Abstract:
This hydrant ( 2 ) comprises an electrically conductive body ( 3 ) having a generally tubular shape and intended for being fixed in the floor flush with a valve mounted on a pipe, for example a water distribution pipe. The hydrant comprises connection means suitable for connecting at least one electrically conductive wire ( 10 ) extending along the pipe, said connection means being connected to the body ( 3 ) such that electric continuity is maintained between the body ( 3 ) and each electrically conductive wire ( 10 ) during use.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a hydrant, and a method for detecting a buried pipe using a hydrant. 
       BACKGROUND 
       [0002]    A hydrant is a device intended to be located at ground level so as to allow the access, using an appropriate key, to the operating member of a valve of a buried pipe, such as a water distribution pipe. 
         [0003]    It is important for saving time and costs, but also for improved safety, to be able to detect the presence of such a pipe, and to localize it accurately, without digging the ground, nor destroying building, on the occasion of the subsequent works. 
         [0004]    Several methods can be used to perform the detection of buried pipes. 
         [0005]    The detection via an electromagnetic channel is the most commonly used method. This electromagnetic detection can be performed using electromagnetic detectors based on the active detection of an electromagnetic signal. 
         [0006]    A first known method of active detection comprises injecting, using a current generator, an electrical signal in an electrically conductive wire associated with the pipe to be identified and disposed following the line of the latter, and this via connection casings installed at regular intervals along the pipe to serve as access points, and of using an electromagnetic detector arranged to detect an electromagnetic field created by an alternating current flowing in the electrically conductive wire. 
         [0007]    Such a detection method proves to be expensive since it requires the installation of a large number of connection casings along the pipe to be detected, each casing being for example disposed either within a technical gallery, or on a non-buried terminal. 
         [0008]    Moreover, such a method is not much suitable for the detection of water distribution pipes, since it is difficult to install the connection casings in the vicinity of water systems. 
         [0009]    A second known method of active detection comprises injecting, using a current generator, an electrical signal directly in the pipe to be identified when the latter is electrically conductive. 
         [0010]    Such a detection method is not suitable for the detection of water pipes, since a large part of the water pipes used are not electrically conductive on the one hand, and the water pipes are mostly inaccessible from the surface on the other hand. Moreover, in the case of cast-iron water pipes, each pipe includes individual elements connected together by elastomeric seals. Thus, an electrical signal injected into the water pipe could not propagate beyond the first elastomer seal, and therefore would make the water pipe monitoring impossible. 
       BRIEF SUMMARY 
       [0011]    The present invention aims to overcome these drawbacks. 
         [0012]    The technical problem underlying the invention is therefore of providing a hydrant which is of simple and economical structure, and which allows an easy and rapid detection of a buried pipe, such as a water distribution pipe. 
         [0013]    To this end, the present invention relates to a hydrant including an electrically conductive body having a generally tubular shape and intended to be fixed in the ground plumb with a valve mounted on a pipe, for example a water distribution one, the hydrant being characterized in that it includes connection means intended to connect at least one electrically conductive wire extending along the pipe, the connection means being connected to the body so as to maintain, in operating conditions, electrical continuity between the body and each electrically conductive wire. 
         [0014]    The structure of the hydrant according to the invention allows to inject an electrical signal in an electrically conductive wire associated with a pipe simply by connecting a current generator directly to the body of the hydrant. The result is an easy localization of the pipe associated with the electrically conductive wire by using an electromagnetic detector arranged to detect the electromagnetic field created by the alternating current flowing in the electrically conductive wire. 
         [0015]    Moreover, the localization of a pipe using a hydrant according to the invention is economical, since it does not require the installation of a large number of connection casings in addition to the installation of the hydrants. 
         [0016]    Advantageously, the hydrant is intended to be located at ground level. 
         [0017]    Preferably, the hydrant is arranged to allow the access to the operating member of the valve mounted on the pipe. In particular, the electrically conductive body is intended for the passage of an actuation key of the operating member of the valve mounted on the pipe. Advantageously, the electrically conductive body includes a tubular part intended for the passage of said actuation key. 
