Trailer with continuous conveyer bed

A trailer assembly is disclosed for receiving, transporting and discharging flowable bulk material. The trailer assembly includes a pair of opposing generally vertical side walls which are secured to a frame member and converged downwardly and inwardly. Flexible flap members extend downwardly from the bottom edges of the side walls. The side walls are joined by a front end wall and a rear wall to define a bin having an open floor. A conveyor is provided as a floor for the bin with the conveyor extending beneath the side walls and having a width greater than the distance between bottom edges of the side walls and positioned closely adjacent to the terminal edges of the flexible flap members. The conveyor includes a pair of opposing endless chains which are mounted about sprockets with the chains connected by cross members. The conveyor includes a continuous belt member secured to the cross members at intervals. Upper tracks of the chains are supported by a support bar secured to the frame member and having a vertical portion which extends between chain links to engage link pins in supporting rolling engagement.

BACKGROUND OF THE INVENTION 
I. Field of the Invention 
This invention relates to a trailer assembly for receiving, transporting 
and discharging flowable bulk material. More particularly, this invention 
pertains to such an assembly having a bin with a conveyor as the bin 
floor. 
II. Description of the Prior Art 
Trailer assemblies comprising bins with conveyors located at the floor of 
the bin are well known. Examples of these are U.S. Pat. No. 2,496,463 to 
Gaddis; U.S. Pat. No, 3,876,089 to Moser and U.S. Pat. No. 4,055,265 to 
Eisenman. The Eisenman patent teaches a bulk bed material carrier for 
receiving, transporting, and discharging bulk quantities of material. 
Specifically, the Eisenman patent teaches a bulk bed material carrier for 
agricultural products. 
While bulk bed material carriers with conveyor floors are well known, the 
use of such carriers in certain applications has resulted in certain 
difficulties. Specifically, it would be desirable to use such carriers in 
the construction industry to haul flowable bulk material such as 
aggregate. Also, it would be desirable to use such carriers to haul 
asphalt using the conveyor floor to discharge the asphalt at a metered 
rate during road paving operations. An example of such a trailer assembly 
for use in the construction trades is a trailer marketed under the trade 
name Flow Boy Model 24B by the J.H. Holland Company. The Flow Boy model 
has opposing chains connected by horizontal transverse rails which scrape 
across the top of a bin floor. Such an arrangement carries asphalt out of 
the bin. However, this arrangement can have disadvantages with aggregate 
which is abrasive and can damage the rails or the floor. Also, such an 
arrangement is not practical with wet concrete. An example of a bulk bed 
material carrier which may be used with concrete, as well as other bulk 
materials, is disclosed in U.S. Pat. No. 4,664,583 to Gust. The Gust '583 
carrier, however, has a plurality of belt sections which effectively cover 
or overlap links of chains attached to which the belt section are attached 
for movement. Thus, if abrasive material becomes caught in the chain, the 
belt sections prevent the material from escaping. Damage to the conveyor 
mechanism may result from the presence of foreign particles in the chain. 
OBJECTS AND SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a trailer assembly for 
handling flowable bulk material with a conveyor floor for discharging the 
material. 
Another important object of the present invention is to provide a trailer 
assembly having a conveyor floored bin which avoids contamination of the 
conveyor mechanism by handled material. 
A still further object of the present invention is to provide a trailer 
assembly with a conveyor floor which minimizes power requirements to 
operate the conveyor when it is carrying a heavy load. 
According to a preferred embodiment of the present invention, a trailer 
assembly for receiving, transporting, and discharging flowable bulk 
material is provided which includes a frame member which supports a pair 
of generally vertical opposing side walls which converge downwardly and 
inwardly. Flexible flaps having terminal edges extend from bottom edges of 
the side walls. A front end wall is secured to the frame member and 
extends between the side walls as does a rear end wall which is secured to 
the frame member. The rear end wall is provided with a horizontal pivot at 
its upper connection to the side walls permitting the rear end wall to 
pivot away from the side walls and define a discharge opening. The rear 
end wall, front end wall and side walls cooperate to define a floorless 
bin for receiving flowable bulk material. The trailer assembly further 
comprises a conveyor which defines a movable floor for the bin. The 
conveyor system includes a pair of endless chains which move around 
sprockets secured to the frame member. The chains are spaced apart a 
distance greater than the width of the bottom of the bin and include 
support members extending inward from the sides of the chains.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIGS. 1 and 2 show a trailer assembly generally designated by the numeral 
10 mounted to the frame of a cab 11. The trailer assembly includes a pair 
of opposing side walls 12 and 13 which are generally vertical and converge 
downwardly and inwardly. As it is intended that the present invention 
would be particularly suitable for conveying heavy construction material, 
the side walls 12 and 13 are braced by rectangular steel bracing 14 which 
surrounds the perimeter of the side walls. Cross bracing 15 further 
supports the side walls and joins the upper bracing and lower bracing 14. 
