Abstract:
A connection device ( 1 ) for optical fibers, for use in a polluted environment includes a first connector ( 2 ) designed to be associated with at least a first optical fiber ( 16 ) and a second connector ( 3 ) designed to be associated with at least a second optical fiber ( 25 ) to be connected to the first fiber, wherein one of the connectors ( 2, 3 ) carries a fluid reserve ( 36 ) having a refractive index equal to that of the optical fibers, and at least pumping means ( 37 ) connected to said fluid reserve and which, in operation, can be actuated in response to connecting and disconnecting movements of the two connectors ( 2, 3 ) to inject, at each connecting/disconnecting movement, the fluid into a space ( 58 ) encompassing the front ends of the two fibers bringing them closer together or spacing them apart.

Description:
BACKGROUND OF THE INVENTION 
     The present invention concerns a connection device for optical fibres, comprising a first connector intended to be associated with at least a first optical fibre and a second connector intended to be associated with at least a second optical fibre which is to be connected to the first fibre. 
     There already exist many devices for connecting optical fibres together or effecting hybrid connections between two cables each containing at least one optical fibre and at least one electrical conductor. The optical fibres used to convey signals or information usually consist of a sheath surrounding a core made from refringent material, whose diameter has a value of between a few microns and a few tens of microns depending on whether it is a case of a monomode or multimode fibre. Under these circumstances, when the connection is to be made in a polluted fluid (liquid or gaseous) environment, for example containing particles of sand or dust or other fine inert or living particles, it is particularly important that, when two optical fibres are connected to each other, the front faces of the fibres to be joined are not soiled by one or more particles and/or that one or more particles do not remain captive between the front faces of the said fibres joined end to end. This is because, if this occurred, the transmission of the signals or information by the said fibres could be seriously affected thereby. 
     When it is a case of joining two optical fibres in air, it has already been proposed to place a drop of a fluid, in general in the form of a gel, having a refractive index equal to or very close to that of the optical fibres, on the end of each of the two optical fibres to be joined and then to place the two optical fibres end to end. Thus optical continuity, that is to say continuity of the refractive index, is ensured in the joining area of two fibres, even if there remains a small interstice between the two fibres after they are joined. 
     However, such a method is difficult to implement when the two optical fibres must be joined in a polluted fluid environment. This is because it is not always possible, in the polluted fluid environment, to manually put drops of gel on the ends of the fibres to be joined. Nor is it always possible to place drops of gel on the ends of the fibres to be joined whilst they are outside the polluted fluid environment, either because one of the two fibres is continuously in the polluted fluid environment and cannot be extracted therefrom, or because, even if a drop of gel is put at the end of a fibre whilst it is situated outside the polluted fluid environment, it is not certain that, after having been immersed in the polluted fluid environment, there will remain a sufficient quantity of gel at the end of the fibre at the time it is joined with another fibre. Such a situation may for example occur when it is a case of connecting optical fibres in an undersea environment, for example in order to connect a cable containing optical fibres to an undersea well head. 
     SUMMARY OF THE INVENTION 
     The purpose of the present invention is therefore to provide a connection device for connecting optical fibres in a polluted environment. 
     To this end, the connection device according to the invention is characterised in that one of the two connectors carries a reserve of a fluid having a refractive index equal to that of the optical fibres, and at least one pumping means which is connected to the said fluid reserve and which, in service, can be actuated in response to the connection and disconnection movements of the two connectors in order, at each connection/disconnection movement, to inject fluid into a space surrounding the front ends of the two fibres bringing them closer together or spacing them apart. 
     Thus, with the connection device according to the invention, when the two connectors are connected to each other in a polluted fluid environment, fluid (gel) having a refractive index equal to that of the optical fibres is injected into the space surrounding the front ends of the two fibres to be joined. The effect of this injection is to drive away any polluted fluid which might be between the front ends of the two fibres to be joined, and to clean the said front ends. After joining the two fibres, the gel thus injected provides optical continuity between the two fibres, even if there remains a small interstice between them after they are joined. In addition, when the two connectors are subsequently separated from each other, gel is once again injected into the space surrounding the front ends of the two fibres whilst they are separated from each other, so that, after their separation, the front ends of the two fibres remain protected by a certain quantity of gel, thus preserving the fibres against an attack by the polluted fluid environment, in particular by sea salt where the invention is applied to connectors intended to be used in sea water. 
