Film cassette for radiographic apparatus

Claim 2

A cassette for use in radiographic apparatus, comprising: an upper lid and a lower lid, both comprised of a quadrilateral thin plate and having flat surfaces, said lower lid having an aperture extending therethrough; a packing having a base portion fixed to said a flat surface of said lower lid, a projection extending from said base portion and a flexible lip having an upper portion overlaying a lower portion thereof and extending beyond said projection, a space being defined by said flat surfaces of the upper and lowerlids and also by said packing for containing a film and intensifying screens, said lower lid defining a passageway between said aperture and said space; and valve means positioned within said aperture for selectively sealing said space from the external atmosphere and allowing the space to communicate with the external atmosphere, said valve means comprised of a valve seat, said valve seat defining lower and upper chambers in said aperture, a valve body positioned in said lower chamber, a shaft coupled to said valve body and upwardly extending therefrom into the upper chamber, a push button coupled to said shaft and housed in the upper chamber, and a coil spring disposed between said push button and said valve seat, said coil spring biasing said valve body against said valve seat.

Claim 3

A cassette for use in radiographic apparatus, comprising: an upper and a lower lid, both comprised of a quadrilateral thin plate and having flat surfaces, said lids each having opposing surfaces and external surfaces, said lower lid defining a pressing plate receiving recess in the external surface thereof, a valve plate receiving recess within the pressing plate receiving recess, a channel outlet through the valve plate receiving recess, and a through hole within the valve plate receiving recess and extending through said lower lid, said through hole being adjacent the channel outlet; and a valve seat receiving depression around the through hole; a packing fixed to the opposing surface of said lower lid and having a proximally-facing peripheral surface upwardly protruding therefrom, said opposing surfaces of said upper and lower lids and said proximally-facing peripheral surface defining a space in which a film and intensifying screens may be positioned, said space being in communication with the through hole; and valve means provided on the lower lid for selectively sealing the space from the external atmosphere and for placing the space in communication with the external atmosphere, said valve means comprised oF a valve plate adapted to be received in the valve plate receiving recess, said valve plate having a hole therein communicating with the channel outlet, a pressing plate adapted to be received in the pressing plate receiving recess, said pressing plate having a hole therein communicating with said channel outlet and having a long slot at a location corresponding to the channel outlet and the through hole, and a valve seat positioned within the valve seat receiving depression, said valve seat having a hole therein communicating with the through hole.

Claim 4

A cassette for use in radiographic apparatus, comprising: an upper and a lower lid, both comprised of a quadrilateral thin plate and having flat surfaces, said lids each having opposing surfaces and external surfaces, said lower lid defining a pressing plate receiving recess in the external surface thereof, a valve plate receiving recess within the pressing plate receiving recess, a channel outlet through the valve plate receiving recess, and a through hole within the valve plate receiving recess and extending through said lower lid, said through hole being adjacent the channel outlet; and a valve seat receiving depression around the through hole; a packing fixed to the opposing surface of said lower lid and having a proximally-facing peripheral surface upwardly protruding therefrom, said opposing surfaces of said upper and lower lids and said proximally-facing peripheral surface defining a space in which a film and intensifying screens may be positioned, said space being in communication with the through hole; and valve means provided on the lower lid for selectively sealing the space from the external atmosphere and for placing the space in communication with the external atmosphere, said valve means comprised oF a valve plate adapted to be received in the valve plate receiving recess, said valve plate having a hole therein communicating with the channel outlet, a pressing plate adapted to be received in the pressing plate receiving recess, said pressing plate having a hole therein communicating with said channel outlet and having a long slot at a location corresponding to the channel outlet and the through hole, and a valve seat positioned within the valve seat receiving depression, said valve seat having a hole therein communicating with the through hole.

Claim 5

A cassette according to claim 2, further comprising a wall formed on a flat surface of said lower wall and extending at the respective side edges of the lid, and guide means formed on said a flat surface inside said wall in spaced parallel relation therefrom, a gap being defined between said guide means and said wall, said packing being provided in said gap.

Claim 6

A cassette according to claim 2, further comprising a flexible lip outwardly extending from the base portion of said packing at a location where said packing is fixed to the opposing surface of the lower lid, and a projection extending from the top surface of said base portion.

Claim 7

A cassette as recited in claim 2, further comprising a plurality of pivotable engaging means provided on the lower lid and adapted to clamp the upper lid to the lower lid when the upper lid is closed onto the lower lid, said pivotable engaging means being provided in spaced relation with each other on one side edge of the lower lid, said engaging means each having a bifurcated cross section, peripheral end portions of the lower lid being adapted to be received in one end of each of the engaging means, said one end of each said engaging means being pivotably secured by a pin to a peripheral end portion of the lower lid, and an open free end of each said pivotable engaging means being adapted to receive both the lower and upper lids when the upper lid is in its closed position.

Claim 8

A cassette as recited in claim 2, wherein said packing has a plurality of indentations formed in its base portion where said packing is fixed to the opposing surface of the lower lid, projections extending from said indentations and recessed grooves being located between adjacent projections, said projections each having a triangular cross section, the hypotenuse of this triangular shape facing said space containing film and intensifying screens.

Claim 9

A cassette according to claim 2, in which said upper and lower lids are movably coupled together at one side by hinge means.

Claim 10

A cassette according to claim 2, in which said pressing plate-receiving recess and said valve plate-receiving recess of said valve means have engaging portions, respectively, and said pressing plate and said valve plate have guide portions complementary in shape with those of said engaging portions, thereby enabling these guide portions to receive said engaging portions of said recesses, respectively.