Abstract: A fluid heater employs a vapor compression cycle system. The vapor compression cycle system includes an evaporator, at least one condenser and a working fluid. The fluid heater includes a fluid conduit which forms a tube-in-tube heat exchanger with the condenser to effect heating of the fluid. A sensor is positioned at the condensing zone of the working fluid, to determine the temperature of the working fluid at the condensing phase of the vapor compression cycle. The output of the sensor is used to control the flow rate of fluid through the fluid conduit in order to achieve a desired target temperature of the fluid leaving the conduit.

Abstract: The present invention relates to a fluid heater comprising a vapour compression cycle system. The vapour compression cycle system includes an evaporator, at least one condenser and a working fluid. The fluid heater also includes a fluid conduit through which a fluid can pass in thermal contact with the condenser to allow, via heat exchange between the fluid and the working fluid, the heating of the fluid. A sensor providing an output from which the temperature of the working fluid at the condensing phase of the vapour compression cycle system can be determined is also included in the fluid heater. The fluid heater system has a flow rate controller to control the flow rate of fluid through the conduit. The fluid heater is controlled using a controller operatively connected with the flow rate controller to vary the flow rate of fluid through the conduit reliant on the output from the sensor to achieve a desired target temperature of the fluid leaving the conduit.

Abstract: Structure for and the method of supporting an initial plurality of longitudinally extending large diameter reinforcing rods in transversely aligned spaced apart relation, separately feeding individual, transversely extending reinforcing rods onto the longitudinally extending reinforcing rods at a welding position, simultaneously welding the transversely extending reinforcing rod to each of the longitudinally extending reinforcing rods at the welding position, subsequently indexing the welded transversely extending reinforcing rod and longitudinally extending reinforcing rods a predetermined distance longitudinally of the longitudinally extending reinforcing rods, repeating the feeding, welding and indexing until transversely extending reinforcing rods are welded in predetermined parallel spaced apart relation over the length of the longitudinally extending reinforcing rods, and during the repetitive feeding, welding and indexing placing additional longitudinally spaced apart large diameter reinforcing rods on

Abstract: Triple action piercing structure comprising an outer cylinder, an inner cylinder, a shaft and radially extending piston means operable between the inner and outer cylinders for providing a plurality of separate pressure chambers between the inner and outer cylinders, specific, simple and efficient passage means for passing a pressure medium into and exhausting the pressure medium from the pressure chambers to produce relative axial movement between the inner and outer cylinders at a particularly high pressure for cylinders of predetermined diameter to facilitate piercing of large diameter openings in thick hard workpieces.

Abstract: Structure for spot welding airport concrete steel mesh. The structure includes supports for supporting a plurality of longitudinally extending large diameter reinforcing rods in parallel spaced apart relation, structure for separately feeding individual, transversely extending reinforcing rods onto the longitudinally extending reinforcing rods at a welding position, a plurlaity of transversely aligned welding guns for simultaneously welding a transversely extending reinforcing rod to each of the longitudinally extending reinforcing rods at the welding position, and piston and cylinder structure for subsequently indexing the welded transversely extending reinforcing rods and longitudinally extending reinforcing rods a predetermined distance longitudinally of the longitudinally extending reinforcing rods, repetitively until transversely extending reinforcing rods are welded in predetermined parallel spaced apart relation over the length of the longitudinally extending reinforcing rods.

Abstract: A triple action welding gun for welding airport runway concrete reinforcing mesh or the like comprising an outer cylinder, an inner cylinder, a shaft and radially extending piston means operable between the inner and outer cylinders for providing a plurality of separate pressure chambers between the inner and outer cylinders, and means for passing into and exhausting from the pressure chambers a pressure medium to produce relative axial movement between the inner and outer cylinders wherein extension of the welding gun is accomplished at a particularly high pressure for cylinders of predetermined diameter to facilitate welding of large diameter reinforcing rods.

Abstract: A steel mesh system for reinforcing concrete for airport landing strips and the like, comprising at least two mesh sections, each including separate groups of spaced apart parallel steel bars positioned perpendicularly to each other and welded together at their intersection, placed side by side, and rigid brackets securing peripheral aligned rods at adjacent sides of the mesh sections together. Each bracket is substantially U-shaped defining a recess to receive the peripheral rods and includes two leg portions separated by a connecting portion. One of the leg portions of each bracket is undercut so that the opening of the recess is of smaller extent than the bottom of the recess. A set screw having a convex end extends through the free end of the other leg of the U-shaped member outwardly of the recess with respect to the center of the parallel bars positioned within the recess.