US2353145A

US2353145A - X-bay machine

Info

Publication number: US2353145A
Authority: US
Publication date: 1944-07-11
Anticipated expiration: 1961-07-11

Description

y 1944. G. H. CHAMBERLAIN, JR 2,353,145

X-RAY MACHINE Filed April 12, 1941 6 Sheets-Sheer. 1

ATTORNEYS,

y 1944. G. H. CHAMBERLAIN, JR 2,353,145

X-RAY MACHINE Filed April'12, 1941 6 Sheets-Sheet 2 V,/ Q/A 4/ INVENTOR.

GEQRGE H- CHAMBERLAIN JA.

BYMM/ ATTORNEYS.

y 1944. a. H; CHAMBERLAIN, JR 2,353,145

X-RAY MACHINE Filed April 12, 1941 6 Sheets-Sheet 3 INVENTOR. GEO/EOE H. CHRMBEELRIN JE.

ATTORNEYS.

July' 11, 1944. G. CHAMBERLAIN, JR

X-RAY MACHINE Filed A'pr 12, 1941 e Sheets-Sheet 4 5 Will WWII HIIMIWIMI MIIIIWIWWNIIHIIWII INVENTOR. GEGEGE H. CHAMBERLAIN JP ATTORNEYS.

J y 1, 1944. G. H. CHAMBERLAIN, JR 2,353,145

X-RAY MACHINE Filed April 12, 1941 s Sheets-Sheet 5 IN VENT OR. CIEORC; H- CHHMB'RLfl/N JR.

A TTORNE S Patented i July- 1 .15,

STATES PATENT OFFICE x-nsr moms GeorgeH. Chamberlain, In, San Jose, Calif. Application April 12, 1941, Serial No. 388,235

17 Claims. (01. 250-615) invention. relates to an improved X-ray machine.

Besides the older type of X-ray machine which is capable of operation in only the familiar, conventional manner, there has been also some comparatively recent development, both here and 1 focus the rays of the X-ray tube with respect to a body section, that is a layer of the body, which it is desired to radiograph, the purpose being to obtain a clearer image.

It is understood, of course, that in this device there is not employed any principle of optics but there is accomplished the same purposeas in the focusing of an optical system and therefore the word focus is here used merely as a means of convenience in affording a clear understanding of the purpose of this machine and the effect obtained therewith.

Briefly, thegeneral principle involved in this comparatively recent development is that the tube and sensitive film are moved during exposure in-such manner that the roentgenographic shadow of a selected body section remains stationary on the moving film while the shadows of all other sections have a relative displacement on the film and are consequently blurred varying amounts depending principally upon the distance of such planes from that of the selected body section.

An examination of the prior art shows that while, to a large extent, the theory embodied therein is substantially correct, the mechanism is either too complicated in both construction and operation for practical purposes, or in some instances the mechanism is not wholly dependable, or it is not capable of sumciently wide adaptability to different technique, or it is too costly for general adoption and use. Furthermore, the principle of operation in some of the prior devices is not sound.

It is therefore the object of the present invention, in a general way, to devise a method and machine for taking radiographs of the type .above referred to, that is sound and feasible in principle and not complicated but comparatively simple and extremely practical in construction and operation.

Another object is to devise such --a machine 86 that is capable of operation according to the principle above referred to, or can be alternately used at anytime in the same manner as the older conventional type of X-ray machine and in an efiicient manner.

It is also an object to devise such a machine that is readily adaptable'to various technique, which is made possible by my particular system of construction and adiustability.

A more specific object is to devise an efllcient and feasible form of machine structure in which there is produced synchronous circular motion of the tube and casette so as to maintain the target of the tube and the casette in parallel fiat planes during such movement.

Another specific object is to devise such a machine in which there can be produced a synchronous spiral motion for the tube and casette in a feasible and emcient manner for the purpose of blurring the shadows outside of the ob- 'jective or nodal plane in an even more nearly complete manner.

A further object is to devise such a machine in which there is provided a means of increased amplitude and an improved means for varying the amplitude at any time, this means co-operating also with the spiral operation whenever employed.

A more specific object is to provide a low center of gravity in such a machine structure and in the arrangement of the base support and drive connection at the bottom part of the machine.

A still further feature of my present machine consists of the parallelogram form of operative connections between the drive means and the casette and tube, whereby there is obtained comparative simplicity and dependability of construction and operation in the manner intended. This also constitutes an object of my present invention.

Another object is to provide, in such a machine, an improved adjusting means for the tube for use in the taking of stereoscopic pictures.

Another object is to provide such a machine with means whereby the tube may be adjusted through ninety (90) degrees so as to occupy vertical position for taking a radiograph of a patient in an erect or standing pomtion, there being provided suitable and eflfective means for supporting the tube in either position.

Another object resides in the provision pg an, improved means of adjustment of the objective plane, this feature also contributing to the stability of the machine structure.

Another object is to provide an improved form of grid.

Another object is to provide a convenient proved machine;

Fig. 2 is a sectional view showing the lower part of the operating mechanism;

Fig. 3 is a side elevation corresponding substantially to Fig. 2 except that it (90) degrees thereto;

Fig. 4 is a detail view Fi Fig. 5 is atop plan view of the mechanism which permits stereoscopic adjustment of the taken on line i-J of tube;

Fip. 6 is an elevation thereof;

Fig. '7 is a view taken on line 1-1 of Fig. 5;

Fig. 8 is a partial plan view of my improved grid, partly broken away;

Fig. 9 is a view taken on line 3-3 of Fig. 8;

Fig. 10 is a more or less diagrammatic elevation of the machine;

Fig. 11 is a front elevation Fig. 12 is a view taken on line i2--|2 of Fig. 11;

Fig. 13 is a partial detail view illustrating a modification of the spiral motion drive means;

Fig. 14 is a sectional view of the locking lever mechanism; and

Fig. 15 is an enlarged Fig. 1.

It is to be understood that the present forms of disclosure are merely for the purpose of illustration and that there may be devised various modifications thereof without departing from the view of the lower part of spirit of the invention as herein set forth and claimed.

Uponthe base I there is fixed the pair of parallel uprights 2 upon which is adjustably mounted the transverse support 3 for the universal,

joint assembly I. The support 3 is adjusted in its elevation by means of racks 5 onthe uprights 2 and companion pinions on the rotary shaft 6 which has the wheel 1 for operation thereof. The scale 3 may be employed for indicating the elevation of the support 3. This means of adjustment is for the purpose of varying the elevation of the objective plane in which is located the nodal point corresponding to the center of the universal joint connection 3 'of the assembly 4. Through the tubular castings of the assembly is at ninety illustrating the roller adjustable bed for supporting the patient;

there extend the parallel posts ID. the assembly 4 being adjustable therealong in the manner explained. As will be understood, the body section which it is desired to radiograph, will be placed in the plane of the nodal point of the machine, which is here indicated at 3. The true nodal point is, of course, within the body of the patient and in the same horizontal plane with point 3.

The lower ends of the posts Ill have transverse axial bearing connection in the cross arm H which has bearing at ninety degrees thereto in the yoke member 12 having swivel connection about a vertical axis in the threaded portion ll of the slidable saddle. Co-operating with the said threaded portion I3 is the companion screwthreaded shaft l4 which is mounted transversely of the turn-table l5, the saddl having a block l6 on the underside of the threaded portion 3 for slidable adjustment within the transverse slot 11 in the turn-table 15. The purpose of this diametrical adjustment is to vary the amplitude, as will be more fully understood from the following. The screw l4 may be adjusted manually by means of the hand wheel I8 so as to thereby set the saddle at the point corresponding to the radius of operation desired for the turn-table. The saddle is slidabl upon the bronze ways 16a and is guided between the steel gibs IGb, one of which can be tightened by means of the locking lever i9 for releasably securing the saddle in the position to which adjusted.

The turn-table I5 is rotated by the electric motor 20 which has belt drive connection 2| with the pulley 22 on the shaft 23 which in turn has drive engagement with the annular worm gear 24 attached to the bottom of the turn-table. The auxiliary shaft- 23. By manipulation of hand-wheels l8 and 26,

the posts I!) can b brought to a rigid vertical position, when it is desired to take a radiograph according to the older conventional manner, as above referred to.

