An Improved Manufacture of Metal Cartridge Cases.
Year: 1889

page_text: Date of Application, 19th Feb., 1889
Complete Specification Left, 13th Nov., 1889-Accepted, 14th Dec., 1889
PROVISIONAL SPECIFICATION.
An Improved Manufacture of Metal Cartridge Cases.
1, WILHELM LORENZ, of 44 Westendstrasse, of Karlsruhe, in the Grand Duchy of
Baden, German Empire, Engineer and Manufacturer, do hereby declare the nature of
this invention to be as follows:-
--
For manufacturing metal cartridge cases for large calibres out of a single piece of
metal, very powerful machines and very heavy and expensive tools are required. In
consequence hereof the difficulty of producing good durable cartridge cases out of a
single piece of metal, and also the cost of such production, increases out of all
proportion to the increase in diameter and length of the cases.
According to my present invention 1 produce metal cartridge cases of large calibres
at a comparatively low cost and with simpler and lighter machines, presses and tools,
while at the same time the cases produced have equal strength and durability with the
others, and for this purpose I make the parts of the cases which can only be produced
with difficulty out of one piece of metal, by pressure, of separate pieces, which are then
firmly united together to a compact whole by melting, soldering or welding, so that all
the parts of the case are as firmly united together as though they were formed of a
single piece. Under the expression "melting" or "soldering" is not to be understood
the ordinary process of soldering with a soldering iron, but a process to be described
hereinafter, whereby the parts to be united are subjected to heat simultaneously on
their whole periphery. In addition to the said melting soldering or welding, the
separate parts can be previously united by screwing, rivetting, folding &c.
With cases of large diameter the base and the cylindrical part may, for example,
be formed out of a single metal disc by drawing and pressing as before, but it is very
difficult also to form the projecting base rim, which limits the insertion of the cartridge
into the gun and which serves for withdrawing or ejecting the cartridge case, by
pressing out the metal of the base.
The material must for this purpose be forced from the centre of the base in all
directions towards the periphery thereof, so as to project sufficiently all round beyond
the cylindrical part of the case. It has been attempted to form such rim of separate
rings which were either shrunk or screwed on, or were forced into conically recessed
seats formed on the cylinder, but these attempts have not been successful, because
such modes of attachment did not possess sufficient strength to withstand the pressure
or blow of the explosion exerted on the base on firing, and the rings consequently
became loose and the seating surfaces deformed so that the cases could only be used
once, or, if used again, they require to have fresh seatings, new screw threads, &c.
formed thereon and be provided with new rings.
According to the present invention cartridge cases in which the base and cylindrical
part are formed out of one piece of metal are provided with a base rim fixed-thereon
in either of the above mentioned ways but in such a manner that the rim forms
practically one and the same piece with the other part and cannot be deformed or
loosened, and this is effected simply by subjecting it to the said melting or soldering
operation, which I will now proceed to describe with reference to the accompanying
drawings.
Fig. 1 shews a cartridge case A formed of one piece of metal but without the base
rim, which is formed separately in the form of a ring B', and is either screwed on, as
shewn at a, or rivetted on as at b and c, being if necessary shrunk on in the first
instance this ring is then united to the body A by melting. If the base and
cylindrical part cannot be formed of one piece by pressing, the two parts are made
separate from each other, in the manner indicated at figs. 2, 3, 3, 4, 4 and 5.
In this case also the usual means of securing the two parts together, such as

page_text: rivetting the cylindrical part C C¹ to the base cup D, B³, folding the same together
with a turned up rim B2 B4 Figs. 2, 4 and 5, will not suffice, as the powerful pressure
or blow of the explosion will already at the first firing cause the loosening of the
rivets and the tearing away of the cylindrical part from the folded base &c., so
that the case is unserviccable for further use: On the other hand the cylindrical
part readily expands more than the base cup so that the connection of the parts
becomes loosened, producing a space between the two parts which becomes filled
.with deposit from the combustion, which thus renders the case unserviceable for use
further use.
.If on the other hand, according to my present invention, all contact surfaces
between cylinder and base or base cup are united by melting, soldering or welding,
all the parts are solidly united together, and the cartridge case is, as regards transport,
firing, and recalibrating for repeated use, to all intents the same as though it were
formed entirely of one piece.
