Portable handheld motor-driven tool

Claim 1

A handheld, portable tool comprising: an engine housing; an internal combustion engine mounted in said engine housing and having a membrane carburetor; said carburetor including a carburetor housing having a housing wall defining an air-intake channel and, a throttle flap rotatably mounted in said channel; a generator driven by said engine for generating a heating current; an electric heating element electrically connected to said generator and mounted on said carburetor in the region of said air-intake channel; said heating element having a positive temperature coefficient at a predetermined temperature region thereby preventing said carburetor housing and said throttle flap from heating to temperature above a predetermined value; and, said heating element being further configured to be a flat member having a flat side and being attached directly to said housing wall so as to cause said flat side to be in heat-conductive contact with said housing wall over the entire surface of said flat side to permit a direct transfer of heat from said heating element through said wall and into said air-intake channel; said engine housing having a ground terminal; and, a contact arrangement for said heating element, said contact arrangement including: a contact carrier for carrying a first contact member electrically connected to said generator; and, a second contact member connected to said ground terminal; said first contact member including first contact means for electrically connecting said first contact member to said heating element; and, said second contact member including second contact means for connecting said second contact member to said carburetor housing.