IM- PROVEMENTS IN THE MANUFACTURE OF GUNPOWDER, AND IN THE MACHINERY CONNECTED THEREWITH
Year: 1857

page_text: LETTERS PATENT to Thomas William Willett, of 89, Chancery Lane, in
the County of Middlesex, Civil Engineer, for the Invention, of "IM-
PROVEMENTS IN THE MANUFACTURE OF GUNPOWDER, AND IN THE MACHINERY
CONNECTED THEREWITH."
Sealed the 23rd April 1858, and dated the 8th December 1857.
PROVISIONAL SPECIFICATION left by the said Thomas William Willett
at the Office of the Commissioners of Patents, with his Petition, on the
8th December 1857.
I, THOMAS WILLIAM WILLETT, of 89, Chancery Lane, in the County of
Middlesex, Civil Engineer, de hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MANUFACTURE OF GUNPOWDEE, AND IN THE MACHINERY
CONNECTED THEREWITH," to be as follows:-
This Invention consists, first, in so constructing incorporating gunpowder
mills that the beds thereof shall rotate about a vertical axis while the hori-
zontal axis of the edge runners shall have no other motion than in a vertical
plane, and its motion in such vertical plane so determine that it shall not
approach within a given distance of the bed
of the mills, which is thus
secured from all risk of contact with the edge runners and from the con-
sequent danger of explosion. Further, for the more safe and ready dischargo
for "IMPROVEMENTS IN THE MANUFACTURE OF GUNPOWDEE, AND IN THE MACHINERY
CONNECTED THEREWITH," to be as follows:-
This Invention consists, first, in so constructing incorporating gunpowder
mills that the beds thereof shall rotate about a vertical axis while the hori-
zontal axis of the edge runners shall have no other motion than in a vertical
plane, and its motion in such vertical plane so determine that it shall not
approach within a given distance of the bed of the mills, which is thus
secured from all risk of contact with the edge runners and from the con-
sequent danger of explosion. Further, for the more safe and ready dischargo

page_text: and recharging of the mill, I so construct it that the mill man can at will
raise the axis of the edge runners yet further from the mill bed, and so to
move them entirely from all contact with the charge thereon.
Secondly, in a new form of press cake. The plates now used to separate
the meal which is in the press box into Inyers have smooth and even surfaces,
and the press cake has therefore a corresponding even surface. Now this part
of my Invention consists in constructing these plates with small ridges pro-
jecting from their surfaces; these ridges produce in the press cake small corre-
sponding indentations. The press cake so made very readily breaks at these
indentations, and is consequently more easily granulated.
Thirdly, in a new arrangement for mixing the saltpetre with the charcoal
previous to mixing these ingredients with the sulphur, and subjecting them to
the action of the incorporating gunpowder mill. For this purpose I employ
a drum-shaped vessel heated externally by steam, and I so construct it that it
can be made to rotate rapidly about its horizontal axis. This vessel has a
suitable cover by which it can be made steam-tight. Into this vessel the salt-
petre and charcoal, in their proper proportions. are introduced with a number
of copper and hard wood balls, and to these is then added a limited quantity
of pure distilled water. The cover is now applied, the vessel heated, and
caused to rotate rapidly upon its axis. This is continued for about half an
hour, when the heat is withdrawn, but the rotary motion is continued till the
vessel and its contents have cooled to about 60° Fah', when the cover may be
removed and the charge withdrawn to be mixed with its proper quantity of
sulphur and worked in the incorporating gunpowder mill.
Fourthly, in mixing saltpetre in a state of solution with charcoal. For this
purpose a common open copper may be used. The saltpetre is first dissolved
by heat in as small a quantity of water as is sufficient for that purpose, and
in that state is added to the charcoal, which has been previously pulverized
and placed in some suitable vessel. The mixture is then stirred well together
and the required proportion of sulphur is added after the mixture has cooled
below 60° of Fah. In the several existing methods where saltpetre in a
state of solution is used in the manufacture of gunpowder the hot solution is
mixed simultaneously with the charcoal and sulphur, and the heat of the
solution believe to act very injuriously upon the sulphur by softening &
toughening it, and in some cases causing the particles previously separated by
grinding to cohere and unite, to avoid which injurious effect on the sulphur
is the object of this fourth part of my Invention.
Fifthly, in a new form of granulating machine. In the present ordinary
machine the press cake is caused to pass between one or more pairs of

