Improvements relating to Explosive Projectiles or Shells and to Cartridges or Charges for use therein.
Year: 1890

page_text: Date of Application, 20th June, 1890
Complete Specification Left, 18th Apr., 1891-Accepted, 20th July, 1891
PROVISIONAL SPECIFICATION.
Improvements relating to Explosive Projectiles or Shells and to
Cartridges or Charges for use therein.
I, JOHN MABRY MCMAHAN, of 15 Park Road, New York, United States of
America, Electrical Engineer, do hereby declare the nature of this invention to be
as follows:-
2
My invention relates to explosive projectiles or shells, and is designed to provide
in a more efficient manner than heretofore for the use, in the said projectiles or
shells, of high explosives such as nitro-glycerine.
One feature of my said invention is the combination of a cartridge or charge
containing nitro-glycerine or similar explosive substances, with the projectile or
shell, in such a manner that, whilst the latter, when fired from a gun, will be
subjected to the entire force of the shock or concussion of the discharge, the effect
of such shock or concussion upon the cartridge or charge in the projectile will be
greatly diminished.
For this purpose I so arrange the cartridge or charge in the projectile that it
can slide to and fro therein, and I provide an air-space between the rear end of the
cartridge or charge and the base or base-plug of the projectile. Moreover I form
in the said base or base-plug, one or more holes whereby the said air-space will be
in communication with the chamber of the gun when the projectile is inserted
therein. I thus provide for permitting the escape from this space into the chamber
of the gun, of the air compressed in the said space by the projectile when moved
forward relatively to its explosive charge or cartridge by the force of the explosion
in the chamber of the gun. By the arrangement above mentioned, I also provide
for permitting the entrance into the said space of the gases generated by the
explosion in the gun, and thus utilize such gases for cushioning the cartridge or
charge, and effectually preventing the transmission of any excessive shock or con-
cussion thereto when the projectile is fired from a gun.
When the powder-charge in the gun is to be ignited at the rear end, I sometimes
provide the base or base-plug with a tube which extends through the powder-charge,
and whereby the gases, generated by the combustion of the said charge will be
admitted into the space in the projectile in rear of the cartridge, for the purpose
of cushioning the said cartridge.
Another feature of my said invention is the production of a cartridge or charge
the case of which is completely filled with the nitro-glycerine, explosive gelatine,
or similar explosive material, and from which the air is exhausted as far as
practicable to obviate the liability to molecular disturbance of the explosive
material and to prevent relative motion of the molecules, and the liability to
generation of heat by compression of air in the cartridge and thus increase the
safety with which such cartridges or charges can be handled, stored or discharged
from a gun, as compared with cartridges or charges containing high explosives, as
heretofore manufactured. In the case of cartridges in which dynamite or other
solid explosive material is employed, after charging the cartridge-case with the
dynamite or similar material, I fill all the interstices with alcohol, glycerine or
other suitable liquid which has a very low freezing point, and exhaust the air
from the said cartridge-case or receptacle.
Another feature of my said invention is the combination of the cartridge or
charge with the projectile in such a manner as to permit rotation of the projectile
relatively to the said cartridge or charge when the projectile enters the rifling, and
thus avoid the communication of any dangerous shock or concussion to the said
cartridge or charge.

page_text: Another feature of my said invention is the construction of the explosive pro-
jectile in such a manner that the cartridge or charge, can be readily removed there-
from and replaced therein, so that the cartridges or charges can be stored separately
in a suitable magazine and inserted in the projectiles when the same are required
I thus effect considerable economy in respect of the space required in the
magazine for storing the explosives.
for use.
My improved cartridge or charge is provided with a suitable fuse whereby it
will be exploded upon impact of the projectile. My cartridge may, moreover, be
provided with a time or distance fuse either instead of, or in addition to the per-
cussion-fuse. To provide for the safe handling and storage of the said cartridges
or charges, sometimes so combine the fuse with the cartridge or charge that it
can be removed and stored separately therefrom and be re-inserted therein when
the projectile is to be used.
