Abstract:
A short-body connector for fluid couplings made of a sleeve-shaped body. In the sleeve-shaped body an internal thread is provided, by which the connector can be screwed onto a threaded connection. Relative to axial extension, the locking groove and locking rib serving to hold the connector in the coupler are located at the height of the thread. That is, the locking rib and locking groove located ahead of the thread in the state of the art have moved to the region of the thread in the arrangement according to the invention.

Description:
CROSS-REFERENCE TO RELATED CASES 
       [0001]    This application is a continuation of copending International Application No. PCT/EP2008/002396, filed Mar. 27, 2008, which designated the United States, and which claims priority to German Patent Application No. 10 2007 0179105, filed Apr. 13, 2007, the disclosure of which is expressly incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates broadly to fluid couplings having a female member or coupler and a male member or plug, and more particularly to a short-body plug for such couplings. 
         [0003]    Detachable fluid couplings are used to connect fluid lines. The fluid coupling includes a coupler and a plug that can be plugged into the coupler. Within the coupler, there are locking elements that hold the plug in the coupler, so that it is not pushed out by the hydraulic force of the fluid. In addition, capturing means can also be contained in the coupler, that hold the plug in an intermediate position, so that fluid under pressure can escape into the atmosphere without a backward force appearing that would push the plug out. 
         [0004]    The plug used for this consists of a tube-shaped male end and a threaded end. The male end is inserted in the socket, while the threaded end is provided to attach the plug to a hose or a tube line. The plug is made correspondingly long, which is especially problematic when the plug is attached to a stiff, immovable part, for example a cylinder valve. 
         [0005]    It is believed that a short-body plug would be desirable. 
       BROAD STATEMENT OF THE INVENTION 
       [0006]    The present invention is directed to a short-body plug for a fluid coupling. 
         [0007]    The short-body plug has a sleeve or tube-shaped body, in which an inner thread is provided to connect the plug to a cylinder valve or a tube line. The outside of the tube-shaped or sleeve-shaped body carries the locking means, which works together with the locking means in the bushing body. The locking means are situated, with respect to the axial direction of the body, at the height of the thread. Thus in the solution according to the invention, the attachment means and the thread are no longer one after the other in the axial direction, but arranged next to each other in the radial direction. The required construction length of the plug is shortened. 
         [0008]    Moreover, means of sealing are provided, in order to seal the plug against the bushing. 
         [0009]    At least the body, preferably the entire plug can be made with rotation symmetry. 
         [0010]    The locking means on the outside can be designed as circumferential ribs, and a circumferential groove, or as a combination of groove and ribs. Which variant is more favorable in each case depends on the other requirements and the dimensions. 
         [0011]    For assembling the plug, it can have a tool-setting surface, for example a hexagon. 
         [0012]    The sealing means that seal the plug with respect to the gushing can be formed from a cylinder surface, for example an outer cylinder surface, when the bushing has a corresponding O-ring seated on the inside, as is encountered very frequently. 
         [0013]    Another possibility for the sealing surface consists of a cylindrical hole in the body. Depending on the design of the complementary bushing, it can be situated in the O-ring in an inner groove of the plug or it can be designed to be flush with the hole. 
         [0014]    Favorable assembly relationships are achieved when the plug arrangement contains an insert piece with a sealing surface to seal a thread support, onto which the plug arrangement is screwed. It is thereby also possible to achieve a deep seated sealing surface of the thread support, as is sometimes encountered in valves of pressure-gas containers. 
         [0015]    The sealing surface can by designed in the shape of a segment of a sphere, which opens the possibility of a metallic seal. 
         [0016]    For a simple connection of the insert piece to the body, the insert piece can carry a radially projecting flange or band that works together with a corresponding shoulder surface in the hole of the body. 
         [0017]    When the plug arrangement is such that the O-ring sealing is formed in the insert piece, the connection between the insert piece and body does not have to be fluid-tight. 