Furthermore, it may be desirable or necessary with large size cartridge cases, to
form the base itself of two or more separate parts, as shewn at Figs. 4 4 5 and 6.
For example, for forming a base rim B4, a base disc can be taken which projects all
round beyond the circumference of the cylinder and this is then connected to a base
cup D. The cylindrical part can then be either fixed to the cylindrical wall of the
base cup, or to the turned over edge B₁ of the base rim, Figs. 4 and 5, or by both
means jointly. It may also be desirable to form the cap chanıber E separately, in
which case it may be fixed in the base disc as indicated.
In the above mentioned arrangements, the mere rivetting, screwing &c. of the
parts together has also not been found sufficient to produce a cartridge case of
sufficient durability. The requisite strength and durability is obtained if a large sized
cartridge case is formed by pressing and drawing the base or part thereof and the
cylindrical part out of one piece, as shewn at Fig. 6 and 6ª, and then strengthening
or closing the base and the lower part of the cylinder, which are subjected to the
greatest strain, by the insertion of a base B with cup D.
If now, in addition to the above mentioned modes of securing the parts together
the surfaces of the several parts that are in contact are melted, soldered or welded
together, cartridge cases are produced which when used act as though they were made
of one solid piece. Also, the cylindrical part and the base cup or base disc can be
made to butt joint against each other, as shewn on the right hand side of Fig. 7,
and then be welded together by any suitable means, such for example as the
electric arc.
On the cylindrical part can be fitted between an inner and an outer base cup, as
shewn at the left hand side of Fig. 7, and be then melted or welded together therewith
by any suitable means. The hollow edges at d Figs. 4 4 5, 6, 6 and 7 become filled
of themselves with metal during such melting.
The particular process by which the melting soldering or welding is effected is
determined according to the nature of the metals or alloys used, for the parts of the
cartridge, so as in each case to effect the strongest and most durable connection of the
parts. The several parts are in the first instance made perfectly clean in the usual
manner, treated with acid, &c., and are then treated with the required soldering
melting or welding medium, suited to the metals to be united, and to the particular
process (wet process, firing, galvanising &c.) employed. Thus for example either the
usual soft solders, such as tin or alloys of tin and lead, or of lead and bismuth may be
used, as also the hard solders such as brass or copper having a large proportion of zinc
or alloys of copper and lead or brass and tin &c.
Or again the melting property of the parts themselves may be made use of for
effecting the desired union thereof.
In order that the surfaces to be united may not oxidize during the melting, soldering
or welding process, their contact with the air or oxydizing gases is prevented in the
usual manner by means of borax, glass powder, &c.
The prepared parts, after having been suitably secured together, are then subjected
to the required heat (when such is necessary) either by means of a circular flame or

page_text: in highly heated crucibles or retorts in a furnace or in a metal bath, or by means of
the electric arc, or in any other manner, so that the uniting media upon the surfaces
in contact are caused to melt and to unite or amalgamate with each other and with
such surfaces, so that an intimate union of these is effected; or, in the case where no
medium is used, so that the said surfaces themselves begin to melt and thus unite
directly with each other.
If the heating is effected in a metal bath the liquid metal of the bath may serve as
uniting medium. For example, the brass base of a cartridge case can be united to a
cylindrical part of zinc by dipping and heating in a bath of tin, or to a cylinder of
sheet iron by dipping and heating in a bath of very fusible brass having a largo
proportion of zinc.
In all cases the liquid metal of the bath forces itself between the closely fitting
heated metal surfaces, and in amalgamating with the same, effects a perfect metallic
union thereof.
During this process the base remains open at bottom and the cap chamber E is
inserted afterwards, in order that the liquid metal may penetrate into the interior of:
the case, and heat the inner metal parts and also force its way from the inside between
the surfaces.thereof.
By way of example, the heating of a cartridge case with screwed or rivetted base
rim B', as described with reference to Fig. 1, is shewn at Fig. 8 as being effected by
means of a circular gas flame. Figs. 9 and 10 shew a furnace G with crucibles H of
refractory material, in which the cartridge cases are introduced with their lower
parts.
