US2499950A - X-ray tube focusing apparatus - Google Patents

Description

. livfiach 7 119% E. R. GOLDFIELD ET AL 2,499,950

X-RAY TUBE FOCUSING APPARATUS 5 Sheets-Sheet l Filed June 15, 1946 mum/ram DW/IV R GoLDF/ELD fiaamr J JrAvA 87 &

Mwfih 9 1950 ER. GOLDFIELD EI Al... 2,499,959

X-RAY TUBE FOCUSING APPARATUS Filed June 13, 1945 5 Sheets-Sheet 2 A 7708 NE YJ March 11950 1 E. R. GOLDFIELD ET AL. 23 9 X-RAY TUBE FOCUSING APPARATUS Filed June 13, 1946 I 5 Sheets-Sheet 3 I INVENT AJ [ow/N R. GOLDF/'LO fiOdif/YT J JrAvA 5 [DGAR I BAJT/N JR.

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ATTORNEY-5 March 7, 1950 E. R. GOLDFIELD ET AL. 2,499,950

X-RAY TUBE FOCUSING APPARATUS Filed June 13, 1946 5 Sheets-Sheet 4 #vvawrom t fow/A/ R. GOLDF/ELD ROBERT J JTA VA foe/1R J EAJT/N'JR.

ATTORNEYJ March 7, 1950 E. R. GOLDFIELD ET AL 2,499,950

X-RAY TUBE FOCUSING APPARATUS Filed June 13, 1946 5 Sheets-Sheet 5 few/N E. GOLOF/L'LD 80mm? J." JrAvA EDGAR J EAJTIN in.

Patented Mar. 7, 1950 2,499,950 X-RAY TUBE FOCUSING APPARATUS Edwin R. Goldfield and Robert J. Stava, University Heights, and Edgar J. Bastin, Jr., Cleveland, Ohio, assignors to Picker X-Ray Corporation Viaite Manufacturing Division, Inc., Cleveland, Ohio, a corporation of Ohio Application June 13, 1946, Serial No. 676,410

3 Claims.

The invention relates to novel and improved means for supporting an X-ray tube. It particularly relates to novel and improved means whereby such tube may be readily and conveniently adjusted in height, in inclination to the horizontal, and in swinging movement in a horizontal plane, so as to facilitate directing the tube on certain desired areas of a subject when said subject is disposed in certain positions relative to the tube.

The apparatus herein to be described is especially adapted for routine examination of specific anatomical regions of a continuous succession of patients. It sometimes becomes desirable to examine all employees of an industrial plant or the like. In a routine examination or periodical check of this nature, it is of course desirable that the project be conducted as rapidly and efliciently as possible, consistent with reliable results. It must normally be expected that the technician operating the X-ray apparatus will be confronted by a considerable variation in the physical characteristics of successive subjects, and consequent adjustment of the apparatus for such variations must necessarily be made, and should be made both readily and rapidly.

In one preferred adaptation of the apparatus herein to be described, and as set forth in our copending application Serial No. 624,172, filed October 24, 1945, the subject stands between the X-ray tube and a fluorescent screen, both screen and tube being maintained in such position that the radiation generated by the tube is directed towards the screen producing thereon a visible image of familiar shadowgraph type. Such image can be studied visually onthe screen, or can be photographed for permanent record, and later studied.

In a routine examination of a substantial number of subjects, each subject steps in succession to a predetermined position, for example on a pedestal or platform which may be raised or lowered to bring any desired portion of the subjccts body in alignment with and between the tube and screen, and the examination is thereupon made or the picture is taken. Those skilled in the medical arts are familiar with the fact that the compensatory adjustment for subject height mentioned above does not necessarily givecomparable results with all subjects, and that an additional adjustment, within a limited range, is often desirable. This is particularly the case when special effects are desired, for example in the achievement or avoidance of special shadow effects in examinations in the general area of the 2 heart and the lungs. Sometimes the clavicle structure requires an X-ray beam directed slightly upwardly or slightly downwardly for the best results. This is easily accomplished by means of our novel tube support.

It is accordingly desirable that the tube support be provided with means for effecting minor but significant changes in the height of the tube, and also in the angularity of the projected radiation with respect to the center of the screen. It is further desirable that the tube support be rotatable in a horizontal plane so that examinations may be made of animate or even inanimate subjects which may not occupy the standing position hereinabove described.

