US3465152A - Compact and lightweight radiography apparatus - Google Patents

Compact and lightweight radiography apparatus Download PDF

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Publication number
US3465152A
US3465152A US583827A US3465152DA US3465152A US 3465152 A US3465152 A US 3465152A US 583827 A US583827 A US 583827A US 3465152D A US3465152D A US 3465152DA US 3465152 A US3465152 A US 3465152A
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United States
Prior art keywords
tube
voltage
ray tube
capacitors
enclosure
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Expired - Lifetime
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US583827A
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English (en)
Inventor
Joseph H D Adler-Racz
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Usines Balteau SA
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Usines Balteau SA
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Publication date
Application filed by Usines Balteau SA filed Critical Usines Balteau SA
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Publication of US3465152A publication Critical patent/US3465152A/en
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/02—Constructional details
    • H05G1/04—Mounting the X-ray tube within a closed housing
    • H05G1/06—X-ray tube and at least part of the power supply apparatus being mounted within the same housing

Definitions

  • the present invention relates to a radiography apparatus constituted by a sealed enclosure in which there is located an X-ray tube which, from a high voltage transformer, is sup-plied with rectified HT through rectifier devices which embody semiconductors and capacitors.
  • X-ray tubes perform best, i.e. will take the highest volta-ge, the highest load and give the longest working life, when supplied with a D.C. voltage
  • the simplest way to obtain a high D.C. voltage is through the medium of a high voltage transformer, rectifiers and filtering capacitors; however, these elements make the equipment bulky, heavy and expensive.
  • the present invention which is designed to overcome these drawbacks, relates to a radiography apparatus in which the X-ray tube situated in a sealed enclosure containing an insulating medium, is supplied with a high rectified voltage by semiconductor rectifiers connected in a circuit which also includes capacitors, is characterised in that the capacitors are constituted by the metallic protective covering of the said X-ray tube, by at least two metal components connected in each case to the electrodes of the said tube, and by the insulating filling of the equipment, the thus formed capacitors being arranged to have a capacitance falling between two predetermined limits; and in that the said capacitance should be sufficiently low in order that, at the end of the positive half wave the said capacitor shall be virtually discharged, and sufficiently high in order that the rectifier current during thenegative half wave, shall not produce across the terminals of the said capacitors a voltage such that there could develop across the terminals of the X-ray tube a voltage which might jeopardize the insulation of said tube.
  • the metal components connected to the electrodes of the X-ray tube are constituted by metal parts provided for supporting the tube, similar to the caps which cover the ends of the tube.
  • the figure presents a schematic view of a radiography apparatus in accordance with the invention, and of itS electrical circuitry.
  • the apparatus illustrated operates at a voltage of 400 kv. and at current of 2 ma.; the voltage ⁇ across the terminals of the X-ray tube is a pulse voltage.
  • a sealed enclosure 2 there is located an X-ray tube 7 around which there is a protective shield 6 which is X- ray opaque.
  • This shield contains a window 6a through which the X-rays can pass, and is integral with the metal support frame 11 fixed to the enclosure 2 which is X-ray transparent.
  • the shield is grounded since the enclosure 2 itself is grounded, for example through a conductor 2a. At its ends, the enclosure 2 carries handles 1 by which the apparatus can be lifted and moved.
  • the cathode 7b is constituted by a filament heated by the current from a transformer 12, the latter supplied with a voltage 220 v. at 50 c./s. through the conductors 14.
  • the HT supplied to the tube 7 is provided from the two groups of dry rectifiers 4a and 4b which are connected to two high voltage transformers 3a and 3b supplied with a low voltage by the conductors 13 and 1S respectively.
  • the two transformers 3a and 3b and the two groups of rectifiers 4a and 4b, are arranged in series at either side of the tube 7.
  • the lsealed enclosure 2 is completely filled by an insulating gas in the form of sulphur hexafiuoride at a pressure in the order of 21/2 atmosphere.
  • the X-ray tube 7 is provided with metal support caps 5a and 5b which are connected to the corresponding electrodes 7a and 7b. These supports 5a, 5b are attached to insulating arms 10 themselves attached to a metal support frame 11 fixed inside the enclosure 2.
  • the capacitance of the capacitors formed by the metal support pieces 5a and 5b, and the protective shield 6, has a value which is predetermined by the dimensioning of the component elements.
  • the metal supports a and Sb have a diameter of around 100 mm. and a length of 100 mm., while the protective shield 6 has an internal diameter of 200 mm.
  • the surfaces of the protective shield 6 and of the two metal support pieces 5a and 5b opposite constitute two capacitors the respective capacitances of which satisfy the conditions set out in accordance with this invention.
  • these capacitances are 8 pf.
  • the capacitive arrangement discharges sufiiciently rapidly and that when the tube ceases to pass current the metal support pieces or caps 5a and 5b are at a potential near ground potential and the capacitors which they constitute together with the protective shield 6, are virtually discharged.
  • the X-ray tube 7 passes no current.
  • the rectifiers 4 which always pass some reverse current, allow a leakage current of about 30 microamps which will charge up each of the capacitors to give a maximum electrical charge of 30 micro-amps x 5 ms., i.e. 150 nanocoulornbs. This means that the potential on the metallic support components 5a and 5b will be no more than in relation to ground.
  • the X-ray tube will cease to conduct current before the positive half wave of the HT reaches zero, so that during the negative half wave the tube carries a small positive voltage or a voltage near zero. The result of this is that the tube operates under less severe conditions and consequently its working life is considerably increased.
  • a surprising but highly advantageous effect of the invention is that each group of rectiiiers carries a maximum voltage of only 200 kv. the practical result of which is that the number of rectifier plates required is reduced by half so that the apparatus described contains around 15,000 plates whereas in known systems around 30,000 are needed.
  • a radiography apparatus comprising an enclosure, an insulating medium in said enclosure, a metal support frame fixed to said enclosure, insulating arms attached to said metal support frame, metal support pieces fixed to said insulating arms, an X-ray tube fixed in said metal support pieces, electrodes in said X-ray tube comprising an anode and cathode each connected to one of said metal support pieces, a protective shield around said X- ray and fixed to said metal support frame, a window in said shield and in said enclosure, a heating transformer connected to said cathode and fixed in said enclosure, a circuit in said enclosure for supplying said X-ray tube with rectified high voltage, said circuit comprising high Voltage transformers, one side of each of said transformers being connected to a low voltage source of current, the other side of cach of said transformers being connected to dry rectifiers, said rectiers in turn being connected to said anode and cathode and to two capacitors, said capacitors being constituted by said metal shield of said X-ray tube and by at least said metal
  • Radiography apparatus as claimed in claim 1, characterised in that said metal pieces connected to the electrodes of the X-ray tube are constituted by the supports which locate the ends of the said tube.
  • Radiography apparatus as claimed in claim 2, characterised in that said pieces supporting the ends of the X-ray tube are in the form of caps which at least partially envelop the said ends.
  • Radiography apparatus characterised in that said pieces supporting the ends of the X-ray tube are separate pieces.
  • Radiography apparatus characterised in that said pieces supporting the ends of the X-ray tube are integral with said tube.

