Abstract: A simple lockup device for a sign having a square tubular extrusion for a post with grooved webs extending midway up the length of the interior of T-section sidewalls of the same, one sidewall web being slotted through its groove partially down from the top of the post for receiving the flange of a sign panel installed in interlocking relation therewith. A locking key bent of a rectangular strip of sheetmetal engages a vertical slot in the top of the panel flange at its middle and at its conjugate ends engages with the grooves in the webs on adjacent sidewalls of the post. A closing cap inserts four depending lugs in four corners of the top of the post in mounting on top of the same.

Abstract: A knockdown sign lockup device having a tubular interlocking ring for inserting in the top of a tubular signpost and engaging a slot in the top of a wing off the signboard extending within the tubular post for lockup of the signboard with the signposts.

Abstract: A knockdown advertising and display sign comprising a single setscrew for retaining a lockup cap which "buttons-up" the final assembly of the sign for simplifying set-ups and change of display panels and lowering manufacturing costs and for improving stability of the sign in the field by reducing its sensitivity to looseness of fit.

Abstract: A table-saw having dual guards, one being that for the saw to run the guard must always be in correct vertical and horizontal operating position covering the whirling saw blade, and the other being that the saw is automatically shut off after a waiting period in the event that the operator is not actually working at a sawing operation. There is a manual over-ride switch for hard-to-do jobs subject to the security of lock and key.