A NEW OR IMPROVED PERCUSSION CAR
Year: 1854

page_text: LETTERS PATENT to Charles Clarke Armstrong, of Birmingham, in the
County of Warwick, Manufacturer, and William Pursall, of Birming-
ham aforesaid, Manufacturer, for the Invention of "A NEW OR IMPROVED
PERCUSSION CAR"
Sealed the 19th May 1854, and dated the 23rd January 1854.
PROVISIONAL SPECIFICATION left by the said Charles Clarke Armstrong
and William Pursall at the Office of the Commissioners of Patents,
with their Petition, on the 23rd January 1854.
We, CHARLES CLARKE ARMSTRONG, of Birmingham, in the County of
Warwick, Manufacturer, and WILLIAM PURSALL, of Birmingham aforesaid,
Manufacturer, do hereby declare the nature of the said Invention for "A NEW
OR IMPROVED PERCUSSION CAP" to be as follows:-
Our said Invention consists of a waterproof percussion cap constructed in
the following manner :-Figure 1 of the accompanying Drawing represents
our Invention in elevation; Figure 2 represents the same in vertical section ;
and Figure 3 represents a portion of the same in vertical section. It consists
of two shelves or caps a, b, see Figure 2, situated one within the other; the
inner one 6 (shown separately in the section, Figure 3) has a cup-like
depression c at its top, in which the detonating composition is put. The two
shells or caps a, b, are raised together by a stamp in the manner in which the
ordinary percussion cap is raised, excepting that the two blanks of which the
shells a, b, are formed are used instead of one blank, the blank of which

page_text: the shell is made having previously had the depression c made therein, and
the said depression filled with the detonating composition; the edges of the cap
are ground in the ordinary manner, by which means the said edges become so
closely united as to make the whole water-tight. During the grinding of the
edge of the cap a portion of the cutting or grinding tool enters the cup, and
grinds or reduces the thickness of the lowest point of the depression c. When
the cap, Figure 2, is placed upon the nipple of a gun, or other fire-arm, and
struck by the hammer of the same, the detonating composition explodes, and
bursts the depression c at its thinnest part, that is to say, immediately over the
whole in the nipple, and fires the powder in the said gun or other fire-arm.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Clarke Armstrong and William Pursall in the Great
Seal Patent Office on the 21st July 1854..
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, CHARLES
CLARKE ARMSTRONG, of Birmingham, in the County of Warwick, Manufac-
turer, and WILLIAM PURSALL, of Birmingham aforesaid, Manufacturer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of January, in the year of our
Lord One thousand eight hundred and fifty-four, in the seventeenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said Charles Clarke Armstrong and William Pursall, Her special licence
that we, the said Charles Clarke Armstrong and William Pursall, our exe-
cutors, administrators, and assigns, or such others as we, the said Charles
Clarke Armstrong and William Pursall, our exccutors, 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 "A NEW OR IMPROVED PERCUSSION CAP," upon the condition
(amongst others) that we, the said Charles Clarke Armstrong and William
Pursall, by an instrument in writing under our hands and seals, or under the
hand and seal of one of us, should particularly describe and ascertain the

page_text: 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.
NOW KNOW YE, that we, the said Charles Clarke Armstrong and William
Pursall, do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, that is to say:-
b
Our said Invention consists of a percussion cap in which the detonating
powder is confined between two plates or sheets of metal, whereby the said
powder is secured from moisture and from the accidents to which the unde-
fended detonating powder is exposed in the ordinary percussion cap. Figure 1
represents in vertical section a percussion cap constructed according to one
method of carrying our Invention into effect, and Figure 2 represents in vertical
section a percussion cap constructed according to another method of carrying
our Invention into effect. The percussion cap, Figure 1, consists of two shells
or caps a, b, one of the said caps 6 being situated within the other cap a, and
constituting a lining thereto. The inner cap b has a cup-like projection c, in
which the detonating powder is contained. The percussion cap constructed
according to the method illustrated in Figure 2 differs from that represented
in Figure 1 in the absence of the projection c in the cap b, Figure 1, the per-
cussion powder in the cap, Figure 2, being contained in the space & between
the two flat closed ends of the caps or shells of which the percussion cap is
composed. We carry our Invention into effect in the following manner :-
We take a blank or piece of sheet metal of either of the forms represented
in Figures 3, 4, and 5, but we prefer to use a blank of the form Figure 5
for the outer cap, and a blank of the form of Figure 3 for the inner; but we
sometimes make both the inner and outer caps of blanks of the form of
Figure 3, and sometimes of blanks of the form of Figure 5. We press or
raise the said blank by means of ordinary pressing machinery into either of
the forms represented in Figures 6, 7, and 8, that is to say, if we wish to
make a percussion cap of the form represented in Figure 1, we give the blank
the form represented in Figure 8; and if we wish to make a percussion cap
of the form represented in Figure 2, we give the blank either of the forms
represented in Figures 6 and 7. We then introduce the percussion powder
into the said blanks, by dropping it into the bottoms of the cones or cups,
Figures 6 and 7, or into the depression in the middle of the blank, Figure 8.
We then take a second flat blank, and combine it with one of the partially
raised and charged blanks, Figures 6, 7 and 8, in the manner illustrated in
the sections, Figures 9 and 10. In making the percussion cap, Figure 1, we

