Abstract: An outdoor tool includes a powerhead, a tool unit powered by the powerhead, and a shaft assembly extending between the powerhead and the tool unit. The tool unit includes a transmission housing, a support plate, a guide bar adjustably supported by the support plate, a drive gear, and a chain circumscribing a portion of the drive gear and a portion of the guide bar, the drive gear operatively coupled to the powerhead. The tool unit further includes a tension adjustment mechanism for adjusting a position of the guide bar relative to the drive gear to increase and decrease a tension in the chain. The tension adjustment mechanism includes an adjustment screw, a threaded adjustment bolt, at least one adjustment gear, and a member coupled to the adjustment bolt and the guide bar. Rotation of the adjustment screw causes translation of the guide bar relative to the drive gear.

Abstract: The present invention refers to a motor saw arrangement comprising a support plate attached to the motor saw chassis or motor saw motor, a detachable clamping plate and a detachable guide bar arranged between the support plate and the clamping plate. The support plate is provided with two first recesses and at least one threaded hole, while the clamping plate is provided with two protrusions adapted to fit inside the respective two first recesses when the clamping plates is attached to the support plate and the protrusions each have a height that exceeds a corresponding height of the guide bar. The guide bar is provided with two keyhole-shaped slots and with a longitudinal slit between the two keyhole-shaped slots and the support plate is further provided with an alignment means. The invention further relates to a method to remove and/or replace a saw chain from a guide bar and to a guide bar intended and adapted for the motor saw arrangement described herein.

Abstract: A chainsaw system includes a chainsaw and a saw blade module, which has a cutting chain and at least one guide unit for forming a guide for at least one part of the cutting chain. The chainsaw system further includes at least one coupling unit for coupling the saw blade module to the chainsaw and at least one release unit that has at least one fastening element and is provided in order to provide tool-free decoupling of the at least one saw blade module which is coupled by means of the coupling unit.

Abstract: A chainsaw having a drive motor. The chainsaw has a fixed part and a movable part. The guide bar is retained on the fixed part in a manner braced between the fixed part and a tensioning element. The movable part is shiftable in a longitudinal direction with respect to the fixed part in order to tension the saw chain with the tensioning element released. The chainsaw has a stop face and a tensioning face. At least one additional contact face that is firmly connected to the fixed part in the longitudinal direction and at least one additional contact face that is firmly connected to the movable part in the longitudinal direction are arranged between the stop face and the tensioning face. All the contact faces lie one after another in the flux of force from the tensioning element to the fixed part.

Abstract: A reciprocating saw blade includes a body, an attachment portion coupled to a first end portion of the body, and a cutting portion formed on the body. The cutting portion includes a plurality of cutting teeth. Each cutting tooth includes a tip, a rake face, and a relief surface. The tips of the plurality of cutting teeth define a plane. The saw blade also includes a plunge point formed on a second end portion of the body for initiating a plunge cut. The plunge point includes a leading tooth and a second tooth. The leading tooth includes a tip and a rake face and defines a leading gullet. The second tooth is positioned in the leading gullet closer to the leading tooth than to a nearest cutting tooth of the plurality of cutting teeth. The second tooth includes a tip that is spaced apart from the plane.

Abstract: A tool coupling device for a receptacle of a machine tool separating device formed as a closed system includes at least one cutting strand tensioning unit that has at least one tensioning element. The tool coupling device also includes at least one operating unit that includes at least one operating element. The cutting strand tensioning unit includes at least one gear unit that is configured to move the tensioning element as a result of an actuation of the operating element of the operating unit.

Abstract: In a chain saw, an operating shaft member axially rotated by a manual operation of a rotating lever is disposed so that an axial direction thereof may be inclined against an attaching surface of a guide bar in which a saw chain is wound around a circumference thereof, a driving bevel gear attached to an end portion of the operating shaft member meshes with a driven bevel gear attached to an end portion of a rotating shaft member, and the rotating shaft member is axially rotated. Thus, the guide bar is moved in a longitudinal direction thereof to adjust tension of the saw chain.

