Expansion envelope with solid front and back panels

Claim 1

A FLATLY FOLDED ENVELOPE OF THE GUSSET TYPES ADAPTED TO BE EXPANDED TO PROVIDE A FLAT BOTTOM BOXLIKE CONTAINER, SAID ENVELOPE COMPRISING SUBSTANTIALLY RECTANGULAR FRONT AND BACK PANELS OVERLYING EACH OTHER, SIDE WALLS EACH HAVING EDGES CONNECTED WITH OPPOSITE SIDE EDGES OF THE FRONT AND BACK PANELS BY SIDE FOLDS, SAID SIDE WALLS EACH HAVING AN INTERMEDIATE REVERSE FOLD WITH RESPECT TO THE SAID SIDE FOLDS TO PROVIDE INWARDLY FOLDED SIDE WALL SECTIONS ONE OVERLYING THE OTHER BETWEEN SAID PANELS, ONE OF SAID WALL SECTIONS OF EACH SIDE WALL HAVING ITS LOWER EDGE FREE AND TERMINATING IN SUBSTANTIAL REGISTRY WITH LOWER EDGES OF SAID FRONT AND BACK PANELS TO BE COMPLETELY CONTAINED WITHIN BOUNDARIES OF SAID FRONT AND BACK PANELS, A BOTTOM CONNECTING THE LOWER EDGES OF SAID FRONT AND BACK PANELS BY TRANSVERSE LINES OF A FOLD AT SAID CONNECTIONS AND HAVING AN INTERMEDIATE TRANSVERSE FOLD DIVIDING THE BOTTOM INTO BOTTOM SECTIONS THAT EXTEND DOWNWARDLY FROM THE LOWER EDGES OF THE FRONT AND BACK PANELS IN OVERLYING RELATION AND CORRESPONDING WITH THE SIDE WALL SECTIONS IN THAT THEY ARE CONNECTED TO THE SAME PANELS, A SINGLE CORNER GUSSET JOINING WITH ENDS OF SAID OTHER WALL SECTION OF EACH SIDE WALL AND WITH THE CORRESPONDING BOTTOM SECTION OF FOLDS FORMING CONTINUATIONS OF SAID TRANSVERSE BOTTOM AND THE SIDE FOLDS, SAID SINGLE CORNER GUSSETS EACH HAVING A DIAGONAL LINE OF FOLD, AND TABS CONNECTED WITH THE SINGLE CORNER GUSSETS ON FOLDS FORMING CONTINUATION OF SAID INTERMEDIATE BOTTOM FOLD AND WITH ENDS OF SAID OTHER BOTTOM SECTION ON CONTINUATIONS OF THE LAST MENTIONED SIDE FOLDS, SAID SINGLE CORNER GUSSETS LYING FLATLY AND LOOSELY UPON THE ENDS OF THE SAID ONE BOTTOM SECTION IN PLANE WITH THE SIDE WALL SECTION TO WHICH THEY ARE CONNECTED AND SAID TABS BEING CONTAINED BETWEEN THE SINGLE CORNER GUSSETS AND THE ENDS OF THE SAID OTHER BOTTOM SECTION, SAID FRONT AND BACK PANELS BEING ADAPTED TO MOVE APART ON THE SIDE FOLDS AS ARTICLES ARE INSERTED AND THE SECTIONS OF THE BOTTOM BREAKING ON SAID TRANSVERSE FOLDS TO FLATTEN THE BOTTOM OF THE ENVELOPE, THE SINGLE CORNER GUSSETS BREAKING ON THE DIAGONAL FOLDS THEREOF AND PROVIDING TRIANGULAR PORTIONS OVERLYING EACH OTHER TO HOLD THE SIDE WALLS FROM BULGING OUTWARDLY FROM THE FOLDS AT THE ENDS OF THE BOTTOM SECTIONS WHILE THE FREE LOWER EDGES OF THE SAID ONE SECTION OF THE SIDE WALLS COOPERATE WITH SAID TABS TO PROVIDE SLIT-LIKE OPENINGS THEREBETWEEN FOR ESCAPE OF AIR DISPLACED BY THE ARTICLES AS THE ARTICLES SQUARE OUT THE ENVELOPE AND FORM A BOXLIKE CONTAINER AS THE ARTICLES CONTACT SAID BOTTOM, SAID CORNER GUSSETS TRAVERSING ONLY ONE-HALF THE WIDTH OF THE GUSSETED BOTTOM AND BEING THE ONLY CORNER GUSSETS EMPLOYED AT SAID BOTTOM THEREBY PROVIDING SAID SLIT-LIKE OPENINGS AT THE OTHER ONE-HALF OF SAID BOTTOM.