FR2666696A1 - DEVICE FOR ATTACHING A HIGH VOLTAGE CABLE. - Google Patents

Abstract

The invention relates to radiology devices and, more particularly, to high voltage connectors. The invention resides in the fact that the male (11) and female (14) parts are held together by means of a threaded ring (20) which, by screwing onto a corresponding threaded part (31), maintains a sleeve (21) on a metal ferrule (17). The sleeve (21), made of two half-shells (22 and 22 '), is metallized (layer 25) so as to ensure electrical continuity between the metal braid (16) and the metal sheath (7) containing the tube to X-rays.

Description

1 2666696

ATTACHMENT DEVICE

HIGH VOLTAGE CABLE

  The invention relates to electrical power supply assemblies for X-ray tubes and, more particularly in such assemblies, the connectors which are used to make the electrical connections between the electrical power source and the X-ray tube which is arranged. in a tank filled with medium

insulating and cooling.

  In diagnostic X-ray installations, X-ray is generally produced using an X-ray tube. According to a common arrangement, on the one hand, the X-ray tube is contained in a metal sheath filled with an electric oil. insulating, the sheath being intended, in particular, to ensure the protection of users against electric shock and X-radiation The sheath equipped with an X-ray tube is called an X-ray assembly On the other hand, the elements for feeding the tube to X-rays and, in particular the elements of a high-voltage generator producing the high voltage of the X-ray tube, are grouped in another enclosure located at a distance from the assembly Depending on the type of high-voltage power supply, monopolar or symmetrical , one or more cables with high electrical insulation carry the positive and negative polarities of the high voltage into the sheath containing the X-ray tube by

  through electrical connection devices.

  Such an electrical connection device or connector is formed in two parts, one of which, called receptacle, constitutes a female part permanently fixed to the sheath; the other part constitutes a male part or end piece intended to be fitted into the receptacle and which is integral with the cable coming from the high voltage generator. Given the very high values that the high supply voltage of an X-ray tube, kilovolts for example, can reach, the receptacle and the end piece are made of electrically insulating materials and have shapes and dimensions imposed by

international standards.

  In order to protect users, the sheath is brought to ground or earth potential, as is the outer casing of the cable or cables made up of a metal braid, one of the manufacturers' constant concerns being that all of the exterior surfaces sheath, connection device and cables are metallic and there is electrical continuity

between all of these.

  The electrical contacts, which are made by an electrical connection device, are made in the bottom of the receptacle between first contact members secured to the end piece and second contact members secured to the receptacle and which pass through the wall of the latter so as to open into the interior of the sheath The receptacle plunges fairly deeply into the interior of the sheath so that the end of the second contact member opens into the interior of the sheath at a sufficient distance from the internal wall of the latter to avoid an electrical breakdown between the metallic sheath which is grounded and this

  contact which is or potential of high voltage.

  As indicated above, the high voltage cables connect the high voltage generator, which is fixed in position, to the X-ray assembly which can be mobile in many radiology systems and this results in mechanical and electrical stresses for the cables, in particular at the level of the attachment of the latter to the corresponding end pieces and of the end pieces to the associated receptacles In addition, the mounting of the end piece on the receptacle can only be carried out after the passage of the cable provided with its end piece through orifices whose dimensions are such that the clamping ring of the end piece on the receptacle cannot pass through and cannot therefore be put in place on

  the nozzle only just before mounting on the receptacle.

  This requires a bore diameter of the ring large enough to allow it to slide around the end piece as well as the installation of at least one intermediate piece having a bore diameter which is less than that of the end piece and an outer diameter which is greater than that of the bore of the ring This intermediate part is generally produced in two thick half-washers which are assembled by a circlip, which leads to an assembly operation which is not always easy In addition, such an assembly does not participate in the mechanical retention of the cable so as to avoid its bending and its deterioration in the bore of the ring as a result of the

displacements of which it is the object.

  An object of the present invention is therefore to provide a device for attaching a cable to an end piece and from the end piece to a receptacle which is simple to manufacture and to assemble. Another object of the invention is to provide an attachment device which contributes to better mechanical strength of the cable on the end piece and to better electrical continuity between the envelope of the cable and the end piece. The invention relates to a device for attaching the male and female parts of a high voltage connector in an X-ray device, the male part of the connector being connected to a high voltage generator by means of a cable comprising a metal casing in the form of a braid which is mechanically and electrically connected to the external wall of said male part by a ferrule and the female part being connected to an X-ray tube placed in a metal sheath and being integral with said sheath, characterized in that the male part is fixed to the female part by a sleeve, in all or part of metal, which rests on at least part of the ferrule and a, threaded ring, in whole or part of metal, which is screwed on a threaded part integral with the sheath or the female part and which cooperates with the sleeve so as to press the latter against the ferrule, said sleeve being produced in two half-co keels which are assembled on the ferrule after fitting the threaded ring on the cable and the assembly ensuring electrical continuity between the

cable braid and sheath.

