Abstract:
A device and method for forming an indented female connector where the dimension of the indented female connector provides for removing a male molding component without damaging a set of internal ribs formed inside the female connector.

Description:
FIELD OF INVENTION  
         [0001]    The present invention relates generally to the molding of plastic parts, and specifically relates to a device for blow-molding a thermoplastic into the shape of an indented female connector.  
         BACKGROUND OF THE INVENTION  
         [0002]    Blow molding of plastics to form hollow shapes such as bottles, containers or the like is well known. Some shapes are difficult to mold into a hollow container with a blow molding process. An example of a shape that is difficult to mold is an indented female connector having a set of internal ribs for engaging with a male connector. Accordingly, there is a need for an improved device for molding an indented female connector as part of a hollow object.  
         SUMMARY OF THE INVENTION  
         [0003]    The present invention meets the above-described need by providing a male mold component that can be inserted into the mold to form the indented female connector in the container and that can be removed without damaging the ribs formed in the indented connector. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]    The invention is illustrated in the drawings in which like reference characters designate the same or similar parts throughout the figures of which:  
         [0005]    [0005]FIG. 1 is a sectional side elevational view of the male mold component positioned inside a portion of the object to be molded;  
         [0006]    [0006]FIG. 2 is a sectional side elevational view of the indented female connector; and,  
         [0007]    [0007]FIG. 3 is a sectional side elevational view showing the mold component in broken lines as it is being removed from the indented female connector. 
     
    
     DETAILED DESCRIPTION  
       [0008]    Referring generally to FIGS.  1 - 3  and initially to FIG. 1, a portion of a hollow molded object  10  is shown in a sectional side view. The portion shown is an indented female connector  16  that is formed in the side of the hollow object  10 . The hollow object  10  is formed from thermoplastic materials by blow molding techniques known to those of ordinary skill in the art. A male mold component  13  is inserted into the mold to form the indented female connector  16  shown. Once the female connector  16  has been molded, the male mold component  13  is removed from the mold as described hereinafter.  
         [0009]    Referring to FIG. 2, the indented female connector  16  is surrounded by a surface  19 . The surface  19  is formed on an upper wall  20  having a thickness indicated at  21 . The surface  19  is disposed substantially perpendicular to a set of inside walls  25  extending inward toward a rib  28  that is integrally formed in the inside walls during the molding process. Depending on the shape of the opening, the rib  28  may be formed on some or all of the inside walls  25 . For a circular opening, the rib  28  may be formed in an annular configuration. For a rectangular opening the rib  28  may extend only along the opposed major lengths of the rectangle.  
         [0010]    The rib  28  may extend from the inner wall inward at an angle of approximately forty-five degrees. As shown in FIG. 2, there is a pair of ribs  28  facing each other and extending inward at approximately a forty-five degree angle from an axis  31  parallel to the inside wall  25 . With reference to the orientation of FIG. 2, the side walls  25  may continue downward and join by means of a section  34  disposed at the bottom of the connector  16 . Although the section  34  is curved in the drawings, the section  34  may be formed in other shapes as well.  
         [0011]    Between the top of surface  19  and the rib  28  is a flex section having a dimension  37 . The distance along the rib is a locking surface  40 , and the portion below the rib  28  is a receiving surface  43 . The opening between opposed ribs  28  has a dimension  44  that will be discussed below.  
         [0012]    Turning to FIG. 3, after the blow molding process is completed, the male mold component  13  is removed from the indented female connector  16  by pulling it in a direction substantially perpendicular to top surface  19 . The opening for removing the male mold component  13  is narrowest at the point between the ribs  28 . This distance is also indicated in FIG. 2 as dimension  44 . When the male mold component  13  is removed, the ribs  28  have to bend away from each other in order to accommodate the large diameter  60  of the lower portion  63  of the male mold component  13 .  
         [0013]    Returning to FIG. 2, it has been discovered that in order to form the ribs  28  and to successfully remove the male mold component  13  without damaging the ribs  28 , a certain relationship between thickness  21  and the dimension  37  applies. If dimension  37  is greater than thickness  21 , the mold  13  can be removed without damaging ribs  28 . If dimension  37  is less than or equal to thickness  21 , the ribs  28  are typically destroyed when the mold  13  is removed.  
         [0014]    While the invention has been described in connection with certain embodiments, it is not intended to limit the scope of the invention to the particular forms set forth, but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.