Also, with my machine it is possible to take conventional radiographs from practically any angle without having to place the patient in an angular position, which of course is very difficult with the previous equipment. In such case, the saddle will be positioned at the proper point upon the turn-table according to the angle desired. Fixedly connected to the cross-arm I I, midway thereof, is the supporting extension or axle 21 which is adapted to move bodily with the yoke member l2 and every point of which describes a circle corresponding to that of the pivotal axis of said yoke member.

The axle 21 has the diametrically opposed yoke arms 28 fixedly secured thereto by means of the taper pin 28a and extending therefrom so as to afford fixed axial rotatable bearing for the transversely disposed shaft 29 which passes through yoke arms 28. To the outer ends of shaft 23 there are pivotally connected the lower ends of the upright rods 30 for movement at ninety (90) degrees to the axis of arms 29. The rods 30 at their upper ends have th same kind of pivotal connection with the ends of the transverse rod 3| which extends through the yoke arms 32 and at ninety (90) degrees to the axis of the shaft 33 so as to permit axial rotatable movement with respect thereto. The yoke member 32 is fixed to the end of the shaft 33 about which there is axial rotatable bearing of the cross arm 34 attached to the posts l0. Thus there is provided what is to be recognized as a parallelogram comprising the upper and lower

parallel arms

23 and 3| and the upright parallel rods 33.

The brackets 35 are suspended from the transverse shaft 3| and support the rigid frame 33 from the casette carriage 31. This frame is clamped to the shaft 33, as indicated at 33a, so as to assist in maintaining the frame in a fixed horizontal plane, the shaft 33 occupying position in a fixed parallel relation to the fixed hori- 25 is a continuation of shaft 7 rental axis 21, as above explained. The supporting frame I! is of sumcient extent that the casette will occupy position directly beneath the point of emission of the Roentgen rays and also beneath the position to be occupied by the patient in the objective plane, as will be understood.

The yoke arms II on the end of the axle I! afford transverse axial bearing for the lower end of the upright rod 30 which extends parallel with the posts II and which has transvers axial bearing at its upper end with the yoke "a which is secured by means of the taper pin b to one end of transversely and substantially horizontally disposed axle 4| for supporting the bracket of the x-ray tube.

The upper ends of the posts II are secured in the tubular castings Ila and the adjustable bracket H which forms part of a universal joint assembly through which the shaft ll extends andhas universal hearing at "c. This universal joint assembly is substantially the same as the one at the lower ends of posts it and also the one through which the shaft 33 extends and also the one of which the joint 8 forms 'part. Since rod )9 always maintains the same attitude as the posts II, it follows that shaft 40 has no movement with respect to its own axis.

Casting lid is secured to the end of shaft III by means of a nut fllb on the end of the shaft and a removable taper pin llc which can be withdrawn when it is required to turn the tube to a vertical position for remote stereo-radiographs, for instance. Thus, as stated, shaft ll does not rotate upon its own axis but simply has a raising and lowering movement with relation to the universal joint assembly through which it extends. Obviously, shaft 40 maintains a'horlzontal attitude as do also

shafts

21 and 33.

Extending from the casting Ila are the parallel horizontally disposed rods 42 which co-operate with the companion rods I! attached to the X-ray tube It for support of the same. The flat rollers it are mounted upon the end clamp means of the cross bracket 41 extending as a brace means between the rods l3; and these rollers 48 have rolling engagement with the flattened sides of the rods 42. Likewise, the rollers 43 are mounted upon the end clamp means of the cross bracket is extending as a brace means between the rods 42; and these flat rollers I! have rolling engagement with the flattened sides of the rods 43. This roller engagement permits adjustment of the X-ray tube for taking stereoscopic pictures and facilitates adjustment of the tube through ninety (90) degrees for taking a radiograph of a patient in an erect or standing position. Also, the transverse rods of the cross brackets 41 and 49 aiford a means for accurately adjusting the rollers in their contact with th flattened ways of the

rods

42 and 43.

There is a plunger rod Ii extending rearwardly from the tube bracket 5. and provided with a plunger 53 within the air cylinder 54 toserve as a pneumatic shock absorber.

The coil springs 55 are connected at their ends to the tube bracket II and the transverse bracket it within which the rods 42 are mounted, and they tend to move the X-ray tube inwardly or towards the left, as viewed in Figs. and 6 of the drawings.

