Quick-release fitting assembly

Description Technical field

The invention relates to a quick-release fitting assembly for connecting two mechanical elements together. More specifically, the invention relates to improvements in quick-release fitting assemblies for mechanical members of hydraulic systems and devices, such as filters, pumps, pipes and the like.

The invention specifically, though not exclusively, concerns a vessel with a quick-release fitting assembly, and more specifically to a water tight vessel, including a quick-release assembly for connecting a vessel body to a cover element, a valve, a pipe fitting or the like, specifically for use in water treatment systems or apparatus. Background of the invention

Water tanks and other pressure vessels are well known components of water treatment systems. In given systems, the vessel is connected to other equipment by a fitting that provides fluid communication between the interior of the vessel and the remainder of the system. Typically, the fitting is a threaded fitting that is screwed onto or into a throat, aperture or opening of the vessel having complimentary threads. In this manner a screw-tight seal is achieved be- tween the fitting and the vessel with the fitting providing fluid communication between the vessel interior and the remainder of the system, e.g. a valve, a pipe or the like.

This type of fitting connection has several drawbacks. In particular, a significant amount of work is needed to install the screw-type fitting and special tools are often required. Additionally, connection between the two fitting parts requires rotation of a female fitting component with respect to a male fitting component. In some cases this requires rotation of a vessel with respect to a stationary male fitting. Large space is required to perform this operation and in some cases this becomes a problem. Also, the final angular position between the two portions of the fitting cannot be easily predicted, and problems may arise if the two screw-fitted portions do not achieve a desired angular position to one another.

Similar problems arise in the connection of two pipes or tubes, in the assembly of wet and dry portions of a pumping arrangement and the like.

In an attempt to at least partly solve or alleviate these problems, EP-A- 1.336.790 discloses a quick-release fitting assembly with a female fitting and a male fitting cooperating with one another. In one embodiment disclosed therein, the female fitting forms an integral part of a vessel body. More specifically, the female fitting is arranged in the opening of said vessel body and the male part is attached to the vessel body by means of a quick-release system. In one embodiment disclosed, male and female fittings are connected by means of a flexible rod which is housed in a first annular groove formed in the male fitting and a second annular groove formed in the female fitting, and more specifically in the cylindrical wall surrounding the opening of the vessel.

US-A-3,625,365; US-A-3,809,247; US-A-3,747,768; US-A-3,828,932; US-A-5,762,785 and US-A-6, 287,462 disclose filters, such as sand filters for the treatment of water, such as in swimming pools or the like. These filters include a vessel with a vessel body having an aperture. A multi-port valve is housed in the aperture of the vessel body or else in a male fitting which is housed in and closes said aperture.

A quick-release fitting assembly for the connection of a multi-port valve to such a filter vessel is desirable.

More generally, there is a need for a quick-release fitting assembly which allows quick connection and disconnection of two components of a hydraulic system, such as pipes, vessels and covers thereof, portions of pumps and the like.

The fitting must be inexpensive to produce, easy and quick to install and uninstall and at the same time must resist to high water pressure and avoid leakage.

Summary of the invention

According to one aspect, the invention provides a vessel with an improved quick-release assembly, which is reliable but at the same time inexpensive and easy to produce and install. In some embodiments, according to the invention a vessel is provided, including a vessel body with a bottom, an opening portion forming a female fitting, and a male fitting retained in said female fitting; wherein: an annular member is arranged around said opening portion; said annular member is provided with a at least one projection co-acting with said male fitting to retain said male

fitting in position within said female fitting. A first retaining groove is provided on an outer surface of said vessel body and a second retaining groove is provided on an inner surface of said annular member, said first retaining groove and said second retaining groove forming a seat for a retention rod, surrounding said opening portion, said retention rod locking said annular member on said vessel body.

The male fitting is thus safely and reliably connected to the female fitting. Connection is easily obtained by simply arranging the male fitting in the female fitting, placing the annular member around the female fitting and introducing the retention rod in the seat formed by said first and second retaining groove. The rod forms a shear lock and withstands shear stresses generated by the pressure inside the vessel. The inner pressure tends to push the male fitting away from seat formed in the female fitting. The force is discharged on the annular member which is safely locked to the vessel body by means of the retention rod. The retention rod can be easily introduced tangentially in the annularly developing seat formed by the two mating first and second retaining grooves. A safety locking device can be provided to prevent the retention rod from accidentally slipping out of the seat. Removing of the male fitting from the female fitting is easily obtained by simply pulling the retention rod out of its seat. Removal of the retention rod is only possible once the inner pressure is released, since otherwise the shear stresses applied on the rod prevents it from being removed. This adds to the safety of the device, since the vessel cannot be accidentally opened before the inside pressure is entirely discharged and the retention rod can freely slip out of the seat. The annular member can have a circular or approximately circular shape. However this is not mandatory. Elliptical shapes, or else polygonal shapes are also possible. The female fitting and male fitting will then assume a similar elliptical or polygonal shape. The only constrain is that the seat formed by the two annular grooves be sufficiently smooth to allow insertion and re- moval of the retention rod.

In some embodiments said annular member includes a passage for the insertion of said retention rod, said passage being substantially tangential to said second retaining groove.

In some embodiments the annular member can be provided with in-

wardly projecting appendages, which co-act with the male fitting. According to a preferred embodiment, said annular member has an overall L-shaped cross- section with a continuous flange-shaped inwardly projecting portion, which retains the male fitting in position. In preferred embodiments said annular member includes a peripheral portion surrounding the outer surface of the vessel body and a flange portion projecting towards the male fitting and co-acting with an annular projection of said male fitting. In one embodiment the opening portion of said vessel body includes an inwardly projecting collar forming a seat for said annular projection and said annular projection is constrained in said seat between said coiiar and said annular member.

In a preferred embodiment, the inwardly projecting collar includes a circumferentially developing wall extending from said seat towards the bottom of the vessel body; and said male fitting is provided with a circumferentially de- veloping extension, oriented towards the bottom of the vessel body and opposing said circumferentially developing wall. Circumferentially developing is intended here as surrounding an axis of the vessel and does not imply that the wall or the extension be circular in shape. As noted above the arrangement can have different shapes, such as polygonal or elliptical. In some embodiments said annular member is provided with a side tab for fixing said retention rod, in order to avoid accidental removal of the retention rod from the seat formed by the two mating annular retaining grooves. In one embodiment said tab is arranged adjacent the tangential passage through which the retention rod is introduced into the seat formed by said two mating annular retaining grooves.

In order to increase the mechanical resistance of the fitting, in one embodiment said first and second retaining grooves are double, i.e. a double groove is provided on said outer surface of the vessel body and corresponding double groove is provided in the inner surface of the annular member. Two re- tention rods or a double retention rod can be introduced in a double seat formed by mutually mating double retaining grooves.

The male fitting can include a central aperture or a seat to receive a device which is to be coupled to said vessel, such as a multiple port valve. In one embodiment, the male fitting is an integral part of a device to be connected to

said vessel, such as a multi-port valve for a filter or the like. In yet another embodiment, said male fitting includes a cover for at least partly closing said opening.

According to a different aspect, the invention provides a filter, such as a sand filter, including a vessel and a valve mounted on said vessel, wherein said female and male fitting connect said valve to said vessel.

According to a more general aspect, the invention provides a quick- release fitting assembly for safely connecting two members of a hydraulic system to one another, which system is inexpensive to manufacture as well as safe and quick to assemble and disassemble, in some embodiments, the quick- release fitting assembly according to the invention includes: a male fitting; a female fitting; an annular member surrounding said female fitting. Said annular member is provided with a projection co-acting with said male fitting to retain said male fitting in position within said female fitting. Furthermore, a first retain- ing groove is provided on an outer surface of said female fitting and a second retaining groove provided on an inner surface of said annular member, said first and second retaining groove forming a seat for a retention rod, surrounding said female fitting, said retention rod locking said annular member on said female fitting. In some preferred embodiments, the retention rod is made of a flexible material. In the context of the present disclosure and claims, a flexible material forming a flexible rod is such a material which allows deformation of the rod, in order for the latter to change its shape and enter into a seat which develops around the fitting. According to some embodiments the flexible rod can be made of plastic material. In other embodiments, the flexible rod can be made of metal, or metal alloys. The material can be selected according to mechanical strength requirements, and/or based on the degree of required flexibility, elastic memory or other mechanical or physical properties, which the device should provide. Further advantageous features and embodiments of the invention are set forth in the dependent claims and will be described here below with reference to the attached drawings. Brief description of the drawings

