Abstract: A recoil starter wherein unidirectional rotating means is enabled to sustain a larger magnitude of torque, obviating the employment of parts which are high in mechanical strength, in rigidity and in working precision, thus making it possible to reduce the weight and the manufacturing cost thereof. The recoil starter includes a driving member, a driven member, and buffering/power-accumulating means interposed between the driving member and the driven member. The buffering/power-accumulating means is enabled, during the driving process, to accumulate the power supplied through the driving process while alleviating impact to the driven member. The accumulated power is subsequently employed to drive the driven member.

Abstract: A recoil starter includes a rotary driving member that is adapted to be rotated by pulling a recoil rope and an interlocking rotary member that is adapted to be rotated independently of the rotary driving member. A buffering spring is coupled between the rotary driving member and the interlocking rotary member. The buffering spring, which may be a torsion coil spring or a spiral spring, applies a rotational bias between the rotary driving member and the interlocking rotary member and is adapted to transmit the rotation of the rotary driving member to the interlocking rotary member.

Abstract: A starter that is capable of minimizing fluctuations in the pulling force of a starter rope so as to make it possible to perform a smooth pulling operation when starting an internal combustion engine includes a driving section (A), a driven section (B), and a buffering/power-accumulating device (15) interposed between the driving section (A) and the driven section (B).

Abstract: A recoil starter wherein unidirectional rotating means is enabled to sustain a larger magnitude of torque, obviating the employment of parts which are high in mechanical strength, in rigidity and in working precision, thus making it possible to reduce the weight and the manufacturing cost thereof. The recoil starter includes a driving member, a driven member, and buffering/power-accumulating means interposed between the driving member and the driven member. The buffering/power-accumulating means is enabled, during the driving process, to accumulate the power supplied through the driving process while alleviating impact to the driven member. The accumulated power is subsequently employed to drive the driven member.

Abstract: A portable power working machine which is provided with an internal combustion engine (20) and is designed to minimize the clogging of an air cleaner (31) attached to the air intake system of internal combustion engine (20). For this purpose, part of air introduced into the main housing (12) by means of the cooling fan (25) is allowed to be sucked again by the cooling fan, thereby enabling it to be recirculated through the carburetor chamber (40) and a circulating air duct (50) disposed outside the carburetor chamber (40), and at the same time, part of air introduced into the carburetor chamber (40) is allowed to be introduced from the air cleaner (31) into the internal combustion engine (20).

Abstract: A recoil starter includes a rotary driving member that is adapted to be rotated by pulling a recoil rope and an interlocking rotary member that is adapted to be rotated independently of the rotary driving member. A buffering spring is coupled between the rotary driving member and the interlocking rotary member. The buffering spring, which may be a torsion coil spring or a spiral spring, applies a rotational bias between the rotary driving member and the interlocking rotary member and is adapted to transmit the rotation of the rotary driving member to the interlocking rotary member.

Abstract: A debris entry preventing member A of an air-cooled type internal combustion engine E is made of a flexible sheet material as a whole and includes a mounting portion 7 to be mounted on a mounting component 15, which will be attached to the internal combustion engine E, and a debris capturing portion 4 having a multiplicity of ventilation holes 5. When the mounting component 15 is attached to the internal combustion engine E, the debris entry preventing member A is mounted thereon together with the mounting component 15 so that the debris capturing portion 4 covers a cooling air intake port 11. As a result, a job for mounting the debris entry preventing member can be easily carried out, no screws and the like are needed for mounting it, the debris entry preventing member can be easily manufactured and its cost can be reduced.

Abstract: To avoid stalling of a two-stroke internal combustion engine as its orientation is changed upon a change of direction in which a working machine such as a chain saw is held, non-atomized fuel is prevented from flowing precipitously into the combustion chamber of the engine. The engine comprises a crank case forming a crank chamber which has an intake port opening into the crank chamber, and a flow control feature at the circumferential inner surface of the crank chamber in the vicinity of the intake port for retarding flow of non-atomized fuel.

Abstract: An air path is provided in the main body of a chain saw so as to connect an air inlet port provided on the main body and a carburetor chamber of the internal combustion engine and also connected to a cooling fan chamber. For use under normal conditions, combustion air is taken from the air inlet port into the carburetor chamber. In case of a rainy or snowy day, the air inlet port is closed and combustion air is taken from the cooling chamber into the carburetor chamber, air control means is provided between the air path and the cooling fan chamber. This air control means generates stagnation of air flow in the cooling chamber in order to supply air into the carburetor chamber and prevent dust and the like from being taken into the air path.

Abstract: An adiabatic intake insulator inserted into a portion for connecting a carburetor to a small two-cycle gasoline engine or the like in which the generation of cracks due to stress concentration when bolts are fastened are restrained and the looseness of the fastening member due to the shortage of fastening torque is prevented. The intake insulator comprises: portions for supporting and securing a carburetor; an intake passage through which air-fuel mixture from the carburetor is introduced to the engine; portions for securing the intake insulator to the engine each comprising a through hole for a bolt and a counterbore for accommodating a head of the bolt; and a channel formed on a circumference of a bottom of the counterbore.

Abstract: The prime mover of a chain saw has an output shaft passing through the body of an oil pump. A fixing screw is inserted through an inserting hole provided in the body and is screwed into a threaded hole provided on the side of the prime mover. A cover plate, covering the area tip of the output shaft, is press fit onto the output shaft. The inserting hole is made as a threaded hole having a diameter through which the fixing screw is freely insertable but is also adapted to receive a removing screw which is larger in diameter than the fixing screw, and which abuts against the side of the prime mover. As a result, the inserting hole can be used in common also as the oil pump removing screwed hole and no extra removing screwed hole is required to be provided.