In making an armour-piercing projectile according to my said invention, I provide
a suitable case or receptacle for containing the nitro-glycerine or other explosive
substance and of such dimensions that it can be inserted in the usual central cavity
or chamber of the projectile, and, when so inserted, a suitable air-space will be left
between its rear end and the base or base-plug of the projectile, which is preferably
screwed into the body thereof. In front and in rear of the said cartridge or charge,
I arrange suitable packing, such as asbestos or other fibrous material mixed with
plumbago. Moreover I fit into the cavity, of the projectile, a metal disc provided
with devices which, whilst permitting backward movement of the same in the said
cavity, will prevent its forward or return movement therein. For instance I form
in the periphery of the said disc suitable recesses having inclined surfaces, and I
place in the said recesses, balls which, when pressure is applied to the rear side of
the disc, will be wedged between the said inclined surfaces and the interior of the
body of the projectile. The object of this arrangement is to prevent the rebound
of the cartridge after the inertia thereof is overcome. I form in the base or base-
plug of the projectile, as above stated, one or more holes for permitting the escape
of air from the said space or the entrance into the said space of gases generated by the
explosion in the chamber of the gun. The area of these holes is suitably regulated
so as to ensure the requisite cushioning of the cartridge or charge when the pro-
jectile is fired from the gun. The area of the said holes is so proportioned
relatively to the transverse sectional area of the cavity of the projectile, that the
said holes serve as reducing valves, permitting sufficient gas to enter the projectile
to form an effective cushion for the cartridge, whilst preventing the entrance of the
gas into the projectile with such rapidity as to drive the cartridge against the head
of the projectile.
I prefer to make the aforesaid case or receptacle of phosphor-bronze or aluminium-
bronze; it may, however, be made of other suitable material.
For the purpose of temporarily retaining the cartridge or charge at the forward
end of the cavity of the projectile, I insert in the body of the projectile behind the
disc, one or more small screws of copper or other suitable metal which will be
sheared off when the projectile is driven forward relatively to its cartridge or
charge. Or I provide other convenient devices for this purpose.
The ends of the said case or receptacle are firmly secured in the tubular portion
thereof, preferably by screwing and brazing then therein, so that the case is
hermetically sealed. The tubular portion or body of the cartridge-case is, if
desired, provided with suitable strengthening ribs. In some instances I make the
rear end of the said case with a tubular extension into which fits the fuse, and I
close the forward end of the said extension by a cap or disc of brass or other
suitable material which is soldered or otherwise secured in place in such a manner
that it will resist the shock or concussion due to the explosion in the gun, but
will be easily displaced by the fuse when the latter is ignited.
The packing at the rear end of the case may be in the form of either a disc or
a ring, and sometimes make the aforesaid metal disc with an annular surface
which bears against the packing, to more effectually ensure the forcing outward

page_text: of the packing against the interior surface or wall of the projectile. This packing
prevents, in some measure, the passage of the air or gases into the space around
the cartridge. Any air which may pass the said packing will serve as a cushion.
at the forward end of the said cartridge, thus slightly retarding the bursting
of the projectile and permitting its entrance into an armour-plate before it
explodes.
I prefer to make the cartridge-case of slightly smaller diameter than the cavity
of the projectile and to provide the said case with flanges at its ends which fit into
the said cavity, so that the cartridge is held in a central position within the pro-
jectile, whilst the projectile may, at the commencement of its forward movement,
rotate about its axis independently of the said cartridge.
To increase the space available for the air-cushion, I sometimes form the base-
plug or sabot with a chamber or cavity of the same diameter as that in the body
of the projectile. Any suitable sabot may be employed, suitable provision being
made for permitting the entrance of the gases into the projectile for the purpose.
above specified.
For effecting the explosion of the projectile upon impact, I sometimes provide,
in the projectile, a cartridge similar to those ordinarily used in rifles or other
small-arms, and so arranged in combination with a striker and with a tube con-
taining a detonator or primer that, when the projectile strikes an object, the striker
will fire the said ordinary cartridge, the bullet of which will then be driven forcibly
against and cause the explosion of the bursting charge of the projectile. The said
striker is, under normal conditions, held away from the said ordinary cartridge by
a spring or in any other convenient manner.
The cartridge-case is provided with suitable apertures into which may be inserted
hollow or tubular plugs having connected therewith pipes for the introduction of
the nitro-glycerine or other liquid and for the withdrawal of the air. The said
case is hermetically closed with the exception of these apertures, and the said
apertures are provided with screw-plugs or other suitable devices for tightly closing
them when the cartridge is properly charged. Moreover when the cartridge is
charged the said holes are filled up with a plastic alloy of mercury and zinc or
other suitable material to more effectually prevent escape of the liquid or the
entrance of air. The cartridge-case is, in the manner above described, filled with
a practically incompressible mass, and molecular disturbance of the particles of
the explosive material is thus avoided.
