Abstract:
An apparatus for unloading packages, parcels, postal items, baggage, etc., from a container having an open side. The apparatus has a sliding wall that is disposed over the open side of the container when the container is receiving within the apparatus. The apparatus, along with the container, is tilted such that the open side of the container is generally directed downward. From this tilted orientation, the sliding wall of the apparatus is withdrawn, incrementally exposing the open side of the container, permitting the controlled egress of the packages, etc., from the container.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention pertains to an apparatus for unloading packages from a container.  
         BACKGROUND OF THE INVENTION  
         [0002]    Traditionally, several methods have been employed for unloading and processing containers of parcels, packages, postal goods, etc. The most basic method involves manually unloading the containers one package at a time. However, this method is very time consuming and has a potential for producing repetitive motion injuries to the people involved in the process. These problems have lead to the advent of a variety of automated, and semi-automated processes.  
           [0003]    In addition to manual unloading methods, there exist a number of automated and semi-automated systems for unloading containers. While the known systems vary according to the design of the container itself, the majority of such systems rely on simply dumping the contents from the container onto a conveyor, slide, or the like. However, such dumping systems are often troublesome when employed to empty containers having bar sides, internal shelves and internal brackets, wherein the contents of the container may hang-up on such features. Additionally, inversion dumping often leads to piling of the contents of the container, rather than spreading them in a smooth dispersion onto the conveyor. Furthermore, the tendency of the contents to pile requires that the mouth of the container be elevated above the conveyor a height sufficient to allow the resultant pile to clear the container. This characteristic of inversion dumping makes an already inherently harsh method even rougher on the packages being unloaded.  
           [0004]    It would, therefore, be desirable to be able to unload packages from an open front container in a manner that minimizes the probability of damage to the packages, and further releases the packages in a controlled manner in order to prevent piling.  
         SUMMARY OF THE INVENTION  
         [0005]    According to the present invention, there is provided an apparatus for unloading containers, wherein the apparatus comprises a tilting carriage. The carriage is configured to receive the container in a manner such that a slidable wall of the carriage is disposed over an open side of the container, thereby fully enclosing the container. With the container in place in the carriage, the carriage is tilted such that the open side of the container is oriented downward, preferably toward a conveyor, slide, or the like. The slidable wall of the carriage is then displaced from the open side of the container, thereby incrementally opening the container. Consistent with the present invention, the container may be positioned in close proximity to a conveyor prior to releasing the contents of the container, therein minimizing damage to the packages resulting from being dropped. Furthermore, the incremental opening of the container provides for a more gradual release of the contents of the container, thereby reducing problems of piling of the contents on a conveyor, or the like.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    Exemplary embodiments of the invention are set forth in the following description and shown in the drawings, wherein:  
         [0007]    [0007]FIG. 1 is a perspective view of an exemplary apparatus consistent with the present invention prior to loading a container;  
         [0008]    [0008]FIG. 2 is a perspective view of an exemplary apparatus consistent with the present invention during the unloading phase.  
         [0009]    [0009]FIG. 3 is a perspective view of an exemplary unloading apparatus consistent with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0010]    An apparatus consistent with the present invention may be used for unloading a variety of packages, parcels, postal items, baggage, etc., from containers having an open front side. Although the present invention is not limited thereto, it will be assumed for the purposes of this description that the containers to be unloaded are mobile, such as rolling containers. The unloading of parcels, etc., takes place by tilting the container so that it is open-side-down over an unloading zone, which may comprise a conveyor, a roller bed, a slide, etc., and further effecting a controlled release of the parcels, etc., from the container onto the unloading zone. For ease of understanding, the present invention will be described below in terms of an exemplary embodiment configured to unload postal items, such as parcels and envelopes, from a rolling container having an open front side and an open top side. It will, however, be readily appreciated by those skilled in the art that the principles of the present invention are susceptible for use in unloading any open front container in a controlled manner.  
