Hilti Aktiengesellschaft

Frank Kohlschmied

Markus Hartmann

Christian Daubner

Rainer Ontl

Christoph Dieing

Oliver Ohlendorf

Axel Fischer

Damir Cehajic

A handheld power toolhas a tool socketto hold a tool along a working axis. A motor-driven, pneumatic striking mechanismhas an exciterwhich is driven by a motor, a strikerthat is coupled to the excitervia a pneumatic chamber, and an intermediate strikerarranged on the working axisin the striking directionbehind the striker. A ventilation openingconnects a cavitysituated between the strikerand the intermediate strikerto the environment. A valvethat closes the ventilation openingis opened when actuated by the intermediate strikerwhen the intermediate strikeris moved into its working position counter to the striking direction

Handheld power tool

A hand-held power tool has a tool holder for holding a tool along a working axis. A hammer mechanism has a striker that is moved periodically at an impact rate along the working axis between a turning point in the proximity of the tool and a turning point remote from the tool. A drive control of the hammer mechanism sets the impact rate to a set point value. A vibration absorber has an oscillator that moves along the working axis about a resting position and one or multiple springs that drive the oscillator back into the resting position. A first sensor is used to determine a phase of the motion of the striker. A sensor is used to determine a first phase of a compression point of the hammer mechanism. Another sensor is used to determine a second phase of a turning point in the proximity of the tool, of the hammer mechanism. A damping controller adapts the set point value in such a way that a phase difference between the first phase and the second phase is less than a threshold value.

Hand-held power tool and control method therefor

A power tool is disclosed. The power tool includes a striker, a guide tube in which the striker is guided along an axis, and a pneumatic chamber, which is closed by the striker, the guide tube and a valve device actuated by its own medium. A volume of the pneumatic chamber changes in the case of a movement of the striker along the axis. The valve device has a swivelable sealing element between the striker and the guide tube. The swivelable sealing element is swiveled into a retracted position when the striker moves in the impact direction and is swiveled into an extended position when the striker moves against the impact direction. In the retracted position, the sealing element has a first inflow surface. In the extended position, the sealing element has a second inflow surface. The second inflow surface is larger than the first inflow surface.

Power tool

A power tool and control method is disclosed. The power tool has a striker, which is guided along an axis parallel to an impact direction. A pneumatic chamber has a volume which varies with a movement of the striker along the axis. A valve device that is actuatable depending upon the movement direction of the striker connects the pneumatic chamber with an air reservoir. The valve device is actuated to open in the case of a movement of the striker in the impact direction and in the case of a movement of the striker against the impact direction is actuated to throttle or close. The throttled or closed valve device restricts an air flow flowing through it to a maximum of one tenth of the value as compared to the air flow in an opened position.

Power tool and control method

A power tool is disclosed. The power tool has a striker, which is guided along an axis in a guide tube. A pneumatic chamber has a volume which varies with a movement of the striker. The pneumatic chamber is closed by the striker, the guide tube and a valve device. The valve device has in a flow channel a sealing element that is moveable between two positions in a bearing along the axis. The flow channel has a first cross-sectional area in a first of the two positions of the sealing element adjacent to a first mating surface of the bearing, and the flow channel has a second cross-sectional area in a second of the two positions of the sealing element adjacent to second mating surface of the bearing offset from the first mating surface along the axis. The second cross-sectional area is greater than the first cross-sectional area.

A hand-held power tool () includes a drive () located in the power tool housing () for driving a working tool (), and a torsional pendulum () at least partially mounted on the housing () for compensating vibrations generated by the drive ().

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Munich, Germany

Frank Kohlschmied