CA2025690A1 - Moving floor type slef-unloading truck body and power drive mechanism - Google Patents

Abstract

ABSTRACT
A self-unloading load hauling box for use on a towed carriage or carried by a powered mobile vehicle wherein the box is a rigid unit having a bottom wall with a floor plate and side walls and front end wall projecting up from the rigid bottom wall. An endless belt is looped around the bottom wall and runs on a driven roller at the rear end of the box and an idler roller at the front end of the box. The endless belt is driven intermittently through an arc of selected length at spaced apart intervals of selected duration to unload contents from the box. The jerky action from intermittently driving the belt has a tendency to cause a vibration, loosening the content in the box and thus results in a relatively even discharge during unloading. Between the upper run of the endless belt and the upper surface of the floor is a friction reducing pad which also absorbs shock loads tending to reduce damage to the belt and/or floor when loading heavy chunk material.
The box has a tail gate mounted in such a manner that during an initial period of opening the tail gate, it restricts discharge of contents from the box and thereafter during further opening pivots freely providing an unrestricted discharge opening.

Description

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File: PROI 003 ~O~ING FLO~R TYP~ SELF-UNL~ADING
TRUC~ BODY ~ND POWER DRIVE MECHANIS~

Field of Invention This invention relates generally to truck bodies for hauling bulk particula~e and chunk material in quantities ~hat weigh several tons and which includes a movable floor for unloading the material and to a drive mechanism for moving the floor. The invention also relates to a truck body and tail gate therefore for controlling the discharge rate during unloading and to a special construction of a truck box.
Back~Eound o~ Invention Conventionally dump trucks are used for hauling earth, rock, rubble, asphalt and the like material. The conventional dump truck or dump type trailer hauling extremely large loads have shortcom:ings related to the necessity of elevating the box to empty its load. Some of the shortcomings are the instability during elevation due to ~ide win~ loads, soft and/or uneven ground, load freezing, wet material, sticking, flat or soft tires, worn fifth wheels, bushings, hinge pins and worn or broken springs. One or a combination of these factors can lead to sideways tipping of the trailer and the attached tractor or the truck on which it is mounted as ~he case may ba, normally resulting in extensive damage. Another shortcoming is the inability to . ~

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elevate the box due to overhead restrictions such as wires or structures. A further shortcoming is the lack of load control during dumping leading to an inability to spread material evenly as for example, when attempting to spread a cold asphalt mix or gravel on a road surface.
It is known in the art to have endless bar type conveyors on the bottom floor of a cargo box to unload the : contents in the box as exemplified by the teachings in U.S.
patent 3,819,072 issued June 25, 1974 to Edward A. Reed, U.S.
: 10 Patent 3,~7,096 issued March 7, 1972 to J.H. Holland and Canadian Patent 1,204,084 issued May 6, 1986 to grause Manufacturing, Inc. It is also known to use a belt which covers the floor and on which the contents rest as exemplified by the teachings of Canadian Patent 895,158 issued March 14, 1972 to Western Sawdust Products, Inc. It is also known to use friction reducing means under the belt for example, as disclosed in United States Patent 3,481,647 issued December 2, 1969 to L.A. Cook.
Summary o~ Inventi~n A principle objec~ of the present invention is to provide a box of a hauler that carries bulk material with an improved conveyor belt and drive system for unloading the contents of the box.
Another object of the invention is to provide a rugged box structure incorporating an endless belt in the floor for unloading the contents of the box.

