Sealed Dashpot Mechanism for Delayed Closing Plumbing Valves

The field of the invention is plumbing valves, and the invention relates more particularly to delayed closing plumbing valves of the type having hydraulic fluid in a sealed chamber, retained between an upper and lower diaphragm positioned about a longitudinally movable valve stem assembly.

Delayed closing valves of this type are shown in three patents which are assigned to the same assignee as the present application, namely, U.S. Pat. Nos. 3,933,337, 4,093,177 and 4,165,857. The present invention comprises an important improvement over these designs. For instance, in the most recent patent, namely, No. 4,165,857, the lower diaphragm indicated in Figure lB by reference character 43 had its lower surface exposed to water. If a grain of sand, or other foreign object, became lodged in the loop formed by the rolling diaphragm, then a hole could be worn through the diaphragm allowing water to enter the chamber 82 and permitting the silicone fluid to escape. Also, the diaphragms of these devices are glued or sealed to both the valve stem and to the body so that the turning of the stem with respect to the body would cause a tearing of the diaphragms. Furthermore, if the valve head 23 became worn causing the valve to leak, there was no way that it could be replaced. Also, if the valve seat became pitted or corroded, it, also, could not be replaced or resurfaced.

It is, thus, an object of the present invention to provide a delayed closing plumbing valve having a protected lower rolling diaphragm. It is another object of the present invention to provide an improved, delayed closing valve which has a removable and replaceable valve seat and valve gasket.

It is another object of the present invention to provide a delayed closing plumbing valve having an improved holding means for attaching the diaphragms to the valve stem.

The present invention is for an improved, delayed closing plumbing valve of the type having a cartridge with hydraulic fluid in a sealed chamber retained between upper and lower diaphragms positioned about a longitudinally movable valve stem assembly. The valve stem assembly is of the type having a deformable valve gasket means for controlling the flow of water and has a one-way piston or check valve in a fluid-filled chamber which separates the chamber into an upper compartment and a lower compartment with a restricted fluid flow path therebetween. Such valves have biasing means aided by water pressure which urge the stem assembly in a direction so that the valve gasket means seats against a valve seat, and the valve cartridge is assembled in an exterior cartridge housing. The improvement of the present invention includes a movable valve seat means, removably affixed at its upper end to the exterior cartridge housing, and the valve seat means has a generally cylindrical hollow housing, having a partially restricted portion at the inner surface near the lower end thereof which is slightly smaller in inside diameter than the outside diameter of the deformable valve gasket means, but which is large enough to permit the passage of the deformable valve gasket means therethrough. The partially restricted portion comprises a valve seat which prevents the flow of water past the valve seat when the valve gasket is positioned therein. The generally cylindrical housing has a hollow body portion which is larger than the lower portion of the exterior cartridge housing which it surrounds which permits the flow of water between the lower portion of the valve exterior cartridge housing and the inner portion of the generally cylindrical housing. Cartridge mounting means, including an angled sealing surface, is located on the exterior surface of the generally cylindrical housing to permit the affixing of the plumbing valve in a plumbing valve body. At least one passageway is formed through the generally cylindrical housing above the angled sealing surface for the passage of water therethrough, whereby when the valve means is open, water may pass into the interior of the generally cylindrical housing, upwardly through the hollow body portion and outwardly through the passageway. When said removable valve seat means is removed, the deformable valve gasket means may be replaced. In a preferred embodiment, a lower diaphragm protecting chamber is positioned beneath the lower diaphragm and has an outer shell affixed to the exterior cartridge housing of the valve. The outer shell has a smooth interior bore which contains a chamber sealing ring which is affixed to the valve stem assembly, and the sealing ring slides along the interior surface of the smooth bore. Preferably, the sealing ring is also used as a biasing spring retainer. The improved diaphragm retaining ring of the present invention has a circular base at the lower end which is held by the valve stem assembly, and an inner conical surface is pushed upwardly over the exterior of the inner ring of the diaphragms. The upper retaining ring, preferably, also holds a one-way piston or movable check valve in its proper place in the hydraulic fluid filled chamber.

FIG. 1 is a cross-sectional view of the improved, delayed closing plumbing valve of the present invention.

FIG. 2 is an enlarged perspective view, partially cut away, of the removable valve seat means of the valve of FIG. 1.

FIG. 3 is a perspective view, partially cut away, of a portion of the valve stem assembly including the chamber sealing ring which protects the lower diaphragm.

FIG. 4 is a perspective view of the diaphragm retaining ring of the valve of FIG. 1.

FIG. 5 is an enlarged cross-sectional view of the one-way piston portion of the valve of FIG. 1.

