1. In bulk mail handling apparatus for loading elongated mail bags from a loading dock into the load receiving area of an end loading transport vehicle backed into load receiving position adjacent the dock to dispose its end opening to receive the bags, with said apparatus including a wheeled conveyor assembly adapted to be mounted on the loading dock adjacent the load receiving position of the vehicle and providing conveyor means extending longitudinally thereof that has a width transversely thereof substantially spanning the transverse dimension of the vehicle area when said assembly is received therein, with said conveyor assembly extending longitudinally of said apparatus for alignment with the vehicle and its end opening in the load receiving position of the vehicle and mounted for movement into and out of the vehicle, said conveyor means presenting an upwardly facing load transporting surface defining a path of movement for the mail bags that extends longitudinally of said conveyor assembly between the unloading end of same at the forward end of said assembly and the load receiving end of same at the rearward end of said assembly, a nutting truck unloading device therefor comprising: a platform secured to the rearward end of said assembly for swinging movement about a horizontal axis between a general horizontal nutting truck receiving position adjacent the level of the wheel support engaging portions of said assembly wheels and extending rearwardly of said assembly rearward end, and an upwardly directed position, said platform when in its said receiving position being adapted to receive a loaded nutting truck thereon, means operably associated with said platform for discharging the nutting truck load onto the rearward end of said conveyor means, and means for releasably securing the nutting truck against tilting movement relative to said platform during operation of said load discharging means.

6. In bulk mail handling apparatus for loading elongated mail bags from a loading dock into the load receiving area of an end loading transport vehicle backed into load receiving position adjacent the dock to dispose its end opening to receive the bags, with said apparatus including a wheeled conveyor assembly adapted to be mounted on the loading dock adjacent the load receiving position of the vehicle and providing conveyor means extending longitudinally thereof that has a width transversely thereof substantially spanning the transverse dimension of the vehicle area when said assembly is received therein, with said conveyor assembly extending longitudinally of said apparatus for alignment with the vehicle and its end opening in the load receiving position of the vehicle and mounted for movement into and out of the vehicle, said conveyor means presenting an upwardly facing load transporting surface defining a path of movement for the mail bags that extends longitudinally of said conveyor assembly between the unloading end of same at the forward end of said assembly and the load receiving end of same at the rearward end of said assembly, a nutting truck and unloading device therefor comprising, in combination: a platform secured to the rearward end of said assembly for swinging movement about a horizontal axis between a general horizontal nutting truck receiving position adjacent the level of the wheel support engaging portions of said assembly wheels and extending rearwardly of said assembly rearward end, and an upwardly directed position, said platform when in its said receiving position being adapted to receive a loaded nutting truck thereon, a nutting truck adapted to be received on said platform and comprising a wheeled frame having open side and upstanding spaced apart planar end walls formed by smooth surfaced material between which mail bags are loaded, means operably associated with said platform for discharging the nutting truck load onto the rearward end of said conveyor means, and means for releasably securing the nutting truck against tilting movement relative to said platform during operation of said load discharging means, whereby, when said truck is received on said platform in said load receiving position thereof and said nutting truck discharging means is operated, said truck end walls facilitated discharge of the bag load from said truck.