Fluid handling – Line condition change responsive valves – Pilot or servo controlled
Reexamination Certificate
1999-10-12
2001-04-17
Buiz, Michael (Department: 3753)
Fluid handling
Line condition change responsive valves
Pilot or servo controlled
C137S460000, C137S486000, C073S861580
Reexamination Certificate
active
06216727
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to automatic water shut off valves for measuring the flow of water through the valve and shutting off the flow of water in response to a predetermined flow condition.
BACKGROUND OF THE INVENTION
It is known to provide automatic water shut off valves that have the ability to sense a water leak and automatically close the valve so as to prevent further leakage and damage. See for example, the disclosures found in U.S. Pat. Nos. 5,771,920 and 5,794,653, the disclosures of which are expressly incorporated by reference. While such automatic water shut off valves are known, many have not had the ability to sense both very small trickle leaks and large catastrophic leaks with great reliability. Further, some of the automatic water shut off valves of the prior art are mechanically cumbersome and very expensive to manufacture and maintain. Therefore, there is and continues to be a need for an automatic water shut off valve that is of a relatively simple design that has the ability to sense and detect relatively small trickle leaks as well as large catastrophic leaks and to shut off the associated valve in response to detecting either.
Water leakage detection systems are generally effective to stop the leakage once the leakage problem has been detected. However, water leakage detection systems of the prior art have done very little to minimize the damage caused by a leak once the leak has indeed occurred. In cases where the home or building is attended, then once a leak occurs and the main supply of water has been shutoff, then steps can be taken to remove standing water from areas and do whatever is required to minimize the damage. The problem comes into play when there is a leak, especially a catastrophic leak, in a home or building that is unattended. For example, a catastrophic leak even though detected and stopped can leave standing water on hardwood floors, for example. If the standing water remains on the hardwood floors for any significant amount of time, one can expect the floor to buckle and be so severely damaged that a new floor is required.
Therefore, there is a need for a water leakage detection system that will communicate the existence of a leakage to a central clearing station, such as a security service, if a home or building is unattended. The reporting of a leak to a central clearing center will permit the away homeowner to be contacted or even a repair service to be contacted so that the water damage can be immediately cleared and the problem causing the leak repaired.
SUMMARY OF THE INVENTION
The problems of the prior art are solved by providing a flow sensor assembly comprising a stationary metering rod with a cylindrical portion and a conical portion. A movable toroidal sensing disk circumferentially engages the cylindrical portion of the stationary metering rod during zero or low flow conditions resulting in high sensitivity at low flowrates. The liquid flows through the annular space between the stationary metering rod and sensing disk. However, at higher flowrates, the toroidal sensing disk is urged to a position circumferentially outward from the conical portion of the stationary metering rod thereby creating a larger flow cross section between the stationary metering rod and the sensing disk resulting in a decrease in sensitivity of the sensor while greatly increasing the range without excessive pressure drop. The movement of the toroidal sensing disk translates into movement of a spring-biased longitudinally adjacent toroidal ferrite. The ferrite has a high magnetic permeability and the position thereof affects the resonate frequency of a coil circumferentially wound about an exterior of the sensor tube. The resonant frequency is measured by a microprocessor which thereby calculates a flowrate based on the known flow/deflection characteristics of the sensor.
The microprocessor is programmable to respond differently to different flow rates. For example, a sudden large increase in the flow for more than ten to twenty minutes would be indicative of a catastrophic leak and the microprocessor could be programmed to shut the valve. Additionally, a long term low volume flow would be indicative of a trickle leak and the microprocessor could be programmed to shut the valve in this instance as well. Other acceptable flow conditions could also be programmed, for example, watering the lawn.
The microprocessor is further preferably connected to a security controller which in turn is connected to a remote station such as a security service computer or the like. Detection of a leak would trigger an alarm at the remote station resulting in the security service calling a plumber or the like as needed. The microprocessor could furthermore be integrated into the security controller if desired.
REFERENCES:
patent: 3805611 (1974-04-01), Hedland
patent: 3847020 (1974-11-01), Jurschak
patent: 4705060 (1987-11-01), Gouldbourne
patent: 5004014 (1991-04-01), Bender
patent: 5038820 (1991-08-01), Ames et al.
patent: 5568825 (1996-10-01), Faulk
Genova Perry A.
Giallo Joseph
Wakefield Keith
Buiz Michael
Coats & Bennett PLLC
FloLogic, Inc.
Krishnamurthy Ramesh
LandOfFree
Water flow sensing device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Water flow sensing device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Water flow sensing device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2474336