US 1337904 A
Description (OCR text may contain errors)
E. E. GREVILLE.
X-RAY TUBE STAND AND TABLE.
APPLICATION FILED APR.4, 1918.
1,387,904. Patented Apr. 20, 1920.
Fig. 1 1 ::;B
E. E. GREVILLE.
I X-RAY TUBE STAND AND TABLE.
APPLICATION FILED APR.4, 1918.
1,337,904. Patented Apr. 20, 19,20.
5 SHEETS-SHEET 2.
I 3E Fig.9. 1 2 .10. M
E. E. GREVlLLE.
X-RAY TUBE STAND AND TABLE.
APPLICATION FILED APR. 4, 1918.
1,337,904. Patented Apr. 20, 1920.
5 SHEETS-SHEET 3.
Fig/2 E. E. GREVILLE.
X-RAY TUBE STAND ANMABLE.
APPLICATION FILED APR. 4, I918- 1,337.,904. I v Patented Apr. 20,1920.
5 SHEETS-SHEET 4- f q/t E. E. Bra/i286.
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. E. E. GREVILLE.
X-RAY TUBE STAND AND TABLE.
APPLICATION FILED APR- 4., L918.
1,337,904. Patented Apr. 20, 1920.
5 SHEETS-SHEET 5- June/$1. E. E reo'ilfe.
ERNEST ELIAS GREVILLE, OF LONDON, ENGLAND.
X-RAY TUBE-STAND AND TABLE.
Specification of Letters Patent.
Patented Apr. 20, 1920.
Application filed. April 4, 1918. Serial No. 226,703.
I '0 all whom it may concern:
Be it known that I, ERNEST ELIAs (innviLLn, surgical-instrument maker, residing at 167 Grays Inn road, London, in the county of Middlesex, England, have invented a new and useful Improved X-Ray Tube-Stand and Table, of which the following is a speci fication.
My invention relates first to X-ray tables used in conjunction with X-ray tube stands; secondly, to X-ray tube stands used sepa rately or in conjunction with X-ray tables; thirdly, t0 the combination of an X-ray table with my X-ray tube stand forming together one complete apparatus known as an K-ray couch. The object of my invention is to provide improved apparatus for the X-ray examination of patients by means of fluoroscopy and X-ray photography, and also for the X-ray treatment of disease for medical or surgical purposes.
In the accompanying drawings:
Figure 1 is a side elevation of the table, and
Fig. 2 is a similar view with the top removed and with a stretcher in position thereon.
Fig. 3 is a sectional plan of the table-with the top in position.
Fig. 4; is an end view of the table with the top in position, and
F ig. 5 is a similar view with the top removed.
Fig. 6 is an elevation of the X-ray tube stand looking from one end of the table, and
Fig. 7 is an elevation of the same looking from a direction at right angles to that of Fig. 6.
Fig. 8 is a detail View drawn to an enlarged scale showing the cradle for supporting the arm carrying the X-ray shield.
Fig. 9 is a detail view drawn to an enlarged scale showing the X-ray shield and its arm separately.
Fig. 10 is a detail View drawn to an enlarged. scale showing the diaphragm shutter and its operating mechanism.
Fig. 11 is a detail view of the scale as employed on the screen and tube arms.
Figs. 12 and 13 are elevations looking from the side and end of the table respectively, showing the tube stand and table assembled.
Figs. 14 and 15 are detail views looking in form an i' directions at right angles to each -other showing a coupling device for the motion mechanisms of the tube and screen arms.
Fig. 16 is a view drawn to an enlarged scale showing gage mechanism for contro1- ling the movements of the tube arm.
Fig. 17 is a view showing details of the means for supporting the tube stand.
Fig. 18 is a perspective View showing a stand for supporting a curtain and a flnorescent screen.
Firstly, I describe my K-ray table .l make my table top of material transparent to the X-rays and so that the top can be removed from the table leaving underneath on the fixed portion of the table supports suitable for receiving the side pieces of a stretcher, so that if a patient on a stretcher is brought to the X-ray table he can be examined by the X-rays without removal from the stretcher, as, when the top of the table is removed, the stretcher bearing the patient can be laid on the supports made to receive the stretcher. W here required for transport, 1 make my table vith folding legs.
