CERTAIN IMPROVEMENTS IN FIRE-ARMS
Year: 1869

page_text: LETTERS PATENT to Sylvanus Frederick Van Choate, of Boston,
County of Suffolk, and State of Massachusetts, United States of
COMPLETE SPECIFICATION filed by the said Sylvanus Frederick Van
Choate, at the Office of the Commissioners of Patents, with his
Petition and Declaration, on the 10th April 1869, pursuant to
the 9th Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, BE IT
KNOWN, that I, SYLVANUS FREDERICK VAN CHOATE, of Boston, County
of Suffolk, and State of Massachusetts, United States of America, have
made an Invention of "CERTAIN IMPROVEMENTS IN FIRE-ARMS," and do hereby
declare the following to be a full, clear, and exact description of the
same, due reference being had to the Drawings accompanying this
Specification, and which will be herein-after duly referred to.
This Invention relates to the construction, combination, and arrange-
ment of those parts of small arms which are connected with the breech,

page_text: and with the lock of such arms as receive a loaded cartridge at and
discharge its empty shell from the breech.
In the Prussian needle gun and in the Chassepot, and others of a
similar type, the breech piece, or piece which slides in the breech frame,
to open and close at the rear the cartridge chamber, and which operates
to thrust into said chamber loaded cartridges, and to extract therefrom
the empty shells, is made cylindrical, so as to be turned to lock and
unlock in the breech frame, and contains all the lock mechanism except
the trigger and trigger spring.
In my fire-arm the breech frame may be made integral with the
barrel, though for obvious reasons of economy and convenience of con-
struction I prefer to make it separate from the barrel, which is then
screwed into the front end of the breech frame. From the end of the
barrel, which is properly bored to receive flanged metallic cartridge
shells, the breech frame is slotted to its rear, the slot opening at the
top of the frame and having straight parallel vertical sides and a
concave bottom concentric with the axis of the barrel. At the rear
of the frame the bottom of the slot is formed with a larger radius to
receive the recoil block or cam, by which the breech piece is locked and
unlocked, said breech piece being of such shape as to fill the described
slot in the breech frame, except only certain minor slots, mortises, and
recesses connected therewith which have functions which will be
described beyond.
Referring now to the Drawings:-
Figure 1 represents a longitudinal section taken in a vertical plane
through the axis of the barrel when the arm is held in position for
firing, the Figure embracing only such a portion of the arm as embodies
my Invention, and representing the breech piece a, as drawn fully to
the rear, ready to receive in the slot of the breech frame b a loaded
cartridge. Figure 2 shows a horizontal section taken in the plane of the
axis of the barrel c, and exhibits the breech piece as closing the barrel
confining the cartridge therein, and ready for the lock to force the
firing pin d against the cartridge to explode it.
The breech piece a is at its front end made with a slight cylindrical
projection, of such diameter as to enter the counterbored rear end of
the barrel which receives the cartridge flange, and the breech piece a
is bored on a line with the axis of the barrel, so as to receive the headed
cylindrical firing pin d, which is entered into its place from the rear of

page_text: the breech piece, the end of the shaft e of the recoil cam f keeping the
firing pin from undue retraction. The end of shaft e is provided with
a head g of the diameter of the breech frame, to the rear end of
which said head gives a smooth rounded finish, said head being provided
with a lever h, used to turn the recoil cam to lock and to unlock the
breech piece, and to push the same forward, and to draw it back. The
recoil cam f is shown in the detail A, and the shaft e, its head g, and
lever h, are shown in the details B and C, as well as in the general
Drawings. To lock or unlock the breech piece, rotation of the shaft e
is required to the extent of 90°, and a slot in the form of a quadrant
is formed in the plain surfaced face of the head g, terminated at each
end by a deeper indentation. In rear of the breech piece is arranged
a headed pin i, forced outward by the spring j, so as to act as a spring
catch in the indentations formed at the ends of the quadrant slot, to
prevent too great movement of the recoil cam, or any accidental change
in its position, said spring and pin also acting on the bottom of the
quadrant as a kind of friction brake. The end of shaft e is peculiarly
formed as and, for reasons to be explained beyond, in connection
with the construction and operation of the lock. In the right-hand
surface of the breech piece a a groove is formed, which in the
movements of the breech piece traverses the screw pin k, which serves
as a stop to determine the movement and to prevent accidental with-
drawal of the breech piece. On the left-hand side of the breech piece
is attached the shell extractor 1, which is made as a spring catch with
the front end bevelled and shaped as shown, so that it can, when a
cartridge is forced home ahead of the extractor end, spring aside by
contact with the rear of the cartridge shell, and spring back after
passing the flange of the shell, and catch upon its front side. The
extractor projects like a spline beyond the surface of the breech piece,
and traverses in the movements of the breech in a channel made in
the breech frame, which channel extends into the barrel for a short
distance, it being cut away to the extent necessary to allow the
bevelled end of the extractor to seize upon the cartridge flange when
forced home into the barrel. The rear end of the shell extractor is set
into a recess formed for the purpose in the breech piece, and is kept in
place by screws or steady pins, the sides of the recess into which the
extractor is set holding the extractor firmly and resisting the various
strains brought upon the breech piece in drawing and pushing and
in locking and unlocking it.

