A chainsaw including a body including a bar stud extending therefrom; a guide bar including a bar stud slot that receives the bar stud, wherein the bar stud slot has a length, and wherein the guide bar is configured to receive a chain; a yoke having a groove defining a length extending in a direction angularly offset from the length of the bar stud slot of the guide bar, wherein the yoke is coupled to the guide bar; a ratchet gear including a one-way motion feature and a post extending into the groove of the yoke, wherein rotating the ratchet gear in a first direction moves the guide bar to tighten the chain, and wherein rotating the ratchet gear in a second direction moves the guide bar to loosen the chain; and a pawl selectively engaged with the one-way motion feature of the ratchet gear.

A chainsaw including a body including a bar stud extending therefrom; a guide bar including a bar stud slot that receives the bar stud, wherein the bar stud slot has a length, and wherein the guide bar is configured to receive a chain; a yoke having a groove defining a length extending in a direction angularly offset from the length of the bar stud slot of the guide bar, wherein the yoke is coupled to the guide bar; a ratchet gear including a one-way motion feature and a post extending into the groove of the yoke, wherein rotating the ratchet gear in a first direction moves the guide bar to tighten the chain, and wherein rotating the ratchet gear in a second direction moves the guide bar to loosen the chain; and a pawl selectively engaged with the one-way motion feature of the ratchet gear.

An electric chainsaw comprises: a first handle having a forwardly and rearwardly extending grip portion provided on a rear or upper portion of a housing housing an electric motor and configured to be gripped by one hand of a worker, the grip portion being provided with a trigger switch for activating the electric motor; a second handle having a laterally extending grip portion provided forward of the grip portion of the first handle and configured to be gripped by the other hand of the worker; an indicator lamp for indicating a remaining charge amount of a battery pack; and a push-button type indicator switch for causing the indicator lamp to indicate the remaining charge amount, wherein the indicator switch is provided at a position where the worker can operate the indicator switch by a finger of the other hand being gripping the grip portion of the second handle.

An electric chainsaw comprises: a first handle having a forwardly and rearwardly extending grip portion provided on a rear or upper portion of a housing housing an electric motor and configured to be gripped by one hand of a worker, the grip portion being provided with a trigger switch for activating the electric motor; a second handle having a laterally extending grip portion provided forward of the grip portion of the first handle and configured to be gripped by the other hand of the worker; an indicator lamp for indicating a remaining charge amount of a battery pack; and a push-button type indicator switch for causing the indicator lamp to indicate the remaining charge amount, wherein the indicator switch is provided at a position where the worker can operate the indicator switch by a finger of the other hand being gripping the grip portion of the second handle.

Electric chain saw with static cooling features a cutting chain fitted so as to turn around a drive sprocket and a guide bar of oblong shape, and an electric motor effecting the drive of this chain, through the intermediary of the sprocket. The electric drive motor drive of the cutting chain is a brushless direct current motor enclosed in a housing formed by at least two components and made of a light metallic alloy, with one surface of the housing being in contact with the drive motor drive, to provide static cooling.

Electric chain saw with static cooling features a cutting chain fitted so as to turn around a drive sprocket and a guide bar of oblong shape, and an electric motor effecting the drive of this chain, through the intermediary of the sprocket. The electric drive motor drive of the cutting chain is a brushless direct current motor enclosed in a housing formed by at least two components and made of a light metallic alloy, with one surface of the housing being in contact with the drive motor drive, to provide static cooling.

The invention relates to a method for operating a work apparatus having a combustion engine. An ignition device is provided for triggering an ignition spark at a spark plug for igniting a fuel/air mixture in a combustion chamber of the combustion engine. The combustion chamber is bounded by a piston which drives a crankshaft in a rotating manner. In order to avoid the combustion engine stopping in rich mode, the speed (n) of the combustion engine is monitored over the period of time (t, ΔT) and the ignition point (ZZP) of the ignition device is advanced if the speed (n) of the combustion engine lies within a predefined speed range (n.sub.min; n.sub.max) within a predefined period of time (t, ΔT) and then the speed n drops below a speed limit value (n.sub.G).

A motor chain saw has a first driven sprocket wheel driving a saw chain lubricated via a supply pump driven by first and second drive wheel, wherein the second drive wheel is connected to the first sprocket wheel. A drive element with coupling section is connected to the first sprocket wheel and the second drive wheel is formed on the drive element. A second sprocket wheel can be used in place of the first sprocket wheel. The first and second sprocket wheels have different geometries. The coupling section has first and second followers correlated with follower surfaces of the first and second sprocket wheels. The coupling section contacts with first followers the follower surfaces of the first sprocket wheel or with second followers the follower surfaces of the second sprocket wheel when used in place of the first sprocket wheel.

A motor chain saw has a first driven sprocket wheel driving a saw chain lubricated via a supply pump driven by first and second drive wheel, wherein the second drive wheel is connected to the first sprocket wheel. A drive element with coupling section is connected to the first sprocket wheel and the second drive wheel is formed on the drive element. A second sprocket wheel can be used in place of the first sprocket wheel. The first and second sprocket wheels have different geometries. The coupling section has first and second followers correlated with follower surfaces of the first and second sprocket wheels. The coupling section contacts with first followers the follower surfaces of the first sprocket wheel or with second followers the follower surfaces of the second sprocket wheel when used in place of the first sprocket wheel.

Improved chain saws, components for chain saws, methods of making chain saws and components, and methods of using chain saws and components are disclosed. In some embodiments, a chain saw comprises a saw bar and a plurality of links, wherein a first link has a hook that engages a recess of a second link, thereby coupling the first link and the second link and allowing them to articulate without decoupling. The saw bar may have a rail, and the links may have grooves such that the links straddle and ride over the rail. The rail may have a projection and the grooves of the links may have notches accommodating the projection such that the projection prevents dislocation of the links. The links may have conical or pyramidal cutting teeth. The chain may be bidirectional. Robotic and automated operation of saws and other instruments are also disclosed.