Improvements in the Manufacture of Explosives, and in Apparatus therefor.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Explosives, and in Apparatus
therefor.
I, HUDSON MAXIM, of 55 Charing Cross Mansions, in the County of London,
Chemist and Mechanical Engineer, do hereby declare the nature of this invention
to be as follows:-
The present invention relates to the manufacture of explosive compounds of the
kind now generally known as "smokeless powders," my object being mainly to
impart to these compounds such configuration or physical shape as will secure the
highest ballistic results.
I have heretofore sought to attain this object by piercing the compound with
numerous longitudinal perforations whereby a minimum surface is presented to the
initial flame of combustion, and as the perforations burn and become larger a
correspondingly increased and constantly increasing burning or combustion surface
is presented to the flame of combustion.
Now according to my present invention and in order to produce the very highest
ballistic results for the purpose of maintaining pressures substantially uniform
throughout the travel of a projectile through the gun, and to give as little initial
pressure as possible in excess of such maintained pressure, I prefer to construct a
powder charge in the following manner, which has special advantages in the
throwing of shells containing high explosives from ordnance and which will
furthermore cause only the minimum of erosion of the powder chamber of
the gun.
To secure this end I first produce a sheet or body of explosive material having
perforations cells or depressions so disposed as to present a practically uniform
thickness of explosive substance between one another, throughout their length, and
preferably also and such a thickness at that part between their bottom and the
opposite surface of the explosive compound as to be substantially equal to the
thickness of explosive substance existing between the perforations.
The said sheet or body of explosive compound is then rolled into the form of a
cylinder preferably of such size and shape as to conform as nearly as possible to
the size and shape of the powder chamber of the gun. The edges of the explosive
compound which come together to form the cylinder may abut, or overlap and
may be sealed together by a suitable solvent of the compound, or by a proper
cement, or such edges may even be left un-united.
This cylinder may be either formed hollow or be so wound upon itself as to
present a spiral form in transverse section, but it is preferably made in the form
of a hollow cylinder. A cylinder so constructed will preferably have no cells or
depressions upon its outer surface, but all the perforations will open into the
interior of the hollow cylinder. On being ignited by the initial flame of explosion
the explosive charge will take fire from the interior of the cylinder and from the
interior of the perforations opening into the said interior of the cylinder, whereby
the exterior of the cylinder will be forced firmly against the walls of the powder
chamber and the ready ignition of the cylinder from its exterior surface be thus
prevented. As the explosive cylinder becomes consumed from the interior and
from within the perforations the explosive compound at the bottom of the perfora-
ious will be simultaneously consumed whereby a maximum of increased burning

page_text: surface will be presented to the flame of combustion with the lowest amount of
initial pressure. Furthermore as the rush of gases arising in the combustion of
the explosive compound is not thrown or impacted against the walls of the powder
chamber, the latter will be subjected to the minimum of erosive effect. Another
advantage of this form of explosive charge is that the gases meeting within the
interior of the hollow cylinder at right angles to its longitudinal axis will be caused
by their impact or momentum of meeting to be thrown or ejected in a direction at
right angles to the perforations from which they are evolved with much increase
of force and velocity, on the principle that bodies of gases thrown upon one
another from opposite directions will when meeting at a common point, be thrown
at right angles to the direction of the original movement with a velocity con-
siderably in excess of the original movement due to the momentum of the gases
and to their perfect elasticity.
In carrying out my present invention I prefer to proceed in the following
manner: The explosive compound is first preferably rolled into sheets of a desired
thickness. The sheets are then laid upon a metallic table, provided with flanges
to prevent the compound from escaping when subjected to pressure as hereinafter
described. A perforated metallic plate is then placed upon the sheet of explosive
compound the number of perforations in the said plate corresponding in number
and position to the perforations it is desired to impart to the explosive compound.
Situated above the perforated plate is another plate having a number of perforating
pins projecting from its underside which pins approximately fit the perforations
in the aforesaid perforated plate. This pin-plate may constitute the piston-head
of a press and the lower or unperforated plate may constitute the bed of the
press. When the before mentioned pin-plate or piston-head is pressed down upon
the perforated plate the pins pass through the perforations of the said perforated
plate and enter the explosive compound beneath, thereby perforating the com-
pound. The perforated plate may at the same time be subjected to pressure by
the pin-plate whereby the explosive compound will be caused to fill all of the
interstices between the perforated plate and the bed of the press and about and
between the perforating pins. The pin-plate is then elevated while the perforated
plate remains stationary until the piston head is raised far enough to withdraw
the said pins from the explosive compound. The perforated plate is removed from
the perforated sheet of explosive compound and the machine is then ready to
receive another sheet of explosive compound to be perforated. It will be seen
that the said perforated plate serves the function of guiding the perforating pins
and of afterwards clearing them from the explosive compound. The aforesaid
pin-plate or piston-head and the unperforated plate or bed of the press may be
made hollow to permit of steam, hot water or other heating medium being admitted
thereto for keeping the parts at the requisite working temperature; the said hollow
parts also permitting of the subsequent admission of cold water or other cooling
medium thereto to stiffen the compound after the perforations have been formed.
