Fluid sensing shut-off devices with timer and methods of operation
First Claim
1. A fluid sensing shut-off device comprising:
- a valve having a valve open position allowing fluid flow between a valve inlet and a valve outlet, and a valve closed position preventing flow between the valve inlet and the valve outlet;
the valve being encouraged to the valve closed position by a spring force;
a stationary magnetic circuit portion;
a magnetic member moveable within the magnetic circuit between first and second positions, the magnetic member forming a closed magnetic circuit having a substantially zero air gap and disposed to hold the valve in the valve open position when in the first position;
one of the stationary magnetic circuit portion and the magnetic member including a permanent magnet, the permanent magnet magnetically holding the magnetic member in the first position with a magnetic force exceeding the spring force once moved to the first position;
a coil disposed to temporarily decrease the magnetic force to less than the spring force on receipt of a current pulse in the coil to allow the spring force to move the magnetic member to its second position and to allow the spring force to move the valve to the closed position;
a sensor configured to sense fluid flow through the valve;
a timer coupled to the sensor to sense the length of time of fluid flow; and
, circuitry coupled to the timer to provide a current pulse to the coil if a duration of fluid flow exceeds a predetermined time limit to allow the spring force to move the valve to the valve closed position.
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Accused Products
Abstract
Fluid sensing shut-off devices with timer and methods of operation to shut off fluid flow if a primary shutoff valve sticks in the on condition. An embodiment is disclosed using a microphone to sense fluid flow, with a microprocessor periodically awakening from a sleep mode to power the sensor and determine if there is flow. If there is flow, the microprocessor times flow, and if flow is not shut off within a predetermined length of time, the microprocessor shuts off the valve. The valve itself normally held in a magnetically latched, valve open state, but may be unlatched by a current pulse to close the valve. Various embodiments and applications are disclosed.
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Citations
28 Claims
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1. A fluid sensing shut-off device comprising:
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a valve having a valve open position allowing fluid flow between a valve inlet and a valve outlet, and a valve closed position preventing flow between the valve inlet and the valve outlet;
the valve being encouraged to the valve closed position by a spring force;
a stationary magnetic circuit portion;
a magnetic member moveable within the magnetic circuit between first and second positions, the magnetic member forming a closed magnetic circuit having a substantially zero air gap and disposed to hold the valve in the valve open position when in the first position;
one of the stationary magnetic circuit portion and the magnetic member including a permanent magnet, the permanent magnet magnetically holding the magnetic member in the first position with a magnetic force exceeding the spring force once moved to the first position;
a coil disposed to temporarily decrease the magnetic force to less than the spring force on receipt of a current pulse in the coil to allow the spring force to move the magnetic member to its second position and to allow the spring force to move the valve to the closed position;
a sensor configured to sense fluid flow through the valve;
a timer coupled to the sensor to sense the length of time of fluid flow; and
,circuitry coupled to the timer to provide a current pulse to the coil if a duration of fluid flow exceeds a predetermined time limit to allow the spring force to move the valve to the valve closed position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A water sensing shut-off device comprising:
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a valve having a valve open position allowing water flow between a valve inlet and a valve outlet, and a valve closed position preventing flow between the valve inlet and the valve outlet;
the valve being encouraged to the valve closed position by a spring force;
a stationary magnetic circuit portion;
a magnetic member moveable within the magnetic circuit between first and second positions, the magnetic member forming a closed magnetic circuit having a substantially zero air gap and disposed to hold the valve in the valve open position when in the first position;
one of the stationary magnetic circuit portion and the magnetic member including a permanent magnet, the permanent magnet magnetically holding the magnetic member in the first position with a magnetic force exceeding the spring force once moved to the first position;
a coil disposed to temporarily decrease the magnetic force to less than the spring force on receipt of a current pulse in the coil to allow the spring force to move the magnetic member to its second position and to allow the spring force to move the valve to the closed position;
a sensor configured to sense water flow through the valve;
a timer coupled to the sensor to sense the length of time of water flow; and
,circuitry coupled to the timer to provide a current pulse to the coil if a duration of water flow exceeds a predetermined time limit to allow the spring force to move the valve to the valve closed position. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification