US3603336A

US3603336A - Fluidically controlled refill mechanism with backflow preventer

Info

Publication number: US3603336A
Application number: US34679A
Authority: US
Inventors: Barry S Fichter; Edward H Bell
Original assignee: American Standard Inc
Current assignee: Trane US Inc
Priority date: 1970-05-05
Filing date: 1970-05-05
Publication date: 1971-09-07
Anticipated expiration: 1988-09-07

Abstract

A refill mechanism, for example, a water closet tank refill apparatus is provided with a fluidically controlled valve which maintains itself in the ''''on'''' position once the fluid flow starts and switches to the ''''off'''' position in response to the attainment of a predetermined liquid level. The flowing fluid in the control chamber of the mechanism, acts as a wall or air barrier. When the fluid flow stops, the barrier is eliminated leaving a substantial distance between the maximum water height and the lowest ''''siphon'''' inlet to the valve, thereby preventing accidental backflow of water from the tank into the main waterline.

Description

United States Patent {72] Inventors Barry S. Fichter Dunellen; Edward H. Bell, Clinton, both of, NJ. [21] Appl. No. 34,679 [22] Filed May 5,1970 {45] Patented Sept. 7, 1971 [73] Assignee American Standard Inc.

New York, NY.

[54] FlLlJllDllCALLY CONTROLLED REFILL MECHANISM Wll'llll BACKFLOW PREVENTER 9 Claims, 5 Drawing Figs.

[52] US. Cl 137/815 [51] lnt.Cl 1815c 3/04 (50] Field ofSearch 137/815; 235/201 PF [56] References Cited UNlTED STATES PATENTS 3,262,468 7/1966 Metzger 137/815 X 3,386,709 6/1968 Drayer 137/81.5 X

Primary ExaminerSamuel Scott Attorneys-Sheldon 11. Parker and Tennes 1. Erstad ABSTRACT: A refill mechanism, for example, a water closet tank refill apparatus is provided with a fluidically controlled valve which maintains itself in the fon position once the fluid flow starts and switches to the off position in response to the attainment of a predetermined liquid level. The flowing fluid in the control chamber of the mechanism, acts as a wall or air barrier. When the fluid flow stops, the barrier is eliminated leaving a substantial distance between the maximum water height and the lowest siphon" inlet to the valve, thereby preventing accidental backflow of water from the tank into the main waterline.

(OFF) PATENTED SEP 7 I971 FIG 2 (REFILL) F IGJ FF) FIG.4

FIG.3 (SHUTOFF) INVENTORS Barry $.Fich1er EdwabH. Bell ATTORNEY FLUIDICALILY CONTROLLED REFILL MECHANISM WITH BACKFLOW PREVENTER BACKGROUND OF THE INVENTION Related Patent Applications The invention is designed for use with a fluidic valve of the type disclosed and claimed in copending U.S. Pat. application, Ser. No. 34,780, filed May 5, 1970, in the name of Barry S. Fichter, and entitled: Pilot Valve Operated Fluidic Valve Field of the Invention This invention relates to a fluidic valve mechanism having a backflow preventer, and more particularly, to a fluidic water closet refill valve mechanism having a backflow preventer in corporated in the liquid-level-sensing portion of the valve mechanism.

Description of the Prior Art The need for an inexpensive, efficient, reliable refill valve, for a varietypf applications has long existed. A typical example is found in the case of water closet refill devices. These devices are characteristically noisy, are excessively subject to wear and do not stay in the full open position during the entire filling operation. They typically begin a slow close procedure well before the tank is filled with water to the desired level.

Furthermore, these valves require the use of a large float and lever arm mechanism and are relatively expensive.

A further problem is that leakage of any sort from the tank causes the water control valve to open, thus replenishing the water due to leakage. A permanent on" situation is thus produced, resulting in flooding or the like.

It has been proposed to use fluidic valves in order to overcome the aforementioned problems. It is necessary, however, that the water level in the tank be precluded from accidentally attaining a level which is as high as or higher than any of the valve ports. Unfortunately, the backflow prevention mechanisms normally employed in combination with water closet refill mechanisms are not suitable for use with fluidic valves which respond to the attainment of a predetermined water level in the tank.

SUMMARY OF THE INVENTION It has now been found that a refill mechanism using a fluidic valve which responds to the attainment of a predetermined level by the water, can be provided with a simple, reliable and positive backflow preventer.

