Abstract:
A truck mounted conveyor system for transporting building materials to a station remote from the truck. The truck with conveyor system comprises a base platform mounted to the truck frame and an inner boom pivotally mounted to the base platform and configured to extend outward of said bed platform over a range of elevations and azimuths. The outer boom pivotally secured to the inner boom with a continuous conveyor belt circumscribing the inner and outer booms. The inner boom including a tensioner mechanism for maintaining a predetermined tension in the conveyor belt wherein the combination of inner boom and outer boom can be configured to minimize the overall length of the conveyor system while in transit in order to comply with applicable state overall vehicle length regulations and also maximize conveyor system length during conveying operations.

Description:
FIELD 
     This invention relates to boom type conveyors for delivering packages or materials onto roofs or other elevated locations. 
     BACKGROUND 
     This disclosure relates particularly to overhead conveyors as are used to deliver materials to elevated locations such as roof tops. In particular, the invention applies to such conveyors which are vehicle mounted and may be part of a delivery truck for transporting materials such as roofing shingles. The truck is driven to a site where roofing or other construction material is to be utilized or building features repaired, and the conveyor is positioned as to its elevation and azimuth using its own power drive equipment. 
     Various forms of delivery trucks of the self-unloading type are used to transport roofing materials to a building site. In general, vehicles presently in service are flat-bed straight trucks fitted with boom-like devices. One such device comprises a turret mounted boom-like conveyor which can convey individual packages from a position at the conveyor turret to a site distant from, and commonly above, the vehicle bed. The swinging conveyor requires the shingle packages to be carried to the discharge conveyor, where they are conveyed to the chosen delivery site, such as upon a roof. 
     SUMMARY 
     The present disclosure relates to those vehicles which utilize an off-loading conveyor fitted to the vehicle body. A vehicle, such as a flat-bed delivery truck, is fitted with a conveyor for carrying packages of material, such as roofing shingles, from the flat bed to the elevated location. The conveyor can swing in an arc about its turret-type mounting adjacent the transfer station, and its angle of incline with respect to the bed platform can be adjusted, so as to reach a wide variety of delivery sites, such as on a roof adjacent where the vehicle is parked, or on the ground adjacent the vehicle. 
     The type of truck commonly utilized with conveyors are known as straight trucks which are subject to Federal weight requirements on the Interstate System and Federal width requirements on the national network, but not to Federal length requirements. Vehicle length regulation remains with the States. However, the most common length restriction is a 40 foot maximum length for straight trucks. 
     A state imposed length restriction limits the total length of the boom to the state length limitation. The inner and outer articulating boom design disclosed herein allows additional length to be added to the overall boom length thereby increasing the versatility of the boom truck and a wider range of projects to which the straight truck/conveyor combination can be used. 
     The principal object of the invention, therefore, is to provide self-unloading apparatus for a vehicle which can carry a large number of loads, for example pallets of stacked packages or a plurality of goods in cartons or cases, which apparatus can move those loads using articulating inner and outer booms to a transfer station where they can easily be off loaded, or transferred to a delivery station with a minimum of lifting, and which can deliver the packages in serial fashion to a chosen site. The disclosed apparatus assists unloading, or in certain instances loading, of such a delivery vehicle to the point that a single person can control the functions of the apparatus and can also place the packages onto the delivery conveyor from the stacks of packages on the palletized loads, or to replace the packages on pallets on the lift platform, with minimized effort and with substantial saving of time. 
     Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims. Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawings in which like numerals represent like components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of the truck mounted conveyor system in a highway transit configuration; 
         FIG. 2  is a side elevation view of an embodiment of the truck mounted conveyor system in a highway transit configuration. 
         FIG. 3  is a side elevation view of an embodiment of the truck mounted conveyor system in an operational conveyor configuration; 
         FIG. 4  is a perspective view of an embodiment of the inner boom; 
         FIG. 5  is a side elevation view of an embodiment of the conveyor inner and outer booms; 
         FIG. 6  is an exploded view of an embodiment of a conveyor belt tensioning mechanism of the inner boom; and 
         FIG. 7  is an exploded view of an embodiment of the conveyor belt inner and outer booms. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosed technology relates to straight non-articulating vehicles which utilize an off-loading conveyor fitted to the vehicle body. A vehicle, such as a flat-bed delivery truck, is fitted with a serial unloading conveyor for carrying packages of material, e.g. roofing shingles. This conveyor can swing in a full circle atop its turret-type mounting, and its azimuth, i.e. its angle of incline with respect to the bed platform can be adjusted, so as to reach a wide variety of delivery sites, such as on a roof adjacent where the vehicle is parked, or on the ground adjacent the vehicle. 