     The connection device according to the invention can also have one or more of the following characteristics: 
     the first connector comprises a first fixed casing or base which has, in its end face turned towards the second connector, a first cavity which is open towards the said second connector and on the bottom of which there project on the one hand at least one fixed optical contact in the form of a socket, in which the first optical fibre is fixed, and on the other hand at least one pusher forced by a first spring towards the second connector; 
     the first optical fibre is provided with a first rigid contact piece which extends axially beyond the end of the fixed optical contact projecting in the said first cavity, and the fixed optical contact carries a protective cowl which, in the disconnected state of the connection device, covers the said first contact piece and is at least partially filled with the said fluid; 
     the protective cowl can slide on the fixed optical contact and has, in the region where it covers the free end of the first contact piece, at least two contiguous lips made from elastomer material, which can separate in order to allow the said first contact piece to pass when the protective cowl is subjected to a thrust directed in the direction of the connection movement of the second connector towards the first connector, counter to the force of a second spring forcing the said protective cowl towards the second connector; 
     the second connector comprises a second moving casing or plug, which can be fitted in the first cavity of the first casing and which has, in its end face turned towards the first connector, a second cavity which is open towards the said first connector and which contains at least one movable optical contact in the form of a socket, in which the second optical fibre is fixed, which is provided with a second rigid contact piece, the said movable optical contact being aligned axially with the fixed optical contact of the first casing when the second casing is fitted in the first cavity of the first casing, and being mounted so as to be able to slide with respect to the second casing between a first position in which the first and second contact pieces of the first and second optical fibres are spaced apart from each other, and a second position in which the said first and second contact pieces are mutually in contact; 
     the second contact piece is situated inside the movable optical contact in the form of a socket, which has, at its end directed towards the fixed optical contact, an entry convergence for guiding the first contact piece of the first optical fibre, and the first and second casings have abutment surfaces cooperating in order to limit the entry of the second casing into the first cavity of the first casing, so that, when the said abutment surfaces are mutually in contact and the movable optical contact is in its first position, the first contact piece is partially engaged in the entry convergence of the movable optical contact; 
     the second connector also comprises a wandering sub-assembly, which carries the said reserve of the said fluid and the said pumping means and which is able to move in the second cavity of the second casing in the direction of the connection-disconnection movement between a first position in which the said wandering sub-assembly is retracted in the second cavity of the second casing, and a second position in which it is partially emerged from the said second cavity; 
     the said wandering sub-assembly is coupled to the movable optical contact by an idle-movement connection and by a third spring so that, in a first part of the travel of the wandering sub-assembly in the direction of the connection movement, the movable optical contact is not driven by the said wandering sub-assembly and, in a second part of the said travel, the said wandering sub-assembly drives with it, by means of the third spring, the movable optical contact until the second contact piece of the second optical fibre comes into contact with the first contact piece of the first optical fibre; 
     the wandering sub-assembly comprises a body in which there are formed at least a first passage for the movable optical contact, a first chamber forming the said fluid reserve and a second, cylindrical, chamber which is connected to the first chamber by a second passage containing a first non-return valve allowing the fluid to pass only from the first to the second chamber, and a piston, provided with a second non-return valve, is disposed in the second chamber and divides the latter into a suction chamber, into which the said second passage opens out, and a delivery chamber which communicates with the said first passage through a third passage formed in the body of the wandering sub-assembly and with a chamber situated inside the movable optical contact in the form of a socket, in front of the second contact piece of the second optical fibre, by means of at least a fourth passage formed in the said movable optical contact; 
     the second non-return valve consists of a lip joint which surrounds the said piston and which allows the fluid to pass only from the suction chamber to the delivery chamber; 
     the piston is provided with a piston rod which extends in the delivery chamber and which projects outside the body of the wandering sub-assembly in the direction of the first connector and in alignment with the pusher of the first connector when the second casing is engaged in the first cavity in the first casing, and a fourth spring having lesser stiffness than the first spring is disposed in the suction chamber and forces the piston and the piston rod towards the said pusher, the said piston being actuated by the pusher when the wandering sub-assembly is moved from its first to its second position, and by the fourth spring when the wandering sub-assembly is moved from its second to its first position; 
