Abstract: To permit efficient utilization of expensive equipment in casting mold manufacturing systems, particularly of a molding press, pattern plates are cycled in one loop of a plurality of work stations, including the station in which molding sand is applied to the mold boxes or flasks, and the single press, and a second loop also including the single press and, preferably, also the sand application station is provided in which loose patterns are placed in flasks, so that the common work stations, and principally the molding press, is efficiently utilized.

Abstract: A relief valve for limiting the pressure of the output of a feed pump being furnished to a main hydraulic pump is provided not only with a bore through the valve disk leading to a chamber at the rear of the guide piston for counteracting, as relief valving continues, the force of the spring tending to keep the valve closed, but also a pressure piston, in the form of an annular flange on the guide piston, subdividing an outer cylindrical space into two chambers respectively connected to a constriction in a hydraulic conduit, so that the amount of flow through the constriction will additionally modify the limit pressure at which relief valving takes place. The device is used to reduce the limit pressure when the feed pump provides excessive oil feed to the main pump.

Abstract: To permit efficient heat welding of pipe fittings, and the like, of thermpolastic material to thermoplastic pipes, by electrically heating of the fitting, the fitting is made in two concentric portions, the inner portion having a heating wire applied to the outside thereof, the heating wire and inner portion being covered by the outer portion, for example injected thereover.

Abstract: An incinerator comprises a pre-drying grate, a combustion grate or drum following the pre-drying grate, and a drop intermediate the pre-drying grate and the combustion grate or drum. The drop is the front wall of an air distribution box extending over the width of the pre-drying grate, this wall including air throughflow apertures whereby air passes from the box to a combustion chamber above the combustion grate or drum. The speed of the air flow from the apertures varies over the wall, with the highest speed flows being adjacent to the side walls of the chamber.

Abstract: The piston is formed with a piston head and a sleeve, fitted together such that the piston head has an outer end diameter matching the diameter of the cylinder, and then is formed with an offset inwardly extending shoulder, against which the piston sleeve can bear, to permit machining of the inner face of the piston head to form a bearing cup for a spherical head of a piston rod, and then assembly of the piston sleeve to bear against the abutment; drain line and oil connection lines may be formed in the piston to lead lubricating oil to the bearing cup. The piston head and sleeve can be connected by adhesives and, if necessary, tangentially located transverse pins.