Abstract: A handheld work apparatus has a guide bar having a periphery along which a chain runs. The work apparatus has a housing and a fastening arrangement for fixing the guide bar to the housing. The fastening arrangement has an actuating device which can be actuated in a fastening direction in order to fix the guide bar. The work apparatus has a tensioning device to tension the chain. The tensioning device includes a tensioning spring. When the fastening arrangement is loosened, the tensioning spring exerts a force in a tensioning direction of the chain on the guide bar. Simple operation and a simple construction are achieved if the tensioning spring is in operative connection with the actuating device and is tensioned during actuation of the actuating device in the fastening direction.

Abstract: A tool coupling device is configured to hold a machine tool cutting device. In particular, the tool coupling device is configured to hold a machine tool cutting device configured as a closed system, having at least one cutting train clamping unit for generating a cutting train clamping force and having at least one tool-holding unit comprising at least one movably mounted tool-holder element. The tool coupling device includes at least one movement-coupling unit by which the tool-holder element can be coupled with a clamping element for a movement of the clamping element of the cutting train clamping unit.

Abstract: An apparatus for automatically adjusting a chainsaw cutting element as the chainsaw cutting element lengthens during use due to thermal expansion includes an elongate flat bar circumscribed by the chainsaw cutting element, a motor for causing the chainsaw cutting element to rotate about the elongate flat bar, a motor housing for housing the motor and a cover housing secured to the motor housing for covering a proximal end of the elongate flat bar and a rotatably mounted sprocket gear that engages a proximal end of the chainsaw cutting element. The elongate flat bar has a first, fully retracted position, a second, fully extended position, and an infinite number of positions of adjustment therebetween. Bias members continuously urge the elongate flat bar to displace during saw operation in a proximal-to-distal direction from the first, fully retracted position to the second, fully extended position to maintain chain tension at all times.

Abstract: To provide an operation lever including a first lever that has a base end portion swingably supported to a peripheral portion of a nut member for fastening a guide bar in a chain saw, and a second lever that is engaged with the first lever in a manner slidable in an axial direction. The operation lever can be placed in a receiving portion of the nut member with an axial length thereof shortened, and can be manipulated to rotate the nut member by being gripped on an outer end portion of the second lever in a state in which the operation lever is lifted out from the receiving portion and the axial length is lengthened. Thus, a sufficient fastening force for the guide bar can be obtained, and operability can be improved.

Abstract: A portable working machine includes a working machine body, bolt members erected on the working machine body, a cover member configured to be attachable to and detachable from the working machine body, in which the cover member has through-holes through which the bolt members are inserted when attaching the cover member, fixing members configured to be fastened to the bolt members to fix the cover member attached to the working machine body, and a holding member attached to an outer surface of the cover member with a predetermined gap space between the holding member and the outer surface of the cover member, in which the holding member is configured to retain the fixing members on an outer side of the outer surface of the cover member when a fastening of the fixing members to the bolt members is released to prevent the fixing members from dropping off the cover member.

Abstract: To provide a chain tension adjustment device for a chain saw. When a first mechanism is rotated around an axis, a bevel gear of a second mechanism is engaged with a bevel gear of the first mechanism and rotated, and a bevel gear of a third mechanism is engaged with the other bevel gear of the second mechanism, so that a shaft portion is rotated. A plate portion integrated with a nut portion of a fourth mechanism screwed on a screw formed on the shaft portion moves in an axial direction, and a guide bar engaged with an engagement portion of the plate portion via an engagement hole moves in a longitudinal direction, to adjust tension of the chain saw by adjusting the movement amount. Thus, fine adjustment can be performed while reducing an operating force, and reducing the weight and the cost.

Abstract: A knob sub assembly for adjusting bar clamp tension holding a chainsaw bar of a chainsaw to a chainsaw body of the chainsaw may include a cap, a nut and a feedback assembly. The nut may be threaded to facilitate engagement with a fixing post of the chainsaw body responsive to a transfer of torque from the cap to the nut when the cap is rotated by an operator. The feedback assembly may be disposed substantially between the cap and the nut to at least selectively transfer torque from the cap to the nut. The feedback assembly may provide feedback to the operator when a predetermined threshold of applied torque is reached.