As a further improvement when using my apparatus for the screen examination of a patient I attach two uprights UP, UP, Fig. 18, to one end of my table either to the legs or the end of the table top, and, between these uprights, ll fix a curtain of canvas or wood W U, 18, to curtain oflf the light from the X-ray tube, which tube is behind the curtain, and, therefore, not shown. The patient stands between this curtain and a fluorescent screen SC, Fig. 18. Should it be desirable to suspend the fluorescent screen I attach it by cords to one or more supports SU, EU, 18, fixed to the two uprights attached to the table. In Fig. 18 A represents a leg of the table. C a side rail.
Lastly, I make my table work in combination with an X-ray tube stand so as to l -ray couch. I attach to the two pairs oi legs of the table two rails one on either side. These rails may be of wood, metal, or other suitable material, and they are so placed and shaped as to provide supports and guides for the base of my tube stand. The upper surfaces of the rails are grooved and shaped to receive the balls, casters, or wheels, on whi h the base of the tube stand runs, or, more conveniently, I
groove the wheels or casters on the base of my stand and fit them to run on corresponding projections on the table rails. From this it results that an X-ray tube stand made to run on the floor can by this modification be placed to run from end to end of the rails of my table thereby forming one complete X-ray couch.
In the accompanying drawings Fig. 1 shows a side view of the table, A and A being the legs, B the removable top, C one of the side rails or runners forming the supports and guides .for the foot of my X-ray tube stand.
Fig. 2 shows a side View of the table with top removed and stretcher D lying in position. C is the side rail or runner.
Fig. 3 shows a sectional view of the table from above with top B in position. E and E show the removable portion of the framework which, when removed, permits the legs to fold or hinge between the side rails shown at C, Fig. l and Fig. 2. F and F are transverse supports for holding in position the legs of the table and for supporting the stretcher shown in Fig. 2.
Fig. 4: shows the end view of the table, B being the removable top; C and C are the side rails.
F ig. 5 shows the end view of the table with table top removed. G and G are projections to support the table top. F is one of the transverse supports also shown at F and F, Fig. 3. II, Fig. 5, is a stop for checking or stopping the movement of the tube stand. J and J are sockets to support the insulated terminals shown at X. and X, Fig. 4:, which carry the wires conveying the high tension discharge to the X-ray tube.
.Secondly, I describe my X- 'ay tube stand.
My X-ray tube stand is so provided with joints and movable parts that it gives easily the required positions of the X-ray tube.
It is also provided with diaphragms to shut off the light of the tube. These diaphragms are worked by crank levers operated by power transmission shafts. The X-ray tube and the diaphragms are carried on one movable arm. Another movable arm of almost similar construction is added to carry a plate-holder when that is required. By a novel arrangement these arms are interlocked so that bothcan be moved while keeping their relative distances to each other whether the movement is forward or backward or in the vertical or horizontal direction.
To make my stand I take a base of suitable material, preferably metal, and of convenient shape, either for resting on the floor or on the rails of the table. This is shown at AB, Figs. 6 and 7.
To the base I attach balls, casters, or wheels, preferably grooved wheels which serve as feet. These are shown at BC and B, Fig. 6 and B and B, Fig. 7.
On the upper part of the base I make a socket CD, Fig. (3 and Fig. 7, into which I it a vertical upright DE, Figs. (3 and 7, preferably of square metal tubing so titted that the upright may move around an imaginary line representing its own vertical 31118.
To this vertical upright I fit a frame or cradle shown in detail in Fig. 8 and shown fitted in position at EF, Figs. (3 and T and Fig. 8. This cradle can be clamped in any position on the vertical upright DE by the clamp N, Figs. 6, S and 13. I attach to this cradle a wire cable WR, Fig. 6, which passes around a grooved wheel shown at FG, lfigs. 6 and 7, fixed on the upper part of the vertical pillar or upright DE. One end oi this cable is attached to the cradle EF (attachment not shown). To the other end of the cable I attach a. counterweight, not
shown. This counterweight passes inside the hollow tube forming the upright or pillar DE, Figs. (5 and 7, and counterweights the cradle EF, Figs. 6 and 13, and all that it carries. The cradle carries a horizontal arm GI-I, Fig. (5, one end of which carries an X-ray shield shown at HI, Figs. 9 and 13. The shield holds and protects the X-ray tube T U Fig. 13, within it. The tube TU is also shown by dotted lines in Fig. 9.
The horizontal arm GII, Fig. (3, can be projected to a. greater or lesser extent by a rack and pinion movement, the handle of which is shown at JK, Figs. 6 and 8. It can also be moved in the vertical direction by a rack and pinion movement, the handle oi which is shown at K, Figs. 6 and 8. Fig. 8 also shows the pinion wheel movements controlled by the handles K and JK.