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Another object of the present invention is to provide a simplified rigid and rugged box structure.
Another object is to provide a tail gate mounted in such a manner that unloading therethrough is selectively restricted controlling the rate of discharge or unrQstricted.
Considerations for the present design, and which will become apparent hereinafter, include the capability to handle all types of materials including asphalt, gravel and the like and with a capability to continue dumping until all material 0 i5 evacuated from the box. ~nother includes the incorporation of an inherent vibrating feature :in the drive to aid in loosening stuck material. Another is the use of a slider bed floor instead of conveyor rollers beneath the belt to provide a solid base while giving some degree of cushioning for protection of the main floor and/or bQlt.
Another is compatibility with either trailer or chassis design truck boxes. Another is the incorporation of a tail gate that selectively restricts unloading to control the rate of discharge or alternatively affords no restriction permitting a rapid rate of discharge of the load.
In accordance with one aspect of the present invention there is provided, a self-unloadingl load hauling, box for use on a towed carriage or carried by a powered mobile vehicle comprising a structurally rigid bottom wall having a floor plate with a flat upper surface, side walls and a front end wall projecting upwardly from said rigid .
- , bottom wall, a first roller at one end of the box and a second roller at an opposite discharge end of the box, an endless runforced resiliently flexible belt looped around said bottom wall and running on said rollers so as to be driven thereby and means for driving said second roller intermittently through a selected arc at spaced apart intervals of selected frequency and duration. The drive means for the driven second roller preferably comprises a torque arm, a clutch connecting said torque arm to said roller, a power driven crank arm and a connecting rod pivotally attached at spaced apart positions thereon respectively to said crank arm and said torque arm. The rotational speed of the crank arm can be selectively varied as can also the effective length of the crank arm. The clutch can be a one way clutch for ~mloading only or a two way clutch for loading as well as unloading.
In accordance with another aspect of the invention, there is provided a robust rigid box unit for hauling bulk material comprising a first rail and a second rail providing a pair of lower spaced apart longitudinally extending lower side rails for said box, each of said side rails being æ
shaped in cross-section and having respectively an upper, outwardly directed flange and a lower, inwardly directed flange; a plurality of parallel spaced apart cross beams extending from one to the other of said first and second side rails and resting on the lower flanges thereof; a floor plate ~ , ... . . .
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extending from one to the other of said first and second side rails and suppor~ed by the upper surface of said cross beams;
and walls comprising of posts, rails and plates, projecting upwardly from the upper flange of said first and second lower side rails providing respective opposîte side walls ~or said box and a front wall, said walls and components thereof and rails being a weldment providing a robust, rigid box unit.

List of Drawin~s The invention is illustrated by way of example in the 10 accompanying drawings wherein:
Figure 1 is a side elevational view of a tractor trailer embodiment incorporating a selE-unloading box provided in accordance with the present invention;
Figure 2 is an enlarged sid~s elevational view of the ~5 box portion only shown in Figure 1;
Figure 3 is a top plan view of Figure 2;
Figure 4 is a bottom view of Figure 2;
Figure 5 is a righthand end elevational view of Figure 2;
Figure 6 is a top plan partial sectional view of the idler and driven roller for the conveyor and drive mechanism for the power driven roller;
Figure 7 is a elevational view of the roller drive mechanism shown in Figure 6.
Figure 8 is a side elevational view of the rear end .: ~

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portion of a truck box provided with a tail gate in accordance with the present invention;
Figure 9 is an oblique view of a rear end portion of one of a pair of lifting arms and pivot support for the tail gate; and Figure 10 is an oblique view of an upper end corner of the tail gate.

Description of Preferred Embodim~nt Illustrated in Figure 1 is a robust rigid box unit 100 for hauling bulk material such as rocks, earth, tree roots, grub materials from land clearing, refuse from building demolition and/or the like, and which is self-unloading without having to be elevated as is the case with the conventional dump truck. The load is dumped by an endless belt conveyor unit 200 that includes an endless reinforced resiliently flexible belt looped around the floor and driven intermittently, i.e. in a stepwise fashion by a drive unit 300. The belt drive unit is illustrated in detail in Figures 6 and 7 and will be described in detail hereinafter.
The box unit 100 i5 shown in Figure 1, carried at one end by a bogey unit 400 and supported at the other end by way of a fifth wheel on a tractor 500. As will be obvious, the box 100 could be carried entirely by the truck or tractor unit 500 of conventional construction, but somewhat different from that illustrated in Figure 1. Also it will be obvious the box 100 could be a tag a]ong type trailer unit with the bogey 400 at the trailing end and a similar bogey at the leading end, but with steerable wheels. Mounting of the ,: ~ , ;~ ~ " ' ' . ' :