In charging a cartridge-case with nitro-glycerine or with dynamite and alcohol
or other liquid, according to my said invention, I proceed as follows, viz. :-1 place
the vessel containing the liquid to be introduced into the said cartridge-case, in a
suitable position below the level of the top of the said case; I then connect the
cartridge-case or receptacle, by means of the aforesaid pipes and tubular plugs,
with the said vessel and with a suitable air-pump, and I commence to exhaust the
air from the said case or receptacle. The nitro-glycerine or other liquid is thereby
drawn from the said vessel into the cartridge-case. The working of the air-pump
must be continued until the said cartridge-case is completely filled with the liquid,
and I prefer to continue to work the said pump until some of the liquid overflows
from the said casc. To provide for collecting the liquid thus overflowing, I connect
the cartridge-case and the air-pump with the upper end of a bottle, jar or other
suitable vessel. When the cartridge-case is thus filled with the liquid, the apertures
in the said case are hermetically closed as above described.
Dated this 20th dow of June 1800
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant..

page_text: COMPLETE SPECIFICATION.
Improvements relating to Explosive Projectiles or Shells, and to
Cartridges or Charges for use therein.
I, JOHN MABRY MCMAHAN, of 15, Park Row, New York, United States of
America, Electrical 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 :-
My invention relates to explosive projectiles or shells, and is designed to provide
in a more efficient manner than heretofore, for the use, in the said projectiles or
shells, of high explosives, such as nitro-glycerine, nitro-gelatine or blasting-
gelatine.
One feature of my said invention is the combination of a cartridge-case or
receptacle containing a bursting-charge composed of one or more of such high
explosives, with the projectile or shell in such a manner that, whilst the latter,
when discharged from a gun, will be subjected to the full effect of the initial
pressure of the propelling charge, the effect of the shock or concussion upon the
bursting-charge of the shell will be greatly diminished.
My improved shells are advantageously applicable for use in guns or ordnance
in which the propelling force is derived from gun-powder or the like, and also
for use in guns in which compressed air or other gas, steam, or liquefied gas is
employed as the ballistic medium.
One feature of my said invention is the provision which I make for cushioning
the bursting cartridge or charge in the shell. For this purpose, I arrange the
cartridge or charge in combination with the body of the shell in such a manner that
there is an air-space between the rear end of the cartridge or charge and the base
or base-plug of the shell, and the said shell, when discharged from a gun, will
move a short distance forward relatively to the said cartridge or charge; moreover
I form in the said base or base-plug, one or more holes whereby the said air-space
will be in communication with the chamber of the gun when the shell is inserted
therein. By these means, I provide for permitting the entrance into the said space
in the shell, of the air or other gases of the propelling charge in the gun, so that
such gases will be utilized in conjunction with the air contained in the said space,
for cushioning the cartridge or charge, and thus effectually preventing the trans-
mission of any excessive shock or concussion to the said cartridge or charge when
the projectile is fired from the gun.
Another feature of my said invention is the combination of the bursting cartridge
or charge with the projectile in such a manner as to permit rotation of the projectile
relatively to the said cartridge or charge, when the driving-ring of the projectile
enters the rifling of a gun, and thus avoid the communication, in this manner, of any
dangerous shock or concussion to the said cartridge or charge.
I find it advantageous to so construct my explosive projectile or shell that the
bursting cartridge or charge can be readily removed therefrom and replaced therein,
so that such cartridges or charges can be stored separately in a suitable magazine
and inserted in the projectiles when the same are required for use.
considerable economy in respect of the space required in the magazine for storing
the explosives, as the empty shells need not be kept in such magazine.
I thus effect
Another feature of my said invention is the production of a cartridge or charge
the case of which is completely filled with the nitro-glycerine, explosive gelatine,
or similar explosive material, or with solid or semi-solid explosive material and a
suitable liquid, the air being exhausted from the cartridge-case or receptacle, and
the space which it formerly occupied therein being filled by the explosive material
or by the said liquid. In this manner, I provide a cartridge-case or receptacle
containing a body or mass which is, as far as practicable, rendered incompressible,
and thus obviate the liability to molecular disturbance of the explosive material,
thereby increasing the safety with which the cartridge or charge can be handled,

page_text: stored or discharged from a gun, as compared with the bursting-charges of shells as
heretofore manufactured containing high explosives.
