Abstract:
A hood for a mechanized sweeper has dual portions connected via a mating surface and includes several downward depending flaps for increasing volumetric efficiency of defined vacuum plenum. The three flaps consist of a front flap, a middle flap, and a rear flap, and are of a cartridge type to facilitate replacement. The front and rear flaps are adjustable to allow for lowering of these two flaps in the event of wear due to friction against a paved road surface. A mechanism for raising the leading edge of the hood is also provided.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to mechanized sweepers. Particularly, sweepers used for sweeping paved areas, roads, paved motor vehicle parking lots, parking areas, parking structures and debris covered surfaces. More particularly, the invention relates to the hood of the mechanized sweeper. 
       BACKGROUND OF THE INVENTION 
       [0002]    Various types of sweepers are used in sweeping paved surfaces. For example, truck mounted sweepers sweep highway and roadway surfaces. In general, pavement sweepers include a standard truck or specially designed chassis upon which the sweeper unit is mounted. Three basic categories of sweeper units are: re-circulating air sweeper, mechanical sweeper, and vacuum air sweepers. Generally, re-circulating air sweeper units include a motor driven fan, sweeping hood, a curved brush, and a debris separation hopper. The curb brush brings the debris into the path of the sweeping hood. The fan re-circulates airflow from the hopper through the sweeping hood and back into the hopper where dust, particles, and other debris are removed from the airflow by known separation techniques. 
         [0003]    In re-circulating air sweepers, the sweeping hood is prone to maintenance from wear and damage. For example, the sweeping hood extends outside the wheel base and may hit objects that the truck otherwise avoids. Particularly, when the truck is cleaning parking lots and parking structures, it is also more likely the hood may hit curbs and support structures within the parking area. Exacerbating this problem, because debris may tend to clump in corners, drivers are forced to drive deep into the corners and near the curbs and support structures which further increases the likelihood of damage from hitting objects. In order to fix the damaged hood, the entire hood must be removed from under the sweeper in a labor and time intensive procedure. 
         [0004]    In addition to damage, the hoods are subject to wear. The hoods include a series of rubber flaps that allow for debris to pass under the hood and be trapped until the re-circulating air may lift the debris into the hopper. The flaps extend to the ground so that the debris may be directed toward the hopper by the re-circulating air. As the sweeper moves through the parking lot, the flaps wear against the pavement. As the flaps wear against the ground, the flaps lose material. Once the material is lost from the flaps, then the hood is no longer able to contact the paved surface at the same hood height. If the flaps do not contact the surface, then the air that is re-circulated under the hood is no longer directed toward the hopper. Instead, the re-circulated air may flow out from underneath the hood and push debris out from the hood back onto the pavement. 
         [0005]    In order to alleviate these problems, the driver generally employs one of two methods. The driver may lower the entire hood, or the driver may replace the rubber flaps. Replacing the rubber flaps requires removing the entire hood from under the sweeper and setting the flaps into the sweeper hood. By replacing the flaps, the hood height is maintained according to the original configuration. Alternatively, the driver may lower the hood so that the rubber flaps again contact the paved surface. Lowering the hood changes the dynamics of the hood. As the hood is lowered, the path of the re-circulating air changes in cross-sectional size. The decreased cross-sectional size requires higher air velocity to maintain the same flow rates. Higher flow rates changes the size of the debris that may be removed, such that larger debris will no longer be picked up by the re-circulating air flow. Therefore, the driver must decide between incomplete sweeping from a lowered hood or increased downtime from constantly replacing flaps. 
         [0006]    Eventually, the flaps must be replaced when the flaps are worn down too low. Replacing the flaps requires removing the entire hood from the sweeper. In a one piece embodiment, the sweeper may need to be elevated prior to removal, and the hood is large and unwieldy to handle. In addition, if a portion of the hood has been damaged, it is likely that the rubber flaps may not be easily replaced without replacing the entire hood. 
