Film changer
First Claim
1. A medical film exposure device for an x-ray apparatus, which comprises:
- a film backing plate and a film pressure plate for receiving unexposed sheets of film therebetween in sequence for exposure of the films;
means for moving the pressure plate between film clamping and unclamping positions relative to the backing plate, the means for moving the pressure plate causing the pressure plate to initially clamp a center portion of one of the unexposed sheets of film and then progressively clamp the remainder of the one of the unexposed sheets of film outward from the center portion as it moves the pressure plate from the unclamping position to the clamping position;
film feeding means for essentially simultaneously feeding one of the unexposed sheets of film between the film backing and pressure plates, and one of the exposed sheets of film from between the film backing and pressure plates, when the pressure plate is in the film unclamping position;
a continuously running drive motor; and
a single revolution clutch for connecting the drive motor to the pressure plate moving means and the film feeding means, to cause, sequentially, the moving of the pressure plate to the film unclamping position, the essentially simultaneous feeding of the unexposed and exposed films, and the moving of the pressure plate back to the film clamping position.
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Accused Products
Abstract
Disclosed is a film feeding mechanism for use during medical x-ray techniques, particularly angiography. Sheets of film are fed sequentially at high speed from a film magazine into a film exposure device, and then into a film receiving cassette, in a manner so as to reduce damage to the films, including the build-up and discharge of static charge on the films. In the film exposure device, a free-floating lower clamping assembly clamps each film against an upper clamping assembly from the center of the film progressively outward towards its leading and trailing ends, to eliminate wrinkling of the film. The upper clamping assembly is of thin construction so as to enable the locating of an object being x-rayed closely adjacent the x-ray film, to produce x-rays of exceptionally high resolution. Feed-in wheels and pinch rollers drivingly engage one of the exposed films after an exposure operation prior to the film being engaged by feed-out wheels and pinch rollers, so as to buckle or peel the exposed film away from the upper clamping assembly and thereby precluding sticking of the film to the assembly. Film jamming in the film exposure device is reduced by a sensing device for detecting film misfeeds, driving the feed-out wheels faster than the feed-in wheels, and by selectively deactivating a film feeding mechanism. An optical type indicia forming device, including an electronic display, produces readily readable white indicia on the films on a dark background. A film-receiving cassette, including a spirally arranged inner guide plate, receives and stores exposed films in a relatively small space for subsequent developing.
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Citations
24 Claims
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1. A medical film exposure device for an x-ray apparatus, which comprises:
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a film backing plate and a film pressure plate for receiving unexposed sheets of film therebetween in sequence for exposure of the films; means for moving the pressure plate between film clamping and unclamping positions relative to the backing plate, the means for moving the pressure plate causing the pressure plate to initially clamp a center portion of one of the unexposed sheets of film and then progressively clamp the remainder of the one of the unexposed sheets of film outward from the center portion as it moves the pressure plate from the unclamping position to the clamping position; film feeding means for essentially simultaneously feeding one of the unexposed sheets of film between the film backing and pressure plates, and one of the exposed sheets of film from between the film backing and pressure plates, when the pressure plate is in the film unclamping position; a continuously running drive motor; and a single revolution clutch for connecting the drive motor to the pressure plate moving means and the film feeding means, to cause, sequentially, the moving of the pressure plate to the film unclamping position, the essentially simultaneous feeding of the unexposed and exposed films, and the moving of the pressure plate back to the film clamping position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A medical film exposure device for an x-ray apparatus, which comprises:
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means for clamping a sheet of film in a exposure position; means for moving the clamping means in a film clamping-to-unclamping-to-reclamping cycle of a preselected fixed time period, the means for moving the clamping means causing the clamping means to initially clamp a center portion of a sheet of film and then progressively clamp the remainder of the sheet of film outward from the center portion as it moves the clamping means from an unclamping position to a clamping position; means for feeding sheets of film into and out of the exposure position at a fixed feed cycle time during the film clamping-to-unclamping-to-reclamping fixed time period; a continuously running, constant speed drive motor; and a single revolution clutch for connecting the drive motor to the film clamping means and the film feeding means, the single revolution clutch being selectively operable at different time intervals to vary the film processing rate. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification