Abstract: A power cutting device for cutting material in tight places. The power cutting device includes a power cutting device comprising a housing. The housing includes a first end and a second end. A first shaft is securely coupled in and extending away from the housing. A handle member is integrally coupled to a second end of the housing. A motor is positioned generally in the housing. A power supply for powering the motor is operationally coupled to the motor. A first actuating element for starting the motor is positioned in the handle member and operationally coupled to the motor. A first gear is mechanically coupled to the motor. A blade supporting member for supporting a cutting a member is positioned generally in the housing and removably coupled to the first shaft. A cutting member for cutting a variety of materials is movably coupled to the blade supporting member and the first gear.

Abstract: An anti-vibration element is provided for disposition between a motor unit and a handle unit of a manually guided implement. The anti-vibration element includes a sleeve-shaped, elastic main body as a vibration damper, with one end portion of the main body being adapted to be disposed in a receiving recess of the motor unit, and the other end portion being adapted to be disposed in a receiving recess of the handle unit. Respective plugs are disposed in the end portions of the main body for non-detachably holding such end portions in the receiving recesses. A cable that serves as a coupling element for preventing separation of the plugs is provided and spans an axial spacing between the plugs and extends through the main body. Each of the end regions of the cable has a respective fitting, an axially inwardly facing end face of each such fitting positively engaging behind an edge of an adjacent one of the handle unit and the motor unit.

Abstract: A cutting device for tooling sandwich plates has as its cutting tool a cutting chain (5) with cutting elements in the form of chain links (27, 28, 29) and a chain guide as the guide mechanism, wherein the chain links (27, 28, 29), lying one behind the other in their direction of movement (23), can swivel relative to one another on a swivel axis running transverse to their plane of movement and are moved by means of the chain guide in the plane of movement sometimes in a straight line, sometimes in a curve. The chain links (27, 28, 29) also have several cutting teeth (34) lying one behind the other in their direction of movement (23), which project radially on the cutting chain (5) and have cutting edges (335), which run transverse to the plane of movement of the chain links (27, 28, 29), wherein the perpendicular projections of the cutting edges (35) are arranged in the plane of movement at least partially along a line curved radially to the outside.

Abstract: A chain saw with vibration-isolating devices, capable of providing a desirable vibration-isolating effect over a wide frequency range and reducing accidental deviation from a desired cutting line in cutting operation. The chain saw includes a main body containing an internal combustion engine which has a crankshaft extending in the lateral direction of the chain saw, a saw chain extending from the main body in the forward direction of the chain saw, a frame member mounting a grip handle thereon, and at least two vibration-isolating devices each interposed between the main body and the frame member to support the main body with respect to the frame member. Two of the vibration-isolating devices are disposed spaced apart from each other in the longitudinal direction of the chain saw. Each of the two vibration-isolating devices includes a pair of first and second vibration-isolating members which are different in frequency range for providing a vibration-isolating effect.

Abstract: Disclosed is a chain saw which includes a chain saw chain braking system. The chain saw has a continuous chain channel guide which includes provision to impede the slideability of a chain saw chain in the continuous chain channel guide.

Abstract: A manually guided, portable implement, especially a power saw, is provided. The implement has a cylinder and a crankshaft that is connected to a piston via a piston rod. The implement has an essentially plastic housing as well as a lower crankcase. A stabilizing plate is nearly entirely embedded in the material of the lower crankcase. The one-piece stabilizing plate is provided with support sockets for bolting the lower crankcase to the cylinder. An overall metallic screw connection can thus be established.

Abstract: To limit the penetration of the outer end of a chain saw into a material being cut by the saw, the chain carrying rail of the saw has a number of uniformly sized holes located at different points along its length into any selected one of which holes a limiting means can be placed, with the limiting means including two rotatable wheels located on opposite sides of the rail.

Abstract: In order to design a motor chain saw with a chain brake device releasable as a back kick brake and as a coasting brake comprising a tension lever (2), movable with respect to the housing of the motor chain saw, which can be moved between a brake position (B) and a ready position (b), a release lever (19) which can take up a coasting brake position (A) and a disengaging position (f), in combination with a supplementary brake device known as a coasting brake, it is proposed that the tension lever (2) is placed linearly slidingly movable with respect to the housing of the motor chain saw and that the release lever (1) is placed slidingly movable with respect to the tension lever (2), whereby both axles of the sliding movement are parallel to each other.

Abstract: A chain saw (1) includes a guide bar (5) supporting a chain (7) and attached to a main body (3). Disposed within the body is an anchor bolt (9) for securing the guide bar to the main body. Disposed within a sprocket cover (8) is a hexagonal nut (11) screwed onto the anchor bolt. Furthermore, provided coaxially with the hexagonal nut is a cylindrical element (15) having a hexagonal cavity (13) that engages the hexagonal nut and is axially movable and rotatable about the same axis as the hexagonal nut. Also provided is a lever (17) disposed at the outer end of the cylindrical element. Provided within the sprocket cover are an adjustment pin (19) engaging the guide bar, a screw stock (20) onto which the adjustment pin is threaded and which extends in the axial direction of the guide bar, a first helical gear (21) disposed at one end of the screw stock, and a second helical gear (23) meshing with the first helical gear. Further provided is a rotating element (25) coaxial with the second helical gear.

Abstract: A portable power working machine has an L-shaped top handle having a top grip portion that is attached to the front portion of the top of a main housing and extends longitudinally above and parallel to the top of the main housing and a rear coupling portion that is attached to the rear portion of the main housing. A side handle has a front grip portion that is connected directly to the front end of the top grip portion of the top handle and a diagonal grip portion that extends diagonally straight as viewed in side elevation from the front grip portion toward the lower end of the rear coupling portion of the top handle. The lower end of the diagonal grip portion of the side handle is connected directly to the rear coupling portion of the top handle.

Abstract: The invention relates to a portable handheld work apparatus such as a motor-driven chain saw, a cutoff machine, a brushcutter or the like. The work apparatus includes an internal combustion engine (1) mounted in a housing (2) which drives a work tool via centrifugal clutch (3). The centrifugal clutch (3) includes a carrier (5) driven by the engine (1). The carrier (5) has rpm-dependent displaceable centrifugal weights (6) which are displaceable against a return force and come into contact engagement against a contact wall (7) of an output part (8) so as to transmit torque. A rotationally-elastic damping element (11) is arranged between the output part (8) and an intermediate element (10) connected to the tool (4) so as to rotate with the intermediate element (10).

Abstract: A chain saw has a spacer plate that provides an initial clearance space between an outer surface of an elongate flat blade that carries the cutting element of the saw and an inner surface of a recessed wall formed in a motor cover that forms a part of the chain saw housing when a pair of locking nuts are loosely seated against an outer surface of the recessed wall. When the locking nuts are firmly seated, the initial clearance space is reduced to no clearance space and the elongate flat blade is firmly held against vibration, but the light contact between the elongate flat blade and the recessed wall enables the elongate flat blade to be displaced in a first direction to loosen the cutting element and in a second direction, opposite to the first direction, to tighten the cutting element. This eliminates any need to loosen the locking nuts to accomplish cutting element adjustment. The spacer plate extends through an elongate slot formed in the elongate flat blade.

Abstract: The invention relates to a drive unit of a portable handheld work apparatus such a motor-driven chain saw having an internal combustion engine. The crankshaft of the engine drives a tool of the work apparatus and a fan wheel. The fan wheel is held within a fan housing on a drive pin of the crankshaft. A crankcase is rigidly connected to a cylinder of the engine and is made of a metal material. The crankcase is configured of two parts and the axis of the crankshaft lies in the partition plane of the crankcase housing parts which can be connected to each other. A metallic chassis of the drive unit includes a crankcase sump as one of the crankcase halves and has a flange surface lying essentially perpendicularly to the crankshaft axis. The flange surface is at least defined in sections by the free-lying end of the crankcase sump. In this way, the weight and the manufacturing costs of the work apparatus are reduced.

Abstract: A motor saw for cutting wood or stone includes a continuous wire loop (18) which carries uniformly-spaced cutting elements (25) and which is tensioned over a saw guide bar (17), from a drive wheel (30) mounted in the machine housing (15) to a loop-guiding sprocket wheel (20) at the outer end of the guide bar (17), said sprocket wheel functioning as a circular saw. As the cutting elements (25) pass over the sprocket wheel (20), they drop into recesses (28) between cog-like sprockets (27) thereon. The sprockets (27) support and guide the wire loop with the cutting elements (25) hanging freely in cutting positions in the recesses (28) between the sprockets. In the case of a duplicated wire loop, a cog claim (51) on the sprockets penetrates between parts (18′, 18″) of the loop so as to prevent the freely-hanging cutting elements (25) from twisting. These cutting elements may be irregularly shaped if desired.

Abstract: A saw chain sharpener for a chain saw and a chain saw having a sharpener in which the bottom surfaces of the cutting teeth of a conventional bottom sharpened saw chain are conveniently sharpened automatically by running the chain under power through the sharpener. The saw chain can be sharpened using the sharpener in a matter of typically twenty to thirty seconds without removing the chain from the chain bar. The sharpener is preferably adapted to be removably mounted to a bracket which is itself preferably removably disposed on the chain saw. The sharpener comprises a sharpening tooth disposed in a housing which is mounted on the chain bar. A top surface of the sharpening tooth frictionally engages bottom surfaces of the cutting teeth of the chain as the chain is run under power. A device for dispensing a sharpening compound to the sharpening tooth during sharpening may be disposed on the sharpener housing.

Abstract: The invention is directed to a low vibration and low noise cutter arrangement for a motor-driven chain saw. The cutter arrangement includes a guide bar and a saw chain. The guide bar has a guide groove for the saw chain which extends along the peripheral edges of the guide bar. The saw chain includes center links and side connecting links which are pivotally connected to each other. The connecting links on the right-hand and left-hand sides of the saw chain include cutting links and side links which are displaced relative to each other. The center links are provided with respective rakers which engage in the guide groove and can be driven in the longitudinal direction of the guide bar by a drive sprocket. The connecting links are supported with slide surfaces on the peripherally extending guide surfaces which lie at both sides of the guide groove.

Abstract: A saw chain for cutting aggregate material has sealing members to seal the pivotal connection between the center drive links and the rivets to prevent entry of contaminates into the bearing surfaces. In one arrangement, O-rings are mounted in grooves of the tie straps with the O-ring being compressively forced against the center drive link. The O-ring prevents entry of contaminants into the bearing surface between the bore of the center drive link and the rivet. In another arrangement spring type cup washers fit in a groove of the tie straps and the cup washers are biased against the center drive link.

Abstract: A cutter head assembly for a motor chain saw has a cutter head housing and a drive shaft mounted in and projecting from the cutter head housing. A drive pinion is mounted on the portion of the drive shaft projecting from the cutter head housing. A guide bar having a first end positioned adjacent to the drive pinion is provided. A saw chain is driven by the drive pinion and circulates on the guide bar. A cover covering the drive pinion and resting at least in an area of outgoing deflection of the saw chain at a housing wall of the cutter head housing defines a cuttings chamber open toward the guide bar. The first end of the guide bar is clamped between the housing wall of the cutter head housing end the cover. The cover has a cuttings ejection opening opposite the housing wall in the vicinity of the area of outgoing deflection. The cuttings ejection opening has a rim extending in a circulating direction of the saw chain and a ramp projecting from a first portion of the rim into the cutting chamber.

Abstract: The bar of a chain saw is attached to a jig which includes a support block pivotally attached to a pair of spaced support arms extending outwardly therefrom for supporting a log or branch to be cut, and fingers extending angularly forwardly and upwardly from the ends of the support arms for scooping up logs and branches from the ground onto the support arms and into contact with a pair of spaced upright, toothed stop arms on the support arms which prevent kickback or twisting of the log or branch as it is being cut by the chain saw as the support block is pivoted relative to the support arms between non-use and use positions.

Abstract: The invention is directed to a portable handheld work apparatus having a motor driven work tool. The work apparatus includes a housing, a handle mounted on the housing for holding and guiding the work apparatus and a safety member having an attachment portion and a lug portion for receiving and accommodating a safety rope therethrough to facilitate holding the work apparatus. The attachment portion and the lug portion conjointly define a single piece. The attachment portion is held on the housing so as to permit the lug portion to move between a rest position wherein the lug portion is at least partially in contact engagement with the housing and an in-use position wherein the lug portion is displaced away from the housing.

