Abstract:
The invention disclosed here is a moving headboard for use in connection with a reciprocating floor slat system. It is particularly well-suited for use in connection with load-hauling trailers that have built-in reciprocating floor slat conveyors for unloading the trailer. Trailers of this kind are used in lieu of hydraulic lifts and involve inching the load off the trailer. The moving headboard sweeps the trailer floor clean during the unloading process.

Description:
TECHNICAL FIELD 
       [0001]    The invention disclosed here generally relates to conveyor systems that are known as reciprocating floor slat systems. More particularly, the invention relates to a moving headboard that cleans the interior floor surface and wall of a truck trailer, or similar walled container, that is unloaded via a built-in reciprocating floor slat system. 
       BACKGROUND OF THE INVENTION 
       [0002]    Reciprocating floor slat conveyors typically involve a set of load-supporting slats that all move together in one direction, and then return, one-third at a time, in the other direction. Because the dynamic frictional surface contact area between slat surfaces and load is less during slat return, the load is inched along by the conveyor apparatus as the slats move back and forth. Floor slat reciprocation is usually always driven by hydraulics, with some variation in unloading speed, depending on different variables. 
         [0003]    Reciprocating floor slat systems are often built into truck trailers that haul bulk materials like gravel, as an example. This type of design is used as an alternative to a dump truck (having a conventional hoist lift). 
         [0004]    When reciprocating floor systems are used in a trailer, it is desirable that the trailer and reciprocating floor be left clean after an unloading operation. For this reason, several “cleanout” designs have been developed in the past. One cleanout design is described in U.S. Pat. No. 7,510,071, which describes a “plow” style cleanout apparatus. A more common type of cleanout apparatus is the flexible tarp system described in U.S. Pat. No. 6,974,296, issued to Simrin. 
         [0005]    All of these cleanout systems involve a floor tarp portion, or something similar, that rides along the floor with the load. Usually, some of the load&#39;s material rests directly on the tarp, thus increasing the frictional forces between the tarp and the reciprocating floor slats underneath, so that the tarp sweeps the floor relatively clean by pulling a vertical barrier or headboard behind it as the trailer is unloaded. Either a portion of the tarp or other structure built aft of the tarp creates the cleanout surface that functions like a moving wall for preventing material from leaking forward as the cleanout apparatus moves aft during the unloading operation. 
         [0006]    At the end of the unloading procedure, the tarp mostly exits and hangs over the end of the trailer before it is reeled back to the forward end of the trailer. One of the problems with this design is that the end of the tarp is sometimes buried in the pile of unloaded material sitting on the ground. The weight of the unloaded material sitting on the buried tarp stresses the tarp material and/or the tarp return mechanism when it is operated to pull the tarp free. Sometimes truck drivers will roll the truck forward to simply pull the tarp out of the load—which creates the same kind of problem. 
         [0007]    A different problem associated with prior art systems is that they have a tendency to allow a certain amount of material to pass (or leak past) their lateral edges during the unloading process. Poor cleanout along the lateral edges of the cleanout system is more of a problem for loads like gravel or sand, as examples, because left-over material from one load may contaminate the next load involving a different kind of material. It is undesirable to have sand from one load mixed with asphalt in the next, as an illustrative example. 
         [0008]    For the above reasons, there is a need to improve upon existing cleanout systems that are tailored for reciprocating floor assemblies. 
       SUMMARY OF THE INVENTION 
       [0009]    The invention is an improved cleanout apparatus for a reciprocating floor slat conveyor. It is specifically designed to clean the floor slat conveyor when the floor is built inside a walled container, like a trailer, or similar walled structure. The cleanout apparatus sweeps material from the floor and sidewalls of the container as the floor slat conveyor unloads material from the container. 
         [0010]    The cleanout apparatus comprises a headboard member that crosses or substantially spans the distance between the two lateral container sidewalls on opposite sides of the headboard member. Depending on the embodiment, the headboard member may be built on and supported by a base or base member, although other implementations are described below. At this point, it is appropriate to mention that patent protection is not intended to be limited to the specifics of any embodiment described here in text and drawings. 
