Patent Publication Number: US-2012024409-A1

Title: Plug connection

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119 to German Patent Application No. 102010032983.5 filed Jul. 31, 2010, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The invention relates to a plug connection. 
     BACKGROUND OF THE INVENTION 
     A plug connection of this type is known from DE-PS 1 235 691. In said plug connection, the connection part, arranged within a receiving opening of a sleeve-shaped housing, and intended for retaining a connection pipe in the housing, consists of a metal clamping ring provided with a longitudinal slot. On its outer side, the clamping ring presents a conicity that corresponds to a portion of the receiving opening, which extends conically to the end of the housing. During the setting up of this plug connection, the connection pipe must be inserted into the receiving opening of the sleeve-shaped housing up to an abutment, and subsequently retracted, until the clamping ring comes to be applied with its conical outer side against the corresponding conical inner part of the receiving opening. Although such a plug connection presents a simple design, it nonetheless has the drawback that, in case of a subsequent removal of the connection line, additional auxiliary tools are required. Said tools must be inserted between the pipe and the clamping ring, to be able to pull out the pipe without friction. 
     Several multipart plug connections with a clamping ring arranged within a housing and a clamping nut that works in cooperation with the clamping ring, and that are connected via an outer threading to an inner threading of the housing, are already known. By screwing the clamping nut into the housing, the clamping ring can be warped and pressed against the connection pipe. However, due to the threaded connection between becomes [sic] the clamping nut and the housing, the setting up and removal of such a plug connection become more difficult. 
     SUMMARY OF THE INVENTION 
     The problem of the invention is to produce a plug connection of the type mentioned in the introduction, which allows a simplified setting up and removal. 
     Advantageous variants and advantageous embodiments of the invention are the object of the dependent claims. 
     In the plug connection according to the invention, the connection part comprises a clamping element with several clamping segments separated from each other by slots, and with a supporting element that works in cooperation with the clamping element, wherein the supporting element presents mutually separated retaining tongues for engagement into the slot of the clamping element, and wherein the clamping segments of the clamping element contain conical outer surfaces for application against a conical inner surface of the receiving opening. As a result of the collaboration between the clamping element and supporting element, a secure retention of the connection pipe, and a simple setting up or removal becomes possible, even without special tools. The clamping element, which has the design of a collet, guarantees a good and secure clamping, while the supporting element with the retaining tongues engaging in the slots of the clamping element, prevents excessive deformation of the clamping segments, and consequently deformation of the connection pipe. By axial shifting of the clamping element and of the supporting element, the plug connection can be pretensioned or loosened in a simple manner. 
     In an advantageous embodiment, the retaining tongues of the supporting element also present on their outer side conical outer surfaces for application against the conical inner surface of the receiving opening. As a result, a good clamping effect is achieved. 
     A particular good clamping can be achieved by providing retaining teeth on the inner side of the clamping segment. 
     In an embodiment that is advantageous in terms of manufacturing technology, the clamping element and the supporting element are manufactured from plastic. They can also be manufactured from another suitable material. 
     A securing element designed as a protective bushing is advantageously associated with the clamping element. By means of this securing element, on the one hand, the parts of the plug connection arranged within the housing are protected from soiling, and, on the other hand, the clamping element and the supporting element are held together. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Special features and advantages of the invention can be obtained from the following description of a preferred embodiment example in reference to the drawing. The figures show: 
         FIG. 1 , a plug connection in a cross-sectional exploded view; 
         FIG. 2 , the plug connection of  FIG. 1  before the insertion of a connection pipe, in a longitudinal cross section; 
         FIG. 3 , the plug connection of  FIG. 1  with inserted and firmly clamped connection pipe, in a longitudinal cross section; 
         FIG. 4 , a clamping element of the plug connection of  FIG. 1  in a perspective view; 
         FIG. 5 , a supporting element of the plug connection of  FIG. 1  in a perspective view, and 
         FIG. 6 , a retaining element of the plug connection of  FIG. 1  in a perspective view. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The plug connection, shown in a cross-sectional exploded view in  FIG. 1 , which is used to connect connection pipes made of plastic to indoor connection fixtures, contains a hollow cylindrical housing  1 , consisting, for example, of ductile cast iron with an epoxide coating, and containing a receiving opening  2  for plugging in a connection pipe  3 , made, for example, of polyethylene, PEX or another suitable plastic. On the side turned away from the receiving opening  2 , the housing  1  presents a connector  5 , which is provided with coupling elements  4  of a quick coupling device, a threading or other connection parts, for connecting the housing  1  to a pipe bridge or the like. 
