US1890178A - Dry cell of the flat type - Google Patents

Description

G. w. HElsE ETAL v 1,890,178

DRY CELL OF THE FLAT TYPE Dec. 6, 1932.

Filed June 1,1. 1924 Patented Dec.- 6, 1932 UNITED STATES PATENT OFFICEl GEORGE W. REISE, OF BAYSIDE, AND ERW'IN A. SCHUMACHER, 0F BROOKLYN, NEW YORK, ASSIGNORS TO NATIONAL CARBON COMPANY, INC., A CORPORATION OF NEW YORK DRY CELL oF THE FLAT TYPE Application led June 11,

rlhis invention relates to improvements in dry cells of the fiat type comprising a bibulous member between the metallic electrode and the depolarizing mix. A principal object of the invention is to increase the eiliciency of such cells by preventing the deterioration of this member due to compression lor other causes.

lVe have discovered that the efficiency of fiat cells and flat cell batteries may be much increased by the use of a compression-resisting bibulous lining orspacer. Uur investigations show that the pulpboard and equivalent material now used in flat cells underl goes a partial dehydration when subjected to pressure. The exact nature of this effect is not clear, but it appears to be a consolida.- tion ofthe lining which makes it unable to transmit and hold liquid in an eicient mana@ ner. The resistance of the cell is accordingly increased and the service capacity reduced.

Further, since the compression of the lining is ordinarily'not uniform, the corrosion of the zinc is likely to be correspondingly irregular and may be excessive upon limited areas of the zinc.

Theseand other difficulties are substantially avoided 0r minimized by the present invention, an illustrative embodiment 0f which B0 is shown in the accompanying drawing.

Fig. 1 is a perspective view of a flat cell battery, partly broken away to show the improved spacing means;

Fig. 2 is a plan view of another form of spacer;

Fig. 3 is an enlarged vertical section on line III-III, Fig.V 2; f

Figs. 4 and 5 are v'iews similar to Fig. 3, showing other forms of spacer;

Fig. 6 is a perspective view of one type of supporting lattice; and

Fig. 7 shows the combination of a lattice with a bibulous sheet.

Referring to Fig. 1 of the drawing, reference numeral 1 denotes a casing containing zinc electrodes 2, blocks of depolarizing m1x 3, and a seal 4, all of which may be of usual type. i

The lining 5, .to which the invention pri- 50 marily relates, is preferably a sheet of bibu- 1924. Serial No. 719,415.

lous material having a relatively low compressibility as compared with the pulpboard ordinarily used in flat dry cells. We have discovered that excellent results are obtained by the use of kraft paper. This is a wood pulpboard well known on the market. It is ordinarily prepared from long fiber sulfate pulp and lis relatively strong and dense as compared with the pulpboard now uscd in the commercial manufacture of Hat cells. Kraft paper is adapted to resist compression in flat cells, but is nevertheless suiiciently porous and absorptive to allow free electrolytic action. The kraft paper or equivalent material is preferably ribbed or corrugated t0 increase its strength, as indicated at 6.

Comparative tests have shown that the improved lining is in general most eiiicient when its ribs 6 are horizontal and adjacent to the zinc. rlhe invention is not limited to this arrangement, as under some conditions it may be desirable to adopt others. The reinforced lining may be pasted in any suitable way. In the cells illustrated, a layer of paste 7 fills the spaces between the ribs and is substantially uniformly in contact with the zinc.

The ribs may be made by shaping the pulpboard after forming it into sheets, or they may be formed as an incident to the making of the sheets. Better results are obtained when the surface of the pulpboard is of the general type shown, but plane surfaced kraft paper or equivalent material of relatively low compressibility maybe used. In such cases it is desirable to incorporate wood slivers or other strengthening means in the sheet.

` The reinforced lining may take a number of other forms, some of which are illustrated sol in Figs. 2 to 5. In Figs. 2 and 3 the lining comprises a bibulous sheet 8 in which a supporting structure 9 is set. The structure is preferably heavy cords, thin wood, or the like, partly embedded in the sheet and joined at the points of intersection in anyv suitable manner. The spaces between the cords should be rather large. We do not contemplate using a close-meshed structure kbetween the bibulous sheet and the zinc, as objectionable compression may occur if the sheet is rigidly supported over a considerable portion of its surface. The form of spacer shown in Fig. 4 ma comprise a bibulous material 10 having a attice-like supporting structure. This structure may be formed in a number of ways. For example, pulpboard or equivalent bibulous material may be provided with ribs or corrugations 11. The concavity of the ribs is pattern similar to that shown in Fig..2', or

in other suitable manner.

The construction shown in Fig. 6 comprises a frame 16 having diagonal supports 17. A bibulous material 18 such as a farinaceous paste or wood pulp may be carried by the frame, or pulpboard sheets, or the like may be set in it. The size and shape of. the compartments for the bibulous material may of course be varied, but generally they should be as large as practicable, to avoid reducing the absorptive area of the sheet. Alterna# tively the frame may merely rest against a sheet of bibulous material. This is illustrated in Fig. 7, in which 19 is the frame and 20 a sheet of pulpboard or the like. The sheet may be corrugated, if desired.

The various spacing means described and their equivalents give excellent results in fiat cell assembly. They have adequate strength to resist the compression to which the cells are subjected, without any objectionable dehydration. In prior batteries this eiect is encountered, sometimes accompanied by exudation of paste. With the improved linings, the cells may safely be put under any reason- -able amount of pressure. Devices for compressing fiat cells, such as wedges, screws, and p other means are well known in the battery art, and form no part of the present invention. The type of battery shown is ofcourse only illustrative. The invention is applicable t0 fiat cells and fla-'t cell batteries generally.

A further important advantage of the compression-resisting spacers is that they provide a protective surface or armor for the bodies of depolarizing mix. In this way the highly objectionable crumbling of the mix under pressure is avoided.

Our invention is broadly a compression resisting bibulous lining for iiat dry cells and the like. It may be used in combination with other bibulous materials, and in various methods of assembly. The embodiments of the invention illustrated are given by way of example only, and various modifications may be made within the scope of the appended claims.

In our application Serial No. 719,416 filed of even date herewith (Patent 1,808,410 of June 2, 1931), compression-resisting linings are described and claimed as applied to cells of the container electrode type.

We claim:

1. A dry cell of, the flat type having an anode, a body of depolarizing mix, a bibulous spacing element between the anode and the body of mix, and compression-resisting members regularly distributed between the anode and `fthe body of mix toprotect portions of said bibulous spacing element from undue pressure.

2. A dry cell comprising Va zinc electrode, a bibulous spacer, electrolyte paste associated therewith and a mix cake, said elements being under compression, said spacer being associated with reenforcing means of relatively small area, whereby the dehydrating effect of the compression pressure upon the spacer is minimized over a relatively large area of the spacer.

In testimony whereof. I aiiix my signature.

' GEORGE W. HEISE.

In testimony whereof, I atlix my signature.

'ERWIN A. SCHUMACHER.

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