Improvements in and relating to Projectiles for Ordnance.
Year: 1899

page_text: Date of Application, 7th Apr., 1899
Complete Specification Left, 6th Jan., 1900-Accepted, 31st Mar., 1900
PROVISIONAL SPECIFICATION.
Improvements in and relating to Projectiles for Ordnance.
I, HIRAM STEVENS MAXIM, of 18, Queen's Gate Place, in the County of Middlesex,
Chevalier of the Legion of Honour, Civil and Mechanical Engineer, do hereby
declare the nature of this invention to be as follows:-
This invention relates to projectiles for ordnance and has for its object to
provide an improved gas-check for preventing or mitigating the erosive action
on the bore of the gun of the incandescent gases of discharge rushing between
the projectile and the surface of the gun.
In some of the devices patented by myself and others for the purpose of
preventing this erosive action, semi-plastic obturating rings have been placed
on the projectile, so made that they will expand radially outward against the
bore of the gun under the gas pressure exerted upon a movable or collapsible
ring or disc arranged on the base of the projectile with its rim contiguous to the
semi-plastic ring..
It has been found in practice that it is extremely difficult to make the semi-
plastic ring with the proper degree of plasticity required; that is to say if it be
too plastic the paraffin wax or tallow with which the ring is provided will, on
the firing of the gun, be suddenly squeezed backward against the pressure of the
gases, into the space behind the projectile; or if the quantity of wax or tallow
used with the said ring be inadequate the ring becomes compressed into a hard
condition and will not with sufficient promptness spread radially outward under
the pressure of the gases.
Now according to my present invention and in order to overcome the above
stated objections, I so construct and arrange, in conjunction with a semi-plastic
ring, a movable metal ring or disc on the base of the projectile, which at the
instant of firing forces the said semi-plastic ring radially outward against the
bore of the gun and then, as the projectile moves along the bore, acts as a
plunger or piston to cause a quantity of wax or tallow or other suitable fatty
substance contained in a cavity in the projectile, to be continuously supplied to
the said semi-plastic ring or to the bore of the gun during the whole or the
greater portion of the travel of the projectile along the bore.
For this purpose the diameter of the base of the projectile is reduced to form
a circumferential cavity or recess and the base also has formed therein an inner
annular groove concentric with the aforesaid circumferential cavity and communi-
cating therewith by a series of transverse holes or passages extending through
the outer wall of the annular groove. The movable metal ring may be con-
structed with two concentric circular flanges separated by an annular groove or
space, one of these flanges being adapted to enter the said circumferential cavity
and the other to enter the said annular groove in the base of the projectile.
This movable ring is held in place on the said base by any suitable means which

page_text: will permit its movement when subjected to the pressure of the gases in the
gun but which will not permit its unintentional detachment from the projectile.
I arrange within the circumferential cavity or recess the semi-plastic ring and
within the inner annular groove I place the wax or tallow with which the said
semi-plastic ring is to be supplied during the passage of the projectile along
the bore.
It will be found advantageous to make the annular flanges of the movable ring
to loosely fit the circular recess and annular groove of the projectile, so that said
ring will freely move when subjected to the gas pressure, and to provide the
said circular recess and annular groove with tightly fitting metal packing pieces
to prevent the entrance of the gases into the said circular recess and annular
groove.
I prefer to construct the semi-plastic ring of some fibrous substance. It may
be composed of several annular parts or sections varying in texture, that is to
say the outermost section may be of fine texture and the innermost section of
coarse texture so that the absorbent capability of the ring is greatest at the part
which lies adjacent to the wax or tallow in the aforesaid annular groove.
The said movable metal ring may be connected to the base of the projectile
by means of a flanged or dished ring or dise of copper or other suitable metal
and in order to further avoid the passage of the gases into the aforesaid annular
groove in the projectile, I prefer to place between the said flanged or dished
ring and the inner circumference of the movable ring a quantity of wax or tallow
or other suitable substance that will act as a gas-check at this point. The said
flanged or dished ring is screwed or otherwise attached to the base of the
projectile and preferably retains the movable ring in place by a lip at the
periphery of the said flanged or dished ring, engaging with a shoulder on the
inovable ring.
The movable ring may be provided at its periphery with a copper band which
when said movable ring shifts, under the pressure of the gases, will act upon
and compress the portion of the semi-plastic ring that lies outside the circum-
ference of the movable ring. I provide in advance of said semi-plastic ring a
copper driving band which may be of any suitable construction.
The annular groove containing the wax or tallow or other fatty substance
may be either partially or completely filled therewith as may be found most
suitable.
When applying my improvements to projectiles used in firing proof charges
in ordnance, I provide the base of the projectile with a movable piece which
may be in the form of a mushroom with its stem fitted in a central recess or
cavity in the base and I secure this movable piece by a long bolt extending
completely through the centre of the projectile and the said movable piece.
Between the head of the mushroom shaped piece and the base of the projectile,
I place the semi-plastic ring and by means of a nut on the said bolt I am able
to force the said head tightly against the semi-plastic ring so as to compress the
latter and cause its circumference to bear against the bore of the gun and
produce a gas-tight joint, after the projectile has been inserted into the breech
of the gun and before firing. The stem of the mushroom is preferably of such
length that a space exists between it and the end of the central recess or cavity.
Into this space I may place the wax or tallow or other fatty substance and
provide for its being forced into the bore of the gun or supplied to the semi-
plastic ring, by suitably arranged passages extending from said space through
the body of the projectile.
a

page_text: Improvements in and relating to Projectiles for Ordnance.
I, HIRAM STEVENS MAXIM, of 18, Queen's Gate Place, in the County of Middlesex,
Chevalier of the Legion of Honour, Civil and Mechanical Engineer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to projectiles for ordnance and has for its object to
provide an improved gas-check for preventing or mitigating the erosive action
on the bore of the gun, which is due to the rushing of incandescent gases of
discharge between the projectile and the adjacent surface of the gun.
In some of the devices patented by myself and others for the purpose of
preventing this erosive action, semi-plastic obturating rings have been placed
on the projectiles, these rings being so made that they will expand radially
against the bore of the gun under the gas pressure exerted upon a movable
or collapsible ring or disc arranged on the base of the projectile with its rim
contiguous to the semi-plastic ring. It will doubtless be understood that, by
the term "semi-plastic" ring, I mean a ring that is capable of being compressed
and squeezed outward against the bore of the gun, when subjected to the great
pressure which arises on the firing of the gun.
It has been found in practice that it is extremely difficult to make the semi-
plastic ring with the proper degree of plasticity; that is to say, if it be too
plastic, the paraffin wax or tallow with which the ring is provided will, on
the firing of the gun, be suddenly squeezed backward, against the pressure of
the powder gases, into the space behind the projectile; or if the quantity of the
wax or taliow used with the said ring be inadequate, the ring becomes com-
pressed into a hard condition and will not with sufficient promptness spread
radially under the pressure of the powder gases.
Now according to my present invention and in order to overcome the above
stated objections, I provide the projectile with a movable metal ring, disc or
base-piece which, not only at the instant of firing forces the said plastic ring
radially against the bore of the gun but also, as the projectile moves along the
bore, acts as a plunger or piston to cause a quantity of wax tallow or other
suitable substance contained in a cavity in the projectile, to be continuously
supplied to the semi-plastic ring (or to the bore of the gun) during the whole or
the greater portion of the travel of the projectile along the bore.
In order that my said invention may be clearly understood and readily carried
into effect I will proceed to describe the same more fully with reference to the
accompanying drawings in which:
Figure 1 is a longitudinal section of the rear portion of a projectile provided
with my improved gas-check and approximately in the position it occupies
within the bore of the gun prior to discharge.
