Locking connector with depressions

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.

FIELD OF THE INVENTION

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

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.

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.

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

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.

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

Referring toFIGS. 1-4, there is shown the coupling of the present invention generally indicated at10. The coupling includes a male part12comprising a pipe section14having exterior threads16at one end and a female part18having internal threads20. The female part18is threaded to the external threads16on the male part so as to couple the threaded pipe section22to the pipe section14.

In this respect the unthreaded pipe section has a flat flange24that is engaged by a collar26on the female part and pressed against an end face28of the male part upon threading the male and female parts together (seeFIG. 2). Such a connection is common in plumbing fixtures such as in sink drains and the like.

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 flange24and the end face26.

The male part12has an entry threaded portion30on a leading end and a trailing or last-to-be-engaged threaded portion32. Along the external threads16are a series of projections34. At least one projection34is located between the entry threaded portion30and the trailing or last-to-be-engaged threaded portion32. It is understood that at least one projection may be positioned adjacent to the external threads16in advance of the entry threaded portion30or trailing the last-to-be-engaged threaded portion32in 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.

The female part18has a leading thread portion38. The trailing or last-to-be connected female thread portion is identified at40. As best seen inFIG. 3in one embodiment the female part18has a constant outside diameter. At least one detent42is located along the internal threads20between the leading thread portion38and the last-to-be connected female thread portion40. It is understood that at least one detent may be positioned adjacent to the internal threads20in advance of the leading thread portion38or trailing the last-to-be connected female thread portion40in the direction of rotation (Arrow B). In one embodiment the invention contains four detents.

Accordingly, it should be appreciated that when a threaded connection is made, the detents42of the threaded female part18pass over the thread portion30on the leading end of the male part. The threading continues unimpeded until the first projection34A encounters the leading thread portion38of the internal threads20.

As finger tightening continues, the first projection34A starts to bind against the inside surface of the internal threads20and then snaps into the first detent42A. 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.

As tightening continues still further, the first projection34A is forced out of the first detent42A and over into the second detent42B while the second projection34B first encounters the leading thread portion38of the internal threads20and then enters the first detent42A. With two projections bearing against the inside surface of the internal threads20, 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.

Tightening the coupling still further forces the two projections,34A and34B, from their respective detents42B and42A, and brings all three of the projections to bear against the inner surface of the internal threads20. This increases still further the force required to finger tighten the male and female parts together. Eventually all three of the projections34will be captured in detents42.

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.

Referring toFIG. 5there is shown an alternative embodiment of the instant invention. The coupling includes a male part12comprising a pipe section14having exterior threads16at one end and a female part18having internal threads20. The female part18is threaded to the external threads16on the male part so as to couple the threaded pipe section22to the pipe section14.

The male part12has an entry threaded portion30on a leading end and a trailing or last-to-be-engaged threaded portion32. Along the external threads16are a series of detents43. At least one detent43is located between the entry threaded portion30and the trailing or last-to-be-engaged threaded portion32. It is understood that at least one detent may be positioned adjacent to the external threads16in advance of the entry threaded portion30or trailing the last-to-be-engaged threaded portion32in the direction of rotation (Arrow A).

The female part18has a leading thread portion38. The trailing or last-to-be connected female thread portion is identified at40. At least one projection48is located along the internal threads20between the leading thread portion38and the last-to-be connected female thread portion40. It is understood that at least one projection may be positioned adjacent to the internal threads20in advance of the leading thread portion38or trailing the last-to-be connected female thread portion40in the direction of rotation (Arrow B).

The male part12and the female part18mate together as described in the previous embodiment. The projections48bear against the outer surface of the exterior threads16until the projections48snap into the detents43, indicating that the connection is near over-tightening.

Referring toFIG. 6there is shown another alternative embodiment of the instant invention. The coupling includes a male part12comprising a pipe section14having exterior threads16at one end and a female part18having internal threads20. The female part18is threaded to the external threads16on the male part so as to couple the threaded pipe section22to the pipe section14.

The male part12has an entry threaded portion30on a leading end and a trailing or last-to-be-engaged threaded portion32. In advance of the entry threaded portion30is a lip60. At lest one protrusion64is along the external threads16between the entry threaded portion30and the trailing or last-to-be-engaged threaded portion32. At least one advance protrusion63is positioned on the lip60in advance of the entry threaded portion30. At least one trailing protrusion65is positioned on the portion trailing the last-to-be-engaged threaded portion32.

The female part18has an entry lip36and the leading thread38of the female part starts slightly inboard of the entry lip36. The trailing or last-to-be connected female thread portion is identified at40. A trailing lip69is positioned trailing the last-to-be connected female thread portion40in the direction of rotation (Arrow B). At least one detent67is located along the internal threads20between the leading thread portion38and the last-to-be connected female thread portion40. At least one leading detent66is positioned along the entry lip36. At least one trailing detent68is positioned along the trailing lip69. 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.

FIG. 7shows a variety of projections that could be alternatively used. The types shown include round shaped projections ofFIG. 7a; triangular shaped projections ofFIG. 7b; trapezoidal projections ofFIG. 7c; semi trapezoidal projections ofFIG. 7d; rectangular projections ofFIG. 7e; and another projection shown inFIG. 7fwith non-symmetrical projections.

Referring toFIG. 8there is shown an alternative detent tapering area81with a detent82. The area in advance of the detent82narrows towards the detent forming a taper. The projection84may easily move down the tapered area and lock into place when in cooperation with the detent82.

FIG. 9shows 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 respectFIG. 9shoes that the holes90are drilled through the wall92of the male part. Convex element94, 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 at98to hold the spheres in place. In this embodiment the material of the convex elements94is 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.

Accordingly, as the pipe collar24and the end face28of the male part are brought together to make a junction as shown inFIG. 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 projections34are captured in one or more of the detents42, there is less of a likelihood of the coupling being separated by vibration.

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.