Abstract: A safety system for power chain saws including two flanges which are mounted on a hand guard frame on the left and right sides. The flanges point toward the rear and trigger the chain brake in the event of the hand slipping laterally and impacting with sufficient force. A further safety system includes a hand lever which is attached to the handle. This mechanism permits starting up of the saw only if the hand lever is pressed against the grip.

Abstract: The invention relates to a guide bar (9) for a saw chain (10) having a sword-shaped base body (16). A peripheral guide groove (11) is introduced into the periphery (17) of the base body (16). an oil-feed channel (22) is provided which opens into the guide groove (11) in the region of the groove bottom (23) and is fed from a transverse channel (21) lying below the groove bottom (23). The inlet opening (20) of the transverse channel (21) is at an outer side (9.1, 9.2) of the base body (16). The position, shape and size of the oil-feed channel (22) as well as the transverse channel (21) can be freely configured. This is achieved by arranging the transverse channel (21) in an insert part (25) separate from the base body (16). The insert part has the oil-feed channel (22). The insert part (25) is mounted in an open cutout (24) of the base body (16). The cutout (24) is open to an outer side (9.1, 9.2) of the base body (16) and extends substantially below the groove bottom (23).

Abstract: Guide bar for saw chain, where the chain is supported 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 where the chain 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, where a cutting action occurs on the bar, but omitted in an area delineated from a point adjacent the oil holes at the attachment end to a point before where a majority of the cutting action occurs.

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: The invention relates to a guide bar for the saw chain of a motor-driven chain saw. The guide bar has a guide groove which extends about the periphery thereof wherein the saw chain runs. The guide groove is delimited by two side plates which are tightly connected to each other and are held at a spacing relative to each other. The side plates are also approximately coincident with each other. At least one of the side plates has a connecting part which projects in a direction toward the other side plate. This connecting part lies with a contact surface on a corresponding counter surface of the other side plate. The connecting part of a side plate extends through the guide groove up to the other side plate and there contacts with its contact surface the counter surface of the other side plate. The contact surface and the counter surface lie approximately perpendicular against each other. In this way, a simple manufacture of the guide bar and an easy assembly thereof is guaranteed.

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: The chain saw tensioner of the present invention provides a sheath anchored at one end to the housing of the chain saw which sheath receives a tensioning shaft slidably therein. The tensioning shaft is interconnected with the housing by a tension screw and is slidably adjustable with respect to the sheath by actuating the tensioning screw. The tensioning shaft and the sheath have matching and aligned slots that cooperate to receive a sliding bolt therethrough. The sliding bolt is interconnected with the blade of the saw and, by actuating the tensioning screw, it may be moved forward with respect to the housing of the saw to move the saw blade forward to tension the chain. Included within the tensioning shaft is a spring interconnected with a bolt rest for receiving and supporting the sliding bolt. The spring provides a bias which acts on the bolt to bias the bolt, and accordingly the saw blade, forward with respect to the housing to tension the chain.

Abstract: The invention is directed to a tensioning arrangement for saw chains of motor-driven chain saws which include a device for longitudinally displacing the guide bar. The clamped guide bar is released so that the adjusting arrangement can be actuated for the longitudinal displacement of the guide bar. By rotating a disc having a spiral slot, a slide piece, which is coupled to the guide bar, is displaced in the longitudinal direction. Assembly is simplified and handling facilitated when the tension in the saw chain is adjusted. This is achieved by making the slide piece on the spiral disc so that it is not released therefrom but instead is held so as to be rotationally and longitudinally displaceable. The slide piece is fixedly connected to the guide bar by using appropriate attachment devices.

Abstract: An attachment for a chain saw is provided for adapting the saw blade to cut small diameter branches without weakening the saw blade holder or causing undesired kickback or jamming. The attachment comprises a pair of L-shaped cutting bars attached on both sides of the saw blade holder and spaced sufficiently apart to accommodate the width of the cutting chain. The cutting bars comprise a support portion and an angle portion, the support portion positioned approximately midway along the length of the saw blade holder and extending along a line parallel to the longitudinal axis of the saw blade holder. The angle portion of the cutting bars projects beyond the lower edge of the blade, and forms a wedge shaped angle or bight between the saw blade attachment and the cutting chain.

Abstract: A guide bar for chain saws comprising a bar body made from a solid steel plate with a groove machined along the edges for guiding a saw chain. At least the portion of the groove sides closest to the edges of the bar body are plated with a first material layer of a thickness related to the average surface roughness (Ra) of the groove sidewalls and thereafter are plated with a much thinner second material layer.

Abstract: Method for hardfacing of parts of the edges of a chainsaw guide bar, where the chain is guided by a groove, where a wear-resistant alloy is applied in a molten state to parts of the edges (12,13) of a guide bar blank and solidified in nearly final configuration, comprising the steps of:making a guide bar blank (10) having edges located at greater distance from the groove bottom (18) along the sides (17) which are not to be hardfaced than in those parts (12,13) which are to be hardfaced, andapplying a mold (15) with an extending plate (14) against the blank with the edge (23) of the plate in contact with the groove bottom (18), andfilling the space between the wall (19) of the mold and the edges (12,13) of the blank with a paste (16) made from finely powderized hardfacing alloy and a liquid, andheating the paste (16) locally to melt the alloy.

Abstract: An anti-vibration element has a tubular elastic base body with a first and a second end for connecting parts in a vibration-damping manner. A dumbbell-shaped bolt has a connecting element and a first and a second clamping element connected to opposite ends of the connecting element. The dumbbell-shaped bolt is inserted into the base body such that the dumbbell-shaped bolt has limited axial displacement. The connecting element can be made of a substantially rigid or a substantially elastic material. In a preferred embodiment, the first clamping element is axially fixed relative to the longitudinal axis of the base body and the second clamping element is axially displaceable relative to the longitudinal axis of the base body.

Abstract: A bar mounted chainsaw cutting depth gauge is described on a chain saw cutting bar for selectively covering a length of the chainsaw bar and bar tip. The gauge includes an elongated base sleeve mountable to the chainsaw bar to cover a portion of the chainsaw bar. A fastener releasably and securely mounts the base sleeve to the chainsaw cutting bar. An outer housing is slidably received over the chainsaw bar and base sleeve for sliding movement along the length thereof from a first or extended position wherein the bar tip is encased within the outer housing and a second or retracted position wherein the bar tip is exposed outward from the outer housing. The outer housing includes an outer tip with a slit formed therein for permitting passage of the chainsaw bar therethrough. A spring is operatively mounted between the base sleeve and outer housing to constantly, yieldably bias the outer housing toward the first extended position.

Abstract: A method for the production of a slideway-type guide for driven chains such as cutting chains includes the application of a wear-resistant hard metal alloy as a running surface to the slideway of the guide. A bar-shaped blank with a dentritic structure, made from the alloy, is produced to form the running surface, a suction casting process being used in particular for this purpose. The blank is treated by hot isostatic pressing with high pressure at a high temperature. This is followed by an annealing process over a number of hours, at the end of which the structure of the alloy is so altered that the previously acicular and, to some extent, lattice-type carbides are dispersed and converted to rounded and, to some extent, spheroidal bodies which are densely and evenly distributed throughout the alloy. The alloy thereby becomes highly wear-resistant. The bars are then shaped so as to fit onto the slideway, and are fixedly connected thereto.

Abstract: The invention is directed to a motor-driven chain saw having a drive motor arranged in a housing. The drive motor drives a saw chain on a guide bar via a sprocket wheel. The guide bar extends forwardly in the longitudinal direction of the chain saw and has an elongated slot in its rearward end facing toward the housing. Stud bolts fixed on the housing extend through the elongated slot in a direction transverse to the longitudinal direction of the chain saw. The rearward end of the guide bar is clamped between the housing and a sprocket-wheel cover through which the stud bolts extend. A holding device separate from the sprocket-wheel cover is provided at the rearward end of the guide bar for holding the rearward end of the guide bar in its position on the housing when the sprocket-wheel cover is removed. This holding device reliably holds the guide bar for mounting the saw chain.

Abstract: The invention is directed to a cutting arrangement for a motor-driven chain saw and is configured as a preassembled component which includes a guide bar having a saw chain and sprocket drive wheel. A tensioning device is integrated into the guide bar for holding the parts of the component together. The tensioning device holds the sprocket drive wheel at a spacing from the end face of the guide bar. The tensioning device is adjustable when placing the component on the housing of the chain saw in such a manner that the sprocket drive wheel is released while the saw chain remains under tension. The component can be disassembled into its individual parts by adjusting the tensioning device.