For a better understanding of the present invention reference is made to

the following detailed description of exemplary embodiments considered in conjunction with the accompanying drawings, in which:

Fig.1 shows a longitudinal section of a sand filter with a multi-port valve attached on top thereof, through a filter covering, said covering being con- nected to the vessel by means of a quick-release assembly according to the invention;

Figs 2 and 3 show details of the quick-release assembly during mounting thereof;

Fig.4 shows a perspective view of the top portion of the sand filter vessel and the cover thereof in a mounted condition; Fig.5 shows a detail of the flexile rod;

Fig.6 shows a diagrammatic representation of a pumping assembly, with a dry part, a wet part and a pre-filter, said pumping assembly including a quick- release assembly according to the invention; Fig.7 shows a longitudinal section of a pipe fitting assembly using a quick-release fitting according to the invention. Detailed description of an embodiment of the invention

Figures 1-5 show a filter, such as a sand-filter, embodying the invention, including a male fitting attached to a female fitting integral with the vessel of the filter. However it shall be understood that the invention can be embodied in different devices or apparatus for water treatment or the like, whenever a male fitting shall be reliably connected to a female part, e.g. included in a vessel body, with a fitting arrangement which is inexpensive to manufacture, simple to assemble and disassemble, but still reliable and safe. In Figs.1-5, 1 designates a sand filter, comprised of a vessel 3 including a vessel body 5, and a multi-port valve 7. The multi-port valve is integral with a male fitting 9 which is attached to the vessel body 5 by means of a quick- release fitting assembly according to the invention.

The vessel body 5 includes a bottom 5A, a side wall 5B and an opening portion forming a female fitting 5C surrounding an upper aperture 5D, arranged opposite said bottom 5A. The male fitting 9 is arranged in the upper aperture 5D and quick-releasingly connected to said female fitting 5C. A water flow column 11 departs from the multi-port valve 7 downwards to a manifold chamber 13 and collectors 15 arranged near the bottom 5A of the vessel body 5. A sand

bed or other filter medium 16 is provided within said vessel body 5, the manifold chamber 13 and the collectors 15 being arranged within the sand bed. A water distributor 19 is provided underneath the multi-port valve to distribute water on the filter medium 16. The multi-port valve and the sand filter are known per se, their operation is conventional and requires no further description here.

To provide a quick-release fitting between the vessel body 5 and the multi-port valve 7 or any other appliance integral to or mounted on the male fitting 9, the vessel 3 is provided with an outer annular member 21 arranged around the opening portion or female fitting 5C of the vessei body 5. in the embodiment shown in the drawings the annular member 21 is circular in shape, but it shall be understood that depending upon the actual shape of the male fitting 9 and/or of the vessel body 5, the annular member can be elliptical or even polygonal or can have any different suitable shape. In the embodiment shown the annular member 21 has a substantially L-shaped cross section, including a first approximately cylindrical portion or skirt 21A, extending substantially coaxi- ally with the vessel body 5 and surrounding the opening portion 5C of the vessel body 5, and a second approximately radial flange portion 21 B, extending towards the axis A-A of the vessel body. The inner surface of the skirt portion 21A of the annular member 21 is provided with a double annular groove 23A ₁ 23B, extending along the annular development of annular member 21. In the mounted position the double annular groove 23A, 23B is arranged opposite a corresponding double annular groove 25A, 25B formed in the outer surface of the side wall 5B of the vessel body 5. When the annular member 21 is mounted on the vessel body 5, the two double grooves 23A, 23B and 25A, 25B define a double seat surrounding the opening portion or female fitting 5C of the vessel body 5. Said double seat is designed to house a double retention rod 27A, 27B. Here below the rod 27A, 27B will be designated as a flexible rod. In order to be suitably flexible, the dou- ble flexible rod 27A, 27B can be made of a suitable plastic material, such as Nylon®, having sufficient flexibility to conform with the annular seat formed by grooves 23A, 23B and 25A, 25B, and having at the same time a sufficient shearing resistance. Other materials are not excluded, including metals, such as aluminium, or metal alloys.

