Film cassette with pressure plate assembly latching system

A cassette for releasably holding a film unit and for locating it at an exposure position therein, said cassette comprising:

• a base section having a bottom wall portion including a first interior film bearing surface;
• a cover section, including a top wall portion having an aperture therein, being locatable in a closed position over said base section wherein said top wall portion is spaced a fixed distance from said first bearing surface and said aperture is in registration therewith, and wherein said base and cover sections cooperate to define a light sealed film withdrawal opening at one end of said cassette;
• a pressure plate assembly, including an exterior surface and a second interior film bearing surface, mounted on said cover section within and in covering relation to said aperture with said second bearing surface facing said first bearing surface for movement toward and away from said base section between a raised film release position wherein said facing bearing surfaces exert minimal pressure on the film unit therebetween to facilitate its withdrawal and a lowered pressure applying position wherein said second bearing surface is closer to said first bearing surface, than in said raised position, and they cooperate to apply a greater pressure to the film unit to locate it at said exposure position;
• means for biasing said pressure plate assembly toward said raised position;
• means for releasably latching said pressure plate assembly in said lowered position including a pair of latch members mounted on said cover section for movement between latching and unlatching positions;
• means for biasing said latch members toward their respective latching positions;
• and
• means on said pressure plate assembly for releasably holding said latch members in their said unlatching positions against the bias of said latch member biasing means when said pressure plate is in said raised position, for releasing said latch members for automatic movement to their said latching positions in response to movement of said pressure plate assembly to said lowered position, and thereafter responsive to movement of said latch members back to their said unlatching positions and the automatic movement of said pressure plate assembly back to said raised position caused thereby for again releasably holding said latching members in their said unlatching positions.