Improvements in the Manufacture of Composite Guns.
Year: 1890

page_text: Date of Application, 16th Jan., 1890
Complete Specification Left, 13th Nov., 1890-Accepted, 16th Feb., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Composite Guns.
I, REINHARD MANNESMANN, of Landore, R.S.O. South Wales, Engineer, do
hereby declare the nature of this invention to be as follows :-
:―
My invention relates to the manufacture of guns consisting of a number of
concentric steel tubes in the following manner. place together concentrically a
number of steel tubes, preferably those produced with a twist of the fibres by
oblique rolling; and when such tubes are used I prefer to arrange them so that
the twist of each crosses that of the tube next to it inside and outside. The tubes
may, if required, be bored and turned before being fitted together, but this is
practically unnecessary if the diameters be such that each tube can be passed freely
into or on to the next. Corrugations may be formed on the tubes, or wires may be
coiled on them, these becoming by the subsequent operations indented into the
tubes.
Within the innermost tube I may sometimes place a round bar or core of very
hard steel with a layer of pulverulent refractory material such as powdered graphite
or sand between it and the tube. I heat the whole and subject it to rolling,
pressing or hammering whereby the tubes are pressed firmly together. The layer
of graphite or its equivalent around the core permits it to be loosened and removed,
and this being done, I again heat the whole and subject it to rolling pressing or
hammering while the interior is cooled by liquid. After this operation the com-
posite tube on cooling is in such a condition that its inner layers are under com-
pression while its outer layers are under tension. When the gun is of taper form,
the rolls that may be employed are of the eccentric or volute kind used for
taper rolling.
Dated this 16th day of Januo 1900
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Composite Guns.
I, REINHARD MANNESMANN of Landore R.S.O. South Wales 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
statements:-
My invention relates to the manufacture of guns consisting of a number of
concentric steel tubes in the following manner. I place together concentrically
a number of steel tubes, preferably those produced with a twist of the fibres by
oblique rolling, and when such tubes are used I prefer to arrange them so that the
twist of each crosses that of the tube next to it inside and outside. The tubes may
if required be bored and turned before being fitted together but this is practically
unnecessary if the diameters be so that each tube can be passed freely into or on to
the next. Corrugations may be formed on the tubes or wires may be coiled on
them these becoming by the subsequent operations indented into the tubes.
Within the innermost tube I may sometimes place a round bar or core of very
hard steel with a layer of pulverulent refractory material such as powdered
graphite or sand between it and the tube. I .heat the whole and subject it to

page_text: rolling pressing or hammering whereby the tubes are pressed firmly together. The
layer of graphite or its equivalent around the core permits it to be loosened and
removed and this being done I again heat the whole and subject it to rolling
pressing or hammering while the interior is cooled by liquid. After this operation
the composite tube on cooling is in such a condition that its inner layers are under
compression while its outer layers are under tension. When the gun is of taper
form the rolls that may be employed are of the eccentric or volute kind used for
taper rolling.
Fig. 1. of the accompanying drawings is a longitudinal section of a pile of tubes,
ready to be heated and worked from the exterior, into a gun barrel. Between the
separate tubes a, b, c, there is so much space that the tubes can be easily pushed
over one another; but in order that they may not become relatively displaced by
the working or by the subsequent use of the gun, each tube, before another is
pushed over it, is wound with wire i which afterwards becomes pressed into the
material as indicated in Fig. 2. The separate tubes may be all of equal length
as shewn in Fig. 1. or shorter tubes can be used at the parts where the gun is to
be thicker.
The shaping of the gun is effected on a core or mandril.
When a core k is used as shewn in Figs. 1. and 2. a layer of powdered refractory
material is interposed between the core and the inner tube a, in order to facilitate
the withdrawal of the core when the shaping is completed or the core without any
separating powder might be left in the gun as indicated in Fig. 3. and afterwards
wholly or partly bored out..
When the bored core is to form the bore of the gun this core should be wound
with wire so that in the shaping operation the innermost tube a may be firmly
bound to the core.
Instead of winding the tubes with wire, their surfaces may be roughened or
indented as shewn in Fig. 4. so that on shaping the gun the ridges of the one tube
are pressed into the metal of the next tube as indicated in Fig. 5.
If the gun is to be rolled over a fixed mandril, it is of advantage in the first place
to close in the ends somewhat, as shewn in Fig. 4. by forging or pressing over short
mandrils ; so as to prevent displacement of the outer tubes by the rolling over a
fixed mandril. The same result can be obtained by widening the inner tube at its
ends or by making it with a flange f as shewn in Fig. 6.
By thus employing a number of tubes of moderate thickness for making heavy
guns, the separate parts can be carefully examined, before they are united as
described. The material can also be selected as required for the different layers.
The inner tube may for instance consist of metal which withstands scaling or wear
while the outer tubes can be made o tougher metal.
As by working metals into thin shapes, their strength is increased, and the
texture is rendered denser, and so by making guns of thin tubes as described, a
greater strength from a given amount of material is obtained than when guns are
made up of thick layers.
Although the above described method of manufacture is chiefly useful in the
production of heavy guns, it can also be used with advantage in making gun barrels,
as such barrels when they consist of different layers have irregularities of the
material evenly distributed, and offer security against distortion by heating and
against explosion to a greater extent than barrels made of one piece on metal.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described method of manufacturing guns and gun barrels, by
drawing a number of tubes over one another, heating and working them together
from the exterior.
2. In manufacturing guns or gun barrels in the manner above referred to, the

page_text: use of rings or wires interposed between the separate tubes or of ridges on the
tubes substantially as and for the purpose set forth.
Dated this 13th day of November 1890.
ABEL & IMRAY,
28, Southampton Buildings, W.C., Agents for the Applicant.