The crucibles are heated by a common fire to such an extent as to effect the melting
or soldering together of the surfaces to be united.
Fig. 11 shews a cartridge case constructed as described with reference to Fig. 5,
introduced without its cap chamber into the metal bath I.
In all cases the parts of the cartridge case will be found after cooling to be united
together so as to form a compact whole. The cartridge case is then treated in a
press, or in a lathe or other machine for finishing it off.
For uniting a base with cup made, for example, of brass with a cylinder of thin
In the middle
sheet iron or steel the process may be employed as indicated at Fig. 6.
of the base is placed a solid block E¹ representing the cap chamber, and the other
part of the inner surface of the thin metal base B as also a portion of the cylindrical
part is covered by a base cup D. The hollow space d of the base rim is left free.
A weighted core F of clay or other suitable material, which is made to fill out the
entire cartridge case, is then forced down on the base cup so that only a small
space e above the cap chamber and another space fabove the edge of the D
cup
are left.
All the surfaces in contact having been treated with a suitable soldering or melting
material, the lower part of the case is subjected to heat, until the brass cup melts or
begins to melt.
This will thereby only be altered in shape in so far as the liquid metal therefor will,
under the pressure of the core, be made to flow together with the soldering medium
or to unite with the surfaces of the iron or steel cylinder and its base with which
it is in contact, and also flow into the hollow d of the rim. The core will be thereby
made to sink down somewhat in proportion to the displacement of the metal, this
being permitted by the spaces at eandf. After cooling the three parts: cylinder AB,
base cup D and cap chamber E¹ will be firmly united together and the cartridge case
can be finished in the usual way either in a press, a lathe or other suitable machine.
This process of melting or welding is used with advantage when the cylindrical
part of the cartridge case is of iron or steel.
Dh, 1011. of Waba 1880
ABEL & IMRAY;
Agents for the Applicant."

page_text: '
COMPLETE SPECIFICATION.
An Improved Manufacture of Metal Cartridge Cases.
I, WILHELM LORENZ of 44 Westendstrasse of Karlsruhe in the Grand Duchy of
Baden, German Empire, Engineer and Manufacturer, do hereby declare the nature
of this invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
For manufacturing metal cartridge cases for large calibres out of a single piece of
metal, very powerful machines and very heavy and expensive tools are required.
In consequence hereof the difficulty of producing good durable cartridge cases out
of a single piece of metal, and also the cost of such production, increases out of all
proportion to the increase in diameter and length of the cases.
According to my present invention I produce metal cartridge cases of large
calibres at a comparatively low cost and with simpler and lighter machines, presses
and tools, while at the same time the cases produced have equal strength and
durability with the others, and for this purpose I make the parts of the cases which
can only be produced with difficulty out of one piece of metal, by pressure, of
separate pieces, which are then firmly united, together to a compact whole by
melting, soldering or welding, so that all the parts of the case are as firmly united
together as though they were formed of a single piece. Under the expression
"melting" or "
soldering" is not to be understood the ordinary process of soldering
with a soldering iron, but a process to be described hereinafter, whereby the parts to
be united are subjected to heat simultaneously on their whole periphery. In addition
to the said melting soldering or welding, the separate parts can be previously united
by screwing, rivetting folding &c.
With cases of large diameter, the base and the cylindrical part may, for example,
be formed out of a single metal disc by drawing and. pressing as before, but it
is very difficult also to form the projecting base rim, which limits the insertion
of the cartridge into the gun and which serves for withdrawing or ejecting the
cartridge case, by pressing out the metal of the base.
The material must for this purpose be forced from the centre of the base in all
directions towards the periphery thereof, so as to project sufficiently all round
beyond the cylindrical part of the case.
It has been attempted to form such rim of separate rnigs which were either
shrunk or screwed on, or were forced into conically recessed seats formed on the
cylinder, but these attempts have not been successful, because such modes of
attachment did not possess sufficient strength to withstand the pressure or blow of
the explosion exerted on the base on firing, and the rings consequently become
loose and the seating surfaces deformed so that the cases could only be used once,
or if used again, they required to have fresh seatings, new screw threads, &c.
formed thereon and be provided with new rings.