By these movements I can cause my X-rav tube shield HI, Fig. 13, carrying the X-ray tube to move either upward ordownward. or forward or backward across the table. In addition to these movements I obtain a circular movement of the horizontal arm around an imaginary line representing the vertical axis of column DE as column DE rotates in its own socket shown at CD, Figs. 6 and 13-. I 1
Therefore, if I swing the arm GII, Fig. 13, with its standard or column DE through the quarter of a circle I bring the arm parallel with the edge of the table-top and as I have sufiicient spa e between the standard and the table top I can rack the arm up ward so that the shield III clears the edge of the table, reaches a level above the table when it can be swung over the table to a position parallel to that shown. in Fig. 13. but above the table.
The column DE can be clamped by the winged screw shown at L, Figs. 6 and 7.
T he X-ray shield HI, Fig. 13, is free to rotate on a horizontal axis formed by an imaginary line passing through the center of the hollow horizontal arm GH, Figs. 13 and 9, by means of a metal rod, or prefer ably a tube, shown at Fig. 9, M and M. being the two ends. This rod or tube, circular in section, passes through the hollow arm GH, Figs. 13 and 9, and has one end fixed to the shield HI, Figs. 13 and 9, the other end being gripped by a fly nut N, Figs. 9 and 13. Therefore, the shield can be so rotated that the aperture AP through which the X-rays are projected) may be di rected either upward as in Fig. 13, downward, or in any intermediate position, and can be clamped in any position of the circle in which it is moved.
When using a diaphragm in connection with the X-ray tube or with the holder in which the X-ray tube is placed I employ the following device for opening 01' closing the diaphragm shutters Q and Q, Q," and Q, Fig. 10. I provide one or more crank levers O and 0, Fig. 1.0, capable of being operated by suitable control handles P and P, Fig. 10, that can be situated at any con venient distance from the diaphragm shutters Q and Q, Fig. 10, the handles P and P, being connected to the levers by power transmission shafts R and 1%, Fig. 10, of any convenient length.
The ends of the lovers 0 and 0, Fig. 10, I attach by hinged junctions, preferably ball and socket junctions S and S to arms 'I and T, Fig. 10, terminating in two other hinged junctions, preferably ball and socket junctions U and U, Fig. 10, which are in turn connected to the controlling handles Y and Y, Fig. 10, of the diaphragm shuttors Q. and Q and Q.
The controlling handles Y and Y each form the verti al limb of a T shaped piece of metal. In this T shaped piece a circular hole is made at the junction of the vertical limb with the cross piece of the T and by a pin through this hole the T shaped piece is connected to a plate fixed to the shield so as to pivot on that point. From this it re suits that the movement of the handle, say the handle Y tilts one end of the cross piece of the T forward and simukaneously the other end backward. As each end of the cross pie e of the T is attached to a leaf of the diaphragm and as each pair of leaves runs in a frame just as a pair of window frames run in a sash frame it will be seen that a movement in one direction of the controlling handle Y closes the two leaves while a movement of the same handle in the opposite direction opens the two leaves.
The same principle is employed to move the second pair of leaves but as they are set at right angles to thefirst pair the combination enables me to get apertures of various sizes, square or oblong, and always in the center of the X-ray shield to which they are fixed.
By this flexible method of transmitting the power exerted at the control handles P and P, Fig. 10, I am enabled to drive levers Y and Y, Fig. 10, around a portion of a circle even though the circular motion is around an axis at right angles to the axis of rotation of the power transmission shaft. By the means described above I am enabled to control two or more leaves or shutters of a diaphragm without the use of cog wheels, chains, worm gear, cord drives or springs.
In addition to the arm carrying the X-ray tube I fit a second arm AC, Fig. 13, of somewhat similar construction on the upright part of the X-ray tube stand. This arm is to carry at option either an X-ray screen or an X-ray photographic plate inclosed in a suitable protective case. For convenience I make the arm carry a tray BD, Fig. 13, on which either the X-ray screen or the X-ray photographic plate may be placed. This tray can be tilted to any angle and may be clamped in position by the screw handle J L, Fig.- 13. This plate tray can also be rotated on its horizontal axis, and can be clamped in position by the clamping screws EGr, Fig. 13, to which it is connected by a rod or tube passing through the inside of the tube AC.
