Unloading gate for a dump truck body

An unloading gate for a dump truck body which is movably mounted on rails in the dump truck body so that it can be actuated to scrape and clean the body during unloading and which has a positive locking means for locking the unloading gate in a fixed position relative to the body.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates in general to an unloading gate for a dump truck 
body and, in particular, to an unloading gate that allows the body to be 
cleaned upon actuation. 
2. Description of Related Art 
Dump trucks have been available for many years, which are used for carrying 
different loads, in particular, in the construction industry dirt is moved 
by very large articulated dump trucks and the material being carried has a 
tendency to stick to the bottom and sides of the body which prevents the 
unloading of all of the materials. Plastic liners have been developed 
which are mounted in the truck body so that the material will slide from 
the body during dumping. However, such liners rapidly wear and some 
materials stick to such liners. 
See also U.S. Pat. Nos. 1,927,653, 1,485,632, 4,145,824, 4,548,131, 
3,880,072, 3,815,323, 2,179,726, 2,166,846, 2,047,602, 2,800,234, 
2,463,987, 3,164,410, 3,827,753, 3,739,715, 3,625,140, 4,467,712, 
4,745,856, and German DE 2 152 881. 
SUMMARY OF THE INVENTION 
The present invention comprises an unloading gate for a dump truck body 
which is mounted on a carriage that has rollers that ride on a pair of 
rails mounted in the bottom of the dump truck body and also has retaining 
rollers for holding the carriage and the unloading gate on the rails. The 
dump truck body can be pivoted upwardly to an unloading position in a 
conventional manner during which time the unloading gate is locked in 
position at the front end of the dump truck body. A lock holds the 
unloading gate so that it is stationary in the dump truck body and the 
lock can be released after which the unloading gate can be moved by the 
carriage so as to scrape and clean debris such as dirt from the dump truck 
body by moving the unloading gate from the front end to the rear end of 
the body. After the unloading gate has moved the full length of the dump 
truck body, it can be returned to its initial position at the front end of 
the body and locked in position so that the dump truck can be reused. 
The locking means for the unloading gate may be actuated by manual, 
electric, hydraulic or pneumatic means and may be actuated remotely such 
as from the cab of the truck. The actuating means for moving the unloading 
gate and carriage upon which it is mounted may be hydraulic, pneumatic, 
electric or mechanical and can be actuated remotely as, for example, from 
the cab of the truck. 
It is an object of the present invention to provide an unloading cleanout 
gate for a dump truck which allows substantially all of the material 
carried by the dump truck to be emptied from the body. 
It is another object of the invention to provide a locking means for an 
unloading gate for a dump truck which positively locks the gate in a 
predetermined position when it is not being actuated. 
Other objects, features and advantages of the invention will be readily 
apparent from the following description of certain preferred embodiments 
thereof taken in conjunction with the accompanying drawings although 
variations and modifications may be effected without departing from the 
spirit and scope of the novel concepts of the disclosure, and in which:

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 illustrates a dump truck 10 which has a tractor 11 and has a rear 
frame portion 12 upon which a dump truck body 17 is pivotally mounted on 
pivot shaft 132 that passes through the frame 12 and is connected to a 
bracket 131 on the rear end of the dump truck body 17. The tractor 11 and 
frame 12 are mounted on ground wheels 13, 14 and 16 and similar wheels are 
mounted on the opposite side of the machine. The dump truck body 17 can be 
pivoted with a pair of hydraulic cylinders 121 which has an upper end 126 
that is connected by pivot pin 124 to a bracket 127 attached to the body 
17. The piston of the hydraulic cylinder 121 is connected to a shaft 122 
which is pivotally connected by a pivot pin 120 to a bracket 123 mounted 
on the frame 12. Hydraulic lines 133 and 134 communicate with the 
hydraulic cylinder 121 and the hydraulic system of the tractor 11 in a 
suitable control is mounted in the cab of the tractor 11 for actuating the 
hydraulic cylinder 121 to operate the body 17 from the horizontal position 
indicated in solid line to the unload position illustrated in dash-dot 
line. It is to be realized that there is a hydraulic cylinder mounted on 
both sides of the truck body and only one of the hydraulic cylinders is 
illustrated in FIG. 1. 
As shown in FIGS. 2-5, the dump truck body 17 has a bottom 20 and side 
walls 21 and 22 and a rear upwardly extending portion 18. 
