AN IMPROVED BOMB; SHELL
Year: 1855

page_text: LETTERS PATENT to Sylvanus Sawyer, of the State of Massachusetts, of
the United States of America, for the Invention of "AN IMPROVED BOMB;
SHELL."
Sealed the 4th March 1856, and dated the 26th December 1855.
PROVISIONAL SPECIFICATION left by the said Sylvanus Sawyer at the
Office of the Commissioners of Patents, with his Petition, on the 26th,
December 1855.
I, SYLVANUS SAWYER, of the State of Massachusetts, of the United States
of America, do hereby declare the nature of the said Invention of "Ax
IMPROVED BOMB SHELL" to be described and represented in the following
Specification and the accompanying Drawings, of which Figure 1 denotes a
side elevation of the same; Figure 2, a top view of it; Figure 3, a bottom
view of it; Figure 4, a central and longitudinal section of it; Figure 5, a
transverse and horizontal section of it.
The said projectile is intended to be discharged from a cannon or howitzer,
provided with helical grooves in its bore, essentially like those in a rifle; the
projectile being made with wings or guides to enter such grooves, and so far
therein, that during the discharge of the piece the grooves may impart to the
shell a whirling or rotary motion on its axis, which shall be maintained during
its flight or course towards the object to which it may be directed.

page_text: In applying to the external surfaces of conical or cylindro-conical shells
lead, when such shells have been made of cast iron, it has been customary to
cast the lead on the cylindrical surface of the shell, or that part of it which,
during its passage through the bore of the gun, would be likely to rub against
the same, the lead or soft metal having been applied as a protection to the gun,
or as a means of not only preventing that wear or tear of it which would result
were the iron surface of the shell to be allowed to come in contact with the
inside surface of the bore, but the bursting of the gun, which is liable to
follow, from the choking of it by the shell, when such friction or tearing of the
bore is produced. Under these circumstances it has been found, that, owing to
the rapid passage of flame over the surface of the lead during the movement
of the shell through the bore, such lead will be instantaneously ripped or melted
off the shell, and consequently rendered useless for the purpose for which it
was applied thereto. I have endeavoured to make a shell in such manner as
to stop the passage of the flame by it, or prevent it from tearing or melting off
the antifriction metal. For this purpose I.so construct the shell and apply
the antifriction metal thereto; 'that the force of the explosion acting in con-
junction with the hard metal at the butt or rear end of the shell shäll expand a
portion of such antifriction metal, so as to firmly press it against the .inner
surface of the bore of the piece, and cut off the passage of the flame by the
shell or its leaden or antifriction coating.
Furthermore, in order to fasten the antifriction metal firmly to the cast-iron
shell or body, I first coat the latter with tin, or some metal which will have a
stronger affinity for the cast iron and the lead or antifriction metal than the
latter has for the iron. This done, I cast on and around the metallic coating
so applied the coating or case of lead or antifriction metal; I also form the
rear part of the iron case or shell frustro-conical or tapering, and apply to such
an extra thickness of antifriction metal, which, when an explosion of the
charge of the gun takes place, shall force or crowd the surplus antifriction
metal up the conical or tapering surface joining the cylindrical body of the
shell, the said surface serving to expand the ring of metal on it, an cause it to
fit closely to the bore of the gun, and so as to prevent windage and the passage
of flame by such ring to such extent as to tear or melt the antifriction metal
in advance of the ring.
Besides the above, I extend the antifriction metal beyond and around the
screw plug of the shell, and screw into it the explosive cap of the shell,
arranging such cap directly over the screw plug, and so that when the shell
is thrown against an obstacle point first, its momentum shall compress the
antifriction or soft metal, so as to cause it to give way and let the explosive cap

