US2163262A - Electrolytic cell - Google Patents

Description

June 20, 1939. H. E. RHODES 2,163,262

ELECTROLYTIC CELL Filed Aug. 9, 1935 INVENTOR llaaurd Z. Y/zozk's BY ATTORNEYS QQQQ CM 451/4001 $7643 PatentedJune-ZO, 1939 I D ELECTROLYTIC CELL Howard E. Rhodes, FloraLPar-k, N. Y., assignor to Aero'vox Corporation, ration of New York Brooklyn, N; Y., a corpo- Application August 9, 1935, serial No. 35,474

7 Claims.

My present invention relates to electrolytic cells, and primarily to electrolytic condensers of the so-called wet type; An object of the invention is to' provide a venting device for an electrolytic cell, more especially of the wet type, which precludes the leak or escape of the liquid contents or any'part thereof,

even though the vent be held downward, and'yet affords adequate escape for gas pressure that may be evolved during use.

Another object is to provide a device of the above type which shall be inexpensive in construction, which afiords no protrusions mechanically vulnerable in handling or of ungainly appearance, but which on the contrary affords an attractive all-metal exterior, not subject to appreciable deterioration after successive ventings and which affords substantial venting protection throughout the effective life of the cell.

Another. object is'to provide a device of the above type in which no visible deposit occurs of salt entrained residue from droplets of electrolyte with gas during venting. v

Another object is to provide an anode structure for a wet cell such as an electrolytic condenser which' is simple and inexpensive in construction, the elements of which are mechanically secure and not subject to deterioration after extensive use, and which afiords a condenser of superior power factor.

In the accompanying drawing, in which are shown one or more of various possibleembodi ments of the several features of the invention,

Fig. 1 is a. view in longitudinal cross-section of a condenser according to the present invention, Fig. 2 is a transverse sectional view taken on line 2--2 of Fig. 1, 'Fig. 3 is a perspective view of the anode unit, and

Fig. 4 is a dropped perspective view of the parts making up the venting unit.

Referring now to the drawing there is shown in Fig. 1 a wet electrolytic condenser comprising the cathode can I, ordinarily of aluminumgthe open end of which is illustratively shown with a rigid insulating closure plug H which may be of vulcanite, hard rubber or the likeand which has a threaded extension l2 that serves'for mounting the unit in conventional manner. The plug rests against a unitary shoulder I3. in the can and is secured in place by rolling the rim of the can, as at H, against a soft rubber gasket 15 lodged in a rabbet in the plug I l.

Mounted on the rubber -plug is the anode structure, which according to-the present invention is of special design. The riser in this embodiment comprises a metal rod 18 having an enlargement l'l resting in a corresponding depression l8 in the closure plug and having its lower end upset at I9 over the terminal lug 20 against the lower end 01' plug l l.

The riser, the main length of which is preferably flatmounts the anode plates proper. For this purpose it is ordinarily preferredto employ three generally identical plates 2|, 22 and 23, the inner ends of which are superposed as at 24 over the riser and are rigidly attached thereto by hollow rivets 25 extending through the riser and said superposed plates to connect the elements into a rigid assembly.

Preferably the anode plates 'are in undulatory form, deeply corrugated as at 26 to afl'ord an increased surface area of anode within the space confines of the container. The general plane of each of the plates preferably radiates from the axis of the riser and said plates are spaced at uniform angular intervals 120 degrees apart as shown, although of course different spacing could be employed, andfour or more of said plates could be used, if desired. Preferably the riser, the plates and the rivets are all of the same film forming metal, ordinarily aluminum, and the plates, rivets and riser are all formed with the usual dielectric film.

The outer ends of the corrugated anode plates would press against the inner wall of the can In in the assembled construction and tend to shortcircuit the condenser. To prevent such shortcircuiting an insulating liner sleeve .8 perforated as at 29 is disposed within the can and is contacted by the outer extremities of the several anode plates.