The delayed closing plumbing valve of the present invention is shown in cross-sectional view in FIG. 1 and indicated generally by reference character 10. Valve cartridge 10 is held to a plumbing fixture body 11 by a brass bonnet 12 which tightens against flange 13 on the exterior of the valve body housing. The exterior valve body housing is made up of three major elements, namely, a top bearing 14, a central cylinder 15 and a spring housing 16. Although such parts may be fabricated from brass, it is advantageous that they be fabricated from a polymer such as the acetal homopolymer sold under the trademark, "Delrin." Such polymer has resistance to corrosion, is lightweight and is capable of withstanding the temperature and pressures commonly occurring in water valve environments.

Top bearing 14 is ultra-sonically welded at 17 to the top of central cylinder 15. Top bearing 14 has a central opening 18 which supports the projecting end 19 of the valve stem assembly.

The valve stem assembly is, likewise, made up of three major pieces, namely, an upper orifice portion 20, a middle stem 21 and a lower stem 22.

The projecting end 19 of the upper orifice portion 20 of the valve stem assembly is supported by the central opening 18 in top bearing 14 and moves freely therethrough. Top bearing 14 also has a bottom recess 23 which holds the outer ring 25 of upper diaphragm 24.

Upper diaphragm 24 and lower diaphragm 26 define a compartment for holding a hydraulic fluid such as a silicone oil and this compartment, itself, is broken into two compartments by a one-way piston or moveable check valve 27, namely, an upper compartment 28 and lower compartment 29. It is important that the hydraulic fluid be separated from contamination, particularly, contamination from water and, thus, it is essential that the diaphragms 24 and 26 be securely sealed at both their outer rings and at their inner rings. Thus, inner ring 30 of upper diaphragm 24 is securely held to the upper orifice portion 20 by a retaining ring 31. It is, however, beneficial that the upper diaphragm be permitted to turn with respect to either the valve stem or the cartridge. If one were to take a pair of pliers and turn the projecting end of the valve stem assembly with respect to the cartridge, the diaphragm would be torn if such turning were not permitted. Since it is desirable to make the assembly of the present invention as vandal proof as possible, such turning is permitted.

Ring 31 is shown in perspective view in FIG. 4 and can be seen to have an upwardly directed conical opening 32 which is pushed upwardly over inner ring 30 which is also held in a groove 33 in the upper orifice portion 20 of the valve stem assembly. This securely holds the inner ring of the diaphragm against the valve stem assembly in a fluid tight relationship. It can be also seen that ring 31 has a plurality of passageways 34 which communicate with a space 35 in the interior surface of ring 31 which, in turn, permits the flow of fluid into a transverse passageway 36 which, in turn, communicates with the axial opening 37 in the orifice portion 20 of the valve stem assembly.

It can also be seen clearly in FIG. 5 that the annular recess 38 at the bottom of ring 31 serves to hold one-way piston 27 in a fluid-tight manner against the orifice portion 20 of the valve stem assembly. One-way piston 27 has an inner annular ring 39 which gradually narrows at 40 where the piston expands upwardly and outwardly into a lip seal portion 41. The outer edge 42 of the lip seal contacts the inner surface 43 as shown in FIG. 1. It can be readily observed that as the valve stem assembly and one-way piston 27 are moved downwardly as oriented in FIG. 1, that the hydraulic fluid 44 moves with ease around the outer edge 42 of piston 27. However, when the piston is moved upwardly, the lip seal 41 moves against the inner surface 43 preventing the flow of fluid around the lip seal and, thus, the fluid is required to move through axial opening 37 where it flows into the lower compartment 29 through transverse passageway 45.

As is evident from FIG. 1, as the valve gasket 46 moves away from the valve seat 49, water may flow from the line pressure compartment 50 through annular passageway 51 out of openings 52 and into the water outlet compartment 53 and from there to the faucet or other water outlet. The rate at which the valve gasket moves upwardly into its closed position, as shown in the left-half of FIG. 1, is controlled by the rate of hydraulic fluid flow through the fluid path including axial opening 37. The rate of flow of fluid is readily adjusted by turning needle valve 54 toward or away from needle valve seat 55 in a conventional manner. Needle valve 54 is sealed in axial opening 37 by an O-ring 56 which, in turn, is sealed by a nut 57 which has a hexagonal opening, larger than the needle of the needle valve.

Returning now to the placement of the one-way piston 27 against the upper orifice portion 20 of the valve stem assembly, it can readily be seen in FIG. 5 that the lower surface 58 of one-way piston 27 abuts a brass retaining ring 59 and is held by a stainless snap ring 60 held in a groove 61 formed in the orifice portion 20 of the valve stem assembly. Note also that a step 62 is formed in the orifice portion of the valve stem assembly so that the downward movement of the valve stem assembly is securely stopped by the abutment of the brass retaining ring 59 against a shoulder 63 positioned in the interior of central cylinder 15.