The trailer assembly 10 also includes a forward wall 16 which is generally 
vertical and joins the forward edges of the side walls 12 and 13. Rigid 
lateral supports 17 and roof portion 18 extend between the upper edges of 
side walls 12 and 13 and provide additional rigid structural support. As 
best shown in FIG.3, a rear wall 19 is provided having a horizontal and 
transverse pivot connection 20 to a brace 17a extending between side walls 
12 and 13 at the rearward end of the side walls. A latch 21 secures the 
rear wall in a closed position as shown in FIG. 3. Rear wall 19, forward 
wall 16 and side walls 12 and 13 cooperate to define a bulk material bin 
10a. 
Flexible flap members 21a and 21b extend from lower edges of side walls 12 
and 13. The floor of the bulk material bin is a moving conveyor which is 
generally shown at 23. The flap members 21a and 21b terminate at edges 21c 
and 21d in close proximity to the conveyor 23. With reference to FIGS. 5 
and 3, it can be seen that the trailer assembly is provided with a frame 
member 24 which comprises a pair of vertical spaced apart support plates 
25 and 26. The support plates 25 and 26 support the side walls 12 and 13 
respectively. Vertical braces 80 are provided at spaced intervals on both 
of plates 25 and 26 and are provided with lower horizontal braces 80b and 
upper horizontal braces 80a to provide rigid structural support. 
The support plates 25 and 26 support a pair of transversely spaced endless 
chain mechanisms 27 defining upper and lower tracks. It will be 
appreciated that both endless chains are identical and a description of 
one will suffice as the description of the other and all identical parts 
will be numbered identically. Shown most clearly in FIG. 3, the chain 
mechanism 27 includes an idler sprocket 28 secured to the frame member 
forward of the bottom edge of the forward wall 16. The idler sprocket 28 
is mounted for rotation about a horizontal axis transverse to the support 
member support plates 25 and 26. Likewise, a driven sprocket 29 is mounted 
on the support member rearward of the rear wall 19. The driven sprocket 29 
is mounted for rotation about an axis parallel to the axis of the idler 
sprockets 28. As shown in FIG. 5, the driven sprockets 29 are joined by 
means of a coupler 30 to a common shaft 31 with both of the sprockets 
driven by means of a power source 32. 
With reference to FIGS. 3 and 4, the chain mechanism 27 includes an endless 
link chain 33 which is entrained in meshing engagement about the drive 
sprocket 29 and idler sprocket 28. The link chain 33 comprises a plurality 
of inner links 34 and outer links 35 alternately arranged with an inner 
link 34 connected to a contiguous outer link 35 by means of a common pivot 
pin 36. As shown in FIGS. 7 and 4, the pivot pins 36 are each surrounded 
by cylindrical rollers 36a. The pair of link chains 33 are interconnected 
by means of transverse cross members 37 which extend between opposing 
outer links 35. As shown in FIG. 4, the cross members 37 have a Z-shaped 
cross section with a generally flat upper surface 38 generally slightly 
below the longitudinal, horizontal centerline 38a of links 34 and 35. The 
term "below" is used only for convenience in referring to the portion of 
the upper track in FIG. 4; it will be understood that the upper surface 38 
would be slightly above the longitudinal, horizontal centerline 38a of the 
links 34, 35 on the lower track. Further, a support member or plate 39 is 
fixed to each inner link 34, extending generally inwardly and 
perpendicularly to inner links 34. 
A continuous flexible conveyor belt or belt member 40 is supported by 
support member 39 and by the upper surface 38 of Z-shaped cross members 
37. The belt 40 has a width less than the transverse distance between the 
inner surfaces of opposite inner links 34 of chains 27. Further, the belt 
40 is supported such that the belt centerline 39a lies horizontally 
coplanar with the link centerline 38a, as best shown in FIG. 4. The belt 
40 is fixed to transverse cross members 37 by elevator bolts preferably at 
four foot intervals along the length of the belt. 
The chain mechanism 27 further includes opposing similar tension adjustment 
means 41 as shown in FIG. 8. Each tension adjustment means 41 includes a 
first fixed member 42 fixed to support plate 25 and 26, respectively, and 
a second slidable member 43 slidably fixed to the first fixed member 42. 
