Sweeper

Claim 1

A SWEEPER COMPRISING, IN COMBINATION, A HOUSING ADAPTED TO BE MOVED ACROSS THE SURFACE TO BE CLEANED, MEANS FOR SUPPORTING THE HOUSING FOR SUCH MOVEMENT, A DEBRIS RECEPTACLE INTO WHICH DEBRIS IS DISCHARGED DURING OPERATION OF THE SWEEPER, SAID HOUSING HAVING AN OPEN LOWER END AND A DISCHARGE OPENING COMMUNICATING WITH THE DEBRIS RECEPTACLE, A ROTATING BRUSH IN SAID HOUSING ENGAGING THE SURFACE TO BE CLEANED, A DUST SEAL FOR PREVENTING DISCHARGE OF DUST INTO THE ATMOSPHERE DURING OPERATION OF THE SWEEPER, SAID SEAL INCLUDING A SUPPLEMENTAL FRAME MOVABLE SUPPORTED ON THE MAIN HOUSING AND FREELY MOVABLE DURING OPERATION OF THE SWEEPER, SAID FRAME INCLUDING A SUBSTANTIALLY HORIZONTAL SHAFT EXTENDING ACROSS SAID SWEEPER ADJACENT THE FRONT SIDE OF THE OPEN LOWER END OF SAID HOUSING, AND A PLURALITY OF INDEPENDENTLY MOUNTED SEALING MEMBERS IN SIDE BY SIDE SEALING RELATIONSHIP WITH EACH OTHER, SAID MEMBERS BEING ROTATABLY MOUNTED ON SAID SUPPORTING SHAFT AND FITTING LOOSELY ENOUGH THEREON TO BE FREELY MOVABLE VERTICALLYI WHEN PASSING OVER PARTICLES OF DEBRIS.