Patent Abstract:
A closure lid for a connecting element of a computer container, comprising an inner part which is maintained on an outer part of said lid and which is provided with an annular groove on the outer periphery thereof, said groove being defined by an annular web on the outer side of the lid and having a sealing ring inserted therein. In order to provide a closure lid which is embodied in such a way that it is possible to prevent the sealing ring from being raised radially from the base of the groove as a result of existing pressure and therefore to relieve the pressure inside the container before the open position of the closure container is reached, the annular web disposed on the outer side of the lid is provided with an uneven bearing surface for the sealing ring.

Full Description:
FIELD OF THE INVENTION 
   The present invention relates to a closure lid for the container neck of a container closure having an inner part that is retained on an outer part provided on its outer circumference with an annular groove defined by an annular rib toward the outer part, and into which a sealing ring is inserted; and a container closure having such a closure lid which is movable between an open position, in which it can be removed from the container neck and a closing position in which it is moved axially with its inner part into the container neck, and the inner part is provided on the outside with an annular groove defined by an annular rib toward the lid and into which a sealing ring is inserted. The container neck at the level of the sealing ring, when the closure lid is in the closing position, has a sealing face on which the sealing ring rests sealingly, and when the closure lid is in a position between the closing and open positions, has a radial neck enlargement for generating a pressure relief gap between the sealing ring and neck enlargement; and the pressure relief gap, via a pressure relief chamber, is in communication with the ambient atmosphere. 
   BACKGROUND OF THE INVENTION 
   One such container closure, and one such closure lid for the container neck of a container closure, are known from German Utility Model DE-U 299 28 541. This reference also describes how such container closures and closure lids are inserted, in order to seal off the container in the closing position of the closure lid, or upon rotation of the closure lid in the opening direction before the closure lid is finally released or removed from the container neck, to achieve a pressure relief on the basis of the still existing overpressure in the container interior, so that liftoff of the closure lid from pressure, which risks a burn injury from hot coolant as it shoots out, can be avoided. 
   In this prior art, one phenomenon of conventional container closures or closure lids, known as the champagne cork effect, is also described. In it, if the closure lid comes loose from the container neck, at elevated internal pressures, despite the radially inward-oriented tension that intrinsically presses the sealing ring against the annular groove, the sealing ring can still remain in contact with the inner wall of the container neck, if the sealing ring comes out of the region of the sealing face into the region of the neck enlargement, in the unscrewing direction of the closure lid. In other words, in this phenomenon, the sealing ring is lifted radially outward from the bottom of the annular groove by the overpressure in the container interior, so that after further unscrewing of the closure lid, the aforementioned champagne cork effect occurs from a sudden pressure relief. The aforementioned prior art avoids this phenomenon by providing that the annular rib toward the lid has pressure relief conduits, which connect the annular groove with the pressure relief chamber, or are open toward the side of the annular rib remote from the groove, whenever the sealing ring has been lifted from the bottom of the annular groove. Although this does substantially prevent the aforementioned champagne cork effect, nevertheless, because the overpressure is only partly reduced, a residual pressure in the container remains, which especially upon very fast release or unscrewing of the closure lid can still cause the closure lid to jump off suddenly, even if only slightly. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is therefore to embody a closure lid for the container neck of a container closure, and a container closure itself, each of the type defined at the outset, in such a way that the champagne cork effect caused by the sealing ring&#39;s lifting radially away from the groove bottom is averted in advance, thus achieving pressure relief of the container interior before the open position of the closure lid is reached. 
   For attaining this object, in a closure lid for the container neck of a container closure, the annular rib toward the outer part is provided with an uneven contact face for the sealing ring, and for a container closure, the same configuration of the annular rib is provided. 