An object of the present invention is to provide novel and improved means for adjusting the vertical height of an X-ray tube, and for simultaneously varying its projection axis with respect to the horizontal, so that axis still intersects the center of the fluorescent screen.

A further object is to provide novel and im-- proved means for facilitating horizontal move-- ment of the tube carrying means towards and from the screen, and for locking the mechanism in desired position.

A further objectis to provide novel and improved means forpermitting swinging movement of the tube assembly in a horizontal plane, and for locking the assembly when the desired position is attained. Other objects and advantages will be apparent from a study of the following description of one embodiment of the invention, in conjunction with the accompanying drawings of said embodiment, in which:

Fig. 1 is a sideelevational view of an X-ray tube support and associated structure for imparting the desired positional adjustments as hereinabove indicated;

Fig. 2 is a fragmentary front elevational View, somewhat enlarged, as seen from the right of Fig. 1;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a sectional view taken on the'line 4-4 of Fig. 1;

Fig. 5 is a sectional view taken on the same line as Fig. 4, but showing certain of the parts in an operating position differing from that of Fig. 4;

Fig. 6 is a sectional view taken on the line 6-45 of Fig. 3;

Fig. 7 is a sectional view taken on the line 1-? of Fig. 1;

Figs. 8 and 9 are sectional views taken respectively on the lines 88 and 9-43 of Fig. '7;

Figs. 10 and 11 are detail views in vertical section, corresponding generally to the showing of the same parts in Fig. 1, but illustrating respectively different operating positions;

Fig. 12 is a fragmentary perspective view, normally contacting parts being exploded for greater clarity, the view illustrating details of certain associated elements in the tube supporting structure;

Fig. 13 is a view in side elevation, and somewhat reduced, illustrating the relationship of the several possible tube positions to the fluorescent screen.

Speaking first generally, an X-ray tube 20, shown in outline in Fig. 1, is fixed in position on the rear face of a mounting plate 2|. In alignment with the zone of emergence 22 of the rays from the tube, the plate is provided, on its front surface, with a hollow cone 23, or other device having walls diverging away from said zone of emergence. The axis of projection of the X-rays is indicated in Fig. 1 by the arrow B, and the cone is constructed from material relatively impervious to X-rays so that it restricts the bundle of emergent rays to such cross sectional area as is desirable or necessary for its intended purpose. The fluorescent screen heretofore mentioned, and shown only diagrammatically in edge view in Fig. 13, is spaced from the cone a distance sufficient to permit a subject to stand between the cone and the screen. Actually, as will later appear, the distance is carefully determined so as to be conformable to factors incident on tube height and the angularity of the projection axis in the several possible operating positions.

The mounting plate 2| is supported on a tube stand 24, movable endwise on the carriage, namely, to the right and left in Fig. 1. Mechanism whereby endwise movement is accomplished and locking means for fixing a predetermined position, will later be described.

The carriage 25 is rotatable in a horizontal plane around a fixed axis on the top of a suitable support such as the column 26. Positioned and locking means are provided, and will later be described, for determining. and fixing the required angle of the carriage in said horizontal 1 plane.

The upper portion of the stand 24 and the lower portion of the mounting plate 2| are provided with complementary interengageable positioning means which simultaneously serves two purposes. namely to adjust the height of the tube and plate, and to vary the angle of the axis of projection of the X-rays to compensate for the height change. Means for fixing a predetermined height and angularity of the projected beam is likewise provided.

The means for accomplishing all said movements, and the respective locking means for the same, will now be described.

Considering first the rotary movement of the carriage on the top of column 26, and referring particularly to Figs. 1, 2, 3 and 7, the top of the column is outwardly flanged at 30 to provide a seat for an indexing plate 3| on top of which is fixed a circular pilot plate 32 forming the axis around which the carriage turns. The carriage 25 is of trough-like character having a horizontal bottom wall 33, two vertical side walls 34, and two outturned shoulders 35 at the top of the side walls. The bottom wall is provided with a centrally located aperture 36 (Fig. 3) which is disposed to have a rotating friction fit around the pilot plate 32. After disposition of the carriage on the indexing plate 3 I, and around the pilot 32, a retaining plate 3! is placed above the assembly, with its edges overlapping the edges of aperture 36. The indexing plate 3| and the flange 30 of the column 26 are maintained in fixed position with respect to each other by screws 38. The retaining plate 31, the pilot plate 32 and the indexing plate 3| are maintained in fixed position with respect to each other by screws 39. The assembly, as best seen in Fig. 3, is thereby so arranged that, if desired, the retaining plate and pilot are separately removable merely by removing screw 39, the indexing plate being still retained by the screws 38 as aforesaid.