     the second casing and the wandering sub-assembly of the second connector also comprises cooperating retention means for retaining the wandering sub-assembly in its first position in the second cavity of the second casing, and the second casing carries a control means which is actuated by the first casing when the said abutment surfaces of the first and second casings come into contact with each other, and which at this moment acts on the said retention means in order to put them in an inactive state such that the wandering sub-assembly can be moved from its first to its second position; 
     the second casing of the second connector has an anchoring ring made from elastomer material, which is fixed by one end to the second casing and which carries at its other end at least one anchoring element able to be attached behind a cooperating anchoring element formed on the first casing of the first connector when the said abutment surfaces of the first and second casings are mutually in contact; 
     to allow the movement of the wandering sub-assembly between its first and second positions, the second connector also comprises a manoeuvring ring which can slide on the second casing of the second connector and which is connected to the wandering sub-assembly in the second cavity by several radial connecting elements passing through oblong slots formed in the second casing; 
     the manoeuvring ring is sized and configured so as to closely surround the anchoring ring when the said manoeuvring ring is in a position corresponding to the second position of the wandering sub-assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other characteristics and advantages of the invention will emerge more clearly during the following description of one embodiment given by way of example with reference to the accompanying drawings, in which: 
     FIG. 1 is a view in axial section of a hybrid (electrical and optical) connection device in accordance with the present invention, the two connectors of the connection device being depicted in the assembled state; 
     FIG. 2 is a view in the direction of the arrow F 1  in FIG. 1, showing a first one of the two connectors of the connection device, seen on end; 
     FIG. 3 is a view in axial section along the line III—III in FIG. 2; 
     FIG. 4 is a view on end, also in the direction of the arrow F 1  in FIG. 1, showing a second of the two connectors of the connection device according to the invention; 
     FIG. 5 is a view in section along the line V—V in FIG. 4; 
     FIGS. 6 to  10  are views in longitudinal section of the two connectors of FIGS. 3 and 5, in the assembled state, the movable elements of the two connectors being depicted in various positions occupied during a connection process; 
     FIG. 11 is a diagram illustrating the relative travels of some of the movable elements of the connection device according to the invention during a connection process. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1 to  5 , a connection device according to the invention can be seen, produced in the form of a hybrid connection device, that is to say one having electrical contacts for making connections between electrical conductors and optical contacts for making connections between optical fibres. The connection device  1  comprises a first connector or male connector  2  (FIGS. 2 and 3) and a second connector or female connector  3  (FIGS.  4  and  5 ). 
     The male connector  2  comprises a fixed casing or base  4  provided with a flange  5  for fixing it, by means of screws or bolts, not shown, for example on a wall of an item of undersea equipment, such as a well head. The casing  4  has, in its end face turned towards the female connector  3 , a cavity  6  which, in the example shown, has a circular cross-section, but whose cross-section could have any other required shape. The cavity  6  is intended to receive a part  7 , with a corresponding circular cross-section, of the casing  8  of the female connector  3 . 
     The casing  4  of the male connector  2  carries six electrical contact pins  9  and two fixed optical contacts  11 , which project into the cavity  6  from the bottom  12  thereof. On the bottom  12  of the cavity  6  there also projects a cylindrical pusher  13  which can slide in a blind cylindrical hole  14  in the casing  4  and which is forced by a spring  15  in the direction of the female connector  3 . 
     Each of the two optical contacts  11  has the shape of a socket in which there is fixed an optical fibre  16  terminating in a rigid contact piece  17 , for example made from ceramic, which extends axially beyond the end of the optical contact  11  projecting into the cavity  6 . In addition, each optical contact  11  carries a protective cowl  18  which, in the disconnected state of the connection device  1 , covers the piece  17  and is at least partially filled with a fluid in the form of a gel having a refractive index equal to or very close to that of the optical fibre  16 . The cowl  18 , which is produced partly from metal and partly from elastomer material, is able to slide on the projecting end of the optical contact  11  when, as will be seen in detail below, it is subjected to a thrust directed towards the bottom  12  of the cavity  6  counter to the return force of a spring  16  which forces the cowl  18  towards the female connector  3 . The cowl  18  has, in the region where it covers the free end of the piece  17 , at least two contiguous lips  18   a  and  18   b  made from elastomer material, which can separate in order to allow the piece  17  to pass between them when the cowl  18  is pushed towards the bottom  12  of the cavity  6 . 
     The part  7  of the casing  8  of the female connector  3  has, in its end face turned towards the male connector  2 , a cavity  21 , for example with a circular cross-section, which, in the connected state of the connection device, is open in the direction of the bottom  12  of the cavity of the male connector  2 . The casing  8  of the female connector  3  rigidly carries six electrical contact elements  22  which project into the cavity  21  from the bottom  23  thereof and which, in the connected state of the two connectors  2  and  3 , are respectively aligned with the contact pins  9  of the male connector  2 . 
