Device for applying electrostatically charged lubricant

• US 5,176,321 A
• Filed: 11/12/1991
• Issued: 01/05/1993
• Est. Priority Date: 11/12/1991
• Status: Expired due to Fees

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Doherty, James E.
• Primary Examiner(s): Kashnikow, Andres
• Assistant Examiner(s): GRANT, WILLIAM ALEXANDER
• Application Number:
  US07/789,900
• Time in Patent Office: 420 Days
• Field of Search: 239/3, 239/690, 239/690.1, 239/704, 239/708
• US Class Current: 239/3
• CPC Class Codes: B05B 5/0255 spraying and depositing by electrostatic forces only
• CPC Class Codes: B05B 5/043 using induction-charging
• CPC Class Codes: B23Q 11/10 Arrangements for cooling or lubricating tools or work incorporated in tools, see the relevant subclass for the tool , e.g. B23B27/10, B23B51/06, B23C5/28, B23D77/006; for circular saw blades B23D59/02, for cooling grinding surfaces B24B55/02
• CPC Class Codes: F16N 15/00 Lubrication with substances other than oil or grease; Lubrication characterised by the use of particular lubricants in particular apparatus or conditions F16N17/00 takes precedence; lubricating compositions, selection of particular substances as lubricants in general C10M
• CPC Class Codes: F16N 7/00 Arrangements for supplying oil or unspecified lubricant from a stationary reservoir or the equivalent in or on the machine or member to be lubricated axle-box lubrication for railway rolling-stock B61F17/00

Abstract

A device for electrostatically charging and dispensing a high resistivity cutting lubricant to a workpiece includes a source of high resistivity cutting lubricant and a capillary tube having an entrant end in fluid communication with the high resistivity cutting lubricant and a tapered discharge end forming a sharp point. A high voltage power supply is used for generating a high voltage of less than 5,000 volts d.c. The power supply has a positive terminal and a negative terminal. A high voltage electrode has its one end connected to the positive terminal of the power supply and has its other end operatively coupled to the discharge end of the capillary tube. A nearby grounded electrode is disposed in a spaced-apart relationship from the discharge end of the capillary tube so as to create a high electric field therebetween for electrostatically charging the lubricant. The lubricant is atomized and projected in the form of a steady and controlled stream of charged particles away from the discharge end of the capillary tube to within the vicinity of or all the way to the workpiece before the stream of charged particles bursts into an aerosol cloud of charged droplets for dispensing them onto the workpiece.

Claims

1. A device for electrostatically charging and dispensing a high resistivity cutting lubricant onto a workpiece comprising:

a source of high resistivity cutting lubricant;

a capillary tube having an entrant end in fluid communication with said high resistivity cutting lubricant and a tapered discharge end forming a sharp point;

a high voltage power supply for generating a high voltage of less than 5,000 volts d.c., said power supply having a positive terminal and a negative terminal;

a high voltage electrode having its one end connected to one of the positive and negative terminals of said power supply and having its other end operatively coupled to the discharge end of said capillary tube; and

a nearby grounded electrode disposed in a spaced-apart relationship from the discharge end of said capillary tube so as to create a high electric field therebetween for electrostatically charging said lubricant,

whereby said lubricant is atomized and projected in the form of a steady and controlled stream of charged particles away from the discharge end of said capillary tube to within the vicinity of or all the way to the workpiece before the stream of charged particles bursts into an aerosol cloud of charged droplets for dispensing them onto the workpiece.

2. A device as claimed in claim 1, wherein said lubricant comprises a high carbon, long carbon chain, fatty alcohol lubricant.

3. A device as claimed in claim 1, wherein said lubricant comprises Boelube brand lubricant.

4. A device as claimed in claim 1, wherein said lubricant has a resistivity greater than 10⁸ Ohm-meters.

5. A device as claimed in claim 1, wherein said grounded electrode comprises a wire loop surrounding the discharge end of said capillary tube and being positioned behind it.

6. A device as claimed in claim 5, wherein said grounded electrode is spaced less than one-half inch from the discharge end of said capillary tube.

7. A device as claimed in claim 1, wherein said high voltage is approximately 3,000 volts d.c.

8. A device as claimed in claim 1, wherein said capillary tube comprises a metallic hypodermic needle.

10. A device as claimed in claim 1, wherein said high voltage power supply comprises an A.C. power supply which converts an A.C. voltage to generate said d.c. high voltage.

11. A device as claimed in claim 1, wherein said high voltage power supply comprises a D.C. power supply which includes a low d.c. battery voltage which is converted to a high A.C. voltage and a rectifier/multiplier for converting the high A.C. voltage to said d.c. high voltage.

9. A device as claimed in claim wherein said capillary tube is formed of a non-metallic material with said high voltage electrode projecting slightly from its end.

12. A method for electrostatically charging and dispensing a high resistivity cutting lubricant onto a workpiece, comprising the steps of:

providing a source of high resistivity cutting lubricant;

passing said high resistivity lubricant through a capillary tube having a tapered discharge end forming a sharp point;

applying a high voltage of less than 5,000 volts d.c. to the discharge end of said capillary tube;

arranging a nearby grounded electrode in a spaced-apart relationship from the discharge end of said capillary tube so as to create a high electric field therebetween for electrostatically charging said lubricant; and

atomizing and projecting said lubricant in the form of a steady and controlled stream of charged particles away from the discharge end of said capillary tube to within the vicinity of or all the way to the workpiece before the stream of charged particles bursts into an aerosol cloud of charged droplets for dispensing them onto the workpiece.