US2739931A - Anodizing metal articles - Google Patents

Anodizing metal articles Download PDF

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Publication number
US2739931A
US2739931A US337393A US33739353A US2739931A US 2739931 A US2739931 A US 2739931A US 337393 A US337393 A US 337393A US 33739353 A US33739353 A US 33739353A US 2739931 A US2739931 A US 2739931A
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United States
Prior art keywords
tape
fastener elements
fastener
bath
electric
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Expired - Lifetime
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US337393A
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English (en)
Inventor
Bernstiel Erwin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
RHONDDA PLATING WORKS Ltd
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RHONDDA PLATING WORKS Ltd
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/04—Anodisation of aluminium or alloys based thereon
    • 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
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S205/00—Electrolysis: processes, compositions used therein, and methods of preparing the compositions
    • Y10S205/917—Treatment of workpiece between coating steps

Definitions

  • the present invention relates to methods of and means T fOI anodizing metal articles, for example fastener ele- .ments of slide fasteners, made of a suitable metal or :metal alloy, such as aluminium or aluminium alloy.
  • the term metal article as hereinafter used shall mean an :article which is, at least in part, made of an anodizable .metal, and similarly the term fastener elements shall :mean such elements made of an anodizable metal.
  • fastener elements of slide fastenersafter the fastener elements have been attached to a carrier tape which comprises an electrically conducting wire at its edge carrying the fastener elements so that the .fastener elements contact the wire and are, thus, electrically interconnected by the wire.
  • the fastener elements are usually attached to carrier tapes of a considerable arbitrary length and spaced along the tape in groups separated one from the next by a length of the tape free from fastener elements, the fastener elements of corresponding groups of two such tapes being interlocked with each other, the tapes being subsequently cut about half way between adjacent groups of fastener elements whereby to obtain pairs of interlocked slide fastener stringers which are finally provided with a slider and-with end members to constitute a complete slide fastener.
  • the wire at the edge of each tape has to be thin so as not unduly to decrease the flexibility of the slide fastener.
  • Such a thin Wire cannot reliably carry a heavy electric current and, more specifically, cannot reliably carry the current across aggregate lengths of thetapes free from fastener elements between successive groups thereof which may be immersed simultaneously in the electrolytic bath at a given moment.
  • the oxide layer formed on the fastener elements during anodizing is a bad electric conductor, which renders it impossible or at least difficult, after the oxidization of the surfaces of the slide fastener elements has been initiated, to establish reliable electric contacts between a current feeding element and travelling slide fastener elements.
  • Fig. l somewhat diagrammatically illustrates a portion of two tapes to which slide fastener elements are attached;
  • Fig. 2 is a section through a tape of Fig. 1;
  • Fig. 3 is a general perspective view of an arrangement of the invention, some parts being broken away;
  • Fig. 4 is a perspective View of a part of the arrangement of Fig. 3 on a larger scale
  • Fig. 5 is a section along the line V-V of Fig. 4;
  • Fig. 6 illustrates a modification of a detail of Fig. 5
  • Fig. 7 illustrates another modification of the detail of Fig. 5.
  • the invention consists broadly in a method of anodizing a metal article, comprising the steps of immersing the article or a part thereof in a suitable anodic bath of an electrolytic cell, anodizing the article or its part while immersed in the anodic bath, scraping the oxide layer formed on thearticle from a portion thereof whereby to provide a sufficiently good electric conduction through such portion, and feeding an electric current to the article through the scraped portion thereof.
  • the oxide layer is scraped from fastener element portions which lie at one and the same side of the tape, while the oxide layer of fastener element portions lying at the other side of the tape is not substantially interfered with.
  • the invention also consists in a method of anodizing electrically interconnected fastener elements attached to a carrier tape, comprising the steps ofimmersing the tape or 'a' section thereof in a suitable anodic bathof an electroly-tic cell to anodize fastener elements of the tape or of the said tape section, removing the tape or the tape section from the anodic bath, scraping the oxide layer formed-on the fastener elements while the 'tape or'the tape section wasim'mersed in the anodic bath from fastener element portions lying at one side of the tape, immersing the tape or the tape section again'in the anodic bath to continue the anodizingof the fastenerelements, removing the-tape or the tape section again from the anodic bath, scraping the oxide layer formed on the fastener elements while the tape or the tape section was immersed in the anodic bath from the fastener element portions lying at the sameone side of the tape as before, and, if necessary, continuing this process until an oxide
  • fastener elements of two tapes are interlocked with each other before the tapes or sections thereof are immersed in the anodic bath, whereby to 'treat the fastener element of the twotapes or the sections thereof simultaneously.
  • the anodizing process may be continued, whereby superficially to anodize the previously scraped portion or portions.
  • the oxide layer may be wholly or in part broken and/ or removed from the said-portions lying at one side of the tape which therefore afford a good electric conduction through such portions of fastener elements and enable gradually to buildup a substantially uniform oxide layer on the fastener element portions lying at the other side of the tape, which advantageously forms the visible front of the completed slide fastener, While the said one side of the tape forms the rear of the slide fastener and is, thus, inmost cases not visible in use. Moreover, experience has shown that in many cases, particularlyif the anodizing process is continued after the scraping process has been terminated, the effect of the scraping is not, or is hardly, visible to the naked eye.
  • the invention also consists in an arrangement for performing the methods hereinbefore described, comprising means for feeding a carrier tape to which slide fastener elements are attached in a zig zag path through an electrolytic cell, and means for scraping fastener element portions lying atone side of the'tape.
  • the feeding means may be arranged relatively to the electrolytic cell in such a manner that each'part of the tape while travelling along the zigzag path is alternately immersed in an anodic bath of the electrolytic cell and removed therefrom, the scrap ing means being arranged for scraping fastener element portions while the tape part carrying the fastener ele ments which are being scraped is removed from the anodic bath.
  • the scraping means may be rotatable brushes, for example Wire brushes, or knurled rollers.
  • Figs. 1 and 2 illustrate portions of tapes 1 having thickened edges 2 to which slide fastener elements 3 are attached.
  • the tapes 1 are of a considerable arbitrary length, and the fastener elements 3 are spaced along the tapes 1 in groups separated one from the next by tape lengths a free from fastener elements 3.
  • Each thickened tape edge 2 comprises a plurality of metal wires 4 which are so arranged that the fastener elements 3 make mechanical and electric contact With'the metal wires 4 whereby the fastener elements 3 are electrically interconnected with one another.
  • the Wires 4 are illustrated as simply placed on top of the thickened edge 2 and held in position'by the fastener elements 3 when clamped on to the tape edges. ln 'actual practice however, the wires are preferably connected to the tape edges 2 in any suitable manner.
  • the arrangement illustrated in Figs. 3 to 5 serves for anodizing the fastener elements 3 of the tapes 1.
  • the arrangement comprises an electrolytic cell formed by a metal tank 10 containing, in'use, a suitable anodic bath 11.
  • a plurality of metallic guide rollers 12 are rota-tably mounted in brackets 13 and 14 of insulating material. The ends of the guide rollers 12 protrude beyond the bracket 14.
  • Gear wheels 15 are keyed to the protruding ends of the guide rollers 12, one to each.
  • Eachpair of adjacent gear wheels '15 mesh with an idling gear Wheel 16.
  • each gear Wheel 15 (except the first gear Wheel 15 nearest the input side of the anodic bath at the extreme lefthand side of Fig.
  • each roller '20' has five guide grooves, the bottoms of the guide grooves being knurled as indicated in Fig. 4 at 20a, the grooves being laterally defined by six raised portions 20b of each knurled roller 20.
  • the Width of'one of the guide grooves formed between adjacentraised portions 20]) corresponds substantially-to the width of a pair of tapes 1 carrying interlocked fastener elements 3.
  • An electric motor 21 drives the last guide roller '12 nearest the output side of the 'ano dic bath (the extreme guide roller at the righthand side of Fig. 3) by means of a pulley 22, a pulley 23 and a belt 24, the pulley 22 being fixed to the rotor of the electric motor '21,and the pulley 23 to the said last guide roller '12.
  • a wringer 25 is arranged at the output side of the anodic 'bath and is driven by the electric motor 21 by means of the pulley 20, a pulley 26 keyed to one of the press rollers of the wringer 25 and abelt 27.
  • guides 31 are mounted which are illustrated as rotatable idling rollers.
  • Each metallic guide roller 12 is provided with a slip ring 32 electrically connected in any known manner to the positive terminal of an electric supply source, the negative terminal of which is connected at 33 to themetal tank 10 acting as the cathode-of the electrolytic cell.
  • Electric resistors 34, 35, 36 are inserted in the electric connections between the first three rollers 1'2 adjacent the input side of the anodic bath and the positive terminal of the electric supply source.
  • the resistance of the resistor 34 is higher than that'of the-resistor 35, which in'turn is higher than that of the resistor 3 6.
  • the electric motor 21 drives the wringer25 and the last guide roller 12 adjacent the output side of theanodicbath.
  • the gear wheel 15 keyed to the said last guide roller 12 drives the idling gear wheel 16 'meshingwith it, the idling gear wheel 16 driving in turn the next gear wheel 15'and so on, whereby all the guide rollers 12 are'driven in the same sense as indicated by the inscribed arrows, the gear wheels 15 and 16 being so dimensioned that all the guide rollers 12 rotate with a substantially equal speed.
  • Each gear wheel 15 (except the first gear wheel at the input side of the anodic bath) drives one of the pinions 17 keyed to the knurled rollers 20. As can be seen from Fig.
  • the knurled rollers 20 rotate in a sense opposite to the sense of rotation of the guide rollers 12. Since the diameter of each pinion is smaller than that of the gear wheels 15, the knurled rollers 20 rotate with a higher speed than the guide rollers 12.
  • the rotation of the guide rollers 12 and the press rollers of the wringer causes the tapes 1 to travel through the anodic bath in a zig-zag path from its input side to its output side in the direction of the arrow A in Fig. 1.
  • the resistors 34, and 36 enable the electric current flowing from the respective guide rollers 12 into the contacting fastener elements 3 to be kept smaller than the corresponding currents flowing into contacting fastener elements 3 from guide rollers 12 not associated with such resistors.
  • the different resistances of the said resistors cause the current through a certain fastener element 3 to increase gradually while the fastener element travels through the electrolytic bath 11, until a high current intensity is reached when the said fastener element contacts the fourth and followingguide rollers 12.
  • the wires 4 it will also be appreciated that it is no longer necessary for the wires 4 to carry an anodizing current through the entire length of the tape portions immersed at any instant of time in the anodic bath. With the arrangement described it is only required that the wires 4 carry the current through the comparatively small length of the tape portions between adjacent guide rollers 12 since at each such guide roller 12 an electric connection with the supply source is established or re-established, while after the first guide roller 12 has been passed by a fastener element 3, the oxide layer on the fastener element 3 is scraped by. the knurled rollers 21 ⁇ immediately before the said element reaches one of the subsequent guide rollers 12. From the drawings it will also be recognized that the knurled rollers 29 act all on one and the same sides of the fastener elements.
  • the knurled rollers 20 in fact remove the oxide layer or only break it up. Whatever, from a scientific point of view, the true explanation may be, it has been found that with the specific embodiment described having twelve guide rollers outside the anodic bath, twelve further guides in the anodic bath and knurled rollers rotated at a high speed, the guide rollers being electrically connected to a terminal of the electric supply source, a satisfactory anodizing was obtained of the surfaces, remote from the guide rollers, of the fastener elements 3 carried on the tapes 1 having wires 4 at their thickened edges 2 in contact with the fastener elements.
  • the wringer 25 serves in known manner to remove liquid electrolyte from the tapes which may subsequently be 6 washed and dyed together with the anodized fastener elements in known manner.
  • the electric direct connection between one fastener element of one tape and an adjacent interlocked fastener element of the other tape may be sufiicient for allowing the electric anodizing current to flow, in which case the wires 4 may be dispensed with or may be only provided for bridging the tape lengths a between adjacent; groups of fastener elements 3.
  • the direct current electric supply source may be replaced by an alternating electric current supply source, in which case the resistors 34, 35, 36 may be replaced by electric impedances such as choke coils.
  • reference numeral indicates a knurled roller similar to the knurled roller 20.
  • the knurled roller 121) is so arranged that it not only scrapes fastener elements of the tape 1 but also scrapes the periphery of the adjacent guide roller 12 to keep the same clean.
  • an idling counter-roller 37 which preferably is made of an elastic material, presses the tapes 1 firmly against the respective guide roller 12 whereby to improve the electric contact between the guide roller 12 and the fastener elements of the tapes 1.
  • a rotating brush 220 which may be a wire brush, for scraping the fastener elements of the tapes 1 and also for cleaning the respective guide roller 12.
  • knurled rollers 20 need not be metallic rollers.
  • gear means are provided between adjacent guide rollers, whereby positively to rotate all the guide rollers for drawing the tape or tapes through the anodic bath.
  • the fastener ele-' 5 instead of treating pairs of tapes the fastener ele-' 5.
