FLUID FLOW INDICATOR WITH AUTOMATIC ALARM TIMER FOR HIGH PRESSURE/LOW FLOW APPLICATIONS
First Claim
1. A fluid flow switch for detecting exceptionally low rates of fluid flow, comprising:
- (a) a housing having an inlet port, an outlet port and an inner piston cylinder extending between and communicating with said inlet port and said outlet port;
(b) a piston carried within said piston cylinder in sealed relation against an inner wall surface thereof, said piston being movable from a resting position to a switch-activating position in response to the presence of fluid flowing through said piston cylinder;
(c) a switch operatively disposed for activation upon movement of said piston to said switch-activating position;
(d) a vent hole extending through said piston to facilitate controlled dissipation of fluid through said piston and the return of said piston to said resting position upon a stoppage of fluid flowing through said piston cylinder; and
(e) a piston biasing member carried within said piston cylinder for urging said piston toward said resting position upon a stoppage of fluid flowing through said piston cylinder.
3 Assignments
0 Petitions
Accused Products
Abstract
A highly sensitive low loss and low flow fluid flow switch is coupled with an automatic timer and/or optional transmitter to indicate the flow of gas to an appliance and to automatically start a reminder timer to turn the appliance off. After a preset time limit has expired, the timer either sounds an alarm or wirelessly triggers an alarm in a remote location. The receiver portion of the wireless timer may be mounted directly to the appliance (grill handle), so that the timer automatically resets when activity (cover opening or closing) is detected, indicating the appliance is still in use. An alarm can also be configured to sound when the grill is attempted to be ignited with the cover closed, thereby avoiding a potential explosion. A biasing attraction magnet is incorporated in the fluid flow switch to offset either the force of gravity or a return spring in order to extend performance to low pressure and low flow applications. The piston is sealed for use in high pressure/low flow applications, and provided with a vent hole for residual gas bleed-off upon a stoppage of gas flow.
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Citations
25 Claims
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1. A fluid flow switch for detecting exceptionally low rates of fluid flow, comprising:
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(a) a housing having an inlet port, an outlet port and an inner piston cylinder extending between and communicating with said inlet port and said outlet port; (b) a piston carried within said piston cylinder in sealed relation against an inner wall surface thereof, said piston being movable from a resting position to a switch-activating position in response to the presence of fluid flowing through said piston cylinder; (c) a switch operatively disposed for activation upon movement of said piston to said switch-activating position; (d) a vent hole extending through said piston to facilitate controlled dissipation of fluid through said piston and the return of said piston to said resting position upon a stoppage of fluid flowing through said piston cylinder; and (e) a piston biasing member carried within said piston cylinder for urging said piston toward said resting position upon a stoppage of fluid flowing through said piston cylinder. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A fluid flow switch and alarm apparatus for detecting exceptionally low rates of fluid flow and producing an alarm warning, comprising:
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(a) a housing having an inlet port, an outlet port and an inner piston cylinder extending between and communicating with said inlet port and said outlet port; (b) a piston carried within said piston cylinder in sealed relation against an inner wall surface thereof, said piston being movable from a resting position to a switch-activating position in response to the presence of fluid flowing through said piston cylinder; (c) an electrical switch adapted to be magnetically activated by a switch-activating magnet carried by said piston when said piston is located in said switch-activating position; (d) a vent hole extending through said piston to facilitate controlled dissipation of fluid through said piston and the return of said piston to said resting position upon a stoppage of fluid flowing through said piston cylinder; (e) a piston biasing member carried within said piston cylinder for urging said piston toward said resting position upon a stoppage of fluid flowing through said piston cylinder; and (f) a power source and wireless transmitter connected to said electrical switch, whereupon activation of said electrical switch transmits power from said power source to said transmitter, thereby causing a wireless signal to be transmitted to a receiver for activation of an alarm. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
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25. A fluid flow switch for detecting exceptionally low rates of fluid flow, comprising:
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(a) a housing having an inlet port, an outlet port and an inner piston cylinder extending between and communicating with said inlet port and said outlet port; (b) a piston carried within said piston cylinder, and an elastomeric seal disposed in sealing relation between an outer surface of said piston and an inner wall surface of said piston cylinder, said piston being movable from a resting position to a switch-activating position in response to the presence of fluid flowing through said piston cylinder; (c) an electrical switch adapted to be magnetically activated by a switch-activating magnet carried by said piston when said piston is located in said switch-activating position; (d) a vent hole extending through said piston in a direction generally parallel to the axis of said piston cylinder, said vent hole being sized appropriately to control dissipation of gas through said piston upon a stoppage of fluid flowing through said piston cylinder and the return of said piston to said resting position, yet restrict fluid flow through said piston sufficiently to cause said piston to move toward said switch-activating position in response to the presence of fluid flowing through said piston cylinder; and (e) a mechanical spring carried within said housing for biasing said piston toward said resting position upon a stoppage of fluid flowing through said piston cylinder.
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Specification