Abstract: The invention relates to a lubricating system for an internal combustion engine (1). The system includes a first conduit means (7) connecting a lubricant supply source (5) to the internal combustion engine (1) for supplying lubricant to the internal combustion engine (1). According to the invention, the system further includes a second conduit means (8) connecting a gas supply source to the first conduit means (7) for supplying gas to the first conduit means such that gas bubbles are formed in the first conduit means (7). A sensor (3) detects whether lubricant or whether gas is present in a certain part of the first conduit (7). The certain part being located downstream the connection of the second conduit means (8) to the first conduit means (7). A control unit (6) is connected to the sensor (3), which control unit (6) is arranged to determine whether lubricant is flowing through the first conduit means (7) or not, in response to the detections of the sensor (3).

Abstract: The invention relates to a lubricating system for an internal combustion engine (1). The system includes a first conduit means (7) connecting a lubricant supply source (5) to the internal combustion engine (1) for supplying lubricant to the internal combustion engine (1). According to the invention, the system further includes a second conduit means (8) connecting a gas supply source to the first conduit means (7) for supplying gas to the first conduit means such that gas bubbles are formed in the first conduit means (7). A sensor (3) detects whether lubricant or whether gas is present in a certain part of the first conduit (7). The certain part being located downstream the connection of the second conduit means (8) to the first conduit means (7). A control unit (6) is connected to the sensor (3), which control unit (6) is arranged to determine whether lubricant is flowing through the first conduit means (7) or not, in response to the detections of the sensor (3).

Abstract: The present invention is related to a retarding device for a hand held cutting machine having a housing (1) and a drive engine, which drives a transmission including a number of transmission members (3?, 2) and driving a rotational or semi rotational cutting tool. The retarding device includes brake means (12, 17) arranged to be in close relation with the transmission and for actuating a retarding force on a transmission member (2), the brake means being arranged to automatically put a retarding force on said transmission member when the speed of rotation or the torque of rotation of said transmission member falls below a predetermined value.

Abstract: A cutting trolley having a frame structure and at least two rear wheels on a rear shaft and at least one front wheel, for a cutter of the type that includes a front handle, a rear handle, and a circular cutting blade in the front end of the cutter. The trolley also includes a cutter carrier having a front attachment device and a rear attachment device for the attachment of a cutter on the carrier via a front handle and a rear handle of the cutter, respectively, for trolley carried operation of a cutter. The cutting trolley has an adjustment means, as part of a displacement device, that can adjust the position of the cutter carrier and hence the cutter and the cutting blade for alignment control and/or curve cutting adjustment, such that the adjustment is possible without interrupting the cutting operation.

Abstract: A cutting trolley (2) includes a frame structure (12) and at least two rear wheels (30, 31) on a rear shaft (32) and at least one front wheel (20), for a cutter (31) of the type including a circular cutting blade (5) in a front end of the cutter, and a front handle (6) and a rear handle (7). The trolley also includes a cutter carrier (13), said cutter carrier including a front attachment device (36) and a rear attachment device (37) for the attachment of the cutter on the carrier via said front handle and said rear handle, respectively, for trolley carried operation of the cutter.

Abstract: The present invention is related to a retarding device for a hand held cutting machine having a housing (1) and a drive engine, which drives a transmission including a number of transmission members (3?, 2) and driving a rotational or semi rotational cutting tool. The retarding device includes brake means (12, 17) arranged to be in close relation with the transmission and for actuating a retarding force on a transmission member (2), the brake means being arranged to automatically put a retarding force on said transmission member when the speed of rotation or the torque of rotation of said transmission member falls below a predetermined value.

Abstract: A method for controlling an ignition system of an internal combustion engine having a primary firing pulse generator for charging a capacitor. An electronic switch is included for discharging the capacitor via an ignition coil to generate an ignition voltage. A microcomputer operates the switch to control the ignition timing of the generator. The microcomputer is in communication with a speed sensor that detects the rotational speed of the engine and a speed limitation control that limits the engine speed to a limitation speed below the clutch-in speed of an included centrifugal clutch. The speed limitation control is active or activated when one of either starting the engine or an operating problem of the power tool is detected. The speed limitation control is deactivated when a low speed state of the engine is detected.

Abstract: A method for controlling an ignition system of an internal combustion engine having a primary firing pulse generator for charging a capacitor. An electronic switch is included for discharging the capacitor via an ignition coil to generate an ignition voltage. A microcomputer operates the switch to control the ignition timing of the generator. The microcomputer is in communication with a speed sensor that detects the rotational speed of the engine and a speed limitation control that limits the engine speed to a limitation speed below the clutch-in speed of an included centrifugal clutch. The speed limitation control is active or activated when one of either starting the engine or an operating problem of the power tool is detected. The speed limitation control is deactivated when a low speed state of the engine is detected.

Abstract: An internal combustion engine including structure for lubricating at least one bearing disposed therein. The engine includes an engine housing including a cylinder with a reciprocating piston of the engine and a crankcase volume with a crankshaft having the at least one bearing operatively connected thereto, wherein the crankcase volume contains at least air and a lubricant. Additionally, the engine includes a counterweight arrangement that provides an essentially solid circular profile, at least one passageway on the counterweight arrangement extending to a location adjacent to the engine housing, and at least one passageway extending through the engine housing from a location adjacent to the counterweight to the at least one bearing, wherein the two passageways are selectably aligned by movement of the piston to cause a lubricating flow between the at least one bearing and the crankcase volume.

Abstract: A crankcase scavenged and lubricated four-stroke engine (1) comprising especially: a mixture-preparation device (15) for supplying an air-fuel-lubricant mixture; an intake channel (16) connecting to the crankcase or cylinder to supply at least air (13) to the crankcase volume (12); an overflow channel (17) connecting to the crankcase or cylinder and to the intake opening (7) with intake valve (8) to supply to the intake at least air and lubricant from the crankcase volume; a valve drive assembly (18) driven by a crankshaft (4) for actuating the intake valve (8) and the exhaust valve (10); a valve drive assembly housing (19, 20, 21, 21?, 22) comprising one or more sections (19, 20, 21, 21?, 22) which is/are separate from the crankcase but in communication exclusively with the crankcase volume via at least one small size passage (23, 24, 25, 26, 27), and each section (19, 20, 21, 21?, 22) of the valve drive assembly housing has a lowest part situated closer to the combustion chamber, than the lowest part of the

Abstract: A carnkcase scavenged and lubricated four-stroke engine (1) comprising especially: a mixture-preparation device (15) for supplying an air-fuel-lubricant mixture; an intake channel (16) connecting to the crankcase or cylinder to supply at least air (13) to the crankcase volume (12); an overflow channel (17) conncting to the crankcase or cylinder and to the intake opening (7) with intake valve (8) to supply to the intake at least air and lubricant from the crankcase volume; a valve drive assembly (18) driven by a crankshaft (4) for actuating the intake valve (8) and the exhaust valve (10); a valve drive assembly housing (19, 20, 21, 21?, 22) comprising one or more sections (19, 20, 21, 21?, 22) which is/are separate from the crankcase but in communication exclusively with the crankcase volume via at least one small size passage (23, 24, 25, 26, 27), and each section (19, 20, 21, 21?, 22) of the valve drive assembly housing has a lowest part situated higher in the axial direction of the cylinder bore, i.e.

Abstract: An internal combustion engine including structure for lubricating at least one bearing disposed therein. The engine includes an engine housing including a cylinder with a reciprocating piston of the engine and a crankcase volume with a crankshaft having the at least one bearing operatively connected thereto, wherein the crankcase volume contains at least air and a lubricant. Additionally, the engine includes a counterweight arrangement that provides an essentially solid circular profile, at least one passageway on the counterweight arrangement extending to a location adjacent to the engine housing, and at least one passageway extending through the engine housing from a location adjacent to the counterweight to the at least one bearing, wherein the two passageways are selectably aligned by movement of the piston to cause a lubricating flow between the at least one bearing and the crankcase volume.

Abstract: A diaphragm carburetor having a carburetor casing defining a mixing passage. A measuring chamber is disposed in the carburetor casing and is partitioned into a fuel chamber and a compensation chamber separated by a control diaphragm. The compensating chamber is closed to the surrounding atmosphere but is connected to a channel. An opening of the channel enters into a space between the air filter and a fuel inlet in the mixing passage. The channel is at least partially defined by a pipe extending through the carburetor casing. The pipe is adapted for assembly/disassembly from outside of the casing. The pipe is attached to a spacer for properly orienting and fixing the pipe relative to the casing during assembly.

Abstract: A starter device for an internal combustion engine comprises a unit (1) which is fixed relative to the engine, a movable unit (2) which is rotatable relative to the fixed unit about an axis of rotation (28), included in the movable unit (2) on the one hand a cord drum (42) with a starter cord (47) and on the other hand a driver device (58) for direct or indirect rotation of the engine shaft on rotation of the cord drum by pulling the starter cord, a return spring chamber (4) accommodating a return spring (3) arranged to be tensioned when the movable unit is rotated by pulling the starter cord and subsequently, by resilience, to return the cord drum to its initial position, and also at least one bearing between said fixed and movable units (2, 1).

Abstract: The invention concerns an arrangement relating to a cutting machine, a circular saw machine, a chain saw machine or the like, which is powered by an internal combustion engine. The machine comprises a working unit and a power unit, the power unit comprising at least a pre-filter and a main filter for intake air, and a motor cylinder. The pre-filter and the main filter are provided in a closed pre-filter chamber and in a closed main filter chamber, respectively, the pre-filter chamber forming a top portion of the power unit extending substantially over the entire length and substantially over the entire width of the power unit. The main filter chamber is located under the pre-filter chamber. A closed hood space is provided between the upper side of the pre-filter body and the inside of the roof of a filter cover, and a passage extends from the closed hood space at the side of or through the pre-filter chamber and the pre-filter body, down to the main filter chamber located under the pre-filter chamber.

Abstract: The invention relates to a cutting machine, circular saw machine or the like powered by an internal combustion engine. The machine comprises a cutting unit or corresponding unit having a rotational tool, and a power unit, which comprises an air-cooled motor cylinder in a motor room limited by a casing which at least partly consists of a cylinder cover; and an impeller rotatable about the crank shaft with impeller wings, which during rotation propels a cooling air flow outwards toward the periphery of a fan housing and further to the motor room under and inside the cylinder cover. At least a first filter chamber with a filter for intake air for the internal combustion engine is provided over the cylinder cover, and a nozzle tube for the intake air extends from an intake port close to the periphery of the impeller up through the motor room terminating in the at least first filter chamber over the cylinder cover.

Abstract: In engine-powered machines (motor cutting saw, motor chain saw) with a centrifugal clutch a wearing on the clutch and belt takes place by a high load at an r.p.m. around or above the skidding r.p.m. of the centrifugal clutch. A step for reducing the said wearing can--according to the invention--be taken by limiting the driving torque of the engine in the above-said r.p.m. interval. The invention means that the cutting machine/motor saw is provided with electronic equipment counting r.p.m. and then controlling the ignition system so that the torque of the engine is lowered in a predetermined interval. In a cutting machine ignition is allowed in, for example, every third revolution within the interval 3000-6000 r.p.m. The working mode can also be widened so that the time difference between several revolutions is detected.