       SUMMARY OF THE INVENTION 
       [0007]    An aspect of the invention provides a hood for a mechanized sweeper. The hood comprises a left portion, a right portion, a central mating surface, and connectors. The left portion has an upper surface extending in a first direction. The right portion has an upper surface extending in the first direction. The central mating surface is configured to attach to the left portion and the right portion. The connectors are configured to attach the left portion and the right portion to the central mating surface. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0008]      FIG. 1  is a diagram of a re-circulating air sweeper; 
           [0009]      FIG. 2  is a view of the hood of the sweeper of  FIG. 1 ; 
           [0010]      FIG. 3  is another view of the hood of the sweeper of  FIG. 1 ; 
           [0011]      FIG. 4  is an expanded view of the hood of  FIG. 1 ; 
           [0012]      FIG. 5  is a view of a front flap of the hood of  FIG. 1 ; 
           [0013]      FIG. 6  is a view of a cartridge flap of the hood of  FIG. 1 ; and 
           [0014]      FIG. 7  is a view of the hood including connections to the sweeper. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]    Turning now to the drawing figures,  FIG. 1  is a diagram of a re-circulating air sweeper  10 . The sweeper  10  includes a cab  12 , a fan  14 , a motor  16 , a sweeping hood  18 , a curb brush  20  and a hopper  22 . The sweeper  10  is generally a specialized vehicle supported on four tires  26  and mounted on a standard utility truck chassis. As the sweeper  10  moves down a road, debris and trash under the hood  18  pass through a flexible hose  28  to the hopper  22  for collection. The brushes  20  in front of the hood  18  rotate and push debris into the path of the hood  18 . The fan  14  blows air through one side of the hood  18 . The air is then returned to the hopper  12  through the flexible connecting member  28 . In this embodiment, the fan is located on the passenger&#39;s side and the return is located on the driver&#39;s side of the vehicle  10 . Having the return  28  on the driver&#39;s side allows for a driver to better align the portion of the hood  18  under the return  28  with trash and debris that is moving under the driver and along the curbs. However, reversing the position of the fan and the return such that the fan  14  is on the driver&#39;s side and the return  28  is on the passenger&#39;s side may also effectively remove debris and trash from the surface. 
         [0016]    The fan  14  is powered by the motor  16 . An intake  21  of the fan  14  pulls air from the hopper  22 , pushes the air through a hood entry and passes the air through the hood  18  back through the return  28  into the hopper  22 . Within the hopper  22 , a filter filters the air prior to passing the air through the intake  21 . In this manner, the air that enters the fan  14  is filtered from small debris which may have been picked up through the air if the intake was vented to atmosphere. The motor  16  is configured to power the re-circulating air sweeper system, but is not responsible for propulsion of the sweeper  10 . However, fluid reservoirs meant to supply both the motor  16  and the engine of the sweeper  10  may be shared between these two components. 
         [0017]    Turning now to  FIG. 2 ,  FIG. 2  is a view of the hood  18  of the sweeper  10  of  FIG. 1 . The hood  18  includes a left section  30 , a right section  32 , a central mating section  34 , and a front flap  36 . The left and right sections  30  and  32  are generally similar in shape and size and are mirror images of one another along a central axis across the central mating section  34 . Generally, the left and right sections  30  and  32  include a rectangular elongated top surface  40  and a skirt end  42 . The skirt end  42  is oriented perpendicular to the elongated top surface  40  extending downward from the top surface  40  and extending parallel to the short axis of the elongated top surface  40 . The left and right sections  30  and  32  also include sweeper connections  46  for connecting the hood  18  to the sweeper. 
         [0018]    Opposite the skirt end  42  on left section  30 , at top surface  40  along its long axis, mating structures  50  are configured to connect sections  30  and  32  via central mating section  34 . Therefore, as may be seen, central mating section  34  attaches the left and right sections  30  and  32  to each other. The central mating section  34  also allows for each side section  30  and  32  to be removed individually from the hood  18  as opposed to a single piece type hood where the entire hood would need to be removed to repair any damage to the hood. 
         [0019]    The central mating section  34  is configured to overlay portions of the side sections  30  and  32  and are connected so that the hood  18  is structurally stiff. However, the connectors  50  between the central mating section  34  and the side sections  30  and  32  may be configured to shear forces exerted on the side sections  30  and  32  such that damage does not occur to side sections  30  and  32 , but instead cause damage to a simple connector. The sections, then, are relatively resilient to direct impacts while maintaining stiffness during normal operating conditions. 
