Such quick fittings or couplings are broadly used for constructing fluid systems, since they greatly reduce the time necessary for making said systems. Prior quick fittings are shown in figures 1 and 2 and substantially comprise: -a fitting body (2) including -at least one end portion (3) for housing and clamping a pipe (6) therein, -a housing chamber (7) in said at least one end portion (3) for housing pipe (6) clamping means (8) and sealing means (9) and, preferably, a washer (11) arranged therebetween, and -closure means (3,12) for closing the assembled fitting (1). Said clamping means generally comprise a serrated ring element (8) made of a stainless steel material, and the sealing means (9) usually comprise an 0-ring. The fitting closure means usually also comprise a cap ring nut (12) which can be threaded on the end portion (3) of the fitting (1) and is provided with an outward projecting tubular projection (13) operating as a guide element for properly coaxially introducing/locating the pipe (6) to be clamped, the cap ring-nut being moreover provided with lugs (14) to be engaged by a clamping tool.

The above quick fittings can have a simple tubular body, a T, Y, L- shape body and the like, provided with clamp end portions as above mentioned.

Since said quick fittings are large-series products, a saving, even small, on their forming materials and making time would be very important in view of the high daily production yield.

To the above it should be further added that said quick fittings are usually made of a pressed metal, in particular pressed brass, since the operators installing then would tend to reject synthetic material fitting bodies which would not be considered suitable to hold the high clamping torques necessary to close the fittings unaltered in the time.

Moreover, in installing fluid system pipes under plaster coatings, technical standard requirements must be met. For example, in some countries, such as Italy, said requirements would provide that the under- plastering installed fittings would be fixedly assembled : in other words, assembled fittings must not be removed or disassembled by using conventional tools.

For meeting these requirements, prior fittings are provided with said lugs on their cap ring nut, which lugs can be disassembled only by a suitable disassembling wrench.

In other countries, such as Belgium, the enforcing rules provide that under-plastering installed fittings cannot be disassembled, even by using special tools. No prior solution, on the other hand, exists at present for meeting this requirement.

Furthermore, said prior quick fittings have several drawbacks and disadvantages. At first, the fitting body, in addition to the chip machining operations for fonning the clamping and sealing means housing, requires an outer thread for connection with the cap ring nut which, per se, represents a discrete component requiring a dedicated chip machining operation both for forming the thread and for making the pipe locating tubular portion. In addition, prior quick fittings cannot be fixedly assembled, i. e. in an irreversible manner, which would be desirable to meet the most stringent rules related to the under plastering installation thereof.

Summary of the invention Accordingly, the aim of the present invention is to provide a quick fitting of the type defined in the preamble of claim 1, which, while advantageously using prior clamping and sealing means, provides an irremovable assembling and can be made much more simply and unexpensively.

The above aim is achieved, according to the invention, by a quick fitting having the features of claim 1.

Further advantageous developments and improvements are defined in the dependent claims.

Thus, the quick fitting according to the invention provides several important advantages. At first, it is possible to omit the mentioned cap ring nut, thereby decreasing the material and labor cost. Moreover, the chip machining of the fitting body can be also decreased, since no thread for coupling the cap ring nut is now required.

A further advantage is that a quicker assembling with a consequent reduction of the overall making cost, while assuring an optimum axial location of the pipe, can be carried out.

Claims 2 and 3 suggest an advantageous teaching concerning the production of locking means which are able to provide an irremovable locking of the quick fitting according to the present invention.

Claim 4 teaches a method for providing a geometric coupling of the quick fitting portions, without deforming them, thereby allowing to easily use synthetic material components.

Claim 5 teaches an advantageous embodiment of an optional component of the quick fitting.

Claim 6 teaches a manner for providing an optimum irremovable locking engagement of the fitting without interfering at all against prior sealing and clamping means.

Claim 7 teaches a manner for properly using the required sealing gasket for improving the positioning of the pipe.

Claim 8 teaches a manner for using the body of the quick fitting to provide an irremovable or irreversible locking and a proper axial positioning of the pipe in the fitting.