According to the present invention cartridge cases in which the base and
cylindrical part are formed out of one piece of metal are provided with a base-rim
fixed thereon in either of the above mentioned ways, but in such a manner that
the rim forms practically one and the same piece with the other part and cannot
be deformed or loosened, and this is effected simply by subjecting it to the said
melting or soldering operation, which I will now proceed to describe with reference
to the drawings accompanying my Provisional Specification.
Fig. 1 shews a cartridge case A formed of one piece of metal but without the
base rim, which is formed separately in the form of a ring B, and is either
screwed on, as shewn at a, or rivetted on as at b and c, being if necessary shrunk on
in the first instance; this ring is then united to the body A by melting. If the
base and cylindrical part cannot be formed of one piece by pressing, the two parts are
made separate from each other in the manner indicated at Figs. 2, 3, 3, 4, 4ª and 5.
In this case also the usual means of securing the two parts together, such as
rivetting the cylindrical part CC to the base cup D, B3; folding the same together

page_text: with a turned up rim B² B* Figs. 2, 4 and 5 will not suffice, as the powerful pressure
or blow of the explosion will, already at the first firing, cause the loosening of the
rivets and the tearing away of the cylindrical part from the folded base &c. so that
the case is unserviceable for further use. On the other hand the cylindrical part
readily expands more than the base cup so that the connection of the parts becomes
loosened, producing a space between the two parts which becomes filled with deposit
from the combustion, which thus renders the case unserviceable for further use.
If on the other hand according to my present invention, all contact surfaces between
cylinder and base or base cup are united by melting, soldering or welding, all the
parts are solidly united together, and the cartridge case is, as regards transport, firing
and recalibrating for repeated use, to all intents the same as though it were formed
entirely of one piece.
Furthermore it may be desirable or necessary with large size cartridge cases to
form the base itself of two or more separate parts as shewn at Figs. 4 4 5 and 6. For
example, for forming a base rim B, a base dise can be taken which projects all round
beyond the circumference of the cylinder and this is then connected to a base cup D.
The cylindrical part can then be either fixed to the cylindrical wall of the base cup,
or to the turned-over edge B of the base rim, Figs. 4 and 5, or by both means jointly.
It may also be desirable to form the cap chamber E separately, in which case it may
be fixed in the base disc as indicated.
In the above mentioned arrangements the mere rivetting, screwing etc. of the parts
together has also not been found sufficient to produce a cartridge case of sufficient
durability. The requisite strength and durability is obtained if a large sized cartridge
case is formed by pressing and drawing the base or part thereof and the cylindrical
part out of one piece as shewn at Fig. 6 and 6" and then strengthening or closing the
base and the lower part of the cylinder, which are subjected to the greatest strain, by
the insertion of a base B with cup D.
If now, in addition to the above mentioned modes of securing the parts together,
the surfaces of the several parts that are in contact are melted, soldered or welded.
together, cartridge cases are produced which when used acts as though they were
made of one solid piece. Also, tho cylindrical part and the base cup or base disc can
be made to butt-joint against each other, as shewn on the right hand side of Fig. 7,
and then be welded together by any suitable means such for example as the
electric arc.
Or the cylindrical part can be fitted between an inner and an outer base cup, as
shewn at the left hand side of Fig. 7, and be then melted or welded together therewith
by any suitable means.
The hollow edges at d Fig. 4, 4ª 5, 6, 6 and 7 become filled of themselves with
metal during such melting.
The particular process by which the melting soldering or welding is effected is
determined according to the nature of the metals or alloys used for the parts of the
cartridge, so as in each case to effect the strongest and most durable connection of the
parts. The several parts are in the first instance made perfectly clean in the usual
manner, treated with acid, &c., and are then treated with the required soldering,
melting or welding medium, suited to the metals to be united, and to the particular
process (wet process, firing, galvanising &c.) employed. Thus for example either the
usual soft solders, such as tin or alloys of tin and lead, or of lead and bismuth may be
used, as also the hard solders such as brass or copper having a large proportion of zinc
or alloys of copper and lead or brass and tin &c.
Or again the melting property of the parts themselves may be made use of for
effecting the desired union thereof.
In order that the surfaces to be united may not oxidize during the melting, soldering
or welding process, their contact with the air or oxydizing gases is prevented in the
usual manner by means of borax, glass powder &c.