In making cartridges containing explosives in a liquid state, I exhaust the air
before or during the filling of the case or receptacle with such liquid. And I her-
metically close the said case or receptacle in such a manner as to ensure that the
entire space within the same shall be absolutely filled with the liquid, and air shall
be effectually excluded therefrom.
In making cartridges in which blasting-gelatine, fulminate of mercury or other
solid or semi-solid explosive material is employed, after charging the cartridge-
case or receptacle with such explosive material, I exhaust the air from the said
case or receptacle, and simultaneously fill the space formerly occupied by such
air, with nitro-glycerine, alcohol, glycerine or other suitable liquid, preferably an
explosive liquid which has a very low freezing point, so that the bursting power of
the shell will be augmented and there will be no liability to freezing of the liquid
at ordinary atmospheric temperatures.
My improved cartridge or charge is provided with a suitable fuse whereby it
will be exploded upon impact of the projectile. The said cartridge or charge
may also be provided with a time or distance fuse, either instead of, or in addition
to the percussion-fuse. And to further provide for the safe handling and storage
of the said cartridges or charges, I sometimes so combine the fuse with the
cartridge or charge that it can be stored separately therefrom, and can be readily
inserted therein when the projectile is to be used.
In the accompanying drawings I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure is a longitudinal central section of an armour-piercing projectile or
shell constructed in accordance with my said invention, the case or receptacle
containing the bursting-charge being shown in side elevation.
Figure 2 is a longitudinal central section, drawn to an enlarged scale, showing
another form or modification of the case or receptacle containing the bursting-charge.
Figure 3 is a longitudinal central section also drawn to an enlarged scale, shewing
a modification in the construction of the rear end or base of the projectile or shell.
Figure 4 is a longitudinal central section, showing a further modification of my
improved case or receptacle for the bursting-charge.
Figure 5 is a sectional elevation, illustrating details of construction.
Figure 6 is a transverse section, and
Figure 7 a sectional elevation, showing a further slight modification of my invention.
Figure 8 is a transverse section, showing a detail of construction.
Figure 9 is a side elevation, partly in vertical central section, illustrating my
improved method of filling or charging the said case or receptacle.
Figure 10 is a side elevation, partly in longitudinal central section, illustrating
another form or modification of my improved explosive projectile or shell.
Figure 11 is a side elevation, partly in longitudinal section, and
Figure 12 a rear elevation, illustrating a further modification of the case or
receptacle for containing the bursting-charge.
Figure 13 is a side elevation, partly in longitudinal central section, showing my
improved shell combined with a casing arranged to slide upon the said shell for the
purpose of cushioning the same.
Figure 14 is a similar view, showing the relative position of the parts during
the flight of the shell.
Figure 15 is a rear elevation of the said sliding casing.
Figure 16 is a transverse section on the line, y, Figure 13, and
Figure 17 is a transverse section on the line y', y', Figure 13.
Like letters indicate corresponding parts throughout the drawings.
A is the body of the projectile or shell, which is formed with a central chamber
or cavity A. The cartridge or charge consists of a suitable case or receptacle B
containing the nitro-glycerine or other explosive substance, and of such dimensions
that, when it is inserted in the central cavity or chamber A' of the projectile and

page_text: is pushed to the forward end of the said cavity, a suitable space will be left between
its rear end and the base C of the projectile. I form in the base C, or in the base-
plug C, one or more holes C² for permitting the entrance into the space in rear of
the cartridge B. of a portion of the air or other gases used or generated in the
chamber of the gun for effecting the discharge of the projectile therefrom. The
area of these holes is suitably regulated so as to ensure the requisite cushioning of
the cartridge or charge when the projectile is discharged from the gun, that is to
say, the area of the said holes is so proportioned relatively to the transverse
sectional area of the chamber or cavity of the projectile, that the said holes serve
as reducing-valves, and permit sufficient air or other gas to enter the projectile to
form an effective cushion for the cartridge, whilst preventing the entrance of the
air or other in such volume as to destroy the efficiency of the said cushion.
prefer to provide several small holes C, as I thus lessen the danger of accidental
closing or stopping up of such holes, thereby ensuring the entrance into the
chamber A of sufficient air or other gas to form an clastic cushion as herein set
forth.
gas
I
A further advantage in using a considerable number of small holes, is the great
reduction of the temperature of the powder-gases, by reason of their contact with a
large surface of the cold metal of the base of the shell.
