The present invention concerns a pipe fitting, particularly between plastic pipe and metal pipe.

More particularly, the invention concerns a pipe fitting that makes it possible to connect pipes of plastic materials simply and quickly to metal pipes.

As is well known, there are different types of pipe fittings for connecting plastic pipes, and also pipe fittings for connecting metal pipes.

In particular, metal pipes are connected to each other using threaded metal pipe fittings.

As regards pipes made of plastic material, the fittings proposed in more recent times are the so-called fast-coupling fittings, made in such a way as to permit extremely fast seal coupling of plastic pipes.

Nevertheless, when it is necessary to connect a plastic pipe to a metal pipe, certain not inconsequential practical problems arise, as there are no specific pipe fittings for this purpose; so it is necessary to use particular solutions that are difficult to put into effect. This type of problem area presents itself, for instance, when an installation needs to be restructered, so it is necessary to fit sections of plastic tubing, which are used predominantly these days, in an installation that was originally made using metal piping.

Again, this type of problem does arise, however, when connections are made from the installation using plastic piping to cocks, taps and valves.

In view of the above, it seems very clear that it is necessary and advantangeous to be able to make use of a pipe fitting that allows direct coupling between plastic pipes and metal pipe ^' s.

Another object of the present invention is to supply a pipe fitting with thickness dimensions that are smaller than those currently available.

The solution proposed, according to the present invention, aims to satisfy the requirement cited, resolving the problem mentioned above, by proposing a pipe fitting made of metal that has at least one end to be threaded for coupling with a metal pipe, and one socket and to fit into a pipe made of plastic material.

Therefore, the specific object of the present invention is a pipe fitting, particularly between plastic pipe and metal pipe, which has at least one

threaded end, for coupling with a metal pipe, and at least one fast connection end, socket structured for connection with a pipe made of plastic material.

According to a first embodiment of the pipe fitting according to the invention.said at least one end, socket structured, includes an external casing part, a pipe locking jaw, inside said casing part, a seal element and an internal metal washer, positioned by the open end part of said casing part, the end casing part becoming distorted at its end, so as to lock said internal metal washer. In a further embodiment of the pipe fitting according to the invention, said at least one socket structured end has an external casing part, a pipe locking jaw made of plastic, inside said casing part, seal elements and spacers, and ring-shaped items, particularly a Seeger ring, that keep said seal element and spacers and said jaw inside said external casing part. Again according to the invention, at least one socket structured end has an external casing part, threaded at its end, a pipe locking jaw made of plastic, inside said casing part, seal elements, and a nut, preferably willed on the outside, fitted with threading for coupling with the threading of said casing part. Preferably, the casing part has a female threading and the nut has a male threading, the outside diameter of the casing part and the nut corresponding substantially.

The pipe fitting in accordance with the invention can be an L-shaped peece or elbow, a T-shaped piece, straight, a long passage nipple, etc., according to the specific requirements of the installation.

Again according to the invention, said pipe fitting will preferably be made of brass.

Obviously, should it be necessary, it can have all its ends as sockets, for connecting plastic pipes only. The present invention will now be described, for illustrative but not limitative purposes according to its preferred embodiments, with particular reference to the enclosed figures of the drawings, wherein: figure 1 is a side view, partially sectional, of a first embodiment of the pipe fitting according to the invention; figure 2 is an exploded view, partially sectional, of the pipe fitting of figure 1 ; figure 3 is a side view, partially sectional, of a second embodiment of the pipe fitting according to the invention;

figure 4 is an exploded view, partially sectional, of the pipe fitting of figure

3; figure 5 is a side view, partially sectional, of a third embodiment of the pipe fitting according to the invention; and figure 6 is an exploded view, partially sectional, of the pipe fitting of figure 5.

Observing first figures 1 and 2, a first embodiment of the pipe fitting according to the invention may be noted.

Pipe fitting 1 has a brass casing 2, with a threaded end 3 and a socket end 4.

A metal pipe, which is not shown, is coupled onto the threaded end 3 by screwing it on, while a plastic pipe, this again not shown, is coupled onto the socket end 4.

The socket part 4 includes a stainless steel jaw 5 inside the casing 2, to lock the pipe, a wather wade made of PVC 6 and an O-ring 7.

Fitted into the open end of the part 4 is a brass washer a which is used to lock the connection elements inside the casing 2.

Once the washer 6 is fitted into the casing 2, the end part of the latter is distorted, locking it so that it is irremovable. Going on now to observe figures 3 and 4, a second form of realization of the pipe fitting in accordance with the invention is shown. The parts corresponding to those in figures 1 and 2 are indicated with the same reference numbers, preceded by a 1.

The pipe fitting 11 in this case, on the socket structured part 14 has a spacer washer instead of the brass washer 19, made of Teflon, and a Seeger-type locking ring 20.

This structure performs the same functions as coupling casing 2 - washer 8 of the previous embodiment.

Now observing the figures 5 and 6, a third embodiment of the pipe fitting according to the invention is shown. In this case too, the parts corresponding to those of the solution ^" according to Figures 1 and 2 are indicated with the same reference numbers, preceded by a 2.

In the solution shown, the locking of the ring 27, of the washer 26 and of the jaw 25 is realized by means of a milled nut 31 that is coupled by screwing it on, by meand of the male threading 32 on the end part of the casing 22, fitted with threading 33.

It may be noted that externally the casing 22 and the nut 31 have the same diameter.

The nut 31 has a milling 34 on the outside to facilitate tightening and removal. The present invention has been described in an illustrative but not .imitative way according to its preferred embodiments, but it must be understood that variations and/or modifications may be made by those skilled in the art without this lying outside the relative scope of the invention, as defined by the enclosed claims.