US2843650A

US2843650A - Sealing means for galvanic cell casings

Info

Publication number: US2843650A
Application number: US642622A
Authority: US
Inventors: Pierre A C Jacquier
Original assignee: SAFT Societe des Accumulateurs Fixes et de Traction SA
Current assignee: SAFT Societe des Accumulateurs Fixes et de Traction SA
Priority date: 1956-03-12
Filing date: 1957-02-26
Publication date: 1958-07-15
Anticipated expiration: 1975-07-15
Also published as: NL302778A; DE1075693B; BE555339A; FR1147193A; FR73041E; CH336101A; FR70897E; NL215300A; NL127683C; ES233940A1; NL113773C; GB813878A

Description

July 15, 1958 P. A. c. JACQUIER SEALING MEANS FOR GALVANIC CELL CASINGS' Filed Feb. 26, 1967 2 Sheets-Sheet 1 A m m w IZL WIIIII/IIIIIIIIYIA.

INVENTOR. Wm AC ATTORNEYS July 15, 1958 RA. c. JACQUIER ,6

SEALING MEANS FOR GALVANIC CELL CASINGS Filed Feb. 26, 1957 2 Sheets-Sheet 2 ATTORNEYS United States Patent SEALING MEANS FOR GALVANIC CELL CASINGS Pierre A. C. Jacquier, Paris, France, assignor to Societe des Accumulateurs Fixes et de Traction (Societe Anonyme), Romainville, France, a French company Application February 26, 1957, Serial No. 642,622

Claims priority, application France March 12, 1956 6 Claims. (Cl. 136-111) This invention relates to galvanic cells and more particularly to improved means for securing fluid-tight casings therefor.

Galvanic cells (either primary or secondary) enclosed in fluid-tight usually disc-shape casings are already known in the art, said casings comprising usually a metal bottom and a metal lid deeply fitted into each other and separated by a tight insulating gasket. The bottom and the lid constitute the two terminals of the cell.

It is also known that it is very difiicult to obtain complete tightness and seals with such casings. This difficulty causes numerous disadvantages such as leakage of corrosive electrolyte, short-circuiting, rapid cell deterioration and the like.

An object of the present invention is the provision of a galvanic cell casing construction providing improved sealing tightness and also improved insulating properties as compared with existing structures.

Other objects and features of the invention are the provision of simple casing structures that are readily assembled and effectively and easily sealed during assembly.

Further objects and features of the invention will become apparent from the following specification and accompanying drawings wherein:

Figure 1 shows in section an electro-chemical cell embodying one form of the invention;

Figure 2 shows on an enlarged scale, a selected portion of Figure l in an initial assembly stage;

Figure 3 shows the same parts after completion of assembly;

Figure 4 is a detailed section of another embodiment of the invention;

Figure 5 is a detailed fragmentary section of a further embodiment of the invention in an initial assembly stage; and

Figure 6 shows the parts of Figure 5 after completion of assembly.

According to one embodiment of the invention, the side wall of the metal bottom member of the casing is covered with and encased in a substantially U-sectioned resilient, tight bushing one of whose legs extends to the full inside depth of the side and the other of whose legs is longer than the outside depth of said side edge. The U-bend of the bushing rides on the rim of said side wall. The internal face of the lid member which is mounted onto the said bottom comes into abutting contact with the bushing covered rim of said bottom, while the rim portion of the lid is obliquely turned down or crimped onto the external face of the bottom.

Preferably the external leg of the tight U-shaped bushing has a thickness which increases from the U-bend to its free edge. Also at least one of the two parts of the casing, either the bottom or the lid, has an outwardly spread bell shape or flare for receiving this increasingly thick bushing leg.

In this way, turn down of the lid is effected upon a thicker part of the bushing so that the material of said thicker part is pressed back into the space comprised by the side wall of the bottom and the side wall of the lid and maintained under compression. This compression cooperates in maintaining tightness of seal.

Referring to the drawings and first to Figures 1 to 3, inclusive, the cell includes a casing 10, comprising a bottom member 11 and a lid member or cover 12 both of metallic material. This casing on assembly contains conventional positive and negative

active materials

13 and 14 and, for example, an electrolyte-saturated separator The side wall 16 of the bottom is encased or enveloped about its entire periphery and to the full extent of its depth by an insulating tight U-sectioned bushing 17 of any desirable, preferably resilient, insulating material. The U-bend 17a as shown extends over and covers or rides on the upper edge or rim of the side wall 16 as shown in Figures 1, 2 and 3. The bottom 11 has the shape of a truncated cone with the sloping wall portion 18.

In its initial shape as shown in Figure 2, the outer leg 17b of the U-shaped bushing 17 increases inthickness outwardly away from the U-bend 17a.

As seen in Figure 2, the side wall 19 of the lid 12 flares downwardly and outwardly to facilitate mounting of the lid 12 on the bushing carrying bottom 11. The said wall 19 additionally is longer than the side wall 16 of the bottom 11.

