Abstract: An improved spring balancer (10) includes a shaft (13) rotatably mounted on a support (11). A first torsional spring (14) acts between the support and the shaft. A second torsional spring (19) acts between the support and a cable drum assembly (63) journalled on the shaft. A third spring (23) acts between the support and another cable drum assembly (26). A fourth cable drum (28) is fixed to the shaft. Four cables (141,142,143,144) are associated with the various cable drums (140,63,26,28) and are connected to a roll-up door (12). When the door is lowered, the various springs will absorb energy. When the door is raised, the various springs will give up energy.

Abstract: A ladder assembly is adapted to be mounted on a suitable support, such as a truck or trailer. The ladder assembly includes a ladder mounted on the distal end of a shaft. The shaft is slidably received in a cylinder. A pair of spaced abutment stops are provided on the support, and provide a recess to receive a portion of the ladder when the ladder is in its upright position. A spring urges the shaft and ladder to move toward the support along the axis (x--x) of the cylinder. The ladder is adapted to be moved between an upright position, at which a portion of the ladder is received in the recess between the abutment stops, and an out-of-the-way horizontal position.

Abstract: An improved roller assembly is provided for guiding movement of a beverage truck overhead door, and for preventing lateral misalignment of lettering or decals on the outside of such door. The improved roller assembly includes a roller, a dished washer, and a shaft. The shaft has self-tapping exteriorly-threaded shank portion, which is received in a hinge section of a door panel.

Abstract: An improved roller assembly is adapted for use with an upwardly-acting door structure. The improved roller assembly includes an inner ring mounted on a shaft, a sectional outer ring arranged to form an outer race for capturing ball bearings between the rings, and an outer cup-shaped member roll formed to hold the assembly together and to provide an outermost tire adapted to be moved along a track.

Abstract: An upwardly-acting door structure is adapted to close an access opening of a body member, such as an automobile-carrying railroad car. The door structure includes a stationary track on either side of the opening, movable tracks mounted for upward and downward movement along the stationary tracks, an upper panel mounted on the movable tracks, a lower panel mounted to move upwardly and downwardly along the movable tracks at twice the speed, flexible chains arranged to interconnect the lower panel with the movable tracks, torsional springs arranged to counterbalance and support the aggregate weight of the raised movable tracks, and handles operatively arranged to raise and lower the movable tracks. The upper and lower panels may be raised to uncover the access opening, or lowered to cover the access opening.