         [0011]    Referring to the drawings, an exemplary apparatus consistent with the present invention is illustrated. The apparatus comprises a carriage  10  configured to receive an open front container  12 . The carriage comprises a floor member  14  for supporting the container  12 , and a ceiling member  16  spaced from the floor member  14  to limit axial movement of the container  12  within the carriage. Furthermore, the ceiling member  16  is configured to prevent spillage of parcels from the container  12  in the event that the container  12  is of an open top design, as illustrated in the exemplary embodiment. Consistent with this requirement, the ceiling member  16  may range from a solid surface to a retaining arm. In the exemplary embodiment illustrated in FIGS. 1 and 2 the ceiling member  16  comprises bar grate sufficient to prevent the spillage of parcels having a minimum dimension greater than the separation of the bars. Similarly, consistent with the above stated requirements, the floor member  14  may range from a solid surface, as illustrated in the exemplary embodiment, to a pair of forks extending in the direction of loading of the container  12 . The employment of these alternate configurations will become more apparent from the below description of the operation of an apparatus consistent with the present invention.  
         [0012]    The carriage  10  is pivotally connected to a base frame  18  by pivots  20  and  22 . Preferably, the carriage  10  is attached to the pivots  20  and  22  by pivot arms  24  and  26 . Pivot arms  24  and  26  provide an increased degree of forward translation of the carriage  10  relative to the base frame  18  during tilting, therein placing a greater amount of the carriage  10 , and therein a greater amount of the container  12 , over the conveyor  28 , which is preferably disposed in front of the carriage  10 , when it is in an upright position, and between the frame members of the base frame  18 . Additionally, it is advantageous to employ support posts  30  and  32  extending from the base frame  18 , wherein the support posts  30  and  32  are configured to receive and support the carriage  10  when it is in a tilted position, as illustrated in FIGS. 2 and 3, enhancing the stability thereof.  
         [0013]    The apparatus of the present invention further comprises a front wall  34  that is slidable along the axis of the carriage  10 . The front wall  34  is configured to be disposed proximate the front of a container  12  when the container is loaded in the carriage  10 . The presence of the front wall  34  effectively provides for full enclosure of the container  12  once it has been loaded into the carriage  10 . As with the ceiling member  16 , the construction of the front wall  34  is dictated by the size of the packages to be carried by the container  12 . As illustrated in FIGS. 1 through 3, when larger packages are anticipated, the carriage  10  may be configured with a bar or slat front wall  34 , wherein the separation between bars is less than the minimum dimension of the packages. When smaller packages are anticipated, the front wall  34  may comprise a grate or solid surface, therein preventing spillage of the contents of the container  12 . As best shown in FIG. 1, preferably the top edge of the front wall  34 , as viewed when the carriage  10  is in an upright position, is angled away from the carriage  10  so that the terminal edge of the front wall  34  lies in close proximity to the conveyor  28  when the carriage  10  is in a tilted position.  
         [0014]    As shown in FIGS. 1 through 3, the carriage  10  further comprises vertical frame components  35   a  and  35   b  as well as  37   a  and  37   b.  The vertical frame components  35   a,    35   b,    37   a,  and  37   b  may be employed to provide the necessary structural integrity of the carriage  10 . Consistent with, and similar to, the above discussed requirements of the floor member  14  and the ceiling member  16 , the vertical members  35   a ,  35   b ,  37   a,  and  37   b  may be present simply as vertically oriented beams, as illustrated in the exemplary embodiment, sufficient to maintain the proper separation of the floor member  14  and the ceiling member  16 , and to maintain the integrity of the carriage  10 . Additionally, the vertical members  35   a ,  35   b ,  37   a,  and  37   b  must be configured to permit the ingress and egress of the container  12 . However, the form and the structure of the vertical members  35   a ,  35   b ,  37   a,  and  37   b  may be varied within these requirements from a plurality of vertical members to a plurality of solid surfaces.  
