IMPROVEMENTS IN SECONDARY PROAL
Year: 1882

page_text: LETTERS PATENT to Francis John Bolton of N° 19 Grosvenor Gardens in
the County of Middlesex for an Invention of IMPROVEMENTS IN SECONDARY
PROVISIONAL SPECIFICATION left by the said Francis John Bolton at the
Office of the Commissioners of Patents on the 28th July 1882.
FRANCIS JOHN BOLTON of No. 19 Grosvenor Gardens in the County of Middlesex
"IMPROVEMENTS IN SECONDARY BATTERIES"
The present improvements relate to secondary or accumulator batteries and part
of my invention consists in subjecting such batteries while forming or charging or
discharging to pressure. And part of my invention consists in improvements in
the construction of the vessel or receptacle in which the elements of the battery are
placed and contained. And part of my invention consists of improvements in the
method of arranging the elements of a secondary battery. And part of my
invention consists of improvements in supporting the active material of the
secondary battery: And part of my invention consists in the manner in which
I effect that the connection between the charging battery and the secondary
battery shall be automatically made and broken. And part of my invention
consists of the method by which I provide connection and communication between
the elements of the battery or between the divisions containing the electrolyte ; and
part of any invention consists in the manufacture of the plates or active elements
of the battery.
1. In carrying out that part of my invention in which I subject a secondary
battery of any form to pressure, I effect this by putting the battery into a closed
vessel of suitable form and strength such as an iron cylinder with closed ends, the
terminals of the battery being extended to the outside of the enclosing vessel and
electrically insulated from it by insulating pieces which are firmly fastened to the
material of the enclosing vessel. In this way of subjecting the battery to pressure
I prefer to use gaseous pressure produced by gases generated in any convenient
manner but preferably by the accumulation of the gases given off during forming
or charging.

page_text: "
"
2. In carrying out my improvements in constructing the casing of secondary
batteries, I make the casing of the battery in the form of a hollow prism or hollow
cylinder closed at the ends, or of two such hollow prisms or hollow cylinders, a
larger and a smaller, enclosing an annular or other shaped space between them
which annular or other shaped space I close at the ends, and for convenience I shall
refer to such batteries (the casing of which consists of two hollow cylinders or
hollow prisms as described) as a "centre-hole" battery, such hollow prisms or
hollow cylinders (and in the case of "centre-hole" batteries, one or both of the
hollow prisms or hollow cylinders) I build up of a succession of shorter hollow
prisms or hollow cylinders and such short hollow prisms or short hollow cylinders
of which my composite pipes are made up I-refer to throughout my Specification as
parts" and for shortness I will throughout iny Specification refer to such hollow
prisms or hollow cylinders as "pipes" and to such as are built up or composed of a
succession of shorter hollow prisms or hollow cylinders as composite pipes," and
1 do not limit myself to the use of truly cylindrical or prismatic pipes as such can
be more or less in the form of truncated cones or pyrainids. The parts of which
my composite pipes are built up I make either of lead or of a dielectric or of a
suitable metal covered where necessary by a dielectric or some of them of a
dielectric or of a suitable metal covered where necessary by a dielectric and some
of them of lead. I complete the casing of the battery by closing the ends of the
pipes or of the space between two pipes (in a "centre hole" battery) by plates of
wood iron steel or other suitable material covered where necessary on the inside by
a dielectric and these two outside plates I furnish with projecting lugs or make the
plates sufficiently large to allow of their being bolted together by bolts parallel or
approximately parallel to the axis of the pipe or pipes and outside the battery or
through the inside pipe where I have a "centre hole" battery. And in the case of
a centre hole" battery in which the outside covering may be in one piece I some-
times fasten the end plates to such pipe by any suitable means. I thus obtain a
casing for my battery which is of such a form of construction as to be able when
required and when a suitable material of sufficient strength is employed, to stand
great internal, pressure. The joints between the pipes and plates may either be
Hat or, in order to render the joint more perfect, one of the meeting surfaces
may be formed with one or more annular grooves while the other surface has
corresponding projections fitting into the grooves.
