Abstract: A tool holder (1) for a rotary hammer which has a tube like tool holder main body (10) having a side wall formed with through holes (11) for receiving corresponding locking bodies (12) and formed with additional through holes (40). The tool holder includes hardened metal driving ribs (46) each located on an insert (42) and the inserts are fitted within the additional through holes (40) so that the ribs extends axially and radially inwardly of the radially inward facing surface of the holder body. The locking bodies (12) are arranged to releaseably engage a corresponding axial closed groove of a tool or bit inserted within the tool holder and the ribs (46) are arranged to releaseably engaging a corresponding axial rearwardly open driving grooves of a tool or bit inserted within the tool holder.

Abstract: An electrically powered belt sander comprising a housing, a dust flow path defined by the housing, a motor mounted in the housing at a first location and having an output shaft, a fan connectable to the motor output shaft and rotateably mounted in the housing at a second location a distance from the motor output shaft, a belt connectable between the motor output shaft and the fan whereby the rotation of the motor output shaft drives the rotation of the fan, and a damper located in the dust flow path and operable for blocking the dust flow path.

Abstract: An overload clutch assembly for a power tool having two torque settings through which rotary drive is transmitted to a spindle. The overload clutch assembly is capable of being between switched between the two torque settings by at least one actuator. The clutch assembly comprises a carrier rotationally mounted on a output clutch spindle; a first clutch plate operational for transmitting torque below a first level; and a second clutch plate operational for transmitting torque below a second level higher than the first; and characterised in that, when the overload clutch is in the higher torque setting, the torque is transferred from the carrier to the output clutch spindle via the second clutch plate only.

Abstract: A vibration reduction apparatus for use with a hammer tool having a hammer piston is disclosed. The hammer piston is caused to reciprocate in the cylinder by rotation of a gear wheel and crank drive. A cam is mounted around the gear wheel, a counterweight surrounds the piston cylinder, and a cam follower is provided on the counterweight. The cam follower on the counterweight is urged into contact with the cam by a biasing element. The external profile of the cam is such that rotation of the gear wheel causes oscillation of the counterweight in anti-phase to motion of the hammer piston to counteract vibrations produced by operation of the hammer action of the tool.

Abstract: A transmission housing for a hammer drill comprises two clamshell halves and that mate to define a first transmission housing chamber and a second transmission housing chamber disposed on either side of a ball bearing race. The first and second transmission housing chambers are interconnected by channels. The rear end of a hollow piston, a cylindrical bearing, a crank pin and a crank plate are disposed in the first transmission housing chamber, and a spindle is disposed in the second transmission housing chamber. Overflow channels and allow movement of air between the first and second transmission housing chambers to reduce compression of air iduring reciprocation of the hollow piston.

Abstract: A handle assembly for a power tool is described and includes a first substantially tubular body portion 210 which contains a first spring 212. A second body portion 216 is slidably mounted within first body portion 210 and contains a second spring 218. A third body portion 222 is also slidably mounted within first body portion 210. The biasing coefficient, or spring constant, of the first spring 212 is less than that of the second spring 218. The first, second and third body portions 210, 216 and 222, and first and second springs, 212 and 218, are all mounted coaxially on threaded bolt 224. In use the third body portion 222 moves within first body portion 210 in a direction towards end portion 214 and the first and softer spring 212 becomes compressed more rapidly than the second and harder spring 218.

Abstract: A power tool has a handle assembly which is biased by a torsional spring. The torsional spring has an engaging arm the position of which is fixed relative to the housing by an adjusting mechanism. The adjusting mechanism has a lever which extends outside the housing of the power tool, and a cam surface, and is mounted on and rotatable at least partially around an axle. In use, the tension in the torsional spring may be adjusted by movement of the lever. The lever is moved, causing rotation of the adjusting cam around the axle. As a result, the cam surface causes the engaging arm of the spring to be moved axially along the axle and more or less tension is applied to the torsional spring.

Abstract: A hand held electrically powered drilling and/or hammering tool comprises a balanced motor sub-assembly including a radial fan mounted to the armature shaft at a first end of the motor with the fan blades facing away from the motor, and motor the sub-assembly is mounted with the axis of the motor angled with respect to the axis of the tool spindle and with the first end of the motor closest to the spindle, and an air outlet is located in the housing near a second end of the motor, and the above components are arranged so that rotation of the fan draws air into its inlet via air inlets and then pushes air from its outlet through the motor and out of the air outlets in the region of the second end of the motor which is remote from the spindle axis.

Abstract: A gear wheel is rotatably mounted on a drive shaft. The drive shaft has a plurality of longitudinal splines formed thereon. A drive sleeve surrounds the drive shaft and has a plurality of the inner splines formed on its interior surface. The inner splines slidably intermesh with outer splines of the drive shaft such that the drive sleeve can slide up and down on but cannot rotate relative to the drive shaft. A coil spring biases the drive sleeve downwardly. Drive sleeve teeth are formed around the bottom edge of the drive sleeve. Corresponding gear plate teeth are formed on the upper surface of the gear wheel and are adapted to engage the drive sleeve teeth when the drive sleeve is in its downward most position under the influence of the coil spring. In this position, the gear wheel is operatively coupled to the drive shaft.

Abstract: An electrically hammer comprising a hollow spindle, a piston, and an intermediate shaft. A wobble drive arrangement includes a wobble sleeve rotatably mounted on the intermediate shaft. A mode change element is selectively engageable, by movement along the intermediate shaft, with a set of drive teeth provided on the intermediate shaft and a set of driven teeth provided on the wobble sleeve. When the mode change element is engaged with both sets of teeth it transmits rotary drive from the intermediate shaft to the wobble sleeve so that the wobble sleeve arrangement reciprocatingly drives the piston. A mode change ring is formed integrally with an axial stop surface and the axial stop surface is engageable with a cooperating end stop surface formed integrally with one of the intermediate shaft and the wobble sleeve to limit the movement of the mode change element along the intermediate shaft.

Abstract: A dual gauge assembly. In an exemplary embodiment, the dual gauge assembly includes a housing. Further, a display face is disposed within the housing for displaying a pressure range. In addition, an indicating device is disposed within the housing for indicating pressure for at least two different pressure sources. Moreover, at least two ports are coupled to the housing for pneumatically coupling the at least two different pressure sources to the indicator assembly. The indicating device provides a visual indication of the at least two different pressure sources within the single housing.