US3178575A

US3178575A - Apparatus for tilting a relatively mov- able x-ray source about a pivot point in the detector plane

Info

Publication number: US3178575A
Authority: US
Publication date: 1965-04-13
Anticipated expiration: 1982-04-13

Description

April 13, 1965 H. E KOERNER APPARATUS FOR TILTING A RELATIVELY MOVABLE X-RAY SOURCE ABOUT A PIVOT POINT IN THE DETECTOR PLANE Filed Nov. 26, 1962 a a P-l INVENTOR WITNESSES United States Patent 3,178,575 APPARATUS FOR TILTING A RELATIVELY MOV- ABLE X-RAY SOURCE ABOUT A PIVGT PGINT IN THE DETECTOR PLANE Harry E. Koerner, Catonsville, Md, assigner to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Nov. 26, 1962, Ser. No. 239,886 6 Claims. (Cl. 25t)61.5)

The present invention relates to Xray apparatus, and more particularly to X-ray apparatus wherein an X-ray tube may be caused to assume different angular attitudes with respect to an object or patient being observed, while the imaging device, fluorescent screen or X-ray film, for example, remains stationary.

In X-ray apparatus affiliated with an X-ray table, as exemplified herein, it is standard practice to include an X-ray tube mounted within the table body and a spotfilm device mounted above the table top for producing and/or recording X-ray shadow images of an object or patient on the table top. It is also standard practice to mount both the X-ray tube and the spotfilm device on carriage means whereby each maybe transported longitudinally and transversely of the table top in unison to diifercnt selected positions according to a preferred technique or area of a patient desired to be examined. This is convenient and avoids in large measure necessity for any excessive movement of a patient in order to accomodate an examination at any particular site or number of sites. It also has been, however, standard practice to so mount the X-ray tube that the center line of its beam is always perpendicular to the plane of the table top, except in relatively complex table equipments for laminography. This leads to the possibility that one shadow image, that of a patients bone for example, may obscure the shadow image of such asan internal organ of the patient desired to be observed, and necessitates turning the patient in order to avoid such obscuring.

In view of the foregoing remarks, it is an object of the present invention to provide an X-ray table apparatus which eliminates, in the majority of cases, any need for such turning of the patient in the event that overlapping .X-ray shadow images initially obscure one another.

In accord withthe preceding object, itis another object of the present invention to provide such apparatus with a minimal degree of increase in complexity relative to previous standard practice. 7

According to the invention, its general features include a construction whereby the X-ray tube may be turned to change the angle at which its beam intersects the table top, thereby affording opportunity for seeing around obscuring parts. It further includes a means whereby the center of the X-ray beam is maintained aligned with the center ofthe fluorescent screen and/ or film on or in the spotfilm device during any such angular movement of the X-ray tube, as well as includes a means whereby the area of X-ray beam as interceptedby such film or fluorescent screen does not change size materially within the prescribed limits of angular movement of the tube.

As an adjunct to such general features as included in the invention,-opportunity is afiorded for a third dimensional image effect when viewing the fluorescent screen during fluoroscopic examinationwhen the angular movement of the energized X-raytube iseflected.

Other objects and advantages of the invention will be- ,come apparent fromthefollowing detailed description of an exemplified embodiment of the invention, when taken in connection with. the accompanying drawing, in which:

FIGURE 1 is a schematic representation in front elevation showing an X-ray table embodying the invention;

3,178,575 Patented Apr. 13, 1965 ice FIG. 2 is is a side elevation view taken along the line IIH in FIG. 1, and

FIG. 3 is a front section view taken along the line Ill-ill in FIG. 2.

Referring to FIGS. 1 and 2, the X-ray table 1 in which the invention is embodied comprises a body portion 2 having a table top 3 and a floor-mounted base 4 which may include means (not shown) aifording tilting support of the table body, although such tilting per se forms no part of the present invention. The table apparatus further includes an X-ray tube 5 including its cone 5a, as a source of penetrating radiation, disposed within the table body, a spotfilm device 6 disposed above the table top 3 and adapted to contain a film cassete 7 and to hold same in at least an attitude parallel to such table top, as well as the usual fluorescent screen 8, or image amplifier tube (not shown) as an image producing means responsive to intersection of the X-ray beam passing through a patient (not shown) lying or sitting on the table top 3. As per the usual practice, the spotfilm device 6 is mounted on a spotfilm tower member 10 extending vertically above the table top 3 at the rear of the table body 2. The spotfilm device 6 is suitably arranged for vertical movement on the tower lit to selected positions at various heights above the table top 3 by means of arms 11 at its opposite sides which find friction-free guided constraint via rollers 12, FIG. 2, cooperative with vertically-extending parallel guide surfaces 13 afliliated with the tower 10. The usual counterweight practice, not shown, for the spotfilm device 6 may be employed to simplify effectuating such vertical movement manually.