"
3. In carrying out that part of my invention which relates to supporting the
active material I use supporting plates which I make of any metal covered with
a dielectric varnish or of a dielectric, and they should be suitably perforated with
holes to allow of the free passage of the electrolyte through them. But in the case
of the supporting plates being made of a porous dielectric as parchment it is not
always necessary to make holes in them. These supporting plates I place where
required so as to maintain the active material of the element which may be porous
lead or salts of lead or salts of other metals, in good connection with the metallic
or other conductor of such element, and I attach them to the casing of the battery
and I sometimes make use of them as ties and thus increase its strength. To effect
this I either sandwich the edges of the plates between some of the "parts" of the
composite pipe or pipes or I construct some of these parts with such plates
attached.
4. In all my batteries which are constructed with a composite pipe and mounted
permanently in series I effect a communication between the cells or compartments
of my battery (so that the pressure in all the cells may be the same) and I effect
this in such a manner that the communication between the cells when the battery
is in its proper position for filling charging or discharging shall not have liquid in
it and I prefer to speak of this as a gaseous communication. I provide plugs or
cocks in the said gaseous communication so that, when I am not working the
battery with internal pressure the removal of one of these plugs or cocks connected
with this gaseous communication may discharge the pressure from the battery.
This communication I also generally apply to batteries mounted in, surface, but

page_text: in this case it is not so important that the communication, when the battery is in
position for charging or discharging, should be free of liquid. Sometimes in the
case of batteries mounted in surface the communication between two adjacent cells
I sometimes make
may be simply a hole through which the electrolyte passes.
the communication in the body of the casing of the battery sometimes outside,
sometimes inside.
5. In carrying out that part of my invention which consists in making and
unmaking an automatic connection between my Dynamo or charging battery and
my accumulator battery, I effect this by causing the pressure arising from the
accumulation of gases in my battery to act on a check or cam which shall advance
a mechanism or series or cycle of mechanisms one point, and thus directly or
through the medium of an electromagnet or electromagnets make or break the
connection between the accumulator battery in question and the charging battery,
and sometimes make the connection with one accumulator and break it with
another.
6. In carrying out that part of my invention which relates to arranging the
elements of the battery I use elements which have the active material on one side
only and I place these elements in pairs but separated by a dielectric. When the
battery is mounted in this manner it forms a series of distinct cells insulated from
each other and I can by a simple commutator arrangement connect all these cells
either in series or in parallel arc. In this form of battery I always use the gaseous
connection between the cells which I have already described.
7. In carrying out that part of my invention which relates to the manufacture
of the plates or active elements of the battery, I make a paste of Chloride or
Oxychloride of lead or of a mixture of them and reduce it to metallio lead
by means of metallic zinc or other suitable metal. I prefer to take a plate
of lead of proper thickness and to pass string or cord or gut or gutta-percha
cord or other suitable material backwards and forwards through holes and
then to cover it with the paste which I then reduce. I thus obtain a plate of lead
coated with a layer of porous lead which adheres to it and to the string or gut
which is imbedded in it. I sometimes stretch a piece of netting of suitable fibre
such as muslin to the metallic plate before putting on the paste and in this manner
I obtain a good adherence of the porous lead when it is reduced, or I insert the
sheet lead plate in a bag or pouch of net of suitable material and I apply the paste
inside the net between the sheet lead plate and the net or partly inside the net and
partly outside, so that the reduced porous metallic lead may be held on to the sheet
lead either wholly or directly by the netting or partly directly and partly indirectly
by the connection through the interstices of the netting between the reduced paste
or either side of the battery.
In order to ensure the complete reduction of the paste of chloride I sometimes
place a thin sheet of zinc or other suitable metal between the lead plate and the
paste or I coat the lead with such metal by electro deposition.
I also sometimes use plates made of an alloy of lead and zinc instead of lead
plates. In this case the zinc in the alloy is converted into chloride as it reduces
the lead in the paste or solution of chloride of lead, and the lead thus reduced
adheres to the sketeton lead plate which is left after the zinc has been dissolved
out. The adherence of the porous reduced lead may be increased in these cases as
described above for lead plates.