For the purpose of maintaining the tube at all times in proper angular position during synchronous operation of the tube and casette in the manner above explained, there is provided therod I. which is pivotally connected at its one end to the rod 3! and at its other end to the tube cone by means of the yoke member lib, so as to constitute a parallelogram with the supporting means for the X-ray tube, as will be understood from Figs. 1, 6 and 10. This feature will be more fully explained below.

with this machine it is possible to take stereolaminagraphs, that is when the patient is lying upon the table, the circular movement of the tube and casette being employed in connection therewith, and it is possible also totake stereoscopic pictures of the patient in standing position. When, however, stereoscopic pictures are being taken of the patient in standing position, the means for producing circular movement of the tube and casette will not be employed but the machine will be used for taking conventional stereoradiographs in the same manner a the older conventional type of X-ray machine.

The X-ray tube can b moved outwardly, or toward the right as viewed in Figs. 5 and 6, when it is desired to take stereoscopic pictures. and there is provided a longitudinally movable horizontal latch pin 56 which will be engaged in operated switch at any desired point. Immediwithin the yoke l2.

ately upon withdrawal of the latch 58, the springs will cause the tube to move to its other position by means of the slidable engagement above described, such movement being cushioned by the pneumatic shock absorber. The tube is shown in middle position in Figs. 5 and 6.

There is also a telescopic connection "a in the rod 58 and I have provided also a solenoid bad for actuating the look 580 which will hold the portion 581: locked in extended position, this solenoid being adapted for remote control by the same switch that is provided for solenoid 51 so that these two solenoids can be operated at the same time. One of the recesses into which the look We may engage is indicated at Ste.

My improved stereoscopic structure is of compact, stable form and afiords an efiicient means of support for the tube in such an arrangement.

By virtue of the

double roller engagement

6 and 48, (Fig. '7), the entire bracket of the X-ray tube can be turned so as to occupy position at ninety degrees to that indicated in the drawings, in case it should be desired to take a radiograph of the patient in standing position for instance. As will be seen, the present arrangement will permit stereoscopic radiographs to be taken when the X-ray tube occupies either position, there being an effective roller engagement in both cases, as will be apparent from the present disclosure, and such means of engagement is equally eflleient and dependable in both instances.

The shaft 21 assumes horizontal position'by reason of the fact that it has bearing in the yoked spindle l2. Attached to shaft 21 by means of a taper pin is the flanged collar 21a which servesas a means of adjustment of cross shaft 29 in horizontal position and also as a means of keeping shaft 21 from rotating upon its own axis Having adjusted shaft 29 to horizontal position, shaft 3| can then be adjusted to horizontal position by adjusting the turnbucklcs on rods 30. The rods further serve as a means of adjusting the casette carriage 31 to horizontal position in two planes. That is, by adjusting rods 30 to equal length, there is eliminated any tipping of the casette carrier 31 either way in line with the table; and by adjusting both rods 30 to the proper length, there is avoided any tipping of the casette carrier 31 in the other direction or cross-wise of the table.

As a means of setting and securing the

flanged collar

27a, 1 have provided the adjustable connection as indicated in Fig. 4. The flanged collar 21a has elongated holes 2111 through which extend the machine cap screws 210. With the machine cap screws 21c loosened, the axle 21 can be turned so as to properly position the shaft 29, whereupon the cap screws are then tightened so as to secure the axle in such position.

The tie-plates lOa, which brace the posts l0, serve to prevent the axle from wobbling, although primarily they prevent the assembly of posts l and the universal joints from developing a reciprocal torque action which might otherwise be set up by swinging the tube in a circle from the lower end of its long am. .That is, these tie-plates Illa keep the

axles

21,33 and In in perfect parallel relation which is vital in having the center ray of the tube always follow the same point on the film, while the axle shaft that passes through the universal joint assembly 9, the ends of which are supported in the mid-way castings The grid here is located in neither the nodal plane nor in direct contact with'the film; and, since the tube and film are both moving during exposure, the image of the grid will not be recorded upon the film. Then, in effect, it has a relative motion and can occupy fixed position. Furthermore, my particular form of grid has the effect of giving uniform absorption of secondary rays and thus produce uniform densities over the film. Because of the cellular structure of my grid, it provides openings from wider angles with the same efiective area of absorption surface,

which is a substantial approach towards the ideal situation as above referred to.

