Abstract: The invention is directed to a closure for a vessel such as a fuel tank or lubricant tank of a portable handheld work apparatus having an internal combustion engine. The closure includes a filling stub formed on the vessel and defining an opening and a cap for closing off the opening seal tight with respect to the ambient when the cap is placed on the filling stub. A holder prevents the cap from being separated from the vessel after the cap has been removed from the filling stub. The holder includes a flexible member having first and second end portions and an elongated flexible segment disposed between the end portions. A first attachment disposed on an inner wall surface of the cap fixedly holds the first end portion on the cap and a second attachment disposed on the vessel fixedly holds the second end portion on the vessel.

Abstract: The invention is directed to an internal combustion engine for a portable handheld work apparatus with an intake pipe or induction elbow being attached to the cylinder. The engine can be a two-stroke engine having an inlet opening in the cylinder for the combustion mixture. A cylinder flange is provided at the inlet opening for connecting the induction elbow for conducting the combustion mixture. The induction elbow is made of rubber-elastic material and fits over the cylinder flange in a form-tight manner and is fixed thereto. The connecting end of the induction elbow is provided with an inner annular shoulder which engages an outer annular slot of the cylinder flange which is adapted with respect to volume and is reliably held by a clamp ring having a fixed diameter. The rubber-elastic material of the connecting end is compressed in the annular slot by the clamp ring thereby seating the induction elbow on the cylinder flange in such a manner that it cannot become disconnected.

Abstract: An air filter for a motor-driven tool such as a portable motor-driven chain saw includes a prefilter through which aspirated air flows into a chamber partly defined by a cover that can be secured to the housing of the motor-driven tool. From this space, the air flows through a main air filter to the carburetor of the motor. The main air filter and the prefilter are configured as a one-piece double filter unit.

Abstract: A guide bar for a saw chain of a motor-driven chain saw has a guide groove formed in the periphery thereof. The drive links of the saw chain have projections known as rakers which protrude beyond the side links of the saw chain and which are guided in the guide groove. The guide bar has at least one supply bore in a groove wall through which lubricating oil is supplied for lubricating the saw chain. In the vicinity of the supply bore, a lubricant surface extending approximately parallel to the groove bottom is provided. This lubricant surface extends to at least one supply surface extending as far as the supply bore. The rakers of the drive links move above the lubricant surface with a narrow spacing. The lubricating oil supplied via the supply bore is guided via the supply surface to the lubricant surface where it forms a film into which the rakers extend as the saw chain revolves.

Abstract: The motor-driven chain saw has a first handle at the back end for holding and operating the tool and a second handle mounted farther toward the front of the tool housing. The second handle is mounted so as to be spaced from and to surround the housing and is used for holding and guiding the tool. One end of the second handle is secured to the underside of the housing, and its other end is secured to the longitudinal housing side on which the guide bar for accommodating the moving saw chain is also mounted. The second handle is bent backward from the transverse plane on this side of the housing, approximately at the elevation of the guide bar, where it is secured to this longitudinal side of the housing nearer the back thereof. A strut extends downwardly and rearwardly from the top of the second handle and its free end is secured to the housing together with the end of the rearwardly-extending portion of the second handle.

Abstract: The invention is directed to a motor-driven chain saw wherein a sprocket for a saw chain and a drive wheel for an oil pump are rotatably journalled on the crankshaft. The oil pump pumps oil for lubricating the saw chain and guide bar. The sprocket and the drive wheel are driven via a clutch drum. In this arrangement, a detachable resilient connecting member is provided to connect the drive wheel of the oil pump to the clutch drum at the peripheral wall of the latter. The resilient connecting member protects the drive wheel and the oil pump from excessive wear.

Abstract: The invention is directed to a motor-driven apparatus such as a motor-driven chain saw or the like. It includes a lubricating-oil pump and an oil supply for a work tool and is equipped with a device for interrupting the supply of oil to the tool. This facilitates use of the chain saw apparatus with an accessory attachment work tool such as a hedge trimmer, drilling tool or the like for which a flow of lubricating oil is unnecessary.

Abstract: The invention is directed to a power chain saw incorporating a braking device having a release handle. The chain saw includes a carrying handle spaced a distance from the release handle. At least one of the handles is made of a plastically deformable material and can be deformed so as to cause the spacing between the handles to be adjusted within predetermined limits.

Abstract: A hand-guided, motor driven working device with at least one working tool, especially a portable power chain saw. The device has a venting device for the fuel tank, with the venting device comprising a flexible tube, which projects from the upper part of the tank chamber. The free end of the tube is closed except for a labyrinth-like passage or opening. The tube is arranged at least partially within a covering or sheathing, and the tube is guided to an essentially dirt- and contamination-free chamber located as far as possible from the tank, the tool, and the motor.