I also sometimes use a gridiron or pigeon-hole plate of lead or of alloy instead
0 of the plate of sheet lead, or wire covered if required with a coating of zinc to
form a network of lead wire or of alloy for the centre of the layers of reduced
porous lead.
Or I use, instead of chloride or oxychloride of lead, a mixture of chloride or
oxychloride of lead or both and oxide of lead (for instance red lead) which I make
5 into a paste and reduce with zinc as described. I thus obtain a strong and
consistent plate of porous metallic lead and oxide of lead.
I also sometimes dispense with the plate of metallic lead or other conductor as

page_text: a support for the porous lead plate which I then make of sufficient consistency by
compressing the porous plate during manufacture.
I also sometimes reduce the paste in a closed vessel and under pressure.
I have described my invention as applied to elements formed with a supporting
plate of lead but any other conducting substance such as carbon can be used.
"
The porous plates obtained by any of the above methods I wash with water and
water acidulated with sulphuric acid, and they are then ready for " forming
and can be used either alternately with plates of oxide or the whole battery can
be made up of these plates and "formed" in the usual manner by successive
reversions of an electric current of proper strength from any convenient source.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Francis John Bolton in the Great Seal Patent Office on the
27th January 1883.
FRANCIS JOHN BOLTON of N° 19. Grosvenor Gardens in the County of Middlesex
IMPROVEMENTS IN SECONDARY BATTERIES
"
The present improvements relate to secondary or accumulator batteries and
part of my invention consists in subjecting such batteries while forming or charging
or discharging to pressure. And part of my invention consists in improvements in
the construction of the vessel or receptacle in which the elements of the battery
are placed and contained. And part of my invention consists of improvements in
the method of arranging the elements of a secondary battery. And part of my
invention consists of improvements in supporting the active material of the
secondary battery. And part of my invention consists in the manner in which I
effect that the connection between the charging battery and the secondary battery
shall be automatically made and broken. And part of my invention consists of
the method by which I provide connection and communication between the
elements of the battery or between the divisions containing the electrolyte; and
part of my invention consists in the manufacture of the plates or active elements
of the battery.
1. In carrying out that part of my invention in which I subject a secondary
battery of any suitable form to pressure, I effect this by putting the battery into a
closed vessel of suitable form and strength such as an iron cylinder with closed
ends, the terminals of the battery being extended to the outside of the enclosing
vessel and electrically insulated from it by insulating pieces which are firmly
fastened to the material of the enclosing vessel. In this way of subjecting the
battery to pressure I prefer to use gaseous pressure produced by gases generated in
any convenient manner, but preferably by the accuinulation of the gases given off
during forming or charging.
"
2. In carrying out my improvements in constructing the casing of secondary
batteries, I make the casing of the battery in the form of a hollow prism or hollow
cylinder closed at the ends, or of two such hollow prisms or hollow cylinders, a
larger and a smaller enclosing an annular or other shaped space between them
which annular or other shaped space I close at the ends, and for convenience I
shall refer to such batteries (the casing of which consists of two hollow cylinders
or hollow prisms as described) as a centre-hole" battery, such hollow prisms or
hollow cylinders (and in the case of "centre-hole" batteries, one or both of the
hollow prisms or hollow cylinders) I build up of a succession of shorter hollow
prisms or hollow cylinders and such short hollow prisms or short hollow cylinders
of which my composite pipes are made up, I refer to throughout my Specification
as "parts" and for shortness I will throughout my Specification refer to such
hollow prisms or hollow cylinders as "pipes" and to such as are built up or
composed of a succession of shorter hollow prisms or hollow cylinders as "composite
pipes," and I do not limit myself to the use of truly cylindrical or prismatic pipes
as such can be more or less in the form of truncated cones or pyramids. The parts
of which my composite pipes are built up I make either of lead or of a dielectric
or of a suitable metal covered where necessary by a dielectric, or some of them of a
dielectric, or of a suitable metal covered where necessary by a dielectric, and some
of them of lead. I complete the casing of the battery by closing the ends of the
pipes or of the space between two pipes (in a "centre-hole" battery) by plates of
wood, iron, steel, or other suitable-material covered where necessary on the insidė
k

page_text: by a dielectric, and these two outside plates I furnish with projecting lugs or make
the plates sufficiently large to allow of their being bolted together by bolts parallel
or approximately parallel to the axis of the pipe or pipes, and outside the battery
or through the inside pipe when I have a "centre-hole" battery. And in the case
of a "centre-hole " battery in which the outside covering may be in one piece, I
sometimes fasten the end plates to such pipe by any suitable means. I thus obtain
a casing for my battery which is of such a form of construction as to be able when
required and when a suitable material of sufficient strength is employed, to stand
great internal pressure. The joints between the pipes and plates may either be flat
or, in order to render the joint more perfect, one of the meeting surfaces may be
formed with one or more annular grooves while the other surface has corresponding
projections fitting into the grooves.
