US3620839A - Lubrication of contact surfaces - Google Patents

Lubrication of contact surfaces Download PDF

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US3620839A
US3620839A US845478A US3620839DA US3620839A US 3620839 A US3620839 A US 3620839A US 845478 A US845478 A US 845478A US 3620839D A US3620839D A US 3620839DA US 3620839 A US3620839 A US 3620839A
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Prior art keywords
particles
contact
graphite
shear
gold
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US845478A
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Rayond James Geckle
Larry John Wilt
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TE Connectivity Corp
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AMP Inc
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R43/00—Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00—Contacts
    • H01H1/60—Auxiliary means structurally associated with the switch for cleaning or lubricating contact-making surfaces
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
    • H01R13/02—Contact members
    • H01R13/03—Contact members characterised by the material, e.g. plating, or coating materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R43/00—Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors
    • H01R43/16—Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors for manufacturing contact members, e.g. by punching and by bending
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/22—Secondary treatment of printed circuits
    • H05K3/24—Reinforcing the conductive pattern
    • H05K3/245—Reinforcing conductive patterns made by printing techniques or by other techniques for applying conductive pastes, inks or powders; Reinforcing other conductive patterns by such techniques
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
    • Y10T428/24893—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] including particulate material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
    • Y10T428/24917—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] including metal layer
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]

Definitions

  • This invention relates to lubrication of surfaces which move relatively over each other and particularly to the surfaces of electrical contact members.
  • a wide variety of electrical devices having contact surfaces are used under greatly varying conditions as regards voltages and currents. Under many circumstances, satisfactory electrical contact can be achieved at the interface of the contact members without special preparation or maintenance of their surfaces; for example, a heavyduty electrical switch intended for high voltage, high current applications can be made of unplated copper and the switch parts can be designed such that extremely high contact pressure is imposed when the contact surfaces are engaged with each other. Under such circumstances, the contact surfaces will clean themselves as they move over each other during opening and closing of the switch. Furthermore, because of the high voltages involved, minor amounts of oxide or other foreign matter on the contact surfaces will not interfere with the function of the switch. If desired, the contact surfaces can be manually cleaned and they may be lubricated to facilitate opening and closing of the switch although such lubrication is not needed to prolong switch life or for any other reason.
  • contact devices having sliding contact surfaces are used for low-voltage low-current applications, such as the contact terminals used in printed circuit board connectors and the pin and socket type contact terminals used in multicontact connectors.
  • Contact devices of these types may be used in relatively complex electronic equipment and often must be of small size because of the vast numbers of contacts required in a given volume. These contacts frequently carry very low-voltage low-current signals and must possess an ex tremely high degree of reliability for the reason that the functioning of the equipment in which they are installed depends upon the operation of large numbers of the terminals.
  • dry circuit conditions is commonly used in the electronics industry to specify the performance requirements of contact terminals designed for extremely low-voltage, lowcurrent applications where a high degree of reliability is necessary and where only a limited millivolt drop can be tolerated at the electrical interface.
  • the achievement of electrical connectors capable of operating under dry circuit conditions has provided a continuing challenge to the ingenuity of the design engineer, who is charged with the responsibility of producing an extremely small terminal having a high degree of physical reliability, and the metallurgist, who must provide surfaces on the contacts which will meet the performance requirements of the industry as regards conducting ability, wear resistance and resistance to the formation of oxides.
  • the high standards of performance required of first quality small electrical contact terminals are often achieved by plating the surfaces of the contacts with gold or other noble metal.
  • Gold is a preferred contact material because of its extremely high resistance to corrosion and its excellent electrical conductivity.
  • pure (unalloyed) gold is an ideal plating for electrical contact terminals because of the fact that pure gold has better electrical conductivity than any possible gold alloy containing a minor amount of another metal and because of the additional fact that pure gold is relatively ductile so that when two contact terminals whose surfaces are plated with pure gold are engaged with each other, the surface platings will plastically deform as the parts are engaged and conform to each other to provide an extensive interfacial contact area for the passage of the electric current.