I have provided also an improved means for in line with the center ray of the tube the particular part of the patients body which is under examination, as for instance the head, the torso or the feet, In the present embodiment of thisfeature, the lower part or the machine structure, including the casette carrier, is enclosed within a stationary base or casing 63 and upon the top of this casing there is arranged a readily movable bed 63a which has rollers 03b or the assembly, indicated at 3, serves to stabilize the moving structure as it is propelled by the vertical supporting spindle of the yoke "I 2.

In Fig. 11 I have indicated anopening 60a. for loading the casette B0. The grid, which in the present form of disclosure, will occupy fixed position, may be attached to the rigid base or to the under-side of the table, directly over the casette, and is indicated by reference numeral 8!.

The details of my present improved form of grid I are illustrated in Figs. 8 and 9 of the drawings. This grid, which occupies fixed position immediately above the film, comprises the spaced parallel lead ribbons Bla between which are arranged the spacing elements Bib. In my present form of grid, the lead ribbons have been drawn through crimping rollers so as to form diamond-shaped cells when placed together with a thin spacer therebetween. For instance, the lead grid elements, before being crimped, may be about from one-sixteenth to one-eighth of an inch wide and about one-sixty-fourth of an inch thick; while the spacers may be about from onethirty-second to one-sixty-fourth of an inch thick. In the present illustration, the grid elements are greatly exaggerated for the sake of a clearer understanding. 'My assembly of grid and spacer elements is encased between two thin aluminum plates which also serve as a filter medlum, these plates being indicated by reference numeral 610. As will be understood, the spacer elements are of a material that is more or less radio-transparent, as for instance Micarta which is made of paper or linen impregnated with varnish, while the grid elements are decidedly radio-opaque. The thickness of the grid elements may vary.

In the conventional type of X-ray machine, it is necessary to move the grid across the face of the film during the exposure lest an image of the grid lines show upon the developed film. Theoretically, the ideal grid would be one of minute cellular structure which. would give maximum absorption of secondary rays and would also leave no line pattern on the developed him.

for facilitating such movement thereof while th patient occupies position thereon. Instead of using the base or casing as a support for the permanently incorporated bed "a, there might be provided a separate bed upon the floor for properly positioning with respect to the casette carrier so as to support a readily adjustable roller-top upon which the body of the patient might be placed. Or, the regular table type of wheeled support for the patient might be moved into proper position over the casing, thereby relieving the handling or the patient.

There has been an attempt in the prior art to provide a spiral path of movement for the tube and the casette carrier for the purpose of blurring the shadows outside of the objective plane more completely and thereby produce a relatively clearer image of the body section in the objective plane. However, so far as any such prior disclosure is concerned, it has not been possible to accomplish such blurring of the shadows without at the same time sacrificing some of the clarity of the radiographed image and without seriously reducing amplitude also. This has been due to the comparatively limited amplitude that has been possible in the prior machines. In the present machine however, there is provided means of comparatively increased amplitude which is made possible by the particular structure and arrangement of the mechanism including the slidable saddle l6 and the companion diametrical slot I! in conjunction with the adjustability of the nodal point. By virtue of the very nature and geometry of my machine structure, it follows that the greater the amplitude, the thinner and clearer the objective layer or plane.

When it is desired to employ the spiral arrangement, there will be effected an automatic this is accomplished upper edge thereof and is adapted to be engaged by the correspondinglybeveled rotatable disk 'or wheel 61 which is fixed upon the screw-threaded shaft i4. When it is desired to turn the shaft ll in one direction and to thus move the saddle pulley 22. This electric motor will have proper limit switches and controlling devices.

The casing 65 which surrounds the worm gear will serve as an oil retainer.

If so desired, there might be interposed between the wheel 61 and the screw 14 a combination of gears for the purpose of changing the speed of the shaft with respect to that of the turn-table. Such a gear combination is here indicated in a general way as being enclosed within the housing l6a indicated in Fig. 13.

Theoretically it might appear to be necessary to provide an automatic means for varying the nodal point according to and in consonance with the automatic change inamplitude incident to the spiral movement, but in actual practice this is not necessary.

In this connection, it should be noted that with my continuous diametrical slot ll it is possible to obtain an amplitude adjustment to any desired degree and m present device is not limited to an adjustment at only certain spaced intervals as in known instances of the prior art.

