Abstract: A hand lever device is disclosed which is adapted so that a throttle valve as a driven member can be adjusted appropriately in its degree of opening via a cable and kept at a desired degree of opening and yet immediately returned to the minimum degree of opening to ensure high safety. Thus, fatigue of an operator's fingers can be diminished. Also, the throttle valve is enabled to be brought to the degree of opening at which it had stood before it was returned to the minimum degree of opening without the necessity of readjustment. The hand lever device comprises an eccentric cam shaft (40) including a supporting shaft portion (42) and a pivot pin portion (41, 43) having pivotal axis (0b) eccentric to axis (0a) of the supporting shaft portion (42), a main lever (30) pivotally fitted on the supporting shaft portion (42), and a sub-lever (50) fixed to the pivot pin portion (41). The main lever (30) and sub-lever (50) are pivotally operated to draw a cable (20) connected to a driven member (CV).

Abstract: A two-stroke internal combustion engine in a working machine such as a chain saw has been prone to stalling when the stance of the machine was changed from slanting down to slanting up. Such stalling is minimized when lower longitudinal scavenging passage in the cylinder block of the engine have smaller cross section as compared with upper scavenging passage, and when the crank chamber of the engine includes a flow restricting portion for impeding the flow of liquid fuel into the lower scavenging passage when the stance is changed. The engine has a cylinder block (12), a crankcase (20), scavenging passages (27, 27), and a flow restricting portion (40) on an inner peripheral surface (22a) of the crank chamber (22).

Abstract: The present invent provides an improvement in the handling and operation of portable working machines, particularly in a loop front handle and an operation lever adjacent to the handle for easy operation. An operation lever mechanism for a handle according to the present invention includes: a rotatably supported body; a swingable operation lever pivotally supported by the rotatably supported body; and an operating portion movable in a direction along an axis X--X of the rotatably supported body, the operating portion connected to a swinging end of the operation lever, wherein the rotation axis X--X of the rotatably supported body is situated so as to encompass a virtual center X of a loop handle or a point adjacent to the center X, and the grip portions of second swinging end of the swingable operation lever rotate and move along an arc of the loop handle.

Abstract: A hand lever device is disclosed for adjusting the degree of openness of a throttle valve via a cable and kept at a desired opening degree and yet immediately returned to a minimum degree of opening to ensure high safety, thereby diminishing fatigue of fingers, and ensuring a desired level of operation. The hand lever device comprises a main lever (3) and a sub-lever (50) is attached to a wind-up tractive member (60) which draws a cable (20) connected to a driven member (CV) in such a manner that one end portion of the cable (20) is wound up thereon, and a torsion coil spring (40) is used as a brake operated by the main lever (30) for braking the wind-up tractive member (60) in order to hold the sub-lever (50) immobilized at any pivotally operated position.

Abstract: A portable electric working machine of the present invention includes a motor case portion housing an electric motor, a working portion driven by the electric motor, a handle connected to the motor case portion or the working portion and a power source switch disposed within a grip portion of the handle. Electric power is supplied to the electric motor through the power source switch. A spark-preventing capacitor accommodated within the motor case portion is interposed between a pair of terminals of the electric motor. The portable electric working machine of the present invention does not require a large-sized grip portion of a handle, and can prevent a locking of contacts of a power source switch due to contact transition by preventing sparking between the contacts so that a small-sized microswitch can be used.

Abstract: An elongated operating shaft supporting a tool at one end, a drive motor at its other end, and transmission means extending through said shaft to drive said tool is provided with a control handle for adjusting the holding and guiding the position and orientation of said tool. The control handle is formed of a unitary body having a handgrip section and an attachment section, which is provided with a hole into which the supporting shaft is inserted and which is formed with sufficient clearance to permit said handle body to be rocked to and fro along the longitudinal axis of the shaft. Spring means is mounted for biasing said handle body along an axis having an inclined position with respect to the longitudinal axis of the shaft so that said surface of the shaft is contacted by the surface of the hole at at least two opposed points, thereby to normally lock the handle body in said inclined position.

Abstract: A power working machine in which maintenance work is improved by having the heads of case fastening and motor fastening screws covered by the gasket provided between the mount base and the transmission cover. This prevents dirt load grease from clogging the heads of such screws. The transmission cover is also provided with through holes for the motor fastening screws and the case fastening screws, respectively.

Abstract: A hand lever device is disclosed for adjusting the degree of openness of a throttle valve via a cable and kept at a desired opening degree and yet immediately returned to a minimum degree of opening to ensure high safety, thereby diminishing fatigue of fingers, and ensuring a desired level of operation. The hand lever device comprises a main lever (3) and a sub-lever (50) is attached to a wind-up tractive member (60) which draws a cable (20) connected to a throttle valve (CV) in such a manner that one end portion of the cable (20) is wound up thereon, and a torsion coil spring (42) is used as a brake operated by the main lever (30) for braking the wind-up tractive member (60) in order to hold the sub-lever (50) immobilized at any pivotally operated position.

Abstract: An exhaust muffler structure of an internal combustion engine in which a catalyzer is readily and easily mounted and removed to carry out the assembling work of the muffler and the maintenance work such as cleaning and replacing the parts of the muffler with ease; the generation of vibration and noise are to be prevented; and the purification capacity and durability of the catalyzer are to be improved. The exhaust muffler structure comprising: an exhaust muffler having inner and outer exhaust muffler halves which are detachably combined with each other; a communication hole formed on the exhaust muffler for guiding exhaust gas from an internal combustion engine to the exhaust muffler; a cylindrical member having a catalyzer between resilient supporting nets, characterized in that the cylindrical member is disposed in a space in the exhaust muffler with a body of the cylindrical member being supported between the both inner and outer exhaust muffler halves.