The means for permitting rotary movement of the carriage having been thus described in the last preceding paragraph, the locking and positioning means therefor will now be explained.

The indexing plate 3| (Fig. 7) is generally circular in peripheral contour, and is provided with edge slots 43, 43a, 43b, circumferentially spaced approximately forty-five degrees apart. The lock lever 44, swingable on a pivot pin 45 on the under side of the carriage, has an upwardly extending pin 46 which passes through a slot 41 in the bottom wall 33 of the carriage, and the upper end of said pin is normally seatable in one of the spaced slots on the index plate, thereby preventing rotation of the carriage. Disengagement of pin 46 from any slot is effected by clockwise movement of the lever 44 (Fig. 7) such movement being achieved by means of a release handle 48 underlying and carried by the carriage 25 as best seen in Fig. 8. One end of the release handle is pivotally connected at 49 to lock lever 44, and the other end of the release handle, near the extremity of the carriage, is hooked to provide a finger pull 5!]. The release handle is reciprocably mounted beneath the carriage b a screw 5| which has a portion 52 passing through a slot 53 in the lever. The assembly consisting of the locking lever and release handle is biased to looking position by spring 54 which is fixed at its opposed ends to handle 48 at 55, and to the bottom wall of the carriage at 56.

It will be apparent that when the release handle is drawn to the right (Figs. '7 and 8) pin 46 is unseated from slot 43 and the carriage may be rotated approximately ninety degrees counter clockwise until pin 46 reaches slot 4317. Once the pin is out of slot 43, and rotation commences, the handle 48 may be released, whereupon spring 54 maintains the pin in sliding contact with the periphery of the indexing plate 3|. The pin will naturally drop by spring bias into the next slot which passes beneath it.

The mechanism permitting endwise movement of the tube stand 24 on the carriage 25 will now be described, referring particularly to Figs. 1 to 6 inclusive, and to the detailed perspective view shown in Fig. 12. All parts shown in Fig. 12 are normally in interfitting engagement, but the view is exploded for clarity in illustrating the specific contour of the various elements.

The tube stand 24 has an upstanding front wall anda pair of spaced downwardly and rearwardly inclined side walls 6|. Between said side walls, and across the lower edge of the front wall is a transverse floor strip 62. Along their lower edges the side walls 6| are upwardly cut away to provide spaced arches 63. The wall portions between the arches are inturned to provide spaced inwardly inclined feet in the plane of the floor strip.

A base plate 61 rests upon carriage 25, straddling the trough portion, and being supported on the carriage shoulders 35. The base plate has a depressed longitudinally centrall located floor 68, and side edge riding flanges 69. Along the outer edges of the flanges 69 are a plurality of spaced downturned guiding fingers Ill. Underneath the two flanges 69 are a pair of respective bearing strips II which are readily slidable endwise on the carriage flanges 35.

A lock plate 13 rests transversely on the riding flanges of base plate 61 and has spaced downwardly extending fingers 14 which pass within the recesses '15 in the base plate. The finger tips 76 are inturned beneath flanges 35 but with freely moving vertical clearance as shown in Fig. 5 when the plate is in unlocked position. The tube stand 24 overlies plates 61 and 13, the feet 65 of the tube stand being rigidly connected with plate 61 and bearing strips H as by bolts 11 passing through holes I99 and |9| (Fig. 12). In the assembled position, and unless looked as later described, the lock plate 13 is freely floating, to a limited extent, as permitted by the clearance above finger tips 16 as aforesaid. The fingers 14 of the lock plate have edge clearance between their side edges and the edges of feet 65, and have vertical clearance by reason of the height of arches 63. In said assembled position the lock plate is loosely retained between the tube stand and the base plate. The floor portion of the base plate 61 is provided with a pair of opposed, upturned lugs 19, one at each end, the lugs having a pair of aligned apertures 89 to serve as end bearings for a shaft 8| upon which are fixedly carried two locking cams 82. The looking plate 13 is provided with downturned end covers 83 which lie outside lugs 80 and which have arches 84 aligned with the bearing apertures 80.

A glance at Figs. 4 and 5 for example will indicate that when shaft BI is rotated from the position shown in Fig. 5 to the position shown in Fig. 4, the raised portion of cam 82 contacts the lowe face of lock plate 13 and brings fingers 16 into tight contact with the lower surfaces of shoulders 35 of the main carriage. This prevents endwise movement of base plate 61 for the reason that the base plate rests on the upper surfaces of the carriage shoulders and operation of the cams produces an opposed gripping force on the lower surfaces of the same shoulders. As best seen in Figs. 1, 2 and 3 the end of the shaft 8| extends under and in front of the wall 60 of stand 24, and a crank arm 85 is fixed to said shaft end for rotation of the shaft. Stop pins 85 in wall 60 provide limit rests for arm 85.

When it is desired to move the tube and stand assembly endwise on the carriage, the crank arm 85 is swung from the locked cam position (Figs. 2 and 4) to the unlocked cam position (Fig. 5), after which endwise sliding movement can be produced between bearing strip H and carriage plate shoulders 35. The tube stand of course moves with the bearing strip.

To prevent accidental removal of the tube and stand assemlby a stop 2 is secured to bottom plate 33 of carriage 25 (Fig. 12) and a slot I03 is cut in plate 61 to receive lever I04, pivotally mounted by means (not shown) so that a portion of lever HM engages stop I92 in the position of the parts shown in Fig. 12. Lifting the lever I94 causes it to clear stop |02 so that plate 51 may be removed from carriage 25.

Still another adjustment of the X-ray tube assembly is one which combines upward or downward movement with relation to the carriage and simultaneous tilting movement of the tube to vary the angle of the radiation beam with respect to a horizontal plane. The mechanism to be described automatically secures the proper tilting angle when the height is changed, with the result that the central or axial beam in the bundle of projected rays always intersects the center of the fluorescent image screen. In connection with the following description reference may be had to Figs. 1, 2, 10, 11 and 13.

The upper portions of the angular side walls 6| of the tube stand are provided with matched pairs of horizontally aligned socket slots in a vertically ascending series, three such pairs 81a, 81b, and 8'7 c being here shown. The tube mounting plate 2| has amxed thereto a crossbar 8B the ends of which extend laterally beyond the mounting plate and are seatable in one or other of the aforesaid aligned pairs of sockets. Since such sockets open upwardly and rearwardly, the mounting plate may be handled manually, and the crossbar ends rested in any desired pair of sockets.

Tilting movement of the mounting plate is automatically controlled by means of the following mechanism.

The front surface of the mounting plate 2| is provided with three vertically spaced bosses 89, 99 and 9| respectively, each one perforated and threaded to receive a suitably threaded shank of a thumb screw 92. Said shank extends through a bushing Q3 lining an aperture in the front wall 69 of stand 24. Bosses 89 and 9| are of equal height from the surface of plate 2|, and the middle boss 90 is somewhat shorter. By comparing Figs. 1, l0 and 11 it will be apparent that when the mounting plate is in the intermediate position of Fig. 1, boss 99 is engaged by the thumb screw shank, and the thumb screw is then turned until bosses 89 and 9| make contact with the rear surface of wall 69, thereby placing the mounting plate 2| and the front wall 69 in parallel relationship. In such position the central axial beam of the X-ray radiation exactly intersects the screen center. This is the full line position R of Fig. 13. v

If the mounting plate is placed in the top position (Fig. 10) boss 9| is above the top edge of wall 60 and bosses 89 and 90, being of unequal heights, the plate 2| is tilted as shown so as to incline radiation axis R downwardly. This is the dot-dash position Ri'of Fig. 13.

The upward tilt of the radiation axis in the lowest plate position, as shown in Fig. 11 and in dotted line R2 in Fig. 13, is achieved by providing an aperture in wallBU which permits boss 89 to extend outwardly therethrough while boss- 9| is engaged by the thumb screw shank. As best seen in Fig. 11 this; permits a backward tilt of the plate 2| giving the radiation axis an upward inclination such as is necessary to intersect the screen center as aforesaid.

The vertical height between sockets 81a, 81b, and 810, the angle of tilt, and the distance to the screen are such that the radiation axes from three positions intersect at the center C of the screen 96 as shown in Fig. 18.

When making a routine check, for example of heart or lung conditions of a succession of patients, the tube stand and fluorescent screen are maintained at a fixed distance from each other. This distance is determined by the point 7'. at which the various radiation axes intersect, such point in turn depending on the vertical displacement of the tube mounting plate in the severahoperating positions, and the angular tilt of said plate in each said position. As hereinbefore indicated, the point of intersection should coincide with the center of the fluorescent screen.