Figure 2 is a similar view but showing the position of the parts just after the
discharge and when the projectile has advanced a short distance along the bore.
Figure 3 is a transverse section taken on the line 1-1 of Figure 1.
Figure 4 shews sectional views of the various parts of the gas-check and the
rear part of the projectile separated from one another so as to more clearly
illustrate their construction.
Figure 5 is a longitudinal section showing a modified form of the gas-check
for service with projectiles used in firing proof charges in ordnance.

page_text: Referring more particularly to Figures 1 to 4:-A is the gun, B the projectile
body, the copper driving band, D the so-called semi-plastic ring and E the
movable base-piece.
The base of the projectile is reduced to form a circumferential corner or
recess (Figure 4) and has an annular groove concentric with the aforesaid
circumferential recess. This annular groove communicates with the circum-
ferential recess by a series of transverse holes or passages 62 (Figure 3) which
extend through the outer wall 63 of the annular groove. The movable base-
piece E is constructed with two concentric circular Hanges e¹ e separated by an
annular groove or space e, the flange e¹ being preferably of greater width than
the flange e. The flange e¹ is adapted to enter the cavity 6 and the flange e
is adapted to enter the annular groove b¹. This ring E is held in place on the
base of the projectile by any suitable means that will permit its forward
movement when subjected to the pressure of the gases in the gun but that will
not permit its unintentional detachment from the projectile. In the drawings I
have shown for this purpose a flanged or dished ring F composed of copper or
other suitable metal which is connected to the base of the projectile by means
of screws ff. Between the said flanged or dished ring and the inner circum-
ference of the movable base-ring E, I place a quantity of wax or tallow or other
suitable substance preferably in the form of a ring f¹ that will act to prevent
the gases of discharge from reaching the annular groove 61. The outer edge or
periphery of the said ring F is provided with a lip which engages with a
shoulder formed in the said base-ring E. Within the annular groove I place
the wax tallow or other suitable substance with which the semi-plastic ring D
is to be supplied during the passage of the projectile along the bore.
It will be found advantageous to make the flanges el e of the movable base-
ring E loosely fit the recess b and the annular groove b¹, so that said base-ring
will freely move forward when subjected to the gas pressure. It is also advan-
tageous to provide the said circular recess and annular groove respectively with
tightly fitting metal packing pieces G H so as to prevent the entrance of the
gases of discharge into the said circular recess and annular groove.
I prefer to construct the semi-plastic ring 1 of fibrous substance. It may be
composed of several annular parts or sections varying in texture, that is to say
the outermost section may be of fine texture and the innermost section may be
of coarse texture, so that the absorbent capability of the ring is greatest at the
part which lies adjacent to the wax or tallow in the aforesaid annular groove b
I is a band of hemp or other appropriate fibrous material which is interposed
between the semi-plastic ring D and the driving band C and which may be
treated with paraffin wax or other substance of a similar nature to render said
band of hemp semi-plastic. This band may be composed of several rings arranged
as shewn in Figure 4.
The movable base-ring E may be provided at its periphery with a copper band
which when said base-ring shifts under the pressure of the gases will act upon
and compress the portion of the semi-plastic ring which lies outside the circum-
ference of the base-ring. In most cases however I prefer to construct the
aforesaid packing piece G of such a width that it will project at its outer
circumference beyond the periphery of the said base-ring E, as represented in
the drawings. It will be found advantageous to form the outer circumference
of said packing piece G bevelled as shewn, so that its strength will be reduced
at such part to permit of its bending rearwardly under the pressure of the semi-
plastic ring when the latter is compressed by the base-ring during the passage
of the projectile along the barrel.
The annular groove containing the wax or tallow or other substance is prefer-
ably only partially filled therewith, so that the flange e² of the movable ring E
will not act to compress said substance and force it through the radial passages 62
until after the projectile has moved some distance along the bore.