3. In carrying out that part of my invention which relates to supporting the
active material, I use supporting plates which I make of any metal covered with a
dielectric varnish or of a dielectric, and they should be suitably perforated with
. holes to allow of the free passage of the electrolyte through them. But in the case
of the supporting plates being made of a porous dielectric as parchment it is not
always necessary to make holes in them. These supporting plates I place where
required so as to maintain the active material of the element which may be of porous
lead or salts of lead or salts of other metals, in good connection with the metallic
or other conductor of such element, and I attach them to the casing of the battery
and I sometimes make use of them as ties and thus increase its strength. To
effect this I either sandwich the edges of the plates between some of the "parts
of the composite pipe or pipes or I construct some of these parts with such plates
attached.
"
4. In all my batteries which are constructed with a composite pipe and mounted
permanently in series I effect a communication between the cells or compartments
of my battery (so that the pressure in all the cells may be the same) and I effect
this in such a manner that the communication between the cells when the battery
is in its proper position for filling, charging, or discharging, shall not have liquid
in it and I prefer to speak of this as a gaseous communication. I provide plugs
or cocks in the said gaseous communication so that when I am not working the
battery with internal pressure the removal of one of these plugs or cocks connected
with this gaseous communication may discharge the pressure from the battery.
This communication I also generally apply to batteries mounted in surface, but in
this case it is not so important that the communication when the battery is in
position for charging or discharging, should be free of liquid. Sometimes in the
case of batteries mounted in surface the communication between two adjacent
cells may be simply a hole through which the electrolyte passes. I sometimes
make the communication in the body of the casing of the battery sometimes outside,
sometimes inside.
5. In carrying out that part of my invention which consists in making and
unmaking an automatic connection between my Dynamo or charging battery and
my accumulator battery, I effect this by causing the pressure arising from the
accumulation of gases in my battery to act on a check or cam which shall advance
a mechanism or series or cycle of of mechanisms one point, and thus directly or
through the medium of an electro-magnet or electro-magnets make or break the
connection between the accumulator battery in question and the charging battery,
and sometimes make the connection with one accumulator and break it with
another.
6. In carrying out that part of my invention which relates to arranging the
elements of the battery I use elements which have the active material on one side
only and I place these elements in pairs but separated by a dielectric. When the
battery is mounted in this manner it forms a series of distinct cells insulated from
each other and I can by a simple commutator arrangement connect all these cells
either in series or in parallel arc. In this form of battery I always use the gaseous
connection between the cells which I have already described.