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  • X-Ray Techniques (AREA)
US583827A 1965-10-15 1966-10-03 Compact and lightweight radiography apparatus Expired - Lifetime US3465152A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR35089A FR1462330A (fr) 1965-10-15 1965-10-15 Appareil de radiographie

Publications (1)

Publication Number Publication Date
US3465152A true US3465152A (en) 1969-09-02

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Family Applications (1)

Application Number Title Priority Date Filing Date
US583827A Expired - Lifetime US3465152A (en) 1965-10-15 1966-10-03 Compact and lightweight radiography apparatus

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US (1) US3465152A (fr)
DE (1) DE1564997A1 (fr)
FR (1) FR1462330A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2448497A1 (de) * 1974-10-11 1976-04-22 Licentia Gmbh Roentgenroehre und vorrichtung mit einer roentgenroehre
FR2427755A1 (fr) * 1978-05-31 1979-12-28 Siemens Ag Generateur radiologique pour appareil de radiodiagnostic muni d'une enceinte remplie d'huile comportant un transformateur a haute tension, un redresseur de haute tension et un tube a rayons x

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10005629A1 (de) * 2000-02-09 2001-08-23 Siemens Ag Röntgenstrahler

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2216210A (en) * 1938-11-19 1940-10-01 Mutscheller Arthur X-ray unit
US2925499A (en) * 1957-02-07 1960-02-16 Siemens Reiniger Werke Ag X-ray apparatus

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2216210A (en) * 1938-11-19 1940-10-01 Mutscheller Arthur X-ray unit
US2925499A (en) * 1957-02-07 1960-02-16 Siemens Reiniger Werke Ag X-ray apparatus

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2448497A1 (de) * 1974-10-11 1976-04-22 Licentia Gmbh Roentgenroehre und vorrichtung mit einer roentgenroehre
FR2427755A1 (fr) * 1978-05-31 1979-12-28 Siemens Ag Generateur radiologique pour appareil de radiodiagnostic muni d'une enceinte remplie d'huile comportant un transformateur a haute tension, un redresseur de haute tension et un tube a rayons x

Also Published As

Publication number Publication date
FR1462330A (fr) 1966-04-15
DE1564997A1 (de) 1969-12-18

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