  • the ductility of gold is, however, a decided disadvantage for disengageable electrical contact members from a wear standpoint.
  • Ductile or soft gold is rapidly worn away from a sliding contact surface so that the base metal or underplating is exposed, which condition leads to the formation of oxide films and degradation of the current carrying ability of the terminal.
  • Such rapid wear and degradation is intolerable in multicontact connectors which must be repeatedly engaged with, and disengaged from each other.
  • the particles of graphite are applied to the contact surface in a manner such that each particle is under a shear stress at the instant of application.
  • the particles therefore undergo basal shear at the instant of application and each particle, after arrival at the surface, comprises at least two graphite platelets, one of which overlaps the other. It has been found that if about to percent of the area of the contact surface is covered with such particles, optimum lubrication of the contact surfaces will be achieved and that the wear or galling of the surfaces on engagement will be substantially reduced. As a consequence, a plating of a given thickness will be rendered capable of withstanding an increased number of wear cycles (that is engagements with a complimentary surface) prior to breakdown of the surface.
  • the particles adhere to the contact surface with a high degree of tenacity and appear to be bonded to the surface.
  • the particles cannot be removed by ultrasonic cleaning with conventional solvents or degreases nor will they be disturbed by any physical means, such as handling, which does not result in removal of the gold plating itself.
  • the particles can be barely seen with the aid of an optical microscope and can be studied in detail only by the methods of electron microscopy. 7
  • FIG. 1 is a schematic representation of the manner in which graphite particles are applied to a contact surface.
  • FIG. 2 is an electron photomicrograph of an individual particle on a surface.
  • FIG. 3 is a perspective view of an apparatus for applying graphite to a contact surface in accordance with the invention.
  • FIG. 3A is a sectional view of the chamber of apparatus of FIG. 3.
  • FIG. 4 is a schematic sectional side view of two contact surfaces illustrating the manner in which the surfaces are lubricated by graphite particles.
  • a lubricating effect in accordance with the invention can advantageously be provided on the contact surface 10 of a conventional printed circuit board contact terminal 8 (FIG. 3) which is adapted to be crimped onto a wire.
  • Contacts of the type shown at 8 are ordinarily mounted in insulating housings which are adapted to be engaged with printed circuit boards so that the individual contact terminals will engage the conductors of the board. Terminals of this type are frequently plated with thin platings of gold and the connectors must be repeatedly engaged with and disengaged from a printed circuit board so that a lubrication affect, which would prolong the life of the plating and/or permit use of a softer or thinner gold plating, would be desirable.
  • the particle 4 of FIG. 2 has an average transverse dimension (extending substantially parallel to the plane of the surface) of about 6 microns and comprises two or more layers 5, each of which comprises a graphite platelet, one of which overlaps the other.
  • the two platelets shown in FIG. 2 were originally in alignment with each other but at the time the particle was deposited on the surface, shear occurred between two sections of the particle so that one section was displaced laterally with respect to the other section to yield the structure of FIG. 2.
  • shear is used above in the sense of its definition to the physical metallurgist, namely a type of deformation in which parallel planes in metalcrystals slide so as to retain their parallel relation to one another, resulting in block movement" (Metals Handbook, I948 Edition, American Society for Metals, Cleveland, Ohio).
  • the height or elevation of a particle 4 of FIG. 2 above the surface cannot be determined with a high degree of accuracy because of the extremely small size of the particles and because of the fact that roughness of the surface is greater than the particle size by order of magnitude.
  • the altitude variations of even a smooth surface i.e. the elevation differences between the peaks and valleys of the surface undulations
  • a relatively smooth surface will have altitude variations of about 10.00001 inches (500 A.) while the height of the particles has been determined to be in the range of about 60 to A. as explained below.
  • Particle height measurement have been made by a shadow replica technique involving the application of a coating of plastic to a graphitized glass surface and the peeling of theplastic replica from the surface in a manner such that the graphite particles adhere to the plastic.