At the rear end of the case or receptacle B, I sometimes arrange suitable
packing, such as a ring or annular piece D of asbestos or other fibrous material
mixed with plumbago. Moreover I sometimes fit upon the rear of the case or
receptacle B, a metal disc or cap E which is secured to the said case or receptacle
in such a manner that, when the shell, on being discharged from a gun, moves
forward a short distance relatively to the said case or receptacle, the packing D
will be squeezed and compressed between the latter and the disc or cap E; the
forcing outward of the packing against the interior surface or wall of the projectile
will thus be ensured. This packing prevents the passage of the air or gases into
the space between the cartridge and the interior surface or wall of the projectile.
The said disc or cap E is preferably secured to the cartridge-case B as follows,
ciz.the base-plug B of the said case is provided with a screw-threaded flange
(Figures and 7) which may be screwed through a corresponding screw-threaded
portion in the cap E, as shown in Figure 5, and the said cap E will then be free
to move to and fro upon the flange e, but cannot be withdrawn therefrom except
by first effecting the engagement of its screw-thread with that of the flange, and
then unscrewing it. The base-plug B2 shown in Figure 5 is provided with a.
chamber d for containing the pellet of a fuse as hereinafter described, and the
flange is, in this case, formed on this chamber d. Or the said disc or cap E
may be secured in any other convenient manner to the case or receptacle B; for
instance, by means of screws e (Figure 4) fitting into slots e' in the chamber or
casing d. The case or receptacle B is provided with devices which, whilst per-
mitting backward movement of the same in the chamber A', will offer great
resistance to its forward movement therein. For instance, I form in the periphery
of the base-plug B2, Figure 2, or in the disc or cap E, Figures 4 and 5, one or
more suitable recesses E' having inclined surfaces E, and I place in the said
recesses, balls F (Figures 4 and 5), or a split or interrupted ring F1 (Figure 2),
which, when pressure is applied to the rear side of the base-plug B, Figure 2, or
to the disc or cap E, Figures 4 and 5, will be wedged between the said inclined
surfaces E2 and the interior of the body of the projectile.
The object of this arrangement is to prevent the rebound of the case or
receptacle B, after the inertia thereof is overcome by the pressure of the air or gas
cushion as hereinafter explained.
The case or holder B is made with annular collars or flanges B', whereby it will
be held central within the projectile or shell without producing sufficient friction to
cause the rotation of the cartridge-case or receptacle B with the shell when the
latter enters the rifling of the gun, so that rotary motion will be imparted gradually
to the said case or receptacle.

page_text: I prefer to make the said case or receptacle B of phosphor-bronze; it may, how-
ever, be made of any other suitable material. The said case or receptacle may, if
desired, be made with perforated partitions, or it may be made in sections connected
by holes or passages B³, as shown in Figure 4, so as to minimize the compression
of the explosive material, when the shell is fired from a gun.
In some instances, I also provide the case B with internal longitudinal webs or
extensions B, Figure 8, which do not extend quite to the centre of the case B, but
which sub-divide the explosive charge and thereby prevent rotation of the same
relatively to case B, thus effectually preventing skin-friction between the case B
and the explosive charge.
For the purpose of temporarily retaining the cartridge or charge at the forward
end of the cavity of the projectile, I find it advantageous to provide the case or
receptacle B, at its rear end, with a spring or catch G adapted to enter an annular
groove A2 in the body of the projectile. Or I insert in the body of the projectile
behind the said case or receptacle B, one or more small screws of copper or other
suitable metal, which will be sheared off when the projectile is driven forward
relatively to its bursting-charge. Or I provide other convenient devices for this
purpose.
The rear end or base-plug B2 of the case or receptacle B is firmly secured in the
tubular portion thereof in any convenient manner, so that the said case is
hermetically scaled at this end. When liquid explosive material is to be used, the
said rear end or base-plug may be simply fitted and brazed in the tubular part of
the case, the said case being afterwards filled from the forward end thereof, as
hereinafter described. When, however, a charge of solid or semi-solid explosive
material has to be inserted in the said case or receptacle B from the rear end
thereof, I prefer to secure the said end or base-plug in the tubular portion by
means of screw-threads, red-lead or other suitable inaterial being applied to ensure
tightness of the joint.
