Control method and apparatus for dispensing high-quality drops of high-viscosity materials

Patent metadata

Field	Value
Publication number	US-10099238-B2
Application number	US-201614996060-A
Country	US
Kind code	B2
Filing date	Jan 14, 2016
Priority date	Jan 19, 2012
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

This invention concerns a method and apparatus for dispensing minute quantities of fluids and more particularly rapidly dispensing highly precise and repeatable, minute amounts of viscous fluids in a non-contact manner. An impacting element is impacted against a hardened insert on a flexible diaphragm to deflect the insert into a jetting chamber and against an outlet orifice in the jetting chamber. The movement of the diaphragm and insert force viscous fluid in the chamber through the outlet orifice and the impact jets that fluid from the outlet orifice, with the impact force being adjusted to jet the fluid from the orifice in a single drop.

First claim

What is claimed is:

1. A method of dispensing high-quality minute quantities of a viscous material from an outlet of a jetting orifice by an expelling mechanism that deforms a flexible diaphragm into a jetting chamber that is in fluid communication with the jetting orifice, with the diaphragm forming a portion of the jetting chamber, the method comprising:
forcing a predetermined amount of the viscous fluid through an inlet channel and into the jetting chamber;
moving an impact element through a predetermined distance corresponding to an impact gap;
impacting the flexible diaphragm with the impact element;
deforming the flexible diaphragm into the jetting chamber an additional distance sufficient to block the fluid flow into the orifice and expel material from the outlet;
measuring the distance the impact element travels before contacting the diaphragm, from a release position that is separated from diaphragm;
and adjusting the predetermined distance the impact element moves and varying the force with which the impact element impacts the diaphragm.

2. The method of claim 1 , further comprising measuring the distance the impact element moves at multiple points in time along its motion.

3. The method of claim 1 , further comprising determining a preferred velocity of the impact element and adjusting the predetermined distance to achieve the preferred velocity.

4. The method of claim 1 , further comprising adjusting the preferred impact distance with a programmable motion element.

5. The method of claim 1 , further comprising determining a preferred velocity of the impact element and adjusting the acceleration of the impact element to achieve the preferred velocity.

6. The method of claim 1 , further comprising placing an electric motor in driving communication with the impact element to vary the impact velocity.

7. The method of claim 1 , wherein the moving step uses pressure and further comprising adjusting the air pressure to vary the impact velocity of the impact element.

8. The method of claim 1 , wherein the diaphragm further comprises an insert made of a material harder than the diaphragm and which insert is located so as to be impacted by the impacting element, and further comprising the step of impacting the jetting outlet with the insert.

9. A method of claim 1 , wherein the expelled material forms a drop of material and further comprising inspecting the quality of the expelled drop of material.

10. The method of claim 1 , wherein the diaphragm further comprises an insert made of a material harder than the diaphragm and which insert is located so as to be impacted by the impacting element, and further comprising resiliently urging the insert against the jetting outlet to block flow into the orifice when electrical power to the expelling mechanism is shut off.

11. A method of dispensing high-quality minute quantities of a viscous material from an outlet of a jetting orifice by an expelling mechanism that deforms a flexible diaphragm into a jetting chamber that is in fluid communication with the jetting orifice, the method comprising:
forcing the viscous fluid into the jetting chamber through an inlet channel;
deforming the flexible diaphragm into the jetting chamber a distance sufficient to block the fluid flow out the orifice;
moving an impact element through a predetermined distance;
impacting the flexible diaphragm with the impact element and ejecting the viscous material from the outlet; and;
adjusting at least one of the predetermined distance or the velocity of the impact element and varying the force with which the impact element impacts the diaphragm.

12. The method of claim 11 , further comprising using a pneumatic cylinder to move the impact element and adjusting the pressure to the cylinder to vary the impact of the impacting element with the diaphragm.

13. The method of claim 11 , further comprising using an electric coil to move the impact element and adjusting the current to the coil to vary the impact of the impacting element with the diaphragm.

14. The method of claim 11 , further comprising using an electric solenoid to move the impact element and adjusting the current to the solenoid to vary the impact of the impacting element with the diaphragm.

15. The method of claim 11 , further comprising using an electric motor to move the impact element and adjusting the current to the motor to vary the impact of the impacting element with the diaphragm.

16. The method of claim 11 , wherein the diaphragm further comprises an insert made of a material harder than the diaphragm and which insert is located so as to be impacted by the impacting element, and further comprising the step of impacting the jetting outlet with the a portion of the insert.

17. The method of claim 11 , further comprising resiliently urging the insert against the jetting outlet to block flow into the orifice when electrical power to the expelling mechanism is shut off.

18. The method of claim 11 , further comprising resiliently urging the flexible diaphragm into its pre-impact position.

19. A method of dispensing quality minute quantities of a viscous material from an outlet of a jetting orifice of a jetting chamber by an expelling mechanism, comprising:
forcing a predetermined amount of the viscous fluid through an inlet channel and into the jetting chamber;
moving an impact element through a predetermined distance;
impacting the flexible diaphragm with the impact element at an impact velocity;
deforming the flexible diaphragm into the jetting chamber a distance sufficient to block the fluid flow into the orifice and expel a drop of material from the outlet;
inspecting the quality of the expelled drop of material; and
adjusting the impact element to vary the momentum with which the impact element impacts the diaphragm.

20. The method of claim 19 , further comprising adjusting the preferred impact distance.

21. The method of claim 19 , further comprising adjusting the preferred impact distance with a programmable motion element.

22. The method of claim 19 , further comprising placing an electric motor in driving communication with the impact element to vary the impact velocity.

23. The method of claim 19 , further comprising driving the impact element with air pressure and adjusting the air pressure used to drive the impact element to vary the impact velocity.

24. A method of claim 19 , wherein the expelled drop forms a single drop of material on the substrate with no satellites.

25. The method of claim 19 , wherein the diaphragm further comprises an insert made of a material harder than the diaphragm and which insert is located so as to be impacted by the impacting element, and further comprising resiliently urging the insert against the jetting orifice to block flow into the orifice when electrical power to the expelling mechanism is shut off.

26. The method of claim 1 , further comprising placing a piezoelectric actuator in driving communication with the impact element to vary the impact velocity.

27. The method of claim 11 , further comprising using a piezoelectric actuator to move the impact element and adjusting the current to the motor to vary the impact of the impacting element with the diaphragm.

28. The method of claim 19 , further comprising placing a piezoelectric actuator in driving communication with the impact element to vary the impact velocity

Assignees

• Graco Minnesota Inc

Inventors

• Ciardella Robert L
• La Duong
• Chin Wai Ching Bessie

Classifications

• B41J2/045

  by pressure, e.g. electromechanical transducers · CPC title

• B05C11/1034

  specially designed for conducting intermittent application of small quantities, e.g. drops, of coating material (B05C5/0225, B05C11/1026 take precedence) · CPC title

• B05B17/04 Primary

  operating with special methods · CPC title

• B05B1/02

  designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, {or having an outlet of particular shape}(B05B1/26, B05B1/28, B05B1/34 take precedence) · CPC title

• B41J2/04 Primary

  generating single droplets or particles on demand · CPC title