Abstract:
A wall outlet (PMI 1  through PMI 3 ) for connection of an optical building wiring system is provided, including a receptacle (RI, RI 3 ) adapted to be fixed in the baseboard (PL) of the wall, into which receptacle optical cords (CO i , CO j , CO 1  through CO 4 ) carrying information to be transmitted to a local area network of a building including a plurality of terminals are inserted, the cords are connected to a terminal associated with the outlet. A removable cover (CI 1  through CI 3 ) is associated with a removable carrier (SCI 1 ) of connectors that enables the optical connection of the cords. The cover is capable of occupying a first standby position, in which it closes the front face of the receptacle, and a second active position for use where the plane of the cover forms a dihedron with the front face. The cords exit laterally relative to the receptacle on either side thereof, parallel to the baseboard. First positioning elements (GMI 1  -GMI 2 , G 1 , EG 2 ) cooperate with second positioning elements (GI 1  -GI 6 , EC.sub. 1 -EC 2 , EC 3  -EC 4 ), belonging to the receptacle, in such a way as to shift the cover from the standby position to the position for use.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a wall outlet for connection of an optical wiring system in buildings. Hence it is more particularly applicable to local area networks in which the transmission carrier is preinstalled in all the offices of an industrial- or commercial-type building, in which the business that occupies it is equipped with a local area network of its own which enables a plurality of information processing terminals (word processing system, desktop computer, etc.) which are installed in each of the offices of the building to communicate with one another. 
     BACKGROUND OF THE INVENTION 
     A data transmission network is known to be made up of a plurality of units, generally called terminals or stations. The latter communicate with one another by way of a transmission system that has a physical transmission carrier made up of either two pairs of telephone wires or a coaxial cable or optical fiber cables. 
     Local area networks are transmission networks limited to a region of limited surface area (building, factory, campus, hospital, etc.), where the distances between stations range from several meters or tens of meters to several kilometers. When this local area network is located in a building, it is increasingly often prewired. This means that all the physical transmission links of the network are installed in the building beforehand, before the users of the building occupy the various places in it. 
     In general, a prewired building includes a general distributor and a plurality of subdistributors. The subdistributors are the basic elements of the wiring system. It is through them that all the local information processing or office automation links, and those of the switched (telephone) network serving all the offices located within a radius of 200 m around the subdistributor converge. The function this subdistributor performs in the area where it is located is patching. This patching makes it possible to create different links which are needed because of the prewiring of the building. It is generally at the level of the subdistributor that the interconnection with the networks of the higher category, to which the local area network of the building is connected is done. The subdistributor then receives the gateways with the other networks and also includes the repeaters of the building network and concentrators. The physical transmission links are installed between the subdistributors and the offices. Naturally, a plurality of subdistributors may be connected among one another to the general distributor. 
     Increasingly often, the physical transmission links are made up of optical fibers, which enable extremely high transmission rates, up to one or more hundred megabits (Mbits) per second, while maximally limiting line losses. 
     Prewired building networks using any of the physical transmission carriers discussed above are described in more detail for instance in the commercial brochures, put out by the Bull Corporation, on the Bull Cabling System (BCS), a cabled network commercial sold by Bull. In each office, a certain number of connection outlets is fixed to the baseboard of walls, located in the lower portion of the walls closest to the floor, the outlets being intended to connect the cords from the terminal or terminals installed in each of bureaus. 
     When the local area network uses a transmission carrier made up of optical fiber cables, the wall outlets are optical connection outlets (the term &#34;optical wall access point&#34; is also used). 
     In current practice, optical prewiring of buildings involves practically only the main skeleton of the wiring and does not extend to the level of the offices, for reasons of customer needs and the cost of this prewiring. Nevertheless, a certain number of manufacturers and customers are interested in wall connection outlets, and one may expect that in the next few years, the technique of developing optical wall connection outlets will gain increasing success. 
