IMPROVEMENTS IN THE MANUFACTURE OF MALLEABLE BRONZE AND ARTICLES MADE THEREOF
Year: 1881

page_text: LETTERS PATENT to Henry Harris Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF MALLEABLE BRONZE AND
ARTICLES MADE THEREOF." A communication from abroad by Léon Létrange,
of Paris, France.
PROVISIONAL SPECIFICATION left by the said Henry Harris Lake at
the Office of the Commissioners of Patents on the 21st July 1881.
HENRY HARRIS LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN THE MANUFACTURE OF
MALLEABLE BRONZE AND ARTICLES MADE THEREOF." [A communication from
abroad by Léon Létrange, of Paris, France.]
Bronze is now used to a great extent for the manufacture of castings, and it has
heretofore been sought to improve the quality thereof by means of an addition of
phosphor, which has the effect of rendering the metal more homogeneous and
harder than without it.
Certain experiments with phosphorous bronze have had special relation to the
production of cast ordnance for artillery. Some experiments have also been made
relatively to cast bells, and attempts have been made to manufacture wire and
cartridge shells, but they were not proceeded with. The alloy heretofore used
consisted of copper, tin, and zinc, like that used for making coins, but with a larger
proportion of copper, and always with a proportion of zinc designed to make the
metal malleable and soft.
What is known as phosphor bronze has now come into general use for bearings
and other cast parts of machinery.
All the processes heretofore in use have remained unemployed, except for
castings, for the reason that the phosphorous has been introduced in a quantity
which is sufficient to harden the alloy, and consequently to deprive it of its natural
qualities. Nevertheless, bronze containing a large proportion of tin has been con-
sidered but slightly malleable, especially gun-metal which contains within a few
units 90 per cent. of copper, and the remainder in tin, there being no zinc. This
Price 6d 1

page_text: alloy cracks and splits when being rolled; it also splits in the furnace when first
being heated or annealed; its surface frequently becomes covered with spots or
stains of eliquated zinc. These inconveniences or defects are caused by a natural
want of homogeneity, which arises from the tendency of the tin to become separated
from the copper by eliquation.
According to the present Invention I impart to the alloy of copper and tin, and
specially to gun-metal, the qualities required to enable it to bear rolling and
subsequent application to the manufacture of a great number of articles.
When bronze is being cast, the qualities proper to the two metals of which the
alloy is composed are obliterated by the presence of the oxygen abstracted from the
atmosphere by the fused metals, but according to my process I free them from the
objectionable ingredient by introducing into the metallic bath a substance which
has great affinity for oxygen (such as manganese or phosphorus), in a quantity
which is just sufficient for absorbing the oxygen and carrying it off in combination
to the surface of the bath, which is the reverse of what has hitherto been done,
that is to say, adding a larger dose of manganese or phosphorus intended to harden
the metal.
The deoxidation of the bronze which I effect is analogous to that which is
applied to iron in the well known "Bessemer" process, in which at the end of the
operation, when the iron is penetrated by oxygen, in consequence of the energetic
action of the air introduced for the purpose of oxidising the foreign matters,
manganese is introduced in the proportion required for being combined with the
oxygen, and for carrying it off into the scoria.
The
But I am very careful not to introduce a quantity of manganese or of phosphorus
which would be sufficiently considerable to be taken into account in the alloy, as
has been done by those who have heretofore operated upon castings.
manganese is introduced into the metal bath in the state of cupro-manganese
previously combined, or phosphuret of manganese. The phosphorus which I prefer
to the manganese may be introduced in its natural state directly into the bath of
copper, tin, or bronze, and incorporated by rapid stirring.
It may be produced by contact of the melted metal by the decomposition of
phosphorous material. I prefer to introduce it in the state of phosphuret of copper
or phosphuret of manganese previously prepared, either into the molten copper
before the tin is introduced, or into the tin intended for the alloy, or into the alloy
at the moment of tapping. The bronze thus deoxidized becomes remarkaby fluid
when in fusion, and acquires when cold a malleability which allows it to be rolled,
and then stamped, wrought, or otherwise worked like copper and brass. It possesses
in the highest-degree-its-natural-qualities-of-elasticity, tenacity, and resistance to
oxidation, a fine and close grain, and a color resembling that of gold, which renders
it capable of advantageously replacing steel, tin, copper, and its various alloys
with zinc.
