fig9 the door 44 is larger than the opening 42 in the door frame 40 so that the door 44 overlaps with the door frame 40 and can therefore not open inwardly of the frame 30 the door 44 being mounted on the outside of the door frame 40 a latch 50 is slidably mounted on the door 44 so that it can be slid to engage a catch 52 mounted on the door frame 40 to selectively prevent the door 44 from opening relative to the door frame 40 keepers 53 are mounted on the door 44 in conjunction with a lever 53a mounted on the latch 50 allows the door 44 to be locked shut or open with a padlock and thereby provides control of use of the conveyor section a catch 53b mounted on the angle support 38a can also receive the latch 50 for latching the door 44 in an open position the entire door ledge assembly 32 is mounted on one side of the square sidewall 22 by means of stationary hinge supports 54a and 54b which are fixedly welded to a hinge pipe 58 which passes through a pipe 60 attached to the door ledge assembly 32 at an angle intersection of the ledge 34 and the door frame 40 to allow this assembly to rotate it can be seen in fig9 that both the ledge 34 and the door frame 40 are approximately the same size that is they have the same outer dimensions and this size is slightly larger than the side opening 30 so that as the door ledge assembly 32 rotates about the hinge shaft 58 the door frame 40 forms a stop against the inside of the sidewall 22 and the ledge.