Abstract: A blower for cleaning a surface is provided. The blower includes a radial blower that is driven by a motor and includes an impeller that is rotatable about a blower axis and a housing that at least partially surrounds the impeller. In the area of the blower axis, the housing is provided with an intake opening on an end wall that is disposed approximately perpendicular to the blower axis. A damping bell is disposed on the end wall in the region of the intake opening. The damping bell is provided with a damping panel that is disposed approximately parallel to and at a distance from the end wall, and covers the intake opening. The damping bell also includes a bell wall that extends about the intake opening and the damping panel in a collar-like manner. At least one intake window is provided in the bell wall.

Abstract: The invention relates to an exhaust-gas muffler on an internal combustion engine in a motor chain saw. The exhaust-gas muffler includes a housing (1) which is assembled of two housing shells (2, 3). The one housing shell (2) has an exhaust-gas inlet (4) and the other housing shell (3) has an exhaust-gas outlet (5). An inner wall (8) as well as a catalytic converting element (7) are provided in the inner space (6) of the muffler housing (1). The catalytic converting element (7) is mounted between the exhaust-gas inlet (4) and the exhaust-gas outlet (5). In order to ensure an adequate catalytic converting treatment of the exhaust gas at low gas counterpressure, it is provided to divide the entering exhaust-gas flow (10) and to conduct at least one of these component flows (23) in contact with the catalytic converting element (7). The component flows (22, 23) are brought together and mixed with other before exiting from the muffler housing (1).