US2190826A

US2190826A - Electrolytic condenser

Info

Publication number: US2190826A
Application number: US53367A
Authority: US
Inventors: Deeley Paul Mcknight
Original assignee: CORNELL DUBILIER CORP
Current assignee: CORNELL DUBILIER CORP
Priority date: 1935-12-07
Filing date: 1935-12-07
Publication date: 1940-02-20
Anticipated expiration: 1957-02-20
Also published as: FR809390A; GB476617A

Description

Feb. 20, 1940. P. MCK. DEELEY 2,190,826

ELECTROLYTIC CONDENSER Filed Dec. 7, 1935 INVENTOR Paul mcilfnzgykigee lsq BY ATTORNEY.

Patented Feb. 20, 1940.

UNITED STATES amaze ELECTROLYTIC CONDENSER Paul McKnight Deeiey, New York, N. Y., aaaignor to Cornell-Dubllier Corporation, New York. N. Y., a corporationof New York Application December 7, 1935, Serial No. 53,387

.SCIaims.

My invention relates to condensers in general and has particular reference to electrolytic condensers. preferably wet electrolytic condensers, although not limited to condensers of this type. The general type of wet electrolytic condenser to which the present invention appertains consists briefly of a container adapted to accommodate an electrolyte solution and an electrode immersed in the electrolyte and constructed in 10 a convenient manner, such as in the form of a strip or sheet of metal, preferably aluminum, wound into a spiral, or folded back and forth upon itself in the manner of accordion pleating, or formed into a helicoidal surface as described in detail in my copending application Serial No. 28,033 filed June 24, 1935; such electrode having a very thin coating of a dielectric film electrolytically formed thereon in a manner well known in the art.

In condensers of the foregoing general character, it is customary if not essential to provide venting means for the interior of the electrolyte container for the purpose of enabling the gas which is formed above the electrolyte during operation of the condenser due to heating or other chemical or physical causes to escape from the container.

It has already been proposed to provide a vent in the form of a thin perforated rubber sheet, the

perforation having the size of a small pin hole in such a manner that under normal conditions; that is, when the condenser is not in operation, the pin hole is fully closed and exposure of the electrolyte to the outside atmosphere and seeping or leaking through the pin hole is substantially prevented. When the condenser is in operation and heated, due to the electric current passed therethrough, the gas developed in the container causes the pressure therein to in- 40 crease whereby the rubber diaphragm is caused to distend or blow up. As a result the pin hole perforation is momentarily enlarged, permitting the excess gas to escape thereby relieving the excess pressure within the container. After the 46 gas has escaped, the rubber sheet or other flexible member assumes its normal position in which the pin hole is closed and the interior of the container sealed from the outside atmosphere.

When using a vent of the above described 60 general characteristic, consisting of a thin diaphragm of rubber or other flexible material conveniently mounted in a wall of the container, preferably the bottom or top end wall, disadvantages are experienced by reason of the fact that 55 the vent is subject to damage during shipment defects.

(CL 22H!) and handling and due to the likelihood of its becoming clogged or obstructed by foreign matter, such as dust and dirt and other obvious The object of the present invention is to prc- I vide a vent construction of improved character for electrolytic condensers which is substantially free from the disadvantages heretofore experi enced in similar constructions inthe art and which is simple in construction and design and m eflicient and reliable in operation.

Further objects and novel aspects of the invention will appear hereinafter from the detailed description taken with reference to the accompanying drawing wherein:

Fig. 1 is an elevational cross-sectional view through an electrolytic condensermounted upon a support or chassis and embodying the features of the present invention.

Fig. 2 is a top view of a condenser according go to Fig. 1.

Fig. 3 is a cross-section of the condenser shown in Fig. 1 taken on line 3-3 of Fig. 1.

Fig. 4 is an enlarged cross-section of the dee pending neck portion of the condenser accord- 1; ing to Fig. 1 taken on line [-4.

Fig. 5 is an enlarged perspective cross-sections a1 view of a combined sealing gasket and breather diaphragm associated with the top and cap of the condenser shown in Fig. 1. i 30 Similar reference characters identify similar parts in the different views of the drawing.

