Motorized street sweeper

Abstract

A street sweeper system is used in a motorized vehicle. The sweeper utilizes a cylindrical brush rotating about a horizontal axis that is typically perpendicular to the vehicle's direction of motion. A conveyor belt catches debris thrown forwards and upward by the brush and moves the debris to a hopper. A conveyor flap is mounted on a lower edge of the conveyor to improve sweeping performance. The conveyor lip covers a space between the lower edge of the conveyor and the ground. A cutoff flap is located on a forward portion of the brush to deflect debris that is passing over the brush. A recirculation flap is located at a rear portion of the brush to recirculate debris that has passed over the top of the brush.

What is claimed is:  
     
         1 . A sweeper for a ground surface having a front end, a back end and a forward direction of motion, the sweeper comprising: 
 a debris mover comprising: 
 an outer surface;  
 a ground contact area defined where the outer surface of the debris mover contacts the ground surface;  
 an axis of rotation, the debris mover rotating about the axis of rotation so that the outer surface of the debris mover moves at least in part towards the front end of the vehicle at the ground contact area;  
 a cutoff area on the outer surface of the debris mover, the outer surface of the debris mover moving at least in part upwards at the cutoff area as the debris mover rotates about the axis of rotation; and  
 a recirculation contact area, the outer surface of the debris mover moving at least in part downwards at the recirculation contact area as the debris mover rotates about the horizontal axis;  
   a cutoff flap mounted forward of the debris mover, the cutoff flap having a distal end adjacent the outer surface of the debris mover along the cutoff area so that a first portion of the debris traveling to the cutoff area is deflected at least in part downward; and    a recirculation flap mounted behind the debris mover, the recirculation flap proximate the recirculation contact area so that a second portion of the debris traveling to the recirculation contact area is deflected back into the debris mover.    
     
     
         2 . The sweeper of  claim 1 , further comprising: 
 a debris collector mounted forward of the debris mover; and    a conveyor flap mounted adjacent a lower edge of the debris collector, the conveyor flap having a distal edge proximate the ground surface, the conveyor flap substantially covering a space defined between a lower edge of the debris collector and the ground surface.    
     
     
         3 . The sweeper of  claim 2 , further comprising a ground gap defined between the distal edge of the conveyor flap and the ground surface.  
     
     
         4 . The sweeper of  claim 2 , wherein the conveyor flap comprises a plurality of slots at the distal edge.  
     
     
         5 . The sweeper of  claim 2 , wherein at least the distal edge of the conveyor flap is oriented an angle between 40 and 50 degrees relative to vertical.  
     
     
         6 . The sweeper of  claim 1 , wherein the cutoff area is located between 45 degrees and 140 degrees from the ground contact area.  
     
     
         7 . The sweeper of  claim 1 , wherein at least a portion of the cutoff flap proximate the distal tip is oriented between 10 degrees and 30 degrees relative to horizontal.  
     
     
         8 . The sweeper of  claim 1 , further comprising a gap between the distal end of the cutoff flap and the outer surface of the debris mover.  
     
     
         9 . The sweeper of  claim 1 , wherein the recirculation flap comprises: 
 a flexible mounting flap fixably attached to the sweeper;    an elongated blade connected to the mounting flap, an edge of the elongated blade engaging the debris mover.    
     
     
         10 . The sweeper of  claim 1 , wherein the recirculation contact area is located between 40 degrees and 80 degrees from the ground contact area.  
     
     
         11 . The sweeper of  claim 1 , wherein the debris mover comprises a brush having bristles.  
     
     
         12 . The sweeper of  claim 11 , wherein a distal end of the recirculation flap extends substantially within the bristles of the brush.  
     
     
         13 . A method of street sweeping of a debris from a ground surface, comprising: 
 moving a conveyance in a forward direction on the ground surface;    rotating a debris mover of the conveyance to move the debris at least in part forward of the debris mover;    catching the debris on a debris collector facing the debris mover to collect the debris;    deflecting back a first portion of the debris thrown into a space defined between a lower edge of the debris collector and the ground surface to recirculate the first portion of the debris back into the debris mover;    deflecting downwards a second portion of the debris that passes upwards along a forward portion of the debris mover to recirculate the second portion of the debris back into the debris mover; and    deflecting forwards a third portion of debris that passes downwards along a rear portion of the debris mover to recirculate the third portion of debris back into the debris mover.    
     
     
         14 . The method of  claim 13 , further comprising drawing a vacuum to move an airborne dust from a space surrounding the debris mover to collect the airborne dust.  
     
     
         15 . The method of  claim 14 , further comprising blocking the airborne dust at the forward portion of the debris mover to prevent escape of the airborne dust therethrough.  
     
     
         16 . The method of  claim 14 , further comprising blocking the airborne dust at the rear portion of the debris mover to prevent escape of the airborne dust therethrough.  
     
     
         17 . The method of  claim 14 , further comprising blocking the airborne dust at the space defined between a lower edge of the collector and the ground surface to prevent escape of the airborne dust therethrough.  
     
     
         18 . A mobile sweeping system for removing a debris from a ground surface, the sweeping system having a forward direction of motion and a sweeping width, the sweeping system further comprising: 
 a debris moving means moving a debris at least in part forwards across the sweeping width;    a debris collecting means catching the debris moved by the debris moving means;    a deflecting means covering at least part of a collector clearance space defined between a lower edge of the debris collecting means and the ground surface, the deflecting means deflecting a first portion of the debris moved by the debris moving means into the collector clearance space back to the debris moving means;    a cutoff means adjacent to a forward portion of the debris moving means where an outer surface of the debris moving means is moving at least in part upwards, the cutoff means deflecting downwards a second portion of the debris passing upwards along the outer surface of the debris moving means; and    a recirculation means proximate a back portion of the debris moving means where the outer surface of the debris moving means is moving at least in part downwards and forwards, the recirculation means deflecting a third portion of the debris passing over and behind the debris moving means back to the debris moving means.    
     
     
         19 . The sweeping system of  claim 18 , wherein the deflecting means comprises a distal edge adjacent the ground surface and a substantially flexible portion along the distal edge.  
     
     
         20 . The sweeping system of  claim 19 , wherein the substantially flexible portion comprises a plurality of slots along the distal edge.  
     
     
         21 . The sweeping system of  claim 18 , further comprising a gap between the cutoff means and the outer surface of the debris moving means.  
     
     
         22 . The sweeping system of  claim 18 , further comprising a flexible mounting means resiliently coupling the recirculation means to the sweeping system.  
     
     
         23 . The sweeping system of  claim 18 , wherein a distal portion of the recirculation means substantially penetrates beneath the outer surface of the debris moving means.  
     
     
         24 . The sweeping system of  claim 18 , wherein the deflecting means causes a restriction of a flow through the collector clearance space, the restriction of flow preventing release of a portion of an airborne dust therethrough.  
     
     
         25 . The sweeping system of  claim 18 , further comprising housing means encompassing a rear portion of the debris moving means and wherein the recirculation means causes an air restriction between the debris moving means and the housing means, the air restriction preventing release of a portion of an airborne dust of the debris therethrough.  
     
     
         26 . The sweeping system of  claim 18 , wherein the cutoff means forms an air restriction between the debris moving means and the debris collecting means, the restriction preventing release of a portion of an airborne dust of the debris therethrough.