Abstract: A flap of an elastomeric material is disposed over an outlet opening in a dust box within a main hopper of an industrial-type sweeper, the outlet opening providing communication between the dust box and the main hopper for emptying of the contents accumulated within the dust box. The flap is positioned over the outlet opening and is operative to provide selective communication between the dust box and the main hopper. During dirt and debris collection, such is accumulated within the dust box, while during emptying the dirt and debris are allowed to fall into the main hopper for egress through the hopper inlet. In one embodiment, the main hopper door controls the selective communication of a slotted flap through connection of one end of the flap to the hopper door. In another embodiment, air pressure regulates the opening and closing of the flap.

Abstract: A sweeper hopper and associated filter assembly as illustrated and described. The filter assembly effectively divides the hopper into a particulate contaminant receiving chamber and a clean air exhaust chamber. The filter assembly includes at least a pair of particulate blocking filter means and means for selectively directing the transient air stream through one or the other or both of the filter means. The filter assembly further includes cleaning means for selectively imparting the filter means, typically during periods of quiescence, to physically loosen and remove particulate contaminants therefrom and direct such contaminants into the contaminant receiving chamber.

Abstract: An overcenter, spring loaded linkage is disclosed for applying a lifting force to a pick-up broom of a street sweeper when the broom is new and heavy, and for applying a downward pressure on the broom when the broom is worn and light in weight. The linkage maintains a substantially constant pick-up broom pattern on the surface being swept throughout the useful life of the broom in spite of a substantial reduction in broom diameter due to wear.