US2286081A - Electrolytic condenser - Google Patents

Description

June 9, 1942. A M. GEORGIEV ETAL 2,286,081

` ELECTROLYTIC CONDENSER Filed July 19, 1939 93 INVENoRs alexander 'earyrev B Paz/ i.' [foe/P61 Patented June 9, 1942 ELECTROLYTIC COND-ENSER Alexander M. Georgiev and Paul F. Koehly, Dayton, Ohio, assgnors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application July 19, 1939, Serial No. 285,336

Claims.

This invention relates to electrolytic condensers and is more particularly concerned with those condensers having a thin mass as compared with their relative length and breadth.

There is a considerably extensive field for the use of electrolytic condensers of the flat type, that necessitates the use of shallow containers in order to provide an assembly that may be mounted in a relatively thin space, such as in the base of an electric motor and the like. Another outlet contributing to the same demand is an instance where there is a need of several similar condenser units that are to be compactly installed in parallel, in series, or in series parallel relation.

It is therefore an object of this invention to provide an electrolytic condenser that while having prescribed electrical characteristics, will be contained in a small volume and adaptable for alternative mounting and eflicient cooling.

It is also an object of the instant invention to provide container means for an electrolytic condenser that may be hermetically sealed without resort bein.U made to the handiwork of a skilled operator.

Another object of the invention is to provide a terminal structure for an electrolytic condenser having a metallic container, which terminal construction Will not only properly insulate the terminals from one another but will also effectively seal their support in the casing member against iiow of electrolyte or vapors therefrom.

A further object is to secure a terminal member in a thin walled casing, so that it cannot be turned therein and result in shorting of the terminal connections and cause rupture of the electrode connectors.

A further object of the invention is to provide a container for an electrolytic condenser that will obviate the necessity for a relief vent.

A further object of the invention is to pro- Vide a condenser construction that will facilitate cooling of an enclosed structure.

The above objects are accomplished in main by providing two substantially symmetrical and cooperable casing members which are preferably of drawn sheet metal, such as steel, sheet iron. tinned iron, or zinc, the drawings being shallow so as to be carried out in a single step. One of the housing members is provided with a pair of apertures for support of the electrode terminals, the material of the housing surrounding the termina] apertures being depressed coincident with the outside extension of the terminal members, thus reducing protuberant structure to a minimum, and providing a structure capable of even stacking without interference from terminals or protuberances on an adjacent structure. In mounting the terminals in the housing member, means are provided for insulating the terminals from the housing and at the same time sealing the opening therethrough against the ilow of electrolyte or vapors therefrom.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is a plan view of a condenser constructed in accordance with our invention.

Fig. 2 is an end view of the same, substantially as indicated by the arrow 2 of Fig. 1.

Fig. 3 is a fragmentary view on an enlarged scale, with parts shown in section, substantially as indicated by the line and arrows 3-3 of Fig. l.

Fig. 4 is an exploded View, showing the relation of the elements contributing to the terminal structure, the view being on an enlarged scale,

Fig. 5 is a view on a smaller scale, illustrating one method of supporting a plurality of condensers, incorporating the instant invention.

With particular reference to the drawing, IB indicates an electrolytic condenser containing a condenser body I2 having a pair of electrode connectors I4 and I6, and wrapped with an insulator I8. The electrode connectors I4 and I 6 are each secured in electrical relation to a terminal member 20 by means of an aluminum washer 22 against which the terminal 20 is riveted as at 24 after passing through an aperture in the electrode connector I4 or I6, and through the washer 22.

The terminal members 20, and their mea-ns of support will be more speciically described in paragraphs to follow. For enclosing the condenser body I2 and for supporting the terminals 20 there is a casing comprising two shallow pans or casing members 3l) and 32, each of which have iiat bottom walls and terminate in iiat rims or iins 3d and 36 respectively. On one of the pans the flange, for instance the fin 34, has a peripheral ange 38 upstanding therefrom, and which is preferably normal thereto, while the other pan, such as the pan 32 has its 1in 36 of such width that the overall dimension of the pan will iit snugly within4 the fiange 38 of the cooperating flange.

One of the pans, for instance the pan 30, is provided with a pair of depressions 40, 42 near one end thereof, which amount to denting in the bottom wall of the pan toward the flange thereof, such as to provide a relatively flat portion 44 having an aperture 46. The bottoms of the depressions 46 and 42 at the inner end of the ilat portion 44, and about the aperture 46 are further depressed so as to form countersinks 48, that are concentric with the apertures 46. The countersinks 48 are thus joined to the surrounding metal of the casing part 30 by the substantially upright walls 50, and the fiat portions 44 are joined on opposite sides by the abrupt rising portions 52 of the case member. With the casing member so fashioned the electrode terminals are thence afflxed in the following manner.