Abstract: A power tool including an inertia responsive element. The power tool comprises a housing, a motor supported by the housing and adapted to be connected to a power source, an output element supported by the housing and selectively coupled to the motor, the motor imparting motion to the output element, and an inertia responsive element for disconnecting the output element from the power source if movement of the housing is greater than a predetermined threshold. In one embodiment, the power tool is a hand held power tool having a handle, and the inertia responsive element disconnects the output element from the power source should the handle move at a rate greater than a predetermined rate. In another embodiment, the power tool is a stationary power tool, such as a drill press. The housing of the stationary power tool includes a base for supporting the stationary power tool on the workpiece.

Abstract: An improved nose sprocket which carries central drive links of a saw chain has a gullet shaped to provide ample space for saw dust to collect and reduce stress concentration within the gullet. The nose sprocket has teeth which define a gullet. The gullet has a bottom portion shaped with a varying radius of curvature. The varying radius of curvature is largest at a deepest portion of the gullet and smallest where the bottom portion meets flank portions of the teeth which carry the central drive links.

Abstract: A plastic handle member for manually guided power chain saws is provided. The handle member comprises a one-piece, at least partially tubular, front handle for holding a separate motor unit, the front handle being provided with a lower profiled bar. A rear control handle is provided having an upper portion for accommodating components for controlling a chain saw. A support member is disposed between the front handle and the control handle for interconnecting them. The front handle, the rear control handle, and the support member comprise a one-piece plastic body made of a single material and in conjunction with the lowered profile bar form a self-contained force polygon that absorbs load and vibrational forces by means of vibration-damping elements provided in supports disposed between the handle member and a housing of the separate motor unit for holding the housing of the motor unit.

Abstract: A chain saw brake device that can instantly halt the rotation of a cutting chain when a motor drive switch is turned off. The chain saw brake device includes a brake band wound around a brake drum, such that by operating a hand guard and pulling the forward end of the brake band, the brake band is tightened around the brake drum, thereby stopping the cutting chain. The rear end of the brake band is fixed to a bent rod, and the bent rod is urged rearwardly by a coil spring when the drive switch is turned off, causing the brake band to tighten around the brake drum. By activating a trigger lever, the movable member, engaged with the trigger lever, is moved forwards, thereby pushing forwards the bent rod, and loosening the brake band.

Abstract: An electric tree trimming apparatus includes an elongate telescoping tubular handle having a bracket provided on its upper end that releasably mounts and electric chain saw with the bar of the saw supported at an obtuse angle with respect to the handle. A coiled extension cord is accommodated within the handle and has a socket supported adjacent the upper end of the handle for releasable attachment to a plug of the saw, and a plug at the opposite end for connection to a power source. A remote trigger switch is mounted on the handle adjacent the lower end and is electrically coupled to the extension cord of the handle to enable remote operation of the saw.

Abstract: A throttle lever device for an engine having a decreased number of parts and capable of facilitating an assembling operation. An operation grip for controlling an engine of a mowing machine or the like is provided on opposite sides thereof with a throttle lever and a lock lever engageable with the throttle lever, respectively. A lock button is arranged in proximity to the lock lever so as to hold the throttle lever at a half throttling position. The throttle lever, lock lever and lock button are arranged so as to be pushable in toward a center of the operation grip. The lock lever and lock button are formed integrally with each other and constantly urged by an elastic member so as to be projected outwardly of the operation grip.

Abstract: There is a need for an efficient cutter to cut openings in drywall for electrical switch and outlet boxes. Existing cutters typically press out an opening and consequently require great hand supplied force and use of a back plate which must be positioned behind the wallboard.

Abstract: A hand-held working tool has a drive motor and a grip connected at a distance to the drive motor. Operating elements, including a throttle lever, a choke actuator, and a short-circuiting switch, are connected to the grip for controlling the drive motor. A transmission device, including a Bowden cable arrangement with a sleeve and a cable enclosed by the sleeve, is provided for connecting the operating elements to the drive motor. The transmission device has an inner tube inserted into the Bowden cable arrangement wherein the inner tube is positioned between the sleeve and the cable so as to be longitudinally displaceable relative to the sleeve and the cable.

