Combination scaffold and ladder

Claim 1

A SCAFFOLD AND LADDER COMBINATION COMPRISING A PAIR OF VERTICALLY ADJUSTABLE SUPPORTS, A YOKE INCLUDING A CROSS MEMBER WITH TRANSVERSELY MOUNTED ENDS ON EACH SUPPORT, A LADDER INCLUDING RAILS AND A PLURALITY OF PIVOTALLY MOUNTED STEPS AND TO A TRANSVERSELY EXTENDING END OF ONE LENGTH AND WIDTH, CONTROL BAR MEANS PIVOTALLY CONNECTED TO EACH STEP AND TO TRANSVERSELY EXTENDING END OF ONE YOKE, MEANS TO PIVOTALLY CONNECT SAID RAILS OF SAID LADDER TO SAID ONE YOKE WHILE PREVENTING LONGITUDINAL MOVEMENT OF SAID LADDER WITH RESPECT TO SAID ONE YOKE, THE PIVOTAL CONNECTIONS OF SAID CONTROL BAR MEANS TO SAID STEPS AND TO SAID ONE YOKE BEING IN PARALLELOGRAM RELATION WITH RESPECT TO THE PIVOTAL CONNECTION OF EACH STEP TO SAID CONTROL BAR MEANS AND THE PIVOTAL CONNECTION OF EACH STEP TO SAID RAILS, AND MEANS ON THE OTHER YOKE SLIDABLE ALONG THE LENGTH OF THE LADDER AND COOPERATING WITH THE RAILS OF SAID LADDER TO PROVIDE FOR SUPPORTING SAID LADDER IN DIFFERENT ANGULAR POSITIONS WITH RESPECT TO SAID FIRST YOKE.