Abstract: To provide a chain tension adjustment device for a chain saw. When a first mechanism is rotated around an axis, a bevel gear of a second mechanism is engaged with a bevel gear of the first mechanism and rotated, and a bevel gear of a third mechanism is engaged with the other bevel gear of the second mechanism, so that a shaft portion is rotated. A plate portion integrated with a nut portion of a fourth mechanism screwed on a screw formed on the shaft portion moves in an axial direction, and a guide bar engaged with an engagement portion of the plate portion via an engagement hole moves in a longitudinal direction, to adjust tension of the chain saw by adjusting the movement amount. Thus, fine adjustment can be performed while reducing an operating force, and reducing the weight and the cost.

Abstract: To provide an operation lever including a first lever that has a base end portion swingably supported to a peripheral portion of a nut member for fastening a guide bar in a chain saw, and a second lever that is engaged with the first lever in a manner slidable in an axial direction. The operation lever can be placed in a receiving portion of the nut member with an axial length thereof shortened, and can be manipulated to rotate the nut member by being gripped on an outer end portion of the second lever in a state in which the operation lever is lifted out from the receiving portion and the axial length is lengthened. Thus, a sufficient fastening force for the guide bar can be obtained, and operability can be improved.

Abstract: In a chain saw, an operating shaft member axially rotated by a manual operation of a rotating lever is disposed so that an axial direction thereof may be inclined against an attaching surface of a guide bar in which a saw chain is wound around a circumference thereof, a driving bevel gear attached to an end portion of the operating shaft member meshes with a driven bevel gear attached to an end portion of a rotating shaft member, and the rotating shaft member is axially rotated. Thus, the guide bar is moved in a longitudinal direction thereof to adjust tension of the saw chain.

Abstract: A handheld work apparatus has a guide bar having a periphery along which a chain runs. The work apparatus has a housing and a fastening arrangement for fixing the guide bar to the housing. The fastening arrangement has an actuating device which can be actuated in a fastening direction in order to fix the guide bar. The work apparatus has a tensioning device to tension the chain. The tensioning device includes a tensioning spring. When the fastening arrangement is loosened, the tensioning spring exerts a force in a tensioning direction of the chain on the guide bar. Simple operation and a simple construction are achieved if the tensioning spring is in operative connection with the actuating device and is tensioned during actuation of the actuating device in the fastening direction.

Abstract: A handheld engine-driven cutter is provided with a disk blade and a four-stroke engine that drives the disk blade. By employing the four-stroke engine, exhaustion of unburned gas and fuel consumption can be reduced. The engine cutter is further provided with a filter through which air provided to the four-stroke engine passes, a carburetor that mixes fuel and the air that passed through the filter, and a casing that houses the filter and the carburetor. The filter and the carburetor are arranged to align on a straight line along a direction of flow of the air passing through the filter and the carburetor.

Abstract: A chain saw includes a housing, a cutting chain, a chain wheel, a guide plate cooperating with the chain wheel to support and guide the cutting chain, a cover plate cooperating with the housing, and a chain wheel tensioning mechanism. The chain wheel tensioning mechanism is wholly combined and disposed movably in the housing so that during the assembly procedure, positions and states of parts such as the cutting chain, the guide plate, the tensioning nut, and the chain wheel can be observed and so that the positioning is accurate and the operation is simple and quick. A distance between the guide plate and the chain wheel is adjusted to tension the cutting chain by use of a tensioning handwheel that is connected to a transmission member where the transmission member causes the tensioning nut fixed on the guide plate to move.

Abstract: An arrangement for attaching a bar of a hand-held motor driven tool, such as a chain saw, to a body of the tool includes at least one first engagement device, a cover portion adapted to bear against a bar such that the bar is arranged between the cover portion and the body, and at least one second engagement device is adapted to engage the first engagement device for securing a bar between the cover portion and the body. The second engagement device is arranged to move a first distance along the first engagement device in a direction of the rotation axis of the second engagement device for securing a bar between the cover portion and the body. The second engagement device is captively attached to a spring biasing member having an undistorted position and a distorted position.

