Abstract:
A free-standing roller apparatus for clearing screens on dispensers sitting within truck dump bodies is provided. The roller apparatus provides a hard bristle, rotating roller attached to an arm, which allows the roller to be lowered onto the dispenser screen. The roller adjusts automatically to the height of each truck.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to screening machines, and more particularly to a roller for cleaning sand and gravel screens. 
     Spreader/dump truck vehicles are well known in the art. Such vehicles are adapted especially for the purpose of spreading road salt and sand on winter roads as well as conventional dump truck purposes, such as transporting salt, sand and other granular materials. Trucks of this type typically contain a dispensing device that sits upon the dump body of the truck. To evenly spread road salt and sand, the granular material within the dispenser must be free of clumps and extraneous material. This is accomplished by attaching a screen, either temporarily or permanently, to the top of the dispenser, thereby providing a dispenser loaded with sifted granular material. To load the dispenser, granular material is poured onto and through the screen into the dispenser within the truck body. Clumped material as well as granular material which is thicker than a predetermined thickness is prevented from entering the dispenser. 
     One of the drawbacks of the above system is that the screen often becomes clogged and requires a worker to climb up onto the screen to push material through or off the screen. Because this screening and truck loading usually takes place during icy conditions, the worker is in danger of falling or sliding off the screen. Since the screen may be 13 feet or more off the ground, a worker falling off the screen is subject to substantial injury. Furthermore, having a worker walking on top of the screen may damage the screen itself. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the limitations of prior art dispenser loading systems by providing a roller apparatus adapted to clear screens on dispensers sitting within truck dump bodies. The present invention roller apparatus provides a hard bristle, rotating roller adapted to being lowered onto the dispenser screen to clear the screen of clumps and debris. 
     The roller apparatus is free standing and is of sufficient size to accommodate a standard or large size dump truck. The truck can be driven through the invention. The roller is attached to an arm, which allows the roller to be lowered onto the dispenser screen. The roller adjusts automatically to the height of each truck that enters the frame. The roller rotates clockwise as the driver moves forward, right to left. The roller rotates to free up material on the screen that is not usable and may cause clogs to the dispenser. 
     These together with other objects of the invention, along with various features of novelty, which characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part of the disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of the invention with a truck within the frame interior. 
         FIG. 2  is a partial top view of the roller assembly. 
         FIG. 3  is a front view of the roller assembly control system. 
         FIG. 4  is a front view, partly in section, of the push rod assembly. 
         FIG. 5A  is a side view of the roller and electrical drive. 
         FIG. 5B  is a side view of the wheel bearing housing. 
         FIG. 5C  is a front view, partly in section, of the roller. 
         FIG. 6A  is a front view, partly in section, of a swing arm. 
         FIG. 6B  is a side view of  FIG. 6A . 
         FIG. 7A  is a top view of a frame junction 
         FIG. 7B  is a side view of  FIG. 7A . 
     
    
    
     DETAILED DESCRIPTION OF INVENTION 
     Referring to the drawings in detail wherein like elements are indicated by like numerals, there is shown a roller apparatus  1  comprised of a frame  20  holding a roller assembly  40 , said frame adapted to accommodate a dump truck  10  within the frame interior. The truck  10  has a front cab  11 , a rear dump body  12 , and a granular dispenser  13  within the dump body  12  and extending rearward from the dump body  12 . The dispenser  13  is adapted to hold a supply of granular material  5  within a dispenser interior  16  and dispensing said granular material  5  out a dispenser rear  15 . The dispenser  13  has a screen  14  attached to the top of the dispenser. Granular material is loaded into the dispenser interior  16  through said screen  14 . 
     The frame  20  has a generally rectangular shape with a top  21 , a bottom  22 , two opposite, parallel sides  23 , an open front  24 , and an open rear  25 , said front and rear defining a frame, longitudinal axis, said top, bottom, front, rear, and sides defining a frame interior  26 . The frame top  21  includes a first top frame crossbeam  27  and a second parallel top frame cross-beam  28  in a spaced relationship with the first crossbeam, each crossbeam extending from side to side, and attached thereto. Each crossbeam  27 ,  28  has a longitudinal axis transverse to the frame longitudinal axis. The second crossbeam  28  lies between the first cross beam  27  and the frame rear  25 . At a point spaced from one of the junctions  29  of the second crossbeam  28  with the frame sides  23 , an elongated, vertical frame bar  30  extends directly upward from the second crossbeam  28 , said vertical frame bar  30  having a longitudinal axis perpendicular to the frame longitudinal axis and second crossbeam longitudinal axis. 
