Apparatus and method for modifying operation of an electric gun driver

• US 7,289,878 B1
• Filed: 05/15/2000
• Issued: 10/30/2007
• Est. Priority Date: 05/15/2000
• Status: Expired due to Fees

• Current Assignee: Nordson Corporation
• Original Assignee: Nordson Corporation
• Inventors: Saidman, Laurence B., Estelle, Peter, Zgonc, David, Means, Scott
• Primary Examiner(s): Mackey; Patrick
• Assistant Examiner(s): SHAPIRO, JEFFREY ALAN
• Application Number:
  US09/571,677
• Time in Patent Office: 2,724 Days
• Field of Search: 700/233, 700/241, 222/1, 222/146, 222/5
• US Class Current: 700/233
• CPC Class Codes: B05C 11/1013 responsive to flow or pressure of liquid or other fluent material B05C11/101 takes precedence; control of flow in general G05D7/00; control of fluid pressure in general G05D16/00
• CPC Class Codes: B05C 11/1044 Apparatus or installations for supplying liquid or other fluent material to several applying apparatus or several dispensing outlets, e.g. to several extrusion nozzles
• CPC Class Codes: B05C 5/02 the liquid or other fluent material being discharged through an outlet orifice by pressure, e.g. from an outlet device in contact or almost in contact, with the work

Abstract

A method and apparatus for providing adjustment of current-related dispensing parameters in an electric dispensing gun. A control circuit receives user-selected inputs corresponding to dispensing parameters of the gun and converts those inputs into digital signals. The digital signals are applied to a digitally programmable driver circuit associated with the liquid dispensing gun to control at least some of the dispensing parameters of the gun. Diagnostic information pertinent to the operation of the dispensing gun is provided to the operator for evaluation and adjustment.

Claims

1. A liquid dispensing system operable by a user for dispensing a liquid onto a substrate, comprising:

at least one solenoid actuated, non-pneumatic, liquid dispensing gun having an electromagnetic coil, a dispensing orifice and a dispensing valve stem movable relative to said dispensing orifice, said coil being operable by a current waveform comprising a higher magnitude initial peak current followed by a lower magnitude hold current;

an input device operable by a user to enter application data representing operating conditions of a liquid dispensing application;

a control circuit connected to said input device and operable to receive said application data representing operating conditions of a liquid dispensing application, said control circuit having one of a software algorithm and a look-up table configured to process said application data and generate digital signals that define desired peak and hold current values corresponding to said application data; and

a digitally programmable driver circuit connected between said control circuit and said electromagnetic coil, said digitally programmable driver circuit comprising a non-volatile memory for storing said desired peak and hold current values, said digitally programmable driver circuit operable to generate a desired current waveform in response to said desired peak and hold current values and apply said desired current waveform to said electromagnetic coil for moving said dispensing valve stem toward and away from said dispensing orifice.

2. The liquid dispensing system of claim 1 wherein said application data comprising at least one of a liquid viscosity, a liquid temperature, a dispensing pattern and pattern definition data, a line speed, an identification of a dispensing gun used, or a combination thereof.

3. The liquid dispensing system of claim 1 wherein said input device comprises a graphical user interface and said control circuit is operable to prompt a user to enter said application data.

4. The liquid dispensing system of claim 1 wherein said digitally programmable driver circuit comprises an input for receiving a pulse commanding the digitally programmable driver circuit to supply the desired current waveform to the electromagnetic coil independent of the control circuit.

5. The liquid dispensing system of claim 1 wherein said control circuit is detachable from said digitally programmable driver circuit and said digitally programmable driver circuit continues to be operable to generate said desired current waveform.

6. The liquid dispensing system of claim 1 wherein said digitally programmable driver circuit comprises at least one digital potentiometer.

7. The liquid dispensing system of claim 1 wherein said digitally programmable driver circuit comprises at least one digital-to-analog converter.

8. The liquid dispensing system of claim 1 further comprising:

a first electrically operated, non-pneumatic, liquid dispensing gun comprising a first electromagnetic coil, a first dispensing orifice and a first dispensing valve stem movable relative to said first dispensing orifice; and

a second electrically operated, non-pneumatic, liquid dispensing gun comprising a second electromagnetic coil, a second dispensing orifice and a second valve stem movable relative to said second dispensing orifice, said second electromagnetic coil being connected in a series circuit with said first electromagnetic coil and said series circuit being connected to said digitally programmable driver circuit.

9. The liquid dispensing system of claim 1 wherein said input device comprises a first input device operable by a user to select first data identifying one of a plurality of models of dispensing guns and said control circuit operable to generate said digital signals that define desired peak and hold current values in response to said first data.

10. The liquid dispensing system of claim 1 wherein said input device comprises a second input device operable by a user to select second data identifying one of a plurality of viscosities of the liquid, said control circuit operable to generate said digital signals defining desired peak and hold current values in response to said second data.

11. The liquid dispensing system of claim 1 wherein said input device comprises:

a first input device operable by a user to select first data identifying one of a plurality of models of dispensing guns; and

a second input device operable by a user to select second data identifying one of a plurality of viscosities of the liquid, said control circuit operable to generate said digital signals defining desired peak and hold current values in response to both said first data and said second data.

12. A method of dispensing liquid from a liquid dispensing system having at least one solenoid-actuated, non-pneumatic, liquid dispensing gun including an electromagnetic coil, a dispensing orifice, a dispensing valve stem movable relative to the dispensing orifice, the electromagnetic coil being operable by a current waveform comprising a higher magnitude initial peak current followed by a lower magnitude hold current, the method comprising:

entering application data representing operating conditions of a liquid dispensing application;

generating with a control circuit digital signals defining desired peak and hold current values of a desired current waveform in response to the application data;

storing the digital signals in a non-volatile memory in a digitally programmable driver circuit connected between the control circuit and the electromagnetic coil;

producing the desired current waveform in response to the desired peak and hold current values stored in the digitally programmable driver circuit; and

energizing the electromagnetic coil with the desired current waveform to move the dispensing valve stem toward and away from the dispensing orifice to dispense liquid from the liquid dispensing gun.

13. The method of claim 12 wherein entering application data further comprises entering application data comprising at least one of a liquid viscosity, a liquid temperature, a dispensing pattern and pattern definition data, a line speed, an identification of a dispensing gun used, or a combination thereof.

14. The method of claim 12 wherein prior to entering application data, the method comprises prompting a user to enter said application data by operation of the control circuit.

15. The method of claim 12 wherein prior to producing the desired current waveform, the method comprises receiving independent of the control circuit a signal commanding the digitally programmable driver circuit to produce the desired waveform.

16. The method of claim 12 wherein after storing the digital signals in the non-volatile memory, the method further comprises detaching and removing the control circuit from the digitally programmable driver circuit and the digitally programmable driver circuit continuing to be operable to generate the desired current waveform.

17. The method of claim 12 wherein entering application data comprises selecting first data identifying one of a plurality of models of dispensing guns and said control circuit operable to generate said digital signals that define desired peak and hold current values in response to said first data.

18. The method of claim 12 wherein entering application data comprises selecting second data identifying one of a plurality of viscosities of the liquid, said control circuit operable to generate said digital signals defining desired peak and hold current values in response to said second data.

19. The method of claim 12 wherein entering application data comprises:

selecting first data identifying one of a plurality of models of dispensing guns; and

selecting second data identifying one of a plurality of viscosities of the liquid, said control circuit operable to generate said digital signals defining desired peak and hold current values in response to both said first data and said second data.