Abstract:
The invention relates to a coupling for a fluid line arrangement, said coupling being characterised in that a plane outer side ( 8 ) of at least one essentially D-shaped sealing ring ( 7 ) of a sealing unit is applied to a plane supporting layer ( 10 ) of a receiving section ( 3 ) of a coupling part ( 1 ). In this way, in addition to a high twist rigidity of the sealing ring ( 7 ) in question, a very effective sealing action is achieved, even in the presence of comparatively weak radial pressure forces.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention provides a coupling for a fluid line arrangement. 
         [0003]    2. Description of the Related Art 
         [0004]    One known coupling for a fluid line arrangement is known from U.S. Pat. No. 4,147,368. The prior coupling comprises a coupling part provided with a sealing unit that is in the form of a sealing ring and by means of which the coupling part and an insert part that can be fitted into the coupling part can be sealed against each other. The sealing ring is disposed in a circumferential, recessed receiving groove provided in the inner wall of the coupling part, has a radially outwardly disposed, planar outer side that contacts a planar support surface of the receiving groove, and is configured with a radially inwardly oriented, arcuate inner side, edge faces oriented at right angles to the outer side being configured between the outer side and the inner side. 
         [0005]    U.S. Pat. No. 3,584,889 and U.S. Pat. No. 3,368,830 each disclose a coupling for a fluid line arrangement, in which a coupling part in the form of a sleeve extending between two line ends of the fluid line arrangement is configured endwise with rectangular sealing-ring receptacles formed by radially broadening the sleeve. In U.S. Pat. No. 3,584,889, a sealing ring having a radially outwardly disposed, planar outer side and an inwardly oriented, arcuate inner side is fitted into each of the sealing-ring receptacles, edge faces oriented at right angles to the outer side and comprising axially projecting elevations being configured between the outer side and the inner side. In U.S. Pat. No. 3,368,830, a sealing ring having a radially outwardly disposed, planar outer side and an inwardly oriented inner side is fitted into each of the sealing-ring receptacles, the inner side being provided with a number of flexible ribs that are deformable and fit themselves to the line ends of the fluid line arrangement. 
         [0006]    Known from DE 200 16 118 U1 is a fluid line arrangement with a complexly configured seal exhibiting various curvatures, grooves and flat sides. 
         [0007]    Known from DE 299 03 469 U1 is a fluid line arrangement with annular seals configured with hooks. 
         [0008]    Known from U.S. Pat. No. 3,891,224 is a D-shaped seal for a manhole composed of ring segments, which seal has a radially outwardly disposed, planar outer side and a radially inwardly oriented, arcuate inner side, with edge faces oriented at right angles to the outer side extending between the outer side and the inner side. The seal is configured with an inner cavity and contacts, by an edge face, an abutment step configured in a ring segment. 
         [0009]    Known from U.S. Pat. No. 3,081,102 is a fluid line arrangement comprising a seal having dome-like and finger-like elevations. 
         [0010]    Known from DE 101 15 399 C1 is a coupling that is to be integrated into a fluid line arrangement and comprises a coupling part provided with a sealing unit having at least one sealing ring. The sealing unit of the prior coupling comprises two sealing rings of round cross section and an intermediate ring disposed between the sealing rings, and is intended to seal against each other the coupling part and an insert part that can be fitted into the coupling part. 
       SUMMARY OF THE INVENTION 
       [0011]    The present invention provides a coupling for a fluid line arrangement which is configured as comparatively small in cross section and in which the, or each, sealing ring is reliably secured against twisting and dropout. 
         [0012]    By virtue of the fact that the sealing unit is provided with a retaining collar having oblique walls and projecting beyond the planar support surface; a step with a contact surface; and a sealing ring that is disposed in back of the retaining collar in the insertion direction of the insert part and that has, visually speaking, a D shape in which the outer side and the inner side merge directly into each other, despite the slender construction of the coupling, the or each sealing ring is secured against dropout and the twisting rigidity of the particular sealing ring is appreciably increased compared to a roundish cross section, thereby appreciably reducing the risk that it will twist portionally on itself. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0014]      FIG. 1  is a partially cut-away side view of an exemplary embodiment of a coupling according to the invention, comprising a sealing unit equipped with a single D-shaped sealing ring; and 
           [0015]      FIG. 2  is a sectional view of the exemplary embodiment according to  FIG. 1  in the region of the sealing ring, with an insert part fitted into the coupling part. 
       
    
    
       [0016]    Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplification set out herein illustrates an embodiment of the invention, the embodiment disclosed below is not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise form disclosed. 
       DETAILED DESCRIPTION 
       [0017]      FIG. 1  is a partially cut-away side view of an exemplary embodiment of a coupling according to the invention. The illustrated coupling according to the invention comprises a coupling part  1 , which is fitted with an adapter  2  for connection to, for example, a hose of a fluid line arrangement not shown in  FIG. 1 . The coupling part  1  is also provided with a receiving portion  3 , which is larger in circumference than the adapter  2  and in this exemplary embodiment includes a receptacle for a locking clamp  4 , by means of which an insert part not shown in  FIG. 1  can be locked against accidentally slipping out of receiving portion  3  after being fitted into receiving portion  3  from an insertion side  5  of coupling part  1  that is disposed oppositely from adapter  2  in an insertion direction pointing from insertion side  5  toward adapter  2 . In this way, the insert part is disposed operationally reliably in a substantially cylindrical receiving space  6  that is surrounded by receiving portion  3 . 
         [0018]    The coupling according to the invention further comprises a sealing unit, which in the illustrated exemplary embodiment is formed by an annularly closed sealing ring  7 . The sealing ring  7  is configured in the illustrated exemplary embodiment with a planar outer side  8  that in the intended arrangement faces outward, and has an arcuate inner side  9  that extends between the edge faces of planar side  8  and is oriented radially inward. In the illustrated exemplary embodiment, the sealing ring  7  has a substantially semicircular cross section and, in stretched-out arrangement, a semicylindrical shape, the planar outer side  8  being disposed in the plane of symmetry if the cross section were complemented to form a full circle or a full cylinder. 
         [0019]    In other useful configurations not depicted here, the arcuate inner side  9  of sealing ring  7  forms a partial circumference of a circle spanning an angular range of less than or more than 180 degrees, such that planar outer side  8  is outside the center of the corresponding full circle. 
         [0020]    In other useful configurations, arcuate inner side  9  has an elliptical outer surface and planar outer side  8  either is disposed in one of the two planes of symmetry of the ellipse, for a symmetrical configuration of the sealing ring  7 , or is offset in parallel to one of said planes should an asymmetrical configuration be useful. 
         [0021]      FIG. 2  is a sectional view of the exemplary embodiment according to  FIG. 1  in the region of sealing ring  7 . As is clearly discernible from  FIG. 2 , the radially outward lying, planar outer side  8  of sealing ring  7  contacts an also planarly configured support surface  10  of coupling part  1 , resulting in very good sealing action even in the presence of very weak radially outwardly acting forces, due to the large area of contact between outer side  8  and support surface  10 . Formed adjacently to support surface  10  is a rear contact surface  11  of a step  12  that projects axially against the insertion direction, while a play compensating space  15  is present between a radially inwardly directed sealing wall  13  and an abutment wall  14  that is part of coupling part  1  and extends substantially in the radial direction. 
         [0022]    It is also clear from the representation according to  FIG. 2  that configured on the edge region of planar support surface  10  that is in front in the insertion direction is a radially inwardly projecting retaining collar  16  having a front wall  17  located in front in the insertion direction and a rear wall  18  positioned in back in the insertion direction. Retaining collar  16  secures sealing ring  7  against accidentally slipping out of coupling part  1 , rear wall  18  usefully having a smaller inclination than front wall  17  so that deformation can occur without damage. 
         [0023]    Also depicted in  FIG. 2  is an insert part  19 , which, analogously to coupling part  1 , can be connected for example to a hose of a fluid line arrangement, also not shown in  FIG. 2 , to create a fluid connection to the hose connected to coupling part  1 . In  FIG. 2 , insert part  19  is depicted in the intended arrangement for creating the fluid connection, in which an end portion  20  of insert part  19  that is in front in the insertion direction comes into contact by its radial outer side with the substantially radially inwardly oriented portions of arcuate outer side  9  and slightly deforms sealing ring  7 , while a wall region of arcuate inner side  9  that is in back in the insertion direction rests against contact surface  11  to bring about sealing action in the region of end portion  20 . Taken all together, this gives the inventive coupling a comparatively high ability to accommodate production tolerances in the radial direction. 
         [0024]    It can further be appreciated from  FIG. 2  that when insert part  19  is arranged as intended between the front face, i.e., that located in front in the insertion direction, of end portion  12  of insert part  19  and the abutment wall  14  of coupling part  1 , a greater tolerance range is also provided in the axial direction, by compensating space  15 . 
         [0025]    While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.