         [0018]    The assembly can be simplified when the insert piece is provided with a spring ring groove with the radial flange that secures the insert piece in the body in the axial direction. After being screwed to the thread support, the spring ring has no function. 
         [0019]    The present invention, accordingly, comprises the construction, combination of elements, and/or arrangement of parts and steps which are exemplified in the detailed disclosure to follow. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein: 
           [0021]      FIG. 1  cross-sectional view of a fluid coupling including a short-body plug in accordance with the present invention and an associated coupler. 
       
    
    
       [0022]    The drawings will be described further in connection with the following Detailed Description of the Invention. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0023]      FIG. 1  shows a fluid-coupling arrangement  1  in the uncoupled state. The coupling arrangement  1  includes a coupler  2  and a plug  3  according to the invention that can be plugged into the coupler  2 . 
         [0024]    The plug  3  has a sleeve-like body  4 , which is provided with an inner thread  5 . With the aid of the inner thread  5 , the body  4  can be screwed onto an outer thread  6  of a cylinder valve, of which only the thread support  7  can be recognized. The outside of the body  4  has rotation symmetry and carries at its back end, i.e., at the end away from the coupler  2 , a hexagon  8  as a tool-gripping surface. Directly adjacent to the hexagon  8 , a circumferential groove  9  with a trapezoidal cross-section is present, which goes over to the insertion end of the plug  3  into a rib  11 . When connected to the rib  11 , the outer circumferential surface of the body  4  is at first a cylindrical surface  12  in design, which goes over into a beveled milled surface  13  at its free end. 
         [0025]    At the height of the milled surface  13 , a circumferential rib  14  projects into the interior of the sleeve-shape base body  4 . 
         [0026]    As can be recognized from the diagram, rib  11  and the groove  9  are situated at the height of the inner thread  5 . In other words, the connecting means for the line to be connected are pushed into the mouthpiece of the plug  2  equally. A very short construction form arises thereby, compared to that of the state of the art, in which the mouthpiece and the thread are arranged one after the other. 
         [0027]    In the interior of the body  4 , an insert piece  15 . The insert piece  15  is likewise tube-shaped, and it contains a stepped hole  16 . 
         [0028]    Starting from the end of the plug, the insert piece  15  forms a cylindrical section  17  with a channel  18  for an outer spring ring  19 . When connected to the cylindrical section  17 , the insert piece forms 1 band or flange  21  that projects radially outward. 
         [0029]    The band or flange  21  works together, as shown, with rib  14 , which projects inward. 
         [0030]    Next, on the flange or band  21 , the insert piece  15  goes over into a cylindrical part  22 , which is closed by an end in the shape of spherical segment  23 . 
         [0031]    As shown, the cylindrical part  22  projects into the cylindrical hole in the screw connection  7 , and the assembled state, it strikes a conical surface  24 . There, the insert piece forms a metal seal with the metallic screw connection  7 . 
         [0032]    In the stepped hole, a ring groove  25  is pushed into the opening region, in which an equalizing ring  26  and an O-ring seal  27  are placed. 
         [0033]    Since the busing part  2  is not the object of the invention, it is sufficient to explain only the parts of it that are important for understanding the way in which the plug  3  works. 
         [0034]    The coupler  2  has a body  30 , into which a base-body sleeve  31  is screwed. The body sleeve  31  contains radial holes  32  for a wreath of locking balls  33 . The position of the locking balls  33  will be controlled on the one hand by an outer control sleeve  34 , which is designed to slide axially on the outside of the base-body sleeve  31 , and on the other hand by an inner control sleeve  35 , which is likewise designed to slide axially in the interior of the base-body sleeve  31 . By means of prestressed springs  36  and  37 , the two control sleeves  34  and  35  are prestressed in the position shown in  FIG. 1 . 
         [0035]    From the body  30 , a mouthpiece  38  projects in the axial direction, which is arranged to be coaxial to the hole in the base-body sleeve  31 . The mouthpiece forms a cylindrical outer circumferential surface  39 , which it designed to work together with the O-ring  27  to form a seal. A fluid hole  41  runs through the mouthpiece  38 . 
