Electric dry cell

March 26, 1935.

J. R. CULLEN

1,995,294

ELECTRIC DRY CELL

Filed April 15, 1933

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Patented Mar. 26_s 1935

1,B5_S2M wherein the elements of the cell are assembled with the exception of the activating material, and said material in the form of an electrolyte or other suitable material in a semi-fluid or pasty condition is introduced into the cell when it is desired to put the cell into use, and it is the primary object of the invention to provide an improved constructed and arranged core or mass of depolarizing material of the cathode of the cell to increase the area thereof exposed to the action of the activating material, whereby the electrical energy generated and the longevity of the cell are greatly increased without increasing the dimensions of the cell.

Another object of the invention is to provide a molded bobbin or core of a depolarizing mixture for dry cells having longitudinal flutes disposed about the exterior surface to increase such surface area for exposure to the activating material of the cell and facilitate the molding and withdrawal of the bobbin from the mold and quantity production of the bobbins.

A further object of the invention is to provide an expansion chamber within the cell arranged to permit a ready discharge of gases created by the activating of the cell into said chamber but prevent the flow of the activating material therein.

। A still further object of the invention is to provide a cell of the deferred action type having a filler opening arranged whereby the activating material may readily be introduced into the cell between the bobbin of depolarizing material and , a zinc container constituting an electrode of the cell and the bobbin having a recess in one end for a reserve supply of the activating material, and the filler opening being arranged for the releasable connection of a closure member of 40 hollow or shell structure adapted to communicate with the expansion chamber when in closing position and receive excess gases from said chamber.

It is another object of the invention to pro45 vide improved means to insulate the electrodes from each other and capable of being positioned in the cell as an integral unit thereby greatly facilitating the assembling of the cell.

It is still another object of the invention to 50 provide a depolarizing core or bobbin for dry cells arranged with the exterior surface adapted to be exposed to the activating material of increased area without an increase in the size of the'enclosing container electrode of the adopted 55 commercial dry cell and arrange the core with

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UNITED STATES PATENT OFFICE

1,995,294

ELECTRIC DRY CELL John ®. Cullen, West Hartford, Conn. Application April 15, 1933, Serial No. 666,243 16 Claims. (Cl. 136—114)

Thi-s invention relates to electric dry cells integral means to maintain the core in. rigid Tins invention relates to eiectr y _ _{relation to the contatoer and the} center electrode centrally of the container and thus eliminating additional means to maintain said core in fixed spaced relation to the container of the cell. .

In carrying out the invention there is utilized a metallic container to constitute an electrode of the cell, said container having one end closed and the other end arranged with an expansion chamber formed by a cupped member having a series of perforations and engaged in the container with the open end facing outwardly from the container, and said bottom end of the container and cupped member closed by a closure' member having an opening in a depressed tubular portion extended through the cupped member into a recess in an end of a core or bobbin of depolarizing material of cylindrical form engaged in and of slightly less diameter than the container in juxtaposed relation to the cupped member, said bobbin having equidistantly spaced flutes about the periphery thereof forming with the wall of the container elongated chambers in communication with the bobbin recess to permit of the passage of the activating material into the chambers filled into the cell through the opening in the closure member of the container into the bobbin recess. The opening in the closure is closed by a releasable closure plug of hollow structure having a circular row of perforations to communicate through a series of perforations in the depressed portion of the container closure member with the expansion chamber to permit excess gases from said 3g chamber to escape into the closure plug. To insulate the depolarizing bobbin from the metallic container there is provided a member preferably of unitary structure embodying a cup shaped portion to engage in the bobbin recess ‘ with equidistantly spaced strips extended/therefrom and over the end. of the bobbin in ^contact with the cupped member forming the expansion chamber and longitudinally of the bobbin and interposed between the fillets of the bobbin alternating with the flutes and the wall of the container. A carbon electrode is extended centrally through the bobbin with one end abutting the cupped portion of the insulating member and the other end extended through and insullated from the end of the container having a contact cap attached thereto.

