IMPROVEMENTS IN ROTATING BREECH FIRE-ARMS
Year: 1853

page_text: PROVISIONAL SPECIFICATION left by the said Samuel Colt at the
Oflice of the Commissioners of Patents, with his Petition; on tlie
3d March 1853.
I, SAMUEL COLT, do hereby declare the nature of "the said Invention
for "IMPROVEMENTS IN ROTATING BREECH FIRE-ARMS" to be as follows:
....
This Invention relates to certain novel means of rotating the breech
cylinder of repeating fire-arms, which means will greatly simplify and
otherwise improve the construction of the arms. Instead of the
ordinary catch, taking into ratchet teeth cut on the hind end of the
breech, I propose to groove the periphery of the cylinder in such a
manner that a pin, by traversing the grooves, will not only effect the
rotation of the cylinder, but also lock it when required. For this
purpose I cut a number of parallel grooves; one for every chamber, in
the periphery of the breech cylinder, and I connect these straight
grooves together by means of diverging curved grooves running from
near the forward end of one groove to near the hinder end of the next
.T

page_text: adjoining groove. Between these straight grooves, and running forward
out of the curved grooves, are short straight grooves into which the
traversing pin cnters when the loaded cylinder is required to be safely
locked. This pin is carried by a sliding block, working in guides, and
connected by a strap or link to the hammer, the movement of which
causes the traverse of the pin. When the pin is drawn back after
firing it meets with an obstruction in the straight groove, which is
placed there to turn it into the diyerging groove; and in passing along
this latter groove it will draw round the cylinder on its axis. If the
hammer is allowed to fall forward when the pin has arrived opposite
the short straight groove, the pin will run up that groove and lock the
cylinder. to prevent a premature discharge of the arm; but, when drawn
back until it reaches the next long straight groove, it will have turned
the cylinder sufficiently to bring the chamber next succeeding that last
fired into a line with the barrel, and will hold the cylinder in position
for firing. A ring of lateral cuts forming inclined planes is made in the
grooves to allow the cylinder to rotate freely when the pin is in a line
therewith, for the purpose of facilitating the loading of the chambers,
which position the pin will take when the hammer is set at half-cock.
Another mode in which I effect the rotation of the breech is to groove
the rear end of the breech in a manner analogous to that just described,
and to fit the traverse or driving pin to the lower part of the hammer.
In this arrangement I shape the rear end of the breech, so that the pin
inay, as it is rocked by the hammer, be always in contact with the
breech.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Samuel Colt, in the Great Seal Patent Office, on
the 3d September 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
SAMUEL COLT, of Spring Gardens, in the County of Middlesex, Gentle-
men, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of March, in the year of our

page_text: Lord One thousand eight hundred and fifty-three, in the sixteenth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Samuel Colt, Her special licence that I, the said
Samuel Colt, my executors, administrators, and assigns, or such others
as I, the said Samuel Colt, 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 law-
fully 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 ROTATING BREECH FIRE-ARMS," being
partly a communication from abroad, upon the condition (amongst
others) that I, the said Samuel Colt, by an instrument in writing under
my hand and seal, 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.
NOW KNOW YE, that I, the said Samuel Colt, do hereby declaro
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, reference being had to the Drawing hereunto
annexed, and to the letters and figures marked thereon (that is to say):
This Invention relates to certain novel means of rotating the breech
cylinder of repeating fire-arms whereby their construction will be
greatly simplified and improved.
In the accompanying drawing I have shewn in several views the
improvements which form the subject of this Invention. Fig. 1, shews
in plan view, and Fig. 2, in side view, one of my improved pistols fitted
with the novel arrangement for rotating the breech cylinder which consti-
tutes the first head of this Invention. Instead of using a catch, which
takes into a ring of ratchet teeth cut on the hind end of the breech
cylinder, I groove the periphery of the breech cylinder in such a manner
that a pin traversed by the hammer along the grooves will not only
effect the desired rotation of the cylinder, but will also lock it when
required. In the breech cylinder a, (which is represented as having

page_text: six chambers) cut a series of straight grooves b, b, which extend
nearly from end to end of the cylinder, and are equal in number to the
chambers for receiving the charges. These grooves b, b, are made
parallel with the axis of the cylinder a, and they are connected together
by means of diverging grooves c. running from near the forward end of
one groove b, to near the hinder end of the next adjacent groove b.
Between these straight grooves b, b, and running forward out of the
curved grooves c, and parallel to the grooves b, are short straight
grooves d, into which the traversing pin employed for driving round
the cylinder a, euters when the loaded cylinder is required to be locked.
The configuration and distribution of these grooves is best shewn at
Figures 3, and 4, the former of which is a detached view of the breech
cylinder on a somewhat enlarged scale, and the latter a diagram shewing
In order to ensure the
the periphery of the cylinder as laid out flat.
steady action of the traversing pin I provide a guide for the block
which carries it in the frame of the arm by forming the frame as shown
at Figures 1, and 2, wherein e, e, is a continuation of the recoil shield
carried over the cylinder a, (instead of under, as in my Patent of
Twentieth June, One thousand eight hundred and forty-nine.) and sup-
porting the barrel f, at its forward end. I would remark that this
frame must be open in the line of the hammer, not merely to allow of
the hammer descending upon the uppermost nipple to discharge the
arm, but also to permit of the ready escape of the fire from the cap on
the nipple; and for this latter reason I may find it convenient to form
this part of the frame of two side straps, of sufficient strength to sustain
the barrel firmly in position, and yet allow of one of the straps being
slotted to form a guide for the block of the traversing pin. This pin,
which in plan I prefer to approach an oval form, is shown at g. (see the
detached Figures 5.) and it is fitted loosely in a block h, which is
secured by a connecting rod i, to the hammer, and by the movements
of the hammer is slidden backwards and forwards in the guide formed
by the frame c. (see the cross section Fig. 6). Surrounding the pin g
and enclosed in a recess made in the block h, to receive it, is a helical
spring, which gives the pin a tendency to stand out below the under
face of the block h, and bearing against the periphery of the breech
T

