Abstract:
A tailgate for use with a vehicle having a chassis and a truck bed. The truck bed has an inside surface and an outside surface. The tailgate may include a pair of mounting blocks positioned on the outside surface of the truck bed. Each of the mounting blocks may include a protrusion. The tailgate also may have a pair of arms. Each of the arms may be positioned on a protrusion for rotation thereabout. A pair of chains may attach each of the arms to the chassis.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates generally to tailgates and more specifically relates to tailgates for haulers, dump trucks, and the like.  
       BACKGROUND OF THE INVENTION  
       [0002]     Haulers, dump trucks, and similar types of vehicles may use a tailgate so as to reduce spills while hauling materials. Commonly, the tailgate is hung over the dump bed such that the gate swings out of the way when the bed is raised so as to permit dumping, i.e., an overhung tailgate.  
         [0003]     For example, Volvo Construction Equipment North America of Ashville, N.C., sells a line of articulated haulers under the designations “A25D”, “A30D”, “A35D”, and “A40D.” One piece of optional equipment is a wire operated overhung tailgate. Although the tailgate is adequate for preventing spills of material from the bed, the required maintenance and the durability of the tailgate may be problematic. For example, the wires that attach the tailgate to the chassis of the truck may snap, rendering the tailgate unusable. Second, the arms of the tailgate may be made out of metal plate. The metal plate, however, is subject to bending, also rendering the operation of the tailgate problematic. Further, the arms of the tailgate are attached to the bed and rotate about a set of bearings. These bearings required routine maintenance and also may be subject to failure. What is desired, therefore is a tailgate for a hauler, dump truck, and the like that is durable and easy to maintain. The tailgate preferably is relatively inexpensive to manufacture and to install.  
       SUMMARY OF INVENTION  
       [0004]     The present invention thus provides a tailgate for use with a vehicle having a chassis and a truck bed. The truck bed has an inside surface and an outside surface. The tailgate may include a pair of mounting blocks positioned on the outside surface of the truck bed. Each of the mounting blocks may include a protrusion. The tailgate also may have a pair of arms. Each of the arms may be positioned on a protrusion for rotation thereabout. A pair of chains may attach each of the arms to the chassis.  
         [0005]     The tailgate further may include a gate mounted on the arms. The gate may include an elongated metal plate. Reinforcing members may be positioned on the elongated plate. A support member may be positioned on the elongated plate such that the support member rests on the truck bed.  
         [0006]     The arms may include tubular members. The arms may include steel of about 0.1875 inches in wall thickness. The arms may be substantially rectangular in shape. The arms may include an aperture therein so as to mate with the protrusion. The arms also may include a chain attachment positioned thereon.  
         [0007]     The mounting block may be welded to the outside surface of the truck bed. The base plate may include reinforcing members positioned thereon. The protrusion may be a metal pin. A collar may be positioned on the protrusion so as to keep each of the arms in place.  
         [0008]     A pair of chain supports may be positioned on the chassis such that each of the chain supports attaches one of the chains to one of the arms. The chain supports each may include an extending member such that the chain is positioned outside of the truck bed. The chains may include chain link.  
         [0009]     A further embodiment of the present invention may provide a vehicle with a chassis. The vehicle may include a dump bed mounted on the chassis, a pair of mounting blocks mounted on either side of the dump bed, a tailgate positioned on the mounting blocks for rotation about the dump bed, and a pair of chains attaching the tailgate to the chassis. The tailgate may include a pair of tubular arms. The mounting blocks may be in the form of a pin. The tailgate may include a reinforced gate. A support member also may be positioned on the tailgate such that the support member rests on the dump bed.  
         [0010]     The method of the present invention may provide for attaching a tailgate to a dump bed of a vehicle, with the dump bed being positioned on the chassis of the vehicle. The method may include the steps of attaching a mounting pin to both sides of the dump bed, mounting the tailgate on the mounting pins, attaching a collar to each of the mounting pins so as to keep the tailgate in place, and attaching a pair of chains to the tailgate and the chassis. The collar may be attached by a pin.  
