Abstract: In a tire, a tread includes a cap layer forming a part of an outer surface of the tire, a base layer disposed inwardly of the cap layer in a radial direction, and an intermediate layer disposed between the cap layer and the base layer in the radial direction. A loss tangent of the intermediate layer at 30° C. is less than a loss tangent of the cap layer at 30° C. and a loss tangent of the base layer at 30° C. is less than the loss tangent of the intermediate layer at 30° C. The tread includes at least two three-layer body portions formed of the cap layer, the intermediate layer, and the base layer, and at least one two-layer body portion that is formed of the cap layer and the base layer and disposed between a first three-layer body portion and a second three-layer body portion.

Abstract: A tire having a tread portion, wherein the tread portion can include a pair of shoulder circumferential grooves, a pair of crown circumferential grooves, and a pair of middle land portions. Each middle land portion can include a plurality of middle sipes. Each middle sipe can have a chamfered portion at at least one of sipe edges on both opposite ends thereof. The chamfered portion can extend from the crown circumferential groove to the shoulder circumferential groove. A first chamfered width of the chamfered portion at a first one of the opposite ends on a crown circumferential groove side can be greater than a second chamfered width of the chamfered portion at a second one of the opposite ends on a shoulder circumferential groove side.

Abstract: In a tire, a tread includes a cap layer forming a part of an outer surface of the tire, a base layer disposed inwardly of the cap layer in a radial direction, and an intermediate layer disposed between the cap layer and the base layer in the radial direction. A loss tangent of the intermediate layer at 30° C. is less than a loss tangent of the cap layer at 30° C. and a loss tangent of the base layer at 30° C. is less than the loss tangent of the intermediate layer at 30° C. The tread includes at least two three-layer body portions formed of the cap layer, the intermediate layer, and the base layer, and at least one two-layer body portion that is formed of the cap layer and the base layer and disposed between a first three-layer body portion and a second three-layer body portion.

Abstract: A tire includes a tread portion including first and second tread edges, circumferential grooves, and land portions. The land portions include a crown land portion, a first middle land portion, and a second middle land portion. Under a 50% loaded condition, the first middle land portion, the crown land portion, and the second middle land portion respectively have axial widths W1m, Wc, and W2m of ground contact surfaces, the widths satisfying the following formula, W1m>Wc>W2m. The crown land portion includes an outer ground contact surface and an inner ground contact surface. The outer ground contact surface and the inner ground contact surface respectively have widths Wco and Wci in the tire axial direction, the widths satisfying the following formula, Wco>Wci.

Abstract: A masking sound outputting device includes: an inputting unit which receives a picked-up sound signal relating to a picked-up sound; an extracting unit which extracts an acoustic feature amount of the picked-up sound signal; an instruction receiving unit which receives instructions for starting an output of a masking sound; and an outputting unit which, in the case where the instruction receiving unit receives the instructions for starting an output, outputs a masking sound corresponding to the acoustic feature amount extracted by the extracting unit.

Abstract: A masking sound outputting device includes: an inputting unit which receives a picked-up sound signal relating to a picked-up sound; an extracting unit which extracts an acoustic feature amount of the picked-up sound signal; an instruction receiving unit which receives instructions for starting an output of a masking sound; and an outputting unit which, in the case where the instruction receiving unit receives the instructions for starting an output, outputs a masking sound corresponding to the acoustic feature amount extracted by the extracting unit.

Abstract: A tire 1 has a plurality of land rows including a center land row C having a plurality of center blocks 50C defined by center lug grooves 40C, and a side land row S having a plurality of side blocks 50S defined by side lug grooves 40S. The tire has (RG1W/RG2W)/(L2/L1) in a range from 0.6 to 1.12 in a state where the tire is in contact with a road surface. ‘L1’ is the greatest ground contact length of the center land row in the tire circumferential direction, ‘L2’ is a ground contact length of the side land row in the tire circumferential direction along a center thereof in the tread width direction, ‘RG1W’ is a width of the center lug groove, and ‘RG2W’ is a width of the side lug groove.

Abstract: A pneumatic tire 1 according to the present invention is summarized as, in a carcass line 5C passing through the center of the carcass layer 5, an outer carcass line 5C-1 extending from a position M where a width TW of the tire is maximum along an outer side in the radial direction of the tire extends along a natural equilibrium profile curve having a shape achieved when a tension in the carcass layer 5 is balanced when the tire mounted on a standard rim is inflated to a standard inner pressure, and a belt normal-line distance BL and a tread normal-line distance TL in a cross over area is constant or becomes shorter from a tire equatorial line CL toward an outside in a tread width direction, the crossover area being an area between the tire equatorial line CL and a lamination end D.