Referring to the drawing, the condenser shown therein comprises a metallic container I prefer ably of cylindrical shape and consisting of a ,5 suitable metal such as aluminum or the like well known in the art. The container has a bottom wall I l and a top wall l3, the latter having a combined sealing gasket and vent or breather diaphragm associated therewith as will 0 be described hereinafter. The bottom end wall II has an enlarged, preferably-screw-threaded hollow attachment neck portion as shown at 2 serving for mounting the condenser on a support. or chassis 3 in an upright position in accordance 45 with the usual practice in the art as shown in the drawing.

The anodic member or filmed electrode shown at 4 which is supported by the riser rod 5 in the example illustrated, consists of a sheet or strip 50 of suitable film forming material, preferably high purity aluminum of relatively small thickness which is folded back and forth upon itself in the manner'of accordion pleatingand riveted or otherwise secured to the riser rod 5. For this purpose the rod I ispreferably' swaged or. flat.- tened throughout its entire upper part being in contact with the electrode 4, and provided with dish-shapednepressions enablin an easy and efficient connection of the central pleat ofthe anode by means of rivets or any other connection I as shown at 6 in the drawing. The pleat-s of the anode in the example shown are of different,

widths, being largest in the middle anddecreasing towards both ends as, seen more clearly from Fig. 3 and should 'have suiilcient rigidity to provide a self-supporting anode structure. By this method of folding a considerable le'ngthof foiL tures in" the form of reduced power factor or equivalent resistance. The rivets 6 should be'of f the same material as the rod 5; that is, highpurity aluminum according to the above example. The rod 5 should also be of him forming '-metal such as aluminum as it is apart of the anode member. In this manner corrosion effects at the joints between the rod 5 and the anode 4 are prevented. r

The carrier or riser rod 5 is forced through a resilient plug 1 of relatively flexible insulating material, such as rubber, said rubber plug being in turn forced Into the container neck 2. The

lower unthreaded part of the neck 2 is deformed or orimped to form axial depressions 2' uniformly spaced around the neck 2, to secure a liquid tight seal between the neck 2, the rubb'er plug I and riser rodl, as seen more clearly from Fig.4. The crimping of the neck can also be done by one or morevcircular grooves in place of axial grooves shown in the drawing as will be understood. The lower end of theriser rod projecting through the plug 1 constitutes the terminal of the anode and may be provided with suitable electrical connecting means, such as a clamping Y material which is not 5 wardly and thenin an outward direction perpendicularly to the axis of the container in such a manner as to provide a rim 'orfiange shown at II. Both the cover It andthe' combined rubscrew or soldering lug shown at 8, which may be either riveted on to the rod 5 or forced on or otherwise suitably connected therewith to secure eflicient electrical contact.

In order to prevent the anode 4 from coming in accidental contact with the wall of the container. a spacing element of suitable insulating attacked or affected in any way by the electrolyte, such as a cylindrical spacer I .of hard rubber, Celluloid or the like. is arranged between the anode and the inner wall of the container. In order to insure free access of the electrolyte to both the container and the anode surface, the spacer I is provided with a plurality of perforations III of suitable size and spacing as shown in the drawing- The top end of the container is shown to be closed by a pair of disc-shaped .cover members 43 and Il, the latter consisting of flexiblematerial such as rubber and serving as a combined sealing gasket and vent or breather diaphragm while the former may consist of metal and serves to protect the vent or breather diaphragm against outside interference. The upper edge of the container is shown to be bent at first ina a,1ao,a'ae g} I I Y I be! gasket and vent'diaphragmpl'i are providedm with mid portions forming cup shaped deprei i sions as'shown at II and I! which fit inside of the container I at I8.

The gasket and vent is its directly inside ofthe container while the eoverproperli, fits in turninside the rubbergasket ll as shown in the drawing. The outer-ledges or'rims of the gasket llthe'cover It then spun over the mbrfiange ii ofth'e container I and into liquid tight I 2 wm therewith, whereby the rim ol mlm'on of the gasket l4 acts as a sealing washer in securing a liquid tight joint and preventing the electrolyte solution from leaking out during the shipmentor'handling of .the condenser. The center portion or cup-shaped depression I1, is formed as a vent or breather diaphragm and provided for this purpose with a thin center section as seen more clearly at I s in Fig; 5. The center section is has a perforation or aperture of pinhole size closed under normal conditions and preventing exposure of atmosphere. In-crderto enable the mid portion I1 to expand or distend readily under the influence of excess pressure developed in thecontainer, I have shown the mid portion I! of the.

cap ll of oonvex'or outwardly arched or vaulted construction so as to allow the rubber diaphragm under internal pressure to distend and curve up 7 like a balloon and open the perforation in the thin center section II. In order to enable the gases passing through the perforation or pin hole in' the section I8 to escape to the outside,

I have furthermore shown the outer cover It provided with apertures or escape holes 20 of.

suitable size and, spacing, as seen from Fig. 2.