  • Compacted graphite particles can be removed from a glass surface for the reason that they do not bond, or bond only slightly, to glass.
  • a thin film of metallic platinum is deposited from a point source at a known angle to the plastic replica surface and measurements are made of the shadows cast by the adhering graphite particles, that is, regions not covered with platinum. These measurements indicate that the particles have a height of approximately 100 A. However, this FIG. should be taken as an indication of the order of magnitude only and not as a precise measurement.
  • each particle contains a multiplicity of platelets so that further shear of the platelets of the particle will take place when the contact surface is rubbed over a mating contact surface.
  • the distance between the basal ⁇ 0001 ⁇ crystal plane of a hexagonal graphite crystal plane is 3.40 A., and platelets with a thickness of 100 A. would therefore be capable of undergoing further basal plane shear until they have been divided into a limited number of about 30 atomic platelets.
  • the individual particles appear to be securely bonded to the contact surface to the extent that removal of the particle is virtually impossible by any process which does not damage or destroy the surface itself.
  • the tenacity of the bond is demonstrated by the fact that when a surface is prepared in accordance with the invention, the part being treated is cleaned, after deposition of graphite, by immersion in a ultrasonically vibrated bath of Freon TF (trichlorotrifluoroethane).
  • Freon TF trichlorotrifluoroethane
  • This cleaning step does not remove the bonded particles of graphite of the type shown in the photomicrograph of FIG. 2 and shown schematically in FIGS. 1 and 4.
  • the cleaning does remove excess particles of graphite which are not bonded to the surface and which would not contribute to the lubricating effect of the invention. After such cleaning, about to 20 percent of the surface should remain covered with graphite particles firmly bonded thereto.
  • the percentage of the contact surface which is covered by graphite particles is not critical. Sufficient graphite should be applied to the surface to achieve the lubrication effect but the surface should not be covered with graphite to the extent that the electrical function of the contact surface will be seriously degraded. If more than 20 percent of the area of the surface is covered by graphite particles, the electrical function of the surface may be degraded to a noticeable extent and if less than 10 percent of the surface is covered, the lubricating effect achieved may be inadequate. For optimum results, about percent of the surface area should be covered with graphite particles.
  • a surface is graphitized in accordance with the invention by forcing a small particle of pure hexagonal graphite against the surface in a manner such that the basal plane of the particle is parallel, or substantially parallel, to the surface after application.
  • the force imposed on the particle at the time of application must be sufficient to cause a stress in the particle which is sufficient to produce basal plane shear in the particle concomitantly with application.
  • fresh graphite surface (which results from the shear of the particle) must be brought into contact with the metal surface being graphitized. A particle thus applied to cleaned clean surface will firmly bond to the surface and will, during subsequent movement of the surface, over a complementary surface, undergo further basal plane shear.
  • the spraying method of graphitizing a surface can be carried out with an apparatus of the type shown in FIG. 3 which comprises a canister 16 mounted on a vibrating unit 17.
  • a plate or disc 18 (FIG. 3A) is mounted inside the canister and a tube 20 extends upwardly through the disc.
  • the disc is provided with a multiplicity of openings having a diameter of about 0.014 inches.
  • a stream of dry nitrogen at a pressure of 50 p.s.i. is introduced through tube 20 and passes downwardly through the openings. This nitrogen stream carries entrained particles through the outlet tube 21 and through the nozzle 23.
  • the stream is directed against the contact surfaces 10 of the terminals and some of these particles adhere to and graphitize the surface in accordance with the invention.
  • the specimen itself may be of any suitable conductive material where a wear problem is anticipated although most of the data have been obtained on gold plated surfaces where the problem has been most acute.
  • the specimen is preferably prepared by thorough cleaning and degreasing prior to the spraying operation.
  • the amount of time required to deposit the graphite on the surface is quite short. An adequate amount of graphite is obtained on the surface if the specimen is merely passed at the rate of about 56 inches per minute past the nozzle.
