Abstract: A pneumatic vane motor with a stator cylinder having an air inlet opening and an air outlet opening, a rotor eccentrically journalled in the cylinder and carrying a number of sliding vanes which divide the cylinder into moving cells, wherein the cylinder comprises a by-pass passage located between the air inlet opening and the air outlet opening and arranged to leak air from a pressurized working cell into a preceding cell before the working cell reaches the outlet opening, thereby using a preceding cell as an expansion volume for sound attenuation.

Abstract: A portable electric grinder with an air cooling system and connected to a remote stationary voltage supply means (19, 20) via a cable (16), wherein a cooling air duct (21) is provided to connect cooling air passages (23a, b) in the grinder housing (10) to a stationary air pumping device, and the air pumping device is provided with a filter unit (24) for preventing dust and other undesirable particles from entering the air duct (21) and reaching the cooling air passages (23a, b) of the grinder housing (10).

Abstract: A portable electric grinder with an air cooling system and connected to a remote stationary voltage supply means (19, 20) via a cable (16), wherein a cooling air duct (21) is provided to connect cooling air passages (23a, b) in the grinder housing (10) to a stationary air pumping device, and the air pumping device is provided with a filter unit (24) for preventing dust and other undesirable particles from entering the air duct (21) and reaching the cooling air passages (23a, b) of the grinder housing (10).

Abstract: A pneumatic vane motor with a stator cylinder having an air inlet opening and an air outlet opening, a rotor eccentrically journalled in the cylinder and carrying a number of sliding vanes which divide the cylinder into moving cells, wherein the cylinder comprises a by-pass passage located between the air inlet opening and the air outlet opening and arranged to leak air from a pressurized working cell into a preceding cell before the working cell reaches the outlet opening, thereby using a preceding cell as an expansion volume for sound attenuation.

Abstract: A straight type power grinder includes an elongate housing having a handle with a power controller at its rear end, and a neck portion at its forward end supporting an output shaft connected to a rotation motor. The neck portion is formed with an integrated mounting flange for a grinding wheel guard. The neck portion and the mounting flange form an auxiliary handle for a comfortable manual support of the grinder during operation.

Abstract: A power tool has a housing, a pneumatic rotation motor supplied with pressure air via an inlet passage, an outlet passage connecting the motor to an exhaust air discharge in the housing, and a speed governor for controlling the pressure air flow through the inlet passage responsive to the motor speed. The outlet passage includes a first outlet duct and a second outlet duct extending in parallel between the motor and exhaust air discharge, and an exhaust valve which controls exhaust air flow through the second outlet duct. The exhaust valve is spring biased toward a closed position and shifted to an open position by an activator which is exposed to the air pressure in the inlet passage downstream of the speed governor and which shifts the exhaust valve to the open position at pressure levels above a certain pressure level in the inlet passage downstream of the speed governor.