C & E. Fein Gmbh & Co.

C. & E. Feini Gmbh & Co.

Walter Blutharsch

Boris E Rudolf

Andreas Peisert

Thomas Veit

A power tool, which is preferably configured as a right-angle grinder, has a motor-driven hollow spindle to drive a tool, which is fastened between a clamping flange and a counterflange by means of a quick clamping device via a tension spindle, coaxial with the hollow spindle, that is tensioned in the axial direction by means of elastic elements and is displaceable in the axial direction relative to the hollow spindle, by means of a clamping lever, between a clamped position in which the tool is nonrotatably retained between the flanges, and a released position. The clamping lever is mechanically coupled to the motor switch by means of a link rod in such a way that the clamping lever can be moved into the released position only when the motor is switched off. This rules out improper operation and any potential damage to the power tool.

Power tool

A portable grinder (10) has a motor-driven drive shaft (15) and a quick-acting chucking device for a grinding tool (43), which comprises a spindle (20), coaxial with the drive shaft (15), which is braced against the drive shaft (15) by a spring (24) in the axial direction and can be displaced in the axial direction relative to the drive shaft (15) by means of a clamping lever (32). One external free end of the spindle (20) retains the grinding tool (43), which in a released position--with the free end of the spindle (20) extended and the spring (24) tensioned--can be removed from the free end, and in a tightened position--with the free end of the spindle (20) retracted and the spring (24) partly relaxed--is non-rotatably joined to the drive shaft. The free end is configured as a bayonet end (40) which extends though the grinding tool (43). An attachment collet (41) with a bayonet opening can be placed from outside onto the bayonet end (40).

Portable grinder with quick-acting chucking device

An adapter for a grinding tool suited for standard attachment to a grinding machine is provided. The standard attachment comprises a receiving threaded bolt and an attachment nut for securing a supplementary tool in a usual manner. The grinding machine includes a motor-driven hollow spindle, to which a counterflange is firmly connected. A bolt receiving the standard attachment at one end thereof and guided by a flange can be screwed into the hollow spindle. Spring elements are provided for pressing the bolt and thereby the flange against the counterflange of the hollow spindle, in order to secure the standard attachment to the grinding tool. The hollow spindle can be axially displaced by a manual actuating device between an assembly position, in which the adapter may be taken off or attached, and a secured position, in which the adapter is secured against rotation and against axial movement within the hollow spindle.

Adapter for attachment of a supplementary tool

In order to so improve a portable machine tool, in particular, an angle grinder, with a drive, with a work spindle having a tool clamping means and with a securing device which is operable from outside an apparatus housing and by means of which the tool clamping means is transferable from a manually releasable position to a manually unreleasable position in which the tool is clamped--and vice versa--that with a design which is as simple as possible from a structural point of view, rotation of the work spindle is not possible while the tool clamping means is being released or manually tightened, it is proposed that a locking device for non-rotatably fixing the work spindle on the apparatus housing be provided and that the locking device automatically lock the work spindle in a non-rotatable manner when the drive is switched off and the securing device is i the position in which the tool clamping means is manually releasable--and vice versa.

Portable machine tool with automatic locking of the work spindle

In a portable machine tool comprising a protective hood mounted by means of a holding part for rotation on a clamping neck of the portable machine tool, in order to prevent unintentional adjustment of the protective hood, it is proposed that the holding part of the protective hood and a locking part facing the holding part and held in a rotationally fixed manner on a grinder housing in the region of the clamping neck be provided with locking elements which can be brought into engagement with one another, that the holding part or locking part comprise at least one locking element and the respective other part several locking elements, and that the locking elements be disengageable against the force of a spring member.

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Stuttgart, Germany

Walter Blutharsch