Abstract: The two-cycle engine includes a piston capable of reciprocating along a cylinder, the piston being provided with piston rings; and a lubrication port provided in the cylinder, the lubrication port being used to supply a lubricant to a sliding surface of the cylinder on which the piston rings slide. Inter-ring spaces are provided, each inter-ring space being between adjacent piston rings. In addition, the two-cycle engine includes a controller used to adjust a lubrication period of lubricating from the lubrication port during movement of the piston toward a top dead center thereof, so that a period before an uppermost inter-ring space passing by the lubrication port is excluded from the lubrication period and a period in which at least part of a lowermost inter-ring space faces the lubrication port is included in the lubrication period.

Abstract: A piston ring is provided with a thermal spray coating that contains tungsten carbide and chrome carbide as a hard phase, and contains nickel as a metallic binder phase, and is characterized in that the thermal spray coating is formed by the spraying of a thermal spray powder that has been produced by means of a granulation sintering method, and that contains hard particles in which the mean particle diameter of the tungsten carbide has been adjusted by means of a BET method to fall within a range of not less than 0.15 ?m and not more than 0.45 ?m.

Abstract: A piston ring is provided with a thermal spray coating that contains tungsten carbide and chrome carbide as a hard phase, and contains nickel as a metallic binder phase, and is characterized in that the thermal spray coating is formed by the spraying of a thermal spray powder that has been produced by means of a granulation sintering method, and that contains hard particles in which the mean particle diameter of the tungsten carbide has been adjusted by means of a BET method to fall within a range of not less than 0.15 ?m and not more than 0.45 ?m.

Abstract: The two-cycle engine includes a piston capable of reciprocating along a cylinder, the piston being provided with piston rings; and a lubrication port provided in the cylinder, the lubrication port being used to supply a lubricant to a sliding surface of the cylinder on which the piston rings slide. Inter-ring spaces are provided, each inter-ring space being between adjacent piston rings. In addition, the two-cycle engine includes a controller used to adjust a lubrication period of lubricating from the lubrication port during movement of the piston toward a top dead center thereof, so that a period before an uppermost inter-ring space passing by the lubrication port is excluded from the lubrication period and a period in which at least part of a lowermost inter-ring space faces the lubrication port is included in the lubrication period.

Abstract: A device for tightening a bolt or a nut has a tightening socket which is releasable from biting engagement with the bolt or nut by disengaging a clutch in a rotation transmission system after completion of tightening, and which is made readily removable from the bolt or nut. The device is characterized in that it comprises power transmission means for coupling a socket drive motor to the socket for power transmission, the clutch incorporated in the power transmission means for selectively effecting or interrupting power transmission from the motor to the socket by a sliding movement, and clutch control means for selectively moving the clutch to an engaged position or a disengaged position. The clutch is moved to the disengaged position by the clutch control means after the motor is deenergized, whereby residual torque delivered by the motor to the bolt or the nut is removed to preclude biting engagement of the socket with the bolt or nut.

Abstract: A solar battery for a time piece comprises an insulated substrate; a plurality of generating regions arranged in a circular pattern around a single point on the insulated substrate, each region including a non-crystalline semiconductor film, and upper and lower electrodes on opposite sides of the film; and connecting layers for reducing the power loss of the battery, including overlapping side areas at surfaces between adjacent regions and overlapping perimeter areas at surfaces on the perimeter of adjacent regions, for joining the upper and lower electrodes of adjacent regions, respectively.

Abstract: In an amorphous silicon solar battery having a terminal portion in contact with a spring contact member so that the solar battery is connected to an external output conductor, the outer surface of the terminal portion is formed of a metal layer and an a-Si film lies between the metal layer and a transparent insulated substrate, the a-Si film being adjacent to the metal layer.

Abstract: A solar cell device in which short-circuiting between a connecting portion of a metal electrode and a transparent electrode of each cell unit is prevented. A plurality of cell units are formed by laminating a transparent electrode, an amorphous silicon layer and a metal electrode disposed on a common transparent substrate, with each two adjacent cell units being connected by an extension of the metal electrode which traverses an edge of the amorphous silicon layer of the cell unit and contacts the exposed extension of the transparent electrode of the adjacent unit. The edge of the amorphous silicon layer traversed by the extension of the metal electrode projects beyond the transparent electrode by a distance significantly greater than the distance between the edges of the amorphous silicon layer and the transparent electrode in the main portion of the cell unit.