page_text: The detail D is a reversed plan of the breech piece with the recoil cam
and cam shaft removed. In the lower or convex surface of the breech
piece, and at its left-hand side, is a groove which traverses the bent
lever m, which is the shell ejector, said ejector having elevations of its
two sides shown in the details E and F, and it is also seen in red lines in
Figure 1. The arms of the bent lever are of unequal length, the front
arm being longest, and arranged so that by gravity it may incline to fall
downward, which brings the short arm into the channel marked n in
detail D. The front end of channel n terminates in an incline between
the convex surface of the breech piece and the bottom of the groove
therein, so that at the last part of the rearward motion of the breech
piece the short arm of m is depressed and the long arm is elevated, thus
throwing the withdrawn and empty shell out of the space left in the
breech frame by the withdrawal of the breech piece. The greater the
disproportion of length between the two arms of the ejector the more
forcible will be the expulsion of the empty shell, which will be thrown
to the right if the ejector be located at the left of the central vertical
plane of the gun, and vice versa, and the throw to the right or left can
also besome what modified by the shape given the long arm of the lever;
this ejector is pivoted in a recess formed in the breech frame. The
incline or bevel given to the termination of channel n at the front end
of the breech piece is made to perform another important function in
connection with the ejecting lever m, besides operating said lever to eject
the shell. If the weapon should be held in a position so that the long
arm of lever m would drop into the channel, and if the channel n
terminated abruptly at its front end, so as to form a square shoulder,
then upon drawing the breech piece back the long arm of the lever m
would catch against such shoulder, and would thus prevent the further
withdrawal of the breech piece; but by means of the incline or bevel of
the front termination of the channel the front or long arm of the ejector
lever me is forced out of the channel, thus preventing any obstruction to
the movement of the breech piece. When the long arm of the ejector m
has been made to assume a perpendicular position immediately in front
of the chamber or front end of the breech piece, it is out of the way, so
that a cartridge may be dropped into the opening in the frame in front
of the ejector beyond the front end of the breech piece, and by the for-
ward movement of the latter the long arm of the ejector is forced down
into its recess, and the cartridge is shoved forward into the chamber of
the barrel. It will be observed that by the backward movement of the

page_text: breech piece the cartridge shell, by the aid of the extractor, is drawn
back its whole length, and nearly the whole length of the movement of
the breech piece, and that the head or flange part of the shell is deposited
upon or over the forward or long arm of the ejector m, before the short
arm of the ejector is operated upon by the cam formed by the bevelled
front termination of the channel n. The cross cut or recoil seat made in
the breech picce, and seen most clearly in detail D, is the space provided
for reception of the recoil cam, there being found in the breech frame,
opposite the space occupied by the cam f, when the breech piece is
closed, spaces into which the cam can be turned to lock the breech piece
securely against recoil upon explosion of the charge. The recoil cam
being held in place on its shaft by a simple pin it will be observed that
on the removal of said pin the shaft e and firing pin may be withdrawn
from the breech piece after that is withdrawn from the breech frame
subsequent to the removal of pin k, when the interior of the barrel will
be exposed to view, and may be swabbed throughout. The rear part of
the barrel is held in place in the stock by a long screw o passing through
the guard and lock strap p, the stock q, into a tapped hole in the breech
frame, said screw operating to hold the guard and lock strap as well as
the barrel, while the rear of the frame is steadied by a dowel pin ",
fitting a washer let into the stock, which washer in practice could, when
desired, be provided with a strap made to extend down the grip part of
the stock on its upper side.
The lock may be described as consisting of the sere trigger 8, the
hammer trigger t, and the sere spring u, and the hammer or main
spring v, all attached to the guard and lock strap p, both triggers being
protected by an ordinary guard. The springs are both flat pieces of steel,
and the triggers are pivoted on pius in the guard and lock strip. There
is an intermediate piece wo introduced between the hammer trigger and
the firing pin, said piece acting to transmit to the firing pin the blow
given by the hammer trigger, and also operating in connection with the
peculiar shape given the end of shaft e, to form a safety apparatus to
prevent explosion of the cartridge, except when the breech piece is both
closed and locked. This intermediate piece 10 has elevations of both of
its sides shown in details G and H, and it is pivoted to an ear formed on
the breech frame, and moves in an opening cut through the material of
the frame. In the breech piece, just in front of the space for the recoil
cam, is cut a mortise communicating with the space containing the head
of the firing pin and the end of the cam shaft, so that when lever /

