Abstract:
A self-transporting conveyor system suitable for handling the discharge of a rock or concrete crusher, for example. The system includes a pair of stacking conveyors and a pair of transfer conveyors all of which are assembled together for towing by a single highway tractor. The conveyors can be set up at a desired site using available equipment, such as a loader, so that the cost of a special crane is avoided. Each stacking conveyor includes a self-contained hydraulic power supply that allows it to hydraulically fold up for transport, and unfold for operation, and enables it to hydraulically pivot back and forth during operation to build a kidney-shaped pile.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to conveyor systems for stacking bulk materials and, more particularly, to such conveyor systems that are readily transportable from site to site. 
     PRIOR ART 
     Material, such as stone, rock or demolition material, is regularly crushed and screened into aggregate products. Crushing equipment is often moved from location to location as the need changes. Mobility is a necessity where equipment is used for crushing demolition materials on site. Because of seasonal high demand, equipment failure or other reasons, there can be a need to temporarily operate portable equipment at permanent installations such as at a stone quarry, for example. 
     In crushing operations for rock, stone, concrete or the like, generally, at least two products are made. Such products can be, for instance, fines and a certain screen size. For each product coming off the screen section of the crusher plant, a conveyor circuit is frequently necessary to move the product away from the screen discharge and, normally, stack it on storage piles. 
     The transport and erection of known portable stacking conveyors has involved substantial time, labor and shipping costs for transport, assembly and disassembly. The typical prior art stacking conveyor had to be transported separately on a highway trailer and often required a crane to unload it, set it up for operation, and later take it down when a job was completed. Consequently a large part of the cost of a job was incurred for equipment transportation and for set up and take down work not associated with production. 
     SUMMARY OF THE INVENTION 
     The invention provides a self-transporting and self-erecting conveyor system. In the illustrated embodiment, the system comprises four conveyors that are transported as a single trailer load drawn by a conventional highway tractor. The conveyor includes two stacking conveyors and two transfer conveyors. The disclosed conveyor system can be conveniently set up and later taken down using available material handling equipment such as a loader. The invention, thus, avoids the scheduling and expense of a mobile crane often required with prior known systems. 
     Each stacking conveyor folds on itself on a horizontal axis to reduce its length for transport. The hinge folding point for each stacking conveyor is arranged so that an area above a main section of the frame is reserved for receiving an associated transfer conveyor for transport purposes. The stacking conveyors are proportioned to lie side by side for transport. The tail or material receiving end of each stacking conveyor receives a common pin that simplifies coupling of the stacking conveyors for transport. 
     Each of the stacking conveyors is fitted with a separate axle and wheel set for road transport and to enable sideways movement for stacking a kidney shaped pile. The wheels are pivotal on the axles to convert from the transport mode where travel is longitudinal to the operational mode where the motion is side to side or radial. The stacking conveyors each have separate self-contained hydraulic power packs that are used for erecting and, alternatively, retracting various parts of the conveyor for operation or for load transport. Additionally, the power pack can be used to drive the wheels to produce side to side movement of the conveyor. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of one of the stacker conveyors hereinafter sometimes referred as a stacker and an associated superposed transfer conveyor; 
     FIG. 2 is a side elevational view of another one of the stacker conveyors and an associated superposed transfer conveyor; 
     FIG. 3 is an elevational view of the tail or material receiving end of the stacker conveyors and the two superposed transfer conveyors on the stacker conveyors all in assembled relation for transport; 
     FIG. 4 is a fragmentary side elevational view of a tail end of a stacker and its fifth wheel pin being moved into working position as indicated by the arcuate arrow; 
     FIG. 5 is a side elevational view of a stacker in an intermediate position between transport and operational modes; 
     FIG. 6 is a fragmentary plan view of an axle and wheel set for one of the stackers; 
     FIG. 7 is a plan view of the stacker conveyors in an intermediate coupled relationship; 
     FIG. 8 is a fragmentary elevational view of a tail end of a stacker supported on a turntable resting on the ground; 
     FIG. 9 is an elevational view of an axle of a stacker; 
     FIG. 10 is an elevational view of a stacker set up in its operational position; and 
     FIG. 11 is a diagrammatic end view of the stackers showing the fifth wheel pin of one stacker in the transport mode where it serves to connect both stackers to a highway tractor. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the figures, there is shown a stacking conveyor system  10  that comprises a pair of stacking conveyors  11 ,  12  and a pair of transfer conveyors  16 ,  17 . FIGS. 1-3 illustrate the conveyors assembled for highway transport. FIG. 7 is a plan view of the stacking conveyors or stackers  11 ,  12  where they are being disassembled from one another in preparation for use. The stackers  11 ,  12  are substantially the same in general construction and relevant differences are discussed below. As between the stackers  11  and  12 , like parts are given the same reference numerals. Each stacker  11 ,  12  has an elongated truss-type frame  20 . By way of example, the stackers  11 ,  12  can have a nominal unfolded working length of  80  feet. Each stacker  11 ,  12  is carried on a separate axle  21 . The frame of the stacker  11  has a main section  22 , a secondary fold-up section  23 , and a small triangular intermediate section  24 . The sections  23 ,  24  pivot about a pin  26  that is common to them and to the main section  22 . A hydraulic cylinder  27  is connected between the main frame section  22  and the triangular section and, similarly, a hydraulic cylinder  28  is coupled between the secondary section  23  and the triangular section. When the rods of these hydraulic cylinders are extended, the frame sections  23 ,  24  are in the folded-up position of FIG. 1, and when the cylinder rods are retracted, these sections are in a straight line configuration. A continuous belt  31  is trained over idler pulleys  32  distributed over the frame sections  22 - 24  and is wrapped around end pulleys  33 ,  34 . A pulley take-up mechanism  36 , known in the art, is provided for the end pulley  33  at the “tail” end of the main frame section  22  to adjust the tension in the belt  31 . When the frame sections  23  and  24  are folded and not in the straight line operating position of FIG. 10, an idler pulley  32 A is removed from the triangular frame section to prevent the belt from being stretched because of an effective increase in the length of the path of the belt  31 . A power pack  37  including an internal combustion engine, a hydraulic pump and suitable hydraulic circuitry including a four-section directional control valve is mounted to the main frame section  22 . The power pack  37  is hydraulically connected to the hydraulic cylinders  27 ,  28  and other hydraulic components described hereinbelow. Each stacker  11 ,  12  includes a retractable manually operated landing gear  38  of known construction. 