The side of the carriage may have afi'ixed thereto ascale98 (Fig. 1) graduated in inches or other units,- and the'endwise movable portion of the apparatus, for example the base plate 63, may carry a pointer 99, which travels along the scale when the tube stand is moved. Normally the distance between the carriage support and the fluorescent screen is fixed, so that the scale reading ma directly indicate the distance from the tube target to the screen. Such endwise movement is usuallynecessary'only when a tube is replaced by another of diiferent structural characteristics, and in'which the tube target is not in identical position with respect to the mounting plate.

In the normal set up, as hereinabove mentioned, wherein the tube, the screen, and the patient are insubstantially fixed and predetermined relative position, swinging movement of the carriage around its pilot pivot is entirely unnecessary, and the pin 460i the lock lever 44 maintains an established position in a specific slot in the indexing plate 3 l. Swinging movement of the carriageis available, for example if it becomes desirable or necessary to direct the radiation angular-1y away from the conventional alignment as above noted. The slots '43, 43a, 43b, in the indexing plate may be spaced any suitable angular distance apart to provide a choice of stopping points, although as shown herein, and'particularly' in Fig. 7, the normal swing does not exceed ninety degrees, being limited by the stop shoulders 94on slots 43 and 432).

Major adjustments in the vertical position of the carriage or the screen may be made in any conventional manner, by rack and pinion, worm and gear, or otherwise. Novel means for doing thisareshown in the above mentioned copending application. The novel and improved means here shown and described for effecting minor but necessary adjustments in both height and inclination angleirepresent' significant contributions to the successful operation of the apparatus.

When the apparatus is in use, the observer, or the camera" for photographicall recording the image produced on the fluorescent screen, occupies a position tothe left of the screen 96 as sh'own'in Fig. 13.

What we claim is:

1; In "X-ray-apparatus' wherein an X-ray tube housing is maintainable in substantially fixed horizontal relationship to fluorescent screen, means for supp'orting'said tube housing including pins horizontally aligned on opposite sides of saidhousing on an axis at right angles to the X -ray beam, a bracket having a plurality of pairsof upwardly opening slots at different vertical levels adapted to receive said pins, and stops engaging between said bracketand said housing in ea'ch'position' to tilt said housing to cause the 8; X-ray beam to strike said screen at approximately the same point.

2. In X-ray apparatus wherein'an X-ray tube housing is maintainable in' substantially. fixed horizontal relationship to a fluorescent screen, means for supporting said tube housing including a bracket and including coacting sets of pin members and slot members, one of said sets connected with said housing and the other set connected with said bracket, said supporting means including a plurality of one of said sets of members at difierent vertical heights, each of said sets of pin and slot members providing a horizontally extending pivotal axis for said housing, said housing being tiltable about said pin and slot members to vary the inclination of the X-ray beam, and stop means between said bracket and said housing when supported on each of said sets of pin and slot members to tilt the housing to cause the X-ray beam to strike substantially the same portion of said screen.

3. In X-ray apparatus wherein an X-ray tube housing is maintainable in substantially fixed horizontal relationship to a fluorescent screen, means for supporting said tube housing including a generally vertical mounting plate having pins horizontally aligned on opposite sides of said housing on an axis at right angles to the X-ray beam, a bracket having three pairs of upwardly opening slots at different vertical levels adapted to receive said pins, three bosses on said plate spaced vertically and positioned to engage against said bracket when said pins are in said slots, a screw held in said bracket and adapted when threaded into said plate to pull said bosses toward said bracket, each of said bosses threaded to receive said screw, the middle of said bosses being of lower height than the top and bottom bosses, which are of equal height, whereby when said screw is threaded into said middle boss said plate is substantially vertical, said top boss being above said bracket when said screw is threaded into said bottom boss, whereby when said screw is threaded into said bottom boss said plate is tilted with its upper end forward, and there being an opening in said plate to receive said bottom boss when said screw is threaded'into said top boss, whereby, in the last named'position, said plate is tilted with its upper end rearward.

EDWIN R. GOLDFIELD. ROBERT J STAVA. EDGAR J. BASTIN, J a.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,797,303 Wappler etal Mar. 24, 1931 1,871,005 Mutscheller et al. Aug. 9, 1932 2,156,170 Augustin et a1 Apr. 25, 1939 2,167,114 Kieffer July 25, 1939 2,235,144 Colcher Mar. 18, 1941 2,400,455 Donaldson May 14, 1946

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