Abstract: An air supply device (1) of a stratified scavenging two-cycle engine includes: a mixture passage (40) that penetrates a carburetor (2) and an insulator (3), the mixture passage being provided by a carburetor-side mixture passage (8) and an insulator-side mixture passage (21); a air passage (41) that is provided by a carburetor-side air passage (9) and an insulator-side air passage (22); a throttle valve (13) provided in a single bore (4) of the carburetor (2), the throttle valve(13) being provided by a butterfly valve that rotates in conjunction with a throttle operation; and a flow rate regulator (28) provided inside the air passage (41), the flow-rate regulator (28) bulging inward in the air passage (41). At least a part of a periphery of a valve body (17) of the throttle valve is close to the flow-rate regulator (28) until the valve body (17) is rotated from an initial position corresponding to an idling speed at a predetermined rotation angle.

Abstract: A throttle cable locking assembly (16) for a power tool (1), in which the power tool (1) includes a source of power (2) having an internal combustion engine, a machine implement (4) engaged to the source of power (2), and a throttle handle (6) connected to the internal combustion engine for regulating power supply to the machine implement (4). The throttle cable locking assembly (16) includes: a cable assembly (18), the cable assembly (18) including a throttle cable (20) extending from the internal combustion engine, an outer cable (30) extending from the internal combustion engine and enclosing a portion of the throttle cable (20), and an engagement member (36) carried by a first end portion of the outer cable (30); and an adjuster bolt capable of being engaged with the engagement member (36) provided on the first end of the outer cable (30). A locking case (48) is provided for securing one end of the adjuster bolt and a portion of the engagement member (36).

Abstract: The present invention relates to a switch device (100) for use in hand-held power tools. The switch device (100) may include at least one chamber (102) whose interior serves as an accommodation space. The chamber (102) may partially encase an operational member (104) for actuating the hand-held power tool through the switch device (100). Further, the switch device (100) is provided with multiple holes (202) on side walls (204) of the chamber (102) to create a passageway for external particulate materials. Also, a bottom surface (205) of the chamber (102) may be sloped to extend from an interior of the chamber (102) to each of the multiple holes (202), to enhance the discharging of the external particulate materials through the holes (202).

Abstract: In a carburetor (1) including a choke valve (7) on the upstream side inside an aspiration passage (3) and a throttle valve (8) on the downstream side, the valves (7) and (8) are disposed at positions such that the valves adjacently oppose each other when having been turned to be in the fully open state, a bulging part (11) that bulges toward the region (A1) between the adjacently opposing valves (7) and (8) is integrally provided inside a venturi (9), and the aspiration passage (3) is divided into an air-fuel mixture passage (4) located on the side where a main jet (10) is provided and an air passage (5) through which leading air circulates by the bulging part and the valves (7) and (8), both of which are in the fully open condition.

Abstract: An engine blower includes: an engine; a fan that is rotated by the engine; a volute case that houses the fan therein and includes an air intake port; and a sponge cover with which an exterior of the air intake port of the volute case is covered.

Abstract: A two-cycle engine having a structure in which the shaft center Ccy of the cylinder 3 is offset onto the exhaust port 32 side with respect to the rotational center Ccr of the crankshaft 4, and the offset amount S of the shaft center Ccy with respect to the rotational center Ccr is set greater than 1 mm and less than 6 mm. Furthermore, in this case, the center of gravity of the counterweight 42 of the crankshaft 4 is shifted onto the rear side in the rotational direction with respect to the line passing the rotational center Ccr of the crankshaft 4 and the center Ccp of the crank pin 41.

