X-ray photographing machine using sheet films

Disclosed is an X-ray photographing machine in which an unexposed sheet film magazine and an exposed sheet film magazine mounted on a movable frame are located in offset positions relative to an axis extending along a rectilinear path of a carrier to transfer a sheet film to an exposure station, the longitudinal axes of the magazines extending in parallel with each other and substantially at right angles to the axis along the carrier path. A sheet feed mechanism is disposed in a space defined by the respective axes of both these magazines and of the carrier path.

BACKGROUND OF THE INVENTION 
This invention relates to an X-ray photographing machine in which a number 
of unexposed sheet films are taken out one by one from a supply magazine 
containing such films, and carried into a film carrier in a stand-by 
position by means of a feed mechanism, the carrier is moved from the 
stand-by position to an exposure position, where it is exposed to X-rays 
for X-ray photographing and returned to the stand-by position, and then 
the film is carried into an exposed film takeup magazine by means of the 
feed mechanism. 
Having various advantages, such as faster operation and ease of 
post-photographing treatment, over those which employ roll films or films 
each contained in a holder of their own, X-ray photographing machines 
using such sheet films or cut films have recently come to enjoy wider use. 
Nevertheless, conventional machines of this type have hitherto been subject 
to several shortcomings, requiring positive improvement. As a premise for 
the description of this invention, therefore, there will now be described 
in brief a prior art X-ray photographing machine using sheet films and 
problems involved therein. 
FIG. 1 shows an outline of the prior art X-ray photographing machine using 
sheet films. In this drawing, there are shown a movable frame a of the 
machine, a support frame b to support the frame a, a table top c bearing 
an examinee d, an X-ray source e, and an image intensifier f disposed on 
the opposite side of the examinee d to the X-ray source e and mounted on 
the movable frame a. 
The movable frame a is capable of general rotation round the examinee d in 
a body with the support frame b as indicated by an arrow g, slide movement 
in the longitudinal direction of the examinee d (or at right angles to the 
plane of the drawing), and vertical motion as indicated by an arrow h 
independent of the support frame b, whereby the movable frame a approaches 
and goes away from the examinee d. 
A rectilinear path j for a film carrier i defined inside the movable frame 
a, and the carrier i is normally located in a stand-by position 1 at a 
considerable distance from an exposure position k. A film supply magazine 
m and a film takeup magazine n are disposed on the opposite side of the 
stand-by position 1 to the exposure position k. Unexposed sheet films p in 
the supply magazine m are drawn out one by one by means of a vacuum sucker 
q, and delivered into the carrier i by means of paired rolls r. Exposed 
films are collected from the carrier i returned to the stand-by position 
into the takeup magazine n through a guide path s by means of the paired 
rolls r. A transfer plate t is switched with every forward or reverse 
feed. 
In the prior art machine of FIG. 1, the movable frame a is relatively long, 
since the magazines m and n are disposed substantially on the extension of 
the carrier path j, that is, they are in line with the stand-by position 1 
and the exposure position k, and that the space between the stand-by 
position 1 and the exposure position k is made considerably wide enough to 
prevent the unexposed film in the carrier i from what is called X-ray fog 
in the stand-by position. 
Such elongated movable frame a would present the following problems. 
(1) Since the movable frame a forms a cantilever structure on the support 
frame b, the longer the frame a, the greater the demand for the 
strengthening of the connection between the movable frame a and the 
support frame b, as well as of the frame a itself, and for the complicated 
structure and increased overall machine size. In particular, mounted near 
the free end of the frame a weighing considerably heavy, the image 
intensifier f has a great influence on the frame structure. 
(2) Since the space between the stand-by position 1 and the exposure 
position k is wide, the transfer distance of the carrier i is long, thus 
increasing loss of time for the transfer. As a result, many opportunities 
of photographing may probably be missed. 
As for the magazines m and n, they involve the following problems. That is, 
as mentioned before, the movable frame a is located in positions at varied 
angles for the photographing of the examinee d from different angles. In 
some shots, for example, the frame a may be turned through an angle of 
180.degree. from the position of FIG. 1, that is, inverted. In such 
position, openings u and v of the magazines m and n are to face downward. 
Accordingly, the sheet films p may possibly slip out of the magazines 
through their openings or bend to cause a handling mistake, so that 
correct and secure handling of films could not be expected. 
SUMMARY OF THE INVENTION 
Accordingly, the primary object of this invention is to provide a 
high-performance X-ray photographing machine which obviates the 
aforementioned defects of the prior art machines, capable of substantial 
reduction of a movable frame in length, lightening of the load on a 
support section without requiring positive strengthening of the frame 
structure, and reduction of the overall size of the machine and transfer 
distance of a carrier, as well as of smooth film treatment without bent or 
slipped out of openings of film supply and takeup magazines during 
operation. 
Another object of this invention is to provide an X-ray photographing 
machine capable of fast and exact conveyance of sheet films in connection 
with the above primary object. 
In order to attain the above objects, there was made the following epochal 
proposal. That is, according to this invention, two magazines are not 
arranged in line with exposure and stand-by positions of a carrier, but 
are located in offset positions relative to such positions, and the 
longitudinal axes of the magazines are disposed substantially at right 
angles to an axis extending along a carrier path. 
Thus, the length of a movable frame is reduced considerably. Moreover, the 
stand-by position is brought as close to the exposure position as 
possible, and, in order to prevent X-ray fog, the movable frame is 
provided with an X-ray screening member such as lead disposed between the 
carrier in the stand-by position and an X-ray source. The screening member 
is allowed to be arranged in spite of its substantial weight because its 
effect on the frame is diminished due to the reduction of the length of 
the movable frame. Moreover, the carrier is formed of two plates, and 
another X-ray screening member is mounted on a hinge portion of these 
plates which is located on the exposure position side, thereby 
additionally preventing the effect of X-ray fog. 
By these measures, the length of the movable frame may be reduced to about 
half that of the conventional one or less. 
In order to prevent the slipping of the sheet films accompanying the 
turning of the movable frame, the machine of the invention includes a 
backup urging means formed of a backup plate and a spring disposed inside 
the film supply magazine, whereby the films are urged across the thickness 
thereof. With respect to the film takeup magazine, the movable frame is 
fitted with a plate member which, along with paired film takeup rolls, 
components of a films feed mechanism, partially enters a film intake 
opening of the magazine when the magazine is located in its operative 
position on the frame. 
Thus, the films contained in both magazines may be arranged in an orderly 
way without regard to the position of the movable frame, eliminating the 
problems of the prior art construction. 
In connection with the aforementioned positioning of the magazines, the 
film feed mechanism is compactly arranged within a space defined by the 
longitudinal axes of the magazines and the axis extending along the 
carrier path.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Now there will be discribed some embodiments of this invention with 
reference to the accompanying drawings. 
Referring now to the drawing of FIG. 2, an L-shaped movable frame 15 can 
move relatively to a support frame 16 in a vertical direction, as 
indicated by an arrow 17, so that it may approach and go away from an 
examinee 19 lying on a table top 18. Also, the frame 15 is capable of 
turning round the examinee 19 in concert with the support frame 16, as 
indicated by an arrow 20, and of movement in the longitudinal direction of 
the examinee 19 or at right angles to the plane of the drawing. 
The support frame 16 is held by a forklike frame (not shown) which is 
rotatably supported by a gantry (not shown). 
The state of the X-ray photographing machine shown in FIG. 2 is an 
upstanding state. 
On the support frame 16 is a source 21 to produce X-rays disposed below the 
examinee 19. An exposure position 22 is located at the free end portion of 
the movable frame 15 on the opposite side of the examinee 19, while an 
image intensifier 23 is mounted on the frame 15 above the exposure 
position 22. 
In FIG. 2, a chain line indicates a state in which a film carrier 24 is 
located in the exposure position 22, while a full line indicates a 
stand-by position 25 where the carrier 24 is normally located. The space 
between the stand-by position 25 and the exposure position 22 is quite 
narrow, as may be seen from the comparison with the prior art construction 
of FIG. 1. Accordingly, a rectilinear path 26 for the carrier 24 defined 
inside the frame 15 is short, so that the carrier 24 may move from the 
stand-by position 25 to the exposure position 22 in the direction of an 
arrow 27 in a reduced period of time. Here an axis extending along the 
carrier path 26 is designated by Z--Z. At the base portion of the movable 
frame 15 is an X-ray screening member 28 such as lead disposed over a 
range corresponding to the length of the carrier 24 just below the 
stand-by position 25 of the carrier 24. Interposed between the carrier 24 
and the X-ray source 21, the member 28 is covered so as not to cause the 
carrier 24 to suffer X-ray fog scattered by the X-ray source 21. 
The carrier 24, consisting of two rectangular plate members 29 and 30 as 
illustrated, is formed of X-ray penetrating material. One end edges or 
edge portion 24a of these plates facing the exposure position side are 
hinge-coupled, and an X-ray screening member 31 is mounted on the 
hinge-coupled portion 24a. Such mounting state may also be well seen from 
FIG. 4. Since X-rays from the X-ray source 21 are applied diagonally to 
the bottom of the carrier 24 in the stand-by position 25, X-rays that 
cannot be intercepted by the screening member 28 at the base portion of 
the frame 15 are covered up by the screening member 31 mounted on the 
hinge-coupled portion 24a. This is done because the screening member 28 at 
the base portion cannot be extended further to the left from the location 
of FIG. 2, for the ease of X-ray photographing. 
Off and above the axis Z--Z of the carrier path 26 are a film supply 
magazine 32 containing unexposed sheet films 33 and a film takeup magazine 
34 containing exposed sheet films 33 disposed at a distance in equally 
offset positions inside the movable frame 15. 
The magazines 32 and 34 can be attached to and detached from the movable 
frame 15, having their corresponding support guide members 35 and 36 
mounted on the frame 15. 
The magazines 32 and 34 as shown in FIG. 2 are in their normal set 
positions relative to the frame 15 that enables X-ray photographing 
operation. The film takeup magazine 34 and the guide member 36 are allowed 
to rock between an operative position indicated by a full line and a 
non-operative position indicated by a chain line, as mentioned later. When 
the film takeup magazine 34 rocks in the direction of the arrow 37 to take 
the operative position, the respective longitudinal axes X--X and Y--Y of 
the magazines 32 and 34 become parallel with each other, and substantially 
perpendicular to the axis Z--Z of the carrier path 26. 
Accordingly, in the X-ray photographing machine of this invention, the 
locations of the magazines 32 and 34 are not in line with the stand-by 
position 25 and the exposure position 22 of the carrier 24, unlike the 
arrangement of FIG. 1. Both these positions 25 and 22 are located at an 
elongated first frame section 15a of the L-shaped frame 15, while the 
magazines 32 and 34 are disposed at a second frame section 15b at right 
angles to the first frame section 15a. Thus, the length of the frame 15 
may greatly be reduced. 
The image intensifier 23 is coupled to the second frame section 15b of the 
frame 15 by means of a bridge member 23a, for further stability in 
strength. 
A film takeout opening 38 of the supply magazine 32 and a film intake 
opening 39 of the takeup magazine 34 face each other at the same height. 
Both magazines have substantially the same shape, each presenting an 
appearance of a rectangular box as shown in the perspective view of FIG. 3 
for the supply magazine 32, for example. The magazines 32 and 34 have 
their respective top plates 32a and 34a and bottom plates 32b and 34b in 
parallel with one another as well as with the longitudinal axes X--X and 
Y--Y, the top plates 32a and 34a having the openings 38 and 39 defined 
therein, respectively. 
The respective openings 38 and 39 of the magazines 32 and 34, which are 
normally open in the set position, are closed with slide covers 40 and 41 
when taking the magazines in or out of the frame 15. In each magazine, the 
sheet films 33 are located in layers along the longitudinal axis X--X or 
Y--Y of the magazine. 
In one magazine or the film supply magazine 32 is a film urging means 42 
formed of a backup plate 43 and a leaf spring 44. By this means 42, the 
unexposed sheet films 33 in the magazine 32 are urged in a direction to 
cross the longitudinal axis X--X. Thus, even if the supply magazine 32 has 
its takeout opening 38 turned downward from the position of FIG. 2 
accompanying the turning of the movable frame 15, the films contained 
therein will never slip out or bend. 
A film feed mechanism is compactly arranged in a location between the film 
supply magazine 32 and the film takeup magazine 34 and above the axis Z--Z 
of the carrier path 26, that is, in a space surrounded and defined by the 
longitudinal axes X--X and Y--Y of the magazines 32 and 34 and the axis 
Z--Z of the carrier path 26. 
