Abstract: A method for forming and attaching a clamping collar to a pipe configured for forming a pipe section in a concrete pumping line for carrying of fluid concrete includes the steps of placing a sleeve on the pipe to provide a heat transfer limit area between the sleeve and the pipe; welding the sleeve to the pipe; heat treating the pipe; and assembling a collar to the sleeve and welding the collar to the sleeve.

Abstract: A pipe section for concrete includes an end coupler interconnecting to another pipe section in a flow line. The coupler has an outer clamp secured extended from the pipe end with a coupling groove. An encircling clamp has sides located in the grooves of adjacent pipe sections to lock the pipe section together. The body and pipe end form an inner recess extending from the pipe end. An insert liner has a tubular portion matching the recess, with the outer surface of the tubular portion tapered to form a gap within the recess. The insert liner has an outer flange matching the outer diameter of the body and abuts the body. The inner wall of the liner has a central transition point from which the wall tapers inwardly in opposite directions to the outer end. The body member is formed of a high strength ductile steel. The insert liner is formed of a wear resistant material having a Rockwell hardness of 80 to 90.

Abstract: A concrete flow line made up of a plurality of end to end pipe sections with pipes connected to each other by a coupling assembly provides for carrying abrasive fluid concrete to a deposit site. The coupling assembly includes an insulating thin sleeve slid over the connecting end of the pipe and spaced from the pipe to form a heat insulating air space therebetween. The thin sleeve is welded to the pipe prior to the hardening of the pipe. After the sleeve is welded in place the inner wall of the pipe is hardened using an induction coil for concentrating of the heat within the inner wall portion in combination with a quenching unit to affect the desired hardening while maintaining an outer ductile wall portion to which the sleeve has been actually welded. A clamping collar or coupler is welded to the sleeve after hardening and forms a connecting end for receiving of a clamp unit which interconnects the adjacent pipe and pipe sections.

Abstract: A thin wall mild carbon steel pipe for pumping concrete has a wall which has an internal diameter of five inches and a wall thickness in the range of 0.170 to 0.200. The composition of the pipe wall by weight is in percentages ranges of 0.27 to 0.34 carbon, 0.30 to 0.60 manganese, less than 0.30 silicon with only traces of phosphorus and sulfur. The pipe has an inner hardened wall portion of RC reading of about 60 and of a thickness in the range of 0.04 to 0.06 inches and a gradual transition in hardness therefrom to an outer ductile wall reading of about 30 RC. The unhardened mild carbon steel pipe is processed by progressively and successively heating axially annular portions of the pipe to a hardening temperature of 1650.degree. F. A quenching brine solution at a temperature below 50.degree. F. is immediately sprayed at a high velocity onto the progressively heated surface to reduce the temperature of the inner wall essentially instantaneously to the temperature of the brine solution.

Abstract: A multi-walled composite tube member is formed from two superimposed pipes having a gap therebetween. The inner pipe is forcibly expanded in excess of the gap to deform and expand the outer pipe. The expander including a mandrel is forced through the aligned pipes while maintaining the longitudinal alignment. The diameter of the mandrel corresponding to the final desired diameter to finally size the composite pipe section and establish a true round inner passage. An induction heating coil operating at a low frequency operating in the range of low hundreds hertz in contrast to a conventional high frequency unit operating at thousands of hertz is coupled to and moved relative to the expanded pipe unit, progressively heats small lengths of the expanded pipe unit. The expanded pipe unit is quenched with a chilled brine solution applied to both surfaces.

Abstract: A semi-liquid cementitious pump nozzle unit for pumping cement, concrete, grout and other abrasive materials includes an air chamber assembly having an outer integral swivel housing. A tubular steel body has a threaded coupling for connection to a pump hose. An air chamber recess extends about the nozzle body with transfer openings located centrally of the recess. An outer air housing in a form of a simple tubular member is telescoped over the end walls and sealed thereto by O-ring seals. The opposite ends of the housing are smooth bearing surfaces. Annular bearing walls project radially outwardly by the nozzle and abutting the bearing surfaces of the housing. The bearing walls may be snap ring units releasably applied to the nozzle body. A nozzle reducer secured to the end of the nozzle body may have an appropriate end directly abutting the air/swivel housing to form a bearing wall. The outer air/swivel housing is secured with the body for a slip fit for ease of disassembly, cleaning and maintenance.

Abstract: A concrete pumping system includes a pipe extender unit for adjustment of a pipe length between two fixed points. The extender unit includes a ductile steel pipe telescoped over a standard pipe, with a seal therebetween. Four jaws of hardened steel have inner teeth on the center portion only which abutt the exterior of the pipe section. The pipe and jaws have end exterior shoulders. A two-piece annular clamp has spaced clamping legs engaging the shoulders to connect the members and force the jaw teeth into the outer wall of the pipe section to affix the pipe extender to the pipe section thereof. The teeth have a radial side and an inclined side joined by an outer flat land.

Abstract: The invention is a variable gain non-Lambertian screen surface (12) for employment in a visual display system. The screen surface provides constant image brightness, independent of changes in viewing angle (22). It is therefore suitable for off-axis viewing. The screen gain continuously varies from a magnitude of one to infinity at different portions on the screen surface in such a manner that the equivalent gain preceived by an off-axis viewer (16) corresponds to the viewer perceiving constant image brightness, independent of changes in the viewing angle.