Abstract: There is provided a portable air blowing working machine capable of obviating frequent operation for the maintenance of air cleaner and hence capable of improving working efficiency. This working machine includes an internal combustion engine having the air cleaner disposed in the air-intake system thereof, and an air blower to be rotationally driven by the engine; which is characterized in that the air cleaner is provided with a suction port for in drawing in external air, with a filter member for cleaning air drawn from the suction port to thereby permit the cleaned air to be introduced into the engine, and with a discharge port for enabling part of the air drawn from the suction port to be discharged out of the air cleaner without permitting part of the air to pass through the filter member; and that an air flow directed to flow from the suction port to the discharge port is permitted to generate inside the air cleaner by making use of the suction force of the air blower.

Abstract: There is provided a portable air blowing working machine capable of obviating frequent operation for the maintenance of air cleaner and hence capable of improving working efficiency. This working machine includes an internal combustion engine having the air cleaner disposed in the air-intake system thereof, and an air blower to be rotationally driven by the engine; which is characterized in that the air cleaner is provided with a suction port for inhaling external air, with a filter member for cleaning air inhaled from the suction port to thereby permit the cleaned air to be introduced into the engine, and with a discharge port for enabling part of the air inhaled from the suction port to be discharged out of the air cleaner without permitting part of the air to pass through the filter member; and that an air flow directed to flow from the suction port to the discharge port is permitted to generate inside the air cleaner by making use of suction force of the air blower.

Abstract: The present invention provides a chain saw having a high degree of safety for its various positions including an upward and a downward position. The chain saw comprises a bar-shaped top handle extending in a lengthwise direction above an upper surface of a main body and a bar-shaped side handle provided next to a left side surface of the main body. When the main body is seen in a plan view, a front end portion of the side handle is intersected transversely with and coupled to a left side surface of a front end portion of the top handle. A right-side support surface extending outwardly in the transverse direction is provided on a right side surface of the front end portion of the top handle. It is located substantially at the same position as a left-side support surface which is comprised of a rear surface of the front end portion of the side handle in the lengthwise direction of the main body.

Abstract: An air cleaner includes a cylindrical cleaning filter, and a case rotatably receiving the cleaning filter therein. A dust-removing brush is disposed to contact with a filter portion of the cleaning filter, and a manipulating device coupled to the cleaning filter and accessible from outside the case enables the cleaning filter to be rotated from outside of the case.

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: A protruding part is provided on the outer periphery of a recoil drum and a movable member is provided to move conjointly with a slide switch S used for starting and stopping an internal combustion engine equipped with an electric spark ignition system. The protruding part contacts the movable member only when the slide switch S is moved toward the OFF-state position. A warning signal generating means is provided and is actuated when the movable member 11 contacts with the protruded part 3a.

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: A chain saw provided an internal combustion engine having a recoil-type starter. The chain saw has a step provided on the machine frame of the chain saw and adapted to be stepped down by at least a portion of the user's foot when the user operates the starter for starting the engine.

Abstract: A power work-machine having a clutch drum of a centrifugal clutch provided on one end of the output shaft has a plurality of peripheral notches formed on its axially extended outer end portion and a dog clutch provided on the drive shaft of a work-machine attachment has clutch claws engaging with the individual peripheral notches.

Abstract: A power working machine having a main body case in which a prime mover is housed, a front handle and a rear handle which handles are gripped by the operator. The front handle has a flat cross-sectional shape reduced in thickness in a direction in which the front handle faces the main body case while being increased in width generally in the longitudinal direction of the machine body.

Abstract: A portable powered working machine such as a chain saw has a casing, a hollow grip formed integrally with the casing and extending from a front portion to a rear portion of the upper wall of the casing. An internal combustion engine is disposed in the casing such that its crankshaft extends transversely of the casing, the internal combustion engine having a cylinder arranged horizontally in a rear portion of the casing and a crankcase disposed in a front portion of the casing. A carburetor is disposed on a front side of the crankcase, while an air cleaner disposed in a rear portion of the grip. A communication pipe extends through the grip portion in the longitudinal direction thereof and connected between the air cleaner and the carburetor so as to form an air passage.