Abstract: A coupling structure for a split boom power tool is provided. The structure permits any of a variety of lower tubular boom members with their working tools to be quickly and easily coupled to or uncoupled from an upper tubular boom member having a power source. The structure includes compatibly sized end portions on the upper and lower boom members that allow them to be quickly and easily telescopically joined and also provide a strengthened joint. A clamping member is provided with a locating tab that is receivable in a locating hole in the tube of the upper boom member to allow the clamp to be quickly and positively positioned at the joint. A plurality of tool orienting openings are provided in the end portion of the upper boom member and clamp to receive a spring loaded locking pin carried in the lower boom member to position the tool at a desired angular working orientation.

Abstract: A coupling structure for a split boom power tool is provided. The structure permits any of a variety of lower tubular boom members with their working tools to be quickly and easily coupled to or uncoupled from an upper tubular boom member having a power source. The structure includes compatibly sized end portions on the upper and lower boom members that allow them to be quickly and easily telescopically joined and also provide a strengthened joint. A clamping member is provided with a locating tab that is receivable in a locating hole in the tube of the upper boom member to allow the clamp to be quickly and positively positioned at the joint. A plurality of tool orienting openings are provided in the end portion of the upper boom member and clamp to receive a spring loaded locking pin carried in the lower boom member to position the tool at a desired angular working orientation.

Abstract: A portable power tool is provided which includes a chassis defining an integral rear handle, a first chamber for lubricating oil generally at a front end of the chassis, a second chamber for fuel generally at a rear end of the chassis, and a recess between the first and second chambers. An internal combustion engine is secured to the chassis within the recess and a front handle is secured to the front end of the chassis. A chain saw unit is also secured to the front end of the chassis and is operably connected to the engine. The chassis includes right and left nylon plastic chassis sections which are vibrationally welded together.

Abstract: A muffler for coupling to an exhaust port of an internal combustion engine includes a housing, a first hollow body within the housing, a catalyzer within the first hollow body, and a second hollow body within the housing. The first hollow body has an inner surface defining a first chamber and an inlet adjacent the exhaust port to admit the exhaust gas into the first chamber. The exhaust gas is exothermally treated as it flows through the catalyst in the first chamber in a direction away from the engine and passes through an outlet of the first hollow body to a second chamber. The second chamber is formed by an inner surface of the second hollow body and an outer surface of the first hollow body. The treated exhaust gas flows through the second chamber in a direction toward the engine over the outer surface of the first hollow body where a thermal reaction takes place and/or further emission reduction takes place by a catalytic coating on the outer surface of the first hollow body.