         [0011]     These and other features of the present invention will become apparent upon review of the following detailed description of the preferred embodiments when taken in conjunction with the drawings and the appended claims. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0012]      FIG. 1  is a perspective view of an existing tailgate system.  
         [0013]      FIG. 2  is a further perspective view of the existing tailgate of  FIG. 1 .  
         [0014]      FIG. 3  is a perspective view of the tailgate of the present invention.  
         [0015]      FIG. 4  is a side plan view of the tailgate of  FIG. 3 .  
         [0016]      FIG. 5  is a perspective view of a mounting block of the tailgate of  FIG. 3 .  
         [0017]      FIG. 6  is a side plan view of the tailgate of  FIG. 3  with the bed extended.  
         [0018]      FIG. 7  is a perspective view of the chain attachment of the tailgate of  FIG. 3 . 
     
    
     DETAILED DESCRIPTION  
       [0019]     Referring now to the drawings, in which like numerals refer to like elements throughout the several views.  FIGS. 1 and 2  show a vehicle  10  with a dump bed  20  mounted on a chassis  30 . The present invention may be used with any type of vehicle  10 , dump bed  20 , or chassis  30 .  
         [0020]     A known tailgate  40  is attached to the dump bed  20 . The tailgate  40  includes a gate  50  mounted onto the dump bed  20  by a pair of arms  60 . The gate  50  and the arms  60  may be made out of metal plate. For example, the plate may be about one (1) inch thick and made out of steel, such as A36 steel, or similar types of materials. The tailgate  40  may rotate about the dump bed  20  via a set of bushings  70 . The bushings  70  generally may be loaded with bearings. A plate  80  welded or otherwise attached to the dump bed  20  may support each the bushings  70 . Rotation of the tailgate  40  as the dump bed  20  is raised may be limited by a wire  90  attached to each arm  60 . The wires  90  may be attached to the chassis  30  of the vehicle  10  and to each of the arms  60 .  
         [0021]      FIGS. 2-6  show an improved tailgate  100  of the present invention. The tailgate  100  may include a gate  110 . The gate  110  may include an elongated plate  120 . The elongated plate  120  may be a metal plate. The metal plate may be made out of steel or similar types of materials. In this example, the plate  120  may be about 0.375 inches thick, about 115.5 inches long, and about 29 inches high. The dimensions of the elongate plate  120 , however, may vary with the dimensions of the dump bed  20  and may be sized accordingly.  
         [0022]     The plate  120  may be reinforced with tubing  130 . In this example, the tubing  130  may extend around the periphery of the plate  120 . Specifically, the tubing  130  may include one or more vertical members  140  and one or more horizontal members  150  that encircle the plate  120  and also provide support ribs. In this example, the tubing  130  may be about three (3) inches in width, about 3 inches in depth, with about 0.1875 inches in wall thickness. The tubing  130  may be substantially rectangular in shape. The tubing  130 , however, may have any desired shape or dimension. Further, multiple support ribs or tubing  130  may be used. The tubing  130  may be welded to the plate  120  via stitch welding or similar types of joinder means. The tubing  130  reinforces the plate  120  and prevents the plate  120  from being bent or damaged.  
         [0023]     The inside surface of the elongated plate  120  also may have a support member  155  extending along the length of the plate. The support member  155  may be identical or similar to the tubing  140  described above and may be welded to the plate  120 . The support member  155  may be positioned about 0.5 inches from the bottom of the plate  120  so as to nest with the dump bed  20 . An angled plate  156  may be positioned on top of the support member  155 . The plate  156  may be about three (3) inches in length and may have an angle of about forty-five degrees. The plate  156  may prevent dirt or other materials from accumulating on the support member  156 .  
         [0024]     Welded to each side of the plate  120  may be a pair of side plates  160 . The side plates  160  may be solid welded to the plate  120  or connected by similar types of joinder means. The side plates  160  may include a metal plate as described above of about 0.5 inches in thickness. Any shape or dimension may be used. A number of bolt holes  170  may be positioned within the side plates  160 . A lifting eye  180  may be attached to the top of the plate  120 .  
