Method and apparatus for flow control

• US 4,921,211 A
• Filed: 02/24/1989
• Issued: 05/01/1990
• Est. Priority Date: 02/24/1989
• Status: Expired due to Fees

• Current Assignee: Recurrent Solutions Limited Partnership
• Original Assignee: Recurrent Solutions Limited Partnership
• Inventors: Parsons, Natan E., Novak, Joel S., Steiner, Kenneth M.
• Primary Examiner(s): Rosenthal, Arnold
• Application Number:
  US07/315,921
• Time in Patent Office: 431 Days
• Field of Search: 251/129.04, 4/623
• US Class Current: 251/129.04
• CPC Class Codes: E03C 1/057 touchless, i.e. using sensors

Abstract

An automatic faucet (100) includes a faucet (102) through which flow is controlled by an electronically operated valve (108). A sensing apparatus (104) senses the motion of objects below the faucet (102) and causes the valve (108) to open when sensed objects exhibit motion that meets certain predetermined criteria. Operation of the valve (108) in response to motion that is not intended to cause water flow is reduced by a technique that involves computing an "average" distance, which represents the position assumed by a sensed stationary object. Specifically, objects sensed near the average distance must exhibit motion more consistently than other objects because the former objects are more likely to be splashing water, which should not result in the valve'"'"'s being opened. Also, some motion greater than 1.5 inches between sensing cycles is ignored because there is a significant likelihood that such apparent motion is caused by the intermittent "disappearance" of a standing-water surface acting as a sonic mirror. To reduce the undesirable insensitivity that might otherwise result from this 1.5-inch threshold, the threshold is increased to 3 inches when the apparent motion does not include a position separated from the sensor by more than the average distance.

Claims

1. A flow-control system, adapted for connection to an electrically operated valve that operates between open and closed states in response to electrical control signals applied thereto, for applying control signals to the electrically operated valve, the flow control system comprising:

A. a position sensor for repeatedly sensing the distances to objects and for generating distance signals representing the sensed distances; and

B. control means responsive to the distance signals for computing an average-distance value from the sensed distances and for applying control signals to the valve to open and close it in accordance with predetermined criteria applied to the sensed distances, which criteria are different when the sensed distance is greater than the average-distance value from what they are when the sensed distance is less than the average-distance.

2. A flow-control system, adapted for connection to an electrically operated valve that operates between open and closed states in response to electrical control signals applied thereto, for applying control signals to the electrically operated valve, the flow control system comprising:

A. a position sensor for repeatedly sensing the distances to objects and for generating distance signals representing the sensed distances; and

B. control means responsive to the distance signals for computing an average-distance value from the sensed distances and for applying control signals to the valve to open and close it in accordance with one of at least two different sets of predetermined criteria applied to the sensed distances, one set of criteria being applied when the sensed distance differs by more than a predetermined difference value from the average-distance value, a different set of criteria being applied when the sensed distance differs by less than the predetermined difference value from the average-distance value.

3. A flow-control system, adapted for connection to an electrically operated valve that operates between open and closed states in response to electrical control signals applied thereto, for applying control signals to the electrically operated valve, the flow-control system comprising:

A. a position sensor for repeatedly detecting objects, the position sensor including an acoustic transducer, means for driving the transducer to cause it to emit ultrasound, and means for detecting echoes produced by objects in the path of the ultrasound and thereby detecting the objects; and

B. means for detecting an alarm condition and driving the acoustic transducer to cause it to emit audible sound in response to the detected alarm condition.

4. A flow-control system as defined in claim 3 wherein the flow-control system includes a power supply and the alarm condition is the low-output state of the power supply.

5. A flow-control system as defined in claim 4 wherein the power supply is a battery.

6. A flow control system, adapted for connection to an electrically operated valve that operates between open and closed states in response to electrical control signals applied thereto, for applying control signals to the electrically operated valve so as to permit flow in the open state and prevent it in the closed state, the flow-control system comprising:

A. a position sensor for repeatedly monitoring a region for the presence of objects;

B. control means, responsive to the position sensor, for generating electrical control signals and applying them to the electrically operated valve to control its state in accordance with the results of the monitoring; and

C. detection means for detecting an alarm condition and generating audible sound in response to the detected alarm condition, the detection means being responsive to the control means to begin the audible sound only after the control means has closed the valve.