         [0018]    It should be noted that each electrically conductive wire is grounded through the body of the hydrant. 
         [0019]    According to one embodiment of the invention, the connection means are mounted on the body so as to maintain, in operating conditions, an electrical continuity between the body and each electrically conductive wire. 
         [0020]    Preferably, the connection means are electrically conductive. 
         [0021]    Preferably, the body delimits at least one housing in which the connection means are housed. According to one embodiment of the invention, the body delimits two housings, for example radially opposite to one another. 
         [0022]    The or each housing opens for example outwardly of the body, and preferably, substantially radially outwardly of the body. 
         [0023]    Advantageously, the body includes a base delimiting at least partially the or each housing. The base forms, for example, the lower wall of each housing. 
         [0024]    Each housing is preferably delimited by an upper wall extending substantially in parallel to the base, two side walls extending substantially perpendicular to the upper wall, and a lower wall formed by the base. The upper and side walls delimiting each housing, each preferably extending from a tubular part of the body. 
         [0025]    According to one embodiment of the invention, the body includes a tubular part and a peripheral flange extending substantially radially from the lower edge of the tubular part, the peripheral flange forming the base. 
         [0026]    Preferably, the base includes at least one passage opening into the or each housing and intended for the passage of an electrically conducting wire. According to one embodiment of the invention, the base includes two passage openings opening into each housing. 
         [0027]    Advantageously, the connection means include at least one electrically conductive connection member to which at least one electrically conductive wire is intended to be connected, and preferably two electrically conductive wires. 
         [0028]    The connection member comprises for example at least one support part and at least one clamping part intended to clamp the corresponding electrically conductive wire against the support part. Each clamping part is advantageously formed by an elastically deformable clamping tongue. These arrangements allow a rapid fixing of an electrically conductive wire, and this without requiring the use of a tool. 
         [0029]    The connection member may be made with the same material as the core of an electrically conductive wire, preferably with stainless steel, for example with the 304L type stainless steel. The connection member is preferably in one piece, and for example made by stamping. 
         [0030]    According to one embodiment of the invention, the connection member includes a substantially planar support part, and a stirrup-shaped part extending over the support part, ends of which are integral with the support part. 
         [0031]    According to one embodiment of the invention, the connection means include two electrically conductive connection members. According to this embodiment, each connection member is preferably mounted in a different housing delimited by the body. 
         [0032]    Preferably, the hydrant comprises at least one protective casing made of an electrically nonconductive material in which the connection means are mounted. The protective casing is preferably housed in the or one of the housing(s) delimited by the body. The protective casing is for example shaped to close at least partially the corresponding housing. 
         [0033]    According to one embodiment of the invention, the protective casing comprises immobilization means arranged to immobilize the connection means. The immobilization means include, for example, two immobilization ribs arranged to press the connection means against the protective casing. 
         [0034]    According to one embodiment of the invention, the protective casing is supported against the upper face of the base. 
         [0035]    The protective casing is for example made of plastic, and may be translucent so as to allow an operator to check the connection of an electrically conductive wire to the connection means. 
         [0036]    The protective casing preferably includes at least one passage opening intended for the passage of an electrically conductive wire. 
         [0037]    According to one embodiment of the invention, the hydrant comprises fixing means arranged to fix the connection means on the body. The fixing means are preferably also arranged to fix the protective casing housing the connection means on the body. The fixing means are preferably electrically conductive so as to ensure electrical continuity between the connection means and the body. The fixing means include for example at least one electrically conductive fixing member, such as a fixing screw. 
         [0038]    According to another embodiment of the invention, the fixing means are arranged to fix by magnetization the connection means on the body. 
         [0039]    The body is preferably made of metal, for example made of cast-iron. 
         [0040]    The present invention also relates to an installation comprising a hydrant according to the invention, and at least one electrically conductive wire connected to the connection means and extending at least partially along a pipe, for example a water distribution pipe. 