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~ 7 --bogey wheel units and king pin for the fifth wheel and the like is by way oP outer side rails on the box to be described more fully hereina*ter~ Hydraulic bogey units of the type for example~ illustrated in U.S. Patent 4,453,73~ issued to J. McGhie et al June 14, 1984, U.S. Patent 4,460,194 issued to J. Mc&hie et al July 17, 1984 and U.S. Patent 4,~68,047 can be used.
The rigid box unit is of all steel (or other rigid weldable material) construction and is a weldment of H or I
beams under the floor, angles Por the side rails (in the form oP a Z shaped beam), hollow re~tangular wall ribs and plate floor and walls~ This is an independent rigid unit that can be mounted on any type of carrier.
As illustrated in detail in Figures 1 to 5, there are two parallel longitudinally extendinq, laterally spaced, side rails 101 and 102 each made from a palir of oppositely directed angle members 103 and 104 joined at spaced intervals by a series of ~usset plates 105. A].ternatively, ~ach of the side rails may be a single Z shaped beam providing in ei~her case respectively an inwardly directed lower 1ange 106 and an outwardly directad upper flange 107. Both of thes~
differant constructions are referred to herein as Z shaped beams supported on the lower flange ~06 and extending from one side rail 101 to the other side rail 102 are a plurality of crossbeams 108~ The crossbeams 108 extend transverse to the length of the box and are spaced apart Prom one another longitudinally along the length of the box. The cross beams for example, may be wide flange W14 x 22 I-beams and 2~

supported on the upper flange is a 3/16 inch heavy steel floor plate 109.
The box has a pair of opposed side walls 110 and 111, each consisting oE a plurality of vertical side posts 112, resting on the upper flange 107 of the side rails and joined together at the top by a horizontal top rail 113. The inner side wall is a steel pla~e 114 extending from the floor plate to the top rail.
The trailer has a front wall 115 having a plate on the inner face and reinforced on the outer side by a front top rail 116, a plurality of front diagonal posts 117, a front wall low~r cross rail 118 and a series of vertical posts. The front wall rigidly attaches the Pront end of the respective side walls to one another.
The rear wall can be left open as is the case in the embodiment shown in Figures 1 to 5 or it can be provided with a tail gate, an embodiment of which is shown in Figures 8 to 12 and described in detail her~3inafter.
The conveyor unloading unit 200 includes an endless belt 201 made from suitable width hinge joined belting. The belting is suitably reinforced and has preferably a nylon or similar slider backing. The belt is looped around a large for example, ~6 inch diameter (crowned) idler roller 202 journaled for rotation a~ opposite ends on the respective side rails 101 and 102 at the front end of the box and a power driven roller 203 of similar size at the trailing end of the box. Each of the rollers are of hollow construction as will be seen from Figure 6. The drive roller 203 has ,.. , .- , :
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2 ~ 3~9 rubber lagging or the like outer surface covering to increase frictional engagement with the belt.
The front roller is attached to the respective side rails 101 and ~02 by respective take up units 204 and 205 for selectively adjusting the tension in the belt.
The belt 201 has an upper span or run 206 that lies ~latwise on a friction reducing pad lO9A made preferably of a suitable plastics material e.g. nylon, teflon, polyethylene or the like that lies flat on the floor plate 109. This pad not only is chosen to reduce friction with the belt taking into account the backing material on the belt, but also to provide a cushion reducing the affect of impact loads on the belt in handling chunk material. A belt friction reducing means consisting of an air cushion is disclosed in the aforementioned United States Patent 3,481,647, but such is not considered suitable for bulk materials and loads to which the present box is intended to be subjected but may be suitable in small load capacities.
The belt has a lower or return run or span 207 located below the floor I-heams which i~ supported by one or more rollers 220 extending across the ~ull width of the belt.
A scraper bar 221 (or bars) and/or brush may, if desired, be associated with the roller for removing debris from the ~urface of the belt.
The power driven roller 2Q3 is journaled on the respective side rails 101 and 102 by respective bearings 208 and 209 and is driven stepwise or in increments by a one-way clutch and oscillating torgue arm in the drive mechanism 300.

Referring principally to Figures 6 and 7, the drive mechanism includes a torque arm 301 incorporating a one-way clutch 302 (e.g. a *Sprag clutch or the like) in one end thereof which mounts such end of the torque arm on the drive shaft 203A of the roller 203. The other end of the torque arm 301 is connected as at 303 by way of a pivot pin to a connecting rod 304 which in turn is connected to a crank arm 305 as at 306 by a pivot pin. The crank arm 305 is mounted on the shaft 307 of a hydraulic motor 308. Th~ hydraulic motor is mounted by way of flanges 309 to the lowsr side rail 101 .
The crank arm 305 in the embodiment illustrated takes the form of a flange or disc attached to the motor shaft 307 and having a stub shaft projecting therefrom and on which the connectiny rod is mounted by way of a suitable spherical roller bearing or the like. The flange has alternative mounting positions 306A and 306B for the stub shaft at differing radii allowing for selective adjustment in the characteristic~ of the drive. The flange is driven in the direction of arrow "A" which in turn causes oscillation of the free outer end of the torque arm represented by the : double ended arrow "B". The oscillation stroke may for example, be about 6 inches to ~ inches on a torque arm length of 34 inches. The frequency or rate of oscillation may be for example, 160 strokes per minute causing the belt on for example, a 16 inch drum roll to travel at a speed of 25 feet per minute. Obviously the hydraulic motor speed can be * Trade Mark ' ,; : ; . :

