Abstract: Grinding with known grinders such as corner, belt or vibratory grinders poses insoluble problems, such as the grinding of inner edges set at an angle to each other for example in retainer strips of window and door glasses. A portable grinder has thus been developed in which the grinding or sanding tool (3, 20, 30) effects an oscillatory movement which, unlike in the state of the art, is effected around a fixed axis of the apparatus (29) with a minimum pivoting angle, preferably between 0.5.degree. and with a high pivoting frequency of between ten thousand and twenty five thousand vibrations per minute. This different oscillation movement makes it possible to provide the grinding or sending tool with almost any shape. Furthermore, grinding does not inevitably have to be made with the transverse surface of the tool (3), in particular the perpendicular surface, in relation to the diametrical axis (29) but it is also possible to use a surface which is almost parallel to the first or is even arched.

Abstract: In a knife for a cutting tool with a pivotally oscillating drive, in particular for severing joint seals or insulations on glass panes, with the knife comprising a holding part for attachment to a drive shaft and a blade part, in order to make replacement more economical when the knife is worn, it is proposed that the blade part be exchangeably attached to the holding part.

Abstract: Grinding with known grinders such as corner, belt or vibratory grinders poses insoluble problems, such as the grinding of inner edges set at an angle to each other for example in retainer strips of window and door glasses. A portable grinder has thus been developed in which the grinding or sanding tool (3, 20, 30) effects an oscillatory movement which, unlike in the state of the art, is effected around a fixed axis of the apparatus (29) with a minimum pivoting angle, preferably between 0.5.degree. and with a high pivoting frequency of between ten thousand and twenty five thousand vibrations per minute. This different oscillation movement makes it possible to provide the grinding or sending tool with almost any shape. Furthermore, grinding does not inevitably have to be made with the transverse surface of the tool (3), in particular the perpendicular surface, in relation to the diametrical axis (29) but it is also possible to use a surface which is almost parallel to the first or is even arched.

Abstract: In order to improve a grinder comprising a grinding tool which is oscillatingly driven through a small pivot angle about a pivot axis fixed on the grinder and which has a grinding surface with at least one corner region, with at least one suction channel extending throughout the grinding tool from an aspirating port to an exhaust port located on a side facing away from the grinding surface, so as to obtain an effective, reliable and, in particular, subsequently attachable dust exhaust system which is designed as simply as possible and does not impair handling of the grinder, it is suggested that the exhaust port be arranged outside of the corner region and that an exhaust hood which can be immovably fixed on the grinder be provided so as to cover the exhaust port in all pivoted positions and allow the corner region of the grinding tool to protrude in an uncovered manner.