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: A saw chain, for power saws, having cutting links alternately on the right-hand and left-hand sides, central driving links, and lateral connecting links. The individual links are pivotally interconnected by means of pins. At least some driving links are provided with a safety projection, which extends in the opposite direction to the direction of rotation. The outer edge of the safety projection is radially farther than the outer edges of the connecting links of the following driving link. As the chain rotates around the free end of the guide rail, in the direction of travel, the rearmost section of the outer edge of the safety projection describes a trajectory which is greater by predetermined amount than the trajectory described by the tip of the cutting tooth.