Multi-purpose folding ladder

Claim 1

A FOLDING MULTI-PURPOSE LADDER COMPRISING A PLURALITY OF LADDER SECTIONS, PAIRS OF HINGE MEANS PIVOTALLY CONNECTING THE ENDS OF ADJACENT LADDER SECTIONS OF SAID PLURALITY OF LADDER SECTIONS, THE PIVOTS OF SAID HINGE MEANS CONNECTED TO OPPOSITE ENDS OF EACH LADDER SECTION POSITIONED ON OPPOSITE SIDES OF THE LADDER PLANE TO ALLOW ZIGZAG FOLDING OF SAID PLURALITY OF LADDER SECTIONS, EACH OF SAID HINGE MEANS INCLUDING A PAIR OF LINK BOXES CONNECTED TO THE ENDS OF ADJACENT LADDER SECTIONS AND PIVOTALLY CONNECTED ADJACENT THEIR INNER ENDS WITH THE INNER ENDS DISPOSED IN OVERLAPPING RELATION WHEN SAID BOXES ARE PIVOTED IN AXIAL ALIGNMENT, A LATCH BAR CONNECTED INTERIOR OF ONE OF SAID LINK BOXES FOR MOVEMENT TRANSVERSE TO THE AXIS OF THE PIVOT AND EXTENDING THROUGH REGISTERED APERTURES IN SAID OVERLAPPING INNER ENDS TO LOCK SAID LINK BOXES AND LADDER SECTIONS IN AXIAL ALIGNMENT, A RETURN SPRING CONNECTED TO SAID LATCH BAR TO NORMALLY URGE IT TO THE LOCKED POSITION, SAID ONE LINK BOX HAVING SLOTS IN THE SIDEWALLS THEREOF EXTENDING PARALLEL TO SAID LATCH BAR, A LATCH RELEASE PIN EXTENDING TRANSVERSELY THROUGH SAID LATCH BAR IN SLIDING RELATION AND PROJECTING THROUGH SAID SLOTS, A PAIR OF BEVELED SURFACE PORTIONS CARRIED BY THE OTHER LINK BOX SLOPING INWARDLY FROM THE INNER END AND TERMINATING IN APERTURES THROUGH THE WALLS THEREOF, ONE OF SAID BEVELED SURFACE PORTIONS POSITIONED TO ENGAGE THE END OF SAID LATCH RELEASE PIN AND THE OTHER BEVELED SURFACE PORTION POSITIONED TO ENGAGE THE PROJECTING END OF SAID LATCH BAR AS SAID LINK BOXES AND LADDER SECTIONS ARE PIVOTED INTO AXIAL ALIGNMENT TO MOVE SAID LATCH RELEASE PIN RELATIVE TO SAID LATCH BAR AND RETRACT SAID LATCH BAR AND RELEASE PIN AGAINST THE FORCE OF SAID RETURN SPRING TO A RELEASE POSITION AND RELEASE THE SAME INTO ENGAGEMENT WITH THE APERTURES AT THE ENDS OF SAID BEVELED PORTIONS TO AUTOMATICALLY LOCK SAID LINK BOXES AND LADDER SECTIONS IN END TO END AXIAL ALIGNMENT.