CA1122457A - X-ray unit - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Apparatus for use in taking chest or other X-rays, including a dispenser for the dispensing of one film sheet at a time and a film holder which receives the film sheet and holds it tightly between intensifier screens and which then releases the film sheet for developing.

Description

Title ~ -~
X-ray Unit ~echnical Field This invention relates, generally, to the exposure of X-ray ~ilm and, more particularly, to ~he handlin~ of such film in a daylight envixon-ment.
Back~ro~nd The image of an X-ray film can be enhanced by the use o intensiier screens lying intima~ely against opposite faces of the fil~.
Thic could be accomplished by the use of metal plates at opposite faces of the film-screen sandwich, except that a metal plate in fron~ of the ilm will block X-rays. It would be desirable to provide a simpLe and low cost device which could hold the film and screens ~ightly together in a unit during exposure and yet be opened to enable ~he dispensing of one film sheet at a time into a space be~ween the screens and tha sub~e-quent release o.~ the fiLm sheet therefrom a~ter exposure.
Disclosure of Invention In accordance with one embodiment o the present invention, an X-ray unit of relatively ~ .

~Z2~L57 simple design is provided, which can hold a film in intimate contact with intensifier scre~ns, and which enables the insertion of a film between the screens and the removal therefrom in 2 simple manner. The apparatus for holding the film against the intensifier screens includes a resilient backing plate behind the film-screen sandwhich and a flexible thin sheet lying in front of the film-screen sandwich, with the opposite sides of the flexible sheet fastened to a mounting frame. With the opposite sides of the flexible sheet held to the mounting frame, a vertical pressing member is moved against the middle of the backing plate to bend it forward and push the film-screen sandwich into a curve that holds the film and screens in intimate contact.
When the pressing member is moved back, a film sheet can be fed between the intensifier screens or an exposed film sheet can be allowed to drop out from between the screens by withdrawing supporting pins that would otherwise support the film.
Description of Drawings In the drawings, which occur in the order Fig. 1, Fig. 4, Fig. 6, Fig. la, Fig. 7a, Fig. 7b, Fig. 7c, Fig~ 2, Fig. 3, Fig. 5, Fig. 8, Fig. 13, Fig. 14, Fig. 9, Fig. 15, Fig. 16, Fig. 12, Fig. 10, Fig. ll:
Figure 1 is a partial perspective view of a chest X-ray unit constructed in accordance with the present invention, shown with a portion of the lighttight housing cut away;
Figure lA is a perspective view of a portion of the unit of Figure 1, showing the manner of construction of the exposure portion thereof;
Figure 2 is a paxtial rear perspective view of the unit o~ Figure 1, showing the mechanism thereof;
Figure 3 is a view taken on the line 3-3 of Figure 2;

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Figure 4 is a view taken on the line 4-4 of Figure 3;
Figure 5 is a partial view of the apparatus of Figure 3, showing the manner in which the pressing member operates;
Figure 6 illustrates three stages in the operation of the unit of Figure l;
Figures 7a-7c illustrate views taken on the line 7-7 of Figure 5, the three views showing ~he unit at different stages of its operation;
Figure 8 i5 an exploded pexspective view of the dispenser portion of the unit of Fig~re 1, showing a film magazine outside of the lS receiver;
Figure 9 is an exploded perspective view of the film magazine of ~igure 8;
Figure 10 is a view taken on the line 10-10 o~ Figure 8~ .
Figure 11 is a view ~aken on the line 1l-11 o Figure 10;
Figure 12 is a partial view o the di~penser por~ion o~ Figure 10, showing it in a condition wherein a film is almost completely dispensed from the apparatus;
Figure 13 is a view taken on the line 13-13 of Figure 10;
Figure 14 is a view taken on the line 14-14 of Figure 13;
Figure }5 is a view taken on the line 15-15 o~ Figure 8;
Figure 16 i9 a view taken on the line 16-16 o Figure 15.

