Note: Descriptions are shown in the official language in which they were submitted.
1086380
Th3 pr3sent invention relates to accumulators or storage batteries
ln genera~, and ~ore p æ ticular~y to ~mprovement5 ~n accumulators of the type
w~lerein the conductLng core and a body of paste~ e active material are con-
fined in an enve~ope.
Ih pr~ent~y kn~wn accu~Llators of the a ove outl med character,
the envelope normally con515ts of ~ynthet-ic plastlc m~ter~al. The core oon-
stitutes a g~id ~which has holes for act~ve matPrial) or a rod. A d~awback
of such accumu~ators i~ that the u5eful l~fe of the core is mNch shorter
than that of a b~x-sha~ed negatLve plate.
A~cording to one aspect of t ~ inv3ntion th~re ,LS p~ovided in an
accumulator, the cc~b mation o a solid plate-like con~uctlve core; a body
of active mat~rial contactin~ at l~ t the]major portion of the exterior
of said core; and an envelope, which confines and contacts said active
material, including porou layers surrounding said bcdy.
According to a seo~nd aspect of the invention there is provided
~n an accumulator, the oo~bination of a solid plate-like conductive core;
a body of active material contacting at least the major portion of the exterior
of said core; and an envelope which aonfines said active material, includ mg
porous layers surrounding said btody, said layers having inner surfaces in
substantially o~ntinuaus contact with sald body and at least one of said
surfaces be~ng profiled.
An advantage of the invention is to provide an accumulator with a
novel and improved conductang core who~e useul life is longer than the use-
ful life of pre æ ntly kncwn cores.
According to one e~bodiment the invention includes a oo~bination
of elements which form part of an accumulator o storage battery and include
a solid-plate like co~ductive lead-contaim ng core, a bcdy of active mEterial
which surrnunds at least the major part of the exterior of the core ~such active
material may forn two slabs which are Ln full surace-to-surface contact with
the twc major suraces of the core), and an envelope which confines the
active material. The envelope i~cludes pcrous layers which surround the active
material
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1(~86380
and may consist of sintered synthetic plastic material, of compacted rock wool,
synthetic plastic filaments or glass fibers, or of other suitable material whichis highly resistant to corrosive action of electrolyte and can stand elevated
temperatures. The envelope may further comprise an outer housing or sheath
having a chamber for the aforedescribed elements. The side walls of the sheath
are outwardly adjacent to the respective major surfaces of the core and have
apertures (preferably vertical slots) which permit the electrolyte to pene-
trate through the pores of the layers and to thus reach the active material.
The inner surfaces of the layers are undulated, serrated, provided with ridges
and grooves or protuberances, or otherwise profiled to enlarge the area of con-
tact with the active material.
The novel features which are considered as characteristic of the
invention are set forth in particular in the appended claims. The improved
accumulator itself, however, both as to its construction and its mode of opera-
tion, together with additional features and advantages thereof, will be best
understood upon perusal of the following detailed description of certain spec-
ific embodiments with reference to the accompanying drawing.
Figure 1 is a fragmentary perspective view of a portion of an accumu-
lator which embodies one form of the invention;
Figure 2 is a horizontal sectional view of the structure which is
shown in Figure 1 but showing two modified layers, and
Figure 3 is an enlarged fragmentary perspective view of one of the
layers shown in Figure 1.
Referring first to Figures 1 and 2, there is shown a portion or unit
1 of an accumulator or storage battery which comprises a solid plate-like con-
ducting core 2, two panels of slabs 3 of active material which are adjacent to
the major surfaces of the core 2, and a confining envelope including two porous
layers 6 which flank the outer sides of the slabs 3. The envelope preferably
further comprises a flat block-shaped apertured synthetic plastic housing or
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sheath 4 having a chamber which confines the elements 2, 3 and 6. The side
walls 5 of the sheath 4 are adjacent to the exposed sides or surfaces of the
respective layers 6.
The inner sides or surfaces of the layers 6 are profiled, i.e.,
they exhibit pronounced raised and recessed portions which can be seen in
Figure 3. Such profiling results in pronounced increase of the areas of sur-
faces which contact the outer sides of the slabs 3 and urge the slabs against
the respective major surfaces of the conducting core 2. The material of the
layers 6 is preferably formed with minute pores.
The area of the inner surface of each layer 6 can be increased in
a number of ways, e.g., by imparting to such inner surface an undulate or ser-
rated shape or by providing the inner surface with longitudinally extending
alternating ribs and grooves. In accordance with one presently preferred em-
bodiment (see Figure 2), the inner surfaces of the layers 6' have a large num-
ber of relatively small ridges 6a the cross-section of each of which resembles
an isosceles or equilateral triangle. Neighboring ridges 6a have abutting --
edges. The extent to which the profiling increases the thickness of the res-
pective layers 6' may be in the range of 1-2 mm, preferably about 1.5 mm.
