Abstract:
A bottom dump trailer cart which includes a cargo compartment having a floor equipped with downwardly pivoting dumping panels is constructed such that the panels protect the wheels from the dumped cargo. The cart is capable of riding over the dumped cargo because of the absence of an axle connecting wheels on opposite sides of the cart, and the provision of a rear wall of the compartment which can be caused to pivot upwardly and rearwardly. A tongue assembly extends forwardly of the cargo compartment. An operating mechanism having expanding hinges enables conversion between a dumping state wherein the dumping panels and rear wall are caused to be free-swinging, and a locked transport state wherein the dumping panels are upwardly secured and the rear wall is secured in a vertical position.

Description:
RELATED APPLICATIONS 
   This application is a Continuation-in-Part of U.S. patent application Ser. No. 10/455,157, Filed Jun. 6, 2003 now U.S. Pat. No. 6,796,615. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a wheeled cargo-carrying vehicle, and more particularly concerns a trailer adapted to dump its cargo downwardly upon the ground in a single discharge. 
   2. Description of the Prior Art 
   Bottom dump vehicles or wagons are frequently used to transport a variety of dense bulk materials such as sand, gravel, salt, hot mix asphalt, coal, ores, and the like. One primary advantage of a bottom dump trailer or truck as opposed to a conventional hydraulic hoist dump truck is that there is no need for vertical elevation to discharge the cargo rearwardly. As such, bottom dump vehicles do not have the risks associated with conventional hydraulic hoist dump trucks such as interference with low electrical or telephone wires and the potential for tipping over due to vertical elevation of a hoisted cargo compartment. Another advantage is that bottom dump vehicles do not require expensive and failure-prone hydraulic systems employed in rear-dump hauling vehicles. 
   U.S. Pat. Nos. 3,183,852 and 3,558,190 disclose hopper cars having horizontally slideable gates or doors to control downward discharge of the contents of the hopper in order to produce an elongated windrow instead of a single large pile. One of the problems encountered with a single large pile is that the rear wheels of the vehicle ride on the sides of the pile, resulting in considerable damage to the sidewalls of the tires on said rear wheels. Also, the pile will impact against an axle associated with the rear wheels. Said sliding doors require expensive heavy duty motors for operation, and the doors are subject to rapid wear due to friction created by sliding interaction with the cargo material. 
   U.S. Pat. No. 6,386,818 to Reed and U.S. Pat. No. 3,917,084 to Swisher, et. al., disclose “live bottom” trailers which employ a horizontally oriented conveyor belt at the bottom of a cargo compartment to move the cargo rearwardly for controlled dumping to produce an elongated windrow. 
   Bottom dumping vehicles designed to discharge in a single dump farm products such cotton and hay are disclosed in U.S. Pat. Nos. 4,362,457 and 3,698,767, respectively. However, said vehicles are designed to discharge their loads as integrated or shaped structures, and do not confront the need to travel over the discharged load. 
   U.S. Pat. Nos. 1,540,812 and 6,705,681 disclose bottom dumping carts designed to discharge their cargo downwardly, and then travel over and away from the pile of dumped cargo. Such carts employ pivoted floor panels that can be released to swing downwardly by virtue of weight of the falling cargo. The rear wall of the cart is hingedly suspended to permit upward and rearward displacement by the pile of dumped cargo as the cart travels forwardly. Following the dumping step, operating means restore the cart to its cargo hauling state by raising and securing the floor panels, and securing the rear wall. Earlier disclosed operating means have, however, been of complex construction, difficult to operate, and lacking in durability. 
   It is accordingly an object of the present invention to provide a farm trailer cart that can dump a loose bulk cargo downwardly upon the ground in a single discharge pile and then be pulled over and away from said pile. 
   It is another object of this invention to provide means for operating a cart of the foregoing object, said operating means being easy and safe to use, of rugged construction and amenable to low cost manufacture. 
   These objects and other objects and advantages of the invention will be apparent from the following description. 
   SUMMARY OF THE INVENTION 
   The above and other beneficial objects and advantages are accomplished in accordance with the present invention by a bottom dump trailer cart comprising:
     a) a cargo compartment defined by a front wall, paired sidewalls, a rear wall adapted to swing rearwardly and upwardly, and a floor having a pair of pivotably supported dumping panels adapted to swing downwardly to a dumping state which permits gravity discharge of the cargo content of the compartment,   b) latching means for controllably preventing movement of said rear wall,   c) at least one wheel positioned below each sidewall at a location that receives said panels in the dumping state,   d) a tongue assembly extending forwardly of said front wall and having means for releasable attachment to a towing vehicle, and   e) operating means which facilitate movement of said panels and latching means to produce said dumping state, and to produce a transport state wherein said panels are upwardly drawn to intercontacting abutment and said rear wall is secured in upright position by said latching means,   f) said operating means comprising expanding hinges activated by pulling cables to force said dumping panels upwardly.   