page_text: with force down, so as to compress the percussion wafer or priming arranged on
top of the screw plug, or in the explosive cap, as the case may be
In the Drawings, A shows the hollow cast-iron body of the shell, which, when
the projectile is used, is, to charged with powder or other proper.material or
inaterials, such body, generally speaking, being formed cylindro-conical, and
provided with a screw plug B,.and a series of.. helical wings E,.E..E..E, E, E,
arranged as seen in the several Figures; C exhibits the covering. of: tin;
while D shows the coating of lead or antifriction metal, it being extended up
above and around the screw plug B, and provided with female screw, as seen
'at'd, d, in Figures 1, 2, and 4, such screw serving to receive a male.screw e, e,
formed, on the explosive cap F. The said cap F constitutes a cover. to the
screw plug B, which is provided with one or more vent holes f,f, leading.down
through it. Above the top of the said plug, and between it and the cap F,
or in the latter, the percussion priming or wafer is to be placed. Under.
all ordinary circumstances, the compressible antifriction metal sustaining the
screw cap.
F will prevent it from being forced down upon the priming, the cap
being formed with a shoulder h, h, to rest on the metal.
When the shell is forced from the gun, the cap first comes in contact with
the object-fired at, and by such, and the force or momentum of its flight, will
be driven down, so as to compress the percussion -priming, and to cause an
explosion of it, the holding metal yielding under the force of the impingement
of the shell, and suffering the explosive cap to so act. The wings E, as well
as the body of the shell, are to be coated with the tin and antifriction metal,
which should also extend over the butt or rear end of the shell, and its
tapering part 'a, a, as seen at b, b, in Figure 4.. Previous to inserting the shell
in the piece of ordnance, a patch or cloth hood or bag may be drawn over it
partially or wholly, so as to separate its sides from the inside surface of the bore.
A shell constructed on the above plan has been found, exceedingly effective
in preventing friction and wear of the gun; and the consequent choking and
bursting of it, which might ensue, besides being of great advantage so far as
saving of ammunition is concerned.
At b, b, Figure 4, I have exhibited the annulus of lead or soft inetal
extending around the tapering or conical part a, a, of the cast-iron body of
the shell. When the explosion of the charge of the gun takes place, this
annulus will be driven up the tapering part a, a, and expanded thereby, and
so as to produce effects as stated.
I claim, combining with the butt or flat rear end of the cylindro-conical iron
shell a layer of lead, or softer metal than that of which the body of the shell
is composed, and 'united or not to a layer of such metal extended around the

page_text: sides of the shell as described, the same operating in manner as specified
while the shell is being projected through the bore of a gun by a discharge of
the powder therein.
I also claim, making the rear part of the shell tapèring or conical, as seen
at a, a, combining therewith a ring or annulus b, b, of lead, or its equivalent,
the same being substantially in manner and for the purpose as herein-before
specified.
I also claim, confining the explosive screw cap to the body of the shell by
means of a softer or yielding metal or casing, which, when the cap or shell
.shall strike an object, shall give away under the force of the blow, and let the
cap down with force, so as to compress the percussion wafer or priming in it,
or on the main screw stopper or plug, and so as to create an explosion thereof,
.as stated.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Sylvanus Sawyer in the Great Seal Patent Office on the
28th April 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SYLVANUS
SAWYER, of the State of Massachusetts, of the United States of America, send
:greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of December, A.D. 1855, in the
nineteenth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Sylvanus Sawyer, Her special license that I, the
said Sylvanus Sawyer, my executors, administrators, and assigns, or such
others as I, the said Sylvanus Sawyer, 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
of "AN IMPROVED BOMB SHELL," upon the condition (amongst others) that I,
the said Sylvanus Sawyer, by an instrument in writing under my hand and
.seal, should particularly describe & ascertain the nature of the said Inven-
tion, 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 I, the said Sylvanus Sawyer, do hereby declare
the nature of iny said Invention, and in what manner the same is to be per-

page_text: formed, to be fully described and ascertained in and by the following Speci-
fication and the accompanying Drawings, of which Figure 1 denotes a side
elevation of the same; Figure 2, a top of it; Figure 3, a bottom view of it;
Figure 4, a central and longitudinal section of it; Figure 5, a transverse or
horizontal section of it.
:
The said projectile is intended to be discharged from a cannon, mortar, or
howitzer provided with helical grooves in its bore, essentially like those of a
rifle; the projectile being made with wings or guides to enter such grooves,
and so far therein, that during the discharge of the piece the grooves may
impart to the shell a whirling or rotary motion on its axis, which shall be
maintained during its flight or course toward the object to which it may be
directed.
.
In applying to the external surface of a conical or cylindro-conical shell
lead or a soft metal, when such shell has been made of cast iron, it has been
customary to cast the lead on the cylindrical surface of the shell, or that part
of it which during its passage through the bore of the gun would be likely to
rub against the same, the lead or soft metal having been applied as a protec
tion to the gun, or as a means of preventing that wear of it which would
result were the iron surface of the shell to be allowed to come in contact
with the inside surface of the bore. Under these circumstances it has been
found, that, owing to the rapid passage of the flame over the lead during the
movement of the shell through the bore, such lead will be instantaneously
ripped or melted off the shell, and consequently rendered useless for the
purpose for which it was applied thereto. I have endeavored to make a shell
in such manner as to stop the passage of flame by it, or prevent it from tearing
or melting off the antifriction metal. For this purpose I so construct the
shell and apply the antifriction metal thereto, that the force of the explosion
acting in conjunction with the hard metal at the but or rear end of the shell
shall expand a portion of such antifriction metal, so as to press it firmly
against the inner surface of the bore of the piece, and cut off the passage
of the flame by the shell, or to the remainder of its leaden or antifriction
coating.
Furthermore, in order to fasten the antifriction metal to the cast-iron
shell or body, I first coat the latter with tin, or some metal which will
have a stronger affinity for the cast iron and antifriction metal than the
latter has for the iron. This done, I cast on and around the metallic
coating so applied the coating or case of lead or antifriction metal.
I also form the rear part of the iron case of the shell frustro-conical or
tapering, and apply to such an extra thickness of antifriction metal, which,