     Federal regulations found at 23 C.F.R. §658 govern truck and bus size and weight; however, vehicle length regulation remains with the State for straight trucks. The most common length restriction, applicable in over twenty states as of 2015, is a 40 foot maximum length for straight trucks. Some states, for example Colorado and Idaho extend that length to 45 feet. With these length limitations a boom secured to a flat-bed straight truck cannot exceed 40 feet. State restrictions can thereby greatly inhibit the scope of projects that a truck mounted conveyor can support as it relates to the available reach of the conveyor. Providing an increase in length of approximately five feet using the inner boom configuration disclosed herein can greatly facilitate the timely completion of construction projects. 
       FIG. 1  reveals a perspective view of a straight truck utilizing a conveyor system  10  employing the disclosed technology. Specifically,  FIG. 1  reveals a straight truck  14 , the length of which is controlled by the applicable state law. The straight truck utilizes a frame area  16  capable of supporting building materials or other supplies for use at, for example, a construction site.  FIG. 2  illustrates a side elevation view of the same truck  14  as shown in  FIG. 1  detailing the travel length of the outer boom structure  18  that is limited by the applicable state law. As discussed above, this outer boom structure  18  can be no longer than 40 feet in over twenty states. The inner and outer boom structures  20 ,  18  are preferably constructed of welded steel or aluminum plate and internal tubular structural members  19 , as best seen in  FIG. 6 , to provide optimal strength with minimal conveyor system weight for carrying loads when the conveyor is in operation. 
       FIG. 3  details the truck  14  shown in  FIGS. 1-2  but in a material conveying configuration. The outer boom  18  and the inner boom  20  when configured as depicted in  FIG. 3  reveal how the inner boom can extend the overall length of the combined conveyor system  26  by, for example, an additional five, or more, feet. It is the capability of the inner boom  20  to align with outer boom  18  to form an increased working length that is very attractive to those in the construction material sales, transport and delivery business. 
       FIG. 4  provides a close-up perspective view of the conveyor system  10  detailing a base element  30  with four outwardly extending double flanges  32  and mounting plates  33  with through holes  33 A, for securing the base element  30  to the frame  16  of the truck  14 . The conveyor system  10  is capable of rotation above the ring gear  34  and can be rotated to any orientation required for delivery of the conveyed materials. The means for rotation of the base element  30  above the ring gear  34  is typically provided by a hydraulic motor  31 ; however, electric drive motors are also contemplated. The output shaft of the drive motor  31  utilizes a gear that engages with the ring gear  34 . As the drive motor  31  is energized the drive gear rotates the ring gear  34  causing the integrated inner and outer booms  20 ,  18  to rotate. 
       FIG. 4  provides further detail on the configuration of the inner boom structure secured to the base element  30 . The inner boom structure  20  is capable of rotating about the base element  30  that is mounted to the frame area  16 . The inner boom  20  is secured to the base element  30  by at least two vertical support elements  40 . The vertical support elements  40  extend upwardly from just above the ring gear  34  of the base element  30 . At the upward end  42  of the vertical support elements  40  are pivot holes  44  extending through the vertical support elements  40  that are utilized to retain a pivot shaft  46  that extends between the two vertical support elements  40 . The pivot holes  44  functioning in concert with the pivot shaft  46  and a first hydraulic cylinder  50  provides the capability to readily change the elevation of the inner boom structure  20 . 
     As seen in  FIGS. 4 and 5 , the first hydraulic cylinder  50  has an end  52  mounted to the vertical support elements  40  above the ring gear  34  at a lower shaft member  56  extending horizontally between openings  58  at the lowermost ends  60  of the vertical support elements  40 . The first hydraulic cylinder end  52  has a ring member  62  that circumscribes the lower shaft member  56  allowing the first cylinder end  52  to readily rotate as the first hydraulic piston rod  64  housed within the first hydraulic cylinder  50  extends out of or retracts into the cylinder  50 . As seen in  FIG. 5 , the end  68  of the first hydraulic piston rod  64  is mounted to an upper horizontal inner boom shaft  70  with a ring member  72 . As with the mounting of the first hydraulic cylinder  50  at the lower shaft member  56 , the same mounting technique at the upper inner boom shaft  70  facilitates rotation, providing elevation and declination of the inner boom  20 . 