This arm AC, Fig. 13, which I call the screen arm being supported in a cradle EF fitted with rack and pinion mechanism and clamp N made broadly like that of the arm that carries the X-ray tube, which I call the tube arm, can, like the tube arm, be easily moved up or down, or swung around with the upright. It can also be moved backward or forward. From these move ments it results that the X-ray screen or photographic plate held by this screen arm can be rotated around its horizontal axis or can be moved upward or downward, forward or backward in relation to the anode of the X-ray tube supported in the X-ray shield HI, Fig. 13. One end of the X-ray tube is shown at TU, Fig. 13.
By a coupling device shown at Fig. 1a and Fig. 15, I, by a single movement conveyed by a rack and pinion or other convenient device, cause the screen arm and the tube arm to move together so that each arm. follows the movement of its fellow in such a way that the screen and the X-ray tube carried by the respective arms move in one of the following directions, viz. up or down, forward or backward, or, if the upright pillar carrying the arms be swung around, in a circular direction, each of the arms keeping the same relation to the other and main taining in movement the same fixed dis-- tance apart at which the arms were first set.
Firstly, I describe this coupling device to show how the two arms are moved by it either forward or backward in the horizon tal direction and how the arms can be uncoupled to move independently.
This device consists of two cog wheels BE and BE, Fig. 14, connected by a chain or rod CE, Fig. 14, inclosed in a suitable casing DF, Figs. 14 and 15, which casing complete with its cogwheels, chain, etc., is readily detachable. Two cogwheels BE and BE, Fig. 14, which are supported in a rigid gear case DF, Figs. 7, 14 and 15, have each a hole through the center, preferably a square hole. These holes are shaped to fit each on a spindle correspondingly shaped to pass through the holes-one spindle ll, Figs. 14 and 15, is engaged by the cogwheel CF, Fig. 15, to the upper or screen arm shown at AC, Figs. 13, 14 and 15, the other spindle, shown at W, Fig. 14, is similarly engaged to the tube arm shown at GH, Figs. 13 and 14. Each spindle has connected to it a handle as shown at JM, Figs. 6 and 15 and J K, Fig. 6. From this it results that the arms AC and GH, Fig. 13, when the gear case with its contained mechanism is in position, are so coupled together that whether moved up or down they move in unison maintaining a fixed distance apart, the exact distance depending on the distance between the holes in the centers of the two cogWheels.
The cogwheels BE and BE, Fig. 14, are coupled together by a toothed rod or chain, preferably a chain as shown at CE, Fig. 14. From this arrangement it results that when the handle of either spindle is moved, say, the handle JM, Figs. 6 and 15, the power is transmitted by the spindle V, Fig. 14, to the other spindle W, Fig. 14, by means of the cog wheels and chain shown at Fig. 1'4.
As the two spindles whose handles J M and JK are shown in Fig. 6, are engaged respectively one to each of the two arms AC and GH, Fig. 6, by a rack and cog mechanism, more clearly shown at JK, Fig. 8, a movement of either of the spindles will produce a corresponding movement backward or forward of the horizontal arms AC and GH, Fig. 6.
lVhen it is desirable to move the arm GH, Fig. 14, independently of the arm AC, Fig. 14, I pull out the clutch handle EH, Fig. 15, which is connected to tne cog wheel CF, Fig. 15, and thereby disengage the cog wheel CF from the rack DG, Fig. 15, which is fixed to the screen arm AC. This movement releases the screen arm AC so that it no longer moves in forward or backward unison with the X-ray tube arm BI-I, Fig. 14.
In Fig. 14 I show two clips EK and EK'. These are fitted to the outside of the gear case DF and are for fixing the gear case to the spindles. By releasing these clips l' can disconnect the gear case and its contents from the spindles W and W attached to the arms AC and CH, Fig. 14, leaving the arms uncoupled and disconnected from one another, as shown in Fig. (3, when each arm is free to move up or down, forward or backward, irrespective of its fellow.
