Abstract: A method and a device for hand-operated machine tools, particularly for hammer drills, for optimal cutting of different substrates by energy adaptation, wherein the machine tool, when turned on, is operated initially—preferably in a pre-selectable manner—in a first operating state (I) with reduced power consumption at reduced nominal voltage (e.g., 170 V). After a predetermined time period of 5 seconds, for example, a second operating state (II) with increased power consumption at full nominal voltage of, for example, 230 V, is switched to automatically. In the first operating state with reduced power consumption, the single-blow energy is reduced and/or the hammer rate and rotational speed are decreased. In particular, such a method and device ensures that cutting is carried out without damage in the case of hollow block material and a precise tap-drilling is ensured in the case of solid material.

Abstract: A drill including a hammer mechanism (7) for generating axial blows to be imparted to a tool (6) receivable in a drill spindle, with the hammer mechanism (7) including a first cam disc (11) connected with the spindle (5) for joint rotation therewith, a second cam disc (12) supported in a drill housing (1) without a possibility of rotation relative thereto but with a possibility of axial displacement therein and having a projection (22) extending through the first cam disc (11) and into the spindle (5) for imparting the axial blows to the tool (6) which is received in the working spindle (5) with a possibility of a limited axial displacement relative thereto, a first spring (14) located between a surface (13) of the second cam disc (12) facing in the direction opposite to the drilling direction and a surface in the housing (1) facing in the drilling direction for biasing the second cam disc (12) into the drilling direction, a second spring (23) located between the surface (13) of the second cam disc (12) and a

Abstract: A boring tool, including a housing part (3), a fisture (35) for transmitting a rotational movement to a borer, the transmitting fixture (35) being supported in the housing part and having a central receiving region (36) for receiving the borer (4), two, spaced from each other, bearing members (33, 34) for supporting the transmitting element (35) in the housing part (3), and an arrangement for enabling inclination of a longitudinal axis of the borer (4) relative to the housing part (3).

Abstract: A drill including an elongate shaft (2) a rear end (5) of which is formed as a shank, and a drilling head (10) provided at the front end of the shaft (2) and having central cutting edges (11, 12) extending from a leading center point (14), which is provided substantially at an extension of a shaft axis, backward toward a circumference of the drilling head, and at least one minor cutting edge (13) a portion (n) of which extending transverse to the shaft axis projects beyond a circumference of the shaft (2), with the projecting portion (n) having a length equal from about 10% to 100% of an entire length of the minor cutting edge.

Abstract: A mixing device for mixing free flowing masses in a container includes: a rotating carrier defining a mixing side, a balancing side disposed opposite the mixing side, and a direction of rotation about the rotational axis of the mixing device; a container carrier for carrying the container, the container carrier being disposed on the mixing side of the rotating carrier and further being adapted to rotate counter to the direction of rotation of the rotating carrier; a housing defining a housing center of gravity and being effective as an active balancing weight for the container carrier for balancing moments on the mixing side and on the balancing side; and a counterweight defining a counterweight center of gravity and disposed on the rotating carrier, the counterweight further having a weight matching a tare weight of the housing. The housing and the counterweight are displaceable radially with respect to the rotational axis of the mixing device on the balancing side of the rotating carrier.

Abstract: An apparatus for mixing at least one flowable mass includes a rotatable support (2), a container carrier (1) and container (4) and a separate housing (3). The container carrier (1) and housing (3) each has a central axis inclined relative to the axis of the rotatable support (2). The container carrier (1) can be driven around its axis opposite to the rotational direction of the rotatable support (2). The apparatus is balanced by an equalizing mass (3a) in the housing (3) disposed diametrically opposite the container carrier (1).

Abstract: Tool for driving fastening elements into a hard receiving material, such as concrete, masonry, rock and the like, has a first device (1) for drilling a fastening element into the hard material and a second device (2) for axially propelling the fastening element into the receiving material after it has been partly drilled in. The first device (1) provides a borehole in the hard receiving material by applying rotary movement to the fastening element, possibly with the addition of axially directed striking force. The second device (2) completes the insertion of the fastening element into the receiving material by directing an axial force produced by high pressure gases against the partly drilled in fastening element.

Abstract: A device for drilling an undercut in a borehole formed into a substrate includes a housing (1) containing a guide sleeve (2) with a bushing (4) arranged eccentrically within and rotatable relative to the guide sleeve. A torsion spring (6) is located between the guide sleeve and the bushing and is stressed when the bushing rotates relative to the sleeve. A drive shaft (8) with a cutter head (9) at one end is supported in the bushing and can be moved from a centered position into an eccentric position relative to the guide sleeve for forming the undercut. The rotational drive of the bushing (4) is afforded by the drive shaft (8) via an eccentric gear train. Furthermore, the gear train includes an internal ring gear (23) couplable to a gear train housing (19) by a wrap-around spring (31).