   By the provisions of the invention, it is attained that whenever the sealing ring comes free of the sealing face of the container neck and gets into the neck enlargement, the sealing ring can either escape in the axial direction, upon subjection of certain regions of its annular circumference to the overpressure prevailing in the container interior, so that the sealing ring deforms axially asymmetrically, or the sealing ring is already deformed in the axial direction because of the design of the annular groove boundary, so that at these circumferential regions it more likely enters the range of the neck enlargement, thus partly and in advance opening up a venting route. This axial deformation, or deformed condition, of the sealing ring not only creates an advance venting route but also prevents the sealing ring from lifting radially outward from the bottom of the annular groove, so that the champagne cork effect phenomenon cannot even arise in the first place. In this way, a total pressure equalization can be achieved even at a relatively high overpressure in the container interior, before the closure lid has reached its fully open position. 
   In a preferred embodiment, the annular rib toward the container is provided with an uneven contact face for the sealing ring, as a result of which a suitably deformed installation position is already predetermined for the sealing ring. This leads to the further advantage of reduced frictional resistance as the closure lid is screwed in onto the container neck or is unscrewed and released from it. 
   In preferred features, the sealing ring contact face of the annular rib toward the outer part and/or of the annular rib toward the container is provided with one or more support ribs that protrude into the annular groove and are distributed over the circumference. The support rib can be disposed or embodied to be offset at angles from one another relative to the support rib of the annular rib toward the container, and/or each annular rib has a pair of diametrically opposed support ribs, and the two pairs are offset from one another by 90°, and/or the support ribs protrude axially from the contact face and have a radial length corresponding to the width of the annular rib. In normal operation, the support ribs bring about a linear support of the sealing ring inside the annular groove and can either fix the sealing ring in deformed fashion or, upon overpressure in the container interior, during the unscrewing motion of the closure lid, they can allow an adequate axial motion of the sealing ring between adjacent support ribs. 
   A further embodiment is defined in that the sealing ring contact face of the annular rib toward the outer part is provided with at least one axial recess which extends radially from the circumferential edge of the annular rib, and in combination with them optionally the recess is provided at two diametrically opposed points and/or has an inner boundary line that is embodied as convexly swooping. 
   A further embodiment is obtained by the recess having a crescent-shaped bottom face, and in an embodiment optionally the crescent-shaped bottom face extends over the entire circumference of the annular rib toward the outer part and over that course varies its radial width constantly from a width corresponding to the width of the annular rib down to zero, and/or an uneven contact face for the sealing ring is provided on an annular rib toward the container that additionally defines the annular groove. 
   In these last two embodiments, wherein the groove bottom of the annular groove, in a widening of the contact face, has an encompassing groove the axial mobility or predeformed fixation of the sealing ring is provided by means of variously designed recesses or indentations in the annular rib contact face or faces. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further details of the invention can be learned from the ensuing description, in which the invention is described and explained in further detail in terms of the exemplary embodiments shown in the drawing. 
       FIG. 1 , is a schematic perspective view, the inner part of a closure lid for the container neck of a container closure, in a first exemplary embodiment of the present invention; 
       FIG. 2 , is a schematic longitudinal section, a container closure of a closure lid, placed in a container neck, of  FIG. 1  showing the status while the closure lid is being unscrewed from the container neck; 
       FIG. 3 , is a view corresponding to  FIG. 2 , but in a second exemplary embodiment of the present invention; 
       FIGS. 4A and 4B , are a section taken along the line IVA-IVA of  FIG. 1  and a section taken along the line IVB-IVB of  FIG. 4A , for a third exemplary embodiment of the present invention; and 
       FIGS. 5A and 5B , are views corresponding to  FIGS. 4A and 4B , but for a fourth exemplary embodiment of the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 and 2 , and the one hand, and  FIG. 3  on the other, show two embodiments, each with a container closure  10  embodied essentially rotationally symmetrically, which has a container neck  11  and a closure lid  12  or  12 ′ screwed onto the container neck. 
   The container neck  11  on the bottom has a narrowed neck portion  13 , which is in communication with an opening in a container, not shown, preferably a radiator for internal combustion engines. An enlarged neck portion  14  is provided in the upper region of the container neck  11  and is joined to the lower neck portion  13  via a conical intermediate portion (ramp)  15 . The container neck  11  is provided with a male thread  16 , by way of which the closure lid  12 ,  12 ′ can be screwed to a female thread  17 , or in other words can be screwed on and unscrewed. 