         [0041]    The present invention further relates to a detection method of a buried pipe, for example a water distribution pipe, comprising the steps of:
       providing a hydrant including an electrically conductive body having a generally tubular shape,   fixing the body of the hydrant in the ground plumb with a valve mounted on the pipe to be detected.   electrically connecting to the body of the hydrant at least one electrically conductive wire intended to extend at least partially along the pipe,   injecting an electrical signal in the body of the hydrant, and   detecting the electromagnetic field generated by the at least one electrically conductive wire.       
 
         [0047]    The step of injecting an electrical signal is preferably carried out using a current generator. The detection step is advantageously carried out using an electromagnetic detector. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0048]    In any case the invention will be understood from the following description with reference to the accompanying schematic drawing representing, as non-limiting example, an embodiment of this hydrant. 
           [0049]      FIG. 1  is a perspective view of a hydrant according to the invention. 
           [0050]      FIG. 2  is a bottom view of the hydrant of the  FIG. 1 . 
           [0051]      FIG. 3  is a perspective view of a connection member of the hydrant of  FIG. 1 . 
           [0052]      FIG. 4  is a perspective view of the connection member of  FIG. 3  mounted in a protective casing. 
           [0053]      FIG. 5  is a perspective sectional view of the hydrant of  FIG. 1 . 
           [0054]      FIG. 6  is a perspective rear view of a protective cover belonging to the hydrant of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0055]      FIGS. 1 to 4  represent a hydrant  2  intended to be located at ground level so as to allow access, using a suitable key, to the operating member of a valve of a buried pipe, such as a water distribution pipe. 
         [0056]    The hydrant  2  includes a metal body  3 , preferably made of cast-iron, having a generally tubular shape. The body  3  comprises a tubular part  4 , a base  5  formed by a lower peripheral flange extending radially from the lower edge of the tubular part  4 , and an upper peripheral flange  6  extending radially from the upper edge of the tubular part  4  . The upper peripheral flange  6  is intended to receive a closing buffer (not shown in the figures) and to be located at the level of the roadway. The tubular part  4  is intended for the passage of an actuating key of the operating member of the corresponding valve. 
         [0057]    The body  3  comprises longitudinal wings  7  intended to rotationally immobilize the body  3  in cooperation with the ground. The longitudinal wings  7  are regularly distributed over the periphery of the tubular part  4 . 
         [0058]    The body  3  delimits two housings  8  radially opposite to one another. Each housing  8  opens radially outwardly of the body  3 . Each housing  8  is delimited by an upper wall  8   a  substantially extending in parallel to the base  5 , two side walls  8   b  substantially extending perpendicular to the upper wall  8   a,  and a lower wall  8   c  formed by the base  5 . The upper and side walls  8   a,    8   b  delimiting each housing  8  each extending from the tubular part  4  of the body  3 . 
         [0059]    As shown in  FIG. 2 , the base  5  comprises a first pair of passage openings  9  opening into one of the housings  8  and a second pair of passage openings  9  opening into the other housing  8 . Each passage opening  9  is adapted to the passage of an electrically conductive wire  10  extending along the pipe. 
         [0060]    As shown more particularly in  FIG. 3 , the hydrant  2  includes an electrically conductive connection member  11  intended to connect two electrically conductive wires  10 . The connection member  11  is advantageously in one piece, and for example made by stamping. The connection member  11  is preferably made with the same material as the core of each electrically conductive wire  10 , and for example with stainless steel, such as the 304L type stainless steel. 
         [0061]    The connection member  11  includes a substantially planar support part  12  of rectangular shape, and a stirrup-shaped folded part  13  extending over the support part  12 , free end of which is fixed on the support part  12 . 
         [0062]    The connection member  11  comprises a first support part  14   a  extending from a first side edge of the folded part  13  and a second support part  14   b  extending from a second side edge of the folded part  13 . The first and second support parts  14   a,    14   b  each extending in the direction of the support part  12  and each having preferably a concave section. 
         [0063]    The connection member  11  comprises a first clamping tongue  15  elastically deformable extending from the support part  12  and intended to clamp a first electrically conductive wire  10  against the first support part  14   a,  and a second clamping tongue (not shown in the figures) elastically deformable extending from the support part  12  and intended to clamp a second electrically conductive wire  10  against the second support part  14   b.  Each of the first and second clamping tongues  15  is more particularly intended to clamp the core of the respective electrically conductive wire  10 . 
