Method of operating drippage prevention system

Patent metadata

Field	Value
Publication number	US-12048944-B2
Application number	US-202017062977-A
Country	US
Kind code	B2
Filing date	Oct 5, 2020
Priority date	May 17, 2017
Publication date	Jul 30, 2024
Grant date	Jul 30, 2024

Abstract

A method of preventing drippage in a fluid dispensing system. The fluid dispensing system includes a first automatic control valve (ACV), an input of the first ACV connected to fluid-source of fluid, the first ACV having positions ranging from fully closed to fully open, and a second ACV, an input of the second ACV being connected to an output of the first ACV, and an output of the second ACV being connected to a nozzle, the second ACV having positions ranging from fully closed to fully open. The method includes generating a first proxy signal representing at least a first indirect measure of a position of the first ACV. The method includes recognizing, based on at least the first proxy signal that a failure state exists in which the first ACV has failed to close. The method includes causing the second ACV to close when the failure state exists.

First claim

What is claimed is:

1. A method of preventing drippage in a liquid dispensing system which has a first automatic control valve (ACV), an input of the first ACV fluidically connected to a source of a liquid to be dispensed, the first ACV having positions ranging from fully closed to fully open, and a second ACV, an input of the second ACV being fluidically connected to an output of the first ACV, and an output of the second ACV being fluidically connected to a nozzle, the second ACV having positions ranging from fully closed to fully open, the method comprising:
generating at least a first proxy signal representing at least a first indirect measure of a position of the first ACV,
recognizing, based on at least the first proxy signal, that a failure state exists in which the first ACV has failed to close; and
causing the second ACV to close when the failure state exists.

2. The method of claim 1 , wherein:
the generating at least a first proxy signal includes:
generating a first pressure signal representing air pressure at a first port of the first ACV; and

the first proxy signal is the first pressure signal.

3. The method of claim 2 , wherein:
the generating at least a first proxy signal further generates at least a second proxy signal representing at least a second indirect measure of the position of the first ACV, and
the generating at least a first proxy signal further includes:
generating a second pressure signal representing air pressure at a second port of the first ACV;

the second proxy signal is the second pressure signal; and
the recognizing that a failure state exists is also based on the second pressure signal.

4. The method of claim 2 , wherein the recognizing that a failure state exists includes:
determining at least a first difference between the at least first proxy signal and a corresponding at least first reference value;
comparing the at least first difference against a deviation threshold; and
determining the failure state to exist when the at least first difference exceeds the deviation threshold.

5. A method of operating a drippage prevention system, the method comprising:
instructing a first automatic control valve (ACV) to fully close, wherein an input of the first ACV is fluidly connected to a source of a liquid, and the first ACV has positions ranging from fully closed to fully open;
detecting a position of the first ACV;
determining whether the position of the first ACV is fully closed; and
instructing a second ACV to fully close in response to a determination that the first ACV is not fully closed following instructing the first ACV to fully close, wherein an input of the second ACV being fluidly connected to an output of the first ACV, an output of the second ACV being fluidly connected to a nozzle, and the second ACV has positions ranging from fully closed to fully open, and closing the second ACV reduces a volume of the drippage prevention system downstream of the first ACV.

6. The method of claim 5 , wherein instructing the first ACV to fully close comprises transmitting an instruction to a pneumatically-controlled valve.

7. The method of claim 5 , further comprising:
detecting a temperature at the input of the first ACV; and
instructing the second ACV to fully close based also on the detected temperature.

8. The method of claim 5 , further comprising :
detecting an air pressure at an output of the first ACV; and
instructing the second ACV to fully close based also on the detected air pressure.

9. The method of claim 5 , further comprising:
detecting a temperature at an output of the first ACV; and
instructing the second ACV to fully close based also on the detected temperature.

10. The method of claim 5 , wherein detecting the position of the first ACV comprises indirectly detecting the position of the first ACV.

11. The method of claim 10 , wherein indirectly detecting the position of the first ACV comprises detecting whether the liquid is dispensed from the nozzle.

12. The method of claim 11 , wherein detecting whether the liquid is disposed from the nozzle comprises using an optical sensing arrangement.

13. A method of operating a drippage prevention system, the method comprising:
controlling a position of a first automatic control valve (ACV), wherein an input of the first ACV is fluidly connected to a source of a liquid, and the first ACV has positions ranging from fully closed to fully open;
controlling a position of a second ACV, wherein an input of the second ACV being fluidly connected to an output of the first ACV, an output of the second ACV being fluidly connected to a nozzle, and the second ACV has positions ranging from fully closed to fully open;
detecting a position of the first ACV;
comparing the detected position of the first ACV with the controlled position of the first ACV;
generating an error signal in response to a determination that the detected position is different from the controlled position; and
instructing the second ACV to fully close in response to generating the error signal.

14. The method of claim 13 , wherein detecting the position of the first ACV comprises indirectly detecting the position of the first ACV.

15. The method of claim 13 , wherein detecting the position of the first ACV comprises determining whether the liquid is exiting the nozzle.

16. The method of claim 13 , wherein fully closing the second ACV reduces a volume of the drippage prevention system downstream of the first ACV.

17. The method of claim 13 , further comprising maintaining the second ACV in the fully open position prior to generating the error signal.

18. The method of claim 13 , further comprising determining the detected position is different from the controlled position based on a deviation threshold.

19. The method of claim 13 , wherein detecting the position of the first ACV comprises using an optical sensing arrangement.

20. The method of claim 13 , wherein controlling the position of the first ACV comprises controlling a pneumatically-controlled valve.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Wang Chien-Hung
• Lin Chun-Chih
• Liao Chi-Hung
• Lee Yung-Yao
• Cheng wei chang

Classifications

• H10P72/0448

  Apparatus for applying a liquid, a resin, an ink or the like · CPC title

• H10P72/0402

  Apparatus for fluid treatment (H10P72/0441, H10P72/0448 take precedence) · CPC title

• G03F7/162

  Coating on a rotating support, e.g. using a whirler or a spinner · CPC title

• F16K23/00

  Valves for preventing drip from nozzles · CPC title

• F16K7/126

  the seat being formed on a rib perpendicular to the fluid line · CPC title