In assembly, the bottom 11 is filled successively with active material 14, separator 15, active material 13 after the bushing 17 has been mounted on the side wall 6. The lid 12 is then mounted over the bottom as shown in Figure 2 so that its side wall 19 encloses the bushing leg 17b. The bottom 11 and the lid 12 are then pressed tightly together and while this pressure is maintained, the lower peripheral edge 19a of the lid 12 is crimped or turned down onto the sloping wall 18 of the bottom 11 as illustrated inFigures l and 3. The crimping action presses the lower rim 19a of the lid tightly against the sloping wall portion 18 of the bottom 17 and compresses the thickened wall 17a of the bushing 17 into the space comprised between the

walls

16 and 19. This compression causes perfect filling of the said space. Moreover it is permanently maintained in this condition so that the compressed bushing effectively seals the contents enclosed within the bottom 11 and the lid 12 forming the cell. Moreover, the crimping tends to force the upper edge of the wall 16 towards the inner face of the lid 12 compressing the portion 17a of the bushing. in this Way, the bushing provides a double-sealing effect first at the region of its compressed portion 17a and secondly at the compressed region 17b between the

walls

16 and 19.

The arrangement of Figure 4 shows modification in the side walls of the bottom and of the lid. In this embodiment the bottom 20 has an upwardly outwardly flaring or bell shaped side wall 21 while the lid 22 has an initially cylindrical unflared side wall 23. The U-sectioned bushing 24 is substantially similar to the bushing 17, its

riphery of the bottom 20. These two steps energetically press the upper edge of bottom wall 21 toward the inner face of lid 22 compressing bushing portion 24a and also push the bushing leg 24b into the space defined between the

walls

21 and 23 compressing it tightly. This compression is maintained by the crimped edge 23a. Double sealing occurs as a result of the compressions of portions 243a and leg 24b of the bushing.

In the embodiment shown in Figures and 6, provision is made for still better cell tightness and sealing of the assembled bottom and lid, and in addition for still better insulation of the positive and negative active materials within the cell. In the embodment one feature of improvement resides in providing the lid member on its inner face with a peripheral groove in which the !Jbend of the bushing and partially the rim of the side wall of the bottom member are lodged. As a result, the rim is maintained in said groove and the side wall of said bottom member is prevented from bending inwardly away mm the side wall of the lid. Additionally the U-bend of the bushing fills the groove substantially and being under compression insures a tight seal.

In addition to this as another feature, the inner leg of the bushing does not extend the full depth of the side wall of the bottom. It extends only to the level of the separator and is provided with a peripheral flange which is pressed against the separator during assembly. With this arrangement complete separation is obtained between the positive and negative compartments of the cell, between which there is no communication except through the separator.

Referring to the Figures 5 and 6, the cell casing 3%, comprises a bottom member 31 and a lid member or cover 32 both of metallic material. This casing on assembly contains positive and

active materials

33 and 34 and, for example, an electrolyte-saturated separator 35.

The side wall 36 of the bottom member 31 is encased or enveloped about its entire outer periphery and to a partial extent of its internal depth by an insulating tight U-sectioned bushing 37 of any desirable, preferably resilient, insulating material. The U-bend 37a extends over and rides on and covers the upper rim of the side wall 36. The bottom member 31 has the shape of a truncated cone with the sloping wall portion 33.

in its initial shape the outer leg 37b of the U-shaped bushing 37 increases in thickness outwardly away from the U-bend 37a. The inner leg 370 of the bushing has a peripheral flange 37d at its rim for purposes to be described.

The side wall 39 of the lid 32 initially flares downwardly and outwardly to facilitate mounting of the lid member 32 on the bushing carrying bottom member 31. The said wall 3% additionally is longer than the side wall 36.

An annular peripherally located groove is provided on the inner face of the lid member 32, for example, by stamping an annular gorge 41 in lid 32 from its outer surface at a short distance from the periphery of the lid. This groove 40 may be fabricated in other ways, for example, by depressing the entire rnid-portion of lid member 32 although this alternative is not advantageous if the cells are to be stacked for series connection.

The active material 34 fits into the bottom member 31 and is covered by the electrolyte-saturated separator 35 which has the same diameter as the inner diameter of wall 36. The upper surface separator 35 lies just below the peripheral flange 37d which rests upon it. The active material 33 has an annular peripheral groove 42 to receive the flange 37d and has a thickness such that on assembly of the lid member 32 with the filled bottom member 31, the upper surface of active material 33 lies spaced from the inner surface of the lid member 32 and the outer surface of the U-bend 37a of the bushing lies engaged within the groove 4-0 as is seen in Figure 5.

For completion of assembly, the lid member 32 and bottom member 31 are pressed together bringing the inner surface of lid member 32 into surface contact with the active material 33 and firmly compressing the material in the U-bend 37a of the bushing 37 within the groove 40 under pressure of the upper rim or edge of wall 36. The lower edge 39a of lid wall 39 is then crimped to apply it tightly against the conical wall 38 of the bottom member 31, compressing the lower edge of leg 37b between them. The crimping drives the lid member more deeply over the bottom member 31 and insures complete surface contact between the lid member 32 and active material 33. At the same time, the rim of side wall 36 of the bottom member 31 is pushed into the groove 453 so that said side wall cannot be bent inwardly by further tightening pressure. it 1C'f JOV3lf material of the U-bend 37a is tightly jammed and compressed in the groove 40 wholly filling any free space there, some part of the elastic material even spreading inwardly at 43 as seen in Figure 6. Moreover the flange 37d of the bushing is jammed tightly 2 inst surface of the separator 35 so that the comp ment containing the active material 34 has no communication with the compartment containing active material 33 except through the separator 35. In this way migration of active material from one compartment to the other along the internal walls of the bottom member 3 is prevented.