In some instances, I make the rear end or base-plug B2 of the cartridge-case B
with a central tubular extension I, into which is fitted a suitable fuse; the for-
ward end of the said extension B may be left solid, or it may be closed by a cap
or disc of brass or other suitable material, which is soldered or otherwise suitably
secured in place. The said closed end or cap should be so arranged that it will
resist the shock or concussion due to the explosion in the gun, but will be easily
displaced by the action of the fuse when the latter is ignited.
In some instances, it may be advantageons to provide the case or receptacle Bat
its forward end, with a cushion J of india-rubber or other suitable material adapted
to bear against the forward end of the cavity A' of the shell.
To increase the space available for the air-cushion, I sometimes form the rear
portion or base C of the shell with a chamber or cavity of the same diameter
as that in the body of the projectile, as shown in Figures 1 and 3. Any suitable
sabot may be employed, suitable provision being made for permitting the entrance
of the gases into the projectile for the purpose above specified. The shell shown
in Figure 1 is provided with a Maxim sabot.
For effecting the explosion of the projecticle upon impact, I can use any
suitable fuse or primer. For instance, 1 sometimes provide the projectile with a
fuse comprising a centre-fire cartridge a similar to those ordinarily used in
rifles or other small-arms, 50 arranged in combination with a striker or pellet b,
that, when the projectile strikes an object, the said pellet will cause the explosion
of the cartridge, the bullet of which will be driven forcibly into the nitro-glycerine
or other explosive material forming the bursting-charge of the projectile, thus
causing the explosion of the said bursting-charge.
In the modification of my invention shown in Figure 4, the striker or pellet b
is restrained from longitudinal or endwise movement relatively to the cartridge a
by means of a pin or stud e fixed in the chamber or casing d and extending into an
L-shaped slot in the pellet b, as shown in Figures 4 and 5. Or the said pellet
may be held out of action by a pin or stud fixed in the pellet and extending into

page_text: an L-shaped slot in the casing d. In either of these cases, the pellet bears
at its rear end against the chamber or casing d, and its release is effected by
the rotation of the case or receptacle B relatively to the said pellet through
the required angle to bring the pin in line with the longitudinal portion of the
slot, after the driving-ring or the shell enters the rifling of the gun.
In the modification of my invention shown in Figures 6 and 7, the pellet is
held out of action by a spring attached to the casing d and engaging in a
notch in the pellet ; or the said spring may be attached to the pellet and
arranged to engage in a notch in the casing d. In either of these modifications,
the rotation of the casing d relatively to the pellet through a small angle,
disengages the spring from the notch and releases the pellet. It is obvious that
other suitable devices may be provided whereby, when the case or receptacle B
commences to rotate about its axis with the projectile after the driving-ring
thereof has entered the rifling of the gun, the said pellet will be released so that
it can move forward upon impact of the projectile.
When my improved shell is fired from a gun, the body A of the shell moves
a short distance forward relatively to the cartridge or charge B, the spring or
catch G being bent over into a suitable notch E3. The gases generated by the
combustion of the powder-charge in the chamber of the gun, enter the shell
through the holes C and, by their action upon the case or receptacle B. gradually
overcome the inertia of the said case or receptacle, thus preventing the commu-
nication of any dangerous shock or concussion thereto. When the driving-ring
or rotating ring of the shell enters the rifling of the gun, the said shell A
commences to rotate independently of the case or receptacle B, to which rotation
is imparted gradually by the friction between the inner surface of the shell
and the flanges B¹. As soon as the case or receptacle B has any tendency to
move forward relatively to the shell under the action of the gas-cushion therein,
the balls or the ring hold back the said case or receptacle B and thus
prevent forward movement of the same relatively to the shell until the latter
strikes an object. To further ensure the efficient action of the balls F or split
ring F, I sometimes form shallow grooves A³ in the inner surface of the shell A
in rear of the case B3, as shown in Figures 10, 13 and 14.
When my improved shells are to be discharged from a gun by means of
gun-powder or the like, it is preferable that the powder-charge should be ignited
at its forward end, so as to effectually ensure the entrance of the powder-gases
into the chamber A¹ of the projectile to serve as a cushion for the purpose above
specified.
The case or receptacle 13 is provided with suitable apertures B3* into which may
be inserted hollow or tubular plugs K, K' (Figure 9) having connected therewith
pipes L, L, for the withdrawal of the air, and for the introduction of the
nitro-glycerine or other liquid.
In charging the case or receptacle with nitro-glycerine or other liquid explosive
material, or with alcohol or other liquid for filling up the interstices of solid or
semi-solid explosive material, I proceed as follows, viz. I place a vessel M
containing the liquid to be introduced into the said case or receptacle B, in a
suitable position relatively thereto, preferably below the level of the top of the
said case or receptacle. I then connect the said case or receptacle B with the
said vessel M, by means of the pipe L, and tubular plug K', and with another
vessel N by means of the pipe L and tubular plug K. The vessel N is connected
by a pipe LA with a suitable air-pump, not shown in the drawing. By means of
the said air-pump, I exhaust the air from the case or receptacle B so that the
nitro-glycerine or other liquid is thereby drawn from the vessel M into the said
case or receptacle. The working of the air-pump must be continued until the
said case is completely filled with the liquid, and I prefer to continue to work the
said pump until some of the liquid overflows from the said case into the vessel N.
When the case or receptacle is thus filled with the liquid, the valves L2, L³ are
simultaneously closed, the pipes L, L' and plugs or corks K, K' are removed from

page_text: the apertures B', which will then evidently be still partially filled with liquid.
Before this liquid is removed, the screw-plugs Q are carefully inserted. The
surplus liquid then remaining in the apertures B is then removed, and the said
apertures are filled with a plastic alloy of mercury and zinc or other suitable
material, thereby hermetically sealing the case B. It is evident that, after the
case B has been entirely filled with the nitro-glycerine or other liquid, it is necessary
to simultaneously close the valves L, L³ to avoid syphoning of the liquid. The
said case or receptacle B is, in the manner above described, absolutely filled with a
practically incompressible mass, and molecular disturbance of the explosive
material is thus avoided.
In
I sometimes provide a cushion in rear of the projectile as well as within the
same in rear of the case or receptacle containing the bursting-charge.
Figures 13 to 17, P is a casing which is provided with a perforated base P¹,
through which the air or gas from the chamber of the gun may enter the said
casing. This casing is fitted upon the shell A so that there is an air-space between
the base of the shell and the base of the said casing, and so that, in the discharge
of the shell from a gun, the said casing will slide forward upon the shell until these
parts occupy the relative positions shown in Figure 14. The air or other gas
entering the casing P serves as an effectual cushion for the shell, and the air or
other gas passing from the interior of the casing P into the cavity A' of the shell
serves as an effectual cushion for the case or receptacle B. The driving-ring A*
is fixed upon the said casing P; and to ensure the rotation of the shell with the
said casing, when the said driving-ring enters the rifling of the gun, the interior of
the casing is made of octagonal shape as shown in Figures 16 and 17, or of
hexagonal or other suitable form in transverse section, and the portion of the shell
adapted to receive the said casing is made of corresponding shape, so as to prevent
relative rotation of the said shell and casing, whilst permitting the necessary
longitudinal movement of the casing upon the shell. To prevent the forward
movement of the casing Pupon the shell except when the same is discharged from
a gun, I may insert in the said casing one or more screws R, Figures 13 and '16
which will be readily sheared off by the shell in the discharge of the same from the
gun. I may, if desired, employ one or more additional or supplementary cushions
or buffers in the casing P in rear of the shell. Although the shells shown in the
drawing are armour-piercing shells, yet it is obvious that my improvements are
also applicable to other shells.
I can, if desired, modify the construction of my improved shell by providing the
same with a piston, which is introduced into the chamber or cavity of the shell in
rear of the case or receptacle containing the bursting-charge, and which, whilst
preventing contact of the heated gases from the chamber of the gun with the said
case or receptacle, will, when acted upon by such gases, compress the air between
it and the said case or receptacle, and thus form an effectual cushion for the latter,
for the purpose above specified.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I wish it understood that
I do not claim generally or irrespectively of my improvements herein described,
the removal or exclusion of air or other compressible gases from the interior of
explosive projectiles or shells, as I am aware that this feature has been broadly
described in the Specification of Letters Patent granted to H. S. Maxim and dated
2nd October 1886, No. 12,561; nor do I claim, except when used in combination
with my improvements herein described, a casing arranged to slide upon a projectile
or shell, and having a buffer or cushion enclosed therein in rear of the said
projectile or shell; but I claim :-
First. The herein described method or manner of providing for the diminution of
the shock or concussion imparted to the bursting-charge of a shell when discharged
rom a gun, by the admission into the said shell of a portion of the air or other
gases of the propelling charge.