The film feed mechanism includes a plurality of paired rolls (advance rolls 
45 and 46, feed-takeout rolls 47 and 48, and transport rolls 49 and 50) 
for forwardly transferring each unexpected sheet film 33 from the supply 
magazine 32 to the carrier 24 in the stand-by position 25. The paired 
advance rolls 45 and 46 are disposed near the takeout opening 38 of the 
supply magazine 32. Between the rolls 45 and 46 and the takeout opening 38 
is a vacuum sucker 51 to draw sheet films out of the takeout opening 38 by 
using a vacuum effect. In the drawing the vacuum sucker 51 rocks from a 
position indicated by full line to a position indicated by a chain line in 
an arrowed direction, and then returns again to the full-line position to 
draw out a single film. The drawn film is indicated by a full line in FIG. 
2. 
The advance roll 46 is supported by the movable frame 15 so that it can 
move from a nipping position indicated by a full line to a position 
indicated by a chain line, with respect to the other roll 45. The roll 46 
moves when the vacuum sucker 51 draws out the film 33. When the drawn film 
touches the immobile roll 45, the roll 46 returns to the full-line 
position to hold the film and then carries it in a forward direction. 
Since the roll 46 is movable, the film may securely be caught by the 
advance rolls 45 and 46. 
The paired feed-takeout rolls 47 and 48 are disposed in close vicinity to 
the end edge of the carrier 24 in the stand-by position 25. These rolls 47 
and 48 are rotated selectively in a forward direction to feed the film 33 
into the carrier 24 and in a reverse direction to take the film out of the 
carrier 24. 
Notches 29a and 30a are formed at the respective both-side corners of the 
end edges of the upper and lower plates 29 and 30 constituting the carrier 
24, the rolls 47 and 48 partially entering the notches 29a and 30a, 
respectively. This situation is clearly shown in FIG. 4. As shown in FIG. 
4, the paired rolls 47 and 48 are provided in two sets, which correspond 
to the side edge portions of the film passing between them. Such 
double-roll construction goes also for the advance rolls, the transport 
rolls, and takeup rolls 52 and 53 as mentioned later. 
The construction of the notches 29a and 30a is intended as follows. That 
is, when the exposed film has returned along with the carrier 24 to the 
stand-by position, corner portions of the film exposed through the notches 
on both sides automatically engage the nipping points of their 
corresponding rolls 47 and 48, thereby facilitating the film takeout by 
means of the rolls. Accordingly, there will not be required any special 
positive film delivery means between the carrier 24 and the rolls 47 and 
48. 
The paired transport rolls 49 and 50 are disposed between the advance rolls 
45 and 46 and the feed-takeout rolls 47 and 48, and film feed guide plates 
54 are interposed between the rolls 49 and 50 and the lower rolls 47 and 
48. By these guide plates 54, the film may smoothly be guided and 
transferred without being abruptly bent. 
The roll 50 of the transport rolls can selectively rock, relatively to the 
roll 49, from a full-line position to a chain-line position in an arrowed 
direction, while maintaining its nipping press against the roll 49. In a 
forward film feeding operation, the roll 50 is in the full-line position 
of FIG. 2, and a tangent which touches the rolls at their nipping point is 
in line with the film feed direction. At this time, both these rolls 49 
and 50 are rotated in the forward direction. In a reverse film feeding 
operation, on the other hand, the roll 50 rocks to the chain-line 
position, and the rotations of both rolls are reversed. Then, the tangent 
passing through the nipping point of the rolls shifts its position from 
the position for the forward feeding. 
Namely, the transport rolls 49 and 50 tend to switch the running course of 
the film between the forward and reverse directions. 
The film feed mechanism further includes the paired takeup rolls 52 and 53 
disposed correspondingly to the intake opening 39 of the takeup magazine 
34 and facing each other. The rolls 52 and 53 constitute, in concert with 
the transport rolls 49 and 50 and the feed-takeout rolls 47 and 48, a roll 
means to reverse the film run. 
The paired takeup rolls 52 and 53 partially enter the intake opening 39 
when the takeup magazine 34 is located in the operative position as 
indicated by a full line in FIG. 2. 