When the gun is fired, the pressure of the powder gases acting on the aforesaid

page_text: the base of the
movable base-ring E, causes the latter to advance towards
projectile and its flange e to compress the semi-plastic ring D, whereby the
latter is forced radially outward against the surface of the bore of the gun as
the projectile travels along the same. The continued advance of the movable
base-ring E, as the semi-plastic ring is squeezed out thereby, permits the
Hange to act upon the material within the annular cavity 6 whereby said
material is compressed and driven through the radial passages 62 into contact with
the said semi-plastic ring D, as shewn in Figure 2, thus assisting in forcing the
said ring radially against the bore of the gun as the projectile travels along
said 'bore.
Referring now to Figure 5. A is the gun, B the projectile body, C the driving
ring and D the semi-plastic ring. In this case I provide the base of the projectile
with a movable base-piece E' in the form of a mushroom, the stem E2 fitting
into a central recess or cavity B₁ in the base of the projectile. The said movable
base-piece E¹ is secured by a long 'bolt E³ extending completely through the
centre of the projectile and the movable base piece, one end of the sail bolt
being enlarged and the other end screw threaded to receive a nut E. Between
the head of the base-piece E' and the base of the projectile I place the plastic
ring D and by means of the nut E' I am able to force the said base-piece E¹
tightly against the semi-plastic ring, so as to compress the latter and cause its
circumference to bear against the bore of the gun and produce a gas-tight joint,
after the projectile has been inserted into the breech. The stem E2 of the
movable base-piece is of such a length that a space exists between it and the
end of the central recess or cavity B₁ so as to enable the base-piece to move
forward under the gas pressure as aforesaid. This space or cavity may contain
wax, tallow or other substance which may be forced therefrom into the bore of
the gun or into the space containing the semi-plastic ring when the pressure
of the gases of discharge drive the said base-piece E¹ forward. The said wax
or tallow may find its way into the bore of the gun through the space surrounding
the aforesaid bolt E3; or may reach the space containing the semi-plastic ring
by suitable passages. In most cases however it will be found unnecessary to
provide the cavity B₁ with the wax or other material, because the semi-plastic
ring D can be made of sufficient size, to ensure its efficiency as a gas check without
the assistance of the said wax or other material.
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 :-
1. A projectile provided with a semi-plastic ring and with a movable base-piece
which at the instant of firing will force the semi-plastic ring outward and then,
as the projectile moves along the bore will operate as a plunger or piston for
causing a quantity of fatty or other substance contained in a cavity in the
projectile to be supplied to the said semi-plastic ring, or to the bore of the gun,
substantially as and for the purpose specified.
2. In a projectile, the combination of a semi-plastic ring and a movable base-
piece having circular flanges, one of which is adapted to enter a recess containing
the said semi-plastic ring and the other to enter an annular groove containing
the fatty or other substance which can be forced into the said recess through
suitable passages for the purpose specified.
3. The construction of the aforesaid flanges on the base-piece, of unequal
width or area, the larger of said flanges engaging with the recess containing the
semi-plastic ring for the purpose specified."
4. The combination with the aforesaid flanged base-piece and the recess and
groove in the projectile, of packing pieces adapted to tightly fit said recess and
groove substantially as and for the purpose specified.
5. The combination with the aforesaid flanged base-piece of a dished ring
for securing said base-piece to the projectile body and of a ring of wax tallow or

page_text: similarly plastic substance interposed between said dished ring and base-piece sub-
stantially as and for the purpose specified.
6. The semi-plastic ring constructed of several annular parts or sections
varying in texture substantially as and for the purpose specified.
7. For use in firing proof charges, a projectile having a mushroom shaped
base-piece held in place by a bolt and nut so that by adjusting said nut on the
bolt the semi-plastic ring can be compressed after the projectile has been
inserted into the breech of the gun substantially as and for the purpose described.
8. A projectile having its gas-check constructed arranged and operating sub-
stantially as described with reference to either of the examples illustrated in
the accompanying drawings for the purposes specified.
Dated this 6th day of January 1900.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.