Runway or street sweeper

Claim 1

In a road sweeper vehicle, a cylindrical broom power driven for rotation of its road-contacting sweeping surface about a horizontal axis and in the direction of the sweeper travel, walls forwardly and rearwardly of the broom forming a broom chamber, and suction means communicating with the front of the broom to receive and remove air-entrained debris being swept upwardly by the broom and to induce ambient airflow downwardly closely adjacent the upwardly rotating upper surface of the broom for mixing with said debris, the top of said chamber being open to atmosphere so that said suction means induces air inflow to the broom chamber through its open top, said suction means including ducting having an inlet at the front of the broom and forming therewith a downwardly progressively narrowing airgap to pass said downward ambient airflow, air entry to the broom chamber at the front thereof being restricted by a flap extending downwardly and rearwardly below the level of said gap, and means to adjust the broom position downwardly and forwardly to compensate for broom wear, said means located to maintain said gap progressive downward narrowing during said downward and forward adjustment.