page_text: 7. In carrying out that part of my invention which relates to the manu
f the plates or active elements of the battery, I make a paste of Chloride or
Oxychloride of lead or of a mixture of them and reduce it to metallic lead by
neans of metallic zinc or other suitable metal. I prefer to take a plate of lead of
proper thickness and to pass string or cord or gut or gutta-percha cord or other
uitable material backwards and forwards through holes and then to cover it with
the paste which I then reduce. I thus obtain a plate of lead coated with a layer
of porous lead which adheres to it and to the string or gut which is imbedded in
it. I sometimes stretch a piece of netting of suitable fibre such as muslin to the
metallic plate before putting on the paste and in this manner I obtain a good
adherence of the porous lead when it is reduced, or I insert the sheet lead
plate on a bag or pouch of net of suitable material and I apply the paste inside
the net between the sheet lead plate and the net or partly inside the net and partly
outside, so that the reduced porous metallic lead may be held on to the sheet lead
either wholly or directly by the netting or partly directly and partly indirectly by
the connection through the interstices of the netting between the reduced paste on
either side of the battery.
In order to insure the complete reduction of the paste of chloride I sometimes
place a thin sheet of zinc or other suitable metal between the lead plate and the
paste, or I coat the lead with such metal by electro-deposition.
I also sometimes use plates made of an alloy of lead and zinc instead of lead
plates. In this case the zinc in the alloy is converted into chloride as it reduces
the lead in the paste or solution of chloride of lead, and the lead thus reduced
adheres to the skeleton lead plate which is left after the zinc has been dissolved
out. The adherence of the porous reduced lead may be increased in these cases as
described above for lead plates.
I also sometimes use a gridiron or pigeon-hole plate of lead or of alloy
instead of the plate of sheet lead, or wire covered if required with a conting of
zinc to form a network of leadwire or of alloy for the centre of the layers of
reduced porous lead.
Or I use, instead of chloride or oxychloride of lead a mixture of chloride or
oxychloride of lead or both and oxide of lead (for instance red lead) which I make
into a paste and reduce with zinc as described. I thus obtain a strong and
consistent plate of porous metallic lead and oxide of lead.
I also sometimes dispense with the plate of metallic lead or other conductor as
a support for the porous lead plate which I then make of sufficient consistency by
compressing the porous plate during manufacture.
I also sometimes reduce the paste in a closed vessel and under pressure.
I have described my invention as applied to elements formed with a supporting
plate of lead but any other conducting substance such as carbon can be used
The porous plates obtained by any of the above methods I wash with water and
water acidulated with sulphuric acid, and they are then ready for "forming" and
can be used either alternately with plates of oxide or the whole battery can be
made up of these plates and "formed " in the usual manner by successive reversions
5 of an electric current of proper strength from any convenient source.
Fig. 1 of the accompanying Drawings shews a part longitudinal section and part
side elevation of one form of the before described battery constructed as a composite
pipe. Fig. 2 shews a cross section of the same.
a is the active material or electrolyte, b, b, are the lead plates which carry it,
c, c, are the "parts" of the pipe which are in this case of lead; d are insulating
layers between the parts and on the end plate; e, e, are the end plates, secured
together by bolts f. g, g, are apertures by which communication is established
between the cells: h is the plug.

page_text: Fig. 3 shews a part longitudinal section and part elevation and Fig. 4 shews
a cross section of a "centre-hole" battery built up of the same "parts" c, lead
plates b, electrolyte a, insulating layers d, end plates e, and apertures g, as in the
previous arrangement, but having in addition inner annular "parts" c', forming
the centre-hole x, and also supporting plates i for the electrolyte. The end plates e
besides being secured by the external bolts fare further secured by the central
bolt passing through the centre-hole.
Fig. 5 shews a part longitudinal section and part elevation and Fig. 6 a cross
section of a similar construction of composite pipe-centre-hole battery to the
foregoing, but enclosed by an external casing k formed in one piece, with the
interposition of a layer of insulating material k between it and the parts of
the battery. In this arrangement the central bolt is dispensed with.
a cross section of an arrangement in which the part c and supporting plate i are
Fig 7 shews
formed in one piece. Fig 8 shews a cross section on line X X Fig. 10, and Figs. 9
and 10 shew longitudinal sections taken respectively on lines Y Y and Z Z of
Fig. 8, of an arrangement of a series battery of rectangular form, but without
supporting plates for the electrolyte. In this case the plates bare cast in one piece
with, or soldered to the "parts" c, with insulating plates d placed between the
contiguous plates bb. g is the communicating passage between the cells which in
this case is gaseous, being forined through the body of the parts c, c, and
communication being established between it and the cells by channels g¹ formed in
the insulating plates d'.
