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: An external surface of a spindle is formed with tapering grooves which become narrower in a direction towards the forward end of the spindle. A slider sleeve is provided with splines which also taper in a forward direction. In this way, the slider sleeve is prevented from rotating relative to the spindle, but can slide axially. A rearward end of the slider sleeve includes a recess containing an elastomeric O-ring. When the drive torque exceeds a predetermined threshold, inclined surfaces of the mutually engaging teeth on the spindle drive gear and slider sleeve slide over each other, as a result of which the drive gear slides forwardly along the slider sleeve against the action of a spring. The spindle drive gear can then rotate relative to the slider sleeve and the cooperating sets of teeth ratchet over each other, preventing spindle drive gear being from rotating the spindle.

Abstract: An electrically powered rotary hammer includes a first switchable gear arrangement for actuating the hammering mechanism and a second switchable gear arrangement for actuating the rotary drive mechanism. The hammer includes a mode change knob, a linkage support, a first linkage slideably supported in the linkage support between the mode change knob and the first switchable gear arrangement and a second linkage slideably supported in the linkage support between the mode change knob and the second switchable gear arrangement. The mode change knob moves the linkages between three positions, a drilling only mode position in which the second switchable gear arrangement only is in its actuating position, a hammer drilling mode in which both the first and second gear arrangements are in their actuating positions, and a hammering only mode position in which the first switchable gear arrangement only is in its actuating position.

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 transmission housing for a hammer drill 320 is formed from three housing portions. A generally L-shaped first housing portion 380a accommodates a spindle 348, a hollow piston 358, the respective spindle and hollow piston drive mechanisms and a mode change mechanism. The first housing portion 380a is mounted to a second housing portion 380b such that a first O-ring 382a is trapped between the two portions to prevent the ingress of dust. The second housing portion 380b holds the lower part of the transmission mechanism inside the first housing portion 380a. The second housing portion 380b forms a motor output aperture 390 for enabling the motor output shaft 336 to engage the transmission mechanism. A third transmission housing portion 380c is mounted to the front of the first housing portion 380a such that spindle 348 projects out of the third transmission housing portion 380c. A second O-ring 382b seals the join between the first and third transmission housing portions 380a, 380c.

Abstract: A portable tool comprising a spindle defining a longitudinal axis, a spring extending around the spindle in the axial direction for biasing a component of the tool, a stop ring extending around the spindle and against which the spring bears. The spindle includes a plurality of circumferentially spaced radially outward projections and the stop ring includes on its internal surface a corresponding plurality of recesses extending from the bearing face of the stop ring to an opposite face, and a corresponding plurality of pockets open at the opposite face. During assembly, the stop ring is fitted over the spindle or sleeve by the passing the recesses over the projections and then rotating the stop ring to align the pockets with projections. The stop ring is axially fixed on the spindle by the pockets engaging the projections under the biasing force from the spring.

Abstract: A power tool cooling system comprises a cooling fan disposed on a motor in a position between the upper field coil and the lower commutator. A transmission housing encapsulates the transmission mechanism. During operation, the fan is driven by the motor and draws air axially through the motor and expels the air radially outwardly through holes in the outer housing of the motor. This causes air to be drawn in through the air vents formed on the top of a tool housing, in the side of the housing and between the housing and a battery pack. The cool air flows outside of the transmission housing, but inside the tool housing such that air does not pass through the transmission mechanism. A plurality of motor openings are also formed in the outer housing of the motor to enable cool air to pass into the motor to cool the motor.

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: An electrically powered hammer comprising a hammer housing (10,15) with a hollow cylindrical spindle (4) mounted within it and an air cushion hammering mechanism mounted within the spindle for generating repeated impacts on a tool or bit of the hammer which hammering mechanism includes a piston (24). A rotatingly driven intermediate shaft (6) is rotatably mounted in the housing and a wobble drive arrangement (12, 16, 18, 20) reciprocatingly drives the piston (24). The wobble drive arrangement includes a wobble sleeve (12) rotatably mounted on the intermediate shaft (6) and a wobble bearing (14, 16, 18) on the wobble sleeve. A support bearing (46, 42) for the intermediate shaft is mounted on the wobble sleeve forwardly of the wobble bearing assembly. The support bearing (46, 42) comprises a bearing ring (46) and the bearing ring is formed with a peripheral flange which can be fixed to a housing part (10) of the hammer housing (10,15).

Abstract: A hand-held powered hammer comprising a hammer housing; a hammering mechanism; a spindle rotatably mounted within the housing; the spindle having a first mode of operation in which the spindle is rotatable within the housing and a second mode of operation in which the spindle is restrained from rotation; a first set of teeth rotatable with the spindle and selectably movable between a first position and a second position, corresponding to the second mode of operation of the spindle; a spindle lock arrangement mounted within the housing and comprising a spindle lock tooth engageable with the first set of teeth when the first set of teeth are in the second position, and a resilient synchronising element positioned to engage the first set of teeth before the first set of teeth reaches the second position, so as to align the first set of teeth for engagement with the spindle lock tooth.

