Abstract: A power tool comprising: a housing 2; a motor mounted within the housing 2; a tool holder 8 rotatably mounted on the housing 2 for holding a cutting tool; at least one striker 612 mounted in a slideable manner within the housing for generating hammering impulses for a cutting tool, which striker is capable of being reciprocatingly driven by the motor along an axis of travel in a reciprocating cycle, when the motor 18 is activated, via a drive mechanism; characterised in that there at least two strikers 612 which are capable of being reciprocatingly driven along their axes of travel by the motor.

Abstract: The patent covers a reciprocating drive mechanism for a striker in a hammer, a rotary hammer, or a power drill having a hammer action, which utilise a sinusoidal cam channel formed on a drive member and a cam follower, in the form of a ball bearing, attached to a driven member which, due to the interaction of the cam and cam follower, results in a reciprocating movement of the driven member. Both the drive member and driven member can be rotatingly driven by a motor, their relative speeds resulting in the reciprocating movement of the driven member. The driven member is connected to the striker either via a mechanical helical spring or an air spring.

Abstract: A rotary hammer incorporating both a reciprocating drive for generating a first hammering action transmittable to a tool bit and ratcheting mechanism for generating a second hammering action transmittable to the tool bit. The first hammering action and the second hammering actions differing in frequency and force of the impacts transmitted to the tool bit. Furthermore, the reciprocating drive and ratcheting mechanism are selectably engageable so that the first hammering action and the second hammering action may be selectably transmitted to the tool bit individually or in combination depending on the desired mode operation.

Abstract: A hand held motor driven electrically powered tool, in particular a rotary hammer, comprising a spindle (40) for rotatingly driving a tool or bit (68), a spindle rotary drive train (14, 5, 10) for rotatingly driving the spindle (40) and an arrangement for detecting blocking events (16, 17). Blocking events occur when the tool or bit of the tool become rotationally fixed in the material being bored in which case the rotary drive on the spindle from the motor causes the tool housing to rotate in a user's grip.

Abstract: An electrically powered rotary hammer comprising a rotary drive mechanism including a spindle drive gear rotatably mounted around the spindle for rotationally driving the spindle, or a part of the spindle, via an overload clutch. The overload clutch is arranged such that below a predetermined torque threshold a spring element or elements maintain(s) the spindle drive gear and a clutch ring in a relative rotational position in which the spindle drive gear locks locking member or members in a first position and such that above the torque threshold the spring element or elements deform(s) and the relative rotational position of the spindle drive gear and a clutch ring changes so that the locking member or members move(s) out of the first position.

Abstract: A power tool has a handle capable of limited movement mounted to its housing. An axle is rotatably connected to the housing and is movable between a first and second positions and is spring biased towards the first position. Arms are connected to and rotate with the axle. Connectors are slidably mounted within guides and are connected at one end to the arms and at the other end to the handle. Vibrations in the body of the power tool cause movement of one end of the handle, which causes movement of a connector and in turn movement of an arm. Movement of the arm causes rotation of the axle which therefore causes movement of the other arm. This in turn causes the related connector to slide within its guide and move the other end of handle. Thus, movement of one end of the handle is coupled to the other end.

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 adjusting means. The adjusting means 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 adjusting means. The lever is moved, causing rotation of the adjusting means 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: An electrically powered hammer comprising a hollow cylindrical spindle mounted within a housing. A portion of the spindle is formed with a plurality of circumferentially spaced holes and a corresponding number of peg elements are fitted to the spindle, such that each peg element extends through a corresponding hole in the spindle and radially inwardly of the internal surface of the spindle, in such a way that the peg elements together form an axial stop for one or more additional hammer components located within the spindle. Each peg element may alternatively or additonally extend radially outwardly of the corresponding hole in the spindle, in such a way that the peg elements together form an axial stop for one or more additional hammer components located around the spindle. The axial stops formed by the peg elements can replace circlips, which are generally used to form the axial stops.

Abstract: A handle assembly for a power tool, the handle assembly comprising:—attachment means for attaching the assembly to a housing of a power tool; handle means adapted to be held by a user of the power tool, wherein the handle means is mounted to said attachment means and is capable of limited movement relative to the housing of the power tool; and vibration damping means acting between said housing and said handle means. The vibration damping means can comprise elastomeric material. The attachment means can be mounted in use to the housing via a bolt on one of the attachment means and the housing passing through a respective aperture in the other of said attachment means and the housing, wherein at least some of the elastomeric material is arranged in use between at least one said bolt and a corresponding said aperture. The handle means can be pivotable and/or slidable relative to said attachment means. The vibration damping means can comprise at least one spring eg. compression/spring or torsion.

Abstract: An electric motor driven hand-held tool, such as a drilling, hammering or screw driving tool having a tool housing within which is located an integrated switch unit (6). The switch unit (6) includes an electronic motor control unit (8), a first actuator which is actuated by a manually operable power member (4) and to which the control unit is responsive to power the motor and a second actuator (10) which is actuated by a manually operable forward/reverse member (14) and to which the control unit is responsive to drive the motor in a selected forward or reverse direction. The forward/reverse member (14) is located remotely from the switch unit (6) on a portion of the tool housing which can be seen by a user of the tool during normal operation of the tool. To facilitate this a linkage arrangement (16) is provided for actuating the second actuator (10) in response to a manual actuation of the forward/reverse member (14). The linkage (16) is pivotally mounted on a closed end of a jam pot motor casing (3).

Abstract: An electrically powered rotary hammer comprising a rotary drive mechanism including a spindle drive gear rotatably mounted around the spindle for rotationally driving the spindle, or a part of the spindle, via an overload clutch. The overload clutch is arranged such that below a predetermined torque threshold a spring element or elements maintain(s) the spindle drive gear and a clutch ring in a relative rotational position in which the spindle drive gear locks locking member or members in a first position and such that above the torque threshold the spring element or elements deform(s) and the relative rotational position of the spindle drive gear and a clutch ring changes so that the locking member or members move(s) out of the first position.

Abstract: A rotary hammer includes a spindle 18 which can be rotatably driven by an intermediate shaft 24 by way of a drive device. A tool holder 16 is arranged for rotation with the spindle 18, and for releasably holding a bit or tool for selective rotation and/or reciprocation. A pneumatic hammering arrangement facilitates repeated impacting of the bit or tool for reciprocation within the tool holder (16). A mode change mechanism includes a knob 18 for selectively operating the rotary hammer in any of three modes, identified as a rotary drive only mode, a hammer only mode and a rotary hammer mode.

Abstract: An electrically powered hammer comprising a hollow cylindrical spindle mounted within a housing. A portion of the spindle is formed with a plurality of circumferentially spaced holes and a corresponding number of peg elements are fitted to the spindle, such that each peg element extends through a corresponding hole in the spindle and radially inwardly of the internal surface of the spindle, in such a way that the peg elements together form an axial stop for one or more additional hammer components located within the spindle. Each peg element may alternatively or additonally extend radially outwardly of the corresponding hole in the spindle, in such a way that the peg elements together form an axial stop for one or more additional hammer components located around the spindle. The axial stops formed by the peg elements can replace circlips, which are generally used to form the axial stops.