This is achieved by having an outlet conduit from the valve in communication with an upper region of a chamber which serves as a liquid level sensor and backflow preventer. The control port of the fluidic valve is in communication with a region of the chamber which is below the aforenoted upper region. The chamber has an air inlet opening at a level which is equal to the height to be attained by the water in the tank.

The chamber also has an elongated vertical opening which is positioned and dimensioned with respect to the outlet conduit from the valve such that water flowing from the outlet conduit substantially completely closes the vertical opening. The only source of air for the control part of the fluidic valve is through the air inlet opening of the chamber.

When the water in the tank reaches a predetermined level, the air inlet opening of the chamber is blocked and the switching action of the fluidic valve is activated, thereby shutting off the valve and stopping the waterflow. Therefore, the vertical opening in the chamber is open and an airgap is produced between the region of the chamber which is in communication with the control port of the fluidic valve and the water in the tank. Thus, a negative pressure in the main waterline which supplies water to the tank through the fluidic valve, cannot siphon water from the tank into the main waterline.

BRIEF DESCRIPTION OF THE DRAWINGS The objects, features and advantages of the present invention will be fully understood as the description ofthe invention proceeds, particularly when taken together with the accompanying drawings wherein like reference numerals indicate similar parts throughout the several drawings, and wherein:

FIG. I is an elevation view, partly in cross section, ofa refill mechanism in accordance with the present invention, said mechanism being in the of position;

FIG. 2 shows the mechanism of FIG. ii, in the refill position;

FIG. 3, shows the liquid level sensor and backflow preventer chamber during the shutoff" operation;

FIG. 4 is another side view of the liquid level sensor and backflow preventer chamber of FIG. 3; and

FIG. 5, is a bottom view of the liquid level sensor and backflow preventer chamber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. I, the fluidic refill mechanism is in the of position when the diaphragm 12 has a greater fluid pres sure exerted on the pilot valve side 13, of the diaphragm I2, than on the sealing side 11, of the diaphragm. When the pilot valve 14 is opened, by moving the diaphragm I6 away from the seat 18, the fluid pressure on the pilot valve side 13, of the diaphragm 12, is released and the fluid pressure on the sealing side ll, of the diaphragm forces the diaphragm away from the seat 117.

Water then flows from the fluidic valve into the water tank (not shown) by means of a main refill conduit 20, and into the rim of the bowl (not shown) by means of a secondary conduit 22. The secondary conduit 22 provides communication between the fluid valve outlet 24, and an inlet 25 to the liquidlevel-sensing and backflow preventer chamber 26.

The control port 30, of the fluidic valve, is in communica tion with outlet port 32, in the chamber 26. The outlet port is positioned just below the inlet port 25, and is advantageously provided with an extension tube 33, which has a diagonally slanted opening proximate the inlet port 25.

During the refill operation, water flowing from the water inlet port 25, seals the vertical, extended opening 40, in the sidewall 42, of the chamber 26.

It is apparent that the elongated vertical opening 40, must be properly dimensional and positioned, such that the waterflow from the water inlet port 25, completely closes the vertical opening.

Air is drawn into the chamber 26, through the bottom air inlet 44, into the outlet port 32 and into the control port 30, of the fluidic valve.

When the level of the water in the tank reaches the air inlet port 44, which is in effect, at the bottom of the backflow preventer chamber 26, air is precluded from flowing into the air outlet port 32.

The water jet from the water inlet port 25 is normally confined between the sidewalls 50 and SI, of the chamber 26, forming a curtain of water.

However, as shown in FIG. 3, the closing off of the air inlet 44, results in a vacuum in the conduit 36, between the sensing or control port and the air inlet port 32, causing the water jet from the water inlet 25 to be pulled toward the tube 33.

. The water fills the tube 33, which is functioning as a sensing tube, and flows to the sensing or control port 30. The power jet of water entering the fluidic valve through the conduit 21, is caused to flip over from its flow along wall 23, to a flow among the opposite wall 27.

This results in the power jet of water to enter the conduit 29, thereby closing the fluid valve.

It should be noted that a more detailed description of the operation of the fluidic valve can be found in the related copcnding U.S. Pat. application, Ser. No. 34,780, filed May 5, I970.