Abstract: A stratified scavenging two-stroke engine includes: a crankcase (2); a cylinder (3) being provided with a cylinder bore (31); an intake passage (4) supplying air-fuel mixture into the crankcase (2) via an intake port (4A); a scavenging passage (5) supplying the air-fuel mixture from the crankcase (2) into the cylinder bore (31) via a scavenging port (5A); a leading-air passage (6) supplying leading air into the scavenging passage (5); and an exhaust passage (7) being disposed on an opposite side of the intake passage (4) with the cylinder bore (31) interposed therebetween, the exhaust passage (7) discharging exhaust gas via an exhaust port, in which the scavenging passage (5) includes a main passage (51) provided near the exhaust port and a sub passage (52) provided near the intake port (4A), the main passage (51) and the sub passage (52) are isolated from each other by a partition (25, 34) that extends over substantially an entire length of the main passage (51) and the sub passage (52), the sub passage (52)

Abstract: A cooling fan includes: a hub; a plurality of cooling vanes provided along an outer circumference of the hub; and an annular connector for connecting the cooling vanes. The hub is provided with a through hole that axially penetrates the hub. A first cover on a case for covering an outward side of the cooling fan is provided with a first outer-air intake. A second cover for partitioning between the cooling fan and a crankcase and for covering an inward side of the cooling fan is provided with a second outer-air intake. With this arrangement, even when one outer-air intake (for instance, the first outer-air intake) adjacent to where the cooling vanes are provided is clogged by a large amount of dust generated during operations, the cooling vanes can breathe from the non-clogged other outer-air intake (for instance, the second outer-air intake) through the through hole, thereby restraining reduction in air flow.

Abstract: A stratified scavenging two-stroke engine includes: a crankcase (2); a cylinder (3) being provided with a cylinder bore (31); an intake passage (4) supplying air-fuel mixture into the crankcase (2) via an intake port (4A); a scavenging passage (5) supplying the air-fuel mixture from the crankcase (2) into the cylinder bore (31) via a scavenging port (5A); a leading-air passage (6) supplying leading air into the scavenging passage (5); and an exhaust passage (7) being disposed on an opposite side of the intake passage (4) with the cylinder bore (31) interposed therebetween, the exhaust passage (7) discharging exhaust gas via an exhaust port, in which the scavenging passage (5) includes a main passage (51) provided near the exhaust port and a sub passage (52) provided near the intake port (4A), the main passage (51) and the sub passage (52) are isolated from each other by a partition (25, 34) that extends over substantially an entire length of the main passage (51) and the sub passage (52), the sub passage (52)

Abstract: An air supply device (1) of a stratified scavenging two-cycle engine includes: a mixture passage (40) that penetrates a carburetor (2) and an insulator (3), the mixture passage being provided by a carburetor-side mixture passage (8) and an insulator-side mixture passage (21); a air passage (41) that is provided by a carburetor-side air passage (9) and an insulator-side air passage (22); a throttle valve (13) provided in a single bore (4) of the carburetor (2), the throttle valve(13) being provided by a butterfly valve that rotates in conjunction with a throttle operation; and a flow rate regulator (28) provided inside the air passage (41), the flow-rate regulator (28) bulging inward in the air passage (41). At least a part of a periphery of a valve body (17) of the throttle valve is close to the flow-rate regulator (28) until the valve body (17) is rotated from an initial position corresponding to an idling speed at a predetermined rotation angle.

Abstract: The present invention relates to an air supply apparatus for a two-stroke stratified scavenging combustion engine. The air supply apparatus includes an air cleaner having an air outlet and a partition, such that the partition substantially divides the air outlet into a first section and a second section. The air supply apparatus further includes a carburetor. The carburetor includes a passage, a throttle valve and a choke valve, such that the throttle valve and the choke valve substantially divides the passage into an air portion and a mixture portion. Further, a first aperture in communication with the first section of the air outlet is provided corresponding to the air portion, and the second aperture in communication with the second section of the air outlet is provided corresponding to the mixture portion. Moreover, an area of the first section is different from that of the second section.