         [0011]    A flexible sheet, connected to the headboard member, rides on top of the reciprocating floor slat member, forward of the headboard member, and extends a certain distance in front of the headboard member. The flexible sheet provides a resting place for material that is being unloaded in between two wing members, or wings, that make up part of the clean out apparatus. The wings are “floating” and slide against the sidewalls as the headboard member moves. 
         [0012]    More specifically, the pair of wing members are laterally mounted relative to each side of the headboard member. Each wing member is connected to the headboard member in a manner so that one is free to at least partially swing about an axis in a relatively unrestricted way. A flexible material like belting, or another kind of material, creates the free-floating action of the wing. In this manner, each wing can easily adjust to the kinds of variations in the lateral sidewalls that are typical to common trailers, as an example. 
         [0013]    Each wing member has a section described here as a “lateral baffle portion” that extends forwardly of the headboard member. While, in the design described here, the baffle portion may be a larger, flat surface section, it defines a surface (regardless of its flatness) that is shaped to generally angle each wing outwardly (toward the sidewall) as the cleanout apparatus rides on the reciprocating floor slat conveyor. 
         [0014]    Each wing member also includes a forward leading edge portion that terminates the leading edge of each wing, although the forward leading edge portion is a section that is angled relative to the baffle portion. 
         [0015]    As an example, the forward leading edge portion may be a section that is created by making a bend in the material making up the lateral baffle portion. Regardless of its specific configuration, however, the forward leading edge portion of the wing defines an edge that wipes against its respective container sidewall as the cleanout apparatus moves. This edge may be made from a rubber belting material, or other suitable material, that has a leading edge surface (pushing toward the load) that terminates at a contact point that wipes, like a wiper blade, against the container sidewall. 
         [0016]    The cleanout apparatus also has a secondary, rearward, sweeper member that follows the wing and is mounted to a lower lateral side of the headboard member. The rear sweeper also swings relative to the headboard member and container walls. In other words, it too floats against the sidewall, although it is smaller. 
         [0017]    The flexible sheet can be made or dimensioned so that it is slightly wider than the distance between the sidewalls. This allows the lateral edges of the sheet to fold slightly in the region where trailer wall meets floor, to assist in the clean out function. 
         [0018]    Other features included as part of the cleanout apparatus involve improvements that help return the apparatus to its original position in the trailer after the trailer load is emptied; and certain other refinements that help adjust the apparatus to the size of the trailer and improve its overall clean sweep function. 
         [0019]    Among other things, the apparatus includes a rail member mounted to an outer surface of the wing that cooperates with a ramp or ramp member mounted to the container sidewall. The rail member is in alignment with the ramp member, the latter being near the container&#39;s end. As the leading edge of the wing slides against the ramp member, it is initially deflected inwardly and then passes over the ramp, like a bump. At that point, the rail member on the wing comes to rest on the ramp and holds the wing&#39;s baffle portion a fixed distance from the sidewall, preventing the leading edge from flaring outwardly relative to the container&#39;s end as at least part of the cleanout apparatus protrudes out from the container (at the end of the unloading process). 
         [0020]    The apparatus also has small plow members mounted to the apparatus near opposite lower corners of the headboard member. These members are designed to clean material from the reciprocating floor slat conveyor, near each container side wall, for certain kinds of floor slat installations. 
         [0021]    Another refinement involves placing adjustment brackets on opposite sides of the apparatus to adjust its width to different variations in container width. One of the overall advantages to the design is that it provides a modular unit that is easy to disassemble for shipping, but easy for the purchaser to assemble and adjust the unit to the dimensions of an existing trailer with the floor already installed. 
         [0022]    One of the challenges to designing a cleanout apparatus for reciprocating floors involves coping with the different kinds of frictional forces that act on the apparatus. The flexible sheet described above has a cleanout function, but it also functions to pull the headboard and wings along the length of the trailer, because of the weight of the load that sits on the sheet. 
         [0023]    The area of the sheet has to be great enough to create enough static frictional contact area so that the floor will not slip underneath the sheet as the floor moves the load. With the wing design described above, the dynamic frictional forces between the wings and sidewalls are reduced sufficiently so that the size of the sheet can be reduced. In effect, this means the sheet can be shortened so that it terminates at or just beyond the leading edges of the wings. When the apparatus reaches the end of its path of travel, a shorter length of the sheet hangs over the trailer&#39;s end and is less likely to be buried by some of the unloaded material. 
         [0024]    The features summarized above, and others not summarized, are described in the following text which is to be read in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    In the drawings, like reference numerals and letters refer to like parts throughout the various views, and wherein: 
           [0026]      FIG. 1  is a pictorial view of the rear-end of a vehicle trailer, with a built-in reciprocating floor slat system, showing the moving headboard design disclosed here; 
           [0027]      FIG. 2  is a pictorial view of the trailer portion shown in  FIG. 1 , with one sidewall of the trailer cut-away; 
           [0028]      FIG. 3  is a pictorial view of a moving headboard constructed in accordance with one embodiment of the invention; 
           [0029]      FIG. 4  is a view like  FIG. 3 , but is taken from a different perspective, looking at the rear and underneath the moving headboard; 
           [0030]      FIG. 5  is a frontal view of the moving headboard shown in  FIGS. 3 and 4 ; 
           [0031]      FIG. 6  is a view like  FIG. 5 , but with the headboard&#39;s side wings removed; 
           [0032]      FIG. 7  is a view like  FIG. 6  (with side wings removed); 
           [0033]      FIG. 8  is a top sectional view of one of the headboard&#39;s side wings and illustrates how the headboard&#39;s side wings are constructed for floating/wiping along a trailer&#39;s sidewall during an unloading operation; 
           [0034]      FIG. 9  is a view like  FIG. 2 , but shows the headboard with side wings removed; 
           [0035]      FIG. 10  is a pictorial view of another embodiment of the moving headboard 
           [0036]      FIG. 11  is a view similar to  FIG. 8 , but is the first in a series of four views, and shows the leading edge portion of a side wing sliding along a trailer wall toward a wedge spacer or ramp member built into the wall—that prevents the leading edge from expanding laterally out past the end of the trailer; 
           [0037]      FIG. 12  is a view like  FIG. 11 , but is the second in the series; 
           [0038]      FIG. 13  is a view like  FIGS. 11 and 12 , but is the third in the series; and 
           [0039]      FIG. 14  is a view like  FIGS. 11-13 , but is the fourth and last in the series. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    Referring now to the drawings, and first to  FIG. 1 . Shown generally at  10  is a moving headboard system (“moving headboard”) constructed in accordance with the invention. 
         [0041]    In  FIG. 1 , the headboard  10  is shown at the aft end of a conventional trailer, indicated generally by arrow  12 . This type of trailer  12  would be very familiar to a person having involvement with the trucking industry and knowledge about how reciprocating floor systems are built into the floor beds of trailers. 
         [0042]    Trailers of this type are typically pulled by semi-trucks or the like. In the figure, the trailer has a rear door  14  that is hinged to the back. As is common, the door  14  swings up when the trailer is unloaded. Also, as is common, the load is inched off the trailer  12  by the built-in reciprocating floor slat system. The load, in this case, is schematically illustrated at  16 . It could be a pile of gravel, as a non-limiting example, although systems of this type are used to haul many different kinds of material in bulk. 
         [0043]    The load bearing slats in a reciprocating floor may have different physical configurations. One configuration involves horizontal supporting surfaces that make the floor look similar to a conventional deck, except the deck slats are closely spaced and move back and forth. Another type of reciprocating floor design involves reciprocating slats that have “peaks” separated by stationary slats that have “valleys.” This type of design is better suited for certain kinds of loads for structural reasons. 
