US2019602A - Shockproof x-ray unit window - Google Patents

Description

Nov. 5, 1935. J. H. FINDLAY 2,019,602

SHOCKPROOF X-RAY UNIT WINDOW Filed Nov. 17, 1933 2 Sheets-Sheet 1 INVENTOR J. H. F/lVDA/q Y ATTORN EY Nov. 5, 1935. J. H. FINDLAY SHOCKPROOF X-RAY UNIT WINDOW.

2 Sheets-sheaf. 2

Filed Nov. 17, 1935 MW w rrfikwrggli u J n i g a 41 M: i 1 1 M m a 25 424 15 Z16 za- INVENTOR JTH. F/AQlt,

ATTORNEY Patented Nov. 5, 1935 UNlTED STATES PATENT F E John H. Findlay, Montclair, N. J., assignor to Westinghouse Lamp Company, a corporation of Pennsylvania Application November 17, 1938, Serial No. 698,421

Claims.

My invention relates to X-ray apparatus and particularly to what is known to the art as shockproof X-ray units.

The expediency of providing a unit of this type 5 has long been recognized in the art in that the possibilities of an operator or patient accidentally contacting any of the high voltage carrying parts is entirely eliminated. It is customary in a shockproof unit to immerse all high tension parts as well as the X-ray tube in a medium having a higher dielectric characteristic than air, such for example as oil, which not only isolates all high tension carrying parts but alsopromotes compactness of the unit. Due to the high dielectric strength of the insulating medium being higher than air not only can the various high tension carrying parts be spaced closer together but the X-ray tube can be considerably shortened.

However, several disadvantageous features are inherent in structures of this type in that during operation of the unit the heat generated by the X-ray tube is transmitted to the surrounding dielectric medium causing expansion thereof which must be compensated for in some manner. Moreover, the X-rays generated by the tube are projected through the oil which acts as a filter therefor and restricts the passage of some of the X-rays having short wave lengths. The unit is usually assembled at the factory with the tube rigidly secured interiorly of the container and it not infrequently happens that the tube is broken in transit.

It is an object of my present invention to provide a shockproof unit in which the X-ray tube is so positioned with respect to the container that none of the dielectric medium is disposed between the tube and casing.

Another object of my present invention is the provision of a shockproof unit in which the casing is provided with a resilient reentrant window so disposed with reference to the ray projecting portion of the tube that the dielectric medium is precluded from filtering any of the generated X-rays.

A further object of my present invention is the provision of a shockproof X-ray unit in which the casing is provided with a resilient reentrant window which so contacts the ray projection portion of the X-ray tube that none of the dielectric medium is disposed therebetween which would tend to filter any of the generated X-rays and which also functions as a shock absorber for th tube during shipment and operation.

Still further objects of my invention will become obvious to those skilled in the art to which it appertains by reference to the accompanying drawings wherein:

Figure 1 is a vertical view partly in section and partly broken away showing a shockproof unit 5 constructed in accordance with my present invention.

Fig. 2 is a sectional view in elevation and on an enlarged scale of the construction shown in Fig. 1. 10

Fig. 3 is a sectional view in elevation and on an enlarged scale of a, modification which my present invention may take, and

Fig. 4 is a sectional view in elevation and on an enlarged scale of still another modification 15 which my invention may take.

Referring now to the drawings in detail I have shown in Fig. 1 a casing 5 of metal which encases an X-ray tube 6 and a high tension transformer (not shown) for energizing the tube both 20 of which are immersed in a cooling and insulating dielectric medium such as oil 1.

The X-ray tube may be supported by the casing in any suitable manner, such for example, as an annular collar 8 of an insulating material 25 consisting of semi-circular sections fastened together as by set screws 9. This collar is in turn provided with laterally projecting lugs I0 disposed about its periphery and is arranged to be secured to the depending end of an annular 30 flange l2 also of suitable insulating material, such as bakelite, hard rubber, porcelain or the like. This flange is cut away to allow the circulation of the cooling and insulating material 1 about the X-ray tube and to form depending a5 prongs I3 to which the lugs ll] of collar 8 are secured as by means of set screws Hi.