page_text: parallel rollers with projecting teeth as is well understood. The objection to
this machine lies in the large proportion of dust made by it, for the teeth of
the rollers so hold the press cake that it is partly broken and partly crushed
by them. Now, in my improved machine the press cake is supported upon
a table having parallel metal ridges, and while so supported it is subjected to
the downward pressure of one or more parallel ridges, and I so determine the
position of these downward pressing ridges that each lies evenly between
some adjacent pair of supporting ridges. When, therefore, pressure is
applied to the downward acting ridges, the press cake is broken with a clear
and even fracture, and but a small portion of the press cake is made into
dust.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas William Willett in the Great Seal Patent Office on
the 7th June 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
WILLIAM WILLETT, of 89, Chancery Lane, in the County of Middlesex, Civil
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of December, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Thomas William Willett, Her special licence, that I, the said Thomas
William Willett, my executors, administrators, and assigns, or such others
as I, the said Thomas William Willett, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time and
at all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF GUNPOWDER, AND IN THE MACHINERY
CONNECTED THEREWITH," upon the condition (amongst others) that I, the said
Thomas William Willett, my executors or administrators. by an instrument in
writing under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Thomas William Willett, do hereby
declare the nature of my said invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement and accompanying Drawings (that is to say):-
This Invention consists, first, in so constructing incorporating gunpowder
mills that the beds thereof shall rotate about a vertical axis while the hori-
zontal axis of the edge runners shall have no other motion than in a vertical
plane, and its motion in such vertical plane I so determine that it shall not
approach within a given distance of the bed of mill, which is thus
secured from all risk of contact with the edge runners and from the con-
sequent danger of explosion. Further, for the more safe and ready discharge
and recharging of the mill, so construct it that the mill man can at will
raise the axis of the edge runners yet further from the mill bed, and so remove
them entirely from all contact with the charge thereon. This part of my
Invention will be more clearly understood by reference to the Drawings here-
unto annexed, in which Figures 1, 2, and 3 represent portions of an incorporat-
ing gunpowder mill of this construction. In all these Figures the same letters
denote corresponding parts. A is the revolving bed supported by the vertical
shaft B, which revolves in the footing C, and is driven by the wheel D. This
bed is retained in a horizontal position by four friction rollers attached to the
framing E. These friction rollers take their bearings upon that part of the
mitt bed marked a, and their general position and arrangement will be at once
understood by reference to Fig. 3, in which E, E, E, E', are the friction
rollers. These rollers and all supporting and driving gearing are placed below
a simple water joint F. and are thus protected from the powder. G. G, are
the edge runners revolving upon the shaft g. g, which at its
extremities is fixed by the keys h, h, to two square brass blocks II, H.
These blocks have a vertical motion only in the standards J, J. and that
motion is restricted as to its downward limit by two stops K, K. which are
30 constructed as to allow the edge runners to approach only within a fixed
distance (by preference one quarter of an inch) of the mill bed, but not to
touch it. The advantages of this construction over the mills commonly
employed in this manufacture are, first, that as the runners cannot touch the
bed, the mill is far less liable to explosions; secondly, that as the edge runner
shafts may all be placed in one line (where several mills are placed near to
each other) and the edge rummers themselves therefore in parallel planes, in the
event of an explosion of one mill of the series it is far less liable to spread to
those adjacent to it, for the runners themselves will form to a, great extent
a protecting barrier to the force of the explosion; also, in the event of an

page_text: explosion, the risk to the mill man is greatly lessened, as he can attend to his
charge, and yet be to a great extent protected by the fixed position of the
edge runners. 0, 0, are two small hydraulic rams supplied by the pipes P, P,
which are connected with the same force pump; when, therefore, the mill
man requires to remove his charge from the mill, he by means of this pump
can at once raise the edge runners from all contact with the charge, when
they will cease to revolve, and by the application of a proper wooden scoop to
the still revolving mill bed the entire charge may be vary easily and quickly
removed. A fresh charge in like manner can be quickly and easily supplied
to the mill bed, and arranged thereon with great evenness and regularity;
after this has been done the edge runners may be allowed gradually and
gently to descend upon the charge. The ploughs R, R, in this mill are held
by a plough beam S, which is supported upon the standards T, T.
The second part of my Invention consists in a new form of press cake.
The plates now used to separate the meal which is in the press box into layers
have smooth and even surfaces, and the press cake has therefore a corre-
sponding even surface. Now, this part of my Invention consists in construct-
ing these plates with small ridges projecting from their surfaces; these ridges
produce in the press cake small corresponding indentations, and the press
cake so made very readily breaks at these indentations, and is consequently
more easily granulated. This second part of my Invention will be more
clearly understood by reference to the Drawings hereunto annexed, in which
Fig. 4 is a section, and Fig. 5 an elevation, of a portion of a plate of this con-
struction. A, A, are the small ridges upon its surface, by preference of a V
form, as here shown. The size and distance apart of these ridges may with
advantage be varied to suit the thickness of the press cake employed, but 1
prefer for general use, with half-inch press cake, that these ridges should be
placed at about three-quarters of an inch apart, and that they should project
from the surface of the plate rather less than one-eighth of an inch.
The third part of my Invention consists in a new arrangement of apparatus
for mixing the saltpetre with the charcoal previous to mixing these ingre-
dients with the sulpher, and subjecting them to the action of the incorporating
gunpowder mills. For this purpose I employ a drum-shaped vessel (by pre-
ference about four feet long and two feet six inches in diameter. This is
heated by a steam jacket, as is well understood, and it is so constructed that
it can be made to rotate rapidly about a horizontal axis. This vessel has (by
preference upon the side of it) a suitable cover, by which it can be made steam-
tight. Into this vessel the saltpetre and charcoal in their proper proportions
are introduced with a number of copper and hard wood balls (by preference

