Abstract: A loading and unloading system for trucks and trailer has a conveyor belt extending along a bed of a truck or trailer between front and rear wind-up rolls. For loading the vehicle the conveyor belt is wound onto the front roll and for unloading the vehicle it is wound onto the back roll. In order to prevent the belt from being pulled off the respective rolls a control system is provided which has a follower engaging the outer surface of the belt wound on one of the rolls. When the roll attains a predetermined maximum or minimum diameter depending on the amount of belt wound thereon, the follower operates a hydraulic valve to terminate the drive for the belt. The control operates in one direction responsive to a maximum predetermined diameter and in the other direction responsive to a minimum predetermined diameter.

Abstract: An internally mounted rotary drum drive mechanism optimizes the space within a drum by utilizing a rim-mounted, motor-driven rotating gearbox for applying torque to the drum through a ring-type mounting flange releasably secured between the gearbox and an internal wall of the drum. Radial screws extend through oversize apertures in the wall of the drum for releasably attaching the gearbox to the drum. A motor mounting flange locates the motor in driving position adjacent the gearbox. The motor mounting flange is supported on a reactor tube extending out of the drum and the reactor tube is supported by an external anchor plate. The drive mechanism may be situated at one end of the drum, and a bearing assembly of similar character to the drive mechanism, but using a rim-mounted dummy gearbox, may be provided internally at the other end of the drum.