When greater hardness and tenacity are to be imparted to the bronze, I add to
the alloy nickel, bromine, tungsten, wolfram, or other metals, which render it hard,
but do not prevent its being malleable.
Bronze thus prepared is malleable, provided that certain means are used for
working the same.
The molten alloy has to be cast in plates in copper moulds, and has to be
annealed before being rolled. It is rolled when cold, and is annealed after each
passage through the rollers; the pressure is light at first, and increases with each
subsequent passage or operation.
Thus prepared the malleable bronze becomes suitable for stamping and chasing,
or otherwise working; its grain is remarkably fine, close and homogeneous, and it
is moreover very sonorous.
Bronze so made I propose to employ for the manufacture by stamping of large
and small bells and gongs, electric-bells, and clock-bells, which hitherto have been
made of cast bronze which is liable to crack or break under shocks and are more
expensive to manufacture than those made according to my Invention.

page_text: When the malleable bronze has been rolled to a suitable thickness it is cut out
in round discs and these round discs are stamped.
By reason of the hardness of the metal this stamping requires powerful tools,
and I prefer to use a hydraulic press, whose slow action is applicable for the
development of the greatest power for overcoming the resistance of so hard a
metal as bronze.
In making bells or other articles of small dimensions I use a fly or similar press,
or I may employ a continuously working apparatus with excentric gear like those
used in the manufacture of coins, buttons, cartridges, and in all the stamping and
punching processes.
For bells to be used in electric-bell apparatus and in clocks the stamping takes
place in a single operation, but bells of greater depth have to pass through the
apparatus repeatedly, and the metal has to be annealed each time it passes. The
excess of thickness generally left standing as a raised disc round the central hole of
cast bells or gongs is replaced by a circular swelling produced by pressure during
the stamping.
The rolled bronze disc may also be chased or worked in the lathe.
The metal being remarkably sonorous, large and small bells and gongs when
stamped may be thinner than those of cast bronze, and nevertheless not be liable
to fracture under the shock. They can moreover be made more cheaply.
The process I have described is applicable to the manufacture from malleable
rolled bronze of certain articles, ordinarily made of copper or brass; I may mention
by way of example, cooking utensils, various articles for domestic use, also
cartridge-shells, and cases for pen-holders.
Saucepans and other articles for domestic use made from a disc of malleable
rolled-bronze, stamped and wrought, have a much greater stiffness and hardness
than copper-saucepans. The fine gold-color of the bronze makes them more
brilliant, the tinning takes more easily on the bronze than on copper; moreover
bronze being less liable to change than copper, means are provided for preventing
the frequent poisoning produced by the latter metal, and in many cases tinning
may be dispensed with. Where brass is used for cartridges the zinc contained
therein has the serious defect that it decomposes the gunpowder in time if aided
by moisture, thus exposing armies to the risk of appearing before the enemy with
deteriorated cartridges. Cartridges made of malleable bronze prevent this incon-
venience, and by reason of the tenacity of the metal the cartridge-shells may be
used twice as many times as those made of brass.
But all these advantages can be obtained only in overcoming the difficulties of
manufacture which are the consequence of the hardness of the metal.
The machines ordinarily used for making cartridge-shells of brass must be
stronger for making the same article in bronze.
It is therefore necessary to proceed with this metal by small and repeated
passages or operations, or stronger machinery must be used.
The passages or operations which require the greatest power can be effected by
a suitable hydraulic press.
The scouring, cleansing, or scaling, has to be effected by dipping the bronze
when heated to a red heat into a water bath charged with sulphuric acid.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Harris Lake in the Great Seal Patent Office on the
21st January 1882.
HENRY HARRIS LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN THE MANUFACTURE OF
MALLEABLE BRONZE AND ARTICLES MADE THEREOF." A communication from
abroad by Léon Létrange, of Paris, France.
Bronze is now used to a great extent for the manufacture of castings, and it
has heretofore been sought to improve the quality thereof by the addition of
phosphorus, which has the effect of rendering the metal more homogeneous and
harder than it would be without it.
