Abstract:
Disclosed herein is a plumbing spout that has back flow protection. The spout positions a check valve vacuum breaker underneath the pull up knob in a plug assembly. The spout provides back flow protection even though it has no fluid control valve for controlling flow through to the spout outlet.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to spouts that have internal back flow protection. 
     Plumbing codes typically require back flow protection when a plumbing outlet is likely to be adjacent contaminated water. For example, kitchen spray units of the type which can be pulled out from the sink or a faucet are typically provided with back flow protection. See e.g. U.S. Pat. No. 4,696,322. The disclosure of this patent and of all other publications referred to herein are incorporated by reference as if fully set forth herein. 
     Back flow protection has also been provided in stop cocks. See U.S. Pat. No. 2,133,804. 
     Back flow protection can be provided to some extent by including a one-way check valve in the supply line, or preferably (and/or additionally) by providing a means to bleed air into the fitting should upstream negative pressure develop (e.g. a supply line to a high rise apartment breaks). This latter approach significantly offsets any suction which might cause contaminated water to be sucked back into the line, and is known as vacuum breaking. 
     However, there is another type of faucet where the hot water is controlled by a first stop cock positioned at one location on a sink, the cold water is controlled by a second stop cock positioned at a second separate location on a sink, and outlets from both valves feed to a centrally located spout which has no valving to control water flow. While each such stop cock could be provided with separate vacuum breaker protection (compare U.S. Pat. No. 2,133,804), this requires two separate stop cocks to be modified to provide such protection. 
     Providing vacuum breaker protection in connection with such spouts is not typical as such spouts are often slanted upward so that their outlets are sufficiently far away from contaminated water below that plumbing codes don&#39;t usually require such protection. However, very low profile designs have been developed for such spouts where the outlet is very close to the base of the spout. Some plumbing codes require back flow protection in connection with such spouts. 
     Complicating matters is the fact that such designs are often provided with a pull up knob that rests on top of the spout. The knob is connected to an extension which projects downwardly through the spout in parallel to the water supply line to link to the drain control mechanism. 
     Thus, it can be seen that a need exists for back flow protection in such spouts. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a plumbing spout connectible to a supply of a fluid (typically water) in order to deliver the fluid to a selected site (preferably a lavatory or bath tub basin). The spout has a housing having an internal hollow. A lower inlet, upper opening and a side outlet passageway are provided in the housing and are all in communication with the hollow. 
     There is also a pull up knob having a downward extension that passes through the housing so as to be suitable to be connected to a drain control valve. Further, there is a plug mounted adjacent the upper opening, the plug having a bore which is in communication with atmosphere at its top and is also in communication with the lower inlet. 
     A check valve is positioned in the plug bore. The valve is normally biased to restrict air from entering the hollow through the bore. However, it permits air to enter the hollow through the bore if negative pressure develops in the hollow. 
     In preferred aspects the plug extension passes through a second bore in the plug, the check valve is spring biased in an upward direction (and is also urged into the closed position by water when water is supplied to the spout), and the spout does not contain any valve for controlling water flow to the housing outlet. Also, the side outlet passageway can be part of a generally horizontal spout outlet extension. If the pull up knob is removed from the spout the check valve can be accessed through the upper opening. 
     It will therefore be appreciated that the present invention provides back flow protection for a spout that is not part of a fluid control valve. The check valve itself can be hidden underneath the pull up knob so as to provide a more aesthetically pleasing appearance than would occur if an air access were readily visible. Further, the assembly can be easily manufactured and assembled. Should the check valve require maintenance, it can easily be accessed without removing the spout from its mounting on a plumbing fixture. 
     The foregoing and other advantages of the invention will appear from the following description. In this description reference is made to the accompanying drawings which form a part hereof and in which there is shown by way of illustration preferred embodiments of the invention. These embodiments do not represent the full scope of the invention. Thus, the claims should be looked to in order to judge the scope of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a left upper perspective view of a spout in accordance with the present invention; 
     FIG. 2 is a vertical cross-sectional view, partially not sectioned, taken along line  2 — 2  of FIG. 1; 
     FIG. 3A is a detailed sectional view of a portion of FIG. 2, albeit with the pull up knob in the closed position; 
     FIG. 3B is an enlarged sectional view of another portion of FIG. 2, showing the check valve in the closed position; 
     FIG. 4A is a view similar to FIG. 3A, but with the pull up knob in the down position and the valve experiencing negative pressure conditions; and 
     FIG. 4B is a view similar to FIG. 3B, but with the check valve in the open position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring first to FIGS. 1 and 2, a spout  10  is provided having a downwardly projecting outlet  11  and pull up knob  12 . The spout can be positioned on a counter or plumbing fixture through a hole  14 . The pull up knob can have threaded into it a downwardly projecting shaft extension  15  which can be connected via linkage  16  to the usual drain control valving. In an especially preferred form, the extension can be guided through a cylinder sleeve  15 A which serves to isolate the extension  15  from the water. 
     Typically, the drain will be located in a basin under the spout opening  11  (not shown). The pull up knob can rest on decorative escutcheon  17  which has a central top opening to permit the extension  15  to slide therein. 
     Below the opening  14  is a coupling  18  which receives and mixes water from a hot water supply line  19  and a cold water supply line  20 . The volume of water entering each of the supply lines  19  and  20  is controlled by conventional stop cocks (not shown). Water mixes in the coupling  18  and then heads upwardly along supply pipe  21  to feed the spout inlet end  23 . It should be appreciated that pull up extensions  15  and  16 , and sleeve  15 A, are parallel to and outside of supply pipe  21 . Water entering inlet  23  will (in the normal course) pass through horizontal outlet pathway  24  via the hollow portion of the spout housing to an outlet  11 . 
     As best seen in FIGS. 3A,  3 B,  4 A, and  4 B, an upper opening  30  is provided in the upper wall  31  of the spout  10 , adjacent the rear wall  32 . A plug  33  is welded, threaded, or otherwise securely mounted in a leak proof manner in the opening  30 . The plug has two vertically extending bores  35  and  36 . 
     Within bore  35  is positioned a check valve cartridge  40 . Preferably this is check valve cartridge CO  010  available from Watts Ocean. It has a piston  41  which is biased upwardly by spring  42  against O-ring seal  43  to normally close off flow through the check valve. A slight restriction in bore  35  can form a shoulder  47  to restrict downward movement of the cartridge  40 . An external O-ring  48  can be positioned around the cartridge  40  to cause the check valve to resist upward movement due to friction between the O-ring and the walls of bore  35 . 
     During normal water flow conditions, water  51  can pass into the check valve and assist in sealing the bore  35 . However, as shown in FIGS. 4A and 4B, during negative pressure conditions water will not be present to assist in the closure, and the spring bias can therefore be easily overcome by the negative air pressure. Air can then bleed into the opening in the inlet  23  through the check valve, thereby relieving the negative pressure. Note that the pathway of air access is via entry  52  which is essentially hidden under the pull up valve. 
     Should it be desired to service or replace the check valve, this can easily be accomplished by unscrewing the pull up knob, unscrewing the escutcheon from extension  34  from the plug, and accessing the cartridge from the top of bore  35 . Further, this mounting system makes it very easy to initially assemble the check valve. 
     It will be evident from the above description to those skilled in the art that various changes and modifications can be made to the above described system without departing from the scope of the present invention. For example, it is possible for the pull up knob extension to pass outside of the plug. However, the plug preferably serves as an additional guide support for the sleeve  15 A. Accordingly, to ascertain the full scope of the invention, reference should be had to the following claims. 
     INDUSTRIAL APPLICABILITY 
     The above disclosure provides a plumbing spout with back flow protection.