Abstract:
A self-locking threaded connection including an externally threaded male part having a hollow center and a series of cooperating members; and an internally threaded female part having a series of cooperating members; the cooperating members consisting of projections and detents. As the parts are threaded together, the reception of the projections into the detents produces both audio and tactile responses indicating that the connection is made and near a destructive over tightening.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a Continuation-in-Part of U.S. Ser. No. 11/252,699 filed Oct. 18, 2005 which is a Continuation-in-Part of U.S. Ser. No. 10/891,399 filed Jul. 14, 2004 and their entire contents are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates generally to a threaded connector, and more particularly but not by way of limitation, to a threaded connector that is self-locking as may be used either alone, or in combination with plumbing fixtures including but not limited to plumbing pipes and in particular to plumbing pipes subject to vibration such as garbage disposal drains and the like.  
       BACKGROUND OF THE INVENTION  
       [0003]     Manufactures have long used various sorts of connections to assure a tight connection that can be undone if necessary, especially in the plumbing industry. Often two pipes are joined together permanently using piping dope or other forms of permanent adhesive that effectively form a plastic “weld.” These sorts of connections are quick and easy to make and do not require the exact tolerances that may be required for threaded connections. A disadvantage of this type of connection is that it is permanently welded in order to prevent fluid leaks. Thus, when there is a need to repair the plumbing the connecting pipes must be cut.  
         [0004]     Alternatively, if the plumbing connection is a threaded connection then gaskets, doping materials or other nonpermanent fluid sealing agents may be employed to assist the threads in making a fluid tight joint. A threaded connection is easily undone to make a repair or to replace one or more plumbing components or fixtures. Threaded connections often use a top lip to hold one pipe against another pipe often with the help of a gasket. However, even when there are in no internal pressures, as in a drain line, it may be difficult to make a threaded connection that forms a fluid tight seal and maintains a fluid tight seal over time.  
         [0005]     This is particularly the case if the plumbing is subjected to vibration, such as the drain from a sink drain, garbage disposal or dishwasher. In such cases the threaded connection may become loosened over time allowing leakage. Hence, plumbing connections in such situations are often over tightened in the attempt to make a tight seal. As it is not uncommon for drains such as sink drains and the like to be formed of plastics (such as PVC), over tightening may result in fractured or broken parts. Over tightened joints are also not easily disassembled or undone when needed. The following invention overcomes these problems by providing a threaded connector that is self-locking when the proper seal connection is made. The self-locking feature makes it difficult to over tighten a plumbing connection that needs to be fastened to a specific tightness and allows for ease of disassembly to undo the connection.  
       SUMMARY OF THE INVENTION  
       [0006]     The invention includes components of a threaded connection, including a male part having external threads and a female part with internal threads. The male part has one or more cooperating members located such that when the female and male parts are mated together in a proper sealing relationship, the cooperating members on the male part mate with and releasably lock with the cooperating members on the female part to resist loosening of the threaded joint. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     The present invention is disclosed with reference to the accompanying drawings, wherein:  
         [0008]      FIG. 1  is a front elevation view partly broken away and in section showing components of the self lock threaded coupling of the present invention prior to assembly;  
         [0009]      FIG. 2  is a side elevation view of the coupling partly broken away and in section showing the coupling as assembled;  
         [0010]      FIG. 3  is a view of the female part of the coupling taken generally along lines  3 - 3  of  FIG. 1 ;  
         [0011]      FIG. 4  is a view taken generally along lines  4 - 4  of  FIG. 2 ;  
         [0012]      FIG. 5  is a front elevation view partly broken away and in section showing components of the self lock threaded coupling of an alternative embodiment of the present invention prior to assembly;  
         [0013]      FIG. 6  is a front elevation view partly broken away and in section showing components of the self lock threaded coupling of an alternative embodiment of the present invention prior to assembly;  
         [0014]      FIG. 7  is a schematic drawing showing various shaped projections;  
         [0015]      FIG. 8  is a schematic drawing showing a tapered thicker section; and  
         [0016]      FIG. 9  is a cross sectional view of the male member showing another embodiment of the invention. 
     
    
       [0017]     Corresponding reference characters indicate corresponding parts throughout the several views. The examples set out herein illustrate several embodiments of the invention but should not be construed as limiting the scope of the invention in any manner.  
       DETAILED DESCRIPTION  
       [0018]     Referring to  FIGS. 1-4 , there is shown the coupling of the present invention generally indicated at  10 . The coupling includes a male part  12  comprising a pipe section  14  having exterior threads  16  at one end and a female part  18  having internal threads  20 . The female part  18  is threaded to the external threads  16  on the male part so as to couple the threaded pipe section  22  to the pipe section  14 .  
         [0019]     In this respect the unthreaded pipe section has a flat flange  24  that is engaged by a collar  26  on the female part and pressed against an end face  28  of the male part upon threading the male and female parts together (see  FIG. 2 ). Such a connection is common in plumbing fixtures such as in sink drains and the like.  
         [0020]     Plumbing connections of the type described are not usually employed in situations where there is an internal pressure. Accordingly, making the connection finger tight usually is sufficient to prevent leakage through the joint. In some cases a gasket (not shown) is inserted between the flange  24  and the end face  26 .  
         [0021]     The male part  12  has an entry threaded portion  30  on a leading end and a trailing or last-to-be-engaged threaded portion  32 . Along the external threads  16  are a series of projections  34 . At least one projection  34  is located between the entry threaded portion  30  and the trailing or last-to-be-engaged threaded portion  32 . It is understood that at least one projection may be positioned adjacent to the external threads  16  in advance of the entry threaded portion  30  or trailing the last-to-be-engaged threaded portion  32  in the direction of rotation (Arrow A). In one embodiment there are three projections. The projections can either be fixedly imbedded into the wall structure of the male part or formed integral with the wall structure.  
         [0022]     The female part  18  has a leading thread portion  38 . The trailing or last-to-be connected female thread portion is identified at  40 . As best seen in  FIG. 3  in one embodiment the female part  18  has a constant outside diameter. At least one detent  42  is located along the internal threads  20  between the leading thread portion  38  and the last-to-be connected female thread portion  40 . It is understood that at least one detent may be positioned adjacent to the internal threads  20  in advance of the leading thread portion  38  or trailing the last-to-be connected female thread portion  40  in the direction of rotation (Arrow B). In one embodiment the invention contains four detents.  
         [0023]     Accordingly, it should be appreciated that when a threaded connection is made, the detents  42  of the threaded female part  18  pass over the thread portion  30  on the leading end of the male part. The threading continues unimpeded until the first projection  34 A encounters the leading thread portion  38  of the internal threads  20 .  
         [0024]     As finger tightening continues, the first projection  34 A starts to bind against the inside surface of the internal threads  20  and then snaps into the first detent  42 A. The snapping of the projection into a detent produces an audio response as well as a tactile sensation that the user can “feel,” both indicating that the coupling is close to being made.  
         [0025]     As tightening continues still further, the first projection  34 A is forced out of the first detent  42 A and over into the second detent  42 B while the second projection  34 B first encounters the leading thread portion  38  of the internal threads  20  and then enters the first detent  42 A. With two projections bearing against the inside surface of the internal threads  20 , the force required to tighten the coupling increases. This increase in the force needed to tighten the coupling as well as the tactile response each time a projection enters a detent cooperate to let the user know that the point is being reached where there is a danger of over tightening the coupling.  
         [0026]     Tightening the coupling still further forces the two projections,  34 A and  34 B, from their respective detents  42 B and  42 A, and brings all three of the projections to bear against the inner surface of the internal threads  20 . This increases still further the force required to finger tighten the male and female parts together. Eventually all three of the projections  34  will be captured in detents  42 .  
         [0027]     While in the embodiment as described the number of detents exceeds the number of projections, it is understood that the number of projections and detents can be equal. Also, the cooperating members can be such that the projections are along the threads of the female part and the detents along the treads of male part. Additionally, the cooperating members may be mixed with both projections have a convex surface and detents having a concave surface on either of the male or female parts. It is further understood that the cooperating members may be located along any portion of the threads, including the crest, flank or root.  
         [0028]     Referring to  FIG. 5  there is shown an alternative embodiment of the instant invention. The coupling includes a male part  12  comprising a pipe section  14  having exterior threads  16  at one end and a female part  18  having internal threads  20 . The female part  18  is threaded to the external threads  16  on the male part so as to couple the threaded pipe section  22  to the pipe section  14 .  
         [0029]     The male part  12  has an entry threaded portion  30  on a leading end and a trailing or last-to-be-engaged threaded portion  32 . Along the external threads  16  are a series of detents  43 . At least one detent  43  is located between the entry threaded portion  30  and the trailing or last-to-be-engaged threaded portion  32 . It is understood that at least one detent may be positioned adjacent to the external threads  16  in advance of the entry threaded portion  30  or trailing the last-to-be-engaged threaded portion  32  in the direction of rotation (Arrow A).  
         [0030]     The female part  18  has a leading thread portion  38 . The trailing or last-to-be connected female thread portion is identified at  40 . At least one projection  48  is located along the internal threads  20  between the leading thread portion  38  and the last-to-be connected female thread portion  40 . It is understood that at least one projection may be positioned adjacent to the internal threads  20  in advance of the leading thread portion  38  or trailing the last-to-be connected female thread portion  40  in the direction of rotation (Arrow B).  
         [0031]     The male part  12  and the female part  18  mate together as described in the previous embodiment. The projections  48  bear against the outer surface of the exterior threads  16  until the projections  48  snap into the detents  43 , indicating that the connection is near over-tightening.  
         [0032]     Referring to  FIG. 6  there is shown another alternative embodiment of the instant invention. The coupling includes a male part  12  comprising a pipe section  14  having exterior threads  16  at one end and a female part  18  having internal threads  20 . The female part  18  is threaded to the external threads  16  on the male part so as to couple the threaded pipe section  22  to the pipe section  14 .  
         [0033]     The male part  12  has an entry threaded portion  30  on a leading end and a trailing or last-to-be-engaged threaded portion  32 . In advance of the entry threaded portion  30  is a lip  60 . At lest one protrusion  64  is along the external threads  16  between the entry threaded portion  30  and the trailing or last-to-be-engaged threaded portion  32 . At least one advance protrusion  63  is positioned on the lip  60  in advance of the entry threaded portion  30 . At least one trailing protrusion  65  is positioned on the portion trailing the last-to-be-engaged threaded portion  32 .  
         [0034]     The female part  18  has an entry lip  36  and the leading thread  38  of the female part starts slightly inboard of the entry lip  36 . The trailing or last-to-be connected female thread portion is identified at  40 . A trailing lip  69  is positioned trailing the last-to-be connected female thread portion  40  in the direction of rotation (Arrow B). At least one detent  67  is located along the internal threads  20  between the leading thread portion  38  and the last-to-be connected female thread portion  40 . At least one leading detent  66  is positioned along the entry lip  36 . At least one trailing detent  68  is positioned along the trailing lip  69 . It is understood that in additional embodiments the projections and detents may be interchanged between the male and female parts and that the cooperating members may be positioned along the threaded portion and along the threaded portion, trailing the threaded portion, or any combination thereof.  
         [0035]      FIG. 7  shows a variety of projections that could be alternatively used. The types shown include round shaped projections of  FIG. 7   a ; triangular shaped projections of  FIG. 7   b ; trapezoidal projections of  FIG. 7   c ; semi trapezoidal projections of  FIG. 7   d ; rectangular projections of  FIG. 7   e ; and another projection shown in  FIG. 7   f  with non-symmetrical projections.  
         [0036]     Referring to  FIG. 8  there is shown an alternative detent tapering area  81  with a detent  82 . The area in advance of the detent  82  narrows towards the detent forming a taper. The projection  84  may easily move down the tapered area and lock into place when in cooperation with the detent  82 .  
         [0037]      FIG. 9  shows another embodiment of the invention showing how the projections, rather than being formed integral the male part, may be embedded into the wall of the male part. In this respect  FIG. 9  shoes that the holes  90  are drilled through the wall  92  of the male part. Convex element  94 , such as a ball bearing or the like, is placed into the holes, the diameter of the convex element being smaller than the diameter of the holes. Then an adhesive such as an epoxy or the like is applied as shown at  98  to hold the spheres in place. In this embodiment the material of the convex elements  94  is preferably harder than the material of the male and female parts. With this arrangement there is less wear of the projections when a coupling is made and this in turn allows for more repeated connecting and disconnecting of the coupling before the amount detents wear to the point that the snap fitting loses its effectiveness.  
         [0038]     Accordingly, as the pipe collar  24  and the end face  28  of the male part are brought together to make a junction as shown in  FIG. 2 . the force required to thread the male and female parts together is at a maximum. As noted above the capture of the projections can be both felt and heard as a “snap” so both tactile and audio signals alert the user that the male and female parts are close to being fully tightened and that further tightening may result in an over tightening of the parts to the point of damaging the threads on either the male or female parts. Theses tactile and audio signals provide cautionary signals in addition to the increase in the resistive force that is felt during the finger tightening. Also, since one or more of the projections  34  are captured in one or more of the detents  42 , there is less of a likelihood of the coupling being separated by vibration.  
         [0039]     While the invention has been described with reference to particular embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope of the invention.  
         [0040]     Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope and spirit of the appended claims.