Abstract: A protective hood assembly for a grinding machine comprising a protective hood having a predetermined size corresponding to the predetermined diameter of the grinding disc; a fastening receptacle attachable to the grinding machine housing and having a shoulder for receiving the protective hood; and a member for securing the protective hood on the shoulder and including a locking portion, the shoulder of the fastening receptacle having an opening for receiving the locking portion upon fastening of the securing member on the shoulder, at least one of shape, arrangement, number, and size of the locking portion and the opening corresponding to the locking portion, being selected in accordance with the predetermined size of the protective hood in such a way as to prevent mounting on the fastening receptacle protective hoods having a size exceeding the predetermined size of the protective hood.

Abstract: A clamping fixture for detachably fixing a disc-like tool to a spindle in cooperation with a tool-fixing member, and comprising a flange member for clamping the tool between the flange member and the tool-fixing member and a supporting element for attaching the flange member to the spindle in a torque-transmitting relationship and having an annular part, the flange member being axially and rotationally displaceable relative to said annular part, the annular part having a first end surface to be axially supported on the spindle and a second end surface and the flange member having an end surface bearing on the second end surface of the annular part with the second end surface of the annular part and the end surface of the flange member having a plurality of complementary sloping end surface portions inclined toward the spindle axis and defining a wedge angle having a size lying in a self-locking range, and the annular part including a plurality of stop surfaces extending substantially parallel to the spindle a

Abstract: An actuation device for a switch of a hand machine tool, particularly for a Totmann switch which provides for fatigue-free operation. The actuation device includes a front wall provided with a locking projection engageable in a recess formed in the wall of the switch housing. A restoring spring acts on an actuation member. Two spaced ribs with inclined surfaces are provided on the housing wall. The locking projection slides along the inclined surfaces of the spaced ribs. The locking projection may be broken away from the front wall of the actuation member whereby the end of the front wall would slide along the inclined surfaces of the ribs.

Abstract: A clamping fixture for axially clamping a tool, on a flange of a driven spindle and comprising a clamping nut having an internal thread to be screwed on an end portion with an outer thread of the driven spindle, a clamping member arranged between the tool and the clamping nut for transmitting an axial clamping force to the tool upon tightening of the clamping nut, a manually operable adjustable member freely rotatable relative to the end portion of the driven spindle, and a gearing for gear-coupling the adjusting member to the clamping nut and gear-coupling the clamping nut to the clamping member.

Abstract: An angle grinder comprising a hollow drive shaft with a counterflange mounted at an end thereof, a spindle extending through the drive shaft and coupled thereto for joint rotation therewith and an axial displacement relative thereto and having a threaded end portion for receiving thereon a clamp nut cooperating with the counterflange for clamping a grinding wheel therebetween, and a slidable wedge extending transversely through the drive shaft and the spindle and having an inclined surface displaceable along respective inclined surfaces of the drive shaft and the spindle to provide for axial displacement of the spindle relative to the drive shaft.