According to preferred embodiments, the flexible rod or retention rod is in the shape of a filament member, i.e. a member having a first main dimension along the longitudinal development, which is several times greater than the dimensions in the other directions, i.e. with a cross section which is negligible if compared to its overall length.

Even though in the embodiment shown in the drawings the retention rod is double, a single retention rod could also be envisaged, depending upon the mechanical resistance required, and/or also taking dimensional or other design constraints into consideration. The double flexible rod can be formed by two separate fiiament component, or by filament components which are connected to one another at the end which remains outside the seat 23A, 25A; 23B, 25B.

In one embodiment the double flexible rod 27A, 27B and more specifically each one of the two filament components thereof, has a circular cross sec- tion, corresponding to a substantially circular cross section of the double seat formed by mating grooves 23A, 23B and 25A, 25B. However, the cross-section of both the seat 23A, 23B; 25A, 25B and the flexible rod 27A, 27B can be different in shape, provided it is sufficiently resistant to shear stresses. For example, said cross-section can be square, elliptical, triangular or the like. What mat- ters is that once the double flexible rod 27A, 27B is inserted into the double seat formed by the two groove pairs 23A, 23B and 25A, 25B, it will provide a sufficient retention between the vessel body 5 and the annular member 21.

The radially inwardly projecting flange portion 21 B of the annular member 21 extends towards the male fitting 9. More specifically, in one embodiment said male portion 9 is comprised of a lateral projection 9A. Preferably said lateral projection 9A is co-extensive with said annular member 21 and is annular in shape. In a different embodiment, said lateral projection 9A is formed by individual radially projecting appendages or fins arranged around the axis A-A of the vessel. When the male fitting 9 is mounted on the vessel body 5, the lateral projection 9A is retained between the radially inwardly extending flange portion 21 B of the annular member 21 and a radially inwardly extending collar 5E forming a seat for said lateral annular projection 9A of said male fitting 9. The collar 5E can be integral with the side wall 5B of the vessel body 5 and preferably co- moulded therewith.

Once the annular member 21 is constrained to the vessel body 5 by means of double flexible rod 27A, 27B, the lateral annular projection 9A of the male fitting 9 is safely retained between the annular member 21 and the collar

5E ₁ such that the male fitting portion 9 cannot be removed from the vessel body 5.

In one embodiment, a circumferentially developing wall 5F projects from the collar 5E towards the bottom 5A of the vessel body 5. The inner surface of collar 5E forms a sealing surface on which a sealing ring such as an O-ring 31 is pressed to provide a sealing closure between the vessel body 5 and the male fitting 9. the sealing ring or O-ring 31 is housed in a groove provided in a circumferentially developing extension 9C of the male fitting 9, said extension 9C projecting towards the bottom 5A of the vessel body 5.

In a different embodiment (not shown) a lip seal can be provided instead of or in addition to the O-ring. In yet a further embodiment a double seal, such as a double lip seal or a double O-ring could be arranged between extension 9C and wall 5F. In a further embodiment the seal can be housed in an annular groove provided in the wall 5F. In still a further embodiment, in addition to or in replacement of the sealing ring 31 , a sealing arrangement could be provided between annular projection 9A and either the collar 5E or the flange portion 21 B or both. In such a case the circumferentially developing wall 5F and/or the extension 9C could be dispensed with, even though said wall 5F and extension 9C are particularly advantageous to provide guidance for the male fitting 9 when it is introduced into the female fitting 5F, 5E.