     The casing  8  of the female connector  3  also carries two movable optical contacts  24  which also project into the cavity  21  and which, in the connective state of the two connectors  2  and  3 , are respectively aligned with the two fixed optical contacts  11  of the male connector  2 . Each of the two movable optical contacts  24  also has the shape of a socket in which there is fixed an optical fibre  25  provided with a rigid contact piece  26 , for example made from ceramic. Each movable optical contact  24  can slide to a limited extent with respect to the casing  8  between a first position in which the contact pieces  17  and  26  of the mutually aligned optical fibres  16  and  25  are spaced apart from each other (FIG.  6 ), and a second position in which the contact pieces  17  and  26  of the optical fibres  16  and  25  are mutually in contact (FIG.  10 ). To this end, each movable optical contact  24  is provided, at its periphery, with a piston  27  which can slide in a blind cylindrical hole  28  which is formed in the bottom  23  of the cavity  21  of the casing  8  and which is closed off by an element in the form of a cylindrical bell  29  screwed into the blind hole  28 . 
     As can be seen in particular in FIG. 5, the contact piece  26  of the optical fibre  25  is situated inside the corresponding movable optical contact  24  in the form of a socket and the latter, has, at its end directed towards the fixed optical contact  11  of the male connector  2 , an entry convergence  31  which guides the contact piece  17  of the optical fibre  16  of the fixed optical contact  11  whilst it enters inside the corresponding movable optical contact  24  when the latter is moved from its first to its second position in a manner which will be described in detail below. 
     Given that, in the example embodiment described here, the cavity  6  in the casing  4  of the male connector  2  and the part  7  of the casing  8  of the female connector  3 , which is intended to be fitted in the cavity  6 , both have a circular cross-section, to allow correct alignment and unequivocal match between the contact pins  9  and the contact elements  22  on the one hand and between the fixed optical contacts  11  and the movable optical contacts  24  on the other hand, during a process of connecting the two connectors  2  and  3 , the part  7  of the casing  8  can for example be provided with a locating pin  32  (FIGS. 1,  4  and  5 ) intended to be engaged in a notch  33  (FIG. 1) provided in the edge of the peripheral wall of the casing  4  surrounding the cavity  6 . 
     In addition, the two casings  4  and  8  of the connectors  2  and  3  have abutment surfaces  34  and  35  for limiting the penetration of the part  7  of the casing  8  in the cavity  6  of the casing  4 . The abutment surface  35 , produced for example in the form of a circular collar on the periphery of the part  8  of the casing  8 , is positioned so that, when the two abutment surfaces  34  and  35  are mutually in contact and when the movable optical contacts  24  are in their first position, the contact piece  17  of the optical fibres  16  of the fixed optical contacts  11  are partially engaged respectively in the entry convergences  31  of the movable optical contacts  24  as shown in FIG.  7 . 
     The female connector  3  carries a reserve  36  of a fluid (gel) having a refractive index equal to that of the optical fibres  16  and  25 , and at least one pumping means  37 , preferably two pumping means, which are associated respectively with the two movable optical contacts  24  in order, at each connection-disconnection movement of the connectors  2  and  3 , to inject a certain quantity of fluid or gel into a space surrounding the front ends of the two contact pieces  17  and  26  of the optical fibres  16  and  25 , in particular into the space  58  which is situated in front of the piece  26  inside the socket forming the movable optical contact  24 . More precisely, the fluid reserve  36  and each of the two pumping means  37  are carried by a wandering sub-assembly  38  which is able to move in the cavity  21  of the casing  8  between a first position in which the said wandering sub-assembly is completely retracted inside the said cavity  21  (FIG.  1 ), and a second position in which it is partially emerged from the said cavity (FIG.  10 ). 
     The wandering sub-assembly  38  comprises a body  39 , roughly cylindrical, which has two passages  41  passing through it from one end to the other, respectively for the two movable optical contacts  24 , and six passages  42 , respectively for the electrical contact elements  22 . All the passages  41  and  42  extend parallel to the direction of the axis of the cylindrical body  39  of the wandering sub-assembly  38 , that is to say parallel to the axis of the cavities  6  and  21  with a circular cross-section. In the passages  42  there are fixed electrical contact sockets (not shown) which are in sliding contact with the electrical contact elements  22  carried by the casing  8  of the female connector  3 . When the part  7  of the casing  8  of the female connector  3  is fitted in the cavity  6  of the casing  4  of the male connector  2  and the wandering sub-assembly  38  is moved from its first to its above mentioned second position, the six contact sockets situated respectively in the six passages  42  slide over the six contact elements  22  and engage by sliding respectively on the six contact pins  11  of the male connector  2 , thus establishing an electrical connection between each of the contact pins  9  and the corresponding contact element  22 . 
