the two-component polyurethane resin is colored. 
     
     
         6 . The structure of  claim 1 , wherein the unidirectional roving layers are provided in a longitudinal direction relative to a length of the transmission class structural cross arm. 
     
     
         7 . The structure of  claim 1 , wherein the unidirectional roving layers are provided in a transverse direction relative to a length of the transmission class structural cross arm. 
     
     
         8 . The structure of  claim 1 , wherein the pultruded glass fibre reinforced polymer composite C-channel comprises fire retardant additives. 
     
     
         9 . The structure of  claim 1 , wherein the pultruded glass fibre reinforced polymer composite C-channel comprises a polyester veil coating. 
     
     
         10 . The structure of  claim 9 , wherein UV inhibitors are incorporated into the polyester veil coating of the pultruded glass fibre reinforced polymer composite C-channel. 
     
     
         11 . The structure of  claim 1 , wherein the pultruded glass fibre reinforced polymer composite C-channel comprises a volume fraction ratio of E-glass to resin of approximately 53 to 47. 
     
     
         12 . The structure of  claim 5 , wherein a color of the two-component polyurethane resin matches a color of a utility pole.