Abstract: A motor chainsaw has a housing enclosing a motor with actuator and a saw chain. A braking device for the saw chain is positioned in the housing. The braking device has a brake drum and a brake band guided around the brake drum. The braking device has a brake lever connected to the housing so as to be pivotable about a first axis of rotation for moving the brake band from a release position into a braking position. A return kick brake for actuating the braking device is provided. The return kick brake has a ready position and an actuated position in which the brake band is in the braking position. The return kick brake has a hand protection grip, a control lever, and a return kick brake spring for loading the control lever. The control lever, when the return kick brake is moved from the ready position into the actuated position, pivots the brake lever into the braking position.

Abstract: The chain of an electromotive chain saw is quickly stopped by the combined use of an electric brake and a mechanical brake when a trigger member is turned off. The rear end of a brake band disposed to tighten a brake drum by operating a hand guard is secured to a bent rod. When the trigger member is released, the brake band is normally tightened around the outer periphery of a brake drum by the urging force of a coil spring. When the trigger member is released, a circuit provided with a brake winding is closed, thereby applying a dynamic braking force. When the dynamic brake force is applied, a centrifugal clutch is released quickly and the speed of stopping the brake drum is accelerated.

Abstract: A portable power tool is provided which includes a chassis defining an integral rear handle, a first chamber for lubricating oil generally at a front end of the chassis, a second chamber for fuel generally at a rear end of the chassis, and a recess between the first and second chambers. An internal combustion engine is secured to the chassis within the recess and a front handle is secured to the front end of the chassis. A chain saw unit is also secured to the front end of the chassis and is operably connected to the engine. The chassis includes right and left nylon plastic chassis sections which are vibrationally welded together.

Abstract: A surgical saw includes a saw assembly for being driven by a powered surgical handpiece and having a pair of parallel, co-planar guide arms, a pair of flexible, endless cutting bands disposed around the guide arms, respectively, and a drive mechanism for driving the cutting bands around the guide arms in a cutting direction. The cutting bands each include a plurality of spaced cutting teeth connected to one another by flexible band segments. The cutting bands are driven by the drive mechanism relative to the guide arms in opposite directions along defined paths to cut anatomical tissue at distal ends of the guide arms. A method of resecting bone includes the steps of driving the cutting bands relative to the guide arms in the cutting direction along the defined paths and inserting the distal ends of the guide arms in the bone to resect the bone along the plane of the guide arms.

Abstract: A manual tool is driven by an electric motor, and has a primary handle and a secondary handle arranged at a distance from each other. A switch is situated in the manual tool and can only be switched on by the simultaneous actuation of two contact mechanisms, one arranged in each handle, the motor being switched off when grip on either handle is released. The tool further comprises an initiating device in the form of a safety interlock mechanism which is adapted to prevent actuation of the switch, unless the safety interlock mechanism is actuated prior to actuation of the contact mechanism arranged in the primary handle. The switching mechanism is particularly suitable for a hedge clipper or chainsaw, especially a cordless tool.

Abstract: An attachment for a chain saw that allows the angle of a cut to be controlled with great precision. The attachment consists of a rigid, rectangular guide frame with an open window construction. An approximately U-shaped blade mount is hingably attached to the guide frame, thus allowing a saw blade to be inserted through the open window of the guide frame and mounted onto the blade mount. The blade mount, and thus the attached saw blade, can move in an arc with respect to the guide frame, and the attachment includes a selecting means by which to determine the angle between the blade mount and the guide frame and a tightening means by which to secure the blade mount and guide frame in the desired position. An additional feature is a directing fence so as to control the direction of a cut. The fence consists of a first and a second bar that are hingably mounted to one another and can thus be rotated and secured so that any desired angle is set between them.

Abstract: A hand held power tool includes a motor coupled to an output element and an inertia switch operative to disable the output element upon movement of the tool at a rate greater than a determined rate. The inertia switch disables the output element by open circuiting the motor or uncoupling the output element from the motor.