With the arrangement of Figures 5 and 6, a very tight union is effected between the lid member and bottom member. Moreover, it is to be noted that the rim of the bushing which lies gripped between the tapered wall 38 of the bottom 31 and the crimped or turned down rim 39a of the lid 32 constitutes an autoclave joint. Any gaseous pressure appearing in the casing tends to increase the tightening and sealing at this gripped part of the bushing. The same remark applies to the other above-mentioned embodiments of the invention.

While specific embodiments of the invention have been described and shown, variations in structural detail within the scope of the appended claims are possible and are contemplated. There is no intention therefore of limitation to the exact details described and shown.

What is claimed is:

l. A substantially leak-proof casing for a galvanic cell comprising a bottom member and a lid member having a side wall fitted one into the other, said bottom member having a side wall, a substantially inverted U-sectioned insulating bushing mounted on said side wall with its U-bend riding on the rim of said wall, said bushing having its outermost leg increasing outwardly in thick- .ess from the U-bend, said lid member having its rim portion turned down against said bottom member to compress said leg of said bushing between the side walls and also to compress said bushing at its U-bend between the first-uamed rim and the inner surface of said lid member.

2. A substantially leak-proof casing for a galvanic cell comprising a bottom member having a sloping wall portion and a side wall, a lid member fitted over said bottom member and having a side wall overlapping said first-named side wall, a substantially inverted U-sectioned insulating bushing mounted on said first-named side wall with its U-bend riding on the rim thereof, said bushing having its outermost leg increasing in thickness from the U-bend positioned between the two side walls, and said second-named side wall being bent tightly against said first-named side wall and having its rim portion bent over and crimped against said sloping wall portion to maintain the said leg member and the U-bent portion of said bushing in sealing compression with said lid member and said bottom member.

3. A substantially leak-proof casing for a galvanic cell comprising a bottom member having a side wall, a substantially inverted U-sectioned bushing mounted on said side walls with its U-bcnd riding on the rim thereof, said bushing having its outermost leg increasing in thickness from the U-bend, a lid member fitted over said bottom member and having a side wall overlapping said firstnamed side wall, one of said side walls flaring to facilitate mounting of the lid member on the bushing carrying bottom member, and said side wall of said lid member being bent against the side wall of the bottom member to compress said leg of said bushing therebetween and also being crimped against a portion of said bottom member to maintain said compression and also to compress the bushing at its U-bend between the inner SUI- face of the lid member and the first-named rim.

4. A substantially leak-proof casing for a galvanic cell comprising a bottom member and a lid member fitted one into the other, said bottom member having a side wall, a substantially inverted U-sectioned insulating bushing mounted on said side wall with its U-bend riding on the rim of said wall, said lid member having anannular peripheral groove to receive said U-bend of said bushing and also a side wall which is mounted over the outer leg of said bushing, said last-named side wall being bent aganist said first-named side wall and also having its rim portion crimped against said bottom member to maintain said leg member of said bushing under compression between said side walls and its U- bend under compression within said groove.

5. A substantially leak-proof casing for a galvanic cell comprising a bottom member and a lid member fitted one into the other, said bottom member having a side wall, a substantially inverted U-sectioned insulating bushing mounted on said side wall with its U-bend riding on the rim of said wall, said lid member having an annular internal peripheral groove to receive said U-bend of said bushing and said rim, and also a side wall which is positioned externally of the outer leg of said bushing and overlaps the first-named side wall, said outer bushing leg increasing in thickness outwardly from said U- bend and lying between said side walls, said side wall of said lid being bent against said side wall of said bottom member and also having its rim portion crimped against said bottom member to maintain said leg member of said bushing under sealing compression between said side walls and the U-bent portion of the bushing under compression in said groove.

6. A galvanic cell comprising a substantially leakproof casing including a bottom member containing superposed active materials with a separator therebetween and having a side wall, a substantially inverted U-sectioned bushing mounted on said side wall with its U-bend riding on the rim of said wall and having an annular flange on its innermost leg abutting said separator and having its outer leg increasing in thickness outwardly from said U-bend, a lid member having a groove to receive said U bend and a side wall overlying said outer leg and bent against said first-named side wall to compress said outer leg between said two side walls and the side wall of said lid member having its rim portion bent and crimped about said bottom to compress and maintain the U-bent portion of said bushing within said groove.

References Cited in the file of this patent UNITED STATES PATENTS 2,174,437 Collins Sept. 26, 1939 2,499,239 Williams Feb. 28, 1950 2,591,532 Fox Apr. 1, 1952 2,707,199 Ruben Apr. 26, 1955