     At points spaced from each junction  31  of the first cross-beam  27  with the frame sides  23 , two elongated swing arms  32  are attached by means of first wheel bearing housings  33  to the first crossbeam  27 . Each swing arm  32  jointly terminates at one end in a counter weight  34 . Each swing arm  32  terminates at its other end in a second wheel bearing housing  35  jointly joined to a center roller bar  36 . The swing arms  32  are braced with a swing arm cross bar  37  having a longitudinal axis transverse to the frame longitudinal axis. The swing arm cross bar  37  interconnects each swing arm  32  at parallel points between the first and second wheel bearing housings  33 ,  35 . The swing arms  32  protrude through the frame top  21  wherein the arms terminate in said counterweights  34  positioned rearward of the first cross beam  27 . 
     The roller assembly  40  is comprised of a roller  41  journaled to the center roll bar  36 . The roller  41  has a plurality of horizontal, hard bristle, brush rows  42  attached thereto. One side of the roller  41  has a first rotary gear  43  fixedly attached thereto. A swing arm electric motor  44  is attached to a junction  45  formed by the swing arm cross bar  37  joined to a swing arm  32 . The electric motor  44  drives a second rotary gear  46  linked by a drive chain  47  to the first rotary gear  43 . In this embodiment of the invention, the roller  41  is adapted to being turned in a clockwise direction. The roller  41  is positioned within the frame interior  26  forward of the first crossbeam  27 . 
     The vertical frame bar  30  has a sensor  39  attached thereto, said sensor  39  adapted to engage a swing arm  32  when the swing arm rotates near to said sensor  50 . Above the sensor  39 , a push rod assembly  50  is attached to said vertical frame bar  30 . The push rod assembly  50  is comprised of a vertical frame electric motor  51  driving a rotary gear  52  attached thereto. The rotary gear  52  engages an elongated push rod  53  contained within a push rod housing  54  also attached to said vertical frame bar  30 . The push rod  53  terminates at each end in a pressure plate  55 . One of the pressure plates  55  is adapted to engage a swing arm  32 . When the sensor  39  engages a swing arm  32 , the sensor  39  activates the vertical frame electric motor  51  which the moves the push rod  53  and an attached pressure plate  55  against the swing arm  32  causing the swing arms  32  to pivot about the wheel bearing housings  33  causing the roller assembly  40  to swing upward to a preset position. A separate electrical switch  38  on the frame  20  reverses the action by the motor  51  on the push rod  53  thereby allowing the roller assembly  40  to swing downward. 
     In operation, the roller apparatus frame  20  is set up on a flat area convenient to a supply of material  5  such as sand or salt. The roller  41 , in a pre-operation mode, is normally in an upward position. A truck  10  containing a dispenser  13  has material  5  loaded onto the dispenser screen  14 . Because the material  5  is typically clumped and often frozen, much of the material  5  on the screen  14  does not enter the dispenser interior  16 . The truck  10  is then driven to the frame rear  25  and into the frame interior  26  with the truck cab  11  just protruding out of the frame interior  16  through the frame front  24 . 
     The truck operator then activates the electrical switch  38  thereby activating the roller assembly  40  and pivoting the roller  41  downwardly onto the material  5  on the dispenser screen  14 . The activated roller electric motor  44  drives a second rotary gear  46  linked by a drive chain  47  to the first rotary gear  43 , thereby turning the roller  41  in a clockwise direction. The roller bristle brushes  42  scrape the material  5  forcing much of it through the screen  14  into the dispenser interior  16  and the remainder material off the screen  14 . The truck driver slowly drives the truck  10  through the frame interior  26  out the frame front  24 . This enables the roller  41  to act on all of the material  5  on the dispenser screen  14 . When the truck  10  exits the frame interior  26 , the roller  41  pivots further downwardly. As the roller  41  moves downwardly, one of the roller assembly swing arms  32  engages the vertical frame bar sensor  39  thereby activating the vertical frame electric motor. This action moves the push rod  53  and an attached pressure plate  55  against the swing arm  32  causing the swing arms  32  to pivot about the wheel bearing housings  33  causing the roller assembly  40  to swing upward to a present position. 
     Since the truck dispenser interior  16  is usually not filled with screened material during the initial pass through the frame  20 , the truck dispenser  13  has additional material  5  loaded onto the dispenser screen  14 . The process of going through the frame interior  26  and having the roller assembly  40  act on the material  5  is repeated. Usually two passes is enough, although the process may be repeated as many times as necessary to fill the dispenser interior  16  with screened material. 
     It is understood that the above-described embodiment is merely illustrative of the application. Other embodiments may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.