     The body  39  of the wandering sub-assembly  38  is coupled to each of the two movable optical contacts  24  by an idle-movement connection  43  and by a spring  44 . The coupling is such that, in a first part of the travel of the wandering sub-assembly  38  in the direction of the connection movement, each movable optical contact  24  is not driven by the body  39  of the wandering sub-assembly and, in a second part of the said travel, the body  39  drives with it the movable optical contact  24  by means of the spring  44  until the contact piece  26  of the optical fibre  25  comes into contact with the contact piece  17  of the optical fibre  16 . After this the body  39  of the wandering sub-assembly  38  continues its travel alone by compressing the spring  44  until the wandering sub-assembly arrives in its above mentioned second position (FIG.  10 ). 
     For this purpose, as can be seen more clearly in FIG. 6, in each passage  41  in the body  39  an annular shoulder  45  is provided which, in the first position of the wandering sub-assembly  38 , is spaced apart from a washer  46  which can slide on the movable optical contact  24  and which is situated at one of the ends of the spring  44 . The other end of the spring  44  can bear against an annular shoulder  47  formed at the periphery of the movable optical contact  24 . 
     Referring once again to FIGS. 1 and 5, it can be seen that the body  39  of the wandering sub-assembly  38  has, in its cylindrical external surface, a peripheral groove  48  which is covered sealingly by a membrane  49  made from elastomer material. The groove  48  and the membrane  49  form together a chamber which contains the fluid or gel having the same refractive index as the optical fibres  16  and  25 , and which constitutes the said fluid reserve  36 . The membrane  49  made from elastomer material balances the pressures prevailing on each side of the said membrane, that is to say in the fluid reserve  36  and in the space surrounding the connection device  1 . 
     The body  39  of the wandering sub-assembly  38  also has, for each pumping means  37 , a cylindrical chamber  51  whose axis lies parallel to the axes of the passages  41  and  42 . At one of its ends, this chamber  51  is in communication with the fluid chamber or reserve  36  through a passage  52  in which there is disposed a non-return valve  53  which allows the fluid to pass solely from the chamber  36  to the chamber  51 . A piston  54  is disposed in the chamber  51  and divides the latter into a suction chamber  55  (FIG.  6 ), into which the passage  52  opens out, and a delivery chamber  56 . This chamber  56  communicates with the passage  41 , in which the movable optical contact  24  is situated, through a passage  57  formed in the body  39  of the wandering sub-assembly  38  and with the chamber  58  situated inside the movable optical contact  24 , in front of the contact piece  26 , through several passages formed radially and longitudinally in the movable optical contact in the form of a socket, so that the passage  57  and the chamber  58  remain in communication continuously, whatever the position of the movable optical contact  24  in the passage  41  of the body  39 . 
     The piston  54  is provided with a non-return valve which allows the fluid to pass solely from the suction chamber  55  to the delivery chamber  56 . This non-return valve can for example consist of a lip joint  59  made from elastomer material, which surrounds the piston  54 . In addition, the piston  54  is provided with a piston rod  61 , which extends in the delivery chamber  55  and which projects outside the body  39  of the wandering sub-assembly  38  in the direction of the male connector  2  and in alignment with the pusher  13  of the latter when the part  7  of the casing  8  of the female connector  3  is engaged in the cavity  6  of the casing  4  of the male connector  2 . A spring  62  disposed in the suction chamber  55  forces the piston  55  and the piston rod  61  towards the pusher  13 . The spring  62  has a lesser stiffness than the spring  15  associated with the pusher  13 , so that the piston  54  is actuated by the pusher  13  when the latter comes into contact with the piston rod  61  during the movement of the wandering sub-assembly  38  from its first to second above mentioned positions. The pusher  13  has an outside diameter greater than that of the piston rod  31  and greater than the inside diameter of the bore of the body  39  in which the said piston rod slides. 
