more Particularly Applicable to Metal Cartridge Cases.
Year: 1886

page_text: Date of Application, 20th Nov., 1886
Complete Left, 15th Aug., 1887.
Complete Accepted, 27th Sept., 1887.
more Particularly Applicable to Metal Cartridge Cases.
I, WILHELM LORENZ 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:-
The reduction in diameter of tubular bodies, such as cartridge cases and the like,
has heretofore been effected by dies of a single piece with a smooth inner surface, the
outer surface of the tubular body under operation being brought in contact simul-
taneously with the entire surface of the die, so that for effecting the reduction in
diameter, a force has to be employed proportionate to the friction due to the entire
surfaces in contact. With hollow or tubular bodies of large size the force required
to overcome this friction may be so great as to exceed the resisting strength of
the hollow body, so that this becomes crushed in, in a radial direction, before it can
be drawn to the smaller diameter.
My invention has for its object to obviate this defect and to reduce the power
required for drawing tubular bodies to a smaller diameter, and it consists in either
employing a series of annular dies with smooth inner surfaces of decreasing diameters,
for the purpose of successively drawing in consecutive lengths of the tubular body
from one diameter to another, or the dies are formed with a greater or less number
of annular or helical grooves of any desired section on their inner surface, so that the
tubular body is only subjected to the compressing action of the die at the separate
projecting annular portions or teeth thereof, situated between the grooves, the surfaces
of such portions in contact being greater or smaller, or reduced to a mere edge,
according to the shape of the grooves by which means the power required to overcome
the frictional resistance of the surfaces in contact will be greatly reduced. These dies may
either be made to operate simultaneously upon the entire length of the tubular object,
such as for cartridge cases of small calibre, or only a portion of the tubular body may
be acted upon at one time by shorter dies, which arrangement is preferable for

page_text: tubular bodies of larger dimensions, both for the purpose of reducing the frictional
contact and consequently the power required, and for facilitating and cheapening the
manufacture of the dies.
As above stated, the dies may also consist of a series of smooth rings of small
height, provided the surfaces in contact be reduced to such an extent that the force
required to overcome the friction does not exceed the resisting strength of the
tubular body, and that the consecutive action of the several rings will gradually effect
the required reduction in diameter of the tubular body along its entire length.
For carrying out the above described invention the dies are according to one
arrangement made of a length corresponding to a certain part of the length of the
tubular body and are formed with a smooth cylindrical portion of a diameter
corresponding to that to which the tubular body is to be reduced thereby, and with a
tapering portion extending from the cylindrical part to the end of the die, where it is
of a diameter equal to that of the tubular object in its unreduced state, and in this
tapering portion are formed annular or helical grooves, so that on forcing or screwing
the tube through the die, each part is first successively acted upon and reduced
slightly in diameter by each annular projection of the tapering part, and is then
finally reduced to the required diameter by passing through the cylindrical part.
After subjecting the tubular body to the action of this die, it may be still further
reduced by the action of one or more similar dies, which may be so formed as either
to reduce the whole length of the body to a uniform diameter or to a uniformly
tapering diameter, or to leave tapering shoulders and cylindrical necks thereon,
as may be required, and the body may be finished in a die extending the whole
length of the tubular body, which dic may either havo a smooth surface as heretofore
or be formed with annular grooves or projections as described.
In using dies of the above described construction for operating simultaneously
upon the whole length of tubular bodies of small size, the body may be consecutively
operated upon by dies of gradually increasing taper.
The before described tapering dies may either have the annular or helical grooves
and projections formed along their entire length, or there may be recessed parts that
do not operate upon the tubular body, alternating with parts having grooves and
projections.
Again, a series of dies with smooth partly tapering and partly cylindrical inner
surface may be made to operate consecutively upon separate parts of the tubular body,
so as by their combined action to reduce it to the required configuration.
Dated this 20th day of November 1886.

page_text: Improved Means for Reducing Tubular Bodies to a Smaller Diameter.
more Particularly Applicable to Metal Cartridge Cases.
I WILHELM LORENZ of No. 61, Kreg-Strasse Carlsruhe Baden, in the German
Empire, Manufacturing Engineer, 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 :-
The reduction in diameter of tubular bodies such as cartridge cases and the like,
has heretofore been effected by dies of a single piece with a smooth inner surface, the
outer surface of the tubular body under operation being brought in contact
simultaneously with the entire surface of the die, soi that for effecting the reduction
in diameter, a force has to be employed proportionate to the friction due to the entire
surfaces in contact. With hollow or tubular bodies of large size the force required
to overcome this friction may be so great as to exceed the resisting strength of the
hollow body, so that this becomes crushed in, in a radial direction, before it can be
drawn to the smaller diameter.
My invention has for its object to obviate this defect and to reduce the power
required for drawing tubular bodies to a smaller diameter, and it consists in either
employing a series of annular dies with smooth inner surfaces of decreasing diameters
for the purpose of successively drawing in consecutive lengths of the tubular body
from one diameter to another, or the dies are formed with a greater or less number
of annular or helical grooves of any desired section on their inner surface, so that the
tubular body is only subjected to the compressing action of the die at the separate
projecting annular portions or teeth thereof, situated between the grooves, the surfaces
of such portions in contact being greater or smaller, or reduced to a mere edge,
according to the shape of the grooves by which means the power required to overcome
the frictional resistance of the surfaces in contact will be greatly reduced.
These dies may either be made to operate simultaneously upon the entire length
of the tubular object, such as for cartridge cases of small calibre, or only a portion of
the tubular body may be acted upon at one time by shorter dies, which arrangement
is preferable for tubular bodies of larger dimensions, both for the purpose of
reducing the frictional contact and consequently the power required, and for
facilitating and cheapening the manufacture of the dies.
As above stated, the dies may also consist of a series of smooth rings of small