Abstract: A throttle cable locking assembly (16) for a power tool (1), in which the power tool (1) includes a source of power (2) having an internal combustion engine, a machine implement (4) engaged to the source of power (2), and a throttle handle (6) connected to the internal combustion engine for regulating power supply to the machine implement (4). The throttle cable locking assembly (16) includes: a cable assembly (18), the cable assembly (18) including a throttle cable (20) extending from the internal combustion engine, an outer cable (30) extending from the internal combustion engine and enclosing a portion of the throttle cable (20), and an engagement member (36) carried by a first end portion of the outer cable (30); and an adjuster bolt capable of being engaged with the engagement member (36) provided on the first end of the outer cable (30). A locking case (48) is provided for securing one end of the adjuster bolt and a portion of the engagement member (36).

Abstract: Since a throttle hole for narrowing a scavenging passage is provided on a partition for closing the scavenging passage, the throttle hole of a desired size can be drilled at a desired location on the partition after preparing the scavenging cover having no throttle hole on the partition. Accordingly, the size and location of the throttle hole can be easily changed in conducting a test for finding the most appropriate size and location of the throttle hole, so that the most appropriate size and location of the throttle hole can be easily found.

Abstract: The present invention relates to a switch device (100) for use in hand-held power tools. The switch device (100) may include at least one chamber (102) whose interior serves as an accommodation space. The chamber (102) may partially encase an operational member (104) for actuating the hand-held power tool through the switch device (100). Further, the switch device (100) is provided with multiple holes (202) on side walls (204) of the chamber (102) to create a passageway for external particulate materials. Also, a bottom surface (205) of the chamber (102) may be sloped to extend from an interior of the chamber (102) to each of the multiple holes (202), to enhance the discharging of the external particulate materials through the holes (202).

Abstract: An air supply device (2) used in a two-stroke engine includes: an insulator (14) having an insulator mixture passage (17) that is in communication with an intake port (5A) provided in an engine body (1) of the two-stroke engine, the insulator being attached to the engine body (1); a carburetor (15) having an insulator mixture passage (17) that is in communication with an insulator mixture passage (17), the carburetor (15) being attached to the insulator (14); an air cleaner (16) having a mixture-side opening (25) that is in communication with the carburetor mixture passage (19), the air cleaner (16) being attached to the carburetor (15); an accumulating portion (29) that accumulates a blow-back fuel returned through the mixture-side opening 25, the accumulating portion (29) being provided inside the air cleaner (16); and an auxiliary passage having a base end connected to the accumulating portion (29) and a distal end connected to a portion affected by a pressure fluctuation inside a crankcase chamber provide

Abstract: An engine blower includes: an engine integrated with a volute for driving a fan; a ventilation tube communicated with the volute; and a handle mounted to the ventilation tube. In the engine blower, the handle has a pair of cases that are assembled with each other, and a conductive resin layer is formed on a surface of a grip of the handle. The resin layer is integrated with gates exposed within the handle. A conductive spring having a coil compressed in a direction in which the cases are assembled with each other and a cable that is electrically coupled with the engine are disposed within the handle. The gate of the resin layer is brought into contact with the coil of the spring and is electrically coupled with the cable via the spring.

Abstract: An engine blower includes a blower having a fan accommodated in a volute case, and an engine having a volute for generating a cooling air for self-cooling. An output shaft of the engine is provided with the fan without attaching a cooling fan for generating the cooling air. An outlet port for delivering a part of a blowing air generated by the fan is provided on the volute case.

Abstract: A muffler includes a muffler body in which a muffler chamber is formed by a base, a cover, and a baffle accommodated in the muffler chamber and disposed in the vicinity of the exhaust gas entry port of the muffler body. A guide portion which changes flow of an exhaust gas that enters from the exhaust gas entry port is integrally provided to the baffle by cut-and-raise of a portion of the baffle.

Abstract: A chain saw as a portable work machine includes: a body in which an engine is accommodated; a carburetor accommodated in a top handle for generating air-fuel mixture to be supplied to the engine; an air cleaner provided on a lateral side of the body; and an intake communication passage that intercommunicates between the air cleaner and the carburetor.