Below the takeup rolls 52 and 53 is a film pressure plate member 55 fixed 
to the movable frame 15, an upper end portion 55a of the number 55 
entering the intake opening 39 of the magazine 34 in the operative 
position. The upper end portion 55a closes up a portion of the intake 
opening 39 below the rolls 52 and 53, thereby preventing the films 33 from 
slipping out through such portion. 
Above the takeup rolls 52 and 53, on the other hand, is a baffle plate 56 
rockably mounted on the movable frame 15, corresponding in particular to a 
portion of the intake opening 39 above the rolls 52 and 53. The baffle 
plate 56 rocks so as positively to drive a film carried through the takeup 
rolls 52 and 53 into the magazine 34 after the film has passed through the 
nipping point of the rolls 52 and 53. 
Thus, the takeup rolls 52 and 53 and the plate member 55 are partially 
admitted in the intake opening 39 of the magazine 34, so that the films 
will never slip out through the intake opening 39 or bend inside the 
magazine even if the intake opening is turned downward accompanying the 
turning of the movable frame 15. 
The takeup magazine 34 is somewhat inclined as indicated by a chain line in 
FIG. 2 when it is first mounted on the frame 15. Thereafter, it rocks as 
indicated by the arrow 37 to the operative position indicated by a full 
line, where it is stationed. Therefore, the takeup rolls 52 and 53 and the 
plate member 55 will constitute no obstacle to the mounting operation. 
For the aforementioned rocking motion of the takeup magazine 34, the 
support guide member 36 is coupled to an eccentric control shaft 57. The 
control shaft 57, which is rotatably mounted on the movable frame 15, has 
a knob portion 57a to be manually turned by an operator at its top end and 
an eccentric pin 57b protruding from its bottom end. The pin 57b engages a 
connecting member 58 fixed to the lower end portion of the guide member 
36. 
The operator is supposed to turn the knob 57a thereby previously setting 
the guide member 36 at a chain-line position around a pivot 59 of the 
guide member 36, and then to attach the takeup magazine 34 to the guide 
member 36 as it is. Thereafter, when the knob 57a is turned again, the 
magazine 34 is driven into the operative position by an eccentric action. 
The takeup magazine 34, may however, may be slided crosswise instead of 
being rocked. 
Disposed between the two magazines 32 and 34, the eccentric control shaft 
57 requires no additional space therefor. Moreover, the gantry and 
forklike support frame (not shown) are not located in the portion above 
the movable frame 15 where the knob 57a is operated, leaving a wide space 
unoccupied, so that the operation of the knob 57a may be quite easy. Such 
ease of operation goes also for the magazines. The magazines are mounted 
and removed also through the top portion of the movable frame 15, which is 
much more expedient than the way of the prior art machine of FIG. 1 in 
which the magazines are handled sideways. 
FIG. 5 shows a somewhat modified arrangement of the film feed mechanism of 
FIG. 2. In this drawing, parts or components corresponding to the ones 
shown in FIG. 2 are designated by reference numerals whose values exceed 
the values of their corresponding reference numerals of FIG. 2 by 100 
each. 
A feed mechanism, which is disposed between a film supply magazine 132 and 
a film takeup magazine 134 and above an axis Z--Z of a path for a carrier 
124, is composed of an advance roll unit 101, transport roll unit 102, 
feed-takeout roll unit 103, and a takeup roll unit 104. 
The advance roll unit 101 and a vacuum sucher 151 are disposed near a 
takeout opening 138 of the magazine 132. The unit 101 is formed of drive 
rolls 105 and 106 spaced along the running direction of films 133, an 
endless drive belt 107 stretched between the drive rolls, and follower 
rolls 108 and 109 corresponding respectively to the drive rolls 105 and 
106, the two follower rolls 108 and 109 being connected with each other by 
means of a lever 110. The lever 110 may rock round a pivot 111 of one 
follower roll 109 to a position indicated by chain line in FIG. 5 in an 
arrowed direction, thereby removing the other follower roll 108 from its 
corresponding drive roll 105. Thus, the unit 101 is made ready to receive 
the sheet film 133. 