   
     BRIEF DESCRIPTION OF THE DRAWING 
     For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing forming a part of this specification and in which similar numerals of reference indicate corresponding parts in all the figures of the drawing: 
       FIG. 1  is a right side view of an embodiment of the cart of this invention shown in its transport state of operation. 
       FIG. 2  shows the embodiment of  FIG. 1  in the dumping state of operation. 
       FIG. 3  is a sectional view taken in the direction of the arrows upon the line  3 — 3  of  FIG. 1 . 
       FIG. 4  is a sectional view taken in the direction of the arrows upon the line  4 — 4  of  FIG. 2 . 
       FIG. 5  is a top view of the embodiment of  FIG. 1 . 
       FIG. 6  is a front view of the embodiment of  FIG. 1 . 
       FIG. 7  is an enlarged fragmentary schematic side view showing the operating mechanism of the cart of  FIG. 1 . 
       FIG. 8  is a top view of the schematic view of  FIG. 7 . 
       FIG. 9  is a fragmentary top view taken in the direction of the arrows upon the line  9 — 9  of  FIG. 3 . 
       FIG. 10  is a rear view of an alternative embodiment of expanding hinge component useful in the cart embodiment of  FIG. 1  and shown in the transport state of said cart. 
       FIG. 11  is a rear view of the alternative embodiment of expanding hinge component of  FIG. 10  shown in the dumping state of said cart. 
       FIG. 12  is a rear view of the alternative embodiment of expanding hinge component of  FIG. 10  shown in an intermediate state of operation. 
       FIG. 13  is a top view of the alternative embodiment of expanding hinge shown in  FIG. 12 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to  FIGS. 1–8 , an embodiment of the farm cart of the present invention is shown comprised of cargo compartment  10 , side wheels  11  positioned below said cargo compartment on each side thereof, a tongue assembly  12  extending forwardly of said cargo compartment, and operating means  13  associated with said tongue assembly. 
   Cargo compartment  10  is comprised of front wall  14  having interior and exterior surfaces  15  and  16 , respectively, and upper and lower extremities  17  and  18 , respectively; opposed sidewalls  19  joined to front wall  14  in spaced apart relationship about longitudinal axis  20  and bounded in part by upper edges  22  which are straight, parallel, and horizontally coplanar. The lower regions of said sidewalls are comprised of opposed downwardly convergent portions  32  which facilitate complete dumping of the contents of the cargo compartment. Said convergent portions  32  terminate in straight lower edges  26 . Said sidewalls extend longitudinally to rear extremities  23 . A rear wall  29  is supported by pivot means  30  associated with the upper edges  22  of said sidewalls adjacent rear extremities  23 , and is capable of swinging movement rearwardly and upwardly. Said front wall and sidewalls are supported by a U-shaped frame  37  which is open beneath said rear wall. The consequence of said U-shaped frame is that there is no portion of the frame which, at the rear of the cart is transversely disposed between said sidewalls. 
   A floor is comprised of a pair of dumping panels  27  elongated between said front and rear walls, pivotably supported by edges  26 , and extending to straight distal extremities  28 . Said dumping panels are adapted to swing toward and away from each other in a path orthogonal to axis  20 . A non-dumping or closed transport state is achieved when said distal extremities are in contacting abutment, as best shown in  FIG. 3 . A dumping state is achieved when panels  27  are separated and downwardly directed, as best shown in  FIG. 4 . 
   Latching means  33  are interactive with rear wall  29  in a manner to secure said rear wall in upright position in abutment with the rear extremities  23  of said sidewalls and the rear extremities of panels  27 , thereby closing said cargo compartment. 
   When the latching means are controllably released from engagement with said rear wall, the rear wall becomes free swinging, and can move rearwardly and upwardly. This is a feature of the dumping state, as best shown in  FIG. 2 . In operation, when the cargo is allowed to fall by gravity effect directly upon the ground below the cart, a single pile is produced. The height of the pile may well be above the level of frame  37 . Consequently, the pivotable nature of the unlatched rear wall permits rearward and upward motion by contact with the top of the pile when the cart is advanced. By virtue of such effect, forward motion of the cart will not be impeded by the dumped pile. Typical cargos suitable for handling by the cart of this invention include top soil, manure, hay, feed and agricultural products. 