page_text: is horizontal, as in Figure 2, then the groove x in the end of shaft e is
in line with the mortise in which the piece wo moves, so that the piece o
can be forced by the trigger or trigger hammer against the firing pin
head. One side of the groove in the end of the shaft e, past which the
piece wo moves in acting on the firing pin, is marked 1 in details B
and C, and in C the sides of the piece, or of the planes in which its
sides move, are indicated by dotted lines; but as it is only when the
lever is in the position in which the breech piece is fully locked that
the path of movement of piece w is clear from obstruction by the part 1 of
shaft e, it follows that the piece w if operated by the action of the trigger
or lock, when the lever h was not quite horizontal, would strike upon
the part 1 of shaft e, and not on the firing pin, and so the cartridge
would not be exploded. To partially depress the piece w after firing,
and to bring it where its further depression will be performed by the act
of drawing back the breech piece to eject the empty shell, and afford an
opportunity to enter a loaded cartridge, the part 1 of the shaft is inclined
to its axis, and on the side of wo adjacent to the part 1 the shoulder of w,
marked 2, is also bevelled. When the said bevelled parts are brought
into contact by the rotation of shaft e, which unlocks the breech piece,
and when the breech piece is fully unlocked, the piece w has been
partially depressed, and the inclined part y of the breech piece acting on
wo, as the breech piece is drawn to the rear, still further depresses w till
its operation on the hammer is such that the sere trigger catches hold
of the hammer trigger, and the gun is thus cocked ready to be discharged
as soon as the head is closed, and the projection 1 is removed from the
path of 10 by turning down the lever h ninety degrees. The extreme
tip z of shaft e serves only to abut against the head of the firing pin to
keep it in place.
As in my Invention the weapon is cocked by the act of withdrawing
the breech piece preparatory to inserting a loaded cartridge in the barrel
it may not be necessary to discharge the piece immediately. In such
case it may be desirable to uncock the gun to relieve the tension of the
main spring, this being equivalent to letting down the hammer in
ordinary percussion muskets; this is effected by pressing one finger
upon the hammer trigger and easing or restraining its movement, while
another finger moves the sere trigger to free the hammer. To cock the
gun after the hammer has been let down, and without withdrawing the
breech piece, it is only necessary to pull strongly and steadily on the
hammer trigger.

page_text: The lock described is well calculated for use with cartridges which
have a fulminate requiring concussion for its explosion. I contemplate,
however, making use of what I term a quick fulminate, such as the
fulminate of silver, etc., which requires only pressure and not concussion
to ignite it. In such case the hammer trigger might be dispensed with,
and only a simple trigger would be needed to push forward the firing
pin. The interior end of the trigger would be modified as to shape, so as
to come into contact with the firing pin, or a suitably shaped inter-
mediate piece worked by the trigger might be employed. In this
arrangement of the lock the arm would be always ready for firing
without cocking, the fulminate being ignited by simple pressure of the
finger upon the trigger, causing the firing pin to press upon the quick
fulminate. To prevent with such a lock a premature or accidental
discharge it would be necessary to combine with the trigger a safety stop
or catch, which would have first to be designedly manipulated before the
trigger could be pulled.
The screws and screw pins, which are likely to require frequent
removal for the purpose of cleaning the gun, are made of heads or
thumb pieces, as shown in the Drawing, to obviate the use of a screw-
driver.
It will be seen that this gun consists of but comparatively few pieces,
that it is remarkably free from springs, that the parts are simple, strong,
and involve but little labor in their production, that the dismemberment
is easy for cleaning, and that all the parts can be readily got at, that the
outside of the gun is free from objectionable protuberances, and that
there are no cuts or grooves exposed, when the piece is closed, to become
foul or clogged with mud, sand, or other foreign matter.
On page 5 of this description I have mentioned that I contemplated a
modified form of my gun in regard to dispensing with the hammer and
the employment of a cartridge having, as I call it, a quick fulminate, so
that ignition of the powder may be produced by pressure of the fire pin,
or by the abrasion or punctuation of the fulminate, instead of concussion
by a stroke of a hammer or otherwise.
Figures 3 and 4 are longitudinal sectional views of my Invention,
showing the arrangement of my arın, which embodies the modification of
the weapon without a lock. In this form the breech frame b is slightly
changed from the one in Figures 3 and 4; instead of having a receiver
with perpendicular sides and open at the rear, the breech frame is cut

