Abstract:
A fitting for connection to a pipe includes a sleeve, in which a body is axially displaced along a sleeve axis, whereby the body has a drill for drilling into the pipe and/or a valve body of a valve. The fitting also includes a branch sleeve, located in particular on the sleeve and to which a branch line can be connected. The fitting is easily constructed in such a way that safety requirements are reliably met and such that a connection to a branch line can be easily established if necessary. According to another aspect of the fitting, a locking device which includes an actuating element is located in the branch sleeve, in such a way that the locking device is actuated by means of the axially displaceable body in the sleeve.

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to a fitting, particularly, for a pipe that is a spot-drilling fitting. 
   A spot-drilling fitting is known from European Patent EP 0 845 630 A2. It includes a housing which is made of plastic and can be connected by electric welding with a plastic pipe. The fitting contains a connecting piece, in which a body, having a drill, can be moved axially to the connecting piece axis in such a manner that a borehole can be introduced into the pipe. The connecting piece has a branch connecting piece which is positioned at a right angle to the body of the connecting piece, for connecting a branch pipeline, in which after the pipe is spot drilled, the medium, such as water or gas, flowing in the pipe, can flow into the branch pipeline. Furthermore, EP 0 572 817 B 1 discloses a spot-drilling fitting with an integrated valve, by which the connection between the pipe and the branch pipeline can be closed or opened, as required. 
   German utility patent DE 93 910 U1 discloses an electric welding sleeve for connecting gas pipelines made of plastic. This electric welding sleeve includes a safety closing device, by which in the event of a pipe break, the supply pipeline is closed off, so that the gas is prevented from flowing out. Where the safety closing device is constructed as a valve, the valve seat is connected with the electric welding sleeve and the valve body and a sealing element are positioned so that they can be moved axially in the electric welding sleeve under the action of a spring. After the valve has been closed automatically, for example, because of a specified pressure difference and/or a pipe break upstream of the closing device, and after the pipe break has been repaired, special measures, such as the application of a counter-pressure, often requiring considerable effort, are required for reopening the flow path when reopening the valve. 
   BRIEF SUMMARY OF THE INVENTION 
   It is, therefore, an object of the present invention to develop a fitting of the aforementioned type having a low construction cost, and operating in such a way that safety requirements are fulfilled with a high degree of reliability and, when required, connection to a branch pipeline can be easily established. A smaller overall size is achieved and manufacturing and installation costs are reduced. 
   This object is accomplished by a fitting for connection to a pipe, the fitting including a connecting piece, having a body which is axially moveable along an axis of the connecting piece; the body of the connecting piece having a drill for spot-drilling a pipe or a valve; the fitting further having a branch connecting piece for connecting to a branch pipeline, and a closing device with an actuating element in the branch connecting piece, such that actuation of the closing device can be performed in the connecting piece by the connecting piece body. 
   The fitting of the present invention is distinguished by simple construction which satisfies the requirements of the valve and by the integrated safety closing device which is actuated by the body which is axially moveable in the connecting piece. The closing device contains an actuating element which is brought into engagement with the body in such a manner that the closing device opens up the connection between the pipe which is connected to the fitting, and the attached branch pipeline which enables the medium, such as, gas or water to flow through the pipe into the branch pipeline. The closing device, therefore, is activated externally. The safety closing device is constructed as an automatically closing valve with a valve body and/or a sealing element in such a manner that for example, in the event that the connected branch pipeline is damaged or has suffered a break, the connection to the pipe is blocked, so that the medium cannot flow out. When the defect is eliminated, the body can be brought into engagement with the actuating element simply by an axial movement, in order to open the safety closing device once again and to reopen the flow path into the branch pipeline. 
   The body which is axially movable in the connecting piece, may contain, in a known manner, a drill for spot-drilling the pipe which is connected with the fitting, and/or a valve body, the fitting being constructed as a spot-drilling fitting or as a valve fitting and/or a combined spot-drilling/valve fitting. These functions can also be carried out advantageously if the flow medium is present under pressure in the pipe or the pipeline of a supply network, such as for gas or water. The fitting may be made of metal as well as of plastic, especially of polyethylene. In the latter case, the connection with the exterior surface of the pipe can be established in a known manner by electric welding. The branch connecting piece, accommodating the safety closing device, preferably is an integral component of the housing of the fitting. Furthermore, within the scope of the invention, the branch connecting piece may be suitably connected, such as by electric welding or over a thread connection with the connecting piece of the fitting containing the axially moveable body. Moreover, the free end of the outflow connecting piece, as an insertion end, may be suitably constructed in the same way as the connecting means and, in particular, have an electric welding sleeve for connection to the branch pipeline. Moreover, when the body is constructed with only one drill, a separate valve function can be eliminated, and is instead performed by the body or the drill, and the connection between the pipe and the branch pipeline can be completely blocked, when required, by the closing device of the invention in the branch connecting piece. 