The terminal members 2li extend from their flange or shoulder portion with a stud portion 54 that is somewhat smaller in cross section than the diameter of the aperture 46 through the casing member. Over this stud portion there is disposed a washer 56 of insulation, whose aperture is counterbored as at 58, the washer being so disposed on the stud that the recess provided by the counterbore 58 is on the side away from the shoulder 25. The terminal 20 with the insulator 56 thus in place, is inserted with its stud 54 extending from the inside of the casing through the aperture 46 of the housing member.

A washer 69 of mobile material, which may be soft rubber or like compressible material, is passed over the end of the stud 54 and pressed down against the flattened portion 48 of the housing. So placing the washer 6l) tends to centralize the stud 54 with respect to the opening 46 since the washer 66 is nicely contained within the rising walls 50 of the countersink and the aperture of the washer closely embraces the stud 54. Over the end of the stud 54 there is then placed a solder shield 62. 'I'he solder shield 62 has an extension 64 on one side thereof, whose lateral sides 66 are straight walls and of a dimension to substantially ll the space between the rising walls 52 of the casing depression. The underside of the solder shield is provided a countersink 68 about its aperture 10, and outside of which there is an annular groove 12 concentric therewith. The solder shield 62 is so disposed on the shank 54 that the countersunk and groove portion is adjacent the mobile washer 60. A plain metallic washer 'I6 is thence passed over the end of the l stud 54, which is followed by a solder lug 18 having a lead connecting tab 86.

While this assembly of elements upon the stud 54 are pressed together, the end of the stud 54 is peened over or riveted as at 82 which action causes the mobile washer 60 to be severely compressed an-d flow through the aperture 46 of the casing into the countersink 58 of the insulator 56, which thereby insulates the stud 54 from the casing 30. The pressure with which the elements are forced together also causes the mobile washer 66 to flow into and fill recesses 68 and 'l2 of the solder shield 62. At the same time, the material of the mobile washer 6U is compressed to more firmly engage the shank of the stud 54, and the peripheral portion of the washer 60 is caused to flow laterally therefrom, such as to ooze out from between the solder shield 62 and the seating portion 43 of the pan, substantially as indicated at 84 and 86.

It is to be noted that each of the elements 56, 66. 62, 16 and 'I8 comprising the assembly to be passed over the stud 54, each have an aperture therethrough designed to closely embrace the shank of the stud. When these elements are forced into compressive relation upon the mobile washer 60, all possibility of electrolyte or vapor leaks through the aperture 46 of the casing member is eliminated, and the terminal member 20, due to the centralizing relation effected by the insulators, washers and formed walls of the casing depression, is electrically isolated from the pan, so as to eliminate any short circuits from that source. Since the sides 66 of the solder lug closely engage the rising walls 52 of the depressed portion of the casing, rotation of the terminal assembly is obviated, which prevents rupture of the electrode connectors I4 within the enclosure and also prevents movement of the terminal 20 into engagement with the metal of the pan on which it is mounted. All of the metallic elements within the casing that might be exposed to the electrolyte therein are composed of corrosion resisting material, thus eliminating the possibility of corrosion or ionic dissolution. The terminal parts are to be of film forming material. Having the condenser electrodes so connected with the terminals, the casing members 3U and32 are thence nested together with their fins 34 and 36 in contacting relation.V With the parts in this position the edges only of the casing may be dip soldered for sealing the two casing members together. The solder joint so effected is indicated at in Fig. 3. The construction thus affords a simple and efficient means of sealing the two casing members together, and is one that may be practiced by an unskilled operator, since it is-only necessary to hold the two casing members together, and dip their edges into the solder bath. The construction lends itself readily to a method of automatic soldering wherein the assembled units may be properly supported by conveyors or the like, that dip and roll the edges of the vcasing members in the solder bath. The point at which the casing members are soldered together is so remote from the active elements of the condenser that overheating of the condenser section within the can is obviated. overheating-of the condenser sections adversely affects the condenser, and may be conductive to oozing of the electrolyte from the seams that are being soldered. Such conditions were experienced in the conventional type of condenser casing of the long stan-ding rectangular casing, fitted with a Bakelite enclosure providing a solder flange. `As a means of forestalling any diflculty with respect to electrolyte ooze and soldering, we may elect to provide a small aperture 92 through one of the casing members, substantially as indicated in Fig. 1, so that if the operator is slow in completing the solder connections of the casing, or such that if the condenser assembly is maintained in too hot a condition While the soldering is being effected, that-a relief is afforded for the escape of a small portion of the electrolyte or gas therefrom while the soldering is being effected. While so doing it is found that electrolyte leaks between the fins 34 and 36, while the unit is being soldered, will be eliminated. At the conclusion of the rim soldering of the casing members the small aperture 92 is closed with a drop of solder, such as to maintain the assembly in sealed condition.