     An optical wall connection outlet preferably has the following characteristics: 
     a relatively low cost; and 
     capable of being prewired or postwired; 
     in postwiring, 
     it should be capable of being installed on demand, 
     should be capable of being moved around, 
     must be capable of being installed, or removed, very quickly, 
     should not require particular tools to be installed, 
     should enable very simply coiling up a certain length of optical cable without excessive strain on the cable, and if possible inside the baseboard; in particular, it must take into account the maximum radius of curvature that a cord of optical fiber can undergo so that it can be coiled without being damaged, 
     finally, it should have a low cost. 
     In prewiring, the qualities desired for an optical wall connection outlet are as follows: 
     it should enable a user to be connected rapidly; 
     it should enable simple coiling of a certain length of cable without excessive strain on it; and 
     it should have a very low cost before use, with the prewiring access point being standardized. 
     Moreover, in either case (postwiring or prewiring), the wall outlet must have a standard format, that is, the shape of a mosaic 50×50 mm in size, or optionally 45×45 mm, which will be the standard used in coming years. In addition, the optical wall connection outlet must be capable of accepting all types of connector. 
     In general, existing optical wall connection outlets are in the following form, described in conjunction with FIGS. 1a and 1b. 
     In FIG. 1a, a wall outlet of a first type, PM 1  is seen, which is made up of a mosaic MOS 1  of rectangular parallelepiped form fixed to the baseboard PL of the wall, the wall not being shown for the sake of simplicity in the drawing. The outlet PM 1  also includes two connection plugs F 1 , F 2  which are perpendicular to the front face FAV 1  of the mosaic, the plane of which front face is parallel to the plane of the wall. The connection plugs F 1  and F 2  in fact have an oblong shape, and the language is misused when it is said they are perpendicular to the front face FAV 1 , when in fact it is their axis of longitudinal symmetry that is perpendicular to the surface of the wall, which is perpendicular to this front face. In FIG. 1a, two optical fibers cords C 1 , C 2  are also seen, connected to the two plugs F 1  and F 2 , respectively. To accomplish this, the two cords, which as shown in this same drawing figure arrive parallel to the wall and to the surface of the floor PLA must be bent to be connected to the two plugs F 1  and F 2  over an extremely short distance, so that these cords C 1  and C 2  do not have a insignificant radius of curvature R. As a result, it is difficult to coil the cable inside the baseboard in the vicinity of the plugs F 1  and F 2 . In the case of the wall outlet PM 1 , the connection of the connection cords of the terminal is done in place. 
     Moreover, the wall outlets of the prior art have the following disadvantages: 
     they do not generally accept more than a single type of connection; 
     the direction in which the cords in use exit, toward the terminal or the station, is fixed; 
     the wall outlet installed, in the case of prewiring, is cumbersome and this is true even if it remains unused thereafter, because it is systematically equipped with its connectors; and 
     finally, it has only a single function: To connect the station or terminal to the incoming cable from the subdistributor. 
     Turning now to FIG. 1b, a wall outlet PM 2  is shown which includes a mosaic MOS 2  with a front face FAV 2  having the same parallelepiped rectangular form as MOS 1  and fixed to the baseboard PL in the same way. This wall outlet PM 2  includes two connection plugs F 3  and F 4 , which are perpendicular to the surface of the floor PLA and are accordingly oriented downward. In this same drawing, one can also seen the connection cords C 3  and C 4  connected to the plugs F 3  and F 4 , and one can observe the presence of a not-insignificant radius of curvature R, which is made necessary to enable connection of the two cords to the two outlets. The disadvantage of the outlet PM 2  is accordingly the same as for the outlet PM 1 , that is, the difficulty of coiling up cable to connect it to the two connection plugs F 3 , F 4 . These problems of the radius of curvature and of cable coiling are even more tricky to solve than in the case of the plugs shown in PM 1 . On the other hand, this installation, with connection plugs oriented downward in the mosaic, prevents all the dust located in great amounts on the floor of the office from collecting on the plugs. 
