US3421872A

US3421872A - Electrical contact cleaner composition

Info

Publication number: US3421872A
Application number: US498102A
Authority: US
Inventors: Clarence Harry Anglin
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-10-19
Filing date: 1965-10-19
Publication date: 1969-01-14
Anticipated expiration: 1986-01-14

Description

United States Patent 3,421,872 ELECTRICAL CONTACT CLEANER COMPOSITION Clarence Harry Anglin, 1122 Corn Tassel Trail, Martinsville, Va. 24112 No Drawing. Filed Oct. 19, 1965, Ser. No. 498,102 US. Cl. 51-304 2. Claims Int. Cl. C09g 1/02 ABSTRACT OF THE DISCLOSURE A cleaning and polishing composition for electrical contacts and the like comprised of a mixture of powdered graphite, pumice and bodied grease of selected viscosity.

This invention relates to an electrical contact cleaner composition and more specifically to a method and composition for reducing the electrical resistance of electrical contacts, switches, controls, television tuner contacts and the like.

It is well known that the flow of current through electrical contacts produces oxidation and other deleterious effects upon the surface of the contacts particularly when the contacts are opened and closed during repeated operations. Certain contacts are known to acquire heavier depositions of oxides and other foreign matter than other contacts, the amount of deposition being determined by the magnitude of the current, the voltage, and the inductive or capacitive effects of the apparatus in circuit with the contacts. As repeated operations cause the depositions to build up upon the surface of the contacts, the impedance across the contacts may increase to a value wherein the apparatus in circuit with the contacts becomes inoperative or at least performs at a greatly reduced efficiency. A particular environment in which electrical contact resistance may prove to be highly undesirable is in the television tuner incorporated as part of the circuitry in the well-known television receiver. In tuner contacts of this and other types, a plurality of rotary contacts are caused to engage a plurality of stationary contacts each time the channel selector is rotated. Accordingly, it becomes an almost hopeless undertaking to remove the foreign deposits acquired by the many contacts by conventional means.

Heretofore, it has been the common practice to manually remove the foreign deposits from the contacts through the utilization of a sharp instrument or other device by scraping the contacts to free the foreign matter and thereby reduce the contact resistance and thus attempt to provide substantially zero resistance across the contacts. This, however, is a hit-or-miss approach in that the contacts themselves may be damaged during the manual removal process so that the contacts continue to register a high impedance to current flow.

Other means are known which have achieved a small degree of success for removing the foreign matter deposited upon electrical contacts, such as the application of carbon tetrachloride to the contacts. However, this procedure has been found to be highly unsatisfactory in that once the solution has been applied to the contacts, the contacts immediately continue to build up deposits upon subsequent operations.

Accordingly, it becomes highly desirable that a method and composition be found which will alleviate the foregoing problems and at the same time continue to maintain the contacts in a zero resistance state throughout normal operations.

Accordingly, it is the principal object of the present invention to improve the operation of current carrying contacts.

It is a further object of the present invention to reduce the contact resistance of electrical contacts.

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It is a still further object of the present invention to provide a method and composition for improving the operation of current carrying contacts such as those found in television tuners and the like.

It is a still further object of the present invention to provide a method and composition for improving the operation of current carrying contacts by once reducing the electrical contact resistance thereof and subsequently maintaining the contacts at a minimum contact resistance throughout their life in normal operation.

The present invention relates to a composition of graphite, pumice and grease which when applied to the contacts will clean the contacts upon subsequent engagement and disengagement of the contacts. The composition does not flow at the usual temperatures encountered so that it remains for continuous subsequent cleaning operations. Further, the method of employing the novel composition for reducing the contact resistance is also envisioned.

In the novel composition herein set forth, graphite of a suitable grade such as micro-fine is mixed with powdered pumice and grease. The grease may be one such as a conventional lubricant mineral oil thickened by 5% to 40% inorganic gels such as silica gel, clays or the like, or a grease compounded of oils plus 5% to 40% fatty acid soaps such as sodium, potassium, etc. The grease is viscous and will not flow at the ordinary ambient temperatures encountered.

A formula for a composition such as that set forth made in accordance with the principles of the present invention and establishing the range of the constituents is as follows:

I Constituent: Percentage by weight Graphite 2-8 Pumice 25-40 Grease 40 60 It will be readily understood that the above formula may be varied appreciably. The graphite is employed as a cleaning and conducting agent; the pumice acts as a polishing and gelling agent; and, the grease serves as a lubricant and gelling agent. The three ingredients are mixed together thoroughly in a mixer and packaged in suitable dispensing type tubes or other containers.

Although the foregoing formula establishes the range of the constituents, perhaps the preferred formula would be as follows:

Constituent: Percentage by weight (approx) Graphite 6 Pumice 34 Grease 60 After the composition has been thoroughly mixed, and packaged in a suitable container, it is now ready for use. As an illustrative embodiment of the method for utilizing the composition, the cleaning of the contacts of a television tuner is selected since tuner contacts being large in number, are highly susceptible to foreign deposits and as such, the foreign deposits quickly produce malfunctions and oscillation of the sensitive circuits coupled thereto. Although the cleaning of television tuner contacts has been selected as an illustrative embodiment, it will be readily apparent to those skilled in the art as to the practice of the invention wherein other contacts, switches, controls, etc. are to be cleaned.

A small quantity of the composition is applied to a row of the tuner contacts when a standard coil tuner is to be employed and to the wafer disk when arotary disk type tuner is used. Next, the channel selector is rotated approximately so that a wiping action is effected between the movable and stationary contacts. Next, the channel selector may be rotated in the opposite direction to complete or at least commence the cleaning method. Alternately, a small quantity of the composition may again be applied to the contacts after the first rotation of the channel selector followed by rotation of the channel selector in the opposite direction. The rotation of the channel selector which produces rotation of the contacts in both directions deposits the cleaning, polishing and lubricating composition on the main contacts. Due to the gelling action of the pumice and grease and also due to the high heat resistance of the grease, the composition will remain on the main contacts and will continue to clean, polish and lubricate the contacts each time the contacts are rotated. In normal operation, no further applications of the composition are required since as set forth, the composition remains on the contacts and continues to cause the contact resistance to remain at substantially zero.

Thus, the present invention may be embodied in other specific forms without departing from the spirit and the essential characteristics of the invention. The present embodiment is, therefore, to be considered in all respects as illustrative and the scope of the invention being indicated by the appended claims rather than the foregoing description, and all changes which come within the meaning and range of the equivalency of the claims are, therefore, intended to be embraced therein.

I claim:

1. An electrical contact cleaner composition comprising a viscous mixture of powdered graphite in a weight range of about 2% to 8%, powdered pumice in a weight range of about 25% to 40%, and bodied grease in a weight range of about 40% to 60%, said composition being nonfluent at ambient atmospheric temperatures.

ZfAn electrical contact cleaner composition comprising a viscous mixture of about 6% by weight of powdered graphite, about 34% by weight of powdered pumice, and about 60% by weight of bodied grease, said composition being non-fluent at ambient atmospheric temperatures.

References Cited UNITED STATES PATENTS 1,003,983 9/1911 Callahan 51--304 1,195,246 8/1916 McCormick 51-295 2,185,262 1/1940 Lupo 51-304 2,417,800 3/1947 Weisser 51-304 2,649,362 8/1953 Fowler 51304 DONALD J. ARNOLD, Primary Examiner.

US. Cl. X.R.