The A hand-held power tool includes a tool holder 2 for holding a tool and a pneumatic striking mechanism for periodically generating impacts on the tool held in the tool holder. The striking mechanism includes a guiding tube, an exciter piston, a striker, a pneumatic chamber closed by the exciter piston and the striker in the guiding tube, and a compensating opening in the guiding tube for ventilating the pneumatic chamber. A cap covers the compensating opening on an outside of the guiding tube. The cap is open in an opening direction which is largely tangential to the guiding tube.

A breaker machine includes a power source, a tool holder arranged to receive a tool and a power driven striking mechanism arranged to strike a tip of the tool with a striking frequency on a hard surface. The breaker machine further includes control circuitry arranged to control an output from the power source and load detection means arranged to detect the load of the power source and transmit information relating to the detected load of the power source to the control circuitry. The control circuitry is arranged to receive information relating to a load of the power source, select a striking frequency based on the information relating to the load of the power source and to apply the selected striking frequency by ramping a current striking frequency to the selected striking frequency based on a predetermined ramping scheme by controlling the output from the power source.

A breaker machine includes a power source, a tool holder arranged to receive a tool and a power driven striking mechanism arranged to strike a tip of the tool with a striking frequency on a hard surface. The breaker machine further includes control circuitry arranged to control an output from the power source and load detection means arranged to detect the load of the power source and transmit information relating to the detected load of the power source to the control circuitry. The control circuitry is arranged to receive information relating to a load of the power source, select a striking frequency based on the information relating to the load of the power source and to apply the selected striking frequency by ramping a current striking frequency to the selected striking frequency based on a predetermined ramping scheme by controlling the output from the power source.

A method for reducing vibrations in a percussion tool includes activating, using an electronic controller of the percussion tool, the motor of the percussion tool, determining, using the electronic controller, that the percussion tool is in a loaded condition, and operating, using the electronic controller, the motor in accordance with a predetermined profile in response to determining that the percussion tool is in the loaded condition. The method also includes determining, using the electronic controller, that the percussion tool is in a no-load condition and operating, using the electronic controller, the motor with reduced speed in response to determining that the percussion tool is in the no-load condition.

A system includes first and second power tools that each have a percussion mechanism, a motor, and a transmission. The transmission includes a striking mechanism and is configured to transfer a driving motion of the motor to an insert tool held in a tool holder. The transmission has a guide tube that is identical in some regions along a working axis and accommodates a striker. The guide tube is rotatably coupled to the motor by a first transmission unit. The striker is driven to linearly oscillate by a piston of a second transmission unit. A ratio between a diameter of the tool holder and a diameter of the guide tube is 1.8 times greater in the first power tool than in the second power tool. A striking energy of the second power tool is mechanically reduced compared to a striking energy of the first power tool.

A hammer drive mechanism for a hammer strike mechanism of a hammer drill is provided including: a drive shaft capable of being rotationally driven by a motor, a rod capable of reciprocatingly driving a piston, and a conversion mechanism that converts the rotary movement of the drive shaft into a reciprocating movement of the rod. The drive shaft comprises a first part connected to the conversion mechanism and a second part capable of being rotationally driven by a motor. The second part connects to the first part via at least one dampener such that rotary movement of the second part is transferred to the first part via the at least one dampener.

A power tool includes a motor, a housing, a battery holder and a cushion. The battery holder is held by the housing to be movable at least in a first direction relative to the housing. The battery holder is configured to removably receive a battery for supplying electric power to the motor. The cushion is held by the housing such that the first direction intersects the cushion. When the battery is attached to the battery holder, the cushion is directly or indirectly disposed between the battery and the housing.

A percussion tool comprises a housing and an electric motor positioned within the housing. The percussion tool further comprises a battery pack supported by the housing for providing power to the motor. The battery pack includes a plurality of battery cells having a nominal voltage of up to 120 Volts. The percussion tool further comprises a percussion mechanism driven by the motor and including a striker supported for reciprocation in the housing. The percussion tool has a ratio of impact energy to mass that is greater than or equal to 2.5 Joules/kilogram.

A handheld tool device includes a hammer mechanism that has at least a striker and a cam guide that drives the striker at least in a hammer-drilling mode. The striker has at least a portion of the cam guide.

An electric power tool is configured to rotate an attachment about a Z-axis. The electric power tool includes a three-axes acceleration sensor and an acceleration detection circuit. The acceleration detection circuit calculates an angular acceleration about the Z-axis based on an input signal from the three-axes acceleration sensor. The acceleration detection circuit calculates a change in an angular velocity based on integrating the angular acceleration for a most recent period. The acceleration detection circuit determines a Z-axis angular velocity about the Z-axis, without adding a previous change in the angular velocity from before the most recent period, as equal to the change in angular velocity. The acceleration detection circuit detects a twisted-motion of the electric power tool based on the Z-axis angular velocity.