The transport roll unit 102, like the aforementioned advance roll unit 101, 
is formed of drive rolls 112 and 113 spaced along the feed direction, an 
endless drive belt 114 stretched between the drive rolls, and two follower 
rolls 116 and 117, these four rolls being rotatably mounted on a single 
rocking plate 118. The plate 118 can rock round a pivot 119 of the drive 
roll 113 to a chain-line position in an arrowed direction. By the rocking 
of the plate 118, the running direction of the film passing through the 
unit 102 is shifted through a fixed angle so that the film may flow toward 
the takeup roll unit 104 in the reverse feed. 
The feed-takeout roll unit 103 is formed of a pair of drive rolls 120 and 
121, an endless drive belt 122 stretched between the drive rolls, and a 
follower roll 123 with its circumference partially touching the belt 122, 
the diameter of the follower roll 123 being larger than that of the drive 
rolls 120 and 121. 
Like the arrangement of FIG. 2, the takeup roll unit 104 is formed of 
paired rolls 152 and 153 in contact with each other. Whereas only a single 
unit is shown in FIG. 3, the mechanism actually includes also another set 
or unit of rolls disposed across the film running direction. 
In the feed roll mechanism of FIG. 5, if the forward feed speeds at the 
advance roll unit 101, transport roll unit 102, and the feed-takeout roll 
unit 103 are V.sub.1f, V.sub.2f and V.sub.3f, respectively, in a forward 
feed process to transfer an unexposed sheet film from the supply magazine 
132 to the carrier 124 in a stand-by position, then, according to this 
invention, the relations between these speeds are as follows: 
V.sub.1f &lt;V.sub.2f &lt;V.sub.3f. That is, the film advances under some pull at 
increasing speed as it is carried in a forward direction. 
Further, in a return or reverse feed process to transfer an exposed sheet 
film from the carrier 124 returned to the stand-by position to the takeup 
magazine 134, if the reverse feed speeds at the takeup roll unit 104, 
transport roll unit 102, and the feed-takeout roll unit 103 are V.sub.4r, 
V.sub.2r and V.sub.3r, respectively, then the relations between these 
speeds are as follows: 
V.sub.3r &lt;V.sub.2r &lt;V.sub.4r 
That is, the film advances under some pull at increasing speed as it is 
carried in a reverse direction. 
Heretofore, feed rolls in a feed mechanism have usually been all set at the 
same speed for each feed direction. Such uniform-speed setting has been 
regarded as absolutely essential to a stable film feed. In this case, 
however, the speed control of the feed rolls in the feed mechanism need be 
highly accurate, requiring what is called closed-loop control in which the 
roll drive speed is detected by means of a tacho-generator or some other 
speed detector provided for a roll driving system, and feed back to the 
driving system. Thus, the construction of the roll driving system is 
complicated, and speed adjustments for the individual rolls, as well as 
reciprocal adjustments with other rolls, need be made closely. 
According to this invention, on the other hand, the aforementioned novel 
speed relations are applied to the film feed mechanism, so that the roll 
speed would not require very close adjustment so long as it satisfies the 
aforesaid relations. Moreover, it is noticed that positive film run with 
improved stability, as compared with the uniform-speed run, can be 
achieved without exerting any bad influence on the film itself. 
The aforesaid speed relations may apply not only to the construction of 
FIG. 5 but to the feed roll mechanism of FIG. 2. 
FIG. 6 shows a driving system for the feed mechanism of FIG. 5. Here the 
driving system is divided into two. The first driving system is comprised 
of a reversible driving motor 160 and an endless-chain transmission, 
mechanism 161, while the second driving system includes a reversible 
driving motor 162 and a gear transmission mechanism 163. Both these 
driving systems are mounted on a movable frame 115 as indicated by a chain 
line. 
In the first driving system, sprocket wheels 164, 165 and 166 are 
coaxial-coupled with the drive roll 106 of the advance roll unit 101, the 
drive roll 152 of the takeup roll unit 104, and the drive roll 113 of the 
transport roll unit 102, respectively. These wheels 164, 165 and 166 are 
coupled by means of an endless chain 167 through an intermediate wheel 168 
to a sprocket wheel 169 fixed on a motor shaft 160a. As for the diameters 
of these three wheels 164, 165 and 166, the diameter of the wheel 164 is 
greater than that of the wheel 166, which is larger than that of the wheel 
165. Such differences in diameter mean differences in number of teeth; the 
larger the wheel, the greater the number of teeth on the wheel. 