     When the connection device  1  according to the invention is in the connected state, the fluid reserve  36  can be filled with fluid for the first time or it can be refilled subsequently if needed through filling channels which are formed in the body  39  of the wandering sub-assembly  38  and which are designated in general terms by the reference  63  in FIG.  1 . In operation, these filling channels are closed off by a screw  64 , which serves as a plug, and by a needle screw  65  which serves as a valve in combination with a seat  66  formed in the body  39 . For filling the fluid reserve  36 , the screw  64  is removed and a feed tube equipped with a screw coupling is screwed in place of the screw  64 , and then the screw  65  is slightly unscrewed in order to move it away from the seat  66 . After this, a fluid or gel with a refractive index equal to that of the fibres  16  and  25  is injected into the fluid reserve  36  through the feed tube and the filling channels  63 . Once the fluid reserve  36  is filled, the screw  65  is tightened against the seat  66 , the screw coupling of the feed tube is detached and the screw  64  is refitted. 
     Preferably the casing  8  of the female connector  3  and the wandering sub-assembly  38  have cooperating retention means for retaining the wandering sub-assembly in its first position, that is to say in its position completely retracted in the cavity  21  of the casing  8 , as long as the part  7  of this casing  8  has not been engaged in the cavity  6  of the casing  4  of the male connector  2 . To this end, as shown in FIG. 1, the wandering sub-assembly  38  has at least one flexible tongue  67  projecting on its peripheral surface, the said tongue engaging in a recess  68  formed in the internal cylindrical surface of the cavity  21  of the casing  8  in order to retain the wandering sub-assembly  38  in the said cavity  21 . In addition, the casing  8  carries a control means, for example a ball  69 , which is actuated by the casing  8  of the male connector  2  when the abutment surfaces  34  and  35  of the casings  4  and  8  arrive mutually in contact, in order to push the flexible tongue  67  out of the recess  68  and thus allow the movement of the wandering sub-assembly  38  from its first position completely retracted in the cavity  21  towards its second position partially emerged from the said cavity. 
     The casing  8  of the female connector  3  can also comprise an anchoring ring  71  made from elastomer material, able to maintain the two casings  4  and  8  in their assembled state after their abutment surfaces  34  and  35  have come into contact with one another. The anchoring ring  71  is fixed by one end to the casing  8  and carries, at its other end, at least one anchoring element  72  able to hook on behind a cooperating anchoring element  73  formed on the peripheral surface of the casing  8  of the male connector  2  when the abutment surfaces  34  and  35  are in contact. The anchoring elements  72  and  73  can for example consist of circular rims formed respectively on the internal peripheral surface of the ring  71  and on the external peripheral surface of the casing  4 . However, at least one of the two rims  72  and  73  could be replaced by several anchoring elements evenly distributed over the internal periphery of the ring  71  or on the external periphery of the casing  4 . 
     To allow the movement of the wandering sub-assembly  38  from its first to its second position and vice-versa when the casings  4  and  8  of the two connectors  2  and  3  have been assembled, the connector  3  also carries a manoeuvring ring  74  which can slide on the casing  8  and which is connected to the wandering sub-assembly  38  by several radial screws  75 , for example three screws angularly spaced apart by 120°. Each screw  75  passes through an oblong slot  76  formed in the cylindrical wall of the casing  8  and opening out into the cavity  21  therein. Preferably, the manoeuvring ring  74  is extended on one side by a cylindrical skirt  74   a  which is sized and configured so as to closely surround the anchoring ring  71  when the manoeuvring ring  74  is in a position corresponding to the second position of the wandering sub-assembly  38 , as shown in FIG.  10 . In this position, the skirt  78   a  of the manoeuvring ring  74  prevents the ring  71  from expanding radially outwards, so that the two connectors  2  and  3  are firmly held in their connected state. 
     Where the connection device  1  is intended to be used in a liquid environment, for example an undersea environment, and therefore in a non-compressible fluid, openings  77  can be provided in the casing  4  and openings  78  can be provided in the casing  8 , in addition to the slots  76 , to allow balancing of the pressures on the two sides of the wandering sub-assembly  38  in the cavities  6  and  21 . Likewise, orifices (not shown) can be provided for balancing the pressures on the two sides of the piston  27  of each movable optical contact  24 . 
     The functioning of the connection device  1  described above will now be described making reference to FIGS. 6 to  11 , FIG. 11 illustrating the respective travels of the wandering sub-assembly  38 , the piston  54  of the pumping means  37  and each of the two movable optical contacts  24  during a process of connection or disconnection. More precisely, in FIG. 11, the shaded band  79  of total length L represents the travel of the wandering sub-assembly  38 , the shaded band  81  represents the travel of the piston  54  and the shaded band  82  represents the travel of the movable optical contact  24 . 
