Patent ID: 7191485

Claim:
A vacuum sweeper movable over the ground to collect debris on the surface of the ground and comprising: a) a hopper having a hopper inlet opening and a hopper outlet opening formed therein; b) a blower having a suction side and a discharge side; c) a vacuum duct having a vacuum nozzle inlet formed at a first end thereof and being flow connected to said suction side of said blower at a second end thereof, said vacuum nozzle inlet opening into a vacuum chamber positioned in closely spaced relation to the ground; d) a blower discharge duct flow connected at a first end thereof to said discharge side of said blower and at a second end thereof to said hopper inlet opening; and e) a return air duct flow connected to said hopper outlet opening at a first end thereof and having an air discharge opening at a second end thereof, said air discharge opening feeding into said vacuum chamber; wherein f) said air discharge opening is at least approximately three times greater in cross-sectional area than said vacuum nozzle inlet.