Abstract: A rectangular tubing, rectangular hole punching device includes a two-sided die carried by a mandrel upon which a rectangular tubing workpiece is sleeved. The two-sided die makes possible a punched rectangular hole having a width extending substantially from one interior lateral side wall of the workpiece adjacent the side of the workpiece being punched to the opposing interior side wall of the workpiece adjacent the side of the workpiece being punched, and includes a pair of tool steel die pieces that are longitudinally spaced from each other. The portions of lateral side walls corresponding to the position of the two sided die within the workpiece are supported against deformation from punching by applying a high compressive force to the portions of the laterally spaced side walls of the workpiece that are in correspondence with the position of the two-sided die, during the punching operation.

Abstract: A module of a filing cabinet houses in a pivotal-lid covered filing cabinet a pendent file. Four castors at respective corners retract upward into the housing for providing compact, fixed-location, vertically stackable storage of a plurality of such modules. With the castors extended a module can be drawn along behind the user at the end of a length of line, transporting heavy loads of documents held in the pendent file. A lever-powered spring-biased system actuated by lines holds the castors up-or-down as desired, and a key-lock may be used to secure the lid.