         [0044]    The headboard  10  described here can be used for either type of reciprocating floor slat system described above, or any other type of similar system where cleanout might be desired or needed. However, as is apparent from the illustrations, the headboard  10  is shown here used in connection with the “peaked” floor system, which is well-known in the industry. 
         [0045]    Turning now to  FIG. 2 , the headboard  10  is illustrated at the aft end of the trailer  12 , but with one sidewall of the trailer removed. After the trailer is unloaded, the headboard  10  is returned to the forward end of the trailer (indicated generally at  18 ) by a winch  20  and strap  22  assembly. The winch and strap configuration  20 ,  22  is common to prior art systems, like the tarp system described above. In most instances, the winch and strap configuration  20 ,  22  limit the headboard&#39;s  10  path of travel, with the length of the unwound strap  22  preventing the moving headboard system  10  from falling out from the end of the trailer  12 . 
         [0046]    The headboard  10  has several different parts or portions. Directing attention now to  FIG. 3 , the headboard  10  includes, first, a headboard portion  24  that normally spans most of the distance between the trailer walls on opposite lateral sides of the headboard  10 . Directing attention briefly to  FIGS. 5 and 6 , for example, the trailer&#39;s lateral walls are illustrated at  26 ,  28 , respectively. 
         [0047]    As illustrated in  FIG. 3 , the headboard  10  also includes two lateral side wings, indicated generally by arrows  30 ,  32 . Each side wing is mounted to the headboard portion  24  by a hinge structure  34 . The hinge structure  34  allows each wing to float against the sidewall. 
         [0048]    The hinge structure  34  can take different forms. However, it can be a flexible material, like rubber, that is connected to headboard  24  and side wing  30  by bars or straps  36 ,  38  that are bolted to these respective parts. Sometimes these parts are called “bolt bars” and, as is apparent from the drawings, bolt bar arrangements are used to connect many of the flexible pieces of the present design to the headboard  10 . 
         [0049]    Referring now to the right-hand side wing  30 , as shown in  FIG. 3 , it has a lateral baffle portion  40  and a forward leading edge portion  42 . The leading edge portion  42  is angled relative to baffle portion  40 . The leading edge portion  42  has an edge  44  that wipes against its respective container sidewall as the headboard  10  moves along the floor. For the sake of clarity, the floor is generally indicated by arrow  46  (see  FIG. 2 ). The same kind of leading edge  44  on the opposite side wing  32  wipes against the lateral container wall  26  on the other side (see, e.g.,  FIG. 6 ). 
         [0050]    The side wings  30 ,  32  may be manufactured from a single sheet of material such as aluminum, for example, with the forward leading edge portion  42  bent at an angle relative to the baffle portion  40 . The leading edge  44  may be created by bolting a strip of another material  48  that has the necessary material characteristics (e.g., durable rubber) so that it can cleanly wipe the container wall without creating unnecessary friction. Three-quarter inch, four-ply conveyor belting is an example of a suitable material. The strip  48  is bolted to the forward-leading edge portion by a strip  50 . 
         [0051]    As will be described in greater detail later, the angular orientation of the leading edge portion  42  coupled with the extended edge  44  created by material  48  is important because it serves to reduce unwanted friction. In general terms, the headboard  10  needs friction with the underlying floor, because adequate friction is necessary to move the headboard  10  with the load. However, friction between side wings  30 ,  32  against the lateral container walls  26 ,  28  is normally unwanted friction because it opposes movement of the headboard  10 . 
         [0052]    As illustrated, the headboard portion  24  generally stands vertically upward. Headboard portion  24  is illustrated as having a slight angle relative to the vertical. Generally speaking, regardless of the angle, it creates a vertically upstanding, moving wall that helps contain and push the load out from the trailer during the trailer unloading process. The headboard portion  24  may be built with an access panel  55  that can be removed (unbolted) if needed. 
         [0053]    As shown in  FIG. 3 , the headboard portion or part  24  is mounted to a base portion  52  and supported by braces  54 . The base portion  52  also rides on the floor and provides another horizontal surface for allowing the floor to frictionally move the headboard  10 . 