Electrolytic condensers so constructed are adaptable for mounting and electrically connecting in banks, as shown in Fig. 5, where-a rack is provided that includes a plurality of rails 54 and 8S each having spaced parallel notches 98 adapted to receive the sealed edges 33 of the condensers IU. The rails 94 and 9S are of nonoonducting material, and preferably have a strip of insulating material within the grooves and folded over the edge 38 of the condensers. The condensers lll may be electrically connected in any number of ways, one of which is suggested by the dashed lines of Fig. 5.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

l. In an electrolytic condenser, the combination comprising, a casing member `naving a depression therein and apertured for reception of a terminal member, said depression providing an annular recess about the aperture therethrough, a shouldered telminal having a shank of relatively small cross section as compared with the casing aperture, an insulating washer closely iitting the shank of said terminal member and having an annular recess surrounding the said shank when the washer is mounted thereon, said shank passing through the casing aperture, and said insulator recess facing the wall of said casing member, a soft rubber washer disposed on the opposite side of said casing member and closely surrounding the shank of said terminal, a solder shield disposed over the shank and having grooves concentric with the shank engaging the soft rubber washer, and means including a part of the shank forcing the solder shield toward the insulating washer and for compressing the soft rubber washer, whereby it flows into the depressions of the insulator, the enlarged aperture of the housing member and the grooves of the solder shield, thereby eifecting complete insulation of the terminal member from the housing, and completes a seal against uid flow through said housing member.

2. In an electrolytic condenser, a shouldered terminal stud, a housing member providing an aperture therethrough substantially larger than the section of the stud, a pair of insulators closely surrounding the stud and disposed one on either side of the housing member, said insulators being recessed concentric with their apertures, said insulators being disposed on the stud so that the recessed portions each face the housing member, a washer of mobile material disposed between one of the insulators and the housing member and closely surrounding the shank of said stud, a backing washer axed against the outer of the insulators, said stud being riveted against the backing washer to compress the mobile material, causing it to flow into the recesses of the insulators and into the enlarged aperture of the housing member for insulating and sealing the terminal member from the casing.

3. An electrolytic condenser comprising in combination, a condenser body having tabs secured to terminal members, a pair of substantially symmetrical housing members for enclosing the condenser body, one of said housing members having aperturcd depressions for support of the said terminals mounted in the depressions, insulating means positioning the terminals centrally of the apertures and insulating the terminals from the housing member, said insulating means having non-rounded extensions engaging the wall of the housing depressions for preventing turning of the terminals relative to the housing, whereby loosening of the terminals and rupturing of the tabs is prevented.

4. In an electrolytic condenser under an hermetic seal, a casing assembly comprising in combination, a pair of shallow drawn thin gauge sheet metal pan-like members, each member having a perimetric rim occupying a common plane, and adapted to engage the rim of the other member, one of the pan members being further deformed to provide a perimetric ledge for receiving and locating the other pan member, and said one pan member being provided at one end thereof with a pair of symmetrical depressions projecting toward the interior of the casing assembly, said depressions including spaced lineally extending shoulder portions adapted to abut terminal insulators, a pair of electrode terminals, means for mounting both terminals in insulated relation each in one of the depressions and with respect to each other, whereby terminal members therein mounted will be prevented from rotating or loosening and means sealing the members one to the other, to prevent passage of fluid matter at their rim junctures, said pan rims providing radiating ns for cooling of said condenser.

5. In an electrolytic condenser under an hermetic seal, a casing assembly comprising in combinaticn, a pair of shallow drawn thin gauge sheet metal pan-like members, each member having a perimetric rim occupying a common plane adapted to engage the rim of the other member, a pair of electrode terminals, means for mounting both terminals in insulated relation on the case assembly and with respect to each other, and means for sealing the members one to the other to prevent passage of fluid matter at their rim junctures, said pan rims providing radiating ns for cooling of said condenser, said means for mounting the terminals comprising depressed formations of one of the pan members each having an aperture therethrough, terminal studs with appropriate insulators mounted in the apertures, and a mobile gasket being disposed against the material of the pan depression and engaged by an outside insulator, all of said insulators being recessed to provide channels for reception of the mobile material when compressed, said outside insulator having lateral extension and engageable with the walls of said pan depression whereby rotation of the terminal assembly is prevented and said outside insulator providing a shield against solder bonding the terminal member to the pan member.

ALEXANDER M. GEORGIEV. PAUL F. KOEHLY.

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