Abstract: A quick change chain saw system includes a swing arm and a hydraulic clamp device. The swing arm extends from the hydraulic clamp device. The swing arm retains drive sprocket components and is retained by a tree harvester or wood processor unit. The hydraulic clamp device includes a hydraulic clamp block, a puck plate, a clamp plate and a detent pin. The puck plate includes a base plate and three stud projections that is actuated with a plurality of pucks in the hydraulic clamp block. Three stud projections extend from the base plate and are inserted through the hydraulic clamp block. The clamp plate is secured to the three stud projections. A spring tensioner is used to bias the chain bar. A retraction tool is used to retract the hydraulic clamp device. The detent pin is used keep the hydraulic clamp in a retracted position for changing the chain blade.

Abstract: A chain saw includes a guide bar for a saw chain, a housing, a sprocket wheel cover, and a stud fixed on the housing for threadably fastening the sprocket wheel cover and the guide bar. The free thread end of the stud has a maximum usable screw-in depth (tmax) for a nut. A stop for the sprocket wheel cover having a stop surface as well as a support surface for contact engaging the stop surface are provided. In the mounted state of the guide bar, a distance (a) remains between the stop surface and the support surface. The support surface contact engages the stop surface when the guide bar is removed and the nut is tightened and screwed onto the studs to a stop screw-in depth. The stop is configured in such a manner that the maximum usable screw-in depth (tmax) is greater than the stop screw-in depth.

Abstract: A chainsaw (100) has a chainsaw body (101), a cutting chain (103) driven by a motor, and a guide bar mounting stud (111) extending from the chainsaw body (101). The chainsaw (100) also has an adjustably connected guide bar (102) having a track for supporting the cutting chain (103) around a periphery of the guide bar (102) and an adjustment pin (114) extending from a side face thereof. The guide bar mounting stud (111) is configured to extend through an elongated slot (112) in the guide bar (102). The chainsaw (100) also has a cam (116) received on the guide bar mounting stud (111) and having an eccentric groove facing the guide bar (102). The adjustment pin (114) is received in the eccentric groove such that rotation of the cam (116) causes the guide bar (102) to move with respect to the chainsaw body (101), thereby tensioning the cutting chain (103).

Abstract: In a chain saw, the tension of a saw chain attached around the outer edge of a guiding bar can be adjusted appropriately by adjusting the force transmitted to a connecting unit during operation of a hand guard. Thus, the saw chain 6 can be easily strained at great tension without use of a strong coil spring.

Abstract: A linear motion mechanism comprises a second rotating shaft having an external thread portion 48a at least at a part of an area in a length direction and an adjusting pin 40 having an opening 60 through which the external thread portion 48a passes. The opening 60 of the adjusting pin 40 has a cross-sectional shape that enables the adjusting pin 40 to move in a radial direction of the second rotating shaft. An inner thread part 62 that engages with and disengages from the external thread portion 48a of the second rotating shaft depending on a position of the adjusting pin 40 is formed on an inner surface of the opening 60. A spring 56 capable of retaining a state in which the external thread portion 48a and the inner thread part 62 engage with each other is arranged on the adjusting pin 40.

Abstract: A chain saw apparatus has a body, a guide bar extending from the body, a drive sprocket rotatably mounted to the body, a chain affixed to the drive sprocket and to the guide bar, an engagement device positioned on the body and cooperative with the guide bar so as to allow the guide bar to move toward and away from the body, and pushing device for automatically moving the guide bar away from the drive sprocket. The pushing device has a slide and an elastic component. The slide bears against a rear end of the guide bar. The elastic component urges between the body and the slide.

Abstract: A saw having a power unit with a drive component and a housing for the power unit with a frame. A bar on the housing guides movement of an operatively positioned cutting chain driven by the drive component in an endless path. The bar is movable guidingly in opposite directions in a predetermined path relative to the housing to thereby vary tension upon an operatively positioned cutting chain. A bar fixing assembly has a knob that is turnable around a first axis relative to the housing in: a) a first direction to a tightened state; and b) a second direction to a loosened state. A first assembly resiliently bears against the knob to at least one of: a) inhibit turning of the knob around the first axis; b) provide a sensory indication to a user grasping and turning the knob that the knob is moving around the first axis; and c) reduce play in the knob.