  • it is necessary to deposit graphite on some specimens of the surface examine the specimens and determine if they have the required percent to percent of graphite thereon, and adjust the variables of the process to achieve optimum results.
  • the specimen After the specimen has been sprayed, it is cleaned in an ultrasonic bath or the equivalent, with a solvent or degreaser to remove any particles which are not bonded to the surface in the manner described above.
  • the surface consists of a relatively bright gold plating, its appearance after cleaning is not significantly different from its original appearance.
  • the graphitized and cleaned surface is bright and shiny and quite often is is impossible, or at least difiicult, to distinguish between a graphitized surface and an untreated surface with the naked eye.
  • Precise light reflectivity measurements will ordinarily reveal the presence of surface treatment in accordance with the invention and, to some extent, can be employed to determine the portion of the surface which is covered with the particles.
  • Particles 4c, 4d, and 4e will bond to surface 10 if the required shear stress is developed upon impact. It is apparent that when these particles strike the surface, the force of the impact will produce a component parallel to the basal planes 6 of the particles which component, if large enough, will cause shear. When these particles shear, their platelets will be spread over the surface 10 in a manner similar to the manner in which the playing cards of a deck are spread over a surface when the side of the deck is tapped. The fresh graphite surface developed by the shear mechanism comes into contact with, and bonds to the surface 10. A schematic representation of particle 4d after bonding is shown at 4d.
  • FIG. 1 is intended only as a theoretical model and is presented for purposes of clarification. The precise details of the phenomenon are undoubtedly more complex than FIG. I would imply.
  • the graphite particles can be ap plied by loading a cloth buffing wheel with small graphite par ticles and pressing the surface against the wheel while it is turning. This method has been successfully practiced and the advantages of increased wear of the surface have been obtained, see example I below.
  • FIG. 5 when two surfaces which have been treated in accordance with the invention are moved relatively over each other, as when two contacts are engaged with each other, the asperities of the surfaces will move across each other and establish electrical contact. It is believed that the lubricating effect of graphite particles in accordance with the invention is achieved by virtue of the fact that the platelets 4 are capable of undergoing further shear after they have been deposited on the surface. As the surfaces move over each other, the graphite platelets which are between the surfaces shear and act to reduce the friction between the surfaces and the galling which otherwise would take place.
  • FIG. 4 like FIG. 1, is intended as a theoretical model which is presented for the purpose of contributing to the understanding of the invention rather than as a pictorial representation.
  • the principles of the invention can be employed in electrical contacts when wear is a significant or potential problem and where it is desired to reduce the force required to engage two contact members with each other. As previously noted, it is contemplated that the invention will find its greatest use in the case of gold contacts because of the high cost of such contacts and the particular problems related thereto.
  • the invention can also be used with contact members plated or composed of silver, nickel and copper or other conductive metals. Where the principles of the invention are used on gold contacts, the advantages of extended wear life, reduced gold plating thickness, reduction in hardness by the use of the gold plating (with attendant improvement in the electrical properties) can all be realized.
  • EXAMPLE I A brass disc 1 inch in diameter and 0.013 inches in thickness was electroplated with nickel to a thickness of 50Xl0 inches. It was then electroplated with gold to a thickness of 50X 10 inches, using a cyanide gold bath containing 0.85 percent silver as a brightener for this plating step. The result gold plating has a Knoop hardness of about 110 to 1 15. The disc was thoroughly vapor degreased with trichloroethylene.
  • One surface of the disc was then graphitized in accordance with the invention by manually pressing the disc for about 5 seconds against a cotton buffing wheel having a diameter of 6 inches which was rotating at a speed of 1,760 rpm.
  • the surface of the wheel had been lightly loaded with graphite filings produced by filing a block of pure graphite.
  • each specimen was placed on a reciprocable carriage and a stylus was mounted above the test surface in a fixture in which the stylus was slidably mounted.
  • the styli comprised brass rods one-fourth inches in diameter having spherical bearing surfaces.