     The outlets PM 1  and PM 2  practically require prewiring and preconnectorization (with the plugs F 1  -F 2  or F 3  -F 4 ). This assumes that the problem of the radius of curvature and coiling of the fiber is mastered. The present invention makes it possible to overcome these problems while meeting all the characteristics and qualities described above. 
     SUMMARY OF THE INVENTION 
     According to the invention, the wall outlet for connection of an optical building wiring system, including: 
     a receptacle adapted to be fixed in the baseboard of the wall, into which receptacle the optical cords carrying the information to be transmitted to the local area network of the building including a plurality of terminals are inserted, 
     and means for connecting the cords to the terminal associated with the outlet, is characterized in that the connection means include: 
     a removable cover associated with a removable carrier of connectors that facilitates the optical connection of said cords, 
     the cover has a first standby position, in which it closes the front face of the receptacle, and second active position for use where the plane of the cover forms a dihedron with the front face, the cords then exiting laterally relative to the receptacle on either side thereof, parallel to the baseboard, 
     including first positioning means cooperating with second positioning means, associated with the receptacle, in such a way as to shift the cover from the standby position to the active position for use. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further characteristics and advantages of the present invention will become apparent from the ensuing description given by way of non-limiting example, in conjunction with the accompanying drawings. 
     In these drawings: 
     FIG. 1, composed of FIGS. 1a and 1b, shows two examples of a wall connection outlet according to the prior art; 
     FIG. 2, composed of FIGS. 2a and 2b, shows the receptacle of the wall outlet according to the invention, intended to receive the cover and the connector carrier; 
     FIG. 3, composed of FIGS. 3a, 3b, 3c, which are three-quarter perspective views, show the various constituent elements of a first exemplary embodiment of the cover intended to be inserted into the receptacle; 
     FIG. 4 is a three-quarter perspective showing how the connector carrier is inserted inside the first model of the cover belonging to a wall outlet according to the invention. This figure also shows the dust protection system, which protects the optical connection when the cover is in the position for use but is not shown in the other drawing figures that show the cover. 
     FIG. 5, composed of FIGS. 5a and 5b, shows the second embodiment of the cover belonging to the wall outlet of the invention, with FIG. 5a being a three-quarter rear perspective view and FIG. 5b being a three-quarter front perspective view. 
     FIG. 6, composed of FIGS. 6a, 6b and 6c, shows in further detail the front face of the second model of the wall connection outlet according to the invention; 
     FIG. 7 shows in three-quarter perspective the first model of the wall outlet according to the invention, in the position for use; 
     FIGS. 8 and 9 show two ways of making connections between a technical site including a subdistributor and various access points located inside an office; 
     FIG. 10 is another drawing, extremely simplified, showing how the distributors are connected to the various offices; 
     FIGS. 11-15 show various ways how one or the other of the two models of the wall connection outlet according to the invention are used; 
     FIGS. 16 and 17, the latter being composed of FIGS. 17a and 17b, show a third embodiment of the wall outlet according to the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 2, 3, 4 and 5 will now be described, which show the various essential constituent elements of the optical wall outlet according to the invention, which correspond to the first and second embodiment of the outlet of the invention, respectively, that is, PMI 1  and PMI 2 . 
     The first embodiment PMI 1  is formed by associating the receptacle RI, shown in FIGS. 2a and 2b, with the cover CI 1  and the connector carrier SCI 1  shown in FIGS. 3a, 3b and 3c, as well as FIG. 4. 
     In addition, the second embodiment PMI 2  is formed by associating the receptacle RI shown in FIGS. 2a and 2b with the cover CI2 shown in FIGS. 5a and 5b. 