Abstract: A pruning device having a chain saw with a flexible chainbar and a double-articulated cutting chain. The chainbar has a relaxed shape of a helix for encircling a tree trunk. The double-articulated cutting chain can curve about two lateral axes so that it may follow the perimeter of the helical chainbar and cut branches from the tree. A remotely located power supply is provided on a wheeled cart for powering the chain saw and supporting and operating a support wand that supports the chain saw and raises and lowers it along the tree trunk.

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: An apparatus for cutting baled crop materials particularly of the cylindrical bale type comprises an apparatus in the form of a conventional chain saw in which the chain is modified so that either the slide links or the guide links include an outwardly projecting cutting plate. The cutting plate is shaped to form a cutting edge having a ramp shape commencing at a position intersecting the previous link and extending outwardly at a gradual inclination of the order of 20.degree. to an outermost point and then a trailing edge which extends backwardly toward the main body of the chain. The width of the cutting plate is less than the width of the chain itself in view of the tension in the bale which pulls the bale apart as it is cut.

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.

Abstract: The invention is directed to a guide bar for portable motor-driven chain saws. The guide bar includes two steel side parts and a center part connected to the side parts. The weight of the guide bar is kept optimally low while at the same time providing adequate stability and the longest possible service life by providing cutouts extending in the longitudinal direction which are provided with a filler of a material having a lower specific gravity. The cutouts of the side parts and the cutout in the center part filled likewise with a lighter material are arranged so as to not coincide with each other when the guide bar is assembled. In this way, a form-tight mounting for the filler is formed in the side parts and in the center part.

Abstract: A quick release device for use with chain saws and which is adapted to quickly attach a bar and chain to the motor assembly of the chain saw. The quick release device comprises a body having an upper jaw and lower jaw. The jaws are adapted to engage notched ends of studs extending from a motor assembly and thereby clamp the bar and chain to the motor assembly. A rotatably threaded shaft cooperates with the body in a unique manner such that turning of the shaft in a manner which causes a clamping action actually biases the jaws away from one another. A head is located on the threaded shaft with a plurality of apertures so that one can readily engage an aperture with a tool thereby facilitating manipulation of the head.

Abstract: The invention relates to a motor-driven chain saw having a motor mounted in a housing for driving a saw chain on a guide bar. The guide bar extends forwardly in the longitudinal direction of the chain saw from a forward housing end face. The housing is held by a grab handle for holding and guiding the chain saw. The handle has an upper segment projecting over the housing transversely to the longitudinal center axis of the guide bar. The upper segment extends at one end with a transition segment into a lateral segment lying approximately parallel to the plane of the guide bar and next to the housing. The cross section of the upper segment and the cross section of the lateral segment are configured in a shape which departs from the circular shape and are approximately the same. This affords an ergonomically advantageous hold and increases the operational safety.

Abstract: The invention is directed to a motor-driven chain saw having a housing and a drive motor mounted in the housing for driving a sprocket wheel. The sprocket wheel, in turn, drives a saw chain guided around the periphery of a guide bar. The flat guide bar projects forwardly in the longitudinal direction of the chain saw and has a rearward end facing toward the sprocket wheel. Stud bolts fixed to the housing lie perpendicularly to the guide bar and project therethrough. The stud bolts also extend through a sprocket wheel cover laterally closing off the housing. The stud bolts have projecting free ends carrying respective nuts. In this way, the rearward end of the guide bar can be tightly clamped between the housing and the sprocket wheel cover. The stud bolts have respective other ends facing away from the guide bar which are tightly seated in the engine block of the drive motor. In this way, the loads acting on the guide bar can be taken up without danger of causing fractures in the housing.

Abstract: A sawing device is attachable to an electric hand drill. The hand drill can be operated by either alternating current or direct current, using a battery. The battery operated drill eliminates the need for electrical cords, so it can be used anywhere. The saw bar may be made of material such as plastic that requires no lubricating oil, is lighter and less abrasive than conventional metal saw bars. There is also a non-metallic insert that will attach to a metal saw bar. This insert may go into the conventional metal saw bars with the same advantages as above. The hand drill rotation is transferred through a connecting shaft to the sprocket that drives the cutting chain, which travels on a chain bar with a single sprocket.