Abstract: An electrically powered hammer comprising a hammer housing (10,15) with a hollow cylindrical spindle (4) mounted within it and an air cushion hammering mechanism mounted within the spindle for generating repeated impacts on a tool or bit of the hammer which hammering mechanism includes a piston (24). A rotatingly driven intermediate shaft (6) is rotatably mounted in the housing and a wobble drive arrangement (12, 16, 18, 20) reciprocatingly drives the piston (24). The wobble drive arrangement includes a wobble sleeve (12) rotatably mounted on the intermediate shaft (6) and a wobble bearing (14, 16, 18) on the wobble sleeve. A support bearing (46, 42) for the intermediate shaft is mounted on the wobble sleeve forwardly of the wobble bearing assembly. The support bearing (46, 42) comprises a bearing ring (46) and the bearing ring is formed with a peripheral flange which can be fixed to a housing part (10) of the hammer housing (10,15).

Abstract: An electrically powered rotary hammer comprising a housing (10) with a tool holder (36) located at a forward end of the housing within which a tool or bit (34) can be releasable mounted so as to be rotatingly driven and so as to be able to undergo limited reciprocation. A rotary drive mechanism (2, 6, 40, 4, 36) mounted within the housing rotatingly drives the tool or bit and a hammering mechanism (2, 6, 72, 12, 18, 20, 26, 24, 4, 3, 5) mounted within the housing repeatedly impacts the tool or bit. A first switcheable gear arrangement (72) is selectively moveable into an actuating position for actuating the hammering mechanism and a second switchable gear arrangement (40) is selectively moveable into an actuating position for actuating the rotary drive mechanism.

Abstract: An external surface of a spindle is formed with tapering grooves which become narrower in a direction towards the forward end of the spindle. A slider sleeve is provided with splines which also taper in a forward direction. In this way, the slider sleeve is prevented from rotating relative to the spindle, but can slide axially. A rearward end of the slider sleeve includes a recess containing an elastomeric O-ring. When the drive torque exceeds a predetermined threshold, inclined surfaces of the mutually engaging teeth on the spindle drive gear and slider sleeve slide over each other, as a result of which the drive gear slides forwardly along the slider sleeve against the action of a spring. The spindle drive gear can then rotate relative to the slider sleeve and the cooperating sets of teeth ratchet over each other, preventing spindle drive gear being from rotating the spindle.

Abstract: A hand-held powered hammer comprising a hammer housing; a hammering mechanism; a spindle rotatably mounted within the housing; the spindle having a first mode of operation in which the spindle is rotatable within the housing and a second mode of operation in which the spindle is restrained from rotation; a first set of teeth rotatable with the spindle and selectably movable between a first position and a second position, corresponding to the second mode of operation of the spindle; a spindle lock arrangement mounted within the housing and comprising a spindle lock tooth engageable with the first set of teeth when the first set of teeth are in the second position, and a resilient synchronising element positioned to engage the first set of teeth before the first set of teeth reaches the second position, so as to align the first set of teeth for engagement with the spindle lock tooth.

Abstract: A portable tool comprising a spindle defining a longitudinal axis, a spring extending around the spindle in the axial direction for biasing a component of the tool, a stop ring extending around the spindle and against which the spring bears. The spindle includes a plurality of circumferentially spaced radially outward projections and the stop ring includes on its internal surface a corresponding plurality of recesses extending from the bearing face of the stop ring to an opposite face, and a corresponding plurality of pockets open at the opposite face. During assembly, the stop ring is fitted over the spindle or sleeve by the passing the recesses over the projections and then rotating the stop ring to align the pockets with projections. The stop ring is axially fixed on the spindle by the pockets engaging the projections under the biasing force from the spring.

Abstract: A tool holder attachable to a spindle of a hammer and which can receive a bit, the bit having a shank with at least one retaining groove extending along part of the shank, the retaining groove having a defined length, a front end and a rear end that limit axial movement of the bit in the tool holder, which tool holder comprises a hollow cylinder having an axis, an axial bore, a rear end that can be attached to the spindle of the hammer, and a front end that can receive the shank of the bit so that the bit is slidable within the cylinder in an axial direction, at least one retaining element that is located so that it can extend radially into the bore of the cylinder and into the at least one retaining groove of the bit so that the retaining element can be hit by the rear end of the retaining groove during the transition to idling and limit the extent of axial movement of the bit within the cylinder, at least one radial restraining element limiting movement of the retaining element in the radial direction, at l