Secondly, I describe how I couple the arms that they move together in the upward or downward direction. The up or down movement is brought about by coupling the upper cradle with the lower cradle by attaching the gear case exactly as above described.
hen thus coupled a turn oi the pinion wheel K, Fig. 6, moves the two arms together in the upward direction, while a turn of the same pinion wheel K, Fig. (3, in the reverse way, moves the two arms together in the downward direction. Although the cradles are locked together the arm (ill can be separately manipulated in the horizontal direction by means of the handle JK, Fig. 6, provided that the cogwhcel CF, F 15. is disengaged from the rack DC by means oi? the clutch handle EH shown in Fig. 15. Further to utilize this movement for the purpose of using the apparatus as a localizer of foreign or other bodies in the patient, I fix on the tray BD, Fig. 13, or on the screen in the tray, cross wires, and I separately manipulate the tube arm Crlil, Fig. 13, and the screen arm AC, Fig. 14, until the anode of the X-ray tube, within the shield I'll, Fig. 13, below the table is in the same vertical line as the cross wires (not shown) fitted to the screen carrier or tray Bl), Fig. 13, above the table. The foreign body in the patient (not shown) who lies on the table is at an intermediate level. I next lock the two arms together by pushing in the clutch handle EH, shown in Fig. 15, and then manipulate the screen arm and with it the tube arm which follows exactly, until the shadow of the foreign body falls on the cross wire. I then known that the cross wire, the foreign body and the anode of the X-ray tube are in the same vertical line. I know the exact distance between the anode of the Xray tube and the cross wire because the cradles supporting the arms which carry them are rigidly locked together at a fixed distance apart, say 50 centimeters. The problem is to exactly locate the :loreign body lying somewhere in the vertical line between the anode and the cross wire. I then pull out the clutch handle Ell, Fig. 15, and thereby unlock the tube arm CH so that it can be moved independently of the screen arm and I displace the anode oi? the X-ray tube from its former position by moving the tube arm a definite fixed distance, say 5 centimeters. This distance is measured by a graduated scale (not shown) one such scale being fixed on the upper surface of each of the hori- Zontal arms Gi l and AC, Fig. 6.
The shadow of the foreign body, therefore, moves from the position on the cross wire to a new position on the screen. The anode, the foreign body and its shadow are of course in the same straight line, but this is no longer a vertical line. I then measure the degree of displacement of the shadow and can then by a simple calculation determine the position of the foreign body.
This calculation is simplified because there are two constants in this method of localizing, which may be expressed thus In the first position when the anode of the X-ray tube, the foreign body, and the shadow of the foreign body on the cross wire of the screen, were in the same vertical line, the distance between the anode and the shadow on the cross wire, was, say, 50 centimeters. In the second position the anode was moved, say, 5 centimeters, and the resulting displacement of the shadow was X centimeters. X representing a measurable distance varying with the position of the foreign body.
By a simple calculation the distance between. the foreign body and the cross wires is found, and from this we can, by deducting the distance between the cross wire and the patient, tell the distance between the foreign body and the patients skin.
Further. by the combination of a graduated scale with a device for displacing the anode of the X-ray tube a fixed distance I can take stereoscopic radiograms. The method is as follows z- To each of the two arms, namely, the screen arm and the tube arm, I attach by screws a centimeter scale such as is shown at AG, Fig. 11. Parallel with and attached to the tube arm is a cylindrical metal rod All, Fi x 16, which passes through two guides (/G and CG, Fig. 16, attached to the support of the tube arm. This cylindrical rod carries a movable piece of metal DI-I, Fig. 16, between the two guides CG and CG, Fig. 16. When-it is necessary to dis place the anode of the X-ray tube a fixed distance (say 6 centimeters) I lock the piece of metal DH, Fig. 16, to the cylindrical rod in contact with one of the guides. By moving the tube arm by rack and pinion until this piece of metal DH, Fig. 16, reaches the opposite guide, the excursion of the tube arm is limited to the known distance between my guides CG and CG, Fig. 16.
By this device I am able to displace the tube arm a definite distance in a dark room without illuminating the room to refer to the scale.
Having described my table and my X-ray tube stand separately, I now describe my X-ray couch, which consists of a combination of X-ray table and X-ray tube stand.
Figs. 12 and 13 show the X-ray tube stand in position on the rails of the Xray table on which it is designed to travel.
Fig. 12, AB shows the base of the stand. B and B show two of th supporting wheels. DE the upright metal column and B the top of the X-ray table.
Fig. 13 shows the end view of the same combination, B being the table top, AB the base. DE the upright metal column, BC and B the supporting wheels. In order that the stand will not become derailed I employ a small roller KL hung on the spindle of the wheel BO, Figs. 13 and 17, which roller engages on the under surface of the rail. Fig. 13, LM shows a screw which may b used for leveling the stand if it should be used apart from the table.
The wheels BC and B, Fig. 13, together with the wheel B shown in Fig. 12 but not shown in Fig. 13, enable the stand to be easily moved from one end of the rails to the other.
