Background Art Various automatic or manual air-relief valves have been developed for use in connection with fluid conditioning equipment, such as swimming pool filters. In operation, these valves are adapted for venting air from the equipment.

Sable et al. U. S. Patent Nos. 4,778, 595 and 4,917, 795 disclose valve assemblies adapted for automatically venting air from swimming pool filters. More particularly, the valve assemblies are equipped with a lower ball- type valve, which opens and closes in response to the water level in the swimming pool filters, and an upper valve, which moves from a closed position to an open position in response to the expulsion of air from the top sections of the filters. While the valve assemblies are adapted to permit air to escape from the filters as water is filled in the filters, they have a complicated and bulky structure. As a result, assembly and disassembly of the valve assemblies are believed to be inefficient and time-consuming.

Moreover, the valve assemblies are constructed in such a way that debris in

the filters can enter the valve assemblies as air vents from the filters. In such circumstances, the valve assemblies are prone to malfunction.

Disclosure of the Invention The present invention overcomes the disadvantages and shortcomings of the prior art discussed above by providing a new and improved air-relief valve assembly adapted for use in connection with a pressure vessel. More particularly, the air-relief valve assembly includes a body sized and shaped so as to be mounted on the pressure vessel and having a first valve opening, which is in communication with the interior of the pressure vessel, and a second valve opening, which is in communication with the exterior of the pressure vessel and the first valve opening. The valve assembly also includes a first closing member for closing off the first valve opening. The first closing member is movable between a closed position, in which the first closing member closes off the first valve opening in a substantially fluid-tight manner, and an open position, in which the first closing member does not close off the first valve opening. A second closing member is housed within the body for closing off the second valve opening. The second closing member is movable between a closed position, in which the second closing member closes off the second valve opening in a substantially fluid-tight manner, and an open position, in which the second closing member does not close off the second valve opening. The first and second closing

members are positioned in their open positions during the filling of liquid in the pressure vessel so as to permit expulsion of gas from the interior of the pressure vessel through the first and second valve openings. The first closing member is movable to its closed position so as to inhibit discharge of fluid from the pressure vessel when the liquid in the pressure vessel rises to a predetermined level. A housing depends from the body for housing the first closing member such that the first closing member is movable between its open and closed positions. The housing surrounds the first valve opening and has at least one slot for permitting fluid communication between the first valve opening and the interior of the pressure vessel through the slot. A filter is mounted to the housing for filtering fluid entering the housing through the slot, whereby debris in the pressure vessel is inhibited from entering the body through the first valve opening and causing malfunctioning of the valve assembly.

Brief Description of the Drawings For a more complete understanding of the present invention, reference is made to the following detailed description of an exemplary embodiment considered in conjunction with the accompanying drawings, in which: FIG. 1 is an exploded perspective view of an automatic air-relief valve assembly constructed in accordance with the present invention;

FIG. 2 is a side elevational view of the valve assembly shown in FIG. 1; FIG. 3 is a cross-sectional view, taken along section line 3-3 and looking in the direction of the arrows, of the valve assembly shown in FIG. 2; FIG. 4 is a view similar to FIG. 3, except that the valve assembly is in an air-relief mode; and FIG. 5 is a view similar to FIG. 3, except that the valve assembly is in a normal operational mode.

Best Mode for Carrying Out the Invention FIG. 1 shows an automatic air-relief valve assembly 10 constructed in accordance with the present invention. The valve assembly 10 is adapted to be mounted to an orifice of a pressure vessel 12 (a portion of which is shown in FIGS. 2 and 3) used for fluid-conditioning equipment, such as a swimming pool filter, and includes a body 14 having an upper end 16 and a lower end 18. More particularly, the body 14 includes a flange 20 (see FIGS. 1-3), which extends radially outwardly from the body 14 and which is located between the upper and lower ends 16, 18, and a pair of bayonet-type connectors 22 (see FIGS. 1 and 2), which are formed on the body 14 below the flange 20. Each of the connectors 22 is sized and shaped so as to mate with a corresponding one of connectors 23 (see FIG. 2) of the pressure vessel 12 in bayonet fashion for removably mounting the body 14 and hence the

valve assembly 10 to the pressure vessel 12. Each of the connectors 22 is provided with a locking detent 24 for engagement with a detent (not shown) of a corresponding one of the connectors 23. An O-ring 25a (see FIG. 2) is mounted between the pressure vessel 12 and the flange 20. The O-ring 25a functions as a spring for causing engagement between the detents 24 of the connectors 22 and the detents of the connectors 23, thereby locking the connectors 22 to the connectors 23. An O-ring 25b is also provided to form a fluid-tight seal between the pressure vessel 12 and the valve assembly 10.

