A hydraulic hammer includes a power cell. A work tool is partially received in, and movable with respect to, the power cell. A sleeve is positioned in the power cell that defines a centerline. A piston is concentrically positioned in the sleeve and movable in the sleeve between a first position in contact with the work tool and a second position out of contact with the work tool. A magnetic guide system includes at least one of a first magnetic guide component disposed in the piston and at least one of a second magnetic guide component disposed in the sleeve that interact to produce magnetic repellent forces therebetween to urge the radial position of the piston towards the center line.

A hand-held power tool has a tool socket 2 to hold a tool on a working axis 11. A pneumatic striking mechanism 6 has an exciter piston 13 that is forced to move periodically along the working axis 11 by a motor 5 and it also has a striker 14 that is coupled to the exciter piston 13 via a pneumatic chamber 18. The exciter piston 13 has a cylindrical main body 21 made of a polymer. One or more rings 24 containing copper surround the main body 21. The rings 24 protrude from the main body 21 in the radial direction.

A power tool with hammer mechanism including: a housing; a hollow spindle located in the housing; a hammering unit including a piston reciprocatingly mounted within the spindle; a swashplate drive unit for driving the piston reciprocatingly; the swashplate drive unit including a swashplate finger engaged with the rear end of the piston; the piston including a through opening mostly perpendicular to the longitudinal axis of the piston at its rear end, a free end of the swashplate finger is received directly in the through opening of the piston, at least a part of outer surface of the free end of the finger contacting at least part of inner surface of the through opening during reciprocation of the piston. Such a direct coupling between the swashplate finger and the drive piston minimizes numbers of the parts, reduces complexity of the assembly and the cost.

A linerbolt removal tool, including: a housing; a moil supported for reciprocating movement by the housing; an inertial body located within the housing; a gas charged accumulator extending from the inertial body away from the moil; a piston moveable within the inertial body between a striking position at which the piston strikes the moil and a retracted position, whereby firing the piston from its retracted position to its striking position includes causing pressurised gas within the accumulator to accelerate the piston toward the moil, wherein the piston has a striking end for striking the moil and an opposing rear end; and a piston cap that encloses the rear end of the piston, wherein during firing, the piston and the piston cap initially accelerate together and prior to the piston reaching its striking position the piston cap separates from the piston, whereby the piston cap isolates the piston from the accumulator.

A piston for a hydraulic hammer of a work machine is disclosed. The piston comprises a first portion having a first diameter, a second portion having a second diameter larger than the first diameter, the second portion having a plurality of grooves, and a third portion having a third diameter less than the second diameter.

A linerbolt removal tool, including: a housing; a moil supported for reciprocating movement by the housing; an inertial body located within the housing; a gas charged accumulator extending from the inertial body away from the moil; a piston moveable within the inertial body between a striking position at which the piston strikes the moil and a retracted position, whereby firing the piston from its retracted position to its striking position includes causing pressurized gas within the accumulator to accelerate the piston toward the moil, wherein the piston has a striking end for striking the moil and an opposing rear end; and a piston cap that encloses the rear end of the piston, wherein during firing, the piston and the piston cap initially accelerate together and prior to the piston reaching its striking position the piston cap separates from the piston, whereby the piston cap isolates the piston from the accumulator.

An improved pneumatically operated percussive tool and implement with a host of innovative design features that provide improved performance, drastically reduced weight, and speed of implement attachment and removal.