Abstract: A device for drilling an undercut in a borehole in a receiving material comprises an axially extending guide sleeve with an eccentric bore and an eccentric bushing located in the eccentric bore and being rotatable therein relative to the sleeve. A tension spring is located between the sleeve and the bushing. During rotation of the bushing, relative to the sleeve, the torsion spring is stressed. A drive shaft with a cutter head at one end extends through the bushing and is brought into an eccentric position relative to the sleeve and at the same time commences an undercut in the borehole. A lock is provided with a set of teeth on the sleeve preventing rotation of the sleeve with the bushing. When the maximum eccentricity of the drive shaft is established, the lock can be released and the sleeve rotated along with the bushing by an eccentric transmission. During such rotation, a complete circumferentially extending undercut can be formed in the borehole.

Abstract: An expansion anchor assembly to be secured in a borehole is made up of an expansion sleeve and an anchor rod. The expansion sleeve has a plurality of expansion sections arranged to be deflected radially outwardly by drawing an expansion cone on the front end of the anchor rod into the sleeve. Each expansion section has a circumferentially extending weakened section forming a bending location. The weakened section is located between a radially inner and a radially outer recess in the expansion section. Each of the recesses has a rectilinear base extending tangentially relative to the expansion sleeve axis with the bases located in a plane disposed normal relative to the expansion sleeve axis.

Abstract: An expansion anchor assembly is made up of an expansion sleeve and an anchor rod. At one end, the expansion sleeve has a plurality of separate expansion parts radially deflectable about bending locations, by drawing an expansion cone on one end of the anchor rod into engagement with the expansion parts. Expansion parts can be displaced radially outwardly into a conically widened undercut in a borehole. To achieve surface area contact with the undercut, when the expansion parts are deflected outwardly, the radially inner and outer surfaces of the expansion parts are provided with a radius of curvature increasing from the bending locations to the free ends of the expansion parts.

Abstract: A device for drilling an undercut (1b) in a borehole (1a) in a target material 1, includes an axially extending guide sleeve (13) containing an axially extending eccentric bore, an eccentric bushing (14) is supported rotatably in the guide sleeve and a drive shaft (15) is supported rotatably in the eccentric bushing. A housing (10, 12) laterally encloses the guide sleeve and bears against the surface of the target material. A blocking member (25) is positioned between the housing (10, 12) and the guide sleeve (13) for permitting rotation of the guide sleeve in only one rotational direction relative to the housing (10, 12). Due to the blocking member (25) entrainment of the guide sleeve (13) is prevented when the eccentric bushing is rotated in the direction opposite to the one rotational direction.

Abstract: A device for driving nails, staples and similar fastening elements includes an electromotor for rotating a driving member. The rotation of the driving member is transferred to a driven member which, in turn, converts the rotational movement into translational movement. The rotational movement from the driving member to the driven member is effected for a limited time period by a clutch so that a drive stroke and a return stroke are carried out. A releasing device actuates the clutch.

Abstract: A device for driving nails and similar fastening elements includes a driver rod performing a reciprocating stroke-like movement for placing the nails. A rotating driving element transmits the driving power to the driver rod so that it carries out the stroke-like movement. During the nail driving operation, the rotating driving element is coupled with the driver rod by a carrier. The carrier is secured to the driving element and moves along an elongated path in converting the rotational movement of the driving element into the stroke-like movement of the driver rod.

Abstract: A suction attachment for use with a drilling tool includes a muzzle part forming an opening through which a drill bit extends into contact with the material to be drilled. The muzzle part has a suction aperture communicating with the drill bit opening and a suction tube connected to the suction aperture. The suction tube includes a venturi tube section having a transverse plane of smallest cross-section spaced from the suction aperture. Extending from the transverse plane is a connecting passage which terminates at its other end in a suction recess formed in the surface of the muzzle part which faces the material to be drilled. The partial vacuum generated at the venturi tube section is transmitted through the connecting passage to the suction recess for holding the attachment on the material to be drilled.

Abstract: For securing an expansion anchor formed of an anchor sleeve and an expansion element into a prepared hole in a receiving material, a conventional piston type explosive powder charge driven setting gun is adapted to hold individual anchors in a guide member mounted on the gun and then by means of a combined sleeve-like piston guide and piston mounted within the guide member to insert the anchor from the guide member into the prepared hole and to drive the expansion element into the anchor sleeve for firmly securing the anchor within the hole.