Referring to FIGS. 1-3, the body 14 includes an opening 26 extending from the upper end 16 to the lower end 18. Holes 28 are formed in the body 14 in an annular fashion adjacent the upper end 16, communicating with the opening 26. Ports 30,32 extend outwardly from the body 14 and communicate with the opening 26. A pressure gauge 34 is coupled to the port 30, while a manual air-relief valve 36 is connected to the port 32.

Referring generally to FIGS. 1 and 2 and specifically to FIG. 3, the body 14 has a plurality of vertical extensions 38 (i. e., ribs) located adjacent the upper end 16 and projecting radially inwardly from the body 14.

The body 14 is also provided with a hollow cylinder 40 located in the opening 26 intermediate the upper and lower ends 16,18. More particularly, the cylinder 40 is formed coaxial with the body 14 so as to define an annular space 42 between the cylinder 40 and the body 14. The annular space 42

permits fluid communication between the opening 26 and the ports 30,32.

The cylinder 40 has a flaring upper end 44, which is integrally connected to the body 14 so as to close off the annular space 42, and an inwardly stepped lower end 46, which includes a lower valve opening. An internal shoulder 48 is formed on the cylinder 40 adjacent the upper end 44 for purposes to be discussed hereinafter. The cylinder 40 also includes an upper valve opening located between the upper and lower ends 44,46 adjacent the internal shoulder 48.

The valve assembly 10 is also provided with a sleeve 50, i. e., an insert, (see FIGS. 1 and 3) mounted in the cylinder 40. More particularly, the sleeve 50 has a channel 52 formed therein. An O-ring 54 is received in the channel 52 for providing a fluid-tight seal between the sleeve 50 and the cylinder 40.

With reference to FIGS. 1 and 3, an upper square-cut sealing ring 56 (i. e., a sealing ring having a rectangular or square cross-section) is mounted to the cylinder 40 adjacent the upper end 44, while a lower square- cut sealing ring 58 (i. e., a sealing ring having a rectangular or square cross- section) is mounted in the lower end 46 of the cylinder 40. More particularly, the upper sealing ring 56 is biased against the shoulder 48 of the cylinder 40 by the sleeve 50 and thus forms a substantially fluid-tight seal between the cylinder 40 and the sleeve 50. A retainer ring 60 is mounted to the lower end 46 of the cylinder 40 for retaining the lower sealing ring 58 in the lower end 46.

Now referring to FIGS. 1-3, the valve assembly 10 is also provided with a cylindrical cage 62 depending downwardly from the cylinder 40. More particularly, the cage 62 has an upper end 64 sized and shaped so as to receive the lower end 46 of the cylinder 40 and attached to same by an ultrasonic-welding process. The cage 62 also has a shoulder 66, which is formed adjacent the upper end 64 of the cage 62, and a plurality of vertically oriented slots 68. The shoulder 66 and the lower end 46 of the cylinder 40 cooperate with one another so as to retain the retainer ring 60 therebetween.

A buoyant ball 70, which is adapted to float on liquid in the pressure vessel 12, is mounted in the cage 62 and is movable between an upper position, in which it engages the lower sealing ring 58 in a fluid-tight manner so as to close off the lower valve opening (see FIG. 5), and a lower position, in which it is disengaged from the lower sealing ring 58 (see FIGS. 3 and 4). A filter sleeve 72 (not shown in FIG. 2) is positioned around the cage 62 so as to coverthe slots 68, inhibiting debris in the pressure vessel 12 from entering the cage 62 and thus the opening 26 of the body 14.

Referring generally to FIGS. 1 and 2 and specifically to FIG. 3, the valve assembly 10 is also equipped with a cap 74 attached to the upper end 16 of the body 14 by an ultrasonic-welding process. The cap 74 has a skirt 76 depending therefrom for surrounding the holes 28 of the body 14 in a spaced manner so as to allow fluid (e. g., air) to be released from the pressure vessel 12 through the opening 26 and the holes 28. The skirt 76

also functions to inhibit debris from entering the body 14. The cap 74 also has a cylindrical projection 78 depending from the cap 74. Ribs 80 extend radially inwardly from the cylindrical projection 78 for purposes to be discussed hereinafter.

With reference to FIGS. 1 and 3, the valve assembly 10 also includes a U-shaped poppet 82 movably mounted in the body 14 and adapted to engage the upper sealing ring 56 for closing off the upper valve opening.