   Further embodiments of the invention are presented in the following detailed description and examples. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Accompanying the specification are figures which assist in illustrating the embodiments of the invention, in which: 
       FIG. 1  schematically shows an axial section of a fitting of the present invention, constructed as a spot-drilling fitting, with an integrated safety closing device; 
       FIG. 2  is an enlarged detailed representation of a safety closing device, with a connection to the branch connecting piece being open; 
       FIG. 3  is a detailed representation, of the safety closing device of  FIG. 2 , with the connection closed; 
       FIG. 4  is a detailed representation, of the safety closing device of  FIG. 2 , at the onset of opening of the connection; and 
       FIG. 5  is a detailed representation, of the safety closing device of  FIG. 2 , with the connection open. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  is a sectional view through a fitting which is constructed as a spot-drilling fitting, with a plastic housing, especially of polyethylene which has a connecting piece  2  and a saddle piece  4 . At an inner surface  6  of the saddle piece, the saddle piece  4  contains a heating coil  8 , by which a tight and firm connection with a plastic pipe (not shown), is accomplished in a known manner. 
   The inner surface  6  is essentially coaxial with a longitudinal axis  10  which is orthogonal to the plane of the drawing and coincides approximately with the longitudinal axis of the pipe. The saddle piece  4  can be fixed to the pipe by a clamp  11  in a known manner. A body  14  which is axially moveable along the axis  12  of the connecting piece and which in the drawing is provided with a drill  16 , at the lower end of the connecting piece  2 , for spot drilling the pipe. According to the drawing, the connecting piece  2  is closed off at the top by means of a cap  18 , through which a spindle  19  which can be rotated about the axis  12  of the connecting piece, is passed. The spindle  19  which protrudes into the connecting piece  2 , is sealed by means of ring seals  20  with respect to the inner surface of the connecting piece  2  or a guide bushing or threaded bushing (not shown), preferably is made of metal and is positioned non-rotationally and axially not displaceable in the plastic of the fitting or of the connecting piece  2 . A lug  21 , with which the axially movable body  14  is connected non-rotationally, engages the hollow spindle  19  telescopically from below. The lug  21  is mounted axially displaceably in the interior of the spindle  19  and the body  14  has an external thread  22  at its outer surface. The external thread  22  engages or cuts the internal surface of the connecting piece  2 . By rotating the spindle  19 , the drill  16  can be moved (in a downward direction in the drawing) for spot-drilling the pipe. After spot drilling, the drill  16  can be moved axially upward once again into the position shown by rotating the spindle  19  in the opposite direction. Alternatively, the connecting piece  2  may contain the aforementioned guide bushing with an internal thread which is engaged by the external thread  22  of the body  14 . 
   A branch connecting piece  24  for connecting a branch pipeline is positioned laterally at the connecting piece  2 , preferably orthogonally to the axis  12  of the connecting piece. The free end of the branch connecting piece  24  is constructed as an insertion end in order to be connectable with the branch pipeline, especially by an electric welding sleeve. Alternatively, the free end of the branch connecting piece  24  may have suitable connecting means, such as an electric welding sleeve or a threaded connection or the like, for connecting the branch pipeline. The branch connecting piece  24  preferably is an integral component of the housing or is connected as a single piece with the connecting piece  2 . Within the scope of the invention, the branch connecting piece may also be constructed as a separate component and, as indicated by the line  26  of dots and dashes, be connected with the fitting housing in a suitable manner, such as by an electrically welded connection or, if the housing fitting and the branch connecting piece are constructed of metal, by a threaded connection or the like with the fitting housing. 
   Pursuant to the invention, a closing device  28 , shown schematically, and constructed, in particular, as a safety closing device, is positioned in the branch connecting piece. Preferably, the closing device  28  is constructed in such a manner that at a specifiable pressure drop in the connected branch pipe line, for example, in the case of damage or a break in the branch pipe line, the connection between the pipe or the interior space  30  of the connecting piece  2  and the branch pipe line is automatically blocked or interrupted and the leakage of flow medium is prevented. 
   The closing device  28  is constructed as a valve which closes automatically due to the existence of a specifiable pressure difference between the interior space  30  and the branch pipe line, the latter of which is connected in series in the flow direction, and contains an actuating element  32 , with which when necessary, the connection can be reestablished. The actuating element  32  is constructed and/or positioned in such a manner that in the blocked position of the closing device  28 , it can be brought into engagement with the body  14 . For this purpose, the actuating element  32  protrudes with its free end  34  by a specified distance  36  beyond the inner surface  38  of the interior space  30 . By axially moving the body  14  in the direction of the arrow  40 , the body  14  with the actuating element  32  or its free end  34 , are engaged in such a manner that the actuating element  32  is moved (shifted to the right as seen in the drawing) for opening the safety closing device  28 . According to the invention, the closing device  28  is activated externally by the body  14 . 