         [0036]    The plug  3  is assembled by the insert piece  15  being first introduced in a pre-assembly step from the back side of the body  4 , until the flange  21  reaches the inner rib  14 . Then the spring ring  19  is placed in the spring-ring groove  18 , whereby the insert piece  15  is secured in the body  4  in the axial direction. The body  4  and the insert piece  15  thereby form a component group consisting of two main components, which are attached immovably to each other with the aid of the spring ring  19  of the flange  21  and the inner rib  14 . 
         [0037]    Then, the O-ring  27  is placed in groove  25  and then the equalizing ring  26 . Its task consists of reducing the effective slit that the O-ring  27  sees on the mouthpiece  38 . Ring  26  floats in groove  25 . 
         [0038]    The unit obtained in this way is now screwed on the thread support  7  and pulled tight. During the tightening, the surface of the spherical segment  23  lies on the conical surface  24  of the thread support  7  and forms a metallic seal that is fluid-tight even at high pressures. 
         [0039]    With this, assembly of the plug is complete. As can be seen, the components that cause the locking of the plug  3  are situated at the height of the inner thread  5  with respect to the axial extent of the plug  3 . 
         [0040]    The unit obtained in this way can now be coupled with the coupler  3  in that the plug  3  is pushed with the cone surface  13  forward, into the inner space of the base-body sleeve  31 . With this, through the pushing movement, the inner control sleeve  3  is pressed against the effect of the spring  36  and releases the mouthpiece  38 . With further pushing movement, the O-ring  27  slides along the outer circumferential surface  39  of the mouthpiece  38 . The pushing movement ends as soon as the rib  11  passes the locking balls  33 , which are arranged in a wreath, and the locking groove  9  receives the wreath of locking balls  33 . Now the other spring  37  pushes the other control sleeve  34  forward in the direction of the plug  3  and the wreath of locking balls  33  is held by corresponding control surfaces in the radially inward position, in which the balls  33  are meshed in the locking groove  9 . The plug  3  is thus locked in the coupler  2  in the axial direction in a form-tight manner. At the same time, the coupled arrangement is fluid-tight, since the insert piece  15  is sealed with the aid of the O-ring  27  on the mouthpiece  38 . A fluid-tight connection is thus created between the hole  41  of the mouthpiece  38  with the stepped hole  16  in the insert piece  15 . The insert piece  15  is in turn sealed by the metal sealing on surfaces  23  and  24  and held in the thread support  7 . 
         [0041]    The plug  3  according to the invention is very short, since the locking means are situated at the height of the inner thread  15  in the design of the ribs  11  and the groove  11 , and not, as in the state of the art, at a distance in the axial direction. The mouthpiece of the plug  3  contains the connecting thread. 
         [0042]    The sealing between the coupler  2  and the plug  3  is locked in the insert piece  15  in the embodiment example shown. with this, the O-ring  27  is protected as well as possible against outside influences. But a possibility also exists of moving the O-ring  27  on the outer cylinder surface  12  and sealing it against a corresponding surface in the base-body sleeve  31 . In such a case, the insert piece  15  can also be omitted, in that, for example, the inner rib  14  is designed in such a way that it can seal the front end of the thread support  7 . 
         [0043]    Another possibility consists of the front part of the insert piece  15 , which contains groove  25 , being made in one piece with the body  4  and using the shoulder surface, which is part of a single piece with the body  4 , at the right end of the flange  21  as a sealing surface. The flange  21  would no longer be a separate component in the one-piece embodiment. Rather, the flange  21  is included in the body  4 . 
         [0044]    As it is anticipated that certain changes may be made in the present invention without departing from the precepts herein involved, it is intended that all matter contained in the foregoing description shall be interpreted in as illustrative rather than in a limiting sense. All references including any priority documents cited herein are expressly incorporated by reference.