US645478A - Accumulator. - Google Patents

Description

(No Model.)

H. LEITNER.

ACCUMULATUB.

(Application filed Mar. 25, 189B.)

Patented Mar. I3., |900.

2 Sheets-Sheet I.

N- 645,478- Patented Mar. I3, |900.

* H. LEITNER.

ACCUMULATOR. (Applicstiog led 15111.17.` 25, 1898.)

2 sheets-sheet 2.

(No Model.)

Tric f:

PATENT HENRY LEITNER, OF LONDON, ENGLAND, ASSIGNOR TO THE ELECTRICAL UNDERTAKINGS, LIMITED, OF SAME PLACE.

ACCUMULATOR.

SPECIFICATION forming part of Letters Patent No. 645,478, dated March 13, 1900. Application filed MarchV 25, 1898. Serial No. 675,203. (No model.)

To all whom, it may concern:

Beit known that I, HENRY LEITNER, eleotrical en gineer,a subj ect of the Queen ofGreat Britain and Ireland, residing at 207 Piccadilly, London, W., England, have invented certain new and useful Improvements in the Construction of Accumulators, of which the following is a specification.

This invention relates to improvements in connection with the construction of accumulators or secondary batteries, and has for its object to provide an accumulator which will be more durable and less likely to get out of order than those hitherto employed, with also the special advantage ofinsuring perfect contact between the active material of the plates and the carriers under all conditions of charge and discharge and expansion and contraction.

The main feature of my invention consists in the utilization in a peculiar manner of the pressure produced by the expansion of the peroxid plates, so as to insure that the parts be kept in proper position and to prevent the lead peroXid from dropping out of the plates, the arrangement also insuring a larger contact-surface.

In order that the invention may be more clearly understood, reference is had to the accompanying drawings, in which- Figure l is a plan of an accumulator constructed according to my invention. Fig. 2 is a vertical section of the same, taken between two of the plates. Figs. 3 and 4c are respectively an elevation and a cross-section of grids for the peroxid plate. Fig. 5 shows a modied form of plate, and Figs. 6 and 7 are respectively a plan and a vertical section of the arrangement as applied to zinc accumulators. Fig. 8 is a detail View.

The peroxid plate I prefer to employ is formed as follows: A double grid or frame A is used, consisting of two lead sheets of suitable proportions provided with contact bars or extensions a at one side. Each of these plates is formed with a series of holes ct,which may be hexagonal 'in shape. These are stamped from .the plate by conical dies, so that the sides of each hole are beveled. The hole is thus slightly larger at one side than at the other, as shown in Fig. a. Two such plates are taken, and after they have been iilled with the paste or Amaterial from which the peroxid is to be formed they are placed face to face,

v so that the larger sides of the holes are at the inside. f The plates are also'arranged so that the holes do not register with each other, the bars of one plate crossing the holes of the other. Owing to the beveled form'of the holes, the plugs of paste will not be liable to fallout even without the pressure produced in the manner hereinafter described'. As, however, the arrangement' hereinafter described prevents the peroXid falling from the plate witho'ut such construction, I may employ the form of plate shown in Fig. 5. This consists of a single grid A perforated to receive the paste. The rim a2 is thicker than the body ofthe plate, and the paste fills up the vplate to the level of the rim, as shown in the drawings. On both sides of the negative plates parallel pieces B of resilient material, such as cellu loid, are fixed. These bars are not secured directly to the plate, but to the inclosing frame hereinafter described. Three of these bars are preferablylemployed in plates of ordinary size; but a larger number may be used.

These separating-pieces, which are used to transmit the pressure and not merely as distance-pieces, I may make of triangular shape in cross-section, and they may also be hollow.

This form allows the sides of the pieces to bulge out on transverse pressure being applied to press the plates together. As the material is elastic, any compression which may occur will not permanently change the shape of the bars, but these will spring back again into their normal shape on the pressure being relieved. A series of plates are placed together, the faces of the positive plates resting against the separating rods or tubes ot' the negative, as shown clearly in Fig. l. The plates when inserted in the case C rest on the supportingbars b, which may be of the same material as the separatingbars. Onboth sides of the series or block of plates so formed a plate D of impregnated Wood or othersuitable material is placed.l This is preferably grooved at one, two, or more parts, and in the grooves bands E of the resilient'insulating material, as Celluloid, above described, are tightly fitted. These bands are continuous IOO and of considerable width to give the required strength and great resistance to a pulling force. Nhen the arrangement is complete, a solid mass is formed, the plates being pressed closely together, separated only by the elastic tubes -or bars.

The resilient casinginclosing the plate consists of a bar or rim F of the same material as the resilient bars,extending completely around the plate and covering part of the lug. On this rim the perforated'sheets f, also of lthe said resilient material, are iixed, so that the plate is completely inclosed. The celluloid is not ijxed to the lead plate at any point, but merely incloses it. The perforations of these sheets do not extend close to the edges, so that side strips of unperforated material are formed which cover the sides of the lead grids and protect them from the action ofthe electrolyte. These rims are shown of square cross-section in Fig. it; but any other suitable cross-section may be employed. The bars B, which in the detail views are rectangular in cross-section, are fixed at their ends only to the unperforated edges of the sheets f, the

main part of these bars being quite clear of the perforated sheets. Any extension in length of the plate will thus stretch the bars, which will return the plates to their proper shape when contraction of the peroxid occurs. A cross-strip f may also be employed,

anyside expansions. As the conducting-lug, as Well as the sides of the grid, is protected by the frame from the solution, it will not be liable to get attacked. inclosing frame or case I prefer to employ only in connection with the negative plate. The positive plate may be left unprotected and simply supported by the side band and by side strips and small supporting-pieces, which prevent the positive plates dropping or shifting -with respect to the negative.

