US2580664A

US2580664A - Dry cell

Info

Publication number: US2580664A
Application number: US667768A
Authority: US
Inventors: Arthur P Drummond
Original assignee: Union Carbide and Carbon Corp
Current assignee: Union Carbide Corp
Priority date: 1946-05-07
Filing date: 1946-05-07
Publication date: 1952-01-01
Anticipated expiration: 1969-01-01

Description

Jan. l, 1952 A. P. DRUMMOND 2,580,654

DRY CELL Filed May '7, 1946 v INVENTOR ARTHUR P.oRuMMoNo BY f Il I l, [3 -fU Y Patented Jan. l, 1952 OFFICE* p DRY CELL Arthur P. Drummond, Cleveland, Ohio, assimor, by mesne assignments, to Union Carbide and Carbon Corporation, a corporation of New York Application May '1, 194s, serial No. esmas' zouims. (criss-133) This invention relates to dry cells, more particularly those of a size and shape intended for flashlights. An object of the invention is to provide a dry cell in which looseness of a jacket has been minimized or prevented. A further object is to provide a contact fit to prevent egress of electrolytev material at the ends of the cell without the necessity of having to use any adhesive or seal against electrolyte material coming out.

It has heretofore been suggested to use a sti. non-bulging, insulating jacket of an appropriate resinous insulating material such as that described and claimed in the cor-pending application of Roland L. Glover, Serial No. 636,835, filed December 22, 1945, for Dry Cell, now PatentA No. 2,552,091, dated May 8, 1951, on which this invention is an improvement. At first it was found too high a percentage of such jacketed dry cells possessed looseness permitting slight longitudinal movement and relative rotation between the cell and the jacket. `A study of the difllculty has shown that the cause was the crimped rib between the metal top and zinc being at such an angle that after spinning over, there was a tendency for the spun-over bead of the jacket to open a. little by yie'ding. Although the jacket was of stii non-bulging material the spun end appeared to possess some slight resilience. To avoid this difllculty the crimped rib has been disposed more nearly perpendicular to the cell axis so that the bead on the jacket may be spun over to a peripheral length more than is needed to hold it in place. The result has been that the previous looseness has not only been eliminated but a tight enough fit'is obtained between .the jacket and the zinc to guard against egress of any electrolyte material which may exude `through the zinc without havingl to .use adhesive. 'Ihus the beaded jacket is supportedby the engagement of its ends with the ends of the cell.

The spun-over jacket ends are retained in their substantially closed position without danger of opening by yielding to cause the jacket to appear loose.

-Referring to the drawings:

Fig. 1 is a partial longitudinal cross section through one embodiment of this invention;

Fig. 2 is a similar view of a modified construction;

Fig. 3 illustrates a step in the process of forming the dry cell of this invention;

'-`Fig. 4 is a partial longitudinal sectionof another embodiment; and

Fig. 5 illustrates a still further embodiment.

As described in the aforementioned Glover Patent No. 2,552,091, a carbon electrode I0 is provided with a longitudinal and axial hole II over which a vented metal cap 24 is fitted. A conventional depolarizing mix I3 and immobilized electrolyte, material I4 are placed between the carbon and zinc velectrode I5 leaving a gas chamber in the upper end of the cell. Surroundi118 the zinc is a stiff jacket I6 of cellulose acctate butyrate as described in the aforementioned application. A star washer I 1 is located between the zinc bottomA I8 and the depolarizing mix. A blanket 3l is also used around the lower part of the depolarizing mix. A metal end or top I9 is crimped over the upper edge portion of the zinc electrode and separated from the metal cap 24 by an insulating washer 23. A gas-permeable washer or disc 22 divides the gas chamber at zo the top .of the cell in the usual manner.

'I'he early` efforts at applying the jacket I6 by spinning over its ends 2li to form beads as illustrated were not wholly successful because the loop, or bead, or spun-over portion con- 25 tinued to open slightly by yielding at the top end only.` 'I'he loop at the bottom did not tend to open or yield as did that at the top but held closed. The cells to which this jacket was first applied had the crimped joint between the zinc and metal cover extending forwardly and outwardly at an acute angle of approximately 45 as had been customary in the art. Upon study it was found the loop or bead did not close, being prevented from doing so by the upward inclination of the crimped joint. The result was a tendency for the spun-over loop to yield or tend to open to some extent with some of the cells. Such resulted in a noticeable looseness between the edge of the cell and the jacket I5. In order to overcome this diiculty the crimped joint between the zinc and metal cover has been arranged horizontally as illustrated with the result that it is possible for the spun-over end 20 of the stiff jacket to form a loop tangent to the incident top surface of the cover I9, the loop extending beyond the point of tangency and being spun over an amount more than enough to hold the loop or bead locked in closed position with less tendency to yield. The improved construction is shown in Fig. l in which the upper bead or spun-over end of the jacket forms a loop which is nearly closed, that is, in which the spun-over end is moved slightly past the point of tangency of the loop with the surface I9 for the purpose mentioned.

