Abstract: An improved roll-up door assembly (10) is configured to be coupled to a storage container, such as a truck trailer (11), and broadly comprises: a roll-up door including a plurality of door panels (12A-12G), of which adjacent panels are hingedly coupled to one another; a hinge (29) having an first hinge plate (30) coupled directly to a bottom panel (12A) of the door, having a second hinge plate (31), and having a hinge joint (32) pivotally coupling the first and second hinge plates to one another for enabling relative movement therebetween; a bottom roller (33) coupled to the second hinge plate for movement therewith about the joint; a counterbalance mechanism mounted on the storage container; a cable (22) connecting the counterbalance mechanism to the bottom door panel; and a snubber (26) surrounding the cable and adapted to engage the counterbalance mechanism when the bottom door panel is moved toward the counterbalance mechanism.

Abstract: The present invention broadly provides a theft-resistant guard (20) for a roll-up door lock mechanism (21). The improvement broadly comprises: the guard (20) being non-removably mounted on the lock mechanism (21) for movement with the handle (29). The guard has a proximal marginal end portion (34) arranged to partially embrace the pivotal connection between the latch cam (24) and plate (23), has an intermediate portion (35) adapted to partially embrace the handle, and has a distal marginal end portion (36) adapted to partially embrace the hold-closed keeper (32) when the handle is in the closed position, such that the guard may not be readily removed from the lock mechanism.