Abstract: A centrifugal clutch intermittently transmits power of rotation about an axis. The centrifugal clutch includes: a plurality of clutch shoes that are pressed against an inner peripheral surface of a clutch drum; a plurality of pivot members configured to rotatably support the clutch shoes; and a pressing member having a plurality of insertion portions that are inserted between head portions of the pivot members and the clutch shoes. The pressing member has a connecting portion that connects between the plurality of insertion portions, and the insertion portions and the connecting portion are curved in a direction of the axis.

Abstract: A torsional vibration damper equipped clutch (20) for a combustion engine (E) includes a clutch drum (32), coupled with a cutter blade (3) through a drive shaft (6), a clutch shoe (34) connected with a crankshaft (16) of the combustion engine (E) and capable of being connected with the clutch drum (32) by the effect of a centrifugal force. The clutch (20) further includes a flywheel (18) fixed to the crankshaft (16) by means of a nut (19), and a holder (36) connected with the flywheel (18) for relative movement in a circumferential direction through a helical compression spring (50). The clutch shoe (34) is supported by the holder (36), and a stopper structure (56) is provided between the flywheel (18) and the holder (36) for transmitting a rotational force of the combustion engine (E) to the holder (36).

Abstract: A centrifugal clutch intermittently transmits power of rotation about an axis. The centrifugal clutch includes: a plurality of clutch shoes that are pressed against an inner peripheral surface of a clutch drum; a plurality of pivot members configured to rotatably support the clutch shoes; and a pressing member having a plurality of insertion portions that are inserted between head portions of the pivot members and the clutch shoes. The pressing member has a connecting portion that connects between the plurality of insertion portions, and the insertion portions and the connecting portion are curved in a direction of the axis.

Abstract: A top plate is provided in a top portion of a cylinder block of a combustion engine of a type, provided with a cooling fan, so as to lie perpendicular to a longitudinal axis of an engine cylinder. An intake side gasket interposed between the cylinder block and an intake unit is extended upwardly to contact the top plate to thereby seal a gap between the top plate and the intake side gasket. An exhaust side gasket interposed between the cylinder block and an exhaust unit is extended upwardly to contact the top plate to thereby seal a gap between the top plate and the exhaust side gasket. A cooling passage for passing therethrough a cooling air from the cooling fan is formed by the cylinder block, the top plate, the intake side gasket and the exhaust side gasket.

Abstract: A two-stroke cycle combustion engine of an air scavenging type includes one or more scavenging passages (13, 14) for communicating a crank chamber (2a) and a combustion chamber (1a) with each other, an air passage (10) for supplying an air (A), an introducing passages (16) for introducing the air (A) from the air passage (10) into an upper portion of each scavenging passage (13, 14) from a direction radially outwardly of a cylinder block (1), and a covering member (21) for covering the introducing passage (16) from an outer side. The covering member (21), the upper portion of each scavenging passage (13, 14) and a part of the introducing passage (16) are formed integrally with each other by a scavenging block (20).

Abstract: A torsional vibration damper equipped clutch (20) for a combustion engine (E) includes a clutch drum (32), coupled with a cutter blade (3) through a drive shaft (6), a clutch shoe (34) connected with a crankshaft (16) of the combustion engine (E) and capable of being connected with the clutch drum (32) by the effect of a centrifugal force. The clutch (20) further includes a flywheel (18) fixed to the crankshaft (16) by means of a nut (19), and a holder (36) connected with the flywheel (18) for relative movement in a circumferential direction through a helical compression spring (50). The clutch shoe (34) is supported by the holder (36), and a stopper structure (56) is provided between the flywheel (18) and the holder (36) for transmitting a rotational force of the combustion engine (E) to the holder (36).

Abstract: A top plate is provided in a top portion of a cylinder block of a combustion engine of a type, provided with a cooling fan, so as to lie perpendicular to a longitudinal axis of an engine cylinder. An intake side gasket interposed between the cylinder block and an intake unit is extended upwardly to contact the top plate to thereby seal a gap between the top plate and the intake side gasket. An exhaust side gasket interposed between the cylinder block and an exhaust unit is extended upwardly to contact the top plate to thereby seal a gap between the top plate and the exhaust side gasket. A cooling passage for passing therethrough a cooling air from the cooling fan is formed by the cylinder block, the top plate, the intake side gasket and the exhaust side gasket.

Abstract: A cylinder block for the two-cycle combustion engine includes a scavenging port open at an inner peripheral surface of the cylinder block so as to orient diagonally upwardly relative to a longitudinal axis of a cylinder bore and defined in the cylinder block in communication with a combustion chamber. This scavenging port is formed by cutting with the rotary cutting tool, then rotated about its own longitudinal axis, from an inner peripheral surface of the cylinder block.

Abstract: A cylinder block includes a scavenging passage, which extends between a combustion chamber and a crankcase chamber to communicate them together and has a scavenging port defined in the cylinder block so as to open at an inner peripheral surface of the cylinder block. An intake passage or exhaust passage, the scavenging passage including the scavenging port and a throughhole defined therebetween are formed by the use of a molding piece movable in a direction towards the fuel intake passage or exhaust passage and the throughhole is closed by a lid.

