Fluid flow regulating systems
First Claim
1. A fluid flow regulating system comprising an electrically powered motor, a fluid impeller which is drivingly connected to and driven by the motor, said motor having a continuously energized operating speed, and a system for controlling the speed of the motor to regulate the flow of fluid delivered by the impeller, said controlling system comprising an electric circuit connected to and for energizing the motor, said circuit having switching means for opening and closing the circuit to deenergize and energize the motor, a dynamic force sensing member which is movably mounted in the path for a stream of fluid delivered by the impeller to detect dynamic fluid flow forces applied to the member by fluid flowing into contact therewith, said switching means being automatically responsive to a movement of the member which reflects an applied dynamic fluid flow force in excess of a predetermined force level to open the circuit and deenergize the motor and to another movement of the member which reflects an applied dynamic fluid flow force less than said predetermined force level to close the circuit and energize the motor, said motor being acceleratable to a speed productive of an applied dynamic fluid flow force having said predetermined force level and being productive of an applied fluid flow force in excess of said predetermined force level at said continuously energized operating speed, whereby the motor is controlled to cyclically accelerate and decelerate in a speed range below said continuously energized operating speed and the impeller continuously delivers the fluid at a flow rate regulated in accord with the controlled speed of the motor.
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Accused Products
Abstract
Fluid flow regulating systems involving systems for controlling the motor speed of fluid pumping devices are disclosed. The speed control systems involve use of a velocity head force sensor that movably responds to the velocity head forces of an air stream delivered by the pumping device, and these movements in the positions assumed by the force sensor are detected and used to control the power delivered to the motor. Temperature change detectors are used in most embodiments to modify the force sensor movements so as to introduce temperature change factors as well as velocity head force change factors into the control of the power circuitry. Force sensor of the pivotal vane, bendable vane and airfoil types are shown, and temperature sensors of the bimetallic and expandable fluid types are also used. A biasing force resistive of the velocity head forces is imparted to the force sensor to establish desired speed levels of operation and bimetallic temperature sensors are used in some embodiments to provide not only the biasing force, but also a variance in the biasing force which is responsive to the changes in temperatures and thus, to introduce the temperature change factors into the force sensor movements.
17 Citations
13 Claims
- 1. A fluid flow regulating system comprising an electrically powered motor, a fluid impeller which is drivingly connected to and driven by the motor, said motor having a continuously energized operating speed, and a system for controlling the speed of the motor to regulate the flow of fluid delivered by the impeller, said controlling system comprising an electric circuit connected to and for energizing the motor, said circuit having switching means for opening and closing the circuit to deenergize and energize the motor, a dynamic force sensing member which is movably mounted in the path for a stream of fluid delivered by the impeller to detect dynamic fluid flow forces applied to the member by fluid flowing into contact therewith, said switching means being automatically responsive to a movement of the member which reflects an applied dynamic fluid flow force in excess of a predetermined force level to open the circuit and deenergize the motor and to another movement of the member which reflects an applied dynamic fluid flow force less than said predetermined force level to close the circuit and energize the motor, said motor being acceleratable to a speed productive of an applied dynamic fluid flow force having said predetermined force level and being productive of an applied fluid flow force in excess of said predetermined force level at said continuously energized operating speed, whereby the motor is controlled to cyclically accelerate and decelerate in a speed range below said continuously energized operating speed and the impeller continuously delivers the fluid at a flow rate regulated in accord with the controlled speed of the motor.
- 8. In a forced air cooling system having a fan arranged to deliver a stream of air into an area to be cooled thereby and having an electrically powered motor with a continuously energized operating speed productive of a flow of air exceeding the normal cooling requirement for the area, a system for controlling the motor speed to regulate the rate of airflow to the area comprising an electric circuit connected to and for energizing the motor, said circuit having switching means for opening and closing the circuit to deenergize and energize the motor, a dynamic force sensing member which is arranged for contact with the flowing air of an air stream delivered by the fan to detect the dynamic airflow forces applied to the member by such contact, said member being reactively movable from one position to another position in response to an applied dynamic airflow force that exceeds a predetermined force level, means biasing the member against such reactive movement with a biasing force that determines said force level and being yieldable to an applied dynamic airflow force in excess of such biasing force, thereby to permit such reactive movement, said biasing means being adapted to movably return the member to its one position as the applied dynamic airflow force following such reactive movement diminishes to below said predetermined force level, said switching means being operative under the control of the sensing member to maintain a closed circuit energized motor condition when the member is at its one position and to maintain an open circuit deenergized motor condition when the member is at its other position, said motor being acceleratable to a speed productive of an applied dyanamic airflow force having said predetermined force level and being productive of an applied dynamic airflow force in excess of said biasing force at said continuously energized operating speed, whereby the motor is controlled to cyclically accelerate and decelerate in a speed range below said continuously energized operating speed and to continuously deliver a stream of air to the area at a flow regulated in accord with the controlled speed of the motor.
Specification