In this manner the container isunder normalconditions sealed from the outside atmosphere and may be handled and shipped with great facility wlthout'any of damage to the interior of the container or likelihood of loss or leakage of the electrolyte from within the con tainer'as well as damage due to the clogging or tne electrolyte is thecontainer to the outside I cess pressure in the container, I have shown the gasket portion II to be provided with integral protuberances or elevations 2| suitablyairanged around the thin center portion is and acting as spacing elements in preventing the diaphragm I1 fromcompletely closing and obstructing the escape holes 20.

c As will be understood, the anode may be formed with a dielectric film by any one of the known methods in the art and the forming may be carried out either before or after mounting in the condenser structure. When using aluminum as electrode metal, an electrolyte consisting of a mixture of borax, boric acid and water has been found to give satisfactory results. Furthermore the anode may have its surface increased by a roughening or chemical etching process to secure an unsmoothsurface with minute depressions and elevations followed by the overlyingv dielectric film with the result of a substantial increase of the capacity of the condenser as is well understood.

Aswill be evidentfrom the above, the invention is not limited to the specific construction shown in the drawing for illustration but is susceptible of modifications and variations coming under its broadest scope as defined in the appended claims.

I claim:

1. A vent structure for an electrolytic condenser or the like having a cylindrical container subject to internal excess gas pressure, comprising a cap having an outer flange and an inner outwardly arched apertured portion, said cap being secured to an open end of said container with its flange forming a narrow gap with the container, a diaphragm having an outer rim and a punctured central portion, the outer rim of said diaphragm being disposed within said gap to effect a liquid and gas tight seal between said container and said cap, the inner portion of said diaphragm underlying said cap, and spacing means intervening between said diaphragm and said cap and surrounding the punctured section 01' said diaphragm, whereby said diaphragm is adapted to distend underneath said cap at first in its entirety until prevented by said spacing means, whereupon only the punctured section will distend further under the action of excess gas pressure developed within said container.

2. A vent structure for an electrolytic condenser or the like having a cylindrical container subject to internal excess gas pressure, comprising a cap having an outer flange and an inner outwardly arched apertured portion, said cap being secured to an open end of said container with its flange forming a gap with the container, a diaphragm having an outer rim and a punctured inner portion, the outer rim of. said diaphragm being disposed within said gap to effeet a liquid tight and gas tight seal between said container and cap, and integral spacing elements of said diaphragm surrounding its punctux-ed section and intervening between the diaphragm and said cap.

3. A vent structure for an electrolytic condenser or the like having a container subject to internal excess gas pressure, comprising an outwardly arched apertured cap having its edge secured to an opening of said container, a normally flat rubber diaphragm having a punctured center section of lesser thickness than its outer portion, the edge of said diaphragm being disposed within the gap formed by said cap and said container to effect a liquid tight and gas tight seal between said cap and said container, said diaphragm spanning said opening underneath said cap, and spacing means surrounding said center section intermediate said diaphragm ing its edge secured to an open end oi said container, a normally flat rubber diaphragm having a punctured center section of lesser thickness than its outer portion, the edge of said diaphragm being disposed within the gap formed by said cap and said container to effect a gas tight and liquid tight seal between said cap and said container, said diaphragm spanning the opening of said container underneath the arched portion of said cap, and a spacing member integral with and surrounding the center section of said diaphragm, said spacing member projecting from said diaphragm intermediate said diaphragm and cap and being normally spaced from said cap.

' 5. A vent structure for an electrolytic device having a container, subject to internal excess gas pressure, said vent comprising an apertured cap secured to an opening of said container, said cap having a rim forming a narrow gap therebetween and said container, a flexible diaphragm having a rim disposed within said gap, the rims 01. said cap and said diaphragm being spun over with the edge of said opening toefiect a liquid tight seal between said cap and said container, said diaphragm being normally spaced from said cap and having a central section of lesser thickness than its outer portion with a normally closed puncture therein, and separating means intervening between said diaphragm and said cap exterior said center section and normally spaced from said cap.

PAUL MOKNIGHT DEELEY.