Improvements in the Manufacture of Explosives.
Year: 1895

page_text: Date of Application, 9th Sept., 1895
Complete Specification Left, 9th Oct., 1895-Accepted, 9th Nov., 1895
Improvements in the Manufacture of Explosives.
1, 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 improvements in the manufacture of explosives
of the kind now generally known as "smokeless powders
" and has for its object,
mainly, the securing of higher ballistic results when employed for throwing
projectiles from ordnance.
Heretofore gun powders or explosive compounds used for propulsive purposes in
ordnance have been usually so constituted and shaped that the combustion surface
is greatest at the moment of ignition so that they necessarily burn with a constantly
decreasing combustion area. Efforts have been made to lessen the falling off of
the combustion area, to some extent, by making longitudinal perforations to extend
through rods, prisms or grains of the explosive. I have heretofore obtained very
good results in perforating rods or grains of smokeless powder longitudinally, by
making the perforations as small as practicable and then cutting the rods or grains
into a length as great as possible without endangering the disruption or breaking
up of the grains in the gun upon ignition; such breaking up being due to the
pressure of the gases generated or evolved within the perforations, and their
inability to escape freely enough when the perforations are made of too great a
length with relation to their diameter.
It is therefore necessary, when grains or strips of explosive compound are
perforated longitudinally, that they should be cut up into rather short lengths,
with the result that they present to the flame of ignition and combustion, an
undesirable area substantially equal to the end areas of all of the grains or bodies
of explosive compound so cut.
By my present invention, instead of perforating rods, strips or bodies in a
longitudinal direction, I perforate them in a direction transverse to their longi-
tudinal axis, in such wise, that the perforations shall be substantially parallel to
one another, whereby there shall exist between the perforations throughout their
length a practically uniform thickness of explosive compound in a direction at
right angles to the perforations and transverse to the longitudinal axis of the rod
or strip. The perforations are preferably staggered, that is, made in staggered
relation, so that one line of perforations shall, as it were, break joint with another
line, whereby the explosive compound shall, as nearly as practicable, be consumed
simultaneously with the intersection of the perforations with one another,
as they enlarge during the consumption of the compound from within. the
perforations.
By my present method, rods strips or sheets of explosive material may be made
of a length to practically conform with the length of the powder chamber of the
gun, thus minimising the end areas of the explosive compound exposel, and at the
same time greatly minimising external areas as compared with and relative to
the internal areas, or areas within the perforations. The perforations may be inade
very small, so as to profit by the maximum of increase of burning surface, without
danger of disruption of the rods or strips by the gas pressures generated within
the perforations.

page_text: The rods or strips may be made of any desired suitable shape, as regards the
external configuration, to best accomplish the desired purpose. It will be seen
that the explosive charges for ordnance made in this manner, that is to say in rods
or strips perforated as described, will have their perforations lying in a line
substantially at right angles to the powder chamber, or substantially at right
angles to the longitudinal axis of the bore of the gun.
Dated this 9th day of September 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in the Manufacture of Explosives.
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 improvements in the manufacture of explosives
of the kind now generally known as "smokeless powders" and has for its object,
mainly, the securing of high ballistic results when such explosives are employed
for throwing projectiles from ordnance.
Heretofore gun powder or explosive compounds used in ordnance have been
usually so constituted and shaped that the combustion surface is greatest at the
moment of ignition so that they necessarily burn with a constantly decreasing
combustion area. Efforts have been made to prevent to some extent the diminution
of the combustion area, by making longitudinally perforated rods, prisms or grains
of the explosive, and I have heretofore obtained very good results, in the use of
smokeless powder, by making such rods or strips with the longitudinal perforations
as small as practicable and then cutting the said rods or strips into blocks grains
or pieces short enough to prevent any liability to their disruption or breaking up
in the gun upon ignition, by reason of the perforations, being of too great a length
relatively to their diameter to allow the gases to escape freely therefrom, the
result being that these short lengths, grains or pieces present to the flame of
ignition and combustion, an area substantially equal to the end areas of all of such
grains or pieces.
By my present invention, instead of perforating the explosive rods, strips or
bodies in a
longitudinal direction, I perforate them transversely to their longi-
tudinal axis, in such a manner that in a charge formed thereof there will be a
uniform thickness of the explosive compound between the perforations throughout
their entire extent. The charge may be manufactured independently of a casing
or carrier and ready to be combined therewith or to be otherwise used.
I prefer that the charge should be of an impervious nature, that is to say
impervious to the gases of combustion as distinguished from charges which are
granular or friable in structure, though of compressed or cake form. I use for
instance an impervious colloid of pyroxylin made by means of a volatile solvent of
the pyroxylin with or without an admixture of nitro glycerin and constituting an
amorphous solid or mass which while in plastic condition is capable of being
shaped, molded, pressed or rolled to any desired form.
In carrying my invention into practice this impervious charge is formed
preferably into rods or strips of any desired length and shape in cross section;
ie. either of round, prismatic, oval or other form, each rod, piece or strip having
parallel perforations extending crosswise or transversely of its length, the per-
forations being preferably arranged in series, the perforations of one series
alternating with those in the adjacent series and in this manner 1 provide equal