Abstract: A safer and easier control of power to the chain by means of a hinged or flexible handle that is pressed or rotated in the direction of cut in order to drive the chain, and is released or rotated away from the direction of cut to stop the chain. This method of stopping the chain is of critical importance when a chainsaw is dropped by the supporting hand, because power to the chain is automatically stopped by the control-handle in the other hand, thereby much reducing the danger of injury or damage.

Abstract: The prime mover of a chain saw has an output shaft passing through the body of an oil pump. A fixing screw is inserted through an inserting hole provided in the body and is screwed into a threaded hole provided on the side of the prime mover. A cover plate, covering the area tip of the output shaft, is press fit onto the output shaft. The inserting hole is made as a threaded hole having a diameter through which the fixing screw is freely insertable but is also adapted to receive a removing screw which is larger in diameter than the fixing screw, and which abuts against the side of the prime mover. As a result, the inserting hole can be used in common also as the oil pump removing screwed hole and no extra removing screwed hole is required to be provided.

Abstract: A guide roller is supported at the tip of the guide plate, over which the chain runs. A tip guard extends over the chain and projects forwardly from the support for the guide roller.

Abstract: A chainsaw guard for enhancing safe operation of a chain saw. The guard includes a housing providing a physical barrier that limits access to the cutter chain of the chain saw. The housing has an opening for exposing a selected portion of the cutter chain for cutting a target object such as the roof of a burning building or the exterior surface of a tree. A coupler adjustably connects the housing to the chain saw. To improve flexibility, the housing includes two sections that can move relative to each other. The housing alone or in cooperation with the object being cut succeeds in enclosing substantially all of the cutter chain at all times to prevent human injury by the cutter chain, and in keeping the cutting edge facing away from the user. The housing further reduces risk of injury by limiting the depth of the cut made by the chainsaw.

Abstract: Method and apparatus for manually applying a selected fit of a saw chain loop to a chain saw. A tensioning procedure is performed simply by loosening a guide bar hold-down screw. The loosened guide bar is slightly spaced away from the mounting plate of the chain saw as a spring extends the guide bar relative to a drive sprocket which tightens the saw chain. The hold-down screw, which has an inclined axis, is then tightened to force the saw bar obliquely toward the mounting plate, simultaneously forcing the guide bar in a longitudinal direction that backs off the saw chain tension by a predetermined amount.

Abstract: A chain saw feed mechanism includes an arm pivotally mounted to the chain saw and carrying a dog for pivotally engaging the workpiece at the kerf. Thrusting the chain saw along the longitudinal axis of the guide bar moves the guide bar along an arc concentric to the point of workpiece engagement and thereby cuts laterally through the workpiece. Longitudinal thrusting force applied by the operator transfers via the lever arm into lateral feed force needed for cutting the workpiece. The feed mechanism is particularly useful in aggregate cutting applications, where the chain saw is heavy and large cutting forces are needed to pass the saw through the aggregate.

Abstract: An intertial-manual actuating chain brake for a chain saw in which a mechanical integrator distinguishes between relatively long duration accelerations developed by a "kickback" producing impulse and normal operating accelerations associated with operational and vibratory forces. Occurrence of a "kickback" impulse, developing a force of required magnitude, direction, and duration causes a spring-mass accelerometer to change from a brake released to a brake applied condition, applying a braking torque to the saw chain. The accelerometer utilizes a pivotable hand guard as the actuating means. The hand guard also provides for manual operation. The hand guard is comprised of a housing and an inertia weight that is connected to the housing. The weight and type of inertia weight can be selected to provide the brake applied condition for a predetermined movement of the chain saw or for a predetermined type of chain saw. The inertia weight can be adjusted to adjust the accelerometer.