     The axle  21  of each stacker  11 ,  12  is asymmetrical with respect to the frame section with which it is attached so that a cantilevered part of the axle can underlie the other stacker and support a wheel  41  horizontally outboard of this other stacker when the stackers are in the assembled transport condition. A wheel  42  is on a telescoping portion  43  of the axle  21  which can be a square or rectangular tube that slides in a larger square or rectangular tube making up the remainder of the axle  21 . FIG. 7 shows the stacker  12  on the left with the telescoping axle and wheel extended, and the stacker  11  on the right with the telescoping axle and wheel retracted. When extended, the telescoping wheels  42  provide stability for the respective stacker when it is in an operating condition and the frame  20  is elevated. In their retracted positions, the telescoping wheels  42  enable the conveyor assembly  10  to meet maximum allowable highway width standards. Each axle tube  43  is extended and retracted hydraulically by an associated hydraulic cylinder  46  (FIG. 9) selectively operated by the hydraulic power pack  37 . The wheel  42  on the left in FIG. 9 has been telescoped outwardly from the indicated phantom position. The wheels  41 ,  42  are supported on vertical axis pivots or king pins on the axles  21 . In one position, a wheel  41 ,  42  has its axis parallel to the axis of the axle  21  while in another position, the wheel  41 ,  42  has its axis nearly perpendicular to the axis of the axle so that the wheel axis intercepts the tail, designated  19 , of the frame  20 . The wheel  42  on the axle telescoping portion  43 , is driven selectively in either direction by a hydraulic motor and gear box assembly  51  (FIG.  9 ). The hydraulic motor and gear box  51  operates through a pair of sprockets  48 ,  49  and a chain drive  50 . The hydraulic motor  51  is selectively operated by the power pack  37  and related directional controls. As shown in FIGS. 1,  2  and  5 , the axle  21  is attached to struts  52 . The struts  52  have ends  54  with pins or rollers that move longitudinally a limited distance in a track  55 . Between the axle  21  and an end of the main frame away from the tail end there is disposed a hydraulic cylinder  53  that selectively raises or lowers the discharge end of a stacker  11 ,  12  by fluid control from the power pack  37 . 
     For purposes of explanation, it will be assumed at this point the conveyor system  10  is assembled for transport. The stackers  11  and  12  have mating right hand and left hand brackets  61 ,  62  that are coupled by a vertical locking pin  63 . Furthermore, interlocking surfaces can be provided at the plane between the stackers  11  and  12  that automatically interengage when one of the stacker frames is finally lowered from an elevated position. As described more fully below, each stacker  11  and  12  has a separate fifth wheel pin to enable it to be separately moved by a highway tractor when desired. When the stackers  11  and  12  are assembled for transport together, the fifth wheel pin  67  of one stacker  12  (FIG. 11) serves both stackers  11  and  12 . To accommodate this versatility, a plate  66  carrying the fifth wheel pin  67  of the stacker  12  is mounted with bracketry that enables it to slide horizontally partially under the other stacker  11 . A plate  68  (FIG. 4) carrying the fifth wheel pin  69  for the other stacker  11  is pivoted underneath the frame through  1800  to make room for the sliding fifth wheel pin plate  66 . Suitable pins and/or bolts are used to hold the plates  66  and  68  in their alternative positions. 
     The transfer conveyors  16 ,  17  are suitably bolted to the main sections  22  of the frames  20  of the stackers  11  and  12  in areas not covered by the fold-up sections  23 . The assembled conveyor system  10  is conveniently transported over public roadways with a conventional road tractor from site to site. 
