Note: Descriptions are shown in the official language in which they were submitted.
Back~roulld of the Invention
1. Field of the Inventiorl
This inventiGn pertains to bat-teries
and is a division of application Serial No. 296,120 filecl
January 31, 197S.
II. Description of the Prio_ Art
Lead storage batteries are oten made with straps
connecting the individual plates in a stac~ together. The
strap has a vertical portion called a lug. Terminals are
provided in the bat-tery for connection of the ba-ttery to
e~ternal electrical cables) the terminals in some batteries
being positioned in the bat-tery side walls. A portion of
the surface of the lug overlaps a portion of the inside
surface of the terminal and the two must be connected together
to form a good electrical connection. In one approach, the
o~erlapping sur~aces of the lug and -terminal are pressed to-
gether by l~elding jaws and electrically-welded connection
is formed. One problem Wi~}l this approach is that the over-
lapping area of contact creates a low electrical resistance
resulting in insurficient heat at the interface causing a
cold weld.
Alternatively, it is known t~o provide the lug por-tion
~ith a projection which is inserted through a hole in a ba-ttery
wall and into a hole or cavity on the terminal. A complete
connection between the terminal and the lug and a good seal
bct~een the terminal, battery wall and lug is obtained by
e~erting pressure on either side of the connection, that is,
by appl~ing pressure against the battery lug iithin the battery
and against the terminal outside the battery so as to squeeze
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them -togcther and sea] the connection against the battery wall.
If desired the step of fusing the COlllleCtiOn together can b~
added by applying heat to the lug and to the teTminal~ See
U.S. Patent Nos. 3 ~57 11S and ; 303 056.
A similar ~pproach to maXing electrical connections
through storage battery par-titions or walls withill the battery
case is disclosed in U.S..Patent Nos. 3 798 071; 3 723 699;
3 687 73~; 3 5S9 94S; 3 3~S 005; and 3 313 65~. In partic-
ular~ the Allen Patent No. 3 723 699 discloses a method of
making an intercell connection by providing a lug on one
side of a partition wi-th a bar thereon which extends into
a hole in the partition wall. The lug on the other side of
the partition does not have a bar but has a ~lat surface
adjacent the partition. A specially shaped elec-trode acts
on the smooth lug whicll has no bar~ forcing t~e~soft lead
of the lug to press into the hole in the partition wall
against the bar on the opposite lug. Then while under
pressure a current is passed fusing the two lugs together.
Problems can occur in obtaining precise alignment
between the relatively large protrusion and openings on
various parts to be connected together or between the pro-
trusions and openings in a partition wall or a battery case
wall through which the protrusions must pass. In addition
the area of contact between the protrusions on one part of
the sur-face or opening on the other part is relatively
large and requlres a grea-t deal of hea-t in order to melt
the lead and fuse the parts together to form the terminal
connection.
Summary of the Invention
The present invention consists of in a battery
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co~nprising a case havillg a-t least one terminal d;sposed
through a wall of said case, said -termillal having a sub-
stantially planar interior surFace in said battery, and
havillo groups of ba-ttery plates and separators wi~hin at
least one cell, at least one of said groups having a lug with
a portion disposed substantially parallel to and spaced apart
from at least a portion of said interior surface of said
terminal, the improvement whcrein said battery comprises a
homogeneous integral connector between said lug portion and
said terminal portion, said connector having a preselected
cross-sectional area.
These and other features of an embodiment oE the in
vention will become apparent from the following description
with reference to the accompanying drawings.
Brief Descri~tion of the Drawin~s~
Fig 1 is a cross-section of a -terminal sealed in a
battery l~all acljacent to a batte~y lug;
Fig. la is a view of the lug, terminal and battery
wall, ta~en as indicated along the lines and arrows la-la in
Fig. l;
Fig. 2 is a cross-section of a lug, terminal and
battery wall of Fig. 1 with the preferred embodi-nent of
insulation means in place;
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Fig. 2a is a view of the lug, insulation,
terminal an~ bat~ery wall, -taken as indicated along the
lines and arrows 2a-2a in ~ig. 2;
Fig. 3 is a cross-section of the lug, terminal,
battery wall and preferred embodiment insulation means of
Fig. 2, showing the welding jaws and an extrucled portion of
the lug in contact with -the terminal;
Fig. 4 is a cross-section of the preferred embodi-
ment of Fig. 3 with an electrical potential shown schema-
tically applied across the welding jaws and showing the
integral and homogeneous connection between the lug and
terminal being fused.
