Sandvik Ab

Sandvik Aktiebolag

Per-Olof Lofgren

Arvo Leini

Staffan Lindberg

Karl Olov Pettersson

Karl-Olof Pettersson

A saw chain is automatically sharpened during use by causing top sides of the cutter links to be pressed against a stationary abrasive block when the saw chain is running around a rim type sprocket. The cutting link includes a cutting edge, and a depth gauge recessed radially from the cutting edge by a distance defining the cutting depth. The generally cylindrical outer periphery of the drive sprocket has raised steps or ramps formed thereon which lift the front end of the cutter links relative to the rear ends, thereby allowing a sufficiently large cutting depth to be achieved without locating the depth gauge far in front of the front rivet. This reduces vibration and instability of the saw chain when sawing.

Automatic chain sharpening device mounted on a chain saw

A chain saw guide bar is formed of a middle plate and a pair of side plates affixed on opposite sides of the middle plate. One (or both) of the side plates carries nozzles for emitting liquid dyes of different respective colors. Channels for conducting liquid dyes to the respective nozzles are formed by grooves cut in the interface between the middle plate and a side plate. Each channel is surrounded by a laser weld which completely isolates the channels from one another to avoid mixing the colors. The laser welds also secure the middle and side plates together. Additional laser welds secure the middle and side plates together, the additional laser welds being discontinuous.

Chain saw guide bar having dye-emitting nozzles

A chain saw guide bar allowing spraying of the cut surface of a stump with liquid, is made from three joined plates with a spraying device comprising one or more supply channels provided as cutouts in the central plate. A plurality of spraying holes are provided in one or both side plates. The spraying holes are offset towards the guide bar edge so far that less than the entire area of spraying hole area overlaps the edge of the supply channel.

Growing community of inventors

Vallsta, Sweden

Per-Olof Lofgren