Abstract: An extrusion machine for making elongated articles of concrete by forcing the concrete through a mold, the article having a relatively large core. The machine is moved forwardly by reaction as the concrete is forced against the molded concrete. A rotatable spiral conveyor extends longitudinally of the mold and moves the concrete through the mold. A nonrotatable forming element in the mold forms the internal cavity. The element is immediately following the downstream end of the conveyor. The forming element has its lower edge positioned so that not more than 10% of the height of the forming element is below the lower edge of the conveyor the lower edge and lower sides of the element being free of any substantial ramp. The longitudinal center line of the element is higher than the center line of the conveyor and includes a ramp extending upwardly from the downstream end of the conveyor. The conveyor forces the concrete over the forming elements to form the concrete article.

Abstract: The apparatus has a plurality of open-ended female dies with a movable lower male die positioned in the lower end of each one. A supply box is shiftable over the female dies to deposit concrete therein, following which a plurality of upper male dies are moved down into the female dies to compact the concrete therein into chairs. Wire supply means feeds wires through the upper male dies and into the concrete in the female dies before the concrete is compacted. After the wires have been cut above the female dies, the upper male dies are retracted and the lower male dies are moved upwardly to eject the compacted chairs from the female dies.

Abstract: A support frame to span and to be moved over the surface of a concrete slab on wheels running on rails extending along side edges of the slap, and having a hopper for depositing a layer of finishing material on the slab surface ahead of at least one roller carried by the frame, said finishing material being confined on the surface by side walls depending from the frame and overlapping the side edges of the slab. Power means rotates the roller, and this roller can be adjusted vertically relative to the frame to adjust the thickness of finishing material being rolled onto the slab surface.

Abstract: A machine for making elongated articles of concrete or the like having reinforcing members extending therethrough, and in which at least one spiral conveyor forces concrete under pressure through a mold causing the machine to move forwardly by reaction as the material is forced against the molded portion of the article. At least one elongated reinforcing member extends through the machine and the mold, and the machine is provided with a support tube extending to the mold to receive the reinforcing member and to support the latter as concrete is directed into the machine. The support tube preferably has a longitudinal slot therein and is mounted to rotate around a longitudinal axis so that the tube can be rotated between a position with a slot opening upwardly and a position with the slot opening downwardly.