US2203100A

US2203100A - Art of bonding metal to insulation

Info

Publication number: US2203100A
Application number: US181661A
Authority: US
Inventors: Osenberg Werner
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-12-24
Filing date: 1937-12-24
Publication date: 1940-06-04
Anticipated expiration: 1957-06-04

Description

June 4, '1940. w OSENBERG 2,203,100

ART 0F BONDING METAL TO INSULATION Filed Dec. 24, 1937 2 sheets-sheet 1 F 4 f-gg? /Q'. Erw L1 E' n Bam Y ft 5g FEM f W L.,

June 4, 1940. w .QSENBERG 2,293,100

ART OF BONDING METAL T0 INSULATIQN Filed Dec. 24, 1937 2 sheets-sheet 2 Patented June 4, 1940 UNITED STATES PATENT OFFICE 2,203,100 ART-F BONDING METAL TO INSULATION Werner Osenberg, Dresden, Germany Application December 24, 1937, Serial No. 181,661 i 8 Claims. (Cl.l 219--3) The present invention is especially concerned with the attachment ofmetallic bodies to carriers, more particularly in the case of electrical apparatus such as contact assemblies, lamp V sockets, sockets for radio tubes or similar apparatus used in radio or the like, and especially where the conducting part is to be fastened to a non-conducting carrier of ceramic material or the like. v

For a clearer understanding of the invention it -may be noted thatv where a Contact piece of conducting material is tc be attached to a carrier of ceramic material which is to be introduced in the usual outlet, the extension of the prong f.

may be introduced through the ceramic carrier and the attachment effected by means of a nut upon the threaded extremity thereof. The requisite pressure in tightening the nut in practice frequently injures the ceramic carrier which as a y result of the application of. pressure may develop cracks or actually break in two.

If the extension of the contact prong is cemented into a bore in the ceramic carrier a permanently useful connection between the carrier and the prong is not to be depended on because in practice the cement will not hold and the greatly that as a result of expansion the same4 will crack or` break.

According to the present invention a satisfactory connection is accomplished without strain upon or excessive' heating of. the ceramic material,

d0v by performing the securing operation by the application of heat electrically 'with the aid of appropriate electrodes.

According to the present invention the ceramic carrier is provided with conformationswith which a portion of the surface area of thesheet metal piece is intimately connected by resort to electrodes applied adjacent such conformation to cause the metal to soften at that region and to be snugly engaged with said conformation either by the pressure exerted by the electrodes or by resort to a separate pressure die applied at the heat softened portion. In a specic application the carrier may be provided with a projection of appropriate form, illustratively of a tenon shape and the electrodes of appropriate form applied to the sheet metal adjacent the sides of the tenon to cause the metal therebetween to become softened and to become readily shaped to the contour of the projection for snug engagement therewith, rendered especially secure by 5 the contraction of the metalin cooling. For localization of the heat generated by the electrodes, the sheet metal might be slotted to form a narrow bridge between the electrodes at which the heat and softening effect are localized. 1o Where the insulating element is in the form of a cylinder and the metal element in the form of a cap to be applied thereto, the cylinder might be provided with peripheral grooves and the electrodes applied to soften the cap metal therel5 'adjacent either to form a bead or a multiplicity of depressions forced into the groove or the rim of the cap might be turned into such grooves.

In the accompanying .drawings in which are shown one or more'of the various possible em- 2o bod'unents of the several features of the invention,

Fig.' l is a view in longitudinal cross-section showing the method of attaching thin sheet metal to a.ceramic or other insulating surface, 25

Fig. 2 shows the finished assembly prepared according to the embodiment of Fig. 1,

Fig. 3 is a view similar to Fig.- l of a modication, i

Fig. 4 shows ai. alternative method of forming 30 the embodiment; of Fig-.1,

Fig. 5 is a view like Fig. 4 of a further alternative,

Fig. 6 is a fragmentary sectional view similar to Fig. 3, showing another embodiment, 35

Fig. 7 shows an alternative form of. pressure roll used in carrying out the process indicated in Fig. 6,

Fig. 8 is a View similar to Fig. 7 of a further alternative, 40

Fig. 9 shows a fragmentary perspective view of` electrodes for producing another embodiment,

` Fig. 10 is a View in longitudinal cross-section showing the product formedby the apparatus of Fig. 9,

Fig'. l1 is a view partly in section of an alternative embodiment of. electrodes in association with the sheet metal,

