Method and apparatus for unloading bulk mail vans

In a facility for unloading discrete bagged and cartoned goods from the load receiving area of an end loading transport vehicle including an unloading dock having an unloading bay defining a load receiving shoulder equipped with a dock plate adapted to bridge the gap between the loading dock and the vehicle end opening when the vehicle is backed into load discharging relation with respect to the bay, and an elongate mobile unloading conveyor assembly mounted on the loading dock for movement along a rectilinear path between a retracted position on the loading dock in which the load receiving end of same is spaced from the dock plate inwardly of the loading dock and an extended relation for movement of the load receiving end of same across the dock plate into the vehicle load receiving area for having applied to the load receiving end of same the bagged and cartoned goods to be unloaded from the vehicle, and means for driving the conveyor to convey the bagged and cartoned goods received thereon onto the loading dock as they are applied to the conveyor load receiving end, the improvement comprising:

• a chassis connected to the unloading conveyor assembly adjacent its load receiving end and disposed in advance of same with respect to the unloading bay,
• said chassis journalling a pair of spaced apart wheels, on which said chassis rides for rotation about a common axis extending transversely of the movement path, with said wheels being spaced from the load receiving end of the conveyor assembly such that in the retracted position of the conveyor assembly, said chassis wheels reset on the loading dock between the conveyor assembly load receiving end and the dock plate,
• said chassis being connected to the conveyor assembly by being pivoted to the conveyor assembly adjacent its load receiving end for swinging movement relative thereto about a horizontal axis extending transversely of the unloading conveyor assembly,
• said chassis journalling an upright shaft for pivotal movement about an axis that is normal to the movement path,
• said shaft and said axis of said wheel being in coplanar relation in an upright plane extending normally of the movement path,
• said shaft having mounted on the upper end of same a conveyor head for movement about an axis extending transversely of said shaft axis,
• said head being cantilever mounted on said shaft to project over the dock plate when horizontally disposed in alignment with the movement path,
• an adjustable strut structure connected between the lower end of said shaft and said head for supporting said head cantilever fashion from said shaft and including means for adjusting the length thereof for adjusting the forward end of said head vertically,
• said head including an endless conveyor presenting an upwardly facing load receiving run and including means for driving said run to move toward the unloading conveyor,
• said endless conveyor having a load receiving ed adjacent the forward end of said head and a load discharge end at the other end of said head disposed to discharge the bagged and cartoned goods onto the load receiving end of said mobile conveyor when said head is substantially aligned therewith,
• said shaft being journalled for free swinging movement of same and said head about said shaft pivot axis, with sufficient static friction opposing said swinging movement to maintain said head and shaft at desired positions of manual adjustment angularly of said shaft pivot axis,
• said head carrying a bag shifting mechanism including:
• a manually maniputable bag gripping hand tool,
• a cable connecting said hand tool to said head adjacent one side of said head intermediate the ends of said head,
• said cable having sufficient length to permit said tool to be manually extended beyond the projecting end of said head for application to a bag to be shifted from a position of rest in the vehicle onto the head conveyor run, when the head has been positioned to be adjacent and directed toward the bag,
• means for drawing said cable longitudinally of said head to draw the bag onto the head conveyor run,
• and means for automatically releasing said tool from the bag when the bag is conveyed by said head conveyor run for manual application to another bag to be shifted onto said head.