  • the guide rollers outside the anodic bath are metal rollers, means being providedfor electrically connecting the metal rollers 'to a terminal of an electric supply source, and further means being provided for electrically connecting theother terminal of the supply source to the anodic bath when in the electrolytic cell, whereby the fastener elements while in mechanical contact with the said guide rollers are connected through the same to the said first terminal of the electric supply source.
  • I V p 6 An arrangement as claimed in claim 5, wherein the means for electrically connecting at least one of the metal rollers to the terminal of the electric supply source comprises an electric impedance for reducing the electric current flowing through the said connecting means.
  • a method of anodizing fastener elements which are electrically interconnected and are attached to a fastener tape comprising the steps of continuously drawing at least a section of the said tape over a first electric contact element in such a manner that the said first contact element successively makes electric contact with each of the fastener elements, to feed an electric current to the interconnected fastener elements, passing the tape section into an anodic bath to anodize fastener elements of the said tape section, removing the tape section from the anodic bath, scraping the oxide layer formed on a part, lying at one side only of the tape, of each fastener element whereby substantially to restore the electric conductivity of the said parts, drawing the tape section over a second electric contact element in such a manner that the said second contact element successively makes electric contact with the scraped parts of the fastener elements to continue the feed of the electric current to the interconnected fastener elements, passing the tape section of cyclically removing the tape section'frorn the anodic bath,' scraping the oxide layer formed on
  • a method of anodizing metal articles which. are electrically interconnected and attached to a flexible carrier, comprising the steps of continuously drawing the articles into and through an anodic bath, drawing the articles over a plurality of spaced electric contact elements in such a manner that each contact element successively makes electric contact with the same part of each article, passing an electric current from a first of the said contact elements through a contacting article to other articles and thence through the anodic bath to a cathode thereby frorning oxide layers on at least some of the articles, in the bath, scraping the oxide layer formed on the said article parts whereby to improve the electric conductivity of the said article parts, passing an electric current from 8 a second of the said contact elements through a scraped contactingjarticle part to other articles and'thence through the anodic bathto the said cathode thereby forming an oxide layer on each of the said articles in the bath, scraping the oxide layer formed at thesaid article parts, and
  • a method of anodizing fastener elements which are electrically interconnected and attached to, a fastener tape comprising the steps of continuously drawing the tape into and through an anodicbath across a plurality of spaced contact elements in such a manner that each contact element successively makes electric contact with a part, lying at one side only of the tape, of each of the said fastener elements, passing an electric current from a first of the said contact elements throughacontacting fastener element to other fastener elements and thence through the anodic bath to a cathode thereby forming an oxide layer on fastener elements, in the bath, scraping the oxide layerformed on the said parts of the fastener elements in the bath whereby to improve the electric con ductivity of the said parts, passing an electric current from a second of the said contact elements through the scraped parts of a contacting fastener element to other fastener elements and thence through the anodic bath to the cathode thereby forming an oxide layer on each of the said fastener elements in the
  • An arrangement for anodizing fastener elements which are electrically interconnected and attached to a carrier tape comprising an electrolytic cell for receiving an anodic bath and having an input and output side, a first electric contact element, a first combination of an electric contact element and a scraping means spaced from the said first electric contact element, and atleast one further combination of an electric contact element and a scrapingmeans spaced from the immediately preceding combination, and means for continuously drawing the carrier tape through.
  • theelectrolyticv cell along an open path from the said input side to the said output side in such a manner that during movement of the can rier tape each fastener elementsuccessively contacts, the, first electric contactelement and during movement of the carrier tape between the input and output side of the electrolytic cell a part lying at one side only ofthecarrier tape of each of the said fastener elements successively contacts the scraping means andimmediately there afterthe electric contact element of each combination, so that the scraping means scrape the said element part and the electric contact element contacts the scraped element part.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Slide Fasteners (AREA)
  • Electroplating Methods And Accessories (AREA)
US337393A 1952-02-26 1953-02-17 Anodizing metal articles Expired - Lifetime US2739931A (en)