"
Figs. 11, 12 and 13 shew exaggerated sections of various modes of constructing
the "parts." At Fig 11 the parts c are formed of a core of iron, copper, wood,
insulite, or other substance covered with a sheet of lead, which at the same time
forms the plate b that carries the electrolyte; i is the insulating plate between the
plates b, and d is the insulating plate between the "parts," formed of a core of any
suitable material coated with insulating material such as paraffin, g is the com-
municating passage, and g¹ a passage leading into it from the cell through the
insulating plate. At Fig. 12 the lead plates bb are formed separate from the lead
coating of the part c, and Fig 13 shews the "parts" notched and the plates b
bulged into the notches by an insulating strip and also secured by brass pins, so
that the plates act as ties to the parts, as previously described. Fig. 14 shews a
vertical section and Fig. 15 a part plan of a commutator, for a series battery by
which it can be used in surface, as before described.
a
Fig. 16 shews diagrammatically one form of the before described arrangement
for automatically making or breaking the connection between the accumulator
battery and the charging source by means of the gaseous pressure in the battery.
For this purpose the passage g is connected to a flexible diaphragm, having
rod m with a hole through it at m¹. Upon this rod rest the lower end of a loaded
trigger or catch n which gears with a ratchet wheel o on a spindle which is
arranged to actuate by its partial rotation any suitable mechanism for effecting
the changes of connection between the battery and the source of current.
Thus on
the pressure in the passage g increasing it will distend the diaphragm until the
hole in its rod is brought underneath the trigger n, whereupon this falling down
on to a stop p, will effect the partial rotation of the ratchet wheel o and its
connections as may be required.
In order to regulate the exact degree of the gaseous pressure at which such change
shall take place, the end of the bar m is pressed upon by a spring q regulated by
a screw T.
Having thus described the nature of my invention and in what manner the same
is to be performed, I claim :-
First. The method of enclosing secondary batteries in an air tight casing so that
there shall be no escape for the gases evolved, whereby the pressure of such gases
increases the action of the battery.
Second The herein described method of forming the casing of secondary
5
5

page_text: batteries in parts so constructed that the electrical connections of each plate are
external, while the said casing is capable of withstanding internal pressure.
Third. The method of effecting communication between the cells of a hermetically
sealed battery by the herein described gaseous communication, so that it can be
connected in series or in surface.
Fourth. The use of supporting plates to maintain the active salts in position,
such plates being sandwiched into the casing as described; also arranging such
sandwiched plates to act as ties to the casing.
Fifth. The herein described construction of "centre-hole" batteries.
Sixth. The herein described method of causing the gaseous pressure in a closed
battery to make or break the electrical connections of the battery.
Seventh. The method of producing an element of a secondary battery by covering
a lead
or other conducting plate with a layer of porous metallic lead, such
conducting plate being for this purpose first coated with a paste or solution of
chloride or oxychloride of lead, or mixtures of these salts, which coating is then
reduced by means of metallic zinc, substantially as herein described.
Eighth. The herein described methods of increasing the adhesion of such porous
layers of lead, referred to in the preceding claim, to the lead or other conducting
plate.
Ninth. In the method of producing a battery element referred to in the seventh
claim, the use of conducting plates previously coated with zinc to facilitate the
reduction, substantially as herein described
Tenth. In the production of a battery element such as is referred to in the
seventh claim, the use of a conducting plate formed of an alloy of lead and zinc,
substantially as herein described.
Eleventh. Constructing an element for secondary batteries by mixing chloride
or oxychloride of lead or mixtures thereof with an oxide of lead, and reducing this
mixture by means of zinc substantially as herein described
In Witness whereof I the said Francis John Bolton have hereunto set my
hand and seal this twenty fifth day of January in the year of our Lord
One thousand eight hundred and eighty-three.
FRANCIS JOHN BOLTON (L.S.)