Removal and Insertion of Inner Tubes and Liners.
Year: 1887

page_text: Date of Application, 16th Apr., 1887
Complete Left, 17th Sept., 1887
Complete Accepted, 13th Dec., 1887
Removal and Insertion of Inner Tubes and Liners.
I EARDLEY MAITLAND of 35 Grove End Road London N.W. Colonel Royal
Artillery, and Superintendent Royal Gun Factory Woolwich, do hereby declare the
nature of my invention for "IMPROVEMENTS IN CONSTRUCTION OF ORDNANCE CHIEFLY
to be as
FOR EASY
follows:-
REMOVAL AND
TUBES
INSERTION OF INNER
AND LINERS
"
The wear of, the charge on the surface of the bore of guns is so great as to
necessitate frequent renewal of the worn part, and it is at present necessary to
dismount ordnance and transport the same to machinery for boring out the worn part
and inserting a new lining, which are expensive and tedious operations, I therefore
build ordnance in such a manner that the part which is subject to wear can be
removed and a new inner tube inserted ready for service without undergoing the
aforesaid expensive and tedious operations, and the same system is applicable also to
the making of guns in parts for easy transport and building together for use, and I
do this by making the main tube of the gun which lies immediately outside the inner
tube which is subject to wear, of such a form, (preferably conical with a taper on all
sides of the interior of 1 in 40 or other suitable taper) that a liner of corresponding
form can be pushed in; and I prevent the liner from rotating within the main tube
by grooves in the tube and projections on the liner to fit these grooves, or I cut
grooves in the liner and make projections in the tube or I adopt such other form
polygonal or otherwise as may be most suitable and I fully prepare the liner to fit
the main tube and to have the rifling of the liner in proper position to match the
rifling of the main tube, or of another liner within the main tube-preferably by
making the number of exterior ribs or grooves a divisor of the number of rifled
grooves in the bore, if the removable liner. should be so arranged as to fit only a
portion of the length of the main tube, and if the other portion of the length of the
main tube should be rifled or lined and rifled. And the removable liner may extend
the entire length or any part of the length of the bore and may be divided in one or
more pieces either transversely or longitudinally. And as it is important that

page_text: permanent expansion of the main tube by firing should be prevented, I strengthen
the main tube by such means as may be most suitable preferably by shrinking on
hoops or winding on wire of such material preferably steel and at such tension as may
best suit the purpose, and I shape the exterior of the main tube so as to conform
generally to the shape of the interior, and if I support it with wire wound on I
increase the diameter by a series of steps, each step heing preferably twice the
thickness of the wire; and I build the exterior of the gun over the wire or over the
hoops in the usual way now adopted in the British Service with tubes and hoops and
locking hoops shoulders and keys as described in the specification to Letters Patent
granted to me on the 2nd February 1884 No. 2600. And if the gun lined in this
manner is a breechloader and has the liner put in from the rear the liner preferably
extends so far back as to contain the obturator or cartridge or other means of
preventing the escape of gas to the rear and further extends back sufficiently to
permit an attachment presently to be described, and behind the liner is inserted a
ring or bush which is fastened into the main tube or into a breech piece or tube
embracing the main tube, so as to keep the liner in its place, and this ring may be
either screwed in or held by an interrupted screw or in such manner as found most
convenient; and inside this ring plays the breech block, or screw, which may be of
the ordinary kind; or the mechanism may be of any breech-loading type. And when
the liner is to be taken out the breech screw or other mechanism is removed and the
ring keeping the liner in place is also removed; a plug is then fixed firmly into the
end of the liner which extends back as said above sufficiently to permit the attachment,
which may be by screw threads or otherwise; and this plug is provided with a
bearing at the exterior for forcing out the liner by hydraulic or steam power; and
the plug is also provided with an obturator or cartridge case and firing apparatus
complete, so that if the gun be loaded in the usual way or from the muzzle with such
powder and shot as may be sufficient, the charge can be fired and the pressure of the fired
charge employed to drive out the liner, and it may be found suitable to place the shot
loosely in the bore in front of the junction of the removable liner within the main
tube or its liner or in such other position as may be found most convenient. And if
it is desired to force out the liner by firing a charge without at the same time
exerting pressure on the walls of the liner, which may tend to hold it fast, I place a
smaller gun in the interior of the liner and connect it with the plug or directly with
the rear part of the liner so that by firing this smaller gun with a heavy projectile I
use its recoil to force out the liner. And if the gun is a muzzle loader, and has the
liner put in from the rear, I force out the liner in substantially the same way except
as regards the parts in which the obturator or the cartridge case are alluded to.
And if the gun is a breechloader and the liner is put in from the front so that the
small end of the taper is to the rear then I wind the wire on the exterior of the main
tube beginning at the rear and winding forwards and backwards to and from each
step and fastening off in front only, and I leave a long end in beginning at the rear
which is carried up behind the coils till these have reached the top step and been
fastened off, after which the long end is wound over these coils and fastened off in
front too; the remaining wires being then wound on in the usual manner.
And to
force out the worn liner, I fit the breech end of the liner to receive hydraulic or steam
machinery, or I fix a plug in the screw thread after removing the breech screw and
obturator, and I fix another plug with firing apparatus in the rear of the main tube or
other portion of the gun embracing the liner, and between these two plugs I place a
charge of powder or other explosive, which on being fired pushes out the liner, and
this arrangement, mutatis mutandis applies to a muzzle loading gun, having the liner
put in from the front also.