     The receiving opening  2  of the housing  1  contains an inner ring-shaped shoulder  6 , as abutment for the connection pipe  3 , and an inner ring shoulder  7 , for the application of a ring-shaped sealing  8 . The sealing  8  presents on its inner side a sealing lip  9  for the sealing application against the outer side of the connection pipe  3 . The plug connection comprises, furthermore, a sheath-shaped clamping element  10 , which can be inserted into the receiving opening  2  of the housing  1 , which contains clamping elements  12  that are separated from each other by slots  11  and flexible in the radial direction, and have conical outer surfaces  13  for application against a conical application surface  14  inside the receiving opening  2 . The plug connection comprises, furthermore, a supporting element  15  that works in cooperation with a clamping element  10 , and that contains mutually separated retaining tongues  16  for engagement in the slots  11  of the clamping element  10 . 
     In addition, a securing element  17 , designed here as a protective bushing and explained in further detail below, is associated with the securing element  15 . 
     As is apparent from  FIG. 4 , the clamping element  10 , which is designed like a collet or a clamping sleeve and preferably manufactured from plastic, presents, in the shown embodiment, four ring segment-shaped clamping segments  12 , which are mutually separated in the peripheral direction by the slots  11 , and which are formed at one of their ends on a collar  18 . At the other ends of the clamping segments  12  that protrude from the collar  18  and are radially springy, retaining teeth  19  are formed on the inner side. The conical outer surfaces  13  provided on the outer side of the claming segments are intended for application against the corresponding conical inner application surface  14  of the housing  1 . In addition, radially protruding retaining brackets  20  are formed on the outer side of the collar  18 , for engagement with the recesses  21 , represented in  FIG. 6 , of the securing element  17  designed as a protective bushing. 
     The supporting element  15  represented in  FIG. 5  contains four protruding retaining tongues  16 , which are formed on a supporting ring  22  and whose shape is adapted to the slots  11  of the clamping element  10  shown in  FIG. 4 . The retaining tongues  16  are also formed with radial springiness on the supporting ring  22 , and designed in such a manner that they complement the clamping element  10  designed as a collet or a clamping sheath, at the time of the insertion of the supporting element  15 , to form a clamping sheath that encloses the connection pipe  3  nearly completely. The retaining tongues presents [sic] inner round application surfaces  23  for application against the outer side of the connection pipe  3 , and conical outer surfaces  24  for application against the conical application surface  14  inside the receiving opening  2  of the housing  1 . 
       FIG. 6  shows the securing element  17  designed as a protective bushing. The securing element  17  contains a ring-shaped front area  25  to retain an annular bead  26  shown in  FIG. 1 , at the end of the housing  1  that is provided with the receiving opening  2 . The securing element  17  presents, furthermore, a ring-shaped rear area  27  for the application and retention against the collar  18  of the clamping element  10 . In the rear area  27 , the slit-shaped recesses  21  for the retaining bars  20  are provided. Between the ring-shaped front and rear areas, the securing element  17 , which is preferably made of rubber, is designed as a cylindrical bellows  28 . 
     Below, the operation and the setting up or removal of the above-described plug connection are explained in reference to  FIGS. 2 and 3 . 
     The plug connection can be delivered as a preassembled and ready-for-installation unit according to  FIG. 2  with the ring-shaped sealing  8  inserted into the housing  1 , the sheath-shaped clamping element  10  inserted into the housing  1 , the supporting element  15  inserted into the clamping element  10 , and the securing element  17 , which is designed as a sealing bushing, slipped onto the housing  1 . The springy clamping segments  12  of the sheath-shaped clamping element  10 , due to the slots  11 , can be pressed radially inwards, so that the sheath-shaped clamping element  10  can be inserted into the receiving opening  2  of the housing  1 , which narrows outwardly. Subsequently, the supporting element  15  is inserted into the clamping segment  10  in such a manner that the retaining tongues  16 , which also present springiness, reach into the slots  11 . 