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varied as can the dimensioning of the drive linkages as can also the drum diameter to vary the rate and/or force of unloadin~. A~ maximum motor speed, one full box length of belt travel can he attained in about 1 minute, thereby providing an ability of dumping the entire load in a very short span. On conventional dump trucks the unloading time is about 5 minutes.
As viewed in Figure 7, the upward stroke of the torque arm and engagement of the clutch cause the roller 203 to rotate in the direction of arrow l'C"~ The clutch disengages on the return stroke of the torque arm. The clutch, if desired, can have means for reversing this permitting also driving the belt in the opposite direction to facilitate loading.
The roller or drum 203 is driven stripwise by the drive mechanism described in the foregoing, causing effectively a jerky motion in movement of the conveyor belt along the bottom o~ the box. This intermittent driving along with belt stretch causes a vibration or jerky action facilitating loosening stuck material and separating the pieces, thereby giving a more even di~charge.
Referring now to Figures 8 to 12, there is illustrated an embodiment wherein a truck ~ox of the foregoing type is provided with a movable gate that selectively provides restricted or unrestricted discharge of the contents of the box. The tail gate is pivotally mounted .
with the pivots being movable and guides are provided such that during an initial opening portion the gate slides , : ,, 2 ~

providing a restricted discharge opening and upon further opening the gate is free to pivot providing an unrestricted opening.
The tail gate, designated 600, i5 a weldment of plates and rails providing a rigid rectangular unit that closes the rear wall of the box. The tail gate projects into the box between the side walls thereof above the discharge belt and has outwardly directed side flanges 601 on opposite sides thereof that engages sloping end posts 150 on the box side walls 110 and 111. The two upper corners of the tail gate have a pivot mounting pin 602 projecting outwardly therefrom. These pins rest in a saddle 603 on respective ones of a pair of gate lifting arms 604 pivotally mounted on and located out~oard of the boxes side walls. Only one lift arm 604 is shown in Figure 8, mounted by pivot pin 605 on wall 110 and i~ will be understood the other of the two arms is similarly mounted on the side wa:Ll 111 of the truck box.
Each of the two lower corners have a guide pin 606 projecting laterally therefrom that slides in a guide slot 607 ~n the respective end post 150. The guide slots are open at the top and each is provided by a flange 608 spaced from the post 150 and rigidly secured thereto. The guide pins, if desired, can be slidably mounted on the tail gate so as not to project at all times into the guide slots permitting the gate to pivot open without requiring initial sliding movement.
Each arm 604 has a lower abutment portion 610 that is engagable with a strike plate 611 extending laterally from ':, ' ' .~

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the gate beyond the side wall end post 150. This engagement takes place after the arm 604 has pivoted sufficiently on pin 605 so as ko raise pivot saddle 603 to the point where lower pins S06 are clear of flange 608. Further pivoting of the arms opens the gate in an open position providing an unrestricted discharge of material from the box.
The arms 60~ can be caused to pivot about their respective pin 605 mounting on the box side walls by hydraulic or pneumatic cylinders (not shown) or by a cable 615 attached as at 616 to the arm at one end and having the other end wound on a power driven winch drum. After discharge of the contents from the box, gravity can b~ relied upon after slacking cable 61S to return the gate to its closed position.
In the ~oregoing the gate 600 is described and in the drawings is illustrated in association with a moving floor type self-unloading box. It is however to be understood the disclosed tail gate may also if desired be used with any other type of box including dump truck boxes. The initial sliding movement of the gates provides a selectively variable in si2e discharge opening restricting and thereby controlling discharge o~ the cont2nt from the box. ~fter the initial sliding movement the gate is free to pivot thereby providing a substantially unrestricted discharge opening. Engagement of the arms 604 with the gate permits opening the gate for complete unrestricted flbw of the contents from the box.