As will be understood, a change in the objective plane would cause a corresponding change in the amplitude but this can be compensated for by making any desired change in the amplitude by adjustment of the saddle along the slot 41. In this connection, my present means of amplitude adjustment is especially advantageous since the saddle can be moved to an extent corresponding exactly with any. degree of change of the nodal point, as above explained.

In my present machine structure there can be identified a compound parallelogram linkage in connection with the operation of the casette carrier; one of these parallelograms comprising the

arms

29 and 3| and the rods 30, the other comprising the axle 21, the rods 30, shaft 33 and the posts Hi. It is by means of this compound parallelogram linkage that the casette carrier is mounted in suitable bearings so as to permit such 1 movement about .its longitudinal axis.

I have provided a clamping means Ill and II that is used to hold shaft 40 parallel tozaxle 21 when the tube-supporting assembly is raised or lowered for focal adjustment, thereby'eliminating the necessity of complicated adjustment; the screw and wheel assembly ll being mounted upon th casting Ila, and the member 10 with the arcuate slot being mounted upon the adjustable bracket ll. Thus, when changing the focal adjustment, the wheel II is tightened so as to maintain the parallel relation between shaft "Ill and axle 21, and the set screws 40d, 58c and Id are loosened so as to permit such adjustment; then when the focal adjustment has been made, the

set screws are tightened and the wheel II is freed so as to permit the screw II to move up and down in the arcuate slot II during operation of the members. The strap "a connects'the castings at the ends of the shaft 40 and the rod 58 so as to maintain them at constant distance apart when the clamp screws are loosened.

maintained in a flat horizontal plane while being moved in a circular path within said plane.

Another parallelogram linkage comprises the rod 39, the axle 40, the posts in and axle 21. This parallelogram linkage serves to compensate for the tendency of the tube to dip upwardly and downwardly in a vertical plane as it would do except for the present provision. With this means, the target of the tube is maintained in a flat horizontal plane as it travels in a circular path within said plane in synchronism and coordination with the simultaneous movement of the casette carrier, as above described. Thus the target and the casette are both moved in flat horizontal planes that are parallel to each other and this relationship is maintained at all times throughout all adjustments of the nodal plane.

ter ray through the nodal point, the tube being 'They include, for instance, the compound parallelogram linkage for the casette carrier, and the compound parallelogram linkage for the tube, for operation in the manner above explained; the means of increased amplitude and 'the means for adjusting the same for all degrees; the supporting of the entire machine, as a self-contained structure, at the base thereof with low center of gravity; the location of the drive connections and the means of amplitude adjustment also at the bottom thereof; the special adapability of this machine structure to various technique, with marked flexibility, including the older conventional manner of operation, the comparative simplicity of design and operation; the comparative low cost of manufacture; the improved form of grid; the improved means of adjustment for taking stereoscopic radlegraphs; the improved means for eiiecting spiral path of movement with increased assurance of maintaining the clarity of the image of the body section being radiographed; the conveniently adjustable bed for supporting the body of the patient; and the compact and dependable form and arrangement of all of the various features of construction herein described.

It is believed that this machine embodies in a feasible and efllcient manner all essential and important features of construction and operation and eliminates complications that have rendered other such machines impractical. This machine is capable of all of the possible uses of the older conventional machine and embodies also the further possibility of operating the casette and the target of the tube in circular paths in parallel fiat horizontal planes in a dependable manner, together with numerous features of advantage above noted and suggested.

What I claim is:

1. In an X-ray machine, the combination of an X-ray tube, a carrier for an X-ray sensitive-fihn, upright supporting means for said tube and film carrier, said supporting means having a universal bearing at a nodal point corresponding to the film and the target of the tube will simultaneously describe paths in planes parallel to the objective plane and thereby effect mechanically a virtual focus of the rays from the tube in the objective plane.

2. In an X-ray machine, the combination of an X-ray tube, a carrier for an X-ray sensitive film, upright supporting means for said tube and film carrier, said supporting means having a universal bearing at a nodal point corresponding to the objective plane, a rotatable base upon which said supporting means is mounted and having adjustable connection with the lower end of said supporting means for varying the amplitude, and operating means connected to said base for effecting such movement of said supporting means about its nodal point that the film and the target of the tube will simultaneously describe circular paths in planes parallel to the objective plane and thereby effect mechanically a virtual focus of the rays from the tube in the objective plane.

3. In an X-ray machine, the combination of an X-ray tube, a carrier for an X-ray sensitive film, upright supporting means for said tube and film carrier, said supporting means having a universal bearing at a nodal point corresponding to the objective plane, a rotatable base upon which said supporting means is mounted and having diametrically slidably adjustable connection with the lower end of said supporting means, and operating means connected to said base for effecting such movement of said supporting means about its nodal point that the film and the target of the tube will simultaneously describe circular paths parallel to the objective plane and thereby efiectmechanically a virtual focus of the rays in the objective plane.

4. In an X-ray machine, the combination of an X-ray tube, a carrier for an X-ray sensitive film, supporting means for said tube and film carrier, said supporting'means having a single universal which said supporting means is mounted and having vertical swivel connection with the lower end of said supporting means, said supporting means including an extension at the lower end thereof occupying a fixed horizontal plane with respect to said turn-table, and operative connections including compound paralellogram linkage between said extension and said tube and film carrier whereby movement of said supporting means about its nodal point will cause the film and the target of the tube to simultaneously describe circular paths in planes parallel to the objective plane and thereby effect a virtual focus of the rays in the objective plane.

'7. In an X-ray machine, the combination of an X-ray tube, a carrier for an X-ray sensitive film, supporting means for said tube and. film carrier, said supporting means at a nodal point corresponding to the objective plane, a horizontally disposed turn-table upon which said supporting means is mounted and havbearing at a nodal point corresponding to the objective plane, means including compound parallelogram linkage for efiecting such movement of said supporting means about its nodal point that the film and the target of the tube will simultaneously describe circular paths the objective plane andthereby effect mechanically a virtual focus of the rays in the objective plane.

5. In an X-ray machine, the combination or an-X-ray tube, a carrier for an X-ray sensitive film, supporting means for said tube and film carrier, said supporting meansdiavlng a universal bearing at a nodal point corresponding to the objective plane, a horizontally disposed turn-table upon which said supporting means is mounted and having vertical swivel connection with the lower end of said supporting means, said supporting means including an extension at the lower end thereof occupying a fixed horizontal plane with respect to said turn-table, and operative connecin planes parallel to tions between said extension and said tube and film carrier whereby movement of said supporting means about its nodal point will cause the film and the target of the tube to simultaneously describe circular paths in planes parallel to the objective plane and thereby efiect a virtual focus of the rays in the objective plane.

6. Inan X-ray tube, the combination of an X-ray tube, a carrier for an X-ray sensitive film, supporting means for said tube and film carrier, said supporting means having a universal hearing at a nodal point corresponding to the objective plane, a horizontally disposed turn-tame upon ing vertical swivel connection with the lower of said supporting means, said supporting means including an extension at the lower end thereof occupying a fixed horizontal plane with respect to said turn-table, compound parallelogram linkage connection between said extension and said film carrier, and means of operative connection between said extension and said tube, whereby movement of said supporting means about its nodal point will cause the film and the target of the tube to simultaneously describe circular paths in planes parallel to the objective plane and there-- by effect a virtual focus of the rays in the objective plane.

8. In an X-ray machine, the combination of an X-ray tube, a carrier for an X-ray sensitive film, upright supporting means for said tube and film carrier, said supporting means having a universal bearing at a nodal point corresponding to the objective plane, a turn-table upon which said supporting means is mounted and having dia-' metrically slidably adjustable connection with the lower end of said supporting means, and means operatable by said turn-table for effecting pro gressively continuous adjustment of said slidable connection so asto eifect a more nearly complete blurring of shadows outside of the objective plane and for effecting such movement of said supporting means about its nodal point that the film and thetarget of the tube will simultaneously describe circular paths parallel to the objective plane so as to eifect mechanically a virtual focus of the rays in the objective plane.

