Apparatus for use in diffusion transfer copying

Claim 1

IN AN APPARATUS FOR USE IN COPYING BY THE SILVER COMPLEX DIFFUSION TRANSFER PROCESS GUIDE MEANS FOR GUIDING AN ASSEMBLY OF A LIGHT-SENSITIVE SHEET AND A RECEIVING SHEET ALONG TWO PREDETERMINED SEPARATE PATHS THROUGH A TANK HOLDING PROCESSING LIQUID, SHEETDRIVING MEANS COMPRISING ROTARY MEMBERS LOCATED AT THE ENTRY END OF THE TANK FOR INTRODUCING THE SHEETS IN SUPERPOSED RELATIONSHIP INTO THE TANK, AND MEANS FOR PRESSING THE SAID LIGHT-SENSITIVE SHEET AND THE SAID RECEIVING SHEET TOGETHER AT THE EXIT END OF THE SAID TANK, WHEREIN THE SHEETS ARE ORIENTED IN SUPERPOSED RELATIONSHIP WITH THE LEADING EDGR OF ONE PROJECTING FORWARDLY OF THE LEADING EDGE OF THE OTHER, IN COMBINATION, AN IMPROVED DELIVERY MECHANISM COMPRISING A FIXED ARCUATE SURFACE ONTO WHICH SAID ASSEMBLY IS MOVED ALONG A NORMAL PATH, SAID SURFACE CURVING GENERALLY LONGITUDINALLY OF SAID ASSEMBLY TO THAT SIDE OF SAID PATH CORRESPONDING TO THE SIDE OF THE ASSEMBLY OCCUPIED BY THE SHEET WITH THE PROJECTING LEADING EDGE, SAID SURFACE BEING ARRANGED ADJACENT THE EDGE OF SAID GUIDE PLATE WITH ITS GENERATRIX IN SPACED GENERALLY PARALLEL RELATIONSHIP TO THE PLATE EDGE, THE LONGITUDINAL EXTENT TO SUCH SURFACE BEING SUFFICIENT TO INCLUDE LOCI FOR TWO TANGENTIAL PLANES, THAT PLANE CONTAINING THE LOCUS NEAREST THE PLATE EDGE PASSING BELOW AND THE OTHER PASSING ABOVE SAID PLATE; A SHEET HOLDDOWN BAR COOPERATING WITH SAID SURFACE TO HOLD THE SHEETS THEREBETWEEN, SAID BAR HAVING ITS AXIS EXTENDING GENERALLY PARALLEL TO THE GUIDE PLATE EDGE AND BEING MOUNTED FOR PIVOTAL MOVEMENT GENERALLY ABOUT THE AXIS OF SAID SURFACE; AND MEANS FOR PIVOTING SAID HOLD-DOWN BAR FIRST TO SAID NEAR LOCUS TO DIRECT SAID SHEETS ALONG SAID FIRST PLANE AND THEN AFTER SAID PROJECTING LEADING EDGE OF SAID FIRST SHEET HAS PASSED UNDER THE EDGE OF SAID SURFACE BUT PRIOR TO THE PASSAGE OF SAID OTHER SHEET EDGE THEREOF FOR RETRACTING SAID BAR TO SAID SECOND LOCUS TO DIRECT SAID OTHER SHEET ALONG SAID SECOND PLANE.