Claims (15)

1. A self-unloading, load hauling, box for use on a land vehicle load hauler comprising a structurally rigid unit including a rigid bottom wall having a floor plate with a flat upper surface and side walls and a front end wall projecting upwardly from said rigid bottom wall; a first roller traversing said bottom wall at one end of the box and a second roller traversing said bottom wall at a discharge end of the box; an endless reinforced resiliently flexible stretchable belt looped around said rollers and having an upper run that traverses the said flat upper surface of said floor plate and means for driving said second roller stepwise through an arc of selected length at repeating spaced apart intervals of predetermined duration.

2. The apparatus of claim 1 wherein said second roller drive means comprises a torque arm, a clutch selectively coupling said torque arm with said second roller to rotate the same stepwise upon oscillation of the torque arm and power means connected to said torque arm to selectively oscillate the same.

3. The apparatus of claim 2 wherein said power means for oscillating said torque arm comprises a power driven crank arm and a connecting rod pivotally attached at spaced apart positions thereon respectively, to said crank arm and said torque arm.

4. The apparatus of claim 1 wherein said torque arm is oscillated at a frequency in the range of 0 to 160 cycles through an arc in the range of six to eight inches.

5. The apparatus of claim 1 including a friction reducing impact load absorbing pad on the upper surface of said floor plate.

6. The apparatus of claim 1 wherein said bottom wall includes a first longitudinal side rail and a second longitudinal side rail located respectively on opposite sides of said floor and a plurality of parallel spaced apart cross beams extending from one side rail to the other, said longitudinal side rails being generally Z shaped in cross section and having an upper; outwardly directed, flange and a lower, inwardly directed, flange.

7. A robust rigid box unit for hauling bulk material comprising a first rail and a second rail providing a pair of lower spaced apart longitudinally extending lower side rails, each of said side rails being Z shaped in cross section and having respectively an upper outwardly directed flange and a lower inwardly directed flange, a plurality of parallel spaced apart cross beams extending from one to the other of said first and second side rails and resting on the lower flanges thereof, a floor plate extending from one to the other of said first and second side rails and supported by the upper surface of said cross beams, and a wall secured to and projecting upwardly from the upper flange of a respective one of said first and second lower side rails, each of said walls comprising a weldment of posts, plates and rails, said walls providing respective opposite side walls for said box and a front wall interconnecting said side walls at the front of said box, said side rails, walls, posts and plates being a weldment providing a robust box unit.

8. A robust rigid box unit as defined in claim 7 including an endless reinforced resiliently flexible stretchable belt looped around said floor plate and cross beams supporting the same, an idler roller journaled on said side rails adjacent a front end of the box and a power driven roller mounted on said side rails adjacent an opposite discharge end of the box, said endless belt being looped around and running in driven relation on said idler roller and power driven roller.

9. The apparatus of claim 1 including means selectively to adjust the position of one roller relative to the other permitting adjusting tension in the endless belt.

10. The apparatus of claim 8 including drive means that drives the roller intermittently.

11. The apparatus of claim 10 wherein said roller is moved intermittently at a selected frequency through an arc of predetermined length.

12. The apparatus of claim 1 including a tail gate, pivot mounting means for said tail gate, means movably mounting said pivot mounting means on said box and means preventing pivotal movement of said tail gate during an initial period of moving said pivot mounting means to open the tail gate whereby during such initial period the tail gate restricts discharge of contents from the box.

13. A truck box and tail gate as defined in claim 12 wherein said tail gate is pivotally mounted on a pair of arms pivotally attached respectively to opposite side walls of the box.

14. A truck box having a tail gate, pivot mounting means for said tail gate t means movably mounting said pivot mounting means on said box and means preventing pivotal movement of said tail gate during an initial period of moving said pivot mounting means to open the tail gate whereby during such initial period the tail gate restricts discharge of contents from the box and wherein said truck box comprises a weldment of members providing structurally rigid unit including a pair of spaced apart longitudinally extending lower side rails of Z shape cross-section disposed with their lower flanges directed inwardly toward one another, cross beams extending from one side rail to the other and resting on said lower flanges, a floor plate, with a flat upper surface, supported on said cross beams, side walls projecting upwardly from the upper flanges of said side rails and a front end wall;

15. A truck box as defined in claim 14 including a first roller in said bottom wall at one end of the box and a second roller in said bottom wall at the discharge end of the box; an endless belt looped around said rollers and having an upper run that traverses the flat upper surface of said floor plate and means for driving said second roller intermittently through an arc of selected length at spaced apart intervals of selected duration.