It is obvious that I may by this method produce a sheet of explosive compound
with any desired number of perforations and of any desired thickness within wide
limits. After forming sheets of perforated compound in this manner the same
may be cut up into strips, parallelograms or rods or may be rolled into a cylinder
of the form and character herein before described.
Instead of perforating the explosive compound by means of a press as above
described, I may employ a cylinder or roller having perforating pins and may
cause the said cylinder or roller to rotate in conjunction with a moving sheet of
explosive compound disposed upon a bed-plate arranged to travel under the said
perforating cylinder or roller; or I may employ a perforating cylinder having
pins arranged to operate in conjunction with a plain cylinder and perforate the
sheets of explosive compound by passing them between the two cylinders. In
order to strip the perforating pins of any of the compound that may adhere to them
1 may employ an endless travelling band having apertures therein through which
the perforating pins pass as the said endless band travels along. It will be seen

page_text: that I may, if desired, make perforated rods or sticks having longitudinal
perforations in the manner first above described for making perforating sheets, by
means of a pin-plate working in conjunction with a perforated metallic plate and
press, the end being attained either by either cutting the explosive compound
into such shape as will leave the perforations in a line longitudinal with the axis
of the finished explosive or by forming pits or depressions in the lower bed plate
and providing the pins in the upper or pin-plate to correspond with the said
depressions.
Dated this 9th day of Sentember 1905
Improvements in the Manufacture of Explosives, and in Apparatus
therefor.
I, HUDSON MAXIM, of 55 Charing Cross Mansions, in the County of London,
Chemist and Mechanical 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 :-
The present invention relates to the manufacture of explosive compounds of
the kind now generally known as "smokeless powders my object being mainly
to impart to these compounds such configuration or physical shape as will secure
the highest ballistic results.
I have heretofore sought to attain this object by piercing the compound with
numerous longitudinal perforations whereby a minimum surface is presented to
the initial flame of combustion, and as the perforations burn and become larger a
correspondingly increased and constantly increasing barning or combustion surface
is presented to the flame of combustion.
Now according to my present invention and in order to produce the very
bighest ballistic results for the purpose of maintaining pressures substantially
uniform throughout the travel of a projectile through the gun, and to give as
little initial pressure as possible in excess of such maintained pressure, I prefer
to construct an explosive charge in the following manner, the said charge having
special advantages in the throwing of shells containing high explosives from
ordnance and furthermore causing only the minimum of erosion of the powder
chamber of the gun.
For these purposes I first produce a sheet or body of explosive compound with
holes cells or grooves which do not extend completely through the sheet or body
and which are so disposed as to present a practically uniform thickness of explosive
material between one another, throughout their length.
The said cellular sheet or body of explosive compound is subsequently rolled
into the form of a hollow cylinder with the aforesaid holes cells or grooves opening
into the hollow interior thereof. The said cylinder is preferably of such size
and shape as to conform as nearly as possible to the size and shape of the powder
chamber of the gun. The edges of the explosive compound which come together
to form the cylinder may abut, or overlap, and may be sealed together by a
suitable solvent of the coinpound, or by a proper cement; or such edges may even
be left unsealed.
The thickness of the material at the bottom of the holes cells or grooves depends
upon the inanner in which the explosive charge is to be used in the gun. If the
said charge is made to fit the powder chamber of the gun as above stated the

page_text: thickness of material at the hottom of the cells should be equal to about one half
of the thickness of material between the cells; but if the said charge is to be
used so that it does not fit the powder chamber, the thickness of material at the
bottom of the cells should be substantially equal to the thickness of material
between the cells.
The cylinder of explosive material may be either formed hollow or be so wound
upon itself as to present a spiral form in transverse section, but as before stated
it is preferably made in the form of a hollow cylinder approximating the size of
the powder chamber of the gun.
In some cases it is preferable to form the ends of the cylinder with tapered
openings as will be hereinafter described.
:-
In order that my invention may be clearly understood I will proceed to describe
the same more fully with reference to the accompanying drawings in which :-
Figure 1 is a vertical section of a machine for use in the moulding of my
improved explosive charge.
Figure 2 is a longitudinal section and Figure 3 a transverse section shewing a
modified construction of the machine.