The cell is charged with' a liquid electrolyte solution 30 to a point above the level of the anode which it submerges. This solution ordinarily is an aqueous one and may be the conventional one of boric acid and sodium borate.

According to the present invention, the average distance from the anode plates to the can is relatively small, for which reason the course of current flow between the anode and the cathode has a short average path through the electrolyte, so that the series resistance is kept at low value and the condenser with the present anode structure therefore has superior power factor characteristics.

In the operation ofelectrolytic condensers, gas pressure may develop from time to time while the condenser is on voltage. This may result from excessive heat in the condenser causedwhich must be relieved, without, however, afiordrubber and 2 amazes by current leakage through film, or by the to the operationabove described, for. were saidproximity of other heat generating apparatus rubber washer permitted to balloon up under such as transformers andtubes. The expansion conditions of .pressure and to conform to the of the liquid and especially of the air' inside the shape of the inside of thehood 3'! before venting,

condenser results in the evolution 'of; pressure electrolyte might creep between the can and the 5 impair .the return of the rubber to its ing any opening that might' permit: any of the flat' condition. i

liquid electrolyte te -leak out. v f While the dished washer 35 'as describedis In the specific embodiment shown, the closed preferred, sinceit afl'ord's the auxiliary inner end of the containenshown uppermost in Fig. 1, has a central aperture 3,l therein 01% to inch metalwasher for the rubber washer would serve in diameter and an uprising peripheral lip 32. A andis within the scope of certain of the claims flexiblerubber washer 33 rests on'the end wall e einwith its periphery substantially in contact with It is, 'of course,-understoQ that h' the inner wall f the lip 32. Said washer has scope'of theinvention'in its broader aspects, the a minute pinhole show'n exa gerated in size at hood element. and the auxilia y 34 which, by virtue of the elasticity of the rubber, o d d t e eby might e' mi edis normally. closed n i su erposed It is also understood that the flexible, elastic -over the rubber washer 33 is a dished spring Washer d the Protective Washer Could be 518- metal washer 35 of smaller diameter, preferably D Parts O the n i' the d seal above described, it is understood that a flat 1 v protection afof phosphor bronze with a central aperture 35 therein of substantially the size of the aperture 3| in the end wall of the; can. Superpo'sed over the rubber washer 33 and spring washer 35 is a protectivejsheet metal domed hood- 31 which has a flat rim 38, superposed over the rubber washer 33 and a concentric shoulder 39 engaging the upstanding rim 4!] of the dished washer 35.

The upstanding lip 32 of the'can' is rolled in ward as at to engage the flange 39 of the dome and to. exert'pressure against the rim of the rubber washer 33, and'incidentally to ,press the dished metal washer against rubber-washer 33 about the aperture 34 Minute venting apertures 42 are provided near the outer part of the dome 31.

The construction described has the advantage that the simple rubberj washer '33 is cut from rubber sheet stock and that the washer 35 and thehood 31 are simple metal ll'he can structure set "forth is quite simple and inexpensive; the extruding die being simply con- -'structed'with a peripheral depression to permit some of the metal from the.slug to be forced 'thereintoto form the lip- 32.

No liquid will ever escape from the unit, re-

gardless whether the device be vigorously, shaken,

orsubjected to such heat as is incurred in trans* portation or use. This is due tothe fact that the rubber-washer 33 forms a satisfactory leak-tight gasket,not only at'the inner portion thereof resiliently engaged by the depressed middle of the. dished washer 35, but also at the outer periphery thereof clamped 'by the hood rim 38. If in the 55.

course of operation, gas pressure'is evolved, thewithout departing from the scope of the invention in its broadest aspects; and that the entire venting imit whether at the end or at the 'side.-.

construction and that the particular anode construction' shown, describedand' claimed may be 35 used with vents other than that made 10,1115": of the subjects of this application.