In the drawing accompanying and forming, a part of this application Figure 1 is a perspective

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Ο ** 1,995,294 view of a dry cell embodying the present invention.

Figure 2 is a longitudinal sectional view, on an enlarged scale, of the cell taken on the line 5 2—2 of Figure 3 looking in the direction of the arrow.

Figure 3 is a cross sectional view taken on the ^{3—3 of ngure 2} looking in the direction of the arrows.

> Figure 4 is a fragmentary sectional view of an end portion of the cell taken on the line 4__4 of Figure 3 looking in the direction of the arrow Figure 5 is a perspective view of the member to insulate the depolarizing core from the container with certain of the equidistantly spaced strips broken away to show the cupped portion of said member.

Figure 6 is a view of the insulating member looking at the top of Figure 5.

Figure 7 is a perspective view of the closure for the open end of the, container and looking at the interior thereof to show the depressed portion with an opening therethrough to fill the actiyatmg material into the cell.

Figure 8 is a perspective view of the hollow closure plug for the filler opening in the closure member shown in Figure 7.

Figure 9 is a perspective view of the contact cap that is attached to the extended end of the carbon electrode.

Figure 10 is a plan view and Figure 10α a cross sectional view of the perforated cupped member for forming the expansion chamber. .

figure 11 is a perspective view of the molded bobbin of depolarizing mix; and

Figure 12 is a perspective view of the closure Plug, on an enlarged scale, looking at the bottom thereof.

In carrying out the embodiment of the invention illustrated in the drawing there is provided a metallic electrode and constituting the anode of the cell in the form of a zinc container of cup shape comprising a tubular body 13 having a central opening in the end wall, as at 14 in ^F1gure 2, for a purpose to be hereinafter described, and the opposite end adapted to be closed ^{dlsk 15 secured} to said end of the body 13 m any suitable manner, as by soldering to constitute the bottom of the container The d!Sk 15 is arranged with a central tubular por3% ^{t0 axtend into th}® container body 13 with the wall converging from the disk and hav^{an opening} through the apex to form a conical opoumg into the container with the wall of said tubular portion extending from the apex in a plane parallel with the axis of said tubular portion, as at 17. A series of perforations 18 ^{are cl}^^cuuyf^ereutially disposed about the conical wall 16 adjacent the closure disk 15 for a purpose to be hereinafter described.

The container is provided with an expansion chamber 19 to receive the gases generated during the activating of the cell, said chamber being formed by a shallow dished- or cup-shaped member 20 of insulating material, such as paper having a diameter to permit the same to be inserted within the end of the container body 13 with the open end opposed to and the flange of said member abutting the closure disk 15 and forming with the closure disk 15 the chamber 19. The cupped member 20 has a central opening 21 to snugly fit about the inclining wall of the so that the expansion chamber is in communi10

SO disk. The chamber-forming member 20 is provided with a series of restricted perforations 22 disposed circularly about the disk portion of said member to serve as vents 18 to permit of the passage of gases from the interior of the con- κ tainer to the expansion chamber 19.

A cathode is mounted in the zinc container before the closure disk 15 and the cupped member 20 are applied to the container and comprises a bobbin or body 24 of a depolarizing mix or material disposed about a carbon electrode 23 of the usual stick form having the opposite ends tapered. The depolarizing mix 24 is molded about the carbon electrode and may consist of suitable material, as powdered graphite, a depolarizer, such as manganese dioxide, and conducting salts, such as ammonium chloride and zinc chloride. To provide a bobbin of depolarizing mix which has a maximum amount of surface area to be exposed to the action of an activating material or electrolyte 25, and also to facilitate the molding and removal of the bobbin from its mold, the bobbin is formed to cylindrical shape with a series of flutes 26 equidistantly spaced about the periphery and extending the full length of the body thereof to cooperate with the wall of the container to form elongated chambers by arranging the fillets 27 or portions between the flutes adjacent the zinc container with an insulator interposed between said fillets and container wall, as clearly shown in Figure 3. The length of the bobbin is such that when the closure disk 15 and the cupped member 20 are applied to the container the one end of the bobbin In the container will abut the container end 14 with a disk 28 of insulating material, such as a suitable paper, interposed between the bobbin and the container end, the opposite end of the bobbin abutting the cupped member 20 and the surface of all of the flutes exposed and in opposed relation to the container body 13. The one tapered end of the carbon stick 23 projects beyond the bobbin and engages the wall of a central opening in the insulating disk 28 which is of less area than the opening in the container end 14, as at 29, the exposed end of the carbon having an electric contact terminal 30 in the form of a cap is arranged with a central protruding nipple 31 and is engaged on the projecting end of the carbon stick and retained thereon by a layer of material having insulating properties, such as pitch or a suitable wax, placed P^p0J? the insulating disk 28 within the opening in the end wall 14 of the container and surrounding the side wall of the cap contact, as shown at 32' in Figure 2, said material also serving as a moisture proof seal.

The end of the bobbin 24 abutting the cupped member 20 is arranged with a central recess 32 in enclosing relation to the outlet or tapered end of the depressed portion 16 of the closure 15, said recess being in communication with the longitudinal flutes 26 of the bobbin through radial passages formed by channels 33 in the end of the bobbin radiating from the recess in alinement with and constituting a continuation bf the flutes, and in spaced relation to the disk portion of the cupped member 20 to form passages therewith, as clearly shown in Figure 2.

The cell is activated by the filling of the flutes 26 with an electrolyte, as indicated at 25, by filling

To produce a deferred action cell after the elements with the exception of the electrolyte have been assembled and secured in the container by the closure 15, a releasable closure is engaged in the 5 outlet means 16. , 4.

In the deferred action type of cell the electrolyte 25 is supplied to the cell from a suitable container, such as a collapsible container or tube, not shown, that is kept in stock by the merchan- 10 diser and supplied to the purchaser with the inactive cell, the tube having a capacity to contain sufficient electrolyte to fill the spaces in the cell, formed by the flutes 26 and the wall of the con- , tainer 13, the bobbin recess 32 and tne passages 15 33 The filling of the recess 32 and passages 33 i cover me expose _Sux- assures the filling of the elongated chamter^to 32 and having a central capacity, providing a reserve supply of the electhe bottom of trolyte, the insulating cup 34 preventing a chem- - J leal reaction between the electrolyte and the de- 20

1,095,294 ages also being filled with the electrolyte after .wWch the inlet means 16issealed.

and passages-------------to assure the filling of the flutes to capacity, and constitute a reserve supply of the electrolyte.

It will be observed that the bobbin of the depolarizing mixture is insulated from the container end 14 by the insulating disk 28 and from the zinc closure disk 15 by the cupped member 20 forming the expansion chamber. To entirely insulate the bobbin of depolarizing mixture and electrode 23 from the container electrode, insulating material, such as paper, is interposed between the fillets of the bobbin and the container, and between the surface of the bobbin recess 32 and the tubular portion 16 of the closure 15. This insulator may be in the form of a jacket of unitary structure (Figures 5 and 6) comprising a cupped section 34. adapted to engage in and cover the exposed surface of the bobbin recess 32 —2 l._ ¹