The tube arm supporting the X-ray tube shield carrying the X-ray tube can be moved transversely or longitudinally across the couch by mechanism already described. In the position of the X-ray shield shown in Fig. 13 the X-rays pass from below the table upward, but, when it is required that the X-rays should pass from above the table downward, I swing out my shield from below the table by rotating the column DE, Fig. 13, on its vertical axis, and, because I have sufficient space between column DE and the edge of the table, when the shield is clear of the table, I, without removing any parts, can elevate the shield by the racking movement already described to the desired height, when I swing it over the table to the position approximately occupied in the diaphragm by the plate arm AC, Fig. 13. I then rotate my shield on its horizontal axis so as to reverse the direction of the X-rays coming from the X-ray tube and then fix it in any desired position over the table.
When the apparatus is in this position I can use it as a co1npressor-that is, as a means of mechanically compressing say, the abdomen of a stout patient in order to reduce to a minimum the thickness of tissue through which the X-rays must pass on their way through the patient.
The patient lies on the table top B, Fig. 13, immediately beneath him is placed an Xray photographic plate suitably protected in a case, above him is the X-ray tube in the tube holder HI, which, as just described, has been moved from below the table to a new position above the table. The shield having been rotated, the rays from the 'X-ray tube pass from above downward through the aperture AP. For the purpose of compression I fit in the aperture AP, between the shield and the patient, a cylindrical or conical tube known as a compressor tube, not shown. I then rack downward the arm GI-I so that the compressor tube forcibly presses on the abdomen ot the patient, thereby reducing the thickness of the tissues between the co1npressor tube and the X-ray plate beneath the patient. l/Vhen the pressure is adequate I clamp the arm G-H in its position above the patient by turning the clamping screw N, Fig. 13. This clamps the cradle EF to the upright metal column DE and thereby holds the compressor tube forcibly in position. To prevent the pressure from lifting the tube stand from the table rail I first clamp the tube stand to the table rail by a clamp actuated by a winged screw shown at FM, Fig. 12. I then take my X-ray photograph, unclamp the cradle and release the patient.
As my shield is now free to rotate and may be clamped in any position, it is evident that I may raek the arm GH, Fig. 13, to the level of the top of the table, swing it parallel with the edge of the table, rotate the shield so that the X-rays are projected horizontally just over the table top, and thus take a lateral X-ray photograph of, say, a fractured thigh. My apparatus, therefore, enables an operator with the same tube, without removing that tube from the shield, and without moving the patient, to take radiograms as previously described from above the table with or without compression, from below the table, or laterally.
Further, by clamping my X-ray shield at an oblique angle I obtain X-rays in the oblique direction, which I can use for radiographic purposes, for instance, by this means I can pass X-rays obliquely through the abdominal wall where there is no bony structure and radiograph the vertebrae and ribs lying beneath the sternum and its con nections without the latter appearing on the radiogram.
Further, by swinging the arm carrying rea /390a my X-ray shield so that the shield is directed away from the table I can, without removing my stand from the table, do radiography, radioscopy or radiotherapy with a patient placed in a position away from the table.
I'Vhat I claim as my invention and desire to secure by Letters Patent, is
1. An X-ray tube-stand comprising a standard with two arms, one carrying the Xmay tube and the other the screen plate, gearing connecting said arms with each other and with the standard, an actuating member for said gearing and a clutch ineluded in said gearing for uncoupling said arms.
:2. An X-ray tube-stand comprising a standard, cradles slidable up and down said standard, arms slidable in said cradles, in in a direction transverse to said standard, gearing connecting said cradles and said standard, gearing connecting said arms and said cradles, actuating members for said arm actuating gearing, gearing connecting said actuating members and comprising a clutch capable of being uncoupled, and. means for connecting said cradles.
3. An X-ray tube-stand comprising a standard, a base to said standard, two arms one carrying the X-ray tube and the other the screen plate, cradles slidably mounted on said standard and having guides in which said arms are slidable respectively, gearing connecting said arms with said eradles and with each other, the gearing connecting said arms including a clutch whereby the arms may b coupled and uncoupled, gearing connecting said cradles and said standard, means for connecting said cradles with each other, a table, guide-rails on said table and wheels on the base of the tube-stand for running on said rails.
4. An X-ray tube-stand comprising a standard, a plurality of cradles movable up and down said standard, arms lllOVfllJlO in said cradles in directions transverse to said standard and means for coupling said eradles so as to move simultaneously.
ERNEST ELIAS GREVILLE.