Also as per the usual practice, the spotfilm tower 10 is supported at its lower end by a cross-carriage 15 which is movable on rollers 16 transversely of the table top 3, i.e., in a direction extending from front-to-back of the table. The rollers 16 are in turn supported on a longitudinal carriage means 17 which is movable on rollers 18 along the length of the table body 2; guide members 19 being mounted in the table top at front and back to accommodate such rollers 18.

in accord with features of the invention, the X-ray tube 5 is pivotally supported via a pin-and-roller means 21 by a member 22 of the cross-carriage 15. The pin-androller means 21 is carried at the upper end of a hanger member 23 secured at its bottom to the X-ray tube 5 at the base of the cone 5a. The member 22 carrying the X-ray tube 5 extends longitudinally of the table and has an elongated through slot 25 in which the pin-and-roller means 21 is free to move therealong for reasons which. hereinafter will become apparent.

To effect the desired tilting movement of the X-ray tube 5 to direct the X-ray beam at different angles upwardly through the table top 3 toward the spotfilm device 6, translational movement of the tube 5 lengthwise of the table is effected while its cone 5a is simultaneously held oriented at a point on the spotfilm device.

The translational movement of the X-ray tube is effected by a motor-andtransmission assemblage 28, a threaded shaft 29 rotated by such assemblage, and a nut 30 pivotally connected to the hanger member 23. The shaft 29 extends parallel to the cross-carriage member 22 and is rotatably supported at a lower level by vertically-extending supports 32 depending from the cross-carriage 15. The pivotal connection of the drive nut 30 for the X-ray tube is via a pin 33 carried by such nut and extending into a slot 34 in hanger member 23 which slot is elongated to provide clearance in the vertical direction for reasons which will become apparent hereinafter.

The holding of the X-ray tube cone 5a aligned with a point on the spotfilm device is accomplished by an elongated vertical tube aligning member 36 secured to the X-ray tube and rockably guided by a roller guide assemblage 38 pivotally supported by the spotfilm device. The member 36 is at the rear of the table, is secured at its bottom to the X-ray tube 5 via a horizontal member 40, and extends upwardly between the tower 19 and the rear of the spotfilm device 6.

The roller guide assemblage 38 includes a plate 41 rockably mounted on a pin 42 secured to the rear of the spotfilm device, and four rollers 43 carried by the plate for rolling engagement with opposite sides of the tube aligning member 36. Support for the X-ray tube 5 is found at the pin-and-roller means 21 near the front of the crosscarriage and at the rear by a similar pin-and-roller means 45 carried by the tube aligning member 36 in rollable support in an elongated horizontal slot 46 in the spotfilm tower 10. To prevent any cocking of the pinand-roller means 21 and 45 during travel along respective slots 25 and 46, other guiding constraints (not shown) are employed.

A transparent indicator scale element 50 is mounted on top of the spotfilm device 6 for extension thereabove in front of aligning member 36 to indicate angular position of the X-ray tube by observance of such member 36.

In operation of the apparatus for radiographic and/ or fluoroscopic techniques, the X-ray tube 5 may be aligned as shown in FIG. 1 in the usual attitude for projection of the X-ray beam perpendicularly of the table top 3 and in alignment with the spotfilm device 6 for producing an X- ray image of an area of a patient (not shown) on such table top. Should it be desired after observing an image on the fluorescent screen 8 or on film in the cassette 7, that an X-ray shot or shots at a different angle on either side of the vertical is desired, the reversible motor-andtransmission assemblage 28 is operated to cause movement of the X-ray tube 5 in a selected direction along the threaded shaft 29 through the medium of the nut 30 and the hanger member 23. During such movement of the X-ray tube 5, the bottom of the tube-aligning member 36 is moved therewith via the horizontal member 4%, while the roller guide assemblage 38 on the spotfilm device 6 prevents the respective portion of the tube-aligning rod in contact therewith from traveling along with its moving lower end. Since the assemblage 38 is free to swivel on pin 42, this results in angulating the member 36 and the attached X-ray tube 5 and cone 5a relative to the true vertical and in holding same aligned with the center of the screen 8 and/ or film cassette '7 during simultaneous linear travel of such tube as effected by the motor-driven threaded shaft 29. Freedom for such simultaneous linear travel and tilting of the X-ray tube is afforded: by the pin 33 which permits the hanger 23 to tilt; the vertical elongation of the slot 34 in such hanger which enables the pin 33 to be moved along shaft 29 while its separation distance from the pin-and-roller means 21 changes during tilting of hanger member 23; the pin-and-roller means 21 and permit tilting of the hanger member 23 and of the aligning member 36 while affording vertical support thereof; the elongation of the slots 25 and 46 permits simultaneous linear movement of such pin-and-roller means 21 and 45; and the rollers 43 of the assemblage 38 permits the aligning member 3-5 to move therebetween as the vertical separtion distance between the pin 42 and the pinand-roller means 21 and 45 changes during movement of the latter along the slots 25 and 46. Indication of the angular attitude of the X-ray tube 5 is afforded by observance of the tube-aligning member 36 through the transparent indicator plate with reference to angle markings on a face of such plate.

In any selected angular attitude of the X-ray tube 5, a fluoroscopic image and/ or a film shot may be made by effecting energization of the X-ray tube in a well-known manner. When the spotfilm device 6 is moved to different vertical positions along the tower 10, the guide assemblage 38 thereon will rock the tube-aligning member 35 thereon about the pin 33 on the drive nut 36 to automatically maintain the X-ray tube 5 and its cone 5a aligned with the spotfilm device irrespective of its previously selected angular attitude.