Abstract: A practical and safe heavy duty hedge, bush and brush cutter having a forwardly mounted dual-sided tine set that comprises a means for readily cutting flexible heavier limbs. The forwardly mounted tine set preferably is part of a comb-like attachment which includes a number of additional dual-sided tine sets that define a plurality of gathering, holding and cutting areas. The attachment is designed so that it can be mounted from one side of a conventional chain saw blade without removing the chain blade from the chain guide and yet provides stopping surfaces on both sides of the guide bar and chain blade of the saw to support severed limbs and branches in such a manner that bias cutting of flexible limbs and shredding of branches is prevented. The comb-like attachment including the dual-sided tine sets defining the gathering, holding and cutting areas for branches to be cut can be installed and removed from one side of the chain saw blade without the use of special techniques or tools.

Abstract: A tree felling apparatus has a U-shaped base with a pair of laterally spaced arms defining a cutting area for receiving therein a tree to be cut and a chain saw mechanism movable through the cutting area for cutting a tree. The chain saw mechanism includes a saw bar which is tapered inwardly from its proximal end to its distal end for even distribution of bending stress across the saw bar.

Abstract: A chain saw safety switch mounted in combination with a chain braking mechanism such that, when chain braking is initiated, both the chain motion about a chain guide bar and motor operation are automatically stopped. The safety switch according to one embodiment of the invention is mounted to the safety guard of the chain braking mechanism in a position such that it may be rendered operable by either a selective action of the saw operator or by the operator's reaction response to a hazardous operating condition. In either case, the safety switch effects short-circuiting of the motor ignition to stop all motor operation while at the same instant, the safety guard effects stoppage of the cutting chain motion about the chain guide bar. Alternatively, the safety switch is mounted in conjunction with the movable safety guard such that short-circuiting of the motor ignition is effected through the chain braking mechanism.

Abstract: A power saw structure having a pivot provided on a forward lower portion of the housing of the drive for providing a fulcrum on a subjacent surface about which the saw structure may be pivoted so as to safely urge the forward distal end of the saw chain into the subjacent surface while maintaining the chain saw structure supported on the subjacent surface through the pivot. In the illustrated embodiment, the pivot structure is a separate structure secured to the housing of the drive. The pivot structure includes an upwardly extending forward portion for supporting the saw structure on the subjacent surface throughout the full range of swinging movement of the saw in cutting through the subjacent surface.

Abstract: A guide bar for a mechanical harvester wherein the guide bar is repairable after bending. The guide bar is provided with a bendable section in a limited zone between the mounting bracket and the principal cutting portion of the bar. A hinge area is thereby created in the zone area to permit bending of the bar without breaking. The rails are removed within this hinge area. The saw chain traverses the short railless section during normal cutting action. Upon bending of the bar, the chain assumes its own curvature in traversing the section and will more readily jump the bar when bending forces are so severe as to likely break the chain.

Abstract: In one embodiment, the anti-pinch device includes a vertical support mounted normal to the saw blade of the chain saw. A pinch arm extends longitudinally above the saw blade and is mounted for translational movement along the length of the vertical support. The pinch arm is attached to a transversely movable mount by a pivot such that the pinch arm can pivotally move with respect to the vertical support and the mount and pinch arm can transversely move up and down the vertical support in a substantially free manner.

Abstract: A chain saw guide bar assembly includes opposing outer laminates in spaced relation as defined by a wire structure lying generally about the periphery of the laminates, but spaced inwardly of the edge boundary thereof whereby a saw chain groove formation results as defined by an exposed or outward facing portion of the wire structure and exposed portions of the inner surfaces of the outer laminates. The wire structure advantageously provides, in combination with the outer laminates, a containment cavity for a foam-adhesive core laminate which expands upon curing to fill the cavity and to adhere to the inner surfaces of the outer laminates. A very rigid yet lightweight chain saw bar results with less production complexity and cost relative to that of other core laminate chain saw bars.

Abstract: The invention is directed to a rearward handle arrangement for a handheld portable tool defining a horizontal axis and having a motor housing and a forward handle fixedly attached to the housing so as to permit two-handed operation of the tool by an operator. The rearward handle arrangement includes: a carrier part for attaching the rearward handle arrangement to the housing of the tool; a rearward handle; and, a bearing journal for rotatably journalling the rearward handle in the carrier part so as to permit the rearward handle to rotate about the horizontal axis relative to the carrier part and the forward handle. The carrier part and the reaward handle conjointly define an interface and an unlatchable detent is disposed at this interface for self-latching the rearward handle on the carrier part at any one of a plurality of predetermined angular positions about the horizontal axis. These angular positions correspond to respective work positions in which the tool can be held by the operator.

