Andreas Stihl

Other

Hermann Weiss

Klaus Hoppner

Dieter Wieland

Gisbert Kohler

Hans Nickel

Wolfgang Weissert

Reinhard Friedrich

Anton Wehle

Volker Schurr

Jurgen Wolf

Wolfgang Dorner

Gotz Landwehr

Gerhard Meyer

Reinhard Gommel

Helmut Lux

Reinhard Siede

Siegfried Frank

Georg Leppla

Luise Stephani

Heinz Layer

Rainer Glockle

Volker Glockle

Klaus Schnaithmann

Wolfgang Kirtz

Jurgen Laser

Hans G Salomon

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.

Internal combustion engine for a portable handheld work apparatus

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.

Portable handheld tool having a handle arrangement decoupled by

The invention relates air-cooled combustion engine powered handheld tool. A fan screen has radial struts and tranverse walls which together define windows. The effective intake suction area of the fan is less than the area of the screen. Wood chips and the like are kept out by the size of the windows and the reduced air flow velocity through the screen.

Portable handheld motor tool having a one-piece fan housing

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.

Handle for a chain saw

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.

Internal combustion engine

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.

Air-intake arrangement for a two-stroke engine

A centrifugal clutch for power saws. The clutch includes a rotating driven centrifugal weight carrier, and a clutch drum which is concentric to the axis of rotation of the carrier. At least one centrifugal weight engages the clutch drum at predetermined speed of the carrier. The centrifugal weight is coupled with at least one return weight in such a manner that the return weight opposes the pressing force of the centrifugal weight when the speed increases over a certain level.

Centrifugal clutch for power saws

A safety device on a power saw which is provided with two handles, especially for a power chain saw. The saw has a brake which engages a drive member of the cutting tool of the saw under the effect of a force retainer; the brake is held in the ineffective or inoperative position by a stop which is actuated by operating elements associated with the two handles. The stop is locked in its locking position and is releasable by means of an adjustment device which is driven by an energy source supplied by the engine of the saw, and is controlled by a control device which is connected to the operating elements which are embodied as key or contact switches.

Safety device on a power saw

A safety device for a power chain saw or the like. The safety device has a mass body which is responsive to acceleration forces and is operatively connected with a brake device. The mass body has at least one support part under a holding force, the mass body being displaceable from a rest position under the effect of the acceleration force (a 'monostable inertia switch'). The mass body in a preferred embodiment is made as a bar or rod magnetically attracted to a supporting surface and capable of being tilted from an upright or vertical position temporarily into electrically conducting engagement with an annular ring spaced therefrom and surrounding the upper free end of the bar or rod, permitting electrical connection to be established to actuate a brake device for stopping the power chain saw in case of an emergency, including tripping, falling, slipping, or sudden shock, as a safety feature of an operator of the power chain saw. Alternatively, uniformly spaced spring means can be provided radially aligned relative to a ball or spherical member also serving as an inertia body for triggering a brake release or actuation signal responsive to acceleration force in all directions rather than only in one plane of movement. A permanent magnet or electromagnet can be used for purposes of actuation of the brake device responsive to accelerating force in any direction. Also, a luminous diode may be arranged in a cover for a recess in which the mass body in the form of a ball or rod is located subject to displacement movement, and this luminous diode is directed in an angle of incidence against a reflector surface of the mass body; a photodiode, photo-transistor or the like is arranged in an angle of reflection relative to the reflector surface. Alternatively, on the cover there is arranged a magnet switch or dry-reed switch, or an inductive or capacitive proximity switch, above the mass body. Control lines are connected and provided with a holding part and an abutment part which are both electrically conductive; an insulation is arranged between the holding part and the abutment part as well as on the outer surface thereof. A cover is arranged above the mass body on the side remote from the counter engagement surface of the holding part; this cover is spaced above the mass body by a distance which is less than the depth of the recess. The mass body may be a permanent magnet, and has an engagement surface which engages against a counter engagement surface of the holding part by way of magnetic force.

Safety device

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.

Growing community of inventors

Steinheim, Germany

Hermann Weiss