Description of A aratus Fiq. 1 illustrates a chest X-ray unit 10 which includes a main frame 1~, an exposure apparatus 14 mounted along the frame for holding a sheet of film 16~ a dispenser 18 above the exposure apparatus for dispensing the film into the exposure apparatus, and an exposed ~ilm receiver 20 located below the exposura apparatus for xeceiving the exposed film.
The unit is prepared for operation by first loading a bulk film magazine 22 in~o a mag~zine-holding portion 24 of the dispenser. Then, a handle 26 on the main frame is pivoted to an upward position 26u to tip back a mounting frame 28 of the exposure apparatus 14 to a position for receiving a film from the dispenser, and a control on panel 30 is operatea to cause ~he dispensing of a ~ilm into the exposurs apparatus. After the film has been received, the handle 26 is moved into a downward position 26d which causes the ~ilm 16 to be held 20 in the exposure apparatus closely against the intensifier screens. A patient then can be posi~
tioned in front of a co~er 27 on the exposure apparatus 14 and an exposure made. Finally, the handle is moved up to i~s cen~ral position 26 and the film 16 drops down into the receiver 20.
Fig. 7a illu~trates ~he arrangement of elements adjacent to film 16 in the exposure station 14. T~e ilm 16 is sandwiched between a pair o~ intensifier .~creen~ 32, 34, and the ~creen and film sand~ich is, in turn, ~andwiched between a 1exible front ~heet 36 and a resilien~ backing plate 38. The screens can be permanently attached to the flexible sheet and pLate, respectivel~ In order to obtain a uniormly ull expo3ure o the film 16 using a minimal Le~el of X-rays, the Zg~5~
s intensifier screens 32, 34 must be held acewise against the film at all areas of the film. This must be accomplished without using a metal plate or other similar member in front of the film that could absorb a significant portion of X~rays.
Fig. LA illustrates the basic manner in which the film 16 is held tightly to all areas of the intensifier screens 32, 34. The backing plate 38 is constructed of a flexibly resilient material such as an 0.1 inch (~.54 mm) thick magnesium plate.
The front sheet 36 is constructed o a tough, -- ~ flexible plastic such as Mylar~ polyester film. ~he opposite sides 40 of the front sheet are wrapped somewhat more than 180 about a pair of vertical mounting rods 42. Each mounting rod is held in a hole presented by a pair of grooves 44, 46 formed respectively in inner and outer bars 48, 50 of the mounting frame 28. The extreme sides of the sheet 36 are wrapped about thin re~aining rods 52 which 20 more securely hold the side of the sheet about tha mounting rods 42. An elongated ver~ical pressing bar 54 extends behind the middle of the backing plate, halfway between the opposite sides of the front sheet. When the pressing bar 54 is moved for~
wardly, in the direction o~ arrow F, it bends the backing plate 38. Since ~he opposite sides 40 of the ~ront sheet 36 are prevented from moving for-wardly, the backîng plate, intensifier screens, film and front sheet a~e all pushed into a gentle curve (Fig. 7b), with the intensifier screens 32, ~4 and ~ilm 16 between them pressed into intimate con-tact at all areas of the ilm. The intensifier screens then can aid in achieving uni.formly full exposure of the film. O course, it would be possi-b}e to fix the position of the pressing bar 54 and instead move back the opposite sides of the frontsheet.
The pressing or pu~her bar 54 is a~ached ~o a forward channel memb~r 56. As shswn in Fig. 5, the channel member 56 carries a pair of rollexs 58, 60 which bear against a rearward channel member 62.
The rearward channel member 62 has a pair of inclined slots 64, 66 at its upper and lower ends which receive a pair o cam members 68, 70 fixed to the mounting ~rame. In addition, a chain 72 is provided to pull down the rearward channel member 62 against the bias of springs 73 ~Figs. 2 and 3).
Springs 73 extend between the fixed rod that mounts cams 68 and a rod 75 that extends through the flanges of channel 62. When the channel member 62 is pulled down, the cams 68, 70 force the rear-ward channel member to move forward, to push the rsllers 58, 60 forward~ and therefore to move ~he forward channel member 56 and pusher bar-54 ~or-wardly.
Fig. 2 shows that the hain 72 that pullsdown the rearward channel member 62 extends around a rotatable pulley 74 and up ~o a tensioning pulley 76. The tensioning pulley 76 is ~ixed to an operating shaft 78 ~o which the handle 26 is fixed. Thus, when the handle 26 is moved down-wardly, the chain 72 is pulled to cause the ~i~m and the intensifier sheets to be bowed ou~wardly and into intimate contact.
Fig. 6 show~ the three positions 28a, 28b, 28c of the mounting rame. ~t 28a~ the top o the mounting rame is til~ed back to receive the ilm 16. At position 28b, the mounting ~rame is vertical and the intensiier screens are held tightly against the film in preparation ~or exposure L5~

