Abstract A film cartridge loaded in the conventional manner with a roll of motion picture film having a magnetic stripe on one surface of the film will clockspring in a radial direction and undergo displacement of some convolutions of the film in a direction parallel to the axis of the film roll if subjected to shaking or impacts during handling of the cartridge prior to use in a camera. When this occurs, friction between the displaced convolution and the adjacent convolutions of the film effectively prevents return of the stepped convolution to its original position. Subsequently, when film is to be pulled from the supply roll during operation of a camera or similar device in which the cartridge is positioned, the stepped convolutions can contact a wall of the cartridge defining the supply chamber in the cartridge and produce a frictional force that opposes normal unwinding of the film. This can result in improperly exposed film. This film stepping problem can be avoided by use of a pull tab which occupies the space between the film in the supply chamber and the cartridge cover and which is removed from the cartridge just prior to insertion of the cartridge in a camera.
In a film cartridge having walls defining a supply chamber for a roll of film or the like having a tendency to become sidestepped in an axial direction, the improvement comprising: a flexible pull tab received in a space between a roll of film in the supply chamber and a wall of the supply chamber so as to prevent sidestepping of the film, said pull tab having an end portion which extends toward the exterior of the cartridge, and said pull tab being removable through an opening in said cartridge.
Claim 2
Dependent Claim
90 words
In a film cartridge having walls defining a supply chamber for a roll of film or the like having a tendency to become sidestepped in an axial direction, the improvement comprising: a flexible pull tab received in a space between a roll of film in the supply chamber and a wall of the supply chamber so as to prevent sidestepping of the film, said pull tab having an end portion which extends toward the exterior of the cartridge, and said pull tab being removable through an opening in said cartridge.
Claim 3
Dependent Claim
22 words
In a film cartridge as in claim 1, the further improvement wherein the wall of the supply chamber comprises the cartridge cover.
Claim 4
Dependent Claim
24 words
In a film cartridge as in claim 1, the further improvement wherein said end portion extends through an exposure aperture of the film cartridge.
Claim 5
Dependent Claim
45 words
In a film cartridge as in claim 1, the further improvement wherein the pull tab comprises a bifurcated portion which extends on opposite sides of a supply post in the supply chamber, and said end portion extends from an exposure aperture of the film cartridge.