The annular flange I2 is provided at its upper end with a portion l5of increased diameter and is joined to a metal ring it in any suitable man- 40 ner, such as by rivets l I. Should it be desired to reinforce the casing 5 at the point of connection of annular flange l2, with its integral metal ring iii, a further metallic ring I8 may be suitably secured thereto, such as by means of rivets I9 45 and welded as at 2B. The X-ray tube having been first secured to the collar 8 by the set screws with an opening therein and depending downwardly from this opening is a cylindrical metallic member 24 in the form of a bellows. A cupshaped member 25 of suitable X-ray transparent material, such as a light atomic weight metal, glass, cellophane, or the like, is in turn secured to the depending edge of the metallic bellows 24 and the bottom or base of this cup-shaped member 25 is slightly concaved to conform to the contour of the glass envelope of the X-ray tube.

The resiliency oi the reentrant window formed by the bellows 24 together with the configuration of the cup-shaped member 25 forces the latter into firm substantially oil-tight contact with the envelope of the X-ray tube thus preventing any of the oil 1 from being disposed between the tube and window and acting as a filter for any of the generated X-rays.

Moreover, should the collar 8 become slightly loosened during shipment of the device injury to the X-ray tube is precluded by the reentrant window acting as a shock absorber. The X-ray tube 6 has its respective electrode terminals connected to the source of energy therefor by conductors 26 and, during operation the heat generated by the tube is transmitted through the anode stem to a cooling radiator 2! exteriorly of the envelope which is immersed in the oil i When the oil becomes heated to such an extent that expansion thereof occurs a second bellows 28 is provided at any suitable location in the casing 5. This latter bellows is slightly more fiexible than that forming the reentrant window in order that it may preferably compensate for the expansion oi the oil. This prevents the expansion of oil from causing the cup-shaped member 25 to become disengaged and allowing oil to fiow between it and the envelope. However, any tendency of expansion oi the glass walls of the envelope or loosening thereof is entirely compensated for by the resiliency of the reentrant window.

In Fig. 3 I have shown a modification oi the structure just described which differs therefrom only in the manner of engagement of the cupshaped member 25 with the envelope of the tube.

In this embodiment the member 25 is again of the same configuration but is provided with an annular groove into which is secured a ring 29. This ring may be of soft rubber or some other composition not deleteriously afiected by the cooling and insulating dielectric medium 1 so that it forms a suction cup firmly adhering to the envelope of the tube thus forming substantially an oil tight seal and again preventing'any of the oil from being disposed between the reentrant window and the X-ray tube.

Fig. 4 shows my invention as adapted to a shock-proof unit utilizing what is known to the art as a double ended X-ray tube. In this particular modification the resilient reentrant window comprising the bellows 24 and cup-shaped member 25 are made integral with the casing 5 and the latter is provided with an annular ring 30 formed by a thickened portion of the casing. This ring is in turn threaded internally for the purpose of enabling the engagement therewith of a ray opaque cone 32. Again the reentrant window comprises the bellows 24 and the cup-shaped member 25 having a concave surface which firmly fits the contour of the envelope of the tube at the point of emergence of the X-rays. Also another bellows, such as shown at 28 Fig. 1, is provided in the casing 5 which is of a more flexible nature than the reentrant window so that this latter bellows first compensates for the expansion of the oil 1.

Although I have shown in Figs. 1, 2 and 3, the reentrant window and X-ray tube as being detachably supported by the casing 5, in order that i the tube may be assembled and then inserted in the casing, it is to be understood that the reentrant window may be formed integral with the casing as in Fig. 4 and the X-ray tube inserted through a detachable cover located elsewhere in 10 the casing. Moreover, the tube may be supported by the casing by any other suitable construction so long as the ray projecting portion of the tube is in firm contact with the reentrant window.