page_text: Improvements in the Construction of Ordnance Chiefly for Easy
Removal and Insertion of Inner Tubes and Liners.
I EARDLEY MAITLAND of 35 Grove End Road London N.W. Colonel in the Royal
Regiment of Artillery and Superintendent of the Royal Gun Factory Woolwich 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 wear of the charge on the surfaces of the bores of guns due to the erosive
action of the powder gas, is so great, as to necessitate frequent renewal of the worn
parts, and it is at present necessary to dismount ordnance and transport the same to
machinery for boring out the worn portions of the gun and inserting a new lining
which are expensive and tedious operations.
I therefore build ordnance in such a manner that the part which is subject to wear
can be removed and a new inner Tube inserted ready for service without undergoing
the aforesaid expensive and tedious operations and the saine system is also applicable
to the making of guns in parts for easy transport and building together for use. And
I do this by making the main Tube of the gun which lies immediately outside the
inner tube which is subject to wear of such a form preferably conical with a taper on
all sides of the interior of one in forty or other suitable taper, that a liner of corre-
sponding form can be pushed in, and I prevent the Liner from rotating within the
main Tube by grooves in the Tube and projections on the liner to fit these grooves, or
I cut grooves in the Liner and make projections in the Tube, or adopt such other
form polygonal or otherwise as may be most suitable and I fully prepare the Liner to
fit the main Tube and to have the Rifling of the Liner in proper position to match
the rifling of the main Tube or of another Liner within the main Tube preferably by
making the number of exterior ribs or grooves a divisor of the number of rifled
grooves in the bore, if the removable Liner should be so arranged as to fit only a
portion of the length of the main tube and if the other portion of the length of the
main Tube should be rifled or Lined and rifled, and the removable Liner may extend
the entire length or any part of the length of the bore and may be divided in one or
more pieces either transversely or longitudinally and as it is important that permanent
expansion of the main Tube by firing should be prevented I strengthen the main Tube
by such means as may be most suitable preferably by shrinking on hoops or by
winding on wire of such material preferably steel and at such tension as may best
suit the purpose; and I shape the exterior of the main Tube so as to conform generally
to the shape of the interior, and if I support it with wire wound on I increase the
diameter by a series of steps each step being preferably twice the thickness of the
wire, and I build the exterior of the Gun over the wire or over the hoops in the usual
way now adopted in the British Service with Tubes and Hoops and locking Hoops
Shoulders and Keys as described in the Specification to Letters Patent granted to me
on the 2nd of February 1884 No. 2600.