Description of the ~referred Embodiments
Although specific forms of the invention have
been selected for illustration in the drawings, and the
followins description is drawn in specific terms for the
purpose of describing this invention, this description is
not intended to limit the scope of the invention which is
defined in the appended claims. -
Referring to Fig. 1, a portion of a battery wall
12 is shown having an aperture 16. The portion of the
battery wall designated generally l~ surrounding the
aperture 16 comprises a ring 14 and an inwardly depending
flange 15. The ring 14 together with the inwardly depend-
ing flange lS create a partial chamber in the battery ~ ~
wall 12. ~ ~`
A terminal 10 is contained within the partial
chamber engaging the inside surfaces of the inwardly de-
pending flange 15 and the ring 14. An extension 11 of the
-terminal engages the inside surface of the battery wall
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--~ for a distance. In the embodiment shown here, the inside
surface of the te~minal 9 along its entire length i5
planar. The terminal is metal and may be lead alloy.
Within the terminal a tapped hole 20 can be provided.
The cell con-taining the terminal also con-tains a
group of battery plates with separators (not shown). A
vertically extending lug 21, connected to the strap of the
group, has a portion adjacent and overlapping a portion of
the inside surface 9 of the terminal 10. The adjacen-t and
overlapping surfaces of the lug and inside surfaces of the
terminal are denoted 22 and 23 respectively in Fig. 1.
Fig. la is a view along the lines and arrows
la-la of Fig. 1 showing the inside surface of the battery
wall 12, the inside surface 9 of tne terminal 10 and a
portion of the lug 21 overlapping a por-tion of the inside
surface 9 of the terminal 10. The aperture 16 in the
battery ~all 12 is shown as a circular dotted line 24
in Fig. la.
In Fig. 2, a preferred embodiment of the insula-
tion means 100 is shown between the battery lug 21 and the
terminal 10. The preferred embodiment insulation means
100 has an aperture 102 and, except for this, the insula-
tion means covers the entire overlapping surfaces 22 and
23 respectively of the ~attery lug 21 and the terminal
connector 10. This is seen more clearly in Fig. 2a where
the bottom edge of the insulation means is shown as the
solid line 11)4 partially dotted where it is overlapped by
the lug 21. The aperture 102 in the insulation means
100 is shown as a dotted circle in Fig. 2a.
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~``~'' In accordance wi.th this invention, welding jaws
; are positioned on either side of the area to be welded.
In Fig. 3, the e~ternal welding jaw 300 contacts the out-
side surface 18 o~ the terminal at 301. The internal
welding jaw 302 has a protrusion 30~ which is adjacent to
the lug 21. The protrusion 304 engages the lug 21 on a
surface 305 opposite the overlappiny surface 22.
A force is applied to the welding jaws movi.ng
the welding jaws toward one another. ~hen this happens,
the protrusion 30~ contacts the lug 21 along the surface
305, forcin~ -the lug 21 to press against the insulation
means 100; the external welding jaw 300, pressed against
the outside surface 18 of the terminal 10 at the pOillt
301, causes the inside surface 9 of the termianl to press
against the insulation means 100. The lug 21 is made of
relatively soft metal such as lead alloy and when the lug
21 is pressed against the insulation means 100, the edge
of the insulation means forming the aperture 102 acts as a
die so that the soft metal is extruded through the aperture
102 and contacts the inside surface of the terminal along
a small contact area 308. The shape of the extension 306 ',
can be seen in Fig. 3 along with the area of contact 308.
The preferred embodiment insulation means is a
flat, relatively thin, rectangularly shaped piece of
material which is capable of electrically insulating the
portion 22 of the lug surface ~hich o~Jerlaps a portion 23
of the terminal 10. A-t the same time, it acts to space
apart the overlapping surfaces of the lug and terminal and
to thermally insulate one surface from the opposing
surface. The insulation means,must be capable of
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withstanding the compression-like ~orce of the welding jaws
and the e~-trusion of lead through the aperture 102.
When an electrical poten-tial is applied across
-the welding jaws 302 and 300 as signified by the plus and
minus signs in Fig. 4, current begins -to flow between the
metal lug and the metal terminal through the relatively
small contact area 308 of Fig. 3 thereby generating a large
amount of heat in that region and causing -the lead of the
lug and terminal to melt, forming a fusion zone 400, shown
cross-hatched in Fig. ~. However, the welding jaws con-
tinue to apply a compressive-type force squeezing the lug
and the terminal together and more cold metal or lead is
introduced into the fusion zone in the aperture 102. As
current continues to flow and more lead continues to melt,
the entire a~erture within the insulation means is filled
with molten lead to form a homogeneous and integral
connection in the fusion zone 400 between the lug 21 and
the terminal 10. The current flow is stopped and the
welding jaws are retracted leaving the lug connected to
the terminal.
It is important to note that no projections were
present on either the terminal or the lug which might
result in requirements for precise alignment and mating of
the projection with either the lug or -tenninal necessitating
the implementation o elaborate alignment procedures each
time a different size battery was introduced for terminal
welding. Instead, in the preferred embodiment a projection ¦ ;
304 is provided on the internal welding jaw 302 which
presses against a substantially planar surface of the lug. ¦ ;
The other planar surface of the lug 21 presses against a
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-~ relatively flat insulation means 100 which can be
positioned quite easily to have its aperture 102 align
with the projection on the ~elding jaw.