The embodiment 'shown in Fig. 2 is similar in many respects to that illustrated in Fig. 1, the corresponding parts being designated by the same referencenumerals as was done in Fig. l with the exception that the letter a is added. One important difference is that the ends 2l of the jacket loops 20a are tucked ln between the zinc and jacket as illustrated. Such a construction prevents the loop from the aforementioned yielding or opening and serves the novel purpose of having the ends 2i of the jacket material function as spacers to separate the jacket from the zinc wall, forming a larger volume exudant chamber 25a than was formed in Fig. 1 construction. Sealing

material

26 and 21 prevents loss of moisture from the exudant chamber as well as guarding against accidental. egress of electrolyte material. Although illustrated, this sealing

material

28 and 21 is not believedto be always necessary but may be used with any of the illustrated embodiments of the invention.

In Fig. 3 two

labutments

31 and 38 are arranged to move relatively toward one another no more than a predetermined distance equal to the length desired for the finished cell before the jacket has been applied. In closing the abutment members 31 and 38 a spinning tool 39 deforms the upper edge of the cover as illustrated. The metal cover i9 may be spun or crimped over the zinc. The result is the formation of an exudant chamber 25 outside the zinc and within the jacket I6 for the purpose mentioned in the aforementioned Glover patent. If desired, perforations shown in Fig. 3 may be made in the zinc either above or below the gas-permeable washer 22 in order that any gas pressure may be equalized on each side of the zinc and not tend to deform the groove in the zinc. 'Ihe jacket i6 may be placed contiguous to the zinc as illustrated or, if desired, a thin absorbent paper may be placed between the zinc and jacket for purposes referred to in said aforementioned application. In the embodiment illustrated in Fig. 1, there is no sealing material around the inner portion of the spun-over jacket loops. since such is not ordinarily necessary although,

l of course, it may be used where great precautions against leakage of electrolyte are desired.

In .the embodiment illustrated in Fig. 4, the same reference numerals designate similar parts except that the letter b has been`added. One diiference in Fig. 4 is the presence of a second gas-permeable ring type washer 28, the outer peripheral edge of which is received within and forms a part of the crimp 29 between the zinc and metal cover. Such a construction makes unnecessary the provision of vent holes in the upper end portion of the zinc above the washer 22h since the gas-permeable washer 28 enables any gas pressures within the zinc to be vented into the exudant chamber 25h. A second gaspermeable strip 30 is preferably located between the lower edge portion of the zinc and the insulating jacket Iiib for the purpose of venting any gas pressure within the exudant chamber through the material 30. The contact between the metal cover and spun over bead 20h of the stiff insulating jacket material Ilb is thought to be tight enough to prevent egress of electrolyte material between the metal top and such bead. The gas-permeable washer 30 is placed in the position illustrated to insure venting the exudant chamber and also serves to space the lower portion of the insulating jacket |61) from the lower edge of the zinc. The jacket in each of Figs.

4 i, 2 and 4 is preferably of the same stiff cellulose acetate butyrate material described in the aforementioned pending application. y.

In Fig. 5 a slightly diilerent construction is illustrated. The metal cover 33 is integral with the jacket 32, the jacket being merely a continuation of the metal cover. As shown in P18. 5 the lower end portion of the metal jacket is bent at 34 contiguous to the metal bottom 3l. In this embodiment the metal jacket 32 may be contiguous to the zinc iSc or the metal bottom 35 may be extended to have its outer edge portion bent up forming a spacer between the zinc and metal sleeve. Where the metal sleeve 32 is then spaced from the zinc an exudant chamber 25e is formed and the upper end portion of the sleeve is spaced from the zinc, preferably by means of a gas-permeable washer 38. The bottom 35 may be contiguous to the bottom of the zinc in order to provide a better mechanical reinforcement for the zinc bottom against bulging under gas pressure with the cell or the bottom 35 may be arranged as illustrated. The outer surface of the jacket 32 is preferably provided with an appropriate electric insulating resinou-'s plastic coating for purposes of insulation and decoration. 'I'he metal 32 is preferably of steel although it might be of aluminum with an anodized finish on both the inside and outside since such a finish is hard and a good electrical insulator. A gasket 40 between the zinc and metal jacket enhances the leakproof character of the cell. Of course this gasket Il might be gas-permeable and extend between lower bent end 3| of the jacket and the reinforcing bottom of the cell. Or the steel jacket might be coated on either or both the inside and outside surface with a thin layer of thermoplastic insulating material should it be desired to insulate the jacket from the zinc. The metal jacket 32 may be contiguous to the zinc where no exudant chamber 25C is needed. By exudant chamber is meant a space into which electrolyte material may exude through the container electrode without causing leakage or bulging under ordinary usage of the cell.