Accordingly, in a drive process in the forward film feed direction as 
indicated by full-line arrows, the shaft of the larger-diameter wheel 164 
rotates more slowly than that of the wheel 166 does. The peripheral speed 
of the drive roll 106 of the advance roll unit 101, therefore, is lower 
than that of the drive roll 113 of the transport roll unit 102. Naturally, 
it is supposed that the diameters of these drive rolls 106 and 113 are 
equal. 
Meanwhile, in a drive process in the reverse film feed direction as 
indicated by broken-line arrows, the shaft of the larger-diameter wheel 
166 rotates more slowly than that of the smaller-diameter wheel 165 does. 
The peripheral speed of the drive roll 113 of the transport roll unit 102, 
therefore, is lower than that of the drive roll 152 of the takeup roll 
unit 104, since the diameters of these drive rolls 113 and 152 are equal. 
In the second driving system, a larger-diameter gear 170 fixed on a shaft 
162a of the reversible driving motor 162 engages a smaller-diameter gear 
171. The smaller-diameter gear 171 is coupled coaxially with the drive 
roll 120 of the feed-takeout roll unit 103. Therefore, the peripheral 
rotating speed and direction of the drive roll 120 are determined by means 
of the driving motor 162 independently of the aforementioned driving 
system including the driving motor 160 and the transmission mechanism 161. 
The aforesaid speed relations may be obtained by combining both these 
driving systems. 
FIG. 7 shows a roll switching operation system in the film feed mechanism 
of FIG. 5. This operation system is also mounted on the movable frame 115 
as indicated by a chain line. 
A lever 173 fixed on the shaft of a rotary solenoid 172 rocks in the 
arrowed direction from a normal position indicated by a full line through 
an angular range indicated by a chain line, based on the operation of the 
solenoid 172. 
The lever 173 is connected to a lever 175 by means of a connecting lever 
174. The lever 175 is capable of rocking round the pivot 111 of the 
follower roll 109. Accompanying the rocking of the lever 175, the 
connecting lever 110 rocks in a body with the lever 175 in the arrowed 
direction from the illustrated position, which corresponds to the 
full-line position of FIG. 5, through an angular range indicated by a 
chain line. 
A return spring 176 is hung on one end of the lever 175, while the other 
end of the lever 175 is connected with one end of a lever 177. The other 
end of the lever 177 is mounted on the pivot of the drive roll 112. In 
this drawing, the transport roll unit 102 is in a state corresponding to 
the full-line position of FIG. 5. 
When the rotary solenoid 172 is operated, the spring 176 is stretched by a 
link motion caused among the levers 173, 174, 175 and 177, thereby rocking 
the lever 110 to move the follower roll 108 in the arrowed direction. At 
the same time, the plate 118 of the transport roll unit 102 rocks around 
the pivot 119 in the arrowed direction through an angular range indicated 
by a chain line. 
Thus, shifting of the follower roll 108 in the advance roll unit 101 and 
switching of the transport roll unit 102 may be achieved simultaneously by 
employing the single rotary solenoid 172 for a driving source and also the 
link motion. 
In FIG. 7, a strip 178 fixed to the lever 177 and a bracket 179 relevant 
thereto constitute a detecting member for the check for the normal link 
motion. 
FIGS. 8 to 12 show a further improved arrangement of the feed-takeout roll 
unit. In this arrangement, parts corresponding to the ones shown in FIG. 5 
are designated by reference numerals whose values exceed the values of 
their corresponding reference numerals of FIG. 5 by 100 each. 
A feed-takeout roll unit 203 is composed of a large-diameter follower roll 
223, drive rolls 220 and 221, an intermediate roll 280, and an endless 
drive belt 222 passed around these rolls. The unit 203 forms a pair with 
its counterpart, and a sheet film 233 is fed with both edge portions 
thereof passed through their corresponding units. 
Thus, the central portion of the film 233 is freed from the unit 203, for 
the following reason. That is, if the central or essential portion of the 
film is passed through the roll unit, its surface will possibly suffer 
scratches or roll marks, which will be sure to inflict serious mischief on 
the resolution of the X-ray photographing. 
Such central film portion would, however, inevitably be slackened while it 
is being fed through the unit, often constituting an obstacle to smooth 
film feed. 
