A cooling device for a rotating machine has a fan assembly coupled with a backing plate. A hub, on the backing plate, secures the cooling device with a shaft. The backing plate includes one or more vents to enable air to exit the cooling device. The fan includes an opening to enable air to enter the cooling device. A chamber is formed between the fan assembly and the backing plate. During rotation, air is drawn into the opening. The air is passed into the chamber and exits through the vents to cool a work surface or working pad attached to the backing plate.

A portable power tool includes a housing, a motor enclosed within the housing, an accessory tool holder secured to the output shaft of the motor, and an attachment interface on a nose portion near the accessory tool holder. An attachment is configured to attached and removed from the nose portion of the housing. The attachment includes a housing interface that is configured to interact with the attachment interface to position the attachment at a predetermined position on the nose portion of the housing. The attachment interface and the housing interface are configured to be magnetically attracted to each other with sufficient force to retain the attachment on the nose portion of the housing during normal operating conditions while allowing the attachment to be removed from the nose portion of the housing by hand by the operator.

A positioning device for a machine tool, in particular for a hand-held machine tool having a rotationally driveable output spindle, includes at least one positioning unit which is provided to stop and/or retain at least one output spindle of the machine tool and/or an insert tool arranged on the output spindle of the machine tool in at least one defined position. The positioning unit is provided for stopping and/or retaining the output spindle and/or the insert tool arranged on the output spindle in at least one defined position in an automatic manner, in particular without a user intervention, in particular starting from a working movement of the output spindle and/or of the insert tool arranged on the output spindle.

A gear head for a hand-held power tool for machining workpieces, in particular for an angle grinder. The gear head including a gear plate, a housing closable by the gear plate, in which a power take-off is accommodated, which is connectable to a drive of the hand-held power tool, the power take-off including a tool shaft protruding from the gear plate, which is at least partially surrounded by a safety guard fastenable to a gear flange of the housing. A securing lever locks the safety guard on the gear flange, the securing lever being adjustable around a pivot axis between a first position, in which the safety guard is rotatably fixedly connected to the gear flange and a second position, in which the safety guard is rotatable with respect to the gear flange against a force of a restoring element acting in a direction of the first position.

A method of abrading the surface of a workpiece is disclosed. The method includes providing a workpiece, an abrading apparatus with a backing pad configured to receive an abrading plate, an abrading plate attachable to the backing pad and a slurry including abrasive grains; attaching the abrading plate to the backing pad; providing the slurry including abrasive grains between the abrading plate and the surface of the workpiece; and operating the abrading apparatus to abrade the surface of the workpiece. Therein, the abrading plate includes a workpiece-facing layer, which workpiece-facing layer faces the surface of the workpiece and includes a metal or a polymer, and the abrasive grains have a hardness on the Mohs scale of greater than 5.

A power tool includes a direct current (DC) unit, a motor, a driving circuit, a capacitor circuit, and a control unit. The capacitor circuit includes a switching element and a capacitor. The control unit drives the switching element to realize the control of charging or discharging of the capacitor. The capacitor circuit is connected between the DC unit and the driving circuit, and can buffer the impact on the power supply side of the power tool, making the power tool compact in structure.

A sliding ring for a grinding device consisting of a grinding element and a hood covering the grinding element and a sliding ring attachable to the side of the hood facing a surface to be machined, the sliding ring having a sliding surface provided for sliding on the surface to be machined, the sliding ring consisting of at least one elastic component and a sliding component, the sliding surface being formed on the sliding component and the elastic component being arranged on the side of the sliding component opposite the sliding surface.

A power tool including a motor configured to rotatably drive an output shaft, a variable motor speed control input, a motor speed limit input, and a motor controller. The motor controller includes an electronic processor and a memory configured to store instructions. When executed by the motor controller, the instructions configure the motor controller to detect a motor speed limit from a setting of the motor speed limit input, and detect a variable speed control setting from the variable motor speed control input. The motor controller generates a motor speed control signal for driving the motor based on the detected motor speed limit and the detected variable motor speed control setting, and transmits the motor speed control signal to a motor driver circuit configured to drive the motor at a speed based on the motor speed control signal.

A filter support for a handheld power tool includes at least one filter support element, a first fastening element, and a second fastening element. The filter support element includes at least one receiving opening configured to receive a filter element. The filter elements of the filter support are preferably associated with air inlet openings of the handheld power tool and are configured to filter dust particles and/or material particles from a cooling air flow. The filter support can be fastened to a handheld power tool via the first and second fastening elements. The first and the second fastening elements of the filter support can be connected to each other. Advantageously, no fastening elements are provided on the handheld power tool.

A power tool includes a housing, an auxiliary handle, and a vibration damping assembly. The auxiliary handle includes a front end and a gripping portion. The vibration damping assembly includes a mass member and an elastic element. The auxiliary handle further includes an end cap arranged at a rear end of the gripping portion where the rear end is far away from the housing relative to a front end of the gripping portion. An accommodating cavity for accommodating the vibration damping assembly is formed around the gripping portion. The elastic element is arranged between a mass member and a cavity wall of the accommodating cavity. A ratio of a natural frequency W1 of the vibration damping assembly to a rotation frequency W2 of an output shaft in rotation is greater than or equal to 0.7 and less than or equal to 1.3.