Claim 9 teaches a manner for alternately using the components of the quick fitting.

Claims 10 and 11 teach further embodiments of the inventive quick fittings suitable for solving any assembling problems in fluid systems.

Brief description of the drawings Further characteristics, advantages and details of the quick fitting according to the present invention will become more apparent from the following disclosure of some embodiments thereof, being shown in the accompanying drawings, where: Figures 1 and 2 are respectively an axial and front cross-sectional views of a prior quick fitting; Figure 3 is a perspective view of a quick fitting according to the invention ; Figure 4 is an axial cross-sectional view through the quick fitting of figure 3; Figure 5 is a further axial cross-sectional view analogous to that of figure 4, showing a second embodiment of the quick fitting according to the invention; Figure 6 is a further axial cross-sectional view through the body of the quick fitting shown in figures 3,4 and 5; and Figures 7,8,9 and 10 are further like axial cross-sectional views of further modified embodiments.

Description of the preferred embodiments In the figures like elements have been indicated by like reference numbers.

As shown in the introductory part of the disclosure, the quick fitting comprises a fitting body 2, for example made of metal or composite materials, having two end portions 3 and 4. Of said portions the end portion 4 can be designed for providing any desired connections, for example a threaded connection or an 0-ring 5 connection for removably engaging it in fluid circuit components, whereas the end portion 3, designed for clamping a system pipe 6 therein, is provided with a housing chamber 7 for housing therein pipe clamping means and related sealing means.

More specifically, said clamping means can comprise, for example, a serrated ring element 8, made of a stainless steel material, and said sealing means usually comprising an O-ring 9. Moreover, an intennediate washer 11 for fonning a chamber-shoulder assembly for properly locating the O- ring upon engaging the pipe is preferably provided.

The reference number 12 shows a cap ring-nut having a tubular portion 13 for coaxially locating or positioning the pipe as it is engaged in the fitting.

The reference number 14 shows front lugs provided for engaging with a specially designed clamping tool, not shown. As shown the cap ring nut 12 is provided with an inner thread for thread engaging an outer thread of the end portion 3 of the fitting.

A known quick fitting constructed as above disclosed has the above mentioned drawbacks and disadvantages.

According to the invention, the closure means for said quick fitting 1 are now designed for providing an irremovable locking, thereby the subject quick fitting can be defined as an"irreversible"type of fitting suitable for meeting, inter alia, the above mentioned stringent requirements related to the assembling of said quick fitting 1 under a plaster coating, that is placed in chases.

According to a first preferred embodiment of the present invention, the quick fitting 1 shown in figure 3 is provided with a fitting body 2 which, at the free end portion of the chamber 7 housing the components 8,9 and 11, is provided, in a single piece, with an annular upsettable crown part 16.

As clearly shown in the figures 3 to 10, and especially in figure 6, this upsettable crown part 16 has preferably a thickness less than that of the wall of the end portion 3 of the quick fitting body 2. This, on a side, facilitates the upsetting operation and, on the other side, allows to reduce the required material amount. In the embodiment of figure 4. said upsettable crown part 16 has a comparatively short length L, for example of 1.5-2.5 mm, the thinned thickness ranging, for example, in a range of 0.8 to 1.3 mm.

As shown in figure 4, upstream of the chamber 7 in the body 2 of the fitting 1, is provided a housing seat 17 for housing therein a positioning washer 18, having a throughgoing hole 19 operating as a sleeve for properly axially locating or positioning the pipe 6 in said fitting 1. To that end, the thickness of the locating washer 18 is advantageously included in the range from 4 to 7 mm. To irremovably lock the quick fitting, after the assembling thereof, while simultaneously achieving a proper positioning of the washer 18, spaced from the 0-ring 19 and without deformations, said locating washer 18 is provided with an outer oblique band 21, the inclination of which corresponds to the inclination to be impressed to the upsettable crown part 16 as it is inwardly upset. This upsetting will be performed by conventional upsetting machines, to provide a geometrically fixed coupling of the upset crown part 16 and the oblique band 21 of the washer 18, without causing the latter to be deformed by the crown part 16 being upset. This advantageously allows to form the locating washer 18 either of a metal material or any desired plastic materials.

