Abstract: A hand lever apparatus is mountable on a working machine for controlling operation of the working machine. The hand lever apparatus includes a main lever and a magnitude-magnifying mechanism. The magnitude-magnifying mechanism includes a pivot pin, a lever member pivotal about the pivot pin, a pulley, and a connecting cable. The lever member has a shorter arm portion and a longer arm portion, which opposes the shorter arm portion and is operatively connected to a throttle cable of a throttle valve of the working machine. The shorter arm portion is operatively connected to the main lever via the connecting cable so that actuation of the finger-manipulable portion pivots the lever member about the pivot pin and causes the longer arm portion to pull the throttle cable away from the throttle valve and open the throttle valve of the working machine from a minimum-opening idling state.

Abstract: A trimming machine includes a centrifugal clutch for transmitting power from an internal combustion engine to a cutting blade. A manually operated throttle lever controls an output from the internal combustion engine by adjusting an opening of a throttle valve via a throttle wire. A friction member arranged to oppose to a clutch drum of the centrifugal clutch. A first swinging member is connected to the friction member and swings between a braking position to be pressed against the clutch drum and a releasing position to be spaced from the clutch drum. A second swinging member is connected to a connecting point at an intermediate portion of the throttle wire and pivots about a pivoting pin thereof with respect to the first swinging member when the throttle wire is moved by operating the throttle lever.

Abstract: A muffler for an internal combustion engine has a vertically elongated expansion chamber into which an exhaust gas from the exhaust port of internal combustion engine is introduced. The expansion chamber is separated level-wise into a first expansion chamber and a second expansion chamber by a partition plate. An exhaust emission purifier formed of an oxidation catalyst is attached to the partition plate, thereby allowing the exhaust gas ejected from the exhaust port to be introduced into the second expansion chamber from the first expansion chamber via the exhaust emission purifier. The exhaust emission purifier is spaced apart from the exhaust port by a predetermined distance in a direction orthogonal to an ejecting direction of the exhaust gas.

Abstract: A separate lubricating device for an internal combustion engine includes a lubricating oil injection nozzle for injecting a lubricating oil into a passage of an air intake system and an electric deliverer for delivering a lubricating oil from an oil tank to the lubricating oil injection nozzle. The electric deliverer is positioned remotely from the lubricating oil injection nozzle. The electric deliverer may, to special advantage, be housed inside the oil tank.

Abstract: A power cutter which comprises a main body provided with a motor, a work-cutting portion including a circular cutting blade to be rotated by the motor and a safety cover covering both sides of an edge portion of the cutting blade so as to form a dust-discharging passageway, a fan attached to the safety cover for sucking and removing dust generated during cutting operations through the dust-discharging passage, a barrier wall attached to the safety cover so as to intercept the dust-discharging passageway, and a main dust-sucking port and a supplementary dust-sucking port disposed respectively in front of and behind the barrier wall as viewed in the rotational direction of the cutting blade.

Abstract: A loop scavenge two-cycle internal combustion engine that includes a partial wall partition disposed between a scavenging path and a cylinder bore, with a cooling port formed in the partial wall partition for enabling fresh gas in the scavenging path to contact directly with a peripheral wall of a piston in the cylinder. The fresh gas in the scavenging path directly contacts and efficiently cools the peripheral surface of the piston to prevent heat rise and distortion within the engine. The partial wall partition and cooling port maximize both cooling efficiently and cylinder strength and durability.

Abstract: A two-stroke internal combustion engine having a crankcase provided with a crank chamber, a suction port which opens to the crank chamber, a scavenging passage opening into the crank chamber, and a crankshaft is provided with a flow control surface formed on an inner peripheral wall portion of the crank chamber which is capable of retarding the flow rate of unatomized raw fuel and which extends from the vicinity of the suction port to the vicinity of the scavenging passage. The flow control surface is comprised of a large number of intersecting unit ribs.

Abstract: A hand-lever device for a trimmer has a rotatably-operated main lever for operating a cable which is coupled to a driven member. A pulling stroke amplifying mechanism for amplifying the stroke of the cable pulled by the main lever is provided between the main lever and the cable. The pulling stroke amplifying mechanism is provided with a wire attaching portion to which a wire for pulling and releasing a cutter braking device is attached.

Abstract: A double-chamber tank comprising; a first storage tank and a second storage tank, which are partitioned by a partitioning wall integrally formed therewith; wherein the first storage tank, the second storage tank and the partitioning wall are constituted by a first split counterpart and a second split counterpart, both splitting the first storage tank, the second storage tank and the partitioning wall into one of upper and lower sections, right and left sections, or fore and rear sections; and wherein both of the first split counterpart and second split counterpart are molded by means of an injection molding method, and are bonded with each other through a bonding between a joining edge of the first split counterpart and a joining edge of the second split counterpart, which is effected by means of a vibration welding.

Abstract: A four-stroke cycle internal combustion engine, having a crankcase. A connecting rod is provided in the crankcase. An inner wall extends to surround all sides and the bottom of the connecting rod. An outer wall extends to surround the inner wall. The upper ends of the outer wall are connected to the inner wall to form an oil reservoir under the crankcase and oil recess areas on both sides of the crankcase therebetween. An oil dipper for splattering the oil contained in the oil reservoir is provided at the big end of the connecting rod. A slit is formed at a bottom of the inner wall for allowing the oil dipper to go though to make contact with the oil.