  • Each rod was plated with gold over nickel to the same thickness as the test specimen and the control specimen but the surfaces of the rods were not graphitized.
  • a static load of 100 g. was imposed on each rod during reciprocation of the specimens.
  • EXAMPLE ll The control specimen and the test specimen were provided with gold over nickel as platings in example I. The procedure of example I was followed except that a static load of 300 g. was imposed on each stylus during reciprocation of the specimens during the wear test.
  • the surface of the control specimen was examined after 22 cycles and it was found that the surface had failed in that the gold plating has been worn away in places exposing the nickel undercoat.
  • the coefficient of friction of the control specimen was found to be 0.86, at the beginning of the wear test and 1.0 after 22 cycles.
  • test specimen having a graphitized surface in accordance with the invention, was wear tested for a total of 1,730 cycles at which time the test was stopped.
  • gold plating on the test specimen was unbroken and continuous.
  • the coefficient of friction at the beginning of the test was found to be 0.2l6 and at the end of the test was found to be 0. l 84.
  • EXAMPLE lll Brass discs as described in Example I were provided with platings of 50X 10" inches of nickel and 100x10 inches of gold over the nickel.
  • the gold was deposited from an acid bath containing 0.1 percent cobalt as a hardener.
  • the gold plating has a'Knoop hardness of about 200-240.
  • the specimens were vapor degreased with trichloroethylene. Portions of the surface of the test specimen were then graphitized by spraying the surface with a stream of nitrogen having entrained graphite particles therein.
  • the spraying apparatus used was a conventional Paasche AUF brush, Model Number 268C supplied by the Paasche Air Brush Company of Chicago, Illinois, the pressure of the nitrogen being l0 p.s.i.
  • the nozzle of the air brush was positioned 2 inches from the plated area so that as the test specimen was moved past the brush a band of graphitized surface one-fourth inches in width was produced. During the subsequent wear test, the stylus was positioned against this band as the specimen was reciprocated.
  • the wear test of the graphitized test specimen was continued and was stopped after 2,925 cycles at which time the surface of the test specimen was examined. It was found that the gold plating on the surface of the test specimen was unbroken. The coefiicient of friction of the test specimen as the beginning of the wear test was found to be 0.145 and was found to be 0. l 5 at the end of the test.
  • EXAMPLE lV Two discs as described in example l were electroplated with a plating of 50 10"" inches of nickel and were then electroplated with silver to a thickness of l00 l0"'" inches.
  • the test specimen was graphitized as described in example lll except that the pressure of the nitrogen in the spraying apparatus was 50 p.s.i. and the nozzle was positioned 3 inches from the surface of the test specimen during spraying.
  • control sample After 75 cycles, the surface of the control sample was found to be worn off in part and the underplating of nickel was visible in places.
  • the coefficient of friction of the control specimen at the beginning of the test was 0.5 and was found to be l.l3 after 75 cycles.
  • test specimen was subjected to a total of 3,500 cycles and its surface was found to be intact at the end of the wear test.
  • the coefficient of friction of the test specimen was found to be 0.15 at the beginning of the test and was unchanged from this FIG. at the end of the test.
  • the two specimens were thoroughly degreased with Freon TF and subjected to a wear test as described above, a load of 300 g. being imposed on the styli during the test.
  • the plating on the control sample was observed to be broken and worn off in places after a total of 400 cycles.
  • the coefficient of friction at the beginning of the test for the control sample was 0.64 and was found to be 0.58 at the end of the wear test.
  • test sample was subjected to a total of 2l ,300 wear cycles in the testing apparatus and its surface was found to be unbroken at the end of the test.
  • the coefficient of friction at the beginning of the test for the test specimen was 0.10 and was found to be 0.137 at the end of the test.
  • contact surfaces of a slide switch of the type shown in application Ser. No. 803,223, filed Feb. 28, 1968 by Joseph L. Lockard have been treated in accordance with the invention with success.