     Turning to the receptacle RI shown in FIG. 2: it is of rectangular parallelepiped form, and its rear face FAR is the one by which the receptacle RI is fixed to the baseboard of the wall, which is identical to the baseboard PL shown in FIGS. 1a and 1b. It is understood that the rear face FAR is fixed to this baseboard by any appropriate means, such as by fitting in a niche or by any other fixation means, such as screwing. 
     The front face FAV of the receptacle RI is the one by which one or the other of the two covers CI 1  and CI 2 , shown in FIGS. 3 and 4 on the one hand and FIG. 5 on the other, is introduced. When these covers are fixed inside the receptacle, the front face FAV is closed completely or partially by the main face of one or the other of the aforementioned two covers (see hereinafter). 
     The receptacle RI includes, disposed on its upper and lower faces, inside the receptacle, three pairs of rails: The pair GI 1  and GI 4 , the pair GI 2  and GI 5 , and the pair GI 3  and GI 6 . The three rails GI 1 , GI 2 , GI 3  are disposed on the lower face of the receptacle, while the rails G 4  through G 6  are disposed on the upper face. It is clear that inside each of the pairs of rails, the two rails composing the pair are facing. One can also say that they face one another. Hence the rail GI 1  faces the rail GI 4  ; GI 2  faces GI 5  ; and GI 3  faces GI 6 . All these rails are female rails. The rails GI 2  -GI 5  are the central rails, while the other two pairs are the side rails. The central rails are perpendicular to the rear face (their axis of longitudinal symmetry is perpendicular to this rear face), while the lateral rails form an angle α with the central rails (their axis of longitudinal symmetry forms an angle α with the axis of longitudinal symmetry of the central rails). This angle α is shown particularly clearly in FIG. 2b, which is a view from above of the lower rails GL 1  through GL 3 , seen from the rear face FAR. The cross section of the rails may be of any shape. In FIGS. 2a and 2b, they have been shown with a rectangular cross section. It is understood that the central portion of the rails, which is hollow, is what is called the cross section of the rails. This cross section is marked S. 
     In FIG. 2a, it can be seen that the side faces FL 1  and FL 2  perpendicular to the baseboard PL are open wide; that is, in their central portion they include a rectangular recess of width L, which enables the passage of the optical fiber cords. 
     The description now turns to FIGS. 3 and 4, which show the first embodiment CL 1  of the cover belonging to the wall outlet of the invention. This cover CL 1  includes a front portion PAV 1  that is rectangular and whose dimensions are practically the same as those of the front face FAV of the receptacle RI. It is understood that the size of this front portion PAV 1  is slightly smaller, by a fraction on the order of tenths of millimeters, than the front face FAV, to allow it to be inserted inside the receptacle. In certain cases, it may also constitute a cap-type of closure, if it is slightly larger in size than the receptacle. The cover CI 1  further includes two male rails in its lower and upper portions, disposed substantially in the plane of symmetry of the front portion PAV 1  (the plane of symmetry which is perpendicular to the plane of the baseboard when the cover is inserted into the receptacle; these are a lower male rail GMI 1  and an upper male rail GMI 2 , which are intended to be inserted into the cross section S of any of the three pairs of female rails GI 1  -GI 4 , GI 2  -GI 5 , GI 3  -GI 6 . In this way, each of the rails GMI 1  and GMI 2  respectively includes one male groove member RMI 1  and RMI 2 . The cross section of these male groove member is shown as rectangular in FIGS. 3a, 3b and 4. This rectangular cross section has the same surface area as the rectangular cross section S of the female grooves of the female rails shown in FIGS. 2a and 2b, in order to enable the male members RMI 1  and RMI 2  to be inserted into the female grooves of the pairs of rails of the receptacle. Thus as can be seen from FIGS. 3 and 4, the male members RMI 1  and RMI 2  are disposed in the lower and upper portion, respectively, of the corresponding male rails GMI 1  and GMI 2 . Furthermore, each of the male rails GMI 1  and GMI 2  includes female grooves RFI 1  and RFI 2 . Also shown in rectangular cross section in these same drawing figures, RFI 1  and RFI 2  are situated in the upper portion of GMI 1  and the lower portion of GMI 2 , respectively. Thus as can be seen from FIG. 3a, for example, the female groove RFI 1  is situated above the groove member RMI 1 . In the same way, the male groove member RMI 2  is located above the female groove RFI 2 . 
