US1954915A - X-ray installation in which alpha compressed gas is provided between the tube and an envelope - Google Patents

Description

April 17, 1934. A. BOUWERS 1,954,915

X-RAY INSTALLATION IN WHICH A COMPRESSED GAS IS PROVIDED BETWEEN THE TUBE AND AN ENVELOPE Filed April 1, 1931 2 Sheets-Sheet 1 [m an 72x W W Patented Apr. 17, 1934 ars trier:

X-RAY INSTALLATION IN WHICH A COM- PRESSED GAS HS PROVIDED BETWEEN THE TUBE AND AN ENVELOPE Albert Bouwers, Eindhoven, Netherlands, assigner to N. V. Philips Gloeilampenfabrieken, Eindhoven, Netherlands Application April 1, 1931, Serial No. 527,014

In the Netherlands April 36, 1930 Claims.

The present invention concerns an improvement in the X-ray installation, described in my copending application, Serial No. 346,245, filed March 11, 1929, with issue date of April 3, 193 1 5 and Patent No. 1,953,391, in which a compressed gas is enclosed between the tube and a closed envelope surrounding the latter.

In an X-ray installation according to this prior application the envelope may be connected by means of piping to a pressure pmnp device whereby the pressure inside the envelope can be re stored if it has fallen below the desired value.

The present invention has for its object to avoid such a particular piping. For this purpose the tube has connected to it a current supply cable provided with a passage which communicates with the space comprised between the tube and the envelope. This passage may further communicate with a device which furnishes the gas pressure in the space surrounding the tube.

This combination affords the advantage that for restoring the gas pressure no pumping devices or pressure conduits have to be coupled with the tube. The latter simply utilizes one or more current supply cables and its exterior does not diifer from that of an installation in which no use is made of gas pressure between the tube and an envelope surrounding the latter. If need be, a measuring device or a safety device may of course be secured to the envelope. 4

The invention will be more clearly understood by referring to the accompanying drawings in which Figure 1 represents schematically an X-ray tube connected to a device for the supply of pressure, while a current supply cable acts as pressure conduit.

Figure 2 shows in section an example of the manner in which such a cable may be connected to the envelope of the tube.

' Referring to Figure 1, inside a metal envelope connected to earth is arranged an X-ray tube, which is supplied with high-tension current by cables 2 and 3 connected to the ends of the member 1. The cable 2 leads to a contact cover 4 secured to a wall and it is thus connected to a high-tension transformer not shown in the drawings.

A tubular conduit 5, of insulating material leads from the said contact cover to a cylinder 6 filled with carbonic oxyd, nitrogen or another suitable gas of high pressure. The conduit 5 communicates with a passage provided in the cable 2, said passage communicating with the space between the envelope 1 and the discharge tube enclosed thereby. The cable 2 consequently supplies both electric current and compressed gas, which furthers the easy movability of the tube for there are no particular conduits which impede the movement of the tube.

In Figure 2 part of the glass wall 10 of an X-ray tube is visible. In a re-entrant portion 11 of this Wall are located current supply conductors 12 and 13 leading to the incandescent cathode. The conductor 13 is secured to a bushing 14 5 having attached to it a resilient contact sleeve 15. the conductor 12 being secured to a contact pin 16. The current is supplied by a cable 17 having two conductors l8 and 19 of which the latter, which has a tubular shape, surrounds the former. Between these two conductors there exists a potential difference sufiicient for heating the cathode. The conductor 18 terminates in a contact sleeve 20 which cooperates with the pin 16 whereas the conductor 19 is secured to a sleeve 21 which is resiliently engaged by the sleeve 15.

The contact members 20 and 21 are secured to a connecting piece 22 of suitable insulating material, which is slid on the end of the cable 17 and which is cemented thereto preferably with 0 the aid of a binder such as shellac so that there is no air between the cable and the conductor 19 protruding therefrom and the connecting piece 22. The cable 17 is enclosed by a metal sheath which is electrically connected, through the in- 5 termediary of rings 23 and 24, with the aid of a screw cap 25 to the metal envelope 26 which entirely surrounds the tube 10. The connecting piece 22'fits into a cavity of a block 27 of insulating material in which are secured the contact members 15 and 16. This block closes the end of an insulating cylinder 28 within which the X-ray tube 10 is located.

