A PIPE FITTING AND A METHOD FOR FORMING THEREOF

FIELD OF THE INVENTION

The present invention relates to pipe fittings, in general and, in particular, to pipe fittings for use with pipes in which a groove can be cut.

BACKGROUND OF THE INVENTION

Pipe fittings for connecting lengths of pipe are well known. When coupling laminar plastic (e.g., polyethylene) pipes, it is known to use a fitting including a rotatable, externally threaded nipple to which the pipe can be attached, the nipple having a base shaped to receive a wrench. Rotation of the nipple by a wrench causes the threads on the nipple to cut into the pipe, thereby preventing removal of the pipe from the fitting.

The threaded nipple is rotatably seated inside a locking nut, having an associated gasket, for tightening the nipple to any fitting having a threaded end.

However, since the nipple must be coupled to the fitting by the locking nut, this connection might leak because of a faulty seal or insufficient tightening by the user.

Therefore, such fitting does not always meet customary standards for use in hidden or inaccessible locations. Accordingly, there is a long felt need for a fitting for coupling to plastic or other such pipes which can be used in any location, including hidden or inaccessible locations.

SUMMARY OF THE INVENTION There is provided according to the present invention a pipe fitting for a groovable pipe (a pipe in which a groove can be cut), the fitting including a housing and a connecting cylinder at least partially disposed in one side of the housing, the connecting cylinder being sealingly mounted in the housing. The fitting further includes an outer sleeve freely rotatable about the connecting cylinder, the outer

sleeve including an integral, external thread adapted and configured to groove and engage an interior wall of the pipe.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be further understood and appreciated from the following detailed description taken in conjunction with the drawings in which:

Figure Ia is a partial sectional side-view illustration of a pipe fitting constructed and operative in accordance with one embodiment of the present invention, with a pipe; Figure Ib is a sectional view through the pipe fitting of Figure Ia taken along line A-A, with a pipe;

Figure Ic is a plan view illustration of the pipe fitting of Figure Ia, without the pipe;

Figure Id is an end view of the pipe fitting of Figure Ic looking from direction B;

Figure 2 is a plan view of a pipe fitting known in the art as "a T piece", constructed and operative in accordance with another embodiment of the present invention; and

Figure 3 is a plan view of a pipe fitting known in the art as "a tap connector", constructed and operative in accordance with an alternative embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to Figures Ia to Id, there is shown a pipe fitting 10 for a pipe 12 in which a groove can be cut, referred to herein as a groovable pipe, constructed and operative in accordance with one embodiment of the present invention. Pipe fitting

10 includes a housing 14 and a connecting cylinder 16 at least partially disposed in one side of the housing 14. The connecting cylinder 16 is sealingly mounted in the

housing 14, preferably in accordance with the appropriate standards for hidden pipe fittings. It will be appreciated that connecting cylinder 16 may also be fully disposed in housing 14 and extend from two open ends of the housing. Connecting cylinder 16 may be formed as an integral part of housing 14. Pipe fitting 10 further includes a sleeve 20 freely rotatable about the outer wall of connecting cylinder 16. Sleeve 20 is mounted in an annular groove 21 about the circumference of connecting cylinder 16. The end of annular groove 21 defines a shoulder 23, which serves as a stop member to prevent sleeve 20 from sliding off of connecting cylinder 16 when sleeve 20 is turned to pull the pipe onto the fitting, and retain the pipe in place. Outer sleeve 20 includes an integral, external thread 22 adapted and configured to groove and engage an interior wall of the pipe 12. If desired, one or more additional grooves 24, or recesses, may be provided on connecting cylinder 16 outside of outer sleeve 20, for receiving an o-ring 26, or other suitable sealing element for sealing engagement with the inner wall of the pipe. Outer sleeve 20 also includes a knob 28, or other manipulable portion, to permit rotation of outer sleeve 20. As can be seen most clearly in Figure Ia, rotation of outer sleeve 20 by means of knob 28 causes the external threads 22 to form grooves in, and engage, the interior surface 18 of the groovable pipe, until an edge of pipe 12 abuts against knob 28, thereby preventing removal of the pipe from the fitting during use. If desired, knob 28 may define a recessed pipe-receiving portion 27, and one or more apertures 29 may be provided through knob 28 to permit a user to verify that the edge of the pipe abuts against knob 28.

It will be appreciated that, while the invention is particularly suitable for use with laminated plastic pipes, such as pipes having an inner layer of polyethylene, it can also be used with any other pipes which have an interior wall which is soft enough to be grooved but strong enough to be retained firmly by sleeve 20 when the piping network is assembled and to remain in place under conditions of engineering requirements and normal use. It will be further appreciated that the invention may be suitable for elastic pipes that maintain the grooves formed by sleeve 20 only while

the pipe is retained by the fitting. Moreover, the invention may also be suitable for some pipes of rigid material, which cannot be grooved by sleeve 20. Such pipes will be pulled onto and firmly retained by frictional force created by turning sleeve 20 when the piping network is assembled. Similarly, the fitting may be made of any material suitable for carrying the particular fluid passing through the pipes.

The pipe fitting 10 of Figure Ia includes a connecting cylinder for coupling to a single pipe. Alternatively, the pipe fitting may have any design and may include a plurality of connecting cylinders with associated sleeves for coupling to a plurality of pipes. Two additional embodiments are shown in Figures 2 and 3, by way of example, only.

It is a particular feature of the invention that the connecting cylinder is sealingly connected to the housing during manufacture, so no separate tightening nut and associated gasket are required.

While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. It will further be appreciated that the invention is not limited to what has been described hereinabove merely by way of example. Rather, the invention is limited solely by the claims which follow.