page_text: And if the Gun lined in this manner is a breech loader and has the Liner put in
from the rear the Liner preferably extends so far back as to contain the Obturator or
Cartridge case or other means of preventing the escape of Gas to the rear, and
further extends back sufficiently to permit an attachment presently to be described.
And behind the Liner is inserted a ring or bush which is fastened into the main
Tube or into a Breech-piece or Tube embracing the main Tube so as to keep the
Liner in its place and this ring may be either screwed in or held by an interrupted
screw, or in such a manner as found most convenient, and inside this ring plays the
breech screw or block which may be of the ordinary kind or the mechanism may be
of any breech loading type..
And when the Liner is to be taken out, the breech screw or other mechanism is
removed and the ring keeping the Liner in place is also removed, a plug is then fixed
firmly in the end of the Liner which extends back as said above sufficiently to permit
the attachment which may be by screw threads or otherwise, and this plug is provided
with a bearing at the exterior for forcing out the Liner by Hydraulic or Mechanical
power, which may consist of a system of screws actuated either by worm gearing or
toothed wheels, or by link or toggle work acted upon by screws-and the plug is also
provided with an obturator or cartridge case and firing apparatus complete so that if
the gun be loaded in the usual way or from the muzzle with such powder and shot as
may be sufficient the charge can be fired and the pressure of the fired charge
employed to drive out the Liner, and it may be found suitable to place the shot
loosely in the bore in front of the junction of the removable Liner with the main
Tube or its Liner, or in such other position as may be found most convenient.
And if it is desired to force out the Liner by firing a charge without at the same
time exerting pressure on the walls of the Liner, which may tend to hold it fast,
place a smaller breech loading Gun in the interior of the Liner and connect it with
the plug or directly with the rear part of the Liner so that by firing this smaller Gun
with a heavy Projectile I use its recoil to force out the Liner.
.
And if the Gun is a muzzle loader and has the Liner put in from the rear I force
out the Liner in substantially the same way except as regards the parts in which the
obturator or the cartridge case are alluded to.
And if the Gun is a breech loader and the Liner is put in from the front so that
the small end of the taper is to the rear, then I wind the wire on the exterior of the
main Tube beginning at the rear and winding forwards and backwards to and from
each step and fastening off in front only and I leave a long end in beginning at the
rear which is carried up behind the coils till these have reached the top step and been
fastened off, after which the long end is wound over these coils and fastened off in
front too. The remaining wires being then wound on in the usual manner.
And to force out the worm liner I fit the breech end of the Liner to receive
Hydraulic or Mechanical power or I fix a plug in the screw thread after removing
the breech screw and obturator and I fix another plug with firing apparatus in the
rear of the main Tube or other portion of the Gun embracing the Liner, and between
these two plugs I place a charge of powder or other explosive which on being fired
pushes out the liner.
The same arrangement mutatis mutandis, applies to a muzzle loader having the
liner inserted from the front.
DESCRIPTION OF ACCOMPANYING DRAWING.
Fig. 1. is a section of a Breechloading Gun ready for removing the taper Liner.
The dimensions given are approximately those of a Gun with a calibre of 13.5 inches.
A is the main Tube-B is the wire wound outside the Tube-C, Care Hoops
with locking shoulders and keys D. D.-E is the taper Liner with grooves and
projections at F to prevent turning and match rifling-G is a plug screwed into the
Liner but free to move with the Liner and is fitted with firing arrangement and
obturator. H is the charge and J. J. the shot.
Fig. 2 is a section of a portion of a Gun and Fig. 3 the end view of the same

page_text: shewing the ring K holding the Liner E in its place and prepared for receiving the
breech screw and firing arrangement-L is the screwed part in the liner which may
be covered with a ring while the Gun is in use-M is a locking ring with projections
to prevent the ring K from turning and secured by screws N N. O. O. are holes for
turning.
Fig. 4 is a section of a portion of a Gun shewing a Hydraulic apparatus for
removing the taper Liner E-P is the cylinder Q, the Ram secured to the Liner E
The waterway R is connected with a pump or accumulator.
The same apparatus can be adapted for forcing the Liners into their place.
Fig. 5 is an enlarged view of a portion of the Liner shewing the grooves and
projections to prevent turning at F.
Fig. 6 is a section of a breech loading Gun shewing another system of separating
parts of the Gun for facilitating transport. The dimensions given are approximately
those of a Gun with a calibre of 6 inches.
G is a plug screwed into the Tube with a cavity H for the blowing out charge-
S is a block screwed into the outer Tube T and fitted with vent. The plug and block
are both removed to receive the Breech screw and firing arrangement.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is
1st. The construction of Ordnance for the removal and insertion of Conical inner
Tubes and Liners substantially as described.
2nd. The application of the same system to the construction of Guns made in parts
for the facility of transport and putting together for use substantially as described.
3rd. The means of separating and putting together parts of Guns by the explosion
of powder or Hydraulic or other Mechanical means substantially as described.
Dated this 14th day of September 1887
E. MAITLAND,
Applicant.