The annular member 21 is provided with an external tab 21T arranged adjacent a passage 21 P provided in a suitable position around the annular development of member 21. The passage is provided for the insertion of the double flexible rod 27A, 27B in the seat formed by the mating grooves 23A, 23B and 25A, 25B and is approximately tangential to the groves 23A, 23B. In one embodiment the tab 21T is provided with an eyelet 21Q for fixing said double flexible rod 27A, 27B to the tab, said double flexible rod having a corresponding eyelet or else a projection which can be snap-fitted into eyelet 21 Q. A reverse arrangement can be provided, with the eyelet on the double flexible rod and the snap-fitting projection on tab 21 T. If two eyelets are provided, one on the tab 21 T and one on the flexible rod 27A, 27B, fixing can be obtained e.g. with an

elastic ring or any other means suitable to prevent accidental removal of the double flexible rod 27A, 27B from the double seat 23A, 23B; 25A, 25B.

The annular member 21 can be provided with handles 21 H for easy gripping the annular member 21 and removing it form the vessel once the double flexible rod 27A, 27 B has been removed.

In the embodiment shown the male fitting 9 is surrounds a multi-port valve 7 and is preferably moulded integral with one of the valve components. In a different embodiment, not shown, the male fitting 9 forms an integral part of any other device, appliance or apparatus which has to be quick-releasingly connected to the vessel body 5. In stiϋ a further embodiment the maie fitting 9 could be a simple vessel closure, or else could house or be integral with a pipe fitting or the like.

As can be understood from the above description, once the male fitting 9 has been arranged in the female fitting formed by the opening portion 5C of the vessel body 5, and once the annular member 21 has been mounted and locked to the vessel body 5 by means of double flexible rod 27A ₁ 27B, the male and female fitting are safely retained in the locked condition and the internal pressure of any liquid or fluid inside the vessel 3 generates a shearing stress on the double flexible rod 27A, 27B which, due to said shearing action, is prevented from being accidentally removed from its seat. The male fitting 9 can be removed from the vessel body 5 only once the pressure inside the vessel 3 has been released and thus a safety condition has been reached. In the de- pressurized condition the flexible rod 27A, 27B can easily be introduced into or removed from the seat 23A, 23B; 25A, 25B to lock the male fitting to the female fitting or unlock it therefrom.

In a different embodiment, not shown, the flexible rod can be a single flexible rod, i.e. comprised of only filament component 27A or 27B, and in such case only individual annular grooves 23A and 25A or 23B and 25B will be provided. The number of rods and seats as well as their cross sectional dimension and shape will be selected based on the dimension of the vessel and/or the pressure which the quick-release fitting has to withstand.

The quick-release fitting described above can be used to releasingly connect a male fitting and female fitting different from the components of a vessel, such a two pipes or the like.

According to some embodiments, the quick-release assembly is used to assemble together different parts of a hydraulic system. In the present description and in the following drawings, a hydraulic system shall be generally understood as a system comprised of at least two mechanical components con- nected together and at least partly defining or delimiting a volume in which a fluid is contained, the pressure of said fluid being generally different than the pressure of the exterior environment.

Fig.6 diagrammatically shows a pump assembly, designated 100 as a whole. The pump assembly 100 includes a pump casing 101 housing a pump rotor (not shown) and a motor 103 for driving the rotor of the pump into rotation.

The pump casing 101 is usually called the wet part of the pumping assembly while the motor is called the dry part of the pumping assembly. The wet and dry parts are mutually connected by a quick-release fitting, which can be designed in quite the same way as the quick-release assembly shown in Figs. 1-5 and described above. Reference number 121 designates an annular member quite the same as annular member 21.

In some embodiments, the pumping assembly is further comprised of a pre-filter 105. In some embodiments said pre-filter 105 includes a pre-filter vessel 107 and a cover 109 closing said vessel 107. The vessel and the cover are connected one to the other with a quick-release fitting assembly 131 designed quite in the same way as the quick-release fitting assembly 21-27 used to connect the filter vessel 5 and the cover 9 one to the other.

Other possible uses of the quick-release fitting assembly according to the invention are conceivable whenever two mechanical parts shall be con- nected together, said parts delimiting an interior volume where a fluid is contained, the pressure of which is different (and usually higher) than the external pressure.

Fig.7 diagrammatically shows the use of a quick-release fitting assembly according to the invention for connecting two pipes P1 and P2. Similar parts are designated with the same reference numbers as in Figs 1-5.