A pair of L-shaped rails 31 and 32 are mounted in the bottom 20 of the body 
17 and extend through an opening formed in the front end of the body 17 
below the upper extending portion 18. A moveable unloading gate 23 has a 
substantially vertical upper portion 24 and a lower tapered portion 26 
which is mounted on a carriage that rides on the rails 31 and 32 as shown 
in FIGS. 2-5. The carriage has a vertical frame members 41 and 42 as best 
in FIGS. 2 and 4, which are attached to the lower portion 26 of the 
unloading gate 23 and has front vertical supporting members 43 and 44 
attached to a lower portion of the unloading gate 23. Horizontal frame 
members such as 46 connect the members 41 and 43 and a horizontal member 
47 connects the vertical members 42 and 44. A transverse member 48 
connects the vertical members 41 and 42 as shown in FIG. 4. Rollers 51, 
61, 71 and 81 are respectively mounted on the lower ends of vertical 
members 44, 43, 42 and 41 and each roller is supported by a suitable shaft 
such as shaft 52 illustrated for the roller 51. The other rollers are 
mounted on similar shafts which extend through the associated vertical 
supporting member. Two rails 31 and 32 are formed with vertical portions 
and horizontal extending portions 30 illustrated in FIG. 5 and a retaining 
roller 53 mounted on the shaft 54 is connected to the vertical member 44 
and its side edge extends into and runs under the extending portion 30 so 
as to hold the carriage on the rail 32. A second horizontally mounted 
roller 63 is mounted on a shaft 64 connected to a vertical member 41 as 
shown in FIG. 3 and rides under the extending portion of rail 31. The 
unloading gate has a downwardly extending portion 27 which fits between 
the rails 31 and 32 and is connected to a lower portion of the tapered 
portion 26 as illustrated in FIGS. 2 and 4. A hydraulic cylinder 101 has 
an extending portion 153 formed with an opening which is received between 
brackets 151 which also have an aligned opening through which a pivot 
shaft 152 is received. The bracket 151 is connected to the rear surface of 
the unloading gate 23. The other end of the hydraulic cylinder 101 has its 
piston shaft 100 connected by pivot pin 103 to a bracket 102 mounted on 
the frame 19 of the dump truck body 17. Hydraulic lines 141 and 142 extend 
to a suitable control that may be mounted in the cab of the tractor 11 so 
as to actuate the multiple hydraulic cylinder 101 so as to drive the 
unloading gate 23 mounted on the carriage and rollers along the rails 31 
and 32 so as to scrape and unload the body 17. 
FIGS. 6-9 illustrating a locking mechanism for the unloading gate 23 so as 
to positively lock the unloading gate 23 to the body 17 so that it will 
not move on the rails 31 and 32 except when the locking means is released. 
A pair of longitudinal beams 312 and 312a are attached to the lower portion 
of the body 17 as shown in FIGS. 3, 5, 6 and 8 and brackets 201 and 202 
are mounted on the members 312a and 312 and rotatably support a shaft 203. 
A crank arm 206 is non-rotatably connected to the shaft 203 and its other 
end is connected by a pin 207 to an end 208 of a piston shaft 209 of a 
hydraulic cylinder 210. The other end 212 of the cylinder 210 is connected 
by a pivot pin 211 to a bracket 213 mounted to the body 17. Hydraulic 
lines,not shown, are connected to the hydraulic cylinder 210 and connect 
to the hydraulic system of the tractor 11 so that the cylinder 210 can be 
actuated from a remote position such as the cab of the tractor 11. 
The shaft 203 is formed with a pair of U-shaped locking brackets 220 and 
223, which in the locked position are receivable over the locking pins 221 
and 224 mounted on the carriage of the unloading gate 26. FIGS. 6, 8 and 9 
illustrate in solid line the locked position for the carriage wherein the 
U-shaped brackets 220 and 223 engage locking pins 221 and 224. A dash-dot 
line position illustrates when the members 220 and 223 are unlocked from 
the locking pins 220 and 224 by activating cylinder 210. 
In operation, initially the unloading gate 23 and carriage are locked by 
the locking cylinder 210 to the body 17 of the truck and the truck is 
loaded with the body 17 being in the horizontal position illustrated in 
solid line in FIG. 1. When the truck is to be unloaded, the cylinders 121, 
on either side of the truck, are actuated so as to tilt the body 17 
upwardly so that the material is unloaded from the rear end of the body 
17. The locking means including the cylinder 210 assures that the 
unloading gate 23 and its carriage will not move from the forward end of 
the body unless desired. When it is desired to actuate the unloading gate 
23, the cylinder 210 is actuated so as to rotate the shaft 203 in a 
counterclockwise direction relative to FIGS. 7 and 8 so that the locking 
members 220 and 223 disengage the locking pins 221 and 224. Then the 
cylinder 101 can be actuated to drive the unloading gate 23 and its 
associated carriage on the rails 31 and 32 so that it scrapes and cleans 
the inside of the body 17 as it moves toward the rear of the body 17. The 
lower portion 27 and the side edges of the unloading gate 23 scrape and 
remove the material in the body 17 so that the body is cleaned and all the 
material can be unloaded. After unloading has occurred, the body 17 is 
returned to the horizontal position and the unloading gate 23 is moved by 
the cylinder 101 to the front position shown in solid line in FIG. 2 after 
which the locking cylinder 210 is actuated so that the bracket members 220 
and 223 lock over the pins 221 and 224 to lock the loading gate 23 and the 
forward loading position. 
It is seen that this invention comprises an unloading gate for a dump truck 
body which rides on a carriage on rails mounted in the dump truck body and 
wherein the unloading gate can be positively locked and unlocked so that 
it can be actuated to clean out the body. 
Although it has been described with respect to preferred embodiments, it is 
not to be so limited as changes and modifications can be made therein 
which are within the full intended scope as defined by the appended 
claims.