9. In an X-ray machine, the combination of up X-ray tube, a carrier for an X-ray sensitive film, upright supporting means for said tube and mm carrier, said supporting means having a single universal bearing at a nodal point corresponding to the objective plane, means located upon opposite sides of said bearing for efiecting vertical adjustment of said bearing so as to vary the elevation of the nodal point, and means for eil'ecting such movement of said supporting means about its nodal point that the film and the target of the.

tube will simultaneously describe circular paths m planes parallel to the objective plane and thereby eifect mechanically a virtual focus or the rays in the objective plane. Y

10. In an X-ray machine, the combination or a holder for an X-ray tube, a holder for an X-ray sensitive medium, upright supporting means for said holders, said supporting means having a universal bearing at a nodal point corresponding to the objective plane, a bus.

having 'a universal bearing.

end a a rotatable turntable upon said base and upon which said supporting means is mounted and having operative connection with the lower end of said supporting means, operating means connected to said turn-table for effecting such movement of said supporting means about its nodal point that the sensitive medium and the target of the tube will simultaneously describe circular paths in planes parallel to the objective plane and thereby effect mechanically a virtual focus of the rays in the objective plane, a bed mounted upon said base above said holder for the sensitive medium, and a roller body-supporting table top horizontally disposed upon said bed in the region of the objective plane and adapted of said supporting means, operating means connected 'to said turn-table for effecting such movement of said supporting means about its -nodal point that the sensitive medium and the target of the tube will simultaneously describe circular paths in planes parallel to the objective plane and thereby eifect mechanically a virtual focus of the rays in the objective plane, a casing mounted upon said base and enclosing said holder for the sensitive medium and the operating means and operative connections, a bodysupporting table top horizontally disposed upon the upper surface of said casing in the region of the objective plane, and roller means between said upper surface and table top permitting transverse rolling adjustment of the table top.

12. In an X-ray machine, the combination of an X-ray tube, a carrier for an X-ray sensitive film, a bracket for said tube, means for supporting said film-carrier and tube bracket, said tube bracket being rotatably adjustable upon said supporting means about a horizontal axis so as to occupy distinctly different positions, means permitting longitudinal adjustment of said tube upon its bracket so as to occupy spaced positions for taking stereoscopic radiographs, and unitary means of support for said tube upon said brackets during longitudinal adjustment thereof in either of said rotatable adjustments.

13. In an X-ray machine, the combination of an X-ray tube, a carrier for an X-ray sensitive film, upright supporting means for said tube and film carrier, said supporting means having a universal bearing at a nodal point corresponding to the objective plane, operating means upon which said supporting means is mounted and being operatively connected thereto for effecting such movement thereof about its nodal point that the film and the target of the tube will simultaneously describe paths in planes parallel to the objective plane and thereby effect mechanically a virtual focus of the rays from the tube in the objective plane, and automatically compensating means for maintaining said tube in proper angular position at all times during such operation of the tube and film.

14. A construction containing the elements in combination defined in claim 13 and in which said last-named means consists of a parallelogram linkage including said supporting means and said tube bracket.

15. A construction containing the elements in combination defined in claim 8 and in which the means for effecting progressively continuous adjustment-of said slidable connection is disconnectible.

16. In an X-ray machine, the combination of an X-ray tube, a carrier for an X-ray sensitive film, upright supporting means for said tube and film carrier, said supporting means having a universal bearing at a nodal point corresponding to the objective plane, a rotatable base upon which said supporting'means is mounted and having operative connection with the lower. el :1 of said supporting means, and operating means connected to said base for effecting such movement of said supporting means about its nodal point that the film and the target of'the tube will simultaneously describe paths in planes parallel to the objective plane and thereby efiect mechanically a virtual focus of the rays from the tube in the objective plane, a. bed mounted upon said base above the carrier for the sensitive film, and a roller body-supporting table top horizontally disposed upon said bed in the region of the objective plane and adapted for transverse rolling adjustment thereupon.

17. In an X-ray machine, the combination of an X-ray tube, a carrier for an X-ray sensitive film, upright supporting means for said tube and film carrier, said supporting means having a single universal bearing at a nodal point corresponding to the objective plane, means for effecting vertical adjustment of said bearing so as to vary the elevation of the nodal point, and means for effecting such movement of said supporting means about its nodal point that the film and the target of the tube will simultaneously describe circular paths in planes parallel to the objective plane and thereby efiect mechanically a virtual .focus of the rays in the objective plane.

GEORGE H. CHAMBERLAIN, JR.