Patent Document

The present invention relates generally to conveyors. More particularly, the present invention relates to platform extensions for conveyors that extend and/or rotate from an end of the conveyor and aid the person unloading the conveyor. 
   BACKGROUND OF THE INVENTION 
   Many types of conveyors are widely known in the art. Conveyors typically comprise a fixed or articulated frame member, or boom, with an endless conveyor belt or chain located about the boom. Conveyors are generally used to transport materials, such as bundles of shingles and other roofing materials from, i.e., a truck to a roof top. Another form of conveyor system that may be utilized in conjunction with the present invention is a latter truck, such as the latter trucks used by fire departments. 
   One inherent problem with conveyors involves the angle of the conveyor in relation to an upper surface, such as a roof. This problem is especially evident when transporting, e.g., shingles onto a residential housing roof or other pitched surface. Since the conveyor is angled upwardly when transporting materials, the end of the conveyor may be vertically-spaced from the roof surface. As such, the person unloading the conveyor may have to reach above his or her head to receive the materials carried by the conveyor. Additionally, pitched roofs render a person&#39;s footing unsafe, especially when removing heavy items from the conveyor. 
   There is a need for a conveyor that provides a more level and safer approach angle for the person unloading materials from the conveyor. Accordingly, the present invention is hereby submitted. 
   SUMMARY OF THE INVENTION 
   One advantage of the present invention is realized by providing a conveyor having a platform or plank extendible from one end of the conveyor. 
   Another advantage of the present invention is realized by providing a conveyor having a platform or plank that is selectively rotatable or pivotable from the main boom of the conveyor. 
   These and other advantages of the present invention are realized by providing a conveyor for transporting materials from a first location to a second location that comprises an elongated boom having a first end, a second end, a top surface, and a bottom surface; a conveyor mechanism such as an endless belt or chain that is operably attached to the elongated boom; and a plank or platform operably attached to the boom adjacent to the bottom surface of the boom, wherein the platform is selectively pivotable from the boom and capable of providing a walking surface for the person unloading the conveyor. The platform may additionally or alternatively be at least partially extendible from one end of the elongated boom. The platform may be attached to a platform support, with the platform support being slidably or rollably attached to the elongated boom. 

