Abstract: This invention relates to a flexible intake system for a crankcase scavenged two-stroke internal combustion engine (10) having an additional air supply to its transfer ducts. The intake system comprises a flexible intake duct (22) connecting a fuel supply unit (21) e.g. a carburettor with an engine cylinder (11) and at least one flexible air duct (40) connecting a valve housing (42) for additional air with the engine cylinder. The end portion of the flexible intake duct (22) and at least one air duct (40) is secured to the cylinder by means of a baffle (23) made of a stiffer material than the ducts (22, 40) themselves.

Abstract: A combined fuel tank and handle unit for a motorized, handheld tool includes a substantially closed volume, a handle, and a joint between two parts of the unit. The joint protrudes a distance beyond the surrounding surfaces. At least one rib is disposed at a distance from the joint on the underside of the tool.

Abstract: A chainsaw having a brake arrangement comprising: a kickback brake drum (10) arranged to rotate together with a drive sprocket driving a saw chain of a chainsaw, a kickback brake for quickly stopping the saw chain if at least one kickback actuator (7) is actuated, the kick back brake including a kickback brake band (11) extending around the kickback brake drum (10) and means for tightening the kickback brake band (17-19, 22) around the kickback brake drum (10), and; a coasting brake weaker than the kickback brake being arranged to brake the saw chain (2) unless a coasting actuator of the chainsaw is actuated, the coasting brake includes a coasting brake band extending around a coasting brake drum (10) arranged to rotate together with the drive sprocket (37), and means for tightening the coasting brake band (20, 22, 23) around the coasting brake drum, wherein the coasting brake band is either at least one longitudinally slit portion (11b) of the kickback brake band or a separate brake band.

Abstract: The present invention provides a clutch drum (7) being a part of a centrifugal clutch (4) for an internal combustion engine (1). The centrifugal clutch (4) is arranged to transmit a rotational motion of a crank shaft (2) at higher engine speed and to declutch at lower engine speed. The clutch drum (7) includes a peripheral portion (8), with thickness B, which is arranged to be engaged on the inside by weighted arms of a driving disc (5) at higher engine speed and the clutch drum further includes an end portion (9), with thickness A, joining a drum hub (13) and the peripheral portion (8), and the thickness A is less than the thickness B.

Abstract: The invention relates to an arrangement for attaching a bar (1) of a hand-held motor driven tool, such as a chain saw, to a body (2) of the tool, the arrangement comprising: at least one bolt (3), having a first part (3a), securely arranged to the body (2), and a second part (3b) extending from the body, the second part having an engagement portion (3c) for engaging a nut (5, 15); a cover portion (4, 14) adapted to bear against a bar (1) such that the bar is arranged between the cover portion (4, 14) and the body (2); and at least one nut (5, 15), captively attached to the cover portion (4, 14). The nut is adapted to engage the engagement portion (3c) of the bolt (3) for securing a bar (1) between the cover portion (4, 14) and the body (2), the nut (5, 15) having a rotation axis (X). The nut is also arranged to move a first distance (A) along the engagement portion (3c) of the bolt (3), in a direction of its rotation axis (X), for securing a bar (1) between the cover portion (4, 14) and the body (2).

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 handle member for a motorized, handheld tool includes a substantially closed volume, a handle, and a joint between two parts of the handle member. The joint protrudes a distance beyond the surrounding surfaces. At least one rib is disposed at a distance from the joint on the underside of the tool.

Abstract: A crankcase scavenged two-stroke engine (1) comprises a cylinder (15) including scavenging ports (31, 31?) and at least one exhaust port, a piston (13), a connecting rod (17), a crankshaft (18) and a generally sealed crankcase (16). The crankcase inducts a fuel/air mixture and is connected to the scavenging ports (31, 31?) by means of transfer ducts (3, 3?) which, as the piston (13) is travelling from a lower position towards a higher position, are inducting pure air let in from connecting ports (8, 8?) near the scavenging ports (31, 31?) in the cylinder (15). The transfer duct (3, 3?) volume is less than 20% of a volume swept by the piston (13) during an entire revolution of the crankshaft (18). Recesses (10, 10?) are formed in an outer periphery of the piston (13), said recesses (10, 10?) co-operating with the connecting ports (8, 8?) in the cylinder wall for controlling the filling of the transfer ducts (3, 3?) with air.

Abstract: A cylinder (1) for a crankcase scavenged two-stroke engine, comprising a cylinder bore (2) with centre line (12) and on opposite sides of the cylinder located closed transfer ducts (3, 3?), which cylinder (1) has an underside (4) essentially perpendicular towards the cylinder bore (2), intended to be connected to a crankcase (5) in a parting plane (A), and besides an inlet (8) for air/fuel mixture, the cylinder is provided with at least one inlet (9, 9?) for additional air to the combustion chamber, which inlet for additional air runs through a cylinder wall (11) and via a recess in the piston and a transfer port (6, 6?) leads down into the transfer ducts (3, 3?).

Abstract: A cylinder (1) for a crankcase scavenged two-stroke engine, comprising a cylinder bore (2) with centre line (12) and on opposite sides of the cylinder located closed transfer ducts (3, 3?), which cylinder (1) has an underside (4) essentially perpendicular towards the cylinder bore (2), intended to be connected to a crankcase (5) in a parting plane (A), and besides an inlet (8) for air/fuel mixture, the cylinder is provided with at least one inlet (9, 9?) for additional air to the combustion chamber, which inlet for additional air runs through a cylinder wall (11) and via a recess in the piston and a transfer port (6, 6?) leads down into the transfer ducts (3, 3?).