     If the clamping element  10  and the supporting element  15  are in the inserted position shown in  FIG. 2  and the collar  18  of the clamping element  10  is applied against the front surface of the housing  1 , the clamping segments  12  and the retaining tongues  16  can be applied radially with springiness. By means of the securing element  17 , which is designed as a supporting bushing, on the one hand, the parts of the plug connection arranged inside the housing  1  are protected from soiling, and, on the other hand, the clamping element  10  and the supporting element  15  are held together in the recesses  21  of the supporting element  15 , when the retaining bars  20  of the clamping element  10  are pushed through. Because the outer shape of the securing element  17  corresponds to a springy bellows, sufficient axial flexibility is achieved for the setting up or removal of the inner components of the plug connection. 
     For the setting up of the connection pipe  3 , the clamping element  10  and the supporting element  15  are shifted on the retaining bars  20  of the clamping element  10  inwards into the housing  1  until the collar  18  is applied against the front surface of the housing  1 . As a result, a sufficient clearance is formed between the conical outer surfaces  13  and  24  of the clamping segments  12  or retaining tongues  16 , and the conical application surface  14  on the inner side of the housing  1 , so that the clamping segments  12  and the retaining tongues can be applied with springiness at the time of the insertion of the connection pipe  3 . The connection pipe  3  is inserted through the sealing  8  into the housing  1  until the pipe front surface abuts against the shoulder  6 . Then, the clamping element  10  and supporting element  15  are pulled axially outwards at the retaining bars  20  until the conical outer surfaces  13  and  24  of the clamping segments  12  or retaining tongues  16  are applied without clearance against the conical inner application surface  14  of the housing  1 . The retaining teeth  19  of the clamping element  10  now lie directly against the connection pipe  3 . Any additional pulling force exerted on the connection pipe  3  leads to the penetration of the retaining teeth  19  into the connection pipe  3 , and thus to the buildup of a retaining force. 
     To prevent the clamping segments  12  from being able to move radially inwards over a distance of any length at the time of the compression by the reaction forces between conical surfaces  13  and the conical inner application surface  14  of the housing  1 , which could lead to a polygonal deformation of the connection pipe and possibly to a pulling of the clamping element  10  out of the housing  1 , the retaining tongues  16  of the supporting element  15  are located in the slots  11  of the clamping element  10 . They prevent, due to radial application, an excessive deformation of the entire unit, thus preventing the axial pulling out of the connection pipe  3 . 
     For the removal of the connection pipe  3 , the clamping element  10  and the supporting element  15  now have to be inserted axially into the housing  1  until the collar  18  comes to be applied against the front surface of the housing  1 . As a result, sufficient clearance is formed between the conical outer surfaces  13  and  24  of the clamping segments  12  or retaining tongues  16  and the conical inner application surface  14  of the housing  1 , such that the clamping segments  12  and the retaining tongues  16  can be applied with springiness. As a result, the clamping between the retaining teeth  19  and the connection pipe  3  is eliminated, so that the latter can be pulled out of [the housing]  1 . 
     After a removal of a connection pipe  3 , the clamping element  10  and the supporting element  15  have to be exchanged prior to a new setting up, because the retaining teeth  19  as a rule suffer prior damage. In the process, the securing element  17  designed as a protective bushing is first pulled off the housing  1 , and then the supporting element is pulled out of the housing  1 . After the retaining tongues  16  have been removed from the slots  11  of the clamping element  10 , the clamping segments  12  can again present inward springiness, and the clamping element  10  can be pulled out of the receiving opening  2  of the housing  1 . 
     While various descriptions of the present invention are described above, it should be understood that the various features can be used singly or in any combination thereof. The invention described and claimed herein is not to be limited in scope by the specific embodiments herein disclosed, since these embodiments are intended solely as illustrations of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.