  • Slide switches of the type shown in the Lockard application have nickel contact surfaces on a printed circuit board which are engaged by berylium-copper spring contacts. Under normal circumstances, it has been found that the contact surfaces of these switch devices fail after about 50,000 operating cycles. The berylium-copper spring contacts tend to become completely worn through and the nickel surfaces fail by wear of the plating. Treatment of the nickel surface with graphite in accordance with the invention results in a doubling of the life of the surface.
  • An electrical contact member which is adapted to be engaged with, and disengaged from a complementary member, said member having a metallic contact surface, said surface having discrete single crystal particles of hexagonal graphite thereon, said particles having their basal planes extending substantially parallel to the plane of said surface, said particles being cold welded by molecular bonding to said surface and said particles covering a minor portion of said surface.
  • a contact member as set forth in claim 1 wherein said contact surface is selected from the group consisting of gold,
  • a contact member as set forth in claim 1 wherein the portions of said surface covered by said particles is between 5 per cent and 40 percent.
  • a method of graphitizing the contact surface of an electrical contact device which is subject to sliding engagement with a complementary contact surface comprising the steps of:
  • a method of treating an electrical contact surface comprising the steps of:
  • Said bonded particles lubricate said surface when said surface is slidably engaged with another contact surface.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Contacts (AREA)
  • Manufacture Of Switches (AREA)
  • Motor Or Generator Current Collectors (AREA)
  • Carbon And Carbon Compounds (AREA)
US845478A 1969-07-28 1969-07-28 Lubrication of contact surfaces Expired - Lifetime US3620839A (en)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
US84547869A 1969-07-28 1969-07-28
GB3975871 1971-08-24
NLAANVRAGE7111956,A NL172608C (nl) 1969-07-28 1971-08-31 Elektrisch contact en werkwijze voor het maken van een dergelijk elektrisch contact.
AU33473/71A AU466090B2 (en) 1969-07-28 1971-09-15 Lubrication of electrical contact surfaces
DE19712149770 DE2149770A1 (de) 1969-07-28 1971-10-05 Elektrischer kontakt und verfahren zu seiner herstellung
FR7136769A FR2156994A5 (de) 1969-07-28 1971-10-13
JP8131171A JPS5429696B2 (de) 1969-07-28 1971-10-14

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JP (1) JPS5429696B2 (de)
AU (1) AU466090B2 (de)
DE (1) DE2149770A1 (de)
FR (1) FR2156994A5 (de)
GB (1) GB1326156A (de)
NL (1) NL172608C (de)

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US3965285A (en) * 1974-07-08 1976-06-22 Robert Dickson Hill Electrically conductive object having an ablative layer thereon for protecting the same from damage by an electrical discharge
JPS5180962A (en) * 1975-01-09 1976-07-15 Hitachi Ltd Denkisetsutenno seizohoho
US4511076A (en) * 1981-04-10 1985-04-16 Braun Aktiengesellschaft Method of soldering circuit boards with solder-repellent contacts
US5169724A (en) * 1991-07-25 1992-12-08 Amphenol Corporation Protectively coated electrical connector part
EP1081251A1 (de) * 1999-08-23 2001-03-07 Lucent Technologies Inc. Elektrolytisch abgeschiedener Metalloberflächenbelag, der abriebfeste Partikel enthält
US6542232B2 (en) * 2001-06-22 2003-04-01 Lucent Technologies Inc. Method of determining the quality of hard gold
WO2003102262A1 (de) * 2002-06-04 2003-12-11 Robert Bosch Gmbh Verbundwerkzeug zur herstellung einer elektrischen kontaktfläche sowie verfahren zur erzeugung einer gleitfähigen und korrosionsarmen elektrischen kontaktoberfläche