The poppet 82 is movable between a lower position, in which it engages the upper sealing ring 56 (see FIG. 3), and an upper position, in which it is disengaged from the upper sealing ring 56 (see FIGS. 4 and 5). The poppet 82 has a finger 84 depending therefrom. The finger 84 is sized and shaped so as to dislodge the ball 70 from the lower sealing ring 58 when the poppet 82 moves from its upper position to its lower position. Ribs 86 extend radially inwardly from the poppet 82, while a cylindrical projection 88 extends upwardly from a bottom portion of the poppet 82. A spring 90 is mounted between the poppet 82 and the cap 74 so as to bias the poppet 82 towards its lower position. The cylindrical projection 88 of the poppet 82 and the cylindrical projection 78 of the cap 74 provide seats for the spring 90, while the ribs 86 of the poppet 82 and the ribs 80 of the cap 74 function as a guide for the spring 90 when the poppet 82 moves between its upper and lower positions.

When an associated pump (not shown) is in a non-pumping cycle, the pressure vessel 12 normally has a liquid level 92 (see FIG. 4) below the valve assembly 10 such that the ball 70 is in its lower position and the poppet 82 is in its lower position (as indicated in FIG. 3). When the pump begins its pumping cycle (i. e., when the pressure vessel 12 is filled with liquid), the liquid level 92 rises and hence causes air 94 (see FIG. 4) contained between the liquid level 92 and the pressure vessel 12 to be pressurized. In response, the poppet 82 moves towards its upper position from its lower position, disengaging from the upper sealing ring 56 and hence allowing the air 94 to vent out from the pressure vessel 12 through the opening 26 and the holes 28 of the body 14 (as indicated by the arrows shown in FIG. 4). When the liquid level 92 rises to a predetermined level (see FIG. 5), the ball 70 moves to its upper position and thus engages the lower sealing ring 58 in a fluid-tight manner, inhibiting the liquid in the pressure vessel 12 from being released (i. e., escaping) through the opening 26 and the holes 28.

When the pump terminates its pumping cycle, the liquid level 92 in the pressure vessel 12 drops, if the pressure vessel 12 is positioned above the water level of an associated swimming pool. In response, the spring 90 causes the poppet 82 to move downwardly from its upper position towards its lower position. The finger 84 of the poppet 82 urges the ball 70 to move downwardly and thus cause same to be dislodged from the lower sealing ring

58. The poppet 82 then moves to its lower position, engaging the upper sealing ring 56. As a result, the poppet 82 inhibits exterior air from entering the pressure vessel 12 and thereby prevents further draining of the liquid from the pressure vessel 12.

If the pressure vessel 12 is positioned above the water level of the swimming pool, the liquid level 92 in the pressure vessel 12 does not generally drop upon termination of a pumping cycle of the pump. As a result, the liquid level 92 maintains the engagement between the ball 70 and the lower sealing ring 58, thereby inhibiting exterior air from entering the pressure vessel 12.

In order to drain the liquid from the pressure vessel 12, the manual air-relief valve 36 is opened by an operator. In this manner, exterior air is permitted to enter the pressure vessel 12 through the valve 36, thereby allowing drainage of the liquid from the pressure vessel 12.

It should be appreciated that the present invention provides numerous advantages over the prior art discussed above. For instance, the valve assembly 10 is believed to have a more compact valve design compared with the prior art devices discussed above. Moreover, because of the filter sleeve 72, debris contained in the pressure vessel 12 is inhibited from entering the valve assembly 10 and hence from causing malfunction or inefficient valve operation. In addition, because the upper sealing ring 56 is located on the body 14, the poppet 82 is adapted to positively engage the

upper sealing ring 56 when it moves from its upper position to its lower position, thereby forming an enhanced seal between the poppet 82 and the upper sealing ring 56. Further, the vertical extensions 38 function as a guide for the poppet 82 when the poppet 82 moves between its open and closed positions.

It should be noted that the present invention can have many variations and modifications. For instance, the bayonet-type connectors 22, 23 can be replaced with conventional connectors. Further, the cap 74 and the cage 62 can be attached to the body 14 and the cylinder 40, respectively, by any conventional process. The upper and lower sealing rings 56,58 can also be replaced by conventional sealing members. Moreover, while the valve assembly 10 is especially adapted for use in connection with swimming pool filters, it can be used in combination with other types of pressure vessel and/or fluid handling equipment.

It will be understood that the embodiment described herein is merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as defined in the appended claims.