  Other objects, characteristics and advantages of the present invention will become apparent on reading the

  following description of a particular example of

  realization, said description being made in relation

  with the accompanying drawings in which: Figure 1 is a sectional view of a high cable

tension mounted in a ferrule, -

  FIG. 2 is a view showing the assembly operations of the elements used in the invention, and FIG. 3 is a view in longitudinal section showing the final assembly of the various elements of the

  attachment device according to the invention.

  A high voltage connector 10 for an X-ray tube comprises (FIG. 1) a receptable or female part 14 which is tightly fixed to a wall (FIG. 3) of the sheath 7 in which the X-ray tube is arranged and a male part 11 or end piece which is mobile and fixed to the end of a cable 12 comprising a certain number of conductors 13 The conductors 13 are connected to male contacts 15 by means and according to a method known elsewhere Male parts 11 and female 14 have the form of elongated cylindrical tubes whose dimensions are such that the male part (end piece) fits without difficulty in the female part (receptacle) and slides there until the contacts 15 are fitted in studs 19 of the

female part.

  The cable 12 is fixed to the end piece there by means of a metal ferrule 17, one end of which is crimped onto a flange 9 and the other end of which encircles the cable and, more precisely, a metal braid 16 of the cable thanks to a ferrule 18 This ferrule ensures, in addition to the fixing of the cable to the end piece, the connection or the electrical earth continuity between the cable and the

sheath 7.

  According to the invention, the mechanical retention of the cable is improved by a sleeve 21 (Figures 2 and 3), one end of which has an internal shoulder 23 which comes to bear on the collar 9 and the other end of which encircles an insulating envelope 24 of the cable 12 which covers the metal braid 16 As the diameters of the collar and of the cable are different, the sleeve 21 has a frustoconical shape to allow adaptation to the diameters over the length of said sleeve. According to the invention, the internal and external walls of the sleeve 21 are coated with a metal layer 25 which aims to ensure the electrical continuity of the mass between the metal braid 16 and the sheath 7 as

  we will show it in relation to figure 3.

  According to the invention, the sleeve 21 is produced in the form of two half-shells 22 and 22 'which are easily assembled by means of pins 26 and 27 which cooperate respectively with blind holes 28 and 29 After this assembly, the layer metal 25 of the shoulder 23 comes into contact with the ferrule 17 and this contact is improved by the screwing of a metal ring 20 as

it will be described below.

  The assembly operations of the male and female parts of the connector are as follows: positioning of the metal ring 20 in position A on the cable by sliding around the male part in the direction of the arrows 26, sliding of the male part 11 in the female part 14 until the contacts 15 are completely fitted into the studs 19 of the female part, fitting of the sleeve 21 by assembling the half-shells 22 and 22 'between the flange 9 and the position A the ring 20, displacement of the ring 20, along arrow 30, so that the threaded part of the ring comes to engage a corresponding threaded part 31 which is integral with the sheath 7, and screwing and tightening of the ring 20 on the part threaded 31 until the internal shoulder of the ring rests on the external shoulder of the sleeve 21 and the internal shoulder 23 of the sleeve abuts on the flange 9 which itself comes into contact

stop on the female part.

  The final result of the assembly is given by FIG. 3 which also shows the electrical continuity between the metallic braid 16 and the sheath 7 via the ferrule 17, the metallic layer 25 of the sleeve 21, the metallic ring 20 and the threaded part 31; in addition, a second electrical connection is made by the contact surface between the outer rim of the sleeve

  21 and the edge of the threaded part 31.

Claims (2)

  1 Device for attaching the male (11) and female (14) parts of a high voltage connector (10) in an X-ray device, the male part (11) or connector end piece being connected to a high voltage generator by the 'intermediate of a cable (12) comprising a metal casing in the form of a braid (16) which is mechanically and electrically connected to the external wall of said male part by a ferrule (17) and the female part (14) being connected to an X-ray tube placed in a metal sheath (7) and being integral with said sheath, characterized in that the male part (11) is fixed to the female part (14) by a sleeve (21), in all or metallic part, which rests on at least a part of the ferrule and a threaded ring (20), in whole or metallic part, which is screwed on a threaded part (31) integral with the sheath or the female part ( 14) and which cooperates with the sleeve (21) so as to press r the latter against the ferrule (17), said sleeve (21) being produced in two half-shells (22 and 22 ') which are assembled on the ferrule (17) after fitting the threaded ring (20) on the cable and the assembly ensuring electrical continuity between the braid (16) of the cable and the sheath (7).   2 Device according to claim 1, characterized in that the sleeve (21) is made of an insulating material and is covered, in whole or in part, by a metallic layer (25).