It will thus be seen that there is herein'described apparatus in which the several featuresof this in? vention are embodied, and which apparatus in its action attains the various objects of the-invention and is well suited to meet-the requirements of practical use. -As many changes'could'be made in the above construction, and many'apparentlywidelydifferent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained inthe above description or shown in the accompanying drawing shall be interpreted limiting sense. 7

Having thus described my invention, what I a claim as new and desire to secure by Letters Pat.-

ent, is: e

, 7 25 and claimed 18 paras illustrative and not in a j l. A vent structure for an electrolytic cell, 'comrubber washer 33- is caused to balloon or how. prising acontajner having an upstanding periphoutwardfrom the region of aperture 34 and eral lip at the outer end thereof and an end wall through e aperture 35 0f Washer In this continuous except for a'relativelysmall axial perand thence escapes through the vents 42. After bowing operation the'pinhole 34 spreads open foration, a flexible washer superposed over said and the gas is delivered into'the domed hood vious near its middle, a rigid hood member prm tecting the exposed face of said washer and having a rim in contact therewith, said container having a lip rolled over said rim to maintain the parts in assembled relation.

2 In. a wet electrolytic condenser structure, a can having a perforatediend wall continuous except for a relatively small am'al perforation and with a peripheral lip rising from said wall, a

the gas pressure has been released the bowed rubber washer 33 snaps back into its plane, by virtue of its elasticity, with the original pinhole 34 closed.

In venting gas pressure, it is possiblethat minute droplets or spray of electrolyte will be entrained with the gas, to settle about the pinhole'of the rubber washer 33, leaving a white deposit of salt thereat. Such salt deposit, howflexible washer centrally gas pervious under pres- 70 ever, is invisible exteriorly and the exposed vent sure and superposed over said end Wall, and means i holes 42 of the dome remain at all times clean clamping said Washer in position immediately andfree from salt or other deposit. about said gas pervious area tolimit the fiexure The spring washer 35 is desirable to restrict to the region covered by said perforation in the the movement o he rubber washer according can, and a protective hood covering said washer '75 perforated end wall, said washerbeing gas per- 60' and said clamping means, said lip being rolled to exert clamping pressure on the rim of said washer.

3. In a wet electrolytic condenser, a can having an end wall continuous except for a relatively small axial perforation, and a peripheral lip rising from the periphery of said end wall, a flexible rubber washer over said end wall and having a small central perforation, a metal hood member protecting said washer and having a peripheral flat rim superposed over the peripheral portion of said washer, said lip being rolled inward over said rim, said hood having small venting perforations. a a

4. In an electrolytic condenser, the combination of a can having an end wall continuous exceptfor a relatively small axial perforation and an upstanding peripheral lip, a flexible rubber washer having a central minute hole superposed over said perforation, a metal washer having a central aperture and superposed over said rubber washer to protect the same, said lip being rolled over and serving to clamp said two washers in position.

5. An electrolytic condenser comprising a can having a central perforated end wall and having a peripheral upstanding lip, a flexible rubber washer having a central pinhole and resting against said end wall, a metal washer having a central aperture and superposed over said rubber washer, and a metal hood having a flat rim superposed over saidmetal washer and affording minute venting apertures, said lip being rolled inward to clamp said hood against said metal and said rubber washers.

6. An electrolytic condenser comprising a can having an end wall with a perforation, a flexible rubber washer superposed over said end wall and having a pinhole at the region of said perforation, a dished spring washer having its outer rim upstanding and perforated in registry with the perforation in said end wall, and a metal hood member exerting pressure upon the upstanding rim of said dished washer and rigidly fixed at its rim to said end wall.

'7. In an electrolytic condenser, the combination of a can having a central perforated unitary end wall and an upstanding peripheral lip, a flexible rubber washer resting against said end wall and substantially contacting the inner periphery of said lip and having a central pinhole, a phosphor-bronze, centrally perforated dished washer superposed over said rubber disk with its outer rim upstanding, a metal hood member having a shoulder engaging said rim and having a flat rim against said rubber washer, said lip being rolled over. against said rim to retain the parts in assembled condition.

HOWARD E. RHODES.

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