Abstract: Disclosed is a rotary actuator utilizing magnetic screws which are stably rotatable at a great torque with little torque variation. The rotary actuator comprising (a) a closed hollow cylinder, a piston sliding within the cylinder, and a rotary shaft which rotates with the sliding of the piston, has (b) a first magnetic screw member which makes a linear motion in synchronism with the sliding of the piston, and is provided with a first spiral magnetized band, and (c) a rotary shaft rotatably supported in relation to the first magnetic screw member, and having a second magnetic screw provided with a second spiral magnetized band. (d) With the sliding of the piston, the second magnetic screw receives the magnetic force from the first magnetic screw to thereby rotate the rotating shaft.

Abstract: Disclosed is a rodless cylinder having a cylinder barrel with a slit formed axially therein. A piston is movably housed in the cylinder barrel. A mounting table is disposed movably along the external surface of the cylinder barrel and connected to the piston through the slit. An external actuator is mounted on the mounting table and designed to be driven by a pressure fluid. A passage, through which a pressure fluid can pass, is defined in the cylinder barrel. An inlet is provided in the cylinder barrel so as to introduce the pressure fluid in the passage to the mounting table side. An outlet is provided on the mounting table so as to supply the pressure fluid introduced from the inlet to the external actuator.

Abstract: A paving material extrusion molding apparatus for continuously laying or molding a paving material wherein the paving material supplied into hoppers is conveyed into a molding element by a plurality of screw conveyors, the paving material is compacted or consolidated by screw thrusts equal to the frictional force produced by the dead weight of the extrusion molding apparatus, a reaction force created by the compaction or consolidation is utilized to float off the entire extrusion molding apparatus, and a reaction force created by the conveyance of the paving material being continuously fed serves to move the extrusion molding apparatus along the predetermined path.

Abstract: The paving material supplied into a hopper is conveyed by screw conveyors into a mold provided in the lower part of the apparatus thereby molding and laying the material. The paving material is densely compacted or consolidated in the mold, and when the paving material is conveyed under pressure further, the mold can be pushed up, and the reaction force of the conveying pressure acts to move the entire apparatus horizontally. Thus, structure having the same sectional shape as that of the mold can be formed and laid continuously on the ground.