If, during fluoroscopic examination, the X-ray tube is maintained energized while it is being angulated as described, the various shadow images of parts of the patient at difi'erent depths will move relatively at different rates and afford opportunity for a third dimensional effect based on visual experience having impressed the sense of sight with the axiom that moving objects at a distance appear to move more slowly than near objects. While such relative movement of the images on the screen presents information as useful as true stereoscopic representations afforded by relatively complex previous X-ray equipment, and looks like the patient or object is being turned. It does not, however, correspond exactly with turning of the patient during fluoroscopic examination, inasmuch as the perpendicular orientation is reversed, but recognition of the fact affords usefulness to the technique.

While the exemplified embodiment of the invention has been described with reference to certain structural and functional details, it will be understood that it is not necessarily limited in all respects to such details and is intended to embrace modifications and structural equivalents which lie within the scope of the appended claims and are readily apparent to those versed in the art.

I claim as my invention:

1. X-ray apparatus comprising an X-ray table having a table top for support of a patient, X-ray imaging means mounted above said table top and movable perpendicularly relative thereto, an X-ray tube mounted within said table for projection of an X-ray beam into intersection with said imaging means, means for effecting movement of said X-ray tube along a path parallel to said table top for projection of the X-ray beam at different positions along such top, and aligning means operable during such movement for tilting the X-ray tube about a pivot point in a plane of said imaging means to maintain such tube aligned with the imaging means irrespective of the latters position.

2. X-ray apparatus as set forth in claim 1, wherein the aforesaid aligning means comprises means disposed at the imaging means for indicating the tilt axis for the X-ray tube.

3. In an X-ray apparatus comprising an X-ray table, a longitudinal carriage in said table, a cross-carriage on said longitudinal carriage, an X-ray tube pivotally carried by said cross-carriage, a spotfilm tower carried by said crosscarriage and extending vertically at the rear of said table, a spotfilm device carried by said tower and extending horizontally over the table top for intersection with the X-ray beam directed upwardly from the X-ray tube, the improvement including a motor means for effecting trans- =latory movement of said X-ray tube transversely of said cross-carriage, and a tube aligning means connected between said X-ray tube and said spotfilm device to tilt such tube during its translatory movement and maintain alignment with said spotfilm device.

4. The improved X-ray apparatus as set forth in claim 3, wherein support for said X-ray tube by said crosscarriage is translational as well as pivotal relative to such cross-carriage, said motor means is carried by the crosscarriage and includes a threaded shaft extending transversely of said cross-carriage and a nut engaging such shaft and pivotally connected to said X-ray tube with a certain degree of freedom for vertical movement relative to the point of vertical support for such tube; and said aligning means includes an aligning member secured to said X-ray tube and extending vertically at the rear of the table into intersection with the plane of said spotfilm device, and guide means cooperating with said aligning member and defining a pivot therefor in said spotfilm plane.

5. The improved X-ray apparatus as defined in claim 4, wherein said spotfilm device is movable vertically along sa1d tower and the aforesaid guide means moves vertically in synchronism therewith to afford automatic align- J ment of the X-ray tube irrespective of the vertical position of the spotfilm device.

6. X-ray apparatus comprising an X- ray table, X-ray imaging means mounted above said table, an X-ray tube mounted within said table for projection of an X-ray beam through the table top and into intersection with said imaging means, mean-s for effecting translational movement of said X-ray tube in a direction parallel and relative to said imaging means, and means operable during such movement for automatically tilting said X-ray tube about a pivot point at the level of said imaging means fi to maintain an angulated alignment with said imaging means Without disturbing the position thereof.

References Citecl by the Examiner UNITED STATES PATENTS 2,000,497 5/35 F0111 25061.5 2,695,362 11/54 Gernet'n 25057 RALPH NILSON, Primary Examiner.

Claims

1. X-RAY APPARATUS COMPRISING AN X-RAY TABLE HAVING A TABLE TOP FOR SUPPORT OF A PATIENT, X-RAY IMAGING MEANS MOUNTED ABOVE SAID TABLE TOP AND MOVABLE PERPENDICULARLY RELATIVE THERETO, AN X-RAY TUBE MOUNTED WITHIN SAID TABLE FOR PROJECTION OF AN X-RAY BEAM INTO INTERSECTION WITH SAID IMAGING MEANS, MEANS FOR EFFECTING MOVEMENT OF SAID X-RAY TUBE ALONG A PATH PARALLEL TO SAID TABLE TOP FOR PROJECTION OF THE X-RAY BEAM AT DIFFERENT POSITIONS ALONG SUCH TOP, AND ALIGNING MEANS OPERABLE DURING SUCH MOVEMENT FOR TILTING THE X-RAY TUBE ABOUT A PIVOT POINT IN A PLANE OF SAID IMAGING MEANS TO MAINTAIN SUCH TUBE ALIGNED WITH THE IMAGING MEANS IRRESPECTIVE OF THE LATTER''S POSITION.