Abstract: To provide a two-stroke cycle combustion engine of an air scavenging type, in which not only can transit from the idling condition to the rapid accelerating condition take place smoothly, but the combustion engine can be smoothly started, there are provided scavenging passages (30, 31) for introducing an air/fuel mixture (M) and an air (A) into a combustion chamber (1a), a valve unit (51, 50) for adjusting the opening of each of an air passage (23) for supplying the air (A) to the scavenging passage (30) and an air/fuel mixture passage (24) for supplying the air/fuel mixture (M) to the scavenging passage (31), and an auxiliary air introducing passage (70) for introducing an auxiliary air to the air/fuel mixture passage (24) at a location downstream of the valve unit (51, 50) in the air/fuel mixture passage (24).

Abstract: A two-stroke cycle combustion engine of an air scavenging type includes one or more scavenging passages (13, 14) for communicating a crank chamber (2a) and a combustion chamber (1a) with each other, an air passage (10) for supplying an air (A), an introducing passages (16) for introducing the air (A) from the air passage (10) into an upper portion of each scavenging passage (13, 14) from a direction radially outwardly of a cylinder block (1), and a covering member (21) for covering the introducing passage (16) from an outer side. The covering member (21), the upper portion of each scavenging passage (13, 14) and a part of the introducing passage (16) are formed integrally with each other by a scavenging block (20).

Abstract: A portable air blower includes a blower fan, a drive unit for driving the blower fan, a casing for covering at least the blower fan and having a side wall with an air intake opening defined therein, and a covering unit for covering the air intake opening. The covering includes an air intake grille fitted to the casing and operable to permit an air to pass therethrough into the air intake opening, but to block foreign matters off therefrom, and a protective shroud held in overlapping relation with the air intake grille for covering the air intake grille on one side of the air intake grille opposite to the air intake opening. The air intake grille has an outermost area having a circumferential edge, which is positioned substantially radially inwardly of an outer peripheral edge of the protective shroud.

Abstract: A combustion engine includes a carburetor, which is a fuel supply device for introducing fuel into an intake air of the engine, and a fan housing for enclosing a cooling fan mounted on a front end portion of a crankshaft. The fan housing is formed with a flange so as to extend towards a position proximate to the carburetor, and a manually operable priming pump is fitted to the flange.

Abstract: To provide a two-stroke cycle combustion engine of an air scavenging type, in which not only can transit from the idling condition to the rapid accelerating condition take place smoothly, but the combustion engine can be smoothly started, there are provided scavenging passages (30, 31) for introducing an air/fuel mixture (M) and an air (A) into a combustion chamber (1a), a valve unit (51, 50) for adjusting the opening of each of an air passage (23) for supplying the air (A) to the scavenging passage (30) and an air/fuel mixture passage (24) for supplying the air/fuel mixture (M) to the scavenging passage (31), and an auxiliary air introducing passage (70) for introducing an auxiliary air to the air/fuel mixture passage (24) at a location downstream of the valve unit (51, 50) in the air/fuel mixture passage (24).

Abstract: An engine including first scavenging passages for fluidly connecting between a combustion chamber and a crank chamber through bearings for the crankshaft, second scavenging passages fluidly connecting directly between the combustion chamber and the crank chamber, a suction chamber formed in a side face of a piston. An air-fuel mixture is sucked into the suction chamber and an air is introduced into the crank chamber. During the intake stroke, the air-fuel mixture from the air-fuel mixture passage is introduced into the first scavenging passages through the suction chambers, and the air is introduced into the crank chamber. During the scavenging stroke, before the air-fuel mixture in the first scavenging passages is introduced into the combustion chamber, introduction of the air in the crank chamber into the combustion chamber through the second scavenging passages starts.

Abstract: A cylinder block for the two-cycle combustion engine includes a scavenging port open at an inner peripheral surface of the cylinder block so as to orient diagonally upwardly relative to a longitudinal axis of a cylinder bore and defined in the cylinder block in communication with a combustion chamber. This scavenging port is formed by cutting with the rotary cutting tool, then rotated about its own longitudinal axis, from an inner peripheral surface of the cylinder block.

Abstract: A cylinder block includes a scavenging passage, which extends between a combustion chamber and a crankcase chamber to communicate them together and has a scavenging port defined in the cylinder block so as to open at an inner peripheral surface of the cylinder block. An intake passage or exhaust passage, the scavenging passage including the scavenging port and a throughhole defined therebetween are formed by the use of a molding piece movable in a direction towards the fuel intake passage or exhaust passage and the throughhole is closed by a lid.

Abstract: A portable air blower includes a blower fan, a drive unit for driving the blower fan, a casing for covering at least the blower fan and having a side wall with an air intake opening defined therein, and a covering unit for covering the air intake opening. The covering includes an air intake grille fitted to the casing and operable to permit an air to pass therethrough into the air intake opening, but to block foreign matters off therefrom, and a protective shroud held in overlapping relation with the air intake grille for covering the air intake grille on one side of the air intake grille opposite to the air intake opening. The air intake grille has an outermost area having a circumferential edge, which is positioned substantially radially inwardly of an outer peripheral edge of the protective shroud.