By the term closed exudant chamber" is meant the provision of a space radially outside the outer electrode into which electrolyte material may exude without leaking outside the cell or jacket under moderate internal pressure. The outer and end walls of such a space are of electrolyte-proof material, so that the jacket walls are not softened and distorted by the exudant electrolyte material in drying.

I claim:

1. In a dry cell having an outer cylindrical electrode, electrolyte and depolarizing material within said outer electrode, a jacket of stiff material having an electrolyte-proof inner surface outside said cylindrical electrode, a closed exudant chamber between said cylindrical electrode and jacket and a metal cover crimped over the top edge of said cylindrical electrode, the combination therewith of the improvement for increasing the volume of said exudant chamber without increasing the over-al1 dimensions of said cell, said improvement comprising an enlargement in said exudant chamber adjacent the top of the cell above a gas permeable insulating disc which is spaced above the electrolyte and depolarizing materials, said enlargement being formed by the cylindrical electrode being bowed radially inward with the upper edge portion o! 1| said cylindrical electrode extending .generally horizontally radially outward from said bowed portion, said cover being crimped over said outwardly extending electrode edge, whereby any excess length in said cylindrical electrode may be taken up in said inwardly bowed portion and the enlargement in said exudant chamber made without increasing the outside diameter of the cell or reducing the space in which electrolyte and depolarizing materials may be maintained.

2. In a dry cell having an outer cylindrical electrode, electrolyte and depolarizing material Within said outer electrode, a jacket of stii material having an electrolyte-proof inner surface outside said cylindrical electrode, a closed exudant chamber between said cylindrical electrode and jacket and a metal cover crimped over the top edge of said cylindrical electrode, the combination therewith of the improvement for increasing the volume of said exudant chamber and for reducing the danger of longitudinal looseness between the jacket and cell, said improvement comprising an enlargement in said exudant chamber adjacent the top of the cell above the electrolyte and depolarizing materials, said enlargement being formed by the cylindrical electrode being bowed radially inward with the upper edge portion of said cylindrical electrode extending generally horizontally radially outward, said cover being crimped over said outwardly extending electrode edge, whereby any excess length in said cylindrical electrode may be taken up in said inwardlybowed portion and the enlargement in said exudant chamber made without increasing the outside diameter of the cell or reducing the diameter of the space in which the electrolyte and depolarizing materials are maintained, the stii jacket being supported at each end by a bead spun over far enough to stay closed and not yield under any tendency for relative longitudinal movement between said jacket and cell.

ARTHUR P. DRUMMOND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 174,821 Johnson Mar. 14, 1876 439,151 Hellesen Oct. 28, 1890 1,199,390 Landau Sept. 26, 1916 1,500,477 Warncke July 8. 1924 1,590,749 Hulbert June 29, 1926 1,679,629 Rollman Aug. 7, 1928 1,711,182 Shrum Apr. 30, 1929 2,006,691 Giesler July 2, 1935 2,011,519 Holst et al Aug. 13. 1935 2,179,816 Drummond Nov. 14, 1939 2,262,836 Deibel Nov. 18, 1941 2,332,456 McEachron et al. Oct. 19, 1943 2,337,452 Compo Dec. 21, 1943 2,392,795 Anthony et al. Jan. 8. 1946 2,396,693 Glover Mar. 19, 1946 2,399,089 Anthony Apr. 23, 1946 2,410,826 Lang et al. Nov. 12, 1946 2,427,561 Keller Sept. 16, 1947 2,440,401 Hirtle Apr. 27, 1948 2,482,514 Ruben Sept. 20, 1949 FOREIGN PATENTS Number Country Date 330,690 Great Britain June 19. 1930 360,657 Germany Oct. 5, 1922 411,434 Great Britain June 1, 1934 684,550 Germany Nov. 30, 1939 OTHER REFERENCES Mills: Top and Bottom Attachments," Product Engineering, August 1945. pages 544 and 545.