>
The prepared parts, after having been suitably secured together, are then subjected
to the required heat (when such is necessary) either by means of a circular flame or

page_text: in highly heated crucibles or retorts in a furnace, or in a metal bath, or by means of
the electric arc, or in any other manner, so that the uniting media upon the surfaces
in contact are caused to melt and to unite or amalgamate with each other and with
such surfaces, so that an intimate union of these is effected; or, in the case where
no medium is used, so that the said surfaces themselves begin to melt and thus unite
directly with each other.
If the heating is effected in a metal bath the liquid metal of the bath may serve as
uniting medium. For example, the brass base of a cartridge case can be united to a
cylindrical part of zinc by dipping and heating in a bath of tin, or to a cylinder of
sheet iron by dipping and heating in a bath of very fusible brass having a large
proportion of zinc.
In all cases the liquid metal of the bath forces itself between the closely fitting
heated metal surfaces, and in amalgamating with the same, effects a perfect metallic
union thereof.
During this process the base remains open at bottom and the cap chamber E is
inserted afterwards, in order that the liquid metal may penetrate into the interior of
the case, and heat the inner metal parts and also force its way from the inside
between the surfaces thereof.
By way of example, the heating of a cartridge case with screwed or rivetted base-
rim B1, as described with reference to Fig. 1, is shewn at Fig. 8 as being effected by
means of a circular gas flame. Figs. 9 and 10 shew a furnace G with crucibles H of
refractory material, in which the cartridge cases are introduced with their lower
parts.
The crucibles are heated by a common fire to such an extent as to effect the melting
or soldering together of the surfaces to be united.
Fig. 11 shows a cartridge case constructed as described with reference to Fig. 5
introduced without its cap chamber into the metal bath I.
In all cases the parts of the cartridge case will be found after cooling to be united
together so as to form a compact whole. The cartridge case is then treated in a press,
or in a lathe or other machine for finishing it off.
For uniting a base with cup made, for example, of brass with a cylinder of thin
sheet iron or steel the process may he employed as indicated at Fig. 6. In the middle
of the base is placed a solid block E¹ representing the cap chamber, and the other
part of the inner surface of the thin metal base B as also a portion of the cylindrical
part is covered by a base cup D.
The hollow space d of the base rim is left free.
A weighted core F of clay or other suitable material, which is made to fill out the
entire cartridge case, is then forced down on the base cup so that only a small space e
above the cap chamber and another space fabove the edge of the cup D are left.
All the surfaces in contact having been treated with a suitable soldering or melting
material, the lower part of the case is subjected to heat, until the brass cup melts or
begins to melt.
This will thereby only be altered in shape in so far as the liquid metal therefor will
under the pressure of the core, he made to flow together with the soldering medium
or to unite with the surfaces of the iron or steel cylinder and its base with which it is
in contact and also flow into the hollow of the rim. The core will be thereby made
to sink down somewhat in proportion to the displacement of the metal, this being
permitted by the spaces at e and f.
After cooling the three parts: cylinder A B, base cup D and cap chamber E¹ will
be firmly united together and the cartridge case can be finished in the usual way
either in a press, a lathe or other suitable machine.
This process of melting or welding is used with advantage when the cylindrical
part of the cartridge is of iron or steel.
It will be understood that the term "welding" herein before employed is not
intended to signify the ordinary welding of metals by heating two pieces of metal
to be united to a welding heat in a fire and then causing them to unite by pressure

page_text: or blows, but the combining of the parts after having been fitted together and if
necessary screwed, rivetted or folded together, by the application of a welding heat
produced by a circular flame or by electricity.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In the manufacture of large cartridge cases composed of several parts, uniting
the several parts at their meeting surfaces or butt joints by melting or welding so as
form a compact whole, substantially as described.
2. A method of manufacturing cartridge cases such as are referred to in the
preceding claim consisting in subjecting the base cup and lower parts to be united
together during the melting operation to the pressure of a heavy core introduced
within the case substantially as herein described with reference to Fig. 6 of the
drawings.
Dated this 19th dox of Navambar 1880
ABEL & IMRAY,
Agents for the Applicant.