Abstract: In an electrostatic sprayer, a pulsating voltage developed using a battery or a generator as a power supply is stepped up using a step-up transformer. A resultant high-voltage pulse is rectified and applied to an electrostatic electrode. A spray jetted from a spray nozzle is thus electrified. Herein, the step-up transformer is located near the spray nozzle. Owing to this structure, a high voltage produced by the step-up transformer can be applied to the electrostatic electrode with a loss minimized.

Abstract: An air-preintroduction type, two-stroke internal combustion engine which is capable of minimizing the quantity of blow-by, thus making it possible to improve the fuel consumption and to reduce the content of poisonous components in the exhaust gases, and is also capable of reasonably and compactly arranging the peripheral components of the engine, thereby making it possible to reduce the number of parts, to lighten the weight thereof, to save the manufacturing cost thereof, and to simplify the working and assembling thereof. The engine is characterized in that an air inlet passageway for introducing air into the scavenging passageways of the engine is provided at a mating face between the cylinder and the crankcase of the engine.

Abstract: The four-stroke cycle internal combustion engine for portable working machines, which employs a toothed belt in the power transmission mechanism thereof, is disclosed. There is provided an OHC type four-stroke cycle internal combustion engine including a power transmission mechanism disposed vertically along a cylinder portion for transmitting the rotation of a crankshaft to a camshaft, wherein the power transmission mechanism comprises intermediate transmission members linked to the camshaft through a toothed belt and a rotation speed transmission member for reducing the rotation speed from the crankshaft and for transmitting it to the intermediate transmission members.

Abstract: A disk cleaner includes a polishing member which is adapted to be rotated while being engaged with a surface of the disk, thereby to polish the surface of the disk. The polishing member is disposed such that the rotational axis of the polishing member is kept perpendicular to the surface of the disk, thereby to cause the disk to rotate in one direction due to a frictional force between the polishing member and the surface of the disk. The rotational axis of the polishing member is spaced apart from a rotational axis of the disk in the radial direction of the disk, whereby only part of the polishing member engages the surface of the disk.

Abstract: A disk cleaner includes a polishing member that is rotated while it is pressed against a surface of a disk to be polished to thereby polish the surface of the disk and an air cooling apparatus that cools the disk by causing outside air to flow along the surface of the disk. The air cooling apparatus is incorporated integrally with the disk cleaner. The cooling apparatus inhibits the peeling of the adhered surfaces as well as the generation of cracks of a DVD of a two-ply structure.

Abstract: A portable power working machine includes a small air-cooled internal combustion engine, a cooling fan, and a carburetor chamber housing therein an air cleaner. A dust-separating air duct is interposed between a region close to the cooling fan and the carburetor chamber housing, the dust-separating air duct being configured to separate dust included in an intake air from air by taking advantage of an air flow, thereby allowing clean air separated from the dust to be fed to the carburetor chamber housing and allowing the dust separated from the intake air to be sucked by the cooling fan.

Abstract: A four-stroke cycle internal combustion engine comprises a connecting rod which has an oil dipper at a big-end thereof, a crankcase, a partition wall which surrounds the connecting rod to provide a separation between the crankcase and an oil reservoir and an outer wall which is outward of and surrounds the partition wall and is connected to the partition wall at upper ends thereof so as to define the oil reservoir below the crankcase. A slit is formed in the partition wall below the connecting rod to allow the oil dipper to protrude into and be withdrawn from the oil reservoir to splash oil in the oil reservoir for lubrication by the oil dipper through a swinging motion of the connecting rod. The depth of the oil reservoir is shallower at least in a part of an outer edge area thereof than that below the oil dipper so that a tip of the oil dipper reaches the oil level even when the oil flows into the outer edge area of the oil reservoir.

Abstract: An engine intake control mechanism has a throttle valve that can be rotated to a cold-starting position in response to the closing movement of a choke valve and, even if the throttle valve is opened beyond the cold-starting position, the choke valve is retained at the cold-starting position. Only when the throttle valve is subsequently actuated to return to its original closed position is the choke valve automatically returned to its original opened position. The engine intake control mechanism is especially useful in top handle type portable power working machines, which are subject to undesirable movements of the throttle control lever on the top handle when the engine is being started.

Abstract: A portable power working machine has an L-shaped top handle having a top grip portion that extends longitudinally above and parallel to the top of a main housing and a rear coupling portion that extends along the rear portion of the main housing. A side handle has a front grip portion that is joined to and extends horizontally and laterally from the front end of the top grip portion of the top handle and a diagonal grip portion which curves out and down from the front grip portion and extends diagonally straight as viewed in side elevation from the front grip portion toward the lower end of the rear coupling portion of the top handle. A starting footstool contiguous to a lower end of the diagonal grip portion extends horizontally to the vicinity of and is joined to the lower end portion of the rear coupling portion of the top handle.

Abstract: A portable power working machine has an L-shaped top handle having a top grip portion that is attached to the front portion of the top of a main housing and extends longitudinally above and parallel to the top of the main housing and a rear coupling portion that is attached to the rear portion of the main housing. A side handle has a front grip portion that is connected directly to the front end of the top grip portion of the top handle and a diagonal grip portion that extends diagonally straight as viewed in side elevation from the front grip portion toward the lower end of the rear coupling portion of the top handle. The lower end of the diagonal grip portion of the side handle is connected directly to the rear coupling portion of the top handle.