It should be apparent that, as said annular crown part 16 is upset, the closure of the fitting 1 end portion 3 will be an irremovable locked one, thereby the fitting can be properly defined as an"inviolable"fitting.

A variation of the embodiment shown in figure 4 provides to form the upsettable crown part 16, instead of a continuous annular crown, as a crown including a plurality of spaced circumferentially arranged small tabs.

This solutions, which is practically operatively equivalent to that shown in figure 4, would reduce the required material amount. Since this embodiment can be easily understood, it will be not further illustrated. On the other hand, in a case of diametrically opposite legs, an axial cross- section of this modified embodiment would precisely correspond to the cross section shown in figure 6.

Reference is now made to the modified embodiment shown in figure 5, which is diversified from the embodiment shown in figure 4 since the locating washer 18 has a L-shape cross section. In this case, as is clearly shown in figure 5, the upset crown element 16 engages against the short side of the L and slightly circumferentially extends under the major outer diameter of the washer 18.

This solution allows a less amount material to be used for fonning the washer which, as in the embodiment of figure 4, is housed and arranged in the seat 17 of the body 2.

The modified embodiment of figure 7 shows that the upsettable annular crown part 16, in addition to a fixed locking upsetting portion 16A is moreover provided with a further portion 16B having a tubular sleeve configuration defining, together with the locating washer 18, a guide surface for coaxially guiding or positioning the pipe 6 in the fitting 1. In this case, the thickness of the locating washer 18 can be smaller than that of the locating washers 18 of the embodiments shown in figures 4 and 5 and said locating washer or gasket 18 can also be formed with a trapezium configuration, as shown in figure 7.

In the embodiments shown in figures 8,9 and 10, the locating washer 18 is lacking, and the upsetting of the fixed locking annular crown part 16 is performed against said 0-ring 9, figures 8 and 9.

In the modified embodiment of figure 9, the upsettable crown part 16 is moreover provided with the portions 16A and 16B shown in figure 7.

In the modified embodiment of figure 10 is also provided a sealing gasket 22, substantially profiled in an annular substantially semicircular portion 23, adapted to provide a sealing ftmction like that of prior O-ring 9, and a fillet portion 24 operating as an axial locating or positioning sleeve for the tube 6 to be introduced into the fitting 1. To properly locate the gasket 22 in the end portion 3, the latter can be provided with an inner annular rib 25 operating as a shoulder.

In the shown exemplary embodiments, the end portion 4 of the quick fitting 1 is made as an end piece which can be removably engaged in a corresponding seat of a component of the fluid system, such as an hydro- thermal sanitary system, for example by the two sealing 0-rings 5. It should be apparent that this end portion could also be designed for a threaded or any other type of engagement, or also in the form of an end portion like the end portion 3 of the fitting 1.

Moreover, it would come within the scope of the invention to provide fitting bodies 2 of L, T, Y, cross shape and so on, the end portions of the fitting being formed as above illustrated with respect to the several modified embodiments.

With respect to the clamping opereation onto the inserted pipe and to the sealing operation in the chamber 7, the fitting 1 according to the invention is as reliable as the prior quick fittings, whereas, with respect to the closure of the fitting, upon assembling the latter, the above shown and disclosed geometric locked connection efficiently provides an inviolable quick fitting, which is optimally suitable for a laying or installation in chases, that is for an under-plastering laying.

From the above construction and operational disclosure of the several illustrated embodiments, it should be apparent that the quick fitting according to the invention efficiently achieves the above mentioned aim and advantages. The mentioned material and machining savings can be of course achieved in different degrees depending on the considered embodiment.

The invention as disclosed is susceptible to several modifications and/or variations by those skilled in the art, for example to provide a curved upsetting of the annular crown part 16, instead of an oblique upsetting, and a geometrical fixed coupling with an associated 0-ring, or the like gasket, or to use pipe clamping means different from the above disclosed clamping means.