Abstract: A plastic handle member for manually guided power chain saws is provided. The handle member comprises a one-piece, at least partially tubular, front handle for holding a separate motor unit, the front handle being provided with a lower profiled bar. A rear control handle is provided having an upper portion for accommodating components for controlling a chain saw. A support member is disposed between the front handle and the control handle for interconnecting them. The front handle, the rear control handle, and the support member comprise a one-piece plastic body made of a single material and in conjunction with the lowered profile bar form a self-contained force polygon that absorbs load and vibrational forces by means of vibration-damping elements provided in supports disposed between the handle member and a housing of the separate motor unit for holding the housing of the motor unit.

Abstract: The invention relates to an antivibration device between a motor unit 2 and a handle unit 9 of a portable handheld motor-driven chain saw 1. The antivibration device includes a sleeve-shaped elastic base body 6 having one of its ends 36 in a receptacle 20 of the motor unit 2 and the other end 46 in a receptacle 90 of the handle unit 9. The ends (36, 46) of the base body are fixed in the receptacles (20, 90) by axially engaging plugs (31, 41) in the end sections (30, 40). The guiding characteristics of the motor-driven chain saw are not affected by base bodies which become damaged or soft. This is so because at least one of the stops 31 has a coupling member 50 which bridges an axial spacing (z) between the plugs (31, 41) and projects into the other plug 41 and is latched so that it cannot be axially separated therefrom. A mechanical connection remains between the handle unit and the motor unit when the base body tears off.

Abstract: The invention relates to a portable handheld work apparatus such as a motor-driven chain saw. The apparatus includes an internal combustion engine as a drive motor for a work tool. The engine is mounted in a housing. The engine draws combustion air from the clean compartment of a filter case via an intake channel. The clean compartment is partitioned from a dirt compartment of the filter case by an air filter. The filter case itself is closed by a hood. The cover is configured as a hood of the motor housing and is pivoted about a pivot axis which is held to the motor housing by at least one bearing. In this way, the air-filter case can be cleaned in a simple manner without a tool. When the hood is flipped open, the filter case is freely accessible so that the necessary maintenance of the air filter or cleaning of the filter case is possible.

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: A throttle trigger device for an internal combustion engine of a working tool has a throttle trigger connected to the handle of the working tool so as to be pivotable about a pivot axis. A throttle trigger lock is connected to the handle of the working tool so as to be pivotable about a pivot axis. A spring is connected between the throttle trigger and the throttle trigger lock. The throttle trigger, the throttle trigger lock, and the spring form a unitary part. The spring rests at an abutment of the handle at least when under load such that the spring is divided into functionally independent sections, whereby a first section extends between the abutment and the throttle trigger and a second section extends between the abutment and the throttle trigger lock.

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: The invention relates to a portable handheld tool such as a motor chain saw, cutoff machine or the like having a motor arranged in a housing. The motor drives a work tool via a drive pinion. The portable, handheld tool is provided with a handle arrangement for holding and guiding the tool with the handle arangement being decoupled from the motor system by antivibration elements. Soft antivibration elements are required to obtain high isolation; whereas, the antivibration elements have to be as stiff as possible in order to reliably guide and hold the handheld tool. The antivibration elements holding the handle arrangement on the side of the drive pinion are arranged to lie approximately in a common plane. This arrangement makes it possible to use softer antivibration elements without the required stiffness for guiding and holding becoming too low.

Abstract: The invention is directed to the handle of a portable handheld tool such as a motor-driven chain saw. The handle is configured as a plastic body homogeneous with its bearing portions. The handle is for the most part hollow and can be configured as a unit to include further functional portions such as recesses for vibration attenuators, air guide portions and the like. The plastic handle is especially suited for portable handheld motor-driven chain saws.

Abstract: The invention relates to internal combustion engines and especially to two-stroke engines for portable handheld work tools such as motor-driven chain saws or the like. Material made of light metal alloys is used in two-stroke engines for portable handheld tools in order to save weight. Thus, the crankshaft bearing is made of steel while the bearing covers holding the bearing are made of a magnesium alloy. Heating causes the bearing cover to expand by an amount greater than the crankshaft bearing whereby the press fit of the crankshaft bearing can become endangered and, in an extreme case, a clearance can develop between the crankshaft bearing and the bearing cover. According to the invention, the press fit between the crankshaft bearing and the bearing cover is maintained by placing a plastic annular segment therebetween having a thermal expansion coefficient so selected that it compensates for the different thermal expansions of the bearing cover and the bearing.

Abstract: The invention is directed to an arrangement for controlling the intake air for the carburetor of a hand-held portable tool such as a motor-driven chain saw or the like. During winter operation, the cooling air that is heated by the engine cylinder is carried through a pass-through opening to the carburetor. During summer operation the pass-through opening is blocked by a slide that is pivotally mounted on a pivot axis. The slide selectively opens or closes the pass-through opening and is configured as a deflector which, in its open position baffles the heated cooling air from the engine cylinder and guides it toward the carburetor.

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 an air-intake arrangement for a two-stroke engine for use in hand-guided, engine-driven apparatus such as motor-driven chain saws. The air-intake arrangement includes an air filter and a baffle wall for guiding fuel particles that are buffeted back out of the air induction channel by the engine. The baffle wall has a curvature to define a deflector to redirect the fuel particles in a largely gaseous state towards the carburetor. The arrangement provides an optimum air-fuel mixture which is not overrich and a trouble-free operation of the engine.

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 portable motor chain saw with a braking device, for stopping the saw chain during recoil, and with a release, for the braking device, which in the release position is operatively connected with a locking mechanism of the braking device. The release is an inertial mass which is freely movable along an acceleration path, with the kinetic energy of the inertial mass in the release position being greater than the resistance force of the locking mechanism. The release is held in the ready position by at least one holder, preferably a spring which extends between the saw housing and the release.

Abstract: A portable motor chain saw with a safety braking device to protect against kick-back, recoil or centrifugal movements of the saw. The saw includes a handle supported against the motor housing by damping elements, and also includes a locking device which on the one hand is connected with the handle, and on the other hand engages against a hand guard in such a way that it is released under the influence of relative movement, of the motor housing with respect to the handle, caused by a kick-back or centrifugal movement, consequently releasing the hand guard. The locking device has an abutment surface extending transverse to the direction of centrifugal movement, and this abutment surface cooperates with a projection directed against it.

Abstract: A control device for the engine of an engine driven saw having a carburetor with a normally closed fuel control or throttle valve and a normally open starting or choke valve. The device includes a selector member which has a "stop" position in which the engine ignition is disabled and an "operating" position in which the throttle valve is freely adjustable. The selector member also has a "warm start" position and a "cold start" position with the throttle valve being held in a position of minimum opening thereby in each position while the starting valve is held closed by the selector member only in the "cold start" position of the selector member.

Abstract: A guiding rail arresting device for motor driven hand saws, especially motor chain saws, in which a sword-shaped guiding rail provided with a guiding groove extending in the longitudinal direction of the guiding rail is adapted to be clamped transverse to the plane of said rail against an abutment having associated therewith a counter guiding member for cooperation with the flanks of the guiding groove. The counter guiding member for at least one of the groove flanks is formed by a supporting element adapted when clamping the rail against the abutment automatically to be clamped against the groove flank.