         [0054]    Included as part of the overall headboard design illustrated here is a flexible tarp, indicated generally by arrow  56 . The tarp  56  is connected to the headboard  10  and creates a load bearing surface between the headboard  24  and side wings  30 ,  32 . Some of the load typically sits on tarp  56  with the force of the load creating friction between the tarp and the floor. The tarp  56  may be connected to the headboard part  24  by using a strip  57  (bolt bar) that clamps the tarp&#39;s edge to the headboard (see  FIG. 7 ). Also, as was summarized above, the tarp  56  may be slightly wider than the width of the trailer such that its outer lateral edges are folded. These folds are generally illustrated at tarp  59  in  FIG. 1 . 
         [0055]    Because of the reduced side wing friction described above, it offers the opportunity to shorten the length of the tarp  56  significantly relative to prior designs. In the  FIG. 3  illustration, for example, the tarp extends forward of headboard  24  about the same distance as the side wings  30 ,  32 . This is advantageous because when the headboard  10  reaches its final position of travel (as illustrated in  FIG. 1 ), the length of the tarp is too short to be caught in the unloaded material. This improvement makes for an easier return of the headboard to the forward part of the trailer part  18  without stressing the tarp. However, it is only an example. There may be other configurations where it is desirable to use a longer tarp, similar to existing systems. 
         [0056]    The side wings  30 ,  32  are free to swing and are driven to slide against and float over the lateral sidewalls  26 ,  28  of the trailer  12  only by load forces during the trailer unloading operation. The free-swinging nature of the wings  30 ,  32  allows the headboard to adjust to variations in trailer width along the length of the trailer. As a practical matter, trailer walls may be approximately 50 ft. in length. It is unlikely any trailer wall will be perfectly straight, over the course of an extended length, which means the headboard has to be able to naturally adjust and float freely against the walls as the headboard moves. The side wings  30 ,  32  are laterally divergent (outwardly) relative to the headboard portion  24  and these different parts create a type of sliding plow, with the counteracting force of the load pushing the wings laterally into the trailer&#39;s walls sidewalls  26 ,  28 . 
         [0057]    Another aspect to the design disclosed here relates to how the headboard  10  operates when it is at the end of the trailer. Because the side wings  30 ,  32  float freely, the lateral forces created by the load may tend to push the side wings out when they eventually extend past the trailer&#39;s wall at the very end. It is important that the forward leading edges do not hook the trailer walls during the headboard return movement. 
         [0058]    In order to prevent this, the outer surface of each lateral baffle portion  40  has a side rail, indicated generally at  58  (see,  FIG. 3 ). Referring now to  FIG. 2  (and FIG.  9 —which shows the headboard with side wings removed), each lateral trailer sidewall has a small “bump” or ramp member or wedge  60  built into the wall at the trailer&#39;s end. The rail  58  on the side wing follows parallel to the wall  26  (see arrow  61  in  FIG. 11 ) until the leading edge  44  (specifically, edge  48 ) hits the slope defined by wedge  60  ( FIG. 12 ). The cam action caused by the slope of wedge  60  drives the leading edge portion  42  laterally inwardly over the length of the ramp (and swings the wing&#39;s leading edge portion laterally inwardly) until the edge  48  passes the bump created by wedge  60 . At that point ( FIG. 13 ), the height or thickness of the wedge  60  creates a spaced resting place for the side rail  58  (the space is indicated by arrow  63  in  FIG. 8  and  FIGS. 11-13 ) attached to the back-side of the wing  32 , as the headboard  10  continues to move at least partially out from the trailer (see  FIG. 14 ). The same thing happens on the opposite side of the trailer with respect to side wing  30 . 
         [0059]    As indicated above, the headboard  10  is shown in the illustrations (see, e.g.,  FIG. 4 ) riding across a “peaked” floor system where the reciprocating slats are triangular in shape and come to an apex, as shown at  62  in  FIGS. 5 and 6 . This type of floor system generally has “V” valleys (indicated generally at  64 ) where stationary slats are located. In the embodiment illustrated, the headboard  10  has plow members  66 ,  68  mounted at each lower corner. These plow members  66 ,  68  ride within the V-shaped valleys adjacent to each lateral sidewall  26 ,  28 . 