of ~he ~ilm. At 28c, the mounting frame is ver~i-cal, but the film is looseLy disposed between the intensifier screen~ so that the film 16 can drop down between a pair of rollers 80 in film receiver 20.
Fig. 3 sh~ws a cam 82 which i~ fixed to the operating shaft 78 and which controls backward pivoting of ~he mounting frame 23. When the handle 26 is ~urned to position 26u, shaft 78 rotates and the cam 82 assumes position 82a; then, the mounting frame 28 can pivot back about an axis 84 to the posi~
tion Z8a. At that position, the space between the intensifier scre~ns is aligned with a guideway 86 through which a sheet of film is dispensed. Sprlngs }5 88 bias the top of the mounting frame rearwardly to assure such tipping. When the shaf~ 78 is turned so that th~ cam is at position 82, the c~m forces the mounting ~rame upri~ht. However, even at the cam position 82, the shaft 78 is not ~urned far enough for the chain 72 to be pulled tight. Whe~
the shaft 78 i5 turned so the cam is at position 8~b, the cam still holds thé mounting frame upright, . but the tensioning wheel 76 on the shaft is then rotatqd far enough to pull the chain 72 tightly enough to pull down the rearward channel member 62 so as to causa its ~orward mo~ement that holds the film in Lntimate contact with the intensifier screen~. Af~er exposure of a film, the handle 26 and cam 82 are moved to their middle position and, as shown in Fig. 7c, a pair o~ 11m holding pins 83 are moved back to allow the ilm 16 to drop into the exposed ~ilm receiver 20 ~Fig. 1).
Pins 83 extend laterally from arms 87 that are pivoted on a sha~t 89. Arms 87 have tabs that engage stops on cakches 90 that are pivoted ~Z2~