   The body  14  accordingly has a double function in that it is used in a known manner for spot drilling the pipe, and it is used for activating the closing device  28  externally. The body  14 , in addition or alternatively to the drill  16 , can be constructed as a component of a valve and contain a valve body or sealing surface  42  which can be brought into a sealing engagement with a valve seat  44  which is disposed at the lower end in the interior of the connecting piece  2  or the fitting housing. 
     FIG. 2  shows the fitting on an enlarged scale with an alternative embodiment of the closing device  28  which is provided in the interior space  47  of the branch connecting piece  24 . In comparison to  FIG. 1 , it is shown here that the drill  16  can be moved in the direction of arrow  40  as far as into the region of the closing device  28 . 
   The interior of the closing device  28  contains a space  46  with a valve seat  48 , to which a valve body  50  is attached, for the passage of the flowing medium. The valve body  50  is in the open position, so that the medium can flow from the interior space  30  through the passage space  48  into the interior space  47  of the branch connecting piece  24  and, from there, into the connected branch line. The valve body  50  is positioned on a bolt-like guide body  52  and is intercepted by means of a spring element  54  on a backing  56  which is supported in the manner shown in the interior of the closing device  28 . The backing  56  contains a central borehole  58  for the guide body  52  and, further removed radially, passage boreholes  60  for the flowing medium. 
   According to the invention, the actuating element  32  which preferably is an integral component of the guide body  52  and has a free end  34 , is assigned to the valve body  50 . As can be seen, the free end  34  is constructed at least partially spherically, and/or as a bearing element, and is surrounded at least partially by a bearing body  62  which is intercepted in the closing device  28  and/or the fitting housing by radial webs  64 . There are free passages for the flowing medium between the webs  64  which preferably are disposed radially. The webs  64  and/or the bearing body  62  are constructed and/or flexibly positioned in such a manner that the guide body  52  can be moved in the direction of the axis  66  with the actuating element  34 , as is explained in greater detail in the following. 
   According to  FIG. 3 , the closing device  28  is shown in the closed position, in which the connection between the interior space  30  of the fitting or the connecting piece and the interior space  47  of the branch connecting piece  28  is blocked. As a result of a pressure difference between the two interior spaces  30  and  47 , the valve body  50  is pressed by the pressure of the medium in the interior space  30  (towards the right in the drawing) onto the valve seat  48  which is preferably a conical valve seat  48 , in such a manner that the connection is blocked by the automatically acting safety closing device  28 . The valve body  50  rests on a preferably conical seating  48  of the guide body  52  in such a manner that in the region of a central bushing  70  of the valve body  52 , the connection is closed off tightly. 
     FIG. 4  is a detailed representation of the fitting at the start of opening of the connection between the two interior space  30  and  47  because of external activation of the safety closing device  28  by means of the body  14 . The body  14  then moves downward in the direction of arrow  40  a sufficient distance that the actuating element  32 , because of the engagement of the body  14 , is moved (to the right in the drawing) in the direction of axis  68 . In this way, a small gap, through which pressure equalization between the interior spaces  30  and  47  becomes possible, is formed between the valve body  50  and the seat  68 , since there is an annular gap between the central bushing  70  and the guide body  52 . The valve body  50  is then shifted (to the left in the drawing) in the direction of the interior space  30  of the fitting by means of spring element  54  which is constructed as a compression spring. 
     FIG. 5  shows the closing device after the connection has been opened, the valve body  50  now having been moved by means of the spring element  54  completely in the direction of the interior space  30 . Subsequently, if the body  14  is moved upward counter to the direction of the arrow  40  until the body  14  is disengaged from the actuating element  32  and/or the bearing body  62 , the valve body  50  and the guide body  52  with the integrated actuating element  32  are moved further in the direction of the interior space  30  by the spring element  54 , until the starting position, illustrated in  FIG. 2 , is assumed. 
   In this starting position, the guide body  52  is located in a defined position with respect to the backing  56  by means of the expanded shoulder  72 . The webs  64  are constructed to be elastically compliable, so that the movements of the bearing body  62  and, also the guide body  52 , as previously described, can be carried out readily. The bearing body  62  and the webs  64  preferably are made of plastic and, more preferably, are a component of a plastic sleeve of the closing device  28 . Moreover, the sleeve of the closing device can also be an integral component of the fitting and be constructed as a single piece with the latter. 
   The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not as restrictive. The scope of the invention is, therefore, indicated by the appended claims and their combination in whole or in part rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.