         [0025]     The tailgate  100  also may include a pair of arms  200 . Each arm  200  may be made out an elongated tube  210 . The tube  210  may be made from steel or similar types of materials. The tube  210  may be about twelve (12) inches in height, about two (2) inches in depth, and may have a wall thickness of about 0.1875 inches. The length and other dimensions of the tube  210  may depend upon the overall dimensions of the dump bed  20  and the vehicle  10  as a whole. The elongated tube  210  may be substantially rectangular in shape, although other shapes may be used.  
         [0026]     Each arm  200  may include an aperture  220  therethrough as will be described in more detail below. In this example, the aperture  220  may be spaced about 63 inches from one end of the arm  200 . The position of the aperture  220  may depend upon the dimensions of the dump bed  20  and the vehicle  10  as a whole.  
         [0027]     One end of each elongated tube  210  may include a tapered end  230 . In this example, the tapered end  230  may have an angle of about 22.5 degrees. The amount of the taper may depend upon the dimensions of the dump bed  20  and the vehicle  10  as a whole. Any desired angle may be used. An end plate  240  may be welded or otherwise attached to the tapered end  230 . The end plate  240  may be a metal plate as described above of about 0.5 inches thick. Any desired shape or dimension may be used. The end plate  240  may have a number of bolt holes  250  therein. The end plate  240  of the arm  200  may align with the side plate  160  of the gate  110  and may be attached by a number of bolts  260  or other type of joinder means.  
         [0028]     The other end of the arm  200  may include a chain attachment  270 . The chain attachment  270  may include two (2) end plates  280 . The plates  280  may be welded or otherwise attached to the arm  200 . The plates  280  may be made out of metal plate as described above of about 0.5 inches thick. The plates may  280  include an aperture  290  therein. A rod  300  may be positioned within the apertures  290 . The plates  280  may be connected by a further plate or other elements so as to stiffen the overall chain attachment  270 .  
         [0029]     Each arm  200  may rotate about the dump bed  20  via a mounting block  310 . Each mounting block  310  may be welded or otherwise attached to the outer surface of the dump bed  20 . The mounting block  310  may be attached via about three passes of  7018  welding rod from top to bottom. Similar types of joinder means also may be used.  
         [0030]     Each mounting block  310  may have a base plate  320 . The base plate  320  may be made out of metal plate about 0.5 inches thick. Steel or similar types of metals may be used. The base plate  320  in this example may be about sixteen (16) inches long and about ten (10) inches high. The dimensions of the base plate  320  may vary with the dimensions of the dump bed  20 , the vehicle  10  as a whole, and the arms  200 . Any desired shape or dimension may be used.  
         [0031]     The base plate  320  may have a plurality of reinforcing ribs  330 . In this example, four (4) ribs  330  may be used. The ribs  330  may be welded to the base plate  320  or otherwise attached. The ribs  330  may be made out of a metal bar of about one (1) inch in height and about a half (0.5) inch in depth. Any desired shape or dimension may be used.  
         [0032]     The base plate  320  may have an aperture of  340  therein. In this example, the aperture  340  may have a diameter of about three (3) inches. A collar  350  or a similar structure may surround the aperture  340 . The collar  350  may be about 1.125 inches in length. The collar  350  also may be made of a metal bar as is described above. The collar  350  may be welded to the base plate  320  or otherwise attached. A pin  360  may be inserted within the aperture  340  and the collar  350 . The pin  360  may be welded therein or otherwise attached. The pin  360  also may be made out of metal as is described above. The pin  360  may have a diameter of about three (3) inches so as to align with the diameter of the aperture  340 . The pin  360  may be about seven (7) inches long. The aperture  340 , the collar  350 , and the pin  360 , however, may have any desired shape or dimension.  