   The closure lid  12  and  12 ′ has a caplike outer part  21 , which fits over the container neck  11  and which is provided with the female thread  17  for screwing onto and unscrewing from the container neck  11 . The closure lid  12 ,  12 ′ also has a cup-shaped inner part  22 , which is shown in perspective in  FIG. 1 , and an inner part  22 ′, respectively. The inner part  22 ,  22 ′ is inserted lockingly with an upper edge  23  into an inner groove on the outer part  21 , so that the outer part  21  and the inner part  22 ,  22 ′ can rotate relative to one another. In the lower region, the basket part  24  provided with the upper edge  23  is adjoined by an annular groove  26 , into which an elastomeric sealing ring  27  in the form of an O-ring is inserted. The annular groove  26 ,  26 ′ is defined on one side by an annular rib  28 ,  28 ′ toward the outer part and by an annular rib  29 ,  29 ′ pointing toward the container. The outer diameter of the annular ribs  28 ,  28 ′ and  29 ,  29 ′ is less than the outer diameter of the sealing ring  27  that rests with radially inward-oriented prestressing on the groove bottom  31  of the annular groove  26 ,  26 ′. 
   In the first exemplary embodiment, shown in  FIGS. 1 and 2 , the annular rib  28  toward the outer part is provided, on its contact face  32 , with support ribs  33  that protrude axially in the direction of the annular rib  29  toward the container interior. The length of the support ribs  33  is equivalent to the radial width of the contact face  32  of the annular rib  28  toward the outer part. The support ribs  33  are very narrow in the circumferential direction and have a likewise relatively slight axial height; in the exemplary embodiment, this axial height is determined such that the inside diameter between the support rib  33  and the opposite face  34  of the annular rib  29  toward the container interior is approximately equal to the thickness of the O-ring  27 . In the exemplary embodiment shown, four support ribs  33  are provided, distributed uniformly over the circumference of the contact face  32  of the annular rib  28  toward the outer part. 
   In the second exemplary embodiment shown in  FIG. 3 , not only is the annular rib  28 ′ toward the outer part provided on its contact face  32 ′, but the annular rib  29  toward the container is also provided on its contact face  37  with axially protruding support ribs  33  and  38 , respectively. Each annular rib  28 ′,  29 ′ has a pair of diametrically opposed support ribs  33  and  38 , respectively, which are oriented axially toward one another or in other words protrude into the annular groove  26 . The pairs of support ribs  33  and  38  are offset from one another by 90°. Thus the sealing ring  27 ′ rests in deformed form in the annular groove  26 ′. Since the height of the support ribs  33  and  38  is such that the inside diameter, between each support rib  33  and  38  and the opposite face  37  of the annular rib  29 ′ toward the container interior and between the support ribs  38  and the opposite face  32 ′ of the annular rib  28 ′ toward the outer part, is approximately equal to the thickness of the O-ring  27 , the sealing ring  27 ′ is fixed in the annular groove  26 ′ with a suitable deformation that is undulating in the circumferential direction. The length of the support ribs  33  and  38  corresponds to that of the support ribs  33  in the first exemplary embodiment. 
   In a completely closed position, not shown, of the closure lid  12 ,  12 ′ or inner part  22 ,  22 ′ in the container neck  11 , the annular sealing face of the lower neck portion  13  of the container neck  11  is located facing the annular groove  26  and thus the sealing ring  27 ,  27 ′, so that this ring rests sealingly in the lower neck portion  13  of the container neck  11 . Thus the sealing ring  27 ,  27 ′ is deformed such that it is compressed into an oval. 