         [0064]    The connection member  11  further comprises two passage openings  16  arranged on the support part  12  and adapted to allow its fixing on the body  3 , as will be explained hereinafter. 
         [0065]    The hydrant  2  also comprises a protective casing  17  made of an electrically non conductive material, for example of plastic. The protective casing  17  may be translucent, for example. 
         [0066]    The protective casing  17  is composed of a fixing base  18  that ensures the positioning and the fixing of the connection member  11 , and of a protective cover  19  intended to be mounted, for example by snap-fitting, on the fixing base  18 . 
         [0067]    As shown in  FIGS. 4 and 6 , the fixing base  18  comprises two pairs of side hooks  21  facing downwards, and the protective cover  19  comprises two pairs of side hooks  22  facing upwards, the hooks  21  being arranged to cooperate with the hooks  22 . The protective cover  19  further comprises a locking tongue  23  arranged to cooperate with the fixing base  18  so as to fix the protective cover on the fixing base. The protective cover  19  includes a notch  24  arranged in the lower edge of the protective cover and intended to receive a tool such as a screwdriver. These arrangements allow to raise the protective cover using a tool inserted into the notch  24  in order to disengage the locking tongue  23  and allow a removal of the protective cover  19 . 
         [0068]    The fixing base  18  comprises an immobilization boss  25  and two immobilization ribs  26  arranged to immobilize the connection member  11 , and more particularly to press the support part  12  against the lower wall of the fixing base  18 . The immobilization boss  25  is particularly arranged to cooperate with the folded part  13 , while the immobilization ribs  22  are more particularly arranged to cooperate with the end parts of the support part  12 . 
         [0069]    As shown in  FIG. 4 , the fixing base  18  also includes two passage openings  27  each adapted for the passage of an electrically conductive wire  10 . 
         [0070]    As shown respectively in  FIGS. 1 and 5 , the connection member  11  is mounted in the protective casing  17 , and these are housed in one of the housings  8  delimited by the body  3 . The protective casing  17  is supported against the upper face of the base  5 . As shown in  FIGS. 1 and 5 , the protective cover  19  is shaped to partially close the housing  8 . 
         [0071]    The hydrant  2  further comprises two fixing screws  28  arranged to fix the connection member  11  on the body  3 , and more particularly on the base  5  of the body  3 . The fixing screws  28  are made of metal so as to ensure an electrical continuity between the connection member  11  and the body  3 . Thus, in operating conditions, the connection member  11  ensures an electrical continuity between the body  3  and each electrically conductive wire  10 . 
         [0072]    Each fixing screw  28  comprises a head supported against the lower face of the base  5 , and a screw body extending successively through a passage opening arranged in the base  5 , a passage opening arranged in the fixing base  18 , and one of the passage openings  16  arranged in the connecting member  11 . 
         [0073]    According to one embodiment of the invention shown in  FIG. 2 , the hydrant  2  includes two connection members  11 , each mounted in a protective casing  17  and each housed in one of the housings  8 , each fixing member  11  being fixed to the base  5  by means of two fixing screws  28  and being adapted for the connection of two electrically conductive wires  10 . 
         [0074]    A detection method of a buried pipe, for example a water distribution one, using a hydrant according to the invention will now be described. 
         [0075]    This method comprises the steps of:
       providing a hydrant  2  according to the invention,   fixing the body  3  of the hydrant in the ground plumb with a valve mounted on the pipe to be detected,   stripping one of the ends of an electrically conductive wire  10 ,   connecting the stripped end of the electrically conductive wire  10  on the connection member  11 ,   injecting an electrical signal into the body  3  of the hydrant  2  using a current generator, and   detecting the electromagnetic field generated by the electrically conductive wire  10  using an electromagnetic detector.       
 
         [0082]    As is obvious, the invention is not limited to the sole embodiment of this hydrant, described above as an example, on the contrary, it rather encompasses all the variants of embodiment.