         [0020]    If a side section  30  or  32  is damaged, then repair may be achieved quicker and more cost effectively by having to only replace a single side portion  30  or  32 . Access to a single side portion  30  or  32  is less labor intensive than fully removing the entire hood. In addition, replacing only a single side section  30  or  32  does not require removing additional connections between the hood  18  and the sweeper. Moreover, the lower costs associated with shipping smaller parts at less weight also reduce the total cost of maintenance. 
         [0021]    As more clearly shown in  FIGS. 3 and 4 , front flap  36  of hood  18  extends from underneath raised sections  31 , 33  of left and right portions  30  and  32 , respectively, and arcuately falls forward and downward to contact a pavement underneath hood  18 . Flap  36  is bounded on each side by end skirts  42  and  42 ′ and is affixed to the underside of raised portions  31 , 33  via fasteners  73 . A supporting bracket rod  74  also biases flap  36  against the underside of portions  31 , 33  when the two connectors  60  are tightened. As shown, a slot is formed through portions  31 , 33  through which connectors  60  intersect rod  74 . Flap  36  also includes corresponding slots  80  through which connectors  60  pass to engage rod  74 . A middle flap  76  is positioned rearward from front flap  36  but in proximity thereto, and is affixed to the underside of portions  30 , 32  near portions  31 , 33 . 
         [0022]    As shown in the figures, flap  36  is held in stationary position by bracket rod  74  relative to middle flap  76 , which is fixed. Fasteners  60  may be loosened and moved rearward within the slot  35  formed in portions  31 , 33  to allow flap  36  to fall vertically under its own weight, thereby lengthening flap  36 . Since flap  76  is raised slightly relative to flap  36 , debris flows relatively easily under hood  18  from the front. Rear flap  64  is longer relative to middle flap  76 , but typically of equal vertical height with flap  36 . Flaps  64 ,  76  and  36 , in conjunction with end skirts  42  and  42 ′ form a vacuum plenum into which debris on the pavement are swept through forward motion of sweeper  10  and brooms  20 . “Vacuum plenum” is hereby defined as the volume of space defined under the hood  18  into which road debris is swept and within which air is held a pressure less than ambient atmospheric pressure during operation of said sweeper  10 . 
         [0023]    The vacuum plenum is ideally a constant volume chamber. When the end skirts  42 , and  42 ′ abut the ground, the volume of the plenum is approximately the product of the length and width of the elongated top surfaces  40  and the height of the end skirts  42 . A constant volume chamber allows for a continuous airflow through the plenum at a known negative pressure. As air enters the plenum from the fan  14 , an equal amount of air exits the plenum through the flexible hose  28 . At each cross section parallel to the end skirt  42  through the plenum, an equal amount of air travels. If the cross section parallel to the end skirt  42  is reduced in size, an increased velocity of air must flow through the plenum in order to move the same volume of air entering and discharging through fan  14 . In accordance with Bernoulli&#39;s principle, as air moves faster, the pressure drops across a surface. A drop in pressure, therefore, determines the size and weight of the debris removed from a road paved surface as the sweeper  10  traverses over a paved road surface. 
         [0024]    Based on these principles, front flap  36  and the end skirts  42  must abut the paved road surface so that air does not flow out from under the hood  18 . The front flap  36  and the end skirts  42  direct flow of air from the fan to the flexible hose  28  and if the front flap does not reach the pavement, air will escape under the hood  18  over the paved surface. Escaping air may even push debris away from the hood  18  further limiting the ability of the air to bring debris under the hood  18  and into flexible hose  28 . 
         [0025]    The front flap  36  is flexible such that debris hitting the flap deform its leading edge rearward so that the debris may enter the plenum for collection. However, due to road surface irregularities, front flap  36  contacts the pavement and losses material due to wear. Over time the flap does not fully contact the pavement and the volumetric efficiency of the hood  18  is reduced. To counteract this wear, front flap  36  is configured so that the flap may be lowered relative to the hood  18 . Connectors  60  attach the front flap  36  to the hood  18  and are received through a slot  35  and a corresponding slot  80  (see also  FIG. 5 ) in the front flap  36  and are threaded through the hood  18 . As connectors  60  are tightened, front flap  36  is compressed and locked in place with bracketed rod  74  between the connector  60  and the hood  18 . The compressed front flap  36  then does not move relative to the hood  18 , but when connectors  60  are loosened front flap  36  may be moved rearward relative to the hood  18  along slots  35  formed therein. This action restores or improves contact with the pavement. Thus, instead of replacing an entire front flap  36 , or being forced to lower hood  18 , the length of the front flap  36  may be adjusted to maintain space under the hood  18  and maintain the contact with the pavement. Vacuum efficiency is thereby economically maintained. 