US20060201419A1 (en) * 1999-10-12 2006-09-14 Toto Ltd. Apparatus for forming composite structures
US20080274333A1 (en) * 2007-04-27 2008-11-06 Toto Ltd. Composite structure and production method thereof
US7768366B1 (en) 2007-10-29 2010-08-03 The United States Of America As Represented By The Secretary Of The Air Force Nanoparticles and corona enhanced MEMS switch apparatus

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US3965285A (en) * 1974-07-08 1976-06-22 Robert Dickson Hill Electrically conductive object having an ablative layer thereon for protecting the same from damage by an electrical discharge
JPS5180962A (en) * 1975-01-09 1976-07-15 Hitachi Ltd Denkisetsutenno seizohoho
JPS5533573B2 (de) * 1975-01-09 1980-09-01
US4511076A (en) * 1981-04-10 1985-04-16 Braun Aktiengesellschaft Method of soldering circuit boards with solder-repellent contacts
US5169724A (en) * 1991-07-25 1992-12-08 Amphenol Corporation Protectively coated electrical connector part
EP1081251A1 (de) * 1999-08-23 2001-03-07 Lucent Technologies Inc. Elektrolytisch abgeschiedener Metalloberflächenbelag, der abriebfeste Partikel enthält
US6274254B1 (en) 1999-08-23 2001-08-14 Lucent Technologies Inc. Electrodeposited precious metal finishes having wear resistant particles therein
SG85726A1 (en) * 1999-08-23 2002-01-15 Lucent Technologies Inc Electrodeposited precious metal finishes having wear resistant particles therein
US20060201419A1 (en) * 1999-10-12 2006-09-14 Toto Ltd. Apparatus for forming composite structures
US7993701B2 (en) 1999-10-12 2011-08-09 Toto Ltd. Composite structure forming method
US20100148389A1 (en) * 1999-10-12 2010-06-17 Toto Ltd. Composite structure forming method
US7553376B2 (en) * 1999-10-12 2009-06-30 Toto Ltd. Apparatus for forming composite structures
US20060222862A1 (en) * 1999-10-12 2006-10-05 Toto Ltd. Brittle material fine particles with internal strain for use in aerosol deposition method
US20080241556A1 (en) * 1999-10-12 2008-10-02 Toto Ltd. Composite structure and method for forming the same
US7736731B2 (en) 1999-10-12 2010-06-15 National Institute Of Advanced Industrial Science And Technology Composite structure and method for forming the same
US6542232B2 (en) * 2001-06-22 2003-04-01 Lucent Technologies Inc. Method of determining the quality of hard gold
US20040241403A1 (en) * 2002-06-04 2004-12-02 Peter Rehbein Composite material for producing an electric contact surface, in addition a method for creating a lubricated, corrosion-free electric contact surface
US7018923B2 (en) 2002-06-04 2006-03-28 Robert Bosch Gmbh Composite material for producing an electric contact surface, in addition a method for creating a lubricated, corrosion-free electric contact surface
WO2003102262A1 (de) * 2002-06-04 2003-12-11 Robert Bosch Gmbh Verbundwerkzeug zur herstellung einer elektrischen kontaktfläche sowie verfahren zur erzeugung einer gleitfähigen und korrosionsarmen elektrischen kontaktoberfläche
US20080274333A1 (en) * 2007-04-27 2008-11-06 Toto Ltd. Composite structure and production method thereof
US8114473B2 (en) 2007-04-27 2012-02-14 Toto Ltd. Composite structure and production method thereof
US7768366B1 (en) 2007-10-29 2010-08-03 The United States Of America As Represented By The Secretary Of The Air Force Nanoparticles and corona enhanced MEMS switch apparatus

Also Published As

Publication number Publication date
NL172608B (nl) 1983-04-18
NL7111956A (de) 1973-03-02
NL172608C (nl) 1983-09-16
JPS4846862A (de) 1973-07-04
FR2156994A5 (de) 1973-06-01
AU3347371A (en) 1973-03-22
DE2149770A1 (de) 1973-04-12
AU466090B2 (en) 1973-03-22
GB1326156A (en) 1973-08-08
JPS5429696B2 (de) 1979-09-26

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