Abstract: This invention relates to a throttle control device for a hand held tool, such as a chain saw. The tool is provided with a forwardly extending wire (17) for transmitting a motion from a throttle control lever (12) turnably arranged about a first axis (14) to a throttle valve. One end of the wire is secured to a wire arm (15) that is turnably arranged about a second axis (16). The wire arm is provided with one or several teeth (19, 20) cooperating with corresponding means on the throttle control lever (12) and the second axis (16) is arranged behind the first axis (15).

Abstract: A crankcase scavenged two-stroke engine (1) comprises a cylinder (15) including scavenging ports (31, 31?) and at least one exhaust port, a piston (13), a connecting rod (17), a crankshaft (18) and a generally sealed crankcase (16). The crankcase inducts a fuel/air mixture and is connected to the scavenging ports (31, 31?) by means of transfer ducts (3, 3?) which, as the piston (13) is travelling from a lower position towards a higher position, are inducting pure air let in from connecting ports (8, 8?) near the scavenging ports (31, 31?) in the cylinder (15). The transfer duct (3, 3?) volume is less than 20% of a volume swept by the piston (13) during an entire revolution of the crankshaft (18). Recesses (10, 10?) are formed in an outer periphery of the piston (13), said recesses (10, 10?) co-operating with the connecting ports (8, 8?) in the cylinder wall for controlling the filling of the transfer ducts (3, 3?) with air.

Abstract: Handle (11) for a hand held engine powered tool comprising at least on lever or button for controlling the tool. The handle (11), and the tool fuel tank placed inside the handle, is made of at least two handle sections joined together. The levers or buttons for controlling the tool is however only secured in one of the handle sections (15, 16) in order to reduce the required grade of precision between the handle sections (15, 16) without affecting the performance of the levers and buttons.

Abstract: Flange assembly for supporting a structure that provides scavenging air supply to an internal combustion engine at the carburetor to the engine. The assembly includes a thin-body flange that is configured to be abuttingly installed upon an end surface of the carburetor. The carburetor has its combustion air intake or port exposed at an outer surface for intaking air for the combustion process. The thin construction of the flange enables advantageous positioning of the adaptive flange. The relative dimensioning of the thin-body flange also contributes to its low-impact as a modification to air inlet arrangement. A combustion air aperture is provided that extends through the thin-body flange. The combustion air aperture is located in the flange for alignment with the combustion air intake. By this alignment, fluid communication is established across the flange and into the carburetor when the flange is abuttingly installed upon the carburetor.

Abstract: A brake triggering device with a pivotably mounted trigger arm (1) located in connection to a handheld working tool's, mainly a chain saw's (2), rear handle (3), with a throttle control (4) and a handle opening (5) located below the handle (3), so that the trigger arm (1), when the saw changes inclination in relation to the operator's forearm, e.g. at the event of kickback or fall, is actuated by the operator's hand or arm, whereby the trigger arm (1) via a transfer mechanism actuates a brake (9) so that this stops the movement of the saw chain. The pivot (10) of the trigger arm is located in connection to a front (11) or a bottom (12) side of the handle opening (5).

Abstract: The invention refers to a cylinder (1) for a two-stroke, crankcase scavenged combustion engine, comprising an inlet pipe (10) for air/fuel mixture, at least one transfer port (17), and at least one outer connecting port (18) intended to be connected to a connecting duct (not shown), whereby the outer connecting port (18) is arranged so that it can be connected to the mentioned transfer port (17) via a piston ported air passage. The outer connecting port (18) is located below the inlet pipe (10) and at least one wall passage (14) extends from the mentioned outer connecting port (18), obliquely upwards through the cylinder wall, to at least one connecting port (16). This design enables the cooling air to flow freely around the cylinder above the inlet pipe (10), which improves the cooling of the cylinder.

Abstract: The invention relates to a crankcase scavenged internal combustion engine (1) of two-stroke type, comprising a cylinder (2) with an inlet tube (10) for air/fuel mixture and a number of transfer ducts (20), a carburetor (12) connected to the inlet tube (10), and an air inlet (24) provided with a restriction valve (25) whereby a piston ported air passage (23, 22, 26, 21) is arranged between the air inlet (24) and the upper part of the transfer ducts (20). The engine's air inlet (24) extends at least partly below and outside the carburetor (12), resulting in a more compact engine design and improved use of the space around the cylinder. Moreover, the cooling air gets better access to the cylinder.

Abstract: A pumping device in connection with saw chain lubrication, especially in connection with a hand-held device, e.g. a chain saw, the pumping device including a pumping house, a piston that is received in the pumping house and means to bring the piston to rotate and simultaneously perform a reciprocating motion in its longitudinal direction, the means including on one hand a worm pinion having means for driving cooperation with a prime mover and on the other hand a gear pinion mounted on the piston. The invention further relates to a worm pinion, preferably included in a device for saw chain lubrication. The invention is characterized in that the worm gear on one hand includes a spirally shaped element, prefabricated as a separate detail, and intended to cooperate with the gear pinion and on the other hand a sleeve shaped element that supports the spirally shaped element.