Abstract: Steering means, particularly for use with internal pipe bending mandrels, wherein upper and lower driven wheels are mutually expanded against the pipe wall by an intermediate free-floating hydraulic cylinder, and wherein at least one of the upper and lower driven wheels are rotatably disposed to provide steering. The steering assembly is affixed as a support at one end of the mandrel and serves to keep the mandrel upright within the pipe.

Abstract: Apparatus for scraping the interior sides of the walls of pipes, having ractable scraper elements at each end of a carrier body. The scraper apparatus is preferably moved in both directions through a pipe, the trailing scraper elements preferably being retracted during movement of the apparatus in each direction. The apparatus is particularly designed for removal of coating materials such as cosmoline from pipes before use of the pipes in pipelines.

Abstract: There is disclosed a technique for mixing concrete in which cement and aggregate are separately discharged from metering devices in free fall paths of precise predetermined cross-section toward a conveyor. The material paths converge toward a rotating mixing device positioned above the conveyor which intermingles the materials before they reach the conveyor. The conveyor includes an air supported endless belt equipped with adjustable wear strips for engaging the belt and limiting movement thereof away from the air support system. Means are provided to prevent belt damage caused by a prong of a mixing device binding a piece of aggregate against the belt.