US3569700A — Rapid radiographic roll film changer having a pre…

Claim 1

Independent Claim 358 words

A rapid radiographic film changer for use in a diagnostic system that interposes an examination subject between an x-ray source and a film, said changer comprising: a. film feed and film takeup means connected by a film pathway; b. a film pressure platen that is adjacent and substantially parallel with a portion of the film pathway and is adapted to transmit an x-ray image to the exposure region of a film in the pathway; c. a sealed film compression chamber having a diaphragm which is expandable to press the exposure portion of a film against the platen when the interior of the chamber is subjected to gas pressure; d. a stationary film compression valve member having inlet and outlet ports, the inlet port communicating with a source of pressurized gas and the outlet port communicating with the interior of the compression chamber; e. a first rotary valve member having a first through port for conducting pressurized gas from the inlet port to the outlet port and the chamber when the ports of the stationary and rotary members begin to align, said rotary valve member also having a through exhaust port angularly spaced from the first port for conducting gas from the outlet port and the chamber when the exhaust port begins to align with said outlet port; f. a stationary film advancing valve member having inlet and outlet ports, the inlet port communicating with a source of gas pressure and the outlet port being adapted to discharge gas against film which extends beyond said pressure chamber; g. a second rotary valve member having a through port for conducting pressurized gas from the last named inlet port to the outlet port and to the film surface whereby to periodically propel the film and form a loop in the film when the second rotary valve member has a predetermined angular relationship with respect to the first rotary valve member; h. motor means; and i. means coupling said motor means and rotary valves for joint synchronous rotation, whereby to pressurize and exhaust said film compression chamber and sequentially project gas against the film to form said loop and advance the film.

Claim 2

Dependent Claim 358 words

A rapid radiographic film changer for use in a diagnostic system that interposes an examination subject between an x-ray source and a film, said changer comprising: a. film feed and film takeup means connected by a film pathway; b. a film pressure platen that is adjacent and substantially parallel with a portion of the film pathway and is adapted to transmit an x-ray image to the exposure region of a film in the pathway; c. a sealed film compression chamber having a diaphragm which is expandable to press the exposure portion of a film against the platen when the interior of the chamber is subjected to gas pressure; d. a stationary film compression valve member having inlet and outlet ports, the inlet port communicating with a source of pressurized gas and the outlet port communicating with the interior of the compression chamber; e. a first rotary valve member having a first through port for conducting pressurized gas from the inlet port to the outlet port and the chamber when the ports of the stationary and rotary members begin to align, said rotary valve member also having a through exhaust port angularly spaced from the first port for conducting gas from the outlet port and the chamber when the exhaust port begins to align with said outlet port; f. a stationary film advancing valve member having inlet and outlet ports, the inlet port communicating with a source of gas pressure and the outlet port being adapted to discharge gas against film which extends beyond said pressure chamber; g. a second rotary valve member having a through port for conducting pressurized gas from the last named inlet port to the outlet port and to the film surface whereby to periodically propel the film and form a loop in the film when the second rotary valve member has a predetermined angular relationship with respect to the first rotary valve member; h. motor means; and i. means coupling said motor means and rotary valves for joint synchronous rotation, whereby to pressurize and exhaust said film compression chamber and sequentially project gas against the film to form said loop and advance the film.

Claim 3

Dependent Claim 128 words

The invention set forth in claim 1 including: a. a potentiometer having a revolving shaft coupled for synchronous rotation with said rotary valve members, said potentiometer being adapted to produce an output electric signal whose magnitude is indicative of the angular position of the rotary valve members; b. a first solenoid valve connected to the inlet of the compression valve and a second solenoid valve connected to the inlet of the film advance valve, said first and second solenoid valves being opened in that sequence in response to the potentiometer signal attaining predetermined consecutive magnitudes before the first film in a series of films is exposeD, whereby all functions in an operational cycle of the film changer are started and maintained in a proper sequence and phase relationship.

Claim 4

Dependent Claim 194 words

A rapid radiographic film changer for use in a diagnostic system that interposes an examination subject between an x-ray source and a film, said changer comprising: a. a film compression chamber and a spaced apart platen located next to the pathway followed by the continuous sheet of film as it is advanced step-by-step through the changer; b. rotary valve shaft means having first, second and third diametrically through ports at different angles about the rotational axis, the first port being adapted to admit pressurized gas to the chamber when at a certain angle of rotation, the second port being adapted to exhaust gas from the chamber as the shaft means rotates further and, the third port being adapted to discharge pressurized gas against the film to form a loop in the film when the shaft means rotates still further, the said first, second and third ports operating in the stated sequence, respectively; and c. motor means mechanically coupled with the rotary shaft means to rotate the same, whereby the rotary valve means affect sequential expansion of the compression chamber, exhaust of the chamber and a gas blast against the film to advance the same.

Claim 5

Dependent Claim 194 words

A rapid radiographic film changer for use in a diagnostic system that interposes an examination subject between an x-ray source and a film, said changer comprising: a. a film compression chamber and a spaced apart platen located next to the pathway followed by the continuous sheet of film as it is advanced step-by-step through the changer; b. rotary valve shaft means having first, second and third diametrically through ports at different angles about the rotational axis, the first port being adapted to admit pressurized gas to the chamber when at a certain angle of rotation, the second port being adapted to exhaust gas from the chamber as the shaft means rotates further and, the third port being adapted to discharge pressurized gas against the film to form a loop in the film when the shaft means rotates still further, the said first, second and third ports operating in the stated sequence, respectively; and c. motor means mechanically coupled with the rotary shaft means to rotate the same, whereby the rotary valve means affect sequential expansion of the compression chamber, exhaust of the chamber and a gas blast against the film to advance the same.

Claim 6

Dependent Claim 99 words

The invention set forth in claim 3 including: a. first and second electrically openable valves having pressurized gas inputs and having their outputs respectively connected to supply gas to the first port for compression the chamber and to the port for discharging gas against the film, the first electrically operable valve receiving a control signal to open it before the rotary valve means reaches an angular position where it can admit gas to the chamber and the second electrically operable valve being operated thereafter so that film will be advanced when the compression chamber has been pressurized and exhausted.

Claim 7

Dependent Claim 50 words

The invention set forth in claim 4 including: a. a rotary shaft means angular position sensor adapted to produce an output signal corresponding in magnitude with the instantaneous angular position of the shaft means, operation of said electrically operable valves being in response to the signal level from said sensor.

Claim 8

Dependent Claim 125 words

The invention set forth in claim 3 wherein said film compression means comprises: a. a semiflexible annulus having a radially inwardly curved cross section; b. base means on which one end of the annulus is supported, said base means having a port for admitting pressurized gas to the interior of the annulus and for exhausting the same by means of the rotary valve means; c. a thin metal diaphragm sealed over the other end of the annulus and adapted to distend into the film pathway toward said platen when the annulus is pressurized; d. x-ray fluorescent screen means interposed between said platen and said diaphragm adjacent the film pathway, whereby distension of the diaphragm will compress the screen means and the film against the platen.

Claim 9

Dependent Claim 46 words

The invention set forth in claim 6 wherein said annulus has a plurality of circumferentially spaced axially extending slits whereby the curved cross section of the annulus may expand radially and thereby increase its axial dimension to enhance compression, and a pliable sealant covering said slits.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1974-03-08	1974-09-07	1975-03-09	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1978-03-08	1978-09-07	1979-03-09	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1982-03-08	1982-09-07	1983-03-09	$7700.00	Window Closed / Lapsed

Rapid radiographic roll film changer having a pressure platen actuated by air pressure

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