With the valve closed, thejet of water from the inlet port 25 ceases to flow leaving the sensing tube 33, open to the air at a height H above the overflow tube 28, and by an additional distance h, which is the distance between the bottom of the chamber 26, on the top of the overflow tube 28.

The water level in the tank will normally be equal to the height of the bottom of the chamber 26, but in any event, cannot be above the top of the overflow tube 28, which is in communication with the bowl of the toilet. Thus water in the tank will never reach the height of the sensing tube 33, and cannot be drawn into the main conduit 53.

It should be noted that although the sensing tube draws in water rather than air, when the water level in the tank reaches a predetermined level, the tube is always filled by fluid from the jet leaving the water inlet port 25 and never by water from the tank (not shown).

Obviously, many modifications and variations of the present invention are possible in the light of the above teaching. It is, therefore, to be understood that the invention may be practiced otherwise than as specifically described herein.

I claim:

1. A water closet refill mechanism having a fluidic valve and a backflow preventer, comprising:

A. a fluidic valve, said fluidic valve having a control port and being automatically closed in response to the termination of air being aspirated through said control port into said fluidic valve; and

B. a backflow preventer and liquid-level-sensing chamber,

said sensing chamber having a water inlet in an upper region, means for providing communication between said control port of said fluidic valve and a region of said chamber which is below said upper region, an air inlet in a lower region of said chamber, and a backflow preventer port at least intermediate said upper region and said lower region, communicating with said control port, said water inlet and said backflow preventer port being relatively positioned such that water flowing into said chamber through said water inlet forms a curtain across said backflow preventer port.

2. The structure of claim 1, wherein said backflow preventer port is an elongated, vertically extending port.

3. The structure of claim 1, wherein said backflow preventer and liquid-level-sensing chamber has an open bottom end, said open bottom end being said air inlet.

4. The structure of claim 1, wherein said backflow preventer and liquid-level-sensing chamber is provided with a conduit which extends through a first wall of said chamber to a point proximate said water inlet, said conduit being at least part of said means for providing communication between said control port of said fluidic valve and said region of said chamber which is below said upper region.

5. The structure of claim 1, wherein said water inlet supplies water to a region intermediate two opposite walls of said backflow preventer and liquid-level-sensing chamber, said two opposite walls being spaced apart a distance such that water from said water inlet substantially completely fills a vertically extending region between said two walls, said region being intermediate said backflow preventer and liquid-level-sensing chamber which is in communication with said control port of said fluidic valve.

6. The structure of claim 5, wherein said backflow preventer and liquid-level-sensing chamber is provided with a vertically extending slot in each of said two opposite walls, the slots serving as means for mounting said backflow preventer and liquid-levcl-sensing chamber on a water closet overflow tube.

7. The structure of claim 6, wherein said slots are positioned such that the region between said slots and another wall of said backflow preventer and liquid-levcl-sensing chamber constitutes said air inlet.

8. The structure of claim 7, wherein said backflow preventer and liquid-level-sensing chamber is provided with a conduit which extends through said another wall of said chamber to a point proximate said water inlet, said conduit being at least part of said means for providing communication between said control port of said fluidic valve and said region of said chamber which is below said upper region.

9. The structure of claim 8, wherein said slots are located in a vertically extending plane which is substantially intermediate of said water inlet and said air inlet.

Claims

1. A water closet refill mechanism having a fluidic valve and a backflow preventer, comprising: A. a fluidic valve, said fluidic valve having a control port and being automatically closed in response to the termination of air being aspirated through said control port into said fluidic valve; and B. a backflow preventer and liquid-level-sensing chamber, said sensing chamber having a water inlet in an upper region, means for providing communication between said control port of said fluidic valve and a region of said chamber which is below said upper region, an air inlet in a lower region of said chamber, and a backflow preventer port at least intermediate said upper region and said lower region, communicating with said control port, said water inlet and said backflow preventer port being relatively positioned such that water flowing into said chamber through said water inlet forms a curtain across said backflow preventer port.

6. The structure of claim 5, wherein said backflow preventer and liquid-level-sensing chamber is provided with a vertically extending slot in each of said two opposite walls, the slots serving as means for mounting said backflow preventer and liquid-level-sensing chamber on a water closet overflow tube.

7. The structure of claim 6, wherein said slots are positioned such that the region between said slots and another wall of said backflow preventer and liquid-level-sensing chamber constitutes said air inlet.