It can thus be readily appreciated by those 15 skilled in the art that I have shown a shockproof X-ray unit in which all high tension parts are isolated to prevent accidental contact therewith by an operator or patient. That by immersing the X-ray tube in a dielectric medium of m higher strength than air I am enabled to utilize a ioreshortened tube and by the employment oi a resilent reentrant window which firmly contacts the envelope of the tube not only is the A dielectric medium precluded from being disposed :5 between the tube and window, but the window acts as a shock absorber for the tube during transit and operation oi the unit.

Although I have shown and described several v modifications of my invention I do not desire to so be limited thereto as various other modifications may be made without departing from the spirit and scope of the appended claims.

What is claimed: r

1. In a shockprooi X-ray unit, the combination it with a casing, of an X-ray tube mounted therein and adapted when energized to generate X-rays,

a body of cooling and insulating material having a higher dielectric strength than air immersing v said X-ray tube, and a reentrant X-ray pervious 4.0 window in said casing adjacent the envelope of said tube through which X-rays emanate and having a yieldable portion with the remaining portion thereof conforming to the contour 0! said envelope for the purpose 01 forming a firm con- 45 tact therewith to prevent the ingress of dielectric medium therebetween and to absorb any shocks to said tube during operation or transit of said unit.

2. In a shockproof X-ray unit, the combination 50 with a casing, of an X-ray tube mounted therein and adapted when energized to generate X-rays,

a body of cooling and insulating material having a higher dielectric strength than air immersing said X-ray tube, and a reentrant X-ray pervious 55 window in said casing having a portion thereof firmly engaging the envelope of said tube adjacent its ray projection portion to form substantially an oil tight seal and prevent the ingress of oil therebetween, and said window having a do further portion thereoi yieldable in the direction of X-ray emanations for the purpose of absorbing shocks and any tendency of expansion by the envelope of said X-ray tube.

3. In a shockproof X-ray unit, the combina- 5 tion with a casing, of an X-ray tube adapted when energized to generate X-rays, a body of liquid cooling and insulating material having a higher dielectric strength than air in said, casing, areentrant member forming an oil tight 10 seal with said casing and extending inwardly thereof, means connected to said reentrant member and to said casing for supporting said reentrant member, means connected to said reentrant member and said X-ray tube for supporting the latter interiorly of said casing and immersed in said dielectric material, and a reentrant window supported by said first mentioned means and firmly contacting the envelope of said,

X-ray tube to prevent any of said dielectric material being disposed therebetween and acting as a filter for any of the generated X-rays.

4. In a shockproof X-ray unit, the combination with a casing, of an X-ray tube adapted when energized to generate X-rays, a body of liquid cooling and insulating material having a higher dielectric strength than air in said casing, a detachable reentrant member of insulating material extending inwardly of said casing and forming an oil tight seal therewith, means connected to said reentrant member and to said casing for supporting said reentrant member, means connected to said reentrant member and said X-ray tube for supporting the latter interiorly of said casing and immersed in said dielectric material, and a reentrant window supported by said first mentioned means and provided with a portion thereof having a concavity conforming to the contour of the envelope of said tube for the purpose of establishing a substantially oil tight contact therewith to exclude said dielectric material and prevent the same from filtering any of the generated X-rays.

5. In a shockproof X-ray unit, the combination with a casing, of an X-ray tube adapted when energized to generate X-rays, a body of liquid cooling and insulating material having a higher dielectric strength than air in said casing, a detachable reentrant member of insulating material extending inwardly of said casing and forming an oil tight seal therewith, means connected to said reentrant member and to said casing for supporting said reentrant member, means connected to said reentrant member and said X-ray tube for supporting the latter interiorly of said casing and immersed in said dielectric material comprising a split collar surrounding the envelope of said tube and secured to said detachable reentrant member, and an X-ray pervious window supported by said first mentioned means and provided with a portion thereof having a concavity conforming to the contour of the envelope of said tube for the purpose of establishing a substantially oil tight connection therewith to exclude said liquid dielectric material and preventing the same from filtering any of the generated X-rays, and the remaining portion of said reentrant window being yieldable in the direction of its longitudinal axis in order to absorb any shock to said X-ray tube and to compensate for any tendency of expansion of said envelope during operation.

JOHN H. FINDLAY.

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