Abstract: A hand-held power working machine in which the clipper blades thereof can be easily dismounted for the exchange or grinding thereof in a way that minimizes the possibility of damage to the power transmission device or the clipper blades in the course of such dismounting. Also, conventional integrated type clipper blades can be mounted thereon. The power working machine includes a working portion provided with a pair of clipper blades and a power transmission device for transmitting a reciprocating driving power to the working portion, wherein the power transmission device includes a pair of intermediate reciprocating driving plates which are couplingly interposed between a pair of reciprocating movement-guiding arms, to be driven by a driving rotor, and the pair of clipper blades.

Abstract: An air-fuel mixture generating device includes a main body equipped with a diaphragm-type fuel pump, a fuel injection valve attached to the main body, and a manual fuel pump attached to the main body for filling a fuel passageway with fuel when the diaphragm-type fuel pump is not operating. The manual fuel pump has an inlet port which communicates with the fuel passageway and a pressure-adjusting valve disposed at the inlet port of the manual fuel pump, thereby enabling it to act not only as an intake valve when the manual fuel pump is operated but also as a relief valve for allowing the fuel inside the fuel passageway to escape into a pump chamber of the manual fuel pump when the pressure of fuel inside the fuel passageway exceeds a predetermined pressure.

Abstract: A portable working machine provided with a centrifugal air blower, which is featured in that a prime mover (50) for driving the air blower (20) is mounted via a supporting coupling member (30) on a volute case (22) of the air blower (20) which is mounted in an upright state; and that an air inlet port of the air blower (20) is positioned on the side of the volute case (22) which is closer to the prime mover (50).

Abstract: An engine cutter which is simple in structure and low in manufacturing cost. This engine cutter comprises a disk cutter, an air-cooled internal combustion engine for rotating the disk cutter, a safety cover partially encasing the disk cutter, and a dust-trapping portion which is mounted on the safety cover for trapping and discharging dust to be generated from a cutting work by the disk cutter; and is characterized in that only single fan to be driven by the engine is provided not only for generating an air flow for sucking and discharging the dust that has been trapped in the dust-trapping portion but also for generating a cooling air flow for cooling the internal combustion engine.

Abstract: A chain saw guide bar has a pair of elongated chain guide plates, which are superimposed with each other and receive a saw chain. Positioning slots extend in the longitudinal direction of the guide plates and receive a pair of fixing stud bolts that project from the main body of the chain saw. A chain-tightening device, which is incorporated into the guide bar, includes a pulley carried by the guide plates in a fixed position distally of the guide slots. One end of a flexible wire is connected to the pulley. The other end of the flexible wire is connected to a circular ring that is slidably received between the guide plates with an opening thereof at least partly registering with the positioning slots. The ring is received on one of the fixing stud bolts. An intermediate portion of the wire is turned partway around a returning member that is stationarily located on a portion of the guide bar proximally of the fixing stud bolt that receives the ring.

Abstract: A dust collector-equipped power cutter includes a prime mover, a cutter, a dust-sucking fan, and a belt-driven power transmission mechanism for transmitting rotation from the prime mover to the cutting disk and to the dust-sucking fan. The belt-driven power transmission mechanism is constructed such that the rotation of the prime mover is transmitted through a single belt to a cutter-driving pulley for the cutting disk and to a fan-driving pulley for the dust-sucking fan.

Abstract: A two-stroke internal combustion engine having a Schnürle scavenging system includes a pair of first scavenging ports and a pair of second scavenging ports. An inner horizontal scavenging angle formed close to an exhaust port and an outer horizontal scavenging angle formed remote from the exhaust port by a pair of scavenging flows blown out of the pair of the first scavenging ports are both set to an angle in the range of from 116 to 124 degrees. An inner horizontal scavenging angle formed close to the exhaust port and an outer horizontal scavenging angle formed remote from the exhaust port by a pair of scavenging flows blown out of the pair of the second scavenging ports are set to angles in the ranges of from 126 to 134 degrees and from 146 to 154 degrees, respectively.

Abstract: A separate lubricating device for a two-stroke internal combustion engine provided with an air intake system and a controlling device includes an injector for injecting lubricating oil into a passage of the air intake system and a lubricating control device associated with the controlling device. The lubricating control device controls the timing and quantity of injection of the lubricating oil into the engine.

Abstract: A four-stroke cycle internal combustion engine is adapted to deliver oil mist from an oil reservoir to a cam chamber together with blow-by gas. It has an oil reservoir, a cam chamber, an oil dipper formed on a connecting rod for agitating oil in the oil reservoir to generate oil mist, a carburetor, and an oil separator provided between the cam chamber and the carburetor and for separating oil contained in oil mist from blow-by gas. The oil separator has a vertically extending first passage which communicates with the cam chamber at an upper end and communicates with the oil reservoir at a lower end and a second passage which communicates with the lower end of the first passage at one end and communicates with a venturi of the carburetor at the other end.

Abstract: A hand lever device for operating a driven member includes a main lever arranged to be pivoted about a first rotational axis, a sub-lever arranged to be pivoted about a second rotational axis and retained in a stationary state at a set pivoted position, a returning member arranged to be rotated about a third rotational axis, and a cable coupled at one end to the driven member and linked at the other end with the main lever and the returning member. When the main lever is pivoted to a set position, it rotates the returning member about the third rotational axis and removes slack from the cable. Pivoting of the sub-lever further rotates the returning member about the third rotational axis to a selected operating position. An accelerating subsidiary lever that is also pivoted about the first rotational axis further pulls, via the returning member, the cable, thereby to further move the driven member.