on a shaft 91. As channels 56, 62 are moved rearwardly, ater an exposure, catches 90 pivot arms 87 sufficientLy to move pins 83 out from beneath the exposed f~lm 16 ~Fig. 7c). After the exposed film has dropped to receiver 20, the operating handle can be moved to position 26u.
With the mounting frame in position 28a, another film can be dispensed through ~uideway 86. As the frame moves to position 28a, the ends of catches 90 engage shaft 78 and the catches are pivoted sufficiently to move the stops away from the ~abs ---on arms 87. When freed in this manner, arms 87 swing forwardly in response to the action of springs 92 and pins 83 move into th~ir film-supporting position (Fig. 7a). When a film has been dispPnsed, the operating handle i5 moved to position 26d. As the handle moves, the channels 56, 62 move forward, a~d the screens move together (Fig. 7b). During ~hese movem~nts, the stops on catches 90 fall i~
behind the tabs on arms 87. With the handle i~
position 26d, the intensifier screens 32, 34, with ~he film 16 therebetweenr can lie a~ least about three inches forward o the dispenser 18, or at least ~he bottom por~ion thereof, where the head of a patient would be positioned during the taking of a chest X-ray.
Following an exposure, handle 26 is moved to its central position. Rearward movement o~ channels 56, 62, responsive to the action of springs 73, also move3 catches 90, arms 87 and pins 83 rearwardly. As noted previously, withdrawal o~ the pins 83 ~Fig. 7c) releases the exposed ~ilm to receiver 20.
Figs. 8-16 illustrate details of the film dispenser 18 which dispenses one film at a ~ 5~;7 time into the exposure apparatus. As shown in Fig. 8, the holding portion 24 of the dispenser has a cover 100 that can be swung open to xeceive the film-holding magazine 2Z. The ~ilm magazlne 22 has a lid 102 at the top that can be opened to receive a stack of film sheets in a darkroom and which then can be closed to make the magazine lighttight. As the magazine 22 is installed in the holding portion 24, it encounters a pair of pins 104 that open a light seal at the bo~tom a~d a receptacle 106 that receives a mating plug on the ---mag~zine. Fig. 10 illustrates the light seal lO~
at the bottom of the magazine 22, and shows the pair of rods llO that are attached to the light seal. Fig. 12 illustrates ~he magazine 22 installed in the holder portion 24 of the dispenser, showing how the pins 104 an the holder depress the rods llO to slide ~he light seal 108 against biasin~
of springs 112 so tha~ a film sheet 16 can pass down through the dispenser~
- As illu~trated in Fig. 10, the magazine 22 includes a vertical pusher plate 114 whose upper end carries a pair of guides 116 that can move forwardly along downwardly inclined guide-ways lI8 in a pair of guide plates 120. Thepusher plate 114 is therefore urged by gravity to move forward, to push a stack of film 16S forwardly and down along an inclined support plate 122. As the ~ilm moves forward and down ~he support plate 122, the frontmoRt film i9 caught between a dispenser roller 124 and blocks 126 at the bottom o~ the pusher plate. The blocks 126, which are especially uqeful for pushing the last ~ilms of the stack into the roller, are constructed of low friction material such as a Delrin~ acetal resin.

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The low friction material of the blocks 126 aids them in sliding down alony a lower support plate 127 and in assuring that when the blocks push the last film against the drive roller 124 the blocks do not retard the film from moviny down.
The forward edge 122e o~ ~he upper support plate 122 is accurately spaced from the drive roller 124 to form a throat 12~ betwe~n them that penmits only one sheet to pass down ~hro~gh the throat. Thus, for ilm sheets of ten mils (thousandth of an inch or 0.0254 mm) thickness r ~~~~
khe edge 122e may be spaced a dista~ce such as twelve mils ~0.0305 mm) from the roller. Also the edge 122e may be formed of a low friction material such as a Teflon~ fluorocarbon resin to facilitate the passage o~ film thereby.
The magazine is normally loaded with film in a darkroom by laying ~he holder horizon-tally and then laying a stack of film on the p-usher pla~e 114. When the holder is tu~ned to the vertical as shown in Fig. 10, or is moved around, it is possible ~or more than one sheet to be pushed into the space above the support plate edge 122e and the drive roLler 124. In order to avoid jamming of film, a backup member 128 is provided which can push the stack of film rearwardly, to push back sheets which have started to gather in and above throat space 129 and the roller. The backup member 128 is pivotally mounted at 130 and ha~ a button 132 protruding ~rom the ~ilm holder housi.ng to enable a technician to press the button a~ter he has loaded the ma~azine 22 in holding portion 24.
The backup member is also useul in that when its e~d 128e pushes back the stack and quickly releases it, the member bends the sheets and "shakes up" the ~ z~

