Abstract: A method for the production of a slideway-type guide for driven chains such as cutting chains includes the application of a wear-resistant hard metal alloy as a running surface to the slideway of the guide. A bar-shaped blank with a dentritic structure, made from the alloy, is produced to form the running surface, a suction casting process being used in particular for this purpose. The blank is treated by hot isostatic pressing with high pressure at a high temperature. This is followed by an annealing process over a number of hours, at the end of which the structure of the alloy is so altered that the previously acicular and, to some extent, lattice-type carbides are dispersed and converted to rounded and, to some extent, spheroidal bodies which are densely and evenly distributed throughout the alloy. The alloy thereby becomes highly wear-resistant. The bars are then shaped so as to fit onto the slideway, and are fixedly connected thereto.

Abstract: The invention relates to a saw chain for a motor-driven chain saw equipped with a guide bar and a drive motor for imparting a force to the saw chain for moving the latter around the guide bar in a predetermined running direction. The chain saw is further equipped with a device for supplying lubricating oil to the saw chain during the movement thereof. The saw chain includes a plurality of cutting links, a plurality of driving links and a plurality of side links all pivotally interconnected by rivets. Abrasive small particles become entrained in the lubricating oil which can lead to premature wear at the pivot locations. The saw chain of the invention includes a hold-back element in front of a rivet to hold back such particles and yet not affect the flow of lubricating oil to the pivot connection.

Abstract: The invention is directed to a composite crankshaft for a two-stroke engine for portable handheld work tools including chain saws, cutoff machines and the like. In composite crankshafts, a crank pin is connected to a crank web by a press fit wherein the inner diameter of the press-fit bore is expanded toward its axial end in order to reduce stress peaks. In this way, the press-fit surface has a radial spacing with respect to the center longitudinal axis of the press fit which changes. The press fit of the crankshaft of the invention is so configured that the radial distance of the press-fit surface changes in dependence upon the axial spacing to the axial center of the press fit according to an exponential function having the equation f(x)=a.multidot.e.sup.b.multidot.x wherein (a) and (b) are pregiven constants, (x) is the axial spacing and f(x) is the radial spacing.

Abstract: The invention relates to a guide bar having a main member made of solid material for a motor chain saw. The guide bar has two flat sides and narrow edges defining a saw chain path. A cutout extends through the main member of the guide bar for reducing weight. The openings in the main member defined by the cutout are closed by cover plates for maintaining the stiffness and are attached to the main member of the guide bar. A fill body is seated in the cutout with an approximately precise fit and is connected to the cover plates in a force-transmitting manner. In this way, a higher torsion stiffness is obtained while at the same time retaining the reduction in weight.

Abstract: A guide bar for a motor-driven chain saw is disclosed wherein the guide bar is provided with a center cutout extending in the longitudinal direction of the bar which is filled out with a bonded fiber material made of plastic and reinforced with long fibers. The guide bar reduces the weight and facilitates manipulation of the chain saw equipped therewith while at the same time providing a high strength and the capacity to take up bending and torsion loads.

Abstract: The invention is directed to a braking arrangement for a chain saw and includes a brake band and a brake drum which form friction partners with their associated friction surfaces during braking. At least the friction surface of one of the friction partners includes a material which is resistant to conversion to martensitic structure. Particularly suitable materials are those having a cubic face-centered lattice structure, such as, for example, austenitic steel or chrome-nickel steel.