         [0015]    In operation, the container  12  may be loaded into the carriage  10  either from the side of the carriage  10 , as shown in the illustrated exemplary embodiment, or alternately may be loaded into the carriage  10  from the rear. The carriage  10 , having the container  12  received therein, is then tilted to a substantially horizontal position about pivots  20  and  22 , and is supported in the horizontal position by support posts  30  and  32 . As previously noted, the carriage  10  may be pivotally connected to the base frame  18  by way of pivot arms  24  and  26 , therein providing a greater forward displacement of the carriage  10 , and the container  12  therein, relative to the base frame  18  and the conveyor  28 . When the carriage  10 , and the container  12  therein, are in the tilted position, the contents of the open front container  12  will be resting on the inside of the front wall  34 .  
         [0016]    The tilting action of the carriage  10  may be achieved either manually, or in an automated or semi-automated manner. In a preferred embodiment consistent with the present invention, the carriage  10  is tilted by a hydraulic or pneumatic actuator, such as a piston disposed between the carriage  10  and the base frame  18 . Alternate automated means for tilting the carriage may include an electric motor acting at one, or both, of the pivots  20  and  22 . Additional methods of achieving a tilting action of the carriage  10  will be readily apparent to those having skill in the art.  
         [0017]    After the carriage  10  has been moved to a generally horizontal position, the container  12  may be unloaded, as onto a conveyor  28  as illustrated in FIG. 2. The container  12  is unloaded by sliding the front wall  34  along the axis of the carriage  10  in the direction of the floor member  14 , i.e., rearward. The rearward displacement of the front wall  34  provides an enlarging opening in the front of the carriage  10  allowing egress of parcels from the container. This growing opening will allow the contents of the container  12  to shingle out, i.e., exit the container in a dispersed manner, wherein the parcels that were at the top of the container  12 , before it was tilted, will be allowed to exit the container  12  first, when the front wall has undergone a minimal of displacement. It will be appreciated at this point that, in order to undergo the unloading operation, the container  12  must be retained within the carriage  10  when the front wall  34  is in an open position. This may easily be accomplished by providing front vertical members  35   a  and  37   a  horizontally spaced from one another a distance less than the width of the container  12 , therein preventing the forward egress of the container  12 . Alternately, the carriage  10  may be provided with detents or other retention features similarly preventing the forward egress of the container  12  when the carriage  10  is in a tilted position, and the front wall  34  is in an open position.  
         [0018]    The sliding action of the front wall  34  may be effected by a variety of mechanical or manual means. In the exemplary embodiment illustrated in FIG. 3, the front wall  34  is actuated by a worm drive mechanism comprising a centrally mounted motor  36  working through a system of gear boxes  38  and  40  and belts  42  and  46  to drive a worm shaft  48  and  50  on either side of the carriage  10 . The worm shaft  48  acts in conjunction with drive feature  50  to effect the translation of the front wall  34  along the worm shaft  48 . It will be appreciated by those skilled in the art, however, that there are a multitude of alternate ways to accomplish the sliding action of the front wall, including, but not limited to, direct belt or chain drive, linear hydraulic or pneumatic actuators, etc.  
         [0019]    Discharging the parcels from the exemplary apparatus in the above-described manner makes it less likely that the contents of the container  12  will become caught in side of the container  12 . Furthermore, the gradual release of the parcels from the container  12 , a product of the sliding front wall  34 , will allow the parcels to be discharged in a metered or single layer, rather than in a pile or clump, therein allowing easier secondary process handling. Finally, the angled nature of the top of the front wall  34  provides a chute between the interior of the container  12  and the conveyor  28 , therein allowing a much more gentle discharge of the contents than simply dumping the parcels out. This characteristic has the result of causing less damage to the parcels during processing.  
         [0020]    It will be appreciated that the exemplary embodiment described and depicted in the accompanying drawings herein is for illustrative purposes only, and should not be interpreted as a limitation. It is obvious that many other embodiments, which will be readily apparent to those skilled in the art, may be made without departing materially from the spirit and scope of the invention as defined in the appended claims.