Abstract:
A mechanized broom-type sweeper truck that includes a pavement engaging brush or broom and an elevator for transported debris to the inlet or entry opening of a debris container includes a slinging roller in the debris container mounted at or subjacent the inlet opening. The slinging roller is journalled in bearings and driven by a motor at a selected rotary speed. Surface features are provided on the roller to engage with and contact any debris coming into contact with the roller to fling, sling, throw debris away from the inlet opening.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
   This application claims the benefit of U.S. Provisional Patent Application No. 60/602,668 filed Aug. 19, 2004 by the inventors herein and in common ownership herewith. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to mechanized sweeper trucks that utilize a primary broom to sweep debris from roadways and, more particularly, to method and apparatus for “leveling” the debris load within the debris container of such vehicles. 
   Mechanical broom sweepers are designed to pick-up debris not normally accepted by conventional regenerative or vacuum-type sweepers; this debris typically including asphalt nodules of varying size consequent to asphalt milling operations, rocks, stones, construction debris, broken masonry, and the like. In a typical design, as shown in schematic fashion in  FIG. 1 , a primary or main broom is rotated against the road surface to brush debris in the forward direction onto a mechanical elevator. The elevator typically includes a set of parallel flights that push the debris along an inclined floor pan to carry the debris upwardly for deposit through an entry opening of a debris collection bin or hopper. Because the density of the collected debris is relatively high, the debris drops from its point of entry and collects directly beneath its point of entry. As the debris pile accumulates and increases in elevation, the collected debris at the top of the pile tends to clog or block the entry opening, even though other parts of the collection hopper are comparatively unfilled. 
   In general, the problem cannot be solved by merely increasing or stepping up the operating speed of the elevator to more energetically throw the debris into the debris collection hopper. The sweeping vehicle and its main broom are best operated in speed ranges that assure the efficient sweeping of debris from the roadway and the efficient projecting of that swept debris into or onto the moving elevator. Thus, for any broom speed, the elevator speed is best maintained in a speed range that prevents a situation in which the elevator flights ‘overrun’ the brush function. 
   Vehicle operators have addressed this problem by abruptly applying the vehicle brakes to cause the debris pile to slump forwardly against the front wall of the debris container away from the entry opening on the rear wall of the debris collection hopper. This solution, while temporarily effective, tends to cause premature wear of the vehicle brakes and tires. 
   SUMMARY OF THE INVENTION 
   A broom-type mechanized sweeper of the type having a broom and a mechanized elevator for transferring debris to the entry opening of a debris hopper is provided with a slinger element that slings, flings, throws, or projects debris coming into contact with the slinger element therefrom. In a preferred form, the slinger element is formed as a cylindrical roller mounted for rotation about an axis and rotated by a motor. Surface features associated with the roller, such as paddles, arms, blades, a weld-bead formation(s), grooves, or a combination thereof, function to contact and engage debris falling into contact with the roller to impart sufficient kinetic energy thereto that the debris is thrown away from the roller. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1  is a simplified schematic view of a representative organization of the broom, elevator, and collection hopper of a broom-type mechanical sweeper; 
       FIG. 2  is a side elevational view of the cab portion of a sweep truck body with a collection hopper and a mechanical elevator (dotted-line illustration); 
       FIG. 3  is a rear perspective view of  FIG. 2  with the collection hopper separated from the truck chassis for reasons of clarity; 
       FIG. 4A  illustrates a perspective view of an exemplary elevator for elevating debris to and into the collection bin; 
       FIG. 4B  is a side elevational view of the elevator of  FIG. 4A ; 
       FIG. 5  illustrates, in schematic form, one form of debris-throwing or slinging element; 
       FIG. 6  illustrates, in schematic form, another form of the debris-throwing or slinging element of  FIG. 5  throwing or launching debris to the forward side of the collection hopper or bin; 
       FIG. 7  illustrates an exemplary slinging roller; 
       FIG. 8  is a detailed view of an exemplary surface feature of the present invention; 
       FIG. 9  is a detailed of another type of surface feature; and 
       FIG. 10  is an end view of the organization of further type of slinger element. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 2  illustrates, in side view, and  FIG. 3  illustrates, in rear perspective view, a portion of a mechanized broom sweeper  10  of the type sold by Schwarze Industries, Inc. of Huntsville Ala. under the M5000 or M6000 designations. As shown, the sweeper  10  includes a commercial truck chassis  12  (only part of which is illustrated) which carries a debris collection hopper  14 . As best shown in  FIG. 3 , the collection hopper  14  includes a laterally aligned entry slot  16  through which debris is delivered by the elevator  18  ( FIG. 2 , dotted-line illustration). 
   As shown in  FIGS. 4A and 4B , the elevator  18  includes a pair of spaced apart shafts  20  that each carry respective spaced apart sprockets  22  and  24 . A first carrier chain  26  is entrained about the sprockets  22  of the shafts  20  and a second carrier chain  28  is entrained about the sprockets  24 . Debris carrying blades or flights  30  are supported between chains  26  and  28  function to push or carry debris along a transfer plate or floor pan  32  upwardly and into the entry slot  16  of the debris collection hopper  14 . The elevator  18  is typically powered by a hydraulic motor (not shown). 
   As discussed above in relationship to  FIG. 1 , the debris being pushed through the entry slot  16  of the debris collection hopper  14  immediately falls therebelow to form a debris pile immediately thereunder. With time, the uppermost extent of the debris pile is located immediately below the entry inlet  16  and hinders the continued efficient operation of the elevator  18 . 