Less pronounced profiling could result in rapid filling of grooves or other
forms of recessed surface portions with lead sulphate. For example, the
length of the sides of triangles shown in Figure 2 at the inner sides of
layers 6~ may be within the aforementioned range (1-2 mm). Such layers can
be produced at relatively low cost and the areas of their profiled surfaces
greatly exceed the areas of equally large flat surfaces. The profiling of
the inner surfaces of the layers should not be too pronounced because this
would reduce the space which is available for the active material (slabs 3).
Figure 3 shows another presently preferred embodiment of the pro-
filing of a layer. The layer 6 which is shown therein consists of a large
number of hollow pyramids 8 whose square bases are located in a common plane
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and each of which has four sides each resembling an equilateral triangle.
The configuration of Figure 3 has been found to be especially suited for use
in the improved accumulator because it insures a highly satisfactory contact
between the slabs 3 and the electrolyte. Such contact is not impeded (or is
impeded to a lesser extent) by development of lead sulphate barriers.
As mentioned above, the pyramids 8 of Figure 3 are hollow, i.e.,
the thickness of the material of the layers 6 may be constant or nearly con-
stant. Otherwise stated, each protuberance (pyramid 8) at that side of a
layer 6 which faces the respective slab 3 is located opposite a complementary
recess or depression at the outer side of the same layer. Such uniform thick-
ness of the porous layers insures that the electrolyte can pass through each
and every zone thereof, including the apices of the pyramids. The layers 6 or
6~ can be produced by deep drawing, injection molding, press-forming or by re-
sorting to any other suitable technique. The inclination of the planes of the
sides of each pyramid with respect to the plane of the respective base is pre-
ferab]y between 60 and 70 degrees.
The layers 6 and 6' can consist of sintered or filamentary synthe-
tic plastic material, compacted glass fibers or rock wool, or any other mater-
ial which exhibits high resistance to acids and can stand elevated tempera-
tures.
The pyramids 8 of Figure 3 are but one of a wide variety of protub-
erances which can constitute the profiling of inner surface of the layer 6.
For example, the illustrated pyramidal protuberances can be replaced with
hollow prismatic, conical, frustoconical, cylindrical or partly conical and
partly cylindrical protuberances. A feature common to all such protuberances
is that the inner surface of the layer is profiled in several directions, i.eO
that it exhibits raised and recessed portions in a direction at right angles
to the longitudinal direction of the core 2 (this also applies for the profil-
ing 6a which is shown in Figure 2) as well as in the longitudinal direction of
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the core. The provision of discrete protuberances instead of ridge-like pro-
tuberances (6a) renders it possible to increase (almost by 100 percent) the
quantity of active material in the recessed portions of the inner surface of
the layer. With reference to Figure 3, this means that the quantity of ac-
tive material which fills the spaces between the common plane of the bases
and the common plane of the apices of the pyramids 8 is nearly twice the quan-
tity of active material which fills the grooves between the ridges 6a of one
of the layers 6' shown in Figure 2 ( it being assumed, of course, that the
height of the pyramids 8 equals or closely approximates the height of the
ridges 6a~.
By increasing the area of the inner surface of each layer 6 or 6~,
one insures a more satisfactory contact between the electrolyte and the active
material, even at maximum load and in spite of the development of lead sul-
phate barriers.
As mentioned above, porous layers (6) having a substantially con-
stant thickness (in spite of the protuberances 8) offer less resistance to the
passage of electrolyte than layers (6') whose thickness varies, either period-
ically (as shown in Figure 2) or at random.
It is also within the purview of the invention to omit the sheath
4, i.e., to confine the part 2 and the slabs 3 in an envelope which consists
of porous material and is sufficiently stable to maintain the slabs 3 in con-
tact with the respective major surfaces of the core 2. Alternatively, the
layers 6 or 6~ can be omitted if the sheath 4 consists of porous material, and
especially if the inner surfaces of the sheath are profiled in a manner as des-
cribed in connection with the inner surfaces of the layers 6 and 6~. The walls
of such sheath are functional equivalents of the layers 6 or 6~.
If the improved accumulator utilizes a sheath 4 for each group of _~s
elements 2,3,6 or 2,3,6', the sheath may consist of polyvinyl chloride.