Returning now to the sealing of the diaphragms to the exterior cartridge housing, the upper diaphragm 24 has an outer ring 25 which is held against the bottom recess 23 of top bearing 14 by a retaining ring 64 which rests on a shoulder 65 formed on the inner surface of central cylinder 15. The outer ring 25, thus, may be compressed by top bearing 14 to securely seal the outer ring against fluid leak. Similarly, the outer ring 66 of lower diaphragm 26 is held between a recess 67 formed at the base of central cylinder 15 and a recess 68 formed in the upper end of spring housing 16. Spring housing 16 is held to central cylinder 15 by an ultra-sonic weld 69, and it can be seen that the outer ring 66 is securely held between these two members. The inner ring 70 of lower diaphragm 26 is held against a shoulder 72 in middle stem 21 by a retaining ring 71 which, like ring 31, has a conical opening 73. Retaining ring 71 is held in place by a stainless snap ring 74 held in a mating groove in middle stem 21.

An important feature of the present invention is the means used to protect the undersurface of lower diaphragm 26 from wear and abrasion from foreign particles in the water. This is accomplished by a chamber sealing ring shown in perspective view in FIG. 3 and indicated by reference character 75. Chamber sealing ring 75 is held against upward movement by a snap ring 76 held in a groove in lower stem 22. Chamber sealing ring 75 is, preferably, formed from a polymer such as an acetal homopolymer. Ring 75 has a smooth outer surface 77 which rides along the smooth inner surface 78 of spring housing 16. The inner surface 79 of chamber sealing ring 75 tightly fits along the outer surface of lower stem 22 and prevents any particles from entering past sealing ring 75. A spring retaining recess 80 retains a spring 81 which provides the force, together with water pressure, for returning the valve stem assembly to its upper, or closed, configuration. Spring 81 is, preferably, a stainless steel spring and its lower end is held by a spring retainer and bearing 82. A slight opening is provided between the inner surface 83 of bearing 82 and lower stem 22 to permit the flow of a very small amount of water held below sealing ring 75 and spring retainer 82. Spring retainer and bearing 82 is still available to hold lower stem 22 in its approximately axial position.

Another important feature of the present invention is the ability of the valve of the present invention to be serviced. This is brought about by the removability of the valve seat housing 84. Valve seat housing 84 is held securely against spring housing 16 by the upward force created by its contact with shoulder 85 of plumbing fixture body 11 and the downward force generated by the tightening of brass bonnet 12 which moves spring housing 16 downwardly where its lower surface 86 abuts the upper surface 87 of valve seat housing 84. When brass bonnet 12 is removed, the entire assembly may be lifted from plumbing fixture body 11, and valve seat housing 84 may simply be pulled away from spring housing 16. Valve gasket 46 comprising O-rings 47 and 48 pass completely through valve seat 49 and, thus, are exposed for inspection or replacement. Similarly, if the valve seat 49 becomes somehow scored or damaged, the entire valve seat housing 84 may readily be replaced. It should be noted that valve seat housing 84 has a plurality of support ribs 88 which contact the exterior base of spring housing 16, helping to retain it in accurate central alignment with respect to valve seat 49.

Yet another important invention is the ability of the delayed closing valve to close without chatter or noise. This is brought about by the provision of a pair of O-rings of different size. The larger O-ring 47 has a larger cross-sectional diameter than O-ring 48. Similarly, O-ring 47 is placed in a first step 89 of a groove, which step has a smaller outside diameter than second step 90 which holds O-ring 48. This combination silences the chatter as the valve stem assembly slowly causes valve gasket 46 to move upwardly into valve seat 49. The slope of valve seat 49, as it widens downwardly, is fifteen degrees from the vertical which has also resulted in a quietly closing valve. This angle is indicated by reference character "a" in FIG. 1.

With the exception of the valve stem assembly, brass bonnet 12, brass retaining ring 59, the snap rings and the spring, essentially all the remaining parts of the valve may be fabricated from polymeric materials which are free from any corrosion and light in weight.

A hydraulic fluid which has been found to be successful in the delayed closing valve comprises a non-toxic silicone fluid identified by the trademark, "Dow Corning 1000CS." The diaphragms may be made from a urethane polymer as may the one-way piston. While an elastomeric one-way piston is shown in the drawings, other one-way pistons could likewise, alternatively, be used. For instance, a rigid piston having large holes therethrough which are parallel to the axis of the valve and which has the upper surface of the piston and holes covered by a movable spring loaded disk could perform the same function.

The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive; the scope of the invention being indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.