Abstract: A vacuum die casting method according to the present invention solves the problems relating to seal performance, differential pressure, and the stability of the degree of vacuum. The method carries out the casting with a casting cavity evacuated. In the method, a molten metal is poured from a molten metal inlet of a plunger sleeve, followed by forming a vacuum chamber surrounding the inlet and an open end of the plunger sleeve located on the opposite side of the die, and an evacuation of the vacuum chamber and the cavity starts before starting an operation of a plunger tip. When the evacuation starts, the plunger tip is positioned between the open end of the plunger sleeve and the inlet so that the vacuum chamber is communicated to the inside of the plunger sleeve through the inlet.

Abstract: A torque transmitting and torsion damping apparatus includes a torsion damper and a friction clutch between a first inertia body and a second inertia body that is supported by said first inertia body for relative rotation. The friction clutch includes a friction plate and a pressure plate that is pressed against the friction disc due to the action of a Belleville spring. The pressure plate has bent-free (straight) projections radially outwardly extending into cutout grooves of the first inertia body. This arrangement allows relative axial movement of the pressure plate to the first inertia body.

Abstract: A torque transmitting and torsion damping apparatus includes a torsion damper and a friction clutch between a first inertia body and a second inertia body that is supported by said first inertia body for relative rotation. The torsion damper include a drive plate assembly for rotation with the first inertia body, a damper hub for rotation with the second inertia body and spring assembly disposed between the drive plate assembly and the damper hub. At radially inward rivet pins and radially outer projections, the drive plate assembly is fixedly attached to the first inertia body, thereby providing split torque transmission from the first inertia body to the drive plate assembly.

Abstract: A method of forming a metallic composite product having a specific gravity no greater than 1.8 and a thermal expansion no greater than 16.times.10.sup.-6 .degree. C. in a preheated mold. The portion of the mold between a cavity and the gate has a stainless steel wire gauge for retaining particles. The mold is filled with screened fly ash, glass, hollow spheres having a particle size in the range of 50 to 200 micrometers and a globularness of at least 90%, which has been preheated to the same temperature as the mold. Molten aluminum alloy is injected into the mold at a pressure in the range of from 40 to 80 kgf cm.sup.2 at the gate and at a flow velocity in the range of 0.08 to 0.20 m/second.

Abstract: A carbon fiber reinforced carbon of the present invention is composed of a sintered body comprising precursor carbonaceous fiber and self-sintering carbonaceous powder with the precursor carbonaceous fiber buried therein. Since the precursor carbonaceous fiber working as a reinforcement and the self-sintering carbonaceous powder working as a binder come to have substantially the same physical properties (strength, shrinkage rate and the like), the boudary adhesion between them improves, thereby giving the sintered body high strength and excellent abrasion resistance. When the precursor carbonaceous fiber is subjected to a surface treatment using a viscous material, the wettability of the surface of the precursor carbonaceous fiber increases, thereby further improving the boundary adhesion between the precursor carbonaceous fiber and the self-sintering precursor carbonaceous powder.

Abstract: Disclosed is a sliding member having a predetermined shape and including: a sintered body obtained by sintering a composite body including: preliminary carbonized carbonaceous fiber; inorganic powder or inorganic fiber; and self-sintering carbonaceous powder with the preliminarily carbonized carbonaceous fiber and the inorganic powder or the inorganic fiber buried therein. The sliding member has a high and stable friction coefficient (.mu.), high strength, excellent abrasion resistance, and is manufacturable at a low cost. Further, the friction coefficient (.mu.) and the other properties of the sliding member can be controlled depending on an application of a sliding member by selecting an optimum inorganic powder or inorganic fiber. Particularly, when boron compound powder is selected as the inorganic powder, the friction coefficient (.mu.) of the sliding member can be suppressed to 0.15 or less, and the load at seizure thereof can be improved to 100 kgf/cm.sup.2 or more.

Abstract: A liquid crystal optical device comprising a pair of substrates provided with electrodes and a layer containing a liquid crystal material sandwiched between the pair of substrates, wherein said layer is formed by irradiating light to a solution of a nematic liquid crystal material and a photo-curable vinyl compound selected so that the refractive index of the resulting cured product agrees to either the ordinary refractive index (n.sub.o) or the extraordinary refractive index (n.sub.e) of the nematic liquid crystal material used, or the refractive index (n.sub.x) of the nematic liquid crystal material when it is randomly oriented, held between the pair of substrates provided with electrodes, to cure the photo-curable vinyl compound and fix the resulting phase separation of the nematic liquid crystal material and the cured product.

Abstract: A liquid crystal optical device comprising a pair of substrates provided with electrodes and a layer containing a liquid crystal material sandwiched between the pair of substrates, wherein said layer is formed by irradiating light to a mixture of a liquid crystal material and a photo-curable compound selected so that the refractive index of the resulting cured product agrees to either the ordinary refractive index (n.sub.O) or the extraordinary refractive index (n.sub.e) of the liquid crystal material used, or the refractive index (n.sub.x) of the liquid crystal material when it is randomly oriented, held between the pair of substrates provided with electrodes, to cure the photo-curable compound and fix the resulting phase separation of the liquid crystal material and the cured product, wherein said layer has at least a portion optically oriented by applying a voltage to the portion across the substrates during the irradiation of light to cure the photo-curable compound.