Abstract: The invention provides an internal combustion engine having a decompression device, wherein the decompression device includes a pressure reducing valve, a recoil starter, and a decompression working mechanism. The decompression working mechanism works in association with the motion of the recoil starter means, for opening and closing the pressure reducing valve. The decompression working mechanism includes a rotatable recoil reel with at least one abutting jut disposed on the outer periphery thereof, a decompression lever which is swingably mounted to a fixed member of the internal combustion engine and which is swung, upon abutting against the abutting jut of the recoil reel, and a decompression rod, formed into a crooked-rod which is pivotally supported by the fixed member and which is rotated upon abutting against the decompression lever.

Abstract: A strapping machine is disclosed which enables a prolonged life of the driving force supplying means for feeding/tightening a band such as an electric motor to be realized, and which enables maintenance operations such as replacement and adjustment of the parts to be carried out with ease, and whose structure can be rendered simple and inexpensive as a whole, and yet which enables energy saving to be realized. The strapping machine comprising a band feeding/tightening means F adapted to conduct feeding, primary tightening, secondary tightening of a band B to be looped around a periphery of an object to be strapped and the like operation; wherein said band feeding/tightening means F is so constructed as to carry out feeding, primary tightening and secondary tightening of the band B by driving a roller 8 by means of a driving means M2 which is capable of being controlled among rotation, reverse rotation and stopped state.

Abstract: An internal combustion engine includes: a cylinder block having a connecting surface formed at a lower portion thereof and a skirt portion extending outwardly from the connecting surface; a crankcase having a connecting surface for contacting the connecting surface of the cylinder block and a bore for inserting the skirt portion therewithin; and, a gasket interposed between the connecting surfaces of the crankcase and the connecting surface of the cylinder block when assembled such that the gasket has a bore formed at the central portion thereof. A pair of detent portions are formed at the outer periphery of the skirt portion with each of the detent portion being different in shape from each other. A pair of recess portions, corresponding to the detent portions, are formed at each of the bores of the crankcase and the gasket.

Abstract: A vacuum cleaner that includes a stationary blade that acts also as a bearing in a suction pipe connected with a fan in the axial line of rotation shaft of the fan. A transmission shaft supported by the bearing extends from the fan rotation shaft of the fan and through the bearing. A rotary blade is mounted at the end of the transmission shaft that extends through the bearing and cooperates with the stationary blade to chop the sucked material finely.

Abstract: A strapping machine is disclosed which is adapted to be capable of constantly attaining a stable secondary tightening force and thereby capable of preventing a band from coming off the object under strapping, which enables a reduced power consumption cost to be realized, and which can be constructed simply and inexpensively as a whole. The strapping machine comprises a feed/backfeed stepping motor M2 as a source of driving force for a mechanism F including a feed/backfeed roller 8 for conducting feed and backfeed of a band B to be looped around a periphery of an object to be strapped and the like operation; the strapping machine being provided with a reverse rotation preventive means 87, S for timely locking rotation of the feed/backfeed roller 8 in the feed direction D.sub.F of the band B while always permitting rotation of the feed/backfeed roller 8 in the backfeed direction D.sub.B of the band B.

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 safety device for a throttle of an internal combustion engine comprises a throttle lever for controlling an opening of a throttle valve of the internal combustion engine, a throttle lever control means for selectively locking and unlocking operation of the throttle lever, a throttle lever control cancellation means for cancelling the throttle lever control means from controlling the throttle lever and an internal combustion engine operation control means, responsive to displacement of said throttle lever control cancellation means, for selectively operating and stopping the operation of said internal combustion engine.

Abstract: A strapping machine is disclosed which enables the operation cams such as the press cam, the heater cam, the slide cam and the like as well as the cam driving motor to be miniaturized, and which is capable of diminishing damages on the operation cams to realize prolonged lives of the cams and hence optimally eliminating cumbersome maintenance operations such as replacement of the cams, and yet whose structure can be rendered simple and inexpensive as a whole, and which enables energy saving to be realized. The strapping machine comprises a band feeding/tightening means F for feeding/tightening a band B to be looped around a periphery of an object to be strapped and the like operation; a band leading end treating means K including a mechanism for conducting a procedure which includes holding, pressing, fusing, cutting the band B and the like operation by actions of a plurality of cams 21, 22, 23, 24, 25 and 26; and a cam driving stepping motor M2 for driving said cams 21, 22, 23, 24, 25 and 26.

Abstract: A blade cover for a rotary blade weed or grass cutter is formed with a body adjustably fixed to a bracket provided on the operating shaft. Either the bracket or the attachment part is provided with long holes extending slantingly downwards to the main body and bolts are inserted into these long holes and fastened so that the position of the attachment part on the bracket is changeable.

Abstract: A water purifying and heating apparatus having a pump supplying water to a purifying filter connected by conduit to a boiler and capable of being used with domestic electric power supply. The load current required for start-up of the pump is reduced, and the automatic flushing effect of the hollow fiber membrane filters is obtained as is hot water as needed, without reducing the treatment efficiency of the purifying filter even though the temperature of water being treated is low.

Abstract: The weeder with rotary spikes in which the weeding operation is adequately and smoothly carried out in accordance with the type of weeds or the like to be weeded; power is effectively distributed without harmful effect to an engine and the like; maintenance work of the weeder is easily performed; and the overall weeding machine is simple in construction and is manufactured with low cost. The weeder with rotary spikes comprises: an operation rod; a gear case attached a tip portion of the operation rod; a rotary drum with a horizontally extending axis mounted to the tip portion of the operation rod through the gear case; and a spike mounting member with a number of spikes thereon detachably mounted to the rotary drum.