Portable duplex vacuum type film holder

Claim 1

A PORTABLE VACUUM TYPE HOLDER FOR A PAIR OF THIN SHEETS OF FLEXIBLE PHOTOSENSITIVE FILM HAVING TOP, BOTTOM AND SIDE EDGES, SAID HOLDER BEING ADAPTED FOR INSERTION INTO A CAMERA AND FOR RETENTION THEREIN MEANS FOR INTERFITTING PARTS, SAID HOLDER COMPRISING: (A) A FRAME MEMBER HAVING TOP AND BOTTOM CROSS PIECES AND A PAIR OF SIDE RAILS; (B) MEANS TO HOLD THE TOP AND BOTTOM EDGES OF SAID SHEETS; (C) A VACUUM CHAMBER DISPOSED WITHIN SAID FRAME MEMBER, (A) SAID CHAMBER COMPRISED OF SUBSTANTIALLY FLAT, SPACEDLY OPPOSED FRONT AND REAR SURFACES, EACH OF SAID SURFACES HAVING A PLURALITY OF APERTURES THERETHROUGH; (D) SHEET HOLDING MEANS SPACED FROM SAID FRONT AND REAR SURFACES OF SAID CHAMBER ADAPTED TO RETAIN THE MIDDLE PORTION OF THE SHEET SIDE EDGES PROXIMATE TO SAID SURFACES IN THE ABSENCE OF VACUUM; AND (E) COUPLING MEANS IN COMMUNICATION WITH SAID CHAMBER, SAID COUPLING MEANS ADAPTED FOR THE APPLICATION OF A VACUUM WHEREBY A PAIR OF THIN, FLEXIBLE SHEETS OF PHOTOSENSITIVE FILM ARE FIRMLY HELD SUBSTANTIALLY FLAT AGAINST SAID FRONT AND REAR SURFACES OF SAID CHAMBER.