Abstract: Tightening device of the screw-nut type includes a tightening member, which can be rotated, and a rotary wrench for this tightening member, equipped with a handling arm. The wrench and the tightening member are joined by a connecting device in such a way that the wrench can swivel in relation to the tightening member around a swivel axis substantially perpendicular to the screwing axis of the tightening member. Thus, it can be placed in a rest position substantially perpendicular to the screwing axis and can rotate the tightening member around the screwing axis or rotated freely in relation to the tightening member around the screwing axis, over a range of angular clearance (?) of at least 170°.

Abstract: A chainsaw has a cam lever and cam assembly that can be used to adjust the tension of a guide bar in the chainsaw. Once the tension of the guide bar has been lessened, the guide bar can be moved back and forth by using a chain-tightening knob and tightening mechanism. The movement of the guide bar causes the chain to tighten or loosen on the guide bar.

Abstract: The present invention discloses a vegetation pruning device comprising a main body; a cutting element; a guide bar for supporting the cutting element; a motor for driving the cutting element; a first handle assembly; a second handle assembly; a locking mechanism for detachably securing the second handle assembly to the first handle assembly; a connecting mechanism being positioned between the first handle assembly and the guide bar; the first handle assembly or the second handle assembly being operable to move linearly toward to or away from the guide bar, the connecting mechanism is provided to change the linearly movement of the first or the second handle assembly to the pivoting of the guide bar. Both of the first handle assembly and the second handle assembly are moving linearly, which makes the operator feel comfortable in any working instance.

Abstract: A linear motion mechanism comprises a second rotating shaft having an external thread portion 48a at least at a part of an area in a length direction and an adjusting pin 40 having an opening 60 through which the external thread portion 48a passes. The opening 60 of the adjusting pin 40 has a cross-sectional shape that enables the adjusting pin 40 to move in a radial direction of the second rotating shaft. An inner thread part 62 that engages with and disengages from the external thread portion 48a of the second rotating shaft depending on a position of the adjusting pin 40 is formed on an inner surface of the opening 60. A spring 56 capable of retaining a state in which the external thread portion 48a and the inner thread part 62 engage with each other is arranged on the adjusting pin 40.

Abstract: A sprocket cover arrangement for a hand-held chain saw has a housing and a sprocket cover that has an opening and is connected to the housing. At least one stud bolt having a first end secured to the housing and having a second end that is a free threaded end is provided. The free threaded end projects through the opening of the sprocket cover to an exterior side of the sprocket cover when the sprocket cover is positioned in an operating position on the housing. A nut is screwed onto the free threaded end of the at least one stud bolt on the exterior side of the sprocket cover so as to secure the sprocket cover on the housing. The nut is secured captively, rotatably and with play in the opening of the sprocket cover.

Abstract: The invention relates to a rapid tensioning apparatus as well as to a chain unit and a sword suitable for it, by means of which the placing of saw chain and sword on the main body of the chain saw can be readily carried out and a tensioning of the saw chain is made possible without problems. In the rapid tensioning apparatus a wedge is mounted on the sword of the chain saw whereas a movable tensioning lever arrangement comprising a counterwedge is positioned on the chassis in the area of the drive shaft. In a special manner the course of the movement of the elements of the tensioning lever arrangement in the transition from the open position to the closed position is designed in such a manner that the counterwedge acts on the wedge mounted on the sword and secures the sword on the chassis by contact pressure. At the same time the sword is pushed longitudinally in the direction away from the drive pinion here by the pushing pressure so that the saw chain is tensioned.

Abstract: A chain saw includes a housing, a sprocket wheel which is provided in the housing for driving a saw chain, and a chain guide for guiding the movement of the saw chain. The chain guide extends out longitudinally from the housing and is movable longitudinally relative to the housing. The chain saw includes a chain tensioning device. The chain tensioning device comprises a driven member arranged on the chain guide and a driving member which drives the driven member to move the chain guide longitudinally and a rotating device rotating the driving member. A stepless clutch device is arranged between the rotating device and the driving member. The chain tensioning device presses the chain guide while it tensioning the saw chain. Thus it prevents effectively the chain guide from loosing after the saw chain is tensioned. The operation of the chain tensioning device is labour-saving. The chain tensioning device has a stable structure and it is hard to be worn.

Abstract: A chainsaw that increases the level of operator safety by reducing or eliminating cut through and kickback injuries without impeding cutting operations, and increases operator comfort through ergonomics, therefore extending stamina. This is accomplished by a dual stage multi-hinged bar device that physically inhibits kickback and cut through injuries. The device, which returns to it's original position after cutting, will open up a total of 88 degrees to allow for cutting of items that are larger than the length of the guide bar. Relocation of the handles leads users toward physically holding the saw in such a manner that creates an ergonomically advantageous body position, reducing fatigue and strains. The body of the saw and the bar device will rotate 45 and 90 degrees both right and left while the operators grip on the saw remain in the same position. The chainsaw also incorporates an easy to use chain adjustment.

Abstract: A chain saw an operator can easily strain a saw chain is provided. In the chain saw 1, the tension of a saw chain 6 attached around the outer edge of a guiding bar 4 can be adjusted appropriately by adjusting the force transmitted to a connecting unit 24 during operation of a hand guard 40. Thus, the saw chain 6 can be easily strained at great tension without use of a strong coil spring.

Abstract: A chainsaw (100) has a chainsaw body (101), a cutting chain (103) driven by a motor, and a guide bar mounting stud (111) extending from the chainsaw body (101). The chainsaw (100) also has an adjustably connected guide bar (102) having a track for supporting the cutting chain (103) around a periphery of the guide bar (102) and an adjustment pin (114) extending from a side face thereof. The guide bar mounting stud (111) is configured to extend through an elongated slot (112) in the guide bar (102). The chainsaw (100) also has a cam (116) received on the guide bar mounting stud (111) and having an eccentric groove facing the guide bar (102). The adjustment pin (114) is received in the eccentric groove such that rotation of the cam (116) causes the guide bar (102) to move with respect to the chainsaw body (101), thereby tensioning the cutting chain (103).

Abstract: A chainsaw has a cam lever and cam assembly that can be used to adjust the tension of a guide bar in the chainsaw. Once the tension of the guide bar has been lessened, the guide bar can be moved back and forth by using a chain-tightening knob and tightening mechanism. The movement of the guide bar causes the chain to tighten or loosen on the guide bar.

Abstract: A chainsaw has a cam lever and cam assembly that can be used to adjust the tension of a guide bar in the chainsaw. Once the tension of the guide bar has been lessened, the guide bar can be moved back and forth by using a chain-tightening knob and tightening mechanism. The movement of the guide bar causes the chain to tighten or loosen on the guide bar.

Abstract: Tightening device of the screw-nut type includes a tightening member, which can be rotated, and a rotary wrench for this tightening member, equipped with a handling arm. The wrench and the tightening member are joined by a connecting device in such a way that the wrench can swivel in relation to the tightening member around a swivel axis substantially perpendicular to the screwing axis of the tightening member. Thus, it can be placed in a rest position substantially perpendicular to the screwing axis and can rotate the tightening member around the screwing axis or rotated freely in relation to the tightening member around the screwing axis, over a range of angular clearance (a) of at least 170°.

Abstract: The chain saw of the present invention includes a cutting device having a cutting chain mounted to turn around a drive sprocket and a guide bar which can be immobilized on a body by a jamming device and moved in two directions tending to move it closer to or further away from the drive sprocket relaxing the tension of the chain or ensuring its tension, respectively. The chain saw features a pushing device tending to automatically move the guide bar away from the drive sprocket, when the jamming device is loosened. The pushing device is formed by a slide against the rear end of which rests the rear end of the guide bar and an elastic component, preferably constituted by a helical spring resting, through the intermediary of its opposite ends against a fixed element of the body and against a surface of the front end of the slide.

Abstract: A keyless adjusting mechanism for a chain saw is disclosed herein, which comprises a protection cover, an adjusting bolt, an adjusting stud, and an adjusting ring with a driver gear, wherein the adjusting bolt is coupled with a driven gear for engaging with the driver gear of the adjusting ring, the adjusting stud is coupled with a chain board and has a threaded hole for engaging with the corresponding adjusting bolt. Accordingly, when the adjusting ring is rotated, the driver gear can bring the driven gear to let the adjusting stud move axially along the adjusting bolt such that the chain could be adjusted to tighten or loosen. In addition, a knob with a handle is coupled to the adjusting ring. The handle can be withdrawn in the knob or extended out of the knob for convenient twist.

