A cutting insert is provided, comprising a top surface, a bottom surface, a plurality of side surfaces spanning therebetween, and a cutting edge formed at an intersection of the side surface and a forwardly-disposed portion of the top the surface. It further comprises a cooling cavity projecting into the insert, a top end thereof being disposed further forwardly than an open bottom end thereof. The cooling cavity defines at least one molding axis such that a solid element having the shape of the cooling cavity and completely inserted therein may be retracted intact therefrom along a linear path parallel to the molding axis. A circumscribing portion is formed on the side surfaces encircling the cutting insert. The circumscribing portion is formed parallel to the molding axis and has a non-zero height along its entire extent. The cutting insert does not extend beyond the circumscribing portion.

An impact tool includes a motor, a driving mechanism, a tool body, an elastically-connected part elastically connected to the tool body to be movable at least in a front-rear direction relative to the tool body, a detecting mechanism configured to detect pressing of a tool accessory against a workpiece, and a control part configured to control driving of the motor based on a detection result of the detecting mechanism. The detecting mechanism includes a movable member that is provided in one of the tool body and the elastically-connected part and configured to be moved by relative movement of the other of the tool body and the elastically-connected part in the front-rear direction, and a detector that is provided in the one of the tool body and the elastically-connected part and configured to detect rearward pressing of the tool accessory by detecting movement of the movable member.

A rectifier circuit for rectifying an AC voltage supplied from a commercial power supply into a DC voltage, a smoothing capacitor for smoothing the output of the rectifier circuit, and an electrically powered tool for supplying the smoothed pulsating DC voltage to a motor by an inverter circuit, wherein when the motor is driven while no load is being applied to a tip tool, the smoothed DC voltage repeatedly generates a maximal value and a minimum value so as to synchronize with the fluctuation in the AC voltage. During no-load rotation, control is performed so that driving is performed at a value that is less than a threshold value D.sub.1 for the duty ratio at which the generation of a gear sound starts in any of the speed dial setting values 1-6. It is thereby possible to suppress a gear sound generated by a power transmission mechanism during no-load rotation.

A drill comprising: a body, the body comprising a housing formed internally with at least two chambers; a rear handle mounted on the body; a tool holder mounted on the front of the body; an electric motor mounted in a first chamber, the electric motor comprising an end cap attached to a motor housing; a transmission mechanism mounted in a second chamber which is in driving connection with the electric motor, the transmission mechanism being driven by the electric motor when the electric motor is activated to either impart impacts to and/or rotate a cutting tool when held by the tool holder. The end cap engages with the housing to form a separating wall which separates the first and second chambers.

A power tool, such as an impact driver, includes a motor having a rotor that rotates relative to a stator, and a centrifugal fan that rotates together with the rotor. A motor housing and a rear housing house the motor. Overlapping parts of the motor housing and the rear housing radially surround an outer circumference of the centrifugal fan. Air exhaust ports are defined in each of the overlapping parts and are offset in an axial direction of the rotor. Fluid communication paths are defined between the air exhaust ports in the overlapping parts. The fluid communication paths have an opening area or width in the axial direction that is smaller than an opening area or width in the axial direction of the air exhaust ports.

It is an object of the invention to provide rational structure for vibration proofing in hammering operation. A driving motor 110 and a striking mechanism 140 are provided in a first body element 101a, and a handle 109 and a battery mounting part 160 are provided in a second body element 101b. The first and second body elements 101a, 101b are moved with respect to each other via a biasing member 181 when vibration is caused by driving of the striking mechanism 140. Further, a first region 100a close to the striking mechanism 140 forms a long-distance moving region 200 in which the first and second body elements 101a, 101b move a longer distance in a longitudinal direction than in the second region 100b less close to the striking mechanism 140.

A hand-held power tool, in particular a hammer drill or a combination hammer, is disclosed. The hand-held power tool includes a tool housing which has a receiving recess designed to replaceably receive a storage battery or a power supply unit. The hand-held power tool has an electric drive motor with a cooling fan. The tool housing has a first vent portion which is located in the receiving recess and through which a volume flow generated by the cooling fan can be guided.

A cutting insert is provided, comprising a top surface, a bottom surface, a plurality of side surfaces spanning therebetween, and a cutting edge formed at an intersection of the side surface and a forwardly-disposed portion of the top the surface. It further comprises a cooling cavity projecting into the insert, a top end thereof being disposed further forwardly than an open bottom end thereof. The cooling cavity defines at least one molding axis such that a solid element having the shape of the cooling cavity and completely inserted therein may be retracted intact therefrom along a linear path parallel to the molding axis. A circumscribing portion is formed on the side surfaces encircling the cutting insert. The circumscribing portion is formed parallel to the molding axis and has a non-zero height along its entire extent. The cutting insert does not extend beyond the circumscribing portion.

An electric power tool has a brushless motor for driving a tip tool, and a motor case is at least partly covered by a motor housing made of aluminum alloy and exposed to an outside. A control board provided with a control circuit for controlling the rotation of the brushless motor is disposed adjacent to the motor housing. The brushless motor and a control board are cooled by cooling air generated by a fun, thereby enhancing the cooling characteristics of the motor control circuit.

The present invention belongs to the field of working processes and transport, more precisely to the field of devices for cooling the drive motor of electric hand-held power tools. A separator (1) of the device for removing dust particles from the cooling air for electric hand-held power tools according to the invention is designed in the shape of a cylinder or preferably as a truncated hollow cone with a bottom ring (11) and an upper ring (12) with a circular surface (121) with a hub (122). The separator has on the circumference in of the cone one or more, preferably nine uniformly distributed ribs (13) rotated for an angle a with regards to the transverse axis of the cone. Each rib (13) has a surface (131), which due to its position enables bouncing off larger dust particles, when a working drive motor (2) spins a fan (3) for cooling the motor (2) and creates suction of outer air through the separator (1) in a handle (42). The cooling air enters the housing (4) through entry slots (421) of the handle (42) and openings (14) of the separator (1), while it leaves through outlet openings (431) of a reducer part (43), which closes the housing (4). Because the larger dust particles are removed before entering the tool, only cooling air with smaller dust particles enters the interior of the electric tool.