Abstract: A portable air-blowing working machine includes a prime mover and an air-blowing system. The air-blowing system incorporates first-stage and second-stage centrifugal air-blowing sections, which are rotatably driven by an output shaft of the prime mover and are interconnected by an air-blowing passage for delivering air discharged from the first-stage air-blowing section to the intake of the second-stage. In operation, external air is drawn into the first-stage air-blowing section, increased therein in velocity and pressure, and then continuously discharged via the air-blowing passage to the second-stage air-blowing section, where the air is further accelerated and compressed before being finally discharged to the atmosphere.

Abstract: A handling device for a power working machine provided rotatably with a rear handle portion, wherein the handling device is constructed such that the rotation of the rear handle portion is always locked whenever the throttle lever for actuating control member of the prime mover is manipulated, and such that, when the rotation of the rear handle portion is once engaged and fixed, a locking mechanism is actuated to lock the rotation of the rear handle portion. The handling device comprises a throttle lever, attached rotatably to the device and designed to actuate a control member of the prime mover, and a handle-engaging member, designed to be engaged with a mount base of the handling device so as to lock the rotational position of the handling device relative to the mount base.

Abstract: A power working machine has a noise level display device which enables the noise level of the machine to be easily recognized with the naked eyes. When compressed air that is pressurized and delivered by a blower fan is delivered to an air-ejecting pipe, a noise level proportional to the magnitude of the force of the ejected air flow is indicated by the noise level display device, which is mounted on the air-ejecting pipe.

Abstract: A brake device disposed in the vicinity of a clutch drum has a leaf spring having a brake pad thereon which is brought into slidable contact with the clutch drum. A cam member and a compression coil spring which opposes a cam member with the leaf spring disposed therebetween are provided on a free end of the leaf spring. The cam member is rotated by a rotatable shaft together with a pinion gear which meshes with a rack formed on a stand. When a trimmer is placed on the ground, the stand is moved upwardly and the brake pad is brought into the braking position where the brake pad slidably contacts with the clutch drum. This braking position is released when an operation lever is operated by an operator.

Abstract: A four-stroke cycle internal combustion engine allowing simplified assembly, high productivity, and still high precision in assembly is made up of a crankshaft; a camshaft; a gear train for transmitting the rotation of the crankshaft to the camshaft; and a housing block. The housing block includes a cylinder portion with the gear train disposed in a longitudinal direction along the cylinder portion. The housing block further includes a bearing portion for supporting the crankshaft, an upper outer wall portion extending vertically downward from the cylinder portion to the bearing portion and a longitudinally oriented gear case for housing the gear train. The housing block is divided into a cylinder block main body part and a cylinder block lower part at the bearing portion of the crankshaft. The cylinder block body portion includes an integrally formed cylinder portion, upper outer wall portion and gear case.

Abstract: A portable trimmer has a supporting tube extending straight forward from an engine at its rearward end to a cutting device at a forward end. A handle-bar is mounted on a middle portion of the supporting tube at an intersecting point. First and second grips extend upwardly from two corresponding ends of the handle-bar. The handle-bar has a first portion extending from an intersecting point to the first grip, and a second portion extending from the intersecting point to the second grip. The first portion extends across a width of an operator's body, and is bent in a rearward direction. The supporting tube has an inclination with respect to a phantom line connecting the first and second grips such that said cutting device is located in front of a center of the operator's body when the operator holds the grips in a natural posture. This portable trimmer increases the area in which weeds can be cut in a single movement, and provides for easy handling.

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: A portable air-blowing working machine includes a prime mover and an air-blowing system. The air-blowing system incorporates first-stage and second-stage centrifugal air-blowing sections, which are rotatably driven by an output shaft of the prime mover and are interconnected by an air-blowing passage for delivering air discharged from the first-stage air-blowing section to the intake of the second-stage air-blowing sections. The inlet portions of the air-blowing passage are respectively positioned at the outer circumferential portion of a volute chamber of the first air-blowing section, and the outlet portion of the air-blowing passage is positioned near the air-intake port of the secondary air-blowing section.

Abstract: A braking device of a portable trimmer according the present invention comprises a cylindrical brake drum portion provided around a cutter blade retainer, an anti-rotation device, and a brake shoe provided inwardly of the brake drum portion and supported by a support shaft. The brake shoe extends along an inner surface of the brake drum portion so that the distance between the support shaft and the line tangent to the middle portion of the brake shoe exceeds the radius of the inner wall surface of the brake drum portion. An anti-rotation device is installed in a vacant space within a gear case and inwardly of the brake drum portion.

Abstract: A power machine comprises an output manipulation system for controlling an output of a power source given to a working member and a brake manipulation system for stopping the movement of the working member. A pair of output manipulation restriction portions is disposed between the output manipulation system and the brake manipulation system. The output manipulation restriction portions abut to each other so as to restrict output manipulation to the working member by an output manipulation member when the working member is in the braked state. Furthermore, a pair of brake manipulation restriction portions is disposed between the output manipulation system and the brake manipulation system. The pair of brake manipulation restriction portions abut to each other so as to restrict brake manipulation of the working member by a brake manipulation member during the power source gives the output to the working member.