IMPROVEMENTS IN THE CONSTRUCTION OF ORDNANCE
Year: 1885

page_text: "
I, JAMES ATKINSON LONGRIDGE of 15 Great George Street in the City of
Westminster Civil Engineer do hereby declare the nature of the said invention.
for "IMPROVEMENTS IN THE CONSTRUCTION OF ORDNANCE and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
・
My Invention relates to further improvements in the construction of ordnance
upon what is known as the Wire system of construction, wherein that part of the
chase which lies between the breech and the trunnions and which principally
receives the radial or bursting strain of the explosion is mainly constructed of
superimposed coils of steel wire wound with tension upon a tubular core.
In guns, as now constructed, the part of the gun which lies between the breech
and the trunnions (or the point at which the gun is attached to its carriage) is
subjected both to the radial strain tending to burst the gun and the longitudinal
strain acting on the breech plug and tending to tear the gun asunder between said
plug and the trunnions, these two strains acting simultaneously upon the same
material,
"wire ""
The object of my present invention is to so construct a
gun that the
longitudinal strain shall be wholly borne by the outside casing or jacket, and no
part of it by the inner tube or the coil. This result is accomplished by the
construction hereafter described, wherein a clearance is left between the coil and
the outer jacket sufficient to allow the expansion of the coil under the bursting
strain, without transferring the strain to the jacket, the obturator or breech plug
having no connection with the inner tube, so that the latter can receive no part of
the longitudinal strain.
"
The object of the invention is secondly to effect the more perfect transmission of
the radial or bursting strain to the wire coil of a
" wire gun, and also to relieve
and modify the strain upon the core or lining of the core, which is accomplished by
the interposition of a material having a very low modulus of elasticity between the
core or inner tube and the wire coil.
23
Reference is to be had to the accompanying drawings forming part of this
specification, wherein figure 1 is a half longitudinal section of a " wire gun
constructed to effect both objects of my invention; figures 2. 3. 4 are slight
modifications. The same letters indicate similar parts in all the figures.

page_text: T is the inner tube or core, C, the wire coil wound either directly upon the
tube T, or upon an intervening layer as hereafter described. J is the jacket or
outer casing which carries the trunnions, or the saddle which replaces the trunnions,
in some cases. S is the steel breech ring into which the breech plug P screws,
which ring is screwed into the jacket J. R is the straining ring screwing onto the
jacket J and applied for the purpose described in a former application for Letters
Patent dated June 11th 1885 No 7127, wherein is also described the method of
coiling the wire.
In the example shown in figure 1, the tube T is provided with a shoulder t
which bears against an inwardly directed flange j on the jacket J, the tube T with
the coil C wound upon it, being inserted in the jacket J from the rear before the
rings S and R are applied.
A check nut ring or hoop is screwed or shrunk upon the tube T against the end
or flange j of the jacket J. Between the external diameter of the coil C and the
internal diameter of the jacket J there is such a difference of dimension, as to leave
sufficient clearance to enable the tube T and coil C to take up all the bursting
strain of the explosion, without transmitting any portion of it to the jacket J.
Between the rear end of the tube T and the breech ring and plug there is also
clearance, so that the tube T shall be perfectly free, and the breech plug P which is
only held in place by its connection through the ring S with the jacket J, transmits
the whole of the longitudinal strain to the jacket and none to the inner tube
and coil.
In the modification shown in figure 2, the tube T is introduced into the jacket J
from the front end, the part in which the breech plug P screws being solid with the
jacket instead of a screw ring S being used, and the tube T is held in place by
a check nut ring or hoop screwed or shrunk on the tube T, or screwed into the
jacket.
In order to more efficiently transmit the radial or bursting strain to the wire coil,
I introduce between the wire coil C and the core or inner tube T (or between the
coil C and the lining tube when the tube T is not continuous) a layer of material
having a very low modulus of elasticity such as gun metal or brass for instance.
This layer is in the form of a tube B, which in figures 1 and 2 surrounds the
tube T, and it may either be limited to that portion which is covered by the coil or
it may extend the full length of the chase.
This intermediate tube B is bored to accurately fit on the core T to which it may
be screwed at the front end or on which it may simply fit with a half lap. The
wire is coiled over B as described in my aforesaid application.
In figure 3 the tube T is not continued to the rear, the part principally covered
by the wire being, replaced by the tube B of a material having a low modulus of
elasticity, which makes with the tube T a bevelled or a socket half lap joint. In
this case the tubes T and B have a continuous thin lining tube L of hard steel or
very hard cast iron extending the whole length of the bore of the gun.
In figure 4 the construction is similar except that B makes a butt joint with T,
which joint is covered by a thin overlapping band b countersunk into B and T.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. A gun in which the breech portion of the chase is constructed of an inner
portion composed of a tube or core (with or without a lining) and wire coiled
thereon, and an outer portion or jacket connected to the inner portion at its front
end so as to be incapable of rearward movement, and a breech plug connected only
to the outer jacket, the inner portion being free from the surrounding jacket and
from the breech plug, so that all bursting strain will be supported by the inner
portion only and none by the jacket and all longitudinal strain will be transmitted
by the breech plug to the outer jacket and none to the inner portion, substantially
as specified.

page_text: 2. In a gun constructed on the coiled wire system, the combination with the
wire coils and with the core or lining tube, of a material having a low modulus of
elasticity interposed in the form of a tube or layer between the wire coils and the
core or lining for more efficiently transmitting the bursting strain to the wire coils
and relieving the extreme strains of compression at rest or of tension under fire of
the inner surface of the core, substantially as specified.