Keieetrow «j.**· 20

i.._o _________.-to support one end of said electrode, the opposite end of the carbon electrode projecting beyond the cell, as hereinbefore described and clearly disclosed by Figure 2. The rim of the cupped section 34 is arranged with equidistantly spaced cut outs 36 conforming in shape to and adapted to register with the channels 33 in the end of the bobbin, and strips of the insulating material extending from the rim of the cup shaped section are interposed between the cut outs 36 to form sections 37 adapted to cover the exposed portion of the end of the bobbin between the channels 33 and flutes 26, and sections 38 continued from the sections 37 are extended in a reverse direction, said sections 38 being of a length equal to the length of the bobbin and adapted to cover - than the Portion 17 and the outer surface of and to be interposed between 40jsjf ^^ter^lengm _wiu the fillets 27 and body of the container, as clearly shown in Figures 3 and 4. The insulating jacket may be applied to the bobbin as it is molded by first placing the jacket in the mold for the bobbin, then positioning the carbon stick with the end engaged in the depression 35, and then filling the depolarizing mix into the mold and tamping · it about the carbon stick, the insulating jacket, bobbin and carbon stick being removed front! the mold as a unit. The cupped section 34 may be constructed separate from the strips 37, 38 to facilitate the forming of the insulating jacket., In the constructing and assembling of the cell there is provided the container having the closed end 14 with the insulating material 3⁹' and contact terminal 30 arranged in the openmg thereof. The insulating disk 28 is then positioned in the container when the bobbin of depolarizing material molded about the electrode 23 and enclosed by the insulating jacket is engaged in the container. The insulating cupped member 20 is then positioned in the container abutting the end of the bobbin and the closure disk 15 secured to the container. By the construction and arrangement of the parts as described the elements of the cell will be assembled in the container in compact and substantially rigid position and the possibility of the parts being displaced and the cell rendered useless by the jarring or dropping of the cell reduced to a minimum.

To activate the cell sufficient electrolyte is sup70 plied to the cell to fill the spaces formed by the bobbin flutes 26, recess 32 and channels 33 connecting the recess with the flute spaces. To produce an activated cell at the factory the electrolytc is —- —____ formed by the bobbin flutes and the recess 32, biuic ώΐινχ υ yxAVLLxvxxxt, --------·- · is introduced into the cell while the cell is in inverted position to facilitate the flowing of the electrolyte into the elongated chambers. After ₂5 the cell is filled with electrolyte the filler opening of the cell is closed by a plug closure member, preferably of zinc, comprising a hollow conical body 39 shaped to conform to the interior shape of the tubular portion 16 of the closure and hav- 30 ing a cylindrical wall portion 40 extended from the apex corresponding to the wall extension 17 of the tubular portion 16 arranged with diametrically opposite pins 41 extending laterally therefrom to slidably engage diametrically opposite longitudinal grooves,42 in the wall extension 17 of the closure tubular portion 16. The portion - -- -· · - ---1 the pins 41 are arranged so that they will engage at the end edge of the portion 17 between the grooves 42 by the rotation of the closure plug, and the end edge of portion 17 may be inclined forming with pins 41 a bayonet joint connection between the closure plug and the filler opening, and firmly draw and releasably retain the closure plug to the filler opening. To form a closed chamber in the shell or body of the closure plug a disk 43 is secured in the larger end of the tubii, lar body 39 and is arranged with a pair of spaced indentions 44 for the application of a tool to . facilitate the rotation of the closure plug in api plying and removing the same.

The hollow structure of the closure plug constitutes an auxiliary expansion chamber and in inlet closing position is adapted to be in constant communication with the expansion chamber 19. For this purpose the body 39 of the closure plug is arranged with an annular recess 45 disposed circumferentially about said body adjacent the larger end adapted to be in opposed relation to co the perforations 18 in the tubular portion 16 whenthe plug is in inlet closing position and said re- cess having a series of perforations 46 through the wall thereof for the passage of the gas into ' the plug chamber, as shown in Figure 2. C5

The perforations 22 in the expansion chamberforming member 20 are so spaced that several of said perforations will be in communication with each of the chambers formed by the flutes 26 to permit of the ready passage of the gases 70 . generated by the chemical reaction in the cell. ;

The electrolyte is preferably of a type which activated cell ar rne xacrory we eieeuu- gelatinizes within ashort time^tro placed into the cell to fill the chambers _{through the} perforation^' ’

1,996,294

22. However should any of the electrolyte lodge m any of the perforations it will be dislodged therefrom by the pressure of the gas generated ^e11’ ^and maintaining communication 6 with the expansion chamber 13 at all times.