Abstract: The present invention provides for noise reduction during operation of a portable blower by reducing the noise or acoustic energy escaping from the housing outlet and blower tube. The noise reduction is achieved by placing sound absorbing material in the blower tube. The sound absorbing material may include flared upstream and downstream ends to reduce turbulence. The sound absorbing material may be held within the blower tube by an insert frame such that substantial portions of the sound absorbing material are exposed to air passing through the blower tube. Also disclosed is a sound absorbing insert that can be placed within an existing blower tube to retrofit portable blowers with noise reduction technology.

Abstract: The present invention provides for noise reduction during operation of a portable blower by reducing the noise or acoustic energy escaping from the housing outlet and blower tube. The noise reduction is achieved by placing sound absorbing material in the blower tube. The sound absorbing material may include flared upstream and downstream ends to reduce turbulence. The sound absorbing material may be held within the blower tube by an insert frame such that substantial portions of the sound absorbing material are exposed to air passing through the blower tube. Also disclosed is a sound absorbing insert that can be placed within an existing blower tube to retrofit portable blowers with noise reduction technology.

Abstract: An improved air inlet cover and impeller for a convertible electric blower/vacuum. The blower/vac includes an electric motor which drives an impeller. A plurality of blades located on the impeller define a frusto-conical surface of revolution. The air inlet cover includes an integral, frusto-conical pressure ring which is located offset but generally congruent to the surface of revolution defined by the impeller blades. The cover additionally includes an air grate that allows the passage of air but prevents the passage of other objects. The grate also includes a choke member for adjusting the effective area of the air inlet into the blower/vac to control the exit air volume and velocity of the blower. The cover also includes a bell-mouthed opening integral with the choke member to increase the efficiency of the blower/vac when in the blower mode.

Abstract: An improved air concentrator nozzle for creating an increased air exit velocity from an extension tube of a portable blower or blower/vacuum. The extension tube tapers from a larger, upstream end to a smaller, downstream end. The nozzle is inserted into the upstream end of the extension tube and drops until it protrudes outwardly from the downstream end of the extension tube. An interference fit between an exterior surface of the nozzle and an interior surface of the downstream end of the extension tube restrains the nozzle relative to the tube.

Abstract: The present invention provides for noise reduction during operation of a portable blower by reducing the noise or acoustic energy escaping from the inlet of the blower housing. The noise reduction is achieved in one respect by placing sound absorbing material in a plenum attached to the inlet opening of the blower housing. Other features of the preferred plenum include louvered openings and angled engagement members to draw the plenum tightly against the blower housing.