In an alterna-te embodiment of this invention, a
battery case can be injection molded to include plas-tic
around the terminal connector leaving an aperture 102 and
thereby eliminate the separate insulation means from the
battery. However, with the separa-te preferred embodiment
insulation means of this invention, there is no need to
provide different terminal post si~es for different pla~e
heights in different size batteries since the insulation
means can be moved easily to accommodate a common terminal
post. For example, a series of batteries with identical
side wall terminal configurations, but with different size
plate heights and lug lengths, migh-t be presented for side
terminal welding. A smaller lug, in the area of the
terminal overlap, will not e~tend as far -toward the battery
top as a lon~er lug. With the preferred embodiment in-
sulation means of this invention, the insulation means can
be moved to insure that the aperture 102 will be positioned ~ -
between the common terminal and ei-ther the longer lug or
the shorter lug without the need of varying the common
terminal configuration.
In one embodiment of the electxical insulation
means, a paper tape or piece of cardboard with an aper-ture
is provided with glue or adhesive already applied to one
side or surface~ This is pasted to the terminal after the
terminal is assembled into the battery wall but before
the groups of plates and separators are added to the cells
in the battery.
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~` In lead storage batteries for automobiles, the
groups of plates within eacn cell are connected through
partitions contained within eac~ battery by formlng inter-
cell connections, the cross-sectional area of which is a
typical area of 0.4 to 0.5 square inches. In such a
battery, the aperture within the insulation means, which
ultimately becomes filled with the homogeneous and integral
connector formed between -the lug and terminal, is of the
same cross-sectional area of Q.4 to O.S square inches. In
applicant's preferred embodimen-t, the aperture in the
paper tape or card is circular and has a diameter of
0.375 inches. It will be seen that this aperture can
easily be varied to provide a lug terminal connection equal
to the ba-ttery intercell connections for a variety of lead
storage batteries.
In the preferred embodimen-t, a battery contains
apertures 16 through the ~all 12 of the bat-tery case.
ithin the apertures formed in the wall 12 of the battery
case, terminals 10 are assembled which sealingly engage
the battery walls 12. A piece of paper tape or cardboard
100 haviny a circular aperture 102 therethrough adheres to
the inside surface 9 of the terminal 10 in the batter~
aperture 16. A group of plates, inserted into the cell
containing the terminal, has a lug 21, which ex-tends upward
from the plates adjacent to and overlapping the insulation
card 100 pas-led on the inside surface 9 of the terminal
10. Welding jaws 300 and 302 are then brought into
contact with the terminal 10 and lug 21, the external
welding jaw 300 pressing against the outer surface 1~ of
the terminal 10 and the internal welding jaw 302 haviny a
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~` projection 30~' thereon which presses aclainst a surface of a
lug. The lug 21 is so positioned relative to -the insula-
tion 100 and terminal 10 that a portion 22 o the lug
surface overlaps a corresponding portion 23 of the insi~e
surface 9 of the terminal 10. The insulation means 100
covers an area which includes all of -this overlapping
surface 22 of the lug except for the aperture 102. As the
welding jaws squeeze, the lug contacts the edye of the
aperture 102 in the insula-tion material 100 and the soft
metal begins to extrude through the aperture 102 to contact
the inside surface 9 of the terminal 10. The area of
contact 308 is quite small compared to the area of the
aperture 102 in the insulation 100. When electrical po-ten-
tial is applied to the welding jaws, a curren-t begins to
flow through this small contact thereby creating a great
amount of heat. The insulation surrounding the aperture
not only pro~ides an electrical insulation so that only a
small area of contact is provided between the lug and the
terminal, but also provides a means of concentrating the
heat at the point OL contact by actinct as bo-th an electrical
and heat insulator. This concentration of the heat creates
molten lead at the point OL contact and with the jaws
continually applying pressure to the lug and terminal,
squeezing them together, more cold lead is extruded into
the aperture 102 where it melts forming an integral and
homogeneous connection 400 between the lug and terminal. I
It will be understood that various changes in
the details, materials and arrangemen-t of parts which have
been herein described and illustrated in order to explain
the nature of this invention, may be made by those skilled
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in thc art within the principal. and scope of tile invention
as e~pressed in the followillcJ claims.
It ~ill be further understood tha-t the "Abstract
of the Disclosure" set forth aho-~e is intended to provide
a non-legal technical statement: of the contents of the
disclosure in compliance with t:he Rules of Prac-tice of the ..
United States Patent and Traclemar~ Office, and is not
intended to limit the scope of the invention described and
claimed herein.
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