The idler sprocket 28 upon which the chains 33 ride is fixed to the 
slidable member 43. When the slidable member 43 is linearly displaced 
relative to the fixed member 42, the idler sprocket 28 is accordingly 
linearly displaced relative to the driven sprocket 29. In this manner, the 
tension of the chains 33 and, thereby, the tension of the belt 40, can be 
adjusted. 
As shown most clearly in FIG. 5, the chains 33 are arranged such that the 
distance between the chains is greater than the width of the distance 
between the side walls at their bottom edge. With this arrangement, the 
belt 40 extends beyond the bottom edges of the side walls 12 and 13. 
Likewise, the chains 33 are positioned such that the belt section 40 is in 
close proximity to the bottom edges of the side walls 12 and 13. 
Accordingly, only a portion of the belt 40 is exposed to the interior of 
the bin with the exposed portions acting as the floor of the bin. Also, 
the portions of the belt 40 extending beyond side walls 12 and 13 are 
sized to have a width sufficient such that the extended portions act as 
supplementary conveyors 45 outside the bin 10a. 
The frame member 24 carries means for supporting the chains and belt; these 
means are most clearly shown in FIGS. 6 and 7. To support the upper track 
of the link chain 33, a support tube 50 is provided. The support tube 50 
is positioned beneath the upper track of the link chain 33 and extends 
approximately the complete length of the chain between the sprockets 28 
and 29. The tube 50 extends between upper horizontal braces 80a and has an 
upper surface flush with the upper surfaces of braces 80a with tube 50 
welded to braces 80a. The support tube 50 is provided with a vertical 
support 51 which is sized to extend between vertical link plates 34 and 35 
of all of the chain links with an upper bearing surface 52 of the vertical 
support 51 engaging rollers 36a in rolling support. 
In operation of the trailer assembly, the rear wall 19 is pivoted to its 
closed position as shown in FIG. 3 and secured in the position by means of 
latch 21. Material to be transported by the trailer is passed into the top 
of the bin between the support bars 17. The material rests on the portion 
of the belt 40 exposed to the interior of the bin 10a. The carried 
material is kept within the bin 10a by means of the close proximity 
between the belt 40 and the terminal edges 21c and 21d of the flexible 
flap members 21a and 21b. Also, the weight of the material results in the 
belt 40 and their supporting cross members 37 becoming slightly concave 
thereby reducing the clearance between the belt 40 and the flexible flap 
members 21a and 21b. Structural support for the belt 40 is provided by the 
cross members 37 and by support members 39 which eliminate the need for a 
rigid floor. Additionally, any sagging of the belt 40 on the upper track 
near its longitudinal center prevents migration of the carried material 
past the sides of the belt 40 since the concave shape tends to draw the 
material back towards the center of the belt. 
When it is desired to discharge carried material from the bin, latch 21 is 
released and the rear wall 19 is free to pivot about the pivot axis of 
transverse pivot connection 20. The rear wall may be supported open in any 
desired manner or could be left to freely pivot with the weight of the 
conveyed material keeping the rear wall 19 in an open position. With the 
rear wall 19 freely pivotable, the power means is activated and the chains 
33 rotate about the sprockets 28 and 29 drawing the belt 40 in a circular 
path with the upper track moving toward the rear wall 19 and the lower 
track moving toward the forward wall 16 with the result that the carried 
material is drawn by the belt 40 out of the bin and discharged. 
Since the belt 40 is fixed at intervals to cross members 37 which are, in 
turn, fixed to inner links 34 of the chains 27, belt 40 remains generally 
coplanar with the chains 27 along the lower track. 
In addition to allowing bulk material to easily be removed from the exposed 
chain without removing the relatively heavy belt 40, the present invention 
also provides for improved power requirements for the chain assembly since 
the chains are supported by the vertical support 51 which engages the 
rollers 36a. This results in greatly reduced friction and greatly reduces 
the load on the power source because the chain rolls instead of slides. 
Further, the Z-shaped cross members 37 eliminate need for a floor. 
From the foregoing, it has been shown that the present invention provides a 
trailer assembly for receiving, transporting, and discharging flowable 
bulk material with the trailer assembly including a bin having a conveyor 
floor. Specifically, it has been shown how the present invention provides 
such a trailer assembly while preventing damage to the conveyor assembly 
by allowing convenient access to the chains for removing material caught 
therein and for allowing caught material to free itself.