Abstract: In a method of manufacturing a laminated magnetic core by laser welding successive core sheets, the core sheets are stacked one on another to form a stacked body of core sheets, and while the stacked body of core sheets is moved in a stepwise manner in a thickness direction perpendicular to a surface of the core sheet with respect to at least one optical fiber exit unit from which a laser beam is projected onto an outer surface of the stacked body of core sheets, the laser beam is intermittently projected onto the stacked body of core sheets such that at least successive three core sheets are welded together, and then the stacked body of core sheets is moved in the thickness direction over a distance substantially equal to at least a twice of the thickness of core sheets.

Abstract: A solenoid controlled valve of the double pilot type includes a valve main body having a valve mechanism, a pair of pilot valve units each being secured to respective sides of the valve main body and having solenoids for driving the valve mechanism of the valve main body, to first and second sets of male terminals connected to the solenoids, a wiring box being secured to a lower surface of an assembly of the valve main body and the pilot valve units, third and fourth sets of female terminals receiving the first and second sets of male terminals, respectively, a fifth set of male terminals connected to the third and fourth sets of terminals via electric wires, and a base secured to a lower surface of the wiring box at its center. The wiring box has formed therein conduits which are communicated with conduits formed in the valve main body and the base.

Abstract: A tap holder for detachably securing a tool to a machine tool including a main portion having a shank which is to be secured to a main shaft of the machine tool, a quick change portion having a float shaft which is inserted into a hole formed in the main portion and a quick change mechanism including a clamp collar, a first coiled spring for pressing the clamp collar toward the main portion, steel balls arranged in holes formed in the float shaft, a supporting ring slidably inserted into the float shaft and a second coiled spring for pressing the supporting ring toward a tool, and a tool supporting portion including a driven shaft whose rear end has a recess formed therein and is inserted into the float shaft and a torque control mechanism. By moving the clamp collar toward the main portion against the resilient force of the first coiled spring, the engagement between the steel balls and the recess of the driven shaft is released and the tool holding portion is removed from the quick change portion.

Abstract: An electromagnetic valve including an electromagnetic unit having a magnetic core, a coil bobbin arranged around the core, an electromagnetic coil wound around the bobbin, a stationary yoke and a first valve seat formed in a flange of the coil bobbin and a valve unit having a movable yoke, a valve stopper provided at an end of the movable yoke whose other end is rotatably coupled with the stationary yoke and a second valve seat provided in opposition to the valve stopper. When the coil is not energized, the valve stopper is resiliently urged against the second valve seat and a first fluid passage connected to the first valve seat is communicated with a valve chamber in the valve unit, but when the coil is energized, the movable yoke is attracted to the core to urge the valve stopper against the first valve seat and a second fluid passage connected to the second valve seat is communicated with the valve chamber.