page_text: place the partially raised and charged blank, Figure 8, upon the second flat
blank in the manner shewn in Figure 10; and in making the percussion cap,
Figure 2, we place a second or plain blank upon the partially raised and
charged blanks, Figures 6 and 7, in the manner shewn in Figure 9. We
then subject the pair of blanks Figure 9, or the pair Figure 10, to the action
of a press such as is represented partly in section in Figure 11, which said
press resembles in all essential respects the press ordinarily used for raising or
pressing percussion caps. The pair of blanks, Figure 10, is placed upon the
die e, Figure 11, as represented, and by the descent of the plunger f the said
pair of blanks is raised into a percussion cap of the kind represented in
Figure 1. Or if the pair of blanks, Figure 9, be placed upon the die e of
the press, Figure 11, the said pair of blanks may be raised by the descent of
the plunger finto a percussion cap of the kind represented in Figure 2.
The edges of the double or compound cap are ground in the way in which
the edges of ordinary percussion caps are ground. When, however, we carry
our Invention into effect in the manner described with reference to Figure 1,
we sometimes construct the grinding tool so that it may enter the cap and
grind the most prominent point of the projection c, in order that when the
percussion cap is placed on the nipple of a gun or fire-arm, and struck by the
hammer of the same, or otherwise made to detonate, the explosion may burst
the part of the prejection c which has been ground, that is to say, the part
immediately over the hole in the nipple. Figure 12 represents in vertical
section a grinding tool of the shape proper to effect the grinding of the edges
of the cap and the internal projection; a percussion cap is represented upon
the said tool. The said grinding of the depression c, Figure 1, is only neces-
sary or desirable when the interior shell or cap b is made of strong sheet
metal. Although we prefer to grind the projection c when the inner cap or
lining is made of sheet metal as thick as that which is usually employed in
the manufacture of percussion caps, yet we wish it to be distinctly understood
that we do not consider the said grinding indispensably necessary, as percus-
sion caps made according to the method described with reference to Figure 1,
and in which the projection c is not ground, answer very well in practice,
although we believe that by thinning the said depression the action of the
percussion cap becomes somewhat more certain. Where the inner cap or shell
v is made of metal so thin as to be ruptured with a slight force, we do not
attempt to reduce the thinness further by grinding. In raising the projection c,
Figure 2, in the blank which forms the inner cap or lining, we sometimes so
form the pressing or raising tools so as to make the said projection so thin at its
most prominent point as not to require the grinding described. In making

page_text: the percussion cap, Figure 2, the blank which forms the outer cap is first
partially raised, and charged with the percussion powder (see Figures 6 and 7),
and the blank which forms the inner cap or lining, requiring no preparation
before raising, the metal of which the said blank for the inner cap is made
may be much thinner than that of which the outer cap is made.
Having now described the nature of our said Invention, and the manner of
performing the same, we wish it to be understood that we do not limit our-
selves to the precise methods of carrying our Invention into effect herein
described, as the same may be varied without departing from the nature of
our said Invention; for example, we do not limit ourselves to the use of any
particular metal or alloy in carrying our Invention into effect, neither do we
confine ourselves to the use of sheet metal of any particular strength; and
although we prefer to make the inner cap or lining of thinner metal than the
outer cap, yet we do not limit ourselves thereto; neither do we confine
ourselves to the use of the same metal in constructing both the inner and
outer caps, as the inner cap may be made of a metal softer than could be
properly used for the outer cap. But we claim as our Invention a percussion
cap in which the detonating powder is enclosed between two caps, or between
a cap and a lining, so that the said detonating powder may be defended from
moisture, and from the injuries to which undefended detonating powder is
exposed, as herein described, and represented in the accompanying Drawing.
In witness whereof, we, the said Charles Clarke Armstrong and William
Pursall, have hereunto set our hands and seals, this Twentieth day of
July, in the year of our Lord One thousand eight hundred and
fifty-four.
CHARLES CLARKE ARMSTRONG. (L.S.)
WILLIAM PURSALL.
(L.S.)
Witness,
GEORGE SHAW.