page_text: Second. A shell provided with a perforated base and with a bursting-charge so
arranged within the said shell that there is an air-space therein in rear of the said
charge, and the shell, when discharged from a gun, will move a short distance
forward relatively to the said charge before the inertia of the latter is overcome,
for the purposes above specified.
Third. A shell wherein the bursting-charge is contained in a case or receptacle
so arranged within the said shell that, when the latter is rotated by the rifling of a
gun, it will impart rotation gradually to the said case or receptacle, for the purpose
above specified.
Fourth. A shell adapted to receive a bursting-charge contained in a separate
case or receptacle, and so constructed that the said case or receptacle can be
conveniently stored separately from the shell and can be readily inserted therein
when the same is to be used, substantially as hereinbefore described.
Fifth. A shell which is provided with a perforated base and wherein the
bursting-charge is contained in a readily removable case or receptacle so arranged
within the said shell that, when the latter is discharged from a gun, it will move a
short distance forward relatively to the said case or receptacle before the inertia of
the latter is overcome, and will impart rotary motion gradually to the said case
or receptacle, substantially as herein before described and for the purposes
specified.
Sixth. A case or receptacle for explosive material adapted for insertion into a
shell and provided with a suitable fuse which may or may not be removable, sub-
stantially as, and for the purposes, above specified.
Seventh. A case or receptacle for the bursting-charge of a shell comprising two
or more chambers connected by suitable apertures or passages, substantially as, and
for the purpose, above specified.
Eighth. A shell adapted to receive a separate case or receptacle for the bursting-
charge, and having a perforated base and a groove or notch with which a spring or
catch on the said case or receptacle will engage when the latter is pushed to
the forward end of the cavity in the shell, substantially as, and for the purpose,
above specified.
Ninth. The combination, with the shell and the removable case or receptacle for
the bursting-charge, of suitable means for retaining the said case or receptacle in
position in the said shell whilst permitting the latter, when discharged from a gun,
to move forward relatively to the said case or receptacle, and suitable means for
preventing the rebound of the said case or receptacle, substantially as described.
Tenth. The employment of an ordinary cartridge in the manner above specified,
for effecting the explosion of a shell upon impact.
Eleventh. The improved removable fuse, comprising the cartridge and the striker
or pellet, substantially as hereinbefore described.
Twelfth. The herein described method or manner of providing for the release of
the striker or pellet of a fuse by the rotation of the shell on entering the rifling
of a gun.
Thirteenth. In or for an explosive projectile or shell, a fuse wherein the striker
or pellet is restrained from longitudinal or end wise movement by a pin or stud
extending into an L-shaped slot, substantially as, and for the purpose, set forth.
Fourteenth. In or for an explosive projectile or shell, a fuse wherein the striker
or pellet is restrained from longitudinal or endwise movement by a spring catch or
stop so arranged that it will be disengaged by the rotation of the shell relatively
to the said striker or pellet, substantially as, and for the purpose, set forth.
Fifteenth. The improved method or manner of charging a shell, or a case or
receptacle for insertion therein, consisting in exhausting the air from the said shell
or receptacle and utilizing the vacuum thus created for drawing liquid explosive
material into the same so as to absolutely fill the said shell or receptacle with such
explosive material, substantially as, and for the purpose, above specified.
Sixteenth. The improved method or manner of charging a shell, or a case or
receptacle for insertion therein, consisting in first introducing into the said shell or

page_text: receptacle solid or semi-solid explosive material, and then exhausting the air from
the said shell or receptacle and simultaneously filling the space formerly occupied
by the air with explosive or other liquid, substantially as, and for the purposes,
above specified.
Seventeenth. A shell containing a removable case or receptacle which is charged
with explosive material and from which the air has been exhausted, substantially
as, and for the purposes, above specified.
Eighteenth. The improved shell provided with the perforated base and with the
removable case or receptacle containing the bursting-charge, and constructed
substantially as described with reference to either of the forms or modifications
shown in the accompanying drawings, for the purposes above specified.
Nineteenth. The combination, with my improved shell, of a casing arranged to
slide thereon and enclosing a buffer or cushion in rear thereof for the purpose above
specified, and connected with the said shell in such a manner as to ensure the rotation
of the latter when the driving-ring on the said casing enters the rifling of a gun,
substantially as described.
101 1
A
1001
J. M. MCMAHAN.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.