The gas supplied by the hollow conductor 19 can flow through apertures provided in spacing 5 rings 29 and 30 into the bushing 14 and subsequently into the space comprised between the tube 10 and the cylinder 28. More towards the middle of the tube and therefore not visible in the drawing, said cylinder is pierced with apertures which establish the communication between the interior space of the cylinder 28 and the space between the cylinder and the envelope 26. The space between the tube and the earthed envelope 26 is thus entirely filled with compressed 1 gas having a pressure of, for example, 1 atm. above atmospheric, said gas being supplied by the hollow cable 17.

What I claim is:

1. In an X-ray installation, an enclosing envelope, an X-ray tube mounted therein and spaced from the wall thereof, said tube being provided with lead-in wires, a current-conducting cable comprising conductors and an insulating covering, said cable extending through an aperture in the envelope, means at said aperture for sealing the space between the cable and the edge of said aperture, means inside of said envelope for connecting the insulated conductors of said cable with the lead-in wires of said X-ray tube, said cable being provided with a gas passage which communicates with the space between the X-ray tube and the enclosing envelope, and means connected to said cable for supplying gas to said space through said passage.

2. In an X-ray installation, a closed metal envelope, an X-ray tube mounted therein and spaced from the wall thereof, said tube being provided with lead-in wires, a high-tension cable having a current-conducting core and a metal envelope, a device for furnishinggas under pressure and means connecting the end of said cable remote from the tube to said device so as to pro vide communication between said device through said gas passage to the space between the tube and enclosing envelope.

3. In an X-ray installation, a closed envelope, an vX-ray tube provided with leading-in conductors and contact members secured at the ends I thereof, said tube being mounted in said closed envelope partially in spaced relation with the wall thereof, a high-tension cable extending through an aperture in saidenvelope and having a duct extending longitudinally therethrough and a current-conducting part for conducting current to said X-ray tube, a terminal piece mounted on one end of said cable and having an axial perforation communicating with the duct in said cable and the free space in the closed envelope and bearing contact members connecting thecurrent conducting part of said cable with the contact members of the X-ray tube for establishing electrical connection between said current-conducting part and operative parts of said X-ray tube,

a tank of compressed gas having better insulating properties than air, means connecting same with the duct in said cable and means adjacent the aperture in said envelope for preventing gas leakage from the enclosing envelope through the space between the cable and the adjacent edge of the envelope.

4. In an Xray installation, an X-ray tube having a filamentary electrode and leading-in wires, an insulating envelope surrounding said X-ray tube, an apertured metal envelope surrounding said insulating envelope and spaced therefrom to provide space between said insulating envelope and the metal envelope, the spaces inside and outside said insulating envelope being in communication with each other, a high-tension cable having a metallic covering and a twin conductor insulated for a considerable portion of the operating voltage of the tube from the surrounding metallic covering, a central duct in said cable, a terminal piece of insulating material mounted on one end of said cable, said terminal piece projecting through the aperture in the wall of the metal envelope and engaging the insulating envelope mounted therein, means defining contact members for connecting the conductors of the cable with the leading-in wires of said tube, one set of contact members belonging to one of the conductors surrounding a set of contact members belonging to the second conductor, the ringshaped space between said two sets of contact members communicatingat one side with the space between the X-ray tube and the insulating envelope and at the other side with the central duct in said high-tension cable and means in- I 5. In combination, an enclosing envelope, an

electrical discharge tube mounted therein and spaced from the wallthereof, said tube having leadin wires, a hollow flexible cable having conductors for supplying current to the tube and its end extending through said envelope, said conductors being connected to said lead-in wires, means including said hollow cable for supplying gas to the space between said tube and said envelope and means for securing the end of said cable to said envelope.

ALBERT BOUWERS.

Images