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BE (1) BE517739A (en(2012))
CH (1) CH313180A (en(2012))
DE (1) DE940862C (en(2012))
FR (1) FR1075365A (en(2012))
GB (1) GB728747A (en(2012))
NL (2) NL176250B (en(2012))

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2963760A (en) * 1957-09-30 1960-12-13 Samuel L Cohn Slide fastener and treatment thereof
US2989444A (en) * 1957-09-30 1961-06-20 Samuel L Cohn Slide fastener assembly
DE1258941B (de) * 1963-01-21 1968-01-18 Ibm Verfahren zur Herstellung von mehrschichtigen Duennfilmschaltungsplatten
FR2834301A1 (fr) * 2001-12-28 2003-07-04 Ykk Corp Procede de realisation d'un film d'oxyde anodique sur une rangee d'elements de chaine de fermeture a glissiere et dispositif de realisation de celui-ci.

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1138711B (de) * 1957-09-28 1962-10-25 Lapidor S A Fuer die Bearbeitung von Zifferblaettern bestimmte Haltevorrichtung

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US938451A (en) * 1905-04-26 1909-10-26 Edison Storage Battery Co Process of making active material for storage-battery electrodes.
US1120191A (en) * 1912-04-04 1914-12-08 Gibbs Company Apparatus for electrolytic production of wire.
US2063515A (en) * 1934-09-08 1936-12-08 Whitehall Patents Corp Separable slide fastener and method of making the same
US2517907A (en) * 1945-01-05 1950-08-08 Conmar Prod Corp Apparatus for electrotreating metal slide fasteners
US2519488A (en) * 1945-02-26 1950-08-22 Edward L Mack Sound reproducing stylus
US2591042A (en) * 1947-01-08 1952-04-01 Conmar Prod Corp Apparatus for electrolytic treatment of spaced metallic elements

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US938451A (en) * 1905-04-26 1909-10-26 Edison Storage Battery Co Process of making active material for storage-battery electrodes.
US1120191A (en) * 1912-04-04 1914-12-08 Gibbs Company Apparatus for electrolytic production of wire.
US2063515A (en) * 1934-09-08 1936-12-08 Whitehall Patents Corp Separable slide fastener and method of making the same
US2517907A (en) * 1945-01-05 1950-08-08 Conmar Prod Corp Apparatus for electrotreating metal slide fasteners
US2519488A (en) * 1945-02-26 1950-08-22 Edward L Mack Sound reproducing stylus
US2591042A (en) * 1947-01-08 1952-04-01 Conmar Prod Corp Apparatus for electrolytic treatment of spaced metallic elements

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2963760A (en) * 1957-09-30 1960-12-13 Samuel L Cohn Slide fastener and treatment thereof
US2989444A (en) * 1957-09-30 1961-06-20 Samuel L Cohn Slide fastener assembly
DE1258941B (de) * 1963-01-21 1968-01-18 Ibm Verfahren zur Herstellung von mehrschichtigen Duennfilmschaltungsplatten
FR2834301A1 (fr) * 2001-12-28 2003-07-04 Ykk Corp Procede de realisation d'un film d'oxyde anodique sur une rangee d'elements de chaine de fermeture a glissiere et dispositif de realisation de celui-ci.

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BE517739A (en(2012))
GB728747A (en) 1955-04-27
CH313180A (de) 1956-03-31
DE940862C (de) 1956-03-29
NL83851C (en(2012))
FR1075365A (fr) 1954-10-15
NL176250B (nl)

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