Abstract: The invention relates to an antivibration device between a motor unit 2 and a handle unit 9 of a portable handheld motor-driven chain saw 1. The antivibration device includes a sleeve-shaped elastic base body 6 having one of its ends 36 in a receptacle 20 of the motor unit 2 and the other end 46 in a receptacle 90 of the handle unit 9. The ends (36, 46) of the base body are fixed in the receptacles (20, 90) by axially engaging plugs (31, 41) in the end sections (30, 40). The guiding characteristics of the motor-driven chain saw are not affected by base bodies which become damaged or soft. This is so because at least one of the stops 31 has a coupling member 50 which bridges an axial spacing (z) between the plugs (31, 41) and projects into the other plug 41 and is latched so that it cannot be axially separated therefrom. A mechanical connection remains between the handle unit and the motor unit when the base body tears off.

Abstract: A saw chain of a chain saw is driven by a drive sprocket assembly including a drive sprocket and a pair of separate drive rings arranged coaxially and rotatably on the drive sprocket. Drive links of the saw chain extend through an annular space formed between the drive rings and enter recesses formed in the drive sprocket to be driven thereby.

Abstract: A drive sprocket arrangement includes a drive sprocket and a drive ring rolling loosely on the outer periphery of the sprocket. Drive links of the saw chain enter recesses in the sprocket via orifices in the drive ring. The drive ring has at an axial inner edge thereof a radially inwardly directed flange to retain the ring on the sprocket, and at an axial outer edge thereof a radially outwardly directed flange to retain the chain in place. The flanges are arranged such that the axial inner edge will be disposed above the axial outer edge when the drive shaft of the chain saw points downwardly.

Abstract: The invention relates to a portable handheld work apparatus such as a motor-driven chain saw. The apparatus includes an internal combustion engine as a drive motor for a work tool. The engine is mounted in a housing. The engine draws combustion air from the clean compartment of a filter case via an intake channel. The clean compartment is partitioned from a dirt compartment of the filter case by an air filter. The filter case itself is closed by a hood. The cover is configured as a hood of the motor housing and is pivoted about a pivot axis which is held to the motor housing by at least one bearing. In this way, the air-filter case can be cleaned in a simple manner without a tool. When the hood is flipped open, the filter case is freely accessible so that the necessary maintenance of the air filter or cleaning of the filter case is possible.

Abstract: A grip arrangement for a motor chain saw, wherein the motor chain saw has a housing and motor arranged in the housing, a saw chain driven by the motor, a chain guide extending in the longitudinal direction of the motor chain saw for guiding the chain saw, includes a handle extending in the longitudinal direction of the motor chain saw. The handle has a first handle end connected to the top of the housing at a forward portion of the housing facing the chain guide and has a second handle end connected at the top of the housing to a rearward portion of the housing remote from the chain guide. The grip arrangement also includes a first lateral grip with a first grip end, a second grip end, and a center portion connected between the first and second grip ends. The first grip end is connected to a handle portion of the handle adjacent to the chain guide and the second grip end is connected laterally to rearward portion of the housing remote from the chain guide in the vicinity of the bottom of the housing.

Abstract: Guide bar for chain saws, where the chain is supposed by a nose sprocket while traversing the front end. Regions of the edges of the guide bar are locally hardened to a higher hardness than the rest of the guide bar. The regions of hardness are only where the chair impacts the bar near an attachment end of the guide bar after having left the drive sprocket of the power socket, and where the chain settles on the guide bar edge after having been supported by the nose sprocket while traversing the nose curvature.

Abstract: A braking device for a motor saw including a rotatable brake drum (11), a brake band (12) surrounding the brake drum and actuatable by a spring (26) which is adapted to stretch the brake band around the brake drum, and a toggle joint mechanism (18,20) adapted to release the brake band from the drum against the action of the spring and to latch the braking device in an operating position in which the brake band is released from the brake drum. The toggle joint mechanism is actuatable by a control means (16) for adjusting the position of the brake band. The toggle joint mechanism is adapted, in the case of rupture of the brake band, to be adjusted by the spring to a position in which re-adjustment of the control means to the operating position is prevented.

Abstract: In a portable work machine, such as a chain saw, a vibration preventive coil spring mounting structure is provided which, upon interposition of a vibration preventive coil spring between a main body having a power source and a covering part having handles and adapted to support the main body, can ensure stable, secure and easy fixing of the coil spring to spring mount seats and which is advantageous from the standpoint of cost. Structurally, of a vibration preventive coil spring (10) is interposed between a main body (2) including a power source and a covering part (3) including grip handles (4, 5) and arranged to partially surround the outer periphery of the main body (2) to support same. Opposite ends (LO a, lob) of the coil spring (10) contact spring mount seats (11, 6a) of the main body (2) and the covering part (3), respectively, and cylindrical resilient fixing members (20, 20) are inserted at the opposite ends (10a, 10b) of the coil spring and abut against inner peripheries thereof.

Abstract: In a portable work machine, such as a chain saw, a vibration preventive coil spring mounting structure is provided which, upon interposition of a vibration preventive coil spring between a main body having a power source and a covering part having handles and adapted to support the main body, can ensure stable, secure and easy fixing of the coil spring to spring mount seats and which is advantageous from the standpoint of cost. Structurally, of a vibration preventive coil spring (10) is interposed between a main body (2) including a power source and a covering part (3) including grip handles (4, 5) and arranged to partially surround the outer periphery of the main body (2) to support same. Opposite ends (LO a, lob) of the coil spring (10) contact spring mount seats (11, 6a) of the main body (2) and the covering part (3), respectively, and cylindrical resilient fixing members (20, 20) are inserted at the opposite ends (10a, 10b) of the coil spring and abut against inner peripheries thereof.

Abstract: A working tool has a large number of cutter rings (2.1 to 2.3) on a curved guide rod (1) of circular cross section. The guide yoke (1) exhibits at least two helical grooves winding in opposite directions along its outer side, the cutter rings engaging into these grooves in each case with at least one guide element. Consecutive cutter rings (2.1, 2.2) engage with their guide elements in each case into contrarotating grooves. When the rings are driven forward during operation of the tool, consecutive cutter rings will rotate in opposite directions on account of the helical grooves (8, 9).

Abstract: A de-vibration element for a handle portion of a motor saw includes a coil spring (10, 30) which is attached between the saw body (19, 39) and the handle portion (13) by an attachment device provided at each end of the spring. In order to increase the resilience of the spring during small load one of the attachment devices includes with an articulated connection which preferably, a ball joint (15, 17; 35, 37).

Abstract: A passive sawdust catcher adaptable to a variety of conventional chain saws consists of a sawdust container and a bracket for connecting the container to the chain saw. The container consists of a fabric bag over a rigid frame, having a top and front opening for receiving or discharging sawdust. The bracket fastens to the bottom of the chain saw body and provides for connection of the container to the chain saw when the bracket is so fastened so that the top and front opening of the container is positioned to receive at least 50% of the discharge stream of sawdust created during a cutting operation.

Abstract: A power tool braking system includes a brake movably mounted to a frame of the power tool and a system for automatically moving the brake to a braking position. The brake has a first portion with a braking surface and a second portion. The system for automatically moving the brake to a braking position comprises a throttle of the power tool having a trigger with a section adapted to engage the brake second portion to move the brake to its braking position upon release of the throttle by a user.

Abstract: A sprocket for a chain including a thick hub portion and a plurality of thinner sprocket rings mounted on the hub. The hub has a rounded polygon peripheral configuration and the rings have complementary bores to receive the hub. The rings have sprocket teeth defined about their outer edges. When the sprocket rings are mounted in face-to-face nesting arrangement on the hub the teeth on adjacent sprocket rings are aligned axially of the hub. A pair of side plates having a greater diameter than the sprocket rings confine the rings on the hub and aid in holding a chain thereon during operation.

Abstract: A device that attaches to a rotary lawn mower to convert it into a weed, brush and small tree cutter. The rotating blade of the lawn mower is replaced with a drive sprocket that engages a continuous loop cutting element. The cutting element is retained in front of the mower by pulley guides. The pulley guides are retained by adjustable brackets attached to the mower. The cutting element is protected by guards that project in front of the mower.