Abstract: A headband for the mounting of devices carried on the head, in particular medical optical instruments, includes removable cushions which are constructed of an elastic material of stable shape and are located on the headband at regions at which it comes into contact with the head of the user. The cushions include strap profiles with edge strips, which extends along the sides of the cushions and which engage the edges of the headband for securing the cushions thereto.

Abstract: An electropneumatic hammer drill includes a housing containing a guide cylinder in which an exciter piston and a percussion piston are displaceably mounted in spaced relation with an air cushion formed between them. A hollow shaft encircles the guide cylinder within the housing and transmits rotary motion to a tool mounted in the hammer drill. A crankshaft for reciprocating the exciter piston via a piston rod is supported in two bearings located in the guide cylinder. The percussion mechanism for the hammer drill made up of the guide cylinder, the exciter piston, the percussion piston, the crankshaft and the piston rod form a subassembly. The subassembly can be inserted into and removed from the hammer drill as a unit.

Abstract: A dust guard cap for the tool holder in a hand-held drilling device is formed of a casing secured on the tool holder and a cover member mounted on and extending across one end of the casing. The cover member forms an opening through which a tool can be inserted into the tool holder. Attached to the cover member and extending inwardly from the through opening is a resilient sleeve-like torus which forms a seal around the tool. An outwardly projecting bead is formed on the inner end of the torus and bears against the casing.

Abstract: A hand-held device for use in drilling or the like includes a tool holder mounted on a rotating spindle. The tool holder is secured to the spindle so that there is no relative rotation between them. The tool holder has a support ring for securing locking elements in locking engagement within recesses in the spindle. A blocking element secures the support ring against rotation so that the locking engagement is maintained. By releasing the blocking element, the support ring can be rotated releasing the locking elements so that the tool holder can be removed from the spindle.

Abstract: In an electropneumatic drill or chipping hammer with an air cushion transmitting driving force of an exciter piston to a percussion piston, a clutch is provided to interengage a drive motor with the exciter piston. The clutch can be selectively engaged by an axially displacing holding sleeve which positions a tool on the front end of the drill or hammer.

Abstract: In a manually operated electrical appliance, such as a hand drill or the like, a handle is secured to and extends from the appliance housing. Electrical components including contacts are located inside the handle, an electrical cable extends into the handle and is connected to the contacts. An elastic electrical insulating material cover is located within the handle enclosing the cable and covering the electric contacts and insulating both from the handle.

Abstract: In a hand-held drill driven by an electric motor, the motor stator is positioned within a metal casing. A plastic layer covers the interior surface of the metal casing and laterally encloses the stator. Openings are formed through the metal casing between its interior and exterior surface and the plastic layer is held in interlocking engagement within these openings.

Abstract: In a drilling machine, a rod-like stop member is mounted on the machine housing for limiting the extent to which a tool held in the machine can drill into a receiving surface. A handle lever, fitted on the housing, releasably locks the stop member in the desired position. The handle lever is pivotally mounted on the housing and has a specially shaped end surface which, in cooperation with a pressure plate, affords the locking engagement with the stop member. The locking engagement is provided by corrugated surfaces on the pressure plate and the stop member. The specially shaped end surface assures that the locked engagement cannot be released until a form-locking engagement between the pressure plate and stop member is overcome.