         [0026]    The hood  18  also includes a rear cartridge flap  64  which extends vertically downward from the upper surface  40  and abuts the pavement at the rear part of the hood  18 . Cartridge flap  64  is supported by hood  18  via rear connectors  70 . Rear connectors  70  are threaded into the cartridge flap  64  and the hood  18  such that as rear connectors  70  are rotated, the rear cartridge flap  64  may be lowered toward the ground. 
         [0027]    The cartridge flap  64  includes a rigid member  86  to attach it to rear connectors  70 . The rigid member  86  is formed from an upper U-shaped member and a downward projecting straight support member. The upper U-shaped member is inverted such that the horizontal part of the U-shaped member may receive the rear connectors  70 , and is rigidly fixed to the underside of the hood  18 . A straight resilient member  88  extends downward a short distance from member  86  to contact the pavement and is flexible. While flap  36  tends to flexibly deform to allow pavement debris to enter underneath hood  18 , rear flap  64  is stiffer to avoid debris rolling out rearward from underneath hood  18 . 
         [0028]    In a fashion similar to front flap  36 , the purpose of the rear cartridge flap  64  is to maintain the depth of the hood  18  and maintain contact between the hood  18  and the pavement. As the rear cartridge flap  64  is worn away from contact with the pavement, the rear connectors  70  may be advanced so that the bottom edge of the rear cartridge flap  64  may maintain contact with the pavement without having to drop the hood  18  downward. Slots  87  are formed in member  86  to allow the fixing of flap  64  against a rear trailing portion of hood  18  with fasteners  85 , while allowing its lowering thereof. 
         [0029]      FIG. 4  is an expanded view of the hood  18  of  FIG. 2 . The hood  18  includes the left section  30 , the right section  32 , the central mating section  34 , the front flap  36 , the rear cartridge flap  64 , a support bar  74 , and interior middle flap  76 . The support bar  74  extends along the long axis of the hood  18  between the end skirts  42 , 42 ′ and receives connectors  60  through slots  35  formed in portions  31  and  33 . The front flap  36 , then, is compressed upon the support bar  74  so that the front flap  36  may be fixed, but includes adjustability through the connectors  60  to allow for lowering of the front flap  36  as discussed above. 
         [0030]    The interior middle flap  76  is located behind the front flap  36 . The middle flap  76  acts as a volumetric check valve for the plenum. As debris passes the front flap  36 , the circulating air under the hood may not escape because the air flows between the interior flap  76  and the rear cartridge flap  64 . As the debris passes the front flap  36 , the front flap falls back into contact with the pavement and the interior flap  76  maintains close proximity with the pavement and the integrity of the plenum under the hood  18  is thereby maintained. 
         [0031]      FIG. 5  is a full view of the front flap  36  of the hood  18  of  FIG. 2 . The front flap  36  includes slots  80 . The slots  80  are configured to receive the connectors  60  through slots  35  of the hood  18  and are configured so that the front flap  36  may be slidably advanced relative to the hood so that the front flap  36  may maintain contact with the paved surface. A lower edge  82  of the front flap  36  is the lower-most projection of the front flap  36  and engages the pavement over which the hood moves, causing wear. The slots  80  in the flap  36  allow for more of the flap  36  to be used prior to removing the flap  36  because the flap  36  may be lowered a distance equal to the length of the slot  80 . Thus, edge  82  of the flap  36  may be incrementally worn a distance equal to the length of the slot  80 , thereby also reducing any environmental impact of dislodged portions of the front flap  36 . 
         [0032]    Increasing the total length of the flap  36  also increases the life of the front flap  36 . As debris contact the front flap, the additional rubber that is flexed over the upper surface of the hood absorbs some of the impact from the debris. Thus, more of the flap  36  may be used to engage debris and the wear of the flap  36  is reduced. 
         [0033]      FIG. 6  is a view of the rear cartridge flap  64  of the hood  18  of  FIG. 3 . The cartridge flap  64  includes a cartridge portion  86  and a flexible rubber member  88 . The cartridge  86  is configured to receive rear connectors  70 , and connectors  85  through slot  87 , to set the depth of the rear cartridge flap  64  over the pavement. The cartridge  86  also includes the rubber member  88 , a flexible but resilient lower portion of rear flap  64 . 
         [0034]    The use of the cartridge  86  allows for minimal rubber use in the rubber member  88 , because cartridge  86  (and thus the rubber member  88 ) may be lowered to a desired depth via rear connector  70 , such that sufficient height is maintained above the pavement while maintaining sufficient volumetric integrity of the plenum over the pavement. 
         [0035]    As may be seen, the cartridge  86  is coupled to the rubber member  88  through a plurality of connectors  89  located along the length of the cartridge flap  86  and the rubber member  88 . In another embodiment, the cartridge  86  may slidably receive the rubber member  88  laterally, for example through a dove tail joint between the cartridge  86  and the rubber member  88 . The rubber member  88 , then, would be supported in the hood by the cartridge  86  and held in place laterally by the end skirts of the hood. In another embodiment, the rubber member  88  may be attached to the cartridge  86  by a compression member exerting a force to squeeze the rubber member  88  to the cartridge  86 . The compression member is configured to fixedly attach the rubber member  88  to the cartridge  86 . Because the rear flap  64  may be more rigid than a front flap, the length of the cartridge may be elongated to increase stiffness. Increased stiffness may come at the expense of more frequent replacement, as the rubber member  88  is likely to wear faster and the amount the flap may be lowered is limited to the depth of the rubber member  88 . 
         [0036]    Turning now to  FIG. 7 ,  FIG. 7  is a view of the hood  18  including connections to the sweeper  10 . The hood  18  is configured to attach to the sweeper via various connectors  46  and brackets. Hood connectors  46  include brackets configured to receive connecting members from the sweeper, such as connecting arms and a connecting piston  96 . The connecting arms are connected to the hood via connectors  46  at hood  18  as shown. The connecting arms allow the hood  18  to rotate relative to the sweeper while still supporting the hood  18 . 
         [0037]    The connecting arms are also pinned to the sweeper, but are shaped such that forces that lift and drop the hood  18  are appropriately transmitted through the connecting arms. The connecting arms are made to deform when forces are exerted on hood  18  that attempt to rotate the hood  18  over the pavement. The connecting arms, then, are the portion of the sweeper that is most susceptible to damage due to impacts from debris to the hood  18 . This allows a simple connecting arm, instead of the hood portions, to be replaced upon the occurrence of damaging impacts. 
         [0038]    The hood  18  is also connected to the sweeper through a piston  96 . The piston  96  attaches to two pulleys  98  through guide wires  100 , and mounting brackets  102  attach the pulleys to the sweeper. The guide wires  100  are attached to the hood  18  through a pair of eye bolts  110 . The piston  96  is configured to quickly lift the hood off the pavement with controls for the piston  96  located within the cab of the sweeper so that the operator may lift and lower the hood from within the cab while operating the sweeper. By popping the hood up, the operator may be able to clear larger, lighter debris that are unable to be swept under the front flap  36  of the hood  18 . Lighter, larger debris are more difficult to ingest under hood  18  than other debris because larger debris require more force to be pushed under the hood  18 . When debris cannot transit under the hood, the debris builds up in front of the hood  18  and limits the effectiveness of the sweeper. When the operator engages the piston, the piston length shortens and the hood  18  is raised. The operator may thereby keep the hood  18  raised as the operator drives over the debris so that the debris is swept under the hood  18 . When the hood  18  is simply kicked up, then the debris is funneled between the interior flap and back flap of the hood  18  and may be removed from the paved surface into the hopper. This saves time and labor where an operator previously would be required to push debris from the front of the hood  18  after stopping the sweeper and laboring in front of the hood  18  to remove the debris. 
         [0039]    While the piston  96  has been attached to the hood  18  through guide wires, it may be possible to directly couple the piston  96  to the hood  18 . Moreover, it may be possible to provide the same effect through other means besides a piston. For example, a four bar linkage, a motor, or a screw drive may raise the hood  18  in order to clear debris from the front of the hood  18 . 
         [0040]    As will be apparent to one skilled in the art, various modifications can be made within the scope of the aforesaid description. Such modifications being within the ability of one skilled in the art form a part of the present invention and are embraced by the claims below.