     A dust cover CP has also been shown, solidly joined to PAV 1 . 
     It can also be seen that the axis of longitudinal symmetry of the male rails GMI 1  and GMI 2  is perpendicular to the plane of the front portion PAV 1 . 
     The two female grooves RFI 1  and RFI 2  are intended to receive the connector carrier SCI 1 , which is inserted by being slid inside them. 
     This connector carrier SCI 1  is shown in FIG. 3c. It includes a rectangular carrier SRI, for example of plastic material, and means for connecting optical fiber cords, constituted for example by two standardized ST-type connectors, indicated by reference symbols RCI 1  and RCI 2 . It will be appreciated that any type of optical connector, preferably standardized, may be installed as the connection means on this connector carrier SCI 1 . 
     The connector carrier SCI 1  is a removable part, and it can be introduced by sliding, from back to front as indicated in FIG. 4, perpendicular to the plane of CI 1 . The support is introduced into the two female grooves RFI 1  and RFI 2 . 
     The first embodiment of the cover CI 1  can occupy two positions: 
     1. Standby Position 
     In this case, the cover CI 1  is introduced into the pair of rails GI 2  -GI 5 . As a result, it completely closes the receptacle RI. There are two possibilities for the standby position. These are as follows: 
     a. Simple standby position: only the receptacle RI and the cover CI 1  are used; the connector carrier SCI 1  may or may not be installed in the grooves RFI 1  and RFI 2 . 
     b. Wired standby position: in this case, the connector carrier SCI is installed in the grooves RFI1-RFI 2 . It is connected to an incoming optical fiber cable but is not in use. The cover then completely closes the receptacle (it is understood that in this case, there is no outgoing optical cord to a terminal). 
     2. Position for Use 
     The cover CI 1  is introduced into one or the other of the pairs of lateral rails GI 1  -GI 4  or GI 3  -GI 6 , depending on whether one wishes to have the cords to the terminal exit on the left or on the right, or naturally depending on the direction in which the optical fiber cable arrives from the subdistributor. In this case, the cover then has an opening enabling the exit of the cord horizontally and substantially parallel to the baseboard PL. This is especially demonstrated by FIG. 7, where the two incoming optical fiber cords CO 1  and CO 2  are seen, which then pass to inside the side face FL 1  of the receptacle RI, in the open portion of this lateral part, and the outgoing cords CO 3  and CO 4  (corresponding to the respective incoming cords CO 1  and CO 2 ) are seen, which go toward the terminal T installed in the office where the wall outlet PMI 1  is mounted. It can clearly be seen from the drawing that the cover CI 1  is shown in the pairs of lateral rails GI 3  -GI 6 , and as a result at an angle α with the plane of the front face FAV of the receptacle RI. Accordingly, there is a free space between the front face PAV 1  of the cover CI 1  and the front face FAV 1  of the receptacle RI, through which space the cords CO 3  and CO 4  pass. It is quite clear that both the cords CO 1  and CO 2  and the cords CO 3  and CO 4  are connected to the respective connection means RCI 1  and RCI 2  of the carrier SCI 1 . 
     Turning to the second embodiment PMI 2  of the wall outlet according to the invention: This second embodiment includes a receptacle RI, identical to that of the first embodiment and accordingly carrying the same symbol, and a cover CI 2 . The latter includes a front portion PAV 2  to which the male rails GMI 3  and GMI 4  are fixed, whose structure is completely identical to that of the male rails GMI 1  and GMI 2  shown in FIGS. 3 and 4. 
     In these two FIGS. 5a and 5b, it can be seen that the front portion PAV 2  includes a boss BO 2 , inside which one or two cords or even two cables (hence four optical fibers) can be passed, as can be better seen from FIG. 6b, which is a view from above of the boss BO 2  inside which the two cords CO 5  and CO 6  are passed. These two cords are embedded in a flexible gasket that holds them in place inside the boss BO 2 . FIG. 6c shows the boss including the two cords CO 5  and CO 6  seen from above, with their fixation system SFI 2 . In FIG. 6a, a complete view is given showing the two cords CO 5  and CO 6  coiled in the baseboard PL in the right-hand portion of the drawing and passing into the boss BO 2 , with the cord inside the boss being parallel to the wall and the floor, as indicated by the arrow A, and the wall outlet PMI 2  being shown in three-quarter perspective mounted on the baseboard PL. 
     Turning to FIGS. 16, 17a and 17b: The third embodiment of the wall outlet of the invention includes a receptacle RI 3  and a cover CI 3 . The receptacle is shown in FIG. 16, while the cover is shown in FIGS. 17a and 17b, FIG. 17a being a three-quarter front view while FIG. 17b is a three-quarter rear view. 
     If one looks at FIG. 16, one sees that the receptacle RI 3  no longer includes rails like the receptacle RI that is common to the first and second embodiments PMI 1  and PMI 2 . The upper and lower horizontal sides FSI 3  and FII 3  of the receptacle RI 3 , as can be seen in this same FIG. 16, include grooves that serve quite simply to facilitate mounting the receptacle inside the base board of the wall where it will be fixed. Hence there is no need to further describe these grooves or the mode of fixation of the receptacle inside the baseboard, which can be done in a known manner and in any case is not one of the characteristics of the invention. 
     The receptacle RI 3  includes a front face FAV 3  that includes a rectangular frame including two vertical lateral sides CLV 1  and CLV 2  and two horizontal lateral sides CLH 1  and CLH 2 . The interior portion of this frame located inside the lateral sides is intended to be plugged completely by the cover CI 3  when the cover is in the standby position (see hereinafter), or to form a dihedron with an angle α with the cover in such a way as to allow the optical cords to pass between the front face FAV 3  and the surface of the cover, in a manner that is strictly identical to that shown in FIG. 7. 
     The receptacle RI 3  also includes vertical lateral sides FL 3  and FL 4  (which are perpendicular to FAV 3 ), by way of which the optical cords can also pass, in the same way as in FIG. 7, for example. 
     The vertical lateral sides CV 1  and CLV 2  in their lower and upper portions include projections that protrude relative to the plane of these sides. These protruding projections are marked DB 1  (the lower portion) and DB 2  (the upper portion) for the vertical lateral side CLV 1 , and DB 3  and DB 4  for the lower and upper portions of the vertical lateral side CLV 2 . Each of the protruding projections DB 1  through DB 4  includes a niche, EC 1  through EC 4  respectively. Each of these niches is made inside the volume constituted by each of these projections DB 1  through DB 4 . It can be seen in FIG. 16 that the niches EC 1  and EC 3  face one another, as do the niches EC 2  and EC 4 . 
     Turning now to FIGS. 17a and 17b, these show the cover CI 3 . This latter has a front portion PAV 3  of substantially rectangular shape, which may include a boss BO 3  identical to the boss of the cover CI 2  shown for example in FIG. 5a or FIG. 5b. Moreover, CI 3  on its left-hand lateral side in FIG. 17A (right-hand lateral side in FIG. 17b), in its lower and upper portions, includes respective pins EG 1 , EG 2  intended to be inserted inside the niches EC 1  and EC 2  of FIG. 16. These pins EG 1  and EG 2  can also be inserted into the niches EC 3  and EC 4 . In the first case (pins inside the niches EC 1  and EC 2 ), the wall outlet thus constituted has a vertical hinge around which the cover CI 3  can pivot relative to the face FAV 3 , in such a way that the cover forms a dehedron of angle α with this face, exactly in the same way as shown in FIG. 7. In this case, the optical cords pass between the from face FAV 3  of the receptacle RI 3  and the front portion PAV 3  of the cover CI 3 . It is understood that the front face PAV 3  may be placed against the front face FAV 3 , and in that case the cover CI 3  completely closes the receptacle RI 3 . The wall outlet PMI 3  is then in what can be called a standby position, described more specifically below. 
     Hence as can be seen in the right-hand portion of FIG. 17a and the left-hand portion of FIG. 17b, the portion PAV 3  of the cover CI 3  includes, in its lower and upper portions, respectively, shoulder EP 3  and EP 4  which are intended to come into contact with the projections DB 4  (in the lower part thereof) and DB 3  (in the upper part thereof in FIG. 16) when the cover CI 3  comes to close the receptacle RI 3 . 
     Turning to FIG. 17b, one can also see that the cover CI 3  includes upper and lower faces PSI 3  and PII 3 , which are horizontal and are intended to come into contact with the lower and upper portions, respectively, of the upper and lower faces FSI 3  and FII 3 , respectively, of the receptacle RI 3 . Moreover, the upper portion PSI 3 , in the center of its lower portion, includes a bar or channel member CN 1  in the form of a U. The lower part PII 3  also includes an angle bar CN 2  in its central and upper portion, also in the form of a U. The two channel members CN 1  and CN 2  face one another and moreover include female grooves RFI 5  and RFI 6 . The connector carrier SCI 1  shown in FIG. 4 can be inserted into the interior of these female grooves. 
     The covers CI 1 , CI 2  and CI 3  can occupy two positions, as follows: 
     1. Standby Position 
     In the same way as the cover CI 1 , the cover CI 2  is introduced into the central rails GI 2  -GI 5 , and as a result completely closes the receptacle. It should be noted that in all the cases of use, CL 2  can also receive the connector carrier SCI 1 . 
     2. Position for Use 
     In this position, the cover CI 2  remains introduced in the central rails of the receptacle. Its specific role is then to enable the passage of one or two cords, thanks to the boss BO 2 , without being connected to them. There is accordingly economy both in terms of the optical budget, since there is less attenuation of the signal transmitted and since connection means, which always weaken the signal, are not used, and in terms of cost, since connection means are dispensed with. The cords CO 5  -CO 6  (or only one of them, CO 5  or CO 6 ) exit toward the terminal T in use, either on the right or left in FIG. 5, by simply inverting the cover CI 1  from top to bottom or bottom to top. 
     Turning now to FIGS. 8, 9, 10, these show schematically how the technical site including the subdistributors are connected to the various optical wall outlets located in one or more offices. Thus in FIG. 8, a technical site LT is seen, connected to a set of offices BU i  in FIG. 8 and BU j  in FIG. 9. In FIG. 10, the technical site LT is connected to a plurality of offices BU 1  through BU 9 , which are assumed to be distributed on either side of a corridor CL, while the technical site is assumed to be shown in the middle of the corridor. 
     As can be seen in FIG. 8, the technical site in a first embodiment is connected by a set of dual-fiber cords CO i  (in FIG. 8, three cords are shown but there may be more) to the office BU i , in which a set of wall outlets PMI i  is located. It is understood that there may be one or more wall outlets, of the type shown in FIGS. 2-7, in each of the offices belonging to the set BU i . 
     In FIG. 9, a second type of linkage between the technical site LT and the set of offices BU j  can be seen, the offices being provided with a set of wall outlets PMI j  according to the invention. The technical site LT is first connected to a proximity box BP by way of a multifiber cable CMF. The proximity box BP is in turn connected, by way of a set of dual-fiber cords CO j  similar to CO i , to all the offices BU j  provided with the wall outlets PMI j . 
     In FIG. 10, the technical site LT is shown connected by way of dual-fiber cords, similar to CO i  or CO j , to various offices. These cords CO i  and CO j  are disposed inside a false floor in the corridor CL, and from this false floor they are redistributed to the interior of each of the offices BU 1  through BU 9 . 
     The optical fiber linkage between the technical site LT and one or the other of the wall outlets PMI i  or PMI j  can be done by prewiring or postwiring, with or without mounting of the connectors at the moment of installation (that is, with or without the presence of the connector carrier of the type SCI 1 ). 
     The use of a proximity box makes it possible to reduce the distance between the subdistributor contained in the local site and the wall outlets. In that case, it is then possible to use cords that are preconnected by the manufacturer at the factory and hence are more reliable between the proximity box BP and the various wall outlets. 
     One or the other of the two embodiments of wall outlets according to the invention make it possible to handle all the instances of possible uses described above. 
     In particular, one can now turn to FIGS. 11-15, which more specifically show what these various instances of use are. 
     First, turning to FIG. 11: This shows a prewired standby linkage. The cover CI 1 , being equipped with its connector carrier SCI 1 , closes the receptacle RI of the wall outlet, here identified by the symbol PMIi. The connector SCI 1  is connected to the technical site LT by the cable CO i . 
     Turning to FIG. 12, this shows a prewired or postwired linkage in the position for use, the cover CI 1  being used and enabling the exit toward the right of the cord CO k  going to the terminal T; the technical site LT is connected as in FIG. 11 to the wall outlet PMI i , by the cable CO i . For further detail on FIG. 12, it will be useful to refer to FIG. 7. 
     Turning to FIG. 13: This drawing corresponds to that shown in FIG. 9; that is, the technical site LT is connected by a multifiber cable CMF to a proximity box BP. In the instance shown in FIG. 13 the wall outlet PMI j  is on standby, and the cover of the outlet, whether it is the cover CI 1  or CI 2 , closes the receptacle RI. In FIG. 13, the situation is on standby for postwiring. 
     Turning to FIG. 14, it has been assumed that the wall outlet PMI j  is of the first embodiment, that is, with a cover of the type CI 1 . A linking cord CO j  is used between the proximity box BP and the wall outlet PMI j , and the terminal T is connected to this wall outlet by way of a cord CO k . The two cords CO j  and CO k  are connected to a connector carrier of the type SCI 1 . In that case, the cover the type CI 1  is in the position for use, enabling the exit of the cord, for instance toward the right. In the case of FIG. 14, either prewiring or postwiring is involved. 
     Turning to FIG. 15: in this figure, the technical site LT is always connected to a proximity box BP by way of a multifiber cord CMF. The proximity box is connected directly to the terminal T by the cord CO j . For that purpose, the cover of the type CI 2  is used, which completely closes the receptacle RI while allowing the cord CO j  to pass by way of the boss of the type BO 2 . In FIG. 15, the wall outlet is identified by the symbol PMI j . For the equipment shown in FIG. 15, a cord CO j  is used, which is prewired directly in the factory of manufacture, with an attendant decrease in cost, reliability and installation speed and even disconnection speed. 
     In summary, the advantages of the wall outlet according to the invention are seen to be as follows: 
     the possibility of economizing on one connection with the cover of the type CI 2  ; 
     the possibility of arrival or departure of the linking cord toward the wall outlet either on the right or on the left thereof (see FIG. 7, for example); 
     both the incoming and outgoing directions of the horizontal cord are parallel to the baseboard, which assures better protection of the cord and offers the best solution in terms of the problem of the radius of curvature R of the optical cord, by facilitating coiling thereof; 
     the wall outlet is very low in cost; 
     it is easy to install, requiring no specialized tool whatever; 
     all possible kinds of use are feasible, with any type of connector; 
     of wall outlets according to the invention can be used with either prewiring or postwiring.