   
     SUMMARY OF THE DRAWINGS 
       FIG. 1  is a perspective view of a conveyor with an extendible and pivotable platform, in accordance with a preferred embodiment of the present invention. 
       FIG. 2  is a perspective view of the conveyor of  FIG. 1 , shown with the platform and platform support detached from the boom 
       FIG. 3  is a perspective view of the conveyor of  FIG. 1  attached to a vehicle and with the platform extended and pivoted downwardly. 
       FIG. 4  is a side schematic view of the conveyor of  FIG. 1 . 
       FIG. 5   a  is a perspective view of a second embodiment of a conveyor with a platform support track. 
       FIG. 5   b  is a perspective view of the conveyor of  FIG. 5   a , illustrated with the platform retracted. 
       FIG. 6  is a close-up perspective view of a portion of the conveyor of  FIG. 5   a , showing the platform support track and a hydraulic cylinder for actuation of the platform. 
       FIG. 7  is a close-up perspective view of a portion of the conveyor of  FIG. 5   a , showing a pivotable connection of the platform and a roller on the platform support track. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   A preferred embodiment of a conveyor  10  is illustrated in  FIG. 1 . The conveyor  10  comprises a main boom  12  and conveyor mechanism  28 ,  128 , such as a belt or chain. The main boom  12  comprises a first end  14  and a second end  16 , and is attached to a base support. Preferably, the conveyor  10  comprises means for adjusting the pitch of the main boom  12  vertically and for translating the main boom  12  radially or horizontally. In a preferred embodiment, a rotatable pedestal  24  of a type known in the art is attached near the first end  14  to a base support. The rotatable pedestal  24  provides radial movement of the main boom  12 . Rotatable pedestal  24  also preferably includes at least one hydraulic actuator  22  that facilitates movement of the main boom  12  vertically. As such, the main boom  12  is preferably adjustable both vertically and horizontally. The controls for the rotatable pedestal  24  and hydraulic actuator  22  are both of a type generally known in the art. 
   The main boom  12  additionally comprises upper or top surface  18  and lower or bottom surface  20 . An endless conveyor mechanism  28 , such as a belt, chain, or other structure known in the art may be operably attached to the main boom  12 , such that materials to be transported are loaded onto the upper surface  18  of the main boom  12  near the first end  14 . The materials are then conveyed toward the second end  16  of the main boom  12  and are unloaded accordingly. It is also contemplated that the main boom  12  may comprise a ladder device with rungs  128  in lieu of an endless conveyor mechanism  28 . 
   Referring now to  FIG. 2 , the conveyor  10  further comprises platform  30 , which may be extendable from the second end  16  and/or rotatable or pivotable downward from the main boom  12 . Preferably, the platform  30  is of sufficient width to enable a person to walk across it. Additionally, the platform is preferably constructed of a rigid material such as steel or aluminum alloy, although any sufficiently rigid material can be utilized without deviating from the scope of the present invention. 
   The platform  30  is preferably pivotally attached at one end to a support means, which in  FIG. 2  is illustrated as carriage  40 . The carriage  40  is preferably rollably or slidably attached to the main boom  12 . In a preferred embodiment, the carriage  40  comprises inwardly-projecting flanges  42  that forms slots  44 . Slots  44  receive outwardly-projecting flanges  26  on main boom  12 . In such an embodiment, carriage  40  is slidably attached to boom  12 . Alternatively, a plurality of rollers could be utilized instead of flanges  26 , without deviating from the scope of the present invention. It is also contemplated that the carriage  40  may be fixed in relation to the boom, with the platform  30  being telescopically extendable. 
   The platform  30  is preferably rotatably attached to carriage  40  at or near one end of the platform  30 , such that the platform is selectively pivotable downward. As such, the user can position the platform  30  to provide a more level walking surface for the person or persons approaching the main boom  12  to unload materials from the conveyor  10 . Any rotatable connection as is known in the art may be utilized. A preferred embodiment for the rotatable connection comprises pins or rods  48  that are received in apertures (not shown) in the carriage  40 . To facilitate rotation of the platform  30 , a hydraulic actuator  46  may by attached to the carriage  40  on one end and to the underside of the platform on the other end, as illustrated in  FIG. 2 . In such an embodiment, retraction of the hydraulic actuator  46  causes downward rotation of the platform  30 . In the same manner, extension of the hydraulic actuator  46  causes the platform to rotate upwardly back to a position substantially parallel to main boom  12 . 
   Rather than carriage  40 , it is also contemplated that the platform  30  may be slidably or rollably attached to the main boom by any suitable support means as is known in the art, without deviating from the scope of the present invention. For example, the platform  30  may be supported by cage or track  126  and slidably or rollably extendible and retractable from the cage or track  126 . In such an embodiment, illustrated in  FIG. 6 , the platform  30  may be rotatably attached to a drive member  50 , such that after a predetermined critical distance of extension, when the joint between the platform and the drive member approaches the end of the cage or track  126 , the platform passively rotates downwardly. 
   Additionally, the platform  30  may be slidably or rollably attached to an elongated support means attached to the main boom  12 , such that the platform  30  is extendible and retractable along the length of the support means but not rotatable in relation to the support means. In such an embodiment, the support means, itself may be rotatable downwardly to adjust the angle of the platform  30 . 
   Extension and retraction of platform  30  is preferably hydraulically actuated. For example, carriage  40  may be translatable longitudinally in relation to the main boom  12  via opposing hydraulic winches  60  ( FIG. 7 ) located at or near the ends of the main boom  12 . To translate the platform  30 , one winch  60  would wind its cable, while the opposing winch unwinds its cable. Alternatively, the hydraulic actuator may be a hydraulic cylinder  52  having its longitudinal axis substantially parallel to the main boom  12 . Alternatively, extension and retraction of the platform  30  may be any other chain or winch drive as is known in the art. For example, opposing sides of the carriage  40  may be attached to chains or cables or the like. The chains or cables may additionally be attached to rotatable spools or drums, powered by any means known in the art, such that by winding the cable around one drum, while simultaneously unwinding the cable from the second drum translates the platform  30  forward or backward in relation to the main boom  12 . 
   Optionally, platform  30  may further comprise at least one stabilizing member or leg  38 . Stabilizing member  38  is preferably adjustable or rotatable downwardly in relation to platform  30 . Optional stabilizing leg  38  may be used, for example, when only one side of the platform is touching a surface such as a roof. 
   In operation, the user first adjusts the elevation and direction of conveyor  10 . The conveyor can either be fixed, manually moveable, or attached to a vehicle  70 . After the elevation and direction of the conveyor  10  is selected, the user subsequently extends the platform  30  from the main boom  12  a predetermined distance, preferably via a hydraulic winch  60 , hydraulic cylinder  52 , or other chain or cable drive. After the platform  30  extends from the main boom  12  a predetermined distance, the user next rotates the platform  30  downwardly, with the end of the platform  30  resting on, if possible, a roof or other upper surface. It should be understood that if the platform  30  is extendible from a rotatable platform support, the user would rotate the platform support, itself, either before or after extension of the platform  30 . Additionally, if the platform  30  is passively rotatable downwardly after extension a predetermined distance, the user only needs to extend the platform a predetermined distance to facilitate its rotation downwardly. 
   If the platform  30  is angled such that only one side of the platform  30  is touching the roof, optional support leg  38  can be engaged downwardly to ensure that both sides of the platform  30  are supported by the roof. 
   The forgoing disclosure is illustrative of the present invention and is not to be construed as limiting thereof. Although one or more embodiments of the invention have been described, persons of ordinary skill in the art will readily appreciate that numerous modifications could be made without departing from the scope and spirit of the disclosed invention. As such, it should be understood that all such modifications are intended to be included within the scope of this invention. The written description and drawings illustrate the present invention and are not to be construed as limited to the specific embodiments disclosed.

Technology Category: b