The apertures or holes 9 in the side walls 5 of the sheath 4 are
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1086380
preferably relatively large elongated slots which extend lengthwise of the
sheath, i.e., they are vertical when the accumulator embodying the improved
structure is in use. This enhances the stability of the sheath 4 without in-
terfering with the flow of electrolyte into contact with the outer sides of
the layers 6.
The narrow end walls 10 of the sheath 4 are formed with centrally
located longitudinal internal grooves or channels 11 which receive the respec-
tive longitudinal marginal portions 12 of the core 2. The insertion of margin-
al portion 12 into the respective channels 11 results in satisfactory ~nchor-
ing and enhances the stability of the core, i.e., the core is less likely to
buckle or to undergo other types of deformation. Moreover, the channels 11
insure convenient and predictable insertion of the core 2 into the sheath 4.
Still further, limited buckling or other deformation of the plate-like core
will not result in excessive shift from the desired optimum position in the
center of the chamber which is defined by the sheath 4.
In accordance with a further feature of the invention, at least one
major surface of the core 2 is profiled to thus enlarge the area of contact
between such side and the respective slab 3. Figures 1 and 2 show that the
cross-section of the core 2 has an undulate outline, i.e., the two major sur-
faces of the core are formed with longitudinally extending rounded ribs 2awhich alternate with recesses 2b bounded by rounded surfaces. The profiled
; portions of the major surfaces of the core 2 are surrounded by a non-profiled
rectangular reinforcing frame 12A which includes the aforementioned vertical
marginal portions 12. The frame surrounds the central portion and contri-
; butes to stability of the core 2. Also, the smooth surfaces of the portions
12 facilitate the insertion of core 2 into the channeled sheath 4.
The profiling of major surfaces of the core 2 enhances the passage
of current and hence the effectiveness of the core. Moreover, such configur-
ation of the major surfaces prolongs the useful life of the core. It is
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preferred to stagger the ribs and recesses of one major surface with respect
to the ribs and recesses of the other major surface in such a way that each
rib of one major surface is located directly opposite a recess in the other
major surface, and vice versa.
It is equally within the purview of the invention to provide the
core 2 with one profiled surface. Profiling which includes ribs and grooves
extending in the longitudinal direction of the core 2 enhances the stability
of the core. When the accumulator is in use, the ribs 2a and grooves 2b are
verticalornearly vertical.
Of course, the major surfaces of the core 2 could be profiled in a
number of other ways without departing from the spirit of the invention. In
each instance, the profiling enlarges the areas of the respective major sur-
faces, and this reduces the current strength (i.e., the density of current)
perunit area which, in turn, reduces the extent of corrosion during charging
and discharge (i.e., the useful life of the core is longer).
The profiling of the major surfaces of the core 2 and/or of the
inner surfaces of the layers 6 or 6~ exhibits another important advantage.
Thus, the protuberances or projections of the core and/or of the layers pre-
vent undesirable sinking of active material. Moreover, the effectiveness of
the improved structure, even during relatively short intervals of overload, is
superior to that of conventional Ironclads or the like. It has been found
that the core 2 exhibits a much greater resistance to deformation than a con-
ventional grid or rod. Furthermore, even a very pronounced deformation cannot
result in contact with a neighboring plate because of the provision of an en-
velope ~layers 6 or 6', sheath 4, or a sheath plus porous layers). The slabs
3 are profiled at both sides, i.e., the areas of both major surfaces of each
slab 3 greatly exceed the areas of flat surfaces. This reduces the likelihood
of excessive accumulations of lead sulphate at the major surfaces of the core,
even in the event of deep discharge.
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~086380
The construction of the remaining components (including the con-
tainer for electrolyte) of the accumulator forms no part of the invention.
To summarize: The improved structure exhibits very pronounced
mechanical stability while offering little resistance to the flow of eletro-
lyte into contact with the slabs 3. This aIlows for short-lasting overload-
ing. The discharge curve of an accumulator which embodies the improved struc-
ture is highly satisfactory and the useful life of the core 2 as well as of
other components is surprisingly long. The enlargement of major surfaces of
the core 2 reduces the current density per unit area which reduces the elec-
trochemical corrosion during charging and discharging. Moreover, the solidcore 2 can stand such corrosive effects for much longer periods of time than
a grid or rod of conventional design. The slabs 3 are properly confined from
all sides so that they are unlikely to sink; at the same time, the slabs are
readily accessible to the eletrolyte.
Without further analysis, the foregoing will so fully reveal the
gist of the present invention that others can, by applying current knowledge,
readily adapt it for various applications without omitting features that, from
the standpoint of prior art, fairly constitute essential characteristics of
the generic and specific aspects of my contribution to the art and, therefore,
such adaptations should and are intended to be comprehended within the mean-
ing and range of equivalence of the claims.
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