Abstract: A sound depressing exhaust means for a pneumatic power tool with a substantially cylindrical housing (10) and a vane motor (11) with exhaust port means (23), has an annular casing (41) surrounding a portion of the housing (10), and four expansion chambers (31-32, 34, 36, 39) arranged in series and combined with four flow restrictions (33, 37, 30, 35) and a sound trap (38). All of the expansion chambers are annular and located concentrically relative to the tool housing (10), and one of the flow restrictions has an annular screen (37) separating two of these chambers (34, 36). The last two of the expansion chambers (36, 39) in the exhaust flow direction contain high frequency absorbing elements (43, 44) of foamed plastic.

Abstract: A hydraulic torque impulse generator comprising a rotationally driven drive member (10; 50), a hydraulic fluid chamber (16; 51) confined in the drive member (10; 50), an output spindle (18; 53) having a rear impulse receiving portion (17; 52) extending into the fluid chamber (16; 51), at least two radially slidable vanes (23, 24; 58, 60) carried by the rear spindle portion (17; 52) and cooperating with corresponding seal portions (25, 26; 62, 63, 64) on the fluid chamber wall, axially extending seal ribs (29, 30; 65, 66, 67) on the fluid chamber wall and corresponding axially extending seal ribs (27, 28; 68, 70) on the rear spindle portion (17; 52). Simultaneous sealing cooperation is obtained more than once during each revolution of the drive member (10; 50) relative to the output spindle (18; 52), whereby the fluid chamber (16; 51) is momentarily divided into at least two high pressure compartments (H.P.) and at least two low pressure compartments (L.P.).

Abstract: A pressure fluid powered machine tool comprising a rotary motor unit displaceably guided in a cylinder bore of a housing to accomplish a combined rotary and linear movement of a working tool such as a drilling or tapping tool. The motor unit is provided with an external pressure fluid supply tube which is rigidly connected to the motor unit in a parallel offset position and which cooperates with a pressure chamber in the housing to establish a controlled fluid communication between the housing and the motor unit. The feed tube also serves as a torque reaction support bar by means of which the torque reaction arising in the motor unit is transferred to the housing.