stack. Any film sheets which have not ~allen down firmly onto the support plate 122 will do so, and the film sheets will lie in a more uniform arrangement for reliable dispensing.
When the film maga~ine 22 has been installed in the holding portion 24 of dispenser 18, a drive pin 134 (Fig. lS) at the end of the drive roller 124 lies in the pa~h o~ a dri~e tab 136 which lies on a motor ~riven wheel~ When a proper button on the control panel 30 of the unit is deprassed, the drive roller 124 is rotated, as indicated in Fig. 10, to move down one ~ilm sheet past a microswitch 138, the thin arm of the micro-switch deflecting out of the way of the film. The film then passes through a guideway 140 and through the guideway 86 into the exposure apparatus 14.
Microswitch 138 is connected to a power source and to control panel 30 through receptacle 106.
The combination of the support plate edge 122e which is accurately spaced from the roller 124, the pusher plate 114 which holds the film upright and gently push~s it against the roller, and the bac~up member 128 which can push back and slightly bend the stack to help avoid sticking of the sheets to one another, all combine to assure regularity and evenness in the stack and therefore reliable feeding of only one shee~ a~ a ~ime past the roller. If a sheet is not fed, which is sensed by lack of operation of the microswitch 138, the technician ~an back up and slightly bend the stack once or twice, and again operate the roller to dispen~e a ilm sheet. Thus, by assuring that the sheets are well positioned in the magazine, uniorm dispensing o~ the sheets is achieved.

Accordlngly, the in~ention provides an X-ray unit which enables the daylight loading of one sheet at a ~ime into an exposure station and the tigh~ holding of that film shPet to in~en-sifier screens at the exposure station, all witha relatively simple and low cost apparatus. The close holding of the ~ilm sheet to the intensifier screens i5 accomplished by the use of a flexible plastic sheet, whose opposite sides are securely held, a resilient backing plate, and a pressing bar that pushes along the center line~ of the resilient backing plate to de~orm it forwardly.
The mounting frame that holds the flexible front sheet, backing plate, and pressing bar is pivotally mounted to enable its top to pi~ot back to xeceive a new sheet of ~ilm from a dispenser located far enough behind the exposure station to avoid interferenc with the taking of chest X-rays.
The combina~ion of a pusher pl~te and backup member 2û whi~h assurP a uniformly held s~ack or ~ilms sheets, allows for reliable dispensing of one sheet at a time.

The application is a division o~ copending Canadian Serial No. 305 242, filed 1978 June 12.

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Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Apparatus for receiving a stack of film sheets and dispensing one film sheet at a time, comprising:
a housing having a region for holding a stack of film sheets wherein each film sheet extends in a largely vertical plane;
a roller at the lower end of said housing;
means spaced slightly from said roller to normally allow only one film sheet at a time to pass by said roller;
and a backing device disposed in said housing with a lower end thereof on a side of said region opposite said roller, said backing device being urged to move so its lower end moves toward said roller to push a film sheet against said roller.

2. The apparatus described in Claim 1 wherein:
said means spaced slightly from said roller includes a support plate with slots therein; and said backing device includes a low friction portion at the bottom thereof having fingers extending through said slots in said support plate and having a low friction forward portion which moves close to said roller to press a last film of a stack against said roller.

3. The apparatus described in Claim 1 including:
a backup member movably mounted on said housing and having a stack-engaging portion which can push against the stack of film from a side thereof opposite said backing device, to push the film sheets away from the roller.

4. The apparatus described in Claim 1 wherein the housing is a lighttight housing, the housing having a sup-port surface which defines the region that holds the largely vertical stack of X-ray film sheets, and wherein the means spaced slightly from the roller defines a narrow throat at the bottom of the stack through which only one film sheet at a time may pass, further comprising:
a backup member movable against the stack of film sheets to move the stack away from the throat, the member then movable quickly away from the stack, whereby to shake up the stack so the film sheets will lie in a more uniform manner.

5. The apparatus described in Claim 4 wherein:
said support surface extends at a downward incline toward said throat and has a plurality of slots, and including:
pusher plate means lying on a side of the film stack opposite the backup member, and having a lower end with fingers extending through said slots in said support surface, for urging the film sheets toward the throat.