   If now, as shown in  FIG. 2 , the closure lid  12  is unscrewed from the container neck  11 , then the sealing ring  27  reaches the region of the conical or ramplike portion  15  of the inside circumference of the container neck  11 , so that the compression of the sealing ring  27  is reduced. Because of the overpressure that prevails as before in the container interior, the sealing ring  27  is now moved axially inside the annular groove  26 , specifically into the regions that are located between the support ribs  33 . Because of this uneven contact face  32  of the annular rib  28  toward the outer part, the axial motion of some regions of the sealing face  27  produces an asymmetrical deformation, so that as  FIG. 2  shows, a connecting path  36  that bypasses the ramp portion  15  and extends into the neck enlargement and is thus a venting route is created in the deformed portions of the sealing ring  27 , before the entire sealing ring  27  gets into the neck enlargement or the upper neck portion  14 . Since the asymmetrical deformation of the sealing ring  27  creates an advance venting route that causes a pressure reduction, the phenomenon of blasting the sealing ring  27  from behind, and thus its lifting from the groove bottom  31 , is avoided. 
   If as shown in  FIG. 3  the closure lid  12 ′ is unscrewed from the container neck  11 , then once again the sealing ring  27 ′ gets into the region of the conical or ramplike portion  15  of the inside circumference of the container neck  11 , thus lessening the compression of the sealing ring  27 ′. Since the sealing ring  27 ′ inside the annular groove  26 ′ is predeformed such that it is undulating in the circumferential direction between the two uneven contact faces  32 ′ and  34  of the two annular ribs  28 ′ and  29 ′, the result, as shown in  FIG. 3 , in the deformed portions of the sealing ring  27 ′ upon loosening of the closure lid  12 ′ is a connecting path  36 ′ that bypasses the ramp portion  15  and extends into the neck enlargement and thus readily creates a venting route, before the entire sealing ring  27 ′ reaches the neck enlargement or the upper neck portion  14 . This venting route  36 ′ is the result of this asymmetrical deformation of the sealing ring  27 ′, particularly in the region of the support ribs  33  of the annular rib  28 ′ toward the outer part. Once again, the phenomenon of blasting of the sealing ring  27 ′ from behind and thus its possible lifting from the groove bottom  31  is avoided because of the pressure reduction that automatically occurs. 
   Thus a pressure relief of the closure lid  12 ,  12 ′ is achieved and completed during the unscrewing of the closure lid, before the closure lid  12 ,  12 ′ with its female thread  17  comes completely free of the male thread  16 . 
     FIGS. 4A and 4B  show one embodiment of an uneven contact face  32 ″ of the annular rib  28 ″ toward the outer part, such that two diametrically opposed recesses  41  are formed in the contact face  32 ″. The two identically mirror-symmetrical recesses  41  have swooping convexly embodied boundary lines  42 . This means that in the region of these recesses  41 , as the closure lid  12 ″ is being loosened from the container neck  11 , the sealing ring  27  can deform axially asymmetrically in the region of these recesses  41 , so that in these regions a pressure relief path is created during the unscrewing motion. For collecting the air or water vapor blown out during the pressure relief, an encompassing groove  43  is provided in the region of the groove bottom and adjacent to the contact face  32 ″. 
     FIGS. 5A and 5B  show a further exemplary embodiment of an uneven contact face  32 ′″, in which this contact face is likewise provided with a recess  51 , which like the recess  41  of  FIGS. 4A and 4B  extends radially inward from the outer circumference of the respective contact face  32 ″ and  32 ′″. The depth of each recess  41  and  51  is relatively slight. In this exemplary embodiment, the recess  51  is embodied as somewhat crescent-shaped, as viewed in plan view; the spacing of the circular inner boundary line  52  from the outer circumferential edge of the contact face  32 ′″ decreases symmetrically. In one region, the spacing between the boundary line  52  and the outer circumference of the contact face  32 ′″ is at maximum equal to the radial width of the contact face  32 ′″, while in the diametrically opposed region, it is equal to zero. In other words, the boundary line  52  extends in a circle, and the circle of the boundary line  52  extends correspondingly eccentrically to the circle of the outer circumference of the contact face  32 ′″. In this exemplary embodiment as well, a collection groove  53  is provided for the water vapor or air to be blown away. In this exemplary embodiment, the axial deformation of the sealing ring  27  is achieved in the region of the crescent-shaped recess  51 .

Technology Classification (CPC): 5