       FIG. 4  also reveals that the inner boom  20  and the outer boom  18  are rotatably mounted to one another with a pivot pin  80  extending between the overlapping second end  82  of the inner boom  20  and the first end  84  of the outer boom  18 . To facilitate rotation of the first end  84  of the outer boom  18  about the second end  82  of the inner boom  18  a second hydraulic cylinder  86  provides the necessary mechanical advantage. A first ring member  90  at the end  92  of the second hydraulic cylinder  86  is secured to a second inner boom shaft  94  disposed between inner boom support flanges  96 . Extending outwardly from the second hydraulic cylinder  86  is a second hydraulic piston rod  98 . The end  100  of the second hydraulic piston rod  98  includes a ring member  102  secured in position by a horizontally mounted outer boom shaft  104  secured in position between two vertical flanges  106 . 
     The actuation of the second hydraulic cylinder  86  allows rotation of the outer boom  18  relative to the inner boom  20 . Such that when the inner boom  20  is in a fully vertical orientation, as shown in  FIG. 5 , and the outer boom is in a fully horizontal orientation the overall configuration can be driven on roads and highways in states where the length of the outer boom  18  may be no greater than the state limit for straight trucks.  FIG. 4  alternatively reveals the configuration of the inner and outer booms  20 ,  18  when maximum extension is needed. 
     As best seen in  FIG. 1  circumscribing the inner and outer boom structures  20 ,  18  is a conveyor belt  110 . As seen in  FIGS. 6 and 7 , the conveyor belt  110  extends over tubular support members  19  while transiting the inner and outer boom structures. Exemplary of such support members are cylindrical rollers extending between the first  112  and second sides  114  of the inner and outer booms  20 ,  18 . The conveyor belt is preferably fitted with cleats  118 , or upwardly extending protrusions, of some configuration to prevent backward slippage of materials placed on the conveyor belt  110  when the outer boom is in an elevated orientation. 
       FIG. 6  details a conveyor belt  110  tensioning mechanism  120  disposed within the inner boom structure  20 . The conveyor belt tensioning mechanism  120  utilizes a shaft  124  spanning from the first side  112  to the second side  114  of the conveyor system  10 . The shaft  124  supports a plurality of idler rollers  134  over which the conveyor belt  110  rides. Each end  129  of the shaft  124  extends into the mechanism used for adjusting the tension of the conveyor belt  110 . Each end of the shaft utilizes a bearing housing  144  configured with slots  148 ,  150  for mating with upper and lower rails  154 ,  156 . The bearing housing  144  is capable of longitudinal translation along the rails  154 ,  156  by adjustment bolts  160  on both sides  128 ,  130  of the inner boom  20 . The adjustment bolts  160  extend through a housing panel  164  rigidly secured to a side panel  170  of the inner boom  20 . When the conveyor belt  110  is installed and circumscribes the inner and outer booms  20 ,  18  the adjustment bolt  160  can be either advanced or retracted as needed to increase the tension load on the conveyor belt  110  or lessen the tension on the belt. 
       FIG. 7  provides an exploded view of the entire conveyor system  10 . The conveyor belt  110  is driven by a drive motor  175  that is operably coupled to a series of rollers  177  that power the overlain conveyor belt  110 . When the conveyor system  10  is in the fully extended position, that is when the inner and outer booms  20 ,  18  are aligned, the conveyor belt  110  is designed to extend the set number of feet of the outer boom length as well as the additional number of feet of the inner boom length for a combined inner and outer boom length. The conveyor belt  110  tension is then set at a predetermined load. When the inner boom  20  and the outer boom  18  are in the stowed position at roughly a 90 degree angle to one another, the conveyor system  10  is designed to allow the pre-set tension in the belt to relax slightly. The relaxed tension in the folded configuration serves to increase the life of the belt. 
     While the preferred form of the present invention has been shown and described above, it should be apparent to those skilled in the art that the subject invention is not limited by the figures and that the scope of the invention includes modifications, variations and equivalents which fall within the scope of the attached claims. Moreover, it should be understood that the individual components of the invention include equivalent embodiments without departing from the spirit of this invention. 
     It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Not all steps listed in the various figures need be carried out in the specific order described.