The material of the bands and bars should possess considerable strength and stretch .very little for a large pull, so that the amount of expansion .which occurs in the accumulator will cause a very powerful reaction, which presses the halves of the plates tightly together, and therefore the plugs in the grids hard up against their conducting-surfaces.

tendency will be to cause the two sheets or perforated plates of lead of whicheach plate is built up to separate, this action taking place owing to the beveled form of the holes and the fact that the plates are placed back to back and are joined together at the edges only. Each plate will thus tend to bulge slightly out on both sides, so as to become expansion is resisted by the outer bands and the separating-pieces, and as these are all resilient they will give slightly to the great pressure produced by the expansion. The expansion owing to this back pressure will thus This arrangement of cause the peroxid plugs to be'pressed -irmly against the lead grids, giving the largest possible conducting-surface. As the peroxid contracts, instead of the pressure beingat once taken oft, as would be the case if the parts were not resilient, the extension or compression of these resilient parts is utilized to recompress the plates until they return to their former size. The plates are thus again pressed quite flat, and the active material in both plates is still kept tightly against the grid. The peculiar formation of the grids enables this action to take place, as the expansion does not tend so much to open the holes, and thus to be transmitted'sidewise,

but only slightly separates the two plates v against the force of the binding material of the whole block. Inthe single-plates the action is similar, with the exception that the peroxid is not inclosed between two grids, `but only by the external casing.

This arrangement also allows a large number of thin plates to be employed instead of a smaller number of thick ones, as in the present construction ot' accumulators. A greater surface is thus provided, which substantially ini creases the efficiency of the accumulator. At

the same time the block of plates formed in y the manner described is quite solid and will g not be injured by rough usage whether me- 5 chanical or electrical.

iixed only at its ends and serving to take up As applied to zinc accumulators, Figs. 6 and Y 7, sufficient space is left between the separating-pieces to allow of thezinc plates G being inserted. These zinc plates are constructed so that they are quite free from pressure, being held in parts by means of insulatingpieces B, which do not, however, bear upon the zinc. These plates are formed with cores g of celluloid or like material,-Fig. 8, which extend a little beyond thel ends of the lead on which the zinc is deposited. The lead base partly surrounds-these plates of celluloid, so as to form a sheath, leaving, however, projecting portions. The corners of the core which are outside the sheath are provided with small blocks g' of celluloid or otherinsulating material, which serve as distancepieces. W'hen these plates are dropped in between the peroxid plates, these distancepieces bear against those plates and keep the When the peroxid in the plates expands, its

zinc entirely clear of any contact. There is thus no danger of zinc being deposited from l The central separating-pieces B' bear against thicker and to increase the width of the block of plates formed as above described. This In the spethis part on each side and assist in holding the zinc plate.

What I claim as my invention, and desire to secure by Letters Patent, is

l. In accumulators, the combination with peroxid plates, separating-pieces of highlyelastic material placed between the said IOJ IIO

plates, and encircling parts encircling the plates and binding them firmly together, of zinc plates having a core of insulating material and distance-pieces or blocks carried by the said core and clear of the zinc, the zinc plates being placed between the resilient separating-pieces, substantially as described and for the purposes specified.

2. In accumnlators the combination with peroxid plates adapted to expand transversely, separating-bars of highly-elastic material placed between the said plates, and bands of elastic material uniting the plates together, of zinc plates having a core of celluloid and distance-pieces or blocks carried by the said core and clear of the zinc, the zinc plates being placed between the resilient separating-bars, substantially as described and for the purposes specified.

3. In accumulators the combination with peroxid plates formed from two grids and adapted to expand transversely, separatingbars of resilient material placed between the said plates, and bands or binding parts also of resilient material inclosing the plates, zinc plates having a core of insulating material extending completely across lthe same, leaving a clear portion of the core at the center, and separating-blocks or distance-pieces f1tted to the projecting parts of the core, the zinc plates being held between the peroxid plates substantially as described.

4. In accumulators of the kind described, peroxid plates having a resilient case formed by a rim of resilient material surrounding the plates, perforated sheets of the same material fixed on the rim at each side and inclosing the plate and resilient bars attached at each end to the frame, the whole forming a resilient case adapted to take up any side expansion of the plate and to return the plate toits normal shape on the contraction taking place, substantially as and for the purposes specified.

5. In accumulators the combination of negative peroxid plates, having a resilient case formed by a rim of resilient material surrounding the edges of the plates and protecting the contact, perforated sheets having an unperforated rim covering the edges of the lead grids and fixed to the rim, and resilient bars on both sides of the said plates fixed at their ends only to the case, with positive plates placed between the negative and separated bythe resilient bars and bands of resilient material binding the block of plates together, substantially as described and shown and for the purposes specified.

In witness whereof I have set my hand in the presence of two witnesses.

y HENRY LEITNER. In presence of- EDwARD P. MACLEAN, HENRY W. MARTIN.

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