Abstract: A tool holder system with first and second spindles, a locking ring slideably mounted on the first spindle, a first biasing mechanism biasing the locking ring towards an indentation position where the locking ring surrounds an indentation on the first spindle, and a moveable locking element mounted on the second spindle, the locking element being engageable to the indentation. The first spindle can be unlocked from the second spindle by sliding the locking ring away from the indentation position against the biasing force of the biasing mechanism and towards the second spindle. Such action moves the locking element to disengage from the indentation.

Abstract: A hammer drive mechanism is provided for converting rotary drive from a motor to reciprocatory movement of an impact member of a hammer drill. The mechanism comprises a rotatable plate adapted to be rotated by the motor, an input drive member associated with the rotatable plate in an eccentric position with respect to the axis of rotation of the rotatable plate, an output drive member associated with the impact member, and a crank shaft having a respective driver adjacent each of its ends. Each driver engages with, and is complementary to a respective one of the drive members. At least one end portion of the crank shaft comprises a lubricating aperture which opens into the adjacent driver to provide a lubrication path to the engaging surfaces of the drivers and the drive members.

Abstract: A tool holder system with first and second spindles, a locking ring slideably mounted on the first spindle, a first biasing mechanism biasing the locking ring towards an indentation position where the locking ring surrounds an indentation on the first spindle, and a moveable locking element mounted on the second spindle, the locking element being engageable to the indentation. The first spindle can be unlocked from the second spindle by sliding the locking ring away from the indentation position against the biasing force of the biasing mechanism and towards the second spindle. Such action moves the locking element to disengage from the indentation.

Abstract: A hammer drive mechanism is provided for converting rotary drive from a motor to reciprocatory movement of an impact member of a hammer drill. The mechanism comprises a rotatable plate adapted to be rotated by the motor, an input drive member associated with the rotatable plate in an eccentric position with respect to the axis of rotation of the rotatable plate, an output drive member associated with the impact member, and a crank shaft having a respective driver adjacent each of its ends. Each driver engages with, and is complementary to a respective one of the drive members. At least one end portion of the crank shaft comprises a lubricating aperture which opens into the adjacent driver to provide a lubrication path to the engaging surfaces of the drivers and the drive members.

Abstract: A mounting assembly for moveably mounting a handle of a power tool to a housing of the power tool is disclosed. The mounting assembly has a metal bar (324) mounted to a housing (290) of the power tool and a vibration damper (332) mounted to a handle (294) of the power tool and slidably mounted to the metal bar. The vibration damper includes a vibration damping member (344) for damping vibrations tending to cause the vibration damper to pivot relative to the metal bar about an axis substantially parallel to the longitudinal axis of the metal bar.

Abstract: A method of manufacturing a ram configured to be mounted for reciprocation in a guide tube section of a powered hammer. The ram includes an outer circumferential surface, a radially outwardly projecting sealing portion, and a helically shaped vent channel defined in the circumferential surface and running from a front end portion of the circumferential surface to a rear end portion of the circumferential surface and being interrupted by the sealing portion. The method includes forming the outer circumferential surface of the ram and the helically shaped vent channel in a single manufacturing operation. For example, the method includes rotating a blank on a machine tool, forming the outer circumferential surface of the ram by applying a first machine tool bit to the blank while the blank is rotating, and forming the helically shaped vent channel in the outer circumferential surface by applying a second machine tool bit to the blank while the blank is rotating, without removing the blank from the machine tool.

Abstract: A driving mechanism for a powered hammer having a motor and a tool holder includes a ram mounted for reciprocation in a guide tube section. The ram has a radially outwardly projecting sealing portion and an outer circumferential surface that defines a helically shaped vent channel running from a front end portion of the circumferential surface to a rear end portion of the circumferential surface and being interrupted by the sealing portion. A piston is driven in reciprocating motion of the motor such that an air cushion is generated in a space between the ram and the piston to cause an impact on the tool bit by movement of the ram towards the tool bit. The space between the ram and the piston is temporarily connected with ambient air through the helical vent channel and a recess in the wall of the guide tube section after causing the impact on the tool bit.

Abstract: A mounting assembly for moveably mounting a handle of a power tool to a housing of the power tool is disclosed. The mounting assembly has a metal bar (324) mounted to a housing (290) of the power tool and a vibration damper (332) mounted to a handle (294) of the power tool and slidably mounted to the metal bar. The vibration damper includes a vibration damping member (344) for damping vibrations tending to cause the vibration damper to pivot relative to the metal bar about an axis substantially parallel to the longitudinal axis of the metal bar.

Abstract: A driving mechanism for a powered hammer having a motor and a tool holder includes a ram mounted for reciprocation in a guide tube section. The ram has a radially outwardly projecting sealing portion and an outer circumferential surface that defines a helically shaped vent channel running from a front end portion of the circumferential surface to a rear end portion of the circumferential surface and being interrupted by the sealing portion. A piston is driven in reciprocating motion of the motor such that an air cushion is generated in a space between the ram and the piston to cause an impact on the tool bit by movement of the ram towards the tool bit. The space between the ram and the piston is temporarily connected with ambient air through the helical vent channel and a recess in the wall of the guide tube section after causing the impact on the tool bit.

Abstract: A method of manufacturing a ram configured to be mounted for reciprocation in a guide tube section of a powered hammer. The ram includes an outer circumferential surface, a radially outwardly projecting sealing portion, and a helically shaped vent channel defined in the circumferential surface and running from a front end portion of the circumferential surface to a rear end portion of the circumferential surface and being interrupted by the sealing portion. The method includes forming the outer circumferential surface of the ram and the helically shaped vent channel in a single manufacturing operation. For example, the method includes rotating a blank on a machine tool, forming the outer circumferential surface of the ram by applying a first machine tool bit to the blank while the blank is rotating, and forming the helically shaped vent channel in the outer circumferential surface by applying a second machine tool bit to the blank while the blank is rotating, without removing the blank from the machine tool.

Abstract: A driving mechanism for a powered hammer having a motor and a tool holder includes a ram mounted for reciprocation in a guide tube section. The ram has a radially outwardly projecting sealing portion and an outer circumferential surface that defines a helically shaped vent channel running from a front end portion of the circumferential surface to a rear end portion of the circumferential surface and being interrupted by the sealing portion. A piston is driven in reciprocating motion of the motor such that an air cushion is generated in a space between the ram and the piston to cause an impact on the tool bit by movement of the ram towards the tool bit. The space between the ram and the piston is temporarily connected with ambient air through the helical vent channel and a recess in the wall of the guide tube section after causing the impact on the tool bit.

Abstract: A driving mechanism for a powered hammer having a motor and a tool holder includes a ram mounted for reciprocation in a guide tube section. The ram has a radially outwardly projecting sealing portion and an outer circumferential surface that defines a helically shaped vent channel running from a front end portion of the circumferential surface to a rear end portion of the circumferential surface and being interrupted by the sealing portion. A piston is driven in reciprocating motion of the motor such that an air cushion is generated in a space between the ram and the piston to cause an impact on the tool bit by movement of the ram towards the tool bit. The space between the ram and the piston is temporarily connected with ambient air through the helical vent channel and a recess in the wall of the guide tube section after causing the impact on the tool bit.