     Immediately following is an outline discussion of the procedures to set up the conveyor system  10  for operation at a site such as where a crusher is processing rock, construction debris or other rock or stone-like material. With the assembly  10  delivered to the site, the landing gears  38  of both stackers  11 ,  12  are deployed and the tractor is disengaged from the king pin  67  used to draw both stackers. 
     A turn and brake light assembly, not shown, can be supplied when the system is operating as a trailer on the highway and can be removed during operation of the stackers. Drive chains  50 , removed from the sprockets  48 ,  49  of the hydraulic motor and gear boxes  51  and associated wheels  42  during highway transport, are installed. The wheels  41 ,  42  can be provided with suitable air brakes and circuitry for operating them while disconnected from a tractor. The transfer conveyors  16  and  17  are unbolted and lifted off by available equipment such as a loader from the top of the stackers  11 ,  12  and appropriately positioned. 
     The plate  66  is released from a bolted connection with the stacker  11  and is slid on its guides laterally until it is centered under the main frame section  22  of the stacker  12  and bolted securely in place. The pivotal plate  68  is unbolted from its retracted position and folded forwardly, FIG. 4, to its forward-most position under the main frame section of the stacker  11  and is bolted in place. A loader or other machinery is used to suspend the tails of the stackers  11  and  12  while the landing gear of each stacker is folded up. Thereafter, the tails of the stackers  11  and  12  are lowered to the ground as shown in FIG.  5 . The power pack  37  of the stacker  11  is operated to extend the hydraulic cylinder  53  to elevate the stacker  11  and disengage overlapping plates or other suitable elements that lock the stackers laterally together for transport. The receiving holes in the brackets  61 ,  62  are large enough relative to the pin  63  to permit this elevation of the stacker  11  relative to the stacker  12 . Suitable pins are provided to mechanically lock the position of the selected extension of the hydraulic cylinder  53 . 
     At the stacker  12 , the side of the frame  22  associated with the outboard or non-telescoping wheel  41  is jacked up and this wheel is rotated about its king pin to position and lock it in its lateral position where its axis of rotation points to the tail end of the stacker. The wheel  41  is lowered and the opposite side of the stacker frame  22  is jacked up. The axle section  43  is then extended or telescoped by operation of the associated hydraulic cylinder  46  using the power pack  37  of this stacker  12  to increase the track of the wheels  41 ,  42  for stability during stacking operations, and the drive wheel  42  is swung about its king pin to its lateral position where its axis of rotation points to the tail end of the stacker. Suitable pins are provided to lock the wheels in their alternative positions. The jack is then released to lower the wheel  42  onto the ground. 
     The stacker  12  is radiated away from the other stacker  11  by operating the hydraulic motor and gear box  51  of this stacker  12 . Stacker  11  is then lowered to its travel position by operating its hydraulic cylinder  53 . The pin  63  joining the tails of the stackers  11  and  12  is removed and a loader or other machinery is hooked to the stacker  11  to separate the tails of the stackers. 
     The wheels  41 ,  42  of the stacker  12  are thereafter jacked up and rotated back about their king pins and locked in their original transport positions. The stackers  11  and  12  are transported to their desired operating positions. A swivel base or turntable  72 , one for each stacker  11  and  12 , is placed on the ground at a point where material is to be delivered and about which it is desired that the respective stacker  11  or  12  will be caused to oscillate laterally when building a kidney-shaped pile. The swivel base is designed to support the tail end of its respective stacker slightly off the ground and permit it to laterally oscillate about a vertical axis of the center of the base so that when the stacker oscillates, it maintains its receiving or tail end in a constant location. 
     Once the stackers have been set in position on the swivel bases  72 , they can be jacked up and their wheels can be pivoted and locked for radial (lateral) motion. At this time the axle of the stacker  11  can be extended as earlier described for the stacker  12 . For each stacker  11 ,  12 , bolts holding the folded back secondary truss section  23  to the main truss section  22  are removed and the associated power pack is energized to fully unfold the secondary truss section by energizing the associated hydraulic cylinders  27 ,  28 . The triangular truss section  24  is bolted to the other sections  22 ,  23  and the idler pulley  32 A is installed in position. Where necessary, the pulley take up  36  can be adjusted to tighten the belt  31 . The pulley  34  at the discharge end of the frame  20  can be operated by an electric motor suitably connected to an electric power source to drive the belt  31  in a circulating path on the frame  20 . 
     The discharge height of each stacker  11 ,  12  is adjusted by operation of the respective hydraulic cylinder  53 . Each stacker  11  and  12  can create a kidney shaped pile, when viewed from above, by causing the stacker to move radially or laterally through operation of the associated hydraulic motor and gear box  51  to rotate the driven wheel  42  in an appropriate direction with operation of the power pack  37 . The transfer conveyors  16 ,  17  can be used to either feed one of the stackers or to otherwise convey material being processed at the site from one point to another. 
     When the work has been completed at a particular site and it is desired to transport the system to another site, the procedures outlined above to set up the stackers for operation are essentially reversed. 
     It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.