Fig. 12 shows the product produced by the embodiment of Fig. 11, 50

Fig-13 is aview in longitudinal cross-section through the electrode arrangement of Fig. 1l,

Fig. 14 is a view in transverse cross-section of a modied projection on the ceramic or other insulating holder,

Fig. 15 is a plan View thereof,

Fig. 16 is a modification of the embodiment of Fig. 14,

Fig. 17 is a plan view thereof,

Fig. 18 is a view in longitudinal'cross-section of another embodiment of ceramic and sheet metal assemblage,

Fig. 19 is a side elevation illustrating another application of the process,

' Fig. 20 is a plan View thereof,

Fig. 21 is' a IView in longitudinal cross-section taken on line 2I-2i of Fig. 22, illustrating a method of applying a sheet metal cap to a cylindrical carrier,

Fig. 22 is a view in longitudinal cross-section illustrating the method of assembly,

Fig. 23 is a view in longitudinal cross-section of an alternative embodiment of the construction shown in Fig. 22,

Fig. 24 shows an alternative embodiment for attaching a sheet metal cap to a ceramic projection,

Fig. 25 is a modification of the embodiment oi Fig. 24,

Fig. 26 is a View in longitudinal cross-section illustrating the method of attaching an electric socket to a ceramic holder,

Fig. 27 is 'a modication of the embodiment of Fig. 26,

Fig. 28 is an elevation View illustrating a iurther modication of the process particularly shown in Fig. 26,

Fig. 29 is a diagrammatic View illustrating the process of using electrodes for heating and softening and an auxiliary pressure tool or die ior eiecting the. deformation of the metal,

Figs. 30, 3l and 32 are fragmentary side elevations' of modified forms oi pressure dies or tools for carrying out the method of Figs. 29,

Fig. 33 is a view in longitudinal cross-section illustrating another modification oi the general process shown in Fig. 27,

Fig. 34 is a plan view of a metal terminal or 111g,

Fig. 35 is a longitudinal cross-.sectional view thereof, y

Fig.` 36 is a fragmentary view of a ceramic holder to which the terminal of Fig. 38 isto be aixed,

Fig. 37 is a side View illustrating another application of the invention,

Fig. 38 is a view in longitudinal cross-section illustrating the product produced by the arrange- ,ment of Fig. 37, and

Fig. 39 is a fragmentary plan view thereof. Referring now to Figs.`l and 2, there is shown a method for securing an angle piece W to a' ceramic carrier. The latter may be provided with a tenen-shaped projection V upon which one flank of the angle piece is superposed as shown in Fig. l. The two electrodes E and E2 with their electric conductors L' and ll2 are so disposed upon the sheet metal piece that the heating occurs in the length oi' metal therebetween which is carried on to such extent that the same softens. As a consequence the metal may be drawn about the projection V to form a cap thereover as best shown in Fig. 2. As the metal then cools it contracts to a greater extent than the ceramic carrier which has been heated relatively slightly in the operation, and as a conse uence of that contraction the sheet metal cap aws tightly'about the ceramic projection to aiford an extraordinarily secure and tight seat thereupon.

sions i3, M in the carrier.

aaoaioo In this connection it is to be, noted that in this process no riveting or the like is required but only the drawing of the material over the projection `on the ceramic carrier and the resultant shrinking of the sheet metal part that has been softened in the operation accomplishes the secure attachment.

Referring to Fig. 3, the insulating carrier l is shown with a flat projection tapering slightly to its upper face and the metallic sheet 3 Which initially is fiat is secured by resort to the electrodes E.

in Fig. 4 an arrangement is shown similarto Figs. 1 and 2 but in this case the iiat electrodes E are shaped or formed as tools to press the iiat sheet metal about the tenori-shaped projection 2.

In Fig. 5 the electrodes e are in the form of rollers which are particularly useful Where the metal part f3 is of considerable Width and the tenon-shaped projection 2 of corresponding length.

In Fig. 6 the attachment of the metal strip b to a support with an ordinary rather than a tenon-shaped projection 2 is also accomplished with roller-shaped electrodes e with the addition of a pressure roller W, which in combination with the two electrode rollers serves to secure the strip to the carrier The pressure roll is' especially advantageous where the metal strip is to be securely rolled upon the carrier with the elimination of any open space therebetween. The pressure roll may have a suitable proile according to the cross-sectional form or vthe projection to which the metal strip is to be attached.