Certain experiments with phosphor bronze have been made having special
relation to the production of cast ordnance. Some incomplete experiments have
also been made relatively to cast bells, and attempts have been made to manu-
facture wire and cartridge cases, but they were not proceeded with. The alloy
heretofore used consisted of copper, tin, and zinc like that used for making coins,
but with a larger proportion of copper, and always with a proportion of zinc in
order to make the metal malleable and soft.
What is known as phosphor-bronze has now come into general use for bearings
and other cast parts of machinery.
All the processes heretofore introduced have remained unemployed except for
castings, because the phosphorus has been introduced in a quantity sufficient to
harden the alloy, and consequently to deprive it of its natural properties. Never-
theless bronze containing a large proportion of tin has been considered slightly
malleable, especially gun metal, which contains within a few units 90 per cent. of
copper and the remainder tin, there being no zinc in it. This alloy cracks and
splits when being rolled; it also splits in the furnace when first being heated or
annealed, and its surface frequently becomes covered with spots of melted tin.
These inconveniences or defects are caused by a natural want of homogeneity,
which arises from the tendency of the tin to become separated from the copper by
fusion.
According to the present Invention I impart to the alloy of copper and tin,
and specially to gun-metal, the qualities required to enable it to bear rolling, and
the subsequent application to the manufacture of a great number of articles.
When bronze is being cast the qualities proper to the two metals of which the
alloy is composed, are obliterated by the presence of the oxygen abstracted from
the atmosphere by the fused metals; but according to my process I free them from
this objectionable ingredient by introducing into the metallic bath a substance
which has great affinity for oxygen (such as manganese or phosphorus), in a
quantity which is just sufficient to absorb the oxygen, and carry it off in com-
bination to the surface of the bath, which is the reverse of what has hitherto been
done, that is to say, adding a larger proportion of manganese or phosphorus in
order to harden the metal.
The deoxidation of the bronze which I effect is analogous to that which is
applied to iron in the well known "Bessemer" process, in which at the end of the
operation when the iron is permeated with oxygen, in consequence of the energetic
action of the air introduced for the purpose of oxidizing the foreign matters,
manganese is introduced in the proportion necessary for it to combine with the
oxygen and carry it off with the scoria.
But I am very careful not to introduce a quantity of manganese or of phosphorus,
which would be sufficiently considerable to be taken into account in the alloy, as

page_text: The
has been done by those who have heretofore operated upon castings.
manganese is introduced into the metal bath in the state of cupro-manganese
previously combined, or of phospuret of manganese. The phosphorus which I
prefer to the manganese may be introduced in its natural state directly into the
bath of copper, tin, or bronze, and incorporated by rapid stirring.
It may be produced by contact of the melted metal by the decomposition of
phosphorous material. I prefer to introduce it in the state of phosphuret of copper
or phosphuret of manganese previously prepared, either into the molten copper
before the tin is introduced, or into the tin intended for the alloy, or into the alloy
at the moment. of tapping. The bronze thus deoxidized becomes remarkably fluid
when in fusion, and acquires when cold a malleability which allows it to be rolled,.
and then stamped, wrought, or otherwise worked like copper and brass. It
possesses in the highest degree its natural qualities of elasticity, tenacity, and
resistance to oxidation, a fine and close grain, and a color resembling that of gold,
which qualities render it capable of advantageously replacing steel, tin, copper, and
its various alloys with zinc."
When greater hardness and tenacity are to be imparted to the bronze, I add to
the alloy nickel, tungsten, wolfram, or other metals, which render it hard but do
not prevent its being malleable.
Bronze thus prepared is malleable, provided that certain means are used for
working the same.
The molten alloy should be cast in plates, in copper moulds, and then annealed.
before being rolled. It is rolled when cold, and is annealed after each passage
through the rollers; the pressure is light at first, and increases with each subsequent.
passage or operation.
Thus prepared the malleable bronze becomes suitable for stamping and chasing
or otherwise working; its grain is remarkably fine, close, and homogeneous, and it
is moreover very sonorous.
Bronze so made I propose to employ for the manufacture by stamping of large
and small bells and gongs, electric bells and clock bells, which hitherto have been
made of cast bronze liable to crack or break under blows, and are more expensive
to manufacture than those made according to my Invention.