page_text: when' an explosion of the charge of the gun'takes place, shall force or crowd
tlie surplus antifriction metal up the conical or tapering surface joining the
cylindrical body of the shell; the said surface serving to expand the ring of
metal on it, and cause it to fit closely to the bore of the gun, and so as to
prevent windage and the passage of the flame by such ring to such extent
as to tear or melt off the antifriction metal in advance of the ring: Besides
the 'above, I extend the antifriction metal beyond and around the screw plug
of the shell, and screw into it the explosive cap of the shell, arranging such
'cap' directly over the screw plug, and so that when the shell is thrown against
an obstacle point first, its momentum shall compress the antifriction or soft
metal, so as to cause it to give way, and let the explosive cap with force down
upon the percussion wafer or priming arranged on top of the screw plug or
in the cap F.
In the Drawings, A shows the hollow cast-iron body of the shell, which,
when the projectile is used, is to be loaded or charged with powder or other
'proper material or materials, such body, generally speaking, being formed
cylindro conical, and provided with a screw plug B, and a series of helical
wings E, E, E, E, E, arranged as seen in the several Figures; C exhibits
the covering of tin, while D shows the external coating of lead or antifriction
metal, it being extended upward above and around the screw plug B, and pro-
'vided with a female screw, as seen at d, d, in Figures 1, 2, and 4, such screw
serving to receive a male screw e, e, formed in the explosive cap F. The
'said 'cap OF constitutes a cover to the screw plug B, which is provided with
one or more touch-holes f, f, leading down through it. On the top of the
said plug or in the cap F the percussion priming or wafer is to be placed.
Under all ordinary circumstances, the compressible antifriction metal sus
taining the cap F will retain it from being forced down upon the priming,
the cap F being formed with a shoulder h, h, to rest on the metal.
When the shell is fired from a gun, the cap first comes in contact with the
object fired at, and by such, and the momentum or force of its flight, will
be driven down upon the percussion priming, so as to cause an explosion
of it, the holding metal yielding under the force of the impingement of the
'shell, and suffering the explosive cap to so act. The wings E as well as the
body of the shell are to be coated with the tin and antifriction metal, which
should also extend over the but or rear end of the body of the shell, and
its tapering part a, a, as seen at b, b, in Figure 3. Previous to inserting the
shell in the piece of ordnance, a patch or cloth hood or bag may be drawn
over it partially or wholly, so as to separate its sides from the inside surface of
the bore. A shell constructed on the above plan has been found exceedingly

page_text: effective in preventing wear of the gun, besides being of great advantage so
far as saving of ammunition is concerned.
At b, b, in Figure 4, I have exhibited the annulus of lead or soft metal
extending around the tapering or conical part a, a, of the cast-iron body of the
shell. When the explosion of the charge of the gun takes place, this annulus
will be driven up. the tapering part a, a, and expanded thereby, and so as
to produce effects as stated.
I claim, combining with the but or flat rear end of the cylindro-conical iron
shell a layer of lead, or metal softer than that of which the body of the shell
is composed, and united or not to a layer of such metal extended around the
sides of the shell, as described, the same serving to operate in manner as
specified while the shell is being projected through the bore of the gun by a
discharge of powder therein.
I also claim, making the rear part of the shell tapering or conical, as seen
at a, a, and combining therewith a ring or annulus b, b, of lead, or its equivalent,
the same being substantially in manner and for the purpose as herein-before
specified.
I also claim, confining the explosive screw cap to the body of the shell by
means of a softer and yielding metal or casing, which, when the shell or cap
shall strike an object, shall give way under the force of the blow, and let the
cap down with force upon the percussion wafer or priming on the main screw
stopper or plug, and so as to create an explosion thereof, as stated.
In testimony whereof, I have hereunto set my signature and seal, this
Seventh day of April, One thousand eight hundred and fifty-six.
SVLVANIS SAWVED
SYLVANUS SAWYER. (L.C.)