According to this invention, therefore, it was suggested that a guide plate 
281 be disposed between the units on both sides. 
Referring to FIGS. 8, 9 and 10, the sheet film flows in the arrowed 
direction in the forward feed operation. At this time, the space between 
the guide plate 281 and the peripheral surface of the follower roll 223 
are widened on the film receiving side, as indicated by a full line in 
FIG. 9. Consequently, the forward end of the film enering the unit 203 may 
smoothly be inserted between and guided by the guide plate 281 and the 
follower roll 223 without being caught by the guide plate 281. 
In the reverse feed operation to transfer the film oppositely to the 
arrowed direction, on the other hand, the guide plate 281 is rocked to a 
position as indicated by a chain line in FIG. 9. As a result, the guide 
plate 281 is removed from the follower roll 223 on the opposite side to 
the film receiving side. Thus, the film 233 fed reversely into the unit 
203 may be received smoothly between the plate 281 and the follower roll 
223. 
FIGS. 10 and 11 show a mechanism for such selective rocking of the guide 
plate 281. In these drawings, however, there is shown but one of the 
paired feed-takeout roll units 203. 
A rocking shaft 282 fixed to the guide plate 281 is rotatably mounted on a 
chassis 283 of a movable frame. A free end of the shaft 282 extends long 
to the opposite side to the guide plate 281 through the chassis 283. At an 
extended shaft portion 281a of the shaft 282, a gear 284 is freely 
sustained by a bearing 285 (FIG. 12). A friction member 286 engages the 
end face of a boss portion 284a of the gear 284. The member 286 is mounted 
on the extended shaft portion 281a. The member 286 is urged against the 
boss portion 284a by a coil spring 287. The using force of the spring 287 
is controlled by means of an adjusting nut 288. 
Further, a rock lever 289 is fixed to the friction member 286. Within the 
rocking range of the rock lever 289 are two stop pins 290 and 291 
projecting from the chassis 283. By these pins 290 and 291, the rocking of 
the lever 289 is restricted to an angular range from a full-line portion 
to a chain-line position as shown in FIG. 10. 
The gear 284 engages gears 292 and 293 in order. The gears 292 and 293 
rotate coaxially with the drive roll 220 and a reversible driving motor 
294, respectively. 
Accordingly, when the motor 294 is driven in the forward film feed 
direction, that is, when the gear 293 is rotated in the direction of a 
full-line arrow, the drive roll 220, given driving force by the gear 292, 
drives the unit 203 in the forward feed direction. 
At the same time, the gear 284 rotates in the arrowed direction. Then, the 
friction member 286 rocks to a position as indicated by full line in FIG. 
10 where the lever 289 is stopped by the pin 290. Accompanying such 
rocking, the extended shaft portion 281a also rocks through the same 
angular range with the lever 289 to turn the guide plate 281 to a 
broken-line position in FIG. 10 (which corresponds to the full-line 
position of FIG. 9). After the lever 289 is stopped by the pin 290, the 
friction surface of the gear 284 slips on the friction member 286 in 
suspension. In the meantime, the friction member 286 continues to receive 
urging force in the direction of the rotation from the gear 284. 
Therefore, the guide member 281 is maintained in the rocked position while 
the driving motor 294 is in operation. 
When the driving motor 294 is reversed to start operation in the reverse 
film feed direction, on the other hand the lever 289 rocks to a position 
as indicated by a chain line in FIG. 10, were it is stopped by the other 
291. In consequence, the guide member 281 rocks from the broken-line 
position of FIG. 10 to the chain-line position of FIG. 9, where it is 
maintained as it is. 
Thus, the rocking operation of the guide member 281 is performed by means 
of driving force provided by the motor 294 to drive the unit 103 and in 
alignment with the direction of the rotation of the motor. Moreover, in 
the arrangement of this invention, switching of the motor drive direction 
and the guide member rock position may automatically be achieved without 
requiring any timing adjustment. 
Furthermore, a spring 297 is stretched between the extended portion of a 
shaft 295 of the follower roll 223 and the extended portion of a shaft 296 
of the drive roll 221. The shaft 296 of the drive roll 221, which is 
allowed to move within a slot 298 in the chassis 283, is so constructed as 
to press the drive roll 221 resiliently against the follower roll 223 
through the belt 222 by means of the action of the spring 297.