page_text: height provided the surfaces in contact be reduced to such an extent that the
force required to overcome the friction does not exceed the resisting strength of the
tubular body, and that the consecutive action of the several rings will gradually
effect the required reduction in diameter of the tubular body along its entire length.
For carrying out the above described invention the dies are according to one
arrangement made of a length corresponding to a certain part of the length of the
tubular body and are formed with a smooth cylindrical portion of a diameter
corresponding to that to which the tubular body is to be reduced thereby, and with
a tapering portion extending from the cylindrical part to the end of the die, where
it is of a diameter equal to that of the tubular object in its unreduced state, and in
this tapering portion are formed annular or helical grooves, so that on forcing or
screwing the tube through the die, each part is first successively acted upon and
reduced slightly in diameter by each annular projection of the tapering part, and is
then finally reduced to the required diameter by passing through the cylindrical
part. After subjecting the tubular body to the action of this die, it may be still
further reduced by the action of one or more similar dies, which may be so formed
as either to reduce the whole length of the body to a uniform diameter or to a
uniformly tapering diameter or to leave tapering shoulders and cylindrical necks
therein, as may be required, and the body may be finished in a die extending
the whole length of the tubular body, which die may either have a smooth
surface as heretofore or be formed with annular grooves or projections as described.
In using dies of the above described construction for operating simultaneously
upon the whole length of tubular bodies of small size, the body may be consecutively
operated upon by dies of gradually increasing taper.
The before described tapering dies may either have the annular or helical grooves and
projections formed along their entire length or there may be recessed parts that do
not operate upon the tubular body, alternating with parts having grooves and
projections.
Again, a series of dies with smooth partly tapering and partly cylindrical inner
suface may be made to operate consecutively upon separate parts of the tubular body,
so as by their combined action to reduce it to the required configuration.
The accompanying drawing shews various forms of dies or implements for carrying
out the above described invention applied by way of example to the manufacture
of cartridge cases. Fig. 1. shews a cylindrical cartridge case A which is to be
reduced in diameter by successive operations of short dies.
b
For this purpose a tapering die B is employed having alternate annular grooves
and projections 6 through which die the case A is gradually driven by moving
either the die or the case, until the die arrives in the position shewn at Fig. 2.
For reducing the diameter of the case to a further extent a correspondingly formed
die B Fig. 3 is employed and for making the neck at the upper end, a die B
having teeth b¹³. In using three successive dies B B B B¹ is by preference made
to overlap the part reduced by B to an extent S', and B2 to overlap the part
reduced by B¹ to an extent S2 in order to avoid any abrupt change in shape, and the
entire case may also be afterwards subjected to the action of a finishing die B³
Fig. 4 having a length corresponding to that of the case A, and which may either
have annular projections as shewn on the left hand side of Fig. 4, or be made
smooth in the ordinary manner, as shewn on the right hand side of Fig. 4.
Fig. 5 shews a diagram of three successive dies B B B, also formed with circular
projections b¹ for successively reducing the cartridge case along its entire length.
Fig. 6 shews a die in which annular recessed portions are made to alternate with
portions having annular projections so as to operate with less frictional surface;
Fig. 7. shews a die in which the projections 6' are made of helical form. Figs. 8 to 11
shew variously formed sections to an enlarged scale for the annular projections in
which the frictional contact surfaces are varied according to requirements.
Fig. 12 is a diagram shewing the action of a number of dies or pressing
rings C C¹ 02 with smooth surfaces, which are made to reduce the size of the
cartridge case at successive lengths c c¹³,

page_text: Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed I declare that what I claim is :-
(1) Reducing tubular bodies to a smaller diameter by means of dies having annular
or helical internal projections and which either act upon the entire length of the
object or consecutively on different portions thereof substantially as herein described.
(2) The use, for reducing the diameter of a tubular body of dies of comparatively
small height which are made to act successively upon different portions of the length
of the said body substantially as herein described.