Fluid handling – Liquid level responsive or maintaining systems – By float controlled valve
Reexamination Certificate
2002-05-22
2004-03-30
Walton, George L. (Department: 3753)
Fluid handling
Liquid level responsive or maintaining systems
By float controlled valve
C073S322500, C137S426000, C137S430000, C137S432000, C137S436000, C137S437000, C137S441000, C137S444000, C137S410000, C285S081000, C285S089000, C285S343000, C285S355000, C285S356000, C285S357000
Reexamination Certificate
active
06712090
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fluid tank valve, particularly a hydraulic refill valve, especially adapted for use in controlling the level of a liquid within a tank.
2. Description of the Prior Art
Hydraulic valves have been used for many years for controlling the level of a liquid within a tank. Such valves are widely utilized in the plumbing industry, particularly in regulating the flow of water into the tank of a toilet, sometimes termed a water closet. Conventional valves of this type, often called ballcock valves, are described, for example, in U.S. Pat. Nos. 3,429,333 and 4,100,928.
While some changes have been made in the construction of ballcock valves throughout the years, the operating mechanisms of conventional, commercially available ballcock valves sold for use in toilets have remained largely standardized for many years. For example, ballcock valves similar to the type described in U.S. Pat. No. 4,100,928 are widely sold throughout the United States and elsewhere by Fluidmaster Inc., located at 30800 Rancho Viejo Road, San Juan Capistrano, Calif. 92675 as the FLUIDMASTER® 400A fill valve.
Conventional valves of this type are typically mounted in the tank of a toilet. An upright fluid supply tube extends upwardly from a hollow mount located on the bottom of the tank at the fluid inlet. The fluid supply tube terminates in a fluid supply outlet at its upper extremity which opens into a valve enclosure. A resilient, flexible diaphragm is mounted within the valve enclosure and is secured relative to the enclosure about its periphery. The diaphragm has a central, tubular core with a vertical passage defined therethrough. Lower and upper sealing rings are located at the lower and upper ends of the diaphragm core and project radially inwardly into a longitudinal passage through the core at the lower and upper ends of the core, respectively. An intermediate sealing ring projects radially inwardly into the longitudinal passage between the upper and lower ends of the diaphragm core. One or more bleed apertures extend radially through the wall of the diaphragm core. The bleed apertures provide a flow path between the central, axial, longitudinal passage within the confines of the core and a back-pressure chamber located above and exteriorly of the diaphragm body and within the confines of the structures forming the valve enclosure.
A metering pin extends longitudinally down the center of the diaphragm core passage. The metering pin includes radially enlarged sealing portions separated by radially reduced portions. The metering pin is raised and lowered by a valve lever arm coupled to a float so that, when the water level in the tank rises, the valve lever is actuated to lower the metering pin to a position in which one of the radially enlarged portions of the metering pin blocks the valve passage at the upper sealing ring. A limited flow of water is then permitted up through the lower sealing ring and past the intermediate sealing ring through the bleed apertures to the back-pressure chamber. Pressure is thereby allowed to build up in the back-pressure chamber, which then closes the body of the valve against a valve seat at the fluid supply outlet. This blocks flow from the fluid supply tube to outlet ports in the valve, thus shutting off the flow of water into the tank.
When the toilet is flushed the float drops due to the falling water level within the toilet tank. This action operates the valve lever arm, raising the metering pin which then unblocks the upper sealing ring. The back-pressure chamber is thereby vented to atmosphere through the bleed apertures. The pressure of water from the fluid supply tube thereupon forces the body of the valve up from the valve seat, thereby permitting the flow of water from the fluid supply tube to the valve outlet ports. This fluid flow ultimately fills the tank, whereupon the float rises to operate the actuating lever arm to again lower the metering pin. With the upper sealing ring again blocked, pressure rebuilds in the back-pressure chamber to again force the body of the valve into a sealing relationship with the valve seat.
The longitudinal fluid passage within the diaphragm core is quite small, and the annular orifices around the metering pin are even smaller. Consequently, even very tiny particulates of sediment, sand, scum, or dirt can cause a blockage within the valve orifices, central passage, or bleed apertures through the wall of the core. The valve will thereafter operate improperly until repaired or replaced.
Clogging of the valve passage is particularly likely since at least a portion of the passage through the core is open to fluid when the metering pin is reciprocated to unseat the body of the valve from the valve seat. At this point in the operation of the valve there is a considerable onrush of water directed straight up into the passage. Consequently, it is not at all unusual for small particles of sediment or grit to enter the lower portion of the passage through the diaphragm core when the body of the valve is unseated. Such particulate matter is then very likely to lodge within the flow pathways through the core of the diaphragm as it is carried by the water passing into and through the diaphragm.
Another problem that has persisted in the operation of conventional ballcock valves is the rather lengthy fill time and noisy operation of the valve, particularly as it approaches a closed condition. This problem occurs due to the inordinately long lever arm that is utilized to manipulate the metering pin. Because of the long lever arm, the enlarged portion of the metering pin that seals against the upper sealing ring approaches the upper sealing ring quite slowly. As a consequence, the rate at which pressure builds up in the back-pressure chamber rises progressively, but very slowly, thus lengthening the time required for sufficient pressure to build up in the back-pressure chamber to seat the body of the diaphragm against the valve seat. During this time there is an annoying hissing noise due to the slow passage of water past the metering pin and through the upper sealing ring.
One of my prior patents, U.S. Pat. No. 3,729,017, incorporated herein by reference in its entirety, addresses this problem. The system described in this patent allows the lever arm operating the metering pin to be shortened considerably by the utilization of an inverted, cup-shaped float disposed atop the valve. The lever arm that operates the metering pin described in this patent is enclosed entirely within the confines of the cup-shaped float. The length of the lever arm is thereby greatly reduced from other conventional ballcock valves. When the water level in the tank drops, the roof of the cup-shaped float bears downwardly on the distal end of the lever arm, thereby forcing it downwardly to operate the metering pin in a desired direction. When the level of water within the tank rises, it lifts the float with it, thus relieving the downward pressure of the roof of the float against the distal end of the lever arm. A spring thereupon urges the distal end of the lever arm upwardly, thereby moving the metering pin in the opposite direction.
While the foregoing system does have the desired effect of reducing the fill time and the duration of the noisy operation of the valve as it nears closure, there is no convenient means for making adjustments so that the valve is actuated at a selected level of water in the tank. Such adjustments are important due to the many variations in the height at which the valve is mounted above the bottom of the tank, the height to which the overflow pipe extends above the bottom of the tank, and other variations in ballcock valve configuration that require small, but important adjustments in the level of water in the tank at which the valve is operated. The improved valve of the present invention provides a simple, but novel solution to this problem.
A further problem that exists in the conventional construction of ballcock valves is that the height adjustme
Thomas Charles H.
Walton George L.
LandOfFree
Hydraulic valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydraulic valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydraulic valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3204739