Fig. 7 for instance shows a shape oi roller1 profile for a peak projection and Fig. 8 a similar roller to be used for attaching the metal to a v rounded projection.

`Where the projection oi the carrier i has a eircular cross-section, one of the electrodes may be formed in the shape of a ring R as shown in Fig. 9 which in the application edects the positioning of the strip d against the projection 2 during softening of the material when the electrode E is applied centrally of the projection to form* the assembly shown in Fig. lil.

As shown in Figs. 1i, i2 and i3, the application of the metal strip tl upon a circular projection 2 of the carrier may be eected by the use of two opposed semi-cylindrical electrodes E.

The surface of the ceramic carrier to which the `sheet metal is to be applied, may be of any suitable roughened form, for instance with sharpy ribs il as shown in Figs. la andV l5, or with rectangular ribs B2 as in Figs. 16 and 17. As shown in Fig. l5 the sharp teeth roughening may be in the form' of corrugations extending transversely across all or'part of the width oi the attachment surface and as illustrativeiy shown in Fig. i7,`

the roughened areas may be arranged in the form of lccmcentric circular conformations. it is understood that in the use .of embodiments such as Figs. i4 to 17 the metal parts may be secured to the carrier by means of pressure stamping dies which have depressions complementary to the projections shown.

llnFig. 18 is shown an embodiment in which themetal part d is shown secured to the carrier Il at a projection 2 formed by grooves or depres- Such grooves H3 'and id could also be formed in the interior of a holloW cylinder to be lined with sheet metal.

lin order to avoid loss oi heat in that' part of the metal piece which is to he shaped by the application of heat, it is desirable, as shown in Figs. 19 and 20 to form slots I6 and I'I which materially minimizes the loss of vheat from the bridging part I8 defined thereby. The speed with which this part may be brought to the required plastic condition is materially increased yin this manner and metal pieces thus prepared may be more rapidly assembled, with economy of labor and electric power.

As shownA in Figs. 21 and 22, .the projection to which thev metal part 2| is to be attached may be formed as a cylinder. The cylindrical projection 2 for that purpose is provided at'its periphery with depressions I9, which extend partially or wholly about the same. To attain rapid heating of the material, at the part to be pressed inward it is desirable to perform the shaping in the manner shown in FigiI 21 where` the two electrodes E are disposed in closely contiguous relation in the region of the grooves or depressions but with suflicient space therebetween for the introduction of a pressure'die 20 at the softened part, which serves to press the material into the depression I9. As a rule it will not be necessary to press the metal part 2| at its entire periphery into the depression I9, but normally it will suiiice if the material is so depressed into two diametrically opposed parts of the depression I9.

In Fig. 23 the depressions 22 ,are so disposed that the rim of the metal part 23 may be bent v thereinto and thereby secure the metal part 23 to the projection 2.

' In place of rod-shaped electrodes e, roller electrodes of suitable profile may be'utilized, par. vticularly in such cases where the projection 2 is circular in cross-section and has

annular depressions

33, 34 as shown for instance in Figs. 24 and 25. In such cases the electrodes e may be passed around the periphery of the

metal part

24 or 25 which is also of circular shape. In the embodiments according to Figs. 21 to 25, 'a normal or a metal glazing or nishing may be fintroduced. In the casefof the temperatures attained in this operation the glazing will melt and pass into intimate engagement between the two parts to be connected so that a 'gas or fluidtight closure is attained e In Fig. 26 is shown a carrier I which hastwo projections 2 to which the metal part 26 is attached with the use of two pairs of electrodes E.

Projections 2 are circular in -cross-section and correspond with the embodiment shown in Figs. 11 to 13. The electrodes `in Fig. 26 are semicircular in cross-section so that-in this manner the attachment of the' metal part 2 6 illustratively shown .in ,the form of a lamp socket may be attained in the same manner as shown in Figs. 11 to 13. e

Fig. 27 shows a carrier I with a projection 2, circular in cross-section, to which in addition to the metallic part 2'! there is simultaneously attached another flat metal part 28. Where illustratively the part 2l represents an .electric socket, part 28 may constitute a metallic conductor which leads the electric current -to the socket. Both

parts

21 and 28 in the embodiment of Fig. l27 are simultaneously attached to the projection 2 by aid of the semi-cylindrical electrodes E.