   Side wheels  11  are positioned below each sidewall. Each side wheel is rotatable upon an individual axle  38  within a holding yoke  39  in a manner such that no axle spans the cart below the cargo compartment. By virtue of said individual axles and consequent absence of a spanning axle, and the absence of a transverse rear frame member, there is no obstruction to a dumped pile of cargo. Accordingly, the cart can be advanced over the pile. Said wheels are positioned in a manner such that panels  27 , when in the dumping state as shown in  FIG. 4 , protect the wheels from interaction with the pile of dumped cargo. Such protection of the wheels in the dumping state is further achieved by virtue of the fact that the width of panels  27 , measured between distal extremity  28  and supporting edge  26  is substantially equal to the distance between frame  37  and the receiving ground surface  57 . 
   Tongue assembly  12  extends forwardly from front wall  14  as an extension of frame  37 . The forward extremity of said tongue assembly contains hitching means  41  for releasable attachment to a towing vehicle. A forward wheel  59  is positioned below said tongue assembly and centered upon axis  20 . 
   An embodiment of operating means  13  is shown pivotably supported by paired brackets  21  mounted upon the front portion of frame  37  and disposed beneath sidewalls  19 . An operating arm  95  is pivotably joined to each bracket  21 , and extends to an upper extremity  96 . A cross bar  97  extends laterally between each extremity  96  in joinder therewith. An extender rod  98  is attached to the center of cross bar  97  and forwardly directed upon axis  20 . An actuating lever  60  joins extender rod  98  at an obtuse angle therewith. 
   Paired pulling cables  62  are attached to the upper extremities  96  of arms  95 , and extend through tubular conduits  64  disposed upon the exterior of each sidewall and terminate in extremities  65  located adjacent each side wheel  11 . 
   An expanding hinge  66  is pivotably secured to the inside of the yoke  39  of each side wheel, and extends to pivoted engagement with the underside  68  of the associated dumping panel  27 . Said hinge is comprised of a first arm  69  extending downwardly from pivot means  90  on said yoke to a distal extremity  70 , and a second arm  80  joined by pivot means  90  to underside  68  and having a lowermost extremity  81  joined by pivot pin  71  to the distal extremity of said first arm. The terminal extremity of each cable  62  is attached to pivot pin  71 . By virtue of such construction, when cable  62  is pulled upwardly, it causes hinge  66  to expand laterally in a scissor-like movement which pushes the associated panel  27  upwardly. Such upward pulling of the cable is produced when actuating lever  60  is forced downwardly. 
   Locking means are associated with the forward portion of actuating lever  60  to keep said lever in its downward position. As best shown in  FIGS. 1 and 2 , an embodiment of said locking means is shown comprised of pivoted handgrip  72  interactive with pivoted hook  73 . A loop  74 , attached to the tongue assembly is adapted to engage hook  73  in the downwardly secured state of lever  60 . An actuating tab  76  is attached to the lowermost, pivoted extremity of the right side operating arm  95  and adapted to force coupling rod  49  rearwardly when lever member  60  is in the lowermost position. Such action causes hinge  52  to secure said rear wall. 
   When lever member  60  is released, permitting upward movement thereof, the weight of panels  27  plus the weight of the cargo causes said panels to swing downwardly to dump the cargo. Spring biasing means may be employed to drive rod  49  forwardly to produce said open state. 
   An alternative embodiment of the expanding hinge employed in the cart of the present invention is illustrated in  FIGS. 10–13  and denoted by numeral  83 . Said alternative hinge  83 , which provides improved efficiency of operation, includes a vertically elongated actuating bar  84 . The distal extremity of cable  62  is attached to the upper extremity of bar  84 . A vertically elongated slot  85  centered within bar  84  slideably accommodates pivot pin  71  which interconnects said first and second arms  69  and  80 , respectively. Said arms, supported by pivot means  90 , are spaced apart sufficiently to slideably embrace opposite sides of bar  84 . A fulcrum rod  86  is orthogonally secured to bar  84  adjacent the lowermost extremity thereof. 
   In operation, when pulling force is applied by cable  62  to actuating bar  84 , hinge  83  begins to expand from the folded configuration shown in  FIG. 11  that it has in the dumping state of the cart. As bar  84  is raised, fulcrum rod  86  acts against oppositely facing angled edges  87  of said arms, forcing them apart in a scissor-like motion. With continued upward movement of bar  84 , pivot pin  71  slideably descends within slot  85 , and the pointed extremities  70  and  81  of said arms are drawn to substantially horizontally opposed positions, causing dumping panel  27  to be in the closed or transport state of the cart, as shown in  FIG. 10 . 
   While particular examples of the present invention have been shown and described, it is apparent that changes and modifications may be made therein without departing from the invention in its broadest aspects. The aim of the appended claims, therefore, is to cover all such changes and modifications as fall within the true spirit and scope of the invention.