         [0033]     Each arm  200  may be mounted on the mounting block  310  by aligning the pin  360  of the mounting block  310  with the aperture  290  within each arm  200 . Once the arms  200  are mounted, a second collar  370  may be attached to the pin  360  and secured via an attachment pin passing through the collar  370 . The collar  370  also may be welded to the pin  360  or otherwise attached. The collar  370  keeps the arm  200  in place on the pin  360 . The second collar  370  may be similar to the first collar  350  in material, size, and dimension.  
         [0034]     Attached to both sides of the chassis  30  of the vehicle  10  may be a chain support  400 . The chain support  400  may include an extending member  410  and a support member  420 . The extending member  410  and the support member  420  may be made out of metal tubing. The metal tubing may be substantially rectangular in shape. The metal tubing may be made out of steel or similar types of materials. The tubing may be about three (3) inches in thickness and about three (3) inches in depth. The extending member  410  and the support member  420  may have any convenient length. Any desired shape or dimension may be used. The dimensions of the extending member  410  and the support member  420  may vary with the dimensions of the dump bed  20  and the vehicle  10  as a whole. The extending member  410  and the support member  420  may be welded or otherwise attached to each other. The extending member  410  extends beyond or in alignment with the arms  200 .  
         [0035]     An extending member plate  430  may be welded or otherwise attached to the extending member  410 . The plate  430  may be made out of steel or similar types of materials. The plate  430  may have a number of apertures  440  therein. The support member  420  also may have a support member plate  450  welded or otherwise attached thereto. The plate  450  also may be made out of steel or similar types of materials. The plate  450  also may have a number of apertures  460  therein. The extending member  410  and the support member  420  may be attached to the chassis  30  of the vehicle  10  or otherwise via bolts or similar types of attachment means as connected through the apertures  440 ,  460  of the plates  430 ,  450 . Similar types of attachment means also may be used.  
         [0036]     A pair of chain plates  470  may be welded or otherwise attached to the far end of the extending member  410 . The chain plates  470  may extend above the extending member  410 . The chain plates  470  each may have an aperture  480  therein. A bolt or similar types of attachment means may be position within the aperture  480 .  
         [0037]     The chain support  400  also may have a horizontal support member  500 . The horizontal support  500  may be positioned between the chassis  30  and the extending member  410 . The horizontal support member  500  may be attached to the chassis  30  and/or the extending member  410  by bolts, welding, or similar types of joinder means.  
         [0038]     Positioned between the chain attachment  270  of each arm  200  and the chain plates  470  of the chain supports  400  may be a chain  510 . The chain  510  preferably is made from steel or similar types of materials. In the example, the chain  510  is in the form of chain-link. The chain  510  generally limits the advance of the dump bed  20  as it is raised.  
         [0039]     In use, the existing tailgate  40  of the vehicle  10  (if one is present) is removed. The mounting block  310  is then welded or otherwise attached to both sides of the dump bed  20 . The arms  200  are then positioned on the mounting block  310  as the aperture  220  of each arm  200  is positioned about the pin  360  of the mounting block  310 . The second collar  370  then may be attached. The chain  510  then may be attached between the chain attachment  270  of each arm  200  and each chain support  400 .  
         [0040]     As is shown in  FIG. 6 , when the dump bed  20  is elevated, the tailgate  100  rotates about each base plate  320  until the full length of the chain  510  is reached. The tailgate  100  then may swing back under gravity as the dump bed  20  is again lowered. The gate  110  may rest on the dump bed  20  via the support member  155 . The use of the elongated tube  210  for the arms  200  provides the tailgate  100  with an increased ability to resist bending and allows the arms  200  to stay largely in alignment. The use of the mounting block  310  advantageously avoids the use of the bushings, the bearings, and the maintenance required with known tailgates  40 . Further, the use of the chain  510  largely avoids the breaking of the wire  90  and the complex attachment means previously used. The use of the support member  155  also reduces the stress placed on the chains  510 . Finally, the reinforced gate  110  provides increase stability to the tailgate  100  as a whole.  
         [0041]     It should be apparent that the foregoing relates only to the preferred embodiments of the present invention and that numerous changes and modifications may be made herein without departing from the spirit and scope of the invention as defined by the following claims and the equivalents thereof.