A gear adjusting device for an electric impact device, comprising a front gearbox housing, a torsional cover rotationally sleeved at the top of the front gearbox housing, a reduction mechanism disposed at the bottom of the front gearbox housing and a tripping structure disposed within the torsional cover. The tripping structure consists of an adjusting screw, a tripping cushion, an adjusting ring and an impact conversion cushion. The adjusting ring can lock the tripping cushion and the impact conversion cushion. The torsional cover and the adjusting ring are provided with corresponding upper bosses and lower bosses, so the torsional cover drives the adjusting ring to rotate during anticlockwise rotation and when the torsional cover rotates clockwise, the adjusting ring does not rotate. Therefore, gear switching can be conducted when the torsional cover is rotated anticlockwise, achieving the effects of short adjustment stroke and quick switching.

A method for producing impacts from rotary motion, the method including: inputting the rotary motion to an input shaft, converting the rotary motion to a linear motion; storing potential energy in one or more elastic elements resulting from the linear motion; and releasing the stored potential energy when the stored potential energy reaches a predetermined level to accelerate an impact mass to produce the impact.

A fastening tool is provided with a housing having a fastener outlet. A striker is mounted for translation in the housing to drive a fastener from the fastener outlet in an unloaded position. A biasing member cooperates with the striker to urge the striker towards the unloaded position. A motor is oriented in the housing. A cam is driven by the motor, and has a cam surface in cooperation with the striker such that rotation of the cam translates the striker to a loaded position and to a release position whereby the biasing member drives the striker to the unloaded position. The cam surface is profiled to require a constant torque from the rotary input during translation of the striker to the loaded position while loading the biasing member.

A hammer drill has a body housing having a motor housing and a gear housing formed in one piece. An electric motor is fixed to the motor housing. A motion converting mechanism, a striking mechanism and a tool holder which form a striking mechanism part are housed in the gear housing so as to be movable with respect to the gear housing. During hammering operation, the striking mechanism part moves with respect to the gear housing under a biasing force of a coil spring, so that vibration caused by the hammering operation is reduced.

A power tool, such as a rotary hammer, includes a housing, an output shaft for mounting a tool accessary and a motor having a motor shaft that generates a rotational output for rotating and linearly hammering the output shaft. The rotational output of the motor shaft is coupled to the output shaft via a driving mechanism that includes a hammer mechanism. An intervening member is axially movable relative to the motor shaft and is operably coupled between the motor shaft and the hammer mechanism. The hammer mechanism and the output shaft are supported by a movable support that is axially movable relative to the housing. Because the output shaft and the driving mechanism are movable relative to the motor and the housing, which preferably includes handle, via the intervening member and the movable support during hammering operations, vibration generated during hammering operations can be dampened before reaching the housing.

Disclosed herein are surgical impact tools and methods of use thereof. The surgical impact tools can include a roller assembly, an impact structure, and a tool holder. The roller assembly can be connected to a motor and include a plurality of rollers supported by a respective roller arm. The impact structure can define a spring and an impact cavity including forward and reverse impact surfaces. The impact structure can include a wall comprising a plurality of thread elements connected to the wall and engageable with the roller assembly. Each of the thread elements can include a pair of helical end surfaces and a pair of axially extending surfaces that are engaged by the plurality of rollers. During use rotation of the roller assembly against the helical ends of the thread elements can cause axial movement of the impact structure to apply a load on the spring and generate impact forces.

A hammer drill includes a tool housing including a motor housing portion; a motor in the motor housing portion; an output spindle driven by the motor; a clutch housing; and a hammering mechanism including a first ratchet and a second ratchet. The hammering mechanism is configured to impart axial impacts to the output spindle. The hammer drill further includes an insert in the clutch housing. The insert includes a body and a plurality of legs extending from the body.

A cam operated apparatus with a cam track (16) and cam follower (12) being engaged with one another, a head element such as a bit operatively connected to the cam track or cam follower means, and rotational drive means such as a motor operatively connected to the other, such that rotational drive causes reciprocal action of the head element and the width (A) of the cam follower means (12) is in the region of 91% to 99%, of the width (B) of the cam track (16), to create a harmonic effect on the head element with low noise and increased power efficiency. Pin-in-wave and wave-in-wave arrangements are described along with tools including the cam operated apparatus.

A cam operated apparatus with a cam track and cam follower being engaged with one another, a head element such as a bit operatively connected to the cam track or cam follower means, and rotational drive means such as a motor operatively connected to the other, such that rotational drive causes reciprocal action of the head element and the width of the cam follower means is in the region of 91% to 99%, of the width of the cam track, to create a harmonic effect on the head element with low noise and increased power efficiency. Pin-in-wave and wave-in-wave arrangements are described along with tools including the cam operated apparatus.