page_text: away on top, as indicated by dotted lines in Figure 3, and as shown at
a, a³, in Figures 4 and 6. The base of the frame at 63 is also cylindrical
instead of being cut out at the top. The breech pin is also in this case
cylindrical, and in its combination is formed most all of the breech
mechanism. The handle h of the bolt or breech pin e in Figures 3 and
4, and the locking or recoil cam f are integral, and move together. In
this form the cam fis perpendicular when the handle h is horizontal,
which is the locked position. In the former plan of breech_bolt, when
the arm is locked, the locking cam as well as the handle are both hori
zontal when the gun is held in position for firing; in the latter case the
slot at the rear of the breech frame is cut out in a perpendicular manner,
so as to allow of the withdrawal of the cam bolt, but in the former case
as in Figure 3, I desire to have the solid metal at 3 remain so as to
serve as a support to the breeeh bolt a when the latter is withdrawn, as
shown in Figure 4, for the insertion of a cartridge. The locking cam f
and handle h are made integral with the forward portion of the breech
bolt by means of a cylindrical pin f. The rear end of this pin is made
square, and fits in a corresponding mortise in the head of the part g, as
seen in Figures 3 and 4, and is secured by a nut g³, which forms a part
of the convex surface of the head of bolt e. The forward end or head i³
of the pin f³ is fitted into the thimble or sleeve piece ³, and is held
firmly by means of its shoulder j³. The head of the pin f performs
similar functions and is turned by the handle the same as shaft e, in
Figure 1, to prevent premature operation of the fire-pin by the hammer
or trigger when the breech bolt or recoil cam is in an unlocked position;
the shape of the cut in the head of the pin however is somewhat
different. The part acting on the hammer intermediate or trigger is
cut out, as shown in Figure 8, the point 6' catching and sliding forward
of the end of trigger m³ serves to thrust it backwards, until, as the
solid part of the head of pin is brought against the forward part of the
end of the trigger m³ or hammer, as the case may be. When in this
position the trigger is held down in the position, as seen in Figure 4,
by the bottom surface of the breech bolt a, neither can it return to its
normal position after the breech bolt has been thrust forward until the
handle is turned to bring the recoil cam f to its locked position. The
forward portion of the breech bolt consists of the piece a which screws
into the thimble piece ³ near the head of the fire-pin d. The fire-pin d
occupies a central position in the breech bolt a, and
cylindrical shaft having a head m³ and point n³, as seen in Figure 3, the
consists of a

page_text: head and shoulder os limiting its forward, and the head of the
pin fs governing its backward movement. In the head of the pin f" is
formed a quadrant slot p³ which serves to regulate the movement of
handle and locking cam f. K is a stop pin screwed into the sleeve
piece h, the point moving in said quadrant slot and serving as a stop
to the motion of the piece fs and cam f, while the head receives the
rear end of the shell extractor . This quadrant slot performs the
functions of the slot in the head of the shaft e, Figure 1, with the ex-
ception of the frictional pressure, which is performed in this case by
the pressure of the head of the piece f³ tightened by screw nut g³ in
Figure 3.
The breech frame, in Figure 3, may be cylindrical or
octagonal as desired, and the tang p is integral with it and secured to
the stock by means of screws or a tang in form of a but strap, as in
the other modification, may be made separate and secured to the stock
receiving the breech pin by a dowel or otherwise. The front end of the
guard strip q is secured to the stock in a similar manner to the first
plan by screw o, which also screws into and secures the breech frame
firmly to the stock. The bottom of the breech frame is slotted in a
proper manner, as shown in Figure 3, to receive and admit of the motion
and operation of the trigger or trigger hammer in order to operate the
fire-pin. The barrel e of the gun is screwed or otherwise secured to
the breech frame, the same as the former plan, and properly chambered
to receive the cartridge with its flanged headed shell, as well as the hook
end of the shell extractor, as seen at r³, Figures 3 and 4.
The shell extractor and guiding bar in this modification of my
Invention is different from all other arms, it being a permanent or
stationary bar, and may be formed as a solid part of the breech bolt,
but for convenience in construction I prefer to make it of a separate
piece and attach it to the bolt by screw pins or otherwise. It will be
observed that this shell extractor is, when secured in its place, immovable
and does not act as a spring to move and snap over the flanged head of
a cartridge shell, but remains firm and rigid. This feature is of great
importance and advantage, as by this means great strength is not only
secured, but also great simplicity and durability. It is formed in the
shape of a flat bar made to conform with the cylindrical form of the
breech bolt if desired, and has a solid head so shaped as to fit over and
against the head or projection of a cartridge shell and to serve to draw
the same backward and out of the chamber of the barrel by the backward