Figure 4 is a longitudinal section, and
Figure 5 a transverse section of a portion of a gun barrel with my explosive
charge in place within the powder chamber thereof.
Figure 6 is a sectional perspective view, and
Figure 7 a transverse section of a modified construction of my explosive charge
provided with internal continuous channels or grooves instead of holes.
I will describe the method of manufacturing my explosive with more especial
reference to Figure 1.
The explosive compound is first preferably rolled into sheets of a desired
thickness and these sheets are then laid upon a metallic table A, which is so
arranged in conjunction with the framing B of the machine that when the said
table is in its raised position as shown in Figure 1, the compound will be prevented,
by the flanges B³, from escaping when subjected to pressure as hereinafter
described. Situated above the table A is a perforated metallic plate C which is
capable of being brought onto the sheet of explosive compound by means of
hydraulic pistons working in cylinders CC¹ and connected by their piston rods to
the aforesaid plate C. The perforations in the said plate correspond in number
and position to the holes cells or depressions it is desired to impart to the explosive
compound. Situated above the perforated plate C is another plate D which is
connected to an hydraulic piston working in a cylinder D'. This plate D has a
number of pins d projecting from its underside which pins approximately fit the
perforations in the aforesaid perforated plate C. A convenient method of
connecting these pins to the plate D is to provide them with heads which will
snugly fit into recesses in the said plate D so that when this plate and the head of
the piston of the cylinder D¹ are connected together, the said pins will be firmly
retained in place.
The plate D into which the pins are fastened and the perforated plate C form
together with their pistons a sort of double piston-bead, and when the machine is
working these two plates or piston-heads move forward together onto the explosive
compound as shewn at Figure 1 the pins being at this time housed in the perforated
plate C. Then the pin plate D moves downward and projects the pins through the
said perforated plate whereby the pins are caused to enter the explosive compound.
In order to give sufficient space for displacement of the explosive compound so
that the penetration of the pins into the said compound is facilitated, the perforated
plate C is made to slightly recede during the penetrating operation, and this is
effected by causing a greater pressure to be exerted upon the pin-plate than upon
the perforated plate C. It will therefore be observed that this machine acts first
to compress the explosive compound and then to cause the pins to penetrate it, the
perforating plate acting as a guide to prevent the said pins from becoming distorted
or bent.

page_text: The perforated plate C may be subjected to pressure by the pin-plate D when
the latter has fully descended, whereby the explosive compound will be caused to
fill all of the interstices existing between the perforated plate and the bed of the
press and about and between the pins. The pin-plate is then elevated while the
perforated plate remains stationary until the pin-plate is raised far enough to with-
draw the said pins from the explosive compound, the perforated plate thereby
serving to strip the pins of any of the compound that might be clinging to them.
The perforated plate is then also raised out of contact with the sheet of explosive
compound, and the machine is then ready to receive and act upon another sheet of
explosive compound.
It will be seen that the said perforated plate serves the functions of guiding the
pins, of afterwards clearing them from the explosive compound and of compressing
the explosive compound. During the formation of the holes, cells or depressions
in the explosive compound, it is necessary to keep the said compound in a heated
condition to render it plastic and this may be effected by forming the aforesaid
bed A of the press, the pin-plate D and the perforated plate C hollow so that
steam, hot water or other heating medium can be admitted thereto for keeping
the parts at the requisite working temperature. The said hollow parts also permit
of the subsequent admission of cold water or other cooling medium thereto to
stiffen the compound after the moulding operation has been performed.
The distance between the plates D and C may be so arranged that the extent to
which the pins d enter the explosive compound can be readily adjusted.
It is obvious that I may by this method produce a sheet of explosive compound
with any desired number of holes, cells or depressions and of any desired thickness
within wide limits and that the extent to which the said pins penetrate the
explosive sheet can also be regulated. After forming sheets of compound moulded
with holes therein in this manner, the saine may be cut up into strips, parallelo-
grains or rods but are preferably rolled into a cylinder of the form and character
herein described.
Instead of forming the explosive compound with holes by means of a press as
above described, may employ a cylinder or roller having pins disposed around its
periphery and may cause the said cylinder or roller to rotate in conjunction with a
moving sheet of explosive compound disposed upon a bed-plate arranged to travel
under the said cylinder or roller. Or I may employ a cylinder having pins
arranged to operate in conjunction with a plain cylinder and form the sheets of
explosive compound with holes by passing them between the two cylinders as
illustrated in Figures 2 and 3.
In these figures D is the cylinder or roller carrying the pins d which are
movably arranged in the said roller so that as the latter revolves, successive rows
of these pins are caused to be projected into the sheet of explosive compound by
means of a fixed guide or cam piece E. The said pins may be provided with
springs for enabling them to be withdrawn into the cylinder D after they have
effected their purpose.
D' is the plain cylinder which is situated below the
cylinder D, and between these two cylinders the explosive compound passes during
the working of the machine. In order to strip the pins of any of the explosive
compound that may adhere to them I may employ an endless travelling band F
passing around rollers G G and having apertures in it through which the pins d
pass as the said endless band travels along.
The aforesaid cylinders D and D' are made hollow to permit of steam hot water
or other heating medium being admitted to them.
The machine described with reference to Figure 1 of the drawings may if
desired be employed for producing rods or sticks with longitudinal perforations,
this end being attained by employing a thick sheet of compound which is
perforated and afterwards cut into such shape as will leave the perforations in
a line longitudinal with the axis of the finished explosive.
Referring now to Figures 4 and 5 H is the explosive charge in a finished
condition and formed in the shape of a hollow cylinder fitting the powder chamber

page_text: of the gun. hhare the holes or cells which occupy a radial position and extend
from the interior of the hollow cylinder into the wall thereof without however
reaching the exterior surface of said cylinder. The ends of these holes or cells,
owing to the bending of the sheet into cylindrical form, assume a more or less
elliptical shape, the major axis of the elliptical ends of the cells on the inside of the
hollow cylinder being longitudinally disposed with relation to the longitudinal axis
of the cylinder and the major axis of the opposite ends of such cells being
transversely disposed to the said longitudinal axis. The openings at the ends
of the said cylinder may be bevelled or formed conically as shewn by the dotted
lines in Figure 4 so that the gases generated during the combustion of the
cylinder in the gun, will be prevented from igniting the exterior of the cylinder.
A cylinder of explosive compound constructed in accordance with my present
invention will have no holes or cells upon its outer surface, but all the holes or
cells will open into the interior of the hollow cylinder. On being ignited by the
initial flame of explosion the explosive charge will take fire from the interior of
the cylinder and from the interior of the said holes or cells whereby the exterior of
the cylinder will be forced firmly against the walls of the powder chamber and the
ready ignition of the cylinder from its exterior surface be thus prevented. As the
explosive cylinder becomes consumed from the interior and from within the holes
or cells, the explosive compound at the bottom of the holes or cells will be
simultaneously consumed whereby a maximum of increase in burning surface will
be presented to the flame of combustion with the lowest amount of initial
pressure. Furthermore as the gases arising in the combustion of the explosive
compound are not thrown or impacted against the walls of the powder chamber,
the latter will be subjected to the minimum of erosive effect.
Another advantage
of this form of explosive charge is that the gases meeting within the interior
of the hollow cylinder at right angles to its longitudinal axis will be caused by
their impact or momentum of meeting to be thrown or ejected in a direction at
right angles to the holes or cells from which they are evolved with much increase
of force and velocity, on the principle that bodies of gases thrown upon one
another from opposite directions will when meeting at a common point, be thrown
at right angles to the direction of the original movement with a velocity
considerably in excess of the original movement, such result being due to the
momentum of the gases and to their perfect clasticity.
In Figures 6 and 7 I have shewn an explosive charge wherein the cells h
instead of being in the form of holes are in the form of continuous longitudinal
grooves, h. These grooves may be produced in an analogous manner to the
holes; plates being used instead of the pins d already described.
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. In the manufacture of smokeless explosives, the formation of the explosive
compound into a sheet which is moulded with holes cells or grooves substantially
as described, and is subsequently rolled into the form of a hollow cylinder or
section of a hollow cylinder for the purpose specified.
2. A hollow cylindrical explosive body having holes, cells or grooves disposed
substantially as described with reference to Figures 4 and 5 or with reference to
Figures 6 and 7 of the accompanying drawings for the purposes specified.
3. The hollow cylinder of explosive material having uniformly arranged
interior holes cells or grooves and having its exterior surface adapted to approxi-
mately fit the powder chamber of the gun, whereby the said cylinder when ignited
from its interior will be expanded forcibly against the walls of the powder chamber
and thus delay combustion of its exterior surface, and prevent erosion of the
powder chamber.
4. In apparatus for use in the manufacture of the aforesaid smokeless explosives

page_text: the combination of the pin holding device and the perforated plate through which
the pins pass substantially as described.
5. In apparatus for use in the manufacture of the aforesaid smokeless explosives,
a piston head armed with pins, a perforated plate or guide for the pins, and means
for operating the one independently of the other substantially as described and for
the purpose specified.
6. The berein described apparatus for moulding smokeless explosive material
substantially as described with reference to Figure 1 or Figures 2 and 3 of the
accompanying drawings.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.