page_text: masses of the explosive between the perforations so that during combustion, as the
perforations gradually enlarge, increased combustion surface is presented and the
entire mass of charge is finally consumed throughout its extent simultaneously.
These rods, pieces or strips may be formed of the required diameter, preferably
approximating the length of the powder chamber of the gun, or in such lengths as
will adapt them to a cartridge, casing or carrier; and may also be of such
dimensions that a single rod or strip or a plurality of rods or strips may be
employed as a charge for a gun. Such an explosive charge may be ignited at the
end by any suitable means, such as a fulminate cap, or an igniting disc or charge in
the base of the shell.
In order that my invention may be fully understood and readily carried into
effect, I will now describe the same with reference to the accompanying drawings
in which
Figure 1 is a longitudinal sectional view of a cartridge containing a charge of
explosive made in accordance with my invention.
Figure 2 is a transverse section on the line x, x of Figure 1.
Figure 3 is a longitudinal section illustrating a charge of my explosive in a gun.
Figures 4, 5 and 6 inclusive are transverse sections showing different forms of
the explosive charge.
In Figures 1 and 2 the explosive charge a is contained in a cartridge shell or
case A of any suitable form, having for instance a body portion which, near its
forward end contracts to a neck that is arranged to receive a ball or projectile d
and a wad c; while the rear end of the shell has a closed head providing a seat
for a suitable fulminate cap as is well understood.
The charge a is preferably prepared in the form of a rod or strip of any appro-
priate shape in cross section, and of a diameter that will permit the rod or strip to
be readily loaded into the shell through the open end of the neck and of a length
suited to extend from the head of the shell to its contracted or neck portion, such
neck, if thought desirable, affording more or less support for the charge to hold it
in a central position with respect to the larger diameter or body portion of the
shell, and thus provide a surrounding chamber for the passage of the initial flame
of combustion from the fulminate cap to the perforations of the charge. This
charge a is as here shown formed of several flat strips or pieces superimposed one
over the other and each piece having a plurality of parallel perforations & extending
transversely through the charge, or in a direction across the greatest length or
axis of such charge. The perforations are arranged preferably in series, the
perforations of one series alternating with those of the other as in Figure 3,
whereby provide equal masses of the explosive between the perforations to ensure
the uniform consumption of the entire charge. The improved explosive charge, in
addition to the well known advantages incident to the use of long rods or strips of
powder approximating the length of the powder chamber of the gun or shell,
provides a structure perforated transversely of its greatest length with a large
number of short parallel holes, to obtain the uniformly increasing burning surface
for securing the greatest accelerating effect upon the projectile; and the shortness
of the holes prevents the charge from being disrupted or broken up during com-
bustion by the pressure of the gases within the perforations, such disruptive action
exploding the powder and bursting the rods or strips into fine pieces. Instead of
forming the charge for a shell as in Figure 1, it may be used as a charge for a
gun B as in Figures 3 to 6. In Figure 3 a portion of the powder chamber of the
gun is shown, its breech piece being closed by a mushroom e seated by the pressure
of the gases against a packing f.
Some of the different forms which the rod or strip-like charge may take are
shown in the drawings. Thus in Figures 1 and 2 the rod is composed of several
flat strips associated into square form; in Figure 3 it is square, and of a single
piece; in Figure 4 it is hexagonal, in Figure 5 a number of rods of any shape
such as square in cross section are associated together to form a charge for a gun
or the like; and in Figure 6 the rod is prismatic.

page_text: The manner of making the perforated charge, I consider immaterial, but it may
be stated that the rod is in some instances formed by pressing the material while in
a more or less plastic condition through a suitably shaped die, such rod being then
perforated with the transverse holes and cut into suitable lengths. In other
instances the explosive material is rolled into sheets, the holes either being molded
in the sheets or formed therein by suitable perforators and the sheet cut into strips
of a size adapted to form a charge.
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. An explosive charge in the form of a rod or a plurality of strips having
parallel or nearly parallel perforations extending at right angles to or transversely
across the longitudinal axis thereof, for the purposes specified.
2. An explosive rod or strip perforated transversely to cr across its longitudinal
axis so that a substantially uniform thickness of explosive material exists between
the perforations throughout their length in a direction at right angles to the
perforations and transverse to the longitudinal axis of the rod or strip for the
purposes specified.
3. A charge or cartridge consisting of or containing an explosive in the form of
a rod or strips having parallel perforations extending at right angles to or trans-
versely across the greatest length or axis thereof, the perforations in the adjacent
series alternating with each other, as and for the purposes set forth.
4. A charge or cartridge consisting of or containing explosive material in the
form of a longitudinal rod or rods or strips each having a plurality of transverse
parallel perforations, which when the charge or cartridge is inserted in the bore
of a gun the said perforations will extend in a direction at right angles to the
longitudinal axis of the bore.
Dated this 9th day of October 1805
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.