Abstract: Leaf blower that is carried on the back of the operator comprising at least an engine (14) and a fan. The fan is provided with an air inlet (13) placed on the side of the fan that is facing away from the back of the operator. The air stream is passing the engine (14) on its way to the air inlet (13) so that the engine (14) is cooled.

Abstract: The subject invention refers to a muffler comprising a muffler housing (1, 2) and generally a catalytic converter element (13) mounted in the housing, which muffler has at least one inner outlet (4) through which exhaust gases cleaned by the catalytic element (13) are intended to pass. Furthermore, according to the invention an outlet duct (30, 31) is arranged in connection to the outside of the housing, comprising a first section (30) for leading exhaust gases in a first direction (A) in parallel with the outside of the housing, and a second section (31) for leading exhaust gases in a second, opposite direction (B), whereby said first and second sections (30, 31) have an essentially equally large cross-sectional area. By way of this outlet duct an improved cooling of the exhaust gases before they are brought in contact with fresh air rich in oxygen can be achieved. A back-pulsation of fresh air into the muffler can also be prevented.

Abstract: Conventional leaf blowers have a supporting frame to where the different components are attached. In order to reduce the noise from the tool and protect some of the components are they provided with covers. This makes the tool heavy and complicated for the operator to use. The claimed invention is a covering casing (10) that also is the supporting structure for the different components in the tool. The casing reduces the amount of noise spread from the tool and protects the components inside the casing (10).

Abstract: A crankcase scavenged and lubricated four-stroke engine (1) comprising especially: a mixture-preparation device (15) for supplying an air-fuel-lubricant mixture; an intake channel (16) connecting to the crankcase or cylinder to supply at least air (13) to the crankcase volume (12); an overflow channel (17) connecting to the crankcase or cylinder and to the intake opening (7) with intake valve (8) to supply to the intake at least air and lubricant from the crankcase volume; a valve drive assembly (18) driven by a crankshaft (4) for actuating the intake valve (8) and the exhaust valve (10); a valve drive assembly housing (19, 20, 21, 21?, 22) comprising one or more sections (19, 20, 21, 21?, 22) which is/are separate from the crankcase but in communication exclusively with the crankcase volume via at least one small size passage (23, 24, 25, 26, 27), and each section (19, 20, 21, 21?, 22) of the valve drive assembly housing has a lowest part situated closer to the combustion chamber, than the lowest part of the