     FIG. 6 depicts the connection device  1  during the engagement of the part  7  of the casing  8  of the female connector  3  in the cavity  6  of the casing  4  of the male connector  2 , at a time when the front end of the cowl  18  covering the contact piece  17  comes into contact with the front end of the movable optical contact  24 , a little before the abutment surfaces  34  and  35  of the casings  4  and  8  come into contact with each other. 
     FIG. 7 shows the state of the connection device  1  after the abutment surfaces  34  and  35  have come into contact with each other and the rim  72  on the anchoring ring  71  has come to be hooked on behind the rim  73  on the casing  4 . At this moment, the cowl  18  has been slightly pushed back, counter to the return force of the spring  19 , by the front end of the movable optical contact  24 , so that the front end of the contact piece  17  is kept exposed and partially engaged in the entry convergence  31  of the movable optical contact  24 . At the same time, the casing  4  has acted on the ball or balls  69  (FIG. 1) which push back the flexible tongue or tongues  67  radially inwards in order to make them emerge from the recess  68  in the casing  8 . The wandering sub-assembly  38  can then be moved from the position depicted in FIG. 7 to the position depicted in FIG. 10 by exerting a thrust on the manoeuvring ring  74  in the direction of the arrow F 2 . 
     After the wandering sub-assembly  38  has moved by a quantity L1 (FIGS. 8 and 11) from the position depicted in FIG. 7, the piston rod  61  encounters the pusher  13 . As from this moment, when the wandering sub-assembly  38  continues to move in the direction of the arrow F 2 , as the spring  15  has a greater stiffness than the spring  62 , the pusher  13  pushes the piston  54  in the suction chamber  55 . However, the valve  53  prevents the fluid or gel contained in the suction chamber  55  from returning to the reserve of gel  36 , and the lip joint  59  of the piston  54  allows the gel to pass to the delivery chamber  56  and, from there, through the passage  57 , to the chamber  58  situated inside the movable optical contact  24 , between the two contact pieces  17  and  26 . By passing through the chamber  58 , the gel cleans the front surfaces of the contact pieces  17  and  26  and drives out any polluted environment, for example polluted sea water, which may be in the chamber  58 , to the cavity  6  in the casing  4  through the entry convergence  31  of the movable optical contact  24  and passages provided for this purpose between the front faces of the said movable optical contact and of the cowl  18 . 
     When the wandering sub-assembly  38  has moved by an additional distance L2 following the distance L1 (FIGS.  9  and  11 ), a little before the front face of the wandering sub-assembly  38  encounters the front face of the pusher  13 , the annular shoulder  45  on the body  39  of the wandering sub-assembly  38  encounters the washer  46  and begins to push the movable optical contact  24  by means of the spring  44  towards the fixed optical contact  11 . During this movement, the contact pieces  17  and  26  move closer to each other, and the movable optical contact  24  pushes the cowl  18  whilst compressing the spring  19 . 
     When the wandering sub-assembly  38  has also moved by an additional distance L3 following the distances L1 and L2 (FIG.  11 ), the front face of the body  39  of the wandering sub-assembly  38  encounters the front face of the pusher  13 . As from this moment, the piston  54  ceases to move with respect to the body  39  of the wandering sub-assembly  38 , so that the gel ceases to be injected into the space  58  between the two contact pieces  17  and  26 . Whilst the wandering sub-assembly  38  continues to move in the direction of the arrow F 2 , its front face pushes the pusher  13  in the cavity  14  of the casing  4 , counter to the return force of the spring  15  (FIGS.  9  and  10 ). During this time, the piston rod  61  is held in contact with the pusher  13  by the spring  62 . 
     After the wandering sub-assembly  38  has moved by an additional distance L4 following the distances L1, L2 and L3, the two contact pieces  17  and  26  come into contact with each other. As from this moment the movable optical contact  24  ceases to be moved by the wandering sub-assembly  38 , which pursues its travel alone over a distance L5 whilst compressing the springs  15  and  44 , until the manoeuvring ring  74  encounters the anchoring ring  71  and the extension  74   a  of the said manoeuvring ring completely surrounds the anchoring ring, as shown in FIG.  10 . At this moment the connection process is complete. 
     The two contact pieces  17  and  26  are now pressed against one another by the spring  44 , and any slight interstice which may remain between them is filled in by the gel present in the chamber  58 . 