Abstract: A guide bar for a mechanical harvester wherein the guide bar is repairable after bending. The guide bar is provided with a pliable section of lowered hardness in a limited zone between a mounting bracket and the principal cutting portion of the bar. A hinge area is thereby created in the zone area to permit bending of the bar without breaking. Reduced hardness is tolerated in the zone area where the least cutting action is encountered.

Abstract: An improved saw bar and a chain sawing assembly includes a frame which houses a drive engine or motor and receives the saw bar, an endless cutting chain, and a sprocket mechanically coupling the drive engine to the cutting chain. The saw bar includes a bar member having a slot formed therein through at least a portion of the thickness of the bar member, with the slot extending from an attachment end to a nose end of the bar member. The saw bar also has a channel assembly, such as a tubular channel assembly, positioned in cooperation with the slot to deliver fluid from the attachment end to a channel outlet. In one embodiment, the saw bar has an idler sprocket pivotally mounted within a sprocket mounting slot formed at the bar member nose end. The channel outlet opens into the sprocket mounting slot to deliver lubrication fluid to the sprocket teeth. In an alternate embodiment, the channel outlet comprises a plurality of apertures along the length of an exposed wall of the channel member.

Abstract: Damping device for a vibration damping system in chain saws having an adjustment spring characteristic for various applications. The element (10) according to the invention is an elongated elastomer element attached in the middle of a handle part and fastened at one end to the driving side of the crankcase. The second end enters into a cylindrical cavity (20) formed in the crankcase wall supporting the start apparatus, said cavity having a larger diameter than the element. In that way the characteristic of the element is primarily determined by the end fastened to the driving side but gradually, when the load on the element increases, also by the end entered into the cavity.

Abstract: A chain guiding rail for use in power chain saws has a tip part defining an arcuate run-in section extending from an end point of a forward-run section to the vertex of the tip part, and a run-out section extending from the vertex point to a start point of a return-run section. The run-out section has a substantially larger diameter and a tangential line at its center point forms an angle (b8) of 40.degree. to 70.degree. with a center axis of the rail. To eliminate kickbacks during operation of the chain saw the vertex is situated in a sector of the tip part which is delimited by reference line coinciding with the center axis or extending in parallel thereto, a perpendicular line relative to the forward-run section at the end point (E) and to the parallel reference line or the center axis, and an arc whose center of curvature coincides with the point of intersection of the parallel reference line with the perpendicular line.

Abstract: A guide bar for a chain saw, the bar having oppositely located flat sides. A plurality of recesses are formed in each of the sides, the recesses on one side being offset from the recesses on the other side. At least some of the recesses are filled with a lightweight material. Some of the recesses may also function as oil reservoirs and oil passages between the guide grooves of the bar.

Abstract: A chain saw body having an upper and lower housing. The prime mover is lowered into the upper housing and held in place in shaped recesses for it. The upper housing is itself lowered onto the lower housing, which mounts the handles and defines a fuel tank. The upper and lower housings are connected via vibration dampening couplings.

Abstract: A guide bar for chain saw comprises a main body of a plate shape. The main body has first and second sides facing each other in the thickness direction of the main body. The main body includes at least a first recess provided on the first side, and a second recess provided on the second side of the main body. The first recess has a first portion communicated with the second recess so that the recesses define in combination a through hole at the communciating portion, and a second portion shielded by the second side of the main body. A filler is packed in said first and second recesses.

Abstract: A chain saw having a resilient deflectable rear handle. The rear handle is connected to a housing of the chain saw at a first end and has a second end that is cantilevered. A portion of the housing is suitably sized, shaped and positioned relative to the rear handle second end to form a deflection overload constraint to prevent the rear handle from deflecting too much. The cantilevered configuration of the rear handle and its deflectability allow vibrations generated during operation of the chain saw to be reduced at an operator's grasping location on the rear handle.

Abstract: A chain saw guide bar including an inner plate and a pair of outer plates fixed to both flat sides of the inner plate. The inner plate has holes formed therethrough. The outer plates also have holes formed therethrough, but they are smaller than the holes of the inner plate. The outer holes are each aligned with one of the inner holes, and the holes are filled with a lightweight material.