Abstract: The invention relates to an auto tensioner of a chain saw. A spiral guide groove (16) of the disk (15) engages with a protrusion 10a of a slider piece (10) and the slider piece (10) is slidably stored in a guide portion (9) formed in a chain cover (2) via a spring (14). A tensioner (11) comprising a protrusion (11) engaged with a guide bar is slidably stored in the slider piece 10 via a coin spring (12). The protrusion (10a) contacts an outer circumference face of the spiral guide groove 16 on a diameter passing through a rotating center of the disk, and an unshown nut for engaging with a stud bold 6 provided on an engine cover side is attached on the rotating center of the disk (15). A rotation of the disk enables to fix the chain cover (2) and move the guide bar.

Abstract: A chain saw is provided in which the tension of a cutting chain extending along a periphery of the guide bar may be adjusted without use of a tool. A locking knob is provided which engages with a cover of the chain saw. Protrusions of the locking knob fit within corresponding notches of the cover. The shape of the protrusions and the notches allow rotation of the locking knob in a first direction but not a second direction. Upon disengaging the locking knob from the cover, the guide bar may move relative to the engine housing and clutch cover to tighten the cutting chain extending along a periphery of the guide bar.

Abstract: The invention relates to an auto tensioner of a chain saw. A spiral guide groove (16) of the disk (15) engages with a protrusion 10a of a slider piece (10) and the slider piece (10) is slidably stored in a guide portion (9) formed in a chain cover (2) via a spring (14). A tensioner (11) comprising a protrusion (11) engaged with a guide bar is slidably stored in the slider piece 10 via a coin spring (12). The protrusion (10a) contacts an outer circumference face of the spiral guide groove 16 on a diameter passing through a rotating center of the disk, and an unshown nut for engaging with a stud bold 6 provided on an engine cover side is attached on the rotating center of the disk (15). A rotation of the disk enables to fix the chain cover (2) and move the guide bar.

Abstract: A part positioner according to the present invention is used for fixing a part having a first pair of opposite portions extending along a mounting surface to the mounting surface by use of a clamping fixture. The part positioner includes a pressing member for pressing the part against the mounting surface with a clamping force of the clamping fixture. The pressing member includes a pressing portion (tapered projection) for pressing the first pair of opposite portions in opposite directions in a position apart from the clamping fixture, owing to a clamping operation of the clamping fixture.

Abstract: A bar adjustment assembly for a chain saw includes a shaft, a bar adjustment pin that is journalled for rotation relative to the shaft, and a pin alignment spring that biases the pin toward an engagement position. A void is provided for accommodating the pin as it is rotated away from the engagement position by a guide bar that has been incorrectly attached.

Abstract: The invention relates to an auto tensioner of a chain saw. A spiral guide groove (16) of the disk (15) engages with a protrusion 10a of a slider piece (10) and the slider piece (10) is slidably stored in a guide portion (9) formed in a chain cover (2) via a spring (14). A tensioner (11) comprising a protrusion (11) engaged with a guide bar is slidably stored in the slider piece 10 via a coin spring (12). The protrusion (10a) contacts an outer circumference face of the spiral guide groove on a diameter passing through a rotating center of the disk, and an unshown nut for engaging with a stud bolt 6 provided on an engine cover side is attached on the rotating center of the disk (15). A rotation of the disk enables to fix the chain cover (2) and move the guide bar.

Abstract: A chain saw includes a retaining assembly for a tensioning arrangement for adjusting the tension of the cutting chain in the chain saw. The retaining assembly includes a rotatable knob for operation with the chain saw's engine chassis, clutch cover, and guide bar and is rotatable about an axis of rotation between a tightening position for holding the guide bar in place and a loosening position enabling the guide bar to be repositioned whereby the tension in the cutting chain is adjusted. A locking mechanism is provided for locking and unlocking the knob. When the locking mechanism is in a locking position, moveable engagement points of the locking mechanism extended beyond the confines of the knob and engage fixed engagement points. When the locking mechanism is in the unlocking position, the moveable engagement points, having moved inwardly of the confines of the knob, are disengaged from the fixed engagement points.