A work tool includes: a motor; a housing including a gripping part; an electronic switch; a controller controlling the motor based on a signal from the switch; an operating part provided at the gripping part; and an intervening part movably intervened between the operating part and the switch. The switch is provided at the housing at a first position in an axial direction of the gripping part, and is switchable between an ON position for driving the motor and an OFF position for stopping the motor. A direction connecting the ON position and the OFF position to each other is a crossing direction crossing the axial direction. The operating part is movable in the crossing direction to drive and stop the motor. The intervening part transmits movement to the switch by a moving amount smaller than movement in the crossing direction of the operating part passing through the first position.

A concrete grinder has a rotating planetary gearbox with counter rotating tooling plates attached. The planetary gearbox is powered directly from a trowel gearbox output shaft, which is connected to a center bore of the planetary gearbox. As the planetary gearbox rotates, tooling shafts are forced to counter rotate because the input shaft of the planetary gearbox is connected to a fixed pulley or sprocket. The planetary gearbox is sealed to keep water, dust or slurry from entering.

A concrete grinder has a rotating planetary gearbox with counter rotating tooling plates attached. The planetary gearbox is powered directly from a trowel gearbox output shaft, which is connected to a center bore of the planetary gearbox. As the planetary gearbox rotates, tooling shafts are forced to counter rotate because the input shaft of the planetary gearbox is connected to a fixed pulley or sprocket. The planetary gearbox is sealed to keep water, dust or slurry from entering.

A grinder including a motor, a switch operated ON and OFF in accordance with an operation of a switch lever to control a rotation of an output shaft of the motor, a spindle that rotates in accordance with the rotation of the output shaft to rotate a disk-shaped grinding wheel and a brake mechanism controllable with respect to a brake plate that integrally rotates with the output shaft, in a housing, the brake plate includes fins.

A grinder including a motor, a switch operated ON and OFF in accordance with an operation of a switch lever to control a rotation of an output shaft of the motor, a spindle that rotates in accordance with the rotation of the output shaft to rotate a disk-shaped grinding wheel and a brake mechanism controllable with respect to a brake plate that integrally rotates with the output shaft, in a housing, the brake plate includes fins.

The power tool has a housing portion that accommodates a motor (6) and a cooling fan (8), and a handle portion (5B). Air suction ports (41, 42a-42d and 43) are arranged in the housing portion, and outside air is sucked into the housing portion by the rotation of the cooling fan. In the power tool, a passage (52) is formed in the handle portion, the passage guiding cooling air from the air suction port (41) rearward away from the cooling fan; the cooling air is caused to flow from an opening (53) into the handle portion to cool a heat-generation mechanism included in a switch mechanism (60); and the cooling air is again returned to the housing portion. In the housing portion, the cooling air is discharged to the outside from air discharge ports (13a and 13b) together with the cooling air from the other air suction ports.

The power tool has a housing portion that accommodates a motor (6) and a cooling fan (8), and a handle portion (5B). Air suction ports (41, 42a-42d and 43) are arranged in the housing portion, and outside air is sucked into the housing portion by the rotation of the cooling fan. In the power tool, a passage (52) is formed in the handle portion, the passage guiding cooling air from the air suction port (41) rearward away from the cooling fan; the cooling air is caused to flow from an opening (53) into the handle portion to cool a heat-generation mechanism included in a switch mechanism (60); and the cooling air is again returned to the housing portion. In the housing portion, the cooling air is discharged to the outside from air discharge ports (13a and 13b) together with the cooling air from the other air suction ports.

A method is disclosed for treating or maintaining a hard surface comprising a stone or stone-like material, the method comprising treatment of the surface with a flexible pad, in the presence of abrasive particles, bonded to the pad, on a contact surface between the pad and the hard surface, wherein the abrasive particles comprise diamond particles, and the treatment is performed in the absence of an effective amount of crystallization agent on the contact surface. The treatment is performed on a substantially regular basis, such as daily, weekly or monthly, and the treatment is performed using a pad comprising an open, lofty, three dimensional non-woven webs of fibers. A tool for use in the method is also provided, as well as a floor-surfacing machine comprising such a tool and a method for manufacturing such a tool. Furthermore, methods for treating or maintaining hard, smooth surfaces such as wood, polymer material, lacquer, linoleum, gelcoat, glass and automotive enamel are disclosed.

A rotating circular disc attaches to a rotary motion abrading tool and converts the rotary motion to a random orbital motion. The disc has a center and has an axis of rotation that is off center and that forms a center of gravity. One embodiment of the disc is a backing plate. A second embodiment of the disc is a polishing pad. A third embodiment of the disc is a combination of a backing plate and a polishing pad.

A rotating circular disc attaches to a rotary motion abrading tool and converts the rotary motion to a random orbital motion. The disc has a center and has an axis of rotation that is off center and that forms a center of gravity. One embodiment of the disc is a backing plate. A second embodiment of the disc is a polishing pad. A third embodiment of the disc is a combination of a backing plate and a polishing pad.