         [0060]    As is also illustrated (see  FIG. 4 , for example), the headboard  10  has a rear, following edge portion, indicated at  70 . This edge portion  70  may be regarded as a following wing that also floats on the sidewall, except near the place where wall meets floor. This rear wing member  70  swings freely and floats like the wing members  30 ,  32  described above. Although not specifically illustrated, its path of travel stops at or near the end of the trailer (see, e.g., region  72  in  FIG. 9 . 
         [0061]      FIG. 8  is provided as an illustration here for the purpose of providing more detail about the side wing and other parts described above. In particular, it identifies specific angles for the leading and rear edges described above. 
         [0062]    Some of the figures (i.e.,  FIGS. 6 ,  7  and  9 ) show the headboard  10  with the side wings removed. This is done here simply to illustrate the location of the plow members  66 ,  68  and the rear edge member  70 . 
         [0063]    One other embodiment is shown in  FIG. 10 . Directing attention there, the headboard  10  illustrated in  FIG. 10  lacks the base and brace members  52 ,  54  illustrated in  FIG. 3 . 
         [0064]    This version suspends headboard part  24  to upper rails (the location is generally indicated at  74 ) via chains  76 ,  78 . The chains are connected to wheels that roll within tracks  74 . This type of upper suspension has been used as an alternative to create a vertical headboard structure with less supporting structure behind the headboard in situations where a trailer is built with tracks in the upper walls. Except for that difference, the overall functional operation of the  FIG. 10  embodiment remains the same. 
         [0065]      FIG. 8  more specifically illustrates the headboard/wiper structure. The edge  48  of the wiper material  44  comes to a point  83  against wall  26  (see  FIG. 11 ). The angle of forward edge surface  75  relative to the wall  26  is about 9 degrees from a line normal to the wall (or 81 degrees from the wall surface). The forward edge surface  75  becomes essentially the same thing as the leading edge of a rubber wiper blade that terminates at point  83 , although it is made of a much thicker and heavier material. 
         [0066]    The rear or following edge portion  70  is configured with a similar wiping material  77  although, as mentioned above, it has a fixed angle. The forward edge surface  79  of the rear portion  70  is at an angle of about 70 degrees relative to the wall  26 . As is best seen in  FIG. 6 , the rear wiper  70  can be laterally adjusted by bolts and slots  81 ,  83  to fit variations in trailer dimensions. 
         [0067]      FIG. 8  also shows greater construction detail relative to how the flexible material  34  mounts side wing  32  to the headboard part  24  of the overall headboard structure  10 . In the illustration, strips  80 ,  82  clamp the flexible “hinge” material  34  to backboard  24  and wing  32 , respectively. 
         [0068]      FIG. 8  also illustrates a lateral adjustment bracket  84 . The position of the bracket  84  is adjustable via bolt  86 . This allows the width of the headboard structure  10  to be adjusted to the trailer width. Plow members  66 ,  68  are carried by bracket  84  on each lateral side of the headboard  10 . 
         [0069]    Finally, referring to  FIG. 9 , the trailer sidewalls  26  may have material variations in the wall that help the functionality of the headboard structure  10 . Specifically, a lower section  89  of the wall may be made of a different material, like steel sheeting, for example, to reduce friction near the floor  46 , whereas upper parts of the wall  91  may be made of a different material such as aluminum. 
         [0070]    An advantage to the foregoing headboard design is that it creates a design that is easy to assemble from packaged components. It can be shipped to any location for use in an existing trailer. 
         [0071]    The foregoing description generally sets forth one or more preferred embodiments for carrying out the invention. It is not intended to limit the scope of patent protection to the specific embodiments. Instead, the scope of patent protection is to be limited by the patent claim or claims that follow, the interpretation of which is to be made in accordance with the doctrines of patent claim interpretation.