In order to accelerate the assembly process and thereby save time and'power, it is possible,

as shown'for instance in Fig. 28 to'previously form the metallic part 29 roughly to the shape desired, in a purely mechanical manner as shown at 30, which parts are Asuperposed over the projections 2 before the electrodes are applied, in

order to eiiect accurate and nal attachment of the metal part 29 to the carrier I.

As shown in Figs. 6 and 7, and 21 and 22, the electrodes maybe utilized solely for heating and softening the metal parts while special dies or Q stamps or pressure rolls serve to press the matoothed serrated contour and Fig. 32 a rectangular-toothed serrated contour.

' If it is desired to aiix the metal part to a body which has only slight heat conductivity, it is preferable to protect this body or carrier from excessive heating by means of an, interlay as shown in Fig. l33. The carrier I here has a projection 2 over which extends `the insulating interlay 35, illustratively made of asbestos and 36 is the metallic piece which is attached to the projection 2 is a single operation with the sheetA 35, by use of theelectrodes E.

In Figs. 34, 35 and 36 is shown another embodiment for attachment of the metal piece 3'I upon the carrierI with the cylindrical projection 2. In this case the ceramic part is covered by means of a silver plating 38. The aperture 39 provided in the metal part 3l is desirably of diameter smaller than that of the projection 2. The application of the metal part 31 is preferably eiected by aid of two opposed semicylindrical electrodes as shown in a number of the previous embodiments including for instance Fig-13. The portion of lthe metal part 3l adjacent the aperture 39 is rolled upward in this operation and in the subsequent contraction becomes particularly tightly lodged against the projection 2.

. "Since a body made of artificial resin or similar materials may be deformed under certain heat applications, that property may be utilized in the application of the metal parts. This is illustrated in Figs. 37, 38 and 39 where the electrodes E are of conical format their pressure ends. Thereby they press corresponding tangs 4I), 4I out of the metal part into the carrier I. Between the tangs 40, 4I there is thus formed a projection '2. f

,Having thus described my invention, what I -claim as new' and desire to secure 'by Letters Patent isz" 1. The method of attaching a flat lsheet metal plate to a ceramic carrier which comprises conforming the carrier with one or more surface irregularities, in its otherwise flat face, superposingthe plate thereover, 'applying electrodes to said plate near the boundaries of the area dened by said irregularities, thereby to cause thesaid sheet metal member between said electrodes to become softened under the heat of the applied current and concurrently with said operation pressing said sheet metal member through said electrodes against said insulating carrier and applying pressure through an auxiliary pressure tool to said sheet metal member throughout the region between the electrodes, thereby to cause .the softened sheet metal to be conformed to the -plate to a ceramic carrier provided with a tenonshaped projection which consists in superposing the metal over the projection, applying electrodes near the opposite edges of the projection thereby to cause the metal between said electrodes to become softened under heat and 'sucking the thus softened material inward about beth sides of the projection by corresponding portions of "the electrodes, while exerting pressure over the entire area of the upper face of the projection by means or a pressure tool interposed between the electrodes.

5. The method of attaching a nat metal plate to an insulating carrier provided with one or more generally circular mounting studs, which method consists in superposing the metal over the mounting studs, applying semi-cylindrical electrodes to the metal adjacent said studs and causing the disc-shaped portion of the metal bounded by said electrodes to become softened and conformed under pressure snugly to engage and encase the studs on the carrier plates'.

6. The method of applying a sheet metal member to a ceramic carrier which consists in glazing the latter with a coating of low melting point, applying electrodes to the sheet metal member to cause the same as well as the glazing to become softened under heat, and shaping the softened metal to the conformation of the carrier, whereby in the subsequent cooling the softened glazing willll in minute voids between the sheet metal piece and its carrier, to aiord a liquid and gas-tight bond therebetween.

7. The method of attaching an electric socket shell to a ceramic carrier provided with one or :more unitary cylindrical mounting studs, which consists in applying electrodes into the socket, one pair for each mounting stud, thereby causing the region defined by each pair of electrodes to be softened under the consequent heat and pressing the thus softened material about the stud or studs.

8. An assembly including a ceramic base and a sheet metal piece rmly bonded thereto, said ceramic base comprising a substantially at face with a tenori-shaped projection integral therewith, the metal element engaging said base and being heat shrunk about the tenori for snug gripping thereof.

WERNER OSENBERG.