In apparatus for unloading bagged goods from the load receiving area of an end loading transport vehicle onto an unloading dock, where the transport vehicle is backed into load discharging relation adjacent the dock to dispose its end opening to pass the bags therethrough, and including an elongate wheeled conveyor movably mounted on the loading dock for movement into and out of the vehicle and having on the forward end of same a cantilever mounted conveyor head having the load receiving end of same at the projecting end of the head, means for adjusting the position of the head load receiving end horizontally and vertically for individual alignment with individual bags stacked in the transport vehicle for transfer to the loader head, and means for moving said conveyor and conveyor head into the vehicle to receive individual bags as the vehicle is unloaded for conveyance to the loading dock, and for withdrawing the conveyor and conveyor head from the vehicle back onto the dock,

• a bag shifting apparatus for mechanically transferring individual bags from random positions, transversely of the vehicle, at rest within a stack of the goods in the vehicle to be unloaded, to the loader head and comprising:
• a manually manipulatable bag gripping hand tool,
• a cable connecting said hand tool to said head inermediate the ends of said head,
• said cable having sufficient length to permit said tool to be manually extended beyond the projecting end of said head for application in gripping relation to the bag to be shifted from a selected position of rest in the vehicle onto the head load receiving end when the head has been positioned to be adjacent and directed toward the bag,
• means for drawing said cable longitudinally of said head to draw the bag onto the head conveyor run,
• and means for automatically releasing said tool from the bag when the bag is conveyed by said head conveyor run for manual application to another bag to be shifted onto said head.

In apparatus for unloading a load of discrete and unpalleted bags of mail from the load receiving area of an end loading transport vehicle onto an unloading dock, where the transport vehicle is backed into load discharging relation adjacent the dock to dispose its end opening to pass the bags therethrough, and including an elongate wheeled unloading conveyor movably mounted on the unloading dock for movement into and out of the vehicle and having on the forward end of same a cantilever mounted conveyor head defining an upwardly facing load transport surface along the length thereof and having the load receiving end of said head at the projecting end of the head, means for adjusting the position of the head load receiving end horizontally and vertically for individual alignment with individual bags stacked in the transport vehicle for transfer to the loader head, with said conveyor head having a width on the order of no more than about one quarter of the width of the vehicle load receiving area whereby a worker station is defined on either side of the load receiving end of the conveyor head when the head is disposed within the vehicle load receiving area, and with the head having a length on the order of the vehicle load receiving area width and having its other disposed in load discharging relation onto the unloading conveyor, and means for moving said conveyor and conveyor head into the vehicle to receive individual bags as the vehicle is unloaded for conveyance to the loading dock and for withdrawing the conveyor and conveyor head from the vehicle back onto the dock,

• the method of mechanically moving the individual bags one at a time from their positions of rest within the vehicle onto the unloading conveyor, said method comprising:
• moving the unloading conveyor toward the vehicle to dispose the load receiving end of the conveyor head closely adjacent the first load depth unit of bags to be unloaded, and with the conveyor head positioned approximately at the longitudinal centerline of the vehicle and with the head load transport surface moving rearwardly of the vehicle at a predetermined rate,
• selecting a bag on the top of the first load depth unit and aiming the head projecting end at the visible portion of the underside of the selected bag, with the head disposed at a level that is below the bag so selected but which is within about a foot of the level of the underside of the bag so selected,
• pulling the selected bag rearwardly of the vehicle until the bag is moved sufficiently out of the bag load depth unit to drop on the head transport surface,
• utilizing the tractional engagement of the bag on the head transport surface to pull the remainder of the bag onto the head and convey same across the head onto the unloading conveyor,
• selecting the next bag of the load depth unit ad repeating said aiming, pulling, and utilizing steps to convey same onto the unloading conveyor,
• repeating said selecting, aiming, pulling, and utilizing steps on the remaining bags of the load depth unit to consecutively convey such bags onto the unloading conveyor, working bag by bag across the length of the bag load depth unit and downwardly of the bag load depth unit,
• repeating the moving step to dispose the load receiving end of the conveyor head closely adjacent the next bag load depth unit of bags to be unloaded,
• repeating the selecting, aiming, pulling and utilizing steps on each bag of the next bag load depth to consecutively convey the bags thereof onto the unloading conveyor,
• and for the remaining bag load depth units in the vehicle load receiving area, repeating said moving, selecting, aiming, pulling and utilizing steps to consecutively convey the bags thereof onto the unloading conveyor.