page_text: movement of the breech bolt, and at the same time it guides the bolt
in its backward and forward motion by playing in a spline way 8³ cut
into the upper roof of the bore in the rear end of the breech frame b, as
seen in Figure 3. The forward end of the guiding bar and extractor /
are secured by a screw pin t, the head of which also serves as a stop to
determine the movement of the breech bolt a, the head us striking
against the solid metal of the breech frame at and v, in Figures 3
and 4, and also preventing the withdrawal of the breech bolt from
the frame b. When it is desirable to withdraw the bolt a for cleaning or
otherwise it is only necessary to extract the screw pin ³.
When the arm has been fired and the empty shell is to be retracted
from the chamber and the breech opened in order to insert another
loaded cartridge the handle is turned to a perpendicular position and
the breech bolt drawn back, as shown in Figure 4. In this plan the
empty shell to may be seen in the position of being ejected from the
arm. This operation is peculiar; it may be seen that there is a small
"cut out" in the bottom of the breech frame at a³ in Figures 3 and 4;
this hollow is formed so as to allow the head or flange of the shell to
describe its radius while the forward end is ascending. At the forward
end of the breech bolt a is arranged a tripper or ejector y pivoted at
its upper end by a screw pin 2³, Figures 3 and 5; this ejector is set
into a slot cut out in the end of the bolt just at one side of the fire-pin,
preferably at the left-hand side, in order to tilt the empty shell to the
right-hand side. The bottom of bolt a has a groove a³, as seen in
Figure 4, cut out in the bottom surface, in which traverses the end of
pin b, Figure 4. This slot terminates at the forward end of the bolt a
in the bottom of the slot formed for the reception of ejector y³. When
the breech bolt a is drawn back it will be seen that the lower edge of
the ejector y will strike against the pin 6, Figure 4, which suddenly
arrests the lower end of the ejector, while the top is carried a little
further back before the breech bolt a comes to its stop, by this means
arresting the ejector. It may be seen that a lever motion is formed
on the head of the shell, whereby it is tilted upward and thrown from
the arm.
When a loaded cartridge is to be placed in the receiver the cartridge
is to be held between the thumb and forefinger with the head downward,
the point or all end upwards at an angle of about 45°. The cartridge
is set into the concave depression x of the breech frame and pushed

page_text: backward, the head sliding on the bed of the frame until it is arrested by
coming against the edge of the ejector. When in this position the upper
portion or rim of the flange will be directly under and into the notch
or hook of the extractor 7, as seen in Figure 4. When by a slight
pressure downward the cartridge will be flat in the trough or bottom
of the receiver or breech frame, the pressure by means of the flange
catching under the hook end of the extractor bringing the breech bolt
slightly forward, which allows the ejector to move back into its groove,
when on pushing the breech bolt forward by the handle h the cartridge
is thrust into the chamber of the barrel, and on turning the handle down
the arm is securely locked and ready for firing by merely pulling upon
the trigger.
The trigger is easily understood by examination of Figures 3 and 4,
and needs no further description than describing the safety bolt d',
Figures 3 and 4, which slides backward and forward in a slot formed in
the guard strip q³ and is moved by the finger pin e* and held firmly by
a pressure spring f screwed to the guard strip of screw pin g', Figures 3
and 4. The end of the safety bolt when brought backwards passes under
the projection formed in the trigger at h* which locks the trigger firmly
and prevents accidental discharge when the arm is to be transported in
boxes or otherwise with a slight change in the shape. A hammer may
be formed of this trigger by attaching a mainspring to the guard strip
in manner of the former mode, and connecting its forward end to the
heel of the trigger, so the spring will force the heel upward, and con-
sequently the top of the trigger, would act as a hammer and strike the
head of the fire-pin. It will be seen that this modification of the
breech may be applied to the former plan of lock movement, and vice
versa.
I claim the above described fire-arm, as a whole, or in detail, or any
modifications of or alterations or improvements in the same.
In witness whereof, I, the said Sylvanus Frederick Van Choate,
have hereunto set my hand and seal, this 23rd day of March,