page_text: cylinder. I have already stated that the grooves b, c, and d, are formed
to receive this pin, which runs therein for the double purpose of rotating
the cylinder to bring up the successive charges, and of locking the
cylinder when it is required to be stationary on its arbor. It will be
understood that so long as the pin is confined to either of the grooves b,
the breech cylinder will be quiescent, and that it is by the traverse of the
pin in the diverging or curved groove c, that an axial motion is imparted
to the cylinder. In order to induce the pin to enter the diverging
groove when drawn back by the hammer an obstruction to the back-
ward traverse of the pin is raised in the grooves b, at the point where
the curved grooves respectively enter the grooves b, and thus the pin is
guided out of the groove b, into the groove c. This obstruction is pro-
duced by raising the floor of the groove b, at the point mentioned, so
that a slanting shoulder taking the curve of the groove c, will be
presented to the receding pin. As, therefore, the pin is compelled to
move in a line parallel with the axis of the cylinder by reason of its
block sliding in the guide formed in the frame e, and as it cannot in its
backward movement pass down the straight groove b, it will bear
against the obstructing shoulder and the edge of the groove c, in a line
therewith, and thereby drive round the cylinder until the next succeeding
straight groove b, is brought into a line therewith, at which time a
fresh chamber will be brought into a line with the barrel. This groove
b, the pin will then enter by rising up an incline at the termination of
the curved groove, and as the hammer falls back to the position of
whole cock" the pin will run to the end of its course. It should be
remarked that the forward movement of the pin in the grooves b, is not
retarded by the obstruction above mentioned, as an incline is made to
permit of the easy passage of the pin over it. When the cylinder is
required to be locked for carrying the arm safely the hammer is drawn
back until the pin has reached a position in one of the diverging grooves
opposite to a straight groove d; it is then allowed to fall forward, and
the pin will be carried into the groove d, and lock the cylinder. To
allow of the free rotation of the cylinder for the purpose of bringing the
chambers severally under the plunger by which the cartridge is driven

page_text: home," a ring of inclined planes is made by chamfering away a
portion of one side of the grooves c, and the planes are so situated that
when the hammer is thrown back at "half cock" the position of the
pin will correspond to the position of the inclines; these inclines will,
therefore, provide a means for the escape of the pin from the grooves,
and thus the cylinder will be free to turn on its arbor to bring up the
chambers, as required, for the purpose of charging the same.
A modification of the mode just described of effecting the rotation of
the breech cylinder by the traverse of a pin in grooves formed in that
cylinder is shewn at Figures 7, and 8. Fig. 7, shews the cylinder
detached, and provided with radial grooves, and grooves which diverge
laterally at its rear end; and Fig. 8, shews the cylinder in longitudinal
section, with a pin a, for rotating it carried by the hammer. The pin
is fitted into a recess formed in the inner end of the hammer, and it is
kept in contact with the breech cylinder by a coiled spring contained in
the recess. The end of the cylinder is hollowed out (see Fig. 8,) to
suit the are described by the traversing pin when rocked by the back-
ward and forward motions of the hammer. With the exception of
rocking instead of traversing in a right line, the action of tho pin is tho
same as in the former-described arrangement. Similar provision. is
made for the transference of the pin from the radial grooves b, to the
curved grooves c, and also for the locking of the cylinder by the pin
entering intermediate grooves d. There is likewise provision made for
preventing the pin from interfering with the free rotation of the
cylinder when the hammer is at half cock by employing a ring of
inclined planes, as before, for raising the pin out of the grooves.
Having now described my Invention, and the manner of carrying the
same into effect, I wish it to be understood that under the above in
part recited Letters Patent I claim,-
First, the general arrangement of parts, as above described, for
effecting the rotation of the breech cylinder.
Secondly, I claim the rotating and the locking of the breech cylinder
by a traversing pin working in grooves formed on the periphery or rear
end of the cylinder, as above described.

page_text: And thirdly, I claim the mode of releasing the traversing pin from
the grooves when the cylinder is required to turn freely on its arbor.
In witness whereof, I, the said Samuel Colt, have hereunto set
my hand and seal, this Thirteenth day of June, in the year
of our Lord One thousand eight hundred and fifty-three.
SAM. COLT. (L.S.)
Witness, A. V. NEWTON.