When the malleable bronze has been rolled to a suitable thickness it is cut into
round discs, and these round discs are then stamped. By reason of the hardness of
the metal this stamping requires powerful tools, and I prefer to use a hydraulic
press, the slow action of which is applicable for the development of the greatest
power for overcoming the resistance of so hard a metal as bronze.
In the accompanying Drawing, Figure 1 shows a front elevation; Figure 2, a:
side view, and Figure 3, a plan of a hydraulic press adapted for stamping bells.
A is the cylinder of the press; B, the matrix in which the disc is stamped; C, a
plunger which presses the disc into the matrix, so as to make it assume the shape.
of the latter. The press should be worked by pressure from au accumulator.
In making bells or other articles of small dimensions I use a fly or similar press,
or I may employ a continuously working apparatus with eccentric gear, like those
used in the manufacture of coins, buttons, cartridges, and for stamping and
punching.
For bells to be used in electric bell apparatus and in clocks, the stamping is
effected by a single stroke, but for bells of greater depth several strokes are required,
between each of which the metal should be annealed. In place of the extra
thickness generally left in the disc around the central hole of cast bells, a circular
swelling is produced by pressure during the stamping.
The rolled bronze disc may also be chased or worked in the lathe. The metal
being remarkably sonorous, large and small bells and gongs when stamped may be
thiuner than those of cast bronze, and nevertheless 'not be liable to fracture under
the blow. They can moreover be made cheaper.
The process
I have described is applicable to the manufacture from malleable
rolled bronze of certain articles ordinarily made of copper or brass. I may mention

page_text: by way of example, cooking utensils, various articles for domestic use, also cartridge-
cases, and pen and pencil cases. Saucepans and other articles for domestic use
made from a disc of malleable rolled bronze stamped and wrought, have a much
greater stiffness and hardness than copper saucepans. The fine gold-color of the
bronze makes them more brilliant, the tinning takes more easily on the bronze
than on copper, and finally bronze being less liable to corrode than copper, avoids
the frequent poisoning produced by the latter metal, and in many cases tinning
may be dispensed with.
Cartridge cases made of malleable bronze offer considerable advantages over
those made of brass. The zinc contained in the latter has this serious defect, that
it decomposes the gunpowder in time if aided by moisture, thus exposing armies to
the risk of appearing before the enemy with deteriorated cartridges. Cartridge
cases made of malleable bronze prevent this inconvenience by reason of the tenacity
of the metal, and it is possible to fire twice as many shots with the bronze cases as
with those of brass.
But all these advantages can be obtained only by overcoming the difficulties of
manufacture, which are the consequence of the hardness of the metal.
The machines ordinarily used for making cartridge cases of brass must be
stronger for making the same articles in bronze. It is therefore necessary to
proceed with this metal by small and repeated strokes, or stronger machinery must
be used. The strokes which require the greatest force can be effected by a suitable
hydraulic press.
The cleansing or scaling must be effected by dipping the bronze when heated to
a red heat into a water bath charged with sulphuric acid. Pen and pencil cases
and boxes for steel pens or matches are manufactured by stamping like the
cartridge cases. The beautiful color of the bronze renders its covering with a layer
of tin or nickel unnecessary.
The bronze has not, like brass, the inconvenience of producing a disagreeable
smell when brought in contact with the hand. It is therefore preferable to brass
for the manufacture of articles requiring frequent handling.
My Invention is also applicable to pen and pencil cases and cartridge cases
rolled and stamped, as hereinbefore described. I may also by my process manu-
facture in malleable bronze uniform-buttons and military equipments, such as
breast-plates and helmets, and the like, which have the advantage of shining with
a brilliancy like that of gold, are very durable, and in many cases do not require
gilding, being but little affected by the atmosphere; they require little or no
cleaning, are hard enough to resist wear and pressure, and may be made of thinner
metal.
Having thus fully described the said Invention, as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
First. The process of manufacturing the alloy of copper and tin commonly known
as bronze, and rendering it malleable and homogeneous by the introduction of
manganese of phosphorous or both combined, substantially as herein before described.
Second. The manufacture of articles of such malleable bronze by stamping,
embossing, chasing, or similar means.
In witness whereof, I, the said Henry Harris Lake, have hereunto set my
hand and seal, this Twenty-first day of January, in the year of our Lord
One thousand eight hundred and eighty two.