   As shown in schematic form in  FIG. 5 , a “slinger’ element  50  is provided to sling, throw, or fling debris from or in the general vicinity of the point or area of entry in the forward direction. The slinger element  50  is mounted for rotation in the direction shown about an axis of rotation A x  and, in the schematic representation of  FIG. 5 , includes surface features in the form of four outwardly extending blades, paddles, or projections  52 . As shown in  FIG. 6 , a slinger element  50  is located subjacent the entry slot  16  and has been provided with shorter arm-like ‘stub’ projections  52  than those shown in  FIG. 5 . The projections  52  shown in  FIGS. 5 and 6  are illustrative only, since in practice, much shorter projections  52  are utilized. As represented in  FIG. 5 , the slinger element  50  is rotated as some speed, usually in the range of a few hundred rpm by a suitable motor (i.e., hydraulic). As debris is pushed through the entry slot  16  by the various flights  30  of the elevator  18 , the larger pieces drop immediately toward and/or onto the slinger element  50  where one or the other of the projections  52  contacts the debris to launch or throw the so-contacted debris forwardly to the side of the debris collection hopper  14  opposite the entry slot  16 . As a consequence, the debris will land upon and contribute to the formation of a debris pile on the side opposite the entry slot  16  or impact the forward wall of the debris collection hopper  14  and fall onto the debris pile. The amount of kinetic energy imparted to the debris should be at least sufficient to successfully transfer substantially all or almost all of the heaviest and largest pieces of debris away from the slinger element  50  to the side of the debris collection hopper  14  opposite thereof. 
     FIG. 7  illustrates a preferred embodiment of a slinger element  50 . As shown the slinger element  50  is formed as a cylindrical roll having a side-to-side dimension of about 60 inches (1.5 meters) sufficient to accommodate the width of the entry slot  16  and a diameter of about 6 inches, although smaller diameter (i.e., 3-4 inch) and larger diameter (i.e., 7-9 inch) rolls are suitable depending upon the application. The slinger element  50  includes a mounting shaft  54  and is carried, at its far end, in a bearing  56 , that, in turn, is carried on a mounting bracket  58 . In a similar manner the near-end of the slinger element  50  is journalled in another bearing  60  which, in turn, is carried on a mounting bracket  62  to support the slinger element  50 . 
   A drive motor  64 , such as a fixed-speed or variable-speed hydraulic motor, is connected to the shaft  54  to drive the slinger element  50  at a sufficient speed for the average size of the debris particles, their density, and the distance that the debris particles are thrown. In general, a rotary speed in the range of 100 to 400 rpm is considered adequate. A shown in  FIG. 7 , speed control can be in the form of an operator-manipulated controller  66  and a control unit  68  that controls the motor  64  in an open loop manner or which, optionally, receives feedback information from a rotational speed sensor  70  to maintain rotary speed as the quantity of debris changes. While a hydraulic drive motor is preferred, other slinger propulsion devices can be used, including pneumatic motors, electric motors, or equivalents thereof. 
   In contrast to the paddle like arm or projections of  FIGS. 4 and 4A , the slinger element  50  of  FIG. 7  has spirally aligned surface features  72  that function to engage the debris and sling, fling, or project the debris away from the entry slot  16 . As shown in the detail of  FIG. 8 , the surface features  72  are formed by depositing at least one weld bead on the surface of the slinger element  50  that, in the case of the embodiment of  FIG. 7 , follows a spiral path or pattern on the surface of the roll. As shown, a plurality of such spiral-path surface features  72  can be used to create the pattern shown. The weld-bead surface feature can be formed by an automatic or pre-programmed welding machine that applies the weld bead as the roll  50  is rotated along its axis A x . While the spiral-pattern of  FIG. 7  is preferred, other patterns are not excluded from the present invention and can include, for example, linear weld beads formed parallel to the axis of rotation A x  of the slinger element  50 . In the preferred embodiment, the weld beam surface feature  72  has an elevation or height from its base to the outermost point of about 0.375 inch, although a smaller or larger-dimension weld bead is suitable depending upon the particular application. 
   In the embodiments of  FIGS. 4 ,  5 , and  7 , the surfaces features that impart kinetic energy to the debris extend outward of the diameter surface of the slinger element  50 . As can be appreciated, the notion of surface features can include features that are less than the outside diameter of the slinger element. For example and as shown in  FIG. 9 , a surface feature can include a groove or slot  74  that can extend laterally across the slinger element  50  or extend in the spiral pattern discussed above; if desired, the outwardly extending surface feature  72  can also be provided in combination with groove or slot  74 . In addition, the slinger element  50  can take the form of a non-cylindrical structure, such as the cruciform type slinger  76  shown in  FIG. 10 . 
   Regardless of the form the slinger element takes or the nature of the surface features, during normal operation of the slinger element, debris falling from the inlet entry  16  toward or to some part of the surface of the slinger element has a high probability of receiving sufficient kinetic energy to sling, fling, throw, or launch the debris to the side of the debris collection hopper opposite from the inlet entry opening to cause the debris pile to form away from the inlet entry opening. 
   As will be apparent to those skilled in the art, various changes and modifications may be made to the illustrated embodiment of the present invention without departing from the spirit and scope of the invention as determined in the appended claims and their legal equivalent.