Filament-wound composite boom pipe

Abstract

A mobile concrete pumping vehicle including a reduced-weight boom arm. The pumping vehicle includes a boom arm that is extendible between a folded position and an extended position. The boom arm carries molded and fabricated composite boom pipe sections. Each pipe section is formed from a composite material having a reinforcing outer layer and a wear resistant inner layer. Preferably, the outer layer is formed using a filament winding process while the inner layer is molded of wear resistant urethane. Each boom section is formed by centrifugal molding a urethane tube then secondarily winding carbon fiber onto the exterior of the tube. The centrifugal force created by the rotating mold provides a bubble free urethane tube. The filament winding provides the hoop strength needed to withstand the internal pressures of the concrete pumping process.

We claim:  
     
         1 . A pumping unit comprising: 
 a multi-section moveable boom arm having a plurality of boom sections, the boom arm being extendable from a folded position to an extended position; and    a boom pipe supported by the boom arm, the boom pipe extending between a supply of material and an outer end of the boom arm,    wherein the boom pipe is comprised of a plurality of joined boom pipe sections each having a filament-wound reinforcing outer layer and a wear resistant inner layer.    
     
     
         2 . The pumping unit of  claim 1  wherein the reinforcing outer layer is formed from a wound layer of braided fiber applied to an outer surface of the inner layer.  
     
     
         3 . The pumping unit of  claim 2  wherein the braided fiber is formed from carbon fiber.  
     
     
         4 . The pumping unit of  claim 2  wherein the wear resistant inner layer is formed from urethane.  
     
     
         5 . The pumping unit of  claim 4  wherein the urethane has a durometer hardness rating between 90-A and 95-A.  
     
     
         6 . The pumping unit of  claim 1  wherein each of the pipe sections includes an end coupling secured to both ends of the supply pipe section, each end coupling being secured to the pipe section by an adhesive.  
     
     
         7 . The pumping unit of  claim 1  wherein the pipe sections are each capable of sustaining an internal pressure of at least 1200 psi.  
     
     
         8 . A mobile pumping vehicle comprising: 
 a vehicle body;    a material supply bin mounted to the body for receiving a material to be pumped by the pumping vehicle;    a multi-section movable boom arm having a plurality of boom sections, the boom arm being mounted to the body and extendible from a folded position to an extended position; and    a boom pipe supported by the boom arm for directing the flow of material from the supply bin to an outer end of the boom arm,    wherein the boom pipe is comprised of a plurality of joined composite pipe sections each having a filament-wound reinforcing outer layer and a wear resistant inner layer.    
     
     
         9 . The mobile pumping vehicle of  claim 8  wherein the reinforcing outer layer is formed from a wound layer of braided fiber applied to an outer surface of the inner layer.  
     
     
         10 . The mobile pumping vehicle of  claim 9  wherein the braided fiber is formed from carbon fiber.  
     
     
         11 . The mobile pumping vehicle of  claim 10  wherein the wear resistant inner layer is formed from urethane.  
     
     
         12 . The mobile pumping vehicle of  claim 11  wherein the urethane has a durometer hardness rating between 90-A and 95-A.  
     
     
         13 . The mobile pumping vehicle of  claim 8  wherein each of the supply pipe sections includes an end coupling secured to both ends of the supply pipe section, each end coupling being secured to the pipe section by an adhesive.  
     
     
         14 . The mobile pumping vehicle of  claim 8  wherein the pipe sections are each capable of sustaining an internal pressure of at least 1200 psi.