page_text: from three-quarters to one inch in diameter,) and to these a limited quantity of
distilled water is then added; the cover is now applied, and the vessel heated
to about 220° Fahrenheit or thereabouts, it is at the same time caused to
rotate rapidly upon its axis. This process is continued for about half an hour
when the heat is withdrawn, but the rotary motion is continued till the vessel
and its contents have cooled to about 60° Fahrenheit, when the cover may be
removed and the charge withdrawn to be mixed with its proper proportion of
sulphur, and worked in the incorporating gunpowder mill. It will be obvious
that by this apparatus the sulphur might at the same time be mixed with the
saltpetre and the charcoal, but I prefer to employ it for the mixture of charcoal
and saltpetre only.
The fourth part of my Invention consists in mixing saltpetre in a state of
solution with charcoal. For this purpose a common open copper may be
used. The saltpetre is first dissolved by heat in as small a quantity of water
as is sufficient for that purpose, and in that state is added to the charcoal,
which has been previously pulverized and placed in some suitable vessel; the
mixture is then stirred well together, and the required proportion of sulphur
is added after the mixture has cooled below 60° of Fahrenheit. In the
several existing methods where saltpetre in a state of solution is used in the
manufacture of gunpowder. the hot solution is mixed simultaneously with the
charcoal and sulphur, and the heat of the solution I believe to
act very injuriously upon the sulphur by softening and toughoning it. and in
some cases causing the particles previously separated by grinding to cohere and
unite, to avoid which very injurious effect upon the sulphur is the object of
this fourth part of my Invention. A very ready method for the solution' of the
saltpetre employed in this part of my Invention consists in the direct action
of a jet or jets of steam to the saltpetre either before or after mixing it
with the charcoal. A covered vessel may be employed for this purpose
but a simple open vessel will practically be found very suflicient for the
purpose.
The fifth & last part of my Invention consists in a new form of granu-
lating machine. In the present ordinary machine employed for this purpose
the press cake is caused to pass between one or more pairs of parallel rollers
with projecting teeth, as is well understood. The great objection to this
machine lies in the large proportion of dust made by it, for the toothed
rollers so hold the press cake that it is partly broken and partly crushed by
them. Now, in ny improved granulating machine the press cake is sup-
ported upon a table constructed of parallel metal ridges, and while sa
supported it is subjected to the downward pressure of one or more parallel

page_text: ridges, and I so determine the position of these downward pressing ridges,
that each lies evenly between some adjacent pair of supporting ridges. When,
therefore, pressure is applied to the down-pressing ridges the press cake is
broken with a clear and even fracture, and but a small proportion of press
cake will be made into dust.
This fifth part of my Invention will be more clearly understood by reference
to the Drawings hereunto annexed, in which Figs. 6 and 7 represent portions
of a granulating machine of this construction.
T .
A, A, are the metal ridges forming the table which immediately sup-
ports the press cake to be granulated. The construction of these ridges
will be more clearly seen by reference to Fig. 7, in which these ridges
are shewn in section. These metal ridges are firmly fixed upon strong and
suitable wooden framing B, on which they are placed at an inclination
sufficient to cause the press cake which may be placed thereon to slide freely
upon their surfaces; C is a table (by preference of wood) covered with copper,
and placed at the same inclination as the metal ridges A. The press cake
may be supplied to this table C from a hopper and endless band, as will bo
well understood. The stop-board D is for the purpose of correcting any
irregularity in the position of the press cake as it passes on to the ridges A,
and also for stopping the passage of a fresh supply of press cake while that
which has been broken is being discharged. E, E, are the pressing ridges;
F1, a second stop-board to prevent the press cake from sliding off the sup-
porting ridges before it has been broken by the downward pressing ridges E,
which are secured to the frame F, which moves upon the joint f, and the
downward motion of this frame is caused by the connecting rod G, which
communicates with a crank H working in the box I, which is filled with oil
above the level of the crank II. I prefer to make both the ridges A and E
of copper, and (by preference) of the form shewn in Figure 7, and for half-
inch press cake I prefer to make the distance of the parallel ridges of both
A and E about three-quarters of an inch apart, and the distance of the surface
of the supporting ridges from the surface of the downward pressing ridges
about three-eighths of an inch apart. The action of this machine is very
simple. The press cake being supplied, as before stated, to the table C,
passes by its own gravity to the supporting ridges A, upon which it is retained
by the second stop board F¹; the other stop board D is then closed to check
any further supply, and by means of the crank H the upper ridges E are
brought gradually down upon the charge, which is thus broken and yet but
very little crushed, and as the ridges E rise from the charge the greater

page_text: portion of it will slide from the ridges A into the bin J as soon as the stop-
board F has been removed, a small portion will also pass between the ridges
A into the second bin L. After the press cake has been this broken, the
granulation may with advantage be completed by the ordinary granulating
machines now in use.
In witness whereof, I, the said Thomas William Willett, have hereunto
set my hand and seal, this Fourth day of June, in the year of our Lord
One thousand eight hundred and fifty-eight.
THOMAS WILLIAM WILLETT. (L.S.)