     Conversely, during a disconnection process, starting from the state depicted in FIG. 10, the manoeuvring ring is moved in the opposite direction to the arrow F 2  and drives with it the wandering sub-assembly  38  in the same direction. Whilst the wandering sub-assembly  38  moves by the distance L5, the springs  15  and  44  are decompressed. At the same time or thereafter, the spring  19  and the cowl  18  push the movable optical contact  24  so that the contact piece  26  separates from the contact piece  17 . 
     After the wandering sub-assembly  38  has travelled the distance L5+L4 in the opposite direction to the arrow F 2 , the pusher  13  arrives in the end of travel position in the cavity  14 , so that the front face of the body  39  of the wandering sub-assembly  38  separates from the front face of the pusher  13 , but the piston rod  61  remains in contact with the pusher  13  under the thrust of the spring  62 . Consequently, as from this moment, an additional movement of the wandering sub-assembly  38  over the distance L3+L2 in the opposite direction to the arrow F 2  produces a relative movement of the piston  54  with respect to the body  39  from the suction chamber  55  to the delivery chamber  56 . As a result the gel is sucked into the reserve of gel  36  through the passage  52  and the non-return valve  53  and enters the suction chamber  55 . Simultaneously, the gel which is situated in the delivery chamber  56  is driven by the piston  54  through the passage  57  as far as the chamber  58  and the entry convergence  31  of the movable optical contact  24 , between the two contact pieces  17  and  26  which separate from each other, thus relining this space  58  and the entry convergence with gel. This action of pumping the gel by the piston  54  continues until the said piston reaches its end of travel position in the delivery chamber  56  and, the wandering sub-assembly  38  continuing its travel in the opposite direction to the arrow F 2  over the distance L1, the front face of the piston rod  61  separates from the front face of the pusher  13 . 
     When the wandering sub-assembly  38  has made its total travel L (L=L5+L4+L3+L2+L1), the casing  8  of the female connector  3  can then be separated from the casing  4  of the male connector  2  by exerting a traction on the casing  8  in the opposite direction to the arrow F 2 . At the start of the separation movement of the casing  8  with respect to the casing  4 , the anchoring ring  71  splays out by deforming elastically so that the rim  72  on the ring  71  passes the rim  73  on the casing  4 . At the same time, the casing  4  ceases to act on the ball or balls  69 , which can then move radially outwards under the thrust of the flexible tongue or tongues  67 . The latter then engage in the recess  68  in the casing  8 , thus holding the wandering sub-assembly  38  in the position depicted in FIGS. 1 and 6. 
     Whilst the casing  8  of the female connector  3  separates from the casing  4  of the male connector  2 , the cowl  18 , pushed by the spring  19 , comes to cover the front end of the contact piece  17 . In closing again, the two lips  18   a  and  18   b  of the cowl  18  trap part of the gel which was situated in the entry convergence  31 , and a certain quantity of gel also remains in the space  58 , inside the socket of the movable optical contact  24  in front of the contact piece  26 . As a result the two contact pieces  17  and  26  remain isolated from the polluted environment surrounding the connection device  1  after separation of the two connectors  2  and  3 . 
     It should be noted that, before the first use of the connection device  1 , gel may be introduced manually into the cowl  18  between the lips  18   a  and  18   b  thereof and gel may also be introduced manually into the space  58  either by direct injection through the entry convergence  31  of the movable optical contact  24 , or from the reserve  36  by manually exerting pressure on the piston rod  61  and releasing it. 
     According to the above, it can therefore be seen that the two contact pieces  17  and  26  and the corresponding ends of the fibres  16  and  25  are protected by the gel contained in the space  58  and in the cowl  18  against any attack by the environment surrounding the connection device  1 , both before, during and after any process of connection or disconnection of the two connectors  2  and  3 . In addition, in the connected state of the two connectors  2  and  3 , the gel provides optical continuity between the two contact pieces  17  and  26  should the slightest interstice remain between them. 
     It goes without saying that the embodiment of the invention which has been described above was given by way of purely indicative and in no way limiting example, and that many modifications may easily be made by a person skilled in the art without departing from the scope of the invention. Thus, in particular, although the invention has been described particularly with regard to a hybrid connection device, it does of course also apply to a connection device having solely optical contacts for optical fibres. In additions the number of optical contacts on each of the two connectors  2  and  3  is not necessarily equal to two but may be greater or lesser than two.