Black Decker Inc.

Martin Lauterwald

Stefan D Gensmann

Michael Stirm

Robert Bradus

Norbert Hahn

Robert Alan Usselman

Ana-Maria Roberts

Reimund Becht

Bruno Meinholf Ruethers

Thomas Michael Stanke

Achim Jung

Ana-Marie Roberts

Andreas Werner Henke

Raimund Becht

Robert Usselmann

Robert Alan Usselmann

A hammer/drill includes a housing, a motor with armature shaft, a spindle rotatably mounted about a longitudinal axis in the housing, a tool holder rotatingly driven by the motor about the longitudinal axis, a hammer mechanism for generating impacts acting on the tool holder, a drive shaft coupleable with the armature shaft, and a switching arrangement to switch between drilling, hammer drilling, and hammering modes. The switching arrangement comprises a selector and coupling part axially displaceable on the drive shaft between lower and upper positions, coupling and decoupling the drive shaft to the armature shaft respectively. The coupling part includes a sleeve comprising a flange, and the selector comprises a fork for engaging a lower part of the flange. A protuberance engages a drive member of the selector to pivot the selector when the spindle is rotated, engaging over only a portion of the rotational movement of the spindle.

Rotary hammer

According to an aspect of the present invention there is provided a rotary hammer comprising an electric motor having its longitudinal axis perpendicular to the axis of the hammer spindle and the tool holder. A single switching arrangement activates and deactivates the hammer mechanism and the rotary drive mechanism for the tool holder. The switching arrangement has a cam portion acting on a coupling part to activate and deactivate the hammer drive mechanism, and acting on a slider part to engage and disengage a coupling sleeve with a drive sleeve to thereby activate and deactivate the rotary drive mechanism of the hammer spindle. The switching arrangement comprises a gear train disposed between the switching element and the cam portion.

A rotary spindlefor a power tool such as a hammer drill is disclosed. The spindlecomprises a first spindle partfor rotation about its longitudinal an axis by means of a motor and having an inwardly directed rim, and a second spindle partfor supporting a drill bit of the hammer drill and having an outwardly directed rim. The second spindle partextends through an aperturein the first spindle partand rimscooperate with each other to prevent removal of the second spindle partfrom the first spindle part. A circliplocks the first and second spindle partstogether and maintains o-ringsunder compression.

Rotary spindle for power tool and power tool incorporating such spindle

A rotary hammer includes a housing, a tool holder mounted on a front portion of the housing, and a motor mounted in the housing. The motor includes an armature shaft arranged substantially perpendicular to an axis of rotation of the tool holder and including toothing. A hammer mechanism is driven by the motor to generate impacts on a tool being held by the tool holder. The hammer mechanism includes a first intermediate shaft adjacent and substantially parallel to the armature shaft facing away from the tool holder. A rotation drive mechanism is driven by the motor to rotatingly drive a tool being held by the tool holder. The rotation drive mechanism includes a second intermediate shaft adjacent and substantially parallel to the armature shaft facing the tool holder. The toothing of the armature shaft meshes with corresponding toothing on at least one of the first intermediate shaft and the second intermediate shaft. A chain drive couples the first intermediate shaft to the second intermediate shaft so that the first and second intermediate shafts are driven together by the armature shaft.

A hand held motor driven electrically powered tool, in particular a rotary hammer, comprising a spindle () for rotatingly driving a tool or bit (), a spindle rotary drive train () for rotatingly driving the spindle () and an arrangement for detecting blocking events (). Blocking events occur when the tool or bit of the tool become rotationally fixed in the material being bored in which case the rotary drive on the spindle from the motor causes the tool housing to rotate in a user's grip. According to a first aspect of the invention an overload clutch () is provided in the spindle rotary drive train for transmitting rotary drive to the spindle below a predetermined torque and slipping above the predetermined torque arranged such that the overload clutch cuts off rotary drive to the spindle, for example by reducing the predetermined torque at which the overload clutch () slips when a blocking event is detected so as to cut off rotary drive to the spindle in response to a blocking event being detected. According to a second aspect of the invention there is provided a mode change mechanism () for selectively disengaging a clutch () so as to cut off the rotary drive to the spindle () and the clutch is disengaged when a blocking event is detected so as to cut off rotary drive to the spindle in response to a blocking event being detected.

Rotary tool

A rotary hammer which comprises a tool holder (,), an air cushion hammering mechanism which comprises a piston (,) and a beat piece (,) slideably located in a cylinder (,&prime;) so that reciprocation of the piston in the cylinder will cause the beat piece to hit a tool located in the tool holder; and means for causing the cylinder to rotate in addition to, or instead of, reciprocation of the piston in order to cause a tool located in the tool holder to rotate. The piston (,) is formed from a plastics material and is sealed in the cylinder (,&prime;) by an annular seal (,) that is located within an annular groove (,) in the piston. The annular seal has an inner diameter that is greater than the diameter of the radially outwardly directed surface of the groove, and the groove has an axial dimension that is greater than that of the annular seal, so that when the cylinder rotates about the piston (without reciprocation of the piston) the seal (,) will rotate with the cylinder (,&prime;).

A rotary hammer comprises an electric motor having its longitudinal axis perpendicular to the axis of the hammer spindle and the tool holder. A single switching element activates and deactivates the hammer mechanism and the rotary drive for the tool holder. The switching element has an eccentric actuating section extending parallel to the main axis of the switching element, acting on a coupling part to activate and deactivate the hammer drive. The switching element has a cam section acting on a slider part to engage and disengage a coupling sleeve (non-rotatable on the hammer spindle) with a drive sleeve to thereby engage and disengage the rotary drive of the hammer spindle.

A tool holder for a rotary and/or chisel hammer is provided with a sleeve body with a central opening for receiving a tool bit with a least one axial locking groove which is closed at both ends for engaging a cylindrical locking body which is located in a through opening in the sleeve body. The sleeve body is surrounded by a displaceable adjustment sleeve which has an area for preventing an outward radial movement of the locking body and which in a displaced position permits the radial outward movement of the at least one locking body. A ring element consisting of several ring segments is located behind the locking body and extends with a support portion into the through opening. With the movement of the locking body it can be displaced to the rear against spring pressure and in its displaced position permits a radially outward movement of the at least one locking body.

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Huenstetten, Germany

Martin Lauterwald