Patent Publication Number: US-2005139381-A1

Title: Low insertion force seating grommet

Description:
TECHNICAL FIELD  
      This invention relates to seating grommets and more particularly to seating grommets having a reduced pull-through or seating force.  
     BACKGROUND ART  
      Prior art seating grommets have comprised relatively massive, solid, hemispherical components of a flexible material such as rubber. See, for example, U.S. Pat. No. 2,225,472. The grommet would be provided with a groove for engaging a wall, usually combined with a flange for inhibiting pull-through. Such grommets frequently required a setting force of up to 75 pounds. As the areas in which these grommets have been employed have been reduced in size (for example, in automobiles) it has become more difficult to find the room necessary to exert such pulling force. Improved grommets having a lesser setting force have been proposed wherein the flexible portion is substantially hollow. Examples of the latter grommets are shown U.S. Pat. Nos. 2,375,373; 3,244,802; 3,372,960; 4,041,241; 4,685,173; 5,337,447; 5,452,494; and 5,732,440. The latter two patents are assigned to the assignee of the present invention. While some of these latter grommets worked well in certain situations, it has become necessary and desirable to reduce the insertion or setting force still further, so that seating grommets could be sued in even smaller environments.  
     DISCLOSURE OF INVENTION  
      It is, therefore, an object of the invention to obviate the disadvantages of the prior art.  
      It is another object of the invention to enhance the use of seating grommets.  
      Yet another embodiment of the invention is the reduction of the seating force of a grommet.  
      Still another object of the invention is the reduction of the seating force while substantially preventing the grommet from being accidentally pulled to far through the opening it is meant to seal.  
      These objects are accomplished, in one aspect of the invention, by a low insertion force seating grommet comprising a hollow body arrayed along a longitudinal axis. The body has a wide end and a narrow end connected by an intermediate portion. The narrow end has a cylindrical aperture and the wide end has a cup-shaped aperture. A flange surrounds the wide end and is provided with a wall-opening engaging portion. A plurality of longitudinally extending relief grooves are formed on the internal surface of the cup-shaped aperture.  
      Other objects are accomplished, in another aspect of the invention by a low insertion force seating grommet assembly comprising a hollow body arrayed along a longitudinal axis. The body has a wide end and a narrow end connected by an intermediate portion. The narrow end has a cylindrical aperture and the wide end has a cup-shaped aperture. A flange surrounds the wide end and is provided with a wall-opening engaging portion. A plurality of longitudinally extending relief grooves are formed on the internal surface of the cup-shaped aperture. A cable is frictionally engaged in the cylindrical aperture and penetrates the cup-shaped aperture. A cover closes the cup-shaped aperture. The cable enters the cover along the longitudinal axis and exits the cover at an angle of  90  degrees relative to the longitudinal axis.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a plan view of an embodiment of the invention;  
       FIG. 2  is a sectional view taken along the line  2 - 2  of  FIG. 1 ;  
       FIG. 3  is an end view of an embodiment of the invention;  
       FIG. 4  is a plan view of an additional embodiment of the invention; and  
       FIG. 5  is a sectional view taken along the line  5 - 5  of  FIG. 4 . 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION  
      For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims taken in conjunction with the above-described drawings.  
      Referring now to the drawings with greater particularity; there is shown in  FIGS. 1-4  a low insertion force seating grommet  10  comprising a hollow body  12  arrayed along a longitudinal axis  14 . The body  12  has a wide end  16  and a narrow end  18  connected by an intermediate portion  20 . The narrow end  18  has a cylindrical aperture  18   a  therethrough and the wide end  16  has a cup-shaped aperture  1     6 a.  A flange  22  surrounds the wide end  16  and is provided with a wall-opening engaging portion  24 . Longitudinally extending relief grooves  26  are formed on the internal surface  28  of the cup-shaped aperture  16   a  and extend from the outer edge of the wide end  16  to the bottom or terminal area of the cup-shaped aperture  16   a.    
      While various configurations and numbers are possible for the grooves  26 , in a preferred embodiment of the invention the longitudinally extending relief grooves are V-shaped and are eight in number, spaced 45 degrees apart.  
      In an additional embodiment of the invention, shown in  FIGS. 5 and 6 , there is provided a low insertion force seating grommet assembly  10   a  comprising a grommet  10  and a cover  30  closing the cup-shaped aperture  16   a.  A cable  32  enters the cover  30  along the longitudinal axis  14  and exits the cover  30  at an angle of 90 degrees relative to longitudinal axis  14 .  
      The cover  30  has a circumferential disk  34  that engages an outer surface  36  of the flange  22  and an internal cone  38  that engages a portion  28   a  of the inner surface  28  of the cup-shaped aperture  18   a.    
      The relief grooves  26  allow the grommet  10  to posses a relatively substantial wall thickness to insure long life and adequate protection while permitting ease of assembly. While more conventional grommets available on the open market can have insertion values on the order of 25 pounds, the grommet described herein has an insertion value of only 12 pounds.  
      The seating grommet assembly  10   a  comprising the grommet  10  and the cover  30  provides additional advantages, namely, the addition of the cover  30  which directs the enclosed cable at a 90 degree angle away from the direction in which the grommet would be inserted (i.e., along longitudinal axis  14 ) and makes it practically impossible